A passive thermal imaging system, includes a first detection unit, a second detection unit, imaging optics and processing electronics. The first detection unit and second detection unit each include at least one first detector array. The imaging optics are configured to image a first wavelength range of received EMR onto the at least one first detector array, and to image a second wavelength range of the received EMR onto the at least one second detector array. The processing electronics are configured to receive a first detected signal from the at least one first detector array and to determine whether a first detection event has occurred based on the first detected signal, and to receive a second detected signal from the at least one second detector array and to determine whether a second detection event and a third detection event have occurred based on the second detected signal.

The present invention relates an optical system for detection of clear air turbulence (CAT), high altitude ice crystals (HAIC), and volcanic ash clouds (VAC) in a three channel system.
CAT, HAIC, and VAC all may posed a threat or discomfort for aircraft in flight. For example, atmospheric ice-particles may pose a threat for engines of aircraft in flight. Ice-particles from HAIC may get into aircraft engines and attach themselves to engine surfaces, building up until ice causes engine failure in some way. The ice particles typically are present in the atmosphere in the form of ice-particle aerosols.
CAT is the turbulent movement of air masses in the absence of any visual cues such as clouds, and is caused when bodies of air moving at widely different speeds meet. The atmospheric region most susceptible to CAT is the high troposphere at altitudes of around 7,000-12,000 meters (23,000-39,000 ft) as it meets the tropopause. Here CAT is most frequently encountered in the regions of jet streams. At lower altitudes it may also occur near mountain ranges. Thin cirrus clouds can also indicate a high probability of CAT.
CAT can be hazardous to the comfort, and even safety, of air travel. The thermal characteristics of CAT are known. Studies show that gust velocity changes in CAT of at least 20 ft sec−1 are associated with temperature changes of 3° C. or higher; very few being less than 1° C. Such studies show that CAT horizontal temperature gradients with a minimum temperature change of 2° C., and at a rate which equaled or exceeded 0.5° C. per minute. Moderately choppy CAT was observed at a 5° C. temperature change
Finally, volcanic ash from VAC may also pose a threat or discomfort for aircraft in flight. VAC can appear instantaneously while an aircraft is in flight, even in the dark, and may be hazardous to aircraft flight through consequent engine failure/damage.
What is needed is an optical system for detecting CAT, HAIC and VAC in a single system.

Combined air-turbulence, ice, volcanic-ash aerosols, passive LWIR optical systems for cruising-airplane safety


A microscope system includes, at least, an objective lens for converting a luminous flux from an object into a parallel luminous flux, an afocal variable magnification optical system for changing a diameter of the parallel luminous flux emergent from the objective lens into a different diameter, and an image forming optical system for forming an image out of the parallel luminous flux emergent from the afocal variable magnification optical system, and the following conditions are satisfied:2·NA(ob)·FL(ob)≧30 (mm)6≦Lexz/X≦10where, NA(ob) is the maximum effective numerical aperture of the objective lens, FL(ob) is a focal length of the objective lens, X=2·NA(ob)·FL(ob), and Lexz is a distance from an object surface to the most distant end of the afocal variable magnification optical system.

1. Field of the Invention
The present invention is related to a microscope system having excellent operation performance, bright image and variable magnification.
2. Description of the Related Art
Single objective lens type stereomicroscope is known as a conventional example of a microscope with excellent operation performance and extendibility. FIG. 1 is a view showing an outline composition of an optical system of such single objective lens type stereomicroscope. The objective lens of this kind of microscope has a focal length in a range of about 200 to 40 mm, and is that configured to assure comparatively low magnification for observation and a long working distance.
However, in the conventional single objective lens type stereomicroscope, due to restrictions of the distance between two right and left optical paths from an afocal variable magnification optical system to an image forming lens, etc., a diameter at the entrance of the afocal variable magnification optical system is limited to ½ or less of the effective diameter of the objective lens. Especially, in a design where a large magnification ratio is achieved by the afocal variable magnification optical system, brightness of the image tends to be insufficient on the higher magnification side because of the lens diameter of the afocal variable magnification optical system as a limiting factor.
This is the same in such case that imaging is carried out by leading luminous flux which has transmitted either of the right or the left afocal variable magnification optical system to an image sensor.
When a fluorescence image is observed by using an objective lens having a considerably large effective diameter compared with the afocal variable magnification optical system, in combination with an illumination system and filters for fluorescence observation, sufficient brightness cannot not be obtained although a large field of view for observation is secured. Especially in an optical system having a large observation range in this way, a careless omission of a weak and minute fluorescence marker etc. easily occur.
Then, in order to increase brightness of an image in a specific magnification and a specific focal length, it is necessary to enlarge the numerical aperture NA of a lens. Enlarging the numerical aperture NA of a lens is equivalent to enlarging a diameter of luminous flux emergent from an objective lens.
Here, the diameter (in millimeters) of luminous flux emergent from the objective lens is expressed as follows:2·NA(ob)·FL(ob)  (1)where NA(ob) is a numerical aperture of an objective lens, and FL(ob) is a focal length (in millimeters) of the objective lens.
Generally a diameter of luminous flux emergent from the objective lens obtained from the condition (1) takes a value from about few mm to 20 mm in a microscope, and tends to be smaller as the focal length of the objective lens becomes shorter. Also in a stereomicroscope of a single objective-lens type, although the diameter of luminous flux emergent from the objective lens itself is about 40 mm or more, the effective diameter of the emergent luminous flux is about 20 mm, for it is limited by the effective diameter of an afocal variable magnification optical system.


In a cellular telephone system, an account manager server is used to monitor all services provided to hand-held devices of the system and to charge the respective customers of the system. The server also provides advertisements to the customers via data channels for the devices. The customers are charged for services based on the number of advertisements (if any) presented on the devices. Optionally, customers may buy goods or services associated with the presented advertisements, in this case, the amount charged for voice and/or data services provided by the system are adjusted as well.

A. Field of Invention
This application pertains to a system and method of providing advertising on hand-held and similar devices, including cell phones and the like. A user elects to receive targeted advertisement in return for rewards, such as either cheaper or free service.
B. Description of the Prior Art
Various hand-held devices have become ubiquitous in various activities, ranging from business to entertainment, shopping, travel, etc. to the point where many people could not conceive living without them. Such devices are used by individuals as primarily means of communicating with each other as well as with various service providers and other entities. More specifically, these devices are used for not only standard voice communications (e.g., mobile telephone calls), but also to obtain and exchange content via emails and texts, as well as web sites, chat rooms and social media such as Facebook and other similar services.
Of course, while individuals pay for accessing these services to their respective service providers, they have gotten used and expect to gain access to the content for free. Therefore, many content providers have resorted to presenting some advertisements together with the contents as a means of obtaining revenue for their services. The advertisements are provided by third parties. However, in most situations, individuals have learned to ignore most advertisements, and accordingly, advertisers are looking for techniques for encouraging individuals using hand-held devices to pay more attention to their advertisements. The present invention provides such a technique.

Advertising system for mobile devices and method of operating the same


A cursor control device horizontally positioned operating surface is mounted on a vertical shaft connected to a biaxial joint which is enclosed in the base of the device. The hand of the operator rests on the operating surface and tips it in any direction so the shaft follows the movement of his/her hand. The motion is interpreted as X and Y coordinates on a computer display screen. The coordinate information is digitized and sent to the main computer to display a cursor on the display screen.

Many devices exist for coupling human input to complex electronic and/or mechanical systems such as computers. In a specific embodiment, this invention involves human coupling actions to a computer's interface graphical operating system using a pointing device. Known devices for addressing a graphical interface include the joystick, mouse, trackball, touch pad, and track point. The latter two are tailored to use in portable (laptop) computers and are typically embedded in the laptop while mice and track balls are external devices that can be used with both laptop or desktop computers.
While embedded pointing devices offer convenience, their functionality is constrained by their form factor. These devices tend to be small and are generally operated by a single finger. This mode of operation engages only a relatively small group of muscles, thereby limiting precision and accuracy. The touch pad additionally suffers from the need for multiple strokes to achieve long displacements of the cursor; it is difficult to traverse the entire screen with a single motion. Mice and track balls suffer from similar drawbacks concerning long cursor displacements. The travel of the mouse is limited to a constrained region of the user's work surface and by the user's reach. Operation often requires the user to lift the device and re-center it on a mouse pad, sometimes repeatedly. The trackball, like the touch pad, almost invariably requires repeated strokes.
A possible software solution for the multiple-stroke problem could be to have quick movement of the pointing device translated into an exaggerated movement of the cursor. By multiplying the input stroke by its "acceleration", a long displacement with a single movement can be achieved. However, since the input signal contains some error, the error is magnified along with the increased movement of the cursor resulting in diminished user control.
A joystick can achieve long displacements without repeated motions. However, its form factor seems to have limited widespread adoption of this device for general purpose pointing. Operating a joystick as a pointing device entails grasping its vertical structure and rocking it off the vertical axis to affect cursor movement. This operation requires awkward bending and twisting of the wrist with the hand in a somewhat unnatural position. Further, switching from the keyboard to the joystick device is a rather slow process as the grip of the joystick must be reestablished.
Therefore, it is an object of the present invention to provide an improved human/machine interface device.
It is another object of the present invention to provide a human machine interface device that provides minimal device movement for activation.
It is a further object of the invention that provides activate positioning with minimal movement of a hand or a portion thereof while the hand is supported in a comfortable palm down position while using the human/machine interface device of the present invention.
An additional object of the invention is to provide a new human machine interface device that enables easy transference of operation between the device and a keyboard.

Hand activated input device with horizontal control surface

International Business Machines Corporation


A display device includes: a display panel; a driver integrated circuit (IC) including a first surface electrically connected to the display panel and a second surface opposing the first surface and electrically connected to the first surface; and a connecting structure including a first side portion electrically connected to the second surface of the driver IC, and a second side portion electrically connected to an external device.

1. Field
One or more aspects of example embodiments relate to display devices. More particularly, one or more aspects of example embodiments relate to display devices including driver integrated circuits (ICs) and connecting structures.
2. Description of the Related Art
In a display device, a driver integrated circuit (IC) may be mounted on a display panel by a chip-on-glass (COG) process, a tape carrier package (TCP) process, or a chip-on-film (COF) process. The COG process is relatively simple compared to the TCP or COF processes, and may increase a ratio of a display area on the display panel to a non-display area.
A data transfer rate to the display panel has increased in accordance with a development of high-resolution display devices. Technologies that enhance the data transfer rate on a printed circuit board and on a flexible printed circuit have been developed. Also, more wires may be located on a smaller area in accordance with a gradual development of IC manufacturing processes.
However, the data transfer rate of wires on the display panel may be limited by a physical limitation of the wires on the display panel. Also, narrowing a width of each pad on the display panel may be more difficult than narrowing a width of each terminal of the driver IC.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, may contain information that does not constitute prior art.


A method of performing dip coating of a layer of a resist material on a surface of a substrate, comprising steps of:

The present invention relates to methods and apparatus for applying a layer of a resist, e.g., a photoresist, to both sides of dual-sided substrates, e.g., disk-shaped substrates. The invention finds particular utility in performing resist coating of substrates as part of manufacturing processing of hard disk magnetic and/or magneto-optical recording media, e.g., for servo patterning, protective layer formation, etc.
Spin coating of wafer-shaped substrates or workpieces is a widely utilized process in the manufacture of semiconductor integrated circuit (xe2x80x9cICxe2x80x9d) devices for applying thin, uniform thickness layers of a coating material, e.g., a photoresist, to the wafer surfaces as part of photolithographic patterning of the IC component devices, interconnections, etc., and is increasingly employed as part of the manufacturing process of disk-shaped magnetic and/or magneto-optical (xe2x80x9cMOxe2x80x9d) recording media, such as hard disks, for patterning the surfaces of such media, as for example, in the formation of servo patterns therein by means of imprint lithographic techniques.
A typical spin coating apparatus according to the conventional art is schematically illustrated in the cross-sectional view of FIG. 1, wherein reference numeral 1 designates a disk-shaped rotatable table or vacuum chuck, supported by a rotatable shaft 2 perpendicular to the plane of table 1, the latter being connected to motor 3 for rotation about a central axis. Wafer 11 is fixed to the surface of table or vacuum chuck 1 by means of suction ports (not shown in the drawing for simplicity).
Reference numeral 4 indicates a process bowl or cup surrounding rotatable table or vacuum chuck 1, the bottom of which includes at least one exhaust port 5 for removal of superfluous (i.e., excess) resist (or other coating material) which is scattered about during the spin coating process due to centrifugal force; reference numeral 6 indicates a plate or flange for regulating the air currents flowing in the process bowl or cup 4 in order to enhance coating thickness uniformity; and reference numeral 7 indicates an exhaust port for connection to an exhaust source; reference numeral 8 designates a coating material dispensing nozzle, operatively connected via feed tube or conduit 9 to a source 10 of a coating material, e.g., a photoresist.
In operation of the above-described spin coating apparatus, the coating material, e.g., a photoresist, is dispensed from nozzle 8 of source 10 onto the surface of wafer 11 as the wafer is spun by means of rotatable chuck 1. The spinning of the wafer distributes the photoresist over the surface of the wafer and exerts a shearing force that separates excess photoresist from the wafer and evaporates solvent therefrom, thereby providing a thin, smooth, uniform thickness layer of photoresist on the surface of the wafer.
More specifically, and with reference to FIG. 2, the spin coating process as described above comprises 3 distinct process steps or phases, as follows:
1. Resist spin-onxe2x80x94generally the substrate or workpiece, in the form of an annularly-shaped disk, spins at a low spindle speed during this phase, e.g., about 500 rpm, with a resist dispensing nozzle at the end of a movable arm initially positioned facing the inner diameter (xe2x80x9cIDxe2x80x9d) of the disk. The nozzle/arm assembly dispenses the coating material, e.g., a resist such as a polymethylmethacrylate (xe2x80x9cPMMAxe2x80x9d) or other photo-sensitive resist, onto the top surface of the disk at a controlled rate and duration. The slow spindle speed ensures that the resist is uniformly distributed from the ID to the outer diameter (xe2x80x9cODxe2x80x9d) of the disk, and the flow rate of the resist is adjusted so as to provide a sufficient amount of resist during the spreading process.
2. Resist spin-offxe2x80x94in order to facilitate uniform spreading of the resist, a high spindle speed (e.g., greater than 1,000 rpm) spin-off step is performed in the next phase to remove superfluous (i.e., excess) resist. Conventional spin coating apparatus, such as illustrated in FIG. 1, therefore include a vacuum exhaust system which operates at the backside of the disk to ensure removal of the excess resist without either re-depositing resist material on the top surface of the disk or other critical equipment components located above the disk.
3. Edge bead removal (not shown in FIG. 2)xe2x80x94subsequent to resist spin-off at high spindle speed, the resist-coated disk is subjected to solvent cleaning at the OD disk edge for edge bead removal and a backside wash in order to ensure that the disk OD does not retain a ring (i.e., edge bead) of accumulated resist at the top edge surface; the backside wash protects against undesired resist contamination of the back side (i.e., bottom) of the disk.
In order to facilitate resist coating of both sides of a disk-shaped substrate or workpiece (i.e., xe2x80x9cdual-sidedxe2x80x9d coating) according to conventional automated manufacturing practices utilizing typical prior art spin coating stations, e.g., as shown in FIG. 1, a disk inversion (or xe2x80x9cflippingxe2x80x9d) station must be provided intermediate separate first and second spin coating stations for sequential coating of the top and bottom disk surfaces. While such an arrangement can be fairly readily implemented, this approach entails several disadvantages, as follows:
1. a certain amount of resist material applied to a first (e.g., top) surface of the disk at a first spin coating station, will inevitably flow to the second surface of the disk, i.e., the bottom or backside surface, which resist flow is problematic at at least the second spin coating station;
2. the area (xe2x80x9cequipment footprintxe2x80x9d) occupied by the overall spin coating station is increased due to the requirement for first and second spin coating stations;
3. excessive equipment downtime due to malfunctioning, maintenance, etc., of the first and second spin coating stations and intermediate substrate (e.g., disk) flipping station; and
4. increased equipment cost due to the necessity for providing the second spin coating station and the substrate flipping station.
In view of the above-described drawbacks and disadvantages associated with conventional spin coating methodology when utilized for coating both sides of a dual-sided substrate, as in the case of disk-shaped magnetic and MO recording media such as hard disks, dip coating techniques in which a vertically oriented substrate is immersed in and removed from a bath of photoresist solution in an open container, have been considered as a potentially desirable substitute therefor. Specifically, such dip coating process/apparatus can be readily implemented for coating both sides of two-sided substrates, with an attendant reduction in photoresist loss which minimizes photoresist usage. However, conventional dip coating techniques utilizing open dip cup apparatus (described in more detail below) incur several disadvantages and drawbacks, as follows:
1. Increase in viscosity over timexe2x80x94The photoresist solution, composed of a polymeric photoresist material and at least one solvent therefor, is contained in a tank or vessel (xe2x80x9cdip cupxe2x80x9d) and exposed to the ambient atmosphere, i.e., air. As a consequence of the continuous exposure of the photoresist solution to air, evaporation of the solvent occurs, resulting in an increase in the viscosity of the photoresist solution over time. The increase in viscosity in turn leads to an increase in the thickness of the photoresist coating formed on the substrate surfaces. However, consistent photoresist coating thickness is vital for obtaining acceptable products or results when utilized as part of a manufacturing process, e.g., as a step in the formation of servo-patterned magnetic and MO recording media utilizing imprint lithography of resist-coated substrates. Specifically, a variation, i.e., an increase, in resist layer thickness is problematic in that the latter is a key process variable or parameter in servo pattern formation via imprint lithography utilizing etching or implantation processing for pattern generation in the media surfaces. For example, if the surface patterning is performed by etching utilizing the photoresist layer in patterned form as a selective masking layer, a photoresist layer which is too thick will result in an insufficiently deep etched pattern. As a consequence of the reduced etch depth, the desired spacing between the transducer head and the base of the etched pit will not be obtained, resulting in a reduction in the signal-to-noise ratio (xe2x80x9cSNRxe2x80x9d). Attentively, if the media surface is patterned by implantation processing utilizing a patterned (i.e., embossed or imprinted) resist layer of varying thickness as an implantation mask, the increased thickness of the photoresist layer arising from the increase in viscosity of the photoresist solution increases the required penetration distance of the implanted species, which in turn reduces the magnitude of the desired alteration of magnetic properties of the selectively implanted areas of the substrate surface forming the desired pattern. Again, the result is the SNR of the medium is disadvantageously reduced.
2. Incorporation of Particulatesxe2x80x94A problem frequently associated with photoresist dip coating processes is the incorporation of particulate matter in the photoresist solution. Specifically, the open dip cup utilized for containing the photoresist solution applied to the substrate surfaces by dipping the substrate thereinto, is highly susceptible to contamination by various types of particulate matter. In instances where the photoresist solution is contaminated with particles, debris, etc., the latter are readily transferred to subsequent substrates immersed in the contaminated photoresist solution in the dip cup. In such event, it becomes necessary to terminate the dip coating process, discard, and then replace the entire volume of photoresist solution in the dip cup. As a consequence, contamination of the photoresist solution with particles, debris, etc., can entirely eliminate the benefit of low photoresist consumption afforded by the dip coating process.
In view of the above-described drawbacks and disadvantages inherent in the open cup dip coating approach for applying a layer of a coating material, e.g., a photoresist layer, to both sides of dual-sided substrates, e.g., disk-shaped substrates such as utilized in the manufacture of semiconductor integrated circuit devices and magnetic and/or MO recording media, there exists a clear need for improved means and methodology for performing dip coating of dual-sided substrates such as semiconductor wafers and disks for magnetic and/or MO recording media. More specifically, there exists a need for an improved means and methodology for simultaneously dip coating both sides of dual-sided substrates in an open dip cup coating station, whereby each of the above-described drawbacks and disadvantages accruing from the use of conventional open dip cup resist coating stations is avoided.
The present invention addresses and solves problems, difficulties, drawbacks, and disadvantages associated with the conventional open dip cup coating station approach for dip coating of a resist material on both sides of dual-sided substrates, e.g., semiconductor wafers and disk-shaped substrates employed in the manufacture of hard disk magnetic and/or MO recording media, the drawbacks and disadvantages including resist thickness variation/increase, particle contamination, downtime, and high resist. usage/waste, while maintaining full compatibility with all aspects of conventional automated manufacturing technology, e.g., for semiconductor IC and recording media manufacture. Further, the means and methodology afforded by the present invention enjoy diverse utility in spin coating of a variety of materials on a number of different types of substrates and workpieces.
An advantage of the present invention is an improved open dip cup apparatus for dip coating a layer of a resist material on a surface of a substrate.
Another advantage of the present invention is an improved apparatus for simultaneously dip coating a layer of a resist material on the oppositely facing major surfaces of a disk-shaped substrate for a magnetic or magneto-optical recording medium.
A further advantage of the present invention is an improved method of performing dip coating of a layer of a resist material on a surface of a substrate.
Still another advantage of the present invention is an improved method of performing simultaneous dip coating of a layer of a resist material on the oppositely facing major surfaces of a disk-shaped substrate for a magnetic or magneto-optical recording medium.
Yet another advantage of the present invention is an improved method and apparatus for performing open dip coating of substrates in a continuous process while maintaining the viscosity of the dip coating liquid constant at a desired level and removing particulate matter therefrom.
Additional advantages and other aspects and features of the present invention will be set forth in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims.
According to an aspect of the present invention, the foregoing and other advantages are obtained in part by an improved apparatus for performing dip coating of a layer of a resist material on at least one surface of a substrate, comprising:
a dip coating vessel having an interior space adapted for containing therein a liquid for dip coating of a substrate, the dip coating liquid comprising a solution of the resist material in a solvent, the vessel being open at the top thereof;
a substrate mounting means for introducing into and withdrawing a substrate from the interior space of the dip coating vessel via the open top; and
a viscosity control system for continuously monitoring and maintaining the viscosity of a dip coating liquid supplied to the dip coating vessel at a predetermined value.
According to an embodiment of the present invention, the viscosity control system includes a recirculation loop for continuously or periodically recirculating the dip coating liquid in the dip coating vessel; wherein, according to a particular embodiment of the invention, the recirculation loop includes a reservoir for the dip coating liquid, with an inlet conduit connected between the reservoir and the dip coating vessel for supplying dip coating liquid from the reservoir to the dip coating vessel, and an outlet conduit connected between the dip coating vessel and the reservoir for returning dip coating liquid from the dip coating vessel to the reservoir.
In accordance with certain embodiments of the present invention, the recirculation loop provides periodic recirculation of the dip coating liquid in the dip coating vessel and comprises a bypass conduit for periodically diverting, thus interrupting, flow of the dip coating liquid between the reservoir and the dip coating vessel; wherein the recirculation loop provides recirculation of the dip coating liquid in the dip coating vessel only when a substrate is immersed in the dip coating liquid in the dip coating vessel and includes a pair of 3-way flow valves for flowing the dip coating liquid through the bypass conduit in response to a signal provided by the substrate mounting means.
According to embodiments of the present invention, the recirculation loop further includes a pump connected to the inlet conduit for recirculating the dip coating liquid; and the recirculation loop further includes a filter connected to the inlet conduit for removing particulate matter from the dip coating liquid.
Embodiments of the present invention include providing the recirculation loop as including a device for continuously measuring the viscosity of the dip coating liquid in the reservoir and a solvent dispensing system for supplying the solvent for the resist material to the reservoir in response to the measured viscosity.
According to certain embodiments of the present invention, the solvent dispensing system includes a tank for containing the solvent and a conduit between the solvent tank and the reservoir for supplying a flow of solvent from the solvent tank to the reservoir; and the solvent dispensing system further includes a valve for controlling the flow of solvent in the conduit between the solvent tank and the reservoir, and valve flow control means responsive to the measured viscosity for controlling the solvent flow and thereby maintaining the predetermined viscosity of the dip coating liquid in the reservoir and in the dip coating vessel.
In accordance with further embodiments of the present invention, the reservoir further includes agitator means for uniformly mixing solvent supplied by the solvent dispensing system with the dip coating liquid in the reservoir; and the substrate mounting means includes means for vertically mounting a disk-shaped substrate comprising a pair of oppositely facing major surfaces to be simultaneously dip coated, and means for rotating the disk-shaped substrate about a central axis.
Another aspect of the present invention is an improved method of performing dip coating of a layer of a resist material on a surface of a substrate, comprising steps of:
(a) providing a dip coating vessel having an interior space containing therein a liquid for dip coating, the dip coating liquid comprising a solution of the resist material in a solvent, the dip coating vessel being open at the top thereof;
(b) providing a substrate having a surface, immersing the substrate in the dip coating liquid in the dip coating vessel via the open top, and withdrawing the substrate from the dip coating vessel via the open top, thereby forming a layer of the resist material on the substrate surface; and
(c) monitoring and maintaining the viscosity of the dip coating liquid supplied to the dip coating vessel at a predetermined value.
In accordance with embodiments of the present invention, step (b) comprises providing and immersing a vertically oriented, disk-shaped substrate having a pair of opposed major surfaces while rotating the disk-shaped substrate about a central axis, thereby simultaneously forming a layer of the photoresist material on each of the pair of surfaces; and
step (c) comprises providing a continuous viscosity control system including a circulation loop for continuously or periodically recirculating the dip coating liquid in the dip coating vessel.
According to embodiments of the present invention, step (c) comprises providing a recirculation loop including a reservoir for the dip coating liquid, with an inlet conduit connected between the reservoir and the dip coating vessel for supplying dip coating liquid from the reservoir to the dip coating vessel, and an outlet conduit connected between the dip coating vessel and the reservoir for returning dip coating liquid from the dip coating vessel to the reservoir.
In accordance with certain embodiments of the present invention, step (c) comprises providing a recirculation loop for periodically recirculating the dip coating liquid in the dip coating vessel, the recirculation loop comprising a bypass conduit for periodically diverting, thus interrupting, flow of the dip coating liquid between the reservoir and the dip coating vessel; wherein step (c) comprises providing a recirculation loop for recirculating the dip coating liquid in the dip coating vessel only when a substrate is immersed in the dip coating liquid in the dip coating vessel, and the recirculation loop includes a pair of 3-way flow control valves for flowing the dip coating liquid through the bypass conduit in response to a signal provided by the substrate mounting means.
According to embodiments of the present invention, step (c) further comprises providing a recirculation loop including a pump connected to the inlet conduit for recirculating the dip coating liquid and a filter connected to the inlet conduit for removing particulate matter from the dip coating liquid, and step (c) further comprises providing a recirculation loop including a device for continuously measuring the viscosity of the dip coating liquid in the reservoir and a solvent dispensing system for supplying the solvent for the resist material to the reservoir in response to the measured viscosity.
In a particular embodiment of the present invention, step (c) comprises providing a solvent dispensing system including a tank for containing the solvent and a conduit between the solvent tank and the reservoir for supplying a flow of solvent from the solvent tank to the reservoir; and according to certain embodiments of the invention, a solvent dispensing system is provided which further comprises a valve for controlling the flow of solvent in the conduit between the solvent tank and the reservoir, and valve flow control means responsive to the measured viscosity for controlling the solvent flow and thereby maintaining the predetermined viscosity of the dip coating liquid in the reservoir and in the dip coating vessel.
In accordance with a further embodiment of the present invention, step (c) further comprises providing the reservoir with agitator means for uniformly mixing solvent supplied by the solvent dispensing system with the dip coating liquid in the reservoir.
According to an embodiment of the present invention having particular utility in the manufacture of recording media, step (b) comprises providing a disk-shaped substrate for a hard disk magnetic or magneto-optical (MO) recording medium and the resist material is a photoresist.
Yet another aspect of the present invention is an improved apparatus for performing dip coating of a layer of a resist material on at least one surface of a substrate, comprising:
an open cup dip coating vessel having an interior space for containing therein a dip coating liquid; and
means for monitoring and maintaining the viscosity of the dip coating liquid supplied to the dip coating vessel at a predetermined value.
Additional advantages and aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments of the present invention are shown and described, simply by way of illustration of the best mode contemplated for practicing the present invention. As will be described, the present invention is capable of other and different embodiments, and its several details are susceptible of modification in various obvious respects. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as limitative.

Photoresist recirculation and viscosity control for dip coating applications

Abstract: (a) providing a dip coating vessel having an interior space containing a dip coating liquid comprising a solution of the resist material in a solvent, the dip coating vessel being open at the top thereof;

Abstract: (b) providing a substrate having a surface, immersing the substrate in the dip coating liquid in the vessel via the open top, and withdrawing the substrate from the vessel via the open top thereof, thereby forming a layer of resist material on the surface; and

Abstract: Also disclosed is an apparatus for performing the method.


A print data processing apparatus process variable print data includes a cache unit, a determination unit, a determining unit, and a writing unit. The cache unit caches image data generated according to a drawing command included in the variable print data as cache data in a cache memory. The determination unit determines whether it is necessary to write the cache data in a secondary storage medium that is different from the cache memory. The determining unit determines cache data to be written in the secondary storage medium, in response to the determination unit determining that it is necessary to write the cache data in the secondary storage medium, based on a number of pages to be processed before each cache data cached in the cache memory is used next. The writing unit writes the cache data determined by the determining unit in the secondary storage medium.

1. Field of the Invention
The present invention relates to a print data processing apparatus, a cache processing method, and a related program.
2. Description of the Related Art
Recently, the demand for variable data printing (VDP) that can realize data printing according to an individual request from each client has expanded. The standard (i.e., VDP languages), such as personalized print markup language (PPML) and portable document format/variable and transactional (PDF/VT) is applied to digital variable data printing. According to the above-described VDP languages, images included in print data can be classified into a reusable object that can be used for a plurality of times and other objects. Thus, the VDP system is designed to cache image data of each reusable object appropriately so that the cached image data can be reused later. As one advantageous features of the VDP languages, a system can speedily perform print processing by caching and reusing data of each reusable object. For example, according to the PPML (one of the VDP languages) , objects can be classified into two groups, reusable objects and other objects, which may be referred to as variable objects.
In general, the cache data of each reusable object in the above-described variable data printing is stored in a built-in memory, such as a random access memory (RAM), of a print data processing apparatus. However, the memory capacity of the processing apparatus is limited. The amount of cache data may exceed the memory capacity. In such a case, the VDP system writes (saves) the cache data that is currently present in the memory to a secondary storage medium, e.g., a hard disk drive, provided in the processing apparatus. Further, when the cache data saved in the secondary storage medium is used, it may be required that the VDP system performs processing for loading the cache data from the secondary storage medium into the memory.
A general swap processing technique is employable to realize the above-described processing for writing and reading cache data to/from a secondary storage medium. However, the processing of the secondary storage medium takes a relatively longtime compared to the processing time of the built-in memory. Therefore, if the number of swap operations increases, the time required for print data processing increases.
Therefore, to improve the efficiency in variable print data processing, an appropriate method is required to reduce the number of operations to be performed to swap cache data to the secondary storage medium.
To solve the above-described issue, there is a conventional technique which is discussed in Japanese Patent Application Laid-Open No. 2010-88104. According to the technique, a processing order of each record of variable print data is determined so as to reduce the number of swap operations and load on the memory area. In this case, a record invariable data printing is a unit for assembling print data pieces. For example, in a printing operation performed on a client-by-client basis, print data pieces of each client constitutes one record.
However, according to the above-described conventional technique, although the number of swap operations can be reduced and the print processing can be accomplished speedily, the output order of printed records may change. It is not only the VDP, but the output order of print data should reflect a user's intent when a print data processing apparatus performs printing of print data. For example, in a case where the print processing is accompanied by post-processing, the inconvenience will arise in the post-processing if the print order of records is not maintained accurately. More specifically, assuming a case that the print data processing apparatus prints a product to be distributed to each employee with an employee number printed thereon by the VDP, and it is desired to output the printed products in order of employee number to facilitate the distribution. In such a case, the order of records cannot be changed if each record corresponds to a specific employee. Further, there is a case where the print data processing apparatus prints a large number of direct mails by the VDP, and an inspection machine in post-processing checks whether addresses and names have been correctly printed. In many cases, the order of right data to be input to the inspection machine is required to be identical to the output order of the printed products. In such a case, the print data processing apparatus is required to output the products without changing the order of records. Therefore, the above-described conventional technique cannot be used to accomplish the variable data printing speedily.
As a method capable of increasing the processing speed while maintaining the output order of printed products correctly, it may be useful to control the swap order of cache data of reusable objects. In this case, determination of a swap priority order for each cache data influences the number of swap operations to be performed in print data processing. Therefore, if the swap priority order determination method is inappropriate, the number of swap operations increases and the time required for the print data processing increases correspondingly.
To solve the above-described issue, it is important to provide an appropriate method for determining the priority order of each cache data, to identify cache data to be written into a secondary storage medium when a plurality of pieces of cache data is present in the memory, so that the processing speed can be increased.

Print data processing apparatus, cache processing method, and storage medium


An oil pump includes a drive gear, which rotates with a drive shaft, a driven gear, which meshes with the drive gear and is supported rotatable on a driven shaft, and a casing having a pump chamber, which accommodates the drive gear and the driven gear. The casing of the gear pump is provided with an intake port and a discharge port, which are in fluid communication with the pump chamber, so that oil is sucked through the intake port and discharged through the discharge port. A gear holder is provided in the casing such that the gear holder supports the driven gear rotatable and holds both sides of the driven gear while the gear holder itself is being supported axially movable by the driven shaft. The gear holder holding the driven gear moves axially by receiving a biasing force and also a pressing force acting against the biasing force.

Generally, the capacity of a gear pump is determined by, for example, the tooth depth and tooth width of the gears, and the discharge flow rate is determined by the capacity and the rotational speed of the gears (i.e., the rotational speed of the pump). In a case where this gear pump is used as an oil pump for supplying lubricating oil into, for example, a vehicular engine, the capacity of the oil pump is set to supply oil at a sufficient amount for the lubrication even if the output of the engine as driving source is small, and therefore, the rotational speed of the pump is relatively low. On the other hand, as the output of the engine becomes larger, and thereby the rotational speed of the pump grows higher, the oil being supplied into the engine becomes excessive. In this condition, there is a possibility that a large driving force is consumed by the oil pump, which may lead to a power loss of the engined.
As a gear pump for solving this problem, there is a variable capacity type gear pump wherein, as the rotational speed of the pump becomes higher, both the drive gear and driven gear or one of them is correspondingly moved axially to reduce the meshing width of the gears and thereby reducing the capacity (refer, for example, to Japanese Laid-Open Patent Publication No. 2000-120559, and to Japanese Laid-Open Patent Publication No. S57-73880). Japanese Laid-Open Patent Publication No. 2000-120559 discloses a gear pump in which the driven gear is held axially by two side plates, with the support shaft of the driven gear being supported by these side plates. In this gear pump, a biasing force is provided on the back of one of the side plates while this biasing force is counteracted by a pressing force that is provided on the back of the other side plate, the pressing force being correspondent to the discharged fluid pressure. In this design, the driven gear, which is sandwiched between both the side plates, moves axially to the position where the pressing force is balanced against the biasing force. As a result, the meshing width of the driven gear with the drive gear varies in correspondence to the discharged fluid pressure.

Gear pump enabling efficient pump capacity change


The present invention provides a monolithic inductor developed using radio frequency micro electromechanical (RF MEMS) techniques. In a particular embodiment of the present invention, a tunable radio frequency microelectromechanical inductor includes a coplanar waveguide and at least one direct current actuatable contact switch positioned to vary the effective width of a narrow inductive section of the center conductor of the CPW line upon actuation the DC contact switch.

The design of microwave and millimeter wave electronics requires components that provide a capability for impedance matching, and/or tuning. Impedance matching is the process through which signals are made to propagate through a high frequency network with a specific amount of reflection, typically as low as possible.
Two of the most common types of components used for impedance matching are capacitors and inductors. Radio frequency micro electromechanical (RF MEMS) techniques have in the past been used to fabricate state-of-the-art tunable capacitors in a variety of different forms. However, to date much less progress has been made in developing RF MEMS tunable inductors.
Prior art in tunable inductors of the RF MEMS type basically consist of topologies in which RF MEMS switches are used to select between different tuning states. Inductors are integral components in RF front end architectures that include filters, matching networks and tunable circuits such as phase shifters. The most common inductor topologies include planar spirals, aircore, and embedded solenoid designs. In comparison to capacitors, however, relatively few tunable inductor configurations have been published; among those presented, many are hybrid approaches that employ MEMS switches to activate different static inductive sections. Furthermore, less attention has been paid to designs that enable control in the sub-nH range as is potentially desirable for matching purposes in applications that use distributed loading of small capacitances, e.g. in loaded-line phase shifters.
Accordingly what is needed in the art is an improved tunable inductor of the RF MEMS type.

Tunable micro electromechanical inductor


Provided is a process for metallizing an insulating substrate by depositing a uniform thin film of a metal on the insulating substrate. The process comprises placing the insulating substrate in an electrochemical cell which contains as the electrolyte a solution of a salt of the metal in a solvent, and which comprises an anode of the metal and a cathode in direct contact with the insulating substrate. A conducting film, which will constitute the cathode, is initially applied to one end of the substrate. The substrate is placed in the electrochemical cell in such a way that the surface to be metallized is vertical and the cathode is located in the upper part. A current is imposed on the electrochemical cell with an intensity such that it creates a current density of between 1 and 50 mA/cm2 in the horizontal section of the electrochemical cell level with the growth front of the film which is deposited.

1. Field of the Invention
The present invention relates to a process for electrochemically metallizing an insulating substrate.
2. Description of the Related Art
Various processes for metallizing insulating substrates, especially for the purpose of manufacturing mirrors by metallizing glass plates, are known.
The oldest processes consist in bringing the insulating plate to be metallized into contact with a solution of a metal salt and of a reducing solution which causes precipitation. The contacting may take place by spraying or by immersion. These processes require the use of a mixture of salts and optionally of additives. Furthermore, they do not make it possible to control either the rate of deposition or the texture, that is to say the quality of the coating obtained.
More recently, processes based on vacuum evaporation deposition have been developed. This technique, very simple in its principle, requires a vacuum to be created before-hand in a chamber in which the evaporation of the metal will take place. The films obtained by vacuum evaporation are in general of good quality, but the high cost of the process limits their use to particular applications such as the production of small mirrors, for example rear-view mirrors used in motor vehicles or mirrors used in optics.
It is known to produce metal coatings on metal substrates electrolytically. Many applications have been developed with very good results. However, it is also known, especially from J. Dini, [Electrodeposition, Noyes Publication, Park Ridge N.J., USA (1992), page 195], that the use of the process with high growth rates causes an irregular dendritic or pulverulent growth. Such coatings are unuseable for industrial applications, as they break down into powder. One solution for limiting or eliminating the formation of dendrites during electrolytic deposition of a metal film on a conducting substrate consists in adding additives to the electrolyte. However, this process is essentially empirical. Good results may be obtained, but they are not easily reproducible. Furthermore, a slight change in the additive content or in its nature may cause considerable changes to the film deposited.
Independently, trials have been conducted in order to transpose the process of electrolytic deposition onto a metal substrate to the metallization of insulating substrates, for example the metallization of glass plates. For example, V. Fleury [xe2x80x9cBranched fractal patterns in non-equilibrium electrochemical deposition from oscillatory nucleation and growthxe2x80x9d, Nature, Vol. 390 November 1997, 145-148] describes a process for the galvanic deposition of a copper film on an insulating substrate. That surface of the insulating substrate which is to be metallized is covered with a thin gold film. The substrate is then placed in a solution of a copper salt and is connected to an anode consisting of copper and a cathode consisting of a gold film, the two electrodes being connected to a current generator. The coating on the surface of the insulating substrate is obtained by the reduction of copper at the cathode. The reduced metal starts by being deposited at the cathode, and then the deposition continues on that surface to be metallized which is covered with the thin non-conducting film of gold. However, this case also results in a dendritic growth which does not form a completely covering uniform thin film. On the contrary, the structure of the coating is extremely arborescent and tortuous. It is known that, in such arborescent growth, the choice of current density imposed on the electrochemical cell allows the rate of formation of the metal coating to be modified, an increase in the current density producing an increase in the deposition rate. However, it has been found that an increase in the current density causes the formation of pulverulent dendritic coatings. Thus, T. R. Bergstrasser and H. D. Merchant [xe2x80x9cSurface Morphology of Electrodepositsxe2x80x9d, pp. 115-168 in Defect Structure, Morphology and Properties of Deposits, Proceedings of the Materials Week Rosemont 1994, Publication of the Minerals-Metals-Materials Society, ed. by H. D. Merchant] show that the higher the current intensity used with respect to the equilibrium current intensity, the more the coatings formed are pulverulent in nature. The three-dimensional powders thus obtained are of no industrial use, their sole advantage being to allow the fundamental study of fractal dendritic growth (J. Dini, ibid. page 175).
The research carried out by the inventor has allowed him to show that, when an electrochemical process is used to grow powders along the surface of a substrate, by applying a markedly higher current density to the electrochemical cell than the current densities above which, according to the prior art, only three-dimensional powders could be obtained, a coating on the substrate was obtained in which the grains are arranged so as to form a uniform covering film and no longer dendrites.
This is why the subject of the present invention is an electrochemical process for the deposition of a continuous thin metal film on an insulating substrate.
The process for metallizing an insulating substrate by depositing a uniform thin film of a metal M on the said insulating substrate consists in placing the said substrate in an electrochemical cell which contains as electrolyte a solution of a salt of the metal M in a solvent and which comprises an anode consisting of the metal M and a cathode in direct contact with the said insulating substrate, then in carrying out an electrolysis at constant current, the said process being characterized in that:
a conducting film, which will constitute the cathode, is initially applied to one end of the substrate;
the substrate is placed in the electrochemical cell in such a way that the surface to be metallized is vertical and the cathode is located in the upper part; and
a current is imposed on the electrochemical cell with an intensity such that it creates a current density of between 1 and 50 mA/cm2 in the horizontal section of the electrochemical cell level with the growth front of the film which is deposited.

Method for electrochemically metallizing an insulating substrate

Centre National de la Recherche Scientifique


A sear bar for evaporating greases in a grill, the sear bar comprising an inverted V-shaped member, said inverted V-shaped member including an apex and two free ends, wherein said apex is situated on the upper portion of the sear bar and wherein said free ends are directed inwardly so as to define a lower portion of the sear bar.

Gas grills have become very prominent in outdoor cooking and barbecuing. Generally, a gas grill will include a cooking vessel containing one or more gas burners and a cooking plate or grill situated above the burners to support the food during cooking. In order to evenly distribute heat generated by the gas burners, lava rock has commonly been placed between the gas burners and the cooking plate or grill.
Lava rock is a porous heat absorbing material and absorbs and spreads the heat from the gas burners to provide a more even distribution of heat to the cooking grill or plate above. The lava rock is generally supported above the burners by a grid structure.
Unfortunately, greases dripping from the food being cooked on the cooking grill tend to drip onto the lava rock and ignite. The resultant flare-ups can be dangerous and can burn the food being cooked. Further, lava rock is porous and therefore absorbs the greases, which drip from the food. As a result, the lava rock is very hard to clean. Finally, because lava rock absorbs heat, the time for heating up the lava rock is lengthy and after the gas burners have been turned off the lava rock stays hot for a long period of time.
In solving the problems with use of lava rock in gas grills, it is known to provide a generally inverted V-shaped member, known as a sear bar, positioned above the gas burners. U.S. Pat. No. 4,727,853 (Stephen et al) and U.S. Pat. No. 4,677,964 (Lohmeyer et al) disclose the use of a plurality of inverted V-shaped members positioned above the gas burners. The plurality of V-shaped members mean that the greases dripping from the food being cooked fall onto the V-shaped members and are evaporated without uncontrolled flare-ups during cooking. U.S. Pat. No. 4,677,964 discloses the use of a second set of inverted V-shaped members positioned transversely to the first set of inverted V-shaped members. This further minimizes flare-ups, but creates a bulky sear bar arrangement.
It is an object of the invention to provide a sear bar which will overcome or substantially ameliorate at least of the deficiencies of the prior art, or to least provide an alternative.


Color coding tape having one or more RFID tags are attached to surgical instruments or other medical devices. Information relating to the medical devices can be written to and/or read from the RFID tags. The medical devices can be usually identified by the color coding tape.

The identification and tracking of surgical instruments and other equipment used in surgical and medical applications is difficult and time consuming. Many of the personnel handling the equipment are minimally educated regarding the application of the equipment, common name, or correct routing through cleaning and preparation for use. Tracking of the equipment to assure proper maintenance, use-life schedule, and location is also difficult. These tasks are generally accomplished through manual record keeping, visual inspection, and processing of all items grouped together without specific item identification. Identification of the equipment is provided through visual marking, either by mechanical etching, coating of a portion of the equipment with a colored plastic film, or identification with a color coding "band" such as the Surg-I-Band color coding system available from Scanlan International of St. Paul, Minn. These methods provide for non-specific identification or group recognition in a variety of use and preparation areas.
With the development of cost effective electronic identification technology several methods have become adopted to provide specific and unique tracking of medical equipment. Limitations include the necessity of applying a label containing the information (bar coding/2D labeling) and access to a "reader" to translate the information. More recently RFID (radio frequency identification) has become adapted for the identification and tracking of some medical equipment. RFID tags are placed on devices and used to record the movement through the use and maintenance cycle of the device. The difficulty with this technology is placement onto new devices. An even greater challenge is the attachment to and implementation of this technology to the entire capital base of equipment currently in use throughout the medical care industry.

Color coded RFID tags for surgical instruments


An optical sensor, an electronic device and a manufacturing method for the same are provided. The electronic device includes a light-permeable display screen and an optical sensor. The light-permeable display screen has a first surface and a second surface facing away from the first surface. The optical sensor is arranged opposite to the second surface of the light-permeable display screen. The optical sensor includes a base plate, an emitter and a receiver. The emitter is coupled to the base plate and faces the second surface of the light-permeable display screen. The receiver surrounds the emitter and is configured to communicate with the emitter.

In an electronic device, a proximity sensor and an ambient-light sensor are generally integrated as a whole. In order to ensure reliability of emitting and receiving signals, a cover plate of the electronic device usually needs to be provided with a hole having a relatively large area. However, operations of proving the hole will reduce a screen-to-body ratio of the electronic device, and also cause a lack of aesthetics.

GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.


A power wrench includes a socket which is rotatably retained in a head portion of the wrench by a retainer. A yoke is actuated to rotate reciprocally by a driving axle. A number of recesses are formed in the middle portion and the upper portion of the socket, each recess in the middle portion of the socket receives a roller, and each recess in the upper portion of the socket receives a ball. When the yoke rotates in one direction, the socket is actuated to rotate by the rollers. When the yoke rotates in a reverse direction, the balls are caused to hold the socket and prevent the socket from backlash.

The present invention relates to a wrench, and more particularly to a power wrench.
A power wrench which is driven by bearing member is disclosed in U.S. Pat. No. 4,603,606 to Headen. A yoke 72 is actuated to rotate with a reciprocating arcuate motion by a rotation of a drive shaft 86 via a pivot ball 80, as shown in FIG. 6 of this patent. The cartridge 10 is driven by the arcuate motion of the yoke 72, and the shaft 16 is driven to rotate by the roller bearing 18. The shaft 16 should be stably held in position by a retaining force in order to prevent the shaft 16 from "backlash" when the core 20 of the cartridge 10 rotates backward. The retaining force should be overcome by the power driving the drive shaft 86. The efficiency thereof is increased on the order of 30% which is unsatisfactory.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional power wrench.


The disclosure concerns a compression unit, in the form of wedge, of a transition for cables, pipes or wires. The wedge is to be placed inside a frame together with a number of compressible modules, which modules are to receive cables etc. The wedge comprises a number of wedge elements. The wedge is moved between non activated and activated positions by means of a screw, received in a through opening of a first wedge element, and a sleeve, received in an opening of a second wedge element. The wedge further comprises at least one clip, of an electrically conductive material, placed inside the wedge. The at least one clip is placed to connect the screw with the frame to connect the screw to earth.

The present invention has been developed in view of transitions having a frame, in which frame a number of modules, for receiving separate cables, pipes or wires, and at least one compression unit are placed. Often the compression unit has the form of a so-called wedge, comprising a number of interacting wedge elements. Such wedges have normally one or more screws to activate the compression unit.
There is a risk that electrically conductive material builds up static charges. Such static charges might discharge at contact with a different potential. This could lead to ignition of possible hazardous gases present.
The one or more screws of the compression unit should be connected to earth in order to avoid the risk of an undesired electrostatic discharge. It is previously known to solve this problem by connecting the one or more screws to an external conductor.


The present invention relates to an optical coherence tomography method, comprising: providing a beam of imaging radiation from a radiation source of an optical coherence tomography apparatus; directing, using directing optics, the beam of imaging radiation towards a fundus of a human or animal eye; and receiving a reflected portion of the imaging radiation by the optical coherence tomography apparatus; wherein the method further comprises: providing, by a tracking camera, a tracking image of an image area covering at least a part of said fundus; analyzing the tracking image for detecting a displacement of the fundus; and adapting, at least dependent on the detected displacement, a direction of the beam of imaging radiation by actuating an optical correction unit of said direction optics; and in addition to said adapting of the direction of the beam of imaging radiation, adapting a location of the image area on said fundus imaged by the tracking camera at least dependent on the detected displacement.

Optical retinal imaging is class of a medical imaging techniques that is applied in medical diagnosis and treatment methods to examine the fundus of an eye. A number of these methods is based on the scanning of a beam of imaging radiation across the fundus. The scanning is performed step-by-step, and image data for a pixel (or for a line of pixels) is obtained from reflected radiation during each scanning step. These optical retinal imaging techniques for example include optical coherence tomography (OCT), confocal scanning laser ophthalmology (cSLO), and line scanning laser ophthalmology (lSLO).
Optical coherence tomography (OCT), for example, is a medical imaging technique that is based on interferometry using a reflected portion of light penetrating into biological tissue. OCT is for example applied in ophthalmology to obtain detailed images of sub-surficial and surficial structures on and below the retina of an eye. In this field, OCT has become a well established method of diagnosing many eye diseases.
In OCT, a beam of imaging radiation is impinged on for example the fundus of an eye and the reflected part is led through an interferometer wherein it interferes with a reference beam. By scanning the imaging radiation across an area of the fundus, a (three dimensional) image may be obtained from the interference pattern. Although OCT has the potential to enable ophthalmologic imaging at high resolution, at present the lateral resolution is strongly limited by eye motions of the eye under examination. These motions may be divided in three different types, including eye tremor, drift and micro saccades. The first one—tremor—may be characterized as a vibrating motion of the eye having a typical frequency around 90 Hz and a typical amplitude of approximately 1 μm. The second type of motion may cause the eye to move across a distance of for example 0.1 mm but at a typical frequency of 1 Hz. The micro saccades may also have a typical period of 1 Hz, with a duration of only 25 ms typically and an amplitude of 25-100 μm. The peak velocity of these micro saccades may be 10 mm/sec.
Adaptive Optics OCT systems presently under development, will enable to reduce the ocular resolution of the system down to approximately 3 μm (micrometer). To enable measurement at this resolution, residual eye motion must somehow be controlled or compensated such that the error introduced is typically below 1 μm (micrometer).
To improve accuracy, OCT systems and other retinal imaging systems for ophthalmologic purposes sometimes cooperate with tracking devices or tracker camera's. The tracker camera may for example include a fundus camera which generates a reference image from which any eye movements can be detected and analyzed. Additional correction optics may then correct the imaging beam to impinge on the correct location on the fundus. The taking of the reference image and the correcting of the beam is usually performed after each scanning step correct for any eye motion occurring during scanning. However, the present tracking devices are still not accurate enough to compensate for eye motion sufficiently, to obtain the required accuracy for correcting the optical retinal imaging system.

Optical coherence tomography method, system and computer program product therefor

NEDERLANDSE ORGANISATIE VOOR TOEGEPAST-NATUURWETENSCHAPPELIJK ONDERZOEK TNO


A method and system for stimulating production of a natural resource (e.g., Oil, gas or water) producing well using vibrational energy delivered to the geological formation through a downhole type apparatus that maybe permanently installed, and continuously or periodically operated even during recovery of the natural resource. The apparatus is constructed to resist corrosion and provides one or more heat sink chambers for controlling heat dissipation during operation. The system is capable of monitoring production, adapting stimulation parameters based on user input and other pertinent parameters.

There exist several extraction methods to improve productivity from oil wells. However in the upstream crude oil industry, 60% to 70% of OOIP (Original Oil In Place) are typically left in the reservoir after the use of normal primary and secondary recovery techniques (Society of Petroleum Engineers. www.spe.org). The benefits of improving extraction methods are substantial. For example, there are thousands of oil wells in Texas, USA, alone, which could benefit from improving oil production output. If it were possible to recover even 50% of the heavy oil deposits, the US could supply 50% of North American demand for another 50 to 75 years (Dr. Franklin Foster, 2006).
A well for extracting fluids from geological formations is constructed by drilling a hole from the surface toward the geological formation that contains a natural resource, and that has adequate permeability to let fluids produced in the formation flow toward the well. The well's walls are lined with a cement layer and a casing that houses and supports a production tube string coaxially installed in its interior. In addition, perforations are made in the well lining in order to connect the well with the reservoir, supplying a path or trajectory inside the formation. Tubes provide an outlet for the fluids obtained from the formation.
Typically, there are numerous perforations that extend radially from the lined or coated well. Perforations are uniformly separated in the lining, and pass to the outside of the lining through the formation. In an ideal case, perforations are only located within the formation, and their number depends on the formation thickness. It is rather common to have nine, and up to twelve perforations per depth meter of formation. Other perforations extend longitudinally, and yet other perforations may extend radially from a 0°-azimuth, while additional perforations, located every 90° may define four sets of perforations around azimuth. Formation fluids pass through these perforations and come into the lined (or coated) well.
Preferably, the oil well is plugged by a sealing mechanism, such as a shutter element, or with a bridge-type plug, located below the level of perforations. This shutter element is connected to a production tube, and defines a compartment. The production fluid, coming from the formation or reservoir, enters the compartment and fills the compartment until it reaches a fluid level. Accumulated oil, for example, flows from the formation and can be accompanied by variable quantities of natural gas. Hence, the lined compartment may contain oil, some water, natural gas, and solid particles, with normally, particles settling at the bottom of the compartment.
The fluid produced in the formation may change its phase when there is a reduction of pressure around the well; this change of phase causes the gasification of the lightest molecules. Also, the oil well can produce very heavy molecules. Over time, due to several reasons, oil well productivity gradually diminishes. Two main causes of the reduction in productivity are related to relative permeability: a decrease of the fluidity of crude oil, and the deposit of solids in the perforations.
Crude oil's fluidity diminishes over time and progressively obstructs pores in a deposit or reservoir. On the other hand, solids such as clays, colloids, salts, paraffin etc. accumulate in perforation zones of the well. These solids reduce the absolute permeability, or interconnection between pores. Problems associated with the causes mentioned above are: obstruction of pores by mineral particles that flow jointly with the fluid to be extracted, precipitation of inorganic scales, decanting of paraffins and asphalt or bitumen, hydration of clay, invasion of solids from the mud and filtration of perforation mud, as well as invasion of termination fluids and solids from brine injections. Each of the above mentioned causes can produce a permeability reduction, or a flow restriction in the zone surrounding oil well perforations. This defines the pore size connecting to the fluid inside formation, allowing the fluid flow from the formation through cracks or fissures, or connected pores, and finally the fluid comes to interstitial spaces within the compartment and is collected. During that flow, very small solid particles from the formation, called "fines," may flow; but instead they tend to settle.
After a certain time, trajectories through perforations extending inside the formation of a reservoir may become obstructed with "fines" or residues. While the "fines" can be kept in a disperse state for some time, they can agglomerate and plug the pore space, reducing the fluid rate or production quantity. This may become a problem that is fed back to the well and cause a production decrease. More and more "fines" can keep settling on perforations, plugging them more and more, even tending to halt a minimum flow rate.
There exist several treatment methods to improve productivity from oil wells. Periodic stimulation of oil and gas wells is done by applying three general types of treatment: acid treatment, fracturing, and default treatment with solvents and heat. Acid treatment consists of using mixtures of acids HCl and HF (hydrochloric acid and hydrofluoric acid), which is injected in the production zone (rock). Acid is used for dissolving reactive components (carbonates, clay minerals, and in a smaller quantity, silicates) in the rock, thus increasing permeability. Frequently, additives are incorporated, such as reaction retarding agents and solvents, to improve acid performance in the acidizing operation.
While acid treatment is a common treatment to stimulate oil and gas wells, this treatment has multiple drawbacks. The cost of acids and the cost of disposing of production wastes are high; acids are often incompatible with the crude oil, and may produce viscous oily residues inside the well; precipitates formed once the acid is consumed, can often be more obnoxious than dissolved minerals; and the penetration depth of active or live acid is generally less than 5 inches (12.7 cm).
Hydraulic fracturing is another technique usually used for stimulating oil and gas wells. In this process, high hydraulic pressures are used to produce vertical fractures in the formation. Fractures can be filled with polymer plugs, or treated with acid (in rocks, carbonates, and soft rocks), to form permeability channels inside the wellbore region; these channels allow oil and gas to flow. However, the cost of hydraulic fracturing is extremely high (as much as 5 to 10 times higher than acid treatment costs). In some cases, fracture may extend inside areas where water is present, thus increasing the quantity of water produced (a significant drawback for oil extraction). Hydraulic fracture treatments extend several hundred meters from the well, and are used more frequently when rocks are of low permeability. The possibility of forming successful polymer plugs in all fractures is usually limited, and problems such as plugging of fractures and grinding of the plug may severely deteriorate productivity of hydraulic fractures.
Another method for improving oil production in wells involves injecting steam. One of the most common problems in depleted oil wells is precipitation of paraffin and asphaltenes or bitumen inside and around the well. Steam has been injected in these wells to melt and dissolve paraffin into the oil or petroleum, and then all the mixture flows to the surface. Frequently, organic solvents are used (such as xylene) to remove asphaltenes or bitumen whose melting point is high, and which are insoluble in alkanes. Steam and solvents are very costly (solvents more so than steam), particularly when marginal wells are treated, producing less than 10 oil barrels per day (1 bbl=159 liters). The main limitation for use of steam and solvents is the absence of mechanical mixing, which is required for dissolving or maintaining paraffin, asphaltenes or bitumen in suspension.
Several other methods have been described to increase oil well output. Challacombe (U.S. Pat. No. 3,721,297) describes a tool for cleaning wells using pressure pulses: a series of explosive and gas generator modules are interconnected in a chain, in such a manner that ignition of one of them triggers the next one and a progression or sequence of explosions is produced. These explosions generate shock waves that clean the wells. There are obvious disadvantages of this method, such as potential damage that can be caused to high-pressure oil and gas wells.
Sawyer (U.S. Pat. No. 3,648,769) describes a hydraulically controlled diaphragm that produces "sinusoidal vibrations in the low acoustic range". Generated waves are of low intensity, and are not directed or focused to face the formation (rock). As a consequence, the major part of energy is propagated along the well axis.
Riggs et al. (U.S. Pat. No. 4,343,356) describes an apparatus for treating shallow wells. Application of a high voltage produces voltage arcs that liberate from the well walls the encrusted material. Among difficulties with this apparatus there is the fact that it is not possible to continually guide the electric arc for achieving a real cleaning of the well. Additionally, safety aspects have not been solved (electrical and fire problems).
Bodine (U.S. Pat. No. 4,280,557) proposes another hydraulic/mechanical oscillator where pulses of hydraulic pressure, created, inside an elastic elongated tube, are used for cleaning encased well walls.
Mac Manus et al. (U.S. Pat. No. 4,538,682) disclosed a method for removing paraffin from oil wells by introducing a heating element into an oil well in order to establish a temperature gradient within the well.
It is known that oil, gas, and water wells are plugged after certain operating time; the fluid discharge diminishes and it becomes necessary to regenerate these wells. Mechanical, chemical, and conventional techniques to regenerate wells include: intensive rinsing, pumping hammer and hydraulic treatment.
Dissolution of sediments using hydrochloric acid, or other acids, mixed with other chemical agents include: Hosing down with high-pressure water, carbon dioxide injection, and generation of pressure shocks using explosives.
Ultrasound techniques have been developed to increase production of crude oil from wells. However, there is a great amount of effects associated with exposing solids and fluids to an ultrasound field of certain frequencies and energy. In the case of fluids in particular, cavitation bubbles can be generated. These are bubbles of gas dissolved in liquid, or bubbles of the gaseous state of this liquid (change of phase). Other associated phenomena are liquid degassing and cleaning of solid surfaces.
Arthur Kuris, in "Method and Apparatus for Fracturing Rock and the Like" (U.S. Pat. No. 3,990,512), discloses a method for recovering oil by application of ultrasound generated when injecting high-pressure fluids, whose purpose is to fracture the deposit to produce new draining channels.
Maki Jr. et al. (U.S. Pat. No. 5,595,243) propose an acoustic device in which a piezoceramic transducer is set as radiator. The device presents difficulties in its manufacturing and use, because an asynchronous operation is required of a high number of piezoceramic radiators.
Vladimir Abramov et al., in "Device for Transferring Ultrasonic Energy to a Liquid or Pasty Medium" (U.S. Pat. No. 5,994,818) and in "Device for Transmitting Ultrasonic Energy to a Liquid or Pasty Medium" (U.S. Pat. No. 6,429,575), propose an apparatus consisting of an alternating current generator operating within the range of 1 to 100 kHz to transmit ultrasonic energy, and a piezoceramic or magnetostrictive transducer emitting ultrasound waves, which are transformed by a tubular resonator or waveguide system (or sonotrode) in transversal oscillations that contact the irradiated liquid or pasty medium. However, these systems are conceived to be used in containers of very large dimensions, at least as compared with the size and geometry of perforations present in wells. This shows limitations from a dimensional point of view, and also for transmission mode if it is desired to enhance production capacities of oil wells.
Julie C. Slaughter et al., in "Ultrasound Radiator of Downhole Type and Method for Using It" (In U.S. Pat. No. 6,230,788), propose a device that uses ultrasonic transducers manufactured of Terfenol-D alloy and placed at the well bottom, and fed by an ultrasonic generator located at the surface. Location of transducers, axially to the device, allows the emission along a transversal direction. This invention proposes a viscosity reduction of hydrocarbons contained in the well through emulsification, when reacting with an alkaline solution injected to the well. This device considers a forced shallow circulation of fluid as a refrigeration system, to warrant continuity of irradiation.
Dennos C. Wegener et al., in "Heavy Oil Viscosity Reduction and Production," (U.S. Pat. No. 6,279,653), describe a method and a device for producing heavy oil (API specific gravity less than 20) applying ultrasound generated by a transducer made of Terfenol alloy, attached to a conventional extraction pump, and powered by a generator installed at the surface. In this invention the presence of an alkaline solution is also considered, similar to an aqueous sodium hydroxide (NaOH) solution, to generate an emulsion with crude oil of lower density and viscosity, thereby facilitating recovery of the crude by impulsion with a pump. Here, a transducer is installed in an axial position to produce longitudinal ultrasound emissions. The transducer is connected to an adjacent rod that operates as a waveguide or sonotrode.
Robert J. Meyer et al. , in "Method for improving Oil Recovery Using an Ultrasonic Technique" (U.S. Pat. No 6,405,796), propose a method to recover oil using an ultrasound technique. The proposed method consists of disintegration of agglomerates by means of an ultrasonic irradiation technique, and the operation is proposed within a certain frequency range, for the purpose of handling fluids and solids in different conditions. Main oil recovery mechanism is based in the relative momentum of these components within the device.
The above-mentioned prior art using ultrasonic waves via a transducer, externally supplied by an electric generator and the transmission cable generally is longer than 2 km. This has the disadvantage of signal transmission losses, which means that a signal must be generated to have enough intensity (or energy) for an adequate operation of transducers within the well, since high-frequency electric current transmission to such depths is reduced to 10% of its initial value. Furthermore, since transducers need to operate at a high-power regime, water or air cooling system is required, which poses great difficulties when placed inside the well. The latter implies that ultrasound intensity must not exceed 0.5-0.6 W/cm2. This level is insufficient for the desired purposes, because threshold of acoustic effects in oil and rocks is from 0.8 to 1 W/cm2.
Andrey a. Pechkov, in "Method for Acoustic Stimulation of Wellbore Bottom Zone for Production Formation" (RU Patent No. 2,026,969), disclose methods and devices for stimulating production of fluids within a producing well. These devices incorporate, as an innovating element, an electric generator attached to the transducer, and both of them integrated in the well bottom. These transducers operate in a non-continuous mode, and can operate without needing an external cooling system. The impossibility of operating in a continuous mode to prevent overheating is one of the main drawbacks of this implementation since the availability of the device is reduced. Moreover, as the generator is located in the well bottom, this equipment maintenance cost rises as it is likely to fail, especially when working in high power applications.
Oleg Abramov et al., in "Acoustic Method for Recovery of Wells, and Apparatus for its Implementation" (U.S. Pat. No. 7,063,144), disclose an electro-acoustic method for stimulation of production within an oil well. The method consists of stimulating, by powerful ultrasound waves, the well extraction zone, causing an increase of mass transfer through its walls. This ultrasonic field produces large tension and pressure waves in the formation, thus facilitating the passage of liquids through well orifices. It also prevents accumulation of "fines" on these holes, thereby increasing the life of the well and its extraction capacity.
Some problems encountered in the solutions proposed by Robert J. Meyer et al., in "Method for improving Oil Recovery Using an Ultrasonic Technique" (U.S. Pat. No 6,405,796), Andrey A. Pechkov, in "Method for Acoustic Stimulation of Wellbore Bottom Zone for Production Formation" (RU Patent No. 2,026,969), Dennos C. Wegener et al., in "Heavy Oil Viscosity Reduction and Production," (U.S. Pat. No. 6,279,653), Oleg Abramov et al., in "Acoustic Method for Recovery of Wells, and Apparatus for its Implementation" (U.S. Pat. No. 7,063,144) and Julie C. Slaughter et al., in "Ultrasound Radiator of Dowhole Type and Method for Using It" (In U.S. Pat. No. 6,230,788), are:
a) some devices to be introduced in the well containing the ultrasound radiator are sensible to degradation by hydrocarbons and corrosion by acids present at the well bottom;
b) some devices are not intended to be used in oil/water wells with high content or presence of gas, due to their almost null capacity to dissipate the heat generated by the mechanic wave radiators when said radiators are not in contact with liquid fluids, situation that eventually will destroy the radiators or other components (cables, wires, coils, others); and
c) some devices are not meant to be used in Gas Reservoirs or Gas wells.
d) some devices have associated environmental treatment costs due to the use of chemicals.
Therefore, what is needed is a method, apparatus and system for improving well productivity that does not present (or at least minimizes) the drawbacks of the existing technologies. The invention provides a system, apparatus and method for increasing production capacity of oil, gas and water wells.

System and method for increasing production capacity of oil, gas and water wells


A device and method to provide backup electrical power to a vehicle data acquisition and recording system. The device operates to control its charging state, discharge state, and interval of discharge to ensure reliable operation of the recording system. The method delineates the process by which continuous electrical power can be supplied to the recording system.

The present invention is directed toward a backup power supply for a crash-survivable data memory unit that is capable of providing continued operation of the device upon loss of electrical power.
The Federal Aviation Administration requires that most commercial aircraft be equipped with a crash-survivable flight data recorder (FDR) and cockpit voice recorder (CVR). Such systems collect vital flight information that provides evidence for the reconstruction and analysis of a subsequent accident. The FDR and CVR is usually powered from a vital electrical bus to ensure operation in all foreseeable operating configurations.
There have been several aircraft accidents in which FDR and CVR recording was discontinued prior to the crash, due to a loss of some or all electrical systems in the aircraft. In these cases, the National Transportation and Safety Board (NTSB) noted that continued operation of either recorder during the power outage could have provided accident investigators with valuable information regarding the cause of the crash.
In its Mar. 9, 1999 letter to the FAA, the NTSB has recommended that, starting in 2005, all aircraft that are required to carry CVRs and FDRs be fitted with an independent power source that is located with the CVR, and automatically engages to provide ten minutes of operation whenever aircraft power to the recorder ceases, either by normal shutdown or through an electrical bus failure/loss. In addition, the NTSB has recommended that all aircraft manufactured after Jan. 1, 2003 be equipped with dual combination (CVR/FDR) recording systems, each powered from a separate, reliable aircraft power supply. Each requirement is an attempt to ensure that FDR and CVR data is recorded during aircraft power outages. There are no systems in the present art, however, that meet the first recommendation, and the second recommendation would be ineffective in collection of data in the event of a total aircraft loss of power.
Backup power sources for FDRs and CVRs have not been previously developed for several reasons. First, older FDRs and CVRs, many of which are still in the field, store data on a continuously-driven magnetic tape. The electrical power required to operate such tape drives, even for a short period of time, requires large and heavy power storage devices that are infeasible for aircraft. Second, a power backup to the CVR and/or FDR could have negative consequences if power to the recorder continues after a crash, allowing it to overwrite vital data in doing so. Finally, the FDR can continue to receive useful data during a power loss only if the sensors supplying it also retain power. The complexity and variation in modern aircraft electrical systems prevents a feasible supply of power to the sensors. Because the CVR and FDR power problems are linked, a division of the backup power supplies for them was deemed an incomplete solution to the overall problem. For at least these reasons, backup power supplies for the FDR and CVR have not been mandated by the NTSB, nor have they been installed on aircraft.
The present invention recognizes and utilizes recent developments in several fields of invention to make possible a backup power supply for vehicle data acquisition and recording systems. For example, traditional magnetic tape storage units have been largely replaced by low-power solid state memory devices. Thus, the size of a backup power storage device that will supply the required amount of power is much smaller, making it feasible for installation in aircraft. In addition, the development of lithium batteries has reduced the size and weight of batteries for a given energy storage requirement. These aspects combined with new smaller and lighter FDR/CVR designs, as described in U.S. Pat. No. 6,153,720 and incorporated herein, make it feasible to incorporate an additional backup power supply into an FDR or CVR as taught by the present invention.
According to one aspect of the present invention, the problems of supplying backup power to FDRs and CVRs are identified by analyzing the specific and different power needs of FDRs and CVRs. Aspects of FDR and CVR operation, during startup, operating, shutdown, accident phase, and post-crash phase are defined. According to another aspect of the invention, a system that ensures reliability of power and continuity of important data acquisition throughout each of the aforementioned phases is described, as summarized in the following paragraphs.
According to yet another aspect of the present invention, a device is disclosed that provides backup electrical power for a vehicle data acquisition and recording system. The device includes a charging control circuit, a discharge control circuit, and a power storage element. The invention receives charging power from an external vehicle electrical bus, and maintains a continuity of power to the recording system in the event of a loss of said bus.
According to still another aspect of the present invention, a method is disclosed for providing backup electrical power for a vehicle data acquisition and recording system, by delineating a process in which a vehicle electrical bus is monitored for power availability, and the system operates either in charging or discharging mode depending on the status of the bus. In addition, a process step includes monitoring the duration of a discharge cycle, and causes a discontinuation of power to the recording system after a pre-determined interval, to ensure that vital data is not over-written after an accident.
These and other aspects of the present invention are described further in the detailed description of the preferred embodiments of the invention which follow.

Power backup application to maintain normal flight recorder operation for a specified period of time in case of aircraft power failure or interruption


Numerous embodiments of a method for depositing a layer of nano-crystal silicon on a substrate. In one embodiment of the present invention, a substrate is placed in a single wafer chamber and heated to a temperature between about 300° C. to about 490° C. A silicon source is also fed into the single wafer chamber.

Polysilicon films formed by Chemical Vapor Deposition (CVD) have wide use in the fabrication of integrated circuits such as microprocessors and memory devices. Polysilicon film deposition processes require adequate physical, chemical, and production-worthy properties. For example, production-worthy properties include uniform thickness and composition for the polysilicon film (e.g., within wafer and wafer-to-wafer), low particulate and chemical contamination, and high throughput for manufacturing. When these properties are met, high electrical performance, reliable, and high yield device wafers can be manufactured at low cost.
In a CVD process, a given composition and flow rate of reactant gases and diluent inert gases are introduced into a reaction chamber containing multiple substrates (e.g., batch furnace). The gas species move to the substrate and the reactants are absorbed on the substrate. The atoms undergo migration and chemically react resulting in a film (e.g., polysilicon) being deposited on the substrate. The un-reacted gases and gaseous by-products of the reaction are desorbed and removed from the reaction chamber. Energy to drive the reactions can be supplied by several methods, (e.g. thermal, photons, catalysis, or plasma). A conventional CVD system typically includes gas sources, gas feed lines, mass-flow controllers, a reaction chamber, a method for heating substrates onto which the film is to be deposited, and temperature sensors. A conventional thermal CVD system utilizes temperature as the primary driver for the reaction of source gases.
In one type of CVD system for polysilicon deposition, a batch of silicon wafers are vertically positioned in a wafer boat for deposition and inserted into a tube-shaped furnace. The wafers are radiantly heated (above 600° C.) by resistive heating coils in the tube. Reactant gases are metered into one end of the tube (e.g., gas inlet) using a mass flow controller. Reaction by-products are pumped out the other end of the tube (e.g., via an exhaust pump).
As semiconductor technology advances, there is a requirement for film deposition to occur at lower and lower temperatures to enable, for example, ultra shallow junctions for sub-100 nanometer (nm) devices. The formation of nano-crystal silicon structures within a film depends on the controlling the size and density of the nano-crystal silicon. One problem with batch furnace systems is that they cannot accommodate nano-crystal film deposition at low temperatures (e.g., below 500° C.). Another problem with batch furnace systems is that they exhibit a disadvantage known as "depletion effects." Depletion effects reduce gas phase concentrations as reactants are consumed by reactions on wafer surfaces. As such, wafers near the inlet are exposed to higher concentrations of reactant gases. Deposition rates are thus greater for wafers placed near the inlet and uniform thickness is difficult to obtain.

Deposition of nano-crystal silicon using a single wafer chamber