A holographic data storage medium includes a polymer film which is set up as a storage layer and whose surface structure can be changed locally by heating. The polymer film is set up for the storage of holographic information via the local surface structure of the polymer film. A reflective layer can be provided on the data storage medium.

The present technology relates to a holographic data storage medium which can be used, for example, for storing image data such as photos, logos, text, and so on but also for the storage of other data.
In a hologram, optical phase information about an object is contained distributed over the surface of the hologram, from which an image of the object can be reconstructed when it is irradiated with light, in particular coherent light from a laser. Holograms are used in industry in many ways, for example in the form of largely counterfeit-proof identifications. Identifications of this type will be found, for example, on credit cards or cheque cards; as what are known as white light holograms, they show a three-dimensional image of the object represented even when lit with natural light. Photographically produced holograms and embossed holograms are widespread, in which a relief structure is embossed into the surface of a material, at which the light used to reproduce the object is scattered in accordance with the information stored in the hologram, so that the reconstructed image of the object is produced by interference effects.
WO 00/17864 describes a data storage medium having an optical information carrier which contains a polymer film set up as a storage layer. The polymer film consists, for example, of biaxially oriented polypropylene. In the previously disclosed data storage medium, the polymer film is wound spirally in a plurality of layers onto a core, there being an adhesive layer in each case between adjacent layers. Information can be written into the data storage medium by the polymer film being heated locally with the aid of a write beam, focused on a predetermined position, from a data drive, as a result of which the refractive index of the polymer film and the reflection capacity at the interface of the polymer film change locally. This can be registered with the aid of a read beam in the data drive, since the read beam is reflected locally more or less intensesly at the interface of the polymer film, depending on the information written in.
The present technology provides a holographic data storage medium which is cost-effective and has wide possible applications.
The holographic data storage medium according to an exemplary embodiment of the invention has a polymer film which is set up as a storage layer and whose surface structure can be changed locally by heating. The polymer film is set up for the storage of holographic information via the local surface structure of the polymer film.
The surface structure or topography of the polymer film may be changed locally by, for example, a laser beam serving as a write beam being focused onto the polymer film, preferably its surface zone, so that the light energy is absorbed there and converted into heat energy. In particular if the laser beam is radiated in briefly (pulsed), the material change in the polymer film leading to the local change in the surface structure is limited to a very small volume owing to the generally poor thermal conductivity of the polymer.
When information is put into the holographic data storage medium, the structure change of the surface is preferably induced point by point, as explained in more detail further below. The local region for the storage of a unit of information (referred to in the following text as a "pit") typically has linear lateral dimensions (that is to say for example a side length or a diameter) of the order of magnitude of 0.5 μm to 1 μm, although other sizes are possible. The height profile of the polymer film, in the event of a change in the surface structure in a pit, typically changes by 50 nm to 500 nm, which depends in detail on the characteristics and operating conditions of the write beam and the characteristics of the data storage medium. The point grid, that is to say the centre spacing between two pits, typically lies in the range from 1 μm to 2 μm. It is generally true that shorter optical wavelengths of the write beam permit a closer point grid.
In order to read information out of the holographic data storage medium according to an exemplary embodiment of the invention, the storage layer can be irradiated with coherent light, so that the surface structure of the polymer film acts like a diffraction grating and a holographic image is produced by interference effects, as explained in more detail further below.
The holographic data storage medium according to the present technology is cost-effective and may be applied in many ways.
The polymer film can be oriented and is preferably biaxially oriented, for example by being prestressed in two directions at right angles to each other within its plane during production. In the case of an oriented polymer film, a high energy density is stored in the film material. As a result of local heating with the deposition of a relatively small quantity of energy per unit area, for example with the aid of a write beam, a relatively intense material change with a change in the local surface structure of the polymer film can be achieved. Biaxially oriented polymer films may be produced from cost-effective mass-produced plastics.
Suitable materials for the polymer film are, for example, polypropylene or polyvinyl chloride, polymer films which have such a material preferably being biaxially oriented. A higher temperature stability and therefore also an improved resistance to ageing and storage stability of the holographic data storage medium, and increased security against loss of data arising from ageing processes may be achieved with polymer films which have an elevated crystallite melting point. Examples of such materials are polyethylene terephthalate (PET), polymethyl pentene (PMP); also poly-2-methyl pentene) and polyimide, a polymer film of such materials also preferably being biaxially oriented. In the case of higher intensities of a write beam, other types of film can also be used.
Preferred thicknesses of the polymer film lie in the range from 10 μm to 200 μm, but smaller or larger thicknesses are also conceivable.
To the polymer film, there can be assigned an absorber dye, which is set up to at least partly absorb a write beam serving to input information and to give up the heat produced in the process at least partly locally to the polymer film. An absorber dye of this type permits local heating of the polymer film which is sufficient to change the surface structure at a relatively low intensity of the write beam. The absorber dye is preferably arranged in the material of the polymer film. However, it can also be arranged in a separate absorber layer, which preferably has a binder; mixed forms are likewise conceivable. For example, the absorber layer can have a thin layer (for example a thickness of 1 μm to 5 μm) of an optically transparent polymer (for example of polymethyl methacrylate PMMA) or, in the case of applications for higher temperature, of polymethyl pentene, polyether etherketone (PEEK) or polyetherimide) which serves as a matrix or binder for the molecules of the absorber dye. The absorption maximum of the absorber dye should coincide with the optical wavelength of the write beam used, in order to achieve efficient absorption. For an optical wavelength of 532 nm of a write beam produced by a laser, for example dyes from the Sudan red family (diazo dyes) or (for particularly polar plastics) eosin scarlet are suitable. For the common laser diodes with an optical wavelength of 665 nm or 680 nm, green dyes, for example from the styryl family (which are commonly used as laser dyes), are more suitable.
A reflective layer can be arranged on that surface of the polymer film which is changed during the storage of holographic information. If this reflective layer is applied after information has been put in, or is not changed or not significantly changed when information is put in, it increases the efficiency of the holographic data storage medium. This is because coherent light used when information is being read out is to a large extent reflected at the surface by the reflective layer and, in the process, modulated by the surface structure, so that a reflectively bright holographic image is produced.
However, the reflective layer can also be configured in such a way that the reflection capacity (reflectivity) of the reflective layer can be changed locally by heating. This may be achieved, for example, with a very thin reflective layer which, under the action of heat from a write beam, is locally partly or completely evaporated. A reflective layer of this type permits a holographic data storage medium in which both the surface structure of the polymer film (and also of the adjacent reflective layer) and the reflection capacity or the optical transmissivity of the reflective layer are changed when information is put in. When information is read out, in addition to phase modulation (because of the varying surface structure), amplitude modulation (because of the varying optical transmissivity) is consequently also obtained. A holographic data storage medium of this type offers numerous possible applications.
In an alternative refinement of the holographic data storage medium, a reflective layer is arranged on that surface of the polymer film which is opposite the surface that is varied during the storage of holographic information. This reflective layer is preferably already present before information is put in and is not changed when information is put in. It is preferably flat and effects reflection of light, which is used to read out information after it has passed through the varying surface structure of the polymer film and the polymer film itself. One advantage of such a reflective layer is the possibility of being able to apply the holographic data storage medium to a nontransparent carrier or virtually any desired substrate. The thickness of the polymer film serving as a storage layer is preferably selected such that no disturbed interference or superposition effects occur.
In a preferred refinement of the present technology, the holographic data storage medium has an adhesive layer for sticking the data storage medium to an object. The adhesive layer makes it possible to stick the data storage medium quickly and without difficulty to a desired object, for example to use the data storage medium as a machine-readable label in which information about the object is stored. Particularly suitable as an adhesive layer is a self-adhesive layer or a layer with a pressure-sensitive adhesive, which, in the delivered state of the data storage medium, is preferably provided with a protective covering that can be pulled off (for example of a film or a silicone paper).
Apart from the layers previously mentioned, the data storage medium according to the present technology can also have additional layers, for example a transparent protective layer or a flexible or dimensionally stable carrier.
The information to be stored can be input into the holographic data storage medium according to the present technology by a method in which holographic information contained in a hologram of a storing object is calculated as a two-dimensional arrangement, and a write beam of a writing device, preferably a laser lithograph, is aimed at a storage layer and/or if appropriate the associated absorber layer of the data storage medium and is driven in accordance with the two-dimensional arrangement in such a way that the local surface structure of the polymer film set up as a storage layer is set in accordance with the holographic information. Since the physical processes in the scattering of light at a storing object are known, for example a conventional set-up for producing a hologram (in which coherent light from a laser, which is scattered by an object (storing object) is brought into interference with a coherent reference beam and the interference pattern produced in the process is recorded as a hologram) is simulated with the aid of a computer program, and the interference pattern or the modulation for the surface structure of the polymer film is calculated as a two-dimensional arrangement (two-dimensional array). The resolution of a suitable laser lithograph is typically about 50 000 dpi (dots per inch). The surface structure of the polymer film can therefore be changed locally in regions or pits with a size of about 0.5 μm to 1 μm. The writing speed and other details depend, inter alia, on the parameters of the write laser (laser power, optical wavelength) and the time of exposure and on the characteristics of the storage layer and any absorber dye.
The holographic information is therefore preferably put in in the form of pits of predefined size; the term "pit" is to be understood here in general terms in the sense of a changed region and not exclusively in its original meaning as a hole or depression. In this case, the holographic information can be stored in a pit in binary encoded form. This means that, in the region of a given pit, the surface structure of the storage layer assumes only one of two possible basic shapes. These basic shapes preferably differ considerably in order that intermediate forms which occur in practice and which are close to one or the other basic shape can be assigned unambiguously to one or the other basic shape, in order to store the information reliably and unambiguously.
Alternatively, the holographic information can be stored in a pit in continuously encoded form, the local maximum height change in the surface structure in the pit being selected from a predefined value range. This means that, in a given pit, the surface structure of the storage layer can assume intermediate shapes between two basic shapes, so that the maximum height change in the present intermediate shape assumes a value from a predefined value range whose limits are given by the maximum height changes of the two basic shapes. In this case, the information can therefore be stored "in grey stages", so that each pit is given the information content from more than one bit.
If a reflective layer is arranged on the surface of the polymer film that is changed during the storage of holographic information, this reflective layer is preferably applied after the local surface structure of the polymer film has been set in accordance with the holographic information. However, the reflective layer can also be applied before the local surface structure of the polymer film is set in accordance with the holographic information. In the latter case, a reflective layer whose reflection capacity can be changed locally by heating permits a holographic data storage medium in which both the local surface structure of the polymer film and the local reflection capacity of the reflective layer can be set in accordance with the holographic information via local heating by means of the write beam. The advantages of these variants are explained further above.
In a method of reading information out of a holographic data storage medium according to the present technology, light, preferably coherent light (for example from a laser), is aimed at a large area of a storage layer of the data storage medium and modulated by the surface structure of the polymer film. As a reconstruction of the holographic information contained in the region covered by the light, a holographic image is registered at a distance from the data storage medium, for example by a CCD sensor which is connected to a data processing device.
The term "large area" is to be understood to mean an area which is considerably larger than the area of a pit. In this sense, for example, an area of 1 mm.sup.2 is a large area. For the scheme according to which information is stored in a holographic data storage medium according to the present technology and read out, there are many different possibilities. It is conceivable to read out from the data storage medium in one operation, by the entire area of the polymer film set up as a storage layer being illuminated in one operation. In particular in the case of larger areas, however, it is advantageous to divide up the information to be stored into a number or large number of individual regions (for example with a respective area of 1 mm.sup.2) and to read out the information only from a predefined individual area in one operation.
The fact that during the reading of information, depending on the configuration of the holographic data storage medium, the light shines through the polymer film or else does not shine through the polymer film (if it is reflected directly at the surface structure or at a reflective layer located there) and may possibly be modulated not only by the surface structure of the polymer film but also by the locally varying reflection capacity of the reflective layer, has already been explained further above.
During the reading of information, as a result of the locally varying surface structure of the polymer film, that is to say its regionally different topography, differences occur in the propagation times of the light waves which originate from various points, that is to say ultimately periodic phase modulation. This applies both to arrangements in which the polymer film is transilluminated (with or without reflection) and for arrangements in which it is not transilluminated (direct reflection at the surface structure). Added to this, in the case of a locally varying reflection capacity, is an amplitude modulation. The region of the polymer film covered by the coherent light acts like a diffraction grating which deflects incident light in a defined manner. The deflected light forms an image of the stored object, which represents the reconstruction of information encoded in the holographic data storage medium.
The holographic data storage medium according to the present technology can be used for different types of storing objects. For example, both the information contained in images, such as photographs, logos, text, and so on, and machine-readable data can be stored and read out. The latter is carried out, for example, in the form of data pages, as they are known, the holographic information contained in a hologram of a graphic bit pattern (which represents the data information) being input into the storage layer as explained. When the said data is read out, a holographic image of this graphic bit pattern is produced. The information contained therein can be registered, for example with the aid of an accurately adjusted CCD sensor, and processed by associated evaluation software. For the reproduction of images, in which high accuracy is not an issue, in principle even a simple matt disc, or, for example, a camera with an LCD screen is sufficient.
In the case of the holographic storage of machine-readable data, it is advantageous that the information does not have to be read out sequentially but that an entire data set can be registered in one operation, as explained. Should the surface of the storage layer be damaged, then, as opposed to a conventional data storage medium, this does not lead to a loss of data but only to a worsening of the resolution of the holographic image reconstructed when the information is read out, which is generally not a problem.


An improved solution for generating depth maps using time-of-flight measurements is described, more specifically a time-of-flight imager and a time-of-flight imaging method with an improved accuracy. A depth correction profile is applied to the measured depth maps, which takes into account propagation delays within an array of pixels of a sensor of the time-of-flight imager.

For the generation of 3D video content it is important to measure the distance of objects located in a scene that is being captured in addition to the usual video data. For this purpose a so-called depth map is determined. Typically a time-of-flight imager is used for this purpose, i.e. a measurement system that creates distance data with help of the time-of-flight principle. The time-of-flight imager includes a light source and a light sensor, which consists of an array of pixels. To measure a depth map, the light source is triggered with a pulse, and all pixels of the sensor are simultaneously triggered with a Transfer Gate (TG) pulse and a Global Shutter Gate (GSG) pulse. For details see K. Fife et al.: "A 0.5 μm pixel frame-transfer CCD image sensor in 110 nm CMOS", 2007 IEEE International Electron Devices Meeting, Vol. 35 (2007), pp. 1003-1006.
Also, WO 2009/135952 discloses methods and sensors for time-of-flight measurements. The sensors are adapted to achieve efficient background radiation suppression at variable background radiation conditions.
Not only background radiation reduces the accuracy of the depth map measurement. To obtain an accurate depth map it is likewise important that the temporal relations between the light source, the transfer gate pulse and the global shutter gate pulse are constant.


An indexed cable arrangement can be installed in a re-enterable housing. The optical fibers of the cable are indexed between a first; ruggedized multi-fiber connector and a second multi-fiber connector. The second multi-fiber connector may be non-ruggedized and disposed within the housing (e.g., at an adapter) or ruggedized and disposed external of the housing (e.g., terminating a stub cable). One or more drop lines are terminated by respective non-ruggedized, single-fiber connectors disposed within the housing. In certain examples, drop lines may be split into multiple connectorized single-fiber outputs.

As demand for telecommunications increases, fiber optic networks are being extended in more and more areas. In facilities such as multiple dwelling units, apartments, condominiums, businesses, etc., fiber optic enclosures are used to provide a subscriber access point to the fiber optic network. These fiber optic enclosures are connected to the fiber optic network through subscriber cables connected to a network hub. However, the length of subscriber cable needed between the fiber optic enclosure and the network hub varies depending upon the location of the fiber optic enclosure with respect to the network hub. As a result, there is a need for a fiber optic enclosure that can effectively manage varying lengths of subscriber cable.

Indexing cable arrangement and enclosure for use therewith


A printing apparatus free from the problem of vibration due to a head maintenance process when a recording head is maintained in the middle of a recording operation. The printing apparatus performs control so that a recording medium is conveyed subsequent to a head maintenance process, when the recording head is maintained in the middle of a recording operation. Even if the position of the recording medium suffers from an error due to the vibration of the apparatus in the course of the maintenance of the recording head, the error in the recording medium position is eliminated by conveying the recording medium in succession to the maintenance. A disturbance-free high-quality image is thus recorded on the recording medium.

1. Field of the Invention
The present invention relates to a control method for a printing apparatus that performs printing by moving a recording head in a direction perpendicular to the direction of conveyance of a copy sheet. More particularly, the present invention relates to a control method for a printing apparatus in a head maintenance operation to restore a recording state of a recording head in the middle of a recording operation.
2. Description of the Related Art
FIG. 3 shows one example of printing apparatus. The printing apparatus shown is a so-called serial printer, which performs printing by moving a recording head in a main scan direction in perpendicular to a direction of paper conveyance (i.e., a sub scan direction). The printing apparatus thus repeats the process of printing in the main scan direction and moving a recording medium in the sub scan direction. FIG. 4 is a sectional view of a major portion of the printing apparatus of FIG. 3. An automatic paper feeder 1 feeds a recording medium to a recording position where the recording head performs printing. Although the automatic paper feeder 1 usually stores a stack of recording media, only one of the recording medium is picked up by a paper feed roller 5 at one time and is supplied to a recording area 8 within a printing apparatus in operation. The recording medium 4, interposed between a pressure roller 6 and a paper conveyance roller 7, advances in an intermittent manner while a recording head (not shown) installed on a carriage 2 performs printing in the course of movement in a main scan direction (namely a direction in perpendicular to the direction of paper conveyance). A diversity of recording heads carry out different printing methods, and an ink-jet recording head, for example, has a portion with a plurality of discharge nozzles mounted therein. In operation, a head maintenance operation to be described later is carried out as necessary. The recording medium 4 that has undergone the printing is then discharged into a discharge tray 3.
The paper conveyance roller 7 rotates when supplied with drive power by a drive motor through a drive gear train (not shown). The pressure roller 6, in contact with the paper conveyance roller 7 or the recording medium 4, also rotates in combination therewith.
In the drive gear train, gears must be meshed with each other with a high degree of precision to accurately transfer the drive power of the drive motor. If the gears abut tightly each other with some load working therebetween, the gears may be damaged due to a mesh degradation and generate mechanical noise. To improve durability and increase low-noise performance, the gear train is typically provided with a backlash.
Specifically, a maintenance unit 9 for carrying out the above maintenance operation may be a suction unit for an ink jet head, a wiping unit for cleaning the face of the ink jet head (where discharge nozzles are arranged), an extra discharging unit for the ink jet head for discharging ink without printing, or some other similar unit. The maintenance unit 9 thus performs the function required to stabilize the printing operation of the ink jet head. Since such a maintenance unit is typically arranged outside the recording area, the maintenance operation is carried out after moving the recording head to the position of the maintenance unit. The maintenance operation typically involves moving the recording head, namely, the carriage 2, out of the recording area. The frequency of maintenance operations changes depending on the pattern to be printed in the printing operation (or a xe2x80x9cprint patternxe2x80x9d) and environmental conditions such as temperature and humidity. To perform a high quality printing, the maintenance operation is performed several times during the printing of a single page.
Referring to FIG. 5, a sequence of the head maintenance process, in the middle of a printing operation, is discussed. The following example is a so-called single direction recording system in which an image is formed when the carriage 2 goes in the main scan and no image formation is carried out when the carriage 2 returns.
In the recording operation, the recording head discharges ink while the carriage 2 scans, and an image is formed on the recording medium 4 (step S501). The paper conveyance roller 7 rotates by a predetermined quantity of rotation to convey the copy sheet while the carriage 2 moves in its back scan direction (in the return direction), and the recording head is prepared to print a next line (step S502).
It is determined in step S503 whether the recording head needs maintaining. When it is determined that a head maintenance operation job is needed, the process goes to step S504 to execute a head maintenance operation. The process returns to step S501 as necessary subsequent to the head maintenance, and steps S501 through S504 are repeated.
When a head maintenance job is performed in the above conventional sequence, the carriage 2 is transferred to a maintenance position prior to the head maintenance operation. The range of scan in the head maintenance operation is different from that in a normal recording operation without performing the head maintenance job. In the head maintenance, the apparatus suffers from a vibration different from the vibration which is generated when the entire apparatus repeatedly scans in the normal printing operation. When a recording operation is executed in immediate succession to the execution of a head maintenance job, a printed image is subject to disturbance. The following causes of the disturbance are contemplated.
The entire apparatus vibrates due to the operation of a drive system that executes the head maintenance. Under such vibration, the paper conveyance roller 7 rotates by a small quantity of rotation corresponding to the backlash of the gear train, causing the recording head to be subject to a relative position error, and thereby leading to a landing error of an ink jet in the direction of paper conveyance. As a result, the printed image is disturbed. When the entire apparatus vibrates due to the operation of the drive system that executes the head maintenance, the vibration is transferred to the recording medium, causing it to vibrate, changing a distance to the recording head (i.e., the distance between the head and the copy sheet), and leading a landing error in the scan direction of the carriage 2 and a disturbance in the printed image.
In view of the above problem, the present invention has been developed. It is an object of the present invention to provide a printing apparatus and a control method for the printing apparatus, which outputs a good quality image by controlling a position error of a recording medium taking place in a head maintenance job in the middle of a printing operation and a vibration of the apparatus.
To resolve the above problem, the present invention provides a control method of a printing apparatus including a conveying unit for conveying a recording medium, a carriage with a recording head mounted thereon, and a maintenance unit for performing a maintenance job on the recording head, wherein the printing apparatus performs recording by intermittently operating the conveying unit to intermittently convey a recording medium by a predetermined travel and by causing the carriage to scan with the conveying unit stopped. When the recording head is maintained by the maintenance unit in the middle of the printing operation, the apparatus controls so that the operation of the conveying unit is stopped subsequent to the finish of a maintenance job.
A printing apparatus of the present invention includes a conveying unit for conveying a recording medium, a carriage with a recording head mounted thereon, and a maintenance unit for performing a maintenance job on the recording head, wherein the printing apparatus performs recording by intermittently operating the conveying unit to intermittently convey a recording medium by a predetermined travel and by causing the carriage to scan with the conveying unit stopped. The printing apparatus includes a control unit for performing control so that the operation of the conveying unit is stopped subsequent to the finish of a maintenance job when the recording head is maintained by the maintenance unit in the printing operation.
In accordance with the present invention, when the maintenance of the recording head becomes necessary in the middle of printing operation to the recording medium, the conveying unit is controlled so that the conveying unit is operated subsequent to the maintenance job. Even if the apparatus suffers from a vibration in the course of the maintenance of the recording head, the entire apparatus is set to a normal printing state, namely, a state as if no maintenance job were done, before the apparatus resumes a printing operation. The image disturbance due to the vibration of the apparatus is thus prevented. Even if the recording medium is in position error due to the vibration subsequent to the maintenance, the error of the recording medium is covered because the conveying unit has operated subsequent to the maintenance.

Printing apparatus and method for controlling the same


Disclosed is both a method and apparatus for delivering cooling air to an electronics rack in a data room in an energy efficient manner. The present apparatus provides directionally delivered cooling air to an electronics rack with usage rates up to 90%. The tiles utilize angled directional vanes for delivering the cooling air. The tiles both conserve energy and increase the overall possible power usage for each cabinet. The tiles greatly increase the cooling efficiencies in the data room and conserve energy.

Electronic equipment racks are generally designed to receive a number of electronic components arranged vertically in the rack, mounted on shelves, and/or to front and rear mounting rails. The electronic equipment may include, for example, printed circuit boards, communications equipment, computers, including computer servers, or other electronic components.
Electronic equipment housed in racks produces a considerable amount of heat, which undesirably affects performance and reliability of the electronic equipment. Often the heat produced by the rack-mounted components is not evenly distributed in the racks. Inadequate supply of cool air and hot air recirculation can reduce equipment reliability substantially and can cause other performance problems. Accordingly, rack-mounted computer systems typically require effective cooling systems to maintain operational efficiency. Cooling can be accomplished by introducing cooled air into an equipment rack and causing the air to flow through equipment in the rack to remove some or all of the heat. The air exits the rack at an increased temperature.
A conventional solution for cooling racks of electronic equipment is to position the equipment racks in rows on a raised floor in a hot aisle and cold aisle configuration, with the fronts of the equipment racks in one row facing the fronts of the equipment racks in an adjacent row. Air cooled by a central air conditioning system is ducted under the raised floor, and perforated or vented floor tiles are provided in the cold aisles to release chilled air towards the fronts of the equipment racks. Chilled air is then drawn into the equipment mounted in the rack and heated air is exhausted out the back of each rack into the hot aisle.
Unfortunately, as technology has rapidly progressed to ever smaller computer chips used to perform more tasks at faster rates the heat produced by such has increased exponentially. The perforated tiles used to deliver air from the subfloor into the room's ambient air can only direct it straight up causing the need for the servers in the cabinets to pull air in a horizontal direction while the natural air flow is in a vertical motion sometimes flowing at a rate of 1000 CFM. However, this process does not work in an efficient manner given the new heat loads encountered in modern data centers.
The rate of actual usage of airflow into the server cabinets as evaluated by floor manufacturing companies ranges from as low as 30% of all air produced in the data centers. This is not to mention that the servers exhaust fans have heat sync's that cause them to ramp up in speed thus using more energy because of the lack of cooling they are receiving from the supply. Studies have been performed to show how even turning up the set point on the air handlers to try to save energy has caused these server fans to use as much energy as the owner thought they were saving by making these changes.
Thus, what is needed is an apparatus and method for delivering a cooling air to the data center racks in an energy efficient manner to meet the needs of ever increasing heat loads.

Apparatus and method for facilitating cooling of an electronics rack


Radio blocs (BRjp) shared in a predetermined frequency band during a periodic radio frame (TRi) between base stations (BS) are allocated to applications in base stations and mobile stations. Each radio block spreading on frequencies (Cj) of said band during a time slot (Mδt) of the radio frame and can be associated with an uplink or a downlink. To meet quality-of-service parameters required by an application, a base station estimates occupation rates of the radio blocks during consecutive radio frames, and allocates to the application at least one radio block having an occupation rate less than a threshold and a periodicity expressed in period of frame and depending on the required quality-of-service parameters. The base station are autonomous for the radio block allocations.

In a radio communication system having a predetermined frequency band according to the mobile WiMAX (Worldwide interoperability for Microwave Access) label and the standard IEEE 802.16e to j, or according to the LTE (Long Term Evolution) technology, sharing the frequency band between base stations is fixed. Initially, each base station has only available a frequency channel consisting in a sub-band of the predetermined frequency band and accordingly, only limited radio resources allocated to it. According to requests of applications in the base station or a mobile station, the base station locally allocates uplink and/or downlink radio resources to each application. Thus, even if the predetermined frequency band is wide, only a few base stations can establish links with mobile stations.
For overcoming such a limitation of the radio resource allocation, it is known to implement a dialog between two base stations, either through a wire connexion, or through a radio path by means of a mobile station recorded in the two base stations. During such a dialog, one of the two base stations takes some radio resources initially allocated to the other base station, for a limited period of time.
However, the number of radio resources can not dynamically progress as a function of the application needs of the base stations, two base stations being unable to dialog remaining without any progress of their initially limited numbers of radio resources. Moreover, the dialog between two base stations makes the associated network infrastructure more complex and slows down the implementation of the radio communication system whose mobility then is restricted.
According to the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol, a node, such as a station, is permanently sensing the shared transmission means for checking the absence of traffic on the carriers from other stations before transmitting the data. The collision detection improves the performance of the CSMA access by stopping the transmission for a random period of time as soon as a transmission collision is detected and reduces the probability of a second collision upon another transmission attempt. Such a protocol is implemented in narrow band systems according to the standard IEEE 802.11, or meeting the WiFi (Wireless Fidelity) label. This invention has in common with the CSMA/CD access, sensing shared radio resources, signalling a data transmission and managing a collision.

Radio resource allocation method in a radio communication system


Novel crosslinkable hot-melt adhesive compositions, curable by atmospheric moisture, include (i) the prepolymerizate of an hydroxylated ethylene/vinyl acetate copolymer with a stoichiometric excess of a polyisocyanate, e.g., a diisocyanate, such prepolymerizate containing an effective crosslinkable amount of free isocyanate functional groups, and, optionally, (ii) an adhesive tackifying resin.

1. Field of the Invention
The present invention relates to novel crosslinkable hot-melt adhesive compositions including a prepolymer containing free isocyanate functional groups which comprises the product of reaction between an ethylene/vinyl acetate copolymer containing hydroxyl functional groups and a polyisocyanate.
The compositions of this invention, typically combined with an adhesive (tackifying) resin, enable production of adhesive bonds which withstand elevated temperatures after crosslinking of the free NCO functional groups, usually under the influence of atmospheric moisture.
2. Description of the Prior Art
The adhesives known to this art are generally in liquid form and become rigid after application, while ensuring the bonding of the surfaces to be united. This stiffening usually results from the polymerization or polycondensation of the basic components of the adhesive.
For a number of years, ever increasing attempts have been made to provide adhesive compositions in solid form as well. These include the hot-melt adhesives which are based on a thermoplastic resin, solid at room temperature, possessing adhesive properties. Such adhesives become fluid when heated, the bonding of the surfaces to be united being ensured when the adhesive again becomes rigid on cooling. These hot-melt adhesives are generally prepared by the combination of two basic constituents: a thermoplastic resin and an adhesive (tackifying) resin, with which there may be combined additives such as waxes, stabilizers, fillers, plasticizers, and others. The most widely used basic thermoplastic resins are the polyamides, atactic polypropylene and, in particular, ethylene/vinyl acetate (EVA) copolymers. In the present state of this art, these hot-melt adhesives have good adhesive properties, but have the disadvantage of exhibiting poor heat strength, a strength which barely exceeds 70.degree. to 80.degree. C.
To overcome this disadvantage, a new generation of crosslinkable hot-melt products has been developed: crosslinkable polyurethane hot-melt adhesives. These adhesives are prepared in conventional manner by reaction of a polyisocyanate with polyols of polyester type, at least one of which is solid at room temperature. Such adhesives are applied at high temperature in the molten state. They have the disadvantage of being incompatible with the adhesive (tackifying) resins, which greatly restricts their formulation options. This is then reflected in a limited capacity for adhesive bonding to certain well-defined supports and substrates. In addition, these products have "open times" on the order of a few minutes, and this is too long for certain high-rate applications. The "open time" of a hot-melt adhesive is the time available to effect the adhesive bonding, between the time when the adhesive in the molten state is applied to the first support to be bonded and the time when the hot-melt adhesive is no longer sufficiently fluid to permit the second support to be properly assembled.
Another type of crosslinkable hot-melt adhesive has been developed from hydroxylated ethylene/vinyl acetate copolymers reacted with a blocked polyisocyanate in stoichiometric amount, as described in JP 108,484 or European Application 88/401,259. These particular hot-melt adhesives, which are compatible with .the adhesive (tackifying) resins, have good adhesive properties, but present the disadvantage of requiring heat treatments at temperatures of at least 120.degree. C. for several minutes to ensure that they are well crosslinked. Such adhesive bonding conditions are not acceptable in the case of certain thermally sensitive supports.

Process for preparing novel moisture-curable hot-melt adhesive compositions


A liquid electrophotographic image forming apparatus including a liquid carrier depositing unit that is arranged at a forward direction of the secondary transfer roller at a paper feed path and deposits liquid carrier on a print side of a sheet of paper that is secondarily transferred.

1. Field of the Invention
The present invention relates to a liquid electrophotographic image forming apparatus, and more particularly, to a liquid electrophotographic image forming apparatus having a unit for depositing a predetermined amount of a liquid carrier on a sheet of paper before an image is transferred onto the sheet of paper.
2. Description of the Related Art
Typically, a liquid electrophotographic printer forms an electrostatic latent image on a photosensitive medium, such as a photosensitive belt or a photosensitive drum, develops the electrostatic latent image with a developing agent having a predetermined color, and transfers the developed electrostatic latent image onto a recording sheet, thereby obtaining a desired image. The electrophotographic printer is largely categorized into liquid and dry electrophotographic printers depending on the type of developing agent. The liquid electrophotographic printer uses a liquid developing agent, which is a mixture of a powder toner and a volatile liquid carrier.
Since the liquid electrophotographic printer using a liquid developing agent uses toner having a fine particle size of approximately 0.5–5 μm, the liquid electrophotographic printer obtains a high-quality image compared to the dry electrophotographic printer using a powder toner when an electrostatic latent image is developed, and harmfulness caused by toner dust is prevented.
FIG. 1 shows a conventional liquid color image forming apparatus disclosed in U.S. Patent Publication Application No. 2003/0044202. Referring to FIG. 1, a plurality of image forming units are arranged in a series on a circulation path of a transfer belt 40 which travels in a closed endless loop by a plurality of rollers 41, 42, and 44. Each image forming unit transfers one of four color images, such as a yellow (Y) image, a cyan (C) image, a magenta (M) image, and a black (K) image, onto the transfer belt 40.
Each image forming unit includes a photosensitive drum 30 which transfers a toner image having a predetermined color onto the transfer belt 40, a charging roller 36 which charges the surface of the photosensitive drum 30 to a predetermined potential, a laser scanning unit (LSU) 38 which forms an electrostatic latent image by radiating light onto the surface of the photosensitive drum 30, and a developing unit which develops the electrostatic latent image to a predetermined toner image. An eraser 34 erases charge on the photosensitive drum 30.
The transfer belt 40 is supported by a driving roller 41, a secondary transfer backup roller 44, and a plurality of primary transfer backup rollers 42 which correspond to the photosensitive drum 30, and rotate, and an image formed on the photosensitive drum 30 is transferred onto the transfer belt 40. A secondary transfer roller 43 faces the secondary transfer backup roller 44 having the transfer belt 40 placed therebetween. The secondary transfer roller 43 transfers the image on the transfer belt 40 onto a sheet of paper 60.
A sheet of paper onto which a color image is transferred by the secondary transfer roller 43, is heated at a predetermined temperature and pressed by a fusing unit 50, which is installed on a paper exhaust path so that the toner image is fused on the sheet of paper 60.
The developing unit includes a developing container 14 in which a developing agent is stored, a developing roller 15, a part of which being soaked in the developing container 14 to face the photosensitive drum 30, a deposit roller 16, a cleaning roller 17, and a metering roller 18.
The developing roller 15 is partly soaked with the developing agent stored in the developing container 14. The deposit roller 16 is installed and soaked with the developing agent stored in the developing container 14. A predetermined voltage is applied to the deposit roller 16 when the deposit roller 16 is spaced a predetermined gap from the developing roller 15. The deposit roller 16 attaches the developing agent to the surface of the developing roller 15 using a potential difference between the deposit roller 16 and the developing roller 15 having a predetermined voltage.
The metering roller 18 is installed adjacent to the developing roller 15 and regulates the developing agent attached to the developing roller 15 by a predetermined thickness.
A cartridge 19 accommodates toner having a predetermined color with a high concentration to be supplied to the developing container 14.
Meanwhile, the developing agent stored in the developing container 14 is mixed with a norpar carrier so that a solid concentration of toner is approximately 5–20 percent by weight. A toner layer having a solid concentration of approximately 25–30 percent by weight is formed on the developing roller 15 by mass/area (M/A) 100–300 μg/cm2. The toner layer develops the photosensitive drum 30, and a toner image is developed on the photosensitive drum 30, a color yellow image is transferred onto the transfer belt 40.
By performing development and transfer operations in the order of the image forming units, each color image is superimposed on and transferred onto the transfer belt 40 so that one color image is formed on the transfer belt 40. The transfer belt 40 is formed of a semiconductive material and does not absorb the carrier.
Subsequently, the color image on the transfer belt 40 is transferred onto a sheet of paper 60 that is fed between the secondary transfer roller 44 and the secondary transfer backup roller 43. Thus, when toner has a positive charge, an electrostatic force is applied to the toner so that a negative voltage is applied to the secondary transfer roller 44 and the color image on the transfer belt 40 is transferred onto the sheet of paper 60.
The amount of charge of dry toner is approximately 50 μC/g, whereas the charge amount of liquid toner is 2–10 times larger than the charge amount of the dry toner. Thus, when the liquid toner having a charge amount larger than the dry toner is transferred onto a sheet of paper, a high electrostatic force is applied to the sheet of paper. However, when a dielectric constant of the sheet of paper is low, transfer efficiency is reduced. In addition, because the dielectric constant of the sheet of paper varies according to the type of paper, printing quality also varies.

Liquid electrophotographic image forming apparatus having a liquid carrier depositing unit


A plurality of optical repeaters are provided on a transmission line between an optical transmitting station and an optical receiving station. A combined transmission line section is provided between optical repeaters. The combined transmission line section is composed of the first optical fiber, which is a positive-dispersion fiber, and the second optical fiber, which is a negative-dispersion fiber. Signal light is inputted to the first optical fiber in each combined transmission line section. Each optical repeater inputs pump light to the second optical fiber.

1. Field of the Invention
The present invention relates to an optical transmission system utilizing Raman amplification.
2. Description of the Related Art
Conventionally, in a long-haul optical transmission system, a plurality of repeaters (optical regenerating repeaters) were provided on a transmission line, and a 3R (retiming, reshaping and regenerating) process was performed to electrical signal converted from optical signal in each repeater. Then, the optical signals were generated from the electrical signals and were transmitted to the transmission line again. However, lately, both the performance and cost of an optical amplifier have been improved and reduced, respectively, and an optical transmission system using an optical amplifier as a linear repeater has been commercialized. Thus, by replacing an optical regenerating repeater with an optical amplifier repeater, the number of components of a repeater apparatus is greatly reduced. Therefore, it is anticipated that reliability is improved and cost is greatly reduced.
As one method for implementing a large-capacity optical transmission system, a wavelength-division multiplexing (WDM) optical transmission system has got attention. In a WDM optical transmission system, a plurality of signal light with different wavelengths are multiplexed in one optical transmission line. Therefore, an information amount to be transmitted through each optical fiber is rapidly increased.
As one method for amplifying an optical signal, Raman amplification has got attention. In Raman amplification, since an optical fiber itself, which is a medium for transmitting optical signals, functions as an optical amplifier, a wide wavelength band can be collectively amplified by properly selecting pump light to be supplied to the optical fiber.
By combining these technologies, a plurality of optical signals with different wavelengths can be collectively amplified by using an optical amplifier. Therefore, a large-capacity and long-haul transmission can be implemented with a simple configuration.
FIG. 1 shows the configuration of a general wavelength division multiplexing (WDM) transmission system. Here, the system is assumed in which an optical transmitting station (OS) 100 transmits multi-wavelength light to an optical receiving station (OR) 110 through an optical transmission line (optical fiber). On this optical transmission line, optical amplifiers (optical repeaters) 120 are located at prescribed intervals.
The optical transmitting station 100 comprises a plurality of optical transmitters (E/O) 101 for generating optical signals with different wavelengths, a multiplexer 102 for multiplexing the optical signals generated by the plurality of optical transmitters 101 and a post-amplifier 103 for amplifying the multi-wavelength light outputted from the multiplexer 102 up to a prescribed level and transmitting the light to the optical transmission line. The optical receiving station 110 comprises a pre-amplifier 111 for amplifying the multi-wavelength light transmitted through the optical transmission line to a prescribed level, a demultiplexer 112 for demultiplexing the multi-wavelength light amplified by the pre-amplifier 111 for each wavelength and a plurality of optical receivers (O/E) 113 for converting each optical signal demultiplexed by the demultiplexer 112 into an electrical signal. The multi-wavelength light that is transmitted from the optical transmitting station 100 is transmitted through the optical transmission line while being amplified by the optical amplifier 120 and is received by the optical receiving station 110.
In the optical transmission system described above, conventionally, as the optical amplifier, an erbium-doped fiber amplifier (EDFA) was widely used. However, lately, a configuration in which the erbium-doped fiber amplifier is replaced with a Raman amplifier or a configuration in which both the erbium-doped fiber amplifier and Raman amplifier are used has been commercialized.
In Raman amplification using an optical fiber, the gain is inversely proportional to the mode field diameter (or core diameter) of the optical fiber. Therefore, an optical fiber with a small mode field diameter is suitable for Raman amplification. The relationship between the mode field diameter of an optical fiber and the gain of Raman amplification has been studied, for example, in "Highly Efficient Distributed Raman Amplification System in a Zero-dispersion-flattened Transmission Line", H. Kawakami et al., ThB5, OAA'99 (1999).
In the design of a WDM transmission system, the non-linear effect of an optical transmission line must be taken into consideration. Specifically, the wavelength dispersion of a transmission line must be managed so as to reduce the degradation of a transmission characteristic due to the non-linear effect of an optical transmission line. A variety of studies have been made as to this problem up to now.
For example, in "Long-haul 16×10 WDM Transmission Experiment Using Higher order Fiber Dispersion Management Technique", M. Murakami et al., pp. 313–314, ECOC'98 (1998)(hereinafter called "Reference 1"), an optical transmission line between an optical transmitting station and an optical receiving station comprises a combined transmission line section composed of one set of a positive-dispersion fiber and a negative-dispersion fiber, and a compensation section composed of an optical fiber for compensating for the dispersion of the combined transmission line section. The optical transmission line between the optical transmitting station and the optical receiving station is composed of a plurality of combined transmission line sections, and optical repeaters are installed between each of them. The compensation section compensates for accumulated dispersion in the plurality of combined transmission line sections. As an example, the average zero-dispersion wavelength of the transmission line and the signal light wavelength are approximately 1551 nm and 1544.5–1556.5 nm, respectively. The wavelength dispersion of each of the combined transmission line section and compensation section are approximately −2 ps/nm/km and approximately +20 ps/nm/km, respectively. Since both the group velocity of signal light and natural emission light, and group velocity of a plurality sets of signal light vary depending on this configuration, the cross-operation time of the non-linear effect becomes short. Therefore, the degradation of the transmission characteristic due to four wave mixing (FWM), cross-phase modulation (XPM) and the like is reduced. Since the average zero-dispersion wavelength is within the signal light wavelength range, the degradation of the transmission characteristic due to self-phase modulation (SPM) and wavelength dispersion is also reduced.
In "1 Tbit/s (100×10.7 Gbit/s) Transpacific Transmission over 7,750 km Using Single-stage 980 nm-pumped C-band Optical Repeaters without Forward Error Correction", T. Tsuritani et al., 11A2–3, OECC2000 (2000)(hereinafter called "Reference 2"), a configuration similar to that of the system described in Reference 1 is disclosed. However, in Reference 1, the wavelength dispersion of each combined transmission line section is negative (−2 ps/nm/km), while in Reference 2, the wavelength dispersion of each combined transmission line section is positive (+2 ps/nm/km).
Furthermore, in "1800 Gb/s Transmission of One Hundred and Eighty 10 Gb/s WDM channels over 7,000 km Using the Full EDFA C-band", C. R. Davidson et al., PD25, OFC2000 (2000)(hereinafter called "Reference 3"), a configuration with nearly zero wavelength dispersion of each combined transmission line section is disclosed. In this system, accumulated dispersion in a plurality of combined transmission line sections is compensated for in the optical receiving station.
Although the gain of Raman amplification greatly depends on wavelength, the gain of Raman amplification can be flattened by using a plurality of pump lights with different wavelengths. For example, in "100 nm Bandwidth Flat Gain Raman Amplifiers Pumped and Gain-equalized by 12 Wavelength-channel WDM High Power Laser Diodes", Y. Emori et al., OFC'99, PD19 (1999), a Raman amplifier which can obtain approximately 100 nm gain band by multiplexing a plurality sets of pump light is disclosed.
In "100 Gb/s (10×10 Gb/s) WDM Transmission over 7,200 km Using Distributed Raman Amplification", M. Nissov et al., ECOC'97 (1997), a technology for transmitting 100 Gb/s signals over 7,200 km by performing distributed Raman amplification using a dispersion shift fiber is disclosed.
Although as described above, a method for managing the wavelength dispersion of a transmission line in order to reduce the influence of the non-linear effect is known, the conventional method has the following problems.
In the systems described in References 1 and 2, accumulated dispersion due to a plurality of combined transmission line sections is compensated for by a compensation section provided after the plurality of combined transmission line sections. For example, if as in the system described in Reference 1, since the wavelength dispersion of each combined transmission line section is negative, an optical fiber composing the compensation section must be a positive-dispersion fiber. However, since usually a positive-dispersion fiber has a large mode field diameter, Raman gain cannot be efficiently obtained. In other words, obtaining a prescribed gain using a positive-dispersion fiber requires extremely large pump power, and the extremely large pump power badly affects the reliability of an pump light source.
To solve this problem, there is a method of providing a short fiber for Raman amplification with an extremely small mode field diameter after the compensation section and compensating for the loss of the compensation section using the fiber for Raman amplification. However, if an optical fiber with an extremely small mode field diameter is used, the non-linear effect becomes large and the transmission characteristic is degraded accordingly. In addition, since a distributed Raman amplifier and a centralized Raman amplifier coexist in a transmission system, the configuration becomes complex and the transmission wave distortion due to the non-linear effect of the entire transmission system increases.
In the system described in Reference 3, since the wavelength dispersion of each combined transmission line section is nearly zero, waveform degradation due to self-phase modulation is reduced. However, since bit arrangement between wavelengths becomes the same in the same position of each combined transmission line section, waveform degradation due to cross-phase modulation becomes a problem.
As described above, in Raman amplification, Raman gain can be flattened over a fairly wide band by multiplexing a plurality sets of pump light. However, to reduce the size of a repeater as much as possible or to reduce power consumption or heat generation as much as possible, the number of pump light sources provided in each repeater must be restricted. For this reason, if the number of channels for transmitting signals is increased, gain deviation increases and transmission characteristic degrades accordingly.


The anodes in a ring laser gyroscope are appropriately positioned for the easy starting of a gas discharge and maintaining the discharge at a lower electrical potential. Two operating anodes are placed symmetrical with and in close proximity to a cathode while a third trigger anode is placed in direct line of sight with the cathode. This configuration allows ease in starting without using a very large starting voltage.

Ring laser gyroscopes are commonly used as angular rate sensors. An integral part of the ring laser gyro is the laser beam source or generator. One form of a laser beam generator comprises a gas discharge device. The gas discharge device is used to create a light beam. This light beam is then transmitted around a closed-loop path. A plurality of cavities in combination with a plurality of mirrors define the closed path. The path is usually triangular or rectangular, but any closed-loop polygonal path could also be used.
Present day gas discharge devices use a He-Ne gas which is excited by an electric current passing therethrough, consequently ionizing the gas and creating a plasma. As is well understood by those skilled in the art, the ionized gas produces a population inversion which results in the emission of photons, and in the case of He-Ne generation of a visible light. The He-Ne gas is contained within the aforementioned closed-loop path. By exciting the gas within the closed-loop path, the emitted visible light is forced to propagate around the closed-loop path. Two counterpropagating light signals are created, each traveling around the close-loop path in opposite directions.
It should be noted that prior art ring laser gyro systems are usually provided with a pair of electrical currents which flow in opposite directions. Each of the electrical currents create plasma in the gas. The current is established by applying electrical potential, of sufficient magnitude, between one cathode and one anode. As a consequence of the electrical current passing through the gas the gas molecule flow is affected. Since the electrical currents usually flow in at least a portion of the path traversed by the laser beams, the gas molecule flow caused by the electrical current results in a bias or error term in the gyro output. Accordingly, in the field of ring laser gyros, a pair of electrical currents are usually generated in order to balance the gas molecule flow effects caused by the individual currents. In ring laser systems of the prior art, a pair of electrical currents can be provided by a single cathode and a pair of anodes symmetrically placed relative to the closed-loop path of the laser beams. This configuration results in the gas flow effects caused by one of the electrical currents to be balanced by gas flow effects caused by the other one of the electrical currents.
Ring laser gyro systems similar to that just described have two inherent characteristics which hinder the ability to make the device lase. First, the body forming the optical cavity is usually of a very high dielectric index material causing the existence of stray capacitance between the electrodes and other parts of the structure. This stray capacitance causes an electrical charge to build up on or in the cavity, creating an electric potential which must be overcome to initiate electrical current between the cathode and anode.
Further, in some systems, particularly triangular ring lasers, the electrodes are not in a straight line relationship with each other through the cavities Current traveling through the gas between the cathode and anode must follow through at least a pair of connected cavity line segments forming the closed-loop path. This configuration requires the discharge current to travel around a corner. As a result, the start up potential required to initiate the electrical currents between each cathode and anode pair is very large and much greater than that required to initiate a current through a straight tube laser.
This type of arrangement where the cathode and the anodes are not in straight line relationship is illustrated in FIG. 1. There is shown a gyro block 110 having a plurality of interconnecting tunnels 12, 14 and 16. Attached to block 110 are a plurality of mirrors 20 which reflect light beams through interconnecting tunnels 12, 14 and 16. The mirrors also enclose the tunnels 12, 14 and 16, forming a closed-loop cavity.
Attached to block 110, on a first side 112, is a cathode 130. Cathode 130 communicates with the closed-loop cavity via a communication port 132 Also attached to block 110 is a first anode 140 and a second anode 142 which are attached to a second side 114 and a third side 116, respectively. First anode 140 and second anode 142 communicate with the closed-loop cavity via communication ports 134 and 136, respectively.
To initiate the flow of a discharge current a very large potential must be applied between the cathode 130 and the first anode 140, as well as between the cathode 130 and the second anode 142. As can be seen, the discharge current is required to flow around a corner (see a first corner 150 and a second corner 152), thus a very large starting potential is required between cathode 130 and the anodes 140 and 142.
In the prior art, initiation of electrical currents between the cathode and anode to cause ionization of the gas and subsequently cause the generation of laser beams is unreliable, usually slow to start, and requires a very large start up electrical potential between each cathode and anode pair.


The present disclosure relates to hybrid brake systems. The hybrid brake systems may comprise one or more electromechanical actuators and one or more hydraulic adjusters. The hybrid brake system may further comprise a housing configured to store and/or conduct fluid. The hybrid brake system may also further comprise a fluid reservoir. The hybrid brake system may be redundant.

Aircraft may employ hydraulic or electromechanical braking systems. Typical hydraulic braking systems employ pistons driven by hydraulic pressure fed from reservoirs. These hydraulic braking systems may be low cost and relatively low weight. On the other hand, electro-mechanical brake systems eliminate the need for all hydraulics which improves field maintenance and reduces environmental risk from to hydraulic leakage.


An apparatus includes a calibration fixture, a calibration position sensor, and interface circuitry. The calibration fixture is sized and shaped to fit over a distal-end of a medical probe, such that the distal-end makes physical contact with a wall of the calibration fixture. The calibration position sensor is fixed in the calibration fixture at a known position relative to the wall, and configured, in response to sensing a magnetic field, to produce position signals indicative of a given position of the calibration position sensor. The interface circuitry is electrically coupled to the calibration position sensor, and is configured to output the position signals.

Position sensors are used, inter alia, for tracking medical devices in a patient body. Various techniques for calibrating and applying such devices and sensors are known in the art.
For example, U.S. Patent Application Publication 2015/0247944, issued as U.S. Pat. No. 9,638,820 on May 2, 2017, describes a calibration jig for a flat location pad. The jig includes a detector assembly, a positioning unit, and interface circuitry. The detector assembly includes an array of multiple magnetic field detectors. The positioning unit is configured to fix the detector assembly at one or more known positions relative to a location pad. The interface circuitry is configured to output electrical signals that are produced by the magnetic field detectors of the detector assembly when the detector assembly is fixed at the known positions, so as to calibrate the position measurements performed by the positioning system.
U.S. Patent Application Publication 2001/0027271, issued as U.S. Pat. No. 6,298,262 on Oct. 2, 2001, describes a method and apparatus for positioning a surgical instrument during stereotactic surgery using a guidance fixture. The guidance fixture includes an upper portion, which includes an instrument guide for moving the surgical instrument along a constrained trajectory relative to the upper portion, and includes an adjustable base supporting the upper portion, which includes a mounting base and an adjustment mechanism.

Calibration jig for a catheter comprising a position sensor


According to an example, a multi-function module for insertion into a slot of a networking chassis includes a front plane having an opening through which a plurality of ports are accessible, a switch carrier board comprising an ASIC that is to operate as an interface between the plurality of ports accessible through the front plane and a plurality of rear connectors, and a microprocessor system board positioned in spaced relation with respect to the switch carrier board, the microprocessor system board comprising a microprocessor, a chipset, and a memory. The ASIC is positioned on a side of the switch carrier board that faces the microprocessor board and the microprocessor is positioned on a side of the microprocessor system board that faces the switch carrier board.

Network switches are hardware-based devices that control the flow of data packets or cells based upon destination address information available in each packet. In environments where relatively large amounts of data switching are needed, multiple network switches are combined into a switch assembly housed in a chassis. Generally speaking, a chassis is a frame or box containing multiple ports into which the multiple network switches, which are typically referred to as modules or blades, are inserted and supported. The chassis typically provides cooling and power resources that are shared among the network switches.

Multi-function module for insertion into a networking chassis slot

Hewlett-Packard Development Company, L.P.


The present invention provides a method for fabricating a stacked capacitor array (1), which comprises a regular arrangement of a plurality of stacked capacitors (2), with a stacked capacitor (2) being at a shorter distance from the respective adjacent stacked capacitor (2) in certain first directions (3) than in certain second directions (4), comprising the following method steps: provision of an auxiliary layer stack (5) having first auxiliary layers (6) with a predetermined etching rate and at least one second auxiliary layer (7) with a higher etching rate on a substrate (8); etching of in each case one hollow cylinder (9) for each stacked capacitor (2) through the auxiliary layer stack (5) in accordance with the regular arrangement, with the auxiliary layer stack (5) being left in place in intermediate regions (10) between the hollow cylinders (9); isotropic etching of the second auxiliary layers (7) to form widened portions (11) of the hollow cylinders (9), without any second auxiliary layer (7) being left in place between in each case two hollow cylinders (9) which adjoin one another in the first direction (3) and with a second residual auxiliary layer (7a) being left in place between in each case two hollow cylinders (9) which adjoin one another in the second direction (4); conformal deposition of an insulator layer (12) in order to completely fill the widened portions (11); deposition of a first electrode layer (13) in the hollow cylinders (9) in order to form the stacked capacitors (2); filling of the hollow cylinders (9) with a first filling (14); removal of the first auxiliary layers (6), the second residual auxiliary layers (7a) and the first filling (14) and completion of the stacked capacitor array (1).

Although it can in principle be applied to any desired integrated circuits, the present invention and the problem on which it is based are explained in connection with integrated memory circuits, in particular DRAM cells, produced using silicon technology.
It is known that a stacked capacitor is preferably connected at the bottom to a transistor in order to form a DRAM cell. During the known fabrication of stacked capacitors, in particular of cylindrical stacked capacitors in a stacked capacitor array, the problem arises of the mechanical stability of the individual stacked capacitors decreasing as their aspect ratio increases. If the aspect ratio of capacitors in column or crown form rises above a certain value, the structures become mechanically unstable. The capacitors may disadvantageously adopt an inclination toward one another as a result of this instability. If two adjacent capacitors are inclined toward one another to such an extent that they come into contact with one another, a short circuit is produced between these two capacitors. Memory errors occur within a stacked capacitor array as a result of a short circuit between two capacitors.
Hitherto, this problem has been solved by keeping the aspect ratio of the individual capacitors below an empirically determined limit value. However, this limits the capacitance which can be achieved per capacitor.
However, to further improve the large scale integration of memory circuits, it is necessary to increase the capacitance of the respective capacitor per unit chip surface area by increasing the aspect ratio.

Method for fabricating a stacked capacitor array having a regular arrangement of a plurality of stacked capacitors


An image forming apparatus has a first detector for detecting that a consumption article has reached its life, a second detector for detecting that the consumption article has reached a certain timing before its life, a third detector for detecting an application of power and/or releasing of a power saving mode of the image forming apparatus, a first controller for making a display portion display an alarm advising a replacement of the consumption article and for making the image forming apparatus inactivate, and a second controller for releasing the alarm display and enabling the use of the image forming apparatus when a specific input is operated during the displaying of the alarm on the display portion.

1. Field of the Invention
The present invention relates to an image forming apparatus, such as a copying machine, a printer, a facsimile machine, or a MFP (Multi Function Peripheral) which is a combined machine having multiple functions including a copying function, a printing function, a scanner function and a facsimile function, for example.
2. Description of Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
For example, the aforementioned MFP is equipped with various consumption articles such as a photosensitive element, a fixing roller and a toner cartridge in an exchangeable manner.
These consumption articles once come to the end of their lives, they become a non-usable state (hereinafter may be referred to as "life"). Therefore, for the purpose of advising the user to replace the consumption article with new one, a conventional apparatus detects the status in which the consumption article came to near the end of the life but is still in a usable state (hereinafter may be referred to as "near life") and displays the status on the display portion thereof to give an alarm for the replacement against the user.
For example, Japanese Unexamined Patent Laid-open Publication H6-138768 A discloses a technique for assuredly detecting whether a toner as a consumption article has come to the empty state to give an advance notice of the toner empty without fail.
Irrespective of such conventional technique, despite the advance notice of the replacement of the consumption article that has reached its near life, the apparatus can be used continuously until the consumption article has finally reached the life without requesting the user to perform a specific operation. Therefore, it was difficult to make the user recognize the necessity of the early replacement of the consumption article.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.

Image forming apparatus and control method thereof

Konica Minolta Business Technologies, Inc.


An apparatus of detecting defects on an optical recording medium includes a defect signal generating circuit for generating a corresponding defect signal according to a surface defect of the optical recording medium, a first synchronous signal generator for generating a first synchronous signal, a defect signal locating circuit, a delay signal generating circuit, and an OR gate. The defect signal includes at least one pulse, whose width corresponds to the physical width of a surface defect. The delay signal generating circuit generates a delay signal corresponding to each pulse when the spacing between two adjacent pulses is smaller than a preset value. An OR operation is performed to the delay signal and the defect signal to obtain a defect extension signal. The first synchronous signal and a second synchronous signal for separating data recording sectors of the optical recording medium are employed to detect widths and addresses of surface defects.

The surface of a common optical recording medium (e.g., CD) or rewritable optical recording medium (e.g., CD-RW) may be scratched in use due to rubbing with other rough surfaces. Once these optical recording media have defects on the surfaces thereof for some reasons, such as scratching, optical media recording devices have to recognize in advance or during recording process at which address or in which sector the optical recording media have surface defects. Although data will still be recorded at addresses having these surface defects, these data will also be duplicated into another spare data area for the safety concern.
In order to know relative information of the width and address of surface defects, optical medium recording devices usually require incorporating with some other hardware. The same results can be acquired with a preset file system of the operating system. Compared with the former, the latter appears to be very complicated. On the other hand, compared with optical medium recording devices, common optical medium reading devices (e.g., CD-ROM) cannot solve the problem of surface defects of disk. Some well-known large companies like Compaq, Sony, Philips, and Microsoft constituted a Mt. Rainier group to advocate a standard of defect management into optical disc devices and operating systems so as to enhance their compatibility and surface defects managing function, thereby solving some unpredictable troubles possibly encountered when optical recording media have surface defects.

Apparatus and method of detecting defects on optical recording media


The invention is directed to a solid-state projection device incorporating a light source, modulator, and control circuitry on a single chip. For example, projection device may include several sets of VCSELs, each associated with a set of MEMs mirrors and coupled to a control circuitry. The device may also include various Pyrex layers for sealing and angling layers. The device may further include detectors associated with the light source. These detectors may be useful in determining the shape and location of the projection surface, building a gesture interface, and determining the operability of proxels. The invention is also directed to methods for using the device for manipulating the image, producing zoom, masking, reverse images, positioning, and keystone correction, among others. The invention may be used in projection display devices, portable display devices, heads-up displays, retinal displays, rear and front projection displays, and other display applications.

Business and other functions are moving to a mobile paradigm. With the expanding use of portable computing devices and portable devices include laptops, cellular phones, and PDAs, among others, many typical portable display and portable projection devices are available. However, typical display technologies are cumbersome, have low quality, and have a high power consumption.
Many typical projection devices are large projection devices designed to be connected to a computer, often a desktop computer. With the proliferation of laptop computers, the market has expanded as the projection devices became more portable. Recently, vendors have developed devices that enable a PDA, such as a Palm or Pocket PC device, to be connected to a projector and drive a presentation, eliminating the need for a laptop computer. Likewise, many high-end projectors include the ability to store and display Powerpoint files without an external device. The typical user of these projectors is the corporate user for the presentation purposes, but the market is expanding to home theatre, specialty displays, and training simulation applications.
Display projection systems are typically large, heavy and power hungry devices. They require high-power and high-temperature light sources to work. This means they also require significant cooling and power supplies. Also, current devices require fairly complex optics to focus and manipulate the display for "keystone correction" and zoom, among other features. Manual correction of the display is required to accommodate environmental issues. Typical devices are shrinking through the use of smaller components, but essentially the technologies used are old. The problems of high-power, large size, durability, and usability remain. These typical display technologies include CRTs, LCDs, Plasma Displays, and Light Valve or DLP® Projectors.
Many typical portable projectors are the size of a large laptop in width and depth but often twice the height of many typical laptops. One typical unit is 1.9″ h×9″×7″ weighing 2.9 pounds. This devise is based on the TI DLP® (Digital Light Processor) technology, outputs 800 ANSI Lumens (a measure of display brightness), and supports XGA (1024×768) resolution. Many typical products range in price from $3000 to $10000 depending on features, brightness, and resolution.
Size and weight reductions are limited utilizing current technology. Fragile, power hungry, and expensive bulbs are required to be precisely assembled with precision optical components to make current devices. This keeps manufacturing costs high and margins low. The current devices are relegated to special use and only one or two per location are owned by a typical business. Although somewhat portable at 3 pounds, the current devices require bulb replacements every 200 or so hours of use at a cost of $200–$300.
Often, projector brightness is measured in ANSI Lumens. In projector specification sheets this measurement is labeled "brightness" but technically is a measure of luminant power. Lumens are a measure of the quantity of light, not illumination or brightness. To determine brightness, the number of lumens are divided by the area to get Lumens/sq.ft.
The specification for ANSI lumen measurement of projectors is independent of projected image size, and uses measurement from nine points around the screen to come up with an average value. Many typical display projectors are rated at between 800–1100 ANSI Lumens.
In contrast, a typical television picture has a brightness of about 20–30 Lumens/sq.ft. Comparison to an 800 ANSI lumen projector depends on the size of the displayed image. Remember, to get the brightness we divide the lumens rating by the display area. An 800 lumen projector is about as bright as a typical TV for a display size of 7½ feet assuming that the screen is not absorbing too much light.
The brightness of a typical 800 lumen projector on a screen to create a 7½ ft diagonal image (which covers 27 sq. ft.) is 30 lumens/sq. ft. (dividing 800 lumens by 27 sq. ft.). For a larger display, the image is less bright. For example, a 10 ft. diagonal size image (covers 48 sq. ft.), the same projector will have a brightness of 17 lumens/sq. ft. (800/48=17)
Many typical projectors are either LCD (Liquid-Crystal-Display) or DLP® (Digital Light Processor) projectors. Both type projectors use a high-intensity lamp that burns at a constant brightness. Each pixel of the LCD panels inside acts as a tiny shutter to block some of that light and vary the brightness on the screen. DLP® projectors have an array of the tiny mirrors and the light is either aimed through the lens onto the screen or aimed at a black "light sink" in the projector to absorb the unneeded light. Whether one pixel or all pixels are transmitting maximum light the bulb brightness will not vary. (Because the LCD Pixels cannot completely block the light, and DLP® projectors leak light even when the pixel's mirror is pointing toward the light sink, both types of projectors typically produce a less than perfect black.)
A 100 W light bulb puts out only 5–7 W of visible light, the rest of the energy is wasted in heat. The 100 W bulb emits the equivalent of about 800 lumens, but a projector that outputs 800 lumens typically requires a 250 W bulb. This is because the bulb outputs light in all directions. Imperfections in the reflector, leakage of light, and the light absorbed going through the LCD panel and the lenses waste about half of the luminous intensity before it leaves the projector. Also, some light is lost in dispersion as it crosses the room to the screen. Getting the light from the bulb to the screen wastes a lot of energy.
To get a very "white" color from a bulb the filament must operate at a high temperature which requires higher voltages and a much larger power supply. This also increases the power lost as heat.
The difference between many typical projectors and many typical televisions is the projection method. In a television CRT (Cathode-Ray-Tube), light is created by a focused beam of electrons hitting the phosphor on the inside of its face. The beam illuminates a very small point and moves that point rapidly across the faces from left to right, top to bottom until it covers the whole surface. This takes place rapidly so the eye doesn't notice and sees the picture as one solid image.
The electron beam intensity is varied as needed to change the brightness of the dot. The primary limitation of brightness in a CRT is its maximum beam current. The average power required to create a complete picture is much lower. If only 10% of the screen needs to be at maximum brightness, then maximum power is required for only 10% of the time. For a scanning type display two measurements are needed, average power (the equivalent to ANSI lumens) and peak power. The average power can be much lower for the same quality picture because it is rarely required that the whole screen be white.
There are CRT based projectors, which typically use 3 very bright CRTs, focused through lenses to project an image. However, they are heavy and large. CRTs are sometimes still used for rear-projection TVs. The peak to average (ANSI) lumens ratio of CRT projectors is typically five to one. For example, a 160 ANSI lumen rated CRT projector will have over 800 peak lumens. Since CRTs can completely cut off the beam current, CRTs can provide a perfect black level. A clean black is just as important to picture quality as a bright white. Because of the basic difference, a CRT projector with a typical, 160-lumen ANSI brightness and 800-plus peak brightness, will actually look brighter than an LCD projector rated at 800 lumens.
Early computer monitors (green screens) could not scan the number of lines required often enough, (at a high-enough refresh rate) so they had phosphors with more persistence. (i.e. they glowed longer after the electron beam hit them.) High persistence phosphors were required to overcome limitations of the electronics and are designed to improve display quality when the device cannot scan fast enough.
All phosphors have some persistence, which is unavoidable. Paradoxically, as display electronics got faster and could drive the beam more quickly (i.e. higher refresh rates), CRT manufacturers have had to work to minimize the persistence of the phosphors in CRTs. Computer monitors have increasingly used lower persistence phosphors at higher refresh rates so they get less image flicker and crisper images of moving pictures like video.
In addition to the display issues, connection to devices may prove problematic. Typical display devices for laptops use connections that are not available for other portable computing devices. Cross compatibility is limited and multiple display devices must be used for multiple portable devices.
These problems persist in many display arenas including heads-up displays, gauge displays, rear projection televisions, front projection televisions, computer monitors, cell phone screens, PDA screens, portable projection devices, and photocopier imaging, among others. As such, this solution may be applied to a variety of display applications.
As such, many typical display devices suffer from the display capabilities, interface formats, and portability. Further, many typical displays are bulky, heavy, expensive, high power consumers, high heat producers, mechanically complex, difficult to setup, and/or fragile, among others. Many other problems and disadvantages of the prior art will become apparent to one skilled in the art after comparing such prior art with the present invention as described herein.