This invention relates to a collecting device (1) for loosening and collecting particulate material from a well. The device includes a first end portion and a second end portion; a feed pipe (6) in the first end portion; a collecting container (8) including at least one container section (10), between the feed pipe (6) and the second end portion. A conveyor (18), in the feed pipe (6), moves the particulate material in toward the collecting device (1). The device further includes a tool (20) at the leading end portion of the conveyor (18) and a fluid outlet (38) at the second end portion; a mono pump (12) driven by a motor (22); and at least one container section (10) in a flow path (40) on the pressure side of the mono pump (12). A method for loosening and collecting particulate materials from a well by means of the collecting device (1) is described as well.

This invention relates to a collecting device for loosening and collecting particulate materials in a well, especially in a petroleum well. It relates, more particularly, to a collecting device which includes a feed pipe with a rotatable conveyor on the suction side of a pump, the conveyor being arranged to move particulate materials up to the pump. The particulate material is carried through the pump when the pump is active and is collected in a portion of a collecting container on the pressure side of the pump. The pump works as a valve when the pump is passive, so that collected particulate material does not flow out of the collecting container when the collecting device is transported up to the surface and out of the well where the collecting container is emptied. The invention also includes a method for collecting particulate material in a well and for bringing the particulate material out of the well.
It happens relatively often that particulate materials in the form of silt, sand, loosened deposits, drill-fluid particles, cuttings and other material settle on the inside of a pipe belonging to a well in the ground. The well may be a well producing oil or a well producing a gas. Such particulate materials may, if they build up to a sufficient degree, be highly obstructive to a fluid flow through the pipe. The deposited material is normally removed by means of a collecting tool. It is known to use various types of collecting tools in connection with coiled-tubing operations, snubbing or drilling operations.
Even in smaller amounts, particulate materials may be a problem even if they do not affect the well production to any significant degree. The particulate materials may, for example, be a hindrance to maintenance works, especially when it is a question of simple methods such as cable works. It is not unusual for deposited sand and other material in a well, even in moderate amounts, to prevent tools from reaching the desired position in the well during maintenance works.
It is common to divide oil wells and gas wells into the following groups:
Conventional wells in which the largest angular deviation from the vertical direction is approximately 65 degrees.
Extended-reach wells (Extended Reach Drilled, ERD) in which the angular deviation relative to the vertical direction is larger than 65 degrees.
Horizontal wells in which some well sections have an angular deviation of approximately 90 degrees relative to the vertical direction.
According to the prior art, in conventional wells, a sand collector is used, which is lowered into the well by means of a cable, for example. The sand collector includes at least one collecting chamber. Sand collectors exist that operate in different ways. A sand collector of a first type may be hammered into the particulate material, and a sand collector of another type may suck into the particulate material by means of an integrated piston arrangement or by a plate opening to a room at atmospheric pressure, whereby the well pressure displaces the particulate material into the collecting chamber.
Most prior-art methods are simple and relatively inexpensive to implement. They are thus well suited for conventional wells in which the particulate material forms bridges covering the entire pipe cross section, and in which it is therefore easy to fill the collecting chambers with particulate materials by means of one of the above-mentioned methods.
Especially two conditions distinguish ERD wells and horizontal wells from conventional wells when it comes to particulate materials and methods of bringing the particulate materials out. Firstly, bridges of particulate material rarely form in the pipe as, owing to gravity, the particulate materials are deposited in the downward-facing circumferential half of the pipe. Prior-art collectors that are arranged to be sucked down into the particulate material are not effective when the particulate materials are distributed along the pipe, as the collectors will, in the main, be filled with fluid.
Secondly, the part of the gravity that acts on the tool in the axial direction of the well pipe decreases with the angular deviation of the well relative to the vertical axis. In horizontal well sections, the gravity on the tool in the axial direction of the well is null. Wireline tools that are dependent on the axial weight component of the tool weight in order to work satisfactorily cannot be used under such conditions. The tools may be supplemented with wireline tractors to improve progress.
The Norwegian patent 315212 discloses a collecting device which is provided with a conveyor worm in which the leading portion of the conveyor worm is provided with a scraper or another suitable tool. The conveyor worm, which is driven by a motor, is arranged to move loosened particulate materials into a collecting container. The device according to NO 315212 has also proved effective in ERD wells and horizontal wells, but has a relatively small collecting capacity.
The patent publication WO 2010/120454 discloses a collecting device for use together with a slickline. The collecting device includes a pump in the upper portion of the device. The pump sucks up particulate materials from the well through an opening in the free, lower end portion of the device. The collecting chamber of the device is positioned on the suction side of the pump. A filter which is positioned between the collecting chamber and the pump retains the particulate material in the collecting chamber while fluid passes the filter and the pump. The pump may be a mono pump. A mono pump is also termed a Moineau pump after the inventor, or a PCP (Progressive Cavity Pump). The operation of the mono pump is known to a person skilled in the art and is not described any further.
Collecting devices for removing particulate materials in a well include elongated, tubular collecting containers. Together with other necessary equipment such as a tool for loosening the particulate material, a motor for driving the tool and a device for displacing the collecting device, such as a wireline tractor, the collecting device and equipment typically form an equipment string of 15 metres. This equipment string is sluiced into the well in a known manner through a lubricator above the wellhead. The lubricator may have a capacity for sluicing in known well tools which are typically up to 30 metres long. The known collecting devices thus do not utilize the sluicing capacity. This is because known collecting devices have a limited ability to fill elongated collecting containers. It is therefore of no importance if the collecting device is provided with a longer collecting container, as this cannot be utilized. Typical known collecting devices have a capacity for removing 20-30 litres of particulate material on every trip into the well. There is a need for a collecting device which has a larger capacity, for example being able to remove 100 litres in each trip. A collecting device like that will, to a substantial degree, increase the efficiency of the work to remove particulate materials from a well. An alternative to using collecting devices as described is to provide a coiled tubing with a suitable collecting tool. It is considerably more complex to mobilize equipment for a coiled-tubing operation than for an operation using wireline-operated equipment. It will therefore be a considerable saving if wireline-operated equipment can be used as an alternative to coiled tubing to remove particulate material in the well.
Collecting devices as disclosed must be arranged in such a way that the material collected will not flow out of the collecting container when the collecting device is being brought up to the lubricator of the well. Especially in the vertical portion of the well, collected material may flow out of the collecting container. Such flow-out can be prevented by the collecting device being provided with a check valve in its lower portion. The check valve may be a flap valve.
The invention has for its object to remedy or reduce at least one of the drawbacks of the prior art or at least provide a useful alternative to the prior art.
The object is achieved, according to the invention, through the features which are specified in the description below and in the claims that follow.
The invention is defined by the independent claims. The dependent claims define advantageous embodiments of the invention.
According to a first aspect, the invention relates to a collecting device for loosening and collecting particulate material from a well, the collecting device including:
a first end portion and a second end portion;
a feed pipe in the first end portion;
a collecting container including at least one container section, between the feed pipe and the second end portion;
a conveyor in the feed pipe, the conveyor being arranged to move the particulate material in towards the collecting container;
a tool at the leading end portion of the conveyor; and
a fluid outlet at the second end portion,
and being such that the collecting device includes a mono pump driven by a motor and at least one container section in a flow path on the pressure side of the mono pump.
A mono pump has some properties that are advantageous when such a collecting device is used. A mono pump has a relatively low sensitivity to particulate material such as gravel and the like. The mono pump may be designed to give a satisfactory flow rate, even at a relatively low rotational speed.
The collecting device is well suited for being moved into and out of a well, in particular a petroleum well, by means of a wireline tractor. The motor of the collecting device may, with advantage, be supplied with energy from the wireline tractor, typically in the form of electrical power or a hydraulic fluid flow.
The particulate materials that are moved into the collecting container by means of the conveyor are mixed with fluid. The fluid outlet, which is typically covered by a filter, makes it possible for the fluid to follow the flow path through the collecting device. By the use of a mono pump in this flow path, the intensity of the fluid flow is increased, and thereby the amount of particulate materials entering the collecting container. A greater ratio of fullness of the collecting container is thereby achieved, before the collecting device must be emptied, than by known collecting devices.
Particulate materials present in the petroleum well are either loose or loosened by means of the tool that may be attached to the leading end portion of the conveyor. The tool may include, for example, hard-metal pieces or other suitable materials. In some cases the tool may include brushes.
The collecting device may further include at least one container section in the flow path on the suction side of the mono pump. By the use of a modular structure, the collecting device may be adapted for the prevailing conditions, both with respect to the number of container sections, which determines the size of the collecting container, and the relative position of the mono pump in the collecting device.
Much of the particulate materials may precipitate from the fluid flow in the container section on the suction side of the mono pump before the fluid passes the mono pump. In some cases, it may be advantageous for the distance of the mono pump from the conveyor to be smaller than the distance from the fluid outlet. At least a portion of the particulate materials in the fluid flow will then pass through the mono pump. This may have the advantage of the particulate materials then following the pressurized fluid further into the collecting container.
A motor housing with the motor may be positioned in the second end portion and the motor drives the mono pump via a driveshaft. Alternatively, the motor may be positioned in a lower portion of a container section on the pressure side of the mono pump and the motor drives the mono pump via a driveshaft.
The conveyor may be rotatable and connected to the mono pump by an intermediate shaft. The conveyor may typically consist of a conveyor worm with screw blades. The mono pump may be connected to the conveyor in such a way that the mono pump and the conveyor are connected to a common shaft. The shaft, which may be articulated or flexible in some other way, is arranged to accommodate the eccentric rotation characteristic of the rotor motion of a mono pump.
In its wall, the feed pipe may include at least one through-going main opening. The feed pipe may be provided with a plurality of through-going main openings distributed around the circumference of the feed pipe. The at least one through-going main opening may be elongated in the longitudinal direction of the collecting device. In its wall, the feed pipe may include at least one through-going relief opening. The feed pipe may be provided with a plurality of through-going relief openings distributed around the circumference of the feed pipe. In a wall, the collecting device may include at least one through-going auxiliary opening at the mono pump, on the suction side of the mono pump. The collecting device may be provided with a plurality of through-going auxiliary openings distributed around the circumference of the collecting device. At least one of the main opening, the relief opening and the auxiliary opening may be closable.
In a portion, the driveshaft may be provided with a screw blade. The upper portion of the driveshaft may be smooth.
At a standstill, the mono pump may form a check valve between the at least one container section on the pressure side of the mono pump and the feed pipe. This has the advantage of the mono pump possibly making a separate closing device between the tool and the collecting container redundant. Such a closing device is necessary in many cases in order to prevent a leakage of collected material from the collecting container out through the feed pipe when the collecting device is moved upwards in the vertical part of the petroleum well.
The conveyor may be supported in an outer bearing housing in the feed pipe. The outer bearing housing may be provided with through-going openings. The outer bearing housing may be provided with a closing device on the side facing the conveyor. The closing device may be a flap valve. The conveyor may be supported in an inner bearing housing in the feed pipe. The inner bearing housing may be provided with through-going openings.
According to a second aspect, the invention relates to a method for loosening and collecting particulate materials from a well by means of a collecting device as described above. The method includes:
moving the collecting device inside a well pipe up to particulate material in the well pipe;
activating the collecting device by starting the mono pump, the conveyor and the tool;
moving the tool into the particulate material to loosen the particulate material;
mixing the particulate material with a surrounding fluid and carrying the particulate material up to the suction side of the mono pump;
carrying the diluted particulate material through the mono pump and into the collecting container on the pressure side of the mono pump;
separating particulate materials and fluid in the collecting container by letting fluid flow out through the fluid outlet;
stopping the mono pump so that separated particulate materials in the collecting container are prevented from flowing out of the collecting device through the feed pipe;
moving the collecting device back and out of the well pipe; and
emptying the collecting container of the collecting device of collected particulate materials.
The method may further include mixing the particulate material in the feed pipe with surrounding fluid which is flowed into the feed pipe through at least one of the main opening or the relief opening or mixing particulate material with surrounding fluid in the collecting container by flowing surrounding fluid through the auxiliary opening. The method may further include flowing surrounding fluid into the feed pipe or the collecting container selectably through at least one of the main opening, the relief opening or the auxiliary opening.
The collecting device and the method according to the invention provide for increased efficiency in cleaning work connected to ERD petroleum wells and horizontal petroleum wells.
In the drawings, the reference numeral 1 indicates a collecting device which is shown, in FIG. 1, in a well pipe 2. In its first end portion, the collecting device 1 includes a feed pipe 6 with an inlet 7, the feed pipe 6 being in fluid communication with a collecting container 8. The collecting container 8, which typically has a modular structure, may include one or more container sections 10. In its second end portion, the collecting device 1 further includes a top section 16, a motor housing 14 and a coupling piece (not shown) which may be attachable to a wire (not shown) or to a wireline tractor (not shown). The wireline tractor can move the collecting device 1 in the well pipe 2.
In what follows, terms like "up/at the top" and "down/at the bottom" are used to indicate directions of the collecting device 1 in its orientation in a vertical portion of a well pipe 2. Directional specifications are used according to their usual sense.
A conveyor 18 is arranged in the feed pipe 6. The conveyor 18 may be rotatable and is shown here in the form of a conveyor worm 18′. The conveyor 18 is provided with a tool 20 at its leading end portion to loosen particulate materials inside the well pipe 2. The tool 20 is shown as a scraper 20′ here. The tool 20 may be of other types such as a brush, a so-called "rock bit" or a so-called PDC bit. The type of tool 20 is selected according to what type of particulate material is to be removed from the well pipe 2.
The conveyor 18 is supported in an outer bearing housing 30 which is provided with through-going openings 33 for the conveyance of particulate materials through the outer bearing housing 30. The conveyor 18 is further supported in an inner bearing housing 32, see FIG. 2. The inner bearing housing 32 is provided with through-going openings 34 for the conveyance of particulate materials through the inner bearing housing 32. The openings 34 also function as sieve openings to prevent larger particles from being carried into the collecting container 8. Further, on its side facing the conveyor 18, the outer bearing housing 30 is provided with a closing device 36 which is arranged to prevent a fluid flow in the direction from the feed pipe 6 to the tool 20. The closing device 36 may include a flap valve. In some cases in which the particulate materials have a high viscosity, the closing device 36 may be left out to facilitate the subsequent emptying of the collecting device 1. Particles passing the through-going openings 33, but being too big to pass the through-going openings 34, are retained by the closing device 36. These particles will be transported out of the well pipe 2 internally in the feed pipe 6.
A mono pump 12 is positioned between the inner bearing housing 32 and the collecting container 8. The conveyor 18 is thus positioned on the suction side of the mono pump 12, and the collecting container 8 is positioned on the pressure side of the mono pump 12, as is shown in the embodiments according to FIGS. 2-4. The through-going openings 34 prevent particles which may damage the mono pump 12 from being carried all the way up to the inlet (not shown) of the mono pump 12.
The motor 22 in the motor housing 14 drives the mono pump 12 via a driveshaft 28. Owing to the operation of the mono pump 12, the driveshaft 28 is provided with articulations 26. An intermediate shaft 24, which is also articulated, extends from the mono pump 12 to the conveyor 18. The driveshaft 28 may be provided with a number of screw blades 29 as shown in FIG. 2. The motor 22 thus drives the conveyor 18 and the tool 20 via the driveshaft 28, the mono pump 12, the intermediate shaft 24 and the associated articulations 26.
The collecting container 8 may include several container sections 10. Each container section 10 may include a portion of the driveshaft 28 and the screw blade 29. Each container section 10 is provided with an upper shaft support (not shown) and a lower shaft support (not shown). In one embodiment, the container section 10 which is positioned the closest to the motor 22 may be provided with a driveshaft 28 with an upper smooth portion 28′ nearest to the motor 22, see FIG. 2. This smooth portion 28′ also extends through the top section 16.
In a lower portion of a wall 62, the feed pipe 6 is shown as provided with a plurality of through-going main openings 64. In its upper portion, the wall 62 is shown as provided with a plurality of through-going relief openings 66. The main openings 64 are shown as elongated openings in the longitudinal direction of the collecting device 1. The openings 64, 66 are distributed around the circumference of the feed pipe 6.
The collecting device 1 is further shown as provided with through-going auxiliary openings 68 in a wall right under the stator (not shown) of the mono pump 12. Auxiliary openings 68 are distributed around the circumference of the collecting device 1.
The openings 64, 66 and 68 may selectably and mutually independently be opened and closed with closing devices (not shown).
In its wall 92, the top section 16 between the upper container section 10 and the motor housing 14 is provided with a plurality of fluid outlets 38. In the figures, the fluid outlets 38 are shown as elongated, through-going openings in the wall 92. The fluid outlets 38 are distributed around the circumference of the top section 16. On its inside, the fluid outlet 38 may be provided with a filter 42 as is shown in FIG. 2. In an embodiment not shown, a container section 10 which is positioned the furthest from the tool 20 may be provided with a plurality of fluid outlets 38 and an internal filter 42.
The feed pipe 6, the mono pump 12, the collecting container 8, the filter 42 and the fluid outlet 38 form a flow path 40 through the collecting device 1.
The collecting device 1 is shown in an alternative embodiment in FIG. 3. In this embodiment, the smooth portion 28′ of the driveshaft 28 is extended through the entire collecting container 8. This may be advantageous when the mixture of particulate material and fluid is loose and the mono pump 12 yields a pressure so high that the mixture may flow up to the filter 42. Screw blades 29, if any, may brake the mixture along the flow path 40.
The collecting device 1 is shown in a further alternative embodiment in FIG. 4. In this embodiment, the motor 22 is positioned at the bottom of the collecting container 8 in a lower portion of a container section 10. Mounting brackets for the motor 22 and wires for the energy supply to the motor 22 are not shown. This embodiment has the advantage of enabling the collecting container 8 to be without any internal obstacles from the motor 22 to the filter 42 with no supports for a driveshaft 28. This simplifies the assembly of several container sections 10 into one collecting container 8. It also leads to there being fewer restrictions and obstructions along the flow path 40.
The collecting device 1 is shown in a further alternative embodiment in FIG. 5. In this embodiment, the collecting device 1 is provided with at least one container section 10 on the suction side of the mono pump 12 and at least one container section 10 on the pressure side of the mono pump 12. Collected particulate materials in the collecting container 8 on the suction side of the mono pump 12 are retained by the closing device 36 so that they cannot flow out of the collecting container 8. FIG. 5 shows an embodiment in which the smooth portion 28′ of the driveshaft 28 is extended through the entire part of the collecting device 8 located on the pressure side of the mono pump 12. The intermediate shaft 24 is also shown as a smooth shaft.
In an embodiment not shown, the collecting device 1 shown in FIG. 5 may be provided with a driveshaft 28 with screw blades 29 as shown in FIG. 2. The driveshaft 28 may have a smooth portion 28′ extending through the top section 16. In a further embodiment (not shown), the intermediate shaft 24 may be provided with a number of screw blades (not shown). In further embodiments not shown, an intermediate shaft 24 with or without screw blades may be combined with a driveshaft 28 with or without screw blades 29.
In an embodiment not shown, the collecting device 1 shown in FIG. 5 may be provided with a motor 22 in a lower portion of a container section 10 as is shown in FIG. 4. The intermediate shaft 24 may be without screw blades as shown in FIG. 5 or with screw blades (not shown).
When the collecting device 1 is moved into the well pipe 2 by means of a wireline tractor (not shown), for example, the resistance to propulsion increases for the wireline tractor as the collecting device 1 is moved into particulate materials. It may be advantageous to pull the collecting device 1 back somewhat when the particulate material has been localized. Then the collecting device 1 is activated and the collecting device 1 is eased into the particulate material with the conveyor 18 activated, tool 20 activated and pump 12 activated. Thereby the particulate materials are loosened while, at the same time, the tool 20 feeds the particulate materials into the conveyor 18. The particulate materials are then displaced internally through the feed pipe 6 by means of the rotating conveyor 18 while the particulate material is simultaneously mixed with ambient fluid entering through at least one of the openings 64, 66, 68. The mixture is carried up to the suction side of the mono pump 12 through the openings 34 in the inner bearing housing 32. The mono pump 12 pumps the mixture of particulate materials and ambient fluid into the collecting container 8.
In well pipes 2 oriented vertically, the particulate materials may form a relatively firm bridge or plug. The tool 20 will dig particulate materials on the surface of the well loose. Fluid present on the surface of the well will mix with the particulate materials and a mixture of fluid and particulate materials is carried into the feed pipe 6. Surrounding fluid may also enter the feed pipe 6 through the main openings 64. The conveyor 18 will further mix particulate materials and fluid together and carry this mixture to the suction side of the mono pump 12. The mixture is carried through the mono pump 12 and out on the pressure side of the mono pump 12. The mixture is carried upwards in the collecting container 8 by a pressure higher than the ambient pressure. In one embodiment as shown, in which the driveshaft 28 is provided with screw blades 29 in a portion, the screw blades 29 will further contribute to the mixture of fluid and particulate materials being carried upwards in the collecting container 8. The fact that the particulate materials are on the pressure side of the mono pump 12 will alone enable the use of an extended collecting container 8. The fact that the driveshaft 28 is provided with screw blades 29 will, in combination with the fact that it is on the pressure side of the mono pump 12, further help to enable the use of an extended collecting container 8.
The openings 34 of the inner bearing housing 32 are chosen with a size that will prevent particles that may damage the mono pump 12 from being carried up to the mono pump 12.
If the particulate materials form a bridge which is so loose that the collecting device 1 sinks into the particulate materials until they cover the main openings 64, the loosened material could be too dry for the mono pump 12 to function effectively. The relief openings 66 are therefore opened so that surrounding fluid may enter the feed pipe 6 through the relief openings 66. If the particulate materials are so loose that even the relief openings 66 are covered, the auxiliary openings 68 are opened so that surrounding fluid may enter the collecting device 1 between the inner bearing housing 32 and the mono pump 12 through the auxiliary openings 68. The auxiliary openings 68 are chosen with a size that will prevent particles that may damage the mono pump 12 from flowing through the auxiliary openings 68. It is thereby ensured that the mono pump 12 will be fed a mixture of particulate material and surrounding fluid.
The mixture of particulate materials and fluid is carried upwards in the collecting container 8 to the top section 16 along the flow path 40. In the top section 16, fluid exits through the filter 42 and the fluid outlet 38 as the pressure inside the collecting container 8 is higher than the ambient pressure. The particulate materials that have a size which is larger than the mesh size of the filter 42 are retained by the filter 42 and separated from the fluid. The separated particles sink down in the collecting container 8 along the inner wall of the collecting container 8.
When the collecting container 8 is filled up with particulate material, the mono pump 12 is stopped. Fluid and particles cannot flow through the mono pump 12 when the rotor (not shown) is stationary relative to the stator. Therefore, at a standstill, the mono pump 12 will function as a check valve which prevents the mixture of fluid and particles from flowing out of the collecting container 8 and out through the feed pipe 6 when the collecting device 1 is being returned to the surface where the collecting container 8 is emptied.
The cleaning operation is repeated until the particulate materials have been removed.
In deviation wells, whether ERD wells or horizontal wells, the method is the same. In such wells, the particulate materials do not form bridges. In most cases, one or more of the main openings 64 will face upwards and not be buried in particulate material. This ensures that surrounding fluid will enter the feed pipe 6 and mix with loosened particulate materials there.
It should be noted that all the above-mentioned embodiments illustrate the invention, but do not limit it, and persons skilled in the art may form many alternative embodiments without departing from the scope of the attached claims. In the claims, reference numerals in brackets are not to be seen as restrictive. The use of the verb "to comprise" and its various forms does not exclude the presence of elements or steps that are not mentioned in the claims. The indefinite articles "a" or "an" before an element does not exclude the presence of several such elements.
The fact that some features are specified in mutually different, dependent claims does not indicate that a combination of these features cannot be used with advantage.

Collecting device for particulate material in a well and a method for collecting the particulate material and transporting it out of the well


In a semiconductor device including a bipolar transistor having a base region formed in a collector region, and an emitter region formed in the base region, the emitter region comprises a high concentration region in contact with the base region, and a low concentration region provided between the base region and the high concentration region. The low concentration region is formed by introducing an impurity with a mask including a large opening. In addition, the high concentration region is formed by introducing an impurity with a mask including a small opening.

FIGS. 9A and 9B are a plan view and a cross sectional view of an NPN type bipolar transistor (Bi-Tr) as a portion of a conventional semiconductor device, e.g., Bi-CMOS, respectively. This Bi-Tr is manufactured as follows. Namely, an N.sup.+ type buried layer 2 is formed on a P-type Si substrate 1 and an N-type collector region 3 is grown thereon. A P-type impurity (B or BF.sub.2, etc.) is ion-implanted into a region where the base is to be formed of the collector region 3. Thereafter, using a resist mark, an N-type impurity (e.g., As) is ion-implanted only into a region where the emitter is to be formed in the region where the base is to be formed. Heat treatment is then conducted. As a result, a P-type base region 4 is formed within the N-type collector region 3, and an N-type emitter region 5 is formed within the P-type base region 4. Thus, a Bi-Tr is provided.
There are instances where a reverse bias may be applied to the junction portion between the emitter region 5 and the base region 4 of the Bi-Tr. Application of such a reverse bias leads to the difficulty that the emitter-base junction breakdown voltage is lowered and the current gain h.sub.FE is also lowered, resulting in considerably deteriorated device characteristics.

Semiconductor device including bipolar transistor with step impurity profile having low and high concentration emitter regions


A method and apparatus for reducing dynamic power consumption in a multi-thread content-addressable memory is described. The apparatus includes a first input configured to receive a first virtual address corresponding to a first thread, a second input configured to receive a second virtual address corresponding to a second thread, a register bank including a plurality of registers each configured to store a binary word mapped to one of a plurality of physical addresses, a first comparator bank including a first plurality of comparators each coupled to an associated register of the plurality of registers in a fully-associative configuration, and a second comparator bank including a second plurality of comparators each coupled to an associated register of the plurality of registers in a fully-associative configuration. An input virtual address to each comparator bank maintains its previous value for when a corresponding thread is not selected.

Virtual memory allows computing systems to better manage memory than if the computing system was limited to managing the actual memory accessible by the computing system. For example, virtual addressing as a memory mapping mechanism allows the computing system to allocate non-contiguous regions to a particular application, while giving the application the appearance of being allocated one contiguous region of memory. Additionally, virtual memory functionality allows a computing system to allocate more memory than is actually available in the computing system to applications. Whenever an application references a memory address (e.g., a virtual address (VA)) on a system that implements virtual memory, the address is translated into a physical address (PA) that refers to the actual memory location. Because applications frequently interact with memory, inefficiency and inflexibility within the virtual memory system can cause performance degradation.
Using virtual addressing, processors can access memory, using physical addresses that are generated from virtual address to physical address translation. To accelerate the virtual address to physical address translation process, processors can use Translation Lookaside Buffers (TLB), which are content addressable memory (CAM) plus random access memory (RAM) structures that cache virtual address to physical address translations.
TLBs are, therefore, hardware structures that are used in computing systems to cache virtual-to-physical address translations and operating system (OS)-page-granularity metadata (e.g., read/write permissions). The TLB is important to performance scalability in computing systems because the TLB is looked up on every memory access, it is in the critical path, and each processor core or accelerator has its own TLB.
Microprocessors implement multiple threads in order to cut down on cell count to make it appear that more processors are present in a system by taking advantage of what could be "dead" cycles in a microprocessor. In many places in the microprocessor, pipe states are tagged with a thread identifier (ID) and existing resources in the processor are shared across threads. This sharing of resources cuts down on cell count but can be expensive with respect to power, especially if there is a high amount of circuit activity in changing from one thread to the other.
For example, FIG. 1 shows a block diagram of multi-thread system 100 implementing a CAM 102. The CAM 102 includes a single bank of registers 104 coupled and corresponding to a single bank of comparators 106 for performing write and lookup operations. The multi-thread system 100 further includes a thread 0 (T0) and a thread 1 (T1), which each include their own search data registers 111 and 112 that store an address or tag to input to the CAM 102. The stored tag for each thread is input to the multiplexer 114, which selects one of the tags for input to the CAM 102 based on a "T1 active" bit. An input address 116 (i.e., the selected tag) is then provided to the CAM 102. Upon performing a lookup operation using the input address 116, the CAM 102 outputs a match result 117 (e.g., "hit" or "miss") based on the CAM entries stored in the bank of registers 104. Lastly, the match result 117 is ANDed with an "any thread valid" bit by an AND gate 118, which ensures that one of the threads (e.g., thread 0 or 1) is valid before outputting the match result 117 as the output 119.
In a typical operation of the multi-thread system 100, the input address 116 is cycled back and forth between thread 0 and thread 1. Since each thread shares the same bank of comparators 106, toggling can occur in the configuration of the bank of comparators 106 on every cycle depending on the address contents provided by the search data registers 111 and 112. A toggling of an input to a component (e.g., XOR, XNOR, OR or AND gate depending on implementation) of a comparator consumes power. Thus, when a larger number of comparators, or components thereof, are toggled, a thrashing of state occurs, resulting in an increase in dynamic power consumption. This can particularly occur when a large number of bits of an input address from one thread are different from bits of an input address from a second thread due to the threads being completely independent. This power consumption can be costly if the toggling occurs cycle to cycle. Thus, there exists the need to reduce power consumption in TLB CAMs implemented in a multi-threaded configuration.

Method and apparatus for power reduction in a multi-threaded mode


A processing device executing a scheduler receives, by a device, a schedule from a remote server computing device, the schedule having a compact format that is understood by the device. The device stores the schedule and the processing device parses the schedule to identify a scheduled event. The processing device executes the scheduled event at a specified time in accordance with the schedule even in the absence of a network connection between the device and the remote server computing device.

Many modern appliances, consumer devices, and other devices include embedded systems that are configured to perform one or more dedicated functions. However, most embedded systems of such devices do not include network connectivity, role based access control capabilities, remote interface capabilities, remote control capabilities, or related capabilities. Designing such functionality into an embedded system, designing application programming interfaces (APIs) for accessing such functionality, designing web services capable of communicating with and controlling the embedded system via this added functionality, and designing applications for taking advantage of this functionality can consume considerable resources of the device manufacturer.
Moreover, a growing number of traditionally dumb and smaller devices have been equipped with network connectivity using simple embedded systems that lack computing resources to perform local processing beyond a dedicated function. Absent network connectivity, such devices are unable to receive instruction. Accordingly, some utility of such devices may be lost when network connectivity is limited or unavailable.

Compact schedules for resource-constrained devices


A smartphone device may have thin borders at the left, right, top, and/or bottom edges of the display screen. To accommodate, e.g., a front camera in spite of a border that is too thin for a camera module and lens, at least one corner of the display may be cut out. Optical sensor(s), emitter(s), or the lens of a front camera may be disposed at the location(s) of the cutout(s). A wide-screen movie may be displayed in letterbox mode with horizontal bars above and/or below the movie, wherein the cutout(s) are located, at least partially, in the region(s) of the horizontal bars, thereby avoiding that larger parts of the movie are hidden by the cutout(s). In other embodiments, an uninterrupted status bar may be displayed between a cutout in the upper-left corner and a cutout in the upper-right corner of the display.

Common smartphones, phablets, or comparable mobile electronic devices contain a front-facing camera placed on the front side of the mobile electronic devices. The front side of the mobile electronic devices also contains a display screen, using a display technology such as liquid-crystal display (LCD) or active-matrix organic light-emitting diode (AMOLED).
For example, the display may use an LC panel. The LC panel may include a thin film transistor (TFT) substrate, a color filter substrate, and LC molecules injected between the TFT substrate and the color filter substrate. The TFT substrate may include gate lines and data lines implemented as matrices. Thin film transistors (TFT) may be formed at crossing points of the gate lines and the data lines. A signal voltage is applied to a common electrode disposed between a pixel electrode and the color filter substrate. Liquid crystal molecules are aligned between the pixel electrode and the common electrode according to the signal voltage, thereby controlling light transmittance. The color filter substrate may include a color filter and a common electrode, the color filter having red, green, and blue filters repeatedly formed in a state where black matrices are disposed therebetween. The common electrode may be formed of a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO).
A pair of polarizers may be arranged on the upper and lower surfaces of the LC panel. The polarizers may be arranged to cross each other. The polarizer disposed under the LC panel serves to polarize light incident onto the LC panel, and the polarizer formed on the LC panel serves as an analyzer. A backlight unit may be disposed beneath the LC panel. The backlight unit may include a diffusion sheet, a reflection sheet, and a prism sheet.
In another example, the display panel may be implemented as an AMOLED display consisting of several layers, e.g., cathode layer, organic active layers, thin-film transistor (TFT) array, and substrate. An active matrix of OLED pixels generates light (luminescence) upon electrical activation. The active matrix of OLED pixels may be deposited or integrated onto the thin-film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel. Known TFT backplane technologies, such as polycrystalline silicon (poly-Si) and amorphous silicon (a-Si), may be used. The display panel may be a flexible display, which enables the display panel to be bent, rolled, or curved at the edges. For example, a flexible OLED-based display may comprise a flexible substrate on which the electroluminescent organic semiconductor is deposited. Optionally, the display panel may have an in-cell touch panel that integrates a capacitive sensor array.
The display screen may be rectangular with an aspect ratio of, for instance, 16:9, 2:1, 19.5:9, or 21:9. Furthermore, display panels with a round shape are known from the prior art. More information about the assembly and structure of round displays (e.g., for smartwatches) can be found, inter alia, in patent application US2017/0168463 A1, titled "Display panel with minimum borders" and patent application US2016/0313593 A1, titled "Divided backlight configuration of a display."
A smartphone with a rectangular display screen may be oriented horizontally or vertically by the user, which may result in operating modes known as "landscape mode" and "portrait mode," respectively. The page orientation can also be described with the terms "landscape orientation" and "portrait orientation."
A user may hold the smartphone horizontally (landscape mode) and may watch a video or movie displayed in full screen mode on the display screen. A feature film or a wide-screen movie may have an aspect ratio of, e.g., 2.35:1, 2.39:1, 2.40:1, or 2.66:1. If the wide-screen movie has an aspect ratio that is wider, i.e., greater, than the aspect ratio of the display screen, the wide-screen movie frames may be displayed on the display screen in a mode known as "letterbox": horizontal bars, typically black bars, are inserted above and below the wide-screen movie.
The display screen of a smartphone typically does not occupy the full front side of the smartphone because a wide border is required at the top and/or at the bottom of the front side to accommodate the lens of a front-facing camera and also to accommodate other optical or acoustic sensors and emitters. As a result, the size of the display screen is reduced.
The front-facing camera of a smartphone may be used for video telephony or to take a self-portrait photograph, commonly known as a "selfie." In recent years, the resolution of the front-facing camera has increased, and it is likely that the resolution will continue to increase in the future (e.g., from 8 megapixels to 13 megapixels) to enable the user to take "selfies" of the highest quality and to record high-quality 4K videos. Therefore, high-quality camera lenses for the front-facing camera and an undisturbed light path are essential.
Patent applications US2017/0123454 A1, US2017/0123453 A1, and US2017/0123452 A1, titled "Camera integrated into a display," patent application US2017/0123575 A1, titled "Optical sensors disposed beneath the display of an electronic device," patent application US2017/0124933 A1, titled "Mobile device with display overlaid with at least a light sensor," patent applications US2017/0126979 A1 and US2017/0126937 A1, titled "Apparatus and method to maximize the display area of a mobile device," and patent application US2015/0271392 A1, titled "System and method for coordinating image capture in a camera hidden behind a display device," suggest disposing the front-facing camera beneath the display screen of the smartphone. However, depending on the display technology of the screen (e.g., LCD, OLED, Micro-LED, etc.), small opaque or semi-transparent structures that may be necessary for the operation of the display screen may blur or cloud the resulting picture of the front-facing camera, because the light path must pass through the display screen. Furthermore, LCD panels often also require removing a diffuser layer to adapt them for use as transparent displays, and the polarizing filters of the LCD panels inherently limit the transmission efficiency of unpolarized light. This may reduce the light sensitivity of a front-facing camera located beneath the display screen, especially in low-light conditions.

Smartphone with front camera and maximized display screen


In a computer chassis having a wall, an interiorly-positioned card cage associated with the wall, and the card cage having a card guide slot therein, a card guide retaining device. In a preferred embodiment, the card guide retaining device has a retainer having (1) a first end extending to within the computer chassis through a retainer aperture in the wall, the retainer aperture corresponding to the card guide slot, and (2) a second end extending to without the retainer aperture exterior to the computer chassis. The first end includes a gripping surface to engage and retain a card guide positioned about the card guide slot. The gripping surface may be a generally rectangular planar member extendable over a retaining tab portion of the card guide to thereby secure the card guide against a card guide ledge of the card cage. The second end has a flanged portion to contact an exterior surface of the wall. The retainer may be moved between an engaged position and a disengaged position from the exterior of the computer chassis via the flanged portion. The retainer is configured to provide a retaining force from the wall to the card guide when in the engaged position.

Within the interiors of their housings, modem personal computers are customarily provided with sheet metal cage structures adapted to receive and removably support a plurality of option or expansion cards which, when operatively installed in their associated cage structure, upgrade the operating capabilities of the computer. These expansion cards may be installed in the computer during its original manufacture or subsequently installed by the computer purchaser. Typical types of expansion cards include network, sound, graphics accelerator and multi-media cards.
An expansion card is basically a relatively small rectangular printed circuit board having, along one side edge, a connector edge portion that plugs into a corresponding socket portion of the cage structure to operatively couple the installed card to the motherboard or system planar of the computer. The socket portions of the cage structure are relatively oriented in a manner such that the expansion cards installed therein are arranged in a spaced apart, parallel, facing series with end edges of the cards being aligned with one another.
Extending along these aligned end edge portions of the expansion cards are sheet metal connecting brackets having outwardly bent securement tab portions positioned adjacent the side edge portions of the cards opposite their connector edge portions. These tab portions rest upon an inturned side wall ledge of the cage structure and have notches formed therein that overlie and register with a spaced series of threaded circular openings in the ledge. Each bracket tab is removably secured to the ledge by a screw that extends through the tab notch and is threaded into its associated ledge opening. This individual securement of the bracket tabs to the cage structure ledge serves to anchor the installed expansion cards in place within the cage structure, thereby preventing the connector edge portions of the cards from being dislodged from their associated connector sockets during shipping and handling of the computer.
This conventional use of individual screws to removably secure the card bracket tabs to the cage structure carries with it several well known disadvantages. For example, during initial installation of the expansion cards within the cage structure one or more of the retaining screws can easily fall into the typically crowded interior of the computer, thereby creating what may be a difficult retrieval problem. Additionally, when a series of expansion cards are installed at the factory each individual bracket retaining screw is typically installed using an automated assembly machine. Several seconds are required to install each screw, thereby appreciably increasing the overall assembly time for each computer in which expansion cards are to be factory installed.
The use of individual card bracket tab retaining screws also creates potential problems and inconveniences for the purchaser of the computer or technicians that subsequently work on the expansion card portion of the computer. For example, when subsequently adding or exchanging expansion cards, the technician or computer owner must unscrew the bracket tab in place and then reinsert the removed screw into the bracket tab of the added expansion card. Often, more than one card must be dealt with. This, of course, requires that multiple screws must be removed and then be reinserted. Each fine this task is carried out, there is the potential for dropping one or more of the individual retaining screws into the computer system. Additionally, when the computer system is being analyzed for a problem, it is often necessary to remove all of the expansion cards to isolate the problem. This requires the technician or computer owner to remove and reinstall all of the individual retaining screws (a process that may have to be repeated several fines during the problem analysis process), thereby further increasing the possibility that one or more screws will be dropped into the interior of the computer system.
To deal with the inconvenience posed by the above discussed conventional attachment system, a system that uses a single bar laid across the top flanges of all of the brackets held down by a single screw has been developed, such as the device disclosed in U.S. Pat. No. 5,317,483 which is incorporated herein by reference. The device disclosed in U.S. Pat. No. 5,317,483 is a substantial improvement over other prior art devices in that it eliminates the plurality of screws involved in the conventional systems. With only one screw being present, only one screw must be removed to remove one or more of the brackets. This, of course, reduces the amount of time spent in the manufacturing process to attach the blank brackets or expansion cards and also decreases the amount of aggravation for the computer user who adds or removes additional expansion cards or blanket brackets after the purchase of the computer. While this system has certainly improved the conventional problem of dealing with a multiplicity of screws it does not address fully the problem which remains; that is the problem associated with the fact that when the cross bar is removed the blank brackets have very little support to stay in their proper position. As such, they have a tendency to fall off during the manufacturing process and during the repair or expansion operations.
Other devices similar to the device disclosed in U.S. Pat. No. 5,317,483 are also known. These other devices also include an elongated bar having gripping members extending perpendicularly from the opposite ends of the elongated bar to form a "U" shape. The device is hinged via bent tabs extending from the back of the device through openings formed in the computer chassis wall. The elongated bar member lays across one or more card guides that have been positioned on the upper ledge of the card cage, and the gripping members engage openings in the side edges of the card cage to hold the card guides about the card cage. While this device eliminates the use of screws completely, it too suffers from the disadvantages. For example, two hands must be used to simultaneously disengage the gripping members from the openings. Additionally, once the bar is removed, all of the card guides are susceptible to falling off. This is particularly true where the card guides are blank card guides.
Accordingly, there is a need in the art for an improved apparatus for removably retaining expansion cards in an associated support cage structure in order to eliminate or at least substantially minimize the above-mentioned problems associated with the conventional use of individual card bracket tab retaining screws and cross bars. The present invention address these needs.

Captive latch mechanism for use with an expansion card cage in a personal computer


An optical system for an optical data recording and reproducing apparatus such as an optical video disc apparatus comprising a diode laser light source, a condenser lens disposed adjacent to the diode laser, a cylindrical lens assembly arranged to exhibit different magnifications to light beams emitted by the diode laser in the direction perpendicular to a junction plane thereof and in the direction parallel to the junction plane, and a concentrating lens for constricting the resulting light beam into a light spot of a small size for projection on a recording medium. Recording of information is attained by the constricted light beam of a substantially circular cross-section with a high recording density at a low energy consumption. When reproducing the recorded information, the constricted beam is laterally enlarged in the transverse direction of the information recording track thereby to assure generation of a signal utilized for tracking control.

1. Field of the Invention
The present invention relates to an optical device using a diode laser as a light source and in particular concerns an optical system which can be applied to an apparatus for recording and/or reproducing optical information, video or audio or both, on or from an optical recording medium formed on a disc with a high density by means of a small size spot of a concentrated laser light beam produced by a diode laser. For example the invention is applicable to an optical video disc apparatus.
2. Description of the Prior Art
In general, the semiconductor laser has advantageous features in that the laser beam can be directly modulated without the need for using an optical modulator and the laser device can be implemented in a highly miniaturized size as compared with other lasers. Thus, the semiconductor laser is increasingly employed in various instruments and apparatus as a light source. When the diode laser is to be used as the light source for an optical recording and reproducing apparatus, it must be capable of producing an output light beam having a reasonably high energy level in correspondence with the optical sensitivity of a recording material. For example, where the recording material is a layer of silver salt deposited on a film and thus necessarily subjected to developing and fixing treatments after exposure to a recording illumination, the output power of the semiconductor laser may be relatively low. However, for a recording medium such as metallic thin film or pigment film, recording energy level in the range of 100 to 1000 mJ/cm.sup.2 is required as measured on the recording medium. Thus, the output power of the semiconductor laser used as the light source has to be on the order of several tens of milliwatts. In order to assure the recording energy level of the magnitude described above on the recording medium, it is desirable that light transfer efficiency should be increased as much as possible in the optical path extending between the diode laser and the recording medium by concentrating the laser beam so as to produce a fine or minute light spot on the recording medium. In this connection, it is noted that the output beam of a diode laser has inherently a relatively large diameter. Thus, concentration or focusing of the laser beam to a diameter as small as possible is required for fulfilling the requirements of concerning the recording energy level described above and at the same time for attaining the recording of a signal at a possibly increased density.
The cross-sectional shape of the light beam at the light emitting plane of a diode laser exhibiting a high output power is related to a plane of a junction of the diode laser and takes an extremely elongated profile having dimensions of several .mu.m in the direction perpendicular to the junction plane and several tens .mu.m in the direction parallel to the junction plane. Further, the light beam emitted from the light emitting plane exhibits a relatively large angular extension, e.g. angular extension of .+-.15.degree. to 20.degree. in the direction perpendicular to the junction plane and .+-.5.degree. to 10.degree. in the direction parallel thereto. Consequently, the semiconductor laser has to be handled in a completely different manner as compared with He--Ne gas lasers or the like.

Optical system having diode laser light source

Matsushita Electric Industrial Co., Ltd.


A magnetic brush type developing device for a single component developer having an axially elongated sleeve and a plurality of magnets disposed in the sleeve for relative rotation therebetween includes a regulating plate extending axially along and substantially adjacent the sleeve surface for regulating the height of developer adhering thereto, and a pair of partition plates arranged substantially perpendicular to the sleeve axis at axially opposite ends thereof and predeterminately adjacent circumferentially-disposed surface portions of the sleeve for preventing an axial flow of developer along the sleeve outwardly beyond the partition plates.

This invention relates to a magnetic brush type developing device for use in an electrophotographic copying machine, and more particularly a magnetic brush type developing device used with a one component developer as is per se well known.
In an electrophotographic copying machine using a magnetic brush developing device, copied matter is obtained by reflecting light from an original to be copied, projecting the light onto a uniformly charged photosensitive member to form thereon an electrostatic latent image corresponding to the original, developing the latent image by a developer to render it visible, and then fixing the latent image on the member or after it is transferred onto a transferring paper such as plain paper. Developer (not shown) is stored in a developing chamber in which a cylindrical sleeve made of nonmagnetic material is so arranged that is is adjacent to the surface of the photosensitive member and a part of the sleeve is dipped into the developer. Inside of this sleeve, a plurality of magnets are arranged adjacent to the inside surface of the sleeve and with a given spacing, and the sleeve and the magnets are so constituted as to be able to relatively rotate. Accordingly, developer in the developer chamber is transported along the sleeve surface with the rotation of the sleeve or the magnets, and a visible image is formed on a photosensitive member as the developer comes into contact with the surface of the photosensitive member. When the developer is transported from the developer chamber, it is regulated at a certain fixed height on the sleeve by a regulating plate arranged adjacent to the outside surface of the sleeve. In other words, the developer adhered to the sleeve surface is transported to a developing position in the form of brush like tufts. Such a developing device as mentioned above is known as a magnetic brush type developing device.
Most of the presently popular electrophotographic copying machines are using a developer comprising magnetic powder (the so-called carrier) and fine grains of colored resin (the so-called toner) which, being constituted independently, define a type of developer called two-component developer. In conradistinction to two-component developer, a developer comprising toner only--that is, so-called one or single-component developer--has been developed. Because this latter type developer comprises magnetized toner having a magnetic substance in resin and containing colorant as occasion demands, density deviation of the copied image due to gradual toner consumption (as caused when using a two-component developer) is not a problem. As a consequence, copying machines using one-component developer do not require any density detecting device, or special toner replenishing device and carrier changes, and have many advantages as of making the developing device itself compact and so forth. Owing to the above facts, single component developer is being gradually put into practical use.
Two-component developer normally comprises carrier comprising a magnetic substance of about 50-200.mu. in diameter of a large grain and fine grain toner of about 5-20.mu. in diameter of a grain, and iron powder is used as the magnetic substance for the carrier. The mixing ratio of carrier and toner is approximately 2-10% by weight of toner with respect to the iron powder.
In two-component developer, a carrier of iron powder is adhered onto the sleeve by influence of magnetic force generated by a plurality of magnets fixedly provided within the sleeve, and transported in accordance with the rotation of the sleeve. The toner is transported in a body with the carrier, because the toner is strongly adhered electrostatically around the surface of the carrier of iron powder; thus, it is very seldom that toner is scattered in the course of transportation. And, since the carrier particle is heavy and its diameter is large, it is rare that it runs out through a narrow opening and so forth.
On the other hand, with a single component developer there is no grain of large diameter corresponding to carrier in the two-component developer; moreover, there are quantities of resin components in the particles of developer, and components of magnetic substances comprising at most 20-80% by weight of the developer, which is far less than that of a two-component developer.
Where a single component developer as stated above is used in a magnetic brush type developing device, and the sleeve or the group of magnets is rotated at a reasonable rate of revolution (e.g. 300 rpm), developer is blown up and scattered in a haze and contaminates in and outside of the developer chamber, or the developer penetrates into rotating shaft bearings of the sleeve or the group of magnets and thereby increases the friction of rotation and subsequently presents an obstacle to rotation of the shaft. The adhesion force of single component developer to the sleeve is reasonably weak, because the ratio of the magnetic component contained in the developer is low. Due to the above, adhesion of the developer to a magnetized portion of the developing device cannot be obtained to the same degree as with a two-component developer, despite compensation made by increasing the magnetic force of the group of magnets. Therefore, the thickness of the layer of developer which is formed on the sleeve becomes thin to a degree of 1-1.5 mm and consequently the clearance between a regulating plate for forming brush-like tufts of the developer and the sleeve necessarily becomes reasonably narrow. The developer, transported through the narrow clearance which regulates its height, spreads towards the outside and swells at both ends of the regulating plate, because of its weak adhesion force to the sleeve; this affects the results of subsequent development.
And, as opposed to the case of toner replenishment of two-component developer, a replenishing quantity of single-component developer does not exert a direct influence upon image density. It is a distinct advantage of single-component developer that a user can decide on the addition of a replenishing quantity at his option; but if replenishment is effected to an extent that as a rotating shaft bearing of the sleeve or the group of magnets is immersed into the developer, it is feared that particles will penetrate into a bearing portion and increase the load or friction of rotation and then cause an obstacle to free movement of the bearing.
At present, several electrophotographic copying machines having a magnetic brush type developing device and using a single component developer have been proposed (e.g. Laid Open Patent Exposure Nos. 52-10146 and 52-34742 in Japan), most of which are of the type in which developer is added or supplied in only a necessary quantity from a toner storing portion equipped atop the sleeve and into the developer chamber of the developing device. However no means to solve the problems peculiar to the above mentioned single-component developer have been introduced.
The present invention is directed to solving the peculiar faults mentioned above that arise when using a single component developer (also sometimes called a magnetic toner) for a magnetic brush type developing device. In accordance with the invention, a partition plate is arranged adjacent to the surface of both axially-directed ends of the sleeve of a developing device; preferably, the partition plate is constructed having a thickness of 0.15-1.0 mm and a clearance between it and the sleeve surface is kept to less than 0.35 mm. And, where the partition plate is set in non-contact with the sleeve surface, an auxiliary partition member is arranged to contact with the partition plate, and a clearance between the auxiliary partition member and the sleeve surface is preferably kept to less than 0.35 mm.
The following is a detailed explanation of the present invention referring to the drawings attached hereto.

Developing device for an electrophotographic copying machine


A method of controlling the morphology of silica or silica-like films formed by coating a precursor formulation of hydrolysable silicate oligomer onto a substrate and curing in a vaporous environment that comprises a base, water and a retarder that retards the hydrolysis of the oligomer.

The inventors have previously invented a silica film having particularly advantageous properties. The film has useful anti-fogging and anti-reflection properties, amongst other potentially useful properties. One method of production of one form of the silica film is described in our co-pending International Application number WO 2005/049757 published 2 Jun. 2005.
Typically low refractive index thin films are made utilising sol-gel processes or vacuum evaporation deposition techniques. The known processes which rely on sol-gel techniques for producing thin films are complex, multi-step processes which are costly, involve high temperature and/or pressure steps in fabrication, and/or require a surfactant for templating. The films produced by these sol-gel processes are typically easy to damage and/or liable to delamination.
The following prior art documents are but a few examples of methods used to produce low refractive index films made from silica.
A number of prior art processes based on known sol-gel technology were described in our earlier application. In addition to those previously discussed, reference may also be had to U.S. Pat. No. 4,652,467. This patent describes a process of depositing a thin film on a substrate from a non-gelled solution made from alcohol and various hydrolysable metal alkoxides, such as TEOS. The described process aims to control porosity and pore size but is quite complex. The process includes adjusting temperature, pH and standing time before chilling, curing and heating to form the film.
U.S. Pat. No. 5,698,266 is directed to a modification of the standard sol-gel method of forming an anti-reflective coating by mixing ethanol, tetraethoxysilane (TEOS) and ammonia and hydrolysing for up to 48 hours to form a colloidal silicon oxide suspension dispersed in an aliphatic alcohol. The silica sol is then filtered to obtain silica particles for deposition onto a substrate, prior to drying. The coated substrate is placed in an ammoniacal environment for up to twelve hours to form an anti-reflective coating. This final step is claimed to improve the binding between the silica particles, and so renders the film more robust.
One of the few prior art processes for producing silica coatings without directly following the conventional sol-gel process is described in U.S. Pat. No. 6,231,989 assigned to Dow Corning Corporation. The patent describes a process of forming a coating from a solution comprising a resin containing at least two Si—H groups in a solvent, such as methylisobutylketone. The solution is coated to a substrate with about 5% of the solvent remaining in the coating. An aqueous basic catalyst causes condensation of the Si—H groups. The solvent is evaporated to leave a porous coating. In summary, the method uses an ammonia vapour step to improve adhesion and mechanical strength of the resultant film, but relies in the main part upon conventional sol-gel methods to produce the coating at room temperature and pressure. The preparation of suitable starting materials containing two Si—H groups is difficult, which limits the usefulness of the technique.
None of the known techniques use simple processing steps to produce films with controlled morphology, such as porosity and pore size.

This patent is subject to a terminal disclaimer.


A processing method including a first step of supplying a first gas including a carbon-containing gas and an inert gas into an inside of a chamber and a second step of generating plasma from the supplied first gas by applying high frequency power for generating plasma and causing a chemical compound including organic matter on a pattern of a predetermined film formed on an object to be processed, wherein a ratio of the carbon-containing gas relative to the inert gas included in the first gas is 1% or less.

1. Field of the Invention
The present invention generally relates to a processing method and a plasma processing apparatus.
2. Description of the Related Art
In recent years, dimensions of semiconductor devices have become minute, and an aspect ratio (A/R) of a hole or a groove in a line and space (L/S) is increasing. In etching that forms a recess part having a high aspect ratio (A/R), it is proposed to vertically form, under a mask, a film to be etched (as described in Patent Documents 1-3, for example).
[Patent Document 1] Japanese Translation of PCT International Application Publication No. 2006-514783
[Patent Document 2] Japanese Translation of PCT International Application Publication No. 2015-530742
[Patent Document 3] Japanese Laid-open Patent Application Publication No. 2013-219099

Processing method and plasma processing apparatus


A grease gun sleeve that comprises of an elongated semicircular body that has a first and second end, the first end has a flattened neck and the second a semicircular neck. A nylon or polyester stretchable material covers the elongated semicircular body to form a tube sleeve. The tube sleeve forms a first and a second end. The tube sleeve has closing means sewn, heat pressed or molded on the ends. In preferred embodiments, the closing means will be an elastic or rubber band that is placed adjacent to the ends. The grease gun sleeve has two pull tabs attached to the ends of the tube sleeve that allow the grease gun sleeve to be manipulated when placed on the hose of a grease gun. The grease gun sleeve is used by first placing the semicircular neck end over the nozzle and hose of a grease gun, then sliding the grease gun sleeve on the hose in a first direction so that the sleeve is fully mounted on the hose, this is the uncovered position, then skidding the grease gun sleeve in a second direction until the flattened neck is past the nozzle so that the closing means rests within the groove of the present invention, the covered position.

The present invention is directed to a grease gun sleeve that is placed over the nozzle and hose of a grease gun to capture grease drool and prevents contamination.
All industries with mechanized equipment require lubrication. Many of these industries are regulated. Therefore, for the purpose of this summary, aviation will be utilized.
In the aviation industry, safety is the key to safe travel. The industry is heavily regulated and maintenance is key. Shops that repair and maintain airplanes must adhere to safety regulations that instruct them as to how they must store materials, equipment, and solvents, for the contamination of solvents used on airplanes can lead to failures of aircraft systems.
One requirement that must be adhered to is the maintenance of grease guns. Nozzles of grease guns must be sealed when not in use. Often this does not happen after the grease guns first use. The reason is that the guns normally come with an end cap that is held by a ring and clip attachment means that are used adjacent to the nozzle to seal the nozzles of grease guns. The ring and clip cap attachment means are a nuisance to the technicians using the guns in the field and often are removed by the technicians.
After the removal of the ring and clip cap attachments, the nozzles are often not properly caped or sealed. Technicians in shops, often place bags with rubber bands on the nozzle ends of grease guns to prevent drool in shops. Sometimes they even hang the guns without placing a sealing means on the nozzle ends, a violation to FAA rules, for not sealing the nozzle end can lead to contamination of the grease or fluid spills below the grease guns.
The inventor of the present invention conceived a device that can be placed on the hose of the nozzle of a grease gun. The device can be slid from one position that allows the end of a nozzle to be covered and to a second position that allows the end to be uncovered. The device prevents drool and contamination when in the covered position. When the device is in the uncovered position, it hugs the hose of the gun and it does not present a nuisance to the technician.
There is a need in the airline lubrication industry for a device that can be placed over the nozzle of a grease gun to capture drool and prevent contamination.

Grease gun sleeve that captures drool and prevents contamination


An isolation circuit, which draws essentially zero current in a normal or stand-by state, uses a normally closed relay in combination with a storage element. A capacitor can be used as the storage element to energize the relay, using previously stored energy, in the event that a communication line to which the isolator is coupled exhibits a short circuit or low voltage condition. In this instance, the prestored energy on the capacitor activates the relay for a predetermined period of time, thereby open circuiting the communication line. When voltage is reapplied to one side of the isolator circuit, the relay is continuously energized and maintained in its open circuit condition until the low voltage or short circuit has been remedied.

Electrical detection or transmission systems typically employ two lines or wires to deliver electrical power to the detector, alarm or other unit requiring electrical power. One of these lines is typically the higher voltage or "hot" line, and the other is the neutral, reference or ground line. One such system is disclosed in Tice et al., U.S. Pat. No. 4,916,432, assigned to the assignee of the present invention, and incorporated herein by reference.
Each set of two lines from a power source may be used to transmit power using electrical pulses, as in the Tice et al. patent, to many detectors or alarms which, for example, may be used throughout an entire floor or section of a large building. In addition, each set of the lines may also be used simultaneously to transmit information, such as the occurrence and location of a fire, between the detectors and a central monitor or control panel.
During the use and operation of these detection or transmission systems, however, faults may develop in the detectors or other equipment which create a short circuit in the transmission lines. These short circuit faults may disable and render inoperative entire sections of the detection system, particularly those sections operating from a common set or pair of transmission lines.
The disabling of such systems, such as fire detection systems, may place otherwise monitored areas at risk pending systems repairs. Accordingly, to avoid such potentially unacceptable risks, a need has arisen for circuits capable of both detecting such short circuit faults and isolating them from the remainder of the system, which may then continue to function normally.
Electrical circuits are currently available which provide some means for detecting and isolating such short circuits. For example, Payne U.S. Pat. No. 4,528,610 discloses an electrical circuit, normally operating in an on state, which switches off in response to a short circuit.
Transistors are used in the transmission line which are normally on and which conduct power or information signals between adjacent transmission line segments. In the event of a short circuit, the transistors no longer have sufficient voltage to be biased in an on state and switch off, isolating the short circuit.
While such known circuits are capable of isolating a short circuit, the known circuitry requires an appreciable electrical current, which may cause significant voltage drops in the line, both during normal operation and in the absence of a short circuit. These current requirements and successive voltage losses limit the number of isolators which may be employed in such a transmission system.
Accordingly, it would be desirable to have short circuit detectors and isolators having minimal current requirements during normal operation and which do not cause successive voltage losses from each detector and isolator unit employed across the lines. In addition, it would be desirable to have such a detector and isolator unit require fewer components, both for ease for manufacture and lower cost to the consumer or other end-user. Thus, there continues to be a need for short circuit detectors and isolators for transmission and detection systems which provide features and benefits of the type described above not heretofore available in such products.

Pittway Corporation, a Delaware Corporation


A dynamic random access memory (DRAM) device includes: a plurality of sense amplifiers; bit lines connected to the amplifiers, respectively; a first group of memory cells arranged in a row and connected to one of the bit lines; and a second group of memory cells arranged in a row and connected to the same bit line; the first and second groups being arranged side by side and adjacently to each other, shifted one from the other by a half of a memory cell pitch, and connected alternately to each other in an open bit line system.

1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particularly, to a dynamic random access memory (DRAM) device.
2. Description of the Related Art
Currently, memory cells each comprising one-transistor and one-capacitor of a DRAM device are further integrated to produce 4 megabit (M) DRAM's and samples of 16M DRAMs.
As the integration degree of the DRAMs is increased, however, the power consumption is greatly increased, and therefore, it is necessary to solve problems that arise due to this large power consumption. For example, a high heat radiation due to the large power consumption exceeds the capacity therefor of a conventional standard package, and thus this heat radiation must be reduced by improving circuit designs by reducing the size of memory cells, and by lowering a parasitic capacitance of a bit line, or the like. Furthermore, the high integration density of DRAM's allows a miniaturization of the memory cells and the DRAM device, which leads to a lowering of the capacitance of a charge storage capacitor, and this lowering of the capacitance leads to an increase of soft errors caused by an incidence of .alpha.-rays. Therefore, preferably the size of the charge storage capacitor is reduced without lowering the capacitance thereof.
Various improved DRAM devices are available; for example, in addition to an open bit line system, a folded bit line system by which the S/N (signal-to-noise ratio) is improved has been proposed, and with regard to the charge storage capacitor of a memory cell, in addition to a usual three dimensional stacked capacitor comprising a lower polycrystalline silicon (poly Si) electrode layer, an upper poly Si electrode layer, and a dielectric film sandwiched between the electrode layers, a tree-like multilayer stacked capacitor having a very high capacitance has been proposed.
Each of the memory cells of a DRAM device comprises a transfer transistor (MOS FET) T and a charge storage capacitor C arranged in a circuit as shown in FIG. 1. This circuit is used in both the open bit line system DRAM and the folded bit line system DRAM. The transistor T comprises a gate electrode 4 (i.e., a word line WL1), a source region 5 of a bit line contact region, and a drain region b of a storage electrode contact region, and the charge storage capacitor C comprises a storage electrode 8, a dielectric film (thin layer) 9, and an opposite electrode 10.
The open bit line system DRAM with a usual three-dimensional stacked capacitor has an arrangement (layout) as shown in FIG. 2. In FIG. 2, the same elements as shown in FIG. 1 are denoted by the same reference numerals and symbols. In this case, the word lines WL1 (4) and WL2 are made of poly Si, and the source region 5 and the drain region 6 are n.sup.+ -type impurity-doped regions. Reference numerals "7A" and "7B" indicate a bit line contact window and a storage electrode contact window, respectively, and are formed in an insulating layer. The storage electrode 8 of the capacitor C is made of poly Si and extends above the word line WL1 (4). The opposite electrode 10 is also made of poly Si and the bit line BL (12) is made of a conductor such as aluminum and metal silicide (e.g., WSi.sub.2). FIG. 2 has two additional scales at a right hand side and a lower side thereof, in which "a", "b" and "c" indicate a minimum line width, a first alignment tolerance, and a second alignment tolerance, and are used for a comparison of the memory cell size (area) as explained hereafter in detail.
The open bit line system DRAM device has been replaced by a folded bit line system DRAM device developed to increase the S/N.
The folded bit line system DRAM device with a usual three-dimensional stacked capacitor is shown in FIG. 3 and 4; (for example, cf. Takemae et al, "Development of 1M DRAM for Aiming at Easy Operation and Production", Nikkei Electronics, No. 370, Jun. 3, 1985, PP. 209-231). FIG. 3 shows a layout (a schematic partial plan view) of the DRAM device and FIG. 4 shows a schematic sectional partial view of the device taken along the line IV--IV of FIG. 3. Note, in these drawings, the same or corresponding elements as those shown in the previous figures are denoted by the same reference numerals and symbols.
The DRAM device is produced by using a p-type silicon substrate (wafer) 1, and is provided with a field insulating film 2 of silicon dioxide (SiO.sub.2) a gate insulating film 3 of SiO.sub.2 , an insulating interlayer (film) 7 of SiO.sub.2 , and an insulating interlayer (film) 11 of phosphosilicate glass (PSG). The stacked capacitor consists of the storage (lower) electrode 8 of poly Si, the dielectric film 9 of SiO.sub.2, and the opposite (upper) electrode 10 of poly Si. Since the storage electrode 8 extends above the word lines WL1 and WL2, the capacitance of the capacitor is increased, and as an electric charge stored in the capacitor of a memory cell corresponds to memory information, as the capacitance of the capacitor is increased, the S/N is improved.
Nevertheless, the miniaturization of DRAMs means that the size of the charge storage capacitor is reduced, and thus there is a possibility of a shortage of the capacitance. Accordingly, a tree-like multilayer stacked capacitor, in which the capacitance (electric charge storing ability) is greatly increased, has been proposed (for example, U.S. Ser. No. 07/206,791 filed on Jun. 15, 1988, now abandoned, and Japanese Patent Application Nos. 62-149143, 62-30641 and 62-314764).
FIG. 5 shows a schematic sectional view of the DRAM device with the tree-like multilayer stacked capacitor, in which drawing the same or corresponding elements as those shown in the previous figures are denoted by the same reference numerals and symbols. As can be seen from FIG. 5, the capacitor consisting of the storage electrode 8, the dielectric film 9 and the opposite electrode 11 has three fin portions 15, 17, and 19, and thus the capacitance thereof is much larger than that of the capacitor of FIG. 4, and as long as such a tree-like stacked capacitor structure is adopted in DRAM devices, the capacitance thereof will allow a further miniaturization of DRAMs, to produce, for example, 16M DRAMs.
Nevertheless, this increase of capacitance due to the tree-like structure causes problems in the production process. Namely, the height of the charge storage capacitance is increased to make a distance between the substrate surface and the top surface of the insulating film 11 greater, which results in a poor step coverage of the bit line 12, regardless of FIG. 5.
The problem (i.e., poor step coverage) had been solved by an improved DRAM device shown in FIGS. 6 and 7, in which the bit line 12 is formed prior to the formation of the tree-like capacitor. FIG. 6 shows a schematic sectional partial view of the improved DRAM device and FIG. 7 shows a layout (a schematic partial plan view) of the device, in which drawings the same or corresponding elements as those shown in the previous figures are denoted by the same reference numerals and symbols. In FIG. 6, the bit line 12 has a doublelayer structure of a poly Si film and a WSi.sub.2 film, and an additional insulating interlayer 13 of silicon nitride (Si.sub.3 N.sub.4) is formed to cover the bit line 12 and the insulating interlayer 7. The tree-like stacked capacitor of the improved DRAM device is the same as that shown in FIG. 5, except for the shape of the opposite electrode 10. FIG. 7 has additional scales similar to those of FIG. 2 at the right hand side and lower side thereof, and these are used for a comparison of the memory cell size (area). When the bit line 12 is formed, since a large step (tree-like structure) does not exist, the step coverage problem is avoided. Furthermore, the fin portions 15, 17 and 19 of the capacitor (FIG. 6) can be further extended above the bit line 12 and beyond the word line WL1 (gate electrode 4), so that the capacitance is further increased.
Where the technique of the improved DRAM device of FIGS. 6 and 7 is applied to an open bit line system DRAM device, a layout (arrangement) of the latter device is obtained as shown in FIG. 8. This layout was formed by the present inventor during experiments in the making of the present invention. In FIG. 8, the same elements as those shown in FIGS. 6 and 7 are denoted by the same reference numerals and symbols, and an additional two scales similar to those of FIGS. 2 and 7 are also shown in FIG. 8.
Although the folded bit line system having an improved S/N is superior to the open bit line system, the tree-like multilayer stacked capacitor provides a capacitance sufficient to obtain a good S/N, in spite of miniaturization, with the result that the open bit line system is preferable since the bit line (parasitic) capacitance is lower than that of the folded bit line system, whereby an output signal voltage is increased and the power consumption is reduced.
The parasitic capacitance of the bit line will be explained.
When the word line WL1 (4) is ON, the following formula is obtained: EQU C.sub.BL V.sub.0 +C.sub.cell V.sub.1 =(C.sub.BL +C.sub.cell)V
where, C.sub.cell is the capacitance of the charge storage capacitor described with reference to FIGS. 1 to 8, C.sub.BL is the parasitic capacitance of the bit line BL (12), V.sub.0 is an initial bit line voltage, V.sub.1 is a voltage of the capacitor, and V is a voltage of the word line WL 1 in an ON condition.
The output signal voltage .DELTA.V is as follows: ##EQU1## and thus is largely dependent upon a ratio of the bit line capacitance C.sub.BL to the capacitor's capacitance C.sub.cell. Therefore, preferably the bit line capacitance is made as low as possible.
In the operation of the DRAM device, to prevent a loss of information, a refresh, i.e., reading and rewriting, operation is periodically carried out at predetermined intervals. When rewriting, the charge storage capacitor must be made high ("H") level by charging up the bit line to the supply (source) voltage. This charge up electric current accounts for about half of the total power consumption. The charge up and discharge electric current is proportional to the bit line capacitance, and thus preferably the bit line capacitance is lowered.
The simplest and most certain means of lowering the bit line parasitic capacitance is to shorten the bit line length.
The bit line length of the folded bit line system DRAM device of FIGS. 6 and 7 is explained with reference to FIG. 9. FIG. 9 schematically shows a relationship between bit lines BL1A, BL1B, BL2A, BL2B, memory cells MC, and sense amplifiers SA1, SA2. In this case, a pair of memory cells MC constitute a unit cell. The length of each of the bit lines BL1A . . . is relatively long, and thus the bit line parasitic capacitance is high. For example, where a sense amplifier SA is provided with 512 memory cells, although 256 cells per bit line exist, there are 512 word lines per bit line. Namely, 512 word lines cross a bit line, and thus the bit line length corresponds to at least the total pitch of 512 word lines.
Further, in addition to the high bit line parasitic capacitance in the above-mentioned folded bit line system DRAM devices, these devices and the open bit system DRAM device of FIG. 8 have a problem of memory cell size (area).
Prior to a discussion of the cell sizes of the DRAM devices of FIGS. 7, 2 and 8, the first and second alignment tolerances "b" and "c" shown in the additional scales of the drawings are explained with reference to FIGS. 10A, 10B, 11A and 11B. In the drawings, reference numerals 31, 32, 33, 34 and 35 indicate a silicon substrate, an insulating film of SiO.sub.2, a poly Si electrode, another (e.g., gate) insulating film, and another (e.g., gate) electrode of poly Si, respectively.
FIGS. 10A and 10B explain the formation of the first alignment tolerance "b". The size of the poly Si electrode 33 must be larger than a contact window size by at least the alignment tolerance "b", as shown in FIG. 10A. If the poly Si electrode 33 is patterned to form a space between the electrode 33 and the insulating film 32, as shown in FIG. 10B, a portion of the silicon substrate 31 is etched at the patterning step.
FIGS. 11A and 11B explain the formation of the second alignment tolerance "c". To bring the poly Si electrode 33 into appropriate contact with the silicon substrate 31, the insulating film 32 must be selectively etched to provide the alignment tolerance "c" between a contact window and the gate electrode 35, as shown in FIG. 11A. If the selective etching of the insulating film is not appropriate, as shown in FIG. 11B, a short occurs between the poly Si electrode 33 and the (gate) electrode 35.
Therefore, the following relationship is determined between the minimum line width "a", and the alignment tolerances "b" and "c": EQU a>c>b
In general the conditions "a=4b" and "c=2b" are predetermined.
Taking the above-mentioned explanation and conditions into consideration, the memory cell size of the DRAM device of FIG. 7 is calculated as follows: ##EQU2## This cell size is relatively large, and if the memory cell size can be further reduced without affecting the properties and functions of the DRAM device, good results will be obtained together with an even better integration.
The memory cell size of the DRAM device of FIG. 2 is calculated as follows: ##EQU3##
The memory cell size of the DRAM device of FIG. 8 is calculated as follows: ##EQU4##

DRAM device having cells staggered along adjacent rows and sources and drains aligned in a column direction