In a ferro-electric memory including reference cells, if one reference cell is associated with a plurality of normal cells, a period in which “L” data is written in the reference cell and a period in which “H” data is written or read out in/from the reference cell are controlled to be shorter than a period in which “L” data is written in each normal cell and a period in which “H” data is written or read out in/from each normal cell, respectively. In this manner, stress applied to the reference cell is reduced and, even if writing or reading is repeatedly performed on the normal cells, the reliability of the reference cell is enhanced and deterioration in characteristics of the reference cell due to repetitive rewriting of data is suppressed.

The present invention relates to memory devices of ferro-electric including normal cells and reference cells and particularly relates to a technique for achieving high reliability by reducing stress on reference cells.
In recent years, with miniaturization in processing and increase in capacity, memory cells containing one transistor and one ferro-electric capacitor (1T1C) capable of reducing the memory cell size have been replacing currently-used memory cells containing two transistors and two ferro-electric capacitors (2T2C) to form ferro-electric memories. The 1T1C memory cells need reference cells in addition to the configuration of normal 2T2C memory cells. Therefore, to increase the speed and enhance the reliability, it has become more and more important to shorten the period necessary for writing or reading data in/from reference cells.
Hereinafter, a conventional ferro-electric memory will be described with reference to drawings. The following technique for this conventional memory is shown in U.S. Pat. No. 6,028,078 or Yaonbae Chung et al., "A 3.3-V 4-Mb Nonvolatile Ferroelectric RAM with a Selectively-Driven Double-Pulsed Plate Read/Write-Back Scheme"; Symposium on VLSI Circuits Digest of Technical Papers, 1999, pp. 97–98.
FIG. 7 is a diagram showing hysteresis characteristics of a ferro-electric for use in memory cell capacitors in a ferro-electric memory. FIG. 8 is a timing chart showing operation in the conventional ferro-electric memory. FIG. 9 is a diagram showing a detailed circuit configuration of the conventional ferro-electric memory. FIG. 10 is a diagram schematically showing the circuit configuration of the conventional ferro-electric memory.
In FIGS. 9 and 10, reference sign RMC0 denotes a first reference cell for writing and reading data. The first reference cell RMC0 includes: a first MOS transistor T0 whose drain is connected to a first reference bit line BL0 and gate is connected to a reference word line RWL; and a first ferro-electric capacitor C0 whose one end is connected to the source of the first MOS transistor T0 at a connection point, i.e., a first storage node ST0, and the other end is connected to a reference cell plate line RCP.
Reference sign RMC1 denotes a second reference cell for writing and reading data. The second reference cell RMC1 includes: a second MOS transistor T1 whose drain is connected to a third reference bit line BL2 and gate is connected to the reference word line RWL; and a second ferro-electric capacitor C1 whose one end is connected to the source of the second MOS transistor T1 at a connection point, i.e., a second storage node ST1, and the other end is connected to the reference cell plate line RCP.
Reference sign RMC2 denotes a third reference cell for writing and reading data. The third reference cell RMC2 includes: an eleventh MOS transistor T10 whose drain is connected to a fifth reference bit line BL4 and gate is connected to the reference word line RWL; and a fifth ferro-electric capacitor C4 whose one end is connected to the source of the eleventh MOS transistor T10 at a connection point, i.e., a fifth storage node ST4, and the other end is connected to the reference cell plate line RCP.
Reference sign RMC3 denotes a fourth reference cell for writing and reading data. The fourth reference cell RMC3 includes: a twelfth MOS transistor T11 whose drain is connected to a seventh reference bit line BL6 and gate is connected to the reference word line RWL; and a sixth ferro-electric capacitor C5 whose one end is connected to the source of the twelfth MOS transistor T11 at a connection point, i.e., a sixth storage node ST5, and the other end is connected to the reference cell plate line RCP.
In FIGS. 9 and 10, reference signs MC0, MC1, MC2, MC3, MC0n, MC1n, MC2n and MC3n denote normal cells. The reference sign MC0 denotes a first memory cell for writing and reading data. The first memory cell MC0 includes: a ninth MOS transistor T8 whose drain is connected to a second normal bit line BL1 and gate is connected to a word line WL; and a third ferro-electric capacitor C2 whose one end is connected to the ninth MOS transistor T8 and the other end is connected to a cell plate line CP.
The reference sign MC1 denotes a second memory cell for writing and reading data. The second memory cell MC1 includes: a tenth MOS transistor T9 whose drain is connected to a fourth normal bit line BL3 and gate is connected to the word line WL; and a fourth ferro-electric capacitor C3 whose one end is connected to the tenth MOS transistor T9 and the other end is connected to the cell plate line CP.
The reference sign MC2 denotes a third memory cell for writing and reading data. The third memory cell MC2 includes: a nineteenth MOS transistor T18 whose drain is connected to a sixth normal bit line BL5 and gate is connected to the word line WL; and a seventh ferro-electric capacitor C6 whose one end is connected to the nineteenth MOS transistor T18 and the other end is connected to the cell plate line CP.
The reference sign MC3 denotes a fourth memory cell for writing and reading data. The fourth memory cell MC3 includes: a twentieth MOS transistor T19 whose drain is connected to an eighth normal bit line BL7 and gate is connected to the word line WL; and an eighth ferro-electric capacitor C7 whose one end is connected to the twentieth MOS transistor T19 and the other end is connected to the cell plate line CP.
The normal cells MC0n through MC3n have the same configurations as those of the normal cells MC0 through MC3, and thus detailed description thereof will be omitted.
The normal cells MC0n through MC3n are arranged in rows (i.e., direction along the word line) and columns (i.e., direction along bit lines). Between two normal cells (e.g., MC0 and MC0n) arranged in the same column, one or more other normal cells (not shown) are placed. The reference cell RMC0 is associated with a plurality of normal cells MC0 through MC0n arranged in the same column as the reference cell RMC0. In the same manner, the reference cell RMC1 is associated with a plurality of normal cells MC1 through MC1n arranged in the same column as the reference cell RMC1. The reference cell RMC2 is associated with a plurality of normal cells MC2 through MC2n. The reference cell RMC3 is associated with a plurality of normal cells MC3 through MC3n.
In addition, in FIGS. 9 and 10, reference sign RST0 denotes a first reference cell resetting circuit. The first reference cell resetting circuit RST0 includes: a third MOS transistor T2 whose gate is connected to a reference-cell-reset starting signal line RST and source is connected to the first storage node ST0 of the first reference cell RMC0; and a fourth MOS transistor T3 whose gate is connected to the reference-cell-reset starting signal line RST, source is grounded and drain is connected to the second storage node ST1 of the second reference cell RMC1.
Reference sign RST1 denotes a second reference cell resetting circuit. The second reference cell resetting circuit RST1 includes: a thirteenth MOS transistor T12 whose gate is connected to the reference-cell-reset starting signal line RST and source is connected to the fifth storage node ST4 of the third reference cell RMC2; and a fourteenth MOS transistor T13 whose gate is connected to the reference-cell-reset starting signal line RST, source is grounded and drain is connected to the sixth storage node ST5 of the fourth reference cell RMC3.
Reference sign RFDR0 denotes a first reference cell reset driver. The first reference cell reset driver RFDR0 includes: a fifth MOS transistor T4 whose gate is connected to a second reference-cell-reset-driver starting signal line XRDIN3 and source receives a power-supply potential; a sixth MOS transistor T5 whose gate is connected to a first reference-cell-reset-driver starting signal line XRDIN2 and source is grounded; and a seventh MOS transistor T6 whose gate is connected to a third reference-cell-reset-driver starting signal line RDIN4 and source is grounded. The drains of these three MOS transistors are connected to the source of the third MOS transistor T2 included in the first reference cell resetting circuit RST0.
Reference sign RFDR1 denotes a second reference cell reset driver. The second reference cell reset driver RFDR1 includes: a fifteenth MOS transistor T14 whose gate is connected to the second reference-cell-reset-driver starting signal line XRDIN3 and source receives a power-supply potential; a sixteenth MOS transistor T15 whose gate is connected to the first reference-cell-reset-driver starting signal line XRDIN2 and source is grounded; and a seventeenth MOS transistor T16 whose gate is connected to the third reference-cell-reset-driver starting signal line RDIN4 and source is grounded. The drains of these three MOS transistors are connected to the source of the thirteenth MOS transistor T12 included in the second reference cell resetting circuit RST1.
Reference sign T7 denotes an eighth MOS transistor whose drain and source connect the first reference bit line BL0 and the third reference bit line BL2 to each other and gate is connected to a reference-level-equalization starting signal line REQ. Reference sign T17 denotes an eighteenth MOS transistor whose drain and source connect the fifth reference bit line BL4 and the seventh reference bit line BL6 to each other and gate is connected to the reference-level-equalization starting signal line REQ.
Reference sign SA denotes a sense amplifier for amplifying the potential difference between the first reference bit line BL0 and the second normal bit line BL1, the potential difference between the third reference bit line BL2 and the fourth normal bit line BL3, the potential difference between the fifth reference bit line BL4 and the sixth normal bit line BL5 and the potential difference between the seventh reference bit line BL6 and the eighth normal bit line BL7, when a sense amplifier starting signal SAE is at an H level.
Reference sign PERI0 denotes a first peripheral circuit connected to the reference word line RWL, the word line WL, the reference cell plate line RCP, the cell plate line CP, the reference-cell-reset starting signal line RST, the reference-level-equalization starting signal line REQ, the first reference-cell-reset-driver starting signal line XRDIN2, the second reference-cell-reset-driver starting signal line XRDIN3, and the third reference-cell-reset-driver starting signal line RDIN4 and the sense amplifier starting signal line SAE. The first peripheral circuit PERI0 controls the reference cells RMC0 through RMC3, the reference cell resetting circuits RST0 and RST1, the reference cell reset drivers RFDR0 and RFDR1, the memory cells MC0 through MC3, the sense amplifier SA and the MOS transistors T7 and T17.
Circuit operation of this conventional ferro-electric memory will be described with reference to the timing chart of FIG. 8 and the diagram of FIG. 7 showing hysteresis characteristics of a ferro-electric constituting the ferro-electric capacitors C0 through C7 of memory cells in the ferro-electric memory.
In FIG. 7, the abscissa indicates a voltage applied to a ferro-electric capacitor, more specifically, a voltage applied to a plate line relative to a bit-line voltage. The ordinate indicates the amount of charge in the ferro-electric capacitors upon the application of the voltage. As shown in FIG. 7, in the ferro-electric capacitors, residual polarization occurs as indicated by points A and G even when a voltage applied between both terminals is zero. A nonvolatile ferro-electric memory for storing data is implemented by utilizing this residual polarization characteristic. When data in a memory cell is "1", a memory cell capacitor is in the state indicated by point A in FIG. 7. When data in the memory cell is "0", the memory cell capacitor is in the state indicated by point G in FIG. 7.
Suppose the first ferro-electric capacitor C0 and the second ferro-electric capacitor C1 in FIG. 9 are included in the reference cells RMC0 and RMC1, the third ferro-electric capacitor C2 and the fourth ferro-electric capacitor C3 are included in the normal memory cells MC0 and MC1. Then, if data is read out from the third and fourth ferro-electric capacitors C2 and C3 with data "1" written in the first and third ferro-electric capacitors C0 and C2 and data "0" written in the second and fourth ferro-electric capacitors C1 and C3, the word line WL, the cell plate line CP, the reference-level-equalization starting signal REQ, the reference word line RWL, the reference cell plate line RCP, the sense amplifier starting signal SAE, the first reference bit line BL0, the second normal bit line BL1, the third reference bit line BL2, the fourth normal bit line BL3, the reference-cell-reset starting signal RST, the third reference-cell-reset-driver starting signal RDIN4, the first storage node ST0 and the second storage node ST1 are at logic voltage levels "L", and the first reference-cell-reset-driver starting signal XRDIN2 and the second reference-cell-reset-driver starting signal XRDIN3 are at logic voltage levels "H", as an initial state.
First, at timing t01 shown in FIG. 8, the reference-level-equalization starting signal REQ is raised to a logic voltage level "H". At timing t02, the word line WL and the reference word line RWL are raised to logic voltage levels "H". At timing t03, the cell plate line CP and the reference cell plate line RCP are raised to logic voltage levels "H".
In this manner, the first MOS transistor T0, the second MOS transistor T1, the ninth MOS transistor T8 and the tenth MOS transistor T9 in FIG. 9 are turned ON, so that a voltage is applied to the first ferro-electric capacitor C0, the second ferro-electric capacitor C1, the third ferro-electric capacitor C2 and the fourth ferro-electric capacitor C3. In addition, the eighth MOS transistor T7 is turned ON, thereby making the first reference bit line BL0 and the third reference bit line BL2 electrically continuous. At this time, data "1" is written in the third ferro-electric capacitor C2, so that the state indicated by point A changes to the state indicated by point B as shown in FIG. 7, and charge Q1 is read out to the second normal bit line BL1. Data "0" is written in the fourth ferro-electric capacitor C3, so that the state indicated by point G changes to the state indicated by point E as shown in FIG. 7. Accordingly, charge Q0 is read out to the fourth normal bit line BL3. On the other hand, data "1" is written in the first ferro-electric capacitor C0, so that the state indicated by point A changes to the state indicated by point C as shown in FIG. 7. Data "0" is written in the second ferro-electric capacitor C1, so that the state indicated by point G changes to the state indicated by point F as shown in FIG. 7. Accordingly, charge QR is read out to the first and third reference bit lines BL0 and BL2.
Then, at timing t05 shown in FIG. 8, the reference cell plate line RCP and the cell plate line CP are lowered to logic voltage levels "L". At this time, the third ferro-electric capacitor C2 changes from the state indicated by point B to the state indicated by point J as shown in FIG. 7. The fourth ferro-electric capacitor C3 changes from the state indicated by point E to the state indicated by point G as shown in FIG. 7. The first ferro-electric capacitor C0 changes from the state indicated by point C to the state indicated by point K as shown in FIG. 7. The second ferro-electric capacitor C1 changes from the state indicated by point F to the state indicated by point H as shown in FIG. 7.
Thereafter, at timing t06 shown in FIG. 8, the reference word line RWL is lowered to a logic voltage level "L". Then, the first ferro-electric capacitor C0 changes from the state indicated by point K to the state indicated by point L as shown in FIG. 7 and the second ferro-electric capacitor C1 changes from the state indicated by point H to the state indicated by point P as shown in FIG. 7.
Subsequently, at timing t09 shown in FIG. 8, the sense amplifier starting signal SAE is raised to a logic voltage level "H". The sense amplifier SA amplifies a potential difference (potential difference V1 shown in FIG. 7) read out to the first reference bit line BL0 and the second normal bit line BL1 and a potential difference (potential difference V0 shown in FIG. 7) read out to the third reference bit line BL2 and the fourth normal bit line BL3, so that data "1" is read out from the third ferro-electric capacitor C2 and data "0" is read out from the fourth ferro-electric capacitor C3. At this time, the third ferro-electric capacitor C2 changes from the state indicated by point J to the state indicated by point I as shown in FIG. 7. The fourth ferro-electric capacitor C3 remains in the state indicated by point G shown in FIG. 7.
On the other hand, at timing t07 shown in FIG. 8, the reference-level-equalization starting signal REQ is lowered to a logic voltage level "L". At timing t09, the first reference-cell-reset-driver starting signal XRDIN2 is lowered to a logic voltage level "L", the second reference-cell-reset-driver starting signal XRDIN3 is lowered to a logic voltage level "L", and reference-cell-reset starting signal RST is raised to a logic voltage level "H". Then, the first ferro-electric capacitor C0 changes from the state indicated by point L to the state indicated by point I by way of the state indicated by point K as shown in FIG. 7. The second ferro-electric capacitor C1 remains in the state indicted by point P shown in FIG. 7.
At timing t10 shown in FIG. 8, the cell plate line CP and the reference cell plate line RCP are raised to logic voltage levels "H". Then, the first and third ferro-electric capacitors C0 and C2 change from the state indicated by point I to the state indicated by point A as shown in FIG. 7. The second and fourth ferro-electric capacitors C1 and C3 change from the state indicated by point G to the state indicated by point D as shown in FIG. 7.
Thereafter, at timing t12 shown in FIG. 8, the reference cell plate line RCP and the cell plate line CP are lowered to logic voltage levels "L". Then, the first and third ferro-electric capacitors C0 and C2 change from the state indicated by point A to the state indicated by point I as shown in FIG. 7. The second and fourth ferro-electric capacitors C1 and C3 change from the state indicated by point D to the state indicated by point G as shown in FIG. 7.
Then, at timing t14 shown in FIG. 8, the sense amplifier starting signal SAE is lowered to a logic voltage level "L". Then, the third ferro-electric capacitor C2 changes from the state indicated by point I to the state indicated by point A as shown in FIG. 7. The fourth ferro-electric capacitor C3 remains in the state indicated by point G shown in FIG. 7.
In addition, at timing t14 shown in FIG. 8, the second reference-cell-reset-driver starting signal XRDIN3 is raised to a logic voltage level "H" so that the fifth MOS transistor T4 is turned OFF. The third reference-cell-reset-driver starting signal RDIN4 is raised to a logic voltage level "H" so that the seventh MOS transistor T6 is turned ON. Then, at timing t15 shown in FIG. 8, the first reference-cell-reset-driver starting signal XRDIN2 is raised to a logic voltage level "H" so that the sixth MOS transistor T5 is turned ON. The third reference-cell-reset-driver starting signal RDIN4 is lowered to a logic voltage level "L" so that the seventh MOS transistor T6 is turned OFF. Then, the first ferro-electric capacitor C0 changes from the state indicated by point I to the state indicated by point A as shown in FIG. 7 and the second ferro-electric capacitor C1 remains in the state indicated by point G shown in FIG. 7.
Lastly, at timing t17 shown in FIG. 8, the word line WL and the reference-cell-reset starting signal RST are lowered to logic voltage levels "L". At this time, the first and third ferro-electric capacitors C0 and C2 are in the state indicated by point A shown in FIG. 7, and the second and fourth ferro-electric capacitors C1 and C3 are in the state indicated by point G shown in FIG. 7.
As described above, in the conventional ferro-electric memory, the period (period (4) in FIG. 8) in which "L" data is written in the reference cells RMC0 through RMC3 is equal to the period (period (1) in FIG. 8) in which "L" data is written in the normal cells MC0 through MC3n. In addition, the period (period (5) in FIG. 8) in which "H" data is written in the reference cells is equal to the period (period (2) in FIG. 8) in which "H" data is written in the normal cells. Moreover, the period (period (6) in FIG. 8) in which data is read out from the reference cells is equal to the period (period (3) in FIG. 8) in which data is read out from the normal cells.
However, in a ferro-electric memory including reference cells, if one reference cell RMC0 is associated with a large number of normal cells (e.g., MC0 through MC0n) in the same row, the reference cell RMC0 is accessed concurrently with every access to the normal cells MC0 through MC0n. Accordingly, since the writing period and the reading period for the normal cells MC0 through MC0n are respectively equal to those for the reference cell RMC0, the reference cell RMC0 is subjected to stress N times (where N is the number of normal cells) as high as that on a normal cell (e.g., MC0). As a result, characteristics such as a characteristic in rewriting data in the reference cell RMC0, which is accessed more frequently than each of the normal cells MC0 through MC0n, deteriorate as compared to characteristics of the normal cells MC0 through MC0n.

Matsushita Electric Industrial Co., Ltd.


There is provided an air bag device in which a bag body can be inflated smoothly in a predetermined form and reduction in cost can be achieved. The air bag device includes an elongated bag body and a wire passes through the bag body along a longitudinal direction of the bag body. The wire is supported movably by a plurality of mounting hardwares. Each mounting hardware passes through slits, which are formed in the bag body and in a cover with the bag body being accommodated therein, to project outward and is fixed at a predetermined position by a bolt. A widthwise dimension of the mounting hardware is made shorter than a longitudinal dimension of each of the slits. For this reason, when the bag body inflates, the bag body suitably moves along the mounting hardwares and tensile force acting in the longitudinal direction of the bag body due to an internal pressure of the bag body at the time of inflation is thereby made uniform. Accordingly, the bag body can smoothly inflate to expand in accordance with a predetermined expanding progress.

1. Field of the Invention
The present invention relates to an air bag device installed in a vehicle.
2. Description of the Related Art
As a so-called side-impact air bag device which is provided on an inner side of a side wall of a vehicle body and detects pressure or the like applied from a lateral direction of the vehicle body to inflate a bag body toward an interior of the vehicle body, for example, there has been proposed the type of air bag device to be mounted on the vehicle body from a front pillar to a center pillar along a roof side.
Namely, as shown in FIG. 5, an air bag device 80 of this type includes a cover 84 whose longitudinal direction coincides with that of a vehicle body 82 (i.e., the direction indicated by arrow B in FIG. 5). The cover 84 is disposed adjacently to the vehicle body 82 from a front pillar 86 to a center pillar 88 along a roof side 90 and is provided to be expandable into a predetermined form due to internal pressure applied from an inner side of the cover 84. Further, as shown in FIG. 6, a bag body 92 in a folded state is accommodated within the cover 84. The bag body 92 is formed so that its longitudinal direction coincides with the longitudinal direction of vehicle body 82 (i.e., the direction indicated by arrow B in FIG. 6). When gas is blown off from a module 94 provided in the center pillar 88 into the bag body 92, the bag body 92 presses against the cover 84 from the inner side thereof while swelling so as to cause the cover 84 to expand, and the bag body 92 further inflates to expand toward the interior of the vehicle body 82 into a predetermined form (the state shown in FIG. 5).
On the other hand, the bag body 92 of the air bag device 80 is ordinarily provided with a plurality of tongue-shaped mounting portions 96. The plurality of mounting portions 96 are formed along the longitudinal direction of the bag body 92 at predetermined intervals and are provided to respectively project out of the cover 84 so as to be fixed by fitting parts (not shown) such as bolts to the front pillar 86, roof side 90, and center pillar 88. As a result, the air bag device 80 can be installed at a predetermined position on the vehicle body 82.
However, in the air bag device 80 mounted in the above-described manner, since the bag body 92 is held by only these mounting portions 96, it is difficult for tensile force F.sub.1 through F.sub.7 between the mounting portions 96, which is caused by the internal pressure of the bag body 92 when the bag body 92 inflates, to coincide with one another. As a result, the expanding progress of the bag body 92 (i.e., the progress of a change in the shape of the bag body 92 from a folded state to a completely expanded state) is different from a previously-set expanding progress, and there is a possibility that an undesirable state such as "slack" (the state indicated by the two-dot chain line in FIG. 5) is caused in the bag body 92 during expansion of the bag body 92 up to the completely expanded state.
In order to overcome the problem like the above, there can be considered methods: the number of mounting portions 96 may be increased; the bag body 92 may be uniformly fixed to the vehicle body 82 along the longitudinal direction thereof; and the like. However, in these methods, the number of fitting parts such as bolts increases and the number of processes for fixing the bag body 92 also increases, thereby resulting in increase in cost.
Further, in the air bag device 80, since the interval between the mounting portions 96, or the like changes in accordance with the shape of the vehicle body 82, component members such as the bag body 92 should be prepared independently for each of vehicle types, which becomes an impediment to a reduction in cost.


A control system having device units removably attachable to a control device such as a computer is arranged to optimize the allocation and distribution of electric power to the device units and also displays of varied kinds. For this purpose, each device unit of the system includes a communication circuit arranged to transmit information of electric power consumption and an operating state of the device unit detachably connected to the control device such as a computer, a stopping circuit for partly stopping a function of the device unit according to a control signal sent in reply from the control device on the basis of information of varied kinds transmitted through the transmission circuit to the control device. The control device, on the other hand, includes a communication circuit arranged to receive the information on the device unit from the device unit, and a control circuit arranged to compare the information of electric power consumption and the operating state received by the communication circuit with information of the amount of electric power which can be supplied to the device unit and to send the control signal to the device unit for partly stopping the function of the device unit according to the result of comparison. Further, the control device changes a display made therein and controls the operation of the device unit according to information of the operating state and the connected state of the device unit.

1. Field of the Invention
This invention relates to a control system, a power supply device, a device unit, an image pickup system, etc., in which a plurality of device units such as an image pickup unit, etc., are removably attached for use to a control device.
2. Description of the Related Art
Computers of the kind having connection terminals such as PCMCIA slots are generally arranged to use card-shaped device units arranged to function differently as a facsimile, memories, etc., with these device units inserted into the connection terminals. The connection terminals are arranged not to limit the usable device units. The operator of such a computer is, therefore, allowed to select any of such card-shaped device units having a desired function. FIG. 1 shows by way of example an image pickup system including a computer and an image pickup unit removably attachable to the computer. The image pickup system is described by way of example as follows.
Referring to FIG. 1, the image pickup system includes an image pickup unit (camera unit) 23 which is formed in a card-like shape, a computer 25 and a connection terminal 26 provided for connecting the image pickup unit 23 to the computer 25.
The image pickup system picks up an image by means of an optical system and a CCD which are disposed within the image pickup unit 23. The image picked up is converted into digital data. The picked-up image data is transferred via the connection terminal 26 to the computer 25. The computer 25 contains therein a display device and a recording device. The picked-up image data from the image pickup unit 23 is displayed and recorded by the computer 25.
In the image pickup system shown in FIG. 1, the computer 25 has another connection terminal 27. A device unit 24 having a function which differs from the function of the image pickup unit 23 is connected to the connection terminal 27, which is arranged to function in the same manner as the connection terminal 26. Any device unit that can be connected to one of the connection terminals 26 and 27 is connectable also to the other connection terminal.
The device unit 24 is, for example, arranged to function as a facsimile (hereinafter referred to as a fax card). With the fax card 24 connected to the connection terminal 27, the picked-up image data recorded within the computer 25 is transmitted. The computer 25 controls the image pickup unit 23 and the fax card 24 which are respectively connected to the connection terminals 26 and 27 and, at the same time, also supplies electric power to them.
The image pickup system shown in FIG. 1 which is configured as described above is capable of performing an image pickup action, recording and displaying the picked-up image data and, with the fax card 24 connected to the computer 25, transmitting the picked-up image data. In a case where the image pickup unit 23 or the fax card 24 is not used, it may be used for some other apparatuses by detaching it from the connection terminal 26 or 27.
The method employed for the above-stated system, however, has presented the following problem.
The computer 25 constantly supplies electric power to the connected device units irrespectively of the operating or nonoperating state of the device units. Accordingly, even when only the fax card 24 is being used while the image pickup unit 23 is also attached to the computer 25 but is not being used, the computer 25 supplies electric power also to the image pickup unit 23, so that electric power is wasted. Alternatively, even when only the image pickup unit 23 is being used with the fax card 24 not being used, the computer 25 supplies electric power also to the fax card 24, so that electric power is wasted.
In cases where the computer 25 is arranged to be driven by the electric energy of a power source of a limited capacity such as a battery or the like, the amount of electric power consumed by the device units connected to the connection terminals of the computer 25 presents a serious problem. When a total of electric power consumed by the device units connected to the computer 25 is larger than the amount of electric power which can be supplied from the computer 25, one of or all of the device units connected to the computer 25 become inoperative or the computer 25 might come to malfunction. Such a malfunction has often caused the image pickup system to stop operating.
Further, in cases where an image pickup action is a primary function, electric power tends to be consumed so much by the fax card 24 to prevent adequate fulfillment of the image pickup action. In such a case, it has been necessary either to remove the fax card 24 from the computer 25 or to manually cut off the supply of electric power to the fax card 24.
Further, the image pickup system and an image signal processing device related thereto have presented the following problems.
There has been no means for enabling the operator of the image pickup system or the computer to confirm the connected state of the image pickup unit. Therefore, if a program of control over the image pickup unit happens to be executed in a state of having the image pickup unit not adequately connected to the computer, either the program or the computer might malfunction to necessitate a long period of time before resumption of its normal state.
Further, with the computer having a plurality of connection terminals, if the connection terminal to which the image pickup unit is connectable is limited among the plurality of connection terminals, there is a probability that the image pickup unit will be connected to a wrong connection terminal.
Further, there has been no means for enabling the operator of the image pickup system or the computer to confirm the operating state of the image pickup unit. Therefore, if the picked-up image data is not monitored by means of a display device contained in the computer, it has been impossible to confirm the operating state of the image pickup unit. Even in a case where the picked-up image data is arranged to be monitored, it has been sometimes hardly possible to intuitionally know the data of operation such as the image pickup speed of the image pickup unit and the number of colors in use, etc.
Further, the image pickup system has been provided with no means for enabling the operator of the image pickup system to know the pickup conditions under which previous image data has been obtained.
Further, in a case where the image pickup unit has a lens cover, the opened or closed state of the lens cover has nothing to do with the operation of the image pickup unit. In such a case, the lens cover has necessitated the operator of the image pickup system to close the lens cover when the image pickup unit is not used. Besides, it has sometimes happened that the operator of the image pickup system inadvertently operates the image pickup unit with the lens cover left closed.

Control system and units removably attachable to the same


An arrangement for securing a current transformer to an electric utility meter housing. The arrangement includes a utility meter base plate which forms a portion of the electric utility meter housing. The utility meter base plate includes (i) a first central axis and (ii) a transformer receptacle defined therein. The transformer receptacle has an opening and a first retention surface. The arrangement also has a current transformer assembly including (i) the current transformer and (ii) a wall member affixed to the current transformer. The wall member defines an annular channel having a second central axis, and the current transformer is positioned within the annular channel. The transformer assembly also includes a tab having a second retention surface. The tab extends from the wall member. The current transformer assembly is secured to the utility meter base plate, such that the first central axis is substantially parallel with the second central axis, when the tab is disposed within the transformer receptacle so that the first retention surface engages the second retention surface. An associated method of securing a current transformer to an electric utility meter is also disclosed.

Electric utility meters, or simply meters, are devices, that among other things, measure electrical energy consumed by a residence, factory, commercial establishment or other such facility. Electrical utilities rely on meters for many purposes, including billing customers and tracking demand for electrical power. A common form of meter utilizes current transformers to sense the electrical current being supplied to the facility being metered. The current sensed by the current transformers is transmitted to circuit boards included in the meter to facilitate measurement of the amount of electrical energy being consumed by the facility.
Heretofore, current transformers have been positioned inside of and secured to meter housings in a variety of ways. For example, one way of securing a current transformer to a meter housing involves attaching a post to a meter base plate within the housing and then inserting the post through a hole defined in the center of the current transformer. The current transformer is then retained on the post by pressing a nut over the end of the post. Alternatively, the end of the post may be melted such that the melted end bonds with the current transformer thereby retaining the current transformer on the post.
Although the above described methods for securing a current transformer to a meter are commonly used, they do have significant disadvantages. For example, melting the end of the post, or having to push a nut over the end thereof, requires manufacturing steps that increase the complexity of manufacturing the meter. In addition, the use of such methods to secure the current transformers within the meter housing inhibits the ability to service the meter. In particular, if a current transformer must be replaced in the meter, then a service technician can encounter difficulty in removing the existing current transformer and inserting a new current transformer. Specifically, if the melting method was utilized for securing the current transformer, the melted end of the post must be cut off before the current transformer can be removed from the post within the meter housing. Once the post end is cut off, it cannot be easily reused, and often the entire meter base plate must be replaced. If, however, a nut was used to secure the current transformer, then the nut must be carefully removed from the post to avoid damaging the current transformer. Carefully removing the nut to avoid damaging the current transformer results in a technician spending additional time disassembling the meter which also increases the cost of servicing the meter.
There exists a need, therefore, for a method and arrangement for securing a current transformer to an electric utility meter housing which addresses one or more of the above discussed problems.

Method and arrangement for securing a current transformer to an electric utility meter housing

Siemens Power Transmission & Distribution


The invention relates to a surfboard assembly that can be controlled, comprising a surfboard (1), which has a stern and a bow and which has a standing surface for a surfer (2), a longitudinal axis (L) oriented from the stern to the bow, a drive having a thrust device, which thrust device can be pivoted in a pivoting plane along the standing surface (13), for producing left and right cornering of the surfboard assembly, and a propulsion unit, at least one sensor (18), which is integrated in the surfboard (1) and detects tilting clockwise and counterclockwise about the longitudinal axis (L) and which controls the pivoting direction of the nozzle (12) in such a way that tilting of the surfboard (1) counterclockwise about the longitudinal axis (L) pivots the nozzle (12) to the left in the pivoting plane.

1. Field of the Invention
The invention concerns a controllable surfboard arrangement.
2. Description of the Related Art
Surfboards have been known for a long time. Surfboards are in the English language use boards without sails on which a surfer can ride the advance of a wave. In the German language use, it is named "wave-riding".
Surfboards have the disadvantage that without the advance of the wave, it is not possible to carry out the water sport. Wind-surfboards in contrast also have a sail on the surfboard, which is connected with articulation to the surfboard at its lower mast end. The windsurfer can therefore use the surfboard even if there are no waves, as long as there is wind.
DE 20 2011 051 071.9 discloses surfboard arrangements which have a jet drive integrated in a surfboard, wherein the jet drive can be controlled by an integral control unit which can be held in the surfer's hand. The integrated control unit is designed for controlling both speed and turning left and right.


A photopolymerizable mixture for photopolymerizable printing plates with an improved resistance to UV-hardenable printing inks, contains 10-45% by weight of at least one thermoplastic, elastomeric, block copolymer comprising of two or more polymer blocks comprising aromatic vinyl units and one or more polymer blocks comprising isoprene and/or isoprene/butadiene units. The block copolymer has a vinyl bond content not above 70%, a glass transition temperature not above 20.degree. C., and a peak temperature of a primary dispersion of tan .delta. not above 30.degree. C.

1. Field of the Invention
The invention involves a photopolymerizable mixture containing elastomeric binder, photopolymerizable, ethylenically unsaturated compounds, and photoinitiators; a photopolymerizable printing plate comprising at least one photopolymerizable layer of such a mixture; and a flexographic printing form made from the plate.
2. Description of Related Art
Photopolymerizable printing plates are known for use in making flexographic printing forms. The printing surface is produced by imagewise exposure of a photopolymerizable layer to actinic radiation and subsequent removal of the unexposed, unphotopolymerized areas of the printing plate. Examples are found in the following patents: DE-C 22 15 090, U.S. Pat. No. 4,266,005, U.S. Pat. No. 4,320,188, U.S. Pat. No. 4,126,466 and U.S. Pat. No. 4,430,417. Such photopolymerizable printing plates usually comprise a support, an optional adhesive or other underlayer, one or more photopolymerizable layers, an optional, elastomeric, intermediate layer, and a cover layer.
A preferred method for making such multilayer photopolymerizable printing plates is a process in which a previously extruded photopolymerizable composition is fed into the nip of a calender and is calendered between a support and a cover element, thus forming a photopolymerizable layer between them. EP-B 0 084 851 discloses a preparation method for a multilayer photopolymerizable printing plate having an added elastomeric layer between the flexible, tear-resistant polymer layer and the photopolymerizable layer.
The photopolymerizable layers contain polymeric binders, photopolymerizable monomers, photoinitiators, and added auxiliaries, such as plasticizers, fillers, stabilizers, etc. The polymeric binders are usually thermoplastic, elastomeric, block copolymers, as described, for example, in DE-C 22 15 090. These are generally A-B-A block copolymers having thermoplastic blocks A and elastomeric blocks B, particularly linear and radial block copolymers with polystyrene end blocks, such as, for example, polystyrene/polyisoprene/polystyrene, (polystyrene/polyisoprene).sub.4 Si, or the corresponding butadiene polymers. The use of polymers having a certain vinyl content is also known for special purposes, such as, for example, for improving printing plate properties with special monomers (EP 0 525 206) or for preparing printing plates without monomer addition. Similar block copolymers and their use in highway engineering and automobile manufacture are described in EP-B 0 362 850. However, polystyrene/polybutadiene/polystyrene and polystyrene/polyisoprene/polystyrene block copolymers are preferred for making flexographic printing forms.
Nevertheless, current state-of-the-art printing forms frequently do not meet requirements for flexographic printing. In particular, when UV-hardenable inks are used, the printing forms are not sufficiently resistant to ink constituents diffusing into the forms. This increases layer thickness, changes image geometry on the printing form surface, and decreases Shore A hardness during printing. This is seen in the printed image as undesired spreading in positive image elements or as fine negative image elements running together.
Therefore, the present invention is based on the problem of making available flexographic printing forms that have improved resistance to UV-hardenable printing inks and that do not have the disadvantages described for printing forms of the current state of the art. In addition, the photopolymerizable printing plates for making these flexographic printing forms should have wide exposure latitude without adversely affecting other essential properties of the photopolymerizable printing plates or flexographic printing forms.

Flexographic printing forms having resistance to UV-hardenable printing inks


In one embodiment, a device receives optical time domain reflectometer (OTDR) trace samples, each sample labeled with an associated fiber optic cable condition. The device alters the received OTDR trace samples to generate a set of synthetic OTDR trace samples. Each synthetic sample is labeled with the label of the received sample that was altered to generate the synthetic sample. The device trains a machine learning-based classifier using a training dataset that comprises the synthetic OTDR trace samples. The device uses the trained classifier to identify a condition along a particular fiber optic cable based on OTDR trace data obtained from that cable.

Many data providers use fiber optic cables for high bandwidth transmissions, including telephone signals, Internet communications, and cable television signals. Fiber optics can carry data over very long distances with less interference. An optical signal is created by a transmitter, and the signal is relayed along the cable by repeaters to ensure that the signal does not become distorted or weak. Deployment of fiber cables can also vary considerably, with many long-distance deployments spanning remote and hard to reach locations, such as underground or underwater cables. Breaks in the optical fibers may occur over the long cable spans between repeaters, which can disrupt transmissions and cause significant data loss.
Problems along a fiber optic cable are typically detected through the use of an optical time domain reflectometer (OTDR). In general, an OTDR takes measurements from a fiber optic cable by transmitting optical power pulses into the cable and using a photodiode to capture the reflected signals. The received readings are then translated into trace results representing the attenuation along the cable versus its length. However, the task of interpreting the trace results is often left to a technician, leading to the very real possibility of problems going unnoticed due to human error. This is particularly true in the case of multiple conditions being present in the fiber optic cable.

Optical time domain reflectometer (OTDR)-based classification for fiber optic cables using machine learning


A view finder according to the present invention has an electroluminescence display element which displays an image of an object, and an optical element which magnifies the image.

1. Field of the Invention
The present invention relates to a view finder and, more particularly, to a view finder used in a video camera or the like.
2. Description of the Related Art
Digital cameras and video cameras incorporating a CCD image pick-up element have recently been spreading as a result of a trend toward CCD image pick-up elements having higher resolution and smaller sizes. FIG. 8A is an external view of a conventional video camera.
2001 represents a video camera body; 2002 represents a liquid crystal panel; 2003 represents a view finder; 2004 and 2005 represent operating switches; and 2006 represents a lens. In the video camera shown in FIGS. 8A and 8B, an image taken in through the lens 2006 is converted by the CCD image-pick up element into an image signal which is in turn recorded on a recording medium. The liquid crystal panel 2002 and view finder 2003 are display devices for displaying the image signal.
As shown in FIG. 8B, a user 2100 can photograph an object while observing an image of the same displayed on the view finder 2003. FIG. 9 shows the conventional view finder 2003. 2100-1 represents either the left or right eye of the user 2100. The view finder 2003 has a small liquid crystal panel 2003-1, and the user can observe an image displayed on the small liquid crystal panel 2003-1.
In the case of the conventional view finder, an image on the view finder 2003 observed by a user 2100 is an image on the small liquid crystal panel 2003-1, and the image is therefore considerably hard to recognize because of its small size and low resolution. As a result, in practice, it has been difficult for a user 2100 to photograph an object while observing an image of the same on the view finder 2003.
Under such circumstances, conventional video cameras include an externally attached liquid crystal panel as represented by 2002 in FIG. 8A. Such a conventional external liquid crystal panel 2002 has a size in a range from about 2 to 4 inches which is larger relative to images observed on the view finder 2003 and which therefore provides a higher resolution. This allows a user 2100 to photograph an object and to reproduce a recorded image while observing an image of the same displayed on the external liquid crystal panel 2002.
However, the external liquid crystal panel 2002 consumes higher power than the small liquid crystal panel 2003-1 of the view finder 2003 does because the screen size of the same is greater than that of the small liquid crystal panel 2003-1 of the view finder 2003. When a video camera is used with such an external liquid crystal panel 2002 therefor in operation, the power consumption is about one and half times as much as that consumed when the external liquid crystal panel 2002 is not operated. Therefore, when a video camera is used with such an external liquid crystal panel 2002 operated, there is a significant influence on the durability of the battery which is one of the most serious problems with a video camera for which out-door usability and portability is important. It has not necessarily been advantageous for a user to use a video camera while checking the display on the external liquid crystal panel 2002.
FIG. 10 is an external view of a conventional digital camera. 3001 represents a digital camera body; 3002 represents a liquid crystal panel; 3003 represents a shutter button; and 3004 and 3005 represent operating switches. A user can take a picture while checking an image displayed on the liquid crystal panel 3002 and can reproduce a recorded image to check the same.
However, the trend toward liquid crystal panels having greater sizes and higher resolutions has resulted in an increase in the power consumption of liquid crystal panels, and this is a significant problem for digital cameras which are intended for out-door use like video cameras.

Electronic view finder utilizing an organic electroluminescence display

Semiconductor Energy Laboratory Co., Ltd.


Recovering text from a damaged electronic file by scanning an arbitrary stream of bytes and extracting text that is encoded as ASCII or Unicode. A byte of the damaged file is read. The read byte may be interpreted using the ASCII encoding standard. The read byte and the immediately preceding read byte may also be interpreted using the Unicode character encoding standard. The interpreted byte(s) is classified based upon the likelihood that the byte(s) is actually text for the particular character set rather than a control character, damaged data, or an element other than a textual character. The classifications are used to adjust a likelihood counter for each character type. The likelihood counter may be an integer value that indicates the probability that a text run has been detected. A text run is a sequence of bytes that is believed to be undamaged text. Each likelihood counter is then examined to determine whether there is a text run for one of the character types. If there is a text run, then the starting position of the text run is saved. The entire text run is output when the text run ends.

Using modern word processing program modules to create and edit electronic files, or electronic documents, is often convenient and efficient. However, under certain circumstances, files may become damaged or corrupted. Damaged files are often unreadable by the application program module that created them. Thus, the time invested in creating the file is lost unless some of the file can be salvaged.
There are many different causes of file damage, or file corruption. One cause is a communication error, i.e., garbled transmission of a file via a modem or network. Another cause of file damage is a disk error, i.e., a failure of the storage media on which the file resides. A bug in an application program module that creates a file may also damage the file. Still another cause of file damage is a failure in an operating system while a user is working with a file. Thus, document corruption is a common problem that is difficult to avoid.
When a file is damaged, users want to retrieve the ndamaged data, i.e. the undamaged bytes, from the file. Users are annoyed if they cannot retrieve any data from a damaged file because the file must be completely reconstructed. In a word processing electronic file, the most important data contained in the file is almost always the actual text of the document. The formatting and the non-textual elements are usually less important. Thus, many different converters have been developed to retrieve undamaged text from a damaged file. Unfortunately, these converters are often incompatible with modem file formats which are described below.
Files created by modem application programs often have complex file formats. Modem file formats typically contain intricate, interconnected data structures. For example, consider the file format of the "WORD 8.0" program, a word processing program module marketed by Microsoft Corporation of Redmond, Washington. The "WORD 8.0" program has a file format comprising both single byte ASCII characters and Unicode characters. Unicode is a worldwide character encoding standard that uses two bytes to identify a character by defining one two-byte value to represent the same character worldwide. Thus, modem file formats, such as the "WORD 8.0" file format, are often quite complex and may contain both single byte characters and multiple byte characters.
The complexity of modern electronic files has some interesting ramifications with regard to damaged files. Should a modem file become damaged, there is a high probability that it will be unreadable by the program that created it. In contrast, corruption of a file stored in a simpler file format is unlikely to cause the file to become unreadable. For example, consider a file stored in the relatively simple file format known as plain ASCII text. If data in a plain ASCII text file becomes damaged, a text editor may be used to read the file and a user may then correct the damaged portions of the file. Thus, the user may extract and salvage uncorrupted portions of the damaged file. However, modern electronic files are often unreadable when damaged because there is a scarcity of applications for extracting data from a modem file format. For example, once again consider the file format of the "WORD 8.0" program. Currently, only one converter and the "WORD 8.0" program itself can read the "WORD 8.0" file format. In contrast, if a plain ASCII text file becomes corrupted so that it is unreadable by a particular converter, there are many other converters that may be used to attempt to retrieve the undamaged data. Unfortunately, the converters designed to recover ASCII text can not extract text from damaged documents with multiple-byte text.
Therefore, if a modem application program file becomes damaged, it is likely that the damaged file will be unreadable by the creating application program. It is also likely that there is no external converter to read the file. Thus, in many cases, there is no way for a user to recover undamaged data contained within a damaged file.
There is a need in the art for a method and system for recovering text from a damaged file with a modem, complex file format. There is a further need in the art for a method and system for recovering text from a damaged electronic file comprising single byte characters and multiple byte characters.

Method and system for recovering text from a damaged electronic file


A continuous positive air pressure (“CPAP”) or ventilator system includes a mask and an air flow generator. The air flow generator is mounted or provided to the mask's wearer. In one embodiment, air flow generator is mounted on the mask.

1. Field of the Invention
The present invention relates to ventilators, e.g., continuous positive air pressure ("CPAP") systems comprising a mask and an air flow generator, wherein the air flow generator is mountable to the mask's wearer. In one embodiment, the present invention provides CPAP systems wherein an air flow generator is mounted on the mask. In other embodiments, the air flow generator may be provided to the body of the wearer, e.g., the arm, leg, chest or waist, and a short air delivery tube can be used to connect the mask with the air flow generator.
2. Description of Related Art
CPAP administration is commonly used to treat respiratory conditions such as obstructive sleep apnea. The procedure for CPAP administration typically involves sealingly engaging a mask over a patient's nasal and/or oral region and supplying pressurized air to a chamber formed by the interior of the mask. In conventional systems, the air is supplied to the mask by an air flow generator typically placed in proximity to the patient's bed. An air delivery tube is thus needed to deliver air generated by the air flow generator to the mask.
There are two main sources of instability of a mask system during use or sleep. Normal patient movement can create instability, for example, a patient rolling on his or her side, which may cause the mask to interfere with the bedding material. Another concern of using an air delivery tube that is connected to an apparatus away from the patient is so-called "tubing drag", which refers to a drag force on the air delivery tube which is draped over the back or side of the bed. Tubing drag can be created or complicated by movement of the wearer. Tubing drag may cause relative movement between the mask seal and the patient's face during the CPAP administration and produce leaks and/or discomfort.
Another concern involving the air delivery tube is the length thereof (often about 2 meters or more), which may impart a lag in the response and rise times in delivering pressured air from the air flow generator to the mask. Increased flow impedance and/or pressure drop due to diameter and length of tubing may also necessitate a larger blower motor to compensate for the pressure drop along the air delivery tube.
U.S. Pat. Nos. 4,590,951; 5,372,130; and 6,435,184 describe masks for safety applications.

This patent is subject to a terminal disclaimer.


A hydraulic energy recovery device for a hydraulic system is disclosed. The hydraulic energy recovery device has a first impeller configured to receive a flow of pressurized liquid, and a second impeller configured to pressurize a flow of liquid. The hydraulic energy recovery device also has a common shaft connecting the first and second impellers.

Work machines such as, for example, dozers, loaders, excavators, motor graders, and other types of heavy machinery use one or more hydraulic actuators to accomplish a variety of tasks. These actuators are fluidly connected to a pump on the work machine that provides pressurized liquid to chambers within the actuators. As the pressurized liquid moves into or through the chambers, the pressure of the liquid acts on hydraulic surfaces of the chambers to effect movement of the actuator. When the pressurized liquid is drained from the chambers it is returned to a low pressure sump on the work machine.
One problem associated with this type of hydraulic arrangement involves efficiency. In particular, the liquid draining from the actuator chambers to the sump has a pressure greater than the pressure of the fluid already within the sump. As a result, the higher pressure fluid draining into the sump still contains some energy that is wasted upon entering the low pressure sump. This wasted energy reduces the efficiency of the associated hydraulic system.
One method of improving the efficiency of such a hydraulic system is described in U.S. Pat. No. 6,480,781 (the '781 patent) issued to Hafner et al. on Nov. 12, 2002. The '781 patent describes a fuel system having a plurality of fuel injectors that are hydraulically actuated by way of high pressure engine oil. The fuel system includes a means for recovering hydraulic energy from oil leaving each of the fuel injectors. The means for recovering hydraulic energy includes a waste accumulating fluid control valve for each injector, and a hydraulic motor connected between a high pressure pump and the waste accumulating fluid control valves. As the actuating oil exits each fuel injector, it enters and drives the motor before being divided into two separate flows. A first of the two flows is directed to the high pressure pump, while the second is returned to an actuation fluid sump.
Although the means for recovering hydraulic energy described in the '781 patent may improve efficiency of the associated fuel system by driving the motor and associated pump with waste oil, it may be limited and problematic. In particular, because the means for recovering does not provide a way to store recovered energy, it may still be wasted if the demand for recovered energy is not immediate. In addition, because the pressure of the fluid exiting the fuel injectors may fluctuate significantly depending on injector operation, and because the means for recovering is directly associated with the high pressure pump, operation of the high pressure pump may also fluctuate significantly. This fluctuation of the high pressure pump could affect injector variability causing engine instability. Further, because oil from the motor may be diverted directly to the high pressure pump, air entrained within the oil may remain in the oil, causing sponginess in the hydraulic circuit.
The disclosed hydraulic system is directed to overcoming one or more of the problems set forth above.

Hydraulic system having in-sump energy recovery device


The present optical modulator includes an optical waveguide core made of a semiconductor material, an electrode, and a plurality of channels made of a semiconductor material doped in an n type or a p type and electrically connecting the optical waveguide core and the electrode to each other. The plurality of channels are provided in a spaced relationship from each other along a propagation direction of light; the optical waveguide core includes a doped region doped in the n type or the p type and a non-doped region. The doped region and the non-doped region are disposed alternately along the propagation direction of light. Each of the plurality of channels is connected to the doped region.

Conventionally, there is an optical modulator using a pn diode or a pin diode. Such an optical modulator as described includes an optical waveguide core including a pn j unction portion or a pin junction portion, an electrode, and a channel that electrically connects the optical waveguide core and the electrode to each other. The optical modulator modulates light by changing an electric signal to be supplied from the electrode to the optical waveguide core through the channel.
As such an optical modulator as described above, for example, there are a rib waveguide type optical modulator that uses a pn diode, a side-wall grating waveguide type optical modulator that uses a pin diode and so forth.
Of such optical modulators, the rib waveguide type optical modulator that uses a pn diode includes a rib portion that functions as an optical waveguide core and a slab portion that functions as a channel. In the rib waveguide type optical modulator, light is confined in and propagates along the rib portion by a film thickness difference between the rib portion and the slab portion. In particular, in the rib waveguide type optical modulator, the slab portion is formed with a fixed thickness over the entire area thereof in the light propagation direction while the thickness thereof is formed smaller than that of the rib portion so that light is selectively confined in and propagates along the rib portion.
Meanwhile, the side-wall grating waveguide type optical modulator that uses a pin diode includes a grating provided partially along the light propagation direction on a side wall of the optical waveguide core, and the grating functions as a channel. In the side-wall grating waveguide type optical modulator, the region in which the grating is formed exhibits an average refractive index lower than that in the optical waveguide core so that light is confined in and propagates along the optical waveguide core. In other words, in the side-wall grating waveguide type optical modulator, the grating has a thickness equal to that of the optical waveguide core and is formed partially along the light propagation direction so that light is selectively confined in and propagates along the optical waveguide core.

Optical modulator and optical transmitter


System and methods for marking a work area boundary of an autonomous vehicle are disclosed. A system may receive an indication that boundary marking for a work area is to be activated, and may transmit an activation signal to a marking actuator based on receiving the indication that boundary marking for the work area is to be activated. The activation signal may cause the marking actuator to begin marking the boundary as a vehicle, that includes the system, traverses the boundary. The system may store information that identifies a plurality of marked locations along the boundary. The system may determine that boundary marking for the work area is to be deactivated, and may transmit a deactivation signal to the marking actuator based on determining that boundary marking for the work area is to be deactivated. The deactivation signal may cause the marking actuator to stop marking the boundary.

When autonomous vehicles are used at a work site, special care must be taken to avoid collisions of the autonomous vehicle with other objects, including people, other vehicles, and/or the like. The likelihood of a collision may be reduced by marking a boundary of a work area of the autonomous vehicle. One device for marking a work area is described in U.S. Pat. No. 5,537,017 (the '017 patent) assigned to Siemens Aktiengesellschaft, which issued on Jul. 16, 1996. The '017 patent describes "a device and process . . . for exploring an unknown working area." The described device "has a sensor, which enables it to detect the area boundary and the markings. [The device] moves in the direction of the area boundary . . . and then runs parallel to the area boundary in the direction of movement . . . . When doing so, it applies at regular intervals markings . . . , which are at a distance from the area boundary . . . ."
In the '017 patent, the term "working area" refers to the area being explored by the device, starting from a predefined boundary that may be extended (i.e., the "working" being performed by the device is exploration). Therefore, the device of the '017 patent is not capable of autonomously marking an entire boundary of a work area of an autonomous vehicle (e.g., to reduce the likelihood of a collision while the vehicle is working).
The disclosed system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.

System and method to mark autonomous work area


A high temperature lubricant composition comprising polycarboxylic acid esters and organophosphorus compounds is described. This composition is useful for lubricating very high temperature diesel engines. A method of rectifying used lubricant compositions is also described.

This invention relates to new synthetic lubricant compositions having exceptional thermal stability.
U.S. Pat. Nos. 2,396,191; 2,936,320; 3,021,357; 3,637,501; 3,912,640; and 4,080,303 are illustrative of prior art attempts to formulate lubricants containing esters of aromatic polycarboxylic acids.
U.S. Pat. No. 3,637,501 describes neo-carbon containing polycarboxylic acid esters wherein the ester groups on the aromatic nucleus contain at least one carbon atom connected directly to four other carbon atoms.
The number of lubricant patents and the importance of changes in composition found in these patents is testimony to the difficulty of making blends capable of simultaneously meeting desired criteria.
Recent technology concerning uncooled or insulated internal combustion engines requires lubricants able to withstand ring reversal temperatures in excess of 6500.degree. F. (343.30.degree. C.). Internal combustion engine operation at temperatures of 900.degree. F. (482.2.degree. C.) is being investigated. Moreover, ceramic elements in internal combustion engines may require lubricants capable of operation at temperatures in excess of 1000.degree.0 F. (537.8.degree. C.) or even 1200.degree. F. (648.9.degree. C.).
Prior art lubricants generally embody molecular structures that are resistant to thermal degradation and oxidation. These structures often incorporate highly branched or hindered carbon atom chains.
Synthetic ester oils had been recognized as useful for high temperature lubricant applications. Moreover, certain classes of esters had been considered superior in thermal properties. For example, Stauffer Chemical Company trade literature for SDL-1.TM. Lubricant refers to " . . . an industry-wide consensus that polyol esters provide the best balance of high temperature stability . . . ".
The "high temperature stability" mentioned in the prior art did not contemplate extraordinary operating temperatures of 900.degree. F. (482.2.degree. C.) or more. These very high engine operating temperatures redefine high temperature operating requirements and necessitate entirely new lubricant formulations.
Conventional practice has been to enhance the performance of lubricants with additives such as rust inhibitors, metal deactivators, and etc. Unfortunately, these additives often solve one problem at the expense of creating another. It is desirable to develop lubricant rectification systems and methods of operating engines that do not require extensive use of additives with deleterious side effects.

High temperature synthetic lubricants and related engine lubricating systems


A microwave circuit utilizes a spiral-like coupler configuration to achieve the functionality of a traditional coupler with higher density and lower volume. A plurality of substrate layers having metal layers disposed on them are bonded to form the package. A plurality of groundplanes may be used to isolate the spiral-like shape from lines extending out to contact pads or other circuitry.

Over the decades, wireless communication systems have become more and more technologically advanced, with performance increasing in terms of smaller size, operation at higher frequencies and the accompanying increase in bandwidth, lower power consumption for a given power output, and robustness, among other factors. The trend toward better communication systems puts ever-greater demands on the manufacturers of these systems.
Today, the demands of satellite, military, and other cutting-edge digital communication systems are being met with microwave technology, which typically operates at frequencies from approximately 500 MHz to approximately 60 GHz or higher. Many of these systems use couplers, such as directional couplers, in their microwave circuitry.
Traditional couplers, especially those that operate at lower frequencies, typically require a relatively long parts housing size (i.e., a long packaging size) since coupling between lines is often required over a long distance.
Popular technologies for microwave technologies include low temperature co-fired ceramic (LTCC), ceramic/polyamide (CP), epoxy fiberglass (FR4), fluoropolymer composites (PTFE), and mixed dielectric (MDk, a combination of FR4 and PTFE). Each technology has its strengths, but no current technology addresses all of the challenges of designing and manufacturing microwave circuits.
For example, multilayer printed circuit boards using FR4, PTFE, or MDk technologies are often used to route signals to components that are mounted on the surface by way of soldered connections of conductive polymers. For these circuits, resistors can be screen-printed or etched, and may be buried. These technologies can form multifunction modules (MCM) which carry monolithic microwave integrated circuits (MMICs) and can be mounted on a motherboard.
Although FR4 has low costs associated with it and is easy to machine, it is typically not suited for microwave frequencies, due to a high loss tangent and a high correlation between the material's dielectric constant and temperature. There is also a tendency to have coefficient of thermal expansion (CTE) differentials that cause mismatches in an assembly. Even though recent developments in FR4 boards have improved electrical properties, the thermoset films used to bond the layers may limit the types of via hole connections between layers.
Another popular technology is CP, which involves the application of very thin layers of polyamide dielectric and gold metalization onto a ceramic bottom layer containing MMICs. This technology may produce circuitry an order of magnitude smaller than FR4, PTFE, or MDk, and usually works quite well at high microwave frequencies. Semiconductors may be covered with a layer of polyamide. However, design cycles are usually relatively long and costly. Also, CTE differentials often cause mismatches with some mating assemblies.
Finally, LTCC technology, which forms multilayer structures by combining layers of ceramic and gold metalization, also works well at high microwave frequencies. However, as with CP technology, design cycles are usually relatively long and costly, and CTE differentials often cause mismatches with some mating assemblies.
Advances have been made in reducing the size of LTCC couplers and FR4 couplers, by using strip-line spiral-like configurations. Examples of spiral-like configurations for couplers using various technologies may be found in U.S. Pat. No. 3,999,150 to Caragliano et al., U.S. Pat. No. 5,689,217 to Gu et al., and U.S. Pat. No. 5,841,328 to Hayashi, all incorporated herein by reference. However, using spiral-like configurations for couplers based on these technologies have certain limitations, as described below.
Hard ceramic materials may provide dielectric constants higher than approximately 10.2, but components utilizing these materials cannot be miniaturized in a stand-alone multilayer realization. For example, bond wire interconnects must be used for the realization of microstrip circuitry, increasing the overall size of the resulting microwave devices. Other ceramic materials have limited dielectric constants, typically approximately 2 to 4, which prevent close placement of metalized structures and tend to be unreliable for small, tight-fitting components operating at microwave frequencies. Additionally, ceramic devices operating at microwave frequencies may be sensitive to manufacturing limitations and affect yields. LTCC Green Tape materials tend to shrink during processing, causing mismatches preventing manufacturers from making smaller coupling lines and placing coupling lines too closely lest they lose their spacing due to shifting during processing. For these reasons, spiral-like configurations of couplers cannot be too compact and the benefits of using spirals are limited.
FR4 materials have other disadvantages. For example, FR4 materials have a limited range of dielectric constants, typically approximately 4.3 to 5.0, preventing manufacturers from placing metalized lines too compactly. Manufacturers utilizing this material also cannot avail themselves of the advantage of fusion bonding. Additionally, FR4 materials are limited in the tolerance of copper cladding that they can sustain—typically 1.4 mils is the minimum thickness, so the dimensional tolerances are limited. As with ceramics, spiral-like configurations of couplers cannot be too compact, and the benefits of using spirals are limited for FR4. MDk materials also have similar disadvantages to FR4.
PTFE composite is a better technology than FR4, ceramics, and MDk for spiral-like couplers. Fluoropolymer composites having glass and ceramic often have exceptional thermal stability. They also allow copper cladding thickness below approximately 1.4 mils, which permits tighter control of etching tolerances. Additionally, these materials have a broad range of dielectric constants—typically approximately 2.2 to 10.2. Also, they can handle more power than most other material. All these features allow spiral-like couplers to be built much more compactly on PTFE than is possible using other types of material. Furthermore, complex microwave circuits can be fabricated using PTFE technology and the application of fusion bonding allows homogeneous multilayer assemblies to be formed.

Spiral couplers manufactured by etching and fusion bonding


To provide a semiconductor memory device capable of writing a checkerboard pattern for interference and investigation by three writings regardless of the magnitude of memory capacity by making a change of a simple circuit configuration free from the need of a data holding circuit and a voltage converting circuit large in circuit area in a memory array in which the order of arrangement of bits is reversedly arranged between data words adjacent in a row direction. A row decoder and a column decoder are respectively configured to enable operation switching to an all selection mode and an even/odd-based selection mode in addition to a single address selection mode of a memory array by a control signal from a control circuit.

Field of the Invention
The present invention relates to a semiconductor memory device, and more specifically to a matrix selection mechanism of a memory array.
Background Art
FIG. 4 is a circuit diagram illustrating a memory array of a related art EEPROM. One address is comprised of a memory word composed of a plurality of bits. A memory cell is comprised of a floating gate 401 for holding data and a control gate 402 for selecting a bit, and holds information of one bit therein. Since the reading of data from a memory normally starts from the MSB, i.e., the most significant bit side of data, MSB data is stored in a memory cell close to a word selector from the MSB side needed to be read earliest. The LSB of a data word, i.e., the least significant bit of data is stored in the farthest memory cell. In the process of manufacturing a memory array using an EEPROM, a checkerboard pattern in which data bits to be stored of memory cells adjacent to each other are brought into an inverted state, is required to be written in order to examine that data interference does not occur between adjacent memory cells.
As a method of writing a checkerboard pattern, there are a method of executing writing for each word, and a method of providing an even/odd-based selection function in each of row decoders of a memory array as proposed in a related art and writing bit-inverted data therein respectively.
[Patent Document 1]
Japanese Patent Publication No. Hei 4 (1992)-66080
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-236795

Semiconductor memory device and data writing method using a checkerboard pattern utilizing existing data supply bit addresses


Aramid and polybenzimidazole fibers and films of improved flame resistance are obtained by impregnation with tungsten hexachloride.

Aramid fibers such as, for example, poly(m-phenylene isophthalamide) (MPD-I) fibers and poly(p-phenylene terephthalamide) (PPD-T) fibers are well-recognized as thermally resistant fibers. Polybenzimidazole (PBI) fiber is another fiber which has been employed in flame resistant applications. These fibers are employed in coats of firefighters, in industrial garments for workers who may be exposed to flame and high temperatures and in many other applications. Thermal stability of the aramid and PBI fibers is attributed to their stiff chain multi-ring structure and to the strong hydrogen bonding between the chains. Further improvement in flame resistance is difficult to attain within the organic fiber framework.

Fiber and film of improved flame resistance containing mixed oxides of tungsten


Various embodiments provide a telescoping strut with a fixed rail feature. The telescoping strut includes an outer tube having slits and holes, an inner tube having rail slots and an insert guide, a threaded insert, and bolts. The threaded insert is positioned in the insert guide of the inner tube, which is inserted in the outer tube. The threaded insert, positioned in the insert guide, is aligned with the holes of the outer tube and the rail slots of the inner tube. The bolts are inserted in to the holes and the rail slots, and are threadably attached to the threaded insert. The insert guide and the rail slots allow the threaded insert and the bolts to slide freely with respect to the inner tube. As a result, the inner tube slides freely within the outer tube until the threaded insert and the bolts are tightened. When a desired length of the telescoping strut is obtained, the bolts and the threaded insert are tightened causing the slits of the outer tube to deform around the inner tube.

Technical Field
The present disclosure is directed to a telescoping strut for supporting and positioning an object, such as a satellite antenna.
Description of the Related Art
Satellite antennas are typically mounted to surfaces, such as a roof or a wall of a house, using a mast and two struts. The length of each strut is adjustable to adapt the position of the satellite antenna to the surrounding environment to ensure that signals are properly received. Most struts include an outer tube and an inner tube that is inserted in the outer tube. The outer and inner tubes are secured to each other with a collar clamp. For example, FIG. 1A is a simplified angled view and FIG. 1B a simplified exploded angled view of a strut 10 as is known in the art. The strut 10 includes an outer tube 12 and an inner tube 14 that is inserted in the outer tube 12. The outer tube 12 and the inner tube 14 are coupled together with a collar clamp 16, a bolt 18, and a nut 20. Namely, the collar clamp 16 is clenched around the outer tube 12 by tightening the bolt 18 and the nut 20. This, in turn, causes the outer tube 12 to deform around the inner tube 14. As a result, the inner tube 14 is held in position by the surface contact between the outer tube 12 and the inner tube 14.
Collar clamps, however, do not provide uniform surface contact between the outer and inner tube. Namely, the collar clamp anchors the outer tube to the inner tube primarily on the side where the bolt and nut are located. For example, the surface contact between the outer tube 12 and the inner tube 14 is predominantly located on the side where the bolt 18 and the nut 20 are tightened. As such, collar clamps create limited surface contact between an outer and inner tube. Consequently, natural forces, such as wind or rain, may cause the inner tube to unintentionally slide within the outer tube and in turn cause the satellite antenna to move out of position, thus, degrading reception. Therefore, it is desirable to mount a satellite antenna to a surface using adjustable struts that are held securely in position to ensure pointing accuracy of a satellite antenna and minimize poor reception of signals. In addition, the inner tube 14 may slide completely out of the outer tube 12 and be dropped on the job site, requiring retrieval when the installation is on the roof, or worse, may be lost in transit or at the job site, rendering the entire strut useless.

Telescoping strut with fixed rail feature


An image forming apparatus includes an image carrying member, a charging device that uniformly charges the image carrying member, an exposure device that forms an electrostatic latent image on the image carrying member, a development device that applies a development bias voltage to form a visible image in which toner is adhered to the electrostatic latent image, a control portion that controls an exposure amount in the exposure device and the development bias voltage and a storage portion that stores an exposure condition and a development condition. The resolution of image data can be switched to at least two types, a standard resolution and a high resolution higher than the standard resolution, and when the resolution of the image data is set at the high resolution, the control portion controls the exposure amount in the exposure device to perform thinning processing on the image.

1. Field of the Invention
The present invention relates to an image forming apparatus that uses an electrophotographic process such as in a copying machine, a printer or a facsimile, and more particularly relates to an image forming apparatus that can produce an output with a plurality of resolutions.
2. Description of the Related Art
For output devices using an electrophotographic process, it is increasingly required to enhance the image quality and the speed, and simultaneously, it is also required that a user can arbitrarily select the resolution according to the purpose, and for these applications, an image forming apparatus having a plurality of resolutions is used.
An electrophotographic process is performed as follows: light corresponding to image information such as an original document or electronic data is applied to the surface of an image carrying member charged by a charging device to form an electrostatic latent image, toner is adhered to the electrostatic latent image to form a visible toner image and the toner image is transferred to a sheet such as paper or photographic paper and is fixed to the sheet to obtain a predetermined image. Here, as a method of switching resolutions, there are known a method of switching the speed of a light change unit that writes the electrostatic latent image and a method of switching the speed of the image carrying member that receives light.
In the method of switching the speed of the light change unit such as a polygon minor, even when the resolution is switched, the speed of the image formation does not change, and even when a low resolution is selected, the print speed is the same as when a high resolution is selected. On the other hand, in the method of switching the speed of the image carrying member, when a low resolution is selected, it is possible to increase the print speed as compared with the case where a high resolution is selected, with the result that it is possible to meet a high-speed print application.
However, in terms of image quality, in the method of switching the speed of the image carrying member, since when a high resolution is selected, the speed of the image carrying member is lowered as compared with the case where a low resolution is selected, the time for development is increased. Consequently, there is a tendency that the density of an image is increased to increase its line width. Hence, when the resolution is switched, even for the same image, different images are disadvantageously output.
For this problem, a method of performing digital processing on image data to decrease the line width is known. A method of optimizing the conditions of image formation in the electrophotographic process to cope with the problem is also known. The amount of toner adhered is related to the characteristics of the image carrying member, the intensity of light in an exposure device, a potential difference between the bias voltage of a development device and the surface of the image carrying member and the like. Hence, for the problem described above, Japanese Unexamined Patent Application Publication No. 2001-265071 discloses that the image formation conditions are examined and that design conditions at the time of switching are indicated. Specifically, according to the sensitivity constant of the image carrying member, a relationship between the desired output of the exposure device and the bias voltage of the development device is indicated.
As a method of controlling the density and the line width of an image, there is a method of using a density sensor and a potential sensor, and a method of using the detection values thereof to control the exposure device and the development device is known. For example, Japanese Unexamined Patent Application Publication No. 2010-50639 discloses that a line drawing is formed, the width and the density thereof are measured and a development bias is adjusted and that a patch image is formed, the density thereof is measured and the exposure amount is controlled. Furthermore, Japanese Unexamined Patent Application Publication No. 2006-276164 proposes an another method because a sensor detects part of an image but it is difficult to detect the entire image formation region. In other words, data on the surface potential of the image carrying member, data on the image and data on the exposure level are used to simulate the profile of the electrostatic latent image, and the quality of the image produced according to the simulated electrostatic latent image is evaluated, with the result that the exposure device and the development device are controlled. Specifically, while the surface potential of the image carrying member by the charging device and the exposure amount by the exposure device, the bias voltage of the development device and the like are being changed, the simulation is repeated, and conditions under which the desired image quality can be obtained are found, with the result that the image formation is performed under such conditions.
In the electrophotographic process, edge processing is normally performed in order to enhance character reproducibility, specifically, the line width of characters. When toner is adhered to the electrostatic latent image on the surface of the image carrying member, the amount of toner adhered by the potential difference (which may hereinafter be referred to as a development gap) between the surface potential and the bias voltage of the development device. Here, in an edge portion of the image, an electrical field enters from its periphery, thus the toner is more likely to be adhered and the toner is adhered to the outside of the periphery of the range of the electrostatic latent image in the edge portion. Consequently, the line width of the character in the toner image is increased as compared with the character width of the electrostatic latent image.
For example, when an output is produced at a resolution of 1200 dpi, the character area of an output image is about 1.3 times as large as that of an image that undergoes the edge processing and that has a resolution of 600 dpi. This is a level at which it can be identified visually, and thus the output result disadvantageously differs depending on the resolution. Hence, the edge processing for thinning the edge portion is performed. For example, for an image where a white character is drawn within a black solid, the edge processing is performed to prevent the white character from collapsing.
The edge processing described above is intended to thin the edge portion of a character/line image, and is performed only for a character/line image. As images, there are a character/line image that is determined by two values and a figure/photo image that is formed with multiple values having a plurality of intermediate values. Since when the edge processing is performed on the figure/photo image, intermediate gradation densities are affected to degrade the image quality, the edge processing is not performed on the figure/photo image. Hence, in order to determine to which one of the images the input image data belongs, the image forming apparatus incorporates a region determination function.
The region determination function incorporates a plurality of line memories for properly determining the region. As the number of line memories is increased, the region to be determined is expanded, with the result that it is possible to enhance the determination accuracy and the determination processing speed. On the other hand, as the resolution of an image to be processed is increased, the amount of information per unit area of the image is increased. For example, an image of 1200 dpi has four times as much information as an image of 600 dpi based on simple calculation. Hence, when a high resolution is used, the amount of data to be processed is increased, and thus it takes more time to perform region determination processing than a case where a low resolution is used. In order to solve this problem, it is necessary to incorporate a larger number of line memories.
However, in terms of cost constraints, it may be difficult to incorporate the necessary number of line memories. In such a case, instead of the edge processing, a method of thinning processing is required. In the technologies proposed in Japanese Unexamined Patent Application Publication No. 2001-265071 and Japanese Unexamined Patent Application Publication No. 2010-50639 described above, there are problems to be solved in the thinning processing in terms of general versatility and accuracy to which setting conditions can be applied. The technology proposed in Japanese Unexamined Patent Application Publication No. 2006-276164 is not sufficient in terms of cost and standby time.
An object of the present invention is to provide an image forming apparatus that can achieve, without increasing the number of line memories, character reproducibility at a high resolution in the same manner as character reproducibility at a low resolution.