Abstract: A workpiece support provides enhanced reliability of operation and enhanced durability. The workpiece support comprises a rod, a sleeve body, a case member, a scraper, an external peripheral hydraulic chamber, and oil passages, and is further provided with an air passage formed between the rod and the internal peripheral surface of the sleeve body, and connected to the small gap between the rod and the scraper, and an air input port for supplying compressed air to the air passage; wherein compressed air is supplied from the air input port to the air passage and expelled from the small gap between the rod and the scraper when the rod is retracted.

Abstract: An image forming apparatus generates a PWM signal corresponding to input image data and controls a timing of a light source to emit a light beam based on the PWM signal in order to perform tone reproduction. The image forming apparatus includes a data processing unit configured to generate the PWM signal for one pixel based on image data for continuous two pixels in the image data. The data processing unit selects an origin of pulse growth in generation of the PWM signal for one pixel in accordance with the image data for the two pixels to generate the PWM signal.

Abstract: A clamping device 2 is provided with a hydraulic cylinder 7 for biasing a collet member 5 upward via a collet supporting member 6 and driving a pull rod 4 downward. A piston member 30 has a greater pressure receiving area than the collet supporting member 6 in the circular hydraulic chamber 31 of the hydraulic cylinder 7. Therefore, the hydraulic cylinder 7 can drive the pull rod 4 downward while the collet member 5 is biased upward. Meanwhile, the collet 5a of the collet member 5 is resiliently deformed in a diametrically expanding manner to engage in the vertical bore 1b of a workpiece 1 while slightly moving downward, ensuring a secure locking of the workpiece 1 to a workpiece receiving surface 3a.

Abstract: A test pattern P3 longer than a length Ld corresponding to a circumferential length of a developing roller is formed along a moving direction of a photosensitive member (or developing roller). The developing roller transports a great quantity of toner on its surface in a first revolution thereof and hence, the test pattern has a high density. When the residual toner runs low, the toner transport quantity is decreased in the subsequent revolution, so that the test pattern P3 is decreased in the density at its portion beyond the length Ld from its head. If a density difference is observed at place corresponding to a boundary between image portions formed in the first revolution and the second revolution, it is concluded that image quality is degraded due to the shortage of residual toner.

Abstract: The present invention presents a work pallet positioning and fixing device capable of positioning in both horizontal and vertical directions through elastic deformation of an annular engaging portion, wherein the engaging portion can elastically deform along the entire periphery and even locally in a circumferential direction thereof.

Abstract: An image forming apparatus which is capable of eliminating density irregularities of an image formed caused by potential irregularities of the photosensitive member when the drum is irradiated by a beam of constant luminous intensity. A laser driver irradiates a beam modulated based on an image signal onto a photosensitive member. A current controller variably controls a driving current for driving the laser driver. A PWM pulse width converter modulates a pulse width of the beam based on the image signal. A potential sensor measures the potential of the photosensitive member after the photosensitive member is irradiated by a beam having a predetermined luminous intensity. A selector causes the current controller to correct the driving current based on low frequency components of irregularities of the potential and changes a modulation coefficient used for modulating the pulse width based on high frequency components of the irregularities of the potential.

Abstract: An image formation device changes the rotational rate of a polygon motor, i.e. the main-scanning rate, and selects one of pulse width conversion tables when an image formation is performed multiple times on a single sheet of transfer paper. The changing of the main-scanning rate is for preventing inconsistent sizes between a first recorded image and a second recorded image caused by shrinkage of transfer paper. The pulse width conversion tables allow the pulse widths to be modulated.

Abstract: A clamping device 2 is provided with a hydraulic cylinder 7 for biasing a collet member 5 upward via a collet supporting member 6 and driving a pull rod 4 downward. A piston member 30 has a greater pressure receiving area than the collet supporting member 6 in the circular hydraulic chamber 31 of the hydraulic cylinder 7. Therefore, the hydraulic cylinder 7 can drive the pull rod 4 downward while the collet member 5 is biased upward. Meanwhile, the collet 5a of the collet member 5 is resiliently deformed in a diametrically expanding manner to engage in the vertical bore 1b of a workpiece 1 while slightly moving downward, ensuring a secure locking of the workpiece 1 to a workpiece receiving surface 3a.

Abstract: The abutment of the rod to the work piece is accomplished in a stable manner by providing an air passage in the inside of the work support for supplying pressurized air for detecting the abutment between the rod and the work piece. Work support is equipped with case, rod, sleeve that elastically deforms to reduce its diameter, hydraulic cylinder for driving rod in an advancing direction, spring for elastically energizing rod in advancing direction, detection nozzle for ejecting pressurized air, air passage connected to detection nozzle, sensor for detecting abutment between the tip of rod and work piece based on air pressure, and a control unit. Work piece is supported by the tip of rod abutting work piece while ejecting pressurized air from detection nozzle, and locks rod by elastically deforming sleeve to reduce its diameter after detecting the abutment of rod by a pressure sensor and control unit.

Abstract: A workpiece support provides enhanced reliability of operation and enhanced durability. The workpiece support comprises a rod, a sleeve body, a case member, a scraper, an external peripheral hydraulic chamber, and oil passages, and is further provided with an air passage formed between the rod and the internal peripheral surface of the sleeve body, and connected to the small gap between the rod and the scraper, and an air input port for supplying compressed air to the air passage; wherein compressed air is supplied from the air input port to the air passage and expelled from the small gap between the rod and the scraper when the rod is retracted.

Abstract: The abutment of the rod to the work piece is accomplished in a stable manner by providing an air passage in the inside of the work support for supplying pressurized air for detecting the abutment between the rod and the work piece. Work support is equipped with case, rod, sleeve that elastically deforms to reduce its diameter, hydraulic cylinder for driving rod in an advancing direction, spring for elastically energizing rod in advancing direction, detection nozzle for ejecting pressurized air, air passage connected to detection nozzle, sensor for detecting abutment between the tip of rod and work piece based on air pressure, and a control unit. Work piece is supported by the tip of rod abutting work piece while ejecting pressurized air from detection nozzle, and locks rod by elastically deforming sleeve to reduce its diameter after detecting the abutment of rod by a pressure sensor and control unit.

Abstract: The present invention presents a work pallet positioning and fixing device capable of positioning in both horizontal and vertical directions through elastic deformation of an annular engaging portion, wherein the engaging portion can elastically deform along the entire periphery and even locally in a circumferential direction thereof.

Abstract: A hydraulic cylinder (4) moves a rod (3) in the direction of the axial center. The interior of a casing member (2) has an annular pressure booster (7) for pressurizing the oil in an external hydraulic chamber (6). The casing member (2) has a pressurized oil feed port (27) for feeding pressurized oil to the rod-moving hydraulic cylinder (4) and the input oil chamber (16) of the pressure booster (7). A throttle valve (8) is interposed in an oil supply channel extending from the pressurized oil feed port (27) to the input oil chamber (16). An oil discharge channel, extending from the input oil chamber (16) to the pressurized oil feed port (27), is provided with a nonreturn valve capable of discharging pressurized oil from the input oil chamber (16). The nonreturn valve (9) is opened when the pressurized oil is discharged through the pressurized oil feed port (27).

Abstract: A hydraulic intensifier generates a hydraulic pressure which is higher than the input hydraulic pressure generated in the discharge port and the outer periphery hydraulic pressure chamber. The hydraulic intensifier, provided inside a case member, has a discharge part connected with an outer periphery hydraulic pressure chamber. An input port supplies input hydraulic pressure from the exterior to an input oil chamber of hydraulic intensifier. Oil is filled in a sealed manner in outer periphery hydraulic pressure chamber.and discharge part. The hydraulic intensifier is driven by the input hydraulic pressure. The rod is locked by the elastic deformation of a thinned tube part of a sleeve body. A relatively small hydraulic locking device having a relatively high power is achieved. Furthermore, a relatively small hydraulic pressure source having reduced pressure is realized.

Abstract: A hydraulic cylinder (4) moves a rod (3) in the direction of the axial center. The interior of a casing member (2) has an annular pressure booster (7) for pressurizing the oil in an external hydraulic chamber (6). The casing member (2) has a pressurized oil feed port (27) for feeding pressurized oil to the rod-moving hydraulic cylinder (4) and the input oil chamber (16) of the pressure booster (7). A throttle valve (8) is interposed in an oil supply channel extending from the pressurized oil feed port (27) to the input oil chamber (16). An oil discharge channel, extending from the input oil chamber (16) to the pressurized oil feed port (27), is provided with a nonreturn valve capable of discharging pressurized oil from the input oil chamber (16). The nonreturn valve (9) is opened when the pressurized oil is discharged through the pressurized oil feed port (27).

Abstract: A laser driving method is adapted for driving a plurality of laser emitting devices. A first current to be supplied to each of the plurality of laser emitting devices is always generated. A plurality of second currents controlled according to a control signal supplied from the outside are generated when necessary. The plurality of second currents are supplied to the respective laser emitting devices under supply of the respective first currents, thereby making the laser emitting devices emit respective laser beams. The plurality of laser emitting devices are caused to emit the laser beams in time division at predetermined timing to detect each of emitted light amounts by one laser monitor. Adjustment is made to at least one of the first current and the second current supplied to each of the laser emitting devices according to a plurality of detected light amounts detected.

Abstract: A laser driving method is adapted for driving a plurality of laser emitting devices. A first current to be supplied to each of the plurality of laser emitting devices is always generated. A plurality of second currents controlled according to a control signal supplied from the outside are generated when necessary. The plurality of second currents are supplied to the respective laser emitting devices under supply of the respective first currents, thereby making the laser emitting devices emit respective laser beams. The plurality of laser emitting devices are caused to emit the laser beams in time division at predetermined timing to detect each of emitted light amounts by one laser monitor. Adjustment is made to at least one of the first current and the second current supplied to each of the laser emitting devices according to a plurality of detected light amounts detected.

Abstract: An image forming apparatus, including a driving circuit for a multichip laser chip, which can limit or interrupt emission of laser light sources in accordance with a result of comparison of an optical output of each laser light source with a limiting value during time-division control is provided. The apparatus includes a plurality of laser light source, a light-amount control device for controlling an optical output of a laser beam from each of the plurality of laser light sources to a constant amount of light by performing time division processing, and a light detection device for detecting optical outputs of the plurality of laser light sources. The light detection device includes sensor units whose number is smaller than the number of the plurality of laser light sources.

Abstract: A laser driving apparatus for driving a plurality of laser beam sources includes a plurality of laser beam sources, a photodetector for detecting amounts of laser beams emitted from the plurality of laser beam sources, a plurality of current sources for driving the plurality of laser beam sources, a plurality of switches respectively interposed between the plurality of laser beam sources and the plurality of current sources, a plurality of controllers for controlling light amounts of the plurality of laser beam sources by comparing the light amounts detected by the photodetector with a reference value and controlling current amounts of the plurality of current sources in accordance with the comparison values, a plurality of sample/hold circuits respectively interposed between the photodetector and the plurality of controllers, and timing adjustment device for outputting a plurality of timing signals of a first type for controlling the plurality of switches and a plurality of timing signals of a second type fo

Abstract: In an APC control lead-in method in an image forming apparatus having a plurality of laser light sources, a laser beam emitted by at least one of the plurality of laser light sources is scanned by a deflector to detect a synchronization signal from the scanned laser beam. A first laser light source as one of the plurality of laser light sources is turned on to be led in APC control of the first laser light source. A second laser light source as the remaining one of the plurality of laser light sources is turned on in synchronism with the synchronization signal after lead-in of the APC control of the first laser light source is complete so as to be led in APC control of the second laser light source.