Abstract: In a digital image forming apparatus, when a latent image is formed on a photoconductor by modulating optical intensity of laser beam, the laser beam is emitted in a period of a duty ratio while modulated according to image data, and the image is formed on a sheet of paper. This process is repeated for four colors for a color document. The duty ratio, defined as a ratio of a light-emitting time of a light exposing the photoconductor to a period for exposing a dot, is changed in the same document. For example, the light emission timing pattern is changed between odd and even lines. In another example, the light-emission timings may be changed at least for one of the reproduction colors. The light-emission timing patterns may be provided for each of reproduction colors. The light-emission timing patterns may be changed to have a constant or different screening angle between colors. Image quality of a half-tone image is improved by using such patterns.

Abstract: A voltage regulator is disclosed which is connected to an external resistor. The voltage regulator provides a regulated voltage and includes first and second transistors. The first transistor has a power terminal connected to a power supply and the second transistor has an output terminal to output the regulated voltage. The second transistor is connected to the first transistor through a common terminal. The external resistive circuit is connected between the common terminal and the output terminal. An output current of the voltage regulator on the output terminal is equal to a sum of a first current passing through the resistive circuit and a second current passing through the second transistor. A control circuit is also provided which is connected to the input of the second transistor to turn on the second transistor for providing the second current when the first current exceeds a predetermined value.

Abstract: A starting system for a prime mover coupled to a generator includes a step-up inverter which converts DC power at a first voltage into AC power at a second, higher voltage. Halfwave pulses in the AC power are selectively applied to the generator by a pulse-population inverter coupled to the step-up inverter such that the generator is operated as a motor to supply motive starting power to the prime mover.

Abstract: A semiconductor memory device includes a plurality of external power supply pads P1 to P3. Connection between external power supply pads P1 to P3 and an external power supply is determined in accordance with the voltage of the external power supply to be used, and the connection is switched by bonding. External power supply of a high voltage level is connected to an external power supply pad P2 which is connected to VDC1 and VDC2. A circuit including memory cells operates using the voltage applied from VDC1 or external power supply pad P3, while a group of word line drivers operates using the voltage applied from VDC2 or external power supply pad P1. VDC1 down converts the external power supply voltage, and VDC2 down converts it in accordance with the level of the voltage of the external power supply voltage, and generates internal power supply voltages, respectively. Accordingly, a semiconductor memory device which operates adapted to different external power supplies can be obtained.

Abstract: A high voltage pulse generating circuit for powering klystrons, and the like. The circuit includes a source of D.C. power having positive and negative terminals, a flyback transformer having a primary winding and a secondary winding, the primary winding having first and second terminals for connection to the source of D.C. power, a sensor for generating a signal indicating the amplitude of the current in the primary winding, and a solid state switching circuit for coupling the source of D.C. power to the primary winding of the flyback transformer. The primary winding is coupled to the power source in response to a control signal, and decoupled from the power source when a predetermined level of current is detected in the primary winding.

Abstract: An image forming apparatus comprises a photoreceptor drum, a supporting member provided inside the photoreceptor drum and supporting plural exposure devices; and a signal passage to transmit an image signal to the plural exposure devices. The signal passage connects the outside and the inside of the photoreceptor drum by passing a part of the supporting member.

Abstract: An electronic circuit includes a dynamic regulator connected to a load and a dc-to-dc converter to reduce a need for bulky and expensive capacitors which would otherwise be required to suppress transients. The dynamic regulator comprises one or both of a current source circuit for actively sourcing current to the load during load current demand transients, and a current sink circuit for actively sinking current from the load during load current excess transients. The dynamic regulator preferably senses the load voltage, and tracks the load voltage. The current source circuit preferably includes a current source switch, and a current source controller for operating the current source switch responsive to the load voltage falling rapidly with respect to the tracked load voltage. In a similar fashion, the current sinking circuit may include a current sink switch, and a current sink controller for operating the current source switch responsive to the load voltage rising quickly above the tracked load voltage.

Abstract: A data processing apparatus is provided which includes at casing having upper and lower cavities arranged in a vertically spaced relationship. A drawer is arranged in the upper cavity and has a hopper for accommodating sheets. The lower cavity functions as a stacker. Sheets are conveyed from the hopper to the lower cavity along a sheet conveying path. An upper image reading or printing head is arranged in the drawer to act on the upper surface of the sheet. A lower image reading or printing head is arranged in the drawer or at a position along the sheet conveying path to act on the lower surface of the sheet. Therefore, it is possible to read information on both surfaces of the sheet or to print data onto both surfaces of the sheet.

Abstract: When reading image data stored on a detachable storage medium such as a magneto-optical disk and outputting the data using an image outputting device, data regarding modes in which the image data is to be output is stored in advance on a storage medium by an apparatus such as a personal computer, for example, which is different from the image outputting device. By loading the storage medium in the image outputting apparatus, the image data is read out and output in accordance with the stored output mode data, whereby it is possible to prevent the image outputting apparatus from being monopolized for a long period of time and to output data easily in a desired output mode.

Abstract: A boost converter for a power factor correction circuit having application in a DC power supply for telecommunication equipment. The boost converter has a pair of independently controlled switches such as MOSFET in series with an inductor. A capacitor is in parallel with each switch and the lossless resonant discharge of the capacitors by energy stored in the inductor eliminates switch losses at turn on. As a result the converter may be operated at higher frequencies, thereby reducing the size and cost of magnetic components in the power supply.

Abstract: A power supply inrush current control circuit includes a current-limiting resistor connected in series with a first relay, a second relay connected in parallel with the current-limiting resistor and first relay, a power factor correction stage connected in series with the parallel combination of first relay and current-limiting resistor, and second relay, a holdup capacitor connected to an output of the power factor correction stage and a DC/DC converter connected to the output of the power factor correction stage. A first timer is connected to the second relay, a second timer is serially connected to the first timer and to the power factor correction stage, and a third timer is serially connected to the second timer and to the DC/DC converter.

Abstract: A technique for making multiple copies that includes the steps of scanning a scan region that contains the image to be copied to produce an array of scan region pixel data that contains pixel data for the entire scan region; printing an image based on the array of scan region pixel data; processing the scan region pixel data to determine a subregion of the scan region that contains printable, non-background information; scanning the subregion of the scan region and providing to a print buffer print data only for the subregion of the scan region that contains printable, non-background information; and printing an image based on the subregion print data.

Abstract: A first current (Iptat) having a magnitude proportional to absolute temperature is passed through a resistor (R3) and a PN-junction (QA) to produce first and second voltages (Vr+Vbe) having, respectively, positive and negative temperature coefficients which when summed provide a temperature stabilized internal reference voltage (Vbgrl). This internal reference voltage (Vbgrl) powers the current generator for currents (I1, 12)) which pass through a second resistor (R8, R9) and a second PN junction (Q20A, Q20B) to produce third and fourth voltages having respectively, positive and negative temperature coefficients which when summed provide a temperature stabilized external reference voltage (Vbgrl) having improved ripple rejection. There is no feedback from the external reference voltage (Vbgr2, V-out) to the first current (Iptat) generator (42).

Abstract: A generator-booster includes a bootstrap capacitor coupled between an output node and a pull-up node. A bootstrap control stage is coupled to the pull-up node and receives a pump signal with two states determining a precharge step and a pull-up step of the bootstrap capacitor. A precharge limiting transistor is supplied with a precharge reference signal and is coupled to the output node and the bootstrap capacitor to prevent a bootstrap capacitor from being charged in excess of a value determined by the precharge reference signal. A limiting stage is coupled to the output node and the bootstrap capacitor to prevent a voltage of the output node from exceeding a value determined by the limiting stage. The bootstrap control stage also provides for decoupling the pull-up node from the pump signal during the pull-up step, after the limiting stage has been turned on.

Abstract: The present invention provides an image forming apparatus including a scanner for reading image data from an original sheet, a first filter for filtering the image data, a second filter provided in parallel with the first filter, and different from the first filter, adding circuit means for adding up the outputs from these filters, and a function for forming an image on the basis of the result of addition

Abstract: A boost power converter for powering a load with an AC source is disclosed. The boost power converter comprises an AC to DC conversion circuit, a resonator, and a boost circuit. The resonator includes an energy storage device and a resonant circuit, and alternately applies energy from the energy storage device to the resonant circuit for powering the load. The AC to DC conversion circuit generates a DC signal in response to the AC source. The boost circuit includes a choke for receiving the DC signal, a rectifier for electrically coupling the choke to the energy storage device, and a switching device for selectively coupling the choke to the resonant circuit for charging and discharging the choke. The resonator operates in full resonant mode with zero voltage switching. The boost power converter is well-suited for ballast applications that drive a fluorescent lamp.

Abstract: A controller for controlling power transducers to maintain a balanced three-phase output voltage with no influence on current control even when an unbalanced load is connected to a three-phase output of an inverter of the power transducer. The controller provides a stable high-precision three-phase voltage to a load by suppressing higher harmonic voltage components even when a non-linear load is connected. The controller includes a voltage regulator circuit having, for each phase, circuitry calculating a mean value of the output voltage of the inverter. The controller detects and controls deviation in the output voltage from a single-phase mean voltage command. The controller determines a voltage deviation ratio from the deviation and multiplies each output voltage value by the voltage deviation ratio and uses the product as a new voltage detection value.

Abstract: An image processor includes an input device that inputs image data representing a target image, and a color gamut mapping device that performs a color gamut mapping process. The image processor also includes a color reproduction process device that performs a color reproduction process, and a judgement device that judges whether a monochromatic mode for forming an image on a recording medium is set. A controller controls the color gamut mapping device and the color reproduction device, with the controller inhibiting the color gamut mapping device from performing a color mapping process on the input image data when a judgment is made that the monochromatic color mode is set.

Abstract: A thermally regulated power system, where the extent to which the temperature of a power module causes a change in the output power of the module depends on the output current of the module. Similarly, the extent to which the output current of the power module causes a change in the output power of the module depends on the temperature of the module. In one embodiment, a thermally regulated down slope power sharing system without a share line includes N+1 power modules coupled in parallel to the same output port, where N is an integer greater than one. The slope of the down slope curve of a power module is changed in response to the temperature of the power module such that a power module operating at a higher temperature outputs less current for a given bus voltage than a power module operating at a lower temperature.

Abstract: According to one embodiment of a switching power supply, a superimposition circuit including a resistor is connected in parallel to the primary coil of a transformer. A superimposition current is supplied to a current sensing circuit during a switching-on period of a switching element. The current sensing circuit detects the current flowing through the primary coil during the switch-on period. According to the detected current, a switch control circuit controls switching on and off of the switching element so as to stabilize the output voltage. When the current becomes low in a case in which the circuit has a light load or receives a high input voltage, noise generally causes substantial adverse effects.