Patent application number | Description | Published |
20080239056 | Semiconductor device, print head and image forming apparatus - A semiconductor device, a print head comprising the semiconductor device and an image forming apparatus comprising the print head are supplied which are able to reduce cost through miniaturizing element size and minishing chip area. The semiconductor device comprises a plurality of light emitting elements; and a shift register circuit that has output terminals respectively corresponding to the plurality of light emitting elements and stores emitting-light instruction data of the light emitting elements, wherein each light emitting element has a first electrode and a second electrode to that lightening electricity of the light emitting element flows, and a third electrode for controlling the light emitting element whether to emit light, the output terminals of the shift register circuit are respectively connected with the third electrodes of the corresponding light emitting element. | 10-02-2008 |
20080292344 | Drive circuit, light emitting diode head, and image forming apparatus - A drive circuit includes a drive element for driving a driven element; a correction data input section for adjusting a drive current of the driven element; a resistor having an end portion connected to ground; and a control voltage generation section for generating a direction value of the drive current. The control voltage generation section includes a calculation amplifier having a first input terminal for receiving a standard voltage, a second input terminal, and an output terminal; a first conductive type transistor having a first terminal, a second terminal connected to the ground, and a control terminal connected to the output terminal; and a current-mirror circuit including a control side transistor and a follower side transistor. The control side transistor has a current output terminal connected to the first terminal. The follower side transistor has a current output terminal connected to another end portion of the resistor and the second input terminal. | 11-27-2008 |
20090051343 | Reference voltage generation circuit, drive circuit, light emitting diode head, and image forming apparatus - A reference voltage generation circuit includes a current-mirror circuit formed of a plurality of MOS (Metal Oxide Semiconductor) transistors each having a source terminal connected to a power source and a gate terminal connected to with each other; and a plurality of transistors each connected to a drain terminal of each of the MOS transistors of the current-mirror circuit for controlling the current-mirror circuit, so that an output current of the current-mirror circuit is converted to a voltage to be output as a reference voltage. Each of the MOS transistors of the current-mirror circuit has the drain terminal connected to a collector terminal of each of the transistors. Accordingly, when a voltage of the power source varies, it is possible to maintain a collector voltage of each of the transistors at a specific level and a collector current of each of the transistors constant. | 02-26-2009 |
20090066312 | Reference voltage generation circuit, drive circuit, light emitting diode head, and image forming apparatus - A reference voltage generation circuit for outputting a reference voltage from an input voltage includes a specific voltage output unit for outputting a specific voltage from the input voltage; a first circuit section for outputting the reference voltage with a positive temperature property from the specific voltage output from the specific voltage output unit; and a second circuit section for setting a level of the reference voltage output from the first circuit section. The specific voltage output unit is formed of a regulator circuit having a first terminal connected to a power source. The first circuit section is formed of a bi-polar transistor element connected to a second terminal of the regulator circuit. The second circuit section is formed of a resistor connected to the second terminal of the regulator circuit, a collector terminal of the bi-polar transistor element, and an emitter terminal of the bi-polar transistor element. | 03-12-2009 |
20090066374 | Drive circuit, light emitting diode head, and image forming apparatus - A drive circuit is provided for selectively driving a driven element. The drive circuit includes a discharge section for discharging charges, which are accumulated in the driven element when the drive element is turned on, when the drive element is turned off. The drive circuit may include a drive element for driving the driven element. The drive element includes a first ground route disposed separately from a second ground route of the driven element. The first ground route is connected to the second ground route through a connection cable. A diode may be disposed between the connection cable and at least one of the first ground route and the second ground route. | 03-12-2009 |
20090079364 | Driving device, driving circuit, LED head, and image forming apparatus - A driving apparatus is provided that has a plurality of driving circuits formed to correspond to a plurality of driven circuits arranged on a predetermined circuit board, each of the plurality of driving circuits including a driving control unit for driving the corresponding driven circuit, a reference voltage generation unit for generating a reference voltage according to a temperature of the corresponding driven circuit, a control voltage generation unit for generating, based on the reference voltage supplied from the reference voltage generation unit, a control voltage for driving the corresponding driven circuit, the control voltage generation unit supplying the generated control voltage to the driving control unit, a switch device formed between the control voltage generation unit and the reference voltage generation unit, and a switch control unit for driving the switch device based on an inputted control signal, wherein the control voltage generation unit is connected to the reference voltage generation unit of another of the plurality of driving circuits via the switch device. | 03-26-2009 |
20090096493 | Driving circuit, LED head and image forming apparatus - A driving circuit is supplied capable of preventing excessive overshoot from occurring when electric current of LED rises; preventing degradation of LED that is caused by peak electric current; and preventing the life of LED from shortening. In the driving circuit, a drive transistor supplies drive electric current to record elements to construct an array, and a reference electric current generating circuit that provides a control voltage to the drive transistor and controls the drive electric current, wherein the drive transistor is composed of a first PMOS transistor and a second PMOS transistor that are connected in series; and the reference electric current generating circuit has a resistance element and a operational amplifier that are used to set a reference electric current for deciding the control voltage, wherein an output of the operational amplifier is provided to a control terminal of the first PMOS transistor; and a drive electric current ON/OFF signal to control on/off of the drive electric current is provided to a control terminal of the second PMOS transistor. | 04-16-2009 |
20090167836 | Light emitting apparatus, optical printhead, and image forming apparatus - A light emitting apparatus includes optical thyristors, a driver circuit that supplies a drive current to the thyristors so that the thyristors emit light, and a control circuit that controls the thyristors. Each thyristor includes an anode, a cathode connected to the ground, and a gate. The thyristor emits light when the drive current flows therethrough. The control circuit controls the gate, causing a control current to flow from the anode to the gate to turn on the thyristors. The control circuit applies a control voltage to the gate, the control voltage being higher than a voltage appearing across the gate and the cathode when the thyristor remains turned on. | 07-02-2009 |
20090237483 | Drive circuit, light print head, and image forming apparatus - A drive circuit is provided for supplying a drive current to drive a plurality of driven elements each having two main electrodes. The drive circuit includes a switch circuit for receiving a drive signal; and a constant voltage circuit connected to the switch circuit for adjusting the drive current at a constant level. | 09-24-2009 |
20090243512 | Drive circuit, light emitting diode head, and image forming apparatus - A drive circuit includes a drive element for supplying a drive current to a driven element; a control voltage generation circuit for outputting a control voltage to the drive element to generate the drive current through inputting a reference voltage; and a switch section for shutting down the reference voltage when the driven element is not driven so that the control voltage decreases to a level not to generate the drive current. | 10-01-2009 |
20090295901 | LIGHT-EMITTING ELEMENT ARRAY, DRIVE CONTROLLING DEVICE, RECORDING HEAD, AND IMAGE FORMING DEVICE - A light-emitting element array comprises: a resistor connected at a first end to a driving unit; and a plurality of light-emitting elements, each of the plurality of light-emitting elements comprising a three-terminal switching element having a first terminal, a second terminal, and a third terminal, the first terminal in each of the plurality of light-emitting elements being connected to a second end of the resistor, the second terminal in each of the plurality of light-emitting elements being connected to ground, and the third terminal in each of the plurality of light-emitting elements being connected to a control circuit. | 12-03-2009 |
20100026214 | Light-emitting element array, driving device, and image forming apparatus - A light-emitting element array has a plurality of three-terminal light-emitting elements such as light-emitting thyristors with anode, cathode, and gate terminals. The anode terminal of each light-emitting element is connected to a driving circuit. The cathode terminal is grounded. The gate terminals of at least some of the three-terminal light-emitting elements are driven from a common buffer, and within this group of three-terminal light-emitting elements, the anode terminals are driven individually. This enables the array of three-terminal light-emitting elements to be driven in essentially the same way as an array of two-terminal light-emitting elements, but without the need for large power transistors between the cathode terminals and ground. | 02-04-2010 |
20100097437 | Driver circuit, optical print head, and image forming apparatus - A driver circuit in an optical print head uses driving transistors to drive a row of light-emitting elements. The gate electrodes of the driving transistors are at least partly oriented so that driving current flows in the channels below the gate electrodes in a direction different from the direction of the row the light-emitting elements. This orientation reduces the temperature dependency of the driving current, so that the optical print head can produce the same high image quality at low ambient temperatures as at room temperature. | 04-22-2010 |
20100123691 | DRIVING CIRCUIT, RECORDING HEAD, IMAGE FORMING APPARATUS, AND DISPLAY DEVICE - A driving circuit includes: pixel driving circuits, each including: a driven element formed of a three-terminal light-emitting element, a control element formed of a three-terminal element and configured to control the driven element, a driving element formed of a three-terminal element and configured to drive the driven element, and a charge holding element configured to hold a charge of the driven element; a first designating circuit configured to output a first designating signal to the control element, the first designating signal designating one of the pixel driving circuits; and a second designating circuit configured to output a second designating signal to the control element, the second designating signal designating a driving state of the driven element. | 05-20-2010 |
20100124438 | LIGHT EMITTING ELEMENT ARRAY, DRIVE CIRCUIT, OPTICAL PRINT HEAD, AND IMAGE FORMING APPARATUS - A light emitting element array includes a plurality of light emitting elements each having a first terminal, a second terminal, and a third terminal. The light emitting elements are arranged next to each other to form a group. The first terminal receives a drive signal, the second terminal is connected to ground, and the third terminal has a threshold voltage or a threshold current controllable from outside so that the light emitting elements are driven in a time division way. | 05-20-2010 |
20100182392 | DRIVE CIRCUIT, OPTICAL PRINT HEAD, AND IMAGE FORMING APPARATUS - A drive circuit for supplying a drive current to a plurality of driven elements includes a plurality of drive output terminals to be connected to the driven elements. The drive output terminals are arranged with a specific pitch in between in an arrangement direction. The drive circuit further includes a plurality of drive transistors. Each of the drive transistors is arranged in an occupied area with a specific width in the arrangement direction larger than the specific pitch. | 07-22-2010 |
20110050838 | SEMICONDUCTOR COMPOSITE DEVICE, METHOD OF MANUFACTURING THE SAME, OPTICAL PRINT HEAD AND IMAGE FORMING APPARATUS - A method of manufacturing a semiconductor composite device, including steps of: preparing a substrate comprising circuit elements, which are part of a driving circuit; attaching an array of driven elements onto the substrate via a passivation layer, the array being formed of a semiconductor thin film having a crystal structure wherein the driven elements are arrayed to be driven by the driving circuit; and forming a metal wire by a photo-lithography method such that the circuit elements are electrically connected with the metal wire to form the driving circuit and the driving circuit is electrically connected to the driven elements with the metal wire. | 03-03-2011 |
20110234001 | DRIVE CIRCUIT, LIGHT PRINT HEAD, AND IMAGE FORMING APPARATUS - A drive circuit is provided for supplying a drive current to drive a plurality of driven elements each having two main electrodes. The drive circuit includes a switch circuit for receiving a drive signal; and a constant current circuit connected to the switch circuit for adjusting the drive current at a constant level. The constant current circuit is formed of a depletion type MOS transistor. | 09-29-2011 |
20110234734 | DRIVING DEVICE, OPTICAL PRINT HEAD AND IMAGE FORMING DEVICE - When the cathode of a light emitting thyristor is at the low (L) level, voltage is applied between the anode and cathode of the light emitting thyristor. In addition, because the gate of each thyristor and the gate of each light emitting thyristor are connected to each other in a self scanning circuit | 09-29-2011 |
20110234741 | DRIVING CIRCUIT, DRIVING DEVICE AND IMAGE FORMING DEVICE - Each of a plurality of gate driving parts outputs a first potential (2 V) during a period in which the gates of a plurality of thyristors belonging to the corresponding set are driven (S | 09-29-2011 |
20110234742 | DRIVE DEVICE, PRINT HEAD AND IMAGE FORMING APPARATUS - A drive device to drive a plurality of three-terminal light emitting elements, comprising: a drive circuit including a first MOS transistor and configured to drive conducting three-terminal light emitting elements among a plurality of three-terminal light emitting elements based on a received drive signal. The first MOS transistor includes: a third terminal connected to a second power supply having a potential different from a potential of the first power supply; a fourth terminal connected to the second terminals connected in common, a second control terminal configured to control a conduction state between the third terminal and the fourth terminal based on the drive signal; and a substrate terminal set to have a potential different from the potential of the second power supply in a direction of increasing threshold voltage of the first MOS transistor. | 09-29-2011 |
20110234743 | DRIVE DEVICE, PRINT HEAD AND IMAGE FORMING APPARATUS - A drive device to drive a plurality of three-terminal light emitting elements includes a drive circuit. The drive circuit includes a first and second conductive type MOS transistor complementarily connected to each other and configured to drive three-terminal light emitting elements that are in conduction state based on a received drive signal. The first conductive type MOS transistor is formed in a substrate region and includes a channel formation region, which is a region wherein a channel is to be formed. An impurity with the same polarity as that of the substrate region is injected in the channel formation region. | 09-29-2011 |
20110261138 | REFERENCE VOLTAGE GENERATION CIRCUIT, DRIVE DEVICE, PRINT HEAD, AND IMAGE FORMING APPARATUS - A reference voltage generation circuit includes a first current-mirror circuit including a first MOS transistor connected to a first power source and a second MOS transistor of the first conductive type connected to the first power source; a second current-mirror circuit including a third MOS transistor and a fourth MOS transistor; a first resistor connected to the first node; a first bipolar transistor having a collector connected to the first resistor, an emitter connected to a second power source, and a base connected to the first node; a second bipolar transistor having a collector connected to the second node, an emitter connected to the second power source, and a base connected to the first bipolar transistor; a fifth MOS transistor connected between the first power source and an output terminal; and a third resistor connected between the output terminal and the second power source. | 10-27-2011 |
20110285805 | DRIVING DEVICE, PRINT HEAD AND IMAGE FORMING DEVICE - A driving device controls light emitting thyristors that each include a scanning circuit sequentially driving each of the plural stages of the light emitting thyristors by controlling scanning thyristors. Herein, terminals of each odd numbered stage of the scanning thyristors is commonly connected to a first clock terminal, and terminals of each even numbered stage of the scanning thyristors is commonly connected to a second clock terminal. A control terminal of a first stage scanning thyristor is connected to the second clock terminal, and another control terminal of a previous scanning thyristor is connected to the second control terminal of a subsequent scanning thyristor. | 11-24-2011 |
20120001996 | DRIVING DEVICE, PRINT HEAD AND IMAGE FORMING DEVICE - A driving device that drives a light emitting thyristor array includes: a first driving circuit operated by a second power source; a scanning circuit including plural stages of scanning thyristors and sequentially scanning the plural stages of light emitting thyristors, a second driving circuit operated by a second power source, generating first and second clock signals for driving the scanning circuit, and outputting the first and second clock signals from first and second clock terminals, respectively, a terminal of an odd numbered stage scanning thyristor is commonly connected to the first clock terminal, another terminal of an even numbered stage scanning thyristor is commonly connected to the second clock terminal, and a control terminal of a first stage scanning thyristor is connected to the second clock terminal via a first resistor. | 01-05-2012 |
20120163868 | DRIVE DEVICE, LED ARRAY, LED HEAD, AND IMAGE FORMING APPARATUS PROVIDED THEREWITH - A drive device for outputting a drive signal for driving a plurality of light emitting elements time-divisionally, the drive device includes a plurality of input terminals receiving input of a drive control signal for the light emitting elements, and a plurality of output terminals connected to the light emitting elements, for outputting the drive signal based on the drive control signal input into the input terminals, in which the input terminals and the output terminals are arranged substantially in a line. | 06-28-2012 |
20120249716 | DRIVER DEVICE, PRINT HEAD, AND IMAGE FORMATION APPARATUS - A driver device scans and drives light emission elements arranged in a branch connection to a common terminal using scan-circuit and data drive portions and clock driver and waveform shaper circuits. The scan circuit portion has scan circuits connected cascadely to one another with output terminals connected to the light emission elements. The driver device outputs first and second clock signals to odd- and even-numbered scan circuits respectively. The light emission elements are sequentially driven from a first to a last scan circuit when the second-clock signal is applied to the first scan circuit. The data-drive portion drives the common terminal. The clock-driver circuit outputs first and second clock pulses with different phases, and a third-clock pulse synchronized with the first and second clock pulses. The waveform-shaper circuit re-shapes the waveforms of the clock signals. | 10-04-2012 |
20130315613 | DRIVE CIRCUIT, LIGHT PRINT HEAD, AND IMAGE FORMING APPARATUS - A drive circuit is provided for supplying a drive current to drive a plurality of driven elements. The drive circuit includes a switch circuit having an input terminal for receiving a drive signal alternately changing between an on state and an off state, and an output terminal connected to the driven elements; and a constant current circuit connected to the switch circuit for adjusting the drive current at a constant level. The constant current circuit is formed of a depletion type MOS transistor. | 11-28-2013 |