Abstract: A print head includes: current-driven non-single crystal light emitting elements arranged in a line; thin film transistors that are provided in one-to-one correspondence with the light emitting elements and each supplies a driving current to a corresponding one of the light emitting elements; a detector that detects, when one of the light emitting elements corresponding to one of the thin film transistors emits light, an output voltage of the one of the thin film transistors; and a hardware processor that determines a control voltage to be applied to each of the thin film transistors when next light is emitted according to the output voltage of the one of the thin film transistors detected by the detector and a driving current to be supplied by each of the thin film transistors to cause each of the light emitting elements to emit light with a target light amount.

Abstract: An optical print head including light emitting elements, drivers, setters, a detector, and a generator. The detector is for detecting a noise component superimposed on a luminance signal, on transmission circuitry for transmitting the luminance signal from a setter to a driver, in a state in which the setter is outputting the luminance signal. The generator, for each light emitting element due to emit light in a line subsequent to a line for which the detector detected the noise component, generates and causes a setter corresponding to the light emitting element to output an adjusted luminance signal such that the light emitting element emits a light emission amount according to image data in a state in which the noise component detected by the detector is superimposed on the adjusted luminance signal.

Abstract: An optical PH includes: a plurality of current-driven light emitting elements that are arranged in a line-shaped region; a controller that outputs a control voltage instructing an amount of a drive current to be supplied to each of the light emitting elements; and a plurality of drivers that correspond one-to-one with the light emitting elements, and each supply the drive current to a corresponding one of the light emitting elements, wherein the drivers each operate as one of: a high-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage higher than the control voltage; and a low-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage lower than the control voltage.

Abstract: An image forming device includes: element arrays each including light emitting elements arranged in main scanning direction, the arrays being arranged in sub scanning direction; a photoreceptor whose surface moves relative to the light emitting elements in the sub scanning direction; a controller outputting control voltage instructing light emission amount for each light emitting element; and drivers each supplying drive current to a corresponding light emitting element according to the control voltage, thus causing the light emitting element to emit light to expose the moving surface of the photoreceptor. Intervals L between the arrays satisfy (D/2)×(V/F)?((V/F)×0.1)?L?(D/2)×(V/F)+((V/F)×0.1) where F expresses frequency of AC noise to be superimposed on the control voltage, V expresses system speed of the surface of the photoreceptor moving relative to the light emitting elements, and D is an odd number.

Abstract: A light emitting device configured to cause a series circuit in which an OLED is connected to a thin film transistor to emit light by applying a predetermined voltage to the thin film transistor includes: a forward direction voltage estimating unit configured to estimate a forward direction voltage in a case where the OLED is caused to emit light at a set light quantity; a driving current amount estimating unit configured to estimate a driving current amount required for causing the OLED to emit light at the set light quantity; a source-drain voltage calculating unit configured to calculate a source-drain voltage applied to the thin film transistor from the predetermined voltage and the forward direction voltage; and a gate-source voltage determining unit configured to determine a gate-source voltage of the thin film transistor corresponding to the source-drain voltage in a case where the driving current amount is a drain current.

Abstract: An image forming device includes: element arrays each including light emitting elements arranged in main scanning direction, the arrays being arranged in sub scanning direction; a photoreceptor whose surface moves relative to the light emitting elements in the sub scanning direction; a controller outputting control voltage instructing light emission amount for each light emitting element; and drivers each supplying drive current to a corresponding light emitting element according to the control voltage, thus causing the light emitting element to emit light to expose the moving surface of the photoreceptor. Intervals L between the arrays satisfy (D/2)×(V/F)?((V/F)×0.1?L?(D/2)×(V/F)+((V/F)×0.1) where F expresses frequency of AC noise to be superimposed on the control voltage, V expresses system speed of the surface of the photoreceptor moving relative to the light emitting elements, and D is an odd number.

Abstract: An optical writing device driving a light-emitting element array, modulating light according to a screening pattern that expresses a dithered image, and performing optical writing by focusing light emitted from the light-emitting element array through a lens array onto a photoreceptor. The optical writing device includes an acquisition unit that acquires a write start position for writing to the photoreceptor in a main scanning direction and a control unit that performs a control when the write start position corresponds to an i-th light-emitting element from a reference position that corresponds to a first light-emitting element in the main scanning direction, i being a positive integer greater than 1, wherein the control unit supplies pixel values to the i-th light-emitting element onwards, the pixel values being assigned from pixels of the screening pattern from an i-th pixel onwards, from a leading pixel of the screening pattern in the main scanning direction.

Abstract: An optical PH includes: a plurality of current-driven light emitting elements that are arranged in a line-shaped region; a controller that outputs a control voltage instructing an amount of a drive current to be supplied to each of the light emitting elements; and a plurality of drivers that correspond one-to-one with the light emitting elements, and each supply the drive current to a corresponding one of the light emitting elements, wherein the drivers each operate as one of: a high-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage higher than the control voltage; and a low-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage lower than the control voltage.

Abstract: An optical print head including light emitting elements, drivers, setters, a detector, and a generator. The detector is for detecting a noise component superimposed on a luminance signal, on transmission circuitry for transmitting the luminance signal from a setter to a driver, in a state in which the setter is outputting the luminance signal. The generator, for each light emitting element due to emit light in a line subsequent to a line for which the detector detected the noise component, generates and causes a setter corresponding to the light emitting element to output an adjusted luminance signal such that the light emitting element emits a light emission amount according to image data in a state in which the noise component detected by the detector is to superimposed on the adjusted luminance signal.

Abstract: A light-emitting device including a light-emitting element and causing the light emitting element to emit different light amounts. The light-emitting device includes: a measurement unit, a predetermined value storage unit, and a driving signal calculation unit. The measurement unit measures a surrounding temperature of the light-emitting element. The predetermined value storage unit stores a predetermined value of a driving signal for causing the light-emitting element to emit light. The driving signal calculation unit executes calculation of a value of the driving signal for causing the light-emitting element to emit a desired light amount by applying a correction factor in accordance with the measured surrounding temperature and the desired light amount to the predetermined value of the driving signal.

Abstract: An optical writing device performing optical writing with a light-emitting element, performing light amount switching, and including: a unit estimating a first value corresponding to a current amount for causing the element to emit a first light amount immediately after the switching; a unit supplying to the element, from immediately after the switching, a current amount corresponding to a first digital value acquired by quantizing the first value; a unit estimating a time amount through which a current amount for keeping the element emitting the first light amount increases from the current amount for causing the element to emit the first light amount immediately after the switching to a current amount corresponding to a second digital value greater than the first digital value by one step; and a unit supplying to the element, when the time amount elapses after the switching, the current amount corresponding to the second digital value.

Abstract: An optical writing device having; a plurality of light-emitting points; a photodiode configured to output a signal which represents a quantity of incident light from a predetermined light-emitting point selected from the plurality of light-emitting points; and a calculation section for calculating a temperature of the photodiode based on a magnitude of a photodiode dark current included in the signal output from the photodiode while the predetermined light-emitting point is OFF.

Abstract: A print head includes: current-driven non-single crystal light emitting elements arranged in a line; thin film transistors that are provided in one-to-one correspondence with the light emitting elements and each supplies a driving current to a corresponding one of the light emitting elements; a detector that detects, when one of the light emitting elements corresponding to one of the thin film transistors emits light, an output voltage of the one of the thin film transistors; and a hardware processor that determines a control voltage to be applied to each of the thin film transistors when next light is emitted according to the output voltage of the one of the thin film transistors detected by the detector and a driving current to be supplied by each of the thin film transistors to cause each of the light emitting elements to emit light with a target light amount.

Abstract: An optical writing device including: a current-driven light-emitting element; a thin film transistor configured to supply the light-emitting element with a drive current based on a luminance signal to put the light-emitting element in an on state; and a controller configured to, for each line of an image page, correct a first value of the luminance signal to yield a second value of the luminance signal, and to supply the thin film transistor with the luminance signal at the second value. The second value compensates for a light amount fluctuation of the light-emitting element that is dependent upon an emission/non-emission history, from an initial line of the image page to the line, of a first continuous period where the light-emitting element is kept in the on state and a second continuous period where the light-emitting period is kept in an off state.

Abstract: An optical writing device including: a current-driven light-emitting element; a thin film transistor configured to supply the light-emitting element with a drive current based on a luminance signal to put the light-emitting element in an on state; and a controller configured to, for each line of an image page, correct a first value of the luminance signal to yield a second value of the luminance signal, and to supply the thin film transistor with the luminance signal at the second value. The second value compensates for a light amount fluctuation of the light-emitting element that is dependent upon an emission/non-emission history, from an initial line of the image page to the line, of a first continuous period where the light-emitting element is kept in the on state and a second continuous period where the light-emitting period is kept in an off state.

Abstract: An optical writing device adopting a low cost and simple structure can obtain temperatures of light emitting elements. The device comprises a plurality of light emitting elements arranged linearly in a main scanning direction. The amount of light emitting of the light emitting elements changes by self-generated heat. The light emitting elements are divided into a plurality of groups. Each of the groups includes a prescribed number of light emitting elements. The device comprises a control unit for calculating the amount of heat generation of the light emitting elements for each of groups from clock time t0 to clock time t0+?t. The control unit calculates the temperature for each of the groups at the clock time t0+?t, based on the amount of heat generation from the clock time t0 to the clock time t0+?t and the temperature at the clock time t0.

Abstract: An optical writing device performing optical writing onto a photoreceptor, including: a light-emitting unit including a plurality of light-emitting elements that form a plurality of element rows spaced from one another in a sub scanning direction, each of the light-emitting elements having a main scanning direction position differing from a main scanning direction position of any other one of the light-emitting elements; a plurality of signal output units, one for each element row, each outputting a light amount signal for each light-emitting element in a corresponding element row, each light amount signal indicating an amount of light to be emitted by a corresponding light-emitting element; and a plurality of drive units, one for each light-emitting element, each, when receiving a light amount signal for a corresponding light-emitting element, supplying a drive current in accordance with the light amount signal to the corresponding light-emitting element.

Abstract: An optical writing device driving a light-emitting element array, modulating light according to a screening pattern that expresses a dithered image, and performing optical writing by focusing light emitted from the light-emitting element array through a lens array onto a photoreceptor. The optical writing device includes an acquisition unit that acquires a write start position for writing to the photoreceptor in a main scanning direction and a control unit that performs a control when the write start position corresponds to an i-th light-emitting element from a reference position that corresponds to a first light-emitting element in the main scanning direction, i being a positive integer greater than 1, wherein the control unit supplies pixel values to the i-th light-emitting element onwards, the pixel values being assigned from pixels of the screening pattern from an i-th pixel onwards, from a leading pixel of the screening pattern in the main scanning direction.

Abstract: A light emitting device configured to cause a series circuit in which an OLED is connected to a thin film transistor to emit light by applying a predetermined voltage to the thin film transistor includes: a forward direction voltage estimating unit configured to estimate a forward direction voltage in a case where the OLED is caused to emit light at a set light quantity; a driving current amount estimating unit configured to estimate a driving current amount required for causing the OLED to emit light at the set light quantity; a source-drain voltage calculating unit configured to calculate a source-drain voltage applied to the thin film transistor from the predetermined voltage and the forward direction voltage; and a gate-source voltage determining unit configured to determine a gate-source voltage of the thin film transistor corresponding to the source-drain voltage in a case where the driving current amount is a drain current.

Abstract: An optical writing device includes a plurality of current driven light emitting elements, first and second power source lines, a designation circuit that outputs a designation potential, first driving circuits provided for each of the light emitting elements to supply driving current to the corresponding light emitting element, second driving circuits provided for each of the light emitting elements to supply driving current to the corresponding light emitting element, and a switching control unit that alternately switches respective states of the first and second driving circuits between a state where one of the first and second driving circuits receives the designation potential while the other driving circuit supplies the driving current, and a state where the other driving circuit receives the designation potential while the one driving circuit supplies the driving current.