Abstract: An optical print head including a light emitting member, an optical member, a detection unit, and a correction unit. The light emitting member is elongated in a longitudinal direction with light emitting elements arranged along the longitudinal direction. The optical member is elongated in the longitudinal direction with optical elements arranged along the longitudinal direction, the optical elements collecting light emitted by the light emitting elements. The detection unit detects an index value of linear expansion difference in the longitudinal direction of the light emitting member and the optical member. The correction unit uses the index value to correct an emitted light amount for each of the light emitting elements in order to offset differences in light collection efficiency caused by the linear expansion difference.

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.

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 including light-emitting elements forming element arrays. The element arrays are each composed of light-emitting elements arranged in line in a main scanning direction, and reside at respective positions along a sub-scanning direction. A correction unit receives signal values in one-to-one correspondence with the light-emitting elements and performs correction to acquire corrected signal values each indicating a light amount of a corresponding light-emitting element. The correction is for eliminating a light amount difference in the main scanning direction occurring for each element array. A driving unit supplies driving currents to the light-emitting elements based on the corrected signal values, and a control unit performs a control of causing at least two element arrays to emit light for different durations within one main scanning period. The control is for eliminating a light amount difference in the sub scanning direction occurring between the at least two element arrays.

Abstract: An optical print head includes: light-emitting elements in line shape; first power line supplying first reference voltage; second power line supplying drive current to each light-emitting element and supplying second reference voltage; DAC outputting first voltage indicating light emission amount of each light-emitting element; first elements for holding first voltage difference between the first reference voltage and the first voltage; second elements each electrically connectable with corresponding first element and for holding second voltage difference between the second reference voltage and second voltage according to the first voltage, and during supply of drive current, controls each first element to hold the first difference by electrically disconnecting the first and second elements, and temporarily suspends supply of the drive current, and controls the second element to hold the second difference by electrically connecting the first and second elements, such that the drive current according to the s

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 print head for forming an electrostatic latent image on a photosensitive body, including: current-driven light-emitting elements disposed in a line shape; an indicator circuit that outputs indicator current indicating light emission amounts to the light-emitting elements; and for each light-emitting element: a holding circuit that, during a main scanning period, accumulates indicator current during a sample period to generate an indicator potential and holds the indicator potential during a hold period; and a drive circuit that supplies drive current to the light-emitting element according to the indicator potential, wherein each of the sample periods is divided into writing periods, and each of the holding circuits holds the indicator potential corresponding to the holding circuit according to a total of indicator current amounts in the sample period corresponding to the holding circuit, the indicator current amounts each indicative of indicator current during one of the writing periods.

Abstract: An optical print head performs optical writing onto target, and includes: current-driven light-emitting elements arranged in rows in a predetermined direction; driving transistors that are each electrically series-connected with the light-emitting elements in one-to-one correspondence, and each supply a driving current to a corresponding light-emitting element; a current control unit that controls, for each light-emitting element, a driving current amount in accordance with variation in light-emitting properties of the light-emitting element that indicate relation between the driving current amount and a light amount emitted by the light-emitting element; an application unit that, upon receiving electrical power supplied from an external power source, applies application voltage to circuits each consisting of a light-emitting element and a corresponding driving transistor; and a voltage control unit that suppresses variation in divided voltage applied to each driving transistor by controlling the application

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 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 including light-emitting elements forming element arrays. The element arrays are each composed of light-emitting elements arranged in line in a main scanning direction, and reside at respective positions along a sub-scanning direction. A correction unit receives signal values in one-to-one correspondence with the light-emitting elements and performs correction to acquire corrected signal values each indicating a light amount of a corresponding light-emitting element. The correction is for eliminating a light amount difference in the main scanning direction occurring for each element array. A driving unit supplies driving currents to the light-emitting elements based on the corrected signal values, and a control unit performs a control of causing at least two element arrays to emit light for different durations within one main scanning period. The control is for eliminating a light amount difference in the sub scanning direction occurring between the at least two element arrays.

Abstract: Optical print head includes: light-emitting elements connected one-to-one to current supply lines branching from first power line at different positions in longitudinal direction; holding elements; signal writing unit writing luminance signal into each holding element, the luminance signal being represented by voltage indicating light emission amount of corresponding light-emitting element; second power line supplying reference voltage to each holding element, the reference voltage being reference when signal writing unit writes luminance signal into holding element; and driving drivers corresponding one-to-one with current supply lines and controlling current supplied to corresponding current supply line from first power line, in accordance with voltage held in corresponding holding element when signal writing unit has written luminance signal into corresponding holding element, wherein power source supplying the reference voltage to second power line is common with power source supplying voltage to signal o

Abstract: An optical print head includes: light-emitting elements in line shape; first power line supplying first reference voltage; second power line supplying drive current to each light-emitting element and supplying second reference voltage; DAC outputting first voltage indicating light emission amount of each light-emitting element; first elements for holding first voltage difference between the first reference voltage and the first voltage; second elements each electrically connectable with corresponding first element and for holding second voltage difference between the second reference voltage and second voltage according to the first voltage, and during supply of drive current, controls each first element to hold the first difference by electrically disconnecting the first and second elements, and temporarily suspends supply of the drive current, and controls the second element to hold the second difference by electrically connecting the first and second elements, such that the drive current according to the s

Abstract: An optical print head for forming an electrostatic latent image on a photosensitive body, including: current-driven light-emitting elements disposed in a line shape; an indicator circuit that outputs indicator current indicating light emission amounts to the light-emitting elements; and for each light-emitting element: a holding circuit that, during a main scanning period, accumulates indicator current during a sample period to generate an indicator potential and holds the indicator potential during a hold period; and a drive circuit that supplies drive current to the light-emitting element according to the indicator potential, wherein each of the sample periods is divided into writing periods, and each of the holding circuits holds the indicator potential corresponding to the holding circuit according to a total of indicator current amounts in the sample period corresponding to the holding circuit, the indicator current amounts each indicative of indicator current during one of the writing periods.