Abstract: A sheet type discrimination device includes: a first light source unit that irradiates a sheet with light having a first wavelength and light having a second wavelength; a detection unit that detects light from the sheet and acquires a detection value based on the light; and a control unit that derives a determination result of a type of the sheet, wherein the first light source unit and the detection unit are located on a same side with respect to the sheet, the detection value includes: a first detection value; and a second detection value, and the control unit discriminates first-type recycled paper by first processing using the first detection value, and discriminates second-type recycled paper different from the first-type recycled paper by second processing using the second detection value.

Abstract: A recording medium determination device includes a light emitter, a light detector, and a hardware processor. The light emitter emits inspection light to a recording medium. The light detector detects incident light including at least one of diffuse reflected light of the inspection light emitted to the recording medium and fluorescent light excited by the inspection light in the recording medium. The hardware processor makes a determination depending on a property of the recording medium based on a detection result of first incident light of the incident light in accordance with first inspection light of the inspection light and second incident light of the incident light in accordance with second inspection light of the inspection light obtained by the light detector. The second inspection light has an intensity whose peak wavelength is shorter than the peak wavelength of the first inspection light.

Abstract: A focus adjusting tool used to perform an initial setting for a pair of autofocus eyeglasses includes an adjusting lens that refracts reflected light from a visual object, a housing including an inner space that allows a parallel movement of the adjusting lens, an adjusting unit that adjusts a position of the adjusting lens inside the housing, and a first end and a second end in a moving direction of the adjusting lens. The first end is provided with a hole for visually observing a visual object through a power variable lens of the pair of autofocus eyeglasses. The adjusting lens adjusts, in response to the position thereof inside the housing, an incident angle of the reflected light from the visual object into the power variable lens, the visual object being located on the side of the second end.

Abstract: A technology aimed at improvement of paper discriminating accuracy is provided. In an image forming apparatus, a control unit derives a discriminating result for types of paper. To be specific, the control unit derives the discriminating result for types of paper using a first detection value based on absorption by the paper of the light having the first wavelength and a second detection value based on absorption by the paper of the light having the second wavelength. The first wavelength ranges from 750 nm to 1100 nm.

Abstract: A recording medium determination device includes a light emitter, a light detector, and a hardware processor. The light emitter emits inspection light to a recording medium. The light detector detects incident light including at least one of diffuse reflected light of the inspection light emitted to the recording medium and fluorescent light excited by the inspection light in the recording medium. The hardware processor makes a determination depending on a property of the recording medium based on a detection result of first incident light of the incident light in accordance with first inspection light of the inspection light and second incident light of the incident light in accordance with second inspection light of the inspection light obtained by the light detector. The second inspection light has an intensity whose peak wavelength is shorter than the peak wavelength of the first inspection light.

Abstract: A focus adjusting tool used to perform an initial setting for a pair of autofocus eyeglasses includes an adjusting lens that refracts reflected light from a visual object, a housing including an inner space that allows a parallel movement of the adjusting lens, an adjusting unit that adjusts a position of the adjusting lens inside the housing, and a first end and a second end in a moving direction of the adjusting lens. The first end is provided with a hole for visually observing a visual object through a power variable lens of the pair of autofocus eyeglasses.

Abstract: An optical print head that performs optical writing to a photoreceptor includes: a light transmissive substrate; a light emitting unit including light emitting element groups, each of which includes two or more light emitting elements disposed on a first main surface of the substrate; a lens array including lenses that correspond one-to-one to the light emitting element groups; light detection units disposed above the second main surface of the substrate in one-to-one correspondence to the light emitting element groups and that detects the light from each of the light emitting elements; and correction unit that corrects light amounts of the light emitting elements of the light emitting element group based on detection of the light detection units.

Abstract: A relative position detection method detecting a position of a light-emitting member relative to a lens array or a position of the lens array relative to the light-emitting member, in which the light-emitting member includes light-emitting elements arranged in a first direction and the lens array includes lenses arranged in the first direction and condenses light from the light-emitting elements to image positions of the light-emitting elements, optical axes of the lenses being orthogonal to the first direction. The method includes: causing the light-emitting elements to emit light; detecting, at a position displaced from the image positions along an optical axis direction, optical intensity distribution of light emitted from the light-emitting elements and transmitted through the lens array; and detecting a position of the light-emitting member relative to the lens array or a position of the lens array relative to the light-emitting member with use of the optical intensity distribution.

Abstract: An optical writing device includes a lens, a plurality of light emitting elements that form one pixel on a photoreceptor through the lens, and a control circuit that controls a light emitting state of each of the plurality of light emitting elements. The control circuit controls the light emitting state of each of the plurality of light emitting elements in accordance with an ambient temperature of the plurality of light emitting elements.

Abstract: A print head for writing data onto a photoreceptor, including a light source panel of light emitting elements arranged in a matrix, optical systems arranged in a matching matrix, light receiving elements, and a corrector. The optical systems each include at least a light-source-side lens and an image-side lens, and focus light from the light emitting elements onto different regions of the photoreceptor. The light receiving elements each include a light receiving surface disposed in a leaked light region and detect light incident on the light receiving surface. The leaked light region is in a gap between the light-source-side lens and the image-side lens of each of the optical systems occupied by optical paths of light transmitted through the light-source-side lenses but not incident on the image-side lenses. The corrector corrects amounts of light to be emitted from the light emitting elements based on the light detected.

Abstract: An optical print head that performs optical writing to a photoreceptor includes: a light transmissive substrate; a light emitting unit including light emitting element groups, each of which includes two or more light emitting elements disposed on a first main surface of the substrate; a lens array including lenses that correspond one-to-one to the light emitting element groups; light detection units disposed above the second main surface of the substrate in one-to-one correspondence to the light emitting element groups and that detects the light from each of the light emitting elements; and correction unit that corrects light amounts of the light emitting elements of the light emitting element group based on detection of the light detection units.

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 image forming device includes: a photoreceptor; a longitudinal light emitting member constituted from light emitting element rows that are arranged in a lateral direction and are each constituted from light emitting elements arranged in a longitudinal direction; an optical member that is longitudinal and is disposed to condense light emitted from the light emitting elements onto the photoreceptor; and a hardware processor that: selects and causes one or more light emitting elements for each light emitting element row to emit light; acquires an exposure amount for each light emitting element row; calculates a distribution of the exposure amounts acquired for the light emitting element rows, and calculates a position in the lateral direction corresponding to a predetermined exposure amount in the distribution; and judges whether a difference between the calculated position and a reference position in the lateral direction at a reference time is less than a threshold value.

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: A print head for writing data onto a photoreceptor, including a light source panel of light emitting elements arranged in a matrix, optical systems arranged in a matching matrix, light receiving elements, and a corrector. The optical systems each include at least a light-source-side lens and an image-side lens, and focus light from the light emitting elements onto different regions of the photoreceptor. The light receiving elements each include a light receiving surface disposed in a leaked light region and detect light incident on the light receiving surface. The leaked light region is in a gap between the light-source-side lens and the image-side lens of each of the optical systems occupied by optical paths of light transmitted through the light-source-side lenses but not incident on the image-side lenses. The corrector corrects amounts of light to be emitted from the light emitting elements based on the light detected.

Abstract: An image forming deviceincludes: a photoreceptor; a longitudinal light emitting member constituted from light emitting element rows that are arranged in a lateral direction and are each constituted from light emitting elements arranged in a longitudinal direction; an optical member that is longitudinal and is disposed to condense light emitted from the light emitting elements onto the photoreceptor; and a hardware processor that: selects and causes one or more light emitting elements for each light emitting element row to emit light; acquires an exposure amount for each light emitting element row; calculates a distribution of the exposure amounts acquired for the light emitting element rows, and calculates a position in the lateral direction corresponding to a predetermined exposure amount in the distribution; and judges whether a difference between the calculated position and a reference position in the lateral direction at a reference time is less than a threshold value.

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 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: A relative position detection method detecting a position of a light-emitting member relative to a lens array or a position of the lens array relative to the light-emitting member, in which the light-emitting member includes light-emitting elements arranged in a first direction and the lens array includes lenses arranged in the first direction and condenses light from the light-emitting elements to image positions of the light-emitting elements, optical axes of the lenses being orthogonal to the first direction. The method includes: causing the light-emitting elements to emit light; detecting, at a position displaced from the image positions along an optical axis direction, optical intensity distribution of light emitted from the light-emitting elements and transmitted through the lens array; and detecting a position of the light-emitting member relative to the lens array or a position of the lens array relative to the light-emitting member with use of the optical intensity distribution.

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.