Abstract: First, second, and third line reading processing is processing of emitting light of each color to first, second, and third line of an original document in first, second, and third lighting order, respectively, and reading reflection light of the emitted light. A color that is first in the first lighting order, a color that is first in the second lighting order, and a color that is first in the third lighting order are different from each other. A color that is second in the first lighting order, a color that is second in the second lighting order, and a color that is second in the third lighting order is different from each other. A color that is third in the first lighting order, a color that is third in the second lighting order, and a color that is third in the third lighting order is different from each other.

Abstract: An image scanner is configured to: while changing a reading position by a position changer and sequentially emitting light of each of three colors in a turn-on sequence from a light source to a document, control a line sensor to read reflection light of emitted light, thereby acquiring gradation image data including gradation values of three colors for each pixel in one line; determine whether a top color shift occurs in the gradation image data at a determination position; in response to determining that the top color shift occurs at the determination position, replace gradation image data at the determination position with black image data; determine whether a bottom color shift occurs in the gradation image data at the determination position; and in response to determining that the bottom color shift occurs at the determination position, replace gradation image data at the determination position with white image data.

Abstract: An image scanner is configured to: while changing a reading position by a position changer and sequentially emitting light of each of three colors in a turn-on sequence from a light source to a document, control a line sensor to read reflection light of emitted light, thereby acquiring gradation image data including gradation values of three colors for each pixel in one line; determine whether a top color shift occurs in the gradation image data at a determination position; in response to determining that the top color shift occurs at the determination position, replace gradation image data at the determination position with black image data; determine whether a bottom color shift occurs in the gradation image data at the determination position; and in response to determining that the bottom color shift occurs at the determination position, replace gradation image data at the determination position with white image data.

Abstract: First, second, and third line reading processing is processing of emitting light of each color to first, second, and third line of an original document in first, second, and third lighting order, respectively, and reading reflection light of the emitted light. A color that is first in the first lighting order, a color that is first in the second lighting order, and a color that is first in the third lighting order are different from each other. A color that is second in the first lighting order, a color that is second in the second lighting order, and a color that is second in the third lighting order is different from each other. A color that is third in the first lighting order, a color that is third in the second lighting order, and a color that is third in the third lighting order is different from each other.

Abstract: An image scanner has an operation clock generator, a photoelectric converter, an AD converter configured to convert the analog pixel signals serially output by the photoelectric converter to digital pixel data by sampling the analog pixel signals in accordance with an operation clock generated by the operation clock generator, a data generator configured to generate read image data representing an read image of the original based on the pixel data converted by the AD converter, a resolution setter configured to set a reading resolution in the sub scanning direction, and a line period determiner configured to determine the line period to be (integer+decimal value) times a modulation period based on the reading resolution set by the resolution setter, the modulation period being inversion of the modulation frequency. The integer is greater than one and the decimal value is determined based on the reading resolution.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image scanner has an operation clock generator, a photoelectric converter, an AD converter configured to convert the analog pixel signals serially output by the photoelectric converter to digital pixel data by sampling the analog pixel signals in accordance with an operation clock generated by the operation clock generator, a data generator configured to generate read image data representing an read image of the original based on the pixel data converted by the AD converter, a resolution setter configured to set a reading resolution in the sub scanning direction, and a line period determiner configured to determine the line period to be (integer+decimal value) times a modulation period based on the reading resolution set by the resolution setter, the modulation period being inversion of the modulation frequency. The integer is greater than one and the decimal value is determined based on the reading resolution.

Abstract: An image scanning apparatus, comprising: a scanning device; a reference member; a correction unit; a controller; and a storage device, the scanning device comprising light receiving elements and a lens array, wherein the controller executes: a preparation process and an executive process, the preparation process comprising: a white reference data obtaining process to obtain white reference data by scanning a white reference original; and a white storing process to obtain white basic data by averaging the white reference data of a particular number of adjoining light receiving elements, wherein the executive process comprises: a reference member data obtaining process to obtain reference member data by scanning the reference member; a lens fluctuation calculation process to calculate fluctuation data of the correction data based on the reference member data; and a correction data generation process to generate the correction data by adding the fluctuation data to the white basic data.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image scanning apparatus, comprising: a scanning device; a reference member; a correction unit; a controller; and a storage device, the scanning device comprising light receiving elements and a lens array, wherein the controller executes: a preparation process and an executive process, the preparation process comprising: a white reference data obtaining process to obtain white reference data by scanning a white reference original; and a white storing process to obtain white basic data by averaging the white reference data of a particular number of adjoining light receiving elements, wherein the executive process comprises: a reference member data obtaining process to obtain reference member data by scanning the reference member; a lens fluctuation calculation process to calculate fluctuation data of the correction data based on the reference member data; and a correction data generation process to generate the correction data by adding the fluctuation data to the white basic data.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image forming apparatus may includes a central processing device, a first switching regulator and a second switching regulator. The central processing device may perform information processing associated with image formation. The first switching regulator may receive an input of a first voltage and output a second voltage which is lower than the first voltage. The second switching regulator may receive an input of the second voltage and output a third voltage which is lower than the second voltage. The third voltage may be input to the central processing device. A first switching frequency which is a switching frequency of the first switching regulator may be lower than a second switching frequency which is a switching frequency of the second switching regulator.

Abstract: An image reading apparatus includes: a reading unit having a plurality of photoelectric conversion elements arranged in a main scanning direction; a white reference plate arranged to face the reading unit; a motor configured to move at least one of an original and the reading unit relative to each other; and a controller configured to: control the reading unit to read the white reference plate to obtain white reference data; determine, based on a driving velocity of the motor, whether relative position between the original and the reading unit has changed by a predetermined distance; and output a displacement signal in a case of determining that the relative position between the original and the reading unit has changed by the predetermined distance.

Abstract: A controller is configured to set a reference gradation value when a gray reference member is illuminated. When the number of pixels, of which the gradation values is equal to or greater than the reference gradation value, is a target number of pixels, both are stored in association with each other. A correction target number which is a minimum target number of pixels from among a plurality of target numbers of pixels respectively providing differences, which is less than a predetermined value, between the reference gradation values stored in association with an M-th target number and an (M+1)-th target number. The controller further determines an anomaly pixel number which is the number of anomaly pixels having gradation values which are equal to or greater than a base gradation value. The gradation values of the determined number of anomaly pixels are corrected.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: An image forming apparatus may be configured to enter a first state where electric power is supplied from a power supply and a second state where no electric power is supplied from the power supply. A capacitor may be connected to the power supply, and may be charged by the power supply in the first state. A controller may be connected to the capacitor, and may operate with electric power supplied from the capacitor in the second state. The controller may operate with electric power supplied from the power supply in the first state. The controller may cause the image forming apparatus to enter the first state upon detecting that the image forming apparatus is in a predetermined state. The controller may acquire the related information and may cause the image forming apparatus to enter the second state.

Abstract: An image scanner includes a transparent plate, a scanning device, a driving device, a positioning member, a light absorbing portion and a white reference portion. The transparent plate has an original placing surface. The scanning device irradiates an original with light by means of a light source and scans reflected light from the original. The driving device reciprocates the scanning device along the transparent plate. The positioning member positions the original placed on the original placing surface of the transparent plate. The light absorbing portion, which is disposed on the original placing surface side of the positioning member and at substantially a central portion of the positioning member in moving directions of the scanning device, absorbs ambient light entering to the original placing surface side of the positioning member through the transparent plate. The white reference portion is provided to the original placing surface side of the positioning member.

Abstract: A controller is configured to set a reference gradation value when a gray reference member is illuminated. When the number of pixels, of which the gradation values is equal to or greater than the reference gradation value, is a target number of pixels, both are stored in association with each other. A correction target number which is a minimum target number of pixels from among a plurality of target numbers of pixels respectively providing differences, which is less than a predetermined value, between the reference gradation values stored in association with an M-th target number and an (M+1)-th target number. The controller further determines an anomaly pixel number which is the number of anomaly pixels having gradation values which are equal to or greater than a base gradation value. The gradation values of the determined number of anomaly pixels are corrected.