Abstract: A toner amount detection sensor has a substrate, and a case housing. In the substrate, the light emitting element, the first light receiving element, and the second light receiving element are attached with an interval to the same first surface. In the substrate, first and second slits and are provided between a region where the light emitting element is attached and regions where the first light receiving element and the second light receiving element are attached. In the case housing, first and second light shielding walls and are disposed in such a manner as to extend to reach the inside of the first and second slits and when attached to the substrate and first and second light shielding walls and are provided between the light emitting element and the first light receiving element and between the light emitting element and the second light receiving element.

Abstract: A toner amount detection sensor has a first light receiving element, a second light receiving element, and a toner amount calculation unit. The first light receiving element is provided on a side opposite to a light emitting element with respect to a plane extending in a direction perpendicular to a surface of a transfer belt. The second light receiving element is provided at a position avoiding a plane containing the light emitting element and the first light receiving element and is provided separately from the first light receiving element. The toner amount calculation unit calculates the toner amount from the light quantity of the light equivalent to the specular reflection light received by the first light receiving element and the light quantity of the diffuse-reflected light received by the second light receiving element.

Abstract: An image forming includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit forms a non-charged area on a circumference surface of the photoreceptor drum and applies a developing bias constituted of a first electric potential to a developing roller to form a first toner image by an electric potential difference between the non-charged area and the developing roller. The charging bias applying unit forms a second toner image by an electric potential difference between the electric potential area and the developing roller. The charging bias applying unit decides a value of a charging bias corresponding to a target electric potential from measurement results of print densities of the first toner image and the second toner image.

Abstract: A toner amount detection sensor has a substrate, and a case housing. In the substrate, the light emitting element, the first light receiving element, and the second light receiving element are attached with an interval to the same first surface. In the substrate, first and second slits and are provided between a region where the light emitting element is attached and regions where the first light receiving element and the second light receiving element are attached. In the case housing, first and second light shielding walls and are disposed in such a manner as to extend to reach the inside of the first and second slits and when attached to the substrate and first and second light shielding walls and are provided between the light emitting element and the first light receiving element and between the light emitting element and the second light receiving element.

Abstract: A toner amount detection sensor has a first light receiving element, a second light receiving element, and a toner amount calculation unit. The first light receiving element is provided on a side opposite to a light emitting element with respect to a plane extending in a direction perpendicular to a surface of a transfer belt. The second light receiving element is provided at a position avoiding a plane containing the light emitting element and the first light receiving element and is provided separately from the first light receiving element. The toner amount calculation unit calculates the toner amount from the light quantity of the light equivalent to the specular reflection light received by the first light receiving element and the light quantity of the diffuse-reflected light received by the second light receiving element.

Abstract: An image forming apparatus includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit controls the charging bias applying unit to form a plurality of electric potential areas of electric potentials with different magnitudes. The bias adjusting unit applies a predetermined developing bias corresponding to a target electric potential to the developing roller, so as to form a plurality of toner images by electric potential differences between the developing bias and the plurality of electric potential areas. The bias adjusting unit decides a value of a charging bias corresponding to the target electric potential from measurement results of print densities of the plurality of toner images measured by the print density measurement unit.

Abstract: An image forming apparatus includes an apparatus main body, a photoreceptor drum, a charging apparatus, an exposure apparatus, a developing device, a charging bias applying unit, a developing bias applying unit, an image condition adjusting unit, and a print density measurement unit. The image condition adjusting unit forms a second electric potential region by applying the charging bias where a first differential electric potential is subtracted from a first tentative charging bias on a circumference surface of a photoreceptor drum, and forms a second toner image by an electric potential difference between the second electric potential region and a developing roller by applying the target electric potential. The image condition adjusting unit decides value of the charging bias corresponding to the target electric potential from measurement results of print densities of a first toner image and the second toner image measured by the print density measurement unit.

Abstract: An image forming apparatus includes an apparatus main body, a photoreceptor drum, a charging apparatus, an exposure apparatus, a developing device, a charging bias applying unit, a developing bias applying unit, an image condition adjusting unit, and a print density measurement unit. The image condition adjusting unit forms a second electric potential region by applying the charging bias where a first differential electric potential is subtracted from a first tentative charging bias on a circumference surface of a photoreceptor drum, and forms a second toner image by an electric potential difference between the second electric potential region and a developing roller by applying the target electric potential. The image condition adjusting unit decides value of the charging bias corresponding to the target electric potential from measurement results of print densities of a first toner image and the second toner image measured by the print density measurement unit.

Abstract: An image forming apparatus includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit controls the charging bias applying unit to form a plurality of electric potential areas of electric potentials with different magnitudes. The bias adjusting unit applies a predetermined developing bias corresponding to a target electric potential to the developing roller, so as to form a plurality of toner images by electric potential differences between the developing bias and the plurality of electric potential areas. The bias adjusting unit decides a value of a charging bias corresponding to the target electric potential from measurement results of print densities of the plurality of toner images measured by the print density measurement unit.

Abstract: An image forming includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit forms a non-charged area on a circumference surface of the photoreceptor drum and applies a developing bias constituted of a first electric potential to a developing roller to form a first toner image by an electric potential difference between the non-charged area and the developing roller. The charging bias applying unit forms a second toner image by an electric potential difference between the electric potential area and the developing roller. The charging bias applying unit decides a value of a charging bias corresponding to a target electric potential from measurement results of print densities of the first toner image and the second toner image.

Abstract: A toner-amount detection sensor includes a light-emitting element, a first light-receiving element, and a toner-amount calculating unit. The light-emitting element emits light toward the surface of the transfer body at a predetermined incident angle. The first light-receiving element is disposed on a side opposite to the light-emitting element with respect to a plane normal to the surface of the transfer body. The first light-receiving element receives light reflected from the surface of the transfer body. The toner-amount calculating unit calculates the amount of toner from the quantity of the reflected light received by the first light-receiving element. The sensor has a relationship of A1<A2<1.5A1 where A1 represents the predetermined incident angle with respect to the plane normal to the surface of the transfer body, and A2 represents an angle of disposition of the first light-receiving element with respect to the plane normal to the surface of the transfer body.

Abstract: A paper type detection apparatus includes a surface-property detection unit, a thickness detection unit, and a paper-type setting unit. The surface-property detection unit detects a surface property of paper by performing image processing on image data of the paper read by an image reading unit. The thickness detection unit causes the image reading unit to read the image data of the paper over which a reference chart with a predetermined black density is laid. The thickness detection unit detects the thickness of the paper based on the difference between the black density of the reference chart and the black density appearing on the image data through the paper. The paper-type setting unit sets the type of the paper associated with the detected surface property and thickness of the paper.

Abstract: A toner-amount detection sensor includes a light-emitting element, a first light-receiving element, and a toner-amount calculating unit. The light-emitting element emits light toward the surface of the transfer body at a predetermined incident angle. The first light-receiving element is disposed on a side opposite to the light-emitting element with respect to a plane normal to the surface of the transfer body. The first light-receiving element receives light reflected from the surface of the transfer body. The toner-amount calculating unit calculates the amount of toner from the quantity of the reflected light received by the first light-receiving element. The sensor has a relationship of A1<A2<1.5A1 where A1 represents the predetermined incident angle with respect to the plane normal to the surface of the transfer body, and A2 represents an angle of disposition of the first light-receiving element with respect to the plane normal to the surface of the transfer body.

Abstract: A paper type detection apparatus includes a surface-property detection unit, a thickness detection unit, and a paper-type setting unit. The surface-property detection unit detects a surface property of paper by performing image processing on image data of the paper read by an image reading unit. The thickness detection unit causes the image reading unit to read the image data of the paper over which a reference chart with a predetermined black density is laid. The thickness detection unit detects the thickness of the paper based on the difference between the black density of the reference chart and the black density appearing on the image data through the paper. The paper-type setting unit sets the type of the paper associated with the detected surface property and thickness of the paper.

Abstract: A toner-amount detection sensor includes a board, a sensor cover, a light emitter, a light receiver, a light-shielding wall, and two locking parts. The light emitter is surface-mounted on the board. The light receiver is surface-mounted on the board. The light-shielding wall is located between the light emitter and the light receiver, abuts the board, and abuts the sensor cover or extends from the sensor cover. The two locking parts are formed at opposite ends of the sensor cover to press the board to lock it from outside the light emitter and light receiver relative to the light-shielding wall, using the abutment between the light-shielding wall and the board as a supporting point.

Abstract: A sheet attribution detection sensor device includes a light emission element configured to emit incident light to a paper sheet, a light receiving element configured to receive a specular reflection component of reflection light from the paper sheet of the incident light in order to specify a thickness of the paper sheet, and light receiving elements configured to receive a diffuse reflection component of the reflection light in order to specify one of surface roughness and color of the paper sheet.

Abstract: A sheet attribution detection sensor device includes a light emission element configured to emit incident light to a paper sheet, a light receiving element configured to receive a specular reflection component of reflection light from the paper sheet of the incident light in order to specify a thickness of the paper sheet, and light receiving elements configured to receive a diffuse reflection component of the reflection light in order to specify one of surface roughness and color of the paper sheet.

Abstract: A toner-amount detection sensor includes a board, a sensor cover, a light emitter, a light receiver, a light-shielding wall, and two locking parts. The light emitter is surface-mounted on the board. The light receiver is surface-mounted on the board. The light-shielding wall is located between the light emitter and the light receiver, abuts the board, and abuts the sensor cover or extends from the sensor cover. The two locking parts are formed at opposite ends of the sensor cover to press the board to lock it from outside the light emitter and light receiver relative to the light-shielding wall, using the abutment between the light-shielding wall and the board as a supporting point.

Abstract: An image forming apparatus of the present disclosure includes: an image carrier configured to carry toner patches; a first sensor configured to irradiate S-polarized light to a low-density patch in a predetermined low density range among the toner patches, and to receive reflection light from the low-density patch; and a second sensor configured to irradiate P-polarized light to a high-density patch in a predetermined high density range among the toner patches, and to receive reflection light from the high-density patch.

Abstract: An image forming apparatus including an image carrying member, a detecting section, and a linear-speed deriving section. The image carrying member carries a toner image. The detecting section detects passages of a mark, provided on the image carrying member, at a plurality of predetermined detection positions. The linear-speed deriving section determines a linear speed of the image carrying member from times at which the detecting section detects the passage of the mark.