Abstract: A processor derives a plurality of unit density values which are each an average value of sensed densities for each of a plurality of unit areas sectioned for each unit length in a test toner image. The processor derives a weighted average of the plurality of unit density values to derive a test image density used for adjusting a control parameter in a printing portion. The unit length is a greatest common factor of two target lengths corresponding to perimeters of two types of target rotating members out of the plurality of rotating members. When a number of the plurality of unit areas is represented by n, n is a value obtained by subtracting 1 from an added value of a first constant and a second constant. The first constant and the second constant are values obtained by respectively dividing the two target lengths by the unit length.

Abstract: An image forming apparatus includes first to third adjustment processing portions. The first adjustment processing portion adjusts an emission light amount of a light-emitting portion of a first sensor based on an electric signal output from a light-receiving portion of the first sensor and corresponding to regular reflection light reflected by a non-toner-adhering surface of an image-carrying member. The second adjustment processing portion adjusts an operation condition of an image forming portion based on a toner concentration of a first toner image in a specific color, that has a concentration smaller than a predetermined saturation concentration. The third adjustment processing portion adjusts an emission light amount of a light-emitting portion of a second sensor based on an electric signal output from a light-receiving portion of the second sensor and corresponding to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration.

Abstract: A toner concentration sensing apparatus includes a first acquisition processing portion, a second acquisition processing portion, and a third acquisition processing portion. The first acquisition processing portion acquires a first sensing value corresponding to light reflected by a first region of an image-carrying member where a toner image is not formed. The second acquisition processing portion acquires a second sensing value corresponding to light reflected by a second region of the image-carrying member where a toner image has been formed. The third acquisition processing portion acquires a component ratio of a component in the second sensing value, that corresponds to light reflected by toner adhered onto a surface of the image-carrying member, using a specific calculation formula determined based on a first relational expression based on the first sensing value and a second relational expression not based on the first sensing value, and the second sensing value.

Abstract: An image forming apparatus includes a developing current detecting portion, a control portion, and a deviation detecting portion. The developing current detecting portion detects a developing current that flows between a developing device and a photoconductor drum during development of an electrostatic latent image. The control portion causes the exposure device to form electrostatic latent images of at least two patch images at different positions from each other and at different timings from each other in a main scanning direction. The deviation detecting portion detects deviation of one of the exposure device and the photoconductor drum with respect to the other based on a detection timing at which the developing current is detected during development of the electrostatic latent images of the at least two patch images.

Abstract: An image forming apparatus includes a transfer processing portion, a detection processing portion, a correction processing portion, and an adjustment processing portion. The transfer processing portion transfers a detection toner image to outside an output area of a transfer object to which a toner image as an output target is transferred from an image-carrying member. The detection processing portion detects a density of the detection toner image that has been transferred to the transfer object by the transfer processing portion. The correction processing portion corrects a detection result of the detection processing portion based on an amount of toner transferred from the image-carrying member to the output area at a transfer timing when the detection toner image is transferred. The adjustment processing portion adjusts an image forming condition based on the detection result after correction by the correction processing portion.

Abstract: A processor derives a plurality of unit density values which are each an average value of sensed densities for each of a plurality of unit areas sectioned for each unit length in a test toner image. The processor derives a weighted average of the plurality of unit density values to derive a test image density used for adjusting a control parameter in a printing portion. The unit length is a greatest common factor of two target lengths corresponding to perimeters of two types of target rotating members out of the plurality of rotating members. When a number of the plurality of unit areas is represented by n, n is a value obtained by subtracting 1 from an added value of a first constant and a second constant. The first constant and the second constant are values obtained by respectively dividing the two target lengths by the unit length.

Abstract: A processor causes a printing portion to execute, when first conveying processing is executed, test print processing for executing processing of forming a plurality of test toner images on a sheet under a print condition that differs for each of the plurality of test toner images. The processor acquires a plurality of first sensing densities when the first conveying processing is executed. The processor causes the printing portion to execute the test print processing when second conveying processing is executed. The processor acquires a plurality of second sensing densities when the second conveying processing is executed. The processor compares the plurality of first sensing densities and the plurality of second sensing densities to adjust the print condition in the print processing when the second conveying processing is executed.

Abstract: An image forming apparatus includes a transfer processing portion, a detection processing portion, a correction processing portion, and an adjustment processing portion. The transfer processing portion transfers a detection toner image to outside an output area of a transfer object to which a toner image as an output target is transferred from an image-carrying member. The detection processing portion detects a density of the detection toner image that has been transferred to the transfer object by the transfer processing portion. The correction processing portion corrects a detection result of the detection processing portion based on an amount of toner transferred from the image-carrying member to the output area at a transfer timing when the detection toner image is transferred. The adjustment processing portion adjusts an image forming condition based on the detection result after correction by the correction processing portion.

Abstract: An image forming apparatus includes a developing current detecting portion, a control portion, and a deviation detecting portion. The developing current detecting portion detects a developing current that flows between a developing device and a photoconductor drum during development of an electrostatic latent image. The control portion causes the exposure device to form electrostatic latent images of at least two patch images at different positions from each other and at different timings from each other in a main scanning direction. The deviation detecting portion detects deviation of one of the exposure device and the photoconductor drum with respect to the other based on a detection timing at which the developing current is detected during development of the electrostatic latent images of the at least two patch images.

Abstract: An image forming apparatus includes an intermediate transfer belt, a density sensor, a cleaning device and a density correction unit. The intermediate transfer belt carries a calibration toner image. The density sensor detects a density of the calibration toner image that passes at a predetermined position. The cleaning device contacts to a part of the intermediate transfer belt in a primary scanning direction, and removes from the intermediate transfer belt the calibration toner image that passed at the predetermined position. The density correction unit performs density correction of a printing toner image in the primary scanning direction. Further, the density correction unit changes a strength of the density correction for a contact range to which the cleaning device contacts on the intermediate transfer belt, the strength changed in accordance with the number of times of a calibration process.

Abstract: An image forming apparatus includes an intermediate transfer belt, a density sensor, a cleaning device and a density correction unit. The intermediate transfer belt carries a calibration toner image. The density sensor detects a density of the calibration toner image that passes at a predetermined position. The cleaning device contacts to a part of the intermediate transfer belt in a primary scanning direction, and removes from the intermediate transfer belt the calibration toner image that passed at the predetermined position. The density correction unit performs density correction of a printing toner image in the primary scanning direction. Further, the density correction unit changes a strength of the density correction for a contact range to which the cleaning device contacts on the intermediate transfer belt, the strength changed in accordance with the number of times of a calibration process.

Abstract: A laser scanning unit includes a first light source, a second light source, a scanning portion, a light detection portion, a timing control portion, and a light source control portion. The scanning portion is configured to cause light emitted from the first light source and the second light source to be scanned. The light detection portion is configured to detect the light that is scanned by the scanning portion. The timing control portion is configured to control a timing of writing an electrostatic latent image according to a timing of light detection by the light detection portion. The light source control portion is configured to: cause the light detected by the light detection portion to be emitted from the first light source in the first mode; and cause the light detected by the light detection portion to be emitted from the second light source in the second mode.

Abstract: A laser scanning unit includes a first light source, a second light source, a scanning portion, a light detection portion, a timing control portion, and a light source control portion. The scanning portion is configured to cause light emitted from the first light source and the second light source to be scanned. The light detection portion is configured to detect the light that is scanned by the scanning portion. The timing control portion is configured to control a timing of writing an electrostatic latent image according to a timing of light detection by the light detection portion. The light source control portion is configured to: cause the light detected by the light detection portion to be emitted from the first light source in the first mode; and cause the light detected by the light detection portion to be emitted from the second light source in the second mode.

Abstract: An electronic device includes an operation panel, an electric power control circuit, an operation confirming circuit, an electric power mode switching circuit, a human body detecting circuit, and a cycle changing circuit. The electric power control circuit switches a plurality of electric power supply modes including a standby mode and a low electric power consumption mode that uses less electric power consumption amount than the standby mode. The operation confirming circuit periodically confirms an operation to the operation panel in the low electric power consumption mode. The electric power mode switching circuit causes the electric power control circuit to switch the electric power supply mode when the operation confirming circuit detects the operation to the operation panel. The cycle changing circuit changes an operation confirmation cycle by the operation confirming circuit corresponding to a detection state of the human body detecting circuit.

Abstract: An image forming apparatus includes an exposing section, a pulse generating section, a frequency storing section, an emission control section, a smoothing section, and a driving-current generating section. The pulse generating section generates a periodic pulse signal indicating light amount of light beam emitted by a light source of the exposing section. The frequency storing section stores in advance a plurality of frequencies of the pulse signal. The emission control section selects, in the rendering of each main scanning line, any one of the plurality of frequencies and instructs the pulse generating section to generate the pulse signal having the selected frequency. The smoothing section smoothes the pulse signal generated by the pulse generating section according to the instruction of the emission control section and generates analog signal. The driving-current generating section generates driving current for the light source of the exposing section on the basis of the analog signal.

Abstract: Image forming apparatus includes elements as follows. Light-amount storing section stores, in the main scanning line divided into a plurality of blocks, light amounts of a light beam irradiated on the blocks. Change-data storing section stores a plurality of change data items set in the vicinity of each of block boundaries of the plurality of blocks. The plurality of change data items are used to cope with each of a plurality of events that are likely to affect the image quality in the vicinity of the block boundary. Irradiation control section selects, out of the plurality of change data items, change data for coping with an event selected out of the plurality of events and instructs Pulse generating section to generate, in the vicinity of the block boundary, pulse signal from which analog signal indicating a change in a value represented by the selected change data is obtained.

Abstract: An image forming apparatus includes a photosensitive body, an exposure unit, a pulse generating unit, a smoothing unit, a drive current generating unit, and a second emitting control unit. The exposure unit includes a light source for emitting a light beam, and causes the light beam emitted from the light source to perform scanning in a main scanning direction, thereby drawing a main scanning line on the photosensitive body. The second emitting control unit causes the light source to emit the light beam, in an APC period of automatically controlling the light quantity of the light beam, by causing the pulse generating unit to generate a pulse signal having a duty ratio of 100 percent, causing the smoothing unit to smooth the pulse signal thereby generating an analog signal, and causing the drive current generating unit to generate a drive current based on the analog signal.

Abstract: Image forming apparatus includes elements as follows. Light-amount storing section stores, in the main scanning line divided into a plurality of blocks, light amounts of a light beam irradiated on the blocks. Change-data storing section stores a plurality of change data items set in the vicinity of each of block boundaries of the plurality of blocks. The plurality of change data items are used to cope with each of a plurality of events that are likely to affect the image quality in the vicinity of the block boundary. Irradiation control section selects, out of the plurality of change data items, change data for coping with an event selected out of the plurality of events and instructs Pulse generating section to generate, in the vicinity of the block boundary, pulse signal from which analog signal indicating a change in a value represented by the selected change data is obtained.

Abstract: A method of manufacturing a glass substrate for an optical disk using a press-mold formed of a super-hard material and having a surface of a prescribed roughness. A track pattern is formed in the surface of the glass substrate by inserting the substrate and a stamper containing track patterns into the press mold and pressing the substrate against the stamper. A film-like thermoplastic synthetic resin is disposed between the glass substrate and the stamper, and the glass substrate is heated to the distortion temperature point of glass.

Abstract: A method of manufacturing a glass substrate for an optical disk using a press-mold formed of a super-hard material and having a surface of a prescribed roughness. A track pattern is formed in the surface of the glass substrate by inserting the substrate and a stamper containing track patterns into the press mold and pressing the substrate against the stamper. A film-like thermoplastic synthetic resin is disposed between the glass substrate and the stamper, and the glass substrate is heated to the distortion temperature point of glass.