Abstract: An image forming apparatus includes a reading table, an image reading device, an image forming device with an exposure device, and circuitry. The reading device reads a pattern on a recording medium on the table, and generates image data of the pattern. The exposure device includes a light emitting element to form an electrostatic latent image, based on which the image forming device forms the pattern. Based on first and second correction values, the circuitry calculates a third correction value to correct a light amount of the light emitting element. The exposure device includes a driving device that drives the light emitting element based on the third correction value. The circuitry sets at least two or more determination areas in each of a white area and a pattern area of the medium, and determines whether the medium has a rise based on density data in the determination areas.

Abstract: An image forming apparatus includes a reading table, an image reading device, an image forming device with an exposure device, and circuitry. The reading device reads a pattern on a recording medium on the table, and generates image data of the pattern. The exposure device includes a light emitting element to form an electrostatic latent image, based on which the image forming device forms the pattern. Based on first and second correction values, the circuitry calculates a third correction value to correct a light amount of the light emitting element. The exposure device includes a driving device that drives the light emitting element based on the third correction value. The circuitry sets at least two or more determination areas in each of a white area and a pattern area of the medium, and determines whether the medium has a rise based on density data in the determination areas.

Abstract: The present invention suppresses a deterioration of transmission performance and reduces an adverse effect on health of a user, irrespective of the kind of selected antennas. A control section includes antenna selecting section configured so that in a case where a plurality of signals are simultaneously transmitted and where a mobile communication terminal is in a certain use state, the antenna selecting section selects at least one of a first antenna through a fourth antenna so that a distribution range of power densities or of specific absorption rates have no overlapping portion or have an overlapping portion equal to or less than a certain range.

Abstract: An image forming apparatus includes circuitry, a reader, and an exposure device that drives lighting elements aligned in a main scanning direction to form a first test image. The circuitry acquires density of first sub-areas, into which the first test image is divided in the main scanning direction, and calculates first correction data based on density of each of the first sub-areas and average density of the first sub-areas, to correct light amounts of the lighting elements. The exposure device forms a second test image with the light amounts corrected. The circuitry acquires density of second sub-areas, into which the second test image is divided in the main scanning direction, and calculates second correction data based on density of a second sub-area adjacent to each of the second sub-areas, to further correct the light amounts. The second sub-areas are differently located from the first sub-areas in the main scanning direction.

Abstract: An image forming apparatus includes a latent image bearer, a latent image writing device, a developing device, a conveyance unit to convey a recording medium, a transfer device, a length data acquisition unit to obtain a length of the recording medium in a conveyance direction of the recording medium, an image forming processor to form a test pattern, and a light quantity correction calculator that acquires image density data of the test pattern and calculates a light quantity correction value to correct a light quantity. The image forming processor sets a position of the test pattern on the recording medium in the conveyance direction of the recording medium and a length of the test pattern in the conveyance direction of the recording medium based on the length of the recording medium in the conveyance direction of the recording medium obtained by the length data acquisition unit.

Abstract: The present invention suppresses a deterioration of transmission performance and reduces an adverse effect on health of a user, irrespective of the kind of selected antennas. A control section includes antenna selecting section configured so that in a case where a plurality of signals are simultaneously transmitted and where a mobile communication terminal is in a certain use state, the antenna selecting section selects at least one of a first antenna through a fourth antenna so that a distribution range of power densities or of specific absorption rates have no overlapping portion or have an overlapping portion equal to or less than a certain range.

Abstract: An image forming apparatus includes an image reading device; an image forming device including a photoconductor, a charger, an exposure device including a light-emitting element, a memory to store a first correction value for correction a light emission amount of the light-emitting element, and a driver to drive the light-emitting element, a developing device, a transfer device, and a fixing device. The image forming apparatus further includes a processor to calculate a second correction value for correcting the light emission amount, based on density data of image data of a predetermined pattern on a recording medium; calculate a third correction value for correcting the light emission amount, based on the first correction value and the second correction value; and determine, before calculating the third correction value, whether placement of the recording medium on the reading table is correct based on the density data.

Abstract: An image forming apparatus includes circuitry, a reader, and an exposure device that drives lighting elements aligned in a main scanning direction to form a first test image. The circuitry acquires density of first sub-areas, into which the first test image is divided in the main scanning direction, and calculates first correction data based on density of each of the first sub-areas and average density of the first sub-areas, to correct light amounts of the lighting elements. The exposure device forms a second test image with the light amounts corrected. The circuitry acquires density of second sub-areas, into which the second test image is divided in the main scanning direction, and calculates second correction data based on density of a second sub-area adjacent to each of the second sub-areas, to further correct the light amounts. The second sub-areas are differently located from the first sub-areas in the main scanning direction.

Abstract: An image forming apparatus includes an image reading device; an image forming device including a photoconductor, a charger, an exposure device including a light-emitting element, a memory to store a first correction value for correction a light emission amount of the light-emitting element, and a driver to drive the light-emitting element, a developing device, a transfer device, and a fixing device. The image forming apparatus further includes a processor to calculate a second correction value for correcting the light emission amount, based on density data of image data of a predetermined pattern on a recording medium; calculate a third correction value for correcting the light emission amount, based on the first correction value and the second correction value; and determine, before calculating the third correction value, whether placement of the recording medium on the reading table is correct based on the density data.

Abstract: An image forming apparatus includes a latent image bearer, a latent image writing device, a developing device, a conveyance unit to convey a recording medium, a transfer device, a length data acquisition unit to obtain a length of the recording medium in a conveyance direction of the recording medium, an image forming processor to form a test pattern, and a light quantity correction calculator that acquires image density data of the test pattern and calculates a light quantity correction value to correct a light quantity. The image forming processor sets a position of the test pattern on the recording medium in the conveyance direction of the recording medium and a length of the test pattern in the conveyance direction of the recording medium based on the length of the recording medium in the conveyance direction of the recording medium obtained by the length data acquisition unit.

Abstract: An image writing device includes an exposure device to repeatedly expose a surface of an image bearer along a main-scanning direction during an image forming period to write an image on the image bearer, a speed change detector to detect a change in moving speed in a sub-scanning direction of the surface of the image bearer, a first signal generation circuit to generate a first signal, an image forming period signal generation circuit to generate an image forming period signal synchronously with the first signal, a second signal generation circuit to generate a second signal, the second signal initially appearing in the image forming period being in synchronization with the first signal, and a line synchronization signal generation circuit to generate a line synchronization signal synchronously with the second signal and transmit the line synchronization signal to the exposure device during the image forming period.

Abstract: An image writing device includes an exposure unit including an exposure head, writing an image onto an image bearing surface of a photoconductor by causing the exposure head to repeatedly expose; and a write control unit transmitting image data to be written by the exposure unit to the exposure unit on a one-line basis. Further the write control unit generates a write cycle reference signal having a cycle corresponding to writing resolution, counts a clock by a predetermined count value, generates a write cycle signal by delaying the write cycle reference signal by a time period, generates a data request signal to request transmission of one line of the image data to a controller unit based on the write cycle signal, and stores the one line of the image data transmitted from the controller unit.

Abstract: An image writing device includes an exposure device to repeatedly expose a surface of an image bearer along a main-scanning direction during an image forming period to write an image on the image bearer, a speed change detector to detect a change in moving speed in a sub-scanning direction of the surface of the image bearer, a first signal generation circuit to generate a first signal, an image forming period signal generation circuit to generate an image forming period signal synchronously with the first signal, a second signal generation circuit to generate a second signal, the second signal initially appearing in the image forming period being in synchronization with the first signal, and a line synchronization signal generation circuit to generate a line synchronization signal synchronously with the second signal and transmit the line synchronization signal to the exposure device during the image forming period.

Abstract: An image writing device includes an exposure unit including an exposure head, writing an image onto an image bearing surface of a photoconductor by causing the exposure head to repeatedly expose; and a write control unit transmitting image data to be written by the exposure unit to the exposure unit on a one-line basis. Further the write control unit generates a write cycle reference signal having a cycle corresponding to writing resolution, counts a clock by a predetermined count value, generates a write cycle signal by delaying the write cycle reference signal by a time period, generates a data request signal to request transmission of one line of the image data to a controller unit based on the write cycle signal, and stores the one line of the image data transmitted from the controller unit.

Abstract: An image forming apparatus includes: a plurality of optical systems, each of which includes a light-beam generating unit that generates a light beam, a rotary polygon mirror that deflects the light beam so as to scan a image carrier, and a light-beam detecting unit that detects the light beam deflected for scanning at a predetermined position on a scanning path by rotationally driving the rotary polygon mirror; a time-difference measuring unit that measures a time difference between light-beam detecting signals; a generation-timing determining unit that determines time of generation timing for generating a start signal that designates a start of an image writing operation so that the generation timing does not overlap another timing when each of the light-beam detecting signals is output from the corresponding time-difference measuring unit; and a start-signal generating unit that generates the start signal based on the time for the generation timing.

Abstract: An optical writing unit includes a plurality of light emitting element arrays, a plurality of clock signal generators, and a plurality of light emitting element controllers. The plurality of light emitting element arrays includes a plurality of light emitting elements aligned in one direction to project light. The plurality of clock signal generators generates image data transfer clock signals having different frequencies. The plurality of light emitting element controllers outputs the image data transfer clock signals received from the plurality of the clock signal generators and image data signals to the plurality of the light emitting element arrays to light up the light emitting elements based on the image data signals. The optical writing unit performs optical writing using light projected from the light emitting element arrays and controlled by the light emitting element controller based on the image data signals.

Abstract: An image forming apparatus includes: a plurality of optical systems, each of which includes a light-beam generating unit that generates a light beam, a rotary polygon mirror that deflects the light beam so as to scan a image carrier, and a light-beam detecting unit that detects the light beam deflected for scanning at a predetermined position on a scanning path by rotationally driving the rotary polygon mirror; a time-difference measuring unit that measures a time difference between light-beam detecting signals; a generation-timing determining unit that determines time of generation timing for generating a start signal that designates a start of an image writing operation so that the generation timing does not overlap another timing when each of the light-beam detecting signals is output from the corresponding time-difference measuring unit; and a start-signal generating unit that generates the start signal based on the time for the generation timing.

Abstract: An optical writing unit includes a plurality of light emitting element arrays, a plurality of clock signal generators, and a plurality of light emitting element controllers. The plurality of light emitting element arrays includes a plurality of light emitting elements aligned in one direction to project light. The plurality of clock signal generators generates image data transfer clock signals having different frequencies. The plurality of light emitting element controllers outputs the image data transfer clock signals received from the plurality of the clock signal generators and image data signals to the plurality of the light emitting element arrays to light up the light emitting elements based on the image data signals. The optical writing unit performs optical writing using light projected from the light emitting element arrays and controlled by the light emitting element controller based on the image data signals.