Abstract:
A method of measuring sensor chip shift comprises the following steps. First, provide a contact image sensor module comprising a plurality of sensor chips arranged in a row on a main board, with each sensor chip having multiple sensors. Next, provide a test chart with a predetermined pattern. Further, enable the multiple sensors of the contact image sensor module to scan the predetermined pattern of the test chart. Moreover, select signal waves sensed by the sensors at the ends of two adjacent sensor chips. Finally, calculate the gap between the sensors at the ends of the two adjacent sensor chips according to the signal waves.
Abstract:
An image formation apparatus of the present invention forms an electrostatic latent image on a moving photosensitive belt by a laser beam produced by a laser device. A belt edge detector 1 detects an edge portion (belt edge) of a photosensitive belt 100 in a main scanning direction. A virtual edge detection circuit 2 generates a virtual edge detection signal 2A which changes a generation timing in accordance with a change of a detection timing of the belt edge detected by the belt edge detector 1. The generation timing of the virtual edge detection signal 2A does not almost follow the detection timing of the belt edge which changes by flaws and non-linearity of the belt edge, and changes in accordance with a slow change of the detection timing. A synchronizing signal generation circuit 3 and a driving circuit 4 drives the laser device so as to start a writing of an image data by the laser beam in synchronization with the virtual edge detection signal.
Abstract:
In a reading device, a light transmissive member has a front surface on which an original is placed. A peripheral member is adjacent to the light transmissive member, and includes a back surface in which a reference hole is formed. The reference hole includes a first edge and a second edge intersecting with each other. A reading sensor faces the back surface of the light transmissive member and the back surface of the peripheral member. The controller controls the reading sensor to read a reading range including the reference hole to obtain a read image, and determines a reference position in the reading range based on the read image. The reference position is determined to an intersection between the first edge and the second edge. The controller sets a reading start position based on the reference position.
Abstract:
An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.
Abstract:
A circuit for detecting a phase error between a clock signal and a beam position includes a beam generator, a sensor, and a phase detector. The beam generator directs a beam toward a beam sweeper in response to the clock signal, and the sensor detects the beam as directed from the beam sweeper. The phase detector determines from the detected beam the error in the clock phase relative to the beam position. Such a circuit can automatically detect the phase error in the pixel clock and correct this error, thus eliminating the need for a manual phase-error corrector. The circuit may also be able to adjust the width and/or the height of a scan region, and thus may also be able to adjust the width and/or height of an image frame within the scan region.
Abstract:
A circuit for detecting a phase error between a clock signal and a beam position includes a beam generator, sensor, and phase detector. The beam generator directs a beam toward a beam sweeper in response to a clock signal. The sensor, which is disposed at a mid line of a region that the beam sweeper scans, detects the beam from the beam sweeper, and the phase detector detects an error in the clock phase from the detected beam. Such a circuit can automatically detect the phase error in the pixel clock and correct this error, thus eliminating the need for a manual phase-error corrector.
Abstract:
A circuit for detecting a phase error between a clock signal and a beam position includes a beam generator, a sensor, and a phase detector. The beam generator directs a beam toward a beam sweeper in response to the clock signal, and the sensor detects the beam as directed from the beam sweeper. The phase detector determines from the detected beam the error in the clock phase relative to the beam position. Such a circuit can automatically detect the phase error in the pixel clock and correct this error, thus eliminating the need for a manual phase-error corrector. The circuit may also be able to adjust the width and/or the height of a scan region, and thus may also be able to adjust the width and/or height of an image frame within the scan region.
Abstract:
An image forming apparatus includes a plurality of image forming stations each having an image carrier and forming an image on the image carrier; a mark detecting unit for detecting a plurality of registration correction marks formed on a recording medium by the plurality of image forming stations; a correction mechanism for correcting a position difference between images formed by the plurality of image forming stations in accordance with a detection result by the mark detecting unit; and a controller for independently controlling an image forming operation of each of the plurality of the image forming stations so that the image density of each of the registration correction marks formed by the plurality of image forming units has a different predetermined image density.
Abstract:
A color registration control method is provided. The color registration control method includes developing a registration pattern with predetermined colors by overlapping a left-half pattern and a right-half pattern of a second pattern, and a left-half pattern and a right-half pattern of a first pattern, which are arranged symmetrically to a center, respectively, in a scanning direction; detecting density information of the left-half pattern and the right-half pattern of the registration pattern by using a first and a second density sensor, and sending the detected information to a comparator; calculating a color registration error by comparing the density of the left-half pattern with the density of the right-half pattern; and outputting from the control unit a color registration control signal according to an error signal received by the comparator.
Abstract:
An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.