US-20260126738-A1 - IMAGE FORMING APPARATUS

Abstract

An image forming apparatus includes an exposure device, a driving control unit, and an exposure control unit. The exposure device is configured to expose a photoconductor drum with light while scanning the light and thereby form an electrostatic latent image. The driving control unit is configured to generate a secondary-scanning-directional reference signal. The exposure control unit is configured to generate a secondary-scanning-directional synchronization signal in synchronization with a primary-scanning-directional reference signal correspondingly to an edge of the secondary-scanning-directional reference signal, and control the exposure device and thereby cause the exposure device to form an electrostatic latent image corresponding to an image signal in synchronization with the secondary-scanning-directional synchronization signal. Further, the driving control unit generates the secondary-scanning-directional reference signal with a waveform that includes at least one additional edge within a predetermined period from the edge.

Inventors

• Masanori KYOGOKU

Assignees

• KYOCERA DOCUMENT SOLUTIONS INC.

Dates

Publication Date

20260507

Application Date

20251104

Priority Date

20241107

Claims (5)

1. 1 . An image forming apparatus, comprising: an exposure device configured to expose a photoconductor drum with light while scanning the light and thereby form an electrostatic latent image; a driving control unit configured to generate a secondary-scanning-directional reference signal; and an exposure control unit configured to generate a secondary-scanning-directional synchronization signal in synchronization with a primary-scanning-directional reference signal correspondingly to an edge of the secondary-scanning-directional reference signal, and control the exposure device and thereby cause the exposure device to form an electrostatic latent image corresponding to an image signal in synchronization with the secondary-scanning-directional synchronization signal; wherein the driving control unit generates the secondary-scanning-directional reference signal with a waveform that includes at least one additional edge within a predetermined period from the edge.
2. 2 . The image forming apparatus according to claim 1 , wherein the exposure control unit comprises an edge detection flag that indicates an edge detection status of the secondary-scanning-directional reference signal, and detects the edge or the additional edge by referring to the edge detection flag; and the edge detection flag is reset by the primary-scanning-directional reference signal.
3. 3 . The image forming apparatus according to claim 1 , wherein the driving control unit generates the secondary-scanning-directional reference signal with a waveform that includes plural additional edges within a predetermined time from the edge.
4. 4 . The image forming apparatus according to claim 1 , wherein the exposure control unit adjusts an image position in a secondary scanning direction correspondingly to a number of detected edges of the secondary-scanning-directional reference signal within one cycle of the primary-scanning-directional reference signal.
5. 5 . The image forming apparatus according to claim 1 , wherein the predetermined period is either equal to or less than a half of a cycle of the primary-scanning-directional reference signal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application relates to and claims priority rights from Japanese Patent Application No. 2024-194862, filed on Nov. 7, 2024, the entire disclosures of which are hereby incorporated by reference herein. BACKGROUND 1. Field of the Present Disclosure The present disclosure relates to an image forming apparatus. 2. Description of the Related Art An electrographic image forming apparatus (a) generates a primary-scanning-directional reference signal corresponding to an exposure scanning period of a photoconductor, (b) generates a secondary-scanning-directional reference signal correspondingly to the primary-scanning-directional reference signal, and (c) determines a position of an image to be formed on the photoconductor on the basis of the secondary-scanning-directional reference signal. FIG. 7 shows a diagram that explains generating a secondary-scanning-directional synchronization signal in synchronization with a primary-scanning-directional reference signal on the basis of a secondary-scanning-directional reference signal. In such an image forming apparatus as mentioned, an exposure control unit controls exposure of a photoconductor drum, a driving control unit generates the secondary-scanning-directional reference signal used to generate a secondary-scanning-directional synchronization signal, and if the exposure control unit and the driving control unit operate asynchronously with each other, then as shown in FIG. 7, for example, the secondary-scanning-directional reference signal VSYNCref outputted by the driving control unit is inputted to the exposure control unit, and when the exposure control unit detects an edge of the secondary-scanning-directional reference signal VSYNCref, the exposure control unit generates the secondary-scanning-directional synchronization signal in synchronization with the first primary-scanning-directional reference signal (BD signal) after the detection of the edge, and resets an edge detection status of the secondary-scanning-directional reference signal VSYNCref for next edge detection. FIG. 8 shows a diagram that explains a case that the secondary-scanning-directional synchronization signal is not properly generated. However, the driving control unit operates asynchronously with the exposure control unit and therefore, as shown in FIG. 8, for example, when the exposure control unit resets the edge detection status in synchronization with the primary-scanning-directional reference signal (BD signal) before the edge detection of the secondary-scanning-directional reference signal VSYNCref, the edge of the secondary-scanning-directional reference signal VSYNCref may not be properly detected. Specifically, when the edge detection by the exposure control unit is repeatedly performed with a cycle TD, if the BD signal appears until the TD elapses from a timing of an edge of the secondary-scanning-directional reference signal VSYNCref, then the edge of the secondary-scanning-directional reference signal VSYNCref may not be properly detected. If the edge of the secondary-scanning-directional reference signal VSYNCref is not detected, then the secondary-scanning-directional synchronization signal VSYNC is not generated as shown in FIG. 8, for example. SUMMARY An image forming apparatus according to an aspect of the present disclosure includes an exposure device, a driving control unit, and an exposure control unit. The exposure device is configured to expose a photoconductor drum with light while scanning the light and thereby form an electrostatic latent image. The driving control unit is configured to generate a secondary-scanning-directional reference signal. The exposure control unit is configured to generate a secondary-scanning-directional synchronization signal in synchronization with a primary-scanning-directional reference signal correspondingly to an edge of the secondary-scanning-directional reference signal, and control the exposure device and thereby cause the exposure device to form an electrostatic latent image corresponding to an image signal in synchronization with the secondary-scanning-directional synchronization signal. Further, the driving control unit generates the secondary-scanning-directional reference signal with a waveform that includes at least one additional edge within a predetermined period from the edge. These and other objects, features and advantages of the present disclosure will become more apparent upon reading of the following detailed description along with the accompanied drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side view that indicates an internal mechanical configuration of an image forming apparatus in an embodiment according to the present disclosure; FIG. 2 shows a diagram that indicates an example of a configuration of an exposure device 2 shown in FIG. 1 and a peripheral configuration of the exposure device 2; FIG. 3 shows a block diagram that indicates an electronic configurat