OPTICAL SCANNING DEVICE AND IMAGE FORMING APPARATUS

• US 20110169906A1
• Filed: 12/28/2010
• Published: 07/14/2011
• Est. Priority Date: 01/13/2010
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: SUZUKI, Seizo
• Granted Patent: US 9,266,351 B2
• Time in Patent Office: Days
• US Class Current: 347/224
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: B41J 2/455 using laser arrays , the laser array being smaller than the medium to be recorded
• CPC Class Codes: B41J 2/473 using multiple light beams, wavelengths or colours
• CPC Class Codes: G02B 26/123 Multibeam scanners, e.g. using multiple light sources or beam splitters

Abstract

Each light source has plural light emitting portions that are arranged at the different positions in at least a sub-scanning corresponding direction. A memory of a scanning control device stores correction data of the deviation of the beam pitch, correction data of the light amount difference, and correction data to decrease an influence of a reciprocity failure, for each combination of pixel forming light emitting portions. When a write signal is generated, a write control circuit of the scanning control device reads the correction data of the deviation of the beam pitch, the correction data of the light amount difference, and the correction data of the reciprocity failure according to the combination of the pixel forming light emitting portions from the memory, overlaps the read correction data to correction data of an APC, and outputs the overlapped data to a corresponding light source unit as light amount correction data.

Claims

1. An optical scanning device that is used in an image forming apparatus where one pixel is formed by at least two light beams and scans a scanned surface of the image forming apparatus in a main scanning direction by the light beams, the optical scanning device comprising:

a light source that has a plurality of light emitting portions arranged at the different positions in at least a sub-scanning direction; and

a control device that controls a driving state of at least one light emitting portion included in a combination of the light emitting portions to emit at least the two light beams to form one pixel, among the plurality of light emitting portions, according to a positional relationship between at least the two light emitting portions included in the combination in the sub-scanning direction.

2. The optical scanning device of claim 1,

wherein the control device corrects driving conditions of the light emitting portions that are included in the combination.

3. The optical scanning device of claim 2,

wherein the control device corrects periodic density irregularity that is generated due to the deviation of the beam pitch on the scanned surface.

4. The optical scanning device of claim 3,

wherein the control device further corrects periodic density irregularity that is generated due to the light amount difference of the light emitting portions included in the combination.

5. The optical scanning device of claim 3,

wherein the control device further corrects periodic density irregularity that is generated due to a reciprocity failure.

6. The optical scanning device of claim 2,

wherein a plurality of combinations exists as the combination of the light emitting portions to emit at least the two light beams to form one pixel,

a table includes correction data of the driving conditions of the light emitting portions included in each of the plurality of combinations is set in advance, and

the control device refers to the table at the time of scanning, acquires the correction data that corresponds to the combination of the light emitting portions to emit at least the two light beams to form one pixel in the scanning, and corrects the driving conditions using the correction data.

7. The optical scanning device of claim 6,

wherein the correction data is correction data to correct the light emission amounts of the light emitting portions.

8. The optical scanning device of claim 1,

wherein a plurality of combinations exist as the combination of the light emitting portions to emit at least the two light beams to form one pixel,

each of the plurality of combinations has a table where the driving conditions of the light emitting portions included in the combination are set in advance, and

the control device refers to the table at the time of scanning, acquires the driving conditions that correspond to the combination of the light emitting portions to emit at least the two light beams to form one pixel in the scanning, and controls driving states of the light emitting portions included in the combination using the driving conditions.

9. The optical scanning device of claim 1,

wherein the light source is a surface emitting laser array where the plurality of light emitting portions are formed on the same substrate.

10. An image forming apparatus, comprising:

at least one image carrier; and

at least one optical scanning device that scans at least one image carrier by light modulated according to image information, the at least one optical scanning device including,

a light source that has a plurality of light emitting portions arranged at the different positions in at least a sub-scanning direction; and

a control device that controls a driving state of at least one light emitting portion included in a combination of the light emitting portions to emit at least the two light beams to form one pixel, among the plurality of light emitting portions, according to a positional relationship between at least the two light emitting portions included in the combination in the sub-scanning direction.

11. The image forming apparatus of claim 10,

wherein the image information is image information of multiple colors.