Image forming apparatus and semiconductor laser modulation driving apparatus

• US 20050089069A1
• Filed: 09/16/2004
• Published: 04/28/2005
• Est. Priority Date: 09/22/2003
• Status: Abandoned Application

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ishida, Masaaki, Nihei, Yasuhiro, Omori, Atsufumi, Ozasa, Dan
• Application Number:
  US10/942,073
• Publication Number:
  US 20050089069A1
• Time in Patent Office: Days
• US Class Current: 372/26
• CPC Class Codes: G06K 15/129 Colour printing

Abstract

A color image forming apparatus produces a latent image on a photosensitive body based on a signal output from a scanning light detecting part in response to detection of scanning light; a semiconductor laser modulation signal generating part includes a clock generating part and a clock modulation part; a semiconductor laser and a semiconductor laser driving part are provided for each color of yellow, magenta, cyan and black; and further, a plurality of the semiconductor lasers are provided for at least one color of yellow, magenta, cyan and black.

Claims

1. A color image forming apparatus comprising:

a semiconductor laser;

a semiconductor laser modulation signal generating part generating a signal for modulating said semiconductor laser;

a semiconductor laser driving part driving said semiconductor laser based one the semiconductor laser modulation signal;

a scanning part scanning a photosensitive body with light output by said semiconductor laser; and

a scanning light detecting part detecting the scanning light output by said semiconductor laser at a predetermined position, wherein;

said color image forming apparatus produces a latent image on the photosensitive body based on a signal output from said scanning light detecting part in response to detection of the scanning light;

said semiconductor laser modulation signal generating part comprises a clock generating part and a clock modulation part;

said semiconductor laser and said semiconductor laser driving part are provided for each color of yellow, magenta, cyan and black; and

further, a plurality of the semiconductor lasers are provided for at least one color of yellow, magenta, cyan and black.

2. The color image forming apparatus as claimed in claim 1, wherein:

said semiconductor laser driving part is produced in a form of a single chip.

3. The color image forming apparatus as claimed in claim 1, wherein:

the semiconductor laser driving parts for two or three colors of yellow, magenta, cyan and black are produced in a form of a single chip.

4. The color image forming apparatus as claimed in claim 1, wherein:

the semiconductor laser driving parts for all colors of yellow, magenta, cyan and black are produced in a form of a single chip.

5. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is provided individually for each color of yellow, magenta, cyan and black.

6. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is provided individually for two or three colors of yellow, magenta, cyan and black.

7. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is provided individually for all colors of yellow, magenta, cyan and black.

8. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is produced in a form of single chip for each color of yellow, magenta, cyan and black.

9. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is produced in a form of a single chip for two or three colors of yellow, magenta, cyan and black.

10. The color image forming apparatus as claimed in claim 1, wherein;

the semiconductor laser modulation signal generating part is produced in a form of a single chip for all colors of yellow, magenta, cyan and black.

11. The color image forming apparatus as claimed in claim 1, wherein:

the clock generating part is provided for each color of yellow, magenta, cyan and black.

12. The color image forming apparatus as claimed in claim 1, wherein:

clock signals for all colors of yellow, magenta, cyan and black are generated by two or three clock generating parts.

13. The color image forming apparatus as claimed in claim 1, wherein:

the single clock generating part generates respective clock signals for all colors of yellow, magenta, cyan and black.

14. A semiconductor laser modulation deriving apparatus comprising:

a semiconductor laser;

a semiconductor laser modulation signal generating part generating a semiconductor laser modulation signal for modulating the semiconductor laser; and

a semiconductor laser driving part driving the semiconductor laser based on the semiconductor laser modulation signal, wherein;

said semiconductor laser modulation driving apparatus transmits the semiconductor laser modulation signal from the semiconductor laser modulation signal generating part to the semiconductor laser driving part as a differential signal with a reduced amplitude, and

both an input part in the semiconductor laser driving part and an output part in the semiconductor modulation signal driving part are configured in a CML type.

15. The semiconductor laser modulation driving apparatus as claimed in claim 14, wherein:

a load of the CML circuit is configured by a resistor or a resistance.

16. The semiconductor laser modulation driving apparatus as claimed in claim 14, wherein;

the CML circuit comprises a plurality of stages.

17. The semiconductor laser modulation driving apparatus as claimed in claim 14, wherein;

one input of the CML circuit is provided as a fixed voltage.

18. The semiconductor laser modulation driving apparatus as claimed in claim 14, wherein:

a current source for the CML circuit is configured to comprise a resistor or a resistance.

19. The semiconductor laser modulation driving apparatus as claimed in claim 14, wherein:

a load resistor or a resistance of the CML circuit is provided as an external component.

20. An image forming apparatus comprising:

at least one light source;

a deflecting part deflecting a laser beam emitted from said at least one light source; and

a leading part leading the laser beam deflected by said deflecting part toward a to-be-scanned medium, wherein;

said at least one light source is driven by the semiconductor laser modulation driving apparatus claimed in claim 14.

21. A color image forming apparatus in a tandem type comprising:

at least one light source;

a deflecting part deflecting a laser beam emitted from said at least one light source; and

a leading part leading the laser beam deflected by said deflecting part toward a plurality of to-be-scanned media, wherein;

said image forming apparatus scans said plurality of to-be-scanned media with the laser beams led by said leading part and forms images on the to-be-scanned mediums, respectively; and

said at least one light source is driven by the semiconductor laser modulation driving apparatus claimed in claim 14.

22. A color image forming apparatus comprising:

a semiconductor laser;

a semiconductor laser modulation signal generating part generating a signal for modulating said semiconductor laser;

a semiconductor laser driving part driving said semiconductor laser based one the semiconductor laser modulating signal;

a scanning part scanning a photosensitive body with light output of said semiconductor laser; and

a scanning light detecting part detecting the scanning light output by said semiconductor laser at a predetermined position, wherein;

said color image forming apparatus produces a latent image on the photosensitive body based on a signal output from said scanning light detecting part in response to detection of the scanning light;

said semiconductor laser modulation signal generating part comprises a clock generating part and a clock modulation part;

said semiconductor laser and said semiconductor laser driving part are provided for each color of yellow, magenta, cyan and black;

further, a plurality of the semiconductor lasers are provided for at least one color of yellow, magenta, cyan and black;

the semiconductor laser modulation signal is transmitted from the semiconductor laser modulation signal generating part to the semiconductor laser driving part as a differential signal with a reduced amplitude; and

both an input part in the semiconductor laser driving part and an output part in the semiconductor modulation signal driving part are configured in a CML type.

23. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is provided individually for each color of yellow, magenta, cyan and black.

24. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is provided individually for two or three colors of yellow, magenta, cyan and black.

25. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is provided individually for all colors of yellow, magenta, cyan and black.

26. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is produced in a form of a single chip for each color of yellow, magenta, cyan and black.

27. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is produced in a form of a single chip for two or three colors of yellow, magenta, cyan and black.

28. The color image forming apparatus as claimed in claim 22, wherein;

the semiconductor laser modulation signal generating part is produced in a form of a single chip for all colors of yellow, magenta, cyan and black.