Optical scanning apparatus having a fixed compound reflective assembly for two-dimensional scan capability and method thereof

• US 5,635,708 A
• Filed: 06/14/1995
• Issued: 06/03/1997
• Est. Priority Date: 06/14/1994
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Obata, Kenzo
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US08/490,526
• Time in Patent Office: 720 Days
• Field of Search: 250/234, 250/235, 250/208.2, 250/566, 250/568, 250/201.1, 250/201.2, 250/203.1-203.6, 235/472, 235/462, 359/201, 359/202, 359/224, 359/212-214, 348/771
• US Class Current: 250/234
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G06K 7/10594 Beam path

Abstract

An optical scanner with high optical scanning speed without low optical information detection accuracy and which has superior shock and vibration resistance because of its light weight has a scanner used for directing the reflected light to a light receiving element during optical scanning of an object to be read. The scanner has an optical scanning mirror and multiple light receiving mirrors placed at the sides of the scanning member. Each of the mirrors are mounted on a base, through supporting columns and beams so that they can be displaced in two-dimensional directions. Also, electrodes are provided opposite each of the mirrors on the base. Then, by generating electrostatic force through the application of electric voltage between the electrodes and the mirrors, the optical scanning mirror is displaced in the optical scanning direction with all of the reflective sides of each of the light receiving mirrors displaced to form a convex shape that always direct the reflected light to the light receiving element. As a result, optical scanning can be performed at a high speed with miniaturization of the apparatus possible.

Claims

1. A light receiving assembly for an optical scanning apparatus, said assembly comprising:

a substrate;

a plurality of light receiving member support means disposed on said substrate; and

a plurality of light receiving members, each of said light receiving members being mounted on a respective one of said plurality of light receiving member support means;

wherein each of said light receiving member support means is for rotating its respective light receiving member about a first axis and about a second axis different from said first axis.

2. The light receiving assembly of claim 1, wherein each of said light receiving member support means comprises:

connecting means for flexibly connecting to said light receiving member support means'"'"' respective light receiving member and to said substrate; and

force generating means for generating a force between said respective light receiving member and said substrate to move said respective light receiving member and deform said connecting means.

3. The light receiving assembly of claim 1, wherein said plurality of light receiving members are reflective elements.

4. The light receiving assembly of claim 1, wherein said plurality of light receiving members are photoelectric elements.

5. The light receiving assembly of claim 2, wherein:

said force generating means comprises a plurality of electrodes electrically separate from said respective light receiving member to be capable of generating an electrostatic force thereon; and

said plurality of electrodes are four electrodes capable of moving said respective light reflective member in a two-dimensional direction.

6. The light receiving assembly of claim 1, further comprising:

a scanning member support means disposed on said substrate; and

a light scanning member mounted on said light scanning member support means;

wherein said light scanning member support means is for moving said light scanning member in at least a one-dimensional direction.

7. The light receiving assembly of claim 6, wherein said light scanning member is a reflective element.

8. The light receiving assembly of claim 6, wherein said light scanning member is a light generating element.

9. A light receiving assembly for an optical scanning apparatus in which light reflected from an information-bearing reading target irradiated by a light beam illuminates said assembly, said assembly comprising:

a substrate;

a scanning member support means disposed on said substrate;

a light scanning member, for generating said light beam irradiating said reading target, mounted on said light scanning member support means, said light scanning member support means being for moving said light scanning member in at least a one-dimensional direction to thereby change a point of irradiation of said reading target by said light beam responsive to movement of said light scanning member by said light scanning member support means;

a plurality of light receiving member support means disposed on said substrate; and

a plurality of light receiving members, each of said light receiving members being mounted on a respective one of said plurality of light receiving member support means to receive light reflected by said reading target in a plurality of directions and reflect said received light to a sensor for generating an electrical signal representative of said information on said reading target;

wherein each of said light receiving member support means is for moving its respective light receiving member in at least a one-dimensional direction responsive to movement of said scanning member.

10. The light receiving assembly of claim 9, wherein said plurality of light receiving member support means and said plurality of light receiving members are disposed in an array.

11. The light receiving assembly of claim 9, wherein said light scanning member is a reflective element.

12. The light receiving assembly of claim 9, wherein said light scanning member is a light generating element.

13. The light receiving assembly of claim 9, wherein said light scanning member support means is further for moving said light scanning member in a two-dimensional direction.

14. The light receiving assembly of claim 9, wherein each of said light receiving member support means comprises:

connecting means for flexibly connecting to said light receiving member support means respective light receiving member and to said substrate; and

force generating means for generating a force between said respective light receiving member and said substrate to move said respective light receiving member and deform said connecting means.

15. The light receiving assembly of claim 14, wherein said connecting means includes an inorganic elastic material.

16. The light receiving assembly of claim 14, wherein said force generating means comprises a plurality of electrodes electrically separate from said respective light receiving member to be capable of generating an electrostatic force thereon.

17. The light receiving assembly of claim 16, wherein said connecting means is electrically connected to said respective light receiving member to be capable of connecting said respective light receiving member to a source of reference potential.

18. The light receiving assembly of claim 16, wherein said plurality of electrodes are two electrodes capable of moving said respective light reflective member in a one-dimensional direction.

19. The light receiving assembly of claim 16, wherein said plurality of electrodes are four electrodes capable of moving said respective light reflective member in a two-dimensional direction.

20. A light receiving assembly for an optical scanning apparatus in which light reflected from an information-bearing reading target irradiated by a light beam illuminates said assembly, said assembly comprising:

a substrate;

a scanning member support means disposed on said substrate;

a light scanning member, for generating said light beam irradiating said reading target, mounted on said light scanning member support means, said light scanning member support means being for moving said light scanning member in at least a one-dimensional direction to thereby change a point of irradiation of said reading target by said light beam responsive to movement of said light scanning member by said light scanning member support means;

a plurality of light receiving member support means disposed on said substrate; and

a plurality of light receiving members, each of said light receiving members being mounted on a respective one of said plurality of light receiving member support means to receive light reflected by said reading target in a plurality of directions and reflect said received light to a sensor for generating an electrical signal representative of said information on said reading target;

wherein each of said light receiving member support means is for moving its respective light receiving member in at least a one-dimensional direction responsive to movement of said scanning member at a timing having a same time period as a period of movement of said light scanning member so that said plurality of light receiving members receive light from said reading target at a same irradiation position, said light receiving member support means maintaining a relative angle between said light scanning member and respective ones of said light receiving members.

21. The light receiving assembly of claim 20, wherein said plurality of light receiving member support means and said plurality of light receiving members are disposed in an array.

22. The light receiving assembly of claim 20, wherein said light scanning member is a reflective element.

23. The light receiving assembly of claim 20, wherein said light scanning member is a light generating element.

24. The light receiving assembly of claim 20, wherein said light scanning member support means is further for moving said light scanning member in a two-dimensional direction.

25. The light receiving assembly of claim 20, wherein each of said light receiving member support means comprises:

connecting means for flexibly connecting to said light receiving member support means respective light receiving member and to said substrate; and

force generating means for generating a force between said respective light receiving member and said substrate to move said respective light receiving member and deform said connecting means.

26. The light receiving assembly of claim 25, wherein said connecting means includes an inorganic elastic material.

27. The light receiving assembly of claim 25, wherein said force generating means comprises a plurality of electrodes electrically separate from said respective light receiving member to be capable of generating an electrostatic force thereon.

28. The light receiving assembly of claim 27, wherein said connecting means is electrically connected to said respective light receiving member to be capable of connecting said respective light receiving member to a source of reference potential.

29. The light receiving assembly of claim 27, wherein said plurality of electrodes are two electrodes capable of moving said respective light reflective member in a one-dimensional direction.

30. The light receiving assembly of claim 27, wherein said plurality of electrodes are four electrodes capable of moving said respective light reflective member in a two-dimensional direction.