Optical device including multiple reflectors and optical systems for reading bar codes

• US 5,925,867 A
• Filed: 03/10/1997
• Issued: 07/20/1999
• Est. Priority Date: 09/27/1996
• Status: Expired due to Fees

• Current Assignee: Oki Semiconductor Company Limited (ROHM Co., Ltd.)
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Hagimoto, Mitsuru
• Primary Examiner(s): Lee, Michael G.
• Application Number:
  US08/814,259
• Time in Patent Office: 862 Days
• Field of Search: 235/454, 235/462, 235/472, 235/461, 235/467, 235/470, 235/457, 235/462.43, 235/462.45, 235/472.01, 235/472.03, 250/235, 250/568, 250/237 G, 250/208.6, 359/2, 359/3, 359/17, 359/558, 359/562, 359/563, 359/566, 359/568, 359/572
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B

Abstract

An optical device reads the information such as bar codes on an object. A light-emitting element emits a read-beam. A lens cover has an inclined surface that is at an angle with the read-beam and reflects the read-beam toward a bar code, the read-beam emerging as a reflected-beam after reflection from the surface of the bar code. The reflected-beam contains a component directly reflected from the bar code and a component randomly reflected by the white and black areas of the bar code. An optical system in the form of a lens is arranged between the lens cover and the light-emitting element, and converges the read-beam to the bar code. The inclined surface is also at an angle with the reflected-beam and reflects the reflected-beam toward a second optical system in the form of a lens which in turn converges the reflected-beam emerging from the inclined surface to a light-sensing element. The light-sensing element detects the reflected-beam. The inclination angle of the inclined surface may be selected such that more randomly reflected light is contained in the reflected-beam than the directly reflected light.

Claims

1. An optical device comprising:

a light-emitting element mounted on a head to emit a first beam of light toward an object;

a light-sensing element mounted on the head to sense a second beam of light, the second beam of light being the first beam of light reflected by a surface of the object;

a first optical system positioned to converge the first beam of light;

a second optical system positioned to converge the second beam of light substantially to the light-sensing element;

a housing in which the light emitting element, the light sensing element, and the first and second optical systems are accommodated;

a cover disposed on the housing, the cover having an inclined surface which reflects the first beam of light toward the surface of the object and reflects the second beam of light toward the light-sensing element via the second optical system; and

wherein said light-sensing element has a reflector for reflecting the second beam of light to change its direction of travel.

2. The optical device of claim 1, wherein said reflector is parallel with said cover, and said second beam of light is reflected by said reflector and subsequently by said cover.

3. An optical device comprising:

a light-emitting element mounted on a head to emit a first beam of light toward an object;

a light-sensing element mounted on the head to sense a second beam of light, the second beam of light being the first beam of light reflected by a surface of the object;

a first optical system positioned to converge the first beam of light;

a second optical system positioned to converge the second beam of light substantially to the light-sensing element;

a housing in which the light emitting element, the light sensing element, and the first and second optical systems are accommodated;

a cover disposed on the housing, the cover having an inclined surface which reflects the first beam of light toward the surface of the object and reflects the second beam of light toward the light-sensing element via the second optical system; and

wherein said light-emitting element has a reflector for reflecting the first beam of light to change its direction of travel.

4. The optical device of claim 3, wherein said reflector is parallel with said cover, said first beam of light is reflected by said cover and subsequently by said reflector.

5. An optical device comprising:

a light-emitting element mounted on a head to emit a first beam of light toward an object;

a light-sensing element mounted on the head to sense a second beam of light, the second beam of light being the first beam of light reflected by a surface of the object;

a first optical system positioned to converge the first beam of light;

a second optical system positioned to converge the second beam of light substantially to the light-sensing element;

a housing in which the light emitting element, the light sensing element, and the first and second optical systems are accommodated;

a cover disposed on the housing, the cover having an inclined surface which reflects the first beam of light toward the surface of the object and reflects the second beam of light toward the light-sensing element via the second optical system; and

wherein said inclined surface is a mirror.