Information reading device

• US 5,064,258 A
• Filed: 12/05/1989
• Issued: 11/12/1991
• Est. Priority Date: 12/09/1988
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Baba, Nobuyuki, Inokuchi, Toshiyuki
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Ryan
• Application Number:
  US07/446,371
• Time in Patent Office: 707 Days
• Field of Search: 350/3.7, 350/3.71, 350/6.2, 250/201.5, 369/103, 235/457
• US Class Current: 359/17
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10663 using hologram
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code

Abstract

An information reading device which comprises a semiconductor laser source which emits a semiconductor laser beam and a first condenser lens for converging the laser beam to form an irradiation beam. A beam shaping optical system is disposed on the optical path of the laser beam to form a predetermined beam section shape of the irradiation beam which is converged by the first condenser lens. A hologram disk is used for deflecting the irradiation beam. The information reading device further comprises an optical path separation system. The optical path of the irradiation beam is separated from that of the reflection beam reflected from the scanning surface irradiated by the irradiation beam. A second condenser lens is arranged from converging the reflection beam separated from the irradiation beam by the optical path separation means. And an optical sensor is arranged for detecting the reflection beam converged by the second condenser lens.

Claims

1. An information reading device comprising:

a semiconductor laser source for emitting a semiconductor laser beam;

a first condenser lens for converging said emitted laser beam to form an irradiation beam;

a beam shaping means for shaping said formed irradiation beam;

a hologram disk for deflecting said shaped irradiation beam;

an optical path separation means arranged so as to separate said shaped irradiation beam and a reflection beam from each other, said reflection beam being reflected from a surface irradiated by said deflected irradiation beam and being then deflected toward said optical path separation means by said hologram disk, said optical path separation means including a reflection portion disposed at a central portion of said optical path separation means for reflecting said shaped irradiation beam toward said hologram disk, and having the substantially same area as a cross-sectional area of said shaped irradiation beam, said cross-sectional area being defined by said optical path separation means when said shaped irradiation beam is made incident on said optical path separation means, said optical path separation means further including a transmission portion connected continuously to an outer circumference of said reflection portion so as to permit said reflection beam deflected toward said optical path separation means to be transmitted;

a second condenser lens arranged on an optical path of said transmitted reflection beam for converging said transmitted reflection beam; and

an optical sensor means for detecting said converged reflection beam.

2. An information reading device according to claim 1, which further comprises:

a first reflection means disposed between said optical path separation means and said hologram disk for reflecting said reflected irradiation beam from said reflection portion toward said hologram disk; and

a second reflection means disposed between said hologram disk and said surface for reflecting said deflected irradiation beam from said hologram disk toward said surface.

3. An information reading device according to claim 2, which further comprises a visible light source for emitting a visible beam in addition to said formed irradiation beam.

4. An information reading device according to claim 1, which further comprises a visible light source for emitting a visible beam in addition to said formed irradiation beam.

5. A hologram laser beam bar code scanner comprising:

a laser source for emitting a laser beam;

a beam deforming means for deforming said emitted laser beam in such a manner that a first length of said deformed laser beam in a vertical scanning direction becomes shorter than a second length of said emitted laser beam in said vertical scanning direction, to thereby form said deformed laser beam having a cross-sectional shape which is long in a horizontal scanning direction and is short in said vertical scanning direction;

a hologram disk means disposed between said beam deforming means and a bar code surface for deflecting said deformed laser beam to thereby produce a deflection laser beam forming on said bar code surface such a cross-sectional shape that a third length in said vertical scanning direction is approximately equal to said first length of said deformed laser beam in said vertical scanning direction and a fourth length in said horizontal scanning direction is shorter than said third length in said vertical scanning direction, and for scanning said bar code surface in said horizontal scanning direction and said vertical scanning direction with said produced deflection laser beam; and

an optical sensor for detecting a reflection laser beam which is reflected from said bar code surface and is thereafter deflected by said hologram disk means and for reading out a bar code information.

6. A hologram laser beam bar code scanner according to claim 5, in which said beam deforming means comprises a pair of cylindrical lenses spaced apart from each other.

7. A hologram laser beam bar code scanner according to claim 5, in which said beam deforming means comprises a beam deforming member provided with an aperture formed in a shape which is long in said horizontal scanning direction and is short in said vertical scanning direction.