Instant portable bar code reader

• US 4,570,057 A
• Filed: 08/06/1984
• Issued: 02/11/1986
• Est. Priority Date: 12/28/1981
• Status: Expired due to Term

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Norand Corporation (Baker Hughes Company)
• Inventors: Laser, Vadim, Chadima, George E. Jr.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US06/637,693
• Time in Patent Office: 554 Days
• Field of Search: 235/472, 235/455, 235/462
• US Class Current: 235/462.45
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10772 Moved readers, e.g. pen, wand
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners

Abstract

An improved bar code reader unit. The bar code is hand-held and has improved focussing and illumination structure.

Claims

1. In a portable bar code reader a hand-held bar code reader unit having an elongated relatively narrow hand grip portion for grasping in the hand of a user and having an enlarged reader head portion of greater width than said hand grip portion,

said elongated hand grip portion having a length and cross sectional configuration so as to be grasped by the hand with all fingers in gripping relation thereto, and said enlarged reader head portion having a length less than the length of said elongated hand grip portion,

said reader head portion having extended window means with a width dimension greater than the width of said hand grip portion which is to be gripped by the fingers of a hand,

extended light source means in said reader head portion for producing a sheet of light energy directed outwardly from the reader head portion through said window means over substantially the entire width of said window means so as to flood a bar code sensing region in front of said window means having a width dimension approximately equal to the width of said window means, having a depth dimension equal to at least about ten millimeters and a height dimension equal to at least about one millimeter, such that a bar code pattern in the sensing region will reflect light from said extended light source means along an optical axis directed generally normal to said window means, and,

lens means for focusing bar code patterns in said sensing region onto an image plane in said reader unit with a resolution of at least forty line pairs per millimeter over a depth range of at least ten millimeters such that bar code patterns with marked curvature as well as flat bar code patterns are read with high resolution and accuracy.

2. In a portable bar code reader according to claim 1, said lens means focusing bar code patterns with said resolution of at least forty line pairs per millimeter over a depth range of at least ten millimeters in said sensing region such that bar code patterns with marked curvature are read with said resolution of at least forty line pairs per millimeter.

3. In a portable bar code reader according to claim 1, said reader head portion having a first mirror means spaced from said window means along said optical axis for receiving reflected light from a bar code pattern in the sensing region and for re-reflecting such light along a second optical axis directed generally toward said window means, and having a second mirror means nearer to said window means than said first mirror means, said second mirror means being disposed relative to said second optical axis so as to direct light from the first mirror means along a third optical axis toward said lens means, and said lens means being located more remote from said window means than said second mirror means.

4. In a portable bar code reader according to claim 3, said lens means having stop aperture means providing an aperture for light directed parallel to the third axis with a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, said width dimension of said aperture being not more than about two millimeters.

5. In a portable bar code reader according to claim 2, said lens means having stop aperture means with an aperture of a width dimension of about two millimeters in a lateral direction corresponding to the high resolution direction of the bar code pattern.

6. In a portable bar code reader according to claim 4, the lens means causing lateral marginal rays of the light energy from the second mirror means which lie in a lateral plane corresponding to the high resolution direction of the bar code pattern to converge in the vicinity of said aperture and thereafter to diverge so as to occupy a laterally extended region at the image plane of the reader unit, said second mirror means having an operative width between the lateral marginal rays generally corresponding to the lateral extent of the image of the bar code pattern at said image plane of the reader unit.

7. In a portable bar code reader according to claim 1, said lens means having stop aperture means with an aperture having a width dimension in a lateral direction which corresponds with the high resolution direction of a bar code pattern in the sensing region, and having a height dimension in a direction at right angles to said lateral direction, and corresponding to a direction parallel to the bar of a bar code pattern in the sensing region, the ratio of the height dimension of said aperture to said width dimension being at least about two to one.