Geometric LED layout for line exposure

• US 4,589,745 A
• Filed: 01/25/1985
• Issued: 05/20/1986
• Est. Priority Date: 01/25/1985
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Plummer, William T.
• Primary Examiner(s): Perkey, William B.
• Application Number:
  US06/695,072
• Time in Patent Office: 480 Days
• Field of Search: 354/4, 354/5, 346/107 R, 250/553, 340/762, 340/782, 178/15, 178/30
• US Class Current: 396/548
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: H04N 1/036 for optical reproduction
• CPC Class Codes: H04N 1/193 using electrically scanned linear arrays , e.g. linear CCD arrays

Abstract

A line exposure array of light emitting diodes arranged in spaced apart relationship with respect to each other along the longitudinal axis thereof and geometrically configured to provide a substantially uniform exposure of a photosensitive material without underexposed stripes appearing on those areas of the photosensitive material immediately adjacent the spaces between the light emitting diodes.

Claims

1. A line exposure array comprising:

an elongated substrate;

having a longitudinal axis and

a plurality of light emitting elements disposed in spaced apart relation along the longitudinal axis of said substrate, each of said light emitting elements being defined by two substantially parallel spaced apart edge lines extending generally in directions parallel to the longitudinal axis of said substrate and interconnected at respective ends thereof by skewed edge lines extending in directions generally oblique to the longitudinal axis of said substrate.

2. The line exposure array of claim 1 wherein said light emitting elements comprise light emitting diodes.

3. The line exposure array of claim 2 wherein at least portions of said skewed edge lines of adjacent light emitting diodes are arranged in substantially parallel spaced apart relation with respect to each other.

4. The line exposure array of claim 3 wherein said edge lines for each of said light emitting diodes are structured to define a trapezoid.

5. The line exposure array of claim 4 wherein each light emitting diode is offset with respect to its immediately adjacent diodes by a select distance in a direction orthogonal to the longitudinal center axis of said substrate.

6. In an electronic image recording apparatus responsive to an electrical signal input representative of a select image for recording that image by exposing a photosensitive material, said image recording apparatus comprising:

a line exposure array having a longitudinal axis and including a plurality of light emitting elements disposed in spaced apart relation along the longitudinal axis of said exposure array, each of said light emitting elements being defined by two substantially parallel spaced apart edge lines extending generally in directions parallel to the longitudinal axis of said line exposure array and interconnected at respective ends thereof by skewed edge lines extending in directions generally oblique to the longitudinal axis of said line exposure array; and

means for holding said line exposure array in light exposing relationship across the photosensitive material and for effecting a relative displacement between said line exposure array and the photosensitive material in a direction transverse to the longitudinal axis of said exposure array to expose the entire surface of the photosensitive material.

7. The apparatus of claim 6 wherein said light emitting elements comprise light emitting diodes.

8. The apparatus of claim 7 wherein at least portions of said skewed edge lines of adjacent light emitting diodes are arranged in substantially parallel spaced apart relation with respect to each other.

9. The apparatus of claim 8 wherein said edge lines for each of said light emitting diodes are structured to define a trapezoid.

10. The apparatus of claim 8 wherein each light emitting diode is offset with respect to its immediately adjacent diodes by a select distance in a direction orthogonal to the longitudinal center axis of said substrate.