Led-array light source

• US 5,639,158 A
• Filed: 08/17/1995
• Issued: 06/17/1997
• Est. Priority Date: 08/19/1994
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Sato, Yuko
• Primary Examiner(s): Gromada, Denise L.
• Assistant Examiner(s): Sember, Thomas M.
• Application Number:
  US08/516,485
• Time in Patent Office: 670 Days
• Field of Search: 362/26, 362/27, 362/30, 362/29, 362/240, 362/241, 362/237, 362/247, 362/249, 362/252, 362/800, 362/298, 362/300, 362/301, 362/307, 362/311, 362/346, 355/228, 355/229, 355/70, 313/500, 313/512
• US Class Current: 362/247
• CPC Class Codes: H04N 1/02815 Means for illuminating the original, not specific to a particular type of pick-up head
• CPC Class Codes: H04N 1/02865 using an array of light sources or a combination of such arrays, e.g. an LED bar
• CPC Class Codes: H04N 1/02885 Means for compensating spatially uneven illumination, e.g. an aperture arrangement
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An LED-array light source comprises an LED-array and a light-transmitting member disposed thereon. The light-transmitting member has a pair of opposed major surface for receiving and emitting output light emitted from the LED-array. A plurality of a first reflectors are formed on a light emitting surface of the light-transmitting member so as to partially reflect the output light toward a light-receiving surface of the light-transmitting member. A second light reflector is provided on the light receiving surface of the light-transmitting member so as to rereflect the light reflected from the first reflector to the emitting surface and thereby guiding the output light from the LED-array to an intermediate area between adjacent LEDs. Thus, it is possible to obtain a uniform linear light source with small number of LEDs.

Claims

1. An LED-array light source comprising an LED-array having a plurality of LEDs aligned in a first direction;

a light-transmitting member elongated along said first direction so as to be disposed above said LED-array, said light-transmitting member having a first surface for receiving output light from said LED-array and a second surface for emitting said output light received at said first surface;

a plurality of first light reflecting members provided on said second surface for reflecting said output light toward said first surface, each of said first light reflecting members having a central region opposite to each of said LEDs and a pair of peripheral regions opposite to an outside area of each of said LEDs; and

a second light reflecting member provided on said first surface to reflect light reflected by said first light reflecting members toward said second surface.

2. An LED-array light source claimed in claim 1, wherein said second light reflecting member has a plurality of windows for passing said output light from said LED-array.

3. An LED-array light source claimed in claim 1, wherein each of said first light reflecting members has a parallel grid-shaped pattern.

4. An LED-array light source claimed in claim 1, wherein each of said peripheral regions of said first light reflecting member has a width smaller than that of said central region thereof.

5. An LED-array light source claimed in claim 1, wherein all of said first light reflecting members have the same width.

6. An LED-array light source claimed in claim 1, wherein said light-transmitting member is a cylindrical member having a longitudinal axis along said first direction.

7. An LED-array light source claimed in claim 3, wherein each grid of said first parallel grid-shaped pattern is extended in a second direction orthogonal to said first direction.

8. An LED-array light source claimed in claim 5, wherein each said first light reflecting member has a width smaller than a gap between adjacent said first reflecting members.