LIGHT BOX

• US 20110063850A1
• Filed: 09/21/2009
• Published: 03/17/2011
• Est. Priority Date: 03/22/2007
• Status: Abandoned Application

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Ikeda, Hideyuki, Oide, Ken, Ishii, Shunji
• Application Number:
  US12/563,541
• Publication Number:
  US 20110063850A1
• Time in Patent Office: Days
• US Class Current: 362/296.01
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light box includes a point like light source, a light reflecting plate arranged around said point like light source and a light diffusion surface plate having light transmissive property and arranged to face said light reflecting plate. The light box can include a case having an opening formed in a direction of light and for housing at least said point like light source and said light reflecting plate inside. Additionally, a receiving concave portion is formed with said light reflecting plate, said point like light source is allocated inside said receiving concave portion, an injection angle of the light from said point like light source is 0°, and a brightness is less than or equal to 15000 cd/m² when spaced apart a distance of 350 mm, and a part or all of the light from said point like light source is provided for an illumination after reflecting at an inner surface of a circumferential wall of said receiving concave portion.

Claims

1. A light box comprised of:

a point like light source;

a light reflecting plate arranged around said point like light source;

a light diffusion surface plate having light transmissive property and arranged to face said light reflecting plate;

a case having an opening formed in a direction of light and for housing at least said point like light source and said light reflecting plate inside; and

wherein

a receiving concave portion is formed with said light reflecting plate, said point like light source is allocated inside said receiving concave portion, an injection angle of the light from said point like light source is 0°

, and a brightness is less than or equal to 15000 cd/m² when spaced apart a distance of 350 mm, and a part or all of the light from said point like light source is provided for an illumination after reflecting at an inner surface of a circumferential wall of said receiving concave portion.

2. The light box according to claim 1, wherein

said point like light source is a light source module, which is arranged in an array on a circuit board, or modularized with a single or a plurality of point like light sources.

3. The light box according to claim 1, wherein the point like light source comprises an LED with a point like light emitting portion sealed by a sealing member.

4. The illumination device according to claim 3, wherein the sealing member is equipped with a light diffusion means.

5. The illumination device according to claim 4, wherein the sealing member comprises a bombshell type sealing member equipped with a light diffusion, or a prism type or a concave lens type sealing member.

6. The light box according to claim 1, wherein

said point like light source includes a light flux control member to scatter the light from its emitting portion.

7. The light box according to claim 2, wherein

said point like light source includes a light flux control member to scatter the light from its emitting portion.

8. The light box according to claim 3, wherein

said point like light source includes a light flux control member to scatter the light from its emitting portion.

9. The light box according to claim 4, wherein

said point like light source includes a light flux control member to scatter the light from its emitting portion.

10. The light box according to claim 5, wherein

said point like light source includes a light flux control member to scatter the light from its emitting portion.

11. The light box according to claim 2, wherein

said light source module is provided with a light flux control member formed by sealing a board in which an LED is implemented with a sealing member to scatter the light from the LED to emit on a surface located on an optical axis of the light from the LED.

12. The light box according to claim 2, wherein the point like light source module is formed such that the light generated from the light emitting portion is emitted through a light flux control member, or the light generated from the light emitting portion is emitted through the sealing member and the light flux control member in this order,

the light flux control member includes a light incident face into which the light from the light emitting portion enters the light flux control member, and a light control emitting face to control the light emission from the light emitting portion,

concerning the light ranging between a direction to which at least maximum strength light is emitted from the LED and a direction to which one half of strength light of the maximum strength light is emitted, the light control emitting face is formed to satisfy a relation between θ

1 and θ

5 to be (θ

5/θ

1)>

1 excluding the light in a vicinity of a reference plane, where the angle formed between the light entering the light flux control member and reaching the light control emitting face, and the line parallel to a reference light axis of the light source module and passing the reaching point is represented by the angle θ

1, and an angle of the emission of the light from the light control emitting face is referred to as the angle θ

5, and the light control emitting face is formed to be the shape in such fashion that a value of θ

5/θ

1 is gradually reduced as the θ

1 increases.

13. The light box according to claim 1, wherein

said receiving concave portion is formed in a reversed multi sided pyramid shape or a reversed multi sided pyramid shape, with a top thereof cut, surrounding said point like light source.

14. The light box according to claim 1, wherein

an apex portion of said receiving concave portion is respectively connected to an apex portion of an adjacent receiving concave portion, and an apex portion of said receiving concave portion is located on a location at or below a bisection point of a distance from an emitting portion of said point like light source to said light diffusion surface plate, and at or above an emitting portion of said point like light source.

15. The illustration device according to claim 1, wherein a diffuse reflectivity of a visible light in the light reflecting plate is at least 80%.

16. The illustration device according to claim 1, wherein the light reflecting plate comprises a thermoplastic resin film or sheet which has fine foams or pores having an average diameter within the range from at least wavelength of the light to 50 μ

m inside thereof.

17. The illustration device according to claim 16, wherein the thermoplastic film or sheet comprises a thermoplastic polyester foam having a thickness of within the range of from 150 to 2000 μ

m, and a specific gravity of within the range of from 0.1 to 0.7.

18. The light box according to claim 1, wherein

a total light ray transmissivity of said light diffusion surface plate is 20-70%.

19. The light box according to claim 1, wherein

a depth distance of said case is formed in a range of 40-60 mm, and said plurality of point like light sources are arranged in a matrix having intervals of longitudinal and lateral directions respectively in a range of 80-120 mm.

20. The light box according to claim 1, wherein

a depth distance of said case is formed in a range of 20-40 mm, and said plurality of point like light sources are arranged in a matrix having intervals of longitudinal and lateral directions respectively in a range of 40-80 mm.