DIFFUSER PLATE, DISPLAY DEVICE, PROJECTION DEVICE, AND LIGHTING DEVICE

• US 20180203334A1
• Filed: 06/23/2016
• Published: 07/19/2018
• Est. Priority Date: 07/16/2015
• Status: Active Grant

• Current Assignee: Dexerials Corporation
• Original Assignee: Dexerials Corporation
• Inventors: HANASHIMA, Naoki
• Granted Patent: US 10,599,022 B2
• Time in Patent Office: Days
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: H04N 9/3152 for shaping the light beam beam shaping per se G02B27/09

Abstract

There is provided a diffuser plate, a display device, a projection device, and a lighting device that can achieve flat diffusion angle distribution characteristics while reducing a high-order diffraction component, the diffuser plate including: a single lens group positioned on a surface of a transparent substrate, in which curvature radii of respective single lenses composing the single lens group are varied as a whole, and peak positions of the respective single lenses are located irregularly, and a lens surface shape of at least one of the single lenses in the single lens group satisfies Equation 1 and Equation 2.

Claims

1. A microlens array diffuser plate comprising a single lens group positioned on a surface of a transparent substrate,

wherein curvature radii of respective single lenses composing the single lens group are varied as a whole, and peak positions of the respective single lenses are located irregularly, and

a lens surface shape of at least one of the single lenses in the single lens group satisfies the following Equation 1 and Equation 2,

2. The diffuser plate according to claim 1, wherein

the respective single lenses are located adjacent to each other.

3. The diffuser plate according to claim 2, wherein

a boundary between the single lenses adjacent to each other includes a curving line.

4. The diffuser plate according to claim 1, wherein

the curvature radius of the single lens is larger than a maximum value of a pitch between single lenses in the single lens group, and in a case in which a circumscribed circle that circumscribes a single lens is considered, a minimum value of a diameter of the circumscribed circle in the single lens group is larger than the maximum value of the pitch between the single lenses.

5. The diffuser plate according to claim 1, wherein

the peak positions of the respective single lenses composing the single lens group are located irregularly within a range of a radius Δ

r with respect to positions of peaks of the respective single lenses in a case in which the single lenses are located regularly, and

in a case in which a circumscribed circle that circumscribes a single lens is considered, the respective single lenses composing the single lens group satisfy Δ

r/a≠

0, where a represents a diameter of the circumscribed circle in each single lens.

6. The diffuser plate according to claim 1, wherein

the transparent substrate is any of a quartz glass, a borosilicate glass, or a white plate glass.

7. A display device comprising the diffuser plate according to claim 1.

8. A projection device comprising the diffuser plate according to claim 1.

9. A lighting device comprising the diffuser plate according to claim 1.