# US 10,871,604 B2 · Display device and image forming apparatus

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- Number: US 10,871,604 B2
- Document ID: US10871604B2
- Status: Granted
- Kind: B2
- Application number: 16/830,593
- Filed: 2020-03-26
- Published: 2020-10-01
- Granted: 2020-12-22
- Earliest claimed: 2019-04-01
- Assignees: Brother Kogyo Kabushiki Kaisha
- Applicants: Brother Kogyo Kabushiki Kaisha
- Inventors: Hiroyuki Ominato; Toshio Sakai; Yohei Hashimoto; Masao Ichiyanagi
- Web page: https://patentgrep.com/patent/US10871604B2

## CPC

- G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces}
- G02B 6/0021: {for housing at least a part of the light source, e.g. by forming holes or recesses}
- G02B 6/0046: {Tapered light guide, e.g. wedge-shaped light guide}
- G02B 6/0073: {Light emitting diode [LED]}
- G02B 6/0016: {Grooves, prisms, gratings, scattering particles or rough surfaces}
- G02B 6/0061: {to provide homogeneous light output intensity}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A display device includes a light guide member, a light source substrate and a liquid crystal panel. The light guide member has a first incidence surface, and an emission surface orthogonal to the first incidence surface. The light source substrate has a light source emitting light toward the first incidence surface, and a substrate on which the light source is arranged. The liquid crystal panel has a second incidence surface arranged to be inclined relative to a surface of the substrate in a position where the liquid crystal panel faces the emission surface of the light guide member. A second angle between the emission surface and the surface of the substrate is greater than 0°, and is equal to or smaller than a first angle between the second incidence surface and the surface of the substrate.

## Claims

### Claim 1

A display device comprising:
a light guide member having a first incidence surface, and an emission surface orthogonal to the first incidence surface;
a light source substrate having a light source that emits light toward the first incidence surface of the light guide member, and a substrate on which the light source is arranged; and
a liquid crystal panel having a second incidence surface arranged to be inclined relative to a surface of the substrate in a position where the liquid crystal panel faces the emission surface of the light guide member,
wherein the light guide member has convex light diffusion portions arranged on the emission surface, and has a constant thickness in an optical axis direction of the light source,
the light diffusion portions of the light guide member are spaced from the liquid crystal panel, and
a second angle between the emission surface of the light guide member and the surface of the substrate is greater than 0°, and is equal to or smaller than a first angle between the second incidence surface of the liquid crystal panel and the surface of the substrate.

### Claim 2 (depends on 1)

The display device according to claim 1,
wherein the light guide member further has a facing surface orthogonal to the first incidence surface, inclined relative to the emission surface, and parallel to the surface of the substrate, and
the facing surface is placed on the surface of the substrate.

### Claim 3 (depends on 2)

The display device according to claim 2,
wherein the substrate has a white part provided in a region of the surface facing the facing surface and colored by white.

### Claim 4 (depends on 2)

The display device according to claim 2,
wherein the light guide member has a concave portion provided on the first incidence surface, and
the concave portion has a surface facing the light source and orthogonal to the facing surface.

### Claim 5 (depends on 4)

The display device according to claim 4,
wherein the concave portion is formed to range from the emission surface to the facing surface.

### Claim 6 (depends on 2)

The display device according to claim 2,
wherein an area of the facing surface is smaller than an area of the emission surface.

### Claim 7 (depends on 1)

The display device according to claim 1, further comprising:
a reflection member configured to surround surfaces intersecting with the emission surface of the light guide member.

### Claim 8 (depends on 1)

The display device according to claim 1,
wherein the second angle is smaller than the first angle.

### Claim 9 (depends on 1)

An image forming apparatus comprising the display device according to claim 1.