Patent EP0545705A1 successfully refreshed from Google Patents.
EP0545705A1
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Liquid crystal display device
Assignee: Sharp Corp
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Filing: 1992-12-03
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Granted: —
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Expires: 2012-12-03
Abstract
Abstract A reflective type liquid crystal display device (60-160) excelling in uniformity and capable of making a bright display is presented. At the front side of the liquid crystal display element (72), that is, at the observer (70) side, a light guide plate (61) is disposed, and a pair of lamps (63a, 63b) are disposed at the outer side of the confronting side surfaces of the light guide plate (61). Collimators (62a, 62b) for limiting the incident angle ϑ to the normal or perpendicular of the upper surface (61a) of the light from the lamps (63a, 63b) are disposed between the light guide plate (61) and lamps (63a, 63b). That is. by the collimators (62a, 62b), the incident angle ϑ to the normal or perpendicular of the upper surface is defined so that the incident light may be totally reflected, and that the reflected light may not be totally reflected by the lower surface (61b). As a result, the light from the lamps (63a, 63b) will not reach the observer (70) directly, and a uniform illumination of the liquid crystal display element (72) may be realized. Besides, at the observer (70) side of the liquid crystal display element (72), a light guide plate (161) forming protrusions (161c) is disposed, and a pair of lamps (63a, 63b) are disposed at the outer side of the confronting side surfaces of the light guide plate (161). Furthermore, between the light guide plate (161) and lamps (63a, 63b), collimators (62a, 62b) for limiting the incident angle ϑ of the light from the lamps into the upper surface (161a) are disposed. Accordingly, the light from the lamps (63a, 63b) does not reach the observer (70) directly, and the light entering the protrusions (161c) formed on the light guide plate (161) is emitted to the liquid crystal display element (72) side. Thus, a uniform illumination into the liquid crystal display element (72) is realized.
Inventors
- 👤 Yoshitaka Yamamoto
- 👤 Yutaka Ishii
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 15:09
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0013; G02B6/0023; G02B6/003; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133615; G02F1/133616; G09; G09F; G09F13/00; G09F13/18; G09F2013/1804; G09F2013/1822; G09F2013/1827; G09F2013/1831
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
195 words
A liquid crystal display device (60) comprising: a liquid crystal display element (72) composed of a transparent substrate (65a), a counter substrate (65b) disposed oppositely to the transparent substrate (65a) reflecting means (68) for reflecting the incident light entered from the transparent substrate side, and a liquid crystal layer (66) interposed therebetween, a light guide plate (61) disposed at the transparent substrate aide of the liquid crystal display element (72), and a light source (63a,63b) disposed at the side of the light guide plate (61), where in the condition of n1 < n · sin ϑ < n2 may be satisfied supposing the refractive index of the light guide plate (61) to be n, thy refractive index of the substance positioned at the opposite side of the liquid crystal display element (72) of the light guide plate (61) to be n1, the refractive index of the substance positioned at the liquid crystal display element side of the light guide plate (61) to be n2, and the incident angle of the light source (63a,63b) light to the opposite side surface of the liquid crystal display element (72) of the light guide plate (61) to be ϑ.
Claim 2
Dependent Claim
190 words
A liquid crystal display device (160) comprising: a liquid crystal display element (72) composed of a transparent substrate (65a), a counter substrate (65b) disposed oppositely to the transparent substrate (65a) reflecting means (68) for reflecting the incident light entered from the transparent substrate side, and a liquid crystal layer (66) interposed therebetween, a light guide plate (161) disposed at the transparent substrate side of the liquid crystal display element (72), and a light source (63a,63b) disposed at the side of the light guide plate (161), wherein plural protrusions (161c,81c) are formed on the surface of the light guide plate (161) at the liquid crystal display element side, and the condition of n1 < n · sin ϑ is satisfied, supposing the refractive index of the light guide plate (161) to be n, the refractive index of the substance positioned at the opposite side of the liquid crystal display element (72) of the light guide plate (161) to be n1, and the incident angle of the light source (63a,63b) light to the opposite side surface of the liquid crystal display element (72) of the light guide plate (161) to be ϑ.
Claim 3
Dependent Claim
48 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein the reflecting means (68) has its reflection surface (68a) formed in a smooth undulated surface, and is disposed on the opposite side surface from the liquid crystal layer (66) to the counter substrate (65b).
Claim 4
Dependent Claim
44 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein the reflecting means (68) has its reflection surface (68a) formed in a smooth undulated surface, and is disposed on the liquid crystal layer side surface to the counter substrate (65b).
Claim 5
Dependent Claim
32 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein when disposing one polarizer (64a), it is disposed at the front side of the light guide plate (61,161).
Claim 6
Dependent Claim
39 words
A liquid crystal display device (60,160) as claimed in claim 5, wherein an air layer (71,71a) with a refractive index n1 (satisfying n1 < n · sin ϑ) is interposed between the polarizer (64a) and ligh guide plate (61,161).
Claim 7
Dependent Claim
51 words
A liquid crystal display device (60,160) as claimed in Claim 5, wherein the surface of the front side of the light guide plate (61,161) is coated with a material with a refractive index n1 (satisfying n1 < n · sin ϑ), and the polarizer (64a) is directly disposed on its surface.
Claim 8
Dependent Claim
40 words
A liquid crystal display device (60,160) as claimed in claim 5, wherein the polarizer (64a) made of a material with a refractive index n1 (satisfying n1 < n · sin ϑ is directly disposed on the light guide plate (61,161).
Claim 9
Dependent Claim
57 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein when disposing two polarizers (64a,64b), one polarizer (64a) is disposed at the front side of the light guide plate (61,161), and the other polarizer (64b) is disposed between the reflecting means (68) located outside the counter substrate (65b) and the counter substrate (65b).
Claim 10
Dependent Claim
41 words
A liquid crystal display device (60,160) as claimed in claim 9, whrerein an air layer (71,71a) with a refractive index n1 (satisfying n1 < n · sin ϑ ) is interposed between one polarizer (64a) and the light guide plate (61,161).
Claim 11
Dependent Claim
52 words
A liquid crystal display device (60,160) as claimed in claim 9, wherein the surface of the front side of the light guide plate (61,161) is coated with a material with a refractive index n1 (satisfying N1 < n · sin ϑ ), and one polarizer (64a) is directly disposed on its surface.
Claim 12
Dependent Claim
41 words
A liquid crystal display device (60,160) as claimed in claim 9, wherein one polarizer (64a) made of a material with a refractive index n1 (satisfying n1 < n · sin ϑ ) is directly disposed on the light guide plate (61,161).
Claim 13
Dependent Claim
28 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein a diffusion plate is disposed at the front side of the reflecting means (68).
Claim 14
Dependent Claim
44 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein a reflector for preventing light leak from the light guide plate (61,161) is disposed at the side of the light guide plate (61,161) not provided with the light source (63a,63b).
Claim 15
Dependent Claim
33 words
A liquid crystal display device (60,160) as claimed in claim 1 or 2, wherein the light source (63a,63b) is lit when sufficient quantity of light is not obtained by the surrounding light alone.
Claim 16
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions (161c) are in a conical form.
Claim 17
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions (161c) are in a pyramidal form.
Claim 18
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions are in a truncated conical form.
Claim 19
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions are in a truncated pyramidal form.
Claim 20
Dependent Claim
22 words
A liquid crystal display device (160) as claimed in claim 2, wherein the sectional shape of the protrusions (81c) is nearly semicircular.
Claim 21
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the sectional shape of the protrusions is ellipsoidal.
Claim 22
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the sectional shape of the protrusions is parabolic.
Claim 23
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the sectional shape of the protrusions is arcuate.
Claim 24
Dependent Claim
23 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions (161c,81c) are in an identical shape differing in size.
Claim 25
Dependent Claim
20 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions (161c,81c) are in plural different shapes.
Claim 26
Dependent Claim
34 words
A liquid crystal display device (160) as claimed in claim 2, wherein the array density of the protrusions (161c,81c) increases continuously or in steps, in proportion to the distance from the light source (63a,63b).
Claim 27
Dependent Claim
34 words
A liquid crystal display device (160) as claimed in claim 2, wherein the size of the protrusions (161c,81c) increases, either continuously or in steps, in proportion to the distance from the light source (63a,63b).
Claim 28
Dependent Claim
30 words
A liquid crystal display device (160) as claimed in claim 2, wherein the protrusions (161,81c) are disposed in other regions than the pixels of the liquid crystal display element (72).
Claim 29
Dependent Claim
76 words
A liquid crystal display device (60) as claimed in claim 1, wherein the liquid crystal display element side surface of the light guide plate (61) is coated with a film made of a light transmitted material of which refractive index is lower than that of the light guide plate (61), and the film thickness of the coating film is decreased, either continuously or in steps, in inverse proportion to the distance from the light source (63a,63b).
Claim 30
Dependent Claim
211 words
A liquid crystal device (60) comprising: a liquid crystal display element (72) composed of a liquid crystal layer (66), a transparent substrate (65a) disposed on one side of the liquid crystal layer (66), a counter substrate (65b) disposed on the opposite side of the liquid crystal layer (66), the liquid crystal layer (66) being interposed between the transparent substrate (65a) and the counter substrate (65b), and reflecting means (68) disposed on the far side of the counter substrate (65b) from the liquid crystal layer (66), for reflecting incident light which has entered the device (60) from the transparent substrate side; a light guide plate (61) of refractive index n disposed on the far side of the transparent substrate (65a) from the liquid crystal layer (66); and a light source (63a, 63b) disposed at one side or edge of the light guide plate (61); wherein n 1< n .sin ϑ< n 2, where n 1 and n 2 are the refractive indices adjacent to, but externally of, the light guide plate (61) on the far side from, and the near side to, said liquid crystal layer (66) respectively, and the incident angle of the light to the normal or perpendicular at the respective surface of the light guide plate (61) is ϑ.
Claim 31
Dependent Claim
224 words
A liquid crystal device (160) comprising: a liquid crystal display element (72) composed of a liquid crystal layer (66), a transparent substrate (65a) disposed on one side of the liquid crystal layer (66), a counter substrate (65b) disposed on the opposite side of the liquid crystal layer (86), the liquid crystal layer (66) being interposed between the transparent substrate (65a) and the counter substrate (65b), and reflecting means (68) disposed on the far side of the counter substrate (65b) from the liquid crystal layer (66), for reflecting incident light which has entered the device (160) from the transparent substrate side; a light guide plate (161) of refractive index n disposed on the far side of the transparent substrate (65a) from the liquid crystal layer (66); and a light source (63a, 63b) disposed at one side or edge of the light guide plate (161); plural protrusions (161c, 81c) formed on the surface of the light guide plate (161) on the near side to the liquid crystal layer (66); wherein n 1< n .sin ϑ, where n 1 is the refractive index adjacent to, but externally of, the light guide plate (161) on the far side from said liquid crystal layer (66), and the incident angle of the light to the normal or perpendicular at the respective surface of the light guide plate (161) is ϑ.
References Cited (Backward Citations)
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