JPS638603A - Diffuse transmission plate - Google Patents

Abstract

PURPOSE:To increase intensity, transmissivity of a transmission light, and an identifying visible range by shifting the optical axis of a lenticular lens on the incident light side and an optical axis of a lenticular lens on the exciting light side, by about 1/2 pitch to provide a light shielding layer on a trough part of the incident light side lenticular lens, and laminating a reflecting layer thereon. CONSTITUTION:A diffuse transmission plate 4 is constituted by shifting an optical axis of an incident light side lenticular lens 1 and an optical axis of an emitting light side lenticular lens 2, by about 1/2 pitch. A recessed part 5 for a light shielding layer is provided on a trough part of the incident light side lenticular lens 1, and also, a light shielding layer 3 is provided on its recessed part 5, and furthermore, a metallic reflecting layer 13 turned to a light source side is laminated on the light shielding layer. Accordingly, the metallic reflecting layer 13 reflects a light beam which has been emitted from a light source 10 and has been projected to the light shielding layer, to the light source side, and this light beam becomes a light source to the diffuse transmission plate gain by a reflecting plate 9, and becomes the incident light to other part than the light shielding layer. Provided that a focal position of the incident light side lenticular lens 1 is in the inside from the surface of the emitting light side lenticular lens 2, the light beam is reflected by the surface of the emitting light side lenticular lens, and the quantity of light which becomes emitting light is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a transmission diffusion plate made of a lenticular lens, and particularly to a transmission diffusion plate suitable for use in a liquid crystal display.

[Prior art]

Originally, a lenticular lens has a shape in which small-diameter cylindrical transparent ronds are arranged in parallel and bonded to each other.

Therefore, in a lenticular lens 1 on the incident light side of a lenticular lens as shown in FIG. In this case, light directed toward the front is blocked by the light shielding layer 3 in range A (a range of θ to the left and right around the optical axis), and the emitted light is emitted only toward the outside of range A.

In FIG. 2, reference numeral SVi indicates a convex portion for a light-shielding layer, reference numeral 6 indicates a trough of the light-emitting side lenticular lens, and reference numeral 7 indicates an adhesive portion.

Therefore, a liquid crystal display element 8 made of a liquid crystal, for example, a DS type (used with a cloudy, diffused pattern) is installed in front of the transmission diffusion plate 4, and a reflection plate 9 is provided behind the transmission diffusion plate 4. A light source 10 is installed (see Figure 3).

Then, there is no input to the liquid crystal display element 8, and the pattern section 1
When there is no 1 (when the entire surface is transparent with non-pattern part 12)
When viewing the liquid crystal display element 8 from the front (range A), there is no light entering the eyes (light emitted from the lenticular lens).
The LCD screen appears black.

However, if you look in a diagonal direction away from the front and outside the range A, the light emitted from the lenticular lens, that is, the transmission diffuser plate 4 enters your eyes, making it appear brighter.

Next, an input is applied to the liquid crystal display element 8, and the pattern portion 1
1 appears (when only the pattern part becomes cloudy and the non-pattern part remains transparent), the predetermined range from the transmission diffuser plate (range other than the front radiation angle 2θ, that is, range other than range A) The emitted light enters the pattern section and is further diffused as scattered light in all forward directions on the surface of the pattern section 11.

Therefore, when viewing the liquid crystal display element 8 from within the front range A (range of the front radiation angle 2θ), the pattern area 11 appears cloudy and bright, while the non-pattern area 12 appears black and clearly displayed. , visual identification [Problem to be solved by the invention] Here, the conventional transmission diffuser plate has a shape in which cylindrical transparent ronds are arranged in parallel and glued together, as shown in FIG. , the width of the adhesive part 7 between the a-rads is narrower than the thickness of the transmission diffusion plate, and is insufficient in terms of strength.If the rond diameter is made smaller in order to make the pitch finer, the plate thickness will also become thinner, so the pitch It was also impossible to make it more detailed.

Moreover, in order to widen the identification visible range, the light-shielding layer must be made that much wider. By doing so, the light transmitting portion becomes narrower, and the loss in the amount of transmitted light increases. This reduces the contrast of the pattern portion of the liquid crystal display element, resulting in poor visual discrimination.

Further, the light shielding layer merely blocks light, and the light irradiated thereon is absorbed as is, resulting in loss.

The present invention solves the above-mentioned problems with the conventional transmission diffuser plate made of a lenticular lens, and increases the intensity, transmittance of transmitted light, and visible range.

[Means to solve the problem]

In the transmission diffusion plate according to the present invention, the optical axis of the lenticular lens on the incident light side and the optical axis of the lenticular lens on the output light side are shifted by approximately 1/2 pitch, and a light shielding layer is provided in the valley of the lenticular lens on the incident light side. A reflective layer is layered on top.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described based on the drawings.

As shown in FIG. 1, the transmission diffusion plate 4 according to the present invention is
The optical axis of the incident light side lenticular lens l and the optical axis of the output light side lenticular lens 2 are shifted by approximately 1/2 pitch.

A light shielding layer recess 5 is provided in the valley of the incident light side lenticular lens 1, and a light shielding layer 3 is provided in the recess 5. A metal reflective layer 13 is further laminated on the light shielding layer toward the light source side.

Then, the light shielding layer 3 is provided at a position closer to the surface of the emitting light side lenticular lens than the focal point of the emitting light side lenticular lens.

Further, the focal position of the incident light side lenticular lens is set outside the surface of the output light side lenticular lens.

The basic operation of the transmission diffusion plate 4 of the present invention is the same as that of the transmission diffusion plate 4 of the prior art, but the optical axis of the incident light side lenticular lens l and the optical axis of the output light side lenticular lens 2 are approximately 1 As is clear from the comparison between FIG. 1 and FIG. 2, if the pitch is shifted by /2, there will be a large difference in the thickness of the troughs of the transmission diffusion plate, and the thickness will increase.

Then, the metal reflective layer 13 laminated on the light shielding layer 3 reflects the light emitted from the light source 10 and projected onto the light shielding layer toward the source side, and the light beam is directed back toward the transmission diffuser plate 4 by the reflection plate 9. Therefore, the light may be incident on parts other than the light shielding layer.

Assuming that the focal point of the lenticular lens 1 on the input light side is located inside the surface of the lenticular lens 2 on the output light side, which is indicated by 0 in FIG. As a result, the amount of light that becomes the emitted light decreases.

Furthermore, if a light shielding layer is provided at a position closer to the surface of the lenticular lens on the exit light side than the focal point of the lens, the loss of the amount of transmitted light can be reduced and the range A that appears black can be expanded.

The light-shielding layer 3 is preferably provided in the recessed portion 5 by a wiping coating method or the like, and when provided by this method, the layer is thick and has a large hiding effect.

Furthermore, if the cross section of the outgoing light side lenticular lens 2 is made into an ellipse with the long axis in the optical axis direction, the permeable area increases, and in particular, as shown in FIG. 5, the long axis/short axis ratio of the ellipse is Q/
A value around 1 is optimal.

By appropriately adopting various conditions such as those mentioned above, it is possible to obtain a transmission diffusion plate with high transmittance.As a result, it is possible to use double transmission diffusion plates, which is difficult to do with conventional ones, due to the high transmittance. becomes. Therefore, if two of the transmission diffusion plates 4 of the above embodiment are used in a stacked manner with the directions of the lenticular lens arrays perpendicular to each other, the same effect as in the horizontal direction described above can be obtained not only in the horizontal direction but also in the vertical direction. It functions as a diffusion plate, and the pattern portion of the liquid crystal display element can be visually identified in two directions: left, right, top, and bottom.

〔effect〕

Thus, according to the present invention, the transmission diffusion plate has increased strength compared to conventional transmission diffusion plates, can provide a finer pitch, has higher light transmittance, and is easier to process.

Furthermore, due to the increase in transmittance, double objects that can be identified in two directions (top, bottom, left, and right) also appear.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the transmission diffusion plate of the present invention, and FIG.
A cross-sectional view of a conventional transmission diffuser plate, FIGS. 3 and 4 are diagrams explaining the principle of a transmission diffusion plate, and FIG. 5 is a graph of the relationship between the long-minor axis ratio of the ellipse in cross-section of an emitted light lenticular lens and the transmittable area. . l...Incoming light side lenticular lens, 2...Outgoing light side lenticular lens, 3...Light blocking layer,
4.4...Transmission diffuser plate, 5...Concave portion for light shielding layer,
5...Protrusion for light shielding layer, 6...Trough of outgoing light side lenticular lens, 7...Adhesive part, 8...
Liquid crystal display element, 9...Reflector, 10...Light source, 11...Pattern portion, 12...Non-pattern portion 1
3...Metal reflective layer. Figure 1 Figure 2 ■ @ @ @ @ O ■---10 □□9 Figure 3 Figure 4

Claims (12)

[Claims] (1) An input light side lenticular lens, an output light side lenticular lens whose optical axis is shifted by approximately 1/2 pitch from the optical axis of the front input light side lenticular lens, and one of the lens surfaces of the input light side lenticular lens. A transmission diffuser plate consisting of a light-shielding layer provided in the area. (2) The transmission diffuser plate according to claim 1, wherein the light shielding layer is located inside the focal point of the outgoing light side lenticular lens. (3) The transmission diffuser plate according to claim 1 or 2, wherein the incident light side lenticular lens has its focal point located outside the valley of the output light side lenticular lens. (4) The transmission diffuser plate according to any one of claims 1 to 3, wherein the light shielding layer is provided with a metal reflective layer on the light source side. (5) The transmission diffuser plate according to any one of claims 1 to 4, wherein the light shielding layer is provided in a concave portion of the lenticular lens surface on the incident light side. (6) The transmission diffuser plate according to any one of claims 1 to 5, wherein the exit light side lenticular lens has a cross section that is a part of an ellipse having a long axis in the optical axis direction. (7) Provided on a part of the lens surface of the incident light side lenticular lens, the output light side lenticular lens whose optical axis is shifted by approximately 1/2 pitch from the optical axis of the front incident light side lenticular lens, and the incident light side lenticular lens. A transmission diffusion plate in which a transmission diffusion plate composed of a light-shielding layer and another similar transmission diffusion plate are stacked so that the lens arrangement directions are perpendicular to each other. (8) The transmission diffuser plate according to claim 7, wherein the light shielding layer is located inside the focal point of the outgoing light side lenticular lens. (9) The transmission diffuser plate according to claim 7 or 8, wherein the focal point of the incident light side lenticular lens is located outside the valley of the output light side lenticular lens. (10) The transmission diffuser plate according to any one of claims 7 to 9, wherein the light shielding layer is provided with a metal reflective layer on the light source side. (11) The transmission diffuser plate according to any one of claims 7 to 10, wherein the light shielding layer is provided in a concave portion of the lenticular lens surface on the incident light side. (12) The transmission diffuser plate according to any one of claims 7 to 11, wherein the exit light side lenticular lens has a cross section that is a part of an ellipse having a long axis in the optical axis direction.