JP6921629B2 - Display device - Google Patents

Description

The present invention relates to a display device that displays a predetermined display pattern on the light emitting surface side of the light guide plate.

Conventionally, as a display device used for amusement machine products and the like, a display device capable of displaying characters, numbers, images, etc. on the front side by injecting light from the end face of a transparent light guide plate made of acrylic resin has been known. There is.

For example, the lighting device of Patent Document 1 includes a panel (light guide plate) made of a light transmitting material, and light from a light source arranged on the end face of the panel propagates inside the panel while repeating total reflection. In addition, this panel has a light emitting window and a rear window arranged so as to face the light emitting window.

FIG. 1A of Patent Document 1 graphically shows the light emitted from the three light sources, and the light is incident on the deformed portion of the rear window and reflected on the surface thereof. As a result, the characters "text" are lit up in the lighting device (paragraphs 0017, 0024, 0025, FIGS. 1A, 1B).

Japanese Patent No. 4741142

However, since the lighting device of Patent Document 1 is designed to emit light with a display pattern on the front side, visibility in an area exceeding the light emission distribution angle (viewing angle) from the panel deteriorates when the display area is expanded. There was a problem.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a display device having a wide viewing angle and capable of clear display.

The present invention is provided on the light guide plate having a rectangular shape, a first light source provided on the side surface of the light guide plate, a second light source provided on the other side surface facing the side surface, and the light guide plate. a plurality of pixel generator for generating the pixels of the predetermined display pattern, a display device including the light guide plate, the incident surfaces which light enters the first light source and the second light source A first region including a center line that divides the light into two equal parts, and a second region and a third region arranged on both sides of the first region are provided, and the pixel generation unit is emitted from the first light source. A first reflecting surface for reflecting light and a second reflecting surface for reflecting light emitted from the second light source are provided, and in the second region and the third region, the first reflecting surface is provided. And so that the light reflected by the second reflecting surface is emitted in the direction of the center line, the light is inclined and aligned with respect to the incident surface.

According to the present invention, the light guide plate of the display device is divided into a first region including the center line thereof, and a second region and a third region arranged on both sides thereof. A first light source is provided on one side surface of the light guide plate, and a second light source is provided on the other side surface facing the one side surface. The reflection surfaces (first reflection surface, second reflection surface) of the pixel generation unit in each region have different inclination angles with respect to the incident surface of the light of the light guide plate. In the first region, the reflecting surface and the incident surface of the light guide plate are parallel to each other, so that the reflected light is emitted vertically from the light emitting surface. On the other hand, in the second region and the third region, the reflecting surface is inclined with respect to the incident surface so that the reflected light is emitted in the direction of the center line of the incident surface (center of the light guide plate).

For example, when the second region is on the left side of the light emitting surface of the light guide plate and the third region is on the right side of the light emitting surface of the light guide plate, the light emitted from the second region enters the right eye of the observer observing the display device and is the second. The light emitted from the three regions enters the observer's left eye. As a result, it is possible to obtain a display device having a wide viewing angle and capable of clear display.

In the display device of the present invention, the inclination angle of the reflecting surface in the second region and the third region with respect to the incident surface is preferably in the range of 5 ° to 30 °.

According to this configuration, the direction of the reflected light can be controlled to be tilted toward the center of the light guide plate by adjusting the tilt angle of the reflecting surface of the pixel generation unit within the range of 5 ° to 30 °. can.

Further, in the display device of the present invention, it is preferable that the inclination angle of the reflecting surface in the second region and the third region with respect to the incident surface gradually increases as the distance from the center line increases.

When the inclination angle of the reflecting surface is gradually increased according to the distance from the center line of the light guide plate, the emitted light emitted from the portion near both ends of the light guide plate is gradually increased in the direction of the center line (center of the light guide plate). It leans greatly. As a result, the viewing angle can be kept large even if the light guide plate is enlarged.

Further, in the display device of the present invention, it is preferable that a condensing lens that collects the light of the first light source or the second light source is provided on the corresponding incident surface.

According to this configuration, by providing the condensing lens on the incident surface, the light emitted from the light source is guided to the pixel generation portion of the light guide plate without being diffused. As a result, even if the light guide plate is made large, the light emission intensity becomes uniform, and a clearer display pattern can be displayed.

The whole perspective view which shows the basic structure of the display device of this embodiment. An enlarged view of the surface of the light guide plate of FIG. 1. The figure (xy plane) explaining the principle of light distribution control performed by a light guide plate. The figure (xz plane) explaining the principle of light distribution control performed by a light guide plate. The figure explaining the relationship between the vector of the reflected light, the reflection angle and the emission angle when the reflection surface bias angle is changed. The figure explaining the adoption example of the light guide plate of this embodiment. An example of a pixel generation unit of a light guide plate capable of incident light from two directions (1). An example of a pixel generation unit of a light guide plate capable of incident light from two directions (2). An example of a pixel generation unit of a light guide plate capable of incident light from two directions (3).

Hereinafter, embodiments of the display device of the present invention will be described.

FIG. 1 is an overall perspective view showing a basic configuration of the display device 1. The display device 1 emits the light source 2, the condensing lens 3 that collects the light emitted from the light source 2, and the incident light toward the light emitting surface side (z-axis direction) to display a predetermined display pattern. It is composed of a light plate 4.

The light source 2 is formed by arranging a plurality of light emitting diodes (LEDs: Light Emitting Diodes) in a row, and is arranged on the end face of the light guide plate 4. The light emitted from the light source 2 mainly has an optical axis perpendicular to the end surface (incident surface). The light emitting diode is not limited to a monocolor diode, and may be a multicolor diode. Further, as the light source, an electroluminescent element, a discharge tube, or the like may be used.

The condenser lens 3 has lenses arranged in a row corresponding to the light emitting diode of the light source 2, and is arranged between the light source 2 and the light guide plate 4. The light emitted from the light source 2 is condensed by the condensing lens 3 and then incidents on the inside of the light guide plate 4 from the end surface. The light emitted from the light source 2 may be directly incident on the end face of the light guide plate 4 without using the condenser lens 3.

The light guide plate 4 is, for example, a transparent thin plate made of acrylic resin, and the light incident from its end face repeats total internal reflection and travels inside. The light guide plate 4 can also be manufactured of a bendable material. The light guide plate is generally a rectangle as shown in the figure, but may be a polygon such as a pentagon or a hexagon.

Inside the light guide plate 4, a large number of minute prism-shaped pixel generation units 4a are provided. Further, the pixel generation unit 4a has a reflecting surface that reflects light traveling inside the light guide plate 4. The light traveling inside the light guide plate 4 is reflected by the reflecting surface and emitted to the light emitting surface side of the light guide plate 4.

Therefore, if the pixel generation unit 4a is arranged according to the characters, numbers, images, etc. to be displayed, one pixel such as characters displayed by the light reflected by the reflection surface of the pixel generation unit 4a can be configured. The observer will be able to visually recognize characters and the like due to the combination of pixels.

As shown in the figure, the light guide plate 4 includes a region C (“first region” of the present invention) of the character “B” including a center line M in the long axis direction in which the light source 2 is arranged, and a left side of the region C. Area L of the letter "A" of the present invention ("second region" or "third region" of the present invention) and region R of the letter "C" on the right side of the region C ("second region" or "third region" of the present invention). There are 3 areas "). Then, in each region, the inclination of the reflecting surface of the pixel generation unit 4a with respect to the incident surface is different.

Next, FIG. 2 shows an enlarged view of the surface of the light guide plate 4 of FIG.

As shown, the central region C, the pixel reflecting surface of the generator 4a _C (black portion) are aligned in parallel with the incident plane. The size of one pixel generation unit 4a _C is about 1 μm × 10 μm, and in reality, the pixel generation unit 4a _C is arranged corresponding to the display pattern.

Next, in the region L, _{the reflection surface (black portion) of the pixel generation unit 4a L} is aligned in a state of being inclined counterclockwise with respect to the incident surface of light. Although the details will be described later, by inclining the reflecting surface, the emitted light emitted from the region L is inclined in the direction of the center line M, and the viewing angle of the light guide plate 4 can be expanded.

Further, the light guide plate 4, with increasing distance from the center line M, i.e., as they become the left end of the light guide plate 4, the reflection surface of the image generating section 4a _L, is greatly inclined with respect to the incident plane. As a result, the emitted light emitted from the left end side of the region L is gradually greatly inclined in the direction of the center line M.

On the other hand, in the region R, _{the reflection surface (black portion) of the pixel generation unit 4a R} is aligned in a state of being inclined clockwise with respect to the incident surface of light. Further, as the distance from the center line M, that is, toward the right end of the light guide plate 4, the _{inclination of the reflecting surface of the image generating unit 4a R} with respect to the incident surface is increased. As a result, the emitted light emitted from the right end side of the region R also gradually tilts greatly in the direction of the center line M.

In reality, three or more rows of pixel generation units 4a are arranged in the area C. Further, the pixel generation unit 4a _L in the region L and the pixel generation unit 4a _{R in the} region R are provided with an inclination angle in the range of 5 ° to 30 ° with respect to the incident surface, for example, in increments of 5 °. The inclination of each reflection surface of the image generation unit 4a _L and the pixel generation unit 4a _R of the region R may be changed so that the angle from the incident surface is the same (the direction of rotation is opposite) according to the x coordinate. The size of the pixel generation unit 4a _L and the pixel generation unit 4a _R is the same as that of the pixel generation unit 4a _C.

The pixel generation unit may have any shape. For example, in a light guide plate having two or more incident surfaces of light, the display pattern may differ depending on whether the light is incident from the first incident surface or the light is incident from the second incident surface. In such a case, the pixel generation unit has a left-right asymmetric shape.

Further, there may be a pixel generation unit long in the long axis direction straddling two or more regions of the region L, the region C, and the region R. In such a case, in the region C, the reflecting surface of the pixel generating portion is parallel to the incident surface, but the field of view is increased by increasing the inclination of the reflecting surface toward the end in the long axis direction of the light guide plate. The corner can be enlarged.

Next, the principle of light distribution control performed by the light guide plate 4 will be described with reference to FIGS. 3A and 3B.

FIG. 3A is an enlarged view of a region R'that is a further enlargement of the region R of FIG. The pixel generation unit 4a _R has a prism shape, and reflects the incident light i incident from the end surface of the light guide plate 4 in the three-dimensional direction.

The pixel generation unit 4a _R of the region R'is arranged on the xy plane, and the reflected light is emitted to the light emitting surface side (z-axis direction) of the light guide plate 4. Further, by inclining the pixel generator 4a _R on the xy plane, it is possible to control the angle (emission angle theta _out) in the x-axis direction of the emitted light j.

For example, the vector of the optical axis of the incident light i is (0,1,0), and the normal vector of the reflection surface of the pixel generation unit (pixel generation unit 4a) without inclination is (0, sin45 °, cos45 °). do.

At this time, when the reflection surface of the pixel generation unit 4a is _{rotated by an arbitrary angle (reflection surface bias angle) θ p} on the xy plane, the normal vector of the reflection surface is based on the three-dimensional rotation matrix around the z-axis.
(-Sin45 ° · sinθ _p , -sin45 ° · _{cosθ p} , cos45 °) ... (1)
Is converted to.

Further, the vector of the reflected light j is
^{_{(-2sinθ p · cosθ p · sin}} 2 45 °, 1-2 (sin45 ° · cosθ p) 2, 2sin45 ° · cosθ p · cos45 °) ... (2)
Given in.

Next, FIG. 3B is a diagram _{showing the pixel generation unit 4a R} of FIG. 3A on the xz plane.

Incident light i proceeds the y-axis direction of the light guide plate 4, is reflected by the reflecting surface of the pixel generator 4a _R. At this time, the reflected light j is _{inclined by an angle θ ref with} respect to the z-axis. Here, the reflection angle θ _ref depends on the x and z components of the vector in (2).
θ _ref = tan ^-1 {-2 _{sin θ p} · cos θ _p · sin ² 45 ° / 2 sin 45 ° cos θ _p · cos 45 °}… (3)
Given in.

Further, the reflected light j is refracted when emitted from the light guide plate 4, but the angle with respect to the z-axis is the emission angle θ _out of the reflected light j. The emission angle θ _out is when the refractive index of the light guide plate 4 is n.
θ _out = sin ^-1 (n · sin θ _ref )… (4)
Given in.

Next, FIG. 4 shows the relationship between _{the reflection angle θ ref} of the reflected light j when the _{reflection surface bias angle θ p} is changed and the emission angle θ _{out in the x-axis direction.} As the refractive index n of the light guide plate 4, 1.49, which is the refractive index of the acrylic resin, was used.

For example, when the reflecting surface bias angle θ _p is 0 °, when (2) is calculated using sin 0 ° = 0, cos 0 ° = 1, sin 45 ° = cos 45 ° = 1 / √2, the vector of the reflected light j is calculated. Is (0, 0, 1). Further, the reflection angle θ _ref and the emission angle θ _out are both set to 0 ° according to the equations (3) and (4), respectively.

Further, when the reflection surface bias angle θ _p is 30 °, (2) is calculated using sin30 ° = 1/2, cos30 ° = √3 / 2, and sin45 ° = cos45 ° = 1 / √2. The vector of the reflected light j is (−0.433, 0.250, 0.866).

The reflection angle θ _ref is −26.6 ° according to Eq. (3), and the emission angle θ _out is −41.8 ° according to Eq. (4). The reflection surface bias angle θ _p in the figure is in 5 ° increments, but in reality, it is often made in smaller increments.

Next, an example of using the light guide plate based on the above results will be described with reference to FIG.

FIG. 5 is a side view of the light guide plate 4 as viewed from the incident surface side (y-axis direction) of light. The light guide plate 4 has a major axis direction of 700 mm, and the central area (100 mm) is the region C in FIG. Pixel generator 4a _C region C, since the reflecting surface bias angle theta _p is at 0 °, the reflected light travels straight in the z-axis direction.

The left side of the central area is the area L in FIG. 1, the width of which is 300 mm. Further, the right side of the central area is the area R in FIG. 1, and the width thereof is 300 mm. In the left and right areas, the reflection surface bias angle θ _{p is set} to 5 ° or more, and the upper limit reflection surface bias θ _{p is set} to 30 ° in consideration of light emission efficiency.

By setting the reflecting surface bias angle θ _p in the range of 5 ° ≤ θ _p ≤ 30 °, the result is that the visibility of the display pattern is good and the viewing angle is large for an observer 400 mm away from the light guide plate 4. Was confirmed. For a light guide plate of about 400 mm × 400 mm, the reflection surface bias angle θ _p may be set in the range of 2 ° ≤ θ _{p ≤ 20 ° in order to ensure sufficient visibility for an observer 440 mm away from the light guide plate.} ..

Finally, various shapes of the pixel generation unit will be described with reference to FIGS. 6A to 6C.

First, FIG. 6A (a) shows an example of a pixel generation unit for a light guide plate capable of incident light from two opposing directions. The pixel generation unit 4b has a height of 0.058 mm, and a predetermined curvature (R = 0.338 mm) is formed on the side surface thereof.

As shown in FIG. 6A (b), the pixel generation unit 4b has a shape in which the lower side (0.034 mm) of the pixel generation unit 1 and the upper side (0.01 mm) of the lower pixel generation unit are in contact with each other. They are arranged in one row with, and each row is arranged with an interval of 0.15 mm.

Then, when light is incident from the curved surface side of the pixel generation unit 4b (in the direction of the arrow in FIG. 6A (b)), the light is reflected toward the light emitting surface side. The observer can visually recognize the predetermined display pattern even when the light is incident from the opposite side. Further, when light is incident from both directions, more reflected light is emitted, and a clear display pattern can be displayed.

Further, with respect to the pixel generation unit 4b, in the areas L and R of FIG. 1, the inclination angle of the lower side of the pixel generation unit 4b with respect to the optical axis is increased toward the end of the light guide plate 4 in the x-axis direction. go. As a result, the emitted light emitted from the left and right ends of the light guide plate 4 is inclined in the direction of the center line M, so that the viewing angle of the display device 1 can be expanded.

Next, FIG. 6B (a) shows an example of another pixel generation unit capable of incident light from two opposing directions.

The pixel generation unit 4c has a height of 0.147 mm, and a predetermined curvature (R = 0.858 mm) is formed on the side surface thereof. Further, as shown in FIG. 6B (b), in the pixel generation unit 4c, the center of the pixel generation unit 1 and the center of the pixel generation unit below the pixel generation unit 4c are arranged in a row with an interval of 0.20 mm. They are aligned and each row is also spaced 0.20 mm apart.

Then, when light is incident from the curved surface side of the pixel generation unit 4c (in the direction of the arrow in FIG. 6B (b)), the light is reflected to the light emitting surface side. As for the pixel generation unit 4c, the inclination angle of the lower side of the pixel generation unit 4c with respect to the optical axis is increased toward the left and right ends of the light guide plate 4. As a result, the emitted light emitted from the left and right ends of the light guide plate 4 is inclined in the direction of the center line M.

Finally, FIG. 6C (a) shows an example of a pixel generation unit for a light guide plate capable of incident light from two opposing directions and displaying different display patterns depending on the incident direction of the light.

The pixel generation unit 4d has a height of 0.10 mm, a predetermined curvature (R = 0.572 mm) is formed on one side surface, and the other side surface becomes two wall portions opened at an angle of 100 °. There is.

As shown in FIG. 6C (b), the pixel generation unit 4d is inclined by about 10 ° with respect to the optical axis of the incident light (in the direction of the arrow in FIG. 6C (b)). Further, the center of the pixel generating portion of 1 and the center of the pixel generating portion on the lower side thereof are arranged in one row with an interval of 0.20 mm, and each row is also arranged with an interval of 0.20 mm. There is. Then, when light is incident on the curved surface side of the pixel generation unit 4d and the opposite side, the light is reflected on the light emitting surface side.

The pixel generation unit 4d can display different display patterns depending on the difference in the reflection surface depending on whether the light is incident from the side surface side having a curvature or the light is incident from the wall surface side of the pixel generation unit 4d. The incident may be switched on and off so that the light is incident from either direction, or the combined display pattern may be displayed by incident the light from both directions.

As for the pixel generation unit 4d, the inclination angle of the pixel generation unit 4d with respect to the optical axis is increased toward the left and right ends of the light guide plate 4. As a result, the emitted light emitted from the left and right ends of the light guide plate 4 is inclined in the direction of the center line M, so that the viewing angle of the display device 1 can be expanded.

As described above, in the display device 1, the reflective surface of the pixel generation unit 4a of the light guide plate 4 is aligned parallel to the incident surface in the region C (center) of the light guide plate 4. Further, the regions L and R arranged on both sides of the region C are inclined with respect to the incident surface so that the light reflected by the reflecting surface is emitted in the direction of the center line M of the light guide plate 4. And are aligned. As a result, it is possible to obtain a display device having a wide viewing angle and capable of clear display.

The above embodiment is an example of the embodiment of the present invention, and various other modifications can be considered. For example, in FIG. 1, the area C, the area L, and the area R are defined for each of the characters “A”, “B”, and “C”, but the present invention is not limited to this. In one character or image, the inclination of the reflecting surface of the pixel generation unit with respect to the incident surface may change.

The pixel generating units 4b and 4c shown in FIGS. 6A and 6B may have a shape having no curvature on the side surface thereof or a shape having different hypotenuse angles on the left and right sides. Further, for example, the pixel generation unit 4b may be divided so that different display patterns can be displayed when light is incident from the left and right ends of the light guide plate 4. This makes it possible to display a three-dimensional image such as a hologram.

The display device 1 of the present embodiment is used, for example, in a gaming machine product. Specifically, since the light guide plate 4 is normally transparent, the player does not notice its existence, but light can be incident on the light guide plate 4 at a predetermined timing to perform the effect. The display device 1 can also be used as a display device for advertisements and guidance.

1 ... Display device, 2 ... Light source, 3 ... Condensing lens, 4 ... Light guide plate, 4a to 4d ... Pixel generator.

Claims (8)

A rectangular light guide plate and
A first light source provided on the side surface of the light guide plate and
A second light source provided on the other side surface facing the side surface, and
A display device including a plurality of pixel generation units for generating each pixel of a predetermined display pattern provided on the light guide plate.
The light guide plate has a first region including a center line that divides each incident surface on which the light of the first light source and the light of the second light source are incident into two equal parts, and a first region arranged on both sides of the first region. It has two areas and a third area .
The pixel generation unit
A first reflecting surface that reflects light emitted from the first light source and a second reflecting surface that reflects light emitted from the second light source are provided.
In the second region and the third region, the light reflected by the first reflecting surface and the second reflecting surface is inclined with respect to the incident surface so as to be emitted in the direction of the center line. A display device characterized by being aligned. In the display device according to claim 1,
The light guide plate comprises a light emitting surface on which light reflected by the pixel generation unit emits light, an opposing surface facing the light emitting surface, a first side surface including the first light source, and the second light source. A second side surface to be provided, and a third side surface and a fourth side surface connecting the first side surface and the second side surface are provided.
The pixel generating unit has an upper side of the third side surface side and a lower side of the fourth side surface side in a top view of the demitsu surface, and the first reflecting surface and the second reflecting surface are , A display device characterized in that each has a predetermined curvature. In the display device according to claim 1,
The pixel generation unit further includes a third reflecting surface that reflects light emitted from the second light source.
The display device, wherein the third reflecting surface has a predetermined curvature. In the display device according to claim 2,
The upper side of the pixel generation unit and the lower side of another pixel generation unit adjacent to the pixel generation unit are in contact with each other and are arranged in a row, and the rows are arranged at regular intervals. A display device characterized by that. In the display device according to any one of claims 1 to 3,
A display device characterized in that the center of the pixel generation unit and the center of another pixel generation unit adjacent to the pixel generation unit are arranged at a certain distance from each other. In the display device according to any one of claims 1 to 5,
A display device characterized in that the inclination angle of the reflective surface with respect to the incident surface in the second region and the third region is in the range of 5 ° to 30 °. In the display device according to any one of claims 1 to 6.
A display device characterized in that the inclination angle of the reflective surface with respect to the incident surface in the second region and the third region gradually increases as the distance from the center line increases. In the display device according to any one of claims 1 to 7.
A display device characterized in that a condensing lens that collects light from the first light source or the second light source is provided on the corresponding incident surface.

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