JPS6128223Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a new display device, and in particular, an object of the present invention is to provide a display device having a plurality of display portions in which the brightness of each display portion is uniform and clear. .

Figure 1 shows an example of a conventional display device.
This is used to display the operating status of an air conditioning system in the passenger compartment of an automobile. This display device a consists of a reflector b, a light bulb c placed at the back of the reflector b, and a display board d placed in front of the reflector b, and the display board d has a plurality of display parts e. It is being formed. In such a display device, the light from the light bulb c is reflected by the reflecting mirror b so as to spread almost uniformly over the entire surface of the display board d, and this reflected light and the light from the light bulb c are directly reflected on the display board d. The display portions e, e, ... from the outside of the display board d are illuminated by direct light directed toward
...can be visually recognized. However, in the case of such a display device, it is possible to ensure sufficient brightness of the display part while using a small-capacity light bulb by also utilizing reflected light. A place where a reflector b to send reflected light almost uniformly over the entire surface of the plate d is unavoidably required, and the depth of the entire device must be increased, and space for it cannot be secured. It has the disadvantage that it cannot be used for

Therefore, the present invention aims to provide a new display device that can ensure sufficient and uniform brightness of the display area while reducing the depth of the device. This will be explained based on a specific example shown in .

Embodiment 1 of the display device of the present invention is shown in FIGS. 2 to 4.
This shows that. This display device 1 consists of a case 2 with an open front, a display plate 3 disposed on the front of the case 2, a light guide plate 4 disposed on the back side of the display plate 3 inside the case 2, and a light receiving portion of the light guide plate 4 arranged opposite to each other. and a light source 5. The case 2 has a display board 3, a light guide plate 4,
It is for holding necessary elements such as the light source 5, and when the light source 5 is a light bulb, it holds a member for holding it, for example, a socket 6. The display board 3 is attached to cover the front opening of the case 2 by appropriate means, and has a plurality of display parts 7. Embodiment 1 of this embodiment is used to display the operating status of an air conditioning system in the passenger compartment of an automobile, so it is designated as "DEF" 7.
₁ , "COLD" 7 ₂ , "WARM" 7 ₃ , "HOT" 7
It has _four display parts. The display portion 7 of the display panel 3 is formed to be light-transmissive, and the remaining portion is formed to be light-opaque. Such a display board 3 is provided, for example, as follows. That is, it is formed by applying black printing 9 to a transparent substrate, for example, a transparent acrylic resin plate 8, except for the display portions such as characters or symbols, and then applying white light-diffusing and transparent printing 10 thereon. do. In the display panel 3 formed in this way, when the display portion 7 is irradiated with light, the light is diffused and transmitted from the display portion 7 through the white diffusion printed surface 10, and when viewed from the front, the display portion 7 is illuminated with light. 7 appears to be shining. The light guide plate 4 is arranged on the back side of the display board 3, and is made of a transparent plate, for example, a transparent acrylic resin, and directs light forward to the back surface of the part corresponding to the display part 7 of the display board 3. In other words, the reflecting section 1 is made up of a large number of conical recesses 11, 11, . . . that reflect toward the display panel 3.
2 is formed, and a light source 5 is further formed within this transparent plate.
The light-receiving end face 13 is provided for receiving the light.
The conical recess 11 allows the inside of the light guide plate 4 to pass through the light source 5.
It has the function of reflecting light from all directions forward, that is, toward the display panel 3, either directly or while repeating internal reflection. In addition, the light receiving end surface 1
3 is formed by hollowing out the approximate center of a light guide plate 4 in a circular shape, and a light bulb 5 serving as a light source is placed opposite to this light receiving surface 13.

In the above display device, the light emitted from the light source 5 enters the light guide plate 4 from the light receiving end face 13, and is transmitted directly or directly into the light guide plate 4.
After several internal reflections, the concave portion 11 is reached. The light that has reached the recess 11 is reflected by the recess 11 toward the front of the light guide plate 4, that is, toward the display panel 3. Therefore, the light entering the light guide plate 4 from the light-receiving end face 13 is reflected by the recess 11, that is, the light is irradiated forward from the portion where the recess 11 is provided. Furthermore, since the reflection section formed by the group of recesses 11 is provided at a location corresponding to the display section 7 of the display panel 3, most of the light that enters the light guide plate 4 is irradiated toward the display section 7. Therefore, the light from the light source 5 can be used efficiently to make the display portion 7 shine. Note that some of the light that enters the light guide plate 4 escapes from the side end surfaces, but if the inner surface of the case 2 is painted white or otherwise to have good reflectivity, the light guide plate 4 The light that escaped is also returned to the light guide plate 4,
It will be reflected forward by the recess 11,
The light from the light source 5 can be used without waste, and a sufficiently bright display can be achieved even when a small-capacity light bulb is used as a light source.

In the above display device, as described above, the light that enters the light guide plate 4 from the light receiving end face is repeatedly internally reflected due to the so-called edge light effect and spreads almost evenly over the entire area of the light guide plate 4. The amount of light reflected from the reflecting section 12 is approximately equal, and therefore the brightness of each display section 7 is also approximately uniform, but as the display board becomes larger, the luminous intensity slightly decreases in the portions that are farther away from the light source. There is a fear. Therefore, even if the display board is large, in order to ensure that there is no difference in display luminosity between the display parts 7 ₁ to 7 ₄ , the amount of light reaching the reflective parts 12 ₂ and 12 ₃ near the light source 5 must be reduced. You should try to reduce it. Therefore, in the display device of the present invention, the display portion (in this embodiment, 7
₂ , 7 ₃ ) (also 12 ₂ , 1
Conical recesses 14, 14, . . . for adjusting the amount of light are formed close to the light attenuation 5 side of 2 ₃ ). Therefore, the light enters from the light receiving end face 13, and the light enters the reflecting part 12 ₂ , 1
2 If there is direct light trying to reach ₃ (the amount will vary depending on the size and amount of the light amount adjustment recesses 14, 1), the light amount adjustment recesses 14, 1
4, the reflection section 12 is obstructed by...
The amount of direct light reaching ₂ , 12 _{and 3} is reduced. or,
The light that passes through the light amount adjustment recesses ₁₄ , _14, . More of them reach parts 12 ₁ and 12 ₄ . Therefore, each reflecting section 12 ₁
The amount of light reaching ₁₂₄ is averaged, and therefore the display luminous intensity of each display portion ₇₁ to ₇₄ is also averaged.

In addition, in the first embodiment, the light amount adjustment recess 1
4, 14, . . . have a deep conical shape, but they may have a shallow depth. For example, as shown in FIG. 5, when the left and right lengths are different with respect to the light-receiving end surface 13 of the light guide plate 4, if there is no recess for adjusting the light amount, the displayed luminous intensity on the shorter side 4'S will be the same as the length. It is significantly higher than that on the long side 4'L, resulting in a very poor appearance. In such a case, light quantity adjusting recesses 14, 14, . 3 If the light is emitted toward the back side (the display part 7 is not formed in this part), the amount of light going to the shorter side 4'S will be reduced, and the display luminous intensity there will be lower than that of the longer side. averaged with that on side 4'L. In such a case, the light quantity adjustment recesses 14, 14, . . . can sufficiently perform their functions even if they have a shallow depth. Of course, the depth may be adjusted as necessary.

FIG. 6 shows another embodiment of the display device of the present invention, which integrates a display panel and a light guide panel. That is, a white diffusion printing 10 is first applied to the surface of the light guide plate 4, and then a black printing 9 is applied on the white diffusion layer 10 except for the areas where the display area is a character or symbol. According to this embodiment, there is an advantage that the number of members is reduced by one, and the cost is reduced accordingly.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing an example of a conventional display device, Fig. 2 is a front view showing an example of the implementation of the present invention, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4. 5 is a rear view of the light guide plate, FIG. 5 is a cross-sectional view taken at the same location as FIG. 3, and FIG. 6 is a still another embodiment of the display device of the present invention. FIG. 4 is a sectional view taken at the same location as FIG. 3; Explanation of symbols, 1...Display device, 3...Display board,
4... Light guide plate, 5... Light source, 7... Display portion, 1
DESCRIPTION OF SYMBOLS 1... Recessed part, 12... Reflection part, 13... Light receiving end surface, 14... Recessed part for light amount adjustment.

Claims (1)

[Claims for Utility Model Registration] (1) Includes a display board having a light-transmissive display portion, a light guide plate and a light source disposed on the back side of the display board,
The light guide plate includes a light-receiving end surface that receives light into the light guide plate, and a reflecting part formed at a position corresponding to the display part of the display board, and the reflecting part is formed on the opposite side of the light guide plate from the face facing the display board. It is formed by a group of a large number of conical recesses that are formed on the surface and reflects the light entering the light guide plate from the light receiving end face toward the display board, and further, a light source is disposed opposite to the light receiving end face of the light guide plate. What is claimed is: 1. A display device characterized in that a conical recess for adjusting the amount of light is formed close to the light source side of the reflecting portion corresponding to the display portion for which the amount of display light is to be reduced. (2) Claim 1 of the utility model registration, which is characterized in that the display plate is formed integrally with the surface of the light guide plate.
Display device as described in section.