JPH08328494A - Display panel of meter - Google Patents

Abstract

PURPOSE: To provide a display panel of a meter with which a bright display of a thin type is obtainable. CONSTITUTION: The radiated light rays from small-sized light source elements L1 to L3 are introduced from the light incident surfaces 181 to 183 of light introducing parts 171 to 173 into a light scattering light transmission body. The light rays introduced into this light scattering light transmission body are guided as a whole toward the central part while these light rays are subjected to the effects, such as scattering in the inside, scattering by the white ink parts 191 to 193 and reflection on the inside surface of the light exit face, in combination. The back light illumination light from the light exit surface of the light scattering light transmission body is gradually emitted through this process. The light diffusibility per unit area is made higher in order of the white ink parts 191 to 193 and, therefore, the uniformity of the brightness of the back light illumination light emitted from the light exit face is maintained high. Part of the light rays past the transparent sheet passes the notched part of a masking and forms a bright part, by which the required scale, characters, etc., are displayed bright. A revolving shaft penetrating a hole 152 and a pointer 16 having a cap part 151 thereof are rotated at the front surface thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a technique for improving a display panel of a meter which requires visibility in a dark place. The present invention is particularly applicable to automobiles, aircraft,
The present invention is advantageously applied to display panels of various meters installed in vehicles such as ships.

[0002]

2. Description of the Related Art Motor vehicles, aircrafts, ships and the like are equipped with various meters such as a speed meter, a fuel level meter, and an altimeter. These instruments have a display panel on which a scale or the like is displayed and a display pointer for rotating or translating the front surface of the display panel. These display panels include
It is customary to incorporate a lighting mechanism to facilitate visual recognition even at night, in bad weather, or when driving in a tunnel. Therefore, taking a speed meter as an example, an illumination mechanism and its characteristics in a structure that has been conventionally adopted will be briefly described.

1 to 3 show a schematic structure of a display panel of a speedometer which has been conventionally used.
Is a sketch as seen from the front side (observation side), and FIG. 2 is a diagram showing the sketch as seen from the back side (light incident side) in element decomposition form. Further, FIG. 3 (1) shows a line D in FIG.
FIG. 3B is a sectional view taken along the line D ′, and FIG. 3B is a sectional view taken along the line EE ′.

In each of the drawings, the display panel of the speedometer, which is designated by numeral 10 as a whole, is roughly divided into a display section and a backlight for illuminating the display section from the back. The display section includes a light diffusion sheet 12, a masking 14 having a cutout corresponding to the bright section 13, and a rotary shaft 15 having a cap section 151.
It is composed of a pointer 16 which turns around. The backlight is composed of a transparent light guide 11 made of acrylic resin or the like and two light source elements L (incandescent bulbs) arranged on the back side thereof. Illustration of the rotating mechanism of the pointer 16 and the like is omitted.

The masking 14 is usually the light diffusion sheet 1.
2 is composed of a light-shielding ink layer printed. The shape of the notch of the masking 14 that provides the bright portion 13 is determined according to the display contents such as the speed scale, numbers, and characters.
Further, a translucent ink layer of a desired color is printed on the light diffusion sheet 12 corresponding to the cutout portion.

The transparent light guide 11 in the portion far from the light source element L
A dot 11C for guiding light to the front side is formed on the surface of the surface by the edge lighting effect. As shown in FIG. 3 (1), light (G1 , G2) is incident on the light diffusing sheet 12 through the stippling 11C, and is emitted as scattering display light G3 in the bright portion 13 where the masking 14 is not present.

On the other hand, at the left and right end portions of the transparent light guide 11 which face the light source elements L, L in the immediate vicinity, projecting portions 11 in the depth direction are provided.
A and 11B are provided. As illustrated in FIG. 3 (2), the light G4 that is strong on the depth direction protrusion 11A (or 11B) is repeatedly guided by internal reflection inside the depth direction protrusion and is guided by the flat plate of the transparent light guide 11. Guided to the department. In order to prevent the brightness of the bright part 13 from locally becoming too strong on the back surface part of the light diffusion sheet 12 near the overhang parts 11A and 11B in the depth direction, a darkening print 12A using black ink. Are formed in a dot shape.

As described above, in the display panel of the conventional speedometer, various additional configurations (stippling, depth direction protrusion, dimming print, etc.) are provided in order to give the bright portion a uniform and sufficient brightness. ) Is provided. Nevertheless, sufficient results have not been obtained in terms of uniformity of brightness of the bright portion and light utilization efficiency for display, making it difficult to use a small-sized and low-power light source element. As a result, the structure of the entire display panel is simplified, the size in the depth direction is reduced (thinned),
There has been a limit in controlling manufacturing costs.

Further, since the backlight illumination light emitted from the transparent light guide has not undergone the light scattering process, a glaring feeling is likely to appear in the bright light portion. By using a light diffusing sheet having a strong light diffusing ability, a display with a soft visual feeling can be performed, but the brightness of the bright portion is sacrificed.

[0010]

SUMMARY OF THE INVENTION Therefore, one object of the present invention is to make it possible to simplify and thin the structure of a display panel provided on various meters mounted on a vehicle or the like. Another object of the present invention is to provide a power-saving display panel capable of performing a uniform and bright display by using a small-sized and low-power light source element. Still another object of the present invention is to provide a display panel which has a simple structure and provides a soft visual feeling.

[0011]

According to the present invention, there is provided a backlight including a light guide plate and a light source means for laterally supplying light to the light guide plate, and the backlight illumination light from the backlight is received from the back surface. A meter (for example, a speed meter) including a plate-shaped member that selectively transmits this to form a bright portion corresponding to display information and a display unit including a display pointer movably arranged on the front surface of the plate-shaped member With respect to the display panel, the above technical problem is solved by improving the mechanism for generating the backlight illumination light.

The light guide plate used for the backlight of the display panel of the present invention is provided with a plurality of light introducing portions radially for receiving the light supply from the light source means. The number of light introducing portions is preferably three or more. Then, the light guide plate is improved so as to promote the generation of the backlight illumination light. This improvement can be embodied in basically two forms.

In the first embodiment, the light diffusing ability per unit area tends to increase on the back surface of the light guide plate made of the transparent light guide or the light scattering light guide, as the distance from the light introducing portion increases. Thus, light diffusing means for generating the backlight illumination light is provided. However, it is preferable that the light diffusing means is provided so as to exclude a region overlapping with the cap portion of the display pointer and a light introducing portion.

In the second embodiment, a light guide plate having a plurality of sections each composed of a light-scattering light guide having a uniform light-scattering ability is adopted. The light scattering ability of each section is given a stepwise difference so that the light diffusing ability inside the light guide plate tends to increase as the distance from the light introducing portion increases. The number of sections can be a minimum of two. In that case, by giving one section a relatively stronger light scattering ability than the other, and by making the cross section along the radial direction of the light guide plate into a wedge shape, the inside of the light guide plate becomes more distant from the light introducing part. The light diffusing ability of can be increased.

However, also in the second embodiment, it is preferable that the region overlapping the cap portion of the display pointer is occupied by a section having a relatively weak light scattering power, contrary to the above tendency.

[0016]

In the meter provided with the display panel according to the present invention, the display by the backlight illumination is performed based on the following operations according to the above two modes. [First embodiment] (1) Radiation light from an LED, an incandescent bulb, or the like is introduced into a light guide plate from a light introducing portion that is radially provided at a peripheral portion of a transparent light guide or a light scattering light guide. (2) As a whole, the light introduced into the light guide plate receives the effects of scattering by the light diffusing means provided on the back surface of the light guide plate and reflection on the inner surface of the light exit surface of the light guide plate as a whole. The light is guided toward the center. Through this process,
The backlight illumination light is gradually emitted from the light emitting surface of the light guide plate. In the light guide plate, in general, the light is hard to reach the portion farther from the light introducing portion, and thus the backlight illumination light emitted from the light emitting surface tends to be weak. However, since the light diffusing means is provided so that the light diffusing ability per unit area increases as the distance from the light introducing portion is increased, the backlight illumination light emitted from the light emitting surface of the light guide plate is The brightness uniformity is kept high.

When a light-scattering light guide is used as the light guide plate, due to the scattering action inside the light-scattering light guide,
The generation of backlight illumination light is promoted. (3) Backlight illumination light having a high uniformity of brightness emitted from the light emitting surface of the light guide plate is incident from the back surface side to a plate-shaped member having a light-transmitting portion corresponding to a scale, characters, etc. to be displayed. . Then, the light having passed through the translucent part forms a bright part corresponding to the scale, characters, etc. to be displayed. Since the brightness of the backlight illumination light is highly uniform, unevenness in the brightness of the bright portion formed by it is unlikely to occur. In addition, since the light emitted from the bright portion is the backlight illumination light generated through the light scattering process, a soft visual feeling can be obtained without using a light diffusing sheet for the display portion.

[Second Embodiment] (1) Radiation light from an LED, an incandescent bulb, or the like is introduced into a light guide plate from a light introduction portion provided radially on the peripheral portion of the light scattering guide. (2) The light introduced into the light guide plate composed of the light-scattering light guide has a composite effect such as scattering inside the light-scattering light guide and reflection on the inner surface of the light emitting surface of the light-scattering light guide. While being received, the light is guided toward the center as a whole. Through this process, the backlight illumination light is gradually emitted from the light emitting surface of the light scattering guide.

In the light-scattering light guide, it is generally difficult for light to reach a portion relatively far from each light introducing portion, and the backlight illumination light emitted from the light emitting surface of the light guide plate tends to be weak. .

However, the light guide plate is constructed such that the ratio of the low scattering power section gradually decreases from the peripheral portion of the light guide plate to the central portion (the portion behind the cab portion) and the ratio of the high scattering power section increases. Therefore, the uniformity of the brightness of the backlight illumination light emitted from the light emitting surface can be kept high.

(3) Backlight illumination light emitted from the light emitting surface of the light guide plate and having high uniformity of brightness is transferred to a plate-shaped member having a light-transmitting portion corresponding to the scales or characters to be displayed on the back side. Incident from. Then, the light having passed through the transparent portion forms a bright portion corresponding to the scale, characters, etc. to be displayed. Since the brightness of the backlight illumination light is highly uniform, unevenness in the brightness of the bright portion formed by it is unlikely to occur. In addition, the light emitted from the bright part is
Since the backlight illumination light is generated through the light scattering process, a soft visual feeling can be obtained without using a light diffusing sheet for the display unit.

With the above operation, it is possible to reduce the thickness of the structure of the display panel of the meter installed in an automobile or the like while securing the display light with high efficiency. In addition, through this, it has become possible to reduce manufacturing costs and power consumption. Furthermore, by using the light-scattering light guide, the softness of the display light can be secured without using an additional configuration such as a light diffusion sheet.

[0023]

First, a first embodiment in which the present invention is applied to a display panel of a speedometer will be described with reference to FIGS. FIG. 4 is a sketch of the display panel of the speedometer viewed from the front side (observation side), and FIG. 5 is a sketch of the view panel viewed from the back side (backlight side) in element disassembly form. Further, FIG. 6 is a cross-sectional view taken along the line A in FIG. 5, and shows a cross-sectional structure of the backlight adopted in the first embodiment. In addition, in each figure, the reference numerals used in the description of the conventional example (FIGS. 1 to 3) are partially diverted.

As illustrated in FIG. 4 or FIG.
The display portion of the display panel of the speedometer, which is entirely instructed by reference numeral 10, has a transparent sheet 121, a masking 14 having a cutout corresponding to the bright portion 13, and a pointer 16 which revolves around a rotary shaft 15 having a cab 151. It consists of Illustration of the rotating mechanism of the pointer 16 and the like is omitted.

The masking 14 is usually the transparent sheet 12
1 is composed of a light-shielding ink layer. The shape of the notch of the masking 14 that provides the bright portion 13 is determined according to the display contents such as the speed scale, numbers, and characters. A transparent ink layer of a desired color may be printed on the transparent sheet 121 corresponding to the cutout portion. A color filter type transparent sheet 121 may be used.

The plate-like light-scattering light guide 17 arranged on the back surface of the display section and the three small light source elements L1 to L3 arranged around the light-scattering light guide body 17 are backlights for supplying backlight illumination light to the display section. Make up the lights. The light-scattering light guide 17 is a light guide having a light-scattering ability inside, and 0.05 wt% of silicone resin fine particles (particle diameter 2 μm) in a resin matrix made of PMMA (polymethylmethacrylate), for example.
A material that is evenly distributed at a ratio of is used.

The plate-like light-scattering light guide 17 is formed of the transparent sheet 1.
21 and a light introducing portion 171 to 173 radially extending in three directions. Code 15
Reference numeral 2 denotes a hole through which the rotary shaft 15 (not shown in FIGS. 2 and 3) of the pointer 16 passes, and the light scattering guide 17 and the transparent sheet 12 are provided.
Penetrates 1. The tip portions of the light introducing portions 171 to 173 are light incident surfaces 181 to 183, through which the radiated light of the light source elements L1 to L3 is introduced into the light scattering guide 17. As the small light source elements L1 to L3, for example,
An LED having a diameter of about 3 mm or a small incandescent bulb can be used.

On the back surface side of the light-scattering light guide body 17, white ink portions 191 to 193 for increasing the conversion efficiency to the backlight illumination light are provided on almost the entire surface, and the light diffusing ability per unit area has three levels. Divide into patterns (for example,
Dots, grids, etc.) or layers are printed. That is, the light diffusing ability per unit area increases in the order of the white ink print portions 191, 192, 193 from the portion relatively close to the light introducing portions 171 to 173 to the portion distant therefrom. Various methods are known as means for adjusting the light diffusing ability per unit area. For example, by changing the density and dot diameter of the white ink dot pattern, the unit of the white ink portion formed in a dot pattern. The light diffusing ability per area can be adjusted.

It is preferable not to form a white ink portion on each of the light introducing portions 171 to 173 and the back portion 194 of the cap portion 151 of the rotating shaft of the pointer 16 which need not be converted into backlight illumination light.

Various methods are known as means for adjusting the light diffusing ability per unit area. For example, a white ink formed in a dot pattern by changing the density and dot diameter of the white ink dot pattern. The light diffusing ability per unit area of the part can be adjusted.

The process in which the display by the backlight illumination is performed in the speedometer of this embodiment will be described below together with the related features. (1) The light emitted from the small light source elements L1 to L3 is introduced into the light introducing section 1
It is introduced into the light scattering guide 17 from the light incident surfaces 181 to 183 of 71 to 173. (2) The light introduced into the light-scattering light guide 17 is “scattering inside the light-scattering light guide 17” and “white ink portion 191.
To 193 ”and“ reflection on the inner surface of the light emitting surface 175 (see FIG. 6) of the light-scattering light guide 17 ”, and the like, and the light is guided toward the center as a whole. . Then, through this process, the light scattering guide 17
The backlight illumination light is gradually emitted from the light emission surface 175 of the.

In the light-scattering light guide 17, generally, the light is harder to reach the portion relatively farther from each of the light source elements L1 to L3, so that the backlight illumination light emitted from the light emitting surface 175 is weak. It tends to be. However, in this embodiment, according to the idea of the present invention, the white ink portions 191, 19
Since the light diffusing ability per unit area increases in the order of 2 and 193, the uniformity of the brightness of the backlight illumination light emitted from the light emitting surface 175 can be kept high.

Further, since the conversion to the backlight illumination light is positively performed inside the white ink portions 191 to 193 and the light-scattering light-guiding body 17, the background light is brighter than the conventional structure in which these are not present. Light illumination light is easily obtained.

(3) The backlight illumination light emitted from the light emitting surface 175 and having high uniformity in brightness is transmitted through the transparent sheet 1.
It is incident on 21 from the back side. (4) The light passing through the transparent sheet 121 is masked 1
4 or its notch. Light incident on the masking 14 is absorbed there, but a bright portion 13 is formed in the notch. Since the brightness of the backlight illumination light is high, the bright portion 13 formed by the brightness is high.
The unevenness in the brightness of the area is unlikely to occur. In addition, the bright part 1
Since the light emitted from 3 is the backlight illumination light generated through the light scattering process, a soft visual feeling can be obtained without using a light diffusing sheet for the display unit.

Next, a second embodiment in which the present invention is applied to a display panel of a speedometer will be described with reference to FIGS. FIG. 7 is a sketch of the display panel of the speedometer viewed from the front side (observation side), and FIG. 8 is a sketch of the view panel viewed from the back side (backlight side) in element disassembly form. Further, FIG. 9 shows the cross-sectional structure of the backlight along the line B in FIG. 8 together with the cross-section of the display portion which overlaps with this. In each drawing, the reference numerals used in the description of the conventional example and the first embodiment (FIGS. 1 to 6) are partially diverted.

As depicted in these figures, reference numeral 1
The display part of the display panel of the speedometer, which is totally instructed by 0, revolves around the light-shielding sheet 141 for masking having the through hole part 131 corresponding to the bright light part 13 and the rotating shaft 15 having the cab part 151. It is composed of a pointer 16. Illustration of the rotating mechanism of the pointer 16 and the like is omitted.

The light-shielding sheet 141 for masking includes
For example, a non-translucent plastic sheet of black, dark blue or the like having a through hole portion 131 corresponding to the display contents such as speed scale, numbers and characters is used.

The plate-like light-scattering light guide 27 arranged on the back surface of the display section and the three small light source elements L1 to L3 arranged around the plate-like light-scattering light guide body 27 are backlights for supplying backlight illumination light to the display section. Make up the lights. As in the case of the first embodiment, the light-scattering light guide 27 has a light introducing portion 27 that radially extends in three directions.
1 to 273. The respective tip portions of the light introducing portions 271 to 273 are light incident surfaces 281 to 283, through which the radiated light of the light source elements L1 to L3 is introduced into the light scattering guide 27.

The light scattering guide 27 includes light source elements L1 to L3.
It is configured such that the light scattering power given to the inside tends to increase as it gets away from. In the present embodiment, the light-scattering guide is formed so that the section 291 having a relatively weak light-scattering ability surrounds the wedge-shaped section 292 having a relatively strong light-scattering ability to form a flat ring as a whole. The light body 27 is configured. The intensity of the light scattering power in both compartments is adjusted by, for example, the ratio of the modified refractive index particles dispersed in the matrix. As an example, PMMA (polymethylmethacrylate) is provided in the compartment 291 having a relatively weak light scattering ability.
A material in which silicone resin fine particles (particle diameter 2 μm) are evenly dispersed at a ratio of 0.03 wt% is used in a resin matrix made of PMMA. By using a material in which silicone resin fine particles (particle diameter 2 μm) are evenly dispersed at a ratio of 0.08 wt% in a resin matrix composed of (methacrylate), it is possible to give a difference in light scattering ability between the two compartments. .

Since it is preferable that the light introducing portions 271 to 273 and the back portion of the cap portion 151 of the rotating shaft of the pointer 16 which do not need to be converted into the backlight illumination light have a strong scattering ability, it is relatively A section 291 having a weak light-scattering power is assigned to the.

Reference numeral 152 represents a hole through which the rotary shaft 15 of the pointer 16 passes. As the small light source elements L1 to L3, for example, LEDs having a diameter of about 3 mm or small incandescent bulbs can be used.

The process in which the display by the backlight illumination is performed in the speedometer of this embodiment will be described below together with the related features. (1) The light emitted from the small light source elements L1 to L3 is introduced into the light introducing section 2
It is introduced into the light scattering guide 27 from the light incident surfaces 281 to 283 of 71 to 273. (2) The light introduced into the light-scattering light guide 27 is “scattered inside the light-scattering light-guide 27” and “reflected at the inner surface of the light emission surface 275 (see FIG. 9) of the light-scattering light-guide 17. As a whole, the light is guided toward the center while receiving the effects of "." Then, through this process, the backlight illumination light is gradually emitted from the light emitting surface 275 of the light scattering guide 27.

In the light-scattering light guide 27, it is generally difficult for light to reach a portion relatively far from the light source elements L1 to L3, and the backlight illumination light emitted from the light emitting surface 275 tends to be weak. Is. However, in this embodiment, in accordance with the idea of the present invention, the partition 291 is gradually formed from the peripheral portion of the light scattering guide 27 to the portion behind the cab 151.
The ratio of the (low scattering capacity section) decreases, and the section 292
Since the light-scattering light guide 27 is configured such that the ratio occupied by the (high-scattering power section) increases, the uniformity of the brightness of the backlight illumination light emitted from the light emission surface 275 is kept high. Can be done.

(3) The backlight illumination light having a high uniformity of brightness emitted from the light emitting surface 275 enters the light shielding sheet 141 from the back surface side. (4) As a result, the bright portion 131 having a shape corresponding to a scale, a number or the like is formed in the portion where the through hole 131 is formed. Light is blocked at other portions, and only the surface color (for example, black) of the light-shielding sheet 141 is observed.

Also in the present embodiment, since the brightness of the backlight illumination light is highly uniform, the brightness of the bright portion 13 formed thereby hardly varies depending on the location. Further, since the light emitted from the bright portion 13 is the backlight illumination light generated through the light scattering process, a soft visual feeling can be obtained without using a light diffusing sheet for the display portion.

The two embodiments have been described above.
The present invention is not limited to these embodiments, and various modifications can be made. Hereinafter, some of them will be exemplarily described.

[1] Modification related to light supply to the light guides (light scattering light guides 17 and 27) used for the backlight 1. The number of light source elements arranged for supplying light to the light guide;
In both embodiments, the number is three (L1 to L3), but other numbers may be used. However, in order to obtain uniform backlight illumination light, it is preferable that the number is 3 or more. Needless to say, the number of light introducing units 171-173, 271-273 is provided according to the number of light source elements.

2. The shape of the light incident surface of the light introducing portion provided in the light guide; in both examples, the planar light incident surfaces 181-1.
However, various modifications may be made to improve the efficiency of optical coupling between the light source element and the light guide. For example, as shown in FIGS. 10 (1) to 10 (3),
A semi-circular concave surface 371, a single V-shaped cut portion 372, and two V-shaped cut portions 373 arranged in parallel can be provided at the tip of each light introducing portion as a light incident surface.

[2] Modification related to the light guide body (light scattering light guide body 17, 27) itself used for the backlight 1. As the light guide used for the backlight of the type (first embodiment) in which the white ink portion is provided on the back surface, a transparent light guide may be used instead of the light scattering light guide. In this case, the light scattering process inside the light guide is not used, but if the intensity and gradient of the light diffusion function of the white ink portion are appropriate, bright and uniform backlight illumination light is formed.

2. In the backlight of the type (second embodiment) in which the scattering ability of the light scattering guide has a gradient, the number of sections having different scattering ability and the shape of each section may be modified. For example, three or more annular sections having different scattering powers may be concentrically arranged so that the entire light scattering guide has a stepwise gradient in the scattering power.

3. A mold with a white ink part on the back (first
It is also possible to incorporate the concept of (Example 2) into a mold (second example) in which the scattering ability of the light scattering guide has a gradient. For example, a white ink portion may be provided as a reinforcement on a part of the back surface of the light scattering guide 27 used in the second embodiment.

4. As the material forming the light scattering guide (17, 27), many materials other than those described above can be used. For example, as the resin matrix, a large number of transparent resin materials (for example, polycarbonate) other than polymethylmethacrylate (PMMA) may be appropriately used. Further, as the modified refractive index particles to be mixed, particles other than silicone-based particles (for example, glass beads, styrene-crosslinked particles, etc.) can be used.

[3] Modification of white ink portion formed on back surface of light guide used for backlight 1. Instead of changing the intensity of the light diffusion function of the white ink portion in three steps as in the first embodiment, it may be changed in two steps or four or more steps. Moreover, a continuous gradient may be given to the strength of the light diffusion function.

[4] Modification related to display unit 1. The related structure for forming the bright portion 13 in the display portion in the first embodiment is the same as that of the bright portion 1 in the display portion in the second embodiment.
It can also be replaced by a related configuration for forming 3.
On the contrary, the related structure for forming the bright part 13 in the display section in the second embodiment can be replaced with the related structure for forming the bright part 13 in the display section in the first example. That is, the main eye of the present invention is to obtain bright and uniform backlight illumination light, and so long as the display is made by selectively transmitting the backlight illumination light, no particular restriction is imposed on the display unit itself.

However, it is a feature of the present invention that the display unit does not need to have a light diffusing function as in the prior art. Due to this feature, as described in the second embodiment,
It is possible to use a single light-shielding sheet having a through hole.

[0056]

According to the present invention, it is possible to simplify and thin the structure of a display panel provided on a meter mounted on a vehicle or the like. Further, it is possible to provide a power-saving display panel capable of performing uniform and bright display by using a small-sized and low-power light source element. Further, the display panel of the present invention has an advantage that the softness of the display light can be secured without using an additional structure such as a light diffusion sheet, since the light that has undergone the light scattering process is used as the backlight illumination light.

[Brief description of drawings]

FIG. 1 is a sketch of a schematic structure of a display panel of a speedometer that has been conventionally used, viewed from the front side (observation side).

FIG. 2 is a diagram showing a schematic structure of a display panel of a speedometer that has been conventionally used in an element disassembly form as viewed from the back side (light incident side).

3A is a sectional view taken along line DD ′ in FIG. 2, and FIG. 3B is a sectional view taken along line EE ′.

FIG. 4 is a sketch of the display panel of the speedometer according to the first embodiment as viewed from the front side (observation side).

FIG. 5 shows a sketch of the display panel of the speedometer according to the first embodiment as viewed from the back side (backlight side) in element disassembly form.

6 is a sectional view taken along the line A in FIG.
2 shows a sectional structure of a backlight used in the first embodiment.

FIG. 7 is a sketch of the display panel of the speedometer according to the second embodiment as viewed from the front side (observation side).

FIG. 8 shows a sketch of the display panel of the speedometer according to the second embodiment as viewed from the back side (backlight side) in an element disassembled form.

9 shows a cross-sectional structure of the backlight taken along the line B in FIG. 8 together with a cross-section of a display portion overlapping with the backlight.

FIG. 10 is a diagram illustrating a modified example of the shape of the light incident surface of the light introducing portion provided in the light guide used in the backlight. In (1), an example in which a semicircular concave surface is provided at the tip of each light introducing section, in (2), an example in which a single V-shaped cut section is provided, and in (3), two V-shaped parallel sections are provided. An example in which a character-shaped cut portion is provided is shown.

[Explanation of symbols]

10 Speed Meter Display Panel 11 Transparent Light Guides 11A, 11B Depth Direction Overhanging Part 11C Dotting 12 Light Diffusing Sheet 12A Light-Attenuating Print 13 Luminous Area 14 Masking 15 Rotating Axis 16 Indicating Indicator 17, 27 Light body 121 Transparent sheet 131 Through hole 141 Light-shielding sheet 151 Display pointer cap portion 152 Hole for passing rotation axis of display pointer 171 to 173, 271 to 273 Light introducing portion 175, 275 Light emitting surface of light scattering light guide 181 to 183, 281 to 283, 381 to 383 Light incident surface 191 to 193 White ink portion 194 Back portion of cap portion 151 291 Light scattering ability is relatively weak area 292 Light scattering ability is relatively strong area L1 to L3 Small light source element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hattori Kotoshi 1-5-5 Kamemaedu, Naka-ku, Nagoya-shi, Aichi Prefecture Hayashi Telemp Co., Ltd. (72) Inventor Takeya Sakai 1-chome, Kamiezu, Naka-ku, Nagoya, Aichi No. 4-5 Hayashi Telempu Co., Ltd. (72) Inventor Jun Izuhara 1-4-5 Kamemaedu, Naka-ku, Nagoya-shi, Aichi Prefecture Hayashi Telempu Co., Ltd.

Claims (10)

[Claims] 1. A backlight including a light guide plate and a light source means for supplying light to the light guide plate from a side, and a backlight illumination light from the backlight is received from a back surface and selectively transmitted therethrough. The display unit includes a plate-shaped member forming a bright portion corresponding to display information and a display pointer movably arranged on the front surface of the plate-shaped member. A plurality of light introducing portions for receiving the supply are provided radially, and the back surface of the light guide plate has a tendency that the light diffusing ability per unit area increases as the distance from the light introducing portion increases. A display panel of a meter, which is provided with light diffusing means for generating backlight illumination light. 2. A backlight including a light guide plate composed of a light scattering guide having a uniform light scattering power inside and a light source means for laterally supplying light to the light guide plate, and the backlight. A display including a plate-shaped member that receives backlight illumination light from a light from a back surface and selectively transmits the light to form a bright portion corresponding to display information, and a display pointer movably arranged on the front surface of the plate-shaped member. A plurality of light introducing portions for receiving light from the light source means are radially provided on a peripheral portion of the light guide plate, and a light introducing portion is provided on a back surface of the light guide plate from the light introducing portion. A display panel of a meter provided with light diffusing means for generating backlight illumination light so that the light diffusing ability per unit area tends to increase as the distance increases. 3. The meter display panel according to claim 1, wherein three or more light introducing portions are provided. 4. The light diffusion means provided on the back surface of the light guide plate is provided so as to exclude a region overlapping with the cap portion of the display pointer. Display panel of the meter described in. 5. The light diffusing means provided on the back surface of the light guide plate is provided so as to exclude the light introducing portion,
A display panel of the meter according to any one of claims 1 to 4. 6. A backlight including a light guide plate and a light source means for supplying light to the light guide plate from a side, and a backlight illumination light from the backlight is received from a back surface and selectively transmitted therethrough. The display unit includes a plate-shaped member forming a bright portion corresponding to display information and a display pointer movably arranged on the front surface of the plate-shaped member. A plurality of light introduction portions for receiving supply are provided in a radial pattern, and the light guide plate has a plurality of sections each made up of a light scattering light guide having a uniform light scattering ability, The display panel of the meter is provided with a stepwise difference in the light-scattering ability of the compartments so that the light-diffusing ability inside the light guide plate tends to increase as the distance from the light introducing portion increases. 7. A backlight including a light guide plate and a light source means for supplying light to the light guide plate from a side, and a backlight illumination light from the backlight is received from a back surface and selectively transmitted through the backlight. The display unit includes a plate-shaped member forming a bright portion corresponding to display information and a display pointer movably arranged on the front surface of the plate-shaped member. A plurality of light introducing portions for receiving the supply are provided in a radial pattern, and the light guide plate has two sections each formed of a light-scattering light guide having a uniform light-scattering ability. One of the sections is given a relatively stronger light scattering ability than the other, and has a wedge-shaped cross section along the radial direction of the light guide plate, and the section becomes farther away from the light introducing section. Before the light diffusing ability inside the light guide plate tends to increase One and the other sequences of the compartments is defined, the meter display panel. 8. The display panel for a meter according to claim 6, wherein three or more light introducing portions are provided. 9. The area of the display pointer, which overlaps with the cap portion, is occupied by a section having a relatively weak light scattering power contrary to the tendency. Display panel of the meter described in. 10. The display panel for a meter according to claim 1, wherein the meter is a speed meter.