JPH10142006A - Display device - Google Patents

Abstract

(57) [Summary] [Problem] To provide a display device in which the structure of light incidence from a light source to a display panel is devised so that the amount of light incident from the light source to the display panel is increased as much as possible. SOLUTION: The light guide plate 20 is arranged along the back surface of the scale plate 10 and introduces the light of the cold cathode tube 50 from the lateral direction. The light guide plate 20 diffuses the light therein. Many silicon-based fine particles are mixed. The light diffusion layer 30 is interposed between the scale plate 10 and the light guide plate 20 to diffuse the incident light from the light guide plate 20. A reflection layer 60 is provided along the light guide plate 20 on the side opposite to the light diffusion layer 30, and reflects light in the light guide plate 20 toward the light diffusion layer 30. An optical sheet 40 is attached to the light diffusion layer 30,
The light diffused by the light diffusion layer 30 is condensed and transmitted through the light transmitting region of the scale plate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle display device for displaying driving information of a vehicle and other various display devices.

[0002]

2. Description of the Related Art Conventionally, this type of display device includes, for example,
There is a pointer device disclosed in JP-A-8-189844. This pointer device has a light guide plate disposed along the back surface of the scale plate, a cold cathode tube disposed at an end of the light guide plate, and a light guide plate after introducing the light of the cold cathode tube into the light guide plate. Is made to enter.

[0003]

Incidentally, in such a pointer device, a reflection layer is formed on the back surface of the light guide plate in order to increase the amount of incident light from the light guide plate to the scale plate. However, even if the light reflecting function of the reflective layer is used, the light is attenuated in the light guide plate, so that it is difficult to sufficiently secure the amount of light incident on the scale plate.

In order to cope with such a problem, the present invention devises a structure of light incident from the light source to the display panel, and increases the amount of light incident on the display panel from the light source as much as possible. It is intended to provide a device.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a light guide plate for introducing light from a luminous body from a peripheral wall portion and entering the display plate has an internal light guide plate. Many silicon-based particles are mixed so as to diffuse light. Further, a reflection layer is provided along the light guide plate on the side opposite to the display plate, and reflects light in the light guide plate toward the display plate. Further, an optical sheet is interposed between the light guide plate and the display plate to collect light incident on the display plate and make the light incident on the display plate.

Accordingly, when the light of the illuminant enters the light guide plate from the peripheral wall portion, the incident light is diffused in the light guide plate by each silicon-based fine particle and travels while being reflected by the reflection layer. In such a process, when light in the light guide plate is incident on the optical sheet, the incident light is condensed by the optical sheet and is incident on the display panel.

[0007] Therefore, a sufficient amount of light transmitted through the translucent non-display area of the display panel can be secured. Therefore, the luminance of the translucent non-display area can be sufficiently increased. According to the second aspect of the present invention, the light inside the light guide plate, which is disposed along the back surface of the display panel and guides the light of the illuminant from the peripheral wall portion and enters the display panel, is diffused. Thus, a large number of silicon-based fine particles are mixed. In addition, a light diffusion layer is interposed between the display panel and the light guide plate to diffuse light incident on the display panel and enter the display panel. Further, a reflection layer is provided along the light guide plate on the side opposite to the light diffusion layer, and reflects light in the light guide plate toward the light diffusion layer.

Thus, when the light of the illuminant enters the light guide plate from the peripheral wall portion, the incident light is diffused in the light guide plate by each silicon-based fine particle and travels while being reflected by the reflection layer. In such a process, when light in the light guide plate enters the light diffusion layer, the incident light is uniformly diffused by the light diffusion layer and enters the display panel.

Therefore, the amount of light transmitted through the translucent non-display area of the display panel is substantially increased, so that an increase in luminance can be ensured. Further, as in the invention according to claim 3, the optical sheet is interposed between the light diffusion layer and the display panel so as to collect the diffused light of the light diffusion layer and to enter the display panel. . As described above, since the diffused light from the light diffusion layer is condensed by the optical sheet and is incident on the display panel, the amount of transmitted light in the translucent non-display area of the display panel can be increased. As a result, the brightness of the translucent non-display area can be improved.

According to the fifth aspect of the present invention, the indicator light source provided on the light guide plate on the side opposite to the display plate emits light through the light guide plate. Openings are formed in the light diffusion layer and the optical sheet at corresponding portions to the indicator light source via the light guide plate.
For this reason, the indicator light source is not visually recognized through the display plate due to the diffusion action of the light diffusion layer and the light condensing action of the optical sheet.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example in which a vehicle pointer device is employed as a display device according to the present invention, and the pointer device is disposed on an instrument panel provided in a vehicle cabin of the vehicle.

The pointer device includes a scale plate 10 as shown in FIGS. This scale plate 10
As illustrated in FIGS. 3 and 5, the transparent resin plate 10
a white light diffusing layer 11 and a black layer 12 capable of transmitting light are sequentially printed on the surface of the scale plate 10a.
As shown in FIG. 1 and FIG. 2, both through-hole portions 14 are formed on the right and left sides.

As shown in FIG. 1, on the surface of the scale plate 10, two substantially circular pattern display portions 15 and 16 are formed. Are formed on the left and right by removing portions other than the scale portions 15a, 16a and the character portions 15b, 16b. Therefore, the scale portions 15a and 16a and the character portions 15b and 16b of the two pattern display portions 15 and 16 are provided.
The other part is the color (white) of the light diffusion layer 11.
In addition, each pattern display part 15 and 16 is located concentrically with each through-hole part 14 on either side.

An indicator 17 is provided at the center of the scale plate 10 in the left-right direction in FIG. In the indicator section 17, both pattern display sections 1 of the black layer 12 are provided.
Light source 1 for each indicator in the area between 5 and 16
As illustrated in FIG. 5, portions corresponding to 10 (described later) are each removed in a square shape to form an opening 17a.

On the back surface of the scale plate 10, a portion corresponding to each indicator light source 110 is provided with an indicator character pattern 17 b (characters P, R, N, D, 3, 2 indicating the shift position of the automatic transmission). ,
L) are respectively colored. Note that each character pattern 17b of the indicator section 17 is formed by a light guide plate 2 described later.
0 may be formed on the surface.

The left-side pattern display unit 15 corresponds to a vehicle speed scale pattern display unit that indicates the vehicle speed of the vehicle.
Further, the right side pattern display section 16 corresponds to a rotation scale pattern display section indicating the rotation number of the engine of the vehicle, and the indicator section 17 corresponds to a shift position pattern display section indicating the shift position of the automatic transmission of the vehicle.

The rectangular light guide plate 20 includes a light diffusion layer 30,
Together with the optical sheet 40 and the reflective layer 60, a laminated body U is formed, and the laminated body U is housed in a holder 70 having a U-shaped cross section together with the left and right cold cathode tubes 50 having a substantially semicircular arc shape. ing. Here, the light guide plate 20 is adhered to the bottom wall 71 of the holder 70 via the reflection layer 60. Note that the holder 7
Numeral 0 is attached to the back surface of the scale plate 10 at the opening. Further, the inner surface of the holder 70 is subjected to a printing process of a white material, and the inner surface of the holder 70 also serves as a reflector of each cold cathode tube 50.

The light guide plate 20 is formed by uniformly dispersing and mixing a large number of silicon-based fine particles in a light guide material such as a transparent acrylic resin or polycarbonate. Here, each of the silicon-based fine particles has a particle size in the range of 1 μm to 3 μm, and each of these silicon-based fine particles is
It acts as a light diffusing particle for the light inside.

Further, since the silicon material forming each of the silicon-based fine particles is transparent, the light entering the light guide plate 20 from the cold cathode tube 50 and the light emitted from the light guide plate 20 have the same color as described later. Present. The reason why the fine particles are formed of a silicon material is that the fine particles are easily dispersed and mixed uniformly in the light guide material constituting the light guide plate 20 and the particle size of each fine particle is in the range of 1 μm to 3 μm. Because it is easy to unify. The distribution of the silicon-based particles in the light guide plate 20 may be substantially uniform.

Thus, the incident light from the cold cathode tube 50 into the light guide plate 20 is uniformly diffused in the light guide plate 20 by each of the silicon-based fine particles, and is emitted to the scale plate 10 as diffused light. . At this time, since the light of the cold cathode tube 50 is incident on the light guide plate 20 from a plane perpendicular to its thickness as described later, the direction of the light emitted from the light guide plate 20 is the normal direction to the light guide plate 20. It tends to deviate.

The cold-cathode tubes 50 are accommodated and supported in the light guide plate 20 in the respective band-shaped openings 21 (see FIG. 5) formed in a substantially semicircular shape along the outer periphery of both the pattern display portions 15 and 16. In addition, the central part in the longitudinal direction of both cold cathode tubes 50 is located outside the end of the light guide plate 20, as exemplified in FIG. Thus, each cold cathode tube 50 emits light into the light guide plate 20 from the inner wall of each opening 21 which is a plane perpendicular to the plate thickness direction by the lighting.

The light diffusion layer 30 is adhered to the surface of the light guide plate 20 (the surface on the scale plate 10 side).
Diffuses the diffused outgoing light from the light guide plate 20 and emits it toward the optical sheet 40. Here, since the light from the light guide plate 20 is incident on the light diffusion layer 30 from the entire back surface, the diffuse light emitted from the light diffusion layer 30 is uniformly diffused around the normal direction to the surface of the light diffusion layer 30. I do.

As shown in FIG. 6, the optical sheet 40 is formed by integrally forming a prism section 42 with a mountain-shaped cross section on the surface of a base sheet section 41. The base sheet portion 41 is made of a transparent polyester-based material, and the base sheet portion 41 is attached to the surface of the light diffusion layer 30 (the surface on the scale plate 10 side). The prism section 42 is formed of a transparent acrylic material, and the prism section 42 faces the back surface of the scale plate 10 at each top.

Both walls 42a, 42 of the prism portion 42
The vertical angle formed by b is approximately 90 °. The pitch between the tops of the prism section 42 is 30 μm to 50 μm.
Value within the range. Thus, the optical sheet 4
In the case of 0, when the diffused light from the light diffusion layer 30 passes through the base sheet portion 41 and enters the prism portion 42, a part of the diffused light is distributed by both the walls 42 a and 42 b of the prism portion 42 to the scale plate 10. The light is refracted so as to approach the normal to the back surface, and is emitted toward the scale plate 10. In addition,
The base sheet 41 and the prism 42 have different refractive indices so as to take such an optical path.

In the optical sheet 40, both walls 42
The light reflected by the base sheet portion 41
Through the light diffusion layer 30 and the light guide plate 20, and the reflection layer 60
And is reflected by the reflection layer 60 and passes through the light guide plate 20 and the light diffusion layer 30 to enter the optical sheet 40. For this reason, the light thus incident on the optical sheet 40 is
As described above, the light is refracted by the walls 42a and 42b so as to approach the normal to the back surface of the scale plate 10 and is emitted toward the scale plate 10.

As described above, the optical sheet 40 plays a role of efficiently condensing the light emitted from the light guide plate 20 and the light diffusion layer 30 and causing the light to enter the scale plate 10. This means that the amount of light incident on the scale plate 10 from the cold cathode tube 50 is greatly increased. In addition, as the optical sheet 40, a brightness enhancement film (BE, manufactured by Sumitomo 3M Limited) is used.
F sheet).

The reflective layer 60 is made of a white reflective material adhered to the back surface of the light guide plate 20.
0 reflects light in the light guide plate 20 toward the light diffusion layer 30. Band-shaped openings 61, 43, and 31 are respectively formed in the corresponding portions of the reflection layer 60, the light diffusion layer 30, and the light guide plate 20 of the optical sheet 40 corresponding to the band-shaped openings 21. reference). Thereby, each cold cathode tube 50 is positioned so as to directly face the back surface of the scale plate 10 and the bottom wall inner surface 71 of the holder 70.

The pointer device includes a casing 80, which is mounted on the back surface of the scale plate 10 so as to accommodate the holder 70. The pointer device includes a left driving device 90 and this driving device 9.
And a left hand 100 driven by zero. As shown in FIG. 2, the left driving device 90
Main body 91 fixed to the bottom wall 81 in the left side of the main body 0
And a pointer shaft 92 rotatably extending from the apparatus main body 91 through the through hole of the holder 70 and the through hole Ua of the multilayer body U.

The left hand 100 is for instructing the vehicle speed on the pattern display section 15.
Is coaxially supported by the boss 101 on the pointer shaft 92 of the left driving device 90. The right hand 100 shown in FIG. 1 has the same configuration as the left hand 100,
It is driven by the same driving device as the left driving device 90 and indicates the number of rotations on the pattern display unit 16. The right hand 100 is supported via a scale plate 10 by a hand shaft of the driving device.

The right cold cathode tube 50 is a light source for the left pattern display unit 16. Then, similarly to the increase in the amount of light incident on the pattern display unit 16 of the left cold cathode tube 50 described above, the laminate U increases the amount of light incident on the pattern display unit 16 of the right cold cathode tube 50. . Each light source 110 for the indicator is attached to a circuit board 111 fixed to the outer end of each cylindrical body 72 (an example of a cylindrical body is shown in FIG. 5) formed on the bottom wall 71 in the holder 70. I have.
Each cylindrical portion 72 is in contact with the back surface of the light guide plate 20 through the reflective layer 60 at the inner end opening thereof.
2 (hereinafter, indicator corresponding unit 22)
) Is thinner than the other portions of the light guide plate 20.

Thus, the amount of light incident on the scale plate 10 from each light source 110 can be properly secured under the diffusion action of each silicon-based fine particle. Each light source 110 is a lamp, but may be a light emitting diode, for example. The light diffusion layer 30 and the corresponding portion of the optical sheet 40 corresponding to the indicator corresponding portion 22 have openings 32, 4, and 4.
4 are formed respectively.

Thus, each of the light sources 110 passes light through the indicator corresponding portion 22 of the light guide plate 20 and each of the openings 31 and 41 to the back surface of the scale plate 10 including the character pattern 17a. The front cover 120 is connected to the scale plate 10 via an annular dial plate 130.
(See FIG. 2). The front cover 120 may be formed of a smoke material having a transmittance of about 20% or less, so that the front cover 120 has a black face when the ignition switch of the vehicle is turned off.

In this embodiment configured as described above, when the ignition switch of the vehicle is turned on, the cold cathode tubes 50 emit light by their lighting.
The light from the cold cathode tubes 50 enters the light guide plate 20 from the inner walls of the openings 21. Then, the incident light is uniformly diffused by the silicon-based fine particles in the light guide plate 20 and is reflected by the reflection layer 60 and proceeds toward each through hole 11 of the scale plate 10.

In such a process, the light guide plate 2 is located because of the arrangement of the cold cathode tubes 50 with respect to the light guide plate 20.
The light within 0 enters the back surface of the diffusion layer 30 with a tendency to shift from the direction normal to the light guide plate 20. Then, the light that has entered the light diffusion layer 30 in this manner is reflected by the light diffusion layer 30.
The light is uniformly diffused and enters the optical sheet 40.
At this time, the light emitted from the light diffusion layer 30 is diffused uniformly around the normal to the light diffusion layer 30, so that the light to the optical sheet 40 is uniformly distributed over the entire back surface of the optical sheet 40. Incident.

Next, when the diffused light passes through the base sheet portion 41 of the optical sheet 40 and enters the prism portion 42, the incident light is applied to both walls 42a, 42a of the prism portion 42.
By b, the light is refracted so as to approach the normal direction to the back surface of the scale plate 10 and enters the scale plate 10. Further, the light reflected toward the inside of the optical sheet 40 by each of the walls 42 a and 42 b passes through the light diffusion layer 30 and the light guide plate 20 and enters the reflection layer 60. Along with this, the incident light is reflected by the reflection layer 60, passes through the light diffusion layer 30 and re-enters the optical sheet 40, reaches the prism part 42,
a and 42b are refracted in the same manner as
Incident on.

As a result, the laminated body U is
, The amount of light incident on the scale plate 10 can be sufficiently ensured. Therefore, it is possible to sufficiently secure the amount of light transmitted through areas other than the scale portions and the character portions of both pattern display portions 15 and 16 on the scale plate 10. Accordingly, it is possible to sufficiently increase the brightness of the light transmitting areas of the pattern display sections 15 and 16. As a result, the contrast between the scale portions and the character portions of the pattern display portions 15 and 16 and the contrast between the scale portions and the character portions are improved, and the visibility can be significantly improved.

In this case, since the light of the optical sheet 40 is uniformly incident on the back surface of the scale plate 10 as described above, even if the transmissive areas of both the pattern display sections 15 and 16 are wide, the entire transmissive area is not affected. Brightness can be made uniform. Also,
Each cold cathode tube 50 is, as described above, a bottom wall 7 of the holder 70.
1, the light of each cold cathode tube 50 is diffusely reflected by the bottom wall 71 of the holder 70. For this reason, even if the brightness of the light-transmitting region of the scale plate 10 is high as described above due to the light diffusion layer 30 and the optical sheet 40, the bottom wall 71 of the holder 70 can only be seen through the scale plate 10, which particularly hinders visibility. Never.

Further, since each of the cold cathode tubes 50 is accommodated in each of the strip-shaped openings 21 of the light guide plate 20, each of the cold cathode tubes 50 is provided with a corresponding one of the display pattern portions 15, as shown in FIG.
16 will be located along the outer circumference. Therefore, these cold cathode tubes 50 can improve the appearance of the scale plate 10 in the lighting state. The effects described above are as follows.
The same holds for the pattern display section 16 on the right side.

When the indicator light source 110 is turned on by turning on the ignition switch IG, the light of the light source 110 is transmitted to the indicator corresponding portion 2 of the light guide plate 20.
2. Character pattern 17b and opening 17 of scale plate 10
a. Thereby, the indicator unit 17 displays the shift position in a character pattern of L, for example, as shown in FIG.

Here, as described above, the thickness of the indicator corresponding portion 22 is reduced, and the corresponding portions of the light diffusion layer 30 and the optical sheet 40 correspond to the opening 32,
44 are formed. Therefore, the amount of light transmitted through the indicator corresponding portion 22 of the light guide plate 20 can be appropriately secured under the diffusion effect of each of the silicon-based fine particles, and the light source 110 controls the light diffusion effect of the light diffusion layer 30 and the optical The light is not visually recognized through the indicator section 17 of the scale plate 10 due to the light collecting action of the sheet 40.

In implementing the present invention, both cold cathode tubes 50A may be used instead of both cold cathode tubes 50, as shown in FIG. 7, and both cold cathode tubes 50A, as shown in FIG. The tube 50B may be employed. In this case, each cold cathode tube 50
A shows both pattern display sections 15, 1 as shown in FIG.
6 so as to be parallel to each other on both upper and lower sides.
Each of the openings is accommodated and supported.

In FIG. 8, the left cold cathode tube 50B
Is a U-shaped. The left cold cathode tube 50B is accommodated and supported in a U-shaped opening formed around the pattern display section 15. The right-side cold cathode tube 50B has an L-shape. The right-side cold cathode tube 50B is accommodated and supported in an L-shaped opening formed in the light guide plate 20 along the upper portion and the right side of the pattern display section 16. . Other configurations are the same as those of the above embodiment.

Further, the present invention is not limited to the cold cathode tube, but may be implemented by employing various light-emitting bodies such as electroluminescence and light-emitting diodes. In practicing the present invention, the present invention is not limited to the vehicle pointer device, but may be applied to various pointer devices, analog display devices, or digital display devices. In this case, it is desirable that the display panel of the display device has a non-translucent display portion corresponding to a scale portion or a character portion, and a non-translucent non-display region around the non-translucent display portion.

In practicing the present invention, the pointer of the pointing device may be a light-emitting pointer having a light source inside, or a light-emitting pointer that receives light from an external light source and emits light. In the above-described embodiment, the cold-cathode tube normally emits white light. However, the present invention is not limited to this. For example, a cold-cathode tube that emits green light may be employed.

In implementing the present invention, the scale plate 1
The black layer 12 may be removed from the area outside the pattern display portions 15, 16, 17 on the surface of the light-emitting layer 11 to form the light diffusion layer 11. As a result, the surface of the scale plate 10 has a region other than the scale portion and the character portion of each of the pattern display portions 15 and 16 and the character pattern of the indicator portion 17 and the light diffusion layer 11.
Is displayed in white.

In practicing the present invention, the light diffusion layer 30 of the laminate U described in the above embodiment is eliminated,
The optical sheet 40 may be directly adhered to the surface of the light guide plate 20 for implementation. In this case, the light emitted from the light guide plate 20 is condensed by the optical sheet 40 under the uniform diffusion of the silicon-based fine particles with respect to the light in the light guide plate 20. Thereby, the light of the optical sheet 40 passing through the translucent area of the scale plate 10 can be increased.

In practicing the present invention, the optical sheet 40 may be omitted from the laminate U described in the above embodiment. In this case, under the uniform diffusion of the silicon-based particles to the light in the light guide plate 20,
The light emitted from the light guide plate 20 is uniformly diffused by the light diffusion layer 40 and enters the scale plate 10. This can also substantially increase the amount of light incident on the scale plate 10.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG.

FIG. 4 is an enlarged view showing a plane of a portion within a circle indicated by reference numeral A in FIG.

FIG. 5 is a sectional view taken along line 5-5 in FIG.

FIG. 6 is an enlarged sectional view of an optical sheet.

FIG. 7 is a partially broken plan view showing a first modification of the embodiment.

FIG. 8 is a partially broken plan view showing a second modification of the embodiment.

[Explanation of symbols]

Reference numeral 10: scale plate, 11: light diffusion layer, 12: black layer, 1
5, 16: scale pattern display section, 17: indicator section, 20: light guide plate, 21: opening, 30: light diffusion layer, 4
0: optical sheet, 50, 50A, 50B: cold cathode tube,
60 ... Reflection layer.

Claims (5)

[Claims] 1. A non-translucent display section (15a, 15b, 16)
a, 16b), a display plate (10) provided with a translucent non-display area (11), linear illuminants (50, 50A, 50B), and disposed along the back surface of the display plate. A light guide plate (20) for introducing the light of the illuminant from the peripheral wall portion (21) and entering the display plate; and a light guide plate provided on the opposite side of the display plate along the light guide plate, and A reflection layer (60) for reflecting light toward the display plate; and a large number of silicon-based fine particles mixed into the light guide plate so as to diffuse the light inside the light guide plate. An optical sheet (4) for condensing the light incident on the display plate and making the light incident on the display plate is provided between the optical sheet (4).
A display device in which 0) is interposed. 2. The non-translucent display section (15a, 15b, 16)
a, 16b), a display plate (10) provided with a translucent non-display area (11), linear illuminants (50, 50A, 50B), and disposed along the back surface of the display plate. A light guide plate (20) for introducing the light of the illuminant from the peripheral wall portion (21) and entering the display plate; and a light interposed between the display plate and the light guide plate and incident on the display plate. A light diffusion layer (30) for diffusing light and entering the display panel; and a light diffusion layer provided on the opposite side of the light diffusion layer along the light guide plate to direct light in the light guide plate toward the light diffusion layer. A display device, comprising: a reflective layer (60) that reflects light; and a large number of silicon-based fine particles mixed into the light guide plate so as to diffuse light therein. 3. Between the light diffusion layer and the display panel,
3. The display device according to claim 2, wherein an optical sheet (40) for condensing the light diffused by the light diffusion layer and entering the display plate is interposed. 4. The optical sheet according to claim 1, wherein the optical sheet is a transparent resin sheet having a plurality of cross-section prisms (42), and the transparent resin sheet transmits light incident on the display panel to each of the cross-section prisms. The display device according to claim 1, wherein the light is condensed by a unit and is incident on the display plate. 5. A light source for an indicator, which is disposed on the light guide plate on a side opposite to the display plate and emits light through the light guide plate, wherein the light guide plate of the light diffusion layer and the optical sheet is provided. 4. The display device according to claim 3, wherein openings (32, 44) are respectively formed in respective corresponding portions to the light source for the indicator.