JPH1055148A - Panel illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a panel illuminator whose part cost and assembling cost are reduced by reducing the number of components. SOLUTION: At this device, a display panel 13 is provided on the surface 12a of a flat light guiding member 12, and a light source 14 is provided at an installation hole 12d which is the rear face of the display panel 13 and a liquid crystal display device 15 as a second display panel that is different from the display panel 13 is provided at an installation recessed part 12d. An illuminating luminous flux from the light source 14 is made as a perpendicular luminous flux (P') nearly uniformly illuminating the display panel 13 from the rear surface by the surface 12a and the rear surface 12e, and the illuminating luminous flux from the light source 14 is made as a horizontal luminous flux (P) illuminating the liquid crystal display device 15 by being led to the rear surface of the liquid crystal display device 15 by a peripheral part 12h and a leg 12j.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a panel lighting device,
In particular, the present invention relates to a panel lighting device provided with two display means.

[0002]

2. Description of the Related Art Conventionally, for example, in a vehicle instrument, FIG.
As shown in FIG. 1A, a speedometer 3 having a display panel 2 for recognizing a vehicle speed by hands 1 and a liquid crystal display as a second display panel provided in a part of an unused area of the speedometer 3 One with an od trip meter 5 having a 4 is known.

The speedometer 3 has a plurality of light sources 6 and 6, and at night or the like, a light guide member (not shown)
The illumination light flux emitted from the pointer 6 and the display panel 2
The recognition is possible.

[0006] As shown in FIG. 4 (B), the od trip meter 5 includes a light source 7 provided on the back surface of the liquid crystal display 4.
And a second light guide member 8 for guiding a horizontal light flux P (horizontal with respect to the surface of the display panel 2) emitted from the light source 7 to the back surface of the liquid crystal display 4. Enabled the recognition of the od trip meter 5
A so-called backlight system is employed.

[0005]

By the way, in the panel lighting device configured as described above, the light sources 6 and 6 for illuminating the display panel 2 need to be illuminated at the same time. In addition, since the light guide member and the light source 7 and the light guide member 8 for illuminating the liquid crystal display 4 are separately provided, there has been a problem that the component cost and the assembly cost are increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a panel lighting device capable of reducing the number of parts and reducing the cost of parts and assembly.

[0007]

According to one aspect of the present invention, there is provided a light-transmitting display panel provided on a surface of a flat light guide member, and a back surface of the display panel. A light source provided to illuminate the display panel substantially uniformly from the back surface by the light guide member, a second display panel different from the display panel provided in the installation portion of the light guide member, and the light guide member. A second light guide that is formed integrally and guides the illumination light flux from the light source toward the back surface of the second display panel;
The gist of the present invention is to include a light guide section.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a panel lighting device according to the present invention will be described with reference to the drawings, applying to an instrument (for example, a speedometer) installed on an instrument panel for a vehicle.

1A and 1B, a panel lighting device 11 includes a light guide member 12, a light-transmitting display panel 13 provided on a surface 12a in a thickness direction of the light guide member 12, and
A light source 14 located on the back of the display panel 13 and a second
Display device 1 having liquid crystal display 15 as display panel
6 is provided.

The light guide member 12 is made of, for example, a transparent resin, and has a flat semi-disc shape in which an arc shape is located above the vehicle body when viewed from the front. Further, the light guide member 12 has an installation recess 12b as an installation portion for installing the liquid crystal display 15, a through hole 12c located substantially at the center of the circular arc shape, and through which a pointer shaft of the instrument penetrates. An installation hole 12d for installing the light source 14 is formed on an extension of a center line (not shown) extending from the center of the concave portion 12b to the center of the through hole 12c. The light source 14 is inserted into the installation hole 12d from the back surface 12e side in the thickness direction of the light guide member 12.

The peripheral wall of the installation hole 12d serves as an annular entrance surface for guiding the illumination light beam emitted from the light source 14 into the light guide member 12 as a horizontal light beam (horizontal with respect to the surface 12a of the light guide member 12). I have.

The back surface 12e of the light guide member 12 is shown in FIG.
As shown in FIG. 5, an annular step portion is formed in a stepwise manner in the thickness direction of the light guide member 12 and concentric with the installation hole 12d. The annular step portion applies the illumination light beam from the light source 14 which has been made into a horizontal light beam by the installation hole 12d to the surface 12a.
Have a plurality of annular reflecting surfaces 12g, 12g,.

The surface 12a of the light guide member 12 is
As shown in (B), the positive refraction angle (α) and the negative refraction angle (β) are set so that the light flux reflected by the annular reflecting surfaces 12g, 12g,. Are provided concentrically with the installation hole 12d as a center.
In FIG. 2B, reference numeral 12n denotes a Fresnel lens having a positive refraction angle, and reference numeral 12o denotes a Fresnel lens having a negative refraction angle.

Each of the Fresnel lenses 12f, 12f.
For example, ten annular reflecting surfaces 12g are formed. At this time, as shown in FIG. 2 (A), the illumination ranges Xi-1, Xi, and Xi per unit area illuminated by the reflected light beams reflected by the respective annular reflecting surfaces 12g, 12g,.
Xi + 1 is substantially equal.

The light guide member 12 emitted from the light source 14
Is spread in proportion to the square of the distance, so that the amount of illumination light flux farther from the light source than the light source near the light source 14 is greatly attenuated.
Therefore, the width in the thickness direction of the annular reflecting curved surfaces 12g is designed to increase as the distance from the light source 14 increases, so that the amount of illumination light flux per unit area becomes substantially the same. .. Become larger as the annular reflecting surfaces 12g move away from the light source 14, so that the light quantity of the illumination light flux closer to the light source 14 and the light quantity of the illumination light flux farther from the light source 14 are made substantially the same. be able to.

As a result, the annular reflecting surfaces 12g, 12g,.
, And Fresnel lenses 12f, 12f,... Serve as a vertical light beam forming means for turning a horizontal light beam P guided into the light guide member 12 by the inner wall surface shape of the installation hole 12d into a vertical light beam P '. I have. This vertical light flux P ′ becomes an illumination light flux for illuminating the display panel 13 from the back surface.

On the other hand, the outer peripheral edge 12h of the light guide member 12 has a V-shaped cross section that tapers toward the edge.
Further, as shown in FIG. 2 (C), tapered prism portions 12i, 12i,...

The prism portions 12i, 12i... Refract a part of the horizontal light beam P diffused radially from the light source 14 in a front view to the installation concave portion 12b as the horizontal light beam P. On this occasion,
The prism portion 12i has an inclined surface located on the back surface 12e side of the light guide member 12 with respect to the thickness of the peripheral portion 12h.
(A V-shaped prism 12 on the same horizontal plane).
3 (B), and the horizontal light flux P directed to the peripheral edge 12h is efficiently folded back by the prism portion 12i as shown in FIG. 3 (B).

The thickness of the peripheral edge portion 12h of the light guide member 12 varies depending on the position of the annular step portion on the back surface 12e, and therefore (the through hole portion 12c substantially at the center of the light guide member 12 and the center of the annular step portion). The light source installation hole 12d is eccentric.) The V-shaped prism portion 1 according to the thickness of the peripheral portion 12h
Changing the ridge line so that the ridge line 2i is located at the center part of the thickness, and an inclined surface located on the surface side of the prism part 12i;
By making the inclined surface located on the rear surface side the same, it is possible to prevent waste of the illumination luminous flux reflected particularly on the inclined surface and traveling toward the rear surface 12e. The angle formed by the front-side inclined surface and the rear-side inclined surface of the prism portion 12i is set to about 90 °.

On the other hand, a leg 12j projecting toward the back surface 12e is formed in the installation recess 12b along the peripheral edge of the installation recess 12b. A reflection surface 12k that reflects the illumination light flux from the light source 14 toward the protruding end is formed on the base side of the leg 12j. A reflection surface 12m that reflects the horizontal luminous flux P reflected by the reflection surface 12k toward the rear surface of the liquid crystal display 15 is formed on the protruding end side of the leg portion 12j. The prism portion 12i and the reflecting surfaces 12k, 12k
“m” indicates that the liquid crystal display 1 is formed integrally with the light guide member 12.
5 serves as a second light guide section for guiding a horizontal light beam P as an illumination light beam from the light source 14 toward the back surface side.

The display device 16 comprises a liquid crystal display 15 and a reflection member 20 for holding the liquid crystal display 15 from the back surface 15a side.
And a holder 21 for holding the reflection member 20. The reflection member 20 is provided with a reflection surface 20a that reflects the illumination light flux reflected by the reflection surface 12m toward the back surface 15a of the liquid crystal display 15. In this case, the liquid crystal display 15 performs switching between display as an odometer and display as a trip meter in this case.
Further, the reflection member 20 may be integrated with the light guide member 12.

In the above configuration, as shown in FIG. 3A, the horizontal light beam P emitted from the light source 14 is
Due to the hole shape of 2d, it becomes a horizontal light flux P diffused radially in front view and along the surface 12a. A part of the radially diffused horizontal light beam P is reflected on the reflection surface 1 on the back surface 12e.
Are reflected to the front surface 12a, and the Fresnel lenses 12f on the front surface 12a illuminate substantially the entire surface of the display panel 13 from the back surface as a vertical light flux P '. The horizontal light beam P illuminates the pointer 19.

Further, another part of the horizontal luminous flux P diffused radially passes through the inside of the light guide member 12 and goes to the outer peripheral edge 12h, and as shown in FIG. The light is reflected toward the installation concave portion 12b so as to be folded back in a sectional view by the prism portions 12i of the peripheral portion 12h. Further, the light passes through the inside of the light guide member 12 and is directly guided to the installation recess 12b.

The horizontal luminous flux P directed to the installation recess 12b is reflected by the reflection surface 12 as shown in FIGS. 3 (B) and 3 (C).
The light is reflected by k and 12 m, and is guided to the reflecting member 20 as shown in FIG.

The horizontal light beam P guided to the reflecting surface member 20 is
The back surface 15a of the liquid crystal display 15 is reflected by the reflection surface 20a.
To the horizontal luminous flux P reflected by the back surface 15a.
As a result, the liquid crystal display 15 is illuminated as a backlight.

As described above, the light beam emitted from the light source 14 enters the light guide member 12 as a horizontal light beam through the peripheral wall surface 12d of the installation hole 12d of the light guide member 12. A part of the horizontal light beam is reflected toward the front surface 12a by the annular reflecting surfaces 12g, 12g,... Formed on the back surface 12e, and the reflected light beam is Fresnel lenses 12f, 12f formed on the front surface 12a. , The light guide member 1
2 is vertically polarized with respect to the surface 12a of the display panel 13
To illuminate. Further, a part of the other horizontal light beam is reflected directly or on the outer peripheral edge portion 12h and guided to the installation concave portion 12b, and thereafter, is reflected by the reflection surfaces 12k and 12m.
To the reflection member 20 which is the back surface of the
With 0, the liquid crystal display 15 can be illuminated from the back.

Accordingly, one light source 14 and one light guide member 12 can simultaneously form different illuminating light fluxes for the display panel 13 and the liquid crystal display 15 as different display means, thereby greatly reducing the number of components. Therefore, the cost of parts and the cost of assembly can be reduced.

[0028]

As described above, in the panel lighting device of the present invention, the light-transmitting display panel provided on the surface of the flat light guide member and the rear surface of the display panel are provided. A light source for illuminating the display panel substantially uniformly from the back surface with the light guide member, a second display panel different from the display panel provided on the installation portion of the light guide member, and integrally formed with the light guide member And the second light guide section for guiding the illumination light flux from the light source toward the back side of the second display panel, so that the number of parts can be reduced, and the cost of parts and the cost of assembly can be reduced. be able to.

[Brief description of the drawings]

FIG. 1 shows a panel lighting device according to an embodiment of the present invention, wherein (A) is a front view of the panel lighting device, and (B) is a longitudinal sectional view of the panel lighting device.

2 (A) is an enlarged view of a light guide member, FIG. 2 (B) is an enlarged view showing a relationship between one annular reflection surface of the light guide member and a Fresnel lens, and FIG. 2 (C) is a light guide member. FIG. 4 is an enlarged view of an outer peripheral edge portion of FIG.

3A is a front view of the light guide member, FIG. 3B is a longitudinal sectional view of the light guide member, and FIG. 3C is a bottom view of the light guide member.

4A and 4B show a conventional panel lighting device, wherein FIG. 4A is a front view of the panel lighting device, and FIG. 4B is a cross-sectional view taken along line AA of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Panel illumination device 12 ... Light guide member 12a ... Surface 13 ... Display panel 14 ... Light source 15 ... Liquid crystal display (2nd display panel)

Continuing from the front page (72) Inventor Kazuo Arai 2--1910 Nisshincho, Omiya-shi, Saitama Kansai Co., Ltd. (72) Inventor Tetsuhide Takeyama 5-9-11, Minami-Nagasaki, Toshima-ku, Tokyo Inside Fujii Optical Co., Ltd. 72) Inventor Toshihisa Higuchi 5-9-11, Minami-Nagasaki, Toshima-ku, Tokyo Inside Fujii Optical Co., Ltd.

Claims (5)

[Claims] 1. A light-transmitting display panel provided on a front surface of a flat light guide member, and a light source provided on a back surface of the display panel and illuminating the display panel substantially uniformly from the back surface by the light guide member. A second display panel different from the display panel provided on the installation portion of the light guide member, and a second display panel formed integrally with the light guide member and receiving light from the light source toward a back side of the second display panel. A panel lighting device, comprising: a second light guide section for guiding an illumination light beam. 2. An illumination light beam for illuminating the display panel is a vertical light beam along a thickness direction of the light guide member, and an illumination light beam for illuminating the second display panel is a horizontal light beam along a surface of the light guide member. The panel lighting device according to claim 1, wherein: 3. The light guide member is provided in an installation hole in which the light source is installed, and is provided on an inner wall surface forming the installation hole, and illuminates a light beam emitted from the light source into a horizontal light beam in the light guide member. 3. The panel lighting device according to claim 1, further comprising: a lens surface that guides as a vertical light beam; and a vertical light beam forming unit that is formed on the front surface and the rear surface and that converts a horizontal light beam into a vertical light beam. 4. The light guide member according to claim 3, wherein a prism portion for refracting a part of the horizontal light beam to the installation portion as a horizontal light beam is formed at a peripheral portion of the light guide member. Panel lighting device. 5. The prism section has a V-shaped cross section in which the inclined surface located on the back surface side of the light guide member has the same inclined surface located on the front surface side with respect to the thickness of the peripheral edge portion. The panel lighting device according to claim 4, wherein the panel lighting device is provided.