JP3106464B2 - Lighting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-transmitting substrate provided with a display plate on which characters, symbols, scales and the like are displayed, and a light source provided behind the display plate to transmit the display plate. The present invention relates to a method for making the light emission luminance of a lighting device for lighting uniform.

[0002]

2. Description of the Related Art Conventionally, as a lighting device of this type, FIG.
As shown in FIG. 8, a display plate A on which characters, symbols, scales and the like are formed by a printing means on a transparent or translucent substrate is provided, and a printed circuit board B is provided behind the display plate A.
It is known that a light source C is arranged on the printed circuit board B, the light source C is turned on by a current supplied to a conductive pattern (not shown) of the printed circuit board B, and the display panel A is transmitted and illuminated from behind. I have.

According to this illuminating device, as shown in FIG. 7, a light source C is formed by forming a reflective layer D made of, for example, white having a high reflectivity on a surface of a printed circuit board B facing a display plate A.
Light is reflected by the reflective layer D to improve the illumination efficiency, or a light case E formed of a resin material such as white between the display panel A and the printed board B as shown in FIG. The light case E is provided with a hole F for inserting the light source C at a position corresponding to the light source C of the light case E.
There has been proposed an apparatus which transmits and illuminates light from a light source C by reflecting the light from a light source C to a back surface of a display panel A by a bottom portion G of the panel.

[0004]

However, in the above-mentioned conventional configuration, the light from the light source C is repeatedly emitted by the white printed circuit board B or the bottom G of the light case F, which is a plane shape in any case. Since the light is reflected and guided to the rear surface of the display panel A, the location of the display panel A directly above the light source C tends to be relatively bright, and the location of the display panel A far from the light source C tends to be relatively dark. There was a problem.

The light source C is an LED (light emitting diode)
In the case of the light source C, since the directivity of light is stronger than that of an incandescent light bulb or the like, there is a problem that this phenomenon is particularly remarkable. Add a light source C to substantially uniform brightness as a whole plate a, and it is common practice to mitigate the variation of light Rukoto increase the number of light sources C,
This was causing the cost to increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an illuminating device which can make the luminous brightness of the entire display panel which is transmitted and illuminated substantially without increasing the number of light sources.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a display plate having characters, symbols, scales and the like on a translucent substrate, and a print plate provided behind the display plate. A substrate, a light source composed of an LED disposed on the display board side of the printed board, and substantially parallel to the display board at a predetermined distance from the display board between the display board and the printed board. A light case having a flat portion, a hole provided at a position corresponding to the light source of the light case, and a periphery of the hole of the light case so as to approach the light source from the periphery of the hole toward the light source. An inclined reflecting surface and a reflecting layer formed on the light source-facing side of the display panel
And is provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A translucent substrate is provided with a display plate on which a transmissive portion and a non-transmissive portion are formed to display characters, symbols, scales, and the like. Arrange. A light source composed of a chip component type LED is surface-mounted on the display board side of the printed circuit board and soldered to a pattern surface (not shown). A light case is interposed between the display panel and the printed circuit board. The light case has a flat portion substantially parallel to the display plate at a predetermined distance from the display plate between the display plate and the printed board, and the flat portion is provided on the printed board. A hole is provided corresponding to the position of the light source to be provided, so that light from the light source can be emitted toward the back surface of the display panel.

According to the present invention, an anti-slope is provided around the hole so as to be inclined toward the light source from the periphery of the hole toward the light source.

In this manner, the light emitted from the light source is repeatedly reflected between the display panel and the light case and is illuminated from the rear side of the display panel to transmit and illuminate the display panel. In general, at a position directly above a light source that is particularly likely to be particularly bright, light is radiated from the light source once, and reflected light returning to the light source position after being surface-reflected by the display panel is reflected by the reflection surface formed on the light case. , Since it reflects toward a position away from the light source, it actively guides and guides the reflected light toward the surrounding area where it tends to be dark,
Light can be distributed efficiently. Therefore, the emission luminance can be made uniform throughout the display panel.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 illustrate a comparative example of the present invention using a lighting device for an instrument as an example.

A display plate 1 is provided on a light-transmitting substrate, on which a transparent portion 1A and a non-transmissive portion 1B are formed and a display 2 such as characters, symbols, and scales is provided, and a printed circuit board 3 is provided behind the display plate 1.
Are arranged opposite to each other. A light source 4 made of a chip component type LED is surface-mounted and soldered on the display board 1 side of the printed circuit board 3.

A light case 5 is interposed between the display panel 1 and the printed circuit board 4, and the light case 5
The display panel 1 is supported on the front side, and the printed circuit boards 3 are stacked and arranged on the rear side by means such as screws (not shown).

The light case 5 is formed of, for example, a white resin material to suppress light absorption, and forms a predetermined distance from the display panel 1 between the display panel 1 and the printed circuit board 4. It has a plane part 6 substantially parallel to the display panel 1, and forms a space 7 between the display panel 1 and the plane part 5. Light emitted from the light source 4 is directly transmitted to the display panel 1.
Is reflected by the rear surface of the light case 5 toward the flat surface portion 6 side of the light case 5, and is again reflected by the flat surface portion 6 of the light case 5 toward the display panel 1, and the space portion 7 reflects the light which is repeatedly reflected. Will be configured.

A circular hole 8 is provided in a part of the flat portion 6 of the light case 5 at a position corresponding to the position of the light source 4 provided on the printed circuit board 3 so that light from the light source 4 is transmitted to the display panel 1.
It is provided so as to be able to irradiate toward the back of.

In the comparative example of the present invention , the printed circuit board 3 is provided around the hole 8 from the periphery of the hole 8 toward the light source 4.
A reflecting surface 9 is provided which is inclined so as to approach the side. The reflecting surface 9 is formed as a concave conical tapered surface, and emits relatively strong light that is emitted from the light source 4, reflected on the back surface of the display panel 1, and returns to the reflecting surface 9, away from the light source 4. The inclination angle is set so that the light is reflected toward the tilted position. The reflecting surface 9 is formed as a continuous inclined surface up to the position of the hole 8 close to the light source 4.

This operation will be described in detail with reference to FIG. 4. FIG. 4A shows that light emitted from the light source 4 is emitted from the display panel 1.
3 shows a state in which light is directly radiated to the back surface of the optical disc. This light is the light with the highest luminance.

FIG. 4B shows that the light emitted from the light source 4 is reflected on the back surface of the display panel 1 and then the light case 5
2 shows that light is guided over the entire display panel 1 by the repeated reflection of the display panel 1 and the flat section 6 of the light case 5.

FIG. 4C shows that, of the light emitted from the light source 4, a relatively strong light at a position slightly deviated from a position directly above the light source 4 is reflected on the back surface of the display panel 1, and then reflected on the light case 5. FIG. 3 shows a state in which light is reflected by a reflection surface 9 provided and directed toward a rear position of the display panel 1 distant from the light source 4. Thereafter, this light is repeatedly reflected between the back surface of the display panel 1 and the flat portion 6 of the light case 5.

The three light traveling patterns described above merely show the basic concept, and in reality light is transmitted by a combination of these, or a combination of light scattering and diffraction. In general, however, the light emitted from the light source 4 is repeatedly reflected between the display panel 1 and the light case 5 and illuminated from the rear side of the display panel 1 to transmit light through the display panel 1. However, in the present invention, FIG.
As shown in (c), in general, at a position directly above the light source 4 that tends to be particularly bright, the reflected light is a relatively strong light that is once reflected from the light source 4 by the back surface of the display panel 1 and returns to the light source 4 position. The light is reflected toward a position distant from the light source 4 by the reflection surface 9 formed on the light case 5 using the light emitting device.

FIG. 5 shows an embodiment of the present invention, in which a reflective layer 10 made of, for example, white or silver is formed by printing on the back surface of the display panel 1 on the side facing the light source 4. In this case, the reflection layer 10 is a non-transmissive portion 1B of the display panel 1.
The light irradiating the non-transmissive portion, which is a portion that does not transmit to the front side of the display panel 1, is reflected brightly to the plane portion 6 side of the light case 5 while suppressing a decrease in luminance. While the reflection of light between the layer 10 and the plane portion 6 of the light case 5 is repeated, the reflected light is made incident on and transmitted through the transmitting portion 1A, thereby increasing the light use efficiency and making it darker.
Actively guides reflected light toward a position distant from the pan light source 4
Guide light and distribute light efficiently throughout the display panel.
And the display panel 1 as a whole has a uniform light emission luminance.
Can be measured. By doing so, the light source 4
This can also alleviate the situation where the display panel 1 at a position corresponding to a position directly above the display panel 1 becomes particularly bright.

According to the present invention, particularly, the light directivity
This is particularly effective when using a light source 4 composed of
That the light from the light source 4 looks like a dot on the display panel 1.
To achieve a uniform distribution of the emission luminance of the entire display panel 1 while preventing the
It is effective as a means for causing

At this time, for example, the formation density, that is, the thickness and the area of the reflection layer 10 are increased in a portion close to the light source 4, and the formation density of the reflection layer 10 is set low in a portion away from the light source 4. It may be set so that the amount of light transmitted through the display panel 1 is adjusted.

In the above-described embodiment, the space 7 is provided between the display panel 1 and the flat portion 6 of the light case 5, and the space 7 is configured as a light reflection path. A light guide made of, for example, a transparent resin material such as acrylic is provided in correspondence with the portion 7, and the entire display panel 1 is illuminated by improving light transmission by utilizing internal reflection and scattering of the light guide. It may be something.

FIG. 6 shows another embodiment.
In this embodiment, a plurality of light sources 4 arranged close to each other are provided on a printed circuit board 3, holes 8 corresponding to the light sources 4 are provided in a light case 5, and reflection surfaces 9 are provided around the holes 8. Make up the whole. This case is particularly suitable when the area of the display panel 1 is large.

The light source 4 is not limited to the surface mount type LED, but may be a lead type.

Further, a hole 8 provided in the light case 5 is provided.
The shape of the reflecting surface 9 is not limited to a circular shape and may be a polygonal shape. The reflecting surface may be formed as a curved surface having a curvature such as a parabolic shape. .

Further, in the display panel 1 of the present invention, the display 2 is formed by the transmissive portion 1A and the non-transmissive portion 1B. The display 2 can be formed by a display color different from that of the display panel 2 and light can be emitted from the entire surface of the display panel 1 as a transmission portion.

[0031]

As described above, according to the present invention, it is possible to provide an illuminating device which can make the luminous brightness of the display panel to be transmitted and illuminated substantially without increasing the number of light sources.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a comparative example of the present invention.

FIG. 2 is a perspective view showing a main part of a comparative example of the present invention.

FIG. 3 is a partially cutaway front view showing a comparative example of the present invention.

FIG. 4 is a cross-sectional view illustrating an operation of a comparative example of the present invention.

FIG. 5 is a sectional view showing an embodiment of the present invention.

FIG. 6 is a perspective view showing a main part of another embodiment of the present invention.

FIG. 7 is a sectional view showing a conventional example.

FIG. 8 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display board 2 Display 3 Printed circuit board 4 Light source 5 Light case 6 Flat part 7 Space part 8 Hole part 9 Reflection surface 10 Reflection layer

Claims (1)

(57) [Claims] 1. A display plate in which characters, symbols, scales and the like are displayed on a light-transmitting substrate, a printed circuit board provided behind the display plate, and a printed circuit board provided on the display plate side of the printed circuit board a light case with a light source consisting been LED, the display plate and the display substantially parallel plane portion and the display panel at a predetermined distance from the plate between the printed circuit board, the light source of the light case A hole provided at a corresponding position, a reflective surface inclined around the hole of the light case toward the light source from around the hole toward the light source, and a light source facing side of the display plate. Reflection formed on
A lighting device , comprising: a layer ;