JPS604221Y2 - Translucent display panel - Google Patents

Description

[Detailed description of the invention] The present invention is a type of display panel (hereinafter referred to as a This relates to the structure of a translucent display panel.

For example, if a light bulb is used to illuminate a transparent panel with a uniform thickness from the back side, the area near the light bulb will be strongly illuminated, but the surrounding area will be dimly lit.

Therefore, when illuminating display information on a panel with a large area, uniform illumination is difficult even if several light bulbs are used.

However, using a large number of light bulbs is not only uneconomical, but also increases the total amount of heat generated, which adversely affects various circuit elements and causes failures.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a translucent display panel that requires fewer light emitting elements, such as light bulbs, to substantially uniformly illuminate a large surface area.

Examples will be described below with reference to the drawings.

FIGS. 1 and 2 show an example in which the present invention is applied to a panel switch incorporating a button switch for controlling electronic equipment mounted on an automobile.

This panel switch includes a main panel 1 made of a transparent material such as acrylic or polycarbonate.

The main panel 1 has a light-transmitting plate portion 2 and a prism portion 3 having a substantially trapezoidal cross section and protruding from the back side of the light-transmitting plate portion.

The transparent plate part 2 has a transparent and thin flexible sheet 4 made of vinyl chloride or polyester bonded to the surface.
Accordingly, a plurality of pieces of display information 5 including transparent parts are provided.

The trapezoidal shape of the prism portion 3 is such that the protruding end is the short side.

The main panel 1 also has square through holes 6 formed at positions facing the display information 5, and through round holes 7 of small diameter provided adjacent to these square holes 6.

A translucent operation button 8 made of the same material as the main panel 1 is inserted into the square through hole 6 so as to be movable in front and back directions.

On the other hand, a light shielding tube 9 is inserted into the through hole 7, and a light emitting diode 10 is placed inside the tube 9.

The main panel 1 further includes a cavity 11 having a substantially trapezoidal cross section formed in a portion of the prism part 3 adjacent to the transparent plate part 2, and a lamp 12 penetrating from the protruding end of the prism part 3 to the cavity 11. ing.

The trapezoidal shape of the cavity 11 also has a short side on the protruding end side of the prism portion 3.

The lamp holes 12 are provided at a plurality of locations at appropriate intervals in the axial direction of the space 11, for example, at a pitch twice as large as the pitch of the operating button 8.

Such a main panel 1 is stacked and fixed on a circuit board 14 via an insulating spacer 13.

At this time, the switch part 16 is positioned between the operation button 8 and the circuit board 14 using the hole 15 formed in the spacer 13, and the light bulb 17 as a light emitting element provided on the circuit board 14 is used.
are inserted into each lamp hole 12.

The switch section 16 is driven by the movement of the operation button B due to the pressing force from the surface of the flexible sheet 4.

When the switch unit 16 is driven, the electric circuit mounted on the circuit board 14 controls the electronic devices and turns on and off the light emitting diode 10.

Incidentally, the light bulb 17 is turned on at the same time as the lighting switch of the automobile is turned on, and continues to be turned on regardless of the switch section 16.

Next, the cross-sectional shapes of the prism portion 3 and the cavity 11 will be explained together with the operation.

First, in FIG. 3, the speed of light a from the light bulb 17 is reflected on the slope 18 of the prism part 3, then reflected on the slope 19 of the cavity 11, and after being further reflected on the slope 18, it is reflected on the surface 20 of the transparent plate part 2. reaches point A.

The light beams c are reflected by the slope 18 and reach points B and C.
reach respectively.

The light flux d reaches the point directly, but the light flux e heading toward the void 11 is refracted at the boundary surface 22 and reaches the point E.

In this way, the brightness of the surface of the transparent plate part 2 is such that the luminous flux from the bulb 17 is totally reflected by the slopes 18 and 19 and reaches a point far from the bulb 17, while the luminous flux reaches a point close to the bulb 17 due to the void 11. By dispersing and reaching the area, it becomes almost uniform over the entire area.

In addition, in FIG. 4, in order for the light beam a to be totally reflected on the slope 18, the angle between the perpendicular 23 of the slope 18 and the light beam a, that is, the incident angle θ.

must be equal to or greater than the critical angle, and therefore the angle θ1 of the slope 18 of the prism portion 3 is set smaller than the complementary angle of the critical angle.

Next, in order for the luminous flux a reflected on this slope 18 to be totally reflected on the other slope 19, the angle between the perpendicular 24 of the slope 19 and the luminous flux a, that is, the angle of incidence θ'0 must also be the same as the critical angle. Therefore, the angle θ of the slope 19
2 is also set smaller than the complementary angle of the critical angle.

In reality, the critical angle between acrylic and air is approximately 42°.
, and the critical angle for carbonate and air is approximately 39
Considering that the angle θ1. θ2 is about 45
° or less.

However, it should be noted that if θ1 is made too small, the illumination effect at points far from the light bulb 17 (for example, A and B) will be weakened.

As explained above using the embodiments, according to the present invention,
A translucent display panel is obtained that requires fewer light emitting elements, such as light bulbs, to substantially uniformly illuminate a large surface area.

It goes without saying that various design changes are possible, such as making the transparent plate section 2 and the prism section 3 separate from each other.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 2 is a sectional view of the same embodiment, and FIGS. 3 and 4 are explanatory diagrams of the operation. 2... Translucent plate part, 3... Prism part,
5... Display information, 11... Blank space, 12
... Lamp hole, 17 ... Light bulb.

Claims (1)

[Scope of utility model registration request] A main panel 1 is made of a light-transmitting material, including a light-transmitting plate portion 2 on the front surface of which displays information including a light-transmitting portion, and a prism portion 3 having a substantially trapezoidal cross section protruding from the back side of the light-transmitting plate portion. A cavity 11 having a substantially trapezoidal cross section and a hole 12 penetrating from the cavity to the protruding end of the prism part to receive a light emitting element for illumination are formed in the prism part. Both the trapezoidal shape and the trapezoidal shape of the void are such that the protruding end side of the prism portion is the short side, and the angle θ1 of the slope 18 of the prism portion and the angle θ2 of the slope 19 of the void are as follows. A translucent display panel characterized in that both angles are set to be smaller than the complementary angle of the critical angle of the material of the prism portion.