JPH0121348Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a novel light guide for a display device. Specifically, in light guides that are used for lighting various control panels and have insertion holes through which switch knobs, etc. The present invention aims to provide a novel light guide for a display device that can be used effectively without waste.

BACKGROUND ART AND PROBLEMS There has been conventionally known a type of display device in which display elements such as characters and symbols are formed in the shape of cut-out characters on a front panel, and the front panel is illuminated from the back side to make the display elements shine. In addition, a transparent light guide is placed on the back side of the front panel so that the display elements are illuminated with an average brightness over the entire surface of the front panel, and a point light source is inserted into this light guide. Conventionally, a method has been used in which the light propagates to make the light guide shine over a surface, thereby making it a surface light source.

FIG. 1 shows a conventional example of such a light guide. A is a light guide made of a transparent material such as acrylic resin. b is a bright portion disposed opposite to the back surface of the front panel (not shown). On the back side of the bright part b, at a location corresponding to the display element formed on the front panel, a reflective part consisting of a large number of conical recesses is formed, and there are also insertion holes c, c through which switch knobs, etc. are inserted. ，
... has also been formed. d is a light guiding part, and bright part b
It is integrally formed on one end edge of the b to make a right angle to the bright part b. A light source arranging part e is formed in a notch shape approximately in the center of the rear end of the light guide part d, and the rear edges on both sides sandwiching the light source arranging part e are inclined surfaces that go forward as they go laterally. f, f. and,
A light bulb g is arranged within the light source arrangement part e.

Thus, in the light guide a shown in FIG. 1, the light from the light bulb g enters into the light guide d from the end surface of the light source arrangement section e that faces the light bulb g. Then, the light that has entered the light guide section d is transmitted directly or to the inclined surfaces f, f.
The light is reflected by the light and travels towards the bright part b while repeating internal reflection, and further propagates into the bright part b via the boundary between the light guide part d and the bright part b. . The light propagated into the bright part b is reflected toward the front of the bright part b by the conical concave point, and is transmitted through a display element of the front panel (not shown). This causes the display elements of the front panel to shine.

However, in such a light guide a, most of the light incident from the light source arrangement part is transmitted to the bright part b.
Since the light is directed almost equally over the entire area, the light also reaches the locations where the through holes c, c, . . . are located. Then, the light that reaches the insertion holes c, c, . In this way, in the conventional light guide a, no consideration was given to the presence of the insertion holes c, c, ... on the surface facing the front panel, and the light incident into the light guide a Quite a lot of it was wasted.

Purpose of the invention Therefore, the present invention eliminates the light traveling toward the insertion hole in a light guide that is used for lighting of various control panels and has an insertion hole through which a switch knob or the like is inserted. It is an object of the present invention to provide a novel light guide for a display device, which enables effective use of light from a light source without waste.

Summary of the Invention In order to achieve the above object, the light guide for a display device of the present invention includes a light source placement portion formed as a cutout or a hole, and a plurality of control reflection surfaces formed near the light source placement portion. In a light guide for a display device made of a transparent material and provided with a reflective part and an insertion hole for inserting a switch knob or the like, the plurality of control reflection surfaces allow the light incident from the light source arrangement part to pass through the insertion hole. It is characterized by being reflected in a direction that does not exist.

Embodiments Hereinafter, details of the light guide for a display device of the present invention will be explained according to illustrated embodiments.

Reference numeral 1 denotes a front panel, on which display elements 2, 2, . . . such as character symbols are formed in the shape of cut-out characters. Such display elements 2, 2, . . . may be formed in the shape of cut-out characters by any appropriate method, but for example,
It can be formed by a method such as applying light-shielding printing to a transparent substrate except for the portions that will become the display elements 2, 2, . In addition, the front panel 1 also has insertion holes 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4 for which the switch knobs 3, 3, . . . are inserted.
...is formed.

Reference numeral 5 denotes a light guide made of a transparent material, such as acrylic resin. The light guide 5 is formed by integrally forming a plate-shaped bright part 6 and a plate-shaped light guide part 7 so that they intersect each other at one side edge at a substantially right angle.

On the back surface of the luminous part 6 at a location corresponding to the display elements 2, 2, .
8,... are formed. Also, the front panel 1
Through holes 4r, 4r, . . . are similarly formed at positions corresponding to the insertion holes 4, 4, .

A light source arranging portion 9 is formed in a notch shape approximately at the center of the rear end of the light guide portion 7 . A rear end surface continuous to the rear open end of the light source arrangement section 9 is formed into an inclined surface 10, 10 that goes rearward as the distance from the light source arrangement section 9 increases. The rear end surface following the sloped surfaces 10, 10 is sloped surface 1.
As the distance from 0 and 10 increases, the surface slopes toward the front, and this is the control reflection surface 11, 11. The rear end surface 1 following the control reflective surfaces 11, 11
2 and 12 are horizontal surfaces. The horizontal plane 1
The rear end surfaces continuous with 2 and 12 are control reflection surfaces 13 and 13 that are inclined toward the front. Reference numeral 14 denotes a triangular hole formed in the light guide section 7, which is disposed in front of the light source arrangement section 9 and between the first through hole 4r,
The side surfaces corresponding to the two sides sandwiching the vertices of the isosceles triangle are the control reflecting surfaces 15, 15.

In addition, 16 is a light bulb for a light source arranged in the light source arrangement part 9.

Thus, in the light guide 5 as described above, the light from the light bulb 16 is introduced into the light guide 7 from the surface of the light source placement section 9 facing the light bulb 16, and propagates within the light guide 5. The light that has reached the bright part 6 is reflected by the reflective part 8,
8, . . . and transmitted through the display elements 2, 2, . . . of the front panel 1, thereby making the display elements 2, 2, . . . shine. In addition, in this light guide 5, a plurality of control reflection surfaces 11, 11, 1 are provided near the light source arrangement section 9.
Since 3, 13 and 15, 15 are formed,
There is no or very little light directed toward the insertion holes 4r, 4r, . . . , and most of the light introduced into the light guide 5 is used to illuminate the display elements 2, 2, . That is, the light directed toward the middle insertion hole _4r2 out of the direct light is reflected by the control reflection surfaces 15, 15, and is reflected between the insertion holes _4r1 and _4r2 and between the insertion holes _4r2 and _4r3 . It is made to pass between the two. Further, the inclined surfaces 10, 10 have a substantially central insertion hole 4.
r ₂ , and since there is no light directed toward these inclined surfaces 10, 10, the light guide section 7
There is no light reflected from the rear end face toward the insertion hole _4r2 .
The control reflective surfaces 11 and 11 are located between the insertion holes 4r ₁ and 4r ₂ and between the insertion holes 4r ₂ and 4r ₃ , and the light reflected by the control reflective surfaces 11 and 11 is Between the insertion holes 4r ₁ and 4r ₂ and the insertion hole 4
It passes between r ₂ and 4r ₃ . Further, since the horizontal surfaces 12, 12 correspond to the insertion holes 4r ₁ , 4r ₃ , and there is no light directed toward the horizontal surfaces 12, 12, there is no light directed toward the insertion holes 4r ₁ , 4r ₃ . Furthermore, since the control reflective surfaces 13 and 13 are located between the insertion hole 4r ₁ and one edge of the bright part 6 and between the insertion hole 4r ₃ and the other edge of the bright part 6, The light reflected by these control reflecting surfaces 13 and 13 is not obstructed by the insertion holes 4r ₁ and 4r ₃ and is reliably guided to the forming portions of the reflecting portions 8, 8, .

Incidentally, in the above embodiment, the reflecting portions 8, 8,...
... was intended here to transmit the reflected light to the display elements 2, 2, ... of the front panel 1, but the display elements were directly represented by stipples or lines on the reflective parts. However, they may be made to shine for display purposes.

Further, in the above embodiment, the light guide section 7 is the luminous section 6.
Although they are continuous at right angles to each other, the present invention is not limited to this, and both may be continuous in a flat plate shape.

Effects of the Invention As is clear from the above description, the light guide for a display device of the present invention includes a light source placement portion formed as a cutout or a hole, and a plurality of control reflections formed near the light source placement portion. In a light guide for a display device made of a transparent material and having a surface, a reflective portion, and an insertion hole for inserting a switch knob or the like, the plurality of control reflective surfaces reflect light incident from the light source placement portion. The light is reflected in a direction where there is no through hole, so in a light guide that is provided with an through hole through which a switch knob or the like is inserted, light traveling toward the through hole is eliminated. hand,
This has the effect that the light from the light source can be used effectively without waste.

[Brief explanation of drawings]

Figure 1 shows an example of a conventional light guide.
is a perspective view, B is a side view seen from the light guide side, FIGS. 2 and 3 show an example of implementation of the light guide for a display device of the present invention, and FIG. 2 is a light guide for a display device of the present invention. FIG. 3 is an exploded perspective view of a display device using a body, and FIG. 3 is a side view of the light guide as seen from the light guide portion side. Explanation of symbols, 3...Switch knob, 4r...Insertion hole, 5...Light guide for display device, 8...Reflector,
9... Light source arrangement section, 11... Control reflection surface, 13...
... Control reflective surface, 15 ... Control reflective surface.

Claims (1)

[Scope of utility model registration request] It is made of a transparent material and has a light source arrangement section formed as a cutout or hole, a plurality of control reflective surfaces formed near the light source arrangement section, a reflection section, and an insertion hole for inserting a switch knob or the like. A light guide for a display device, characterized in that the plurality of control reflection surfaces reflect light incident from the light source placement portion in a direction in which there is no through hole. .