JPH0220715Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pointer illumination device installed in a vehicle instrument such as an automobile, and in particular a reflective surface that efficiently reflects light rays introduced into a translucent substrate into the translucent pointer. It concerns an improved structure.

In general, vehicle instruments are illuminated from the side of the instrument dial toward the surface of the dial to make it easier to read measured values such as driving speed at night. An illumination method using a light guide has been proposed in which a light beam from a light source enters the pointer using a light guide to illuminate the pointer more brightly and improve visibility.

By the way, as a lighting method using the light guide, a light shielding layer and a transparent display section are printed on the surface of the light guide, or a thin plate is placed on the substrate made of a light transmitting material that constitutes the dial. There is a method of introducing a light beam and having it enter the inside of a translucent pointer using a reflective surface provided around the drive shaft through hole.For example,
As shown in FIG. 2, a rotational drive shaft 3 of an instrument mechanism (not shown) is passed through a through hole 2 formed in the middle of a translucent dial plate 1 on which a light shielding layer and a translucent display portion are formed.
is erected, and a translucent pointer 4 is provided at the upper end of the drive shaft 3.
A reflective surface 6 is formed on the upper part of the pointer base 5, and is configured to reflect the light rays incident from the lower surface 7 toward the tip of the pointer, illuminating the entire pointer 4 brightly. Here, as a structure for reflecting the light rays introduced into the dial 1 from the light sources 8 and 9 into the pointer 4, the inner wall of the through hole 2 is formed into a substantially conical shape to form a reflecting surface 10. In this case, the same lighting effect can be obtained even if the light sources 8 and 9 are placed on either side of the periphery of the dial 1, and the light sources 8 and 9 have the advantage that there is no restriction on the placement position of the light sources 8 and 9.
The light beam introduced into the dial 1 cannot efficiently enter the pointer 4, and the entire pointer 4 cannot be brightly illuminated.

That is, since the reflective surface 10 has a conical shape, the reflective surface 1 corresponding to the side surface with respect to the light sources 8 and 9
The light beam reflected at 0a cannot enter the pointer 4,
Only the light reflected from the reflective surface 10b in the direction of the light sources 8 and 9 enters the pointer 4 (actually, the light rays that are diffusely reflected within the dial 1 are reflected by the reflective surface 10a and enters, but the amount of light ) alone is not sufficient to brightly illuminate the entire pointer 4.

Also, as shown in Figure 3, there is a
A lighting device has been proposed that forms a reflective surface 12 inclined at 45 degrees and reflects efficiently into the pointer 4 from the side of the through hole 2. In this case, the through hole 2 has a width h.
This results in a loss of the reflective surface, resulting in a loss in the amount of reflected light. In particular, since the portions of the light sources 8 and 9 located on the optical axis are removed, the loss has a considerable effect on the illumination of the pointer 4.

It is an object of the present invention to provide a pointer illumination device which solves the above-mentioned drawbacks of the conventional device and which has a reflecting surface shape with little loss and can provide effective illumination.

Here, the lighting device of the present invention includes an optical axis connecting the pointer rotation center and the light source at least on the light source arrangement side around the rotation axis through hole formed in the transparent substrate,
A first reflective surface is formed that is inclined toward the light incident side, and a second reflective surface that is inclined in the same direction as the first reflective surface and substantially parallel to the first reflective surface is formed at a position below the pointer base on the side of the through hole. The structure is such that the incident light beam in the thickness direction of the substrate is efficiently reflected into the pointer by each reflecting surface.

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

In FIG. 1, a dial plate 1 made of a translucent material
A through hole 2 is formed in the middle, through which a rotary drive shaft 3 erected from an instrument mechanism (not shown) passes. It is formed into an angular shape with sides parallel to the above, and is preferably an inner peripheral wall connected to the side orthogonal to the optical axis, on the side where the light rays from the light sources 8 and 9 enter, from the front surface to the back surface of the dial 1. are respectively formed with first reflective surfaces 13 and 14 having an inclination angle of 45 degrees, and extending from the center of the upper part of both walls of the through hole 2 to the back surface of the dial 1, are the same as the first reflective surfaces 13 and 14. Second reflective surfaces 15 and 16 are formed which similarly have an inclination angle of 45 degrees.

In addition, a pointer 4 made of a translucent material is attached to the upper end of the rotary drive shaft 3 so as to be approximately parallel to the dial 1, and the light rays entering from the lower surface 7 of the pointer base 5 are reflected by the reflecting surface 6 at the tip of the pointer. Formed to reflect to the side. Here, the first reflective surfaces 13, 14 and the second reflective surfaces 15, 16 are connected to the pointer base 5.
It is formed at a lower position encompassed by the lower surface 7 of the dial 1, and among the light beams entering the dial 1 from the light sources 8 and 9, the first reflective surfaces 13, 14, the second reflective surfaces 15, The light beam reflected by the pointer 16 enters the lower surface 7 of the pointer base 5 and illuminates the pointer 4.

According to the above configuration, among the light rays introduced into the dial 1 from the light sources 8 and 9, those in the direction of the optical axis connecting the rotary drive shaft 3 are reflected by the first reflective surfaces 13 and 14 and are reflected into the pointer 4. Also, since the light rays on the sides of the through hole 2 are reflected by the second reflective surfaces 15 and 16 and enter the pointer 4, the light rays that have entered around the through hole 2 are reflected on the dial 1. The light can be used extremely efficiently as illumination light for the pointer 4 with almost no loss in the thickness direction and the projected width of the pointer base 5. Therefore, the pointer 4 is evenly illuminated as a whole, is in good harmony with the dial 1, and the correspondence with the indicator scale can be read at a glance, making it possible to provide illumination with an extremely high visibility effect when driving at night. .

In addition, in the above embodiment, a display part such as a scale is formed on the surface of a translucent substrate by printing, etc., and the entire translucent dial is constructed, and a through hole is formed in the middle to make it symmetrical between the left and right sides. Although we have described the case of illumination using multiple light sources arranged at different positions, it is also possible to place a thin plate with a display section such as a scale on a translucent substrate for pointer illumination, and use this as a dial plate. It is also good as
In addition, when the light source placement position is restricted and illumination is performed by a single light source, the first and second reflective surfaces may be formed only on the inner wall in the light source placement direction, and the through hole may be formed on the substrate. In cases where the light guide area from the light source is restricted, the first reflective surface that includes the optical axis connecting the pointer rotation center and the light source, and the side that enters the light guide area. A configuration may be adopted in which a single second reflective surface is formed on both sides. In any case, by forming a first reflective surface that includes a light guiding path toward the center of rotation of the pointer and is inclined at a certain angle, and a second reflective surface that is inclined in the same direction and approximately parallel to the first reflective surface on the side thereof. , extremely good pointer illumination can be obtained.

[Brief explanation of the drawing]

Figures 1a and b are cross-sectional explanatory diagrams and a plan view of the reflective surface showing an embodiment of the present invention, Figure 1c is a perspective view of a part of the proposed device in cross section, and Figures 2a and b are conventional illumination lights. Planar explanatory diagram and sectional view taken along line A-A of the device, 3rd
Figures a and b are an explanatory cross-sectional view and a plan view of a reflective surface showing another conventional device. Dial: 1, Through hole: 2, Pointer: 4, Light source:
8, 9, first reflective surface: 13, 14, second reflective surface: 15, 16.

Claims (1)

[Scope of utility model registration request] It consists of a substrate made of a transparent material, a pointer made of a transparent material and attached to the end of a rotating shaft that is erected through a through hole in the substrate, and a light source that enters a light beam into the substrate. A pointer illumination device in which an inclined reflective surface is formed around the hole to reflect and introduce light rays from a light source to the pointer side,
The through hole is formed as a square hole having at least a side perpendicular to the optical axis connecting the light source and the center of rotation of the pointer and a side parallel to the optical axis, and an inner peripheral wall connected to the side of the through hole perpendicular to the optical axis. forming a first reflective surface inclined at a constant angle from the front surface to the back surface of the substrate, and extending in the same direction as the first reflective surface along a side parallel to the optical axis on the side of the through hole; A pointer illumination device characterized in that a second reflective surface is formed that is inclined substantially in parallel.