JPH052822Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention improves display visibility by transmitting light into the interior of the translucent pointer to illuminate the indicating section of the pointer. This invention relates to a pointer illumination device for increasing the height of the vehicle, which is mainly installed in instruments of automobiles, motorcycles, etc.

(Prior Art) In general, this type of pointer illumination device is disclosed in, for example, Japanese Utility Model Application Publication No. 59-66198 and shown in FIG. , a light-transmitting thin plate 2 is superimposed on the surface of a light-transmitting light guide 1 made of synthetic resin, and transparent characters, scales, etc. are applied to the surface of this thin plate 2, so that the light guide 1 is The characters and scales are illuminated and displayed by the irradiated light beam from the light source 3 from the light guide 1, and the irradiated light beam from the light guide 1 is further directed into the base 5 of the pointer 4. A device using a light guide to illuminate the indicator 6 has been proposed. In addition, as a pointer illumination device that does not use a light guide, a device with a small light bulb built into the base of the pointer has been proposed, as disclosed in Japanese Utility Model Application Publication No. 60-27362. In the device, when the light source 3 or a small light bulb is turned on, the indicator 6 is illuminated from inside and shines, so that the indicator 6 can be read visually even when the surroundings are dark, such as at night.

By the way, in addition to displaying the pointer 4 by illumination only at night, recently, it has been used as a vehicle instrument.
There is a need for a configuration in which the pointer is not visible when the ignition switch is off, but visible only when the ignition switch is on, so that the pointer appears only when the vehicle is being operated. Similar to this type of request, for example, as disclosed in Japanese Utility Model Publication No. 57-54009, the protective cover on the front of the instrument is colored, and the instruments are used without lighting during daytime. When using the protective cover, ambient light is absorbed by the protective cover, making the interior appear dim.On the other hand, when using the instrument panel at night, the reflected light from the protective cover and the light reflected on the facing plate become quite dark. In addition, very little light passes through the colored protective cover, and in some cases this facing plate is almost invisible, leaving only the illuminated instruments visible.

(Problem that the invention attempts to solve) However, when using this method and placing a colored protective cover on the front side of the pointer, the brightness of the pointer is low, even when the ignition switch is turned on. However, there was a problem in that the light used to illuminate the pointer was absorbed by the colored protective cover, making it difficult to see the pointer.

The present invention has been made based on the above-mentioned problems, and it is an object of the present invention to provide a pointer illumination device having a structure in which the pointer is visible when the ignition switch is turned on, and becomes difficult to see when the ignition switch is turned off.

[Structure of the idea]

(Means for Solving the Problems) The present invention provides a pointer illumination device that transmits the irradiated light from a light source into the interior of a translucent pointer to display illumination.
A reflective surface that reflects and guides the irradiated light beam transmitted into the inside of the pointer upward is provided on the back surface of the indicating portion of the pointer, and the reflected light reflected by the reflective surface is twisted at approximately 45 degrees to the surface of the pointer indicating portion. 1/4 to pass through
A λ plate is provided, and a polarizing plate that transmits only light in a specific direction is provided above the pointer.

(Function) When the ignition switch is turned on, light from the light source passes through the inside of the pointer, is reflected by the reflective surface, is twisted approximately 45 degrees through the 1/4λ plate, and then passes through the polarizing plate. This allows only light in a specific direction to pass through to the driver, allowing him to see the pointer. on the other hand,
When the ignition switch is turned off, the light source is off, and the ambient light that travels to the pointer first passes through a polarizing plate and becomes light with only a specific direction component.The light of this specific direction component is divided into approximately After being twisted by 45 degrees, it is reflected by the reflective surface, and when it passes through the 1/4λ plate again, it is further twisted by about 45 degrees, and the light is reflected by about 90 degrees, that is, in the direction perpendicular to the specific direction that passed through the polarizing plate. Since the light is converted into component light, it is cut off when passing through the polarizing plate again and cannot be transmitted to the driver, so the pointer is not illuminated by ambient light.
The guideline becomes difficult to see.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. In FIG. 1, reference numeral 11 denotes a pointer with a rectangular cross section that is attached to a meter (not shown) via a pointer shaft 12, and is molded from a transparent resin material.
A small light bulb 13 is built into the base 11A of the pointer 11, and the bottom surface of the indicator 11B at the tip of the pointer 11 is inclined at an angle θ with respect to its surface so that the light transmitted from the light bulb 13 is reflected upward. At the same time, a reflective surface 14 is formed on the bottom surface by vapor deposition of a metal film or printing of white paint. In addition, a surface 1 that reflects light from the light bulb 13 is provided on the surface of the instruction section 11B.
A 1/4λ plate is attached by pasting or the like, and transmits the reflected light reflected upward by 4 by twisting it at about 45 degrees. Reference numeral 16 denotes a polarizing plate that is disposed above the pointer 11 and transmits only light in a specific direction, for example, light in the X-axis direction parallel to the plane of the paper. Protective glass 1
It is arranged on the inner surface side of 7 by adhesion or the like.

In the device of the present invention constructed in this way, when the ignition switch is turned on, the light bulb 13 is always on, and the light A of the light bulb 13 is emitted from the pointer 1.
1 and is reflected upward, ie, toward the driver, by the reflective surface 14 formed on the indicator 11B. This reflected light is transmitted through the 1/4λ plate 15 provided on the surface of the indicator 11B while being twisted by approximately 45 degrees, and is further polarized by the polarizing plate 16 above the 1/4λ plate 15, which polarizes only the X-axis direction component. The light passes through the vehicle, reaches the driver, and the pointer 11 is illuminated.
In this case, since the light reflected by the reflective surface 14 has omnidirectional components, even if the light is twisted by about 45 degrees by the 1/4λ plate 15, the amount of light transmitted through the polarizing plate 16 is reduced to 1/4.
There is no influence of the λ plate 15.

On the other hand, when the ignition switch is turned off, the light bulb 13 goes out, and it is naturally impossible to see the pointer 11 when the surroundings are dark. However, when the surroundings are bright, the pointer 11 should be visible, but according to this configuration, the ambient light advancing from above is first converted into polarized light with only the X-axis direction component by the polarizing plate 16, and then proceeds to the indicator 11B. /4λ plate 1
5, it is twisted approximately 45 degrees and enters the indicator portion 11B. Then, after being reflected on the reflective surface 14, 1/
The light is further twisted by about 45 degrees by the 4λ plate 15 to become light with a component in the Y-axis direction perpendicular to the plane of the paper. However, this Y-axis direction component light cannot pass through the polarizing plate 16, which transmits only the X-axis direction component light.
Most of the light is cut off by this polarizing plate 16 and cannot be transmitted to the driver's side. Therefore, after the ambient light B that enters from above the polarizing plate 16 enters the pointer 11 and is reflected, it cannot be transmitted above the polarizing plate 16 again, and only the light A from the light bulb 13 is transmitted from the polarizing plate 16. Since it can be transmitted upward, it is possible to provide a new vehicle instrument in which the pointer 11 is difficult to see when the ignition switch is off, and the pointer 11 is visible when the ignition switch is on. Note that the angle θ formed between the bottom surface and the surface of the indicator portion 11B is preferably small, and the reflective surface 14 may be colored with various pigments other than the metal film.

Although one embodiment of the present invention has been described above in detail, it can be modified as appropriate within the scope of the gist of the present invention. For example, in the embodiment described above, a type in which the light bulb 13 is built into the base 11A of the pointer 11 has been described, but it can be similarly applied to a type using a light guide shown in the conventional example shown in FIG. Further, the polarizing plate 16 may not be provided over the entire protective cover 17 above the pointer 11, but may be separately provided above the pointer 11, which covers at least the rotation range of the pointer 11, regardless of the protective cover 17.

[Effect of idea]

As described in detail above, the present invention provides a pointer illumination device that transmits the irradiated light from a light source into the interior of a translucent pointer to display an illumination display. A reflective surface that reflects and guides the light upward is provided, and a 1/4λ plate that transmits the reflected light reflected by the reflective surface with a twist of about 45 degrees is provided on the surface of the pointer indicator, and The device is equipped with a polarizing plate that transmits only light components in a specific direction. When the ignition switch is on, the pointer indicator can be seen by the light from the light source, and when the ignition switch is off, the surrounding light can be seen on the pointer. It is possible to provide a new pointer illumination device in which the pointer indicator is difficult to see because even if the pointer is illuminated, the reflected light from the pointer cannot be transmitted upward to the driver's side.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. 11... pointer, 11B... indicator, 13... light bulb (light source), 14... reflective surface, 15... 1/4λ plate,
16...Polarizing plate.

Claims (1)

[Scope of utility model registration request] In a pointer illumination device that transmits an irradiated light beam from a light source into a translucent pointer for illumination display, the pointer has a reflective surface on the back surface of the indicating portion that reflects and guides the irradiated light beam that has passed inside the pointer upward. and providing a 1/4λ plate on the surface of the pointer indicating portion that transmits the reflected light reflected by the reflecting surface with a twist of about 45 degrees,
A pointer illumination device characterized in that a polarizing plate is provided above the pointer to transmit only light in a specific direction.