JPH0431337B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a see-through plate disposed as a front cover of a display device, such as an indicating instrument, and in particular, the present invention relates to a see-through plate disposed as a front cover of a display device, such as an indicating instrument, and in particular, in the case of external light irradiating the surface of the see-through plate. This invention relates to a see-through plate that reflects light rays reflected on its surface out of the field of view in a direction other than the viewing direction.

[Related technology and problems thereof] Generally, display devices such as instruments and image display devices of automobiles, or various measuring instruments are disposed with a transparent plate covering the front surface of the display device.

This type of display device will be explained using automobile instruments as an example. Generally speaking, when a flat transparent plate made of a glass substrate or a synthetic resin substrate with translucent properties is used as a front cover for an indicating instrument such as a vehicle, external light shining onto the surface of the flat transparent plate is used. Because the surface of the see-through plate shines as it reflects in the direction of the driver's line of sight, there is a problem that it becomes difficult to read display devices placed behind it, such as the dial of an indicator, or a display using a fluorescent display tube. Ta. In order to solve these problems, various structures have been proposed in which the see-through plate covering the front of the instrument has an anti-glare function.

For example:
As disclosed in No. 122913, on the surface of the transparent plate,
It forms many sloped surfaces whose cross sections are serrated,
We have proposed a see-through plate that has an anti-glare function by partially reflecting external light on an inclined surface and guiding the reflected light to a direction other than the driver's line of sight.

However, since the tops of the many serrated slopes provided on the surface of this transparent plate are pointed, the tops of the slopes may chip if the transparent plate is wiped or an object hits it. As a result, the surface of the see-through plate is easily scratched. Such scratches may reflect external light rays and direct them toward the line of sight, or may be caused by an internal light source located on the back of the indicator dial, or by a self-luminous indicator such as a fluorescent display tube or light emitting diode. When the irradiated light beam from the instrument passes from the inside of the indicator to the viewing plate and then to the outside, the light beam is focused on this polarized part, and the scratched area appears to be shining due to this focused light beam, and the inside is visible. This may impede the reading of displays, etc.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and it is possible to reflect the light rays reflected on the surface of the see-through plate out of the field of view in a direction other than the viewing direction, and to prevent the top of the slope from being chipped. The object of the present invention is to provide a see-through plate that can be clearly viewed for a long period of time.

[Structure of the Invention] In order to achieve the above object, the present invention forms protrusions with sawtooth cross-sections in fine parallel lines on the surface of a see-through plate, and chamfers the top of the tips of the protrusions. This prevents some of the external light from being reflected on the see-through plate and traveling in the line of sight direction, and also prevents the top of the tip of the protrusion from chipping to improve visibility.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 and FIG. 2 show one embodiment of the present invention, which will be explained here using an example of an indicating instrument such as an automobile. In the figure, an indicator body 12 is disposed inside an indicating instrument 11 such as a speedometer mounted on the instrument panel of a car, and a dial 13 is disposed on the front side of this instrument body 12.
A see-through plate 14, which will be described later, is provided on the front side of the indicator 11 as a front cover for the indicator 11. A hood 15 is formed protruding from the periphery of the indicator 11 to absorb light reflected by the transparent plate 14 and block light from above, and a transparent dial 13 is installed inside the indicator 11 from behind. A light source 16 for illuminating is provided, and the dial 13 is illuminated by lighting the light source 16 at night.
They have lighting to display.

The surface of the transparent plate 14 has a vertical surface 19 substantially parallel to the line of sight direction 18 of the driver 17 and a vertical surface 1 here.
9 and an inclined surface 21 inclined at an angle θ with respect to the line of sight direction 18, the protrusion 22 has a sawtooth cross-sectional shape, and the protrusion 22 has a fine parallel line shape so that the ridgeline of the apex 20 is in the horizontal direction. It is continuously formed. Further, the top portion 20 of the protrusion 22 is chamfered along the ridgeline direction to form a rounded shape. moreover,
A light shielding plate 2 is provided inside the transparent plate 14 along the vertical plane 19.
3 is buried and formed, and the light shielding plate 32 is configured to block light rays having diagonal components from above and below, and to transmit straight, ie, horizontal light rays.

The operation of the present invention configured as described above will be explained. First, a large number of protrusions 22 made up of a vertical surface 19 and an inclined surface 21 are continuously formed on the surface of the transparent plate 14, and a part of the external light irradiated from behind the driver 17 is transmitted to the surface of the transparent plate 14. However, since it is reflected out of the field of view by the inclined surface 21 provided on the surface thereof, the dial 13 can be read well.

In addition, a protrusion 22 formed on the surface of the transparent plate 14
Since the top portion 20 of is chamfered along the ridgeline direction, the rounded top portion 20 is less likely to chip. That is, the surface of the see-through plate 14 on which the protrusion 22 is formed is prone to dust, but even if the surface is wiped with a cloth, the top portion 20 is less likely to chip, and the surface of the see-through plate 14 is prevented from being scratched. The visibility of the board 14 is increased.

Further, a part of the external light incident on the transparent plate 14 is reflected on the back surface of the transparent plate 14 and travels to the vertical axis 19 and the inclined surface 21 forming the protrusion 22, and the top of this
Try to repeat the internal reflection at 20 locations. but,
Inside the transparent plate 14, there is a light shielding plate 2 along the vertical plane 19.
3 is embedded, it absorbs the reflected light that is reflected on the back surface of the transparent plate 14 and proceeds to the top portion 20, thereby suppressing internal reflection. Therefore, it is possible to suppress the convergence of reflected light due to repeated internal reflections at the 20 locations on the top of the protrusion 22, and prevent the ridgeline locations on the top 20 from appearing lifted in a band-like manner. In addition, this light shielding plate 2
3 gives directionality to the internal light rays from the night light source 16, and by controlling the irradiation direction of the internal rays, the light rays irradiated from the inside from all directions are divided into horizontal components by the light shielding plate 23. Only light rays or light rays traveling in a straight line can pass through, thereby preventing the light rays entering the transparent plate 14 from converging on the top 20 points of the protrusions 22 on the front side thereof.

[Other Embodiments] Although one embodiment of the present invention has been described in detail above, various modifications can be made within the scope of the gist of the present invention. For example, as shown in FIG. 3, the base 24 of the vertical surface 19 can also be chamfered into a rounded shape. In this way, the narrow base 24 can be easily molded, and dirt and the like attached to the base 24 can also be wiped off. Further, as shown in FIG. 4, the chamfering of the top portion 20 is not limited to a rounded shape, but it is also possible to cut the top portion 20 parallel to the surface of the see-through plate 14 for chamfering. Furthermore, as shown in FIG. 5, in order to prevent light from condensing at 20 points on the top 20, the chamfered top 20 may be colored with an opaque agent 25 of a different color along the ridgeline. Since the colored portion of the opaque agent 25 is thin like a line, there is no problem in reading the dial 13, and it is possible to prevent light from condensing at the top 20 locations. In this case, the light shielding plate 23 shown in FIGS. 1 to 4 is unnecessary.

Further, in FIGS. 1 to 5, the light shielding plate 23 and the light-blocking agent 25 are provided to suppress light condensation at the top 20, but the top 20 may be simply chamfered.

Further, in each of the above embodiments, the back surface of the transparent plate 14 is made flat, but the rear surface may also be formed with a protrusion 22, an inclined surface 21 may be formed downward from the top 20, or the transparent plate 14 may be colored. It is also possible to do so. Further, the present invention is not limited to instruments for vehicles, but can also be applied to other instruments and see-through plates used in display devices such as televisions.

[Effects of the Invention] As described in detail above, according to the present invention, by forming protrusions with a serrated cross section on the surface of the transparent plate in the form of fine parallel lines, external light can be directed to the surface of the transparent plate. Even if the reflected light is reflected by the camera, this reflected light can be guided out of the field of view in a direction other than the line of sight.The chamfered top of the tip of this protrusion prevents the sharp top from chipping or scratching, making it easy to see through. The display medium inside the board can be clearly seen.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view showing one embodiment of the present invention, FIG. 2 is a perspective view showing the main parts of a see-through plate, and FIG.
4 and 5 are front views showing main parts of other embodiments of the see-through plate. 11...Instrument panel, 12...Indication instrument, 13...
Dial plate, 14... Transparent plate, 18... View direction, 1
9... Vertical surface, 20... Top, 21... Inclined surface,
22... protrusion, 23... light shielding plate.

Claims (1)

[Claims] 1. A see-through plate, characterized in that protrusions with a serrated cross-section are formed in fine parallel lines on the surface of the see-through plate, and the tops of the tips of the protrusions are chamfered.