JPS6111605Y2 - - Google Patents

Description

Detailed Description of the Invention This invention relates to a color-filtered light guide plate for illuminating the dial of a speedometer, and in particular to an improvement in the mounting structure of the color filter fitted around the edge of the total counter window.

BACKGROUND ART Recently, in order to improve visibility at night in vehicle speedometers, dial illumination has been implemented in which the speed scale and numbers on the dial are illuminated in a predetermined color, such as at the edges.

An example of such dial illumination will be described with reference to FIGS. 1 and 2.

A light guide plate 1 is disposed on the back side of a dial plate 2, and the dial plate is molded from a translucent colored resin such as polycarbonate with a colored border, and its surface has a speed scale 3 and a number 4 formed thereon. The remaining parts are opaquely treated, for example painted or printed in a dark color that does not allow light to pass through.

In such a configuration, light is directly irradiated from the end of the light guide plate 1 from a light source (not shown), and these irradiated lights are reflected inside the light guide plate and irradiate the back surface of the dial 2, and these irradiated lights Then, by transmitting only the portion of the dial 2 representing the speed scale 3 and numerals 4, the speed scale 3 and numerals 4 are illuminated in a specified color, such as at the edges.

Generally, such a vehicle speedometer has a built-in totalizer and a trip totalizer, and windows 5 and 6 for displaying the total counter number are formed on the light guide plate 1 and the dial plate 2. There is.

Therefore, in conventional dial lighting, a portion of the light that has passed through the light guide plate 1 leaks from the edge of the total counter window of the light guide plate, and these leaked lights then pass through the total counter window 5 of the dial plate 2. 6 may leak onto the front of the dial. These leaked lights are direct light from the light source and are different from the color of the illumination light that illuminates the speed scale 3 and numbers 4 on the dial 1, so they are not only extremely annoying to the driver, but also cause the illumination to There was a problem in that the light was canceled out, resulting in poor visibility at night.

In addition, the light leaking to the front of the dial through the light guide plate and each total counter window on the dial is, as mentioned above, direct light from the light source, so it is quite strong, and this strong light is reflected in the speedometer dial. There was also the problem that if the light reflected off the windshield through the plate and entered the driver's line of sight, it would interfere with driving operations.

In order to solve these conventional problems, the applicant and others have fitted a resin filter (color filter) of the same color as the colored resin forming the dial around the edge of the total counter window of the light guide plate. A color filter has been developed in which the light leaking from the edge of the total counter window of the light guide plate is made the same color as the illumination light that passes through the portions of the dial representing the speed scale and numbers.

An example of this will be explained with reference to FIG. 3. Similar to the conventional example shown in FIGS. 1 and 2, the light guide plate 1 has total counter windows 7 and 8, and is molded from a transparent colored resin. The dial plate 2 is placed on the back side of the dial plate 2, the surface of which has been treated to be opaque, with the exception of portions representing the speed scale 3 and numerals 4.

Color filters 9 and 10 are fitted around the edges of each total counter window 7 and 8 of the light guide plate 1, and these color filters are molded from colored resin of the same color as the colored resin forming the dial plate.

By fitting such a color filter around the edge of the total counter window of the light guide plate, the light leaking from the edge of the total counter window of the light guide plate is transmitted through the speed scale and the portion of the dial representing the numbers. Therefore, even if leaked light of the same color as the illumination light leaks to the front of the dial through the total counter window of the dial,
It is not an eyesore for the driver, but rather improves the lighting effect and increases visibility.

In addition, the light leaking from the edge of the total counter window of the light guide plate through such a color filter is attenuated when passing through the color filter, so even if this leaked light is reflected by the windshield through the speedometer's dial, However, the light is so weak that it does not adversely affect driving operations.

However, if a speedometer equipped with such a light guide plate with a color filter is installed adjacent to the engine compartment of a vehicle, the temperature inside the speedometer will be considerably higher than the normal outside temperature. In this case, as mentioned above, the color filter is molded from resin and easily undergoes plastic deformation due to heat.
The color filter was plastically deformed by the high temperature heat inside the speedometer, and its upper and lower surfaces began to sag as shown in Figure 4b, which partially concealed the total counter numbers of the totalizer and trip totalizer. This causes the inconvenience that it becomes unreadable.

The present invention has been devised to overcome these conventional disadvantages.

According to the present invention, the color filter fitted around the edge of the total counter window of the light guide plate with color filter for illuminating the dial in the speedometer as described above is at least wider than the distance between the upper and lower surfaces of the total counter window. It is shaped in the form of a hollow spindle-shaped longitudinal section with a large maximum center spacing, the spindle part of which is contracted and fitted around the edge of the total counter window of the light guide plate.

A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

5-7, the light guide plate 1 has windows 7 and 8 for displaying the total counter numbers of the totalizer and trip totalizer. For example, in the case of one of the total counter windows 7, the sixth total counter window is
As shown in the figure and FIG. 7, concave stepped portions 11a and 11b are formed on both sides around the edge. On the other hand, the color filters 9 and 10 fitted around the edges of the total counter windows 7 and 8 of the light guide plate 1 are as shown in FIGS. 6 and 7 in the case of one color filter 9, for example. , flanges 12a and 12 on both sides around the top surface.
b, and these flanges are fitted into the recessed steps 11a and 11b of the total counter window 7 (see FIG. 6).

The color filter 9 is molded from resin of the same color as the colored resin forming the dial, but in this case, as shown in FIG. B
It is formed in the form of a hollow spindle-shaped longitudinal section with a maximum center spacing C greater than , and the spindle portion is slightly contracted and fitted into the total counter window 7 of the light guide plate 1, as shown in FIG. 8b.

Therefore, by adopting such a color filter structure, the spindle part is contracted when it is fitted into the total counter window of the light guide plate, so that the force of expanding it to return to its original shape is constantly acting on it. Therefore, even if a speedometer equipped with a light guide plate with a color filter is installed adjacent to the engine compartment of a vehicle and the color filter undergoes plastic deformation or expansion and contraction due to high temperature heat inside the speedometer, the color will not change. The upper and lower surfaces of the filter are prevented from sagging, thereby eliminating the inconvenience that the total counter numbers of the totalizer and trip totalizer are partially hidden and become unreadable.

It should be noted that the present invention is by no means limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention. for example,
In the structure for fitting the light guide plate of the color filter into the total counter window, it is not necessary to form a flange and a recessed step, and the present invention can be similarly applied to a speedometer without a trip totalizer.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a conventional vehicle speedometer, Fig. 2 is a right side view thereof, Fig. 3 is a front view showing a light guide plate with a color filter, and Fig. 4a is a total counter window of the light guide plate. A vertical cross-sectional view of the portion, FIG. 4b shows the hanging state of the color filter of the light guide plate due to thermal deformation, a view similar to FIG. 4a, and FIG. 5 shows an example of the light guide plate with color filter according to the present invention. Front view, No. 6
The figure is a cross-sectional view taken along the line A-A of FIG. 5, FIG. 7 is an enlarged perspective view showing the total counter window of the light guide plate and the color filter fitted in this window removed, and FIG. A diagram for explaining the radial relationship between the total counter window and the color filter in a longitudinal section of the total counter window portion of the light guide plate, and 8b
This figure is a longitudinal sectional view similar to FIG. 8a, showing how the color filter is fitted into the total counter window. 1...Light guide plate, 2...Dial board, 7, 8...Total counter window, 9, 10...Color filter.

Claims (1)

[Scope of utility model registration request] In a light guide plate with a color filter that guides light from a light source disposed on the back side of a dial in a speedometer and illuminates the back side of the dial, a color filter is fitted around the edge of the total counter window. 1. A light guide plate with a color filter for dial illumination in a speedometer, characterized in that the light guide plate is formed in the shape of a hollow spindle-shaped longitudinal section having a maximum center distance that is larger than the distance between the upper and lower surfaces of the total counter window.