JPS6212978Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light guide plate with a color filter for dial illumination in 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.

Recently, in order to improve visibility at night, vehicle speedometers have been equipped with dial illumination that illuminates the speed scale and numbers on the dial in a predetermined color such as green.

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

A light guide plate 1 is arranged on the back side of a dial plate 2, and the dial plate is molded from a translucent colored resin such as polycarbonate, which is colored translucent and green, and its surface forms a speed scale 3 and a number 4. The remaining parts are opaquely treated, such as painted or printed in a dark, murky 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, only the portions of the dial plate 2 representing the speed scale 3 and the numbers 4 are transmitted, so that the speed scales 3 and the numbers 4 are illuminated in a prescribed color such as green.

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

Therefore, in conventional dial illumination, 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 that uses this color filter to make the light leaking from the edge of the total counter window of the light guide plate the same color as the illumination light that passes through the portion of the dial representing the speed scale and numbers.

An example of this will be explained with reference to FIG. 3. Like 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. It is placed on the back side of a dial plate 2 whose surface is opaque except for the 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, for example, in a location adjacent to the engine compartment of a vehicle, the temperature inside the speedometer will be considerably higher than the normal outside temperature. but,
In this case, as mentioned above, the color filter is molded from resin and is susceptible to plastic deformation due to heat. Therefore, the color filter is plastically deformed due to the high temperature heat inside the speedometer, especially in its central part, as shown in Figure 4b. The upper and lower surfaces of the total counter are deformed to the maximum extent and are separated from the upper and lower edges of the total counter window, causing the inconvenience that the total counts of the totalizer and trip totalizer are partially hidden and become unreadable.

The present invention has been made in order to eliminate such conventional inconveniences.

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 dial illumination in the speedometer described above is integrally molded on the upper and lower surfaces of at least the approximately central portion thereof. These bosses are press-fitted into holes formed in the upper and lower edges of the total counter window.

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

In FIG. 5, the light guide plate 1 has total counter windows 7 and 8 for an integrator and a trip integrator. These total counter windows have holes 11 at their upper and lower edges, for example, as shown in FIG. boss 12
is press-fitted. Note that this color filter is molded from resin of the same color as the colored resin forming the dial, as in the past.

By configuring as described above, even if the speedometer equipped with the light guide plate with color filter is installed adjacent to the engine room of the vehicle, the color filter will not undergo plastic deformation or expansion due to the high temperature heat inside the speedometer. The bosses formed integrally on the upper and lower surfaces of the color filters, which are most prone to thermal deformation even when subjected to shrinkage, are press-fitted into the holes formed on the upper and lower edges of the total counter window, and the bosses are press-fitted into the holes formed on the upper and lower edges of the total counter window. is prevented from being thermally deformed and separated from the upper and lower edges of the total counter window, thereby eliminating the inconvenience that the total counts of the totalizer and trip totalizer are partly 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,
Bosses can be formed not only on the upper and lower surfaces of the approximately central portion of the color filter, but also on other portions to more effectively prevent thermal deformation of the color filter. Further, the shapes of the bosses formed integrally on the upper and lower surfaces of the color filters and the shapes of the holes formed on the upper and lower edges of the total counter window may be of any shape as long as they can be press-fitted into the boss holes. The invention is equally applicable to speedometers that do not have 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 longitudinal sectional view of the total counter window portion of the light guide plate. 1... Light guide plate, 2... Dial board, 7, 8... Total counter window, 9, 10... Color filter, 11
...hole, 12...boss.

Claims (1)

[Scope of utility model registration request] In a light guide plate with a color filter that is disposed on the back side of a dial of a speedometer and guides light from a light source to illuminate the back side of the dial, the color filter fitted around the edge of the total counter window has at least A color for dial illumination in a speedometer, characterized in that it has bosses integrally formed on the upper and lower surfaces of the total counter window, and these bosses are press-fitted into holes formed in the upper and lower edges of the total counter window. Light guide plate with filter.