JPH0740174Y2 - Instrument lighting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a light-transmissive display device of an instrument used in a vehicle or the like, and particularly to uniformly irradiate light from a light-emitting body onto a display portion.

[Conventional technology]

2. Description of the Related Art Conventionally, an illumination device for an engine tachometer of a vehicle instrument has a display section consisting of an arc-shaped scale and numerical values, and a curved cold cathode tube is arranged along the arc-shaped display section. Then, the light from the cold cathode tube is transmitted to the display section to perform night illumination.

[Problems to be solved by the device]

In the conventional vehicle instrument lighting device, the light from the cold cathode fluorescent lamp is weak at the end on the electrode side, and it is difficult to sufficiently illuminate the display unit located in front of the cold cathode fluorescent lamp. was there.

Therefore, an object of the present invention is to provide an illuminating device that can uniformly illuminate the entire display portion even when the display portion is provided in front of the electrode side end portion using a cold cathode tube. There is.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, in the illuminating device for an instrument of the present invention, a display plate provided with an arc-shaped display part through which light is transmitted, and a display plate disposed behind the display plate and arranged along the display part. Between the light-emitting body that is curved and has electrodes on both ends thereof and emits light when a voltage is applied to the electrodes, and between the electrode-side end of the light-emitting body and the display plate and the end of the light-emitting body. The display plate is provided so as to cover the upper part of the light-emitting body and blocks light rays from the electrode-side end of the light-emitting body, and a reflection plate having a reflection part arranged to form an acute angle. The reflecting portion blocks light rays from the electrode-side end portion of the light-emitting body, and causes light rays from other than the electrode-side end portion to face the reflecting portion in the display portion and to be above the electrode-side end portion. A structure is adopted in which the positioned portion is irradiated almost vertically and transmitted.

The reflector of the illumination device of the instrument configured as described above blocks a weak light ray from the end portion on the electrode side among the light rays from the light-emitting body while facing a part of another strong light ray to the reflecting portion. The light is reflected so that it is transmitted substantially perpendicularly to the display unit.

[Effect of device]

As described above, in the present invention, the weak light from the light emitter is blocked by the reflector, and only the strong light from the light emitter is transmitted by the reflector substantially perpendicularly to the display unit facing the reflector. As a result, this display section can be displayed brightly. Further, by blocking the weak light rays as described above, there is an excellent effect that the entire display section can be uniformly illuminated without causing the same brightness as the light-emitting body in the display section.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a portion of an engine tachometer of a vehicle instrument, and FIG. 3 is a perspective view showing a main part thereof.

As shown in the figure, the engine tachometer is composed of a case 1, an in-machine unit 2, a pointer 3 and a display plate 4.

The case 1 is for mounting the instrument main body on the front surface of the vehicle compartment, and the instrument internal unit 2 for driving the pointer 3 is fixed to the case 1 with screws.

A rotary shaft 21 projects from the in-machine unit 2 and rotates a predetermined angle according to the speed of the vehicle as is well known.

The display plate 4 is formed of a translucent plastic plate, and by printing a black non-translucent background on its front surface,
An arc-shaped graduation 41 that matches the orbit of the pointer 3 and a display portion that is composed of numerical values 42 that are mounted on a predetermined graduation of the graduation are formed. Further, a through hole (not shown) through which the rotary shaft 22 penetrates is formed in the center of the display plate 4, and a white semitransparent light guide plate 6 is provided on the entire back surface. Then, on the back side of the light guide plate 6, two convex portions 61 are formed with a predetermined interval.

The reflection plate 7 is made of glossy aluminum, and as shown in FIG. 2, a flat portion 71 that is in close contact with the back surface of the light guide plate 6 and a convex portion 61 of the light guide plate 6 that is provided in this plan view 71 penetrates through. Through hole 72
And reflecting portions 73 formed on both sides of the flat portion 71 and forming two reflecting surfaces that are bent with respect to the flat portion, and three engaging portions 74 formed for attaching to the light guide plate 6. Has been done.

Then, the through hole 72 of the flat portion 71 of the reflection plate 7 is formed in the light guide plate 6.
Of the light guide plate 6, and the engaging portion 74 is bent to the front surface side of the light guide plate 6 to fix the reflection plate 7. At this time, the reflection part 73 of the reflection plate 7 and the back surface of the light guide plate 6 are fixed. The angle is sharp.

Further, the luminous body 5 is curved along the arc-shaped display portion,
A cold-cathode tube having electrodes at both ends thereof,
It is fixed to the case 1 along the outer periphery of the.

The display plate 4 including the light guide plate 6 and the reflection plate 7 as described above.
Is housed in the case 1, and at that time, the rotary shaft 21 of the in-instrument unit 2 penetrates and projects into the through hole of the display plate 4, and the pointer 3 is attached to the tip of this rotary shaft to configure the instrument. .

At this time, the reflection surface of the reflection portion 73 of the reflection plate 7 faces the display portion, and the back surface of the reflection surface faces the end portion of the cold cathode tube 5 on the electrode side.

Then, the instrument is mounted inside the vehicle so that the display surface of the instrument is substantially perpendicular to the line of sight of the driver.

Next, a case where the tachometer of the engine having the above configuration is illuminated and displayed will be described.

When the cold cathode tube 5 is energized, light is emitted from the entire surface. This light enters the light guide plate 6 to be diffused and is emitted as white light. A part of the light emitted from the light guide plate 6 passes through the display section composed of the scale 41 and the numerical value 42 and is confirmed by the driver.

Light emitted from a point 51 near the center of the cold cathode tube 5 is shown by solid lines 51a to 51d in FIG.

As shown in the figure, the light beam from one point 51 is emitted in each direction. Of these light rays, the light 51a that illuminates the light guide plate 6 and the display plate 4 substantially perpendicularly is recognized as the strongest light by the driver, and therefore the display portion located there is displayed brightly.

Reference numeral 51b is the one that is reflected by the case 1 and then is irradiated onto the display unit, and is directly reflected on the display unit without being reflected.
Similarly, since the light component in the vertical direction is small because it forms an acute angle with respect to the display plate 4, it is recognized as weak light by the driver, and the display unit located here is displayed dark.

Considering this on the entire surface of the cold cathode tube, at each point,
The light emitted substantially perpendicularly to the display plate 4 is confirmed as strong light.

However, the light emitted from the cold-cathode tube is weak on the electrode side and is strong on the central portion side, and accordingly, light and dark appear on the display portion.

Therefore, in the present invention, the reflection plate 7 blocks weak light generated from the end portion on the electrode side, and the light ray 51d emitted from one point 51 near the center is made substantially perpendicular to the display portion facing the reflection portion. This display can be displayed brightly by illuminating it and letting the driver confirm it as strong light.

Furthermore, by disposing a reflecting plate in the space between the electrode side of the cold cathode fluorescent lamp 5 and the display plate, the entire instrument can be stored compactly without increasing the size of the instrument.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an engine tachometer of a vehicle instrument, FIG. 2 is a perspective view showing a reflector, and FIG. 3 is a perspective view showing an essential part of the engine tachometer. 4 ... Display plate, 41 ... Scale, 42 ... Numerical value, 5 ... Emitting body (cold-cathode tube), 51a to 51d ... Light path, 7 ... Reflector, 73 ... Reflector.

Claims (1)

[Scope of utility model registration request] 1. A display plate provided with an arc-shaped display part through which light is transmitted, a display plate disposed behind the display plate, curved along the display part, and having electrodes at both ends thereof. A light-emitting body that emits light when a voltage is applied to the electrode, and is provided between the electrode-side end of the light-emitting body and the display plate and covers the upper end of the light-emitting body. Of the display plate for blocking light rays from the end portion on the electrode side and a reflection plate having a reflection portion arranged so as to form an acute angle, the reflection portion of the reflection plate from the end portion on the electrode side of the light emitter. While blocking the light rays, the light rays from other than the end portion on the electrode side are transmitted substantially perpendicularly to the portion of the display portion facing the reflection portion and located above the end portion on the electrode side. A lighting device for a measuring instrument characterized in that