JP2002098557A - Dial plate structure for instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dial plate structure achieving thinner-sized instrument by improving luminance distribution uniformity. SOLUTION: The dial plate structure 2 of the instrument forms a light- impermeable layer 16 leaving an indication pattern 15 on the face of its transparent substrate 11. Also it is characterized by forming an indication pattern 31 corresponding to and slightly thicker than the indication pattern 15 on a back side high-reflectivity layer 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dial structure of an instrument used for an instrument of a vehicle such as an automobile.

[0002]

2. Description of the Related Art A vehicle such as an automobile is provided with an instrument such as a speedometer in front of a driver's seat. This instrument has, for example, a structure as shown in FIG. That is, while the dial 2 is attached to the upper surface of the lower case 1,
A circuit board 3 is attached to a lower surface portion of the lower case 1. A pointer shaft hole 4 is formed in the dial 2, and a drive device such as a movement 5 is attached to the circuit board 3 so that the pointer shaft 5 a protrudes from the pointer shaft hole 4 of the dial 2. A pointer 6 is attached to the tip of a pointer shaft 5a protruding from the pointer shaft hole 4. A light source such as an incandescent bulb 7 is attached to the circuit board 3 via the lower case 1 or the movement 5 (not shown), and the light from the incandescent bulb 7 is transmitted to the base of the hands 6 on the back side of the dial 2. A light guide plate 8 for guiding is attached. An upper case 10 having a transparent front cover 9 is attached to the upper part of the lower case 1 by fitting.

As shown in FIGS. 6 and 7, the dial 2 has a light-transmissive white print layer 12 formed on the entire surface of a transparent substrate 11. A light-opaque layer 16 such as a black print layer is left on the upper surface side, leaving a required display pattern 15 such as a scale 13 or a numeral 14.
Are formed.

According to such a configuration, in the daytime, the white print layer 12 reflects external light such as sunlight, so that the display by the display pattern 15 can be visually recognized.

[0005] During nighttime illumination, light emitted from the incandescent bulb 7 reaches the back surface of the dial 2 directly or after being reflected by the inner surface of the lower case 1, and the transparent base material 11 from the back side of the dial 2. Further, by transmitting through the white print layer 12, the display pattern of the character / scale portion of the dial 2 is illuminated by transmission.

Here, the incandescent bulb 7 transmitted through the dial 2
As shown in FIG. 8, light having a distribution of luminance 18 is brightest near the bulb zenith 17 and becomes darker as the distance from the bulb zenith 17 increases.

Since the luminance 18 of the dial 2 becomes non-uniform due to this distribution, a means called halftone dimming is used to correct the non-uniformity of the luminance 18.

As shown in FIG. 7, an opaque or translucent black ink is printed in the form of dots on the back side of the dial 2 (dot printing layer 19), and the distribution of the dots (dots By adjusting the area ratio between the portion 20 and the portion 21 having no dot, as shown in FIG. 9, the transmittance 22 is changed to correct the luminance of the dial 2 (the corrected luminance 23). Things.

Specifically, the transmittance 22 is lowered by increasing the ratio of the area occupied by the dots in the vicinity of the bulb zenith 17, and the transmittance is reduced by decreasing the ratio of the area occupied by the dots as the distance from the bulb zenith 17 increases. Rate 22
To eliminate unevenness in luminance of the dial 2.

[0010]

However, such a conventional dial structure of an instrument has the following problems.

That is, as shown in FIG. 10, the halftone dimming includes a peak position (reference numeral 17) of the luminance 18 when the halftone print layer 19 is designed and a peak position (reference numeral 24) of the luminance 23 after the instrument is assembled. ), The halftone print layer 1
9 may not be successful, and conversely, a peak portion 26 may occur in the luminance 23 after the instrument is assembled.

The misalignment 25 causes a manufacturing error or an assembly error between the mounting position of the incandescent bulb 7 and the mounting position of the dial 2 on which the halftone dot printing layer 19 is formed, and the position of the filament 27 in the incandescent bulb 7. It frequently occurs due to reasons such as falling down and variations in the light distribution characteristics of the incandescent bulb 7.

On the other hand, in recent years, instruments have been reduced in thickness for the purpose of securing the interior space of the vehicle and reducing costs, but in order to reduce the thickness, the distance between the incandescent valve 7 and the dial 2 has to be reduced. Need to be shorter.

However, when the distance 28 between the incandescent bulb 7 and the dial 2 is reduced, the luminance distribution of the incandescent bulb 7 becomes steeper, the maximum luminance near the bulb zenith 17 becomes extremely high, and the bulb zenith 17 As the distance increases, the degree of decrease in luminance becomes more rapid.

Then, since the problem that the correction of the luminance 23 of the dial 2 becomes unsatisfactory due to the position shift 25 appears in an enlarged manner, the distance 28 between the incandescent bulb 7 and the dial 2 is shortened to, for example, about ten and several mm or less. If this is attempted, it becomes a very serious problem, and halftone dimming is one of the factors that hinder the thinning of the instrument.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dial structure for an instrument which can solve the above-mentioned problems, improve the uniformity of the luminance distribution, and achieve a thinner instrument. is there.

[0017]

According to the first aspect of the present invention, there is provided an instrument in which a light-impermeable layer is formed on a surface side of a transparent substrate while leaving a display pattern. In the dial structure, on the back side of the transparent substrate,
A display pattern corresponding to the display pattern and slightly thicker than the display pattern is formed by the back surface side high reflective layer.

According to the first aspect of the present invention, in the daytime, the external light such as sunlight is reflected by the back surface-side high-reflection layer, so that the display by the display pattern is visually recognized. You.

During nighttime illumination, light from the light source enters the transparent substrate from a portion where the backside high-reflection layer is not provided, propagates through the transparent substrate, and is reflected by the backside high-reflection layer. Then, the light is emitted from the display pattern of the light-impermeable layer to the surface side of the transparent substrate, whereby the display by the display pattern is recognized.

As described above, a display pattern corresponding to the display pattern of the light-opaque layer and slightly thicker than the display pattern is formed on the rear surface side of the transparent base material by the rear-surface high-reflection layer. Since the display pattern is in an indirect illumination state, the display pattern is less affected by variations in luminance peaks caused by various factors.

Therefore, the uniformity of the luminance distribution is improved,
It is possible to reduce the thickness of the instrument beyond the limit in the case of halftone dot dimming.

[0022] The invention described in claim 2 is characterized in that a halftone dimming layer is formed on the back side of the transparent substrate.

According to the second aspect of the present invention, a halftone dot dimming layer is formed on the back surface side of the transparent substrate, so that the halftone dimming layer can be formed in addition to the indirect illumination effect. Halftone dimming can be performed simultaneously.

According to a third aspect of the present invention, a surface-side high-reflection layer is formed between the surface of the transparent substrate and the light-impermeable layer while leaving the display pattern. And

According to the third aspect of the present invention, the transparent substrate is propagated by the surface-side highly reflective layer formed between the transparent substrate and the light-impermeable layer. Light can be reflected with higher efficiency to reach the backside high-reflection layer, and the overall brightness of the instrument can be increased.

[0026]

First Embodiment A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 show a first embodiment of the present invention. Note that the same or equivalent parts as those in the conventional example are denoted by the same reference numerals and description thereof will be omitted.

First, the structure will be described. In the dial 2 of the first embodiment, a display pattern 15 such as a scale 13 or a numeral 14 is left on the surface side of a transparent substrate 11 made of polycarbonate, acrylic material or the like. A light-opaque layer 16 such as a black print layer is directly formed.

On the back side of the transparent base material 11, a display pattern 31 corresponding to the display pattern 15 and slightly thicker than the display pattern 15 is provided with a high reflection on the back side such as a light-opaque white print layer. It is formed directly with the active layer 32. That is, the display pattern 31 by the back side high reflective layer 32
Are formed so as to have a required amount of overlap margin 33 with respect to the contour portion of the display pattern 15 by the light-opaque layer 16.

Further, on the back side of the transparent base material 11, a light-opaque white printing layer having a required incident gap 34 with respect to the outer peripheral portion of the display pattern 31 by the back side high reflection layer 32. The display pattern outer covering portion 35 is formed by, for example, the above.

Next, the operation of the first embodiment will be described.

In the daytime, external light such as sunlight enters the transparent base 11 from the front side of the transparent base 11, and the display pattern 31 of the back side high reflective layer 32 formed on the back side. The reflection by the portion allows the display by the display pattern 15 to be visually recognized.

At the time of night illumination, light from a light source such as the incandescent bulb 7 passes through the portion of the rear surface of the transparent substrate 11 where the rear surface side high-reflection layer 32 does not exist, that is, from the entrance gap 34 into the transparent substrate 11. And propagates through the transparent base material 11 by being reflected by the light-impermeable layer 16 such as a black print layer, and then reflected by the display pattern 31 of the backside high-reflection layer 32 to impede light. When the light is emitted from the display pattern 15 of the transmissive layer 16 toward the surface of the transparent substrate 11, the display by the display pattern 15 is recognized.

As described above, the display pattern 31 corresponding to the display pattern 15 of the light-opaque layer 16 and slightly thicker than the display pattern 15 is provided on the rear surface side of the transparent base material 11.
Is formed in the back side high reflection layer 32, the display pattern 15 is in an indirect illumination state with respect to light from a light source such as the incandescent bulb 7, so that the dial plate 2 has a variation in luminance peak generated due to various factors. Very little influence is attached.

As a result, the uniformity of the luminance distribution of the dial 2 is improved, the distance 28 between the incandescent bulb 7 and the dial 2 can be shortened, and an instrument exceeding the limit in the case of halftone dimming can be obtained. Can be made thinner.

Further, by appropriately adjusting the gap size of the incident gap 34 according to the distance from the incandescent bulb and the position and size of characters and scales, the amount of light transmitted through the display pattern portion at night can be adjusted (brightness). Adjustment).

In the above embodiment, the transparent substrate 11
Is not provided with the light-transmitting white print layer 12 shown in the prior art, but may be provided as necessary.

Further, in the above embodiment, only the case where the entrance gap 34 is provided is shown. However, when the position of the character / scale portion of the dial is far away from the incandescent bulb 7 (the brightness is separated from the light source). Is low),
In some cases, only the display pattern 31 corresponding to the scale portion is provided, and the display pattern outer covering portion 35 is not formed.

[0039]

Second Embodiment FIG. 3 shows a second embodiment of the present invention. The same or equivalent parts as those in the first embodiment will be described with the same reference numerals.

First, the structure will be described. In the second embodiment, a halftone dimming layer 36 is formed on the back side of the transparent substrate 11 and on the back side of the back side high reflection layer 32. I have. The halftone dimming layer 36 may be formed on the front surface of the dial 2 or may be formed only on the part of the gap 34 for incidence as shown in FIG.

Next, the operation of the second embodiment will be described.

As described above, by forming the halftone dimming layer 36 on the back surface side of the transparent substrate 11, the halftone dimming by the halftone dimming layer 36 can be performed in addition to the indirect illumination effect. it can. Therefore, the uniformity of the luminance distribution of the dial 2 is further improved, and the distance 28 between the incandescent bulb 7 and the dial 2 can be further shortened. Is possible.

Further, by forming the dot light control layer 36 only in the portion of the gap 34 for incidence, it is possible to reduce the printing cost.

Further, by using the light amount adjustment by adjusting the gap size of the incident gap 34, it is possible to further finely adjust the brightness.

The other parts are the same as those in the first embodiment.
, And the same operation and effect can be obtained.

[0046]

Third Embodiment FIG. 4 shows a third embodiment of the present invention. The same or equivalent parts as those in the first embodiment will be described with the same reference numerals.

First, the structure will be described. In the third embodiment, the surface of the white base layer or the like is left between the surface of the transparent substrate 11 and the light-impermeable layer 16 except for the display pattern 15. The side high reflection layer 38 is formed.

It is desirable that the surface-side high-reflection layer 38 is formed to be light-impermeable.

Further, an unformed portion where the surface-side high-reflection layer 38 is not provided may be provided in a portion such as the vicinity of the zenith of the light source such as the incandescent bulb 7 where high-efficiency propagation is not required.

Next, the operation of the third embodiment will be described.

As described above, by forming the surface-side high-reflection layer 38 between the transparent substrate 11 and the light-impermeable layer 16, the surface-side high-reflection layer 38 propagates through the transparent substrate 11. To the rear surface side high-reflection layer 32
, And it is possible to increase the brightness of the entire instrument.

By providing an unformed portion without the front-side high-reflection layer 38 for a portion that does not require highly efficient propagation, such as near the zenith of the light source, such as the incandescent bulb 7,
A kind of dimming function can be exhibited.

The other parts have the same configuration as the first and second embodiments, and the same operation and effect can be obtained.

[0054]

As described above, according to the first aspect of the present invention, the display corresponding to the display pattern of the light-opaque layer and slightly thicker than the display pattern is provided on the back side of the transparent substrate. Since the display pattern is in an indirect illumination state by forming the pattern with the backside high-reflection layer, the influence of the variation of the luminance peak caused by various factors is greatly reduced. For this reason, the uniformity of the luminance distribution is improved, and the thickness of the instrument exceeding the limit in the case of the halftone dot dimming can be reduced.

According to the second aspect of the present invention, by forming the halftone dimming layer on the back side of the transparent substrate, the halftone dimming by the halftone dimming layer is simultaneously performed in addition to the indirect lighting effect. be able to.

According to the third aspect of the present invention, the light propagating through the transparent substrate is more efficiently reflected by the surface-side high-reflection layer formed between the transparent substrate and the light-impermeable layer. Thus, it is possible to reach the backside high-reflection layer, thereby achieving a practically useful effect that it is possible to increase the luminance of the entire instrument.

[Brief description of the drawings]

FIG. 1 is a partially enlarged side sectional view of a dial according to a first embodiment of the present invention.

FIG. 2A is a partial external plan view of a dial,
(B) is a partial plan view of the light-opaque layer, (c)
FIG. 3 is a partial plan view of the back side high reflection layer.

FIG. 3 is a partially enlarged side sectional view of a dial according to a second embodiment of the present invention.

FIG. 4 is a partially enlarged side sectional view of a dial according to a third embodiment of the present invention.

FIG. 5 is a side sectional view of an instrument according to a conventional example.

6 is a partial external plan view of the dial of FIG. 5;

FIG. 7 is a partially enlarged side sectional view of the dial of FIG. 5;

FIG. 8 is a graph showing dial luminance.

FIG. 9 is a graph showing corrected dial luminance.

FIG. 10 is a graph showing corrected dial luminance when a positional shift occurs.

[Explanation of symbols]

 2 Dial 11 Transparent substrate 15 Display pattern 16 Light-impermeable layer 31 Display pattern 32 Backside high reflection layer 36 Halftone dimming layer 38 Front side high reflection layer

Claims (3)

[Claims] 1. A dial structure of an instrument in which a light-impermeable layer is formed on a front side of a transparent base material while leaving a display pattern, wherein a back side of the transparent base material corresponds to the display pattern and A dial structure of an instrument, wherein a display pattern slightly thicker than the display pattern is formed on the back surface side high-reflection layer. 2. The dial structure of an instrument according to claim 1, wherein a halftone dot light control layer is formed on the back side of said transparent substrate. 3. The surface-side high-reflection layer is formed between the surface of the transparent substrate and the light-impermeable layer while leaving the display pattern. Instrument dial structure.