JPS63203435A - Visorless meter for vehicle - Google Patents

Abstract

PURPOSE:To prevent the reflection of a meter on a window by forming the outside surface of a light transmitting plate into a saw-toothed form and forming the inside surface of the light transmitting plate into a saw-toothed form inclined in the same direction to the inclined surface of the above-described saw-toothed surface, having a different inclination angle, in the light transmitting plate structure on the front surface of the meter for vehicle. CONSTITUTION:As for a meter 1 for vehicle, a meter inside device 3 is fixed inside a meter casing 2, and a prism plate 4 as a light transmitting plate is laid on the front surface. In this case, the prism plate 4 is made of acrylic resin having a refractive index of 1.5, and a plurality of saw-toothed inclined surfaces are formed on the front and back surfaces. In this case, the inclined surface 4a on the outside surface is formed into a steep inclined surface having an angle of about 80 deg. with respect to the direction (a) of an indicator axis 7, and the inclined surface 4b on the inside surface is formed into the more gentle inclined surface than the inclined surface 4a on the outside surface having an angle of about 70 deg. formed with respect to the direction (a) of the indicator axis. Therefore, the prism plate 4 is formed into a sectional shape in which the thickness increases towards the lower part.

Description

[Detailed Description of the Invention] jLt Upper Nidansarawa 1 The present invention relates to a meter that is mainly installed on an instrument panel in front of a driver in a four-wheeled motor vehicle, and which includes a visor that covers the upper part like an eaves. This is related to the visorless meter that was removed.

1. In conventional vehicle meters, the transparent plate itself has a curvature (as shown by the two-dot chain line in Figure 2) to prevent sunlight reflected from the meter surface from entering the driver's eyes. ), the reflected light was allowed to travel to either of the upper F, and was intercepted and absorbed by the meter visor.

The meter visor also had the role of preventing not only external light but also light from inside the meter from reflecting on the front window.

However, since the meter visor itself protrudes from the instrument panel toward the driver, the presence of the meter visor has the disadvantage of hindering the driver's sense of openness ahead.

Therefore, an example (Japanese Unexamined Patent Publication No. 133317/1983) has been disclosed in which the meter visor is removed and the meter visor is removed to make the meter thinner and to provide a transparent plate with good visibility so that the reflected light does not enter the eyes.

The same side is illustrated and explained in FIG.

A transparent plate 08 integrally formed with a large number of curved surfaces 01 tilting upward and forward is disposed on the cylindrical surface of the dial 03 of the instrument 02 attached to the instrument panel 01, and above and below the transparent plate 08, a hood 05 protrudes slightly forward. It is provided.

Therefore, the light reflected from the surface of the transparent plate 08 is reflected downward and absorbed by the hood 05, so that it does not enter the driver's field of vision and has an anti-glare effect.

Furthermore, the thickness of the transparent plate 08 itself can be reduced, and the forward protrusion of the hood 05 can also be reduced, making it possible to reduce the thickness of the apparatus.

° しと 口 Same Conventional example, like a Fresnel lens, divides a single transparent plate with curvature into multiple parts, maintains the curvature of each part, and aligns all the parts in the thickness direction. The hoods above and below the valve (with thinner transparent plates) are designed to be thinner.
The protrusion (visor) has also been reduced.

However, this conventional example does not take into account the so-called meter window reflection, in which illumination light from inside the meter is projected onto the front window at night.

To explain the window reflection of this meter based on Figure 2,
The eye point of a driver seated in the driver's seat of a four-wheeled motor vehicle varies depending on the seat height of the driver, but is generally limited to a certain narrow spatial area, and the most common eye point at present is E.

Horizontally in front of the eye point E, a front window W is installed obliquely forward and downward, a steering wheel S is arranged below it, and a column cover C that covers the rotation axis of the steering wheel S and a front window W are installed. An instrument panel P is located between them, and a meter M is equipped on the instrument panel P.

The driver looks ahead while driving, and his field of vision is the area shown by diagonal lines.

Now, if the internal illumination light of the meter M passes through the transparent plate G on the front and reaches the front windshield W section (section 12 from E+ indicated by the thick line) included in the viewing area, the image of the meter will appear in the sections 11 and 12. is projected, and the driver can visually perceive and recognize it as a reflection on the meter window.

Therefore, the transmitted light of the transparent plate G is E of the front window W.
If the area other than 1 to E2 is illuminated, the driver will not be able to recognize the reflection on the meter window.
Considering the straight line GIEt connecting the upper end G1 of the light-transmitting plate G and El of the front 1 quind W, it is sufficient to prevent the outermost light of the light transmitted through the light-transmitting plate G from being emitted above this straight line G+E+.

On the other hand, in the case of the conventional example, since the thickness of each curved portion of the transparent plate 08 remains the same, the illumination light from inside is emitted in parallel although the position is shifted after passing through the transparent plate 08. When applied to the meter M in FIG. 2, there is a risk that the transmitted light will be emitted at an angle greater than the straight line G+E+ and reach the E1 to E2 portions of the front window W, resulting in window reflection.

The - of.

The present invention has been made in view of the above, and an object thereof is to provide a visor-less meter for a vehicle that has an anti-glare effect in a meter without a visor and prevents the meter from reflecting on the front window. It is in.

Therefore, the present invention provides a translucent plate structure in front of a meter in a vehicle, in which the outer surface of the translucent plate is made into a planar shape or a sawtooth shape having a steeply sloped surface from the upper front to the lower back, and the inner surface of the translucent plate is The visor-less meter for a vehicle has a sawtooth shape having an inclined surface inclined in the same direction as the inclined surface of the outer surface and having a gentler slope.

Therefore, if you look at a partial cross section of the light-transmitting plate, as shown in Figure 3, it is formed so that its thickness gradually increases as it goes downwards, so the internal illumination light directed upwards is as shown in Figure 3. After passing through the transparent plate G as shown by the arrow, the light is emitted with a relaxed angle of inclination.

Since the light parallel to the internal illumination light is not emitted as in the conventional case, but is emitted at a relaxed angle of inclination, it is necessary to set the angle of the inclined surface on the back side of the transparent plate and the inclined surface on the front side appropriately. Accordingly, it is possible to form transmitted light having a maximum inclination angle gentler than the inclination angle of the straight line G+Et in FIG. 2 without making both surfaces extremely gently inclined, and it is possible to prevent reflections in the meter window.

FriendJdLJl An embodiment of the present invention illustrated in FIGS. 4 and 5 will be described below.

FIG. 4 is a longitudinal sectional view showing the internal structure of the meter 1 according to this embodiment.

A meter e13 is fixed inside the meter casing 2, and a prism plate 4 serving as a transparent plate is stretched on the front side.

A dial plate 5 is arranged between the inside of the meter a3 and the prism plate 4, and a light guide plate 6 is in contact with the back surface of the dial plate 5, and a part of the outer peripheral edge of the light guide plate 6 is bent at a right angle. The bent part 6
A lighting bulb 9 is arranged opposite to the end surface of a.

A finger button shaft 7 passes through the center of the dial 5 and the light guide plate 6, and a pointer 8 is fitted to the tip of the finger button shaft 7.

During the day, the deflection of the dial 5 and pointers 8 can be seen through the prism plate 4 using extraneous light from the sun, and at night, the inside of the meter casing 2 is brighter than the outside by lighting the lighting bulb 9, and the light guide plate 6 The light travels through the prism plate 4, brightly illuminating the back side of the dial plate 5, and making the scales, letters, etc. drilled in the dial plate 5 stand out, and the illumination light passes through the prism plate 4 and appears in the eyes of the operation name. Now you can read the scale.

A partially enlarged view of the cross section of the prism plate 4 is shown in FIG. 5 and will be described.

The prism plate 4 is made of acrylic and has a refractive index of 1.5.

A plurality of sawtooth-shaped inclined surfaces are formed on both surfaces, and the inclined surface 4a on the outer surface (outside of the meter) forms a steep slope with an angle of 80° with the direction a of the pointer shaft 7, The sloping surface 4b (inner side) has a slope that is gentler than the sloping surface of the outer surface that forms an angle of 70 degrees with the pointer axis direction a, and has a cross-sectional shape in which the wall thickness becomes thicker as it goes downward.

Note that the surfaces other than the inclined surfaces are approximately parallel to the pointer axis direction a.

Most of the external light passes through the prism plate 4, and part of it is reflected at the front of the prism plate 4, but the reflected light is reflected from the front inclined surface 4a of the prism plate 4 and travels as substantially downward light. Therefore, the reflected light does not directly enter the driver's eyes and has an anti-glare effect.

Next, regarding internal illumination light, the light that is incident on the inclined surface 4b on the inner surface of the prism plate 4 is incident on the inclined surface 4b from all directions, but the light that has passed through the prism plate 4 has a limit in the upward direction. There is.

That is, on the inclined surface 4b of the inner surface having an inclination angle of 70° with respect to the finger η-axis direction a, the incident light directed upward at an inclination of 70° is the light with the maximum gradient, and now the incident light is directed upward at an incident angle of 89°. Let's examine the optical path of the incident light ■.

The angle of refraction is calculated to be 41.8°, so the angle of incidence to the front of the prism plate 4 is 31.8°, and the angle of exit thereof is 52°.

The angle of the outgoing light with respect to the pointer axis direction a is 42°.

Therefore, for the light incident on the inclined surface, the outgoing light directed upward, which forms an angle of 42° with the pointer axis a, is the light with the maximum gradient.
There is no emitted light with a gradient greater than this.

Next, consider a person 19 who is on the inner surface of the prism plate 4 and faces a surface other than the inclined surface 4b (hereinafter referred to as the lower surface 4C).

The lower surface 4C is substantially parallel to the pointer axis 7, and the incident light is included in the slope range of 70° from Oo.

Therefore, when we trace the optical path of the incident light 2 (incident angle 89°) that is approximately parallel to the pointer axis 7, it is refracted at the lower surface 4C at a refraction angle of 41.8'' and reaches the outer surface 4a of the prism plate 4. The angle of incidence on the outer surface 4a is 58.2°, which is larger than the critical angle of incidence of 42° for total reflection, and is totally reflected without being refracted.

Since the incident light ■ is totally reflected on the outer surface 4a, the lower surface 4
Other light incident on C is incident on the outer surface 4al at an even larger angle of incidence, so it is all reflected and does not leak to the outside.

From the above, the illumination light inside the meter is transmitted through the prism plate 4 and is emitted as output light with a maximum slope of 42°, and there is almost no light with a slope of 42° or more.

When the meter 1 having such a prism plate 4 is mounted on a four-wheeled motor vehicle, the maximum slope of the emitted light that does not cause window reflection (the angle formed by the pointer axis a and the straight line G+E+) in FIG. 2 is measured with a slight margin. Then, the angle is approximately 42 degrees, and since the internal illumination light of the meter 1 has a slope of 42'' as its limit, it is not emitted to the E+-E2 portion of the front window W that causes window reflection, but is emitted further above El, causing window reflection. will not occur.

As described above, in the case of this embodiment, the reflected light of external light by the prism plate 4 in front of the meter travels downward and has an anti-glare effect, and the internal illumination light is emitted within the window reflection area on the front window. It is possible to prevent window reflections.

Next, FIG. 6 shows a second embodiment in which the outer surface of the transparent plate of the meter is made flat and coated with an anti-reflection coating.

In the embodiment described above, the inclined surface 4a on the outer surface of the prism plate 4 had an inclination angle of 80°, but in this embodiment, it has an inclination angle of 9G', that is, a plane perpendicular to the pointer shaft 7.

This transparent plate 10 is also made of acrylic with a refractive index of 1.5, and the outer surface 1
Magnesium fluoride M (J
A thin film 11 made of F2 is coated to a predetermined thickness.

Regarding external light, reflected light on the surface of the thin film 11 and
A phenomenon occurs in which the reflected light at the interface between the transparent plate 10 and the book membrane 11 interferes and cancels each other out, so that an extremely low reflectance can be obtained and the reading of the meter pointer is not hindered.

Regarding the internal illumination light, of the light incident on the inclined surface 10b of the inner surface of the light-transmitting plate 10, looking at the optical path of the incident light (2) with an incident angle of 89°, the refraction angle is 4
It is refracted at an angle of 1.8° and is incident on the outer surface 10a at an incident angle of 21.8°, and the refraction angle of the thin film 11 is 23.6°.
In the end, the exit angle is 33.9°.

This emitted light is the emitted light with the maximum slope, which is sufficiently smaller than the maximum slope angle of 42° of the emitted light in the above embodiment, so that window reflection on the front window does not occur.

Above 1st. In the second embodiment, we considered that window reflection does not occur for the main light incident on the transparent plate of the internal illumination light, and there is almost no practical problem with this. A third embodiment of the present invention in which excess output light is removed from the incident light is illustrated in FIG. 7 and will be described.

The rotation uses the same light-transmitting plate 4 as in the first embodiment, and a light-shielding film 20 is applied to the FQ portion of the inclined surface 4b of the inner surface.

The incident light that we are going to consider now enters from the inclined surface 4b, and the lower surface 4C of the inner surface of the prism plate 4 other than the inclined surface 4b.
When some of such light is emitted from the prism plate 4, there is light whose slope exceeds 42°.

Such light is only a small portion, and is light that enters from the lower part of the inclined surface 4b of the inner surface. That is, even if the light incident above the inclined surface 4b is reflected by the lower surface 4G, it is totally reflected by the outer inclined surface 4a.

The optical path at the lowest end of the inclined surface 4b of the light incident on the inclined surface 4b, which is reflected by the surface 4G and further totally reflected by the inclination angle 4a of the outer surface, is shown by a broken line in FIG.

The doujinshi light ■ enters the inclined surface 4b at an incident angle of 18.2°,
It is reflected at the right end of the lower surface 4C and enters the inclined surface 4a of the outer surface at an incident angle of 42°.

The incident angle of 42° is the critical angle that causes total internal reflection, and the same ray ■
is totally reflected on the inclined surface 4a.

When the light that enters the slope 4b above the incident light ray is reflected by the lower surface 4C, it is incident on the front slope 4a at an angle greater than the critical angle, so it is totally reflected, but below the light ray Considering the light incident on the inclined surface 4b with a small incident angle, after being reflected on the lower surface 4C, it is incident on the front inclined surface 4a at an angle less than the critical angle, and goes out without being totally reflected and is rJJ. .

Although this light is only a small portion, most of it is emitted upward, so there is a risk that it will reach the front window and cause a slight reflection on the window.

Therefore, in order to block the light that may cause such window reflection by the inclined surface 4b, in this embodiment, the lower end of the inclined surface 4b is covered with a light shielding film 20.

Since the light-shielding film 20 covers only a small portion of the inclined surface, it is possible to almost completely prevent window reflection without reducing the amount of internal illumination light so much.

Next, as another embodiment, a fourth embodiment in which the lower surface 4C blocks light that may cause the above-mentioned window reflection will be described as shown in FIG. 8.

The rotation is made by applying a graining process consisting of fine irregularities to the lower surface 4G of the inner surface of the prism plate 4, which diffusely reflects the light incident on the lower surface 4C and lowers the reflectance, increasing the amount of light that is normally small. Window reflection can be prevented by reducing this.

Since the lower surface 4C is grained, the transmittance of light incident from below can be reduced, so there is no need to consider window reflection caused by the same light, and the design of the sloped surface of the outer surface of the prism plate 4 is accordingly improved. becomes free.

In addition to the above-mentioned embodiments, it is also conceivable to perform graining on the lower surface 4C at the same time as covering with the light shielding 1g120.

Furthermore, even when the outer surface of the transparent plate has an inclined surface, the anti-glare effect can be perfected by applying an anti-reflection coating to the surface.

Further, the angle of inclination of the inclined surface of the light-transmitting plate is not limited to the above embodiment, and can be freely designed by considering the average thickness and strength of the light-transmitting plate and suppressing window reflection as much as possible.

1 Mamerikou 1 The present invention allows the translucent plate itself to be designed to be thin by making the cross section of the translucent plate in front of the meter have a specific shape with a serrated inclined surface that becomes thicker as it goes downward. In addition, since the light-transmitting plate itself has an anti-glare effect, it is possible to eliminate the need for a pipe that obstructs the sense of openness in front of the driver, and to prevent the meter from reflecting on the front window.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of a conventional visorless meter, Figure 2 is an explanatory cross-sectional view of the front part of the driver's seat of a four-wheeled motor vehicle to explain the reflection of the meter on the front window, and Figure 3 is A partially cutaway sectional view showing the cross-sectional structure of a light-transmitting plate according to the present invention, FIG. 4 is a cross-sectional view of a meter according to a first embodiment of the present invention, and FIG. 5 is a cross-sectional view of a light-transmitting plate according to the same embodiment. Figure 6 is a cross-sectional view of a second embodiment of the transparent plate coated with an anti-reflection coating, and Figure 7 is a third embodiment of a transparent plate in which a part of the inner surface of the transparent plate is coated with a light-shielding film. FIG. 8 is a cross-sectional view of a light-transmitting plate according to a fourth embodiment in which a portion of the inner surface of the light-transmitting plate is textured. 1...meter, 2...meter casing, 3...
...Meter internal unit, 4...Prism plate, 4a, 4b,
4C... Slanted surface, 5... Dial plate, 6... Light guide plate,
6a...Bending portion, 7...Pointer shaft, 8...Pointer, 1
0...Transparent plate, 10a. 10b... Inclined surface, 11... Thin film, 20... Light shielding film, E... Eye point, W... Front window, S
...Steering wheel, C...Column cover,
P...Instrument panel, M...Meter,
G... Translucent plate.

Claims (4)

[Claims] (1) In the structure of a transparent plate in front of a meter in a vehicle, the outer surface of the transparent plate has a planar shape or a sawtooth shape having a steeply sloped surface from the upper part of the front to the lower part of the back, and the inner surface of the transparent plate has the shape of A visorless meter for a vehicle, characterized by having a sawtooth shape having an inclined surface inclined in the same direction as the inclined surface of the outer surface and having a gentler slope. (2) The visor-less meter for a vehicle according to claim 1, characterized in that the outer surface of the transparent plate is coated with a non-reflective coating. (3) The visor-less meter for a vehicle as set forth in claim 1 or 2, wherein a light-shielding coating is applied to the lower tip of each slope on the inner surface of the light-transmitting plate. (4) The visor-less meter for a vehicle as set forth in claim 1 or 2, wherein fine irregularities are formed on the inner surface of the light-transmitting plate other than each inclined surface.