JPS61156001A - Display device - Google Patents

Abstract

PURPOSE:To prevent the erroneous reading and image distortion owing to parallax by providing the front part of a display medium so as to incline with the rear part of a substrate or sheet material and setting the angle of inclination thereof in the direction approximately orthogonal with the refraction direction of the refracted ray emitted from the rear of prisms. CONSTITUTION:The substrate 3 is formed with the many fine prisms 6 having the saw-tooth sectional shapes each consisting of a perpendicular face 4 and slopes 5 provided continuously therewith into a parallel wire shape. The front part of an instrument 2, i.e., a dial 2a is provided so as to incline with the rear part of the substrate 3. The angle of inclination thereof is set approximately the same as the angle theta of refraction of the refracted ray (d) emitted from a flat face 7 on the rear of the substrate 3. The dial 2 is therefore in the state facing nearly exactly the virtual visual line direction A and the parallax owing to the graduation position of the dial 2a and the indication of the hand 2b in an indicating instrument, etc. is prevented, by which good visibility is obtd. The erroneous reading and image distortion which are liable to rise in the case of the instrument 2 to be used as a display medium and having a step like the dial 2a and the hand 2b are thus eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a p-water device, in particular, a system in which prisms having a serrated cross-section are provided in fine parallel lines on at least the surface of a translucent substrate or sheet material. , relates to a display device comprising a display medium provided behind the light-transmitting substrate or sheet material.

[Conventional technology and its problems]

Japanese Unexamined Patent Application Publication No. 56-133701 has proposed this kind of device, which proposes an external 2111 The inclined surface is geometrically designed to guide the surface reflected light generated by the irradiation to the outside, and the front surface is formed with a large number of continuous prisms.
It is formed of a substrate whose back surface is a flat surface and which guides light reflected from the surface out of the visual field.

However, when the display medium is placed parallel to the substrate after surgery, the display medium is refracted within the substrate by the prism, so when looking at the display medium, the image appears to be misaligned with the real image position of the display medium. is read. In addition, at this time, the light rays refracted inside the substrate reach the display medium, so the display medium is essentially viewed from an oblique direction, and in the case of a deep display medium, for example, in the case of an indicator on a vehicle, etc. The user may be looking at the indicated position and the scale position on the dial from an oblique direction, which may cause parallax.

[Purpose of the invention]

An object of the present invention is to improve visibility by suppressing parallax of a display medium.

[Summary of the invention]

The present invention provides a display device in which prisms having a serrated cross section are provided in fine parallel lines on at least one side of a translucent substrate or sheet material, and a display medium is provided behind the substrate or sheet material. The front surface of the display medium is provided to be inclined with respect to the back surface of the substrate or sheet material, and the angle of inclination is set to be approximately perpendicular to the direction of refraction of the refracted light rays emitted from the back surface of the prism. This makes it possible to view the surface of the display medium almost directly in the morning.

〔Example〕

The display device of the present invention is effective for various display media, but to explain the case where the display medium is a vehicle instrument as an example, it can be used for an instrument 2 mounted on an instrument panel 1 as shown in FIG. Transparent substrates 3 are arranged at intervals on the front side,
In this case, the substrate 3 also serves as a protection plate to prevent dust from entering from the outside. Further, in this embodiment, the substrate 3 is the 21st],'
! As shown in FIG. 3, a surface portion has a large number of sawtooth prisms 6 arranged in fine parallel lines, and a flat surface 7. Most of the incident light ray a from the outside passes through the inside of the substrate 3, and a part of it is reflected back to the front side of the substrate 3. The unsightly reflected light rays are reflected by the inclined surface 5 of the prism 6 provided on the surface side of the substrate 3, and the surface reflected light 1
Since the light beam b is guided out of the field of view, the reflected image caused by the surface reflected light beam mb is prevented as much as possible.

Furthermore, if the inclination angle of the inclined surface 5 is α in FIG.
The external incident ray a from the line of sight direction has an angle of incidence and a reflection angle of α, and the surface reflected ray is guided out of the field of view, and the refraction angle β obtained from sin α = mouth sin β (n is the refractive index of the medium) The refracted light @C enters the substrate 3, and the refracted light C enters the flat surface 7 on the back side of the substrate 3 at an incident angle r obtained by α−β=“, and the refraction angle θ obtained by the following equation The refracted light becomes @d.

sinθ=n sin r When α-β=r is inserted into the above equation, sijθ==nsin(α-β) =n(sinαcosβ-cosαsioβ), and when is inserted, a parallax of the refraction angle θ is generated and the angle of the substrate 3 is Letting L be the distance between the back surface and the front surface of the display medium, the display medium will move and display the distance t obtained by the following formula %.

By the way, in the present invention, as shown in FIG.
Since the refraction angle θ of the refracted light ray d emitted from Parallax caused by instructions can be prevented and good visibility can be obtained. If there is a difference in level between the dial 2a and pointer 2b of the meter 2 that serve as display media, misreading and image distortion due to parallax are likely to occur.
Such problems are solved.

Further, FIG. 4 shows a second embodiment of the present invention, in which an instrument 2 mounted on an instrument panel 1 is disposed almost flat in the line of sight direction, and a substrate 3 covering the front side of the instrument 2 is arranged. are arranged at an angle. In this case, the front surface of the substrate 3 is flat, and the back surface thereof has a sawtooth cross-sectional shape consisting of a vertical surface 4 provided substantially perpendicular to the substrate 3, and an inclined surface 5 provided continuously with this vertical surface 4. A large number of prisms 6 are formed in the form of fine parallel lines. In this way, the dial 2a of the meter 2 is provided at an angle with respect to the base plate 3, and the angle of inclination is set to be almost the same as the refraction angle of the refracted light beam coming out of the prism 6 on the back surface of the base plate 3. 2a has the same effect as the first embodiment in that it is almost directly in front of the line of sight and can prevent parallax. Note that prisms 6 may be provided on both the front and back surfaces of the substrate 3 as shown in FIG.
There is an aspect that can be set to a large value.

〔Effect of the invention〕

The present invention provides a display device in which prisms having a serrated cross-section are provided in fine parallel lines on at least one side of a transparent substrate or sheet material, and a display medium is provided behind the substrate or sheet material. The front surface of the display medium is inclined with respect to the back surface of the substrate or sheet material, and the angle of inclination is set to be approximately perpendicular to the direction of refraction of the refracted light rays emitted from the back surface of the prism. It is possible to view the surface almost directly in front of the viewer, which has the effect of preventing misreading and image distortion due to parallax.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the device in use, FIG. 2 is an enlarged sectional view of essential parts of the board, FIG. 3 is a perspective view of the board, and FIGS. 4 and 5 are sectional views of other embodiments. 3... Substrate 6... Prism 7... Flat, surface d... Refracted ray

Claims (1)

[Claims] Prisms with a sawtooth cross-section are provided in fine parallel lines on at least one side of a translucent substrate or sheet material,
In a display device in which a display medium is provided behind the substrate or sheet material, the front surface of the display medium is provided at an angle with respect to the back surface of the substrate or sheet material, and
A display device characterized in that the angle of inclination is set in a direction substantially perpendicular to the refraction direction of the refracted light beam coming out from the back surface of the prism.