JPS62150324A - Display device - Google Patents

Abstract

PURPOSE:To lead in enough an external light beam from a lighting window in the daytime, and to prevent a light leak from the lighting window at night, by providing an electrochromic display element whose transmittivity is varied by applying a voltage, on the lighting window. CONSTITUTION:A display window 12 is provided in front of a housing 11, and in the rear of this display window 12, a liquid crystal display element 13 is provided. On the rear surface of this liquid crystal display element 13, a semipermeable light leading body 14 is provided, and in case a light source 15 is lighted at night, etc., an internal light beam which is emitted from the light source 15 and reflected from a curved reflecting plate 16 is led to the liquid crystal display element 13 aide. Also, on the housing 11 of the upper face side of the light leading body 14, a lighting window 17 for taking in an external light beam such as a solar light, etc., is pierced, and an electrochromic display element 18 having an optical shutter function for controlling passing of a light beam is fitted into this lighting window 17.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a display device in which a housing is provided with a lighting window that takes in external light, and displays are displayed using external light from the lighting window during the day and internal light during the night. .

[Related technology and its problems]

This type of display device using a liquid crystal display element is disclosed in Japanese Utility Model Publication No. 56-53369, for example, in which light is irradiated from the rear side of a transmissive liquid crystal display element, and the light that has passed through the liquid crystal display element is reflected. The display image on the reflector is reflected by the plate and viewed through a display window formed in the frame. When this display device is used in a vehicle, for example, as shown in FIG. 4, a reflective plate 3 is mounted on the front side of a transmissive liquid crystal display element 2 horizontally disposed on a hood 1 of the vehicle, and is inclined at a predetermined angle θ. A light guide 6 is disposed on the rear side of the liquid crystal display element 2 via a color filter 5 so that the driver 4 can see the reflected display image.

When the surroundings are dark, such as at night, the internal light of the light source 7 is guided by the light guide 6 and passes through the color filter 5. On the other hand, when the surroundings are bright, such as during the day, external light entering through the windshield 8 enters the hood 1. Lighting window 9 drilled on the top surface
The light passes through the light guide 6 and the color filter 5 to illuminate the liquid crystal display element 2, respectively.

However, when the light source 7 is turned on at night, etc., this light is transmitted to the light guide 6.
Not only is it reflected towards the liquid crystal display element 2 side, but also
A part of it is a lighting window 9 that takes in external light through a light guide 6.
This light leaks out of the hood 1 and is reflected on the windshield 8, obstructing the driver's 4 view. For this reason, there is a method of fitting a mechanical shutter into the lighting window 9 and closing the shutter when the light source 7 is turned on, but since it is mechanical, the structure is complicated and an actuator etc. is also required for opening and closing. becomes. Another method is to install a viewing angle control film (VCF) or the like on the lighting window 9 to guide the leaked light in a direction that does not obstruct the view, but on the other hand, the amount of incident external light during the daytime is reduced and is sufficient. It may not be possible to obtain sufficient brightness, or it may not be possible to completely prevent light leakage.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a display device that can sufficiently introduce external light through a daylight window during the day, and can effectively prevent light leakage from the daylight window at night. It is something.

[Structure of the invention]

To achieve the above object, the present invention provides a display device in which a housing is provided with a lighting window that takes in external light, and displays are displayed mainly by external light during the day and by internal light at night, by applying a voltage to the lighting window. It is characterized by disposing an electrochromic display element whose transmittance changes.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings. 1st
The figure shows a first embodiment of the present invention, in which a display window 12 is provided on the front surface of a housing 11 of a display device.
A liquid crystal display element 13 is provided behind the. A semi-transparent light guide 14 made of a transparent light guide synthetic resin material such as polycarbonate, resin, acrylic resin, etc. is disposed on the rear surface of the liquid crystal display element 13, and is used to turn on the light source 15 at night. In this case, the light is emitted from the light source 15 and the curved reflector 16
Internal light reflected from the liquid crystal display element 13 is guided to the liquid crystal display element 13 side.

Furthermore, a lighting window 17 is provided in the housing 11 on the upper surface side of the light guide 14 to take in external light such as sunlight. Chromic display element (rE
cDJ) 18 is fitted.

As shown in FIG. 2, in ECDlB, a transparent display electrode 20 is formed on a transparent substrate 19, and a coloring layer 21 of a transition metal oxide such as tungsten oxide (Wool) is formed on the display electrode 20, and the opposite A counter electrode 23 is provided on a counter substrate 22 to
The transparent substrate 19 and the counter substrate 22 are injected with an electrolytic solution 25 which provides ion conduction to the color forming layer 21 via a spacer 24 to seal the space between the two electrodes 20 and 23. Reversing switch 2 that can change the voltage polarity
A power supply 27 is connected via 6. Then, by operating the reversing switch 26 and applying voltages of different polarities to the coloring layer 21, the coloring layer 21 can be reversibly oxidized and reduced to obtain a colorless (transparent) or colored state. This phenomenon occurs when tungsten oxide is used as the transition metal oxide, an aqueous solution is used as the electrolytic solution 25, and the positive charge transfer carrier of the electrolytic solution 25 is a proton (H"), x H"+WO3+ x 6-;=! l(”X (W
O3) e-z (colorless) (colored) It is explained by the reaction formula. Note that 28 is a variable resistor, and by changing the resistance value, the voltage applied to ECD1B can be changed, and the coloring density, that is, the light transmittance of EC01B can be varied. In FIG. 1, 29 is a printed circuit board on which drive circuits for the liquid crystal display element 13 and light source 15 are mounted, and 30 is an electronic circuit board for the power supply 27, variable resistor 28, etc.
This is a printed circuit board on which a CDlB drive circuit is mounted, and the reversing switch 26 is connected to this printed circuit board 30 and placed at a position where it can be easily operated by the user.

Therefore, in the present invention having the above-mentioned structure, when the surroundings are bright such as during the daytime when the light passing through the daylight window 17 is introduced by the ECDlB fitted in the daylight window 17 and transmitted through the liquid crystal display element 13, the reversing switch 26 is operated. ECDlB is colorless (
Transparent) state to increase the transmittance of external light. For example, when tungsten oxide is used as the coloring layer 21, when a positive voltage is applied to the display electrode 20 side, the coloring layer 21 is oxidized and the ECD, 18 becomes colorless (transparent), and external light passes through the ECD 18. and incorporated into the light guide box.

On the other hand, when it is dark such as at night when the light source 15 is turned on and the internal light is transmitted through the liquid crystal display element 13 through the light guide, the reversal switch 26 is reversed to turn the ECD 18 into a colored state and reduce the light transmittance. . In this case, when a negative voltage is applied to the display electrode 20 side, contrary to when the surroundings are bright, the coloring layer 21 is reduced and the ECD 18 becomes colored, and the internal light traveling from the light guide body toward the lighting window 17 side is Since the light transmittance of the ECD 18 is low, most of the light is absorbed, and leakage of light to the outside from the lighting window 17 can be almost completely prevented.

In this way, the electrical structure in which the ECD 18 is fitted into the lighting window 17 and the reversing switch 26 is operated can reliably prevent internal light from leaking, and prevent the leaked light from being reflected on the windshield of a vehicle or the cowling of a two-wheeled vehicle, for example. prevention and improve visibility.

FIG. 3 shows a second embodiment of the present invention, in which the present invention is applied to a mirror reflection type liquid crystal display device in which a display image of a liquid crystal display element is reflected by a mirror for viewing. In this case, a display window 32 is provided on the front surface of the housing 31, a reflective mirror 33 is provided inwardly on the inside of the display window 32, and a liquid crystal display element 34 with a display surface facing downward is provided on the upper surface side of the housing 31. The light guide 36 that guides the internal light from #35 to the liquid crystal display element 34 is stacked one after another from bottom to top, and above that is the lighting window 3 that introduces external light into the light guide 36.
7 is provided, and the ECD 18 is fitted into this lighting window 37 to regulate the light passing through the lighting window 37. In this case, as in the first embodiment, the ECD 18 is made transparent during the daytime, etc., and external light is actively taken in. On the other hand, at night, the ECD 18 is made transparent.
The CD 18 is colored to effectively prevent internal light from leaking through the lighting window 37.

Although the embodiments of the present invention have been described above in detail, they can be modified as appropriate within the scope of the gist of the present invention. For example, in the embodiment described above, a liquid crystal display element was used as the display element, but if the display element is a transmission type, a display element formed by adding a pattern or the like to a transparent acrylic plate can be used. In addition, internal light sources include lamps,
Self-luminous light sources such as discharge tubes can be used.

〔Effect of the invention〕

As described in detail above, according to the present invention, in a display device in which a housing is provided with a lighting window that takes in external light, and a display is displayed mainly by external light during the day and by internal light at night, the light can be transmitted by applying a voltage to the lighting window. By arranging an electrochromic display element whose rate changes,
By regulating the light passing through the lighting window, sufficient external light is introduced through the lighting window during the day, and at night, almost all light leakage from the lighting window is prevented, and light leaking from the housing is prevented from being reflected on the glass, etc. outside the housing. A display device that can effectively prevent this can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the first embodiment of the present invention, and FIG. 2 is an E
FIG. 3 is a sectional view showing a second embodiment of the present invention, and FIG. 4 is a sectional view showing a conventional example. 11--Housing 13-Liquid crystal display element 14--Light guide 15-Light source 17-Lighting window 18...ECD 26-Reversing switch

Claims (1)

[Claims] In a display device in which a housing is provided with a lighting window that takes in external light, and displays are displayed mainly by external light during the day and by internal light at night, an electrochromic display element whose transmittance changes with the application of voltage is disposed in the lighting window. A display device characterized by: