JPS6311914A - Light quantity adjusting glass device - Google Patents

Abstract

PURPOSE:To always control light quantity entering a car room, etc., after passing through glass plates to the optimum value, by providing a pair of protective glass plates, light quantity control layer which is put between the glass plates and whose light transmittance is variable, and control circuit which controls the light transmittance of the light quantity control layer. CONSTITUTION:If the maximum voltage is impressed across transparent electrodes 34 and 35 by adjusting a variable resistance 52 when one's eye are dazzled by irregularly reflected light beams or the rays of the sun are strong and one feels hot, the molecular arrangement of the material constituting liquid crystal 31 is disturbed to the polarizing direction which is 90 deg. shifted from the polarizing directions of the 1st and 2nd polarizing plates 38 and 39 and the light beams advancing from the 1st polarizing plate 38 use intercepted by the liquid crystal 31 and its light quantity becomes the minimum. Since the polarizing direction of the liquid crystal 31 is made to coincide with the orientation of the 1st and 2nd polarizing plates 38 and 39 and the light beams advancing from the 1st polarizing plate 38 passe through a protective glass plate 12 through the liquid crystal 31 and 2nd polarizing plate 39 with the same light quantity, the light quantity does not drop and an excellent visual field is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a light amount adjusting glass device whose light transmittance can be controlled.

B. Conventional technology Window glasses used in automobiles, etc. are preferably close to transparent in order to ensure good visibility, but on the other hand, they block diffusely reflected light from the outside and suppress "dazzle". Or,
Alternatively, there is a desire to reduce the amount of light in order to suppress heat rays and prevent the car's room temperature from rising. For this reason, conventionally, window glass has been colored or a film has been attached to it.

In addition, near-transparent protective glass for measuring instruments is also used to make it easier to see internal devices and meters.

Problems that the C0 invention aims to solveHowever, since the transmittance of light is constant in this type of tinted window glass, if visibility at night is poor or the sunlight is extremely strong, light will pass through the glass. There is also a possibility that light cannot be suppressed sufficiently.

Furthermore, even with the protective glass of a measuring instrument, when the instrument is used in an environment with strong sunlight, it may be difficult to see the inside due to reflected light.

An object of the present invention is to provide a light amount adjusting glass device that eliminates the above-mentioned problems by adjusting the light transmittance of the glass.

Means for Solving Problem D6 The present invention provides a pair of opposing protective glasses, a light amount control layer with variable light transmittance interposed between the protective glasses, and a variable light transmittance control layer of the light amount control layer. and a control circuit for controlling the control circuit.

The light transmittance of the light amount control layer is controlled under the action of the 80 action control circuit,
The amount of light passing through the glass is adjusted.

Therefore, when the sun is strong, the amount of light is reduced to alleviate glare and heat, and at night, the amount of light is maximized to ensure good visibility.

F. Embodiment FIGS. 1 and 2 show an embodiment in which the present invention is applied to a windshield of an automobile. The windshield 1 is constructed as shown in FIG. That is, in FIG. 2, a light amount control layer 3 whose light transmittance is adjusted is sandwiched between a pair of opposing transparent protective glasses 11 and 12.

The light amount control layer 3 includes a pair of alignment films 32 sandwiching a liquid crystal 31.
, 33 are sandwiched between a pair of transparent electrodes 34.35, and the transparent electrodes 34.35 are sandwiched between a pair of glass substrates 36 and 37, and a pair of first and second polarizing plates 3 are further provided on the outermost layer.
8.39 are arranged. Here, it is assumed that the polarization directions of the first and second polarizing plates 38 and 39 are the same. Further, a liquid crystal device is constituted by a liquid crystal 31, alignment films 32, 33, transparent electrodes 34, 35, and glass substrates 36, 37.

The pair of transparent electrodes 34 and 35 are configured so that a desired Q voltage is applied from the control circuit 5, as shown in FIG. That is, the control circuit 4 includes a power source 51 and a variable resistor 52.

In the glass device configured in this way, the variable resistor 52 is used when the glass device is dazzling due to diffusely reflected light or when the sun is strong and hot.
When the maximum voltage is applied to the transparent electrode 34.35 by adjusting the voltage, the molecular alignment of the material constituting the liquid crystal 31 is disrupted and the polarization direction becomes 90 degrees different from the polarization direction of the first and second polarizing plates 38.39. , the light entering from the first polarizing plate 38 is blocked by the liquid crystal 31 and the amount of light is minimized. Furthermore, when the applied voltage is zero, the polarization direction of the liquid crystal 31 matches the directions of the first and second polarizing plates 38, 39, and the light entering from the first polarizing plate 38 is transmitted to the liquid crystal 31.39. Since the light passes through the protective glass 12 via the second polarizing plate 39 with the same amount of light, there is no reduction in the amount of light and a good visibility is ensured.

Note that if an ultraviolet filter is used, the liquid crystal 31 is not irradiated with ultraviolet rays, and the light resistance of the liquid crystal 31 is improved.

Although the present invention has been described above in the case where it is applied to the windshield of a vehicle, it can be similarly applied to the protective glass 41 of the instrument panel 4 of a measuring instrument, etc., as shown in FIG. In FIG. 3, 42 is a knob for adjusting the light transmittance of the protective glass, and the resistance value of the variable resistor as shown in FIG. 1 is controlled.

Although not shown, the present invention can also be applied to a protective glass case for a take-up. Furthermore, although the amount of light is controlled using polarized light in the above example, a light amount control layer that is colored by applied voltage may be sandwiched between a pair of protective glasses.

In order to prevent the effects of the G0 invention, the amount of light can be reduced, and the amount of light that passes through the glass and enters the interior of the vehicle can always be controlled to an optimal value.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing the case where the present invention is applied to an automobile windshield, Fig. 2 is a sectional view showing the structure of the windshield, and Fig. 3 shows an example of an instrument panel to which the present invention is applied. FIG. 1: Windshield 3: Light control layer 5: Control circuit

Claims (1)

[Scope of Claims] 1) A pair of opposing protective glasses, a light amount control layer with variable light transmittance interposed between the protective glasses, and a control circuit that controls the light transmittance of the light amount control layer; A light amount adjusting glass device characterized by comprising: 2) The light amount adjusting glass device according to claim 1, wherein the light amount control layer comprises a pair of polarizing plates and a liquid crystal device sandwiched between them.