JPH08313973A - Finder device - Google Patents

Abstract

PURPOSE: To obtain a display in a finder which can be easily seen without depending on brightness of the place where the device is used. CONSTITUTION: This finder device is equipped with a liquid crystal cell 6 comprising two glass substrates 3, 4 having transparent electrodes 2a, 2b, a polymer dispersion liquid crystal 5 held between the substrates, and light sources 7, 8 facing each other which are disposed on the side faces of the glass substrates 3, 4. When a picture is photographed in a dark place, the light sources 7, 8 are turned on. As a result, the light from the light sources 7, 8 enters the glass substrates 3, 4, propagates along the plane of the glass substrates, and enters the polymer dispersion liquid crystal 5. Because the liquid crystal molecules are dispersed in random directions in an area of the liquid crystal 5 where no voltage is applied by electrodes 2a, 2b, the light is scattered and the area can be seen bright and raised.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder device equipped with a liquid crystal display for displaying characters and figures using liquid crystal.

[0002]

2. Description of the Related Art For example, a finder system of a conventional camera incorporates a liquid crystal display to display various kinds of information necessary for photographing to enhance the operability of the camera. Conventionally, such a liquid crystal display has a structure as shown in FIG. That is, 101 is a liquid crystal cell, and polarizing plates 102 are attached to the upper and lower surfaces thereof, respectively. The liquid crystal cell 101 includes two glass substrates 104, 104 each having a transparent electrode 103, and a gap member 110 made of particles having a predetermined particle size for maintaining a constant gap between the glass substrates 104, 104. It is formed by filling the liquid crystal 105. An alignment film 106 for uniformly aligning liquid crystal molecules is interposed between the transparent electrode 103 and the liquid crystal 105. In addition, the transparent electrode 10
A power source (not shown) is connected between 3 and 103.

In the conventional liquid crystal display having such a structure,
When the power is off and no voltage is applied to the liquid crystal cell 101, incident light from the upper polarizing plate 102 is incident on the liquid crystal cell 101.
Since it passes through the inside and then the lower polarizing plate 102,
The display will be transparent. On the other hand, when the power is on and the voltage is applied to the liquid crystal cell 101, the incident light from the upper polarizing plate 102 can pass through the liquid crystal cell 101 but cannot pass through the lower polarizing plate 102. Therefore, it is displayed in black.

[0004]

However, in the liquid crystal display used in the conventional finder system, since the two polarizing plates 102 are used, the light transmittance is low and the light utilization efficiency is poor. It was not always sufficient as a transmissive display. In addition, the conventional liquid crystal display can display clearly when it is shot in a bright place because it is displayed using external natural light or illumination light, but it is not displayed when shot in a dark place. There was a problem that it would be possible. The present invention has been devised in view of such circumstances, and an object of the present invention is to provide a finder device that always realizes a clear viewfinder display regardless of whether the shooting location is bright or dark.

[0005]

In order to achieve the above object, the present invention provides an objective optical system and a transparent polymer material in which liquid crystal is dispersed and which is provided in the vicinity of an image forming position of the objective optical system.
In the finder device, the display comprising a liquid crystal cell filled between the first and second glass substrates provided with transparent electrodes and an eyepiece optical system for observing an image by the objective optical system, It is characterized by comprising a light source that emits light that enters the inside of the display from the side of the container.

According to a second aspect of the present invention, in the finder device according to the first aspect, the liquid crystal is a P-type liquid crystal, and its refractive index for ordinary rays is substantially equal to the refractive index of the polymer material. And According to a third aspect of the invention, in the finder device according to the first aspect, the liquid crystal is an N-type liquid crystal, and its refractive index for extraordinary rays is substantially equal to the refractive index of the polymer material. Claim 4
According to the invention of claim 1, in the finder device according to claim 1, the transparent electrodes in close contact with the first and second glass substrates respectively comprise a plurality of electrodes of a first group and a second group. The arrangement direction of the electrodes and the arrangement direction of the electrodes of the second group are different from each other. According to a fifth aspect of the present invention, in the finder device according to the fourth aspect, the arrangement direction of the electrodes of the first group and the arrangement direction of the electrodes of the second group are orthogonal to each other. According to a sixth aspect of the present invention, in the finder device according to the first aspect, the light source is arranged near a side portion of the display. According to a seventh aspect of the invention, in the finder device according to the first aspect, a large number of fine irregularities are formed on a side portion of the display on which light from the light source is incident. According to an eighth aspect of the invention, in the finder device according to the first aspect, a scattering member that scatters light is arranged on a side portion of the display on which light from the light source is incident. According to a ninth aspect of the present invention, in the finder device according to the first aspect, a reflecting member that reflects light to another side portion of the display device that faces a side portion of the display device on which light from the light source is incident. Are arranged close to each other. The invention of claim 10 relates to claim 9
In the finder device described above, the reflection member is a thin metal film that is in close contact with the other side portion of the display. The invention of claim 11 is the finder apparatus according to claim 9 or 10, characterized in that the other side portion of the display is a smooth surface. According to a twelfth aspect of the present invention, the light source emits, as the light entering the inside of the display, light polarized in parallel to a display surface of the display. According to a thirteenth aspect of the present invention, in the finder device according to the twelfth aspect, the light source includes a polarizing member that imparts polarized light parallel to the display surface of the display to the light emitted from the light source. . The invention of claim 14 is characterized in that it is incorporated in a camera.

According to the present invention, when the finder device is used in a bright place and a sufficient amount of light is incident from the plate surface of the glass substrate, the light source stops emitting light. In that case, the incident light passes through the glass substrate and enters the polymer material in which the liquid crystal is dispersed, that is, the polymer dispersed liquid crystal. At this time, in the region of the liquid crystal cell in which no voltage is applied, the optical axes of the liquid crystal molecules are random, and light scattering occurs at the interface between the liquid crystal and the polymer, which reduces the light transmittance. ,
The area of the liquid crystal cell is displayed in black. On the other hand, in the area of the liquid crystal cell where a voltage is applied, the optical axes of the liquid crystal molecules are aligned in the direction of the electric field, and there is no difference in the refractive index at the boundary between the liquid crystal and the polymer material, so the scattering of light weakens and the , The area is transparent.

On the other hand, when the surroundings are dark and sufficient light does not enter from the plate surface of the glass substrate, the light source is caused to emit light for use. In this case, the light from the light source enters from the side of the glass substrate, and the incident light travels along the plate surface in the glass substrate as illumination light and enters the polymer dispersed liquid crystal. At this time, in the region of the liquid crystal cell where no voltage is applied, the optical axes of the liquid crystal molecules are random,
Illumination light is scattered at the interface between the liquid crystal and the polymeric material, and that area of the liquid crystal cell appears to float in the dark background.
On the other hand, in the region of the liquid crystal cell where a voltage is applied, the optical axes of the liquid crystal molecules are aligned in the direction of the electric field, so there is no difference in the refractive index at the boundary between the liquid crystal and the polymer material, and the illumination light is scattered. Since it passes without passing through, the area becomes transparent. Therefore, according to the present invention, it is possible to display various information in the finder in an easy-to-see manner regardless of whether the place where the finder device is used is bright or dark, and to improve the operability of, for example, a camera in which the finder device is incorporated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. A finder device incorporated in a camera will be described below as an example of the finder device according to the present invention. FIG. 1 is a cross-sectional view of a liquid crystal display constituting the viewfinder device of this camera, and FIG. 2 is a plan view thereof. The liquid crystal display 1 includes a gap member (not composed of particles having a predetermined particle size) between two glass substrates 3 and 4 to which transparent electrodes 2a and 2b are closely adhered, in order to maintain a constant gap between the glass substrates. (Illustration), a liquid crystal cell 6 filled with a polymer-dispersed liquid crystal 5, and light sources 7 and 8 arranged so as to face each side surface of the glass substrates 3 and 4. The polymer-dispersed liquid crystal 5 is one in which liquid crystal droplets 12 are dispersed in a polymer material 11, and is specifically manufactured by using a material as described below. Each of the transparent electrodes 2a and 2b is composed of a plurality of electrodes as will be described later, but in order to facilitate understanding, in the following, first, the electrodes 2a and 2b will be described.
It is assumed that both 2b are one electrode.

Refractive index of glass substrate 3 and polymer dispersed liquid crystal 5
The refractive index of is that the incident light from the plate surface of the glass substrate 3 can enter the polymer dispersed liquid crystal 5 after traveling through the inside, and the incident light from the light source 7 to the side surface of the glass substrate 3 is inside the glass substrate 3. While advancing along the plate surface, it is necessary to satisfy the relationship that allows the liquid crystal to enter the polymer dispersed liquid crystal 5. This also applies to the relationship between the glass substrate 4 and the polymer dispersed liquid crystal 5. Therefore, in this example, the refractive index of each constituent element satisfies the following expression (1).

[0011]

N _g <n _o , n _e , n _p (1) where n _o is the refractive index of the liquid crystal molecule with respect to the ordinary ray, and n _e
Is the refractive index of the liquid crystal molecules to extraordinary rays, _ng is the refractive index of the glass substrate 3, and _np is the refractive index of the polymer material 11.
The materials of the polymer material 11 and the liquid crystal droplets 12 that compose the polymer-dispersed liquid crystal 5 satisfy the following conditions in terms of refractive index. That is, when the liquid crystal is P-type (dielectric anisotropy Δε> 0),

[0012]

[Number 2] n _p ≒ n _e (2) When this condition is satisfied, the voltage to the liquid crystal cell 6 is applied, the liquid crystal cell 6 becomes transparent.

When the liquid crystal is N type (dielectric anisotropy Δε <0),

[0014]

## EQU3 ## n _p ≈n _o (3) When this condition is satisfied, when a voltage is applied to the liquid crystal cell 6, the liquid crystal cell 6 becomes transparent.

The light sources 7 and 8 are preferably light emitting diodes (LEDs), for example. As shown in FIG. 2, the light source 7 is preferably arranged to face the front, rear, left and right side surfaces of the glass substrate 3. Similarly, it is preferable that the light source 8 is also arranged to face the front, rear, left and right side surfaces of the glass substrate 4. When the light sources 7 and 8 are arranged in this manner, the glass substrates 3 and 4 are arranged.
It is possible to increase the amount of incident light from the side surface of the glass substrate and to evenly distribute the incident light in the glass substrates 3 and 4.

The light sources 7 and 8 may be either one of them. Further, it is preferable that the light sources 7 and 8 are arranged to face the front, rear, left and right side surfaces of the glass substrates 3 and 4, as described above, but the amount of incident light from the side surfaces of the glass substrates 3 and 4 can be increased, and the incidence thereof can be increased. The arrangement and structure of the light sources 7 and 8 may be other than the above as long as the light can be uniformly distributed in the glass substrates 3 and 4.

Next, the liquid crystal display 1 constructed as described above.
An example of the operation will be described with reference to FIGS. 3 and 4.
Here, it is assumed that the liquid crystal is P-type. Also, the electrodes 2a,
As shown in FIG. 1, an AC power supply 10 is connected to 2b through a switch 9. First, when sufficient natural light or external illumination light is obtained and the camera shooting location is bright, and sufficient incident light is obtained from the plate surfaces of the glass substrates 3 and 4, the light emitting operations of the light sources 7 and 8 are stopped. To use. In this case, the incident light from the plate surface of the glass substrate travels in the glass substrates 3 and 4 and then enters the polymer dispersed liquid crystal 5 to travel. At this time, if the switch 9 is in the OFF state, the AC voltage V of the power supply 10 is not applied to the liquid crystal cell 6, and the optical axis of the liquid crystal droplets 12 (the long axis direction of the liquid crystal molecules) becomes random ((in FIG. 3). See B)). Therefore, as shown in FIG. 4A, light scattering occurs at the interface between the liquid crystal droplets and the polymer material, the light transmittance is reduced, and the liquid crystal cell 6 becomes an opaque black display. On the other hand, when the switch 9 is on, the voltage V of the power source 10 is applied to the liquid crystal cell 6, and the long axis direction of the liquid crystal molecules is aligned in the electric field direction ((A) in FIG. 3).
reference). Therefore, there is no difference in the refractive index at the boundary between the liquid crystal and the polymer, light scattering is weakened, and light is transmitted, so that the liquid crystal cell 6 is transparently displayed.

On the other hand, when the natural light and the external illumination light are not sufficiently obtained and the camera photographing place is dark and the incident light cannot be obtained from the plate surfaces of the glass substrates 3 and 4, the light source 7 is used. , 8 are used for light emission operation. In this case, the incident light that has entered the side surfaces of the glass substrates 3 and 4 from the light sources 7 and 8 travels inside the glass substrates 3 and 4 along the plate surface thereof and also enters the polymer dispersed liquid crystal 5 and travels. (See FIG. 4B). At this time, if the switch 9 is in the OFF state, the AC voltage V of the power source 10 is not applied to the liquid crystal cell 6, and the long axis direction of the liquid crystal molecules becomes random. Therefore, as shown in FIG. 4B, the illumination light from the light sources 7 and 8 is scattered at the interface between the liquid crystal droplets and the polymer material, and the liquid crystal cell 6 appears to float in the dark background. On the other hand, when the switch 9 is in the ON state, the AC voltage V of the power source 10 is applied to the liquid crystal cell 6 and the long axis direction of the liquid crystal molecules is aligned in the electric field direction. Therefore, there is no difference in the refractive index at the boundary between the liquid crystal droplets and the polymer material, and the illumination light from the light sources 7 and 8 is transmitted without being scattered. Further, since the incident light from the plate surface of the glass substrate is also transmitted, the liquid crystal cell 6 becomes a transparent display.

As described above, according to the liquid crystal display 1, it is possible to perform a display that is easy to see regardless of whether the photographing location of the camera is bright or dark. Further, since it is not necessary to use a polarizing plate, the utilization efficiency of light is high and a clearer display can be performed.

Next, an example of a method of manufacturing the liquid crystal cell 6 of the liquid crystal display 1 shown in FIGS. 1 and 2 will be described. First, as a liquid crystal material, BL008 (n _o = 1.
527, n _e = 1.807) and an ultraviolet curable resin (n _p = 1.524) (product number NOA65) manufactured by Norland Co., Ltd. as a polymer material. Next, the prepared liquid crystal material and polymer material are mixed with each other.
Mix 0 parts by weight and stir well.

Subsequently, the sufficiently stirred mixture is filled between two glass substrates ( _ng = 1.516) 3 and 4 to which the transparent electrodes 2a and 2b are adhered. At this time, the two glass substrates 3 and 4 are held by a certain means or a gap material is interposed so that the two glass substrates 3 and 4 are not in contact with each other and keep a constant distance. . After the mixture is filled, the filler is irradiated with ultraviolet rays to cure the polymer material, and the gap between the glass substrates 3 and 4 becomes stable. As a result, liquid crystal droplets 12 are dispersed in the polymer material 11 as shown in FIG.
A liquid crystal cell 6 having a polymer dispersed liquid crystal 5 having a predetermined thickness is completed. The size of the liquid crystal droplets 12 can be adjusted in various ways by changing the intensity of the ultraviolet rays applied to cure the polymer material.

In the method of manufacturing the liquid crystal cell 6 as described above, the weight ratio of the liquid crystal material to the polymer material is 5 to 80%.
The weight ratio can be arbitrarily selected, and the amount of ultraviolet rays for curing the polymer material can be arbitrarily selected in the range of 5 to 50 mW / cm 2. Further, the distance (gap) between the two glass substrates 3 and 4 can be arbitrarily selected within the range of 3 to 50 μm.

Next, the experimental results of the produced liquid crystal cell 6 will be described. The preparation conditions are that the weight ratio of the liquid crystal material and the polymer material is 50:60, and the layer pressure of the polymer dispersed liquid crystal 5 is 8 μ.
m, and the diameter of the liquid crystal droplets 12 is about 1 to 3 μm. Then, the relationship between the applied voltage of the liquid crystal cell 6 and the light transmittance was determined by actual measurement. Results are shown in FIG. When the applied voltage V to the liquid crystal cell 6 is 0 volt, the transmittance is 0% as shown in FIG. When the applied voltage V to the liquid crystal cell 6 is gradually increased from 0 volt, the transmittance gradually increases from 0% and then rapidly increases as shown in FIG. The transmittance is saturated. In addition to the above-mentioned liquid crystal materials, BL manufactured by Merck Ltd.
034, BL035, BL036, ML-1003 and the like can be used, and as the polymer material, acrylic resin,
Methacrylic resin, urethane acrylate resin, epoxy resin, epoxy acrylate resin and the like can be used.

Next, the transparent electrodes 2a and 2b will be described in detail. In the liquid crystal cell 6 shown in FIG. 1, in order to display characters and figures by so-called matrix display, the transparent electrode 2a has a plurality of transparent and strip-shaped electrodes (signal electrodes) as shown in FIG. The transparent electrodes 2b are arranged at a predetermined interval in the X direction, while the transparent electrodes 2b are formed by arranging a plurality of transparent strip-shaped electrodes (scanning electrodes) at a predetermined interval in the Y direction orthogonal to the X direction. Has been done. Therefore, it is possible to selectively make each region of the liquid crystal 5 transparent or opaque by sequentially applying a scanning voltage to each strip electrode of the electrode 2b and simultaneously applying a signal voltage to a necessary one of the strip electrodes of the electrode 2a. , Characters and figures can be displayed.

FIG. 7 is a sectional view showing another example of the liquid crystal display. Similar to the liquid crystal display 1 shown in FIG. 1, this liquid crystal display 31 is arranged such that the light sources 7 and 8 are opposed to each other on the side surfaces of the glass substrates 3 and 4, and the light source 32 is also arranged on the side surface of the polymer dispersed liquid crystal 5. Are opposed to each other to improve display efficiency in a dark place. The other configurations are similar to those of the liquid crystal display 1 shown in FIG. 1, and therefore, the same reference numerals are given and the description thereof is omitted.

In the liquid crystal display 31 having such a structure, the light from the light sources 7 and 8 traveling along the plate surfaces in the glass substrates 3 and 4 enters the polymer-dispersed liquid crystal 5 and the light from the light source 32 is high. The incident light on the side surface of the molecule-dispersed liquid crystal 5 is reflected by the glass substrates 3, 4
While proceeding to the inside of the liquid crystal 5 while being reflected by the inner surface of the. Therefore,
When the light from the light sources 7 and 8 is scattered by the liquid crystal molecules, the light from the light source 32 is also scattered by the liquid crystal molecules, and when the shooting place is dark, the liquid crystal cell 6 is displayed brighter and raised.

FIG. 8 is a sectional view showing still another example of the liquid crystal display. This liquid crystal display 71 is the liquid crystal display 1 of FIG.
Is different from the light sources 17 and 18 in the polarizing plate 7 respectively.
It is that it has A and 8A. Each of the light sources 17 and 18 is composed of the above-mentioned light sources 7 and 8 and polarizing plates 7A and 8A. Polarizing plates 7A and 8A are light sources 7 and 8 respectively.
Is for giving polarized light parallel to the display surface of the liquid crystal display 71, that is, the plate surfaces of the glass substrates 3 and 4 to the light emitted by the light source 7 and the light sources 7 and 8 in front of them. However, they are arranged so as to be orthogonal to the optical path of the light emitted from the light sources 7 and 8.

In the liquid crystal display 71, since the polarizing plates 7A and 8A are arranged, the glass substrates 3 and 4 are formed.
The light incident from the side surface of is the light polarized parallel to the plate surfaces of the glass substrates 3 and 4. Then, as described above, the switch 9
When is off, the illumination light from the light sources 7 and 8 is scattered, and the liquid crystal cell 6 appears to float in a dark background and becomes an opaque display. On the other hand, when the switch 9 is on, the illumination light is not scattered. Since the liquid crystal cell 6 is transparent, the liquid crystal cell 6 is in a transparent display. However, in the liquid crystal display 71, since the light incident on the glass substrates 3 and 4 is polarized as described above, the liquid crystal cell 6 in the opaque display and the transparent display is shown. The difference in transparency (or opacity) is large, and therefore, it is possible to display characters and figures with higher contrast.

Next, the entire viewfinder device of a camera incorporating such a liquid crystal display will be described with reference to the drawings. FIG. 9 is a sectional view showing a viewfinder system of a single-lens reflex camera in which the liquid crystal display 1 shown in FIG. 1 (and therefore FIG. 6) is incorporated. In FIG. 9, reference numeral 41 is a taking lens composed of a plurality of lenses, and has a diaphragm (not shown) between the lenses. The main mirror 42 passes through this photographing lens 41
The light reflected by is imaged on the focusing plate (focus plate) 43,
The image is observed by a pupil (not shown) through the liquid crystal display 1, the condenser lens 44, the pentaprism 45 and the eyepiece lens 46. In the figure, 47 is a film.

The light source 26 is composed of the light sources 7 and 8 shown in FIG. Further, a light shielding plate 48 is provided on the peripheral portion of the plate surface of the glass substrate 3 of the liquid crystal display 1 so that the light of the light source 26 does not irradiate the plate surface. As described above, the camera finder device according to the present embodiment includes the liquid crystal display 1
Since it is equipped with, the shooting information of the camera can be easily displayed in the viewfinder regardless of whether the shooting location of the camera is dark or light.
Therefore, the operability of the camera can be improved.

FIG. 10 is a sectional view showing a viewfinder device of a single-lens reflex camera which is an improvement of the liquid crystal display 1. In the liquid crystal display 51 of this finder device, the liquid crystal display 1
As described above, the light from the light sources 7 and 8 is not directly incident on the glass substrates 3 and 4, but the light from the light source 52 is guided to each side surface of the glass substrates 3 and 4 via the prism 53. Since other configurations are similar to those in the case of FIG. 9, the same reference numerals are given and the description thereof is omitted.

FIG. 11 is an exploded perspective view showing an example of a real image type finder device of a compact camera, in which a liquid crystal display 21 of the same type as the liquid crystal display 1 of FIG. 1 is incorporated as a focusing screen. In this case, the objective lens 61
Liquid crystal display 2 in which light passing through ~ 63 functions as a focusing screen
1, and this image is observed by the pupil through the prism 64 and the eyepiece lens 65.

In the above-mentioned embodiment, the light sources 7 and 8 are arranged so as to face each other with the glass substrates 3 and 4 sandwiched therebetween, but the light sources may be arranged only on one side to secure a sufficient amount of illumination light. It is possible. That is, as shown in FIG. 12, a light reflection plate 72 is arranged on the side of the liquid crystal cell 6 opposite to the light sources 7 and 8. In this case, the light that has entered the glass substrates 3 and 4 from the light sources 7 and 8 and has exited from the end portion on the opposite side of the glass substrate is reflected by the reflection plate 72 and again enters the glass substrate. To do. Therefore, the lights emitted from the light sources 7 and 8 function as illumination light without waste, and a clear display can be realized. It should be noted that the side portions of the glass substrates 3 and 4 on the side of the reflection plate 72 have less loss as the light transmittance is higher, and thus it is desirable to have a surface as smooth as possible. In addition, the reflector 72
May be formed by adhering a thin film of metal such as aluminum to the end portion of the liquid crystal cell 6, or may be formed by vapor deposition of metal such as aluminum. Such a configuration in which the illumination light is reflected at the end of the liquid crystal cell can also be applied to the liquid crystal display of the type shown in FIG. In the liquid crystal display shown in FIG. 1 or 7, the light from the light sources 7, 8, 32 is incident.
It is preferable that the side portions of the liquid crystal cell 6 scatter light to some extent. Therefore, for example, a large number of fine irregularities may be formed on the side surface thereof, or a scattering plate for scattering light may be arranged on the side portion of the display. By scattering the incident light, the light that enters the liquid crystal 5 from the glass substrate or the light that enters from the side of the liquid crystal 5 and is reflected on the inner surface of the glass substrate becomes uniform regardless of the location and prevents uneven display. it can.

[0034]

As described above, according to the present invention, the first objective optical system and the transparent polymer material provided in the vicinity of the image forming position of the objective optical system and having the liquid crystal dispersed therein are provided with the transparent electrodes.
In a finder device including a display device composed of a liquid crystal cell filled between the second glass substrate and an eyepiece optical system for observing an image by the objective optical system, the inside of the display device from the side of the display device. Since a light source that emits light that enters the finder device is provided, various information can be displayed easily in the finder regardless of whether the place where the finder device is used is visible, and the operability of, for example, a camera in which the finder device is incorporated is improved. be able to. Since it is not necessary to attach a polarizing plate to the plate surface of the glass substrate as in the conventional display device, the light utilization efficiency is high, and in this respect also, clear display in the viewfinder is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a liquid crystal display constituting a finder device according to the present invention.

FIG. 2 is a plan view showing the liquid crystal display of FIG.

FIG. 3 is an explanatory diagram of an operation depending on whether or not a voltage is applied to the liquid crystal cell.

FIG. 4 is an explanatory diagram of a display state of a liquid crystal cell.

FIG. 5 is a diagram showing an example of the relationship between the applied voltage and the transmittance of a liquid crystal cell.

FIG. 6 is a perspective view showing in detail a transparent electrode which constitutes the liquid crystal display of FIG.

FIG. 7 is a cross-sectional view showing another example of a liquid crystal display.

FIG. 8 is a sectional view showing still another example of a liquid crystal display.

FIG. 9 is a cross-sectional view showing a viewfinder device of a single-lens reflex camera provided with a liquid crystal display.

FIG. 10 is a cross-sectional view showing a viewfinder device of a single-lens reflex camera equipped with a liquid crystal display.

FIG. 11 is a developed perspective view showing a real image type viewfinder device of a compact camera including a liquid crystal display.

FIG. 12 is a cross-sectional view showing a liquid crystal display using a reflector.

FIG. 13 is a perspective view of a conventional liquid crystal display.

[Explanation of symbols]

 1, 21, 31, 51, 71 Liquid crystal display 2 Polarizing plate 2a, 2b Transparent electrode 3, 4 Glass substrate 5 Polymer dispersed liquid crystal 6 Liquid crystal cell 7, 8, 26, 32, 52 Light source 7A, 8A Polarizing plate 11 High Molecular material 12 Liquid crystal droplets 41 Photographic lens 42 Main mirror 43 Focus plate 44 Condenser lens 45 Penta prism 46 Eyepiece 48 Light shield plate 53 Prism 72 Reflector plate

Claims (14)

[Claims] 1. An objective optical system and a transparent polymer material provided in the vicinity of an image forming position of the objective optical system, in which liquid crystals are dispersed, between a first and a second glass substrate provided with a transparent electrode. In a finder device including a display composed of a filled liquid crystal cell and an eyepiece optical system for observing an image by the objective optical system, emitting light entering the inside of the display from a side portion of the display. A finder device having a light source. 2. The finder device according to claim 1, wherein the liquid crystal is a P-type liquid crystal, and its refractive index for ordinary rays is substantially equal to the refractive index of the polymer material. 3. The finder device according to claim 1, wherein the liquid crystal is N-type liquid crystal, and its refractive index for extraordinary rays is substantially equal to the refractive index of the polymer material. 4. The transparent electrodes, which are in close contact with the first and second glass substrates, respectively, are composed of a plurality of electrodes of a first group and a second group, respectively. The viewfinder device for a camera according to claim 1, wherein the arrangement directions of the electrodes of the two groups are different. 5. The arrangement direction of the electrodes of the first group and the second direction
The finder device according to claim 4, wherein the arranging directions of the electrodes of the group are orthogonal to each other. 6. The finder device according to claim 1, wherein the light source is arranged near a side portion of the display. 7. The finder device according to claim 1, wherein a large number of fine irregularities are formed on a side portion of the display on which light from the light source is incident. 8. The finder device according to claim 1, wherein a scattering member that scatters light is arranged on a side portion of the display device on which light from the light source is incident. 9. A reflecting member for reflecting light is arranged in proximity to the other side portion of the display unit, which is opposite to the side portion of the display unit on which the light from the light source is incident. Finder device described. 10. The finder device according to claim 9, wherein the reflection member is a thin film of metal that is in close contact with the other side portion of the display. 11. The viewfinder device according to claim 9, wherein the other side portion of the display is a smooth surface. 12. The finder device according to claim 1, wherein the light source emits, as the light entering the inside of the display, light polarized in parallel to a display surface of the display. 13. The finder device according to claim 12, wherein the light source includes a polarizing member that imparts polarized light parallel to the display surface of the display to the light emitted from the light source. 14. The finder device according to claim 1, which is incorporated in a camera.