JP3777664B2 - Liquid crystal panel, liquid crystal display device and camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal panel, and relates to a liquid crystal panel that is useful when applied to, for example, a finder display unit such as a single-lens reflex camera or a video camera.
[0002]
[Prior art]
Conventionally, there has been a technology related to a liquid crystal focusing screen that uses a liquid crystal panel to display various shooting information such as shutter speed, aperture value, and shootable range in a finder such as a single-lens reflex camera or a video camera. Proposed.
[0003]
That is, the liquid crystal dynamic scattering mode is used to switch the focusing screen between a transmission state and a diffusion state depending on the presence or absence of an applied voltage. As an invention relating to the liquid crystal focusing screen, there is, for example, JP-A-59-195633.
[0004]
In recent years, a liquid crystal panel using a polymer dispersed liquid crystal in which a polymer substance and a liquid crystal are dispersed with each other has been proposed, and an invention applied to a focusing screen of a camera has also been proposed (for example, JP-A-3-42621). . The present invention relates to a transparent substrate having a transparent electrode on the inner surface of a layer in which a nematic liquid crystal having positive dielectric anisotropy is dispersed in a transparent polymer substance having a refractive index substantially equal to the refractive index of the liquid crystal with respect to ordinary light. In addition, a projection that refracts incident light on the inner surface of one of the transparent substrates is provided along a display pattern such as a viewfinder frame, so that a diffusion state in which focusing can be performed when no voltage is applied is provided. When a voltage is applied, a transmission state is formed, and light is refracted and seen as a pattern such as a viewfinder frame at a position where the protrusion is formed.
[0005]
[Problems to be solved by the invention]
However, the viewfinder display in the invention of the prior application is provided with a protrusion on the transparent substrate so that it can be seen by light refraction, so the contrast is not sufficient, and in particular, the shutter speed and aperture value etc. are expressed with fine characters and symbols. In the case of performing the display, there is a problem that characters and the like are unclear and inferior in visibility.
[0006]
Therefore, there has been a demand for the development of a liquid crystal panel that can clearly display shooting information while keeping the viewfinder bright.
[0007]
Therefore, the present inventor examined a focusing screen in which the viewfinder field part is composed of a liquid crystal panel of polymer type liquid crystal (PDLC) and the display part is composed of a twisted nematic (TN) liquid crystal panel having a good contrast using a polarizing plate. did.
[0008]
However, when a PDLC liquid crystal panel and a TN liquid crystal panel are combined, it has become clear that the boundary of the TN liquid crystal panel becomes conspicuous due to the presence of a polarizing plate or the like.
[0009]
An object of the present invention is to provide a liquid crystal panel that, when applied to a finder display unit such as a camera, can display various types of photographing information with good visibility while keeping the inside of the finder bright.
[0010]
Another object of the present invention is to provide a liquid crystal panel in which the boundary is not noticeable even when a PDLC liquid crystal panel and a TN liquid crystal panel are combined.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of transparent substrates, wherein the liquid crystal layer is a combination of a first liquid crystal portion and a second liquid crystal portion. And a mask region is provided on one of the transparent substrates along a boundary between the first liquid crystal unit and the second liquid crystal unit, and the mask region includes the first liquid crystal unit and the first liquid crystal unit. The light transmittance is gradually increased as the distance from the boundary with the second liquid crystal portion increases.
[0012]
For example, a polymer-dispersed liquid crystal in which a polymer is dispersed in a liquid crystal layer composed of liquid crystal molecules is sealed in the first liquid crystal portion, and a nematic liquid crystal or a strong liquid crystal is sealed in the second liquid crystal portion. Since the dielectric liquid crystal is encapsulated, for example, when a liquid crystal display device having the liquid crystal panel is applied to a display in a finder of various optical devices such as a single lens reflex camera, a video camera, a telescope, a binocular, and a microscope. Can secure brightness in the viewfinder by the first liquid crystal part having high translucency, and can display characters, symbols, etc. clearly and with good visibility on the second liquid crystal part with good contrast. .
[0013]
In addition, since the mask region is provided along the boundary between the first liquid crystal portion and the second liquid crystal portion, the boundary between the liquid crystal portions is not conspicuous, and the field of view in the viewfinder can be kept good. it can.
[0014]
The said mask area | region is comprised with the translucent metal thin film layer (chromium (Cr) etc.) formed in the inner surface of the said transparent substrate, and the translucent colored resin layer formed in the outer surface of the said transparent substrate. Thus, it becomes possible to make the boundary between the liquid crystal parts appear to have a gradation that gradually shifts from the transparent region to the opaque region.
[0015]
When the liquid crystal panel according to the present invention is applied to the display in the viewfinder as described above, the first liquid crystal unit and the second liquid crystal unit are transparent so-called reverse when no voltage is applied. It is desirable that the mode is suitable, and that the area of the first liquid crystal portion be wide and that the portion be a visual field region for confirming the subject. As a result, it is only necessary to apply a voltage only to the display portion of the second liquid crystal unit excluding the visual field region that usually occupies most of the viewfinder, so that the power consumption can be reduced and the first visual field region can be reduced. It is possible to secure a sufficient amount of light transmitted through the liquid crystal unit to make the inside of the finder bright and easy to see.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 shows a configuration example of a single-lens reflex camera to which a finder display device using a liquid crystal panel according to the present invention is applied. In FIG. 1, 1 is a camera body case, 2 is a photographing lens, 3 is a film, 4 is a reflecting mirror, 5 is a pentaprism, 6 is an eyepiece lens, and 7 is a viewfinder display panel.
[0018]
FIG. 2 is a plan view showing a schematic configuration of a liquid crystal panel P applied to the finder display panel 7, and FIG. 3 is a sectional view taken along the line AA. FIG. 4 shows a longitudinal sectional view of another embodiment of the liquid crystal panel P, and FIG. 5 shows a specific example of a pattern displayed in the viewfinder by the liquid crystal panel P according to this embodiment.
[0019]
As shown in FIG. 2 and FIG. 3, the liquid crystal panel P is a first liquid crystal unit in which a mixture 11 in which a polymer substance and liquid crystal are dispersed is enclosed between a pair of transparent glass plates 10a and 10b. The liquid crystal cell C1 is composed of a polymer dispersion type liquid crystal cell C1 and a liquid crystal cell C2 as a second liquid crystal portion in which a twisted nematic (TN) liquid crystal or a ferroelectric liquid crystal (FLC) 12 is sealed. Although not particularly limited, the liquid crystal cell C2 is provided in an L shape across the lower side and the right side of the liquid crystal cell C1.
[0020]
Transparent electrodes 13, 14, 15, 16 made of ITO (Indium-Tin Oxide) constituting segment electrodes and common electrodes are formed on the inner surfaces of the two transparent glass plates 10 a, 10 b by vapor deposition or the like. Further, an alignment film (not shown) made of polyimide or the like is applied to the surface by spin coating or the like. For example, the alignment film is subjected to an alignment process by exposing its surface and rubbing it in a predetermined direction. In this case, the alignment directions of the alignment films on each substrate are set to be orthogonal to each other, and the distance between the transparent glass plates 10a and 10b is set by a spacer (not shown) so that a gap of about 10 μm is generated between the alignment films. ing.
[0021]
In addition, a partition member 18 made of a transparent resin or the like is provided at the boundary K between the liquid crystal cells C1 and C2 of the transparent glass plates 10a and 10b, and chromium ( A translucent metal thin film layer 17 as a mask region formed by vapor deposition of Cr) or the like is provided wider than the width of the partition member 18. In this embodiment, the metal thin film layer 17 is formed in an L shape as shown in FIG.
[0022]
For example, when both the liquid crystal cell C1 and the liquid crystal C2 are made transparent when the voltage is turned off, the mask region is made of chromium (Cr) near the boundary K between the liquid crystal cells C1 and C2, as shown in FIG. Are formed such that the diameters of the dots D, D... Formed with a metal thin film such as polka dots gradually decrease as the distance from the boundary K increases. As a result, the light transmittance can be gradually increased as the distance from the boundary K increases, and the brightness in the vicinity of the boundary K appears to gradually shift in a gradation when looking through the viewfinder, thereby making the boundary K inconspicuous. can do. In order to obtain the same effect, a metal thin film layer such as chromium (Cr) may be formed so that the film thickness gradually decreases with the boundary K as the center.
[0023]
As shown in FIG. 7, when only the liquid crystal cell C1 is transparent and the L-shaped liquid crystal cell C2 is non-transparent when the voltage is off, the mask region is located on the liquid crystal cell C2 side with the boundary K interposed therebetween. Are formed such that the diameters of dots D ′, D ′,..., Such as a polka dot-like chrome (Cr) thin film, gradually become smaller as the liquid crystal cell C1 is moved to the liquid crystal cell C1 side.
[0024]
It should be noted that in the portion that extends to the boundary K, semicircular dots D ″, D ″, which are set so that the C1 side is large and the C2 side is small so that the brightness is the same on the liquid crystal cell C1 side and the C2 side. .. form.
[0025]
Thus, the change in light transmittance can be made substantially the same between the liquid crystal cell C1 side and the liquid crystal C2 side with the boundary K interposed therebetween, and the brightness near the boundary K naturally shifts when looking through the viewfinder. This makes it possible to make the boundary K inconspicuous. In order to obtain the same effect, a metal thin film layer such as chromium (Cr) that gradually decreases in thickness as it moves from the liquid crystal cell C2 side to the liquid crystal cell C2 side across the boundary K is formed. May be.
[0026]
A sealing member 19 for preventing leakage of the sealed liquid crystal is provided at the peripheral portion of the liquid crystal panel P so as to surround the liquid crystal panel P, and both end portions of the partition member 18 are in contact with the sealing member 19 to be liquid crystal. The liquid crystals of the cells C1 and C2 are divided so as not to mix with each other. Note that the seal member 19 and the partition member 18 may be formed of the same material at the same time.
[0027]
The polymer dispersed liquid crystal sealed in the liquid crystal cell C1 is, for example, a polymer prepared by irradiating ultraviolet light to a mixture of 4-biphenyl methacrylate and liquid crystal PN-001 in a ratio of 1: 9 as a polymer precursor. Or the like in which particles are dispersed in the form of particles. As a result, when no voltage is applied between the electrodes 13 and 14, a transparent state with a light transmittance of 70% is obtained, and when an alternating voltage of 30 Hz and 5 V is applied, the direction of the liquid crystal changes only at the electrode portion, and a light scattering state occurs. The liquid crystal cell has a contrast of about 15: 1. In this embodiment, the electrodes 13 and 14 are formed in the same pattern as the mark 30 shown in FIG.
[0028]
As the twisted nematic (TN) liquid crystal sealed in the liquid crystal cell C2, a general liquid crystal such as a fluorine compound is used. When a ferroelectric liquid crystal is used, a general FLC single compound is blended. A mixture or the like is employed. The electrodes 15 and 16 in the liquid crystal cell C2 are formed in the same pattern as the marks and character segments 31 to 35 shown in FIG.
[0029]
A pair of L-shaped polarizing plates 20a and 20b are provided on the outer surfaces of the transparent glass plates 10a and 10b in the region corresponding to the liquid crystal cell C2 according to the alignment direction of the liquid crystal molecules. Thus, the liquid crystal cell C2 functions as a so-called reverse mode liquid crystal cell that transmits light when there is no voltage.
[0030]
Since the liquid crystal cells C1 and C2 are both transparent in the state where no voltage is applied in this way, in the finder display panel which can be mostly transparent, the voltage is applied only to a few electrode portions having a shape corresponding to the display pattern. Therefore, power consumption can be greatly reduced.
[0031]
Further, in the finder, the portion of the liquid crystal cell C1 that becomes a visual field area for confirming the subject has a light transmittance of 70% or more, so that a bright and easy-to-view visual field area can be obtained. In the liquid crystal cell C1, key-like patterns 30, 30,... As shown in FIG. 5 are displayed so as to indicate the photographing range corresponding to the photographing mode.
[0032]
On the other hand, in the finder, the portion of the liquid crystal C2 that is mainly an area for displaying various shooting information is inferior in terms of transmittance compared to the liquid crystal cell C1 due to the presence of the polarizing plates 20a and 20b. A good (about 100: 1 or more) display can be obtained, and even a fine symbol or character can be clearly displayed with high visibility and easy to see. In the liquid crystal cell C2, for example, as shown in FIG. 5, a mark 31 representing the level of exposure, a 4-digit character segment 32 representing the shutter speed, a level meter 33 representing the subject depth, and a symbol 34 representing the state of the strobe. , Various kinds of shooting information such as a mark 35 indicating the presence or absence of focus are displayed.
[0033]
Further, a translucent metal thin film region 17 is provided wider than the partition member 18 along the partition member 18 serving as the boundary K between the liquid crystal cells C1 and C2, and has been described above with reference to FIGS. Thus, since the particle size and distribution of the dot-like vapor-deposited particles D such as chrome are adjusted so that the lightness appears to gradually shift around the boundary K, the liquid crystal cells C1 and C2 can be seen when looking through the viewfinder. The vicinity of the boundary K can be made inconspicuous by making the brightness gradually shift in a gradation shape by the metal thin film layer 17, and it is possible to configure an easy-to-see finder by reducing the uncomfortable feeling due to the boundary K.
[0034]
As described above, when the liquid crystal panel P according to the present embodiment is applied to a finder such as a single-lens reflex camera, photographing information is clearly displayed in the liquid crystal cell C2 with high visibility while ensuring sufficient brightness by the liquid crystal cell C1. It is possible to obtain a finder display that can display both brightness and liquid crystal display.
[0035]
In the present embodiment, the case where the metal thin film layer 17 is formed on the inner surface of one of the transparent glass plates 10a is described in order to make the finder easier to see without making the boundary K between the liquid crystal cells C1 and C2 inconspicuous. The configuration is not limited.
[0036]
That is, as shown in FIG. 4 (note that the same components as those in FIG. 3 described above are denoted by the same reference numerals and will not be described in detail), in the liquid crystal panel P ′ according to another embodiment, By placing a translucent colored resin (for example, methacrylate colored in clear blue) 30 with a predetermined thickness on the boundary K between the outer surface of the transparent glass plate 10a and the polarizing plate 20b so as to straddle both. A similar effect of blurring the boundary K between the cells C1 and C2 in a gradation can be obtained.
[0037]
In the above embodiment, the case where the liquid crystal panel according to the present invention is mainly applied to a finder of a single-lens reflex camera or a video camera has been described. However, the present invention is not limited to this, and brightness and ease of viewing a liquid crystal display are described. For example, it can be applied to a finder for a wide range of optical devices such as a microscope, binoculars, and a telescope.
[0038]
Furthermore, the use of the liquid crystal panel according to the present invention is not limited to a finder, and if the liquid crystal panel according to the present invention is applied to an instrument display in an automobile or other window glass, it is bright and has excellent visibility and excellent visibility. Display (for example, speed display, various operation information displays, clock display, temperature display, etc.) can be made compatible.
[0039]
The liquid crystal sealed in the liquid crystal cells C1 and C2 is not limited to the combination of PDLC and TN liquid crystal, but may be a combination of two types of liquid crystals having different transmittances such as a combination of guest-host (GH) liquid crystal and TN liquid crystal. If applicable.
[0040]
In the above embodiment, the case where the segment system is used for the display of the liquid crystal cells C1 and C2 has been described. However, the present invention is not limited to this. For example, various displays may be performed by a matrix display system. it can.
[0041]
【The invention's effect】
As described above, according to the present invention, in a liquid crystal panel including a liquid crystal layer sandwiched between a pair of transparent substrates, the liquid crystal layer is composed of a first liquid crystal unit and a second liquid crystal unit having different transmittances. For example, a polymer dispersed liquid crystal in which a polymer is dispersed in a liquid crystal layer composed of liquid crystal molecules is sealed in a first liquid crystal portion, and a nematic liquid crystal or a ferroelectric liquid crystal is sealed in a second liquid crystal portion. And a mask region is provided on one side of the transparent substrate along the boundary between the first liquid crystal portion and the second liquid crystal portion, so that a liquid crystal display provided with the liquid crystal panel is provided. When the apparatus is applied to display in a finder of various optical devices such as a single-lens reflex camera, the first liquid crystal unit with high translucency can ensure the brightness in the finder and has good contrast. Character on the second LCD There is an effect that the symbols and the like can be displayed clearly good visibility.
[0042]
In addition, since the mask region is provided along the boundary between the first liquid crystal portion and the second liquid crystal portion, the boundary between the liquid crystal portions is not conspicuous, and the field of view in the viewfinder can be kept good. it can.
[0043]
The mask region is composed of a light-transmitting metal thin film region (such as chromium (Cr)) formed on the inner surface of the transparent substrate and a light-transmitting colored resin layer formed on the outer surface of the transparent substrate. This makes it possible to make the boundary between the liquid crystal portions blur in a gradation and to appear to move naturally.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory diagram illustrating a configuration example of a camera to which a liquid crystal panel according to the present invention is applied.
FIG. 2 is a plan view showing a schematic configuration of a liquid crystal panel according to the present invention.
3 is a cross-sectional view taken along line AA of the liquid crystal panel shown in FIG.
FIG. 4 is a cross-sectional view of a liquid crystal panel according to another embodiment.
FIG. 5 is a plan view illustrating a display pattern of a viewfinder of a camera to which a liquid crystal panel according to the invention is applied.
6A and 6B are a plan view and a partially enlarged view showing a configuration example of a mask region as a main part of a liquid crystal panel according to the present invention.
7A and 7B are a plan view and a partially enlarged view showing another configuration example of a mask region as a main part of a liquid crystal panel according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Camera body case 2 Shooting lens 3 Film 4 Reflection mirror 5 Penta prism 6 Eyepiece lens 7 Finder display panel 10a, 10b Transparent glass plate (transparent substrate)
11 Polymer and liquid crystal mixture (PDLC)
12 Twisted nematic liquid crystal or ferroelectric liquid crystal 13, 15 Transparent electrode (segment electrode)
14,16 Transparent electrode (common electrode)
17 Metal thin film layer (mask area)
18 Partition member 19 Seal member 20a, 20b Polarizing plate 30 Translucent colored resin (mask region)
P Liquid crystal panel C1 Polymer liquid crystal cell (first liquid crystal part)
C2 liquid crystal cell (second liquid crystal part)
K boundary between liquid crystal cells C1 and C2

Claims (11)

A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates,
The liquid crystal layer is configured by combining a first liquid crystal part and a second liquid crystal part,
One of the transparent substrates is provided with a mask region along a boundary between the first liquid crystal part and the second liquid crystal part,
The liquid crystal panel, wherein the mask region is formed such that the light transmittance gradually increases as the distance from the boundary between the first liquid crystal portion and the second liquid crystal portion increases. A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates,
The liquid crystal layer is configured by combining a first liquid crystal part and a second liquid crystal part,
One of the transparent substrates is provided with a mask region along a boundary between the first liquid crystal part and the second liquid crystal part,
The mask region is configured such that the light transmittance gradually increases as one of the liquid crystal units moves from the other liquid crystal unit across the boundary between the first liquid crystal unit and the second liquid crystal unit. A liquid crystal panel characterized by that.   The liquid crystal panel according to claim 1, wherein the first liquid crystal portion and the second liquid crystal portion are transparent when no voltage is applied.   The other of the first liquid crystal portion and the second liquid crystal portion is transparent when no voltage is applied, and the other is opaque when no voltage is applied. 2. A liquid crystal panel according to 2.   The first liquid crystal portion is filled with polymer dispersed liquid crystal in which a polymer is dispersed in a liquid crystal layer composed of liquid crystal molecules, and the second liquid crystal portion is made of nematic liquid crystal or ferroelectric liquid crystal. The liquid crystal panel according to claim 1, wherein the liquid crystal panel is sealed.   6. The liquid crystal panel according to claim 1, wherein the mask region is a translucent metal thin film layer formed on an inner surface of the transparent substrate.   The liquid crystal panel according to claim 6, wherein the mask region is formed of a thin film layer of chromium (Cr).   The mask region is composed of a set of a plurality of dot-like chromium (Cr) thin films each having a different diameter, and the diameter of the mask region is reduced as the distance from the boundary decreases. The liquid crystal panel according to any one of 1 to 5.   6. The liquid crystal panel according to claim 1, wherein the mask region is a translucent colored resin layer formed on an outer surface of the transparent substrate.   The liquid crystal panel according to claim 1, wherein the liquid crystal panel is configured to perform separate display on the first liquid crystal unit and the second liquid crystal unit, respectively. Liquid crystal display device.   A finder configured by the liquid crystal display device according to claim 10, wherein the first liquid crystal unit is configured to be capable of displaying at least a shooting range and the like, and the second liquid crystal unit can display various shooting information. Camera characterized by.

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