JPS6156319A - Liquid crystal shutter device - Google Patents

Abstract

PURPOSE:To obtain a shutter device with can display a neutral tint by constituting the respective liquid crystal elements provided in each area of a path of light, so that light of each wavelength being different from each other of an incident light can be made to pass through and cut selectively. CONSTITUTION:A light which is made incident from the right of a liquid crystal shutter device 5 is polarized when it passes through a polarizing plate 11, also passes through filters 12, 13 and 14 through a glass substrate 10, and red, green and blue lights are obtained, respectively. These lights transmit through transparent electrodes 19, 20 and 21. At this time, in case when a voltage is applied, for instance, between the electrodes 19, 25, the red light which has transmitted through a liquid crystal 33a transmits through a polalizing plate 24. However, when no voltage is applied, the direction of a molecular axis of the liquid crystal 33a is twisted, and the polarized red light which is made incident on the liquid crystal 33a is cut off by the polarizing plate 24, and cannot transmit through the device 5. Other green light and blue light are also constituted in the same way. in such a way with respect to each of the red light, the green light and the blue light, a shutter operation of transmission and cut-off can be realized, and accordingly, a neutral tint can also be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a liquid crystal shutter device used in a so-called hard copy device included in a video recording/playback device.

BACKGROUND ART In conventional so-called hard copy devices such as video devices, a liquid crystal shutter device has been used in a monochrome printer device. This liquid crystal shutter device transmits or blocks light from a light source to selectively form an image on photosensitive paper. In this shutter device, there was no intermediate gradation between black display and white display on the photosensitive paper, and color display was not possible.

In addition, a color printer device does not use a liquid crystal shutter device, but instead uses an optical system such as a lens to form an optical image displayed on a cathode ray tube, which is an optical display device, onto photosensitive paper. had obtained a printed copy. In such color printer devices, image distortion caused by the distortion of the optical image formed on the cathode ray tube appears on the printed matter, and the size of the printed matter is basically limited by the size of the cathode ray tube. In addition, there were other problems such as the color printer itself becoming larger.

Problems to be Solved by the Invention It is an object of the present invention to solve the above-mentioned problems and provide a liquid crystal shutter device constituting a color printer device capable of displaying intermediate colors.

Means for Solving the Problems The present invention provides a liquid crystal shutter device that is interposed in a light path and that passes or blocks light. Each @ region is provided with a liquid crystal element having a characteristic of transmittance for each mutually different wavelength of the light passing through the passage, and each liquid crystal element in each region has a mutually This is a liquid crystal shutter device characterized by selectively passing and blocking light of different wavelengths.

Embodiment FIG. 1 is a perspective view of a liquid crystal shutter device 5 according to an embodiment of the present invention, and FIG. 2 is a system diagram for explaining the basic configuration of an optical printer device 2 using the liquid crystal shutter device 5. be. The configuration and operating state of the optical printer device 2 will be explained using FIG. The optical printer device 2 condenses light from a light source 3 using a condensing means 4 such as a lens. The light that has passed through the condensing means 4 is incident on the liquid crystal shutter device 5, and is separated into three color lights, for example red, green, and blue, as will be described later.

A so-called shutter operation of the liquid crystal shutter device 5, which will be described later, is controlled by a control device 6.

At this time, the liquid crystal shutter device 5 is arranged so as to extend in a direction f''ii perpendicular to the conveying direction of the photosensitive paper indicated by the arrow A and in a direction parallel to the photosensitive paper. Further, the length Lf'i in the longitudinal direction of the liquid crystal shutter device 5 is, for example, about 30 cm.
The length in the direction of arrow A can be, for example, about 1 cm.

The light that passes through the liquid crystal shutter device 5 and is separated into three colors of light enters the photosensitive paper that is conveyed in the vertical direction in Figures 4 to 12 by the rows 28 and 9, and the ratio of the light distribution of the three colors is determined. Colors are developed on photosensitive paper according to the color.

FIG. 1 is a cross-sectional view of a portion that is a unit of operation of the liquid crystal shutter device 5, and FIG. 3 is an exploded perspective view of the liquid crystal shutter device 5 of FIG. The configuration and operating state of the liquid crystal shutter device 5 will be explained using FIG. 1 and FIG. 3. The glass substrate 10 is formed into a plate shape from, for example, borosilicate glass, and a polarizing plate 11 is formed on its surface. On the surface of the glass substrate 10 opposite to the surface facing the polarizing plate 11, there are filters 12, 13, 14, each having a characteristic of passing only light of a predetermined wavelength. Light blocking body 15, 16, 1 such as Niraglu
It is composed of 7.18.

A plurality of transparent electrodes 19, 20, 21 are formed of indium oxide or the like on the surface of the filters 12, 13, 14 opposite to the surface facing the glass substrate 10.

An alignment film 22 made of a polymeric material such as polyimide is formed overlying the transparent electrodes 19, 20, 21, and the like.

The counter glass substrate 23 is also formed into a plate shape from borosilicate glass, and a polarizing plate 24 is formed on the front surface thereof. On the surface of the opposite glass substrate 23 opposite to the surface facing the polarizing plate 24, transparent electrodes 25, 26 made of, for example, indium oxide are provided.
．． 27 is deposited.

An alignment film 28 made of polyimide or the like is formed to cover the transparent conductors 25, 26, and 27. The above-mentioned transparent electrode 25. ~
, 27 extend in the front-rear direction of the paper surface of FIG.
Transparent electrodes 19.h~, 21 and parallel to the light shields 15°~, 18, etc. ~.

21.

Transparent electrode 19. as described above. ~, 21 and 25, ~,
Each of the glass substrates 1o and 23 provided with 27 and the like is opposed so that the alignment films 22 and 28 formed on the respective surfaces face each other, and support members 29 and 30 are placed between the alignment films 22 and 28.
, 31, 32. At this time, the orientation [22
, 28 and support member 29. ~, 32 space 33. j4, 35 are twisted nematic liquid crystals 33a, 3 with different optical characteristics as described later.
4a and 35a are enclosed. Further, the transparent electrodes 25, 26, and 27 of the operating unit portion shown in the third figure are respectively transparent electrodes 1
9, 20, and 21 are located at the same position in the left stone direction in FIG. 3, and filters 12, 13, and 14 are arranged at the same positions as these positions.

The operating state of the liquid crystal shutter device 5 having the above structure will be explained with reference to FIG. Here, the filter 12,
13 and 14 have the property of transmitting only red, green, and blue, respectively.

Further, the relationship between the direction of polarization of the polarizing plates 11 and 24 and the twisting of light when passing through the liquid crystal is set so that the light passes through the liquid crystal shutter device 5 when a voltage is applied.

As mentioned above, the liquid crystals 33a, 34a, and 35a are configured to transmit or block light of different colors, respectively.In order to increase the contrast regarding the light of each color when the shutter is operated, the following is done. . Regarding the liquid crystal shutter device 5 of this embodiment, which is a field effect liquid crystal display element (hereinafter abbreviated as TN-FEM LCD) using twisted nematic liquid crystal, the refractive index in the molecular axis direction of the liquid crystal to be injected and the molecular axis Let Δn be the difference between the refractive index in the vertical direction, d be the length of the liquid crystal injection portion in the thickness direction, and let the wavelength of the incident light be Δn. Regarding the light transmittance Ts obtained at this time, the following Gooch-T
By the above first equation in which the equation of arry holds true, ^=
450 nm, 550 rLm.

In each case of 650 nm, change (d・Δn),
FIG. 4 is a graph showing the value of Ts. (In 100 is for λ=45On=m, and lie:/1
01 is for λ=55t)nm, and line 10-2
is the case when λ=650 nm. As shown in FIG. 4, if the wavelength of the light incident on the liquid crystal differs, the value of d·Δn that minimizes the transmittance Ts differs. Therefore, in order to improve the cost of the shutter operation of the liquid crystal shutter device 5, the liquid crystals 33a, 34a, 35a corresponding to each color light are
The numerical value (d·Δn) for lCN needs to be determined so that the transmittance Ts becomes minimum.

Assuming that the length d is a predetermined constant value,
By appropriately determining the value Δn indicating the optical anisotropy of the liquid crystal, the liquid crystal 3
Let the respective numerical values (d·Δn) regarding 3a, 34a, and 35aK be the values at points PL, P2°P3 in FIG. Such liquid crystal 33a, 3
By using 4a and 35a for the paths of red, green, and blue light, respectively, it is possible to have a minimum M transmittance for each light when no voltage is applied.

Referring to FIG. 1ml, light from a light source that enters the liquid crystal shutter device 5 having the above-described configuration from the right side in FIG. 1 is polarized when it passes through the polarizing plate 11. The polarized light passes through filters 12, 13, and 14 via the glass base &10, and red, green, and blue lights are obtained, respectively. These lights pass through the transparent electrodes 19, 20, 21. At this time, for example, when a voltage is applied between the electrodes 19 and 25, the red light transmitted through the liquid crystal 33a is transmitted through the polarizing plate 24. The same applies to other green light and blue light.

On the other hand, when no voltage is applied between the electrodes 19 and 25, the direction of the molecular axis of the liquid crystal 33a is twisted, and the polarized red light incident on the liquid crystal 33a is blocked by the polarizing plate 24 and cannot pass through the liquid crystal shutter device 5. . The same applies to other green light and blue light.

In this way, the shutter operation of transmitting and blocking red light, green light, and blue light, respectively, was realized. At this time, the filters 12, 13.14 are connected to the pair of glass substrates 10.
Since the filters 12, 13 .
It was possible to prevent external influences on the liquid crystal shutter device 14, and to significantly improve the reliability of the liquid crystal shutter device 5 during actual operation.

The contrast value for each color light obtained by the above-mentioned shutter pre-work of the liquid crystal shutter device 5 having the above configuration and operating state, that is, (transmittance when voltage is applied)
/ (transmittance when no voltage is applied) was able to achieve a value of 200 or more according to experiments by the inventor of the present invention. In this experiment, a liquid crystal shutter device similar to that shown in Fig. 1 was used, and E-Merck's ZLI-2244 was used as the liquid crystal material.
/100 (Δn=0.075) and ZLI-2008
/100 (Δn=0.15) to give a favorable value of Δn, and LLC2-79-185 manufactured by Sanritsu Electric Co., Ltd. was used as the polarizing plate 11.24.

In the above embodiment, the value of (d・Δn) that gives the minimum transmittance value for each color light of red light, green light, and blue light is d.
was obtained by fixing Δn to a constant value and varying Δn. That is, the first
In the figure, the length d was kept constant and the composition of the liquid crystal was varied. However, the present invention is not limited to such embodiments, and may be realized by keeping the liquid crystal composition constant and varying the lengths d of the spaces 33, 34, and 35 in FIG.

Effects According to the present invention as described above, double-channel liquid crystal elements are provided to which the light from the light source enters, and filters are provided inside these liquid crystal elements to control the light from the light source at a predetermined wavelength. This allows only the light that is present to pass through, and selectively passes or blocks this light at a large light amount ratio by the action of a liquid crystal or the like. Therefore, a liquid crystal shutter device capable of displaying intermediate colors and capable of configuring a highly reliable color printer device has been realized.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a part of the liquid crystal shutter device 5 according to an embodiment of the present invention, FIG. 2 is a simplified system diagram of the optical printer device 2, and FIG. FIG. 4, which is a partially exploded perspective view, is a grab for explaining the operating state of the liquid crystal shutter device 5. 5... Liquid crystal shutter device, 10.23... Glass substrate, 11.24... Polarizing plate, 1g, 20, 21ii2
5.26,27...transparent electrode, 121,1'3.,1
-4...Filter, 22.28...Alignment film,
33a, 34a, 35a...LCD agent Patent attorney Kei Hyakkyo Part 1 Figure 1

Claims (1)

[Claims] A liquid crystal shutter device that is interposed in a light path and passes or blocks light, comprising a plurality of regions that are distributed across the path and that pass or block light, each region including: Liquid crystal elements having different transmittance characteristics for different wavelengths of light passing through the passage are provided, and each liquid crystal element in each region selectively transmits light of different wavelengths of incident light. The liquid crystal element includes a pair of substrates, transparent electrodes disposed at opposing positions on each substrate, an alignment film covering each transparent electrode, and a liquid crystal interposed between the alignment films. . A liquid crystal shutter device, characterized in that a plurality of filters are provided between the substrate and the liquid crystal on the upstream side in the direction of light incidence, allowing only light of wavelengths blocked by the liquid crystal to pass through.