JPH08313858A - Liquid crystal optical element and formation of film on translucent substrate used for liquid crystal optical element - Google Patents

Abstract

PURPOSE: To add higher freedom to the selection of an electrical connection system to driving circuits without inducing the degradation in the performance as liquid crystal etalon. CONSTITUTION: A first projecting part 53a is formed by projecting one glass substrate 53 from the other glass substrate 51. A first conductive film part 77 is formed on the transparent electrode 61a of the first projecting part 53a and a third conductive film part is formed on the transparent electrode 61 of the first projecting part 53a respectively by a plating method so as to be made flush with a reflection film 65. A second conductive film part 79 is formed on the transparent electrode 59 in the second projecting part 51a of another glass substrate 51 as well by the plating method so as to be made flush with a reflection film 63. The first and second conduction film parts 77, 79 are conducted to each other by conductive paste 81. The first projecting part 53a of the glass substrate 53 is provided thereon with a third conductive film part in addition to the first conductive film part 77. The first conductive film part 77 and the third conductive film part are the electrode taking-out parts to the external driving circuits.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a liquid crystal is sealed between a pair of transparent substrates, and incident light is repeatedly reflected by a reflective film provided on the inner surfaces of both transparent substrates so that only light of a specific wavelength is emitted. Relates to a liquid crystal optical element that selectively transmits.

[0002]

2. Description of the Related Art A Fabry-Perot etalon, which is one of optical elements, has a structure in which a pair of translucent substrates having a reflective film on the inner surface are arranged at a fixed interval and are superposed on each other. Then, when light is incident on this, reflection of the incident light is repeated by the reflection films of both substrates, and only a specific wavelength in phase is selectively transmitted through this etalon.

The transmission wavelength λ is represented by λ = 2nd / m. However, n: Refractive index of a substance arranged between transparent substrates d: Distance between transparent substrates m: Order of reflection Transparent electrodes are provided on a pair of transparent substrates in the above etalon by providing transparent electrodes. By enclosing a liquid crystal in between, the refractive index can be changed by controlling the voltage due to the birefringence of the liquid crystal, and the wavelength of the light transmitted through the etalon can be selected by the voltage. Can be used as a filter.

FIG. 6 is a sectional view showing the structure of a liquid crystal etalon. In this liquid crystal etalon, the glass substrates 1 and 3 are alternately arranged to expose each end of the transparent electrodes 9 and 11 to the outside, and the exposed transparent electrodes 9 and 11 are used as electrode extraction portions to the outside. As a specific method for extracting such an electrode, there is a method as shown in FIGS. 7 and 8, for example.

In the structure shown in FIG. 7, the liquid crystal etalon 27 shown in FIG. 6 is arranged between a circuit board 29 having a drive circuit for driving the liquid crystal etalon 27 and a holding member 31, and the upper side is arranged. Exposed transparent electrode 9 on glass substrate 1
And a conductive portion of the circuit board 29, and between the exposed transparent electrode 11 and the holding member 31 of the lower glass substrate 3, a conductive rubber connector 33 and a conductive rubber connector 33, respectively.
35 are arranged. One end of an FPC (flexible circuit board) 37 is provided between the conductive rubber connector 35 and the holding member 31, and the other end of the FPC 37 is connected to the circuit board 29 side. In this state, the circuit board 29 and the holding member 31 are clamped and fixed by the bolt 39 and the nut 41, so that the conductive rubber connectors 33 and 35 are pressed and the circuit board 29 and the liquid crystal etalon 27 can be electrically connected. Becomes

In the structure of FIG. 8, a conductive adhesive 43 is applied to the exposed transparent electrodes 9 and 11 of the upper and lower glass substrates 1 and 3, and one end of a lead wire 45 is connected to the conductive adhesive 43.
The other end of the lead wire 45 is connected to a circuit board (not shown).

On the other hand, in the liquid crystal panel used in the general segment type liquid crystal display, as shown in FIG. 9, the reflective film 13 is provided for the liquid crystal etalon shown in FIG.
15 is unnecessary, and in such a liquid crystal panel,
With respect to the electrode 9 of the upper glass substrate 1, the electrode formed on the lower glass substrate 3 (this electrode is in a non-conducting state with the electrode 11 on the glass substrate 3) is transferred through a transfer 47 made of a conductive paste. It is configured to energize.

[0008]

When taking out the electrode terminals to the outside, comparing the method performed from the upper and lower glass substrates like a liquid crystal etalon with the method performed from one glass substrate like a liquid crystal panel, A liquid crystal panel having the same electrode connection surface has more freedom in selection of electrical connection methods such as a conductive rubber connector, a pin terminal, an FPC, and a thermocompression bonding film connector typified by heat seal. The mounting structure design becomes easy.

When a liquid crystal panel system which facilitates the design of the mounting structure is applied to a liquid crystal etalon, the liquid crystal etalon has a reflective film on a transparent electrode, and the reflective film is a dielectric multilayer film having a thickness of about 2 μm. Therefore, even if a conductive paste forming the transfer is printed thereon, electrical continuity cannot be secured. Further, there is also a method of printing a conductive paste on the transparent electrode outside the reflection film, but the print control cannot be sufficiently performed because of the reflection film, which is required for the liquid crystal etalon.
Since the gap, which is the distance between the glass substrates, cannot be controlled, the performance is degraded.

Therefore, an object of the present invention is to make the selection of the electrical connection method to the drive circuit more liberal without causing the performance deterioration as the liquid crystal optical element.

[0011]

In order to achieve the above object, the present invention forms a transparent electrode, a reflective film, and a liquid crystal alignment film in this order on the surfaces of a pair of translucent substrates that face each other. Then, in the liquid crystal optical element in which liquid crystal is sealed between the pair of translucent substrates formed with the film, the pair of translucent substrates are:
Each has a protrusion that protrudes from the portion where the liquid crystal is sealed, and the surface of the protrusion of the one transparent substrate facing the other transparent substrate has a third surface on the transparent electrode.
A conductive film portion and a first conductive film portion provided on the translucent substrate in a non-contact state with the transparent electrode including the third conductive film portion and on the same surface as the reflective film. A surface of the protruding portion of the other translucent substrate facing the one translucent substrate has the same surface as the reflective film facing a part of the first conductive film portion. To this end, a second conductive film portion is provided on the transparent electrode, and a conductive portion is provided between each of the first and second conductive film portions to electrically connect them. .

[0012]

According to the liquid crystal optical element having such a structure, the electrodes can be taken out from the third conductive film portion and the first conductive film portion on the protruding portion of the one transparent substrate, so that the drive circuit is provided. The selection of the electrical connection method to the circuit becomes free, and the mounting structure design of the liquid crystal optical element on the circuit board becomes easy. Further, since the first, second, and third conductive film portions can be formed by vapor deposition, plating, or the like, it is easy to form the same surface with respect to the reflective film, and the gap control between the translucent substrates can be enhanced. Accuracy can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a liquid crystal etalon which is a liquid crystal optical element showing an embodiment of the present invention. This liquid crystal etalon, like the one shown in FIG. 6, has anti-reflection films 55, 57 on the outside of two transparent glass substrates 51, 53 as a pair of translucent substrates which are arranged to face each other. While forming a film, a transparent electrode (mainly ITO: Indium
Tin Oxide) 59, 61, reflective films 63, 65, alignment film 6
7, 69 are sequentially formed into a film, and the film-formed glass substrate 51,
A liquid crystal 71 is sealed between 53. The outer peripheral portions of the liquid crystal 71 and the alignment films 67 and 69 are sealed with a sealing material 73, and the glass substrate 5 is placed inside the sealing material 73.
A spacer 75 is provided to keep the distance between 1 and 53 constant.

Each of the two glass substrates 51 and 53 has projecting portions 51a and 53a which project to the right in the drawing from the portion in which the liquid crystal 71 is enclosed, and one glass substrate 53 side is the first projecting portion. The portion 53a and the other glass substrate 51 side are referred to as second protrusions 51a. First protrusion 53 on the glass substrate 53 side
a further projects from the second projecting portion 51a on the glass substrate 51 side, and the glass substrate 53 is formed longer than the glass substrate 51.

FIG. 2A is a plan view of the lower glass substrate 53 in FIG. 1 with the alignment film 69 omitted, and FIG. 2B is a sectional view taken along line AA of FIG. 2A. is there. Figure 2
In the lower right corner in (a), a transparent electrode 61a is formed which is separated by an electrode non-forming portion 53b in which the transparent electrode 61 is not formed, and the first conductive film portion 77 is formed on the transparent electrode 61a. Are formed at a distance t, that is, in a non-contact state with the transparent electrode 61. First conductive film portion 7
As shown in FIG. 2B, 7 is formed so as to form the same surface as the reflection film 65. The reflection film 65 is not formed on the portion of the first protruding portion 53a that protrudes from the second protruding portion 51a, and this portion is formed with the third conductive film portion 78 at the same time when the first conductive film portion 77 is formed. , The first conductive film portion 7
It is formed so as to be on the same plane as 7.

FIG. 3 (a) is a bottom view of the upper glass substrate 51 in FIG. 1 with the alignment film 67 omitted, and FIG. 3 (b) is a sectional view taken along line BB of FIG. 3 (a). is there. FIG.
The second conductive film portion 79 is formed on the transparent electrode 59 in the upper right corner (a facing the first conductive film portion 77 of the glass substrate 53 in the assembled state of FIG. 1) in FIG. The film is formed so as to form the same surface as 63.

The method for forming the reflective films 63 and 65 is as shown in FIG.
The reflective film 65 is formed on the glass substrate 53 on which
Are patterned as shown by the diagonal lines. The patterning method may be either mask vapor deposition or etching after blanket vapor deposition.

The first, second, and third conductive film portions 77, 7
9 and 78 are formed by patterning the reflection films 63 and 65 and then formed into a film. As a method therefor, there is vapor deposition or plating of a metal film. In this example, the film thickness is relatively large, and in such a case, a plating method capable of forming a thick film is preferable. In the plating method, first, on the transparent electrode 59 of the glass substrate 51 and the transparent electrodes 61, 61a of the glass substrate 53 on which the reflective films 63 and 65 are patterned, electroless plating of nickel (Ni) (film thickness of about 0) is performed. 0.5 μm) to form a low resistance electrode, and gold (A
u) displacement plating (film thickness of about 0.05 μm) is applied, and finally gold (Au) is electroplated. The film thickness is controlled by the amount of electricity during plating. In addition, as the film forming material,
It is not limited to Ni and Au.

The portion of the first conductive film portion 77 thus formed facing the second conductive film portion 79, or the second conductive film portion 79.
A conductive paste 81 as a conductive portion is formed on the conductive film portion 79.
Is printed or applied, and in this state both glass substrates 51, 5
As shown in FIG. 1, the first three
The conductive film portion 77 and the second conductive film portion 79 are electrically connected by the conductive paste 81. Around the conductive paste 81, a sealing material 83 similar to that provided around the spacer 75 is provided. In this state, the first conductive film portion 77 becomes an electrode extraction portion to the outside through the second conductive film portion 79 and the conductive paste 81 with respect to the transparent electrode 59 on the glass substrate 51 side, while the third conductive film portion 77 is formed. The conductive film portion 78 serves as an electrode lead-out portion to the outside of the transparent electrode 61 on the glass substrate 53 side, and by energizing each of these electrode lead-out portions, a voltage is applied between the transparent electrodes 59 and 61 to cause a liquid crystal etalon. Will be driven.

FIG. 5 shows the liquid crystal etalon 8 shown in FIG.
Circuit board 8 provided with a drive circuit for driving
7 shows a mounting structure for No. 7. In FIG. 5A, the two pin terminals 89 are sandwiched by the sandwiching portions 89 a of the first conductive film portion 77.
And the third conductive film portion 78 so as to be in contact with the first protruding portion 53a of the glass substrate 53, and the leg portions 89b thereof are connected to the conductive portion of the circuit board 87.

In FIG. 5B, one end of the conductive rubber connector 91 having the same thickness is in contact with the first conductive film portion 77 and the third conductive film portion 78, and the other end is in contact with the circuit board 87. In this state, the liquid crystal etalon 85 is fixed to the holder 93. The holder 93 is composed of an L-shaped body portion 93a and a spring member 93b.
By sandwiching the liquid crystal etalon 85 via the circuit board 87 between the spring member 93b and the spring member 93b, the conductive rubber connector 91 is pressed, and the circuit board 87 and the liquid crystal etalon 85 can be electrically connected. The circuit board 87 may be a flexible wiring board.

According to the liquid crystal etalon as described above, the transparent electrodes 59 and 61 on the pair of glass substrates 51 and 53 are provided.
Since the electrodes can be taken out only from the one glass substrate 53 having the third conductive film portion 78 and the first conductive film portion 77, the liquid crystal etalon can be mounted on the circuit board as shown in FIG. As shown, the electrical connection system such as the conductive rubber connector 91 and the pin terminal 89, the thermo-compression film connector represented by the FPC and the heat seal can be freely set, and the mounting structure design can be facilitated. The assembly process can be simplified.

The first, second, and third conductive film portions 7 are also provided.
7, 79 and 78 are formed on the transparent electrodes 61a, 59 and 61 outside the patterned reflective films 65 and 63 by plating, respectively, so that they are easily formed on the same surface as the reflective films 65 and 63, and the liquid crystal High-precision gap control required for etalons is also easy.

[0025]

As described above, according to the present invention, the electrodes can be taken out from the third conductive film portion and the first conductive film portion on the protruding portion of the one transparent substrate. The selection of the electrical connection method to the drive circuit becomes free, and the mounting structure design of the liquid crystal optical element on the circuit board can be facilitated. Further, since the first, second, and third conductive film portions can be formed by vapor deposition, plating, or the like, it is easy to form the same surface with respect to the reflective film, and the gap control between the translucent substrates can be enhanced. Accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal etalon showing an embodiment of the present invention.

2 (a) is a plan view of the lower glass substrate in FIG. 1 with the alignment film omitted, and FIG. 2 (b) is A-A of (a).
It is sectional drawing.

3A is a bottom view of the upper glass substrate in FIG. 1 in which the alignment film is omitted, and FIG. 3B is a BB line of FIG.
It is sectional drawing.

FIG. 4 is an explanatory diagram showing a film forming method of the reflective film in FIG.

5 is a cross-sectional view showing a mounting structure of the liquid crystal etalon of FIG. 1 on a circuit board, in which (a) uses pin terminals;
(B) uses a conductive rubber connector.

FIG. 6 is a cross-sectional view showing a structure of a conventional liquid crystal etalon.

7 is a cross-sectional view showing a specific method for extracting electrodes of the liquid crystal etalon shown in FIG.

8 is a cross-sectional view showing a specific method for extracting electrodes of the liquid crystal etalon shown in FIG.

FIG. 9 is a cross-sectional view of a liquid crystal panel used in a general segment type liquid crystal display.

[Explanation of symbols]

 51, 53 glass substrate (translucent substrate) 51a second protruding portion 53a first protruding portion 59, 61, 61a transparent electrode 63, 65 reflective film 67, 69 alignment film 71 liquid crystal 77 first conductive film portion (electrode extraction) 78) Third conductive film part (electrode extraction part) 79 Second conductive film part (electrode extraction part) 81 Conductive paste (conductive part) 85 Liquid crystal etalon (liquid crystal optical element)

Claims (4)

[Claims] 1. A transparent electrode, a reflective film, and a liquid crystal alignment film are sequentially formed on surfaces of a pair of translucent substrates that face each other, and a liquid crystal is formed between the pair of translucent substrates. In the encapsulated liquid crystal optical element, the pair of translucent substrates is
Each has a protrusion that protrudes from the portion where the liquid crystal is sealed, and the surface of the protrusion of the one transparent substrate facing the other transparent substrate has a third surface on the transparent electrode.
A conductive film portion and a first conductive film portion provided on the translucent substrate in a non-contact state with the transparent electrode including the third conductive film portion and on the same surface as the reflective film. A surface of the protruding portion of the other translucent substrate facing the one translucent substrate has the same surface as the reflective film facing a part of the first conductive film portion. In order to achieve this, a second conductive film portion is provided on the transparent electrode, and a conductive portion electrically connecting the first and second conductive film portions is provided between the first and second conductive film portions. And liquid crystal optical element. 2. A protrusion of one light-transmissive substrate is further protruded from a protrusion of the other light-transmissive substrate to form one light-transmissive substrate longer than the other light-transmissive substrate. The third conductive film portion and the first conductive film portion in the formed portion,
The liquid crystal optical element according to claim 1, wherein the liquid crystal optical element is configured as an electrode lead-out portion to the outside. 3. The reflective film is formed as a dielectric multilayer film by mask vapor deposition or etching after overall vapor deposition, and then the first, second, and third conductive film portions are formed by plating. A method for forming a film of a transparent substrate used in the liquid crystal optical element according to claim 1 or 2. 4. The plating method according to claim 3, wherein electroless plating of nickel is performed to form a low resistance electrode, displacement plating of gold is performed, and gold is finally electroplated. A method for forming a film on an optical substrate.