JP4862460B2 - Reflective liquid crystal display element, manufacturing method thereof, and liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display element, a manufacturing method thereof, and a liquid crystal display device. Specifically, the present invention relates to a reflective liquid crystal display element having a structure in which a liquid crystal substance is held between a pair of opposing substrates, a manufacturing method thereof, and a liquid crystal display device using such a reflective liquid crystal display element.

  2. Description of the Related Art Conventionally, liquid crystal display elements called liquid crystal panels and liquid crystal cells have been used in various display devices such as projection displays (projectors), and display units such as various portable electronic devices and various information processing terminals. This liquid crystal display element is roughly classified into a transmissive type and a reflective type. The transmissive liquid crystal display element modulates light from a backlight disposed on the back surface and emits it as transmitted light, while the reflective liquid crystal display element is incident. The modulated light is modulated and emitted as reflected light.

  Here, in the image display by the liquid crystal display element, a voltage is applied between a pair of substrates arranged facing each other through a predetermined gap, and the light transmittance is based on the birefringence characteristics of the liquid crystal substance held in the gap between the substrates. If the distance between the substrates arranged facing each other is not uniform in the screen, the electric field strength applied between the electrodes facing each other is different in the screen, which causes a serious problem in image quality.

  Therefore, with regard to transmissive liquid crystal display elements, display quality in which the distance between the substrates is adjusted with high accuracy and uniformity using photolithography technology and etching technology that can achieve relatively good positional accuracy, dimensional accuracy, and shape accuracy. As shown in FIG. 4, the surface of the flattening film 402 of the TFT substrate (driving circuit substrate) 401 and the position of the black matrix 403 are flattened so that an excellent liquid crystal display element can be manufactured with low cost and high productivity. There has been proposed a liquid crystal display element made of the same organic material as the film and having a projection 405 that forms a predetermined interval (hereinafter referred to as a liquid crystal gap) between the TFT substrate and the counter substrate (transparent substrate) 404 (hereinafter, referred to as a liquid crystal gap). For example, see Patent Document 1.)

  By the way, in recent years, as the resolution of projectors has been increased in size, size, and brightness, a reflection type liquid crystal display element has attracted attention as a display device that can be increased in size and size and can be expected to have high light utilization efficiency. Actually put into practical use (for example, see Patent Document 2).

  For example, an active reflective liquid crystal display element 200 shown in FIG. 5 includes a glass substrate 202 provided with a transparent electrode 201 made of a transparent conductive material such as ITO (Indium-Tin Oxide), and aluminum as a main component. The driving circuit board 204 provided with the reflective pixel electrode 203 made of a metal material is disposed so as to face each other, and the edge thereof is sealed with a sealing material 205, and the liquid crystal 206a is sealed inside, thereby the liquid crystal layer 206. Has a formed structure. Note that a film 208 formed as a secondary film is formed on the entire back surface of the drive circuit substrate when each pixel on the front surface of the drive circuit substrate is formed. An alignment film 207 for aligning the liquid crystal 206a in a predetermined direction is provided on the opposing surfaces of the glass substrate 202 and the drive circuit substrate 204, respectively. The drive circuit substrate 204 is formed by, for example, forming a C-MOS (Complementary-Metal Oxide Semiconductor) type semiconductor switching drive circuit on a silicon substrate, and the reflective pixel electrode formed thereon is formed from the glass substrate 202 side. It has a function of reflecting incident light and a function of applying a voltage to the liquid crystal layer 206.

  In the reflective liquid crystal display element 200, a voltage is applied to the liquid crystal layer by applying a voltage between the transparent electrode 201 of the glass substrate 202 and the reflective pixel electrode 203 of the drive circuit substrate 204 facing each other. . At this time, in the liquid crystal layer 206, the optical characteristics change according to the potential difference between the electrodes, and the light passing therethrough is modulated. Thereby, the reflective liquid crystal display element 200 can perform gradation display by light modulation.

  Here, in the transmissive liquid crystal display element, elements such as transistors and capacitors used for driving each pixel and their wirings become a light-shielding body that does not transmit light, whereas in the reflective liquid crystal display element, the reflective liquid crystal display element Elements such as transistors and capacitors and their wirings can be arranged below the pixel electrode. That is, one of the advantages of the reflective liquid crystal display element is that the separation of each pixel, which is the fate of the structure of the transmissive liquid crystal display element, can be reduced.

However, with regard to the reflective liquid crystal display element, the liquid crystal gap control method that is effective in the above-described transmissive liquid crystal display element cannot be employed.
That is, in the case of the transmissive liquid crystal display element, the protrusions are arranged at the position of the black matrix. However, in the case of the reflective liquid crystal display element, the protrusions are effective display parts because there is no black matrix. The liquid crystal gap control method described above cannot be employed because it protrudes and can be recognized as a defect in image quality.

  Therefore, conventionally, for example, the liquid crystal gap is controlled by adjusting the amount of liquid crystal to be sealed.

Japanese Unexamined Patent Publication No. 2000-206541 (page 2-9, FIG. 1) JP 2003-57674 A

However, due to the stress of the drive circuit board itself, there is a limit to the liquid crystal gap control under process conditions, and it has been difficult to sufficiently control the liquid crystal gap.
That is, in order to sufficiently control the liquid crystal gap, it is important to control the shape of the drive circuit board, but the shape of the drive circuit board is sufficient due to the stress imbalance between the front side and the back side of the drive circuit board. As a result, it becomes difficult to sufficiently control the liquid crystal gap.

Note that it is sufficient that the liquid crystal gap is controlled in the state of the reflective liquid crystal display element obtained by bonding the glass substrate and the drive circuit substrate with a sealant and sealing the liquid crystal. Flatness is not necessarily required in the state of a single substrate.
That is, for example, both the glass substrate and the drive circuit substrate are intentionally formed into a concave shape (concave shape with respect to the outside of the reflective liquid crystal display device), and the liquid crystal is sealed in the gap between the two, thereby reflecting the liquid crystal display device. In this state, a method of ensuring the flatness of the glass substrate and the drive circuit board is also conceivable. Therefore, the flatness is not necessarily required in the state of the drive circuit board alone, and the drive circuit can sufficiently control the liquid crystal gap. The shape of the substrate is desired.

  The present invention has been made in view of the above points, and provides a liquid crystal display element capable of adjusting a liquid crystal gap dimension with high accuracy, a method for manufacturing the same, and a liquid crystal display device using such a liquid crystal display element. It is for the purpose.

  In order to achieve the above object, a liquid crystal display device according to the present invention includes a transparent substrate, a drive circuit substrate disposed facing the transparent substrate via a predetermined gap, the transparent substrate, and the drive circuit substrate. In a liquid crystal display element including a liquid crystal held in a gap, a predetermined film is provided in a predetermined region on the back surface of the drive circuit board.

Here, by providing a predetermined film in a predetermined region on the back surface of the drive circuit board, stress imbalance between the front side and the back side of the drive circuit board can be alleviated, and the shape of the drive circuit board is highly accurate. It becomes possible to control to. The “predetermined region” means a region where a predetermined film is to be formed in order to alleviate the stress imbalance between the front side and the back side of the drive circuit board when the drive circuit board is formed in a desired shape. The “predetermined film” means, for example, a film that is formed on the front side of the drive circuit board in forming a pixel, and is formed on the back side of the drive circuit board. .
Hereinafter, the point that the shape of the driving circuit board can be controlled with high accuracy by providing the predetermined film in the predetermined area on the back surface of the driving circuit board will be described in detail. In the following description, the “predetermined film” will be described by taking as an example a film formed as a secondary film when forming each pixel on the surface of the drive circuit board. However, the predetermined film is limited to such a film. The film may be a film intentionally formed in a predetermined region on the back surface of the drive circuit board.

First, as one cause of the stress imbalance between the front side and the back side of the drive circuit board, a predetermined film is formed on the back side of the drive circuit board when forming each pixel on the front side of the drive circuit board. A membrane is conceivable.
That is, a film formed to form each pixel on the front side of the drive circuit substrate (for example, a SiO ₂ film (film indicated by reference numeral 301a in FIG. 6) formed to form a gate oxide film), a gate electrode A phosphorus-doped amorphous silicon film (film indicated by reference numeral 302a in FIG. 6) formed to form a gate electrode, and a tetraethoxyoxy siren film (film indicated by reference numeral 303a in FIG. 6) formed to form the periphery of the gate electrode. ) Etc.) is formed only in a partial area on the front side of the drive circuit board (when forming in only a partial area on the front side of the drive circuit board, the film is formed in the entire area on the front side of the drive circuit board. In contrast to the case where unnecessary regions are removed after performing the step, a film (for example, a gate oxide film formed to form a gate oxide film) is formed on the back side of the drive circuit substrate. the formation of the SiO ₂ film on the front side Forming a secondarily SiO ₂ film (film shown in FIG. 6 numeral 301b) which is deposited on the back side of the drive circuit board, phosphorus-doped amorphous silicon film on the front side of the drive circuit board to form a gate electrode In this case, a phosphorus-doped amorphous silicon film (a film indicated by reference numeral 302b in FIG. 6), which is secondarily formed on the back side of the drive circuit board, and a tetraethoxyoxysilencer on the front side of the drive circuit board to form a peripheral portion of the gate electrode. A tetraethoxyoxy siren film (film indicated by reference numeral 303b in FIG. 6), which is secondarily formed on the back side of the drive circuit board when forming the film, is formed on the entire back area of the drive circuit board. It is considered that the difference in the film formation region is a cause of the stress imbalance between the front side and the back side of the drive circuit board.
Therefore, a predetermined film formed as a secondary film when each pixel on the front surface of the drive circuit board is formed in a predetermined area on the back surface of the drive circuit board, in other words, By removing the predetermined film formed on the entire back surface so that only a predetermined region remains, the stress imbalance due to the difference between the film formation regions on the front side and the back side of the drive circuit board can be alleviated. .

Note that, when removing all of the predetermined film formed on the entire back surface of the drive circuit board, it is considered that the degree of freedom of the shape of the drive circuit board is limited.
That is, the back side of the drive circuit board is not intentionally formed, but it is formed as a secondary film. When all of the deposited films are removed, there is only one stress relationship between the front side and the back side of the drive circuit substrate, and the shape of the drive circuit substrate determined from these stress relationships is also one. . On the other hand, when the predetermined region in which the film to be formed as a secondary film is appropriately adjusted, in other words, when the region to be removed from the back surface of the drive circuit substrate is appropriately adjusted, the drive circuit Since the stress relationship between the front side and the back side of the substrate can be adjusted, the desired shape of the drive circuit substrate can be met.

  In order to achieve the above object, a method of manufacturing a liquid crystal display element according to the present invention includes a transparent substrate, a drive circuit substrate disposed facing the transparent substrate with a predetermined gap therebetween, the transparent substrate, In a method of manufacturing a liquid crystal display element including a liquid crystal held in a gap between the drive circuit substrates, the method includes a step of forming a predetermined film in a predetermined region on the back surface of the drive circuit substrate.

  Here, by forming a predetermined film in a predetermined region on the back surface of the drive circuit board, the stress imbalance between the front side and the back side of the drive circuit board can be alleviated, and the shape of the drive circuit board is highly accurate. It becomes possible to control to. The “predetermined region” means a region where a predetermined film is to be formed in order to alleviate the stress imbalance between the front side and the back side of the drive circuit board when the drive circuit board is formed in a desired shape. The “predetermined film” means, for example, a film that is formed on the front side of the drive circuit board in forming a pixel, and is formed on the back side of the drive circuit board. .

In addition, the method for manufacturing a liquid crystal display device according to the present invention includes a transparent substrate, a drive circuit substrate disposed facing the transparent substrate with a predetermined gap, and being held in the gap between the transparent substrate and the drive circuit substrate. In a manufacturing method of a reflective liquid crystal display element that modulates incident light and emits it as reflected light , a sub-film is formed when each pixel on the surface of the drive circuit board is formed . With the film formed on the entire back surface of the drive circuit board, the film is partially removed to alleviate the stress imbalance between the front side and the back side of the drive circuit board. Therefore, the film is left only in the region where the film is to be formed .

  Furthermore, in order to achieve the above object, a liquid crystal display device according to the present invention includes a liquid crystal display element, and the liquid crystal display device displays an image using light modulated by the liquid crystal display element. The element includes a transparent substrate, a drive circuit substrate disposed facing the transparent substrate via a predetermined gap, and a liquid crystal held in the gap between the transparent substrate and the drive circuit substrate. A predetermined film formed as a sub-layer when each pixel on the front surface of the drive circuit board is formed is provided in a predetermined area on the back surface of the driving circuit board.

  Here, in the predetermined area on the back surface of the drive circuit board, a predetermined film formed as a secondary film when each pixel on the front surface of the drive circuit board is formed is provided. The stress imbalance with the back side can be alleviated, and the shape of the drive circuit board can be controlled with high accuracy. The “predetermined region” means a region where a predetermined film is to be formed in order to alleviate the stress imbalance between the front side and the back side of the drive circuit board when the drive circuit board is formed in a desired shape. The “predetermined film” means a film that is formed on the front side of the drive circuit board in forming the pixels, and is formed on the back side of the drive circuit board.

  In the above-described liquid crystal display element, the manufacturing method thereof, and the liquid crystal display device of the present invention, the shape of the drive circuit substrate can be controlled with high accuracy, so that the liquid crystal gap dimension can be adjusted with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.
FIG. 1 is a schematic cross-sectional view for explaining a reflective liquid crystal display element as an example of a liquid crystal display element to which the present invention is applied. The reflective liquid crystal display element 1 shown here is a transparent liquid crystal arranged in a face-to-face relationship. The substrate 2 and the drive circuit board 3, the liquid crystal layer 4 formed by injecting the liquid crystal 4a between the transparent substrate and the drive circuit board, and the edges of the transparent substrate and the drive circuit board are sealed. The sealing material 5 to be provided is provided.

Here, the transparent substrate is made of, for example, a glass substrate, and a transparent electrode 6 having optical transparency is formed over the entire surface on the opposite surface of the glass substrate. This transparent electrode is made of a transparent conductive material such as ITO, which is a solid solution material of tin oxide (SnO ₂ ) and indium oxide (In ₂ O ₃ ), and has a common potential (for example, ground potential) in all pixel regions. It is comprised so that it may be applied.

  As shown in FIGS. 1 and 2, the drive circuit board includes, for example, a C-MOS type or n-channel MOS type FET (Field Effect Transistor) 7 and a capacitor 8 which is an auxiliary capacitor for supplying a voltage to the liquid crystal layer. Are formed by arranging a plurality of switching drive circuits 9 in the form of a matrix for each pixel on a silicon substrate. A plurality of signal lines 10 electrically connected to the source electrodes of the FETs and scanning lines 11 electrically connected to the gate electrodes of the FETs are arranged on the silicon substrate in directions orthogonal to each other. The intersection position of these signal lines and scanning lines is a display area 12 corresponding to each pixel 12a. Further, outside these display areas, a signal driver 13 for applying a display voltage to each signal line and a scanning driver 14 for applying a selection pulse to each scanning line are formed as logic portions. Note that the switching drive circuit is generally manufactured by a higher withstand voltage process than that of the logic portion because the transistor is required to have a withstand voltage corresponding to the drive voltage of the liquid crystal layer.

  On the silicon substrate, a plurality of substantially rectangular reflective pixel electrodes 15 electrically connected to the drain electrodes of the FETs are arranged in a matrix for each pixel. This reflective pixel electrode has a high reflectance in the visible region, for example, aluminum (Al), specifically, copper (Cu) or silicon (Si) used for wiring in the LSI process is added by several weight percent or less. It consists of a metal film mainly composed of aluminum (Al). This reflective pixel electrode has a function of reflecting light incident from the transparent substrate side and a function of applying a voltage to the liquid crystal layer. In order to further increase the reflectance, a multilayer film such as a dielectric mirror is used. May be laminated on the Al film. The reflective pixel electrode has a thickness of about 50 to 500 nm.

  A liquid crystal layer described later is interposed between the reflective pixel electrode and the transparent electrode. In addition, alignment films 16 and 17 are formed on the opposing surfaces of the transparent substrate and the drive circuit substrate, which cover the transparent electrode and the reflective pixel electrode, respectively. In order to align the liquid crystal molecules in the liquid crystal layer in a predetermined direction, these alignment films are made of, for example, a polymer film such as polyimide whose surface is rubbed or an inorganic material such as silicon oxide (SiO) on the silicon substrate. On the other hand, it consists of an obliquely deposited film or the like deposited from an oblique direction.

  The liquid crystal layer is so-called vertical alignment liquid crystal in which nematic liquid crystal having negative dielectric anisotropy is vertically aligned by the alignment film described above. When a voltage is applied, the liquid crystal molecules are tilted in a predetermined direction. Then, gradation display is performed by changing the light transmittance by the birefringence generated at that time.

  Here, the vertical alignment means a state in which the initial molecular alignment of the liquid crystal is aligned perpendicular to the substrate. However, when the liquid crystal molecules are perfectly vertically aligned, the application of voltage causes the liquid crystal molecules to tilt in random directions, resulting in uneven brightness. Therefore, in order to make the tilt direction of the liquid crystal molecules uniform, the pretilt angle for tilting the long axis of the liquid crystal molecules with respect to the normal line of the substrate is slightly in a certain direction (generally, the diagonal direction of the device). To be vertically aligned. On the other hand, if the pretilt angle is too large, the vertical alignment is deteriorated, the black level is increased and the contrast is lowered, or the VT (drive voltage-transmittance) curve is affected. Therefore, in general, the pretilt angle is controlled within an angle range of 1 ° to 7 °.

  The sealing material is made of an epoxy resin or the like, and after dispersing an appropriate number of glass beads (not shown) between the transparent substrate and the driving circuit substrate, the sealing material has a thickness of about several μm between the alignment films. Is formed so as to be sealed. The sealing material can also be formed so as to cover the side surfaces of these alignment films.

By the way, in a predetermined region on the back surface of the silicon substrate of the reflective liquid crystal display element, a film 18 formed as a secondary film when each pixel on the surface of the silicon substrate is formed is formed.
Specifically, the back surface of the silicon substrate is irradiated with a laser beam in a state where a film formed as a secondary film is formed on the entire back surface of the silicon substrate when forming each pixel on the surface of the silicon substrate. Thus, the film formed on the back surface of the silicon substrate is partially removed to leave the film only in a predetermined region of the silicon substrate. Note that the film may be partially removed by a general-purpose photolithography technique and an etching technique. Further, the film formed in the predetermined region on the back surface of the silicon substrate does not necessarily need to be a film formed as a secondary film when forming each pixel on the surface of the silicon substrate. A predetermined film may be intentionally formed in a predetermined region on the back surface of the silicon substrate after removing all of the film formed as a secondary film when forming each pixel.

  In the reflective liquid crystal display device configured as described above, since a film is formed in a predetermined region on the back surface of the silicon substrate, the stress imbalance between the front side and the back side of the silicon substrate can be alleviated. Since the shape of the substrate can be stably controlled, the liquid crystal gap dimension can be adjusted with high accuracy. Thereby, it is possible to control the gap between the silicon substrate and the glass substrate arranged facing each other so as to be uniform within the screen, and it is possible to perform high-quality display with uniform screen.

FIG. 7 shows a reflective liquid crystal display element (conventional liquid crystal display element) in which a film formed as a secondary film is formed on the entire back surface of the silicon substrate. A reflection type liquid crystal display element (the liquid crystal display element of the present invention) in which a film formed as a secondary film is formed in a predetermined region on the back surface of the silicon substrate. The voltage value required in order to make it the brightness of is measured in various places in the screen, and the graph which showed the measurement result is shown. The horizontal axis (X-axis) of the graph shows the luminance variation in the reflective liquid crystal display element at a certain gradation in terms of voltage value. The smaller this value, the more the luminance variation in the reflective liquid crystal display element. 7 shows that the gap in the reflective liquid crystal display element is uniform, and symbol A in FIG. 7 is the liquid crystal display element of the present invention, and symbol B in FIG. 7 is a conventional liquid crystal display element. .
From the graph shown here, the voltage value is distributed in the range of 0.19 V to 0.29 V in the conventional liquid crystal display element, whereas the liquid crystal display element of the present invention is in the range of 0.05 V to 0.13 V. It can be seen that the liquid crystal display element of the present invention has less voltage value variation than the conventional liquid crystal display element. That is, it can be seen that the liquid crystal display element of the present invention has a smaller variation in the distance between the silicon substrate and the glass substrate which are arranged facing each other than the conventional liquid crystal display element.

  FIG. 3 is a schematic diagram for explaining a reflection type liquid crystal projector which is an example of a liquid crystal display device to which the present invention is applied. The reflection type liquid crystal projector 100 shown here is a so-called three-plate system which is red, green and blue. 1 is a projection-type liquid crystal display device that uses a reflective liquid crystal display element shown in FIG. 1 for three light valves corresponding to three primary colors and displays a color image enlarged and projected on a screen (not shown).

  Specifically, the reflective liquid crystal projector includes a lamp 101 that is a light source that emits illumination light, and separation that separates illumination light from the lamp into red light (R), green light (G), and blue light (B). The dichroic color separation filter 102 and the dichroic mirror 103 which are optical means, and an R light valve which is a light modulation means which modulates and reflects the separated red light (R), green light (G) and blue light (B). 104R, G light valve 104G and B light valve 104B, a combining prism 105 which is a combining optical means for combining the modulated red light (R), green light (G), and blue light (B), and combined illumination And a projection lens 106 as projection means for projecting light onto the screen.

  Here, the lamp emits white light including red light (R), green light (G), and blue light (B), and includes, for example, a halogen lamp, a metal halogen lamp, a xenon lamp, or the like.

  Further, in the optical path between the lamp and the dichroic color separation filter, the fly-eye lens 107 for making the illuminance distribution of the illumination light emitted from the lamp uniform, and the P and S polarization components of the illumination light as one polarization component A polarization conversion element 108 that converts (for example, an S-polarized component), a condenser lens 109 that collects illumination light, and the like are disposed.

  The dichroic color separation filter has a function of separating white light emitted from the lamp into blue light (B) and other color lights (R, G), and the separated blue light (B) and other color lights ( R, G) are reflected in opposite directions.

  Further, a total reflection mirror 110 that reflects the separated blue light (B) toward the B light valve is disposed between the dichroic color separation filter and the B light valve, and the dichroic color separation filter and the dichroic mirror A total reflection mirror 111 that reflects other separated color lights (R, G) toward the dichroic mirror is disposed between them.

  The dichroic mirror has a function of separating the other color light (R, G) into red light (R) and green light (G), and transmits the separated red light (R) toward the R light valve. The separated green light (G) is reflected toward the G light valve.

  Also, R, G, and B polarization beam splitters 112R, 112G, and 112B for guiding the separated color lights R, G, and B to the light valves are provided between the light valves 104R, 104G, and 104B and the combining prism. Has been placed. These R, G, and B polarization beam splitters have a function of separating each incident color light R, G, and B into a P polarization component and an S polarization component, and one polarization component (for example, an S polarization component) is converted into R, The light is reflected toward the G and B light valves, and the other polarization component (for example, P polarization component) is transmitted toward the synthesis prism.

  The R, G, and B light valves are composed of the above-described reflection type liquid crystal display elements, and while polarization-modulating light of one polarization component (for example, S polarization component) guided by each polarization beam splitter according to the video signal, The polarization-modulated light is reflected toward each polarization beam splitter.

  The synthesizing prism is a so-called cross-cube prism, and has a function of synthesizing each color light R, G, B of the other polarization component (for example, P polarization component) that has passed through each polarization beam splitter, and projects the synthesized light. The light is emitted toward the lens.

  The projection lens has a function of enlarging and projecting light from the combining prism toward the screen.

  In the reflective liquid crystal projector configured as described above, white light emitted from the lamp is separated into red light (R), green light (G), and blue light (B) by the dichroic color separation filter and the dichroic mirror. . The separated red light (R), green light (G), and blue light (B) are S-polarized light components, and enter each light valve through each polarization beam splitter. The red light (R), green light (G), and blue light (B) incident on each light valve are polarized and modulated in accordance with the drive voltage applied to each pixel of each light valve, and then each polarized beam. Reflected towards the splitter. In the modulated red light (R), green light (G), and blue light (B), only the P-polarized component light passes through each polarization beam splitter and is synthesized by the synthesis prism. Light is magnified and projected on the screen by the projection lens.

  As described above, this reflection type liquid crystal projector performs color image display by enlarging and projecting an image corresponding to the light modulated by the light valve on the screen.

  By the way, as described above, the reflective liquid crystal display elements constituting each light valve can perform high-pixel display with a uniform screen, so that even the reflective projector shown here has a uniform high-quality display. Can be performed.

  In the present embodiment, a projection type liquid crystal display device that projects onto a screen like a reflection type projector has been described as an example. However, the present invention is a direct view type liquid crystal that directly looks at a reflection type liquid crystal display element. The present invention can be widely applied to display devices.

It is typical sectional drawing for demonstrating the reflection type liquid crystal display element which is an example of the liquid crystal display element to which this invention is applied. It is a schematic diagram which shows the structure of a drive circuit board | substrate and a switching drive circuit. It is a schematic diagram for demonstrating the reflection type liquid crystal projector which is an example of the liquid crystal display device to which this invention is applied. It is typical sectional drawing for demonstrating the control method of the liquid crystal gap in a transmissive liquid crystal display element. It is typical sectional drawing for demonstrating the conventional reflection type liquid crystal display element. It is typical sectional drawing for demonstrating the predetermined film | membrane formed into a film on the back surface of a drive circuit board | substrate. It is a graph which shows the variation of the voltage value required in order to obtain predetermined | prescribed brightness.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reflective type liquid crystal display element 2 Transparent substrate 3 Drive circuit board 4a Liquid crystal 4 Liquid crystal layer 5 Sealing material 6 Transparent electrode 7 FET
DESCRIPTION OF SYMBOLS 8 Capacitor 9 Switching drive circuit 10 Signal line 11 Scan line 12a Pixel 12 Display area 13 Signal driver 14 Scan driver 15 Reflective pixel electrode 16, 17 Orientation film 18 Film 100 Reflective liquid crystal projector 101 Lamp 102 Color separation filter 103 Dichroic mirror 104R R Light valve 104G G light valve 104B B light valve 105 Synthetic prism 106 Projection lens 107 Fly eye lens 108 Polarization conversion element 109 Condenser lens 110, 111 Total reflection mirror 112 Polarization beam splitter

Claims (4)

A transparent substrate;
A drive circuit board disposed facing the transparent substrate via a predetermined gap;
In a reflective liquid crystal display element comprising a liquid crystal held in a gap between the transparent substrate and the drive circuit substrate, and modulating incident light and emitting it as reflected light ,
A predetermined film is provided in a predetermined region on the back surface of the drive circuit board ;
The predetermined film is a film formed secondarily when forming each pixel on the surface of the drive circuit board,
The reflection type liquid crystal display element , wherein the predetermined region is a region where the predetermined film is to be formed in order to alleviate a stress imbalance between the front side and the back side of the driving circuit board . A transparent substrate; a drive circuit substrate disposed opposite to the transparent substrate with a predetermined gap; and a liquid crystal held in the gap between the transparent substrate and the drive circuit substrate, and modulates and reflects incident light. In the method of manufacturing a reflective liquid crystal display element that emits light ,
In a state where a film formed as a secondary film when forming each pixel on the surface of the drive circuit substrate is formed on the entire back surface of the drive circuit substrate , the film is partially removed, A reflective liquid crystal characterized in that the film is left only in a region where the film is to be formed in order to alleviate the stress imbalance between the front side and the back side of the drive circuit board of the drive circuit board. A method for manufacturing a display element. Method of manufacturing a reflection type liquid crystal display device according to claim 2, characterized in <br/> to perform a partial removal of the front Kimaku by irradiating a laser beam on the back surface of the drive circuit board. In a liquid crystal display device that includes a reflective liquid crystal display element that modulates incident light and emits the reflected light as reflected light , and displays an image using light modulated by the reflective liquid crystal display element.
The reflective liquid crystal display element is
A transparent substrate;
A drive circuit board disposed facing the transparent substrate via a predetermined gap;
A liquid crystal held in a gap between the transparent substrate and the drive circuit substrate,
In a predetermined region on the back surface of the drive circuit board, a predetermined film formed as a sub-layer when each pixel on the front surface of the drive circuit board is formed is provided ,
The liquid crystal display device according to claim 1, wherein the predetermined region is a region where the predetermined film is to be formed in order to alleviate a stress imbalance between the front side and the back side of the drive circuit board .

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