JP3559104B2 - Display device - Google Patents

Description

[0001]
[Industrial applications]
The invention disclosed in this specification relates to a display device that projects an image.
[0002]
[Prior art]
2. Description of the Related Art A display device that projects an image on a screen using a liquid crystal display panel is known. As such a projection type display device, a technique described in Japanese Patent Application Laid-Open No. 60-31291 is known. FIG. 3 shows an outline of a conventionally known projection display device.
[0003]
FIG. 3 shows a configuration in which images corresponding to RGB are combined and a color image is projected and displayed on a screen (or an appropriate projection surface). In FIG. 3, reference numeral 301 denotes light for displaying an R (red) image, which is transmitted through the color filter 304 and then applied to the liquid crystal panel 307. In the liquid crystal panel 307, appropriate light modulation is performed, and an image corresponding to R is formed. In the transflective mirror 313, the images corresponding to G and B reflected by the total reflection mirror 312 are combined with the image corresponding to R modulated by the liquid crystal panel 307. An image (color image) obtained by synthesizing the RGB images is projected on a screen 315 via a projection lens 314.
[0004]
A general liquid crystal panel 307 (same for 308 and 309) has a configuration in which a pair of glass substrates is disposed between a pair of polarizing plates disposed at different angles of 90 degrees, and a TN type liquid crystal is disposed between the pair of glass substrates. Has a configuration that is held therebetween.
[0005]
Reference numeral 302 denotes light for displaying a G (green) image, which is transmitted through the color filter 305 and then transmitted through the liquid crystal panel 308, and is subjected to predetermined light modulation. By this light modulation, an image corresponding to G is formed. The G image formed by performing light modulation on the liquid crystal panel 308 transmits through the semi-transmissive mirror 311. The transflective mirror 311 combines the B image and the G image reflected by the total reflection mirror 310.
[0006]
Reference numeral 303 denotes light for displaying a B (blue) image, which is transmitted through the color filter 306 and then transmitted through the liquid crystal panel 309 to perform predetermined light modulation. The B image light-modulated by the liquid crystal panel 309 is reflected by the total reflection mirror 310 and is combined with the G image by the semi-transmissive mirror 311.
[0007]
The display device based on the principle described above is required to satisfy the following items.
(1) The overall configuration is made as small as possible.
(2) Reduce the number of components. (Simplifies the configuration)
(3) The temperature rise is suppressed.
(4) A configuration in which RGB optical axes are easily aligned.
(5) RGB optical path lengths are made uniform.
[0008]
(1) and (2) are necessary requirements in pursuing problems such as good handling of the device, low cost, and low failure rate. This requirement is important when commercializing the device.
[0009]
The problem (3) is a serious problem when the light emission intensity of the light source is increased to obtain the required luminance.
[0010]
Due to the structure of the projection type display device, light is transmitted several times through various filters, liquid crystal panels, and optical elements such as semi-transmissive mirrors until an image is finally displayed as shown in FIG. There is a need to. For this reason, there is a fundamental problem that the displayed image becomes dark.
[0011]
In order to solve this problem, it is necessary to use a lamp having a high emission intensity (bright light source). However, a lamp having a high luminous intensity heats a portion to be irradiated with the light, thereby increasing the temperature inside the device.
[0012]
As is well known, a liquid crystal material is liable to change in physical properties with an increase in temperature. That is, as the temperature increases, the response speed of the liquid crystal changes, and the optical modulation ability changes. As a result, the display becomes unclear.
[0013]
Further, when the temperature rises, there arises a problem that the optical characteristics of an optical device such as a lens or a mirror change, or the optical axis is shifted.
[0014]
In order to solve such a problem, it is necessary to arrange an appropriate cooling means and keep the inside of the apparatus below an allowable temperature. As this cooling means, a configuration in which forced air cooling is generally performed using an air cooling fan is employed.
[0015]
In this case, it is necessary to create a certain space inside the device in order to enhance the air cooling effect so that air flows. However, such a configuration contradicts the requirements (1) and (2). In addition, the noise of the air cooling fan also becomes a serious problem. In addition, there is also a problem in that forced air cooling using an air cooling fan causes dust to adhere to the surface of the liquid crystal panel or the surface of the optical system.
[0016]
When a high-quality image is to be displayed, the requirements described in (4) and (5) above are important. However, when the configuration as shown in FIG. 3 is adopted, it is particularly difficult to satisfy the requirement shown in (5). That is, since the spatial distance between each liquid crystal panel and the projection lens 314 is different, each image optically modulated by the liquid crystal panel cannot be focused on the projection lens 314.
[0017]
The configuration shown in FIG. 3 is characterized in that by changing the focal length of the projection lens 314, an image can be displayed even when the distance to the projection plane changes. Another feature is that an image can be set to an arbitrary size by changing the distance to the projection plane.
[0018]
However, when each of the RGB images is out of focus in the projection lens 314, moving the projection lens 314 causes a color shift or an unclear image.
[0019]
As a method of solving the problem of the inconsistency of the focal positions of the images from the respective liquid crystal panels in the projection lens, there is a method of making the positions of the respective liquid crystal panels of RGB slightly different and adjusting the focal positions. However, arranging the RGB liquid crystal panels at different positions conflicts with the requirement of (2) to reduce the number of components in the sense that the configuration becomes complicated. It also conflicts with the requirement of (1) in that the whole becomes larger. It also conflicts with the requirement (4) in that the optical axis alignment becomes difficult.
[0020]
Further, as a method of solving the problem of the inconsistency of the focal positions of the images from the respective liquid crystal panels in the projection lens, there is a method of correcting an optical path length using an optical system in which various lenses are combined. However, such a configuration complicates the optical system and does not satisfy the requirements of (1) and (2). In addition, the requirement (4) is not satisfied in the sense that the optical axis alignment becomes difficult.
[0021]
As described above, it is difficult to satisfy all of the plurality of requirements described above. Therefore, for example, an apparatus for obtaining an image having a high luminance (bright screen) has a large size as a whole and has a high cost. This means that the above requirements (1) and (2) have been abandoned and other requirements have been satisfied.
[0022]
[Problems to be solved by the invention]
The invention disclosed in the present specification has been described above,
(1) The overall configuration is made as small as possible.
(2) Reduce the number of components. (Simplifies the configuration)
(3) The temperature rise is suppressed.
(4) A configuration in which RGB optical axes are easily aligned.
(5) RGB optical path lengths are made uniform.
It is an object of the present invention to provide a projection-type display device satisfying such requirements.
[0023]
[Means for solving the problem]
One of the inventions disclosed herein is:
An optical modulation element that optically modulates incident light;
Liquid for cooling is arranged in contact with the output side of the optical modulation element,
A focal length of the output light of the optical modulation element is set to a predetermined distance according to a length of the output light of the optical modulation element passing through the liquid.
[0024]
FIG. 1 shows a specific example of the above configuration. FIG. 1 shows three liquid crystal panels (liquid crystal electro-optical devices) 111, 113, and 114 for RGB as optical modulation elements that optically modulate incident light. The three liquid crystal panels are integrated using a pair of glass substrates 107 and 109, which contributes to simplifying the entire configuration. That is, apparently, three liquid crystal panels corresponding to RGB are integrated in one liquid crystal panel.
[0025]
Although three liquid crystal panels for RGB are shown in FIG. 1, a configuration in which a larger number of panels are arranged may be employed. In addition, not only the RGB images are combined but also the same image may be formed by a plurality of liquid crystal panels. In this case, the brightness of the images can be increased by overlapping the plurality of images. Further, when there is a defect in the liquid crystal panel, the defect can be made inconspicuous. Further, instead of a form in which color images are combined, a configuration in which a plurality of same or different images are overlapped or combined may be employed.
[0026]
In the configuration shown in FIG. 1, a liquid for cooling each liquid crystal panel exists in a region indicated by 121. This liquid is in contact with the output side of each of the liquid crystal panels 111, 113, and 114 (the surface through which the image passes through the panel and exits). In the configuration shown in FIG. 1, the entire liquid crystal panel is in contact with the liquid, and the entire liquid crystal panel is cooled. As this liquid, a fluorine-based inert liquid can be used. For example, a liquid that is usually referred to as "Fronat" can be used. Also, certain oils, such as seda oil, can be used.
[0027]
Further, in the configuration shown in FIG. 1, the image emitted from the liquid crystal panel 111 passes through the liquid existing in the area 121 at the shortest distance, and the image emitted from the liquid crystal panel 113 is located next in the area 121. An image passing through the liquid and coming out of the liquid crystal panel 114 passes through the liquid existing in the region 121 at the longest distance.
[0028]
With such a configuration, the focal length of the image coming out of the liquid crystal panel 114 is shortened, and then the focal length of the image coming out of the liquid crystal panel 113 is shortened. Then, the position of the focal point of each of the RGB images passing through the projection lens 119 can be the same or substantially the same.
[0029]
That is, the focal length of the output light of each liquid crystal panel is set (adjusted) to a predetermined distance according to the length of the output light of each liquid crystal panel passing through the liquid, and the focal position of the output light (image) from each panel is set. Is finally adapted.
[0030]
The configuration of another invention is as follows.
Means for generating a plurality of incident lights divided into a predetermined wavelength region,
At least one optical modulation element provided corresponding to each of the plurality of incident lights,
A cooling liquid in contact with the optical modulation element,
Has,
The light emitted from the optical modulation element passes through the liquid at different lengths.
[0031]
FIG. 1 shows a specific example of the above configuration. In the configuration shown in FIG. 1, dichroic mirrors 103, 104, and 105 are provided as means for generating a plurality of incident lights corresponding to a predetermined wavelength region. Although FIG. 1 shows a configuration using a dichroic mirror, light having a required wavelength region may be obtained using various optical filters such as a color filter. Further, a lamp or light emitting means for generating light having a required wavelength range may be used. In addition, the plurality of lights having a predetermined wavelength range may have different wavelength ranges or may partially or entirely overlap.
[0032]
Further, in the configuration shown in FIG. 1, optical modulation elements (liquid crystal panels) 111, 113, and 114 are arranged corresponding to a plurality of incident lights of the RBG. In FIG. 1, one liquid crystal panel indicated by 111 is arranged for light corresponding to R. However, a configuration may be adopted in which a plurality of liquid crystal panels are arranged for light corresponding to R, and the transmitted light (light-modulated image) is superimposed. In the case of such a configuration, since two liquid crystal panels are provided for each of RGB, a total of six liquid crystal panels are required.
[0033]
In the configuration shown in FIG. 1, a cooling liquid for cooling the liquid crystal panels 111, 113, and 114, which are optical modulation elements, exists in an area indicated by 121. The distance that passes through the cooling liquid has a different length depending on the image from each liquid crystal panel.
[0034]
That is, in the configuration shown in FIG. 1, the distance from the liquid crystal panel 114 to the projection lens 119 is longer than the distance from the liquid crystal panel 113 to the projection lens 119. Further, the distance from liquid crystal panel 113 to projection lens 119 is longer than the distance from liquid crystal panel 111 to projection lens 119. In such a configuration, the image from the liquid crystal panel 114 passes through the liquid existing in the area 121 over the longest distance. Then, the image from the liquid crystal panel 113 passes through the liquid existing in the area 121 over the next long distance. The image from the liquid crystal panel 111 passes through the liquid existing in the area 121 at the shortest distance.
[0035]
The configuration of another invention is as follows.
A plurality of optical modulation elements provided corresponding to each of the plurality of incident lights,
A cooling liquid in contact with the optical modulation element,
Has,
Light emitted from the optical modulation elements passes through the liquid at different lengths, and the focus positions of the images modulated by the plurality of optical modulation elements at predetermined positions are adjusted or substantially adjusted. .
[0036]
FIG. 1 shows an example of a specific configuration of the above configuration. In the configuration shown in FIG. 1, light (image) emitted from each of the liquid crystal panels 111, 113, and 114, which is an optical modulation element, passes through a cooling liquid existing in an area 121 at different lengths, The focus position of each of the RGB images passing through the projection lens 119 is adjusted.
[0037]
Of course, the plurality of incident lights in the configuration of the present invention is not limited to a combination of RGB lights.
[0038]
The configuration of another invention is as follows.
Means for generating incident light divided into three wavelength regions of RGB;
At least three optical modulation elements provided corresponding to the incident light of RGB,
A cooling liquid in contact with the three optical modulation elements;
Light emitted from the three optical modulation elements passes through the liquid at different lengths,
Means for condensing and projecting light emitted from the three optical modulation elements;
Has,
Since the light emitted from the optical modulation element has a different length in the liquid, the focal positions of the images optically modulated by the three optical modulation elements are matched or substantially matched by the projecting unit. And
[0039]
As a specific example of the above configuration, the configuration shown in FIG. 1 can be given. The configuration shown in FIG. 1 includes means 103, 104, and 105 for generating incident light divided into three wavelength regions of RGB, and at least three optical modulation elements (liquid crystal) provided corresponding to the incident light of RGB. Panels) 111, 113, 114, and a cooling liquid in contact with the three optical modulation elements existing in areas 121 and a liquid existing in an area indicated by 121 exited from the three optical modulation elements. It has a configuration in which light passes through different lengths, and means 116, 117, 118, and 119 for condensing and projecting light emitted from the three optical modulation elements 111, 113, and 114, respectively.
[0040]
The focal position of the image optically modulated by the three optical modulators is different because the light emitted from the optical modulators 111, 113, and 114 has different lengths in the liquid existing in the region indicated by 121. Are fitted or roughly fitted in the projection means 119.
[0041]
The configuration of another invention is as follows.
Having a plurality of liquid crystal electro-optical devices integrated using the same translucent substrate,
A cooling liquid is arranged in contact with the plurality of liquid crystal electro-optical devices,
In at least two of the plurality of liquid crystal electro-optical devices, having a configuration in which the transmitted light passes through the liquid with different lengths,
It is characterized by having.
[0042]
In this configuration, light transmitted through at least two liquid crystal electro-optical devices has a configuration in which the light is focused or approximately focused at a predetermined location.
[0043]
The above configuration realizes simplification of the overall structure of the device by integrating a plurality of optical modulation elements using the same translucent substrate. A specific example of this configuration is the configuration shown in FIG. In the configuration shown in FIG. 1, liquid crystal panels 111, 113, and 114 are integrated using a pair of glass substrates 107 and 109. With such a configuration, the overall configuration can be simplified.
[0044]
[Action]
In a configuration in which images from a plurality of optical modulation elements are combined, by allowing the images from each optical modulation element to pass at different distances in the liquid for cooling each optical modulation element, finally, When combining each image, the focus position of each image can be adjusted. Further, by using a structure in which the liquid crystal panel is cooled with a liquid, a light source with high luminance can be used. Then, the brightness of the displayed image can be increased.
[0045]
For example, in the configuration shown in FIG. 1, the distance from the liquid crystal panel 114 to the projection lens 119 is longer than the distance from another panel to the projection lens. Therefore, the configuration is such that the image traveling from the liquid crystal panel 114 to the projection lens 119 passes through the liquid existing in the area 121 at the longest distance.
[0046]
Then, since the focal length of the image becomes shorter as the image passes through the liquid, the reduction rate of the focal length of the image from the liquid crystal panel 114 to the projection lens 119 can be maximized. By appropriately setting the reduction ratio of the focal length, the position of the focal point of the image from the liquid crystal panel 111 and the position of the focal point of the image from the liquid crystal panel 114 are matched. This can be considered as optically bringing the liquid crystal panel 114 closer to the projection lens 119.
[0047]
In this way, the focal position of the image from the liquid crystal panel 111 and the focal position of the image from the liquid crystal panel 114 can be brought into a state where the focal position of the image passes through the projection lens 119.
[0048]
That is, by setting the distance through which the image from the liquid crystal panel 114 passes through the liquid existing in the area indicated by 121, the focal length of the image from the liquid crystal panel 121 is shortened, and the focal position is set to The focal position of the image.
[0049]
FIG. 4 is an image diagram for explaining the above principle. 4 are the same as those shown in FIG. Although the description of each liquid crystal panel is simplified, the details are the same as those shown in FIG.
[0050]
FIG. 4 shows the apparent positions of the RGB liquid crystal panels obtained by immersing the liquid crystal panel in the liquid indicated by reference numeral 121. FIG. 4 does not show the position where the liquid crystal panel actually exists, but shows that when viewed from the projection lens side, each liquid crystal panel looks as if it were at that position. .
[0051]
As shown in FIG. 4, the apparent (optical) position of each liquid crystal panel viewed from the projection lens side differs according to the difference in the distance that the image from each liquid crystal panel passes through the liquid. For example, the focal point of the image from the liquid crystal panel 114 through which the image passes the longest distance is shortened, and when viewed from the projection lens side, the liquid crystal panel 114 is in a state as if it were close to the projection lens 119.
[0052]
In this way, the optical distance of the projection lens 119 from the liquid crystal panel 114 and the optical distance of the projection lens 119 from the liquid crystal panel 111 can be matched. That is, the position of the focal point (image position) of the image from the liquid crystal panel 114 in the projection lens 119 and the position of the focal point (image position) of the image from the liquid crystal panel 118 can be matched.
[0053]
By doing so, even if the focal point of the projection lens 119 is changed, the position of the focal point of the image from the liquid crystal panel 111 and the position of the focal point of the image from the liquid crystal panel 114 change in the same manner, and the connection between the two is changed. The image does not shift.
[0054]
In addition, by adjusting the focal length of the image from the liquid crystal panel 113 according to the same principle, the configuration can be such that the images from all the liquid crystal panels are focused at the same position. That is, by setting the passing distance of an image in a material having a high refractive index (in this case, a liquid), the optical length from each liquid crystal panel to the projection lens 119 is made the same. At 119, the position of the focal point of each of the RGB images can be made the same. In addition, a configuration in which an image is not shifted in RGB can be provided.
[0055]
【Example】
The present embodiment relates to a configuration in which images corresponding to RGB formed by a liquid crystal electro-optical device (liquid crystal panel) are combined and a color image is projected. The configuration shown in this embodiment is
(A) Liquid crystal panels corresponding to RGB are integrated and integrated.
(B) Using a liquid having an appropriate refractive index, cooling of a liquid crystal panel and adjustment of an optical path length (focal length of an optical image) are simultaneously performed. The optical path lengths (focal lengths of optical images) are made uniform in all of the RGB images.
[0056]
FIG. 1 shows a schematic configuration of a projection type liquid crystal display device of the present embodiment. In FIG. 1, light emitted from a lamp 101 that emits white light, which is a light source, is corrected by a lens 102 to light having a uniform traveling direction (parallel light), and dichroic mirrors 103, 104, and 105 correspond to RGB, respectively. Is split into light.
[0057]
In the dichroic mirror 103, light having a wavelength distribution corresponding to B is split. The light corresponding to B reflected by the dichroic mirror 103 is incident on the liquid crystal panel 114 for B and undergoes predetermined optical modulation. The liquid crystal panel 114 (the configuration shown by 111 and 113 is also the same) is an optical modulation element that functions as an independent liquid crystal electro-optical device.
[0058]
The liquid crystal panel 114 has a configuration in which a TN type liquid crystal 114 is held between glass substrates 107 and 109, and a pair of polarizing plates 106 and 110 are arranged outside the glass substrate.
[0059]
Although not shown, a sealing material for sealing the liquid crystal in a predetermined region, an alignment film for aligning the liquid crystal, an electrode for applying a predetermined electric field to the liquid crystal, and a switching element for holding a charge in the electrode. A thin film transistor and a peripheral circuit for driving the thin film transistor (the peripheral circuit is also formed of the thin film transistor) are formed.
[0060]
In the dichroic mirror 104, light having a wavelength distribution corresponding to G is split. The light corresponding to G reflected by the dichroic mirror 104 is incident on the G liquid crystal panel 113 and undergoes predetermined optical modulation.
[0061]
The liquid crystal panel 113 has a configuration in which a TN type liquid crystal 112 is held between glass substrates 107 and 109, and a pair of polarizing plates 106 and 110 are arranged outside the glass substrate.
[0062]
In the dichroic mirror 105, light having a wavelength distribution corresponding to R is split. The light corresponding to R reflected by the dichroic mirror 105 enters the R liquid crystal panel 111 and undergoes predetermined optical modulation.
[0063]
The liquid crystal panel 111 has a configuration in which a TN liquid crystal 108 is held between glass substrates 107 and 109, and a pair of polarizing plates 106 and 110 are arranged outside the glass substrate.
[0064]
The image of B that has been optically modulated by the liquid crystal panel 114 is reflected by the mirror 116, and further enters the projection lens 119 via the semi-transmissive mirrors 117 and 118. The G image that has been optically modulated by the liquid crystal panel 113 is reflected by the semi-transmissive mirror 117 and further enters the projection lens 119 via the semi-transmissive mirror 118. The R image optically modulated by the liquid crystal panel 111 is reflected by the semi-transmissive mirror 118 and enters the projection lens 119.
[0065]
At the stage when the light enters the projection lens 119, the RGB images are combined. Then, the focus of the synthesized image is adjusted by the projection lens 119, and the projection is performed on the screen 120 or an appropriate projection surface. In FIG. 1, the lens 102 and the projection lens 119 are shown as if they were constituted by a single lens. However, a more complicated optical system may be used as the lens 102 or the projection lens 119 according to the required image quality.
[0066]
In the configuration shown in FIG. 1, the entire liquid crystal panel indicated by 111, 113, and 115 is immersed in the cooling liquid. This liquid exists in a region indicated by a dotted line 121. This liquid needs to be a material having a high refractive index and high translucency. Further, it is necessary to form a window with a light-transmitting material at least in a portion where light is transmitted. It is also necessary to sufficiently seal the liquid crystal cell so that the liquid does not enter the liquid crystal cell.
[0067]
It is preferable to use an inert material typified by a CFC-based liquid as the liquid in order to shield the liquid crystal cell from moisture from the outside.
[0068]
Although not shown in FIG. 1, a radiator made of a suitable material for cooling the cooling liquid existing in the region 121 may be provided.
[0069]
In the configuration shown in FIG. 1, the length of light (image) from the liquid crystal panel passing through the liquid is made different depending on the spatial distance from each liquid crystal panel to the projection lens 119. That is, the distance in the liquid through which the light from each liquid crystal panel passes is set according to the difference in the spatial distance from each liquid crystal panel to the projection lens 119. By doing so, the positions of the focal points of the images reaching the projection lens 119 from the respective liquid crystal panels can be made substantially the same.
[0070]
For example, the spatial distance from the liquid crystal panel 113 to the projection lens 119 is longer than the spatial distance from the liquid crystal panel 111 to the projection lens 119. Therefore, the focal length of the image exiting the liquid crystal panel 113 is shortened so that the image (light) exiting the liquid crystal panel 113 and the image exiting the liquid crystal panel 111 are aligned. For this purpose, the image output from the liquid crystal panel 113 is made to pass through the cooling liquid over a longer distance. Since the refractive index of the cooling liquid is higher than that of air, the focal length of the image can be shortened by passing the image through the cooling liquid. By reducing the focal length of this image, it is possible to realize a situation where the position of the liquid crystal panel 113 approaches the projection lens 119 as shown in FIG. By doing so, the focal position of the image coming out of the liquid crystal panel 111 and the focal position of the image coming out of the liquid crystal panel 113 can be matched.
[0071]
The spatial distance from the liquid crystal panel 114 to the projection lens 119 is longer than the spatial distance from the liquid crystal panel 113 to the projection lens 119. Therefore, the image coming out of the liquid crystal panel 114 is made to pass through the cooling liquid over a longer distance. Then, the focal length of the image projected from the liquid crystal panel 114 can be shortened. That is, when viewed from the projection lens 119, as shown in FIG. 4, the liquid crystal panel 114 can be optically brought into a state close to the projection lens 119 side. Then, the focal position of the image projected from liquid crystal panel 113 and the focal position of the image projected from liquid crystal panel 114 can be matched.
[0072]
In this way, the focal length of each image of RGB can be changed, and finally, the focus position (image formation position) of each image can be adjusted in the projection lens 119. The accuracy of the focus alignment of each image may be set within a predetermined range according to the required image quality.
[0073]
In the configuration shown in FIG. 1, by setting the length of the image from each liquid crystal panel that passes through the liquid for cooling the liquid crystal panel, the position where the image from each liquid crystal panel is formed can be set appropriately. Features.
[0074]
That is, utilizing the fact that the focal length of an image passing through the liquid for cooling is shortened in accordance with the refractive index of the liquid, the light emitted from each liquid crystal panel finally focuses on the same position (images are formed). ).
[0075]
By adopting the configuration shown in this embodiment, it is possible to adjust the focal position (image forming position) of each of the RGB images passing through the lens 119. By changing the focal point of the projection lens 119 in this manner, a clear image without color shift is displayed even if the distance to the projection plane is changed or the size of the projected image is changed. be able to.
[0076]
Another feature of the configuration shown in FIG. 1 is that three liquid crystal panels 111, 113, and 114 corresponding to RGB are integrated and integrated in one liquid crystal cell. With such a structure, simplification in a manufacturing process in which a step of injecting liquid crystal between glass substrates (a panel assembling step) only needs to be performed once can be realized.
[0077]
Further, since the RGB liquid crystal panels are formed using the same substrate, there is no need to perform optical axis alignment between the liquid crystal panels. Further, the configuration is simplified and the size is reduced.
[0078]
In addition, the configuration as shown in FIG. 1 does not require the optical axis adjustment and the focusing of each of the RGB images by adjusting the optical system, so that the adjustment process is not required. This means that high productivity can be obtained, which is very useful industrially.
[0079]
In the configuration shown in this embodiment, a mirror is used for 116, and a semi-transmissive mirror is used for portions indicated by 117 and 118. However, a dichroic mirror may be used for these parts.
[0080]
Further, in the configuration shown in this embodiment, light corresponding to each of the RGB wavelength regions is obtained using a dichroic mirror. However, light corresponding to RGB may be obtained using a color filter. Alternatively, light sources corresponding to RGB may be separately prepared.
[0081]
Further, as a configuration of the liquid crystal panel, a passive matrix type, or an active matrix type using MIM type elements may be employed. Further, a ferroelectric liquid crystal or a dispersion liquid crystal may be used as the liquid crystal material.
[0082]
By adopting the configuration shown in this embodiment,
(1) The overall configuration is made as small as possible. (Simplify)
(2) Reduce the number of components.
(3) The temperature rise is suppressed.
(4) A configuration in which RGB optical axes are easily aligned.
(5) RGB optical path lengths are made uniform.
Requirements can be satisfied.
[0083]
That is, by integrating the liquid crystal panels corresponding to R, G, and B as shown by 111, 113, and 114 in FIG. 1, the requirements (1), (2), and (4) can be realized.
[0084]
Further, the liquid crystal panel is integrated, and the liquid crystal panel cooling means and the means for adjusting the focal position of each of the RGB images are constituted by using a liquid, so that (1), (2), (3) and (5) Requirements can be realized.
[0085]
Further, since the integrated configuration is cooled by the liquid, a simple configuration can be realized and the cooling efficiency can be increased. As a result, a lamp having a high light emission intensity can be used, and an image having high luminance can be displayed.
[0086]
[Example 2]
The present embodiment relates to a configuration in which the liquid crystal panels 111, 113, and 114 of FIG. 1 are integrated. FIG. 1 shows a configuration in which three liquid crystal panels denoted by 111, 113, and 114 are integrated. This configuration is a configuration in which the functions of three liquid crystal panels are substantially built in one liquid crystal panel, and a pair of glass substrates and a polarizing plate constituting the panel are common. .
[0087]
FIG. 2 shows an example of the configuration shown in FIG. FIG. 2 shows a configuration for integrating three active matrix type liquid crystal panels on one glass substrate 201. Note that what is indicated by 107 in FIG. 1 corresponds to the glass substrate 201 in FIG.
[0088]
FIG. 2 shows a liquid crystal panel portion for B having an active matrix type pixel region 204 driven by the peripheral circuits 202 and 203 (which will eventually constitute a liquid crystal panel for B), and a peripheral circuit 205. A liquid crystal panel portion for G having an active matrix type pixel region 207 driven by the peripheral circuits 208 and 209 and a liquid crystal panel portion for R having an active matrix type pixel region 210 driven by the peripheral circuits 208 and 209 include: The state in which they are integrated on the same glass substrate 210 is shown.
[0089]
Each peripheral circuit is constituted by a thin film transistor using a crystalline silicon film formed on a glass substrate. In this configuration, in the pixel region, switching thin film transistors are arranged for each of the pixel electrodes arranged in a matrix. Further, the peripheral circuit region is also formed of a thin film transistor.
[0090]
These thin film transistors are formed using a crystalline silicon film obtained by crystallizing an amorphous silicon film formed on a glass substrate by laser light irradiation or heat treatment.
[0091]
Here, an example in which a glass substrate is used has been described. However, quartz or another material having transparency can be used for the substrate.
[0092]
[Example 3]
The present embodiment is characterized in that a dichroic mirror or the like constituting an optical system other than the liquid crystal panel is also immersed in the cooling liquid. FIG. 5 shows a schematic configuration of the present embodiment.
[0093]
In FIG. 5, reference numeral 501 denotes a housing filled with a liquid. The dichroic mirrors 103 to 105, the RGB liquid crystal panels 111, 113, and 114, the mirror 116, and the semi-transmissive mirrors 116 to 118 are accommodated therein while being immersed in liquid. 5 that are the same as those shown in FIG. 1 indicate the same components as those in FIG.
[0094]
In the configuration shown in FIG. 5, a portion indicated by 502 is hollow, and air (or an inert gas) is present in this portion instead of a liquid. With such a configuration, the focal length of an image from each liquid crystal panel is changed, and the focal position of each of the RGB images passing through the projection lens 119 is adjusted.
[0095]
When the image passes through the hollow portion indicated by 502, the focal length of the image increases according to the passing distance. This is because the refractive index of air or an inert gas is smaller than that of a liquid. Therefore, the positions of the liquid crystal panels 111 and 113 are apparently far from the projection lens 119 in accordance with the passage distance of the hollow portion 502 (the passage distance of the image from each liquid crystal panel). That is, the optical distance between the liquid crystal panels 111 and 113 and the projection lens 119 becomes longer. By adjusting the length of the optical length, the focal length of each of the RGB images can be adjusted in the projection lens 119.
[0096]
In other words, by making the optical length from each liquid crystal panel to the projection lens 119 the same, the position of the focal length of each image of RGB can be adjusted in the projection lens 119.
[0097]
When the configuration as shown in FIG. 4 is employed, most of the optical system can be immersed in the cooling liquid, so that, for example, dust (dust) adheres to the surface of the dichroic mirror or the semi-transmissive mirror. Can be prevented. In addition, the cooling effect can be increased as a whole.
[0098]
Although not clear in FIG. 5, the portion of the housing 501 and the hollow portion 502 through which light (image) is transmitted needs to be made of a light-transmitting material.
[0099]
【The invention's effect】
The integrated RGB liquid crystal panel is immersed in a liquid for cooling, and the length of light passing through the liquid for cooling is made different, so that a focal position of an image from each liquid crystal panel at a predetermined position. Can be combined.
[0100]
For example, in the configuration shown in FIG. 1, the focus position of each of the RGB images can be adjusted by the projection lens 119. By doing so, it is possible to prevent the image quality from deteriorating even when the focus of the projection lens 119 is changed and the image is enlarged or the size of the projection area is changed.
[0101]
Further, since the entire liquid crystal panel is cooled by the liquid, a lamp having high luminance can be used, and a bright image can be displayed.
[0102]
By utilizing the invention disclosed herein,
(1) The overall configuration is made as small as possible.
(2) Reduce the number of components. (Simplifies the configuration)
(3) The temperature rise is suppressed.
(4) A configuration in which RGB optical axes are easily aligned.
(5) RGB optical path lengths are made uniform.
All such requests can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a projection type liquid crystal display device.
FIG. 2 is a diagram showing a schematic configuration of an integrated liquid crystal panel.
FIG. 3 is a diagram showing a configuration of a conventionally known projection type liquid crystal display device.
FIG. 4 is a diagram showing apparent positions of RGB liquid crystal panels.
FIG. 5 is a schematic diagram showing a configuration of a third embodiment.
[Explanation of symbols]
101 lamp
102 lens
103, 104, 105 dichroic mirror
106, 110 Polarizing plate
107, 109, 201 Glass substrate
108, 112, 114 liquid crystal
Liquid crystal panel for 111R
LCD panel for 113G
114 B liquid crystal panel
116 mirror
117, 118 Transflective mirror
119 Projection lens
120 Projection surface (screen)
121 Area where cooling liquid exists
202, 203, 205 peripheral circuits
206, 208, 209 Peripheral circuit
204, 207, 210 pixel area
Light for 301R
Light for 302 G
Light for 303 B
Color filter for 304R
305 G color filter
Color filter for 306 B
307, 308, 309 Liquid crystal panel
310, 312 mirror
311, 313 transflective mirror
314 Projection lens
315 Projection surface (screen)

Claims (4)

First, second, and third dichroic mirrors for splitting light from the light source;
First, second and third liquid crystal panels formed integrally on a pair of substrates for modulating light split by the first, second and third dichroic mirrors;
The first, in contact with the whole of the second and third liquid crystal panel of the first, to cool the entire second and third liquid crystal panel, a cooling liquid having a refractive index greater than air,
A projection lens for projecting images from the first, second, and third liquid crystal panels;
A display device, wherein the distances at which the images pass through the cooling liquid are different so that the focal positions of the images from the first, second, and third liquid crystal panels are the same . First, second, and third dichroic mirrors for splitting light from the light source;
First, second and third liquid crystal panels formed integrally on a pair of substrates for modulating light split by the first, second and third dichroic mirrors;
The first, in contact with the whole of the second and third liquid crystal panel of the first, to cool the entire second and third liquid crystal panel, a cooling liquid having a refractive index greater than air,
A projection lens for projecting images from the first, second, and third liquid crystal panels;
The distance that the image from the first liquid crystal panel passes through the cooling liquid is equal to the second liquid crystal panel so that the focal positions of the images from the first, second, and third liquid crystal panels are the same. The image from the third liquid crystal panel is shorter than the distance through which the image from the third liquid crystal panel passes through the cooling liquid, and the image from the second liquid crystal panel passes through the liquid through the cooling liquid. A display device that is longer than the distance to be displayed. Display device, wherein the cooling liquid according to claim 1 or claim 2 is translucent. Display device characterized by claims wherein the cooling liquid according to any one of claims 1 to 3 is an inert liquid or oil fluorine.

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