JP2008191371A - Projector and temperature control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality of a projected image, in a three-plate type liquid crystal projector, for instance. <P>SOLUTION: The projector (1100) includes a plurality of liquid crystal devices (1110R, 1110G and 1110B) which correspond to a plurality of light beams having wavelengths different from each other, respectively and modulate the corresponding light beams; a projection optical system (1114) which projects the plurality of modulated light beams; and a temperature varying means (300) which varies the temperature of at least one liquid crystal device among the plurality of liquid crystal devices so as to make it different from the temperature of the other liquid crystal devices among the plurality of liquid crystal devices. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector including three liquid crystal light valves that modulate, for example, red light, green light, and blue light, and a temperature control method.

  This type of projector is equipped with a powerful light source such as a metal halide lamp, for example, and by incorporating a mechanism for cooling the liquid crystal panel, it is possible to suppress the deterioration of liquid crystal characteristics due to the temperature rise of the liquid crystal panel due to the radiant heat of the light source. Figured. For example, Patent Document 1 describes a liquid crystal display device having a configuration in which a liquid crystal panel and a cooler are integrated.

  On the other hand, this type of projector is provided with a heating means for heating the liquid crystal panel, so that the response speed of the liquid crystal material at a low temperature and the deterioration of the electro-optical characteristics can be compensated. For example, in Patent Document 2, a heating unit that heats a liquid crystal light valve to increase the temperature of the image forming surface, and a heating amount by the heating unit are controlled so that the temperature of the image forming surface of the liquid crystal light valve becomes an appropriate temperature A projection display device comprising a temperature control means is described. Patent Document 2 describes a technique for reducing color unevenness by reducing a temperature difference between liquid crystal layers of each liquid crystal light valve in a three-liquid crystal light valve type projection display device.

JP-A-8-146378 JP-A-9-258161

  However, according to the background art described above, only the characteristic deterioration of the liquid crystal material is focused, and the wavelength of light incident on the liquid crystal panel is not taken into consideration. For example, the liquid crystal panel is incident on each liquid crystal panel such as a three-plate liquid crystal projector. When the wavelengths of light are different, there is a technical problem that the quality of the projected image may be degraded.

  The present invention has been made in view of the above-described problems, for example, and an object thereof is to provide a projector capable of improving the quality of a projected image and a temperature control method thereof.

  In order to solve the above-described problems, a projector according to the present invention projects a plurality of liquid crystal devices that respectively correspond to a plurality of lights having different wavelengths and modulate the corresponding lights, and the plurality of modulated lights. A projection optical system; and a temperature varying unit configured to vary a temperature of at least one liquid crystal device among the plurality of liquid crystal devices so as to be different from a temperature of another liquid crystal device among the plurality of liquid crystal devices.

  According to the projector of the present invention, the plurality of liquid crystal devices are liquid crystal light valves used in, for example, a liquid crystal projector. Each liquid crystal device modulates corresponding light and emits modulated light. The projection optical system is configured to include, for example, a projection lens, and displays the modulated light emitted from each liquid crystal device on a screen or the like.

  The temperature variable means typically includes at least one of a heating means and a cooling means and a control means such as a CPU (Central Processing Unit) that controls the at least one means. Specifically, for example, the heating means may correspond to a second light source different from the projection light source, a heater that sends out hot air, or radiates radiant heat. In the former, the liquid crystal device is heated by receiving light irradiation and converted into heat, and in the latter, the temperature is raised by receiving the heat itself. The cooling means may be a Peltier element or a cooling fan.

  The temperature varying means varies the temperature of at least one liquid crystal device among the plurality of liquid crystal devices so as to be different from the temperatures of other liquid crystal devices. Specifically, the temperature of one liquid crystal device is varied so that the wavelength of light incident on the one liquid crystal device approaches a temperature set based on optical characteristics with respect to the wavelength of the light. Here, “optical characteristics” according to the present invention typically means at least one of transmittance, viewing angle, and contrast, but may be any physical quantity or parameter indicating optical characteristics. Needless to say, the temperature of the other liquid crystal device may also be variable so as to approach the temperature set based on the optical characteristics with respect to the wavelength of the incident light.

  As a result of the above, according to the projector of the present invention, it is possible to suppress the deterioration of the characteristics of the liquid crystal material due to high or low temperature and improve the quality of the projected image. In addition, the life of the liquid crystal device can be extended.

  In one aspect of the projector according to the aspect of the invention, the temperature varying unit may set a temperature of at least the one liquid crystal device based on an optical characteristic of the one liquid crystal device with respect to light modulated by the one liquid crystal device. The temperature of the one liquid crystal device is varied so as to be close to.

  According to this aspect, the transmittance, viewing angle, contrast, and the like in the liquid crystal device can be improved.

  Note that “based on optical characteristics” means, for example, by experiment or simulation, for each wavelength of light incident on the liquid crystal device, the relationship between the temperature of the liquid crystal device and the transmittance, viewing angle, contrast, etc. Considering the obtained relationship and the temperature characteristics of the liquid crystal material, the transmittance, viewing angle, contrast, etc. of the liquid crystal device reach a predetermined standard, or at least one of the transmittance, viewing angle, contrast, etc. It means that one is the maximum.

  Further, when the usage environment of the projector is limited, for example, when it is fixed at a predetermined place, that is, when it is known in advance that the set temperature is high or low with respect to the environmental temperature, The variable means may be configured to include only one of the heating means and the cooling means.

  In an aspect in which the temperature is set based on the optical characteristic, the optical characteristic is a transmittance, and the set temperature is a value of the one liquid crystal device when a predetermined voltage is applied to the one liquid crystal device. It may be a temperature at which the transmittance is maximum.

  If comprised in this way, the improvement of the transmittance | permeability can be aimed at at least.

  In the case where the temperature is set based on a plurality of optical characteristics such as transmittance, viewing angle, contrast, etc., one of the plurality of optical characteristics may be set to a maximum temperature, or a plurality of optical characteristics may be set. You may set to the temperature where all reach a predetermined reference | standard.

  In an aspect in which the temperature is set based on the optical characteristic, the optical characteristic is a viewing angle, and the set temperature is determined when the predetermined voltage is applied to the one liquid crystal device. It may be the temperature at which the viewing angle is maximized.

  With this configuration, at least the viewing angle can be improved.

  In an aspect in which the temperature is set based on the optical characteristic, the optical characteristic is a contrast, and the set temperature is a contrast of the one liquid crystal device when a predetermined voltage is applied to the one liquid crystal device. May be the temperature at which becomes the maximum.

  With such a configuration, at least the contrast can be improved.

  In the aspect in which the temperature is set based on this optical characteristic, the predetermined voltage may be 5V.

  With this configuration, the temperature can be set so that the transmittance, viewing angle, and contrast of the liquid crystal device can be improved with a practically usable voltage.

  In another aspect of the projector of the present invention, the temperature variable unit includes a heating unit.

  According to this aspect, the liquid crystal device can be positively heated and can be quickly brought close to the predetermined temperature. The heating means only needs to be able to raise the temperature of the liquid crystal device, and may be a device that heats the liquid crystal device directly or indirectly, for example, a hot plate, a heater, an electromagnetic heating device, or the like. .

In another aspect of the projector of the present invention, the temperature variable means includes a cooling means.
According to this aspect, the liquid crystal device can be actively cooled, and can be quickly brought close to the predetermined temperature. The cooling means only needs to be able to lower the temperature of the liquid crystal device, and may be a device that directly or indirectly cools the liquid crystal device, such as a cooling fan, a Peltier element, or a water cooling device.

  In another aspect of the projector according to the aspect of the invention, the temperature varying unit includes a temperature detecting unit that detects the temperatures of the plurality of liquid crystal devices.

  According to this aspect, for example, the temperature detection means that is a temperature sensor detects the temperature of each of the plurality of liquid crystal devices periodically, irregularly, or continuously. Accordingly, it is possible to prevent the liquid crystal device from being overheated or cooled, and to easily maintain a predetermined temperature corresponding to each liquid crystal device, which is very advantageous in practice.

In another aspect of the projector of the present invention, the temperature varying means varies the temperature of the plurality of liquid crystal devices in a range of 20 degrees Celsius or more and 60 degrees Celsius or less. If this temperature is less than 20 degrees Celsius, It has been found that the response speed and electro-optical properties of the material are degraded. On the other hand, it has been found that when this temperature exceeds 60 degrees Celsius, the liquid crystal is irreversibly altered. However, in this embodiment, since this temperature is set in the range of 20 degrees Celsius or more and 60 degrees Celsius or less, it is possible to prevent the deterioration of the characteristics of the liquid crystal material of the liquid crystal device, and at the same time, the transmittance in each of the liquid crystal devices, Since viewing angle, contrast, etc. can be improved, it is very advantageous in practice.

  In another aspect of the projector of the present invention, the plurality of lights include red light, green light, and blue light, and the plurality of liquid crystal devices includes a red liquid crystal device that modulates the red light, and the green light. A green liquid crystal device for modulating, and a blue liquid crystal device for modulating the blue light.

  According to this aspect, a high-quality color image can be displayed. The light is not limited to three colors, but may be two colors or four or more colors.

  In the aspect including the red light, the green light, and the blue light, the temperature changing unit may change the temperature of the blue liquid crystal device in a wider temperature range than the red liquid crystal device and the green liquid crystal device. Good.

  With this configuration, it is possible to improve the quality of the projected image as long as the temperature of the red liquid crystal device and the green liquid crystal device is varied so as to approach a predetermined temperature. According to the research of the present inventors, it has been found that the optical characteristics of the liquid crystal device with respect to blue light are less dependent on temperature than the optical characteristics of the liquid crystal device with respect to red light and green light.

  In the aspect including the red light, the green light, and the blue light, the temperature varying unit may set the temperature of at least one of the red liquid crystal device and the green liquid crystal device to be lower than the temperature of the blue liquid crystal device. It may be variable.

  According to this configuration, when the liquid crystal in the liquid crystal device is a VA (Vertical Alignment) type liquid crystal, the transmittance, viewing angle, contrast, and the like of the liquid crystal device can be effectively improved. It has been found by research.

  In order to solve the above-described problem, the temperature control method of the present invention modulates a plurality of lights each having a different wavelength, a plurality of liquid crystal devices respectively corresponding to the plurality of lights, and the plurality of modulated lights. A temperature control method for the plurality of liquid crystal devices in a projector including a projection optical system for projecting, wherein the temperature of at least one liquid crystal device among the plurality of liquid crystal devices is set to another liquid crystal device among the plurality of liquid crystal devices. A temperature varying step for varying the temperature so as to be different from the above temperature.

  According to the temperature control method of the present invention, it is possible to improve the quality of the projected image as in the projector of the present invention described above.

  Note that the temperature control method of the present invention can also employ various aspects similar to the various aspects of the projector of the present invention described above.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, a projector according to an embodiment of the present invention will be described with reference to FIGS.

(projector)
First, a projector according to this embodiment will be described with reference to FIG. FIG. 1 is a plan view showing a configuration example of a projector. In this embodiment, a three-plate projector is described, but the number of liquid crystal panels provided in the projector is not limited to three, and may be two or four or more.

  In FIG. 1, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp, and liquid crystal panels 1110R, 1110G, and 1110B. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and liquid crystal as a light valve corresponding to each primary color. Incident on panels 1110R, 1110B and 1110G.

  The liquid crystal panels 1110R, 1110G, and 1110B have red light (R), green light (G), and green light (G) according to driving voltages applied to the liquid crystal layer according to R, G, and B primary color signals supplied from the image signal processing circuit. And blue light (B).

  The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In this dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of combining the images of the respective colors, a color image is projected onto a screen or the like via the projection lens 1114 as an example of the “projection optical system” according to the present invention.

  When attention is paid to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display images by the liquid crystal panels 1110R and 1110B are horizontally reversed with respect to the display images by the liquid crystal panel 1110G. Further, since light corresponding to the primary colors R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

(LCD panel)
Next, the configuration of the liquid crystal panel included in the projector 1100 described above will be described with reference to FIGS. Since the panel structures of the liquid crystal panels 1110R, 1110G, and 1110B are the same as each other, description of the panel structures of the liquid crystal panels 1110R and 1110G will be omitted below.

  2 is a plan view of the liquid crystal panel 1110B viewed from the counter substrate side, and FIG. 3 is a cross-sectional view taken along the line HH ′ of FIG. Here, the liquid crystal panels 1110R, 1110G, and 1110B are TFT (Thin Film Transistor) active matrix driving type liquid crystal panels with a built-in driving circuit, and use liquid crystal molecules having negative dielectric anisotropy. Accordingly, the liquid crystal panels 1110R, 1110G, and 1110B are liquid crystal panels in which liquid crystal molecules are driven in the VA mode. In each of the drawings referred to below, the scale of each layer and each member is different in order to make each layer and each member recognizable on the drawing.

  2 and 3, in the liquid crystal panel 1110B, the TFT array substrate 10 and the counter substrate 20 are disposed to face each other. The TFT array substrate 10 is made of a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate, and the counter substrate 20 is made of a transparent substrate such as a quartz substrate or a glass substrate, for example. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are surrounded by an image display region 10a corresponding to a region where a plurality of pixels are provided. They are bonded to each other by a sealing material 52 provided in the sealing area located.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or an ultraviolet / heat combination type curable resin for bonding the two substrates, and is applied to the TFT array substrate 10 in the manufacturing process, and then irradiated with ultraviolet rays. And cured by heating or the like. In the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance (ie, gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed. Note that the gap material may be arranged in the image display region 10a or a peripheral region located around the image display region 10a in addition to or instead of the material mixed in the seal material 52.

  In FIG. 2, a light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10 a is provided on the counter substrate 20 side in parallel with the inside of the seal region where the seal material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. The sampling circuit 7 is provided so as to be covered with the frame light shielding film 53 on the inner side of the seal region along the one side. The scanning line driving circuit 104 is provided so as to be covered with the frame light-shielding film 53 inside the seal region along two sides adjacent to the one side.

  On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20. Further, a lead wiring 90 for electrically connecting the external circuit connection terminal 102 to the data line driving circuit 101, the scanning line driving circuit 104, the vertical conduction terminal 106, and the like is formed.

  In FIG. 3, on the TFT array substrate 10, a laminated structure in which pixel switching TFTs as drive elements, wiring lines such as scanning lines and data lines are formed is formed. Although the detailed structure of this laminated structure is not shown in FIG. 3, pixel electrodes 9a made of a transparent material such as ITO are formed in an island shape in a predetermined pattern on each of the laminated structures. Has been.

  The pixel electrode 9a is formed in the image display region 10a on the TFT array substrate 10 so as to face a counter electrode 21 described later. On the surface of the TFT array substrate 10 facing the liquid crystal layer 50, that is, on the pixel electrode 9a, an alignment film 16 is formed so as to cover the pixel electrode 9a.

  A light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. For example, the light shielding film 23 is formed in a lattice shape when viewed in plan on the facing surface of the facing substrate 20. In the counter substrate 20, a non-opening area is defined by the light shielding film 23, and an area partitioned by the light shielding film 23 is an opening area through which light emitted from the backlight is transmitted. The light shielding film 23 may be formed in a stripe shape, and the non-opening region may be defined by the light shielding film 23 and various components such as data lines provided on the TFT array substrate 10 side.

  On the light shielding film 23, a counter electrode 21 made of a transparent material such as ITO is formed so as to face the plurality of pixel electrodes 9a. In order to perform color display in the image display region 10a on the light shielding film 23, a color filter (not shown in FIG. 3) may be formed in a region including a part of the opening region and the non-opening region. An alignment film 22 is formed on the counter electrode 21 on the counter surface of the counter substrate 20.

  The liquid crystal layer 50 includes liquid crystal molecules having negative dielectric anisotropy and is driven in the VA mode. When the liquid crystal panel 1110B is used, polarizing plates are arranged on both sides of the liquid crystal layer 50 so that the polarization axes are orthogonal to each other, and modulates blue light in a normally black mode (black display).

  2 and 3, on the TFT array substrate 10, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, the image signal on the image signal line is sampled and supplied to the data line. Sampling circuit 7, precharge circuit for supplying a precharge signal of a predetermined voltage level to a plurality of data lines in advance of an image signal, for inspecting quality, defects, etc. of the liquid crystal device during manufacture or at the time of shipment An inspection circuit or the like may be formed.

(Temperature variable device)
Next, a configuration of a temperature variable device 300 as an example of the “temperature variable means” according to the present invention provided in the above-described projector 1100 will be described with reference to FIG. FIG. 4 is a block diagram of the temperature variable device 300 according to this embodiment. In FIG. 1, for convenience, one fan for the lamp unit is shown. However, the projector 1100 may be provided with a plurality of fans having different cooling areas separately or in combination. Good.

  In FIG. 4, a temperature variable device 300 includes temperature sensors 301R, 301G, and 301B, heaters 302R, 302G, and 302B, cooling fans 303R, 303G, and 303B, a CPU 310, and a memory that stores predetermined temperatures T1, T2, and T3. 320. Here, “temperature sensors 301R, 301G, and 301B”, “heaters 302R, 302G, and 302B”, “cooling fans 303R, 303G, and 303B”, and “predetermined temperatures T1, T2, and T3” according to the present embodiment are respectively shown. These are examples of “temperature detection means”, “heating means”, “cooling means”, and “temperature set based on optical characteristics” according to the present invention.

  The predetermined temperature T1 is a temperature set based on the optical characteristics of the liquid crystal panel 1110R for red light, and the predetermined temperature T2 is a temperature set based on the optical characteristics of the liquid crystal panel 1110G for green light. The predetermined temperature T3 is a temperature set based on the optical characteristics of the liquid crystal panel 1110B with respect to blue light.

  Further, the heater and the cooling fan may not be provided for each liquid crystal panel. That is, for example, a heater may be provided only in a liquid crystal panel used at a temperature higher than that of other liquid crystal panels, and all of the plurality of liquid crystal panels may be cooled by a single cooling fan. Or you may provide a cooling fan only in the liquid crystal panel used at low temperature. In this case, the liquid crystal panel may be heated by light from the lamp unit. This makes it possible to reduce costs compared to the case where a heater and a cooling fan are individually provided.

  When the temperature variable device operates, first, the temperatures of the liquid crystal panels 1110R, 1110B, and 1110G are detected by the temperature sensors 301R, 301G, and 301B. Next, the CPU 310 compares the detected temperatures of the liquid crystal panels 1110R, 1110B, and 1110G with predetermined temperatures T1, T2, and T3 corresponding to the liquid crystal panels 1110R, 1110B, and 1110G, or detects the detected temperatures as predetermined. It is determined whether or not the temperature is higher than T1, T2, and T3.

  For example, when it is determined that the temperatures of the liquid crystal panels 1110R and 1110G are higher than the predetermined temperatures T1 and T2, and the temperature of the liquid crystal panel 1110B is determined to be lower than the predetermined temperature T3, the CPU 310 cools the liquid crystal panels 1110R and 1110G. Then, the cooling fans 303R and 303G are controlled to control the heater 302B so as to heat the liquid crystal panel 1110B.

  Here, a method for setting the predetermined temperatures T1, T2, and T3 will be described with reference to FIGS.

  First, the transmittance of the liquid crystal panels 1110R, 1110G, and 1110B will be described with reference to FIGS. FIG. 5 is a conceptual diagram when the transmittance for each temperature of the liquid crystal panels 1110R, 1110G, and 1110B is obtained by simulation, and FIG. 6 is the liquid crystal used when the inventors of the present application obtain the transmittance of the liquid crystal panel by simulation. FIG. 7 is an example of a transmittance characteristic diagram obtained by simulation.

  When obtaining the transmittance of the liquid crystal panel 1110B by simulation, as shown in FIG. 5, the slow axis 211 in the polarizing plate 210 and the slow axis in the polarizing plate 220 are provided on both the light incident side and the light emitting side of the liquid crystal panel 1110B. The polarizing plates 210 and 220 are arranged so that the phase axes 221 are orthogonal to each other. It should be noted that the same arrangement is used when obtaining the transmittance of the liquid crystal panels 1110R and 1110G.

  The transmittance is obtained by simulation based on the following formula (1).

ここで、式（１）において、Ｔは透過率であり、θは液晶パネル１１１０Ｂの明視方向であり、λは液晶パネル１１１０Ｂに入射する光の波長であり、ｄは基板間のギャップであり、Δｎは屈折率である。

Here, in Expression (1), T is the transmittance, θ is the clear viewing direction of the liquid crystal panel 1110B, λ is the wavelength of light incident on the liquid crystal panel 1110B, and d is the gap between the substrates. , Δn is a refractive index.

  In the present embodiment, the clear viewing direction θ is 45 degrees or 135 degrees, for example, and the wavelength λ of light incident on the liquid crystal panels 1110R, 1110G, and 1110B is 650 nm (red light), 550 nm (green light), for example. And 450 nm (blue light), and the gap d between the substrates is, for example, 2.3 μm. As the refractive index Δn, a value corresponding to the temperature of the liquid crystal panel 1110B is selected from a list as shown in FIG.

  FIGS. 7A to 7C show the relationship between the transmittance and the applied voltage of the liquid crystal panels 1110B, 1110G, and 1110R obtained by simulation under the above conditions. Here, FIG. 7A shows the transmittance of the liquid crystal panel 1110B (that is, blue light), FIG. 7B shows the transmittance of the liquid crystal panel 1110G (that is, green light), and FIG. The transmittance of the panel 1110R (that is, red light). In the present embodiment, the results are shown when the temperatures of the liquid crystal panels 1110B, 1110G, and 1110R are 0 degree, 20 degrees, 40 degrees, 60 degrees, and 80 degrees Celsius, respectively. In the case of the arrangement shown in FIG. 5, the transmittance is 50% at the maximum.

  When attention is paid to the transmittance of each of the liquid crystal panels 1110B, 1110G, and 1110R at the voltage of 5 V in FIGS. 7A to 7C, the transmittance of the liquid crystal panel 1110B increases as the temperature increases. In the liquid crystal panels 1110G and 1110R, it can be seen that the transmittance increases as the temperature decreases. It is considered that this is because the refractive index Δn decreases as the temperature increases.

  As a result, in order to improve the transmittance, it is desirable that the temperature of the liquid crystal panel 1110B is as low as possible and the temperature of the liquid crystal panels 1110G and 1110R is as high as possible. However, according to the research of the present inventors, generally, when the temperature is less than 20 degrees Celsius, the response speed and electro-optical characteristics of the liquid crystal material are deteriorated, that is, the transmittance, viewing angle, contrast, and the like are deteriorated. . On the other hand, when the temperature exceeds 60 degrees Celsius, it has been found that the liquid crystal changes irreversibly, and the basic function as the liquid crystal deteriorates or disappears (that is, the characteristics of the liquid crystal material deteriorate). Yes. Therefore, in this case, the predetermined temperature T3 may be set to 60 degrees Celsius, and the predetermined temperatures T1 and T2 may be set to 20 degrees Celsius.

  Next, the viewing angles of the liquid crystal panels 1110B, 1110G, and 1110R will be described with reference to FIG. FIG. 8 is an example of a viewing angle characteristic diagram obtained by simulation. Conditions such as the wavelength of light λ and the gap d between the substrates in the simulation are the same as those for obtaining the transmittance. 8A shows the viewing angle of the liquid crystal panel 1110B (ie, blue light), FIG. 8B shows the viewing angle of the liquid crystal panel 1110G (ie, green light), and FIG. 8C shows the viewing angle of the liquid crystal panel 1110R. The viewing angle (ie for red light).

  FIG. 8 shows a ratio between the viewing angles of the liquid crystal panels 1110B, 1110G, and 1110R when the applied voltage is 0V and the viewing angles of the liquid crystal panels 1110B, 1110G, and 1110R when the applied voltage is 5V. . Also, the darker the region, the higher the illuminance.

  As shown in FIG. 8A, in the liquid crystal panel 1110B, the darker area is enlarged, that is, the viewing angle is larger as the temperature is higher. On the other hand, as shown in FIGS. 8B and 8C, in the liquid crystal panels 1110G and 1110R, the darker regions are enlarged as the temperature is lower.

  As a result, also when improving the viewing angle, it is desirable to make the temperature of the liquid crystal panel 1110B as low as possible and the temperature of the liquid crystal panels 1110G and 1110R as high as possible. Accordingly, in this case, similarly to the transmittance, the predetermined temperature T3 may be set to 60 degrees Celsius, and the predetermined temperatures T1 and T2 may be set to 20 degrees Celsius.

  Next, the contrast of the liquid crystal panels 1110B, 1110G, and 1110R will be described with reference to FIG. FIG. 9 is an example of a contrast characteristic diagram obtained by simulation. Conditions such as the wavelength of light λ and the gap d between the substrates in the simulation are the same as those for obtaining the transmittance. In FIG. 9, B is the contrast of the liquid crystal panel 1110B (ie, blue light), G is the contrast of the liquid crystal panel 1110G (ie, green light), and R is the liquid crystal panel 1110R (ie, red light). ) Contrast.

  FIG. 9 shows the ratio between the contrast of the liquid crystal panels 1110B, 1110G, and 1110R when the applied voltage is 0V and the contrast of the liquid crystal panels 1110B, 1110G, and 1110R when the applied voltage is 5V.

  As shown in FIG. 9, in the liquid crystal panel 1110B, the contrast is remarkably improved as the temperature increases. In contrast, in the liquid crystal panels 1110G and 1110R, the contrast is improved as the temperature is lowered.

  As a result, when improving the contrast, it is desirable that the temperature of the liquid crystal panel 1110B is as low as possible and the temperature of the liquid crystal panels 1110G and 1110R is as high as possible. Accordingly, in this case, similarly to the transmittance, the predetermined temperature T3 may be set to 60 degrees Celsius, and the predetermined temperatures T1 and T2 may be set to 20 degrees Celsius.

  As described above, the transmittance, viewing angle, and contrast are improved by setting the temperature of the liquid crystal panels 1110G and 1110R to 20 degrees Celsius so that the temperature of the liquid crystal panel 1110B is 60 degrees Celsius. be able to. Therefore, according to the projector according to the present embodiment, it is possible to improve the quality of the projected image.

  According to the research of the present inventor, since the adjustment conditions for green light are generally strict, if green light can be adjusted independently of the other colors, similar effects to this application can be obtained. It is.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within a scope not departing from the gist or concept of the invention that can be read from the claims and the entire specification. The temperature control method thereof is also included in the technical scope of the present invention.

It is a top view which shows the structural example of the projector which concerns on this embodiment. It is the top view which looked at the liquid crystal device concerning this embodiment from the counter substrate side with each component. It is the HH 'sectional view taken on the line of FIG. It is a block diagram of the temperature variable apparatus which concerns on this embodiment. It is a conceptual diagram at the time of calculating | requiring the transmittance | permeability for every temperature of a liquid crystal panel by simulation. It is the table | surface which showed an example of the refractive index used when this inventor calculated | required the transmittance | permeability of a liquid crystal panel by simulation. It is an example of the transmittance | permeability characteristic figure obtained by simulating the transmittance | permeability for every temperature of a liquid crystal panel. It is an example of the viewing angle characteristic figure obtained by simulating the viewing angle for every temperature of a liquid crystal panel. It is an example of the contrast characteristic figure obtained by simulating the contrast for every temperature of a liquid crystal panel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 7 ... Sampling circuit, 9a ... Pixel electrode, 10 ... TFT array substrate, 10a ... Image display area, 20 ... Counter substrate, 21 ... Counter electrode, 23 ... Light shielding film, 16, 22 ... Alignment film, 50 ... Liquid crystal layer, 52 DESCRIPTION OF SYMBOLS ... Sealing material 53 ... Frame light shielding film, 90 ... Lead wiring, 100 ... Liquid crystal device, 101 ... Data line drive circuit, 102 ... External circuit connection terminal, 104 ... Scanning line drive circuit, 106 ... Vertical conduction terminal, 107 ... Vertical conduction material, 300 ... temperature variable device, 1100 ... projector, 1110R, 1110G, 1110B ... liquid crystal panel

Claims (14)

A plurality of liquid crystal devices that respectively correspond to a plurality of lights having different wavelengths and modulate the corresponding lights;
A projection optical system for projecting the plurality of modulated lights;
A projector comprising: temperature varying means for varying a temperature of at least one liquid crystal device of the plurality of liquid crystal devices so as to be different from temperatures of other liquid crystal devices of the plurality of liquid crystal devices.   The temperature varying means is configured to cause the temperature of the one liquid crystal device to approach the temperature set based on the optical characteristic of the one liquid crystal device with respect to light modulated by the one liquid crystal device. The projector according to claim 1, wherein the temperature of the apparatus is variable. The optical property is transmittance;
The projector according to claim 2, wherein the set temperature is a temperature at which the transmittance of the one liquid crystal device is maximized when a predetermined voltage is applied to the one liquid crystal device. The optical property is a viewing angle;
The projector according to claim 2, wherein the set temperature is a temperature at which a viewing angle of the one liquid crystal device is maximized when a predetermined voltage is applied to the one liquid crystal device. The optical property is contrast;
The projector according to claim 2, wherein the set temperature is a temperature at which a contrast of the one liquid crystal device is maximized when a predetermined voltage is applied to the one liquid crystal device.   The projector according to claim 3, wherein the predetermined voltage is 5V.   The projector according to claim 1, wherein the temperature varying unit includes a heating unit.   The projector according to claim 1, wherein the temperature varying unit includes a cooling unit.   The projector according to claim 1, wherein the temperature variable unit includes a temperature detection unit configured to detect a temperature of each of the plurality of liquid crystal devices.   10. The projector according to claim 1, wherein the temperature varying unit varies the temperature of the plurality of liquid crystal devices within a range of 20 degrees Celsius or more and 60 degrees Celsius or less. The plurality of lights includes red light, green light, and blue light,
The plurality of liquid crystal devices include a red liquid crystal device that modulates the red light, a green liquid crystal device that modulates the green light, and a blue liquid crystal device that modulates the blue light. The projector as described in any one of thru | or 10.   12. The projector according to claim 11, wherein the temperature varying means varies the temperature of the blue liquid crystal device in a wider temperature range than the red liquid crystal device and the green liquid crystal device.   13. The temperature changing unit according to claim 11 or 12, wherein the temperature changing means changes the temperature of at least one of the red liquid crystal device and the green liquid crystal device lower than the temperature of the blue liquid crystal device. projector. A plurality of liquid crystal devices in a projector comprising: a plurality of liquid crystal devices that respectively modulate a plurality of lights having different wavelengths; and a projection optical system that projects the plurality of modulated lights. A temperature control method,
A temperature control method comprising a temperature varying step of varying a temperature of at least one liquid crystal device among the plurality of liquid crystal devices so as to be different from temperatures of other liquid crystal devices among the plurality of liquid crystal devices.

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