JPH11258568A - Display device - Google Patents

Abstract

(57) [Problem] To improve the color mixing of other colors in red having relatively weak intensity in a single-panel type not using a color filter,
It is another object of the present invention to provide a display device that can reduce a loss of light amount due to a mismatch between an opening in a pixel region and a focused image of a light beam focused on the opening. A focal length of a micro lens is set such that an image forming position of a red light beam is located in a red pixel region in a liquid crystal panel. For this reason, when the color mixture occurs at the same rate because the light intensity on the long wavelength side of the metal halide lamp used as the light source is small, the problem that the purity of red is significantly reduced is solved, and the color purity is high and bright. Thus, a liquid crystal projector with high display quality can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a projection type liquid crystal display device for projecting light transmitted through a liquid crystal display panel.

[0002]

2. Description of the Related Art As a flat panel display device smaller and lighter than a CRT display device, a liquid crystal display device, a plasma light emitting display device, and the like have attracted attention. These display devices are broadly divided into a self-luminous type, which emits a light beam by itself, to display an image, and a non-light emitting, transmittance control type, which displays an image by controlling the transmittance of a light beam illuminated from a light source. Is done. A liquid crystal display device, which is widely used in various fields as a favorite of a next-generation display device, is a representative of the latter transmittance control type.

Further, a projection type liquid crystal display device for displaying a large screen is known. In this projection type liquid crystal display device, light from a lamp is condensed and incident on a liquid crystal panel, and the transmitted light beam is projected on a screen by a projection lens to display an image having a large screen size. That is, the projection type liquid crystal display device enlarges and projects the light beam transmitted through the liquid crystal panel, which two-dimensionally modulates the intensity of the transmitted light beam, by an optical system to display a large screen image.

In recent years, rear type liquid crystal projectors incorporating the projection type liquid crystal display device have been developed. These rear-type liquid crystal projectors have characteristics of being smaller and lighter than conventional CRT type projectors, and are expected to develop in the future. In particular, such a rear-type liquid crystal projector is expected to have high luminance and low cost.

Conventionally, as a color display system of such a projection type liquid crystal display device, one liquid crystal panel is associated with each of red, that is, R light beam, green, that is, G light beam, and blue B light beam, and a dichroic mirror is used. There are known a three-panel liquid crystal projector that separates and combines color components, and a single-panel liquid crystal projector provided with a color absorption filter, a so-called color filter, for each pixel. The three-panel LCD projector is capable of high-brightness display because there is little reduction in efficiency due to color separation and synthesis, and the single-panel LCD projector can realize a low-cost system because it has only one liquid crystal panel. It is said that there is a characteristic.

On the other hand, for example, Japanese Patent Laid-Open No.
In recent years, as in No. 8, color separation is performed by a dichroic mirror, and the separated three-color light beams are guided to corresponding three-color pixels on two liquid crystal panels by microlenses. An inexpensive display system with a high luminance to some extent is being realized.

A typical example of this display method is shown in FIG.
And (b). As shown in FIG. 6A, this display method includes a light source 601, a dichroic mirror 602,
It comprises an optical stop 6020, a condenser lens 6021, a micro lens 603, a liquid crystal panel 604, a field lens 605, a projection lens 606, and a screen 607.

[0008] The dichroic mirror 602 is arranged to be inclined at a predetermined angle in order to separate light beams in respective wavelength ranges. For this reason, the white light from the light source is separated by the dichroic mirror 602 into the three primary colors R, G,
Beams 608R, G, and B in each wavelength range of B are separated. These beams 608R, G, and B are incident on the same liquid crystal panel 604 from different angles. At this time, the beams 608R, G, and B are respectively focused on three pixels corresponding to R, G, and B on the liquid crystal panel 604 by a single microlens 603 disposed on the liquid crystal panel 604.

At this time, the imaging position of each beam focused by the microlens 603 differs depending on the wavelength range of each beam, and the distance from the exit surface of the microlens 603 to the position where the beam is imaged is blue component, Green component and red component increase in order. In this display method, the imaging position FG of the green light beam 608G is set to be located within the green pixel area 609G of the liquid crystal panel 604, as shown in FIG. B light beam 608B
Is formed in the blue pixel region 6 of the liquid crystal panel 604.
09B is closer to the microlens 603 than the liquid crystal panel 60.
4 is located closer to the screen 607 than the red pixel area 609R.

The beams 608R, G, B of these color components
After the transmittance is controlled by the liquid crystal panel 604,
The light passes through a field lens 605 and a projection lens 606 and is enlarged and projected on a screen 607.

With this structure, a single-panel type color display without using a color filter can be performed. Since a dichroic mirror is used for color separation / combination, a decrease in efficiency at the time of color separation is small. Therefore, it is possible to realize a liquid crystal projector that has a simple structure, is inexpensive, and can also expect a light condensing effect by a microlens.

[0012]

However, in such a display system, when a light beam is condensed by a microlens, a light beam of a certain color component cannot be completely condensed and spreads so that an aperture of a pixel region of a different color component adjacent to the light beam spreads. There is a problem in that the light enters the portion and lowers the color purity.

That is, in an illumination light source using a combination of a discharge type lamp such as a metal halide lamp used for a liquid crystal projector and various reflectors such as an elliptical reflector, the illumination light is not parallel light due to the size of the light emitting body of the lamp. And has a certain spread angle with respect to the optical axis. In this illumination optical system, a stop is inserted so that each light beam separated for each color component is incident only on the opening of the corresponding color component pixel region. However, in general, a microlens has an aberration, so that even parallel light is not focused at one point, and it is difficult to focus a light beam having a spread angle at a focal position of the microlens. It is.

In this liquid crystal projector, the focused image of the R light beam, G light beam and B light beam by the microlens is formed on the aperture plane in the pixel area corresponding to the focal plane of the microlens by the difference of the image formation position due to the difference in wavelength. The light beam of the predetermined wavelength component is incident not only on the opening of the pixel region that should be focused but also on the opening of the adjacent pixel region without being completely condensed due to the difference and the aberration of the microlens.

This will be described with reference to FIG. The pixel regions 701R, G, and B for each color component in the liquid crystal panel have openings 702R, which are regions through which light beams of the respective color components are transmitted.
G and B are arranged. These openings 702R, G, B
In, the converged images 703R, 703R, 703B, 703R, 703B, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R, 703R,

As shown in FIG. 7, light beams 704G and 704B from the adjacent green pixel region 701G and blue pixel region 701B enter the opening 702R in the red pixel region arranged at the center. Therefore, the light beam emitted from the opening 702R in the red pixel region is a so-called mixed color light beam in which a color component different from the primary color R light beam is mixed.

As can be seen from FIG. 6, since the G light beam is set so as to form an image in the pixel area 609G by the microlens, the focused image for the G light beam becomes small and easily transmitted. While B
The light beam and the R light beam are respectively applied to the pixel area 609B.
And 609R, the focused images for the B light beam and the R light beam may spread and enter adjacent pixel regions.

As described above, when the ratio of the mixed color light beam to the display light beam to be originally incident on the opening of the corresponding pixel area, that is, the total transmittance of the display light beam and the mixed color light beam is 100%. Is defined as the ratio of the transmittance of the mixed color light, that is, the% display value.

When R is a display pixel, the transmittance of the display light beam incident on the red pixel region, that is, the R light beam is represented by T.
r, when the transmissivities of the mixed color light beams incident on the red pixel region, that is, the G light beam and the B light beam are Tg and Tb, respectively, the color mixture ratio for the R light beam is (Tg + T
b) / (Tr + Tg + Tb).

FIG. 8 shows how the color purity of the display color decreases with respect to the color mixture ratio in the liquid crystal projector as described above.
The XY chromaticity diagram of FIG. It can be seen that as the color mixing ratio increases, the display color approaches white, ie, approaches W. Also,
Among the three colors of R, G, and B, R has a color mixing ratio of 0.
Since the distance from the% state to W is long, it can be seen that the color purity is greatly reduced. Since the intensity of the spectrum on the long wavelength side of the metal halide lamp is small, the intensity of the R light beam, which is the integrated value, becomes relatively smaller than the B light beam and the G light beam, and the B light beam and the G light beam This is because it is easier to mix colors than a light beam. It has been found that this tendency increases as the arc length of the metal halide lamp decreases, and the spectral intensity also decreases.

Japanese Patent Application Laid-Open No. Hei 4-60538 discloses that the use of a dichroic mirror increases the efficiency over the color filter system, but the above-mentioned problem in display quality is hardly specified. . Further, it is described that only a condensed image fits in an opening by a desk calculation based on a size of a light emitting arc of a light source lamp, a focal length of a condenser lens of an illumination system, and a focal length of a microlens.

However, in actuality, as described above, due to the problem of color mixing due to microlens aberration and the problem of reduced light use efficiency, a liquid crystal projector with a high display quality and high color purity is bright. Practical application is difficult.

Therefore, the present invention has been made to solve the above-mentioned problems, and in a single-panel system using no color filter, it is possible to improve color mixing of other colors in red having relatively low intensity. It is another object of the present invention to provide a display device that can reduce a loss of light amount due to a mismatch between an opening in a pixel region and a focused image of a light beam focused on the opening.

[0024]

According to the present invention, there is provided a display panel having a light modulation layer for controlling light transmittance, and a light source from a light source. Separating means for separating light into at least a first light flux group of a first wavelength component and a second light flux group of a second wavelength component having a higher intensity than the first light flux group; Imaging means for causing the first light flux group to form an image on the predetermined transmission area while being incident on a predetermined transmission area of the display panel; and a modulated light whose transmittance is controlled by a light modulation layer of the display panel on a screen. And a projection device for projecting.

According to the fourth aspect, an array substrate provided with driving means for driving the first electrode disposed for each pixel region, and the second electrode disposed to face the array substrate and facing the first electrode An opposing substrate having the first substrate and the first substrate interposed between the array substrate and the opposing substrate.
A liquid crystal display panel having a liquid crystal layer that controls the transmission intensity of light transmitted from the array substrate side to the counter substrate side according to the electric field intensity between the electrode and the second electrode; and at least light source light from a light source. A first light flux group having a first wavelength component and the first light flux group;
Separating means for separating the light into a second light flux group of a second wavelength component having a higher intensity than the light flux group; and causing the first and second light flux groups to enter the pixel region provided on the array substrate of the liquid crystal display panel. Image forming means for forming an image of the first light flux group on the pixel region; and projecting means for projecting light whose transmission intensity is controlled by a liquid crystal layer of the liquid crystal display panel onto a screen. A display device is provided.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a display device according to the present invention, particularly, a projection type liquid crystal display device will be described in detail with reference to the drawings. FIG. 1A is a diagram schematically showing a configuration of a projection type liquid crystal display device according to the display device of the present invention, and FIG. 1B is a diagram showing a light beam of each color component incident on the liquid crystal panel. It is a figure showing a situation.

That is, as shown in FIG. 1A, the projection type liquid crystal display device has a light source unit 1 functioning as a light source.
1. Condenser lens 16 functioning as optical means, dichroic mirror 17 functioning as separating means, micro lens 18 functioning as image forming means, liquid crystal panel 19 functioning as display panel, field lens 114 functioning as projecting means, and projection lens 115 and a screen 116.

The light source section 11 has a metal halide lamp 12 for generating white light as light source light, an elliptical reflector 13 for reflecting the generated white light, a light flux correcting lens 14, an aperture 15, and the like. Further, the elliptical reflector 13 is subjected to a process of cutting the UV light beam and the IR light beam, thereby preventing an extra temperature rise of the optical system.

The condenser lens 16 substantially parallelizes the divergent white light that has passed through the stop 15 in the light source unit 11. The dichroic mirror 17 separates the white light into light beams as a plurality of wavelength components, that is, light beams as a luminous flux group of color components. The dichroic mirror 17 emits light beams of red, green, and blue wavelength components from the white light, that is, an R light beam. A dichroic mirror 1 arranged at a predetermined angle with respect to the optical axis so as to separate the G light beam and the B light beam.
7R, 17G and 17B.

The microlenses 18 are provided on the surface of a counter substrate 19a of a liquid crystal panel 19, as shown in FIG. The micro lens 18 is provided with an R light beam 112 separated by the dichroic mirror 17.
The R, G light beam 112G, and B light beam 112B are applied to the corresponding pixel regions 111R, 111G,
The light is guided to 111B, and each beam is imaged in the liquid crystal panel 19.

The focusing action of the light beam by the micro lens 18 differs depending on the color component of each beam, that is, the wavelength range. That is, since the refractive index generally differs depending on the wavelength of the light beam, the light beams having different wavelengths are focused at different positions. In this case, the focal length of the micro lens 18 is set such that the R light beam 112R is focused on the pixel region 111R in the liquid crystal panel 19 or in the vicinity thereof. That is, the image forming position FR of the R light beam 112R is set so as to be located at or near the corresponding pixel region 111R.

For this reason, both the image forming position FG of the G light beam 112G having a shorter wavelength than the R light beam 112R and the image forming position FB of the B light beam 112B are the R light beam 112R.
A distance shorter than the imaging position FR of the micro lens 1
Located on the 8th side. Therefore, the G light beam 112G is
An image is formed on the microlens 18 side of the pixel region 111G in the liquid crystal panel 19, and a widened image is formed in the pixel region 111G. The B light beam 112B is
An image is formed further on the microlens side than the light beam 112G, and an image having a wider spread than the G light beam 112G is formed in the pixel region 111B.

The liquid crystal panel 19 has a first
An array substrate 19b provided with a pixel electrode as an electrode and a thin film transistor or TFT as a driving means for driving the pixel electrode, and a counter substrate 19a disposed opposite to the array substrate 19b and provided with a counter electrode as a second electrode And a liquid crystal layer 19c functioning as a light modulation layer sandwiched between the array substrate 19b and the counter substrate 19a. Pixel regions 111R, 111G, and 111B are provided on the array substrate 19b so as to correspond to light beams of the respective color components.

The field lens 114 is connected to the liquid crystal panel 1
9, the light beams 112R and 112G of the respective color components transmitted through
Gives convergence to 112B. The projection lens 115 includes the light beams 112R and 11 that have passed through the field lens 114.
2G and 112B are projected on the screen 116.

In the projection type liquid crystal display device having the above-described structure, the metal halide lamp 1
The white light generated from 2 is reflected by the elliptical reflector 13 so as to have a converging property, and is guided to the condenser lens 16 via the light flux correcting lens 14 and the diaphragm 15. Then, the white light is transmitted to the condenser lens 16.
, And is guided to the dichroic mirror 17. The dichroic mirror 17 reflects the white light at different angles, so that the R light beam 112R including the red component and the G light beam 112R including the green component.
The light is separated into a B light beam 112B containing G and blue components.

The light beams 112R, 112G, 112B of the respective color components separated by the dichroic mirror 17
Is guided to the micro lens 18 and is focused in the liquid crystal panel 19. At this time, due to the converging action of the micro lens 18, the R light beam 112R is
Is formed on or near the array substrate 19b in the red pixel region 111R, and the G light beam 112G
The light beam 112R is imaged on the microlens side from the imaging position FR, and the B light beam 112B is imaged on the microlens side from the imaging position FG of the G light beam 112G.

Therefore, a focused image of the R light beam 112R is formed in the red pixel region 111R on the array substrate 19b of the liquid crystal panel 19. Further, the R light beam 112 is applied to the green pixel region 111G on the array substrate 19b.
G light beam 112 having a spot shape larger than the focused R image
An image of G is formed. Further, an image of the B light beam having a spot shape larger than that of the G light beam 112G is formed in the blue pixel region 111B on the array substrate 19B.

Each of the light beams 112R, 112R transmitted through the liquid crystal panel 19 according to the image signal of the image to be displayed.
The transmittance of G and 112B is controlled. The light beams 112R, 112G, and 112B that have passed through the pixel regions 111R, 111G, and 111B in the liquid crystal panel 19 are projected on a screen 116 by a projection lens 115 via a field lens 114.

Thus, a color image corresponding to the image signal is displayed on the screen 116. The liquid crystal panel applied to the above-mentioned projection type liquid crystal display device is configured as follows.

FIG. 2 is a plan view of a liquid crystal panel applied to the projection type liquid crystal display device, and FIG. 3 is a sectional view of the liquid crystal panel shown in FIG. 2 taken along line AA'-A. is there.
The liquid crystal panel 19 includes an array substrate 19b, a counter substrate 1
9a and a liquid crystal layer 19c.

The array substrate 19b is formed along a plurality of pixel electrodes 220 arranged in a matrix, a plurality of scanning lines 217 formed along rows of the plurality of pixel electrodes 220, and a plurality of columns of the plurality of pixel electrodes 220. A plurality of signal lines 21
4. A scanning line driving circuit (not shown) formed around a display area where a plurality of pixel electrodes 220 are arranged and sequentially driving a plurality of scanning lines, and a plurality of signal lines 2 formed around the display area
And a signal line driving circuit (not shown) for driving the driving circuit 14. Further, a plurality of polysilicon thin film transistors (hereinafter, referred to as polysilicon thin film transistors)
215 are formed near the intersections of the plurality of scanning lines 217 and the plurality of signal lines 214 corresponding to the plurality of pixel electrodes 220, respectively, and are driven via the corresponding scanning lines 217, respectively. It is used as a switching element for supplying a video signal voltage from the signal line 214 to the corresponding pixel electrode 220.

The opposing substrate 19a includes a plurality of pixel electrodes 220
The liquid crystal layer 19c is held between the array substrate 19b and the counter substrate 19a. The microlenses 18 are assigned to a set of pixel electrodes 220 each associated with one of the three primary colors.
Is fixed to the opposing substrate 19a at a position opposing to.

Here, the liquid crystal panel 19 will be further described together with the manufacturing steps. As the semiconductor layer 215A of the polysilicon TFT 215, an amorphous silicon film is deposited on the glass substrate 211 by about 500 angstroms by a plasma CVD method (PECVD method), dehydrogenated, and then polycrystalline silicon is formed by a laser annealing method. It is formed by patterning in an island shape.

Subsequently, the semiconductor layer 215A is covered with a gate insulating film 223 deposited at about 1000 angstroms, and further formed with a molybdenum-tungsten alloy (MoW) layer deposited at 4000 angstroms.
By scanning the molybdenum-tungsten alloy layer, the scanning line 217 is formed.

The gate electrode 213 of the TFT 215 is constituted by a part of the scanning line 217. Impurities are self-aligned in the semiconductor layer 215 using the gate electrode 213 as a mask.
A, and the storage capacitance line 218 is formed.

Subsequently, the first interlayer insulating film 224 is
The silicon oxide film 17 is formed by depositing about 5000 Å of silicon oxide. Source and drain contact holes 272 are formed in the first interlayer insulating film 224.

Subsequently, the signal line 214 and the drain electrode 21
Reference numeral 9 denotes a multilayer structure of Mo / Al / Mo, which is formed on the first interlayer insulating film 224 so as to have a thickness of 6000 Å.

Thereafter, a second interlayer insulating film 225 is formed by depositing silicon nitride by about 5000 angstroms, and a light shielding layer 271 is formed on the second interlayer insulating film 225 corresponding to a portion of the display area which needs to be shielded from light. It is formed.

Subsequently, a third interlayer insulating film 226 is formed by depositing an acrylic resin to a thickness of about 2 μm, thereby flattening the unevenness in the display area and its peripheral area. This third interlayer insulating film 226 preferably has a thickness of about 1 to 6 μm. The pixel electrode 220 is formed after providing a contact hole 273 penetrating through the second interlayer insulating film 225 and the third interlayer insulating film 226. The third interlayer insulating film 226 is made of an organic material layer other than acrylic resin or SOG (spin-on glass) if flattening can be effectively achieved.
Etc. may be formed as a material. Further, the third interlayer insulating film 226 may be a composite layer in which an inorganic layer is stacked on an organic layer. If the organic material layer is photosensitive, the process can be shortened, but the organic material layer may not be photosensitive.

According to the above-described steps, the array substrate 1
9b is created. The counter substrate 19a was prepared by attaching a non-alkali glass 228 (n = 1.52) manufactured by Corning Corporation and a transparent counter electrode 229 to a thickness of 0.4 mm.
Polish until use.

When the array substrate 19b is formed as described above, an alignment film (not shown) made of, for example, polyimide is formed so as to entirely cover the pixel electrode 220, and is subjected to an alignment process. On the other hand, also for the counter substrate 19a, a similar alignment film is provided on the glass substrate 228 for the counter electrode 2a.
29 is formed so as to cover the entire surface and is subjected to an orientation treatment. At this time, in order to achieve a TN (twisted nematic) display mode as a liquid crystal layer 19c sandwiched between the array substrate 19b and the counter substrate 19a, the liquid crystal on each substrate is twisted by 90 degrees. The rubbing process is performed.

The array substrate 19b and the counter substrate 19a
These alignment films are faced to each other and bonded together, and then the sealing material is thermally cured. The liquid crystal layer 19c
Liquid crystal is injected by a conventionally known reduced pressure injection method from a liquid crystal injection port provided in a part of a sealing material, and then the injection port is sealed with a sealing material.

On the surface of the array substrate 19b and on the surface of the counter substrate 19a, polarizing plates (not shown) are arranged such that their deflecting surfaces are orthogonal to each other. On the other hand, as the microlens 18 to be bonded to the liquid crystal panel 19, a planar microlens array made by Nippon Sheet Glass was used. The micro lens 18 is a refractive index distribution type lens by selective ion diffusion. The glass used for forming the microlens is soda glass as a main component, and has a thickness of 2 mm.

A liquid crystal panel 19 is horizontally arranged below the microlens 18 with the opposing substrate 19a facing upward, and an ultraviolet-curable adhesive Loctite 349 is provided on the opposing substrate surface.
(N = 1.54) was applied and brought into close contact with the microlens surface. At this time, pressure was applied from the upper surface of the microlens, and the distance between the cured lens surface and the pixel opening surface, that is, the distance between the adhesive layer and the thickness of the counter substrate was set to 430 μm.

The alignment mark provided on the array substrate 19b in the liquid crystal panel 19 is adjusted to a predetermined position by focusing the alignment mark on the microlens 18, and then, is irradiated with ultraviolet rays (370 nm, 40W) for 4 minutes to be cured.

The micro lens 18 may be formed by molding a plastic or glass by a mold or machining, or may be of a type in which a resin lens is formed on a plane glass by a mold. Naturally, the present invention can also be applied to a type in which a resin is buried therein and a resin is buried therein.

The pixel thus formed has a pixel length of 71 μm.
With a delta arrangement of m, a pixel width of 84 μm, and a color pixel width of 28 μm, a pixel opening having a pixel opening width of 16 μm and a pixel opening length of 40 μm became possible.

By the way, as already described with reference to FIG. 7, in the conventional example, since the wavelength of green light is usually optimized, the focus image of the G light beam is focused small on the array substrate, and Each focus image of the light beam and the B light beam is large. Therefore, the transmittance of the G light beam is the highest.

On the other hand, when the focal length of the microlens 18 is shortened so as to optimize the wavelength of red light as in the projection type liquid crystal display device of this embodiment, as shown in FIG. Red pixel area 901R on substrate
The focus image of the R light beam on the upper side is small and focused, and the respective focus images of the G light beam and the B light beam on the green pixel region 901G and the blue pixel region 901B are larger than the focus image of the R light beam. Become. For this reason, the transmittance of the R light beam is highest.

In the projection type liquid crystal display device having such a configuration, a liquid crystal panel having the above-described pixel pattern is manufactured, and several samples are prepared by attaching a microlens 18 having a different focal length to the array substrate. Then, the transmittance of the display light beam, the transmittance of the mixed light beam, and the mixed color ratio of each sample were measured.

The color mixing ratio is defined as follows. That is, the ratio of the transmission amount of the mixed light beam to the transmission amount of all the light beams transmitted through the red pixel region, that is, the sum of the transmittances of the display light beam and the mixed light beam is 1
The ratio of the transmittance of the mixed color light when it is set to 00%, that is, the% display value is defined as the color mixing ratio.

When red is the display pixel, the transmissivity of the display light beam, that is, the R light beam, which passes through the red pixel region of the liquid crystal panel is Tr, and the mixed color light beam, that is, the G light beam, which passes through this red pixel region. And the transmittance of the B light beam is defined as Tg. When Tb is used, the color mixing ratio is (Tg + Tb) /
(Tr + Tg + Tb).

FIG. 10 shows the display light beam (R) with respect to the distance from the surface of the array substrate to the focal position of the macro lens.
The measurement results of the transmittance of the light beam (light beam) and the mixed color light beam (G light beam and B light beam) are shown.

In FIG. 10, the abscissa indicates that the focal position of the micro lens is behind the array substrate, that is, the screen side is positive, and the focal position of the macro lens is forward of the array substrate, that is, the counter substrate side is negative.

As shown in FIG. 10, even when the distance from the surface of the array substrate to the focal position is large, the increase rate of the mixed color light beam is not so large, and conversely, the decrease rate of the transmittance of the display light beam is smaller. Was found to be high.

Therefore, as shown in FIG. 11, it is possible to suppress the color mixing ratio to a low value. From this result, when the focal length of the microlens is changed with respect to the thickness of the counter substrate, the focal length of the microlens is adjusted so that the image position of the R light beam is in the red pixel region so as to optimize the red wavelength. It can be seen that the transmittance is improved and the color mixture ratio is reduced by setting the position to be. By applying the present invention, in a single-panel projection liquid crystal display device that does not use a color filter, if the color mixture occurs at the same rate because the light intensity on the long wavelength side of the metal halide lamp used as the light source is small, It is possible to solve the problem that the reduction in red purity is remarkable, and to realize a liquid crystal projector with high color purity and high brightness and high display quality.

In the above-mentioned measurement, the color mixture ratio with respect to the illumination angle was measured using a projection type liquid crystal display device having a microlens having an optimized focal length with the smallest color mixture ratio. Here, the illumination angle is an incident angle of each light beam incident on the microlens, and is indicated by a spread angle with respect to an optical axis passing through the lens center of the microlens. FIG. 4 shows a measurement result of the color mixing ratio with respect to the illumination angle. As shown in FIG. 4, the measurement result A of the color mixture ratio with respect to the illumination angle in the projection type liquid crystal display device of this embodiment was lower than the measurement result B of the conventional example in the illumination angle range of 0 to 3 degrees. . For example, when the illumination angle is 1.6 degrees, the color mixture ratio is reduced from 2% in the conventional example to 1.2%.

The color purity when the color mixture ratio changes is shown in the chromaticity coordinates of FIG. In FIG. 5, the primary colors are the colors of the light reflected from the dichroic mirror, that is, the R light beam, the G light beam, and the B light beam itself,
On the other hand, the color purity of the display color beam passing through the liquid crystal panel according to the conventional method and the present invention is shown.

As shown in FIG. 5, the color purity of the display color beam according to the example of the present invention is very close to the color purity of the primary color, and it can be seen that the decrease in color purity due to color mixing is suppressed. From this measurement result, it can be seen that the projection type liquid crystal display device according to the present embodiment shows good color purity characteristics.

As described above, according to the projection type liquid crystal display device of the present invention, the problem that the metal halide lamp has a low spectral intensity on the long wavelength side and the red color purity is remarkably reduced is solved. A single-panel liquid crystal projector that does not use a color filter with good color purity and high brightness and high display quality can be realized.

[0071]

As described above, according to the present invention, in a single-panel system using no color filter, it is possible to improve the color mixture of other colors in red having a relatively low intensity and to improve the aperture in the pixel region. And a display device capable of improving the loss of the light amount due to the mismatch between the light beam focused on the aperture and the focused image of the light beam.

[Brief description of the drawings]

FIG. 1A is a diagram schematically showing a configuration of a projection type liquid crystal display device according to a display device of the present invention.
(B) is a diagram showing a state of a light beam of each color component incident on the liquid crystal panel.

FIG. 2 is a plan view of a liquid crystal panel applied to the projection type liquid crystal display device shown in FIG.

FIG. 3 is a sectional view of the liquid crystal panel shown in FIG.
It is sectional drawing cut | disconnected by the A line.

FIG. 4 is a diagram showing measurement results of a color mixing ratio with respect to an illumination angle in a conventional display device and the display device of the present invention.

FIG. 5 is a chromaticity coordinate diagram showing the color purity of the conventional display device and the display device of the present invention for the primary colors.

6A is a diagram schematically showing a configuration of a projection type liquid crystal display device in a conventional display device, and FIG. 6B is a diagram showing light of each color component incident on a liquid crystal panel. It is a figure showing a situation of a beam.

FIG. 7 is a view showing a focused image of a light beam of each color component on an array substrate of the display device shown in FIG. 6;

FIG. 8 is a diagram for explaining a decrease in color purity due to color mixing in a conventional display device.

FIG. 9 is a diagram illustrating a focused image of a light beam of each color component on an array substrate of the display device illustrated in FIG. 1;

10 shows a display light beam (R light beam) and a mixed color light beam (G light beam and B light beam) with respect to the distance from the surface of the array substrate to the focal position of the macro lens in the display device shown in FIG. FIG. 9 is a diagram showing the measurement results of the transmittance of FIG.

FIG. 11 is a diagram illustrating a measurement result of a color mixture ratio in the display device illustrated in FIG. 1;

[Explanation of symbols]

 11 light source unit 17 dichroic mirror 18 microlens 19 liquid crystal panel 19a counter substrate 19b array substrate 19c liquid crystal layer 111 (R, G, B) pixel area

Claims (6)

[Claims] 1. A display panel having a light modulation layer for controlling light transmittance, a light source light from a light source, a first light flux group of at least a first wavelength component, and a second light flux group having a higher intensity than the first light flux group. Separating means for separating the first and second light flux groups into a predetermined transmission area of the display panel; and separating the first light flux group into the predetermined transmission area. A display device comprising: an image forming unit that forms an image; and a projecting unit that projects modulated light whose transmittance is controlled by a light modulation layer of the display panel onto a screen. 2. The image forming apparatus according to claim 1, wherein the first wavelength component has a longer wavelength than the second wavelength component, and the imaging unit moves the second light flux group a distance shorter than a position where the first light flux image is formed. The display device according to claim 1, wherein the image is formed by: 3. An optical unit for converting the first and second light beams incident on the display panel into a substantially parallel light beam group having a spread angle of 3 degrees or less with respect to an optical axis. The display device according to claim 1. 4. An array substrate provided with driving means for driving a first electrode disposed for each pixel region, and a counter substrate provided with a second electrode opposed to the array substrate and opposed to the first electrode. And the transmission intensity of light that is sandwiched between the array substrate and the opposing substrate and that transmits from the array substrate side to the opposing substrate side according to the electric field intensity between the first electrode and the second electrode. A liquid crystal display panel having a liquid crystal layer for controlling a light source, a light source light from a light source being converted into at least a first light flux group of a first wavelength component and a second light flux group of a second wavelength component having a higher intensity than the first light flux group. Separating means for separating, the first and second light flux groups being incident on the pixel region provided on an array substrate of the liquid crystal display panel,
Imaging means for forming an image of the first light flux group on the pixel area; and projection means for projecting light whose transmission intensity is controlled by a liquid crystal layer of the liquid crystal display panel onto a screen. Display device. 5. The image forming apparatus according to claim 1, wherein the first wavelength component has a longer wavelength than the second wavelength component, and the imaging unit moves the second light flux group a distance shorter than a position where the first light flux group is imaged. The display device according to claim 4, wherein the image is formed by: 6. An optical means for converting the first and second light fluxes incident on the liquid crystal display panel into substantially parallel light fluxes having a spread angle of 3 degrees or less with respect to an optical axis. The display device according to claim 4.