JPH07325214A - Color filter and projection type display device using the same - Google Patents

Abstract

PURPOSE:To provide a projection type display device which is small in size, light in weight and excellent in color reproducibility. CONSTITUTION:Nearly parallel beams emitted from a light source 331 are made incident on a color filter 16. The light beams of three primary colors whose purity is high are transmitted through the color filter 16, and unnecessary light beams of cyan and yellow are removed by the filter 16. The reflected light beam from the filter 16 is made incident on a light valve constituted of a transmission type liquid crystal panel 338 and a polarizing plate 333. The liquid crystal panel 338 has picture element structure where the color filter 336 transmitting the component light beams of red, green and blue corresponding to the respective picture elements is arranged. The emitted light beam from the light valve is enlarged and projected on a screen by a projection lens 339. By using the color filter in a projection type display device using three PD liquid crystal panels, the color purity of the projected image is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter having a stack of dielectric thin films for cutting cyan and yellow colors and a projection type display device for enlarging and projecting a display image on a liquid crystal panel.

[0002]

2. Description of the Related Art A method for illuminating an image formed on a small light valve according to a video signal with illumination light and enlarging and projecting the optical image on a screen by a projection lens in order to obtain a large-screen image. Is well known in the past. In particular, in recent years, a projection type display device using a liquid crystal panel as a light valve has attracted attention (for example, Japanese Patent Laid-Open No. 2-25).
No. 0015).

Various methods have previously been proposed for performing color display using a liquid crystal panel. For example, 2
There are a GH method that uses a color dye mixed in liquid crystal, an ECB method that uses the birefringence of the liquid crystal, a color filter method that combines a color filter and a liquid crystal cell, and the like. In the color filter system, red, green, and blue color filters are finely processed and attached to each pixel of the liquid crystal panel. Since it has a simple structure and can support full-color display, it has been considerably put into practical use in combination with a simple matrix system or an active matrix system.

FIG. 37 shows an example of the construction of a conventional projection display device of the color filter type. The lamp 331a emits light containing red, green, and blue color components (hereinafter, referred to as white light), and the light emitted from the lamp 331a is converted into nearly parallel light by the concave mirror 331b.
The substantially parallel light from the concave mirror 331b has its infrared rays and ultraviolet rays removed by a filter that cuts ultraviolet rays and infrared rays (hereinafter referred to as UVIR cut filter), then passes through the field lens 332 and enters the light valve 344.

The light valve 344 is a twisted nematic liquid crystal panel (hereinafter referred to as a TN liquid crystal panel) 338.
And polarizing plates 333 provided on the incident side and the emitting side thereof
a, 333b. The liquid crystal panel 338 is
A counter substrate 334 on which a counter electrode is formed, and a thin film transistor (hereinafter referred to as a pixel electrode and a switching element)
The TN liquid crystal 337 is sandwiched between the TN liquid crystal 337 and the array substrate 335 on which the glass substrate 3 is formed.
On the 34 side, there is a pixel structure in which a color filter 336 that transmits red, green, and blue light is arranged corresponding to each pixel.
A color image is formed on the light valve 344 as a change in transmittance according to a video signal. This color image is enlarged and projected on a screen (not shown) by the projection lens 339.

[0006]

The color reproducibility of a color filter type projection display device is determined by the spectral characteristics of the color filter and the light source. In particular, in order to obtain good color reproducibility, the spectral characteristics of the color filter and the matching with the light source are important.

In the projection display device shown in FIG. 37, the spectral characteristics of the color filter are shown in FIG. 39.
The spectral characteristics of each of the red, green, and blue color filters are not steep, and their transmission wavelength bands are wide. Further, the spectral characteristic of the light source used for the projection display device such as the metal halide lamp is a continuous spectrum as shown in (FIG. 7), and the spectral characteristic of the light transmitted through each color filter is considerably wide band. . As a result, there is a problem that the color reproducibility of each pixel of the projected image is deteriorated.

Further, the color filter used in the liquid crystal panel has a drawback that it is inferior in light resistance and durability. In particular, when a light source of high brightness and high output is used as in a projection display device, the amount of heat generated by absorption of unnecessary light by the color filter also increases, resulting in severe deterioration.

In order to solve the above problem, it is possible to use a color selective filter to reflect and remove unnecessary color components of light emitted from the light source. In order to realize this, a filter having a high reflectance only for light in a very narrow wavelength band is required.

An interference filter (hereinafter referred to as a color filter) utilizing a dielectric multilayer film is generally used to reflect light in a predetermined wavelength range. In this dielectric multilayer film, a high refractive index layer and a low refractive index layer are alternately laminated on a glass substrate, and the final layer counted from the glass substrate side has an optical film thickness of 0 in order to suppress ripples in the transmission region. It is general that the low refractive index layer has a thickness of 0.125λ and the optical thickness of the other layers is 0.25λ. In addition, λ is a reflection peak wavelength.

FIG. 6 shows the spectral transmittances in the case of a 12-layer structure in which the odd layers are high refractive index layers and the even numbers are low refractive index layers from the glass substrate (refractive index 1.52) side. The high refractive index layer has a refractive index of 2.30, and the low refractive index layer has a refractive index of 1.30.
46 SiO2 is used. Also, the reflection peak wavelength λ
Is 575 nm.

As can be seen from FIG. 6, the transmittance is 50%.
% Width of wavelength (hereinafter referred to as half width) is 200 nm
As described above, the low transmittance region covers a wide range of green, yellow, and red. Therefore, the wavelength band is 50
When it is desired to reflect only yellow light or cyan light having a wavelength of nm or less, it is difficult with the conventional configuration.

Approximately yellow is light in a band centered around 580 nm, and cyan is 490 nm.
Light in a band centered around the vicinity. As a band, for example, it may be considered that the band is about ± 20 nm with respect to the center wavelength. The spectral transmittance of the red, green, and blue color filters of the liquid crystal panel depends on the constituent material of the filters. Further, it is necessary to achieve white balance with light that has passed through the red, green, and blue filters, but the white balance depends on the spectral distribution emitted by the light source.

Therefore, the central wavelengths and bands of yellow light and cyan light referred to in the present invention depend on the spectral characteristics of the color filter or / and the spectral characteristics of the light source and the color purity (color characteristics) of the optical image on the screen to be obtained. However, it is not always unique.

The color filter of the present invention is designed so that the display image of a liquid crystal panel or the like has good color purity in consideration of the spectral transmittance of the color filter and the spectral distribution of the light source. Therefore, the yellow light and the cyan light cut by the color filter depend on the light source, the color filter and the like and cannot be uniquely determined. However, it will be clear that the characteristics and the like of the light source and the color filter are uniquely determined. This is because the yellow light and the cyan light to be cut are determined so as to secure the brightness and color purity of the display image above a certain level. The main technical idea of the color filter of the present invention is not limited to the band and wavelength of the yellow light and the cyan light to be cut, and the main purpose is a thin film capable of satisfactorily cutting only the cyan light and the yellow light with a transmission type color filter. In the configuration. However, as a matter of course, when the light source strongly emits light of a specific wavelength, it goes without saying that the thin film structure needs to be set so as to cut the specific wavelength.

In this case, the technical idea of the color filter of the present invention, and in a broader sense, the technical idea of the projection display device, includes the type of lamp of the light source and the thin film structure of the color filter and / or the dichroic mirror. It can be said that it is in combination with color separation means.

In the liquid crystal panel 338 using TN liquid crystal, it is necessary to use a polarizing plate 333 to make incident light linearly polarized. It is necessary to dispose a polarizing plate also on the emission side of the liquid crystal panel 338 in order to detect the light modulated by the liquid crystal panel. In other words, a polarizing plate (hereinafter referred to as a polarizer) for converting light into linearly polarized light and a polarizing plate (hereinafter referred to as an analyzer) for detecting modulated light are provided before and after the TN liquid crystal panel 338. It is necessary to arrange one polarizing plate. When the pixel aperture ratio of the liquid crystal panel is 100% and the amount of light incident on the polarizer is 1, the amount of light emitted from the polarizer is 40%, the transmittance of the liquid crystal panel is 80%, and the transmittance of the analyzer is 80%. Therefore, the total transmittance is 0.4 × 0.8 × 0.8 = about 25%, and only 25% of light can be effectively used. Therefore, the TN liquid crystal panel can realize only low-luminance image display.

Most of the light lost by the polarizing plate or the like is absorbed by the polarizing plate and converted into heat. The heat heats the liquid crystal display panel by the polarizing plate itself and radiant heat. In the case of a projection display device using a liquid crystal panel as a light valve, the amount of light incident on the polarizing plate 333a is tens of thousands of lux or more. Therefore, when the TN liquid crystal panel 338 is used for the projection type display device, the polarizing plate, the panel and the like are in a high temperature state, which causes remarkable performance deterioration in a short period of time.

As described above, the TN liquid crystal panel 338.
The projection display device that uses a light valve as a light valve has a low light utilization rate and a screen brightness of a projected image is low. Therefore,
A projection display device using a polymer dispersed (PD) liquid crystal panel that does not use a polarizing plate has been proposed. The PD liquid crystal panel as a light valve used in the projection display device performs light modulation by scattering or transmitting incident light.

Operation of PD liquid crystal panel (see FIG. 40)
A brief description will be given using (a) and (b). (Fig. 40 (a)
(B) is an explanatory view of the operation of the PD liquid crystal panel. The polymer dispersed liquid crystal layer 192 includes a counter electrode 341 and a pixel electrode 342.
It is held in between. In the liquid crystal layer 192, a water-drop-like liquid crystal (hereinafter, referred to as water-drop-like liquid crystal) 211 is a polymer 38.
Dispersed in 2. A TFT (not shown) or the like is connected to the pixel electrode 342, and a voltage is applied to the pixel electrode 342 by turning the TFT on and off to change the alignment direction of liquid crystal molecules on the pixel electrode 342 to modulate light. (Fig. 40
As shown in (a)), when no voltage is applied,
The water droplet liquid crystals 381 are oriented in irregular directions. In this state, the polymer 382 and the water droplet liquid crystal 381
A refractive index difference occurs between and, and the incident light is scattered. Here (Fig. 4
As shown in 0 (b), when a voltage is applied to the pixel electrode 342, the directions of the liquid crystal molecules are aligned. When the refractive index when the liquid crystal molecules are aligned in a certain direction is matched with the refractive index of the polymer 382 in advance, incident light is not scattered and the array substrate 3 is not scattered.
It is emitted from 35. The PD liquid crystal panel is not limited to the one in which the liquid crystal is in the form of water droplets 381, and the polymer 382
There is also a type in which liquid crystal is filled in the sponge-like hole. References herein to PD liquid crystals are not limited to one of the above types.

As a device that realizes good color reproducibility and high brightness display, a projection display device using three PD liquid crystal panels has been proposed. The device has one lamp and three
A liquid crystal panel is provided. The three PD liquid crystal panels are in charge of modulating red, green and blue lights, respectively. 1
The white light emitted from the two lamps is split into red, green and blue light paths (hereinafter referred to as color separation) by a dichroic mirror. A PD liquid crystal panel is arranged in each of the optical paths. The light modulated by each liquid crystal panel is combined into one optical path by a dichroic mirror (hereinafter referred to as color combination), and enlarged and projected on a screen by a projection lens or the like.

However, in a projection display device using a PD liquid crystal panel as a light valve, since all natural light (called random polarization) is used, the PS polarization components orthogonal to each other in a color separation or color synthesis optical system are dispersed. Due to the difference in the characteristics, the spectral characteristics of the dichroic mirror and the like deteriorate. Therefore, the hue of the projected image is inferior to that of the projection display device using the TN liquid crystal panel as a light valve. This is because a dichroic mirror or a dichroic prism tilted at 45 degrees with respect to the optical axis is used for the color separating means and the color combining means.

This dichroic mirror or dichroic prism has a structure in which transparent dielectric multilayer films having different refractive indexes are laminated on a transparent plate or a prism surface, and a multilayer film structure is formed by an optical interference effect with almost no light absorption loss. It has a function of separating a transmission wavelength band and a reflection wavelength band at an arbitrary wavelength according to the above. It is known that in such an optical multilayer film, as the incident angle θ of light increases from zero, the difference in spectral characteristics corresponding to P-polarized light and S-polarized light becomes remarkable with respect to the surface on which the multilayer film is formed. .

Here, P-polarized light and S-polarized light will be defined. P-polarized light refers to light that oscillates on a plane including the plane normal to the dichroic mirror (in the case of a dichroic prism, the normal to the light separating surface) and the traveling direction of the light ray. S-polarized light refers to light that vibrates in a direction perpendicular to the vibrating direction of the P-polarized light.

In the case of a projection type display device using a TN liquid crystal panel, since a polarizing plate is used, its polarization axis is arranged so as to use only P polarized light or S polarized light, and only one polarized light is used. Used. Therefore, even if the spectral dependence of the dichroic mirror or the dichroic prism is polarization-dependent, sharp color separation characteristics can be obtained, and a good hue of the projected image can be obtained.

On the other hand, when a PD liquid crystal display panel is used, the light incident on the liquid crystal panel is randomly polarized light (both P-polarized light and S-polarized light), so that the dichroic mirror and dichroic prism have spectral characteristics. In, the spectral action corresponding to the average value of P-polarized light and S-polarized light is shown. Therefore, the color purity decreases. Therefore, the hue of the color-synthesized projection image is inferior to that of the projection display device using the TN liquid crystal panel.

A technique for solving the above-mentioned problems is disclosed in Japanese Patent Laid-Open No. 3-8.
It is disclosed in Japanese Patent Publication No. 7721. In the projection display device, the incident angle θ on the dichroic mirror is 10 ° <θ <4.
It is set to 0 ° to reduce the deterioration of the hue caused by the use of the dichroic mirror.

As disclosed in the above publication, by satisfying the condition that the arrangement angle of the dichroic mirror is 10 ° <θ <40 °, the polarization dependence of the spectral characteristic of the dichroic mirror is reduced. Therefore, the problem of hue deterioration that occurs in a dichroic mirror or the like is improved.

In the projection display device disclosed in the above publication, the color separation characteristic for random polarized light is improved by setting the angle between the dichroic mirror and the optical axis to be 40 ° or less. Therefore, the deterioration of hue can be reduced. However, the following problems occur.

In the specification of the present invention, the terms hue and color purity may be used interchangeably. For example, improving the color purity means increasing the area of the triangle connecting the R, G, and B chromaticity points in the XY chromaticity chart. The first problem is that the back focus of the projection lens becomes long. Since the angle of the dichroic mirror with respect to the optical axis is small, the distance between the projection lens and the panel becomes long. To lengthen the back focus, it takes a lot of load to design the projection lens. There are problems such as an increase in the number of lenses and an increase in the lens diameter. These increase the cost of the liquid crystal projection display device and increase the system size.

The second problem is system size. The area (volume) occupied by the color separation / color synthesis optical system by the dichroic mirror is larger than that of the projection display device using the TN liquid crystal panel arranged at an angle of 45 degrees (referred to as 45 degree incidence). The optical system size is directly reflected in the system size. System size is an important issue for popularization as home electric appliances. The projection type display device using the CRT projection tube as a light valve has a problem in that the system size is large, and has not been widely used as a home television. Further, since the dichroic mirror requires a large area as compared with the case of 45-degree incidence, the cost is increased.

A projection type device using a liquid crystal panel as a light valve is characterized in that it can be miniaturized. If the size of the optical system becomes large, there is no difference from the projection type display device using the CRT projection tube. Therefore, it will not be widely used as a home TV.

The present invention solves the above conventional problems, and provides a color filter for selectively reflecting cyan light and yellow light and a projection display device using the color filter which is bright and has excellent color reproducibility. To do.

[0034]

In order to solve the above problems, the color filter of the present invention comprises a first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light. The first dielectric multilayer film and the second dielectric multilayer film are laminated on both sides or one side of a transparent substrate, and a high refractive index layer and a low refractive index layer are alternately laminated on the transparent substrate side. The final layer counting from the above is a low refractive index layer.

The optical thickness of the first dielectric multilayer film is
Low refractive index layer is approximately 0.375λ_Y, The final layer of the high refractive index layer
Excluding layer is approximately 1.125λ_YAnd the final layer of the low refractive layer is
0.188λ_Y(However, λ_YIs the center wavelength of yellow light)
And the optical thickness of the second dielectric multilayer film is low.
The folding rate layer is approximately 0.625λ_CExcluding the last layer of high refractive index layer
Layer is approximately 1.875λ_CAnd the final layer of the low refractive layer is approximately 0.
313λ_C(However, λ _CIs the center wavelength of cyan light)
It

The first dielectric multi-layer film and the second dielectric multi-layer film.
In the layer film, the low refractive index layer is MgF ₂, SiO₂, Al₂
O₃And the high refractive index layer is TiO 2.₂, ZnS,
CeO₂, ZrTiO_Four, HfO₂, Ta₂O_Five, ZrO₂of
It is either. Preferably the high refractive index layer is TiO₂And Z
It has a structure of at least two layers in which nS are alternately laminated.
Is desirable.

The projection display device of the present invention includes a light source that emits white light, a liquid crystal panel that is illuminated by the light emitted from the light source and forms an optical image according to a video signal, and the color filter of the present invention. Projection means for projecting the optical image modulated by the liquid crystal panel.

The color filter is arranged on the light emitting surface of the light source and reflects unnecessary cyan light and yellow light. The liquid crystal panel has a pixel structure having a color filter that transmits red, green and blue light corresponding to each pixel. A PD liquid crystal panel or a TN liquid crystal panel is used as the liquid crystal panel. Further, when the TN liquid crystal panel is a reflection type, the polarization beam splitter (PBS) is used to modulate the light obtained by separating the P polarized light and the S polarized light by the panel.

As the light source, it is preferable to use a metal halide lamp containing neodymium (Nd) as an enclosed metal element. The lamp has a long life and good electricity-to-light conversion efficiency. However, it strongly emits light in the emission spectrum around 490 nm and around 577 nm. Therefore, the color filter is configured to cut off light having at least one of the two wavelengths.

A second aspect of the projection display apparatus of the present invention is that the light source for emitting white light, the color filter of the present invention, and the light emitted by the light source are used as an optical path for red light, an optical path for green light and a blue light. Of the three light paths, a color separation means formed of a dichroic mirror or a dichroic prism, light modulation panels arranged in the respective three light paths, and an optical image formed by the three light modulation panels are substantially the same. It is provided with a projection means for superimposing and projecting at a position.

The color filter is arranged on the light emitting surface of the light source and reflects unnecessary cyan light and yellow light. As the light modulation panel, a PD liquid crystal panel, a panel which is developed by TI Company and forms an optical image as a change in the tilt of a micro mirror (hereinafter referred to as DMD. For details, see JP-A-4-230722.
(See Japanese Patent Laid-Open No. 5-196880)
Is exemplified.

A projection type display device according to the third aspect of the present invention comprises first and second liquid crystal panels having the same number of pixels, a field memory for holding a video signal as image data, and a data read from the field memory for a first time. The switching means applied to the first and second liquid crystal panels, the optical image formed by the light modulating means of the first liquid crystal panel, and the optical image formed by the second light modulating means are vertically shifted by half a pixel. The projection means for projecting is provided.

The first and second liquid crystal panels have mosaic color filters of three colors of red, green and blue, and have the same pixel pitch and pixel arrangement.

[0044]

As shown in (FIG. 6), in the dielectric multilayer film structure in which the optical film thickness per layer is λ / 4 (λ is the reflection peak wavelength), the half width of the high reflection region is narrow (50 nm or less). ) Color filters cannot be realized.

On the other hand, the optical film thickness ratio of the low-refractive index film and the high-refractive index film constituting the multilayer film is set to 1: X (X> 1),
The half width can be narrowed slightly by increasing X. However, as the film thickness ratio is increased, the stress in the low refractive index film and the stress in the high refractive index film are out of balance due to the internal stress of the thin film, which may cause cracks on the surface of the multilayer film.
Therefore, it is desirable that the optical film thickness ratio of the low-refractive index film and the high-refractive index film is not larger than 1: 3, but under this condition, the half-value width reflects only yellow light or sheaan light. Is not enough for.

Next, this type of interference filter has a spectral performance that, in addition to the reflection peak at the wavelength λ, the reflection peak appears periodically on the shorter wavelength side than the wavelength λ.
Moreover, it has a characteristic that the half width becomes narrower as the cycle is repeated. Therefore, it is sufficient to shift to the center wavelength of the yellow light or the sheaan light by utilizing the periodical reflection peak having the narrow half width. Specifically, the film thickness of the alternating multilayer film in which the optical film thickness ratio of the low refractive index film and the high refractive index film is 1: 3 may be relatively thick, and the half width corresponding to yellow light is 50 nm or less. It is desirable to shift the second period to realize the above, and to shift the third period to achieve the half width of 40 nm or less corresponding to cyan light.

In the case of yellow light reflection, the optical film thickness of the multilayer film is approximately 1.5 times, and the low refractive index layer has a thickness of 0.375.
λ, 1.125λ for the high refractive index layer, and approximately 2.5 times for cyan light reflection, 0.625λ for the low refractive index layer and 1.875λ for the high refractive index layer. Good.

When there is a risk of cracks due to the internal stress of the high-refractive-index film, which is thicker than the low-refractive-index film, the high-refractive-index layers per layer have almost the same refractive index and It is more desirable to form it as a combination of TiO ₂ and ZnS having the characteristics that the directions are opposite to each other, since the stress can be relaxed.

Although the reflection peak has the fourth and subsequent periods, it is not preferable in terms of durability because the thickness of the multilayer film becomes too thick.

When it is desired to cut both the yellow light and the cyan light with one filter, the first dielectric multilayer film for reflecting the yellow light and the second dielectric multilayer for reflecting the cyan light as described above. This can be achieved by synthesizing a membrane. But,
If the first and second dielectric multilayer films are successively laminated on one surface of the glass substrate forming the multilayer film, both the total number of layers and the film thickness are greatly increased, which may cause cracks. Therefore, it is not preferable. Therefore, the above problem can be solved by separately forming the first multilayer film and the second multilayer film on both surfaces of the glass substrate.

In the projection display device of the present invention, even if the light emitted from the lamp for the light source has a continuous spectrum, unnecessary components of light are removed by using the color filter of the present invention and the purity is high. It can be converted into white light composed of light components of three primary colors of red, green and blue.

As a result, the light band of each pixel corresponding to red, green and blue in the projected image can be made narrower than the light transmission band of the color filter. Therefore, it is possible to improve the deterioration of the hue of the projected image caused by the broadband spectral characteristics of the color filter, and it is possible to obtain a projected image with excellent color reproducibility.

Further, since the unnecessary light is removed by the color selecting means, the unnecessary light components that have been conventionally absorbed in the color filter are reduced, and the heat generation inside the color filter due to the light absorption is reduced, resulting in deterioration. Can be suppressed and the durability of the color filter can be improved.

The light source for illumination preferably has a metal halide lamp, in which case the color filter preferably reflects light having a wavelength of 577 nm in the emission spectrum of the metal halide lamp. The emission spectrum at said wavelength is very strong. Therefore, the color filter used in the projection display apparatus of the present invention is designed with the main point at the wavelength. Therefore, the projected image has a practically sufficient hue.

In a projection display device using three display panels for modulating red, green and blue lights, white light emitted by a lamp is separated into three optical paths of three primary colors by using color separation means.

A dichroic prism or a dichroic mirror is mainly used as the color separating means. Either of the above-mentioned elements may be used in the projection display apparatus of the present invention, but in order to facilitate the description, a dichroic mirror will be mainly described as an example.

It is known that the light reflected by the dichroic mirror has a wider band for S-polarized light than for P-polarized light. On the contrary, the light passing through the dichroic mirror is wider in the P polarized light than in the S polarized light band.

For example, if the dichroic mirror is R
In the case of a dichroic mirror that reflects light, the S-polarized component of the R light reflects light with a wide band wavelength, and the P-polarized component of R light transmits light with a wide band wavelength. Therefore, the S-polarized R light also reflects light close to the G light band, and the P-polarized R light also transmits light close to the G light band. That is, it means that the dichroic mirror cannot properly separate the R light. As shown in the conventional example, this is a factor that deteriorates the hue. In a TN liquid crystal display panel or the like, there is no problem because a polarizing plate is used and light modulation is performed using only one of P-polarized light and S-polarized light, but it is a problem in a display panel that does not use polarized light. The display panel corresponds to a PD liquid crystal panel, DMD or the like. Further, a display panel using PLZT may be applicable. Therefore, the technical idea of the projection display device of the present invention is applicable / applied to all cases where a display panel that modulates random light is used as a light valve.

In the projection type display device of the present invention, the color filter of the present invention is used, and among the wavelengths of light emitted from the light source,
Cyan light and yellow light are cut. The cut band is determined in consideration of the characteristics of the dichroic mirror. The band of light reflected by the dichroic mirror is wider for S-polarized light than for P-polarized light. Therefore, the cut band of the color filter is set so that the reflected S-polarized light band is the same as the P-polarized light band. Each of the red (R), green (G), and blue (B) color bands that reflects cyan light and yellow light by one color filter and is transmitted by the color filter,
It is important that the band is set to be equal to or less than the band of P-polarized light that passes through the dichroic mirror.

However, the spectral characteristic of the light emitted from the light source is not constant over the entire wavelength band. For example, a metal halide lamp has a strong emission spectrum of mercury at 577 nm. Therefore, the design of the color filter must consider the wavelength of the spectrum with the strongest and highest energy content. Since the projection display device of the present invention is configured to reflect the wavelength of 577 nm, which is the band of yellow light, the projected image has a very good hue.

A liquid crystal panel normally used as a light valve has an aspect ratio of 4: 3 and is compatible with NTSC. In recent years, there is a strong need to display a 16: 9 high-definition image. Liquid crystal panels with an aspect ratio of 4: 3 are inexpensive because they are mass-produced products, but the aspect ratio is 1
A 6: 9 liquid crystal panel is expensive because it needs to be manufactured exclusively. Therefore, in a liquid crystal panel with an aspect ratio of 4: 3, a method of cutting the top and bottom (making it a non-display area) and displaying a 16: 9 image can be considered. But in this case
The number of horizontal scanning lines is an issue.

In recent years, the number of pixels of the liquid crystal panel has increased, and XG
A liquid crystal panel corresponding to A (vertically 768 dots × horizontal 1024 dots) has also been manufactured. However, to display a high-definition image, about 1000 dots (1000 horizontal scanning lines) are required. The liquid crystal panel compatible with XGA has only 768 dots and cannot be supported. Furthermore, if the upper and lower screens are cut to 16: 9, it is impossible to obtain a predetermined number of vertical scanning lines.

In the following description of the present invention, the number of dots in the vertical direction of the liquid crystal panel is treated almost synonymously with the horizontal scanning line of the CRT. Further, one row of pixel columns corresponding to one horizontal scanning line is called a pixel row.

On the other hand, the aperture of the pixel of the liquid crystal panel is as low as 50% or less. This is because TFTs, signal lines, etc. are formed in the non-opening portions. Therefore, it is usual that there is a space of about half a pixel between the opening of the pixel and the opening of the pixel adjacent to the pixel.

In the present invention, the images of the two liquid crystal panels are superimposed and projected on the screen. At that time, the pixel openings of the two liquid crystal panels are vertically shifted by half a pixel on the screen. In other words, one liquid crystal panel secures 1/2 of the required horizontal scanning lines, and two liquid crystal panels obtain the required number of horizontal scanning lines. For example, in order to realize the number of horizontal scanning lines of 1000 (1000 dots vertically) by using two liquid crystal panels compatible with XGA, it is sufficient to display an image at 500 dots vertically on each liquid crystal panel. At this time, the number of dots required for displaying an image with an aspect ratio of 16: 9 is about 8
It becomes 90 dots.

Needless to say, if a high-definition image can be realized by using two liquid crystal panels, a projection display system can be constructed at low cost. In addition, the operating clot of the liquid crystal panel can be reduced, which is preferable. Each liquid crystal panel is equipped with R, G, B mosaic color filters. Therefore, it goes without saying that a good hue can be realized by using the color filter of the present invention to cut the cyan light and the yellow light emitted from the light source.

[0067]

Embodiments of the projection display apparatus of the present invention will be described below. The configuration of the projection type display device in the first embodiment of the present invention is shown in FIG. Reference numeral 331 is a light source as a light generating means, 16 is a color filter of the present invention, 338 is a light valve, and 339 is a projection lens.

The light source 331 is a lamp 331a and a concave mirror 33.
1b and UVIR filter 331c. The lamp 331a is a metal halide lamp in which dysprosium (Dy) and neodymium (Nd) are enclosed in the arc tube. The emission spectrum is shown in (FIG. 7). As is clear from FIG. 7, the spectral distribution of the light emitted by the metal halide lamp is a mixture of a large number of continuous emission spectra of Dy and Nd and an emission line spectrum of mercury. The concave mirror 331b is made of glass,
A multilayer film that reflects visible light and transmits infrared light is deposited on the reflecting surface. Visible light included in the emitted light from the lamp 331a is reflected by the reflecting surface of the concave mirror 331b, and the reflected light becomes almost parallel light. Concave mirror 331b
The infrared light and the ultraviolet light are removed by the UVIR filter 331c, and the reflected light emitted from is emitted.

The color filter 16 of the present invention used in the projection display device of the present invention will be described below. FIG. 2 shows an enlarged model of the color filter of the present invention in the first embodiment. Reference numeral 11 is a glass substrate having a refractive index of 1.52, 12 is a first dielectric multilayer film, and 13 is a second dielectric multilayer film.

A first dielectric multilayer film 12 and a second dielectric multilayer film 13 are formed on both surfaces of the glass substrate 11, respectively. The first dielectric multilayer film 12 is a low refractive index layer of SiO ₂
(Refractive index 1.46) 14a to 14f and TiO ₂ (refractive index 2.30) 15a to 15f which are high refractive index layers have an alternating 12-layer structure, and the optical film thickness of SiO ₂ 14a is 0.1.
188λ _Y (λ _Y = 577 nm), SiO ₂ 14b-14
The optical film thickness of f is 0.375λ _Y , TiO ₂ 15a to 15
The optical film thickness of f is 1.125λ _Y. The second dielectric multilayer film 13 is a low refractive index layer of SiO ₂ 14 g
14l and TiO ₂ 15g to 15l which is a high refractive index layer have an alternating 12-layer structure, and the optical film thickness of SiO ₂ 14l is 0.313λ _C (λ _C = 490 nm), SiO ₂ 14g
Optical film thickness of ~ 14k is 0.625λ _C , TiO ₂ 15g
The optical film thickness of ˜15 l is 1.875λ _C.

FIG. 4 shows the spectral transmittance of the color filter 16. The first dielectric multilayer film 12 reflects yellow light (half-value width about 550 to 600 nm) and the second dielectric multilayer film 13 reflects cyan light (half-value width about 475 to 505 nm) at 90% or more at peak wavelengths, respectively. Only the three primary color lights of red, green and blue show high transmittance.

By reducing the difference in refractive index between the high refractive index layer and the low refractive index layer, the half-value width of the reflection wavelength region can be further narrowed.

FIG. 3 shows an enlarged model diagram of the color filter of the present invention according to the second embodiment. Reference numeral 21 is a glass substrate having a refractive index of 1.52, 22 is a first dielectric multilayer film, and 23 is a second dielectric multilayer film.

A first dielectric multilayer film 22 and a second dielectric multilayer film 23 are formed on both surfaces of the glass substrate 21, respectively. The first dielectric multilayer film 22 is a low refractive index layer of Al ₂ O ₃
(Refractive index 1.62) 24a to 24h and TiO ₂ (refractive index 2.30) 25a to 25h which is a high refractive index layer have an alternating 16-layer structure, and the optical film thickness of Al ₂ O ₃ 24a is 0.
188λ _Y (λ _Y = 577 nm), Al ₂ O ₃ 24b-24
The optical film thickness of h is 0.375λ _Y , TiO ₂ 25a to 25
The optical film thickness of h is 1.125λ _Y. The second dielectric multilayer film 23 is a low refractive index layer of Al ₂ O ₃ 24i-
24p and TiO ₂ 25i to 25p which are high refractive index layers have an alternating 16-layer structure, and Al ₂ O ₃ 24p has an optical film thickness of 0.313λ _C (λ _C = 490 nm) and Al ₂ O ₃ 24i.
˜24o optical film thickness 0.625λ _C , TiO ₂ 25i
The optical film thickness of ˜25p is 1.875λ _C.

FIG. 5 shows the spectral transmittance of the color filter 16. The first dielectric multilayer film 22 reflects yellow light (half-value width about 555 to 595 nm) and the second dielectric multilayer film 23 reflects cyan light (half-value width about 480 to 500 nm) at 90% or more at peak wavelengths, respectively. Only the three primary color lights of red, green and blue show high transmittance.

The first shown in (FIG. 2) and (FIG. 3)
Although the first dielectric multilayer film and the second dielectric multilayer film are formed on both surfaces of the glass substrate in each of the first and second embodiments, two kinds of dielectric multilayer films are stacked on one surface. Even if formed, similar performance can be obtained. However, when the number of continuous layers increases and internal stress of the thin film may cause cracks on the surface of the dielectric multilayer film, it is preferable to form the glass substrate separately on both surfaces.

The film thickness of the high refractive index layer and the low refractive index layer is
1.875λ used for reflecting cyan light in the example
Even if the film thickness is thicker than _C or 0.625λ _C , a high reflectance is periodically obtained, but in practice, cracks occur even when the film thickness per layer becomes thicker than the film thickness used in the examples. Not desirable due to risk.

The absolute value of the reflectance at the peak wavelength can be increased by increasing the number of dielectric multilayer films.

In the embodiment, SiO is used as the low refractive index layer.₂,
Al₂O₃, TiO as high refractive index layer₂I used
MgF2 as the low refractive index layer, ZnS as the high refractive index layer,
CeO ₂, ZrTiO_Four, HfO₂, Ta₂O_Five, ZrO₂To
You may use.

Further, if the absolute value of the peak reflectance is increased as in the case where the difference in refractive index between the high refractive index layer and the low refractive index layer is small as in the second embodiment, the layers of the dielectric multilayer film are It is necessary to increase the number, and there is a concern that cracks may occur depending on the number of layers. In this case, the high-refractive index layer may be a combination of TiO ₂ and ZnS, which have almost the same refractive index, and the internal stresses cancel each other. The two types of refractive index are approximately 2.30, and the stress directions are tensile stress in TiO _{2 and} compressive stress in ZnS. For example, one high-refractive-index layer has three layers of TiO ₂ , ZnS, and TiO ₂ , respectively. The thickness of the film is 3
The division is preferable because the internal stress of the entire multilayer film can be relaxed.

As is clear from the above, (FIG. 6)
As described above, with a dielectric multilayer film structure in which the optical film thickness per layer is λ / 4 (λ is a reflection peak wavelength), a color filter having a narrow half-width (50 nm or less) in a high reflection region cannot be realized.

On the other hand, the optical film thickness ratio of the low-refractive index film and the high-refractive index film constituting the multilayer film is set to 1: X (X> 1),
The half width can be narrowed slightly by increasing X. However, as the film thickness ratio is increased, the stress in the low refractive index film and the stress in the high refractive index film are out of balance due to the internal stress of the thin film, which may cause cracks on the surface of the multilayer film.
Therefore, it is desirable that the optical film thickness ratio of the low-refractive index film and the high-refractive index film is not larger than 1: 3, but under this condition, the half-value width reflects only yellow light or sheaan light. Is not enough for.

Next, this type of interference filter has a spectral performance that, in addition to the reflection peak at the wavelength λ, the reflection peak appears periodically on the shorter wavelength side than the wavelength λ.
Moreover, it has a characteristic that the half width becomes narrower as the cycle is repeated. Therefore, it is sufficient to shift to the center wavelength of the yellow light or the cyan light by utilizing the periodical reflection peak having the narrow half width. Specifically, the film thickness of the alternating multilayer film in which the optical film thickness ratio of the low refractive index film and the high refractive index film is 1: 3 may be relatively thick, and the half width corresponding to yellow light is 50 nm or less. It is desirable to shift the second period to realize the above, and to shift the third period to achieve the half width of 40 nm or less corresponding to cyan light.

In the case of yellow light reflection, the optical film thickness of the multilayer film is set to about 1.5 times, and the low refractive index layer has a thickness of 0.375.
λ, 1.125λ for the high refractive index layer, and approximately 2.5 times for cyan light reflection, 0.625λ for the low refractive index layer and 1.875λ for the high refractive index layer. Good.

Although the reflection peak has the fourth and subsequent periods, it is not preferable in terms of durability since the multilayer film becomes too thick.

In the color filter of the present invention, λ _Y = 577
It is necessary to consider that the thickness is set to nm. The metal halide lamp shown in (FIG. 7) has a very strong emission spectrum at 577 nm. This spectrum is due to mercury atoms. The wavelength of 577 nm corresponds to the yellow light band. Therefore, unless the light having a wavelength of 577 nm can be sufficiently cut, the hue of the projected image projected on the screen cannot be improved.

490 nm is the emission spectrum by Nd. Although the peak value is not so great in the spectral characteristics of FIG. 7, a very strong emission spectrum is generated depending on the amount of Nd added. The metal halide lamp containing Dy and Nd has good spectral characteristics and has a long life. However, the emission spectra of yellow and cyan are strong.

The color filter 16 of the present invention is characterized in that it can sufficiently cut the emission spectra of 490 and 577 nm and that the half band width of the cut band is as narrow as about 50 nm. In this sense, the color filter of the present invention has a synergistic effect when used in combination with a metal halide lamp.

Hereinafter, the color filter in this specification (FIG. 2) or (FIG. 3), or a configuration similar thereto, also means a filter.

The light valve is composed of a transmissive TN liquid crystal panel 338 and two polarizing plates 333a and 333b arranged on the incident side and the emitting side thereof. As shown in FIG. 38, the liquid crystal panel 338 has a TN liquid crystal layer 337 sandwiched between two array substrates 335 and a counter substrate 334, and a TN liquid crystal layer 337 is provided between the counter substrate 334 and the counter electrode 341. Corresponding to each pixel, color filters 336 that transmit the three primary colors red, green, and blue are arranged in a mosaic pattern. The color filter 336 has a spectral characteristic as shown in (FIG. 39).

In the light valve, when a voltage is applied to the pixel electrode 342 of the liquid crystal panel 338, light enters a transmissive state, and an optical image is formed as a change in transmissivity according to the magnitude of the applied voltage.

The substantially parallel light from the light source 331 enters the color filter 16. In the color filter 16, only the highly pure three primary color light components are transmitted according to the spectral characteristics shown in FIG. 4 and the like. The transmitted light from the color filter 16 passes through the field lens 332 and enters the light valve. The field lens 332 is for causing the light passing through the peripheral portion of the liquid crystal panel 338 to enter the projection lens 339.
Only the P-polarized component of the light that has entered the light valve passes through the polarizing plate 333b, and a color image is formed as a change in transmittance according to a video signal. Here, the output light from the light valve enters the projection lens 339 and is enlarged and projected on a screen (not shown). Focus adjustment of the projected image is performed by moving the projection lens 339 along the optical axis 340.

Regarding the projected images of the red, green, and blue pixels on the screen, the respective spectral characteristics are shown in FIG. 19 (a),
Shown in (b) and (c)). The broken line is the spectral characteristic in the conventional configuration as shown in FIG. 37, and the solid line is the spectral characteristic when the color purity is improved by using the color filter 16. By using the color filter 16, the components of the light band which are considered to deteriorate the color purity are reduced, and the bands of the red, green and blue components are narrower than the light transmission band of the color filter. I understand. (FIG. 8) is a spectral distribution when the lights transmitted through the R, G, and B color filters are combined. The metal halide lamp having the spectral characteristic shown in FIG. 7 has the spectral characteristic shown in FIG. 8 in which cyan light and yellow light are cut by the color filter 16.

FIG. 10 shows the color reproducibility of the projection type display device having the above structure (solid line). Conventional configuration (dotted line)
It can be seen that the color reproduction range is wider than that of.

By removing unnecessary light components of the light emitted from the light source in the color filter 16, the amount of light absorbed by the color filter 336 in the liquid crystal panel 338 can be reduced, and the color filter 336 can be reduced. Since the amount of heat generated by the absorption of unnecessary light is reduced, deterioration of the color filter 336 can be suppressed.

The color filter 16 may be arranged at a position between the light valve and the projection lens 339 (shown by A) or in an optical path between the projection lens 339 and the screen (not shown). However, when the color filter 16 is arranged in the optical path closer to the screen than the light valve, yellow light and cyan light may enter the light valve or the like again and cause halation or the like. Therefore,
Not very desirable. The configuration in which the color filter 16 is arranged at the position A shown above is a matter that can be applied to the projection display device in another embodiment of the present invention.

Hereinafter, in the projection type display device of the present invention,
A video display method using a liquid crystal panel or the like will be described. The above-mentioned display method can be applied to other projection type display devices of the present invention, and the display panel is not limited to the TN liquid crystal panel and the PD liquid crystal panel, but is applicable to the DMD, for example.

In this display method, the first and second display methods different from each other are executed individually or selectively.
(FIG. 11) shows a display image on the display for explaining the first display method, and (FIG. 12) shows a display image on the display for explaining the second display method.

First, the first display method will be described.
In FIG. 11, (a) shows an image when the first frame of the input progressive scanning video signal is displayed on the display as it is, and (b) shows the second frame of the input progressive scanning video signal. The image is displayed as it is on the display. Note that the first and second frames are temporally consecutive frames. First, the first line of the first frame of the input progressive scan video signal is selected, doubled on the time axis and displayed on the first line on the display. Next, the third line of the first frame is selected, doubled in the time axis and displayed on the third line on the display. Hereinafter, only the odd lines of the first frame are sequentially selected, such as the fifth line, the seventh line, ...
The time axis is doubled and displayed on an odd line on the display. On the other hand, in the second frame, only the even lines are sequentially selected, and the time axis is doubled and displayed on the even lines on the display. As a result, one frame composed of the odd lines of the first frame and the even lines of the second frame as shown in FIG. 11C is displayed. The above operation is similarly performed on the third frame and the fourth frame, and thereafter repeated. As described above, since it is sufficient to display one frame including the odd line of the first frame and the even line of the second frame during the two-frame period of the input progressive scan video signal, the input sequential scan The video signal can be displayed at half the speed as compared to when it is displayed as it is.

Next, the second display method will be described.
In FIG. 12, (a) shows an image when the first frame of the input progressive scanning video signal is displayed on the display as it is, and (b) shows the second frame of the input progressive scanning video signal. The image is displayed as it is on the display. First, the first line of the first frame of the input progressive scanning video signal is selected, doubled in the time axis and simultaneously displayed on the first and second lines on the display. Next, select the third line of the first frame,
The time axis is doubled and the 3rd and 4th on the display
Are displayed at the same time. After that, the 5th and 7th lines ...
In this way, only the odd lines of the first frame are sequentially selected, the time axis is doubled, and the odd lines and the adjacent even lines on the display are simultaneously displayed. As a result, the image shown in (FIG. 12B) is obtained. On the other hand, in the second frame, only the even lines are sequentially selected, the time axis is doubled, and the even lines and the adjacent odd lines on the display are simultaneously displayed. As a result, the image shown in FIG. 12C is obtained. The above operation is performed in the third frame, the fourth
Do the same for the frame and repeat. As described above, since it is sufficient to display one frame including the odd line of the first frame and the even line of the second frame in the two-line period of the input progressive scan video signal, the input progressive scan video signal 1 / compared to when is displayed as is
It can be displayed at a speed of 2.

Although two display methods have been described above, it is preferable to select the first display method for a still image and the second display method for a moving image. Since the image of the still image is stopped, the discontinuity of the image in the vertical direction is more likely to be visually recognized than that of the moving image. Therefore, in the case of a still image, by interpolating between frames using the first display method,
It is preferable to ensure an apparent vertical resolution. On the other hand, since a moving image has a large temporal change in image, when the first display method is applied, so-called moving image blur (jerkiness obstruction or the like) occurs. Therefore, in the case of moving images, it is preferable to prevent the occurrence of moving image blur by performing interpolation in the frame by the second method.

In the first display method, when the display time (light emission time) is very short, from several milliseconds to several tens of milliseconds as in a CRT display, for example, when the frame cycle of the input sequential video signal is 60 Hz. , The display cycle of the same line becomes 30 Hz, and flicker occurs. However, in a display such as an active matrix type liquid crystal display in which TFTs as switching elements are arranged in pixels, the display state is kept until refreshed, the scanning line interpolation is completely performed. In the second display method, the CRT display requires the electron gun to have a multi-gun configuration (for example, two electron guns are prepared).
In an active matrix type liquid crystal display, it can be easily realized by activating two gate lines at the same time.

Next, the video signal display circuit will be described with reference to the drawings. FIG. 13 shows a video signal display circuit according to an embodiment of the present invention. In FIG. 13, the video signal display circuit includes a display line selection circuit 139 for selecting a display line and expanding the video signal on the time axis, and a signal suitable for liquid crystal driving mainly for γ correction and AC conversion. A source signal processing circuit 135 for converting to a liquid crystal panel, a liquid crystal panel 338 in which a plurality of pixels are arranged in a matrix, a source drive IC 141 connected to a source line of the liquid crystal panel 338 to apply a voltage to the liquid crystal 337, and a horizontal start pulse HD. And the gate drive IC control signals (GCK1, GCK2, GST1, G in response to the vertical start pulse VD).
ST2, GEN1, GEN2) generating gate drive I
C control circuits 137a and 137b, and a gate drive IC 140a whose operation is controlled based on a gate drive IC control signal from the gate drive IC control circuits 137a and 137b,
140b, a display method selection circuit 136 that selects one of the gate drive IC control circuits 137a and 137b according to the nature of the image (whether it is a still image or a moving image), and a switching signal from the display method selection circuit 136 in response to the switching signal. A switch 138 for selectively switching the outputs of the gate drive IC control circuits 137a and 137b and outputting them to the gate drive ICs 140a and 140b.
With. The display line selection circuit 139 responds to the A / D converter 131, the line memory 132 that stores the image signal for one scanning line, the D / A converter 134, and the horizontal start pulse HD and the vertical start pulse VD. Line memory control circuit 1 for controlling the operation of the line memory 132 by generating memory control signals (WCK, WEN, RCK)
33 and 33.

The gate drive ICs 140a and 140b are ICs having the same configuration and function. However,
The first gate driving IC 140a is connected to the odd-numbered gate lines of the liquid crystal panel 338 and sequentially activates the odd-numbered gate lines. The second gate driving IC 140b is connected to the even-numbered gate lines of the liquid crystal panel 338 and sequentially activates the even-numbered gate lines.

FIG. 14 shows the gate drive IC 140.
Shows a more detailed configuration of the. In (Fig. 14),
The gate drive IC 140 is an n / 2-bit (n is the number of gate lines of the liquid crystal panel 338) shift register 14
5, a changeover switch group 142 having n / 2 changeover switches 146, and an output buffer group 143 having n / 2 output buffers 147. The shift register 145 includes n / 2 D-type flip-flops 144.
And one inverter 145. The start signal GST1 (or GST2) is applied to the data input terminal D of the first D-type flip-flop 144, and the polarity is inverted by the inverter 145. It is given to the clear terminal C. In addition, the clock signal GCK1 (or GCK
2) is given to the clock terminal CK of each D-type flip-flop 144. Further, the Q output of the D-type flip-flop 144 at the previous stage is given to the data input terminal D of each of the second and subsequent D-type flip-flops 144. The shift register 145 having the above configuration has the kth (k
= 1 to n / 2), the Q output of the D-type flip-flop 144 is taken out as a k-th bit signal and given to the A terminal of the k-th change-over switch 146 in the change-over switch group 142. The B terminal of each changeover switch 146 is grounded. The output terminal C of each changeover switch 146 is connected to the A terminal when the enable signal GEN1 (or GEN2) is at the high level, and is connected to the B terminal when it is at the low level. The signal output from the output terminal C of each changeover switch 146 is given to each output pin 148 via the corresponding output buffer 147 in the output buffer group 143. Each output pin 148 is connected to a corresponding gate line (gate signal line) of the liquid crystal panel 338.

The operation of the video signal display circuit configured as described above will be described below. FIG. 15 shows a timing chart of the memory control signal input to the line memory 132 and the input / output video signal of the line memory 132. First, the drive control operation of the source line will be described with reference to this (FIG. 15). Display line selection circuit 139
First, the progressive scan video signal input to the A / D converter 1 is input.
At 31, it is converted into a digital video signal. The line memory 132 takes in a digital progressive scan video signal at a timing synchronized with the write clock signal WCK while the write enable signal WEN is at a high level. That is,
The first line of the first frame is the write enable signal WE
Since N is at high level, it is captured in synchronization with the write clock signal WCK, and the second line of the first frame is not captured because the write enable signal WEN is at low level. By repeating the above operation, the odd lines of the first frame are sequentially loaded into the line memory 132.
Similarly, the first line of the second frame is not captured because the write enable signal WEN is low level, and the second line of the second frame is captured in synchronization with the write clock signal WCK because the write enable signal WEN is high level. . By repeating the above operation, the even lines of the second frame are sequentially loaded into the line memory 132. Further, by repeating the above-described operations frame by frame, the odd lines of the odd frames and the even lines of the even frames are sequentially captured in the line memory 132. The digital video signal taken into the line memory 132 is read in synchronization with the read clock signal RCK, which has a frequency that is half that of the write clock signal WCK. The signal output from the line memory 132 is a digital video signal obtained by doubling the time-axis extension of the odd line of the odd frame and the even line of the even frame of the captured progressive scanning video signal. Converted to analog video signal.

Next, the source signal processing circuit 135 performs γ correction on the progressive scan video signal which is line-selected and doubled in time axis, and inverts the polarity for each frame to drive the liquid crystal panel 338 with an alternating current. And input to the source drive IC 141. The source driving IC 141 sequentially writes and holds the input video signal to each sample and hold circuit (not shown) inside the IC. At this time, the source drive IC 141
Since the signal input to is a progressive scanning video signal that is doubled in the time axis, the write clock to each sample and hold circuit generated by the shift register (not shown) does not extend in the time axis. Compared with 1/2. The gate line xi of the liquid crystal panel 338 is the gate drive IC 14
When the thin film transistor 343 is activated by 0 and turned on, the image data held in each sample hold circuit is applied to the pixel electrode 342 through the source line yj. As a result, the video signal for one scanning line is written in the liquid crystal panel 338. An image is obtained on the liquid crystal panel 338 by repeating the above operation and scanning the gate line by the gate driving IC 140.

Next, the drive control operation of the gate line will be described. The scanning of the gate line is determined by the gate drive IC control signals (GCK1, GST1, GEN1 or GCK2, GST2, GEN2) output from the first and second gate drive IC control circuits 137. As described above, the gate driving ICs 140a and 140b are ICs having the same function, and activate the gate lines of the liquid crystal panel 338 sequentially and selectively by controlling the gate driving IC control signal. The gate drive IC 140 is
When the start signal GST1 (or GST2) is at high level, the clock signal GCK1 (or GCK2) rises (when it changes from low level to high level)
The internal shift register 145 (see FIG. 14) is reset by and the first gate line is selected (retraced).
Then, every time the clock signal GCK1 (or GCK2) rises, the second signal and the third signal are sequentially selected. Then, when the enable signal GEN1 (or GEN2) is at a high level, a signal is output to the selected gate line to activate the gate line. This turns on the thin film transistor 343 connected to the selected gate line. Enable signal GEN1 (or G
When EN2) is low level, no signal is output to the selected gate line and the gate line is not activated. Therefore, the thin film transistor 3 connected to the gate line
43 is in an off state. Here, the first gate drive IC
140a is connected to the odd-numbered gate lines of the liquid crystal panel 338, and the second gate drive IC 140b is connected to the even-numbered gate lines.

FIG. 16 is a timing chart of the gate drive IC control signal output from the first gate drive IC control circuit 137a, and FIG. 17 is output from the second gate drive IC control circuit 137b. Gate drive IC
The timing chart of a control signal is shown. Hereinafter, the drive control operation of the gate line will be described in more detail with reference to these (FIG. 16) and (FIG. 17).

In FIG. 16, the clock signal GCK
1, a start signal GST1 and an enable signal GEN1 are gate drive IC control signals input from the first gate drive IC control circuit 36 to the first gate drive IC 140a, and include a clock signal GCK2, a start signal GST2,
The enable signal GEN2 is a gate drive IC control signal input from the second gate drive IC control circuit 137b to the second gate drive IC 140b. Clock signal GC
K1 is a high level with a cycle of two line periods, and a start signal G
ST1 is high level in the first line of the first frame, and enable signal GEN1 is high level in the first frame period (however, low level in the last line of the first frame period). Therefore, when the first frame starts, the first signal The gate driving IC 140a has the first gate line (x in FIG. 13).
Activate sequentially from 1). First gate drive IC
Since 140a is connected to the odd-numbered gate lines of the liquid crystal panel 338, the odd-numbered lines of the liquid crystal panel 338 are sequentially activated every two line periods in the first frame period. Since the enable signal GEN1 is at the low level during the second frame period, the odd lines of the liquid crystal panel 338 are not activated.

On the other hand, the clock signal GCK2 is at a high level in a cycle of two line periods, the start signal GST2 is at a high level in the second line of the second frame, and the enable signal GEN2 is used.
Is high level from the second line of the second frame, so the second
When the frame starts, the second gate drive IC 140b
Sequentially activates from the second gate line (x2 in FIG. 13). Since the second gate driving IC 140b is connected to the even-numbered gate lines of the liquid crystal panel 338, the even-numbered lines of the liquid crystal panel 338 are sequentially activated every two line periods in the second frame period. Since the enable signal GEN2 is at the low level during the first frame period, the even lines of the liquid crystal panel 338 are not activated.

Therefore, the first of the input progressive scan video signals
It is possible to select only the odd lines of the frame, double the time axis extension, and display the odd lines of the liquid crystal panel 338. Also, only the even lines of the second frame of the input progressive scan video signal can be selected, doubled in the time axis and displayed on the even lines of the liquid crystal panel 338. The above operation is repeated in units of two frames.

In FIG. 7, a clock signal GCK1, a start signal GST1, and an enable signal GEN1 are gate drive IC control signals input from the second gate drive IC control circuit 137b to the first gate drive IC 338b, and a clock signal GCK2. , The start signal GST2 and the enable signal GEN2 are gate drive IC control signals input from the second gate drive IC control circuit 37 to the second gate drive IC 140b. In the first frame period, the clock signal GCK1 is at a high level in a cycle of two line periods, the start signal GST1 is at a high level in the first line, and the enable signal GEN1 is at a high level during the first frame period (however, in the last period of the first frame period). Since the line period is low level, when the first frame starts,
The gate drive IC 140a is sequentially activated from the first gate line (x1 in FIG. 13). Further, in the first frame period, the clock signal GCK2 is at a high level in a cycle of two line periods, the start signal GST2 is at a high level in the first line, and the enable signal GEN2 is at the first level.
Since it is at a high level during the frame period (however, it is at a low level during the last line period of the first frame period), when the first frame starts, the second gate driving IC 140b starts from the second gate line (x2 in FIG. 13). Activate sequentially. The first gate drive IC 140a is the liquid crystal panel 3
38 connected to the odd-numbered gate lines,
Since the gate drive IC 140b of the liquid crystal panel 338 is connected to the even-numbered gate lines of the liquid crystal panel 338, the odd line and the next adjacent even line of the liquid crystal panel 338 are simultaneously activated every two line periods in the first frame period. After that, odd-numbered lines and even-numbered lines are activated at the same time every two lines in a cycle of two line periods.

On the other hand, in the second frame period, the clock signal GCK1 is high level in the cycle of two line periods, and the start signal GST1 is high level in the last line of the first frame. Gate line (X1 in FIG. 13) is selected. However, since the enable signal GEN1 is at the low level in the first line period of the second frame, the first gate line is not activated. After that, since the enable signal GEN1 becomes high level from the second line second line period, the first gate driving IC 140a changes to the second level.
When the frame 2 line period starts, the third gate line (X3 in FIG. 13) is activated sequentially. Further, since the clock signal GCK2 is at a high level in a cycle of two line periods, the start signal GST2 is at a high level in the second line, and the enable signal GEN2 is at a high level from the second line second line period, the second gate drive IC 14
0b is activated sequentially from the second gate line (x2 in FIG. 13) when the second frame 2-line period starts. The first gate drive IC 140a is the liquid crystal panel 3
38 connected to the odd-numbered gate lines,
Since the gate driving IC 140b is connected to the even-numbered gate lines of the liquid crystal panel 338, the even-numbered lines and the next adjacent odd-numbered lines of the liquid-crystal panel 338 are simultaneously activated every two line periods in the second frame period. After that, even and odd lines are sequentially activated by two lines at a time in a two-line period cycle.

Therefore, the first of the input progressive scan video signals
It is possible to select only the odd-numbered lines of the frame, double the time axis, and simultaneously display the odd-numbered lines and the adjacent even-numbered lines of the liquid crystal panel 338. Also, only the even lines of the second frame of the input progressive scan video signal can be selected and doubled in the time axis to be displayed on the even lines and the adjacent odd lines of the liquid crystal panel 338 at the same time. The above operation is repeated in units of two frames.

As described above, the gate drive IC control signals of both the first and second gate drive IC control circuits 137a and 137b cause the first frame to be changed in two frame periods of the input progressive scan video signal. Since it suffices to display one frame consisting of an odd line and an even line of the second frame, it is possible to display the input progressive scan video signal at half the speed as compared to when it is displayed as it is. Therefore, it is not necessary to separately drive the liquid crystal panel 338, and it is possible to prevent a luminance difference from occurring.

As described above, the gate line scanning method is the same as the first gate drive IC control circuit 137a or the second gate drive IC control circuit 137a.
It is determined by the gate drive IC control signal output from the gate drive IC control circuit 137b. In other words, the display method of the liquid crystal panel 338 is determined depending on which gate drive IC control circuit outputs the gate drive IC control signal. The gate drive IC control signal is selected by the switch 138 which responds to the switch signal output from the display method selection circuit 136. Display method selection circuit 13
A progressive scanning video signal converted into a digital signal by the A / D converter 131 is input to the circuit 6. The display method selection circuit 136 calculates the difference for each frame of the input progressive scan video signal, and determines whether it is a still image or a moving image based on the size of the difference. As a result, in the case of a still image, the gate drive IC output from the first gate drive IC control circuit 137a
In the case of a moving image, the control signal is selected as the gate drive IC control signal output from the second gate drive IC control circuit 137b. In a display that retains the display state until refreshed, such as an active matrix liquid crystal panel, vertical resolution is ensured because interpolation is performed between frames in the case of still images, and in the case of movies in frames. The moving image blur does not occur because the interpolation is performed, and a good image can be obtained even though the input progressive-scan video signal is displayed at half the speed as compared to when it is displayed.

In the above embodiment, switching by automatic detection is described, but in addition to this, if the user can forcibly switch the switching device, it will be more practically convenient.

As described above, since the video information for one frame is displayed in the two-frame period, the input progressive scan video signal is displayed at half the speed as compared with the case where it is displayed as it is. be able to. As a result, even when a wide band (high data rate) progressive scan video signal of a personal computer, a workstation or the like is displayed on a display which is difficult to display at high speed such as a matrix type liquid crystal panel, the image quality does not deteriorate. That is, it is not necessary to separately drive the display as in the conventional example, and it is possible to prevent the occurrence of a brightness difference.

Further, since the first display control means and the second display control means are selectively activated, depending on the nature of the progressive scanning video signal (for example, still image or moving image). The optimum display can always be performed.

Further, when the value indicating the correlation between adjacent frames of the progressive scan video signal is equal to or more than a predetermined value (that is, in the case of a still image), the first display control means is selectively activated,
When it is less than the predetermined value (that is, when it is a moving image), the second display control means is selectively activated.
In the case of a still image, interpolation can be performed between frames to ensure vertical resolution, and in the case of a moving image, interpolation can be performed within frames to prevent the occurrence of moving image blur.

The projection type display device shown in FIG. 1 uses a TN liquid crystal panel as a light valve. However, since the TN liquid crystal panel uses a polarizing plate for light modulation,
There is a problem that the image display brightness is low. There is also a problem that the display contrast is lowered because the polarization state of the color filter collapses.

The PD liquid crystal panel using the polymer liquid crystal for the light modulation layer does not have the above-mentioned problems and can realize high brightness and high contrast display. The technical idea of using the color filter of the present invention in a projection display device can be applied to a device using a polymer liquid crystal panel as a light valve. The projection display device of the present invention using a polymer liquid crystal panel for the light valve will be described below.

FIG. 20 is a sectional view of a PD liquid crystal panel used in the projection type display device of the present invention. In addition, it is drawn as a model for easy understanding, and the physical thickness or shape does not necessarily match. In addition, parts unnecessary for explanation are omitted. The above matters also apply to other drawings.

The counter substrate 334 and the array substrate 335 are glass substrates having a thickness of 1.1 mm and a refractive index of 1.5.
It is 2. A pixel electrode 342 made of ITO, a TFT 343 as a switching element for applying a signal to the pixel electrode 342, various signal lines (not shown), and the like are formed on the array substrate 335.

A light shielding film 191 is formed on the TFT 343. The light shielding film 191 mainly prevents the light scattered by the liquid crystal layer 192 from entering the semiconductor layer of the TFT 343. When light is incident on the semiconductor layer, the TFT 343 enters a photoconductor state in which the TFT 343 is not turned off (hereinafter referred to as a photocon). As a material for forming the light shielding film 191, an acrylic resin in which carbon is dispersed is exemplified.
Further, a method of forming an insulating thin film of SiO2 or the like on the TFT 343 and patterning a metal thin film as the light shielding film 191 on the insulating thin film is also exemplified. Note that P
In the D liquid crystal panel, it is preferable that the TFT 343 is formed by polysilicon technology so that photocon is less likely to occur. Of course, it goes without saying that it may be formed using amorphous silicon. However, in that case TF
Sufficient shading is required for T343.

A red, blue and green mosaic color filter 336 is arranged on the counter substrate.
A counter electrode 341 is formed on the surface 6.

P is provided between the counter electrode 336 and the pixel electrode 342.
The D liquid crystal 192 is sandwiched. The liquid crystal material used for the liquid crystal panel is preferably a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal, and may be a single liquid crystal compound or a mixture of two or more liquid crystal compounds or a mixture containing a substance other than the liquid crystal compound. Among the liquid crystal materials mentioned above, a relatively large nematic liquid crystal of cyanobiphenyl difference extraordinary refractive index n _e and ordinary index n _o or, most preferred nematic liquid crystal of stable chlorine based on changes over time . As the polymer matrix material, a transparent polymer is preferable, and as the polymer, an ultraviolet curable resin is used in terms of easiness of manufacturing process, separation from the liquid crystal phase and the like. As a specific example, an ultraviolet curable acrylic resin is exemplified, and a resin containing an acrylic monomer or an acrylic oligomer which is polymerized and cured by ultraviolet irradiation is particularly preferable.

Although the ratio of the liquid crystal material in the PD liquid crystal layer is not specified here, it is generally about 20 to 90% by weight, preferably about 50 to 85% by weight. If it is 20% by weight or less, the amount of liquid crystal droplets is small and the scattering effect is poor. On the other hand, when it is 90% by weight or more, the polymer and the liquid crystal tend to be phase-separated into upper and lower layers, the ratio of the interface becomes small, and the scattering property is deteriorated. PD liquid crystal layer 192
The structure depends on the liquid crystal fraction and is approximately 50% by weight.
In the following, the liquid crystal droplets exist as independent droplets, and when the content is 50% by weight or more, the polymer and the liquid crystal form a continuous layer intricately intermingled with each other.

The average particle size of the water-drop liquid crystal or the average pore size of the polymer network is preferably 0.5 μm or more. Above all, 1.2 or more and 1.5 μm or less is preferable. The thickness of the liquid crystal layer 192 is preferably in the range of 5 to 20 μm, more preferably 8 to 15 μm. If the film thickness is thin, the scattering characteristics are poor and the contrast cannot be obtained. On the contrary, if it is thick, high voltage driving must be performed.

The transparent plate 174 is a light-transmissive plate having a large thickness, and more specifically, a cylindrical or quadrangular prismatic glass plate having a diameter not less than the maximum diameter d of the effective display area of the display panel. Besides, a transparent resin such as an acrylic resin or a polycarbonate resin can be used, and these are relatively inexpensive and can easily be produced in any shape. It is also preferable because it is light in weight. The transparent plate 174 is an optical coupling agent 17.
Optically connected by 9. The optical coupling agent 179 is specifically a transparent silicone resin, an ultraviolet curable adhesive,
Examples include epoxy transparent adhesives and ethylene glycol. It is preferable that the optical coupling agent has a refractive index of about 1.4 to 1.5 and a difference in refractive index from a glass substrate such as a counter electrode substrate is within 0.05. The term “optically connect” means that the substrates are adhered or joined with a transparent material having a refractive index substantially equal to that of the substrates.

Black paint 171 is applied to the invalid display surface 175 of the transparent plate 174 so that the light reflected at the interface between the air and the transparent plate 174 can be absorbed.

The center thickness t of the transparent plate 174 and the counter substrate 334 of the PD liquid crystal panel 173 is set to satisfy the following equation, where n is the refractive index and d is the maximum diameter of the effective display area of the liquid crystal panel. .

[0134]

[Equation 1]

The reason why (Equation 1) must be satisfied is described in Japanese Patent Application No. 04-145277, and therefore its explanation is omitted. The center thickness t can be shortened by making the surface of the glass plate in contact with air a concave surface, that is, a concave lens shape. This matter also applies to Japanese Patent Application No. 04-145.
Since it is described in Japanese Patent Publication No. 277, the description is omitted.

As described above, by setting the transparent plate 178 to a thickness satisfying (Equation 1), light is emitted from the liquid crystal layer 192 of the liquid crystal panel 173 and reflected at the interface between the transparent plate 174 and air. Are absorbed by the black paint 171. Therefore, it does not return to the liquid crystal layer 192 of the liquid crystal panel again.

Although the transparent plate 174 is connected to the array substrate 335 in FIG. 20, it is not limited to this. For example, it may be connected to the counter substrate 334, or may be connected to both the counter substrate 334 and the array substrate 335. For example, a configuration such as (FIG. 21) is applicable.

Although the transparent plate 174 is connected to the liquid crystal panel 173 by the optical coupling agent 179, the invention is not limited to this, and the thickness of the counter substrate 334 or the array substrate 335 of the liquid crystal panel satisfies (Equation 1). If so, it is clear that the transparent plate 174 need not be used.

FIG. 18 shows the configuration of the projection type display device in another embodiment of the present invention. 331 is a light source, 16 is a color filter, 176 is a light valve, and 339 is a projection lens. However, components that are unnecessary for the description are omitted.

The light emitted from the lamp 331a is a concave mirror 331.
The light is condensed by b, the ultraviolet light and the infrared light are removed by the UVIR cut filter 331c, and the light is emitted. Light source 3
Light emitted from the light source 31 passes through the color filter 16, the field lens 332, the liquid crystal panel 173, and the transparent plate 174 in this order, and enters the projection lens 340. The color filter 16 removes an optical component in a band that is considered to deteriorate color purity according to the spectral characteristics shown in (FIG. 4) or (FIG. 5). The transparent plate 174 is optically coupled to the emission side of the PD liquid crystal panel 173 by an optical coupling agent 179, and the ineffective surface 175 of the transparent plate 174 is coated with black paint 171. As described above, the transparent plate 174 has a thickness that satisfies (Equation 1), so that the liquid crystal layer 19 of the liquid crystal panel is formed.
Light emitted from the light source 2 and reflected by the emission surface 178 of the light valve 176 is absorbed by the black paint 171. Therefore, it does not return to the liquid crystal layer 192 of the liquid crystal panel 173 again. Note that 172 is an antireflection film that prevents reflection of light that is emitted or the like. In this way, the increase in brightness due to the re-emitted light from the liquid crystal layer 192 can be suppressed, so that the contrast of the display image on the liquid crystal layer 192 becomes good and the contrast of the projected image is improved.

The size of the pupil of the projection lens 340 is such that when the pixel at the center of the screen of the liquid crystal panel 173 is in the transparent state,
About 90% of the light emitted from the pixel
Is set to be incident. Field lens 332
Is an optical system that refracts light passing through the peripheral portion of the display area of the liquid crystal panel 173 inward and makes it enter the pupil of the projection lens 339.
Used to prevent the periphery of the projected image from becoming dark. Focus adjustment of the projected image is performed by moving the projection lens 339 along the optical axis 340.

An optical image is formed on the liquid crystal panel 173 as a change in the light scattering state according to the video signal. The projection lens 339 takes in light included in a certain solid angle of the light emitted from each pixel. If the scattered state of the emitted light from each pixel changes, the amount of light included in the solid angle changes, so that the optical image formed as a changed scattered state on the liquid crystal panel 173 is displayed on the screen (not shown). Converted to changes in illuminance. In this way, the optical image formed on the liquid crystal panel 173 is enlarged and projected on the screen 177 by the projection lens 339. Also in this embodiment, the color filter 16
By using, the color reproducibility can be improved by the same operation as in the above-described embodiment. In addition, metal halide lamp 3
Matters such as determining the reflected light band of the color filter 16 in consideration of the spectral characteristic of 31a are the same as or similar to those of the previous embodiment.

FIG. 19 is a modification of (FIG. 18).
Plano-concave lens 1 arranged on the exit side of the light valve 176
The configuration is the same as that of FIG. 18 except for 74a.

The projection lens 339 is arranged in combination with the plano-concave lens 174c so that the optical image on the liquid crystal layer 192 is focused on a screen (not shown). Concave 1
Since the emitted light from 78 needs to enter the projection lens 339, the incident angle to the liquid crystal panel 173 needs to be convergent light. Focus adjustment of the projected image is performed by moving the projection lens 339 along the optical axis 340.

The light emitted from the light source 331 is the color filter 1
6. PD liquid crystal panel 1 via field lens 332.
It enters 73. Since the emission surface 178 of the light valve 176 is a concave surface, as described above, the liquid crystal layer 192 is formed.
Since the increase in brightness due to the re-emitted light from is suppressed, the contrast of the display image on the liquid crystal layer 192 becomes good, and the contrast of the projected image is improved. Also, plano-concave lens 1
Black coating 171 applied to the side surface 175 of 74c, concave surface 1
The antireflection film 172 vapor-deposited on 78 exhibits the same effect as in the previous embodiment, and improves the contrast of the projected image.

In the previous examples, the liquid crystal display panel was a transmissive type. Therefore, the projection display device was also a transmission type. The technical idea of the present invention of improving the color purity of the display image of the projection type display device by using the color filter can be applied to the reflection type. A reflective liquid crystal display panel is used as the light valve used in the reflective projection display device. As an example of a reflective display device, the pixel electrode 223 shown in FIG. 23 may be formed using aluminum (Al) or the like as a reflective electrode. In the case of a reflective display panel, light is incident from the counter electrode 221 side and emitted again from the counter electrode 221 side. Therefore, the transparent plate 174b is the opposite substrate 33.
Optically connect to the 4 side.

When the display panel used in the projection type display device is a reflection type, it is necessary to consider the surface reflection of each optical system component. The light reflected by the surface of the display panel is displayed on the display panel 17
Since the light is not modulated by the liquid crystal layer 192 of No. 3, when the light is projected on the screen, the contrast of the display image is lowered.

The antireflection film for preventing the interface reflection between a certain medium and air is formed by laminating three or two thin films.
In the case of three layers, it is used to prevent reflection in a wide wavelength band of visible light, and this is called a multi-coat. In the case of two layers, it is used to prevent reflection in a specific visible light wavelength band, and this is called a V coat.

Aluminum oxide in case of multi-coat
(Al₂O₃) Has an optical film thickness of nd = λ / 4, zirconium
Mu (ZrO₂) Is nd = λ / 2, magnesium fluoride
(MgF₂) Is formed by stacking nd = λ / 4. Normal,
In the case of G light, λ is 520 nm or its value
As a thin film is formed. In the case of V coat, it is silicon monoxide
Con (SiO) with an optical film thickness nd = λ / 4 and a magnesia fluoride
Nesium (MgF₂) Is nd = λ / 4 or oxide
Thorium (Y₂O₃) And magnesium fluoride (Mg
F ₂) Is formed by stacking nd = λ / 4. SiO is blue
Since there is an absorption band on the side, Y is required to modulate blue light.₂O₃
It is better to use. Y from the stability of the substance₂O₃Is cheaper
It is preferable because it has been set. Note that λ here is the modulation
It is the peak wavelength of the light to be emitted, that is, the central wavelength. n is a thin film
Refractive index, d is a physical film thickness.

TFTs 334 and the like are formed on the array substrate 335. A reflective electrode 223 is formed on the TFT 334 via an insulating film 224. Reflective electrode 223
And the TFT 334 are electrically connected to each other at a connection terminal 222. As the material of the insulating film 223, an organic material typified by polyimide or the like or an inorganic material such as SiO ₂ or SiNx is used. The surface of the reflective electrode 223 is formed of an Al thin film. Although it may be formed by using Cr or the like, the reflectance is lower than that of Al, and since it is hard, the peripheral portion of the reflective electrode 223 is easily broken.

The connection terminal portion 222 has a depression of 0.5 to 1 μm, but this is not a problem because the PD liquid crystal panel 173 does not require treatment such as alignment. The aperture ratio is 80% or more when the pixel size is 100 μm square, and 70% or more even when the pixel size is 50 μm square. However, TFT3
34, etc. are uneven, and the reflection efficiency is somewhat reduced. In order to eliminate the unevenness, the surface of the reflective electrode 223 may be polished. A reflectance of 90% or more can be achieved by polishing.

Although not shown, the source signal line and the gate signal line are also formed on the array substrate 335. Since the reflective electrode 223 covers the signal line and the TFT 334, the liquid crystal is aligned by the electric field generated from the signal line and the TFT, and image noise is not generated.

Transparent dielectric thin films 221a and 221c are formed in front of and behind the ITO thin film 221b serving as a counter electrode to form a three-layer structure, which has an antireflection function.

The antireflection film 221 is composed of the first dielectric thin film 221a and the ITO thin film 221 in order from the glass substrate 334 side.
b, and the second dielectric thin film 221c has a three-layer structure, and the optical thickness (nd) of the ITO thin film 221b is λ /
2, the optical thickness of each of the first thin film 221a and the second thin film 221c is λ / 4.

First thin film 221a and second thin film 22
The refractive index of 1c is preferably 1.60 or more and 1.80 or less.
As the material of the dielectric thin films 221a and 221c, SiO,
Al ₂O₃, Y₂O₃, MgO, CeF₃, WO₃, PbF₂
Use either of. In particular, the dielectric thin films 221a and 221
Al as a constituent material of c₂O₃Or Y₂O₃Is preferred
Yes.

The structure of the reflection type projection display apparatus of the present invention is shown in FIG. 331 is a light source, 16 is a color filter,
Reference numeral 175 is a light valve, 212 is a plane mirror, and 211 is a projection lens.

As described above, it is known that the light reflected by the multilayer film has a wider band for S-polarized light than for P-polarized light. On the contrary, it is known that the P-polarized light transmitted through the multilayer film is wider than the S-polarized light. A light valve that uses polarized light, such as a TN liquid crystal panel, has no problem, but color separation becomes a problem when both P and S polarized light (hereinafter referred to as random light) is used as in a PD liquid crystal panel.

The main purpose of the present invention is to cut the light in the cyan and yellow bands by the color filter 16. Since the multilayer film has different light reflectances for P-polarized light and S-polarized light, the color filter 16 narrows the S-polarized light in the cyan and yellow bands.

The projection lens 211 is composed of a first lens group 211a on the liquid crystal panel 173 side and a second lens group 211b on the screen 177 side. A plane mirror is provided between the first lens group 211a and the second lens group 211b. 212 is arranged. The scattered light emitted from the pixel at the center of the screen of the liquid crystal panel 173, after passing through the first lens group 211a, approximately half enters the plane mirror 212 and the rest does not enter the plane mirror 212, and the second lens group It is incident on 211b. The normal line of the reflecting surface of the plane mirror 212 is the projection lens 21.
The optical axis 340 is tilted by 45 °. Light source 331
The light from is cut by the color filter 16 in the cyan and yellow bands. Next, the light is reflected by the plane mirror 212 and transmitted through the first lens group 211a.

The light reflected by the liquid crystal panel 173 passes through the first lens group 211a and the second lens group 211b in this order and reaches the screen. A light beam that exits from the center of the aperture of the projection lens 211 and travels toward the liquid crystal panel 173 receives the liquid crystal layer 192.
It is made to enter almost vertically to, that is, telecentric.

In FIG. 22, a PD liquid crystal panel is used as a light valve, and a transparent plate or plano-concave lens 174c is optically connected to the panel. However, it may be considered that the PD liquid crystal panel without the transparent plate 174 or the plano-concave lens 174c is used as a light valve.

A projection type display device using a reflection type TN liquid crystal panel as a light valve can also be considered.

The block diagram is shown in FIG. Light source 33
The light emitted from No. 1 is reflected by the color filter 16 in the light components other than those in the cyan and yellow bands, enters the polarization beam splitter (hereinafter referred to as PBS) 231, and reflects S-polarized light. The reflected light reflects the TN liquid crystal panel 232.
Incident on. The panel 232 modulates incident light based on a video signal, the modulated light passes through the PBS 231 and the projection lens 233, is reflected by the plane mirror 234, and is projected on the screen 177.

The projection type display device of the present invention described above uses one liquid crystal panel. Besides, a configuration using two liquid crystal panels is also conceivable. The block diagram is shown in (FIG. 25). Reference numerals 243a and 243b denote TN liquid crystal panels having the mosaic-like color filters described in the above embodiments. 231a and 231b are PBSs.

The white light emitted from the light source 331 is cut into cyan light and yellow light by the color filter 16, and the cut light is separated into P-polarized light and S-polarized light by the PBS 231a. The S-polarized light is reflected by the PBS 231a, the angle is bent by the mirror 241b, and the field lens 24
The light passes through 2b and enters the liquid crystal panel 243b. Also P
The polarized light transmitted through the PBS 231b is also angled by the mirror 241a, and the P-polarized light is reflected by the field lens 242a.
And is incident on the liquid crystal panel 243a. Each liquid crystal panel 243 modulates incident light, and the modulated light is P
It is combined by the BS 231b and enlarged and projected on a screen (not shown) by the projection lens 339.

Similarly, as shown in FIG. 26, the light source 331
A projection-type display device having two units may be considered. In this case, the PBS 231a becomes unnecessary.

An optical image 261a of the liquid crystal panel 243a and an optical image 261b of the liquid crystal panel 243b are displayed on the screen.
Are superimposed and imaged. Explanatory drawing at that time (Fig. 27)
Shown in. As is clear from FIG. 27, the liquid crystal panel 243
a pixel 262a image and the liquid crystal panel 243b pixel 26
The image of 2b is formed with a half pixel shift. Speaking of a television image, the horizontal scanning line of one screen is arranged between the horizontal scanning lines of another screen.

The liquid crystal panel 243 has a vertical length of 768 × horizontal 10.
It corresponds to 24 XGA, and the diagonal size of the panel is 10.
It is 4 inches. Also, the lamp 331 of the light source is 250 W
A metal halide lamp having an arc length of 6.0 mm is used, and the field lens 242 is an aspherical plastic lens.

The aspect ratio of a panel that is normally mass-produced is 4: 3, as is the case with an XGA panel. recent years,
Although a high-definition panel with an aspect ratio of 16: 9 has been prototyped, it is at a research and development level and is very expensive. Nevertheless, there is a great need to display an image with an aspect ratio of 16: 9 on a large screen. Therefore, the upper and lower display parts of the liquid crystal panel with the aspect ratio of 4: 3 are set to the non-display area (black display or blue back display) and the
There is an attempt to display an image at 6: 9. But,
In this case, there arises a problem that the number of horizontal scanning lines (the number of vertical dots) is insufficient. In other words, although a horizontal scanning line number of about 1000 is required to display a high-definition image, the liquid crystal panel has only 1000 dots or less. Even more, if a panel having an aspect ratio of 4: 3 is used with 16: 9, it cannot be realized with 1000 horizontal scanning lines at all.

According to the present invention, two liquid crystal panels receive half the number of horizontal scanning lines of one screen, and the number of horizontal scanning lines is 100.
The idea is to achieve zero. That is, each liquid crystal panel may display 500 dots vertically.

The pixel aperture of the liquid crystal panel is usually as low as 50% or less. This is because TFTs, signal lines, etc. are formed in the non-opening portions and block incident light. Therefore,
There is a constant distance between the opening of the pixel and the opening of the pixel adjacent to the pixel. Therefore, as shown in (FIG. 27), the opening of the other liquid crystal panel is imaged on the non-opening.

As described above, it is possible to properly superimpose two images on each other, which is peculiar to the projection type display device using the liquid crystal panel as a light valve. In a projection display device using a CRT, the system size is large and the influence of the earth's magnetic field is not easy.

Another point is that an active matrix type liquid crystal panel is used. Since an image can be held for each pixel for one frame period, interpolation can be easily performed between frames. On a CRT, each pixel is displayed only for a moment, which is not easy.

In order to realize 1000 horizontal scanning lines (1000 dots vertically) by using two XGA liquid crystal panels, an image may be displayed at 500 dots vertically on each liquid crystal panel. At this time, the number of dots required for displaying an image with an aspect ratio of 16: 9 is about 890. As for the display state, even if the black display area 272 (non-display or blue back display) is arranged in the peripheral portion as shown in FIG. 28 (a), the upper and left and right portions as shown in FIG. 28 (b) are displayed. The black display area 272 may be arranged in the area.

The mass-produced inexpensive aspect ratio is 4:
Needless to say, if a high-definition image having an aspect ratio of 16: 9 can be realized by using the liquid crystal panel No. 3, an inexpensive projection display device can be provided. Further, compared to displaying a high-definition image on one liquid crystal panel, displaying on two liquid crystal panels can reduce the operating clock to 1/2, which is preferable. This is because the operating clock required to display a high-definition image reaches about 80 MHz. By cutting the cyan light and the yellow light by the color filter 16 of the present invention, it is possible to display a hue that is practically sufficiently resistant to high-definition image display. Therefore, the technical idea of the present invention regarding the color filter 16 is applied to the projection type display device such as (FIG. 25).

The image display circuit of the projection type display device shown in (FIG. 25) and (FIG. 26) will be described below with reference to (FIG. 29). Note that the video display circuit has been described once with reference to FIG. 13 and the like, so the description will focus on the differences from the previous embodiment.

(FIG. 30) to (FIG. 31) are (FIG. 25)
FIG. 6 is an explanatory diagram of a display method of a projection display device that displays one image by superimposing display images of two liquid crystal panels such as the above.

The image data processing circuit is the A / D converter 13
1. Field memory (or frame memory) 28
3, a D / A converter 134, a field memory control circuit (or a frame memory control circuit) 284, and the like. The video signal is digitized by the A / D converter 131 and stored in the field memory 283. The reason why the video signal is digitized in this way is to convert it into image data that matches the black display area 272 and the image display area 273 as shown in FIG. 28. That is, the conversion of the time axis of the video signal and the timing of the data output to the source signal line processing circuit 282 are controlled. Field memory 28
The timing of inputting data and the like to No. 3 is considered to be inferred from the description of the line memory 132 in FIG.

Next, the source signal processing circuit 282 outputs D /
The γ circuit 285 is added to the video signal output from the A converter 134.
Γ correction is performed. Next, a phase division circuit 286 and a polarity switching circuit 28 for alternating-current driving the liquid crystal panel 292.
The polarity is inverted line by line (1H) at 9, and the source drive IC
Input to 141. Basically, it is the same as the source signal processing circuit 135 in FIG. Other operations and configurations of the gate drive IC control circuit 137 and the display method selection circuit 136 are similar to or similar to the description using (FIG. 13), and those skilled in the art can easily understand or infer. Therefore, the description is omitted.

The panel display circuit 290 may be characterized in the video display circuit shown in FIG. It has switches SW1 and SW2 inside, and is configured so that a signal can be applied to at least one of the liquid crystal panels 292a and 292b by switching the switch SW. This operation will be described together with the description of the display method from (FIG. 30) to (FIG. 32).

FIG. 30 is an explanatory diagram of the first display method. (FIG. 30 (1)) shows the display image of the liquid crystal panel 292a, and (FIG. 30 (2)) shows the display image of the liquid crystal panel (292b) as a model. In addition, it is assumed that the video signal is transmitted by the interlace method (see FIG.
The display images from (0) to (FIG. 32) correspond to the image display area 273 of (FIG. 28). That is, in (Fig. 28) A
The part 3 corresponds to the part of the image display area 273. Of course, the scanning operation of the gate drive IC 291 is also performed on the portions corresponding to the portions A1 and A2, but the pixel electrode 342 is controlled to be in a voltage or no voltage state so that an image is displayed in black. Also, there are black display areas (non-display areas) 272 on the left and right of the A3 portion, which are (FIG. 30).
It may be considered that the video signal is such that the left and right of each line of (1) are displayed in black. Further, since the video signal is transmitted by the interlace system, one display screen is composed of two fields, a first field and a second field, and the two fields are called one frame.

In the first field in FIG. 30, in the panel selection circuit, SW1 is a1 terminal and SW2 is a2.
The terminal is switched to and the image data is written only in the liquid crystal panel 292a. On the other hand, in the second field, SW1
Is switched to the b1 terminal and SW2 is switched to the b2 terminal, and the image data is written only in the liquid crystal panel 292b. At this time, the liquid crystal panel 292a holds the data written in the first field. The display images on the liquid crystal panels 292a and 292b are interpolated to form one screen.
If 2a is responsible for the odd-numbered rows of the one screen and the liquid crystal panel 292b is responsible for the even-numbered rows, the odd-numbered row image is rewritten in the first field and the even-numbered row image is rewritten in the second field. Become. As described above, if the two liquid crystal panels 292 are used to form one-screen display in two fields, the operation speed can be reduced to half as compared with the case where one screen display is formed using the liquid crystal panels. Since this effect and the like have been described in (FIG. 11), description thereof will be omitted. However, since the number of liquid crystal panels is two in the embodiment of (FIG. 30), it goes without saying that the operating speed is 1/2 that of the example of (FIG. 11).

Of course, when the transmitted video signal is a non-interlaced signal, it can be dealt with by switching the switch SW of the panel selection circuit 290 every one horizontal scanning period (one line (1H)). This explanatory view is shown in (FIG. 31). For the image data of the 1_1 line, set the switch SW1 to a1.
SW2 is applied to the liquid crystal panel 292a by setting SW2 to a2 terminal, and the image data of 1_2 line is set to the liquid crystal panel 292b by setting switch SW1 to b1 terminal and SW2 to a2 terminal.
Apply to. As described above, SW1 and SW2 are switched every 1H and applied to the liquid crystal panels 292a and 292b. The liquid crystal panel 292a displays images of odd lines, and the liquid crystal panel 292b displays images of even lines.

Image display can be performed regardless of whether the image signal transmitted as described above is of the interlace system or the non-interlace system. At that time, since two liquid crystal panels are used, the operation speed of the gate and source driving ICs is set to 1 as compared with the case of forming one image display screen with only one.
It can be reduced to / 2. Therefore, it is preferable because it can deal with a signal of high operating frequency such as a high-definition image.

Next, the second display method will be described with reference to FIG. The video signal transmission is interlaced. In FIG. 32, SW1 of the panel selection circuit 290
Are connected to terminals a1 and b1. That is, switch S
It is short-circuited to both the W1 terminals a1 and b1 terminals. Similarly, SW1 is also shorted to both the a2 and b2 terminals. In this way, the output from the source signal line processing circuit 282 is simultaneously applied to the source drive ICs 141a and 141b, and the output from the gate drive IC control circuit 137 is also simultaneously applied to the gate drive ICs 291a and 291b. To be done. That is, the liquid crystal panels 292a and 292b perform the same operation.

As is apparent from FIG. 32, in the first field, the image data is written in the liquid crystal panels 292a and 292b sequentially from the line 1_1. Next second
In the field, 2_ is displayed on the liquid crystal panels 292a and 292b.
Image data is sequentially written from one line. At this time, it should be noted that the second field is the second
The point is that image data is written from the second line. That is, the data of the 1st line of the first field written in the first line is not rewritten. Also, considering one frame, the image of 1_2 line is displayed in the second field during the first field, and the image of 2_1 line is displayed during the second field. Similarly, in the third line, the image of 1_3 line is displayed during the first field, and the image of 2_2 line is displayed during the second field. That is, the image display of each line is a display in which the image of the first field and the image of the second field are mixed. The reason for rewriting the image data from the second line in the second field will be apparent if the transmitted video signal is considered to be an interlaced signal. That is, in the interlaced signal, the odd (even) image data in the first field and the even (odd) image data in the second field are transmitted.

In the above display method, one image display is formed on the screen by using two liquid crystal panels, so that the operation speed of the drive IC and the like can be reduced, which is advantageous.

Although the above has mainly described two display methods, the first display method (see FIG. 30) is selected for a still image and the second display method (see FIG. 33) is selected for a moving image. It is preferable to select it. Since the image of the still image is stopped, the discontinuity of the image in the vertical direction is more likely to be visually recognized than that of the moving image. Therefore, in the case of a still image, it is preferable to ensure an apparent vertical resolution by performing interpolation between frames using the first display method. On the other hand, since a moving image has a large temporal change in image, when the first display method is applied, so-called moving image blur (jerkiness obstruction or the like) occurs. Therefore, in the case of moving images, it is preferable to prevent the occurrence of moving image blur by performing interpolation in the frame by the second method.

Although the description has been given for the implementation of (FIG. 13), it is preferable that the display method selection circuit 136 controls the panel selection circuit 290 to switch between the first display method and the second display method. The display method selection circuit 136 includes A /
The progressive scan video signal converted into a digital signal by the D converter 131 is input. The display method selection circuit 136 calculates the difference for each frame of the input progressive scan video signal, and determines whether it is a still image or a moving image based on the size of the difference. As a result, the panel selection circuit 2 uses the first display method for a still image and the second display method for a moving image.
Control 90. In a display that maintains the display state until refreshed, such as an active matrix liquid crystal display, vertical resolution is ensured because interpolation is performed between frames in the case of still images, and in the frame in the case of moving images. The moving image blur does not occur because the interpolation is performed, and a good image can be obtained even though the input progressive-scan video signal is displayed at half the speed as compared to when it is displayed.

In the above embodiment, switching by automatic detection is described, but in addition to this, if the user can forcibly switch the switching device, it will be more practically convenient.

The technical idea of improving the color purity of a display image by the color filter 16 is as follows: a projection type display device using one liquid crystal panel having the color filter shown in FIG. 1; It is not applied only to the projection display device using a single liquid crystal panel. For example, it is also effective for a projection display device (called a three-plate projection display device) that performs color display by using three liquid crystal panels without a color filter. The three-plate projection display device of the present invention will be described below.

Embodiments of the three-plate projection display device of the present invention will be described below with reference to the drawings. FIG. 33 is a configuration diagram of a three-panel projection display device in the first example of the present invention.

The light source 12 includes a lamp 331a and a concave mirror 331.
b, UVIR filter 331c. Lamp 3
Reference numeral 31 is a metal halide lamp or a xenon lamp, which emits light containing color components of three primary colors of R, G, and B.
The concave mirror 331b is made of glass, and has a reflective surface on which a multilayer film that reflects visible light and transmits infrared light is deposited. UV
The IR filter 331c is formed by depositing a multilayer film that transmits visible light and reflects infrared light and ultraviolet light on a glass substrate. A part of the visible light included in the light emitted from the lamp 331a is reflected by the reflecting surface of the concave mirror 331b. The reflected light emitted from the concave mirror 331b is reflected by the UVIR filter 33.
Infrared rays and ultraviolet rays are removed by 1c and emitted. Note that 16 is the color filter 16 described above.

The display panel 176 used as the light valve may be any display panel that modulates both P and S polarized light. As an example, a display panel that forms an optical image as a change in the light scattering state, for example, JP-A-3-87.
The PD liquid crystal display panel disclosed in Japanese Patent Laid-Open No. 721 and the optical writing type spatial light modulator disclosed in Japanese Patent Laid-Open No. 2-93519 are exemplified. In addition, a display panel that forms an optical image as a change in the diffraction state, for example, Japanese Patent Laid-Open No.
The diffractive display panels disclosed in JP-A-9-104659 and JP-A-62-237424 may also be used.

The present invention may use any of the above-mentioned display panels as the display panel as the light valve used in the projection type display device, but from the viewpoint of reliability, light modulation characteristics and the like (see FIG. 2).
The PD liquid crystal display panel shown in 3) is used as a light valve.

The projection lens 211 includes a first lens group 221a on the liquid crystal display panel side and a second lens group 22 on the screen side.
1b, and a plane mirror 212 is arranged between the first lens group 221a and the second lens group 221b. The scattered light emitted from the pixel at the center of the screen of the display panel 176 is transmitted through the first lens group 211a, then about half of the light is incident on the plane mirror 212, and the rest is the plane mirror 21.
It is incident on the second lens group 211a without entering 2. The normal line of the reflecting surface of the plane mirror 212 is inclined 45 ° with respect to the optical axis 340 of the projection lens 211. The light from the light source 331 is reflected by the plane mirror 212 and is reflected by the first lens group 211a.
And is incident on the display panel 176. Display panel 1
The reflected light from 76 is transmitted through the first lens group 211a and the second lens group 211b in this order and reaches the screen 177. A light ray that exits from the center of the diaphragm of the projection lens 211 and travels toward the display panel 176 is made substantially vertical to the liquid crystal layer, that is, telecentric.

Here, in order to facilitate the explanation, 176
It is assumed that c is a display panel that modulates R light, 176a is a display panel that modulates B light, and 176b is a display panel that modulates G light.

Reference numeral 293 is a dichroic mirror,
This serves both as a color synthesis system and a color separation system. The band of the UVIR filter 331c is a half value of 430 nm to 690.
nm. Hereinafter, when describing the band of light, it is expressed by half value. The dichroic mirror 293a reflects R light,
G light and B light are transmitted. The G light is reflected by the dichroic mirror 293b and enters the display panel 176b. The proper value for each color band is 600 nm for the R light band.
The band of 690 nm and G light is 510 to 570 nm, and the band of B light is 430 nm to 490 nm. Each display panel 1
At 76, an optical image is formed as a change in the scattering state according to each video signal. The optical system formed by each display panel is color-synthesized by the dichroic mirror 293, enters the projection lens 211, and is enlarged and projected on the screen 177.

First, in order to facilitate understanding, a case where the color filter 16 is not provided will be described with reference to FIG. (A) to (e) in FIG. 34 show the spectral distribution of light, the dotted line indicates the P-polarized component, and the solid line indicates the S-polarized component. However, in order to facilitate understanding of the spectral distribution, wavelength bands and the like are illustrated as models.

The light emitted from the lamp 331a is reflected by the mirror 2
It is reflected at 12. The spectral distribution of the light is shown in FIG.
(A)). (FIG. 34 (a)) to (FIG. 34 (e))
The horizontal axis of the graph is the wavelength of light (nm). The dichroic mirror 293a reflects the R light, and its spectral distribution is shown in FIG. 34 (b). Dichroic mirror 29
3b reflects the G light and transmits the B light. The spectral distribution of the reflected G light is shown in FIG.
The spectral distribution of light is shown in FIG. 34 (d). The dichroic mirror 293c narrows the band of R light to improve color purity.

As shown in FIG. 34, when the dichroic mirror is arranged at an angle of about 45 ° with respect to the optical axis 340, the spectral distribution of reflected light theoretically has a wider band for S-axis light, P-polarized light becomes narrower. If the incident angle becomes smaller, the bands of P-polarized light and S-polarized light will match, but the optical system for color separation / color synthesis will become larger.

When the liquid crystal layer 192 of the display panel 176 is in the transmissive state, the light color-separated by the dichroic mirrors 293a and 293b (FIGS. 34 (b) (c) (d)) is reflected by the reflective electrode 223 of the display panel 176. Then, the light is again incident on the dichroic mirrors 293a and 293b and color combination is performed. That is, the spectral distributions of (FIGS. 34 (b) (c) (d)) are maintained as they are. The spectral distribution of the light combined by the dichroic mirror is shown in FIG. 34 (e). The light of the spectral distribution enters the projection lens 211 and is projected on the screen 177.

As can be seen from FIG. 34 (e), R,
It can be seen that the wavelength bands of the G and B lights overlap. This occurs because the band of light reflected by the dichroic mirror differs between P-polarized light and S-polarized light. For example, G
Of the light incident on the display panel 176b that modulates the light, S
The polarized light includes light in the R light and B light bands.
Therefore, the display panel 176b originally needs to modulate only G light, but also modulates R light and B light. Therefore, the hue of the projection type image is lowered.

When overlap occurs as shown in FIG. 34 (e), the hue decreases. The hue can be improved by cutting the wavelength of light in the overlap region with the color filter 16. The color filter of the present invention is a filter capable of satisfactorily cutting cyan and yellow light as shown in (FIG. 4) (FIG. 5), and has a synergistic effect when combined with a three-panel projection display device using both PS light. Demonstrate. The wavelength reflected by the dichroic mirror is narrower for P polarized light than for S polarized light.
Therefore, the wavelength cut by the color filter 16 may be designed with the P-polarized band as the center. R, G, at that time
The band of B light may be set to the above-mentioned proper band. The color filter 16 may be arranged at the position A in FIG. 33.

From the above results, it is understood that the color filter 16 can limit the band of light and can improve the hue of the projected image. In the structure of the present invention, the dichroic mirror 293 is used.
Is about 45 ° with respect to the coaxial 340 (the incident light angle is 45
°) is located. Therefore, the size of the optical system for color separation / color combination can be made compact. This is an excellent configuration as compared with the projection display device disclosed in Japanese Patent Laid-Open No. 3-87721.

The reflection type three-plate projection display device of the present invention has two
The color combining / separating system is composed of one or three dichroic mirrors. Therefore, the optical system can be significantly downsized and the cost can be reduced. Further, since the reflective display panel 176 is used, the contrast is better and the pixel aperture ratio is higher than that of the transmissive display panel, so that light luminance display can be performed. Moreover, since there is no obstacle on the back surface of the display panel, the panel can be easily cooled.
For example, forced air cooling or liquid cooling from the back surface can be easily performed, and a heat sink or the like can be attached to the back surface.

In the display panel 176, the liquid crystal layer 192 that modulates the R light has a larger particle diameter of the liquid crystal droplets or the liquid crystal film has a larger thickness than the liquid crystal layer 192 that modulates the other G and B lights. And configure. This is because the longer the wavelength of light, the lower the scattering characteristics and the lower the contrast. The particle size of the water-drop liquid crystal can be controlled by controlling the ultraviolet light during polymerization or by changing the material used. The liquid crystal film thickness can be adjusted by changing the bead diameter of the liquid crystal layer.

In the above description, the average particle diameter of the water-drop liquid crystal was changed, but a PD liquid crystal panel in which the liquid crystal is not water-drop in the polymer, for example, proposed by Dainippon Ink and Chemicals, Inc. It may be read that the average pore diameter of the polymer network is changed in the PD liquid crystal panel.

The projection type display device and display panel of the present invention described above are of the reflection type. The technical idea of the invention described above can be applied and developed to the transmission type. An example thereof is shown in FIG. 35.

Here, in order to facilitate the explanation, 317G
Is a PD display panel for modulating G light, 317R is a PD liquid crystal display panel for modulating R light, and 317B is a liquid crystal PD display panel for modulating B light. Therefore, regarding the wavelengths that are transmitted and reflected by each dichroic mirror, the dichroic mirror 315a reflects R light and transmits G light and B light. The dichroic mirror 315c reflects G light,
R light is transmitted. The dichroic mirror 315b is B
The light is transmitted, the G light is reflected, and the dichroic mirror 315d reflects the B light and transmits the G light and the R light. 313 is a total reflection mirror.

The light emitted from the light source 331 is reflected by the total reflection mirror 313a and the direction of the light is changed. Next, unnecessary light of cyan and yellow wavelengths is cut off by the color filter 16 from the light. The light whose band has been cut is dichroic mirrors 315a, 315.
The R, G, and B lights are separated into three primary color optical paths by b, and the R light enters the field lens 316R, the G light enters the field lens 316G, and the B light enters the field lens 316B. Each field lens 316 collects each light, and the display panel changes the orientation of the liquid crystal corresponding to each video signal to modulate the light. R, G, B modulated in this way
The lights are combined by the dichroic mirrors 315c and 315d and enlarged and projected on a screen (not shown) by the projection lens 318.

In (FIG. 33) and (FIG. 35), R light, G light and B light are reflected by the dichroic mirror.
Although the light is separated into the three primary colors, the invention is not limited to this. For example, a dichroic prism or the like may be used instead of the dichroic mirror.

The previous example was an example using a PD liquid crystal panel. In addition, the technical idea of the present invention can be applied to a three-plate projection display device using a display panel that controls the tilt of the micromirrors to form an optical image. An example thereof (FIG. 36) is shown.

In FIG. 36, reference numeral 323 is a micro mirror display panel. As an example of the display panel, Japanese Patent Laid-Open No.
For example, Japanese Patent Laid-Open No. 230722 and Japanese Patent Laid-Open No. 5-196880 are exemplified.

Unwanted yellow light and cyan light of the white light emitted from the lamp 331a are cut by the color filter 16 and separated by the prism 332 into lights of three wavelength bands of R, G and B. A display panel 323 is arranged for each wavelength band. The display panel 3
Reference numeral 23 changes the tilt of the mirror corresponding to the pixel based on the video signal to form an optical image. The formed optical image is projected on the screen by the zoom lens 321.

The effect of the color filter 16 of the present invention is also effective for the projection type display device having the structure as described above (FIG. 35). Therefore, the color filter of the present invention is effective for all projection display devices that use a display panel that modulates random light. Especially, the effect is effective when a metal halide lamp is used as a light source.

[0217]

Although the color filter of the present invention is a transmission type filter, since it uses a periodic reflection band on the short wavelength side, it can sufficiently cut the yellow light and the cyan light, and its band. Is also narrow. Moreover, the R, G, and B lights are satisfactorily transmitted. Also, since the first or second periodic reflection band is used, the film thickness of the dielectric multilayer film of one layer does not become thick and cracks and the like do not occur. Further, by alternately using TiO ₂ and ZnS for the high-refractive-index dielectric film, stress generated between the dielectric films is relaxed, and high reliability is realized. Furthermore, when used in combination with a metal halide lamp, the peak wavelength due to mercury atoms in the lamp or the like is taken into consideration, so when used as a projection display device, the color purity and hue of the displayed image can be made very good.

In the projection display device using the liquid crystal panel using the color filter of the present invention, by using the color filter of the present invention, unnecessary light components of the white light emitted from the light source are removed to obtain a projected image. It is possible to narrow the band of each color light of red, green and blue. Further, since unnecessary light components incident on the light valve are reduced, unnecessary absorbed light in the color filter can be reduced and heat generation of the color filter can be reduced. As a result, it is possible to provide a projection display device that suppresses the deterioration of the color filter, is small in size, lightweight, low in cost, and has excellent color reproducibility.

In the projection display apparatus of the present invention using two liquid crystal panels, since the images of the two liquid crystal panels are superimposed and projected on the screen, the operating frequency can be reduced and high definition display can be supported. Further, since one image is displayed by interpolating a part of the horizontal scanning lines of each liquid crystal panel, it is possible to easily support a 16: 9 high-definition image.

Further, since the video information for one frame is displayed in the two-field period, it is 1/2 as compared with the case where the input progressive scan video signal is displayed as it is.
Can be displayed at the speed of. As a result, even when a wideband (high data rate) progressive scan video signal of a personal computer, a workstation, or the like is displayed on a display that is difficult to display at high speed such as a matrix type liquid crystal display, the image quality does not deteriorate.

Since the first display method and the second display method are selectively activated, it is always optimal depending on the nature of the progressive scan video signal (for example, still image or moving image). Various displays can be performed.

Further, when the value indicating the correlation between adjacent frames of the progressive scan video signal is equal to or more than a predetermined value (that is, in the case of a still image), the first display method is selectively activated, and when the value is less than the predetermined value. Since the second display method is selectively activated (in the case of a moving image), the vertical resolution can be secured by interpolating between frames in the case of a still image and in the case of a moving image. Interpolation can be performed within the frame to prevent the occurrence of moving image blur.

Further, since the three-plate projection display device of the present invention uses the color filter of the present invention to correct the disagreement between the reflections of the P-polarized light and the S-polarized light that occur in the dichroic mirror, the hue of the projected image can be improved. Furthermore, the color filter of the present invention has a synergistic effect when used in combination with a metal halide lamp.

Further, since the incident angle of the light incident on the dichroic mirror can be set in the vicinity of 45 degrees,
The size of the optical system becomes small, and the system size of the projection display device can be made compact. The hue of the projected image is also practically sufficient. Further, since the back focus of the projection lens can be greatly shortened, the lens design can be facilitated and the size of the lens can be reduced to realize cost reduction.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a projection display device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a color filter of the invention.

FIG. 3 is a characteristic diagram of a color filter according to another embodiment of the present invention.

FIG. 4 is a characteristic diagram of another color filter of the present invention.

FIG. 5 is a characteristic diagram of a color filter according to another embodiment of the present invention.

FIG. 6 is a characteristic diagram of a conventional color filter.

FIG. 7: Spectral distribution map of synchrotron radiation of a metal halide lamp

FIG. 8 is a spectral distribution diagram of light band-limited by the color filter of the present invention.

FIG. 9 is a spectral distribution diagram of light passing through a color filter.

FIG. 10: xy chromaticity diagram

FIG. 11 is an explanatory diagram of a projection display device according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram of a projection display device according to another embodiment of the present invention.

FIG. 13 is a circuit block diagram of the projection display device of the present invention.

FIG. 14 is a circuit block diagram of the projection display device of the present invention.

FIG. 15 is a timing chart of the circuit of the projection display device of the present invention.

FIG. 16 is a timing chart of the projection display device of the present invention.

FIG. 17 is a timing chart of the projection display device of the present invention.

FIG. 18 is a configuration diagram of a projection display device of the present invention.

FIG. 19 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 20 is a sectional view of a display panel.

FIG. 21 is a sectional view of a display panel.

FIG. 22 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 23 is a sectional view of a display panel.

FIG. 24 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 25 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 26 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 27 is an explanatory diagram of a display method of the present invention.

FIG. 28 is an explanatory diagram of a projection display device of the present invention.

FIG. 29 is an explanatory diagram of a projection display device of the present invention.

FIG. 30 is an explanatory diagram of a projection display device of the present invention.

FIG. 31 is an explanatory diagram of a projection display device of the present invention.

FIG. 32 is an explanatory diagram of a projection display device of the present invention.

FIG. 33 is a configuration diagram of a projection display device of the present invention.

FIG. 34 is an explanatory diagram of a projection display device of the present invention.

FIG. 35 is a configuration diagram of a projection display device of the present invention.

FIG. 36 is a configuration diagram of a projection display device of the present invention

FIG. 37 is a configuration diagram of a conventional projection display device.

FIG. 38 is an explanatory diagram of a liquid crystal panel

FIG. 39 is a spectral distribution of light transmitted through a color filter of a liquid crystal panel.

FIG. 40 is an explanatory diagram of a polymer dispersed liquid crystal panel.

[Explanation of symbols]

16-color filter 11, 21 Glass substrate 12, 13, 22, 23 Dielectric multilayer film 131 A / D converter 132 Line memory 133 Line memory control circuit 134 D / A converter 135, 282 Source signal processing circuit 136 Display method selection Circuit 137a, 137b Gate drive IC control circuit 138 Switching circuit 139 Display line selection circuit 140a, 140b Gate drive IC 141, 141a, 141b Source drive IC 144 D-type flip-flop 146 Switch 147 Buffer 171 Black paint 172 Antireflection film 173 Polymer Dispersed liquid crystal panel 174 Transparent substrate 175 Side surface 176 Light valve device 177 Screen 178 Light emission surface 179 Transparent binder 179a Concave lens 191 Light-shielding film 192 Polymer dispersed liquid crystal layer 211 Projection lens 212 Planar mirror 221 Counter electrode 222 Connection part 223 Reflective electrode 224 Insulating film 231 Polarizing beam splitter 232 Reflective liquid crystal panel 233 Lens 234, 241 Mirror 243 Field lens 243 Liquid crystal panel 261, 271 Optical image 262 Pixel 272 Black display area 273 Image display area 281 Image data processing circuit 283 Field memory 284 Field memory control circuit 290 Panel selection circuit 292a, 292b Liquid crystal panel 293a, 293b, 293c, 315a, 315b,
315c, 315d Dichroic mirror 316R, 316G, 316B, 332 Field lens 317R, 317G, 317B Liquid crystal panel 318, 339 Projection lens 331 Condensing optical system 321 Zoom lens 331 Light source 331a Lamp 331b Concave mirror 331c UVIR cut filter 322a, 322b, 322b, 322b 323 display panel 333a, 333b polarizing plate 334 counter substrate 335 array substrate 336 color filter 337 liquid crystal layer 338 TN liquid crystal panel 340 optical axis 344 light valve 341 counter electrode 342 pixel electrode 343 TFT 381 water droplet liquid crystal 382 polymer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H04N 9/31 C (72) Inventor Yoshihiro Masumoto 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. In the company

Claims (28)

[Claims] 1. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
A color filter characterized by being λ _C (where λ _C is the center wavelength of cyan light). 2. In the first dielectric multilayer film and the second dielectric multilayer film, the low refractive index layer is any one of MgF ₂ , SiO ₂ and Al ₂ O ₃ , and the high refractive index layer is TiO ₂ , ZnS, CeO ₂ , ZrTi
The color filter according to claim 1, wherein the color filter is any one of O ₄ , HfO ₂ , Ta ₂ O ₅ , and ZrO ₂ . 3. The first dielectric multilayer film and the second dielectric multilayer film, wherein the high refractive index layer is composed of at least two layers in which TiO ₂ and ZnS are alternately laminated. Item 1. The color filter according to Item 1. 4. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
A color filter for λ _C (where λ _C is the center wavelength of cyan light), an optical modulator that has a pixel structure and forms an optical image according to a video signal supplied from the outside, and red, green, and blue A projection display device comprising: a light generation unit that emits light containing color components of three primary colors; and a projection unit that projects an optical image formed by the light modulation unit. 5. In the first dielectric multilayer film and the second dielectric multilayer film, the low refractive index layer is any one of MgF ₂ , SiO ₂ and Al ₂ O ₃ , and the high refractive index layer is TiO ₂ , ZnS, CeO ₂ , ZrTi
The projection display device according to claim 4, wherein the projection display device is any one of O ₄ , HfO ₂ , Ta ₂ O ₅ , and ZrO ₂ . 6. The light generating means has a metal halide lamp containing neodymium (Nd) as an enclosed metal element, and the color filter is arranged between the light generating means and the light modulating means. The center wavelength λ _Y of yellow light is 577n
The projection display device according to claim 4, wherein m is m. 7. The light modulating means is a twisted nematic liquid crystal panel in which each pixel has a pixel structure in which red pixels, green pixels and blue pixels are alternately arranged, and a color filter is the red pixels or green pixels. 5. The projection display device according to claim 4, wherein light of a part of the wavelengths included in the wavelength band that can pass through the pixel or the blue pixel is selectively reflected. 8. The light modulating means has a pixel structure in which each pixel has red pixels, green pixels and blue pixels arranged alternately.
A polymer-dispersed liquid crystal panel that forms an optical image as a change in the light-scattering state, wherein the color filter has a part of wavelengths included in a wavelength band that can pass through the red pixel, the green pixel, or the blue pixel. 5. The projection display device according to claim 4, wherein the light of the above is selectively reflected to increase the color purity of the optical image projected corresponding to the red pixel, the green pixel, or the blue pixel. 9. A transparent substrate or a concave lens is optically coupled to at least one of the light incident surface and the light emitting surface of the polymer dispersed liquid crystal panel by a transparent coupling member. The projection display device described. 10. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both sides or one side of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
λ _C (where λ _C is the center wavelength of cyan light), a reflective twisted nematic liquid crystal panel that has a pixel structure and forms an optical image in accordance with an externally supplied video signal, and three primary colors Light emitting means for emitting light containing color components, a polarizing beam splitter, and projection means for projecting an optical image formed on the liquid crystal panel, the liquid crystal panel corresponding to each pixel. The pixel structure includes a color filter that transmits red, green, and blue light, the polarization beam splitter is disposed in an optical path between the light source and the liquid crystal panel, and the color filter is the liquid crystal panel. And a projection means arranged in an optical path between the projection means and the projection means to narrow the band of at least one component light of red, green, and blue component light forming a projection image of the pixel structure. Dress Place 11. The light generating means includes a metal halide lamp containing neodymium (Nd) as an enclosed metal element, and a color filter is arranged between the light generating means and the light modulating means. Λ _Y that determines the optical thickness is 577 nm
11. The projection display device according to claim 10, wherein: 12. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
A color filter of λ _C (where λ _C is the center wavelength of cyan light), a light generation unit that emits light containing color components of three primary colors, and a light emitted by the light generation unit is used as a red optical path and a green color. Color separation means for separating into three light paths of a light path of 1 and a blue light path, a light modulation means arranged in each of the three light paths to form an optical image as a change of a light scattering state, and the three light modulation means. And a projection means for projecting the optical image of 1) at substantially the same position and projecting it. 13. The light generating means has a metal halide lamp containing neodymium (Nd) as an enclosed metal element, and the color filter is arranged between the light generating means and the light modulating means. Λ _Y that determines the film thickness is 577 nm
13. The projection display device according to claim 12, wherein: 14. In the first dielectric multilayer film and the second dielectric multilayer film, the low refractive index layer is any one of MgF ₂ , SiO ₂ and Al ₂ O ₃ , and the high refractive index layer is TiO ₂ , ZnS, CeO ₂ , ZrTi
13. The projection display device according to claim 12, which is any one of O ₄ , HfO ₂ , Ta ₂ O ₅ , and ZrO ₂ . 15. The light modulating means is a polymer dispersed liquid crystal panel, and a transparent substrate or a concave lens is optically coupled to at least one of a light incident surface and a light emitting surface of the liquid crystal panel by a transparent coupling member. Claim 1 characterized by the above.
2. The projection display device according to 2. 16. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
Includes λ _C (where λ _C is the center wavelength of cyan light) color filter, three reflective polymer dispersed liquid crystal panels that modulate red light, green light, and blue light, and three primary color components Light generating means for emitting light, a function for separating the light emitted by the light generating means into three optical paths of a red light optical path, a green light optical path and a blue light optical path, and three polymer dispersed liquid crystal panels The light generation means includes a color separation / combination means having a function of combining the light modulated by the optical path into one optical path, and a projection means for projecting the light in the optical path combined into the one optical path. A projection display device characterized in that it has a metal halide lamp containing neodymium (Nd) as a substrate, and the color filter is arranged between the light generating means and the light modulating means. 17. The central wavelength of yellow light of the color filter, λ _Y, is 577 nm, and the low refractive index layer in the first dielectric multilayer film and the second dielectric multilayer film is M.
gF ₂ , SiO ₂ , or Al ₂ O ₃ , and the high refractive index layer is TiO ₂ , ZnS, CeO ₂ , ZrTi
The projection display device according to claim 16, which is any one of O ₄ , HfO ₂ , Ta ₂ O ₅ , and ZrO ₂ . 18. The projection display device according to claim 16, wherein a transparent substrate or a concave lens is optically coupled to the light incident surface of the polymer dispersed liquid crystal panel by a transparent coupling member. 19. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
A color filter of λ _C (where λ _C is the center wavelength of cyan light), three reflection-type light modulating means for modulating red light, green light, and blue light respectively, and light containing color components of three primary colors Emitting light generation means, a function of separating the light emitted by the light generation means into three optical paths of a red light optical path, a green light optical path and a blue light optical path, and modulation by three polymer dispersed liquid crystal panels The color filter includes: a color separation / combination means having a function of combining the combined light into one optical path; and a projection means for projecting the light of the combined optical path into the one optical path; A projection type display device, characterized in that it is arranged between the light modulation means and the light modulation means is a display panel which forms an optical image by tilting a micro mirror corresponding to a pixel. 20. A first array of pixels arranged in a matrix
And a second light modulating means, a data holding means for holding a video signal as image data, and output data from the data holding means are switched for each field, frame, or one horizontal scanning period, and the first light modulating means. And a switching means for alternately applying to the second light modulation means, and an optical image formed by the first light modulation means and an optical image formed by the second light modulation means are shifted by approximately half a pixel in the vertical direction. A projection display device comprising a projection means for projecting. 21. The projection display device according to claim 20, wherein at least one of an upper end and a lower end of the optical image is a non-display area. 22. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both surfaces or one surface of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
A color filter of λ _C (where λ _C is the center wavelength of cyan light), a light generating unit that emits light containing color components of three primary colors, and a red pixel, a green pixel, and a blue pixel are arranged alternately. The first and second light modulators having the pixel structure described above, the data holding unit that holds the video signal as image data, and the output data from the data holding unit are switched for each field, frame, or horizontal scanning. The switching means for alternately applying the first light modulation means and the second light modulation means, the optical image formed by the first light modulation means and the optical image formed by the second light modulation means are arranged in the vertical direction. A projection display device, comprising: a projection unit that shifts the image by approximately half a pixel and projects. 23. The projection display device according to claim 22, wherein at least one of the upper end and the lower end of the optical image is a non-display area. 24. The light generating means has a metal halide lamp containing neodymium (Nd) as an enclosed metal element, and the color filter is arranged between the light generating means and the light modulating means, and the color filter has a yellow color. Λ _Y that determines the central wavelength of light
23 is the projection display device according to claim 22, wherein is 577 nm. 25. A first dielectric multilayer film that reflects yellow light and a second dielectric multilayer film that reflects cyan light are laminated on both sides or one side of a transparent substrate, and the first dielectric multilayer film. The film and the second dielectric multilayer film have a structure in which a high refractive index layer and a low refractive index layer are alternately laminated, and a final layer counted from the transparent substrate side is a low refractive index layer, optical film thickness of the first dielectric multilayer film, a low refractive index layer is substantially 0.375Ramuda _Y, final layer is substantially of the high refractive index layer layers substantially 1.125Ramuda _Y and the low-refractive layer except the last layer of 0.188
λ _Y (where λ _Y is the center wavelength of yellow light), and the optical thickness of the second dielectric multilayer film is about 0.625 λ _{C for} the low refractive index layer and the final layer of the high refractive index layer. Is about 1.875λ _C and the final layer of the low refractive index layer is about 0.313.
λ _C (where λ _C is the center wavelength of cyan light) color filters, and first and second twisted nematic liquid crystal panels having a pixel structure in which red pixels, green pixels, and blue pixels are alternately arranged A light generating means for radiating light containing color components of three primary colors and illuminating the liquid crystal panel with the light; a polarizing beam splitter for synthesizing optical images formed by the first and second liquid crystal panels; And a data holding means for holding the image data as image data, and a switch for alternately applying the output data from the data holding means to the first liquid crystal panel and the second liquid crystal panel by switching for each field, frame, or horizontal scanning. And projection means for projecting the optical image formed by the first liquid crystal panel and the optical image formed by the second liquid crystal panel by shifting them by approximately half a pixel in the vertical direction. The light generating means has a metal halide lamp containing neodymium (Nd) as an enclosed metal element, and the color filter is arranged between the light generating means and the light modulating means, and the central wavelength of the yellow light of the color filter. Determines λ _Y
Is a 577 nm projection type display device. 26. A first pixel in which pixels are arranged in a matrix
And a second light modulating means, a data holding means for holding a video signal as image data, and a writing means for sequentially writing output data from the data holding means to the same pixel row of the first and second panels, A light generating unit that emits light containing color components of the three primary colors, an optical image formed by the first light modulating unit, and an optical image formed by the second light modulating unit are shifted by approximately half a pixel in the vertical direction. A projection display device comprising a projection means for projecting. 27. The projection display device according to claim 26, wherein at least one of an upper end and a lower end of the optical image is a non-display area. 28. A color filter between the light generating means and the panel.
Is disposed, and the color filter has a first dielectric multi-layer that reflects yellow light.
The layer film and the second dielectric multilayer film that reflects cyan light are transparent.
The first dielectric multilayer film and the second dielectric multilayer film are laminated on both surfaces or one surface of a bright substrate.
The high refractive index layer and the low refractive index layer are alternately laminated,
The final layer, counting from the transparent substrate side, becomes the low refractive index layer.
And the optical thickness of the first dielectric multilayer film has a low refractive index.
Rate layer is approximately 0.375λ _Y, Layers other than the final layer of the high refractive index layer
Is approximately 1.125λ_YAnd the final layer of the low refractive layer is approximately 0.1
88λ_Y(However, λ_YIs the center wavelength of yellow light)
The optical thickness of the second dielectric multilayer film is such that the low refractive index layer is
Approximately 0.625λ_C, Except for the last layer of the high refractive index layer
1.875λ_CAnd the final layer of the low refractive layer is approximately 0.313.
λ_C(However, λ_CIs the central wavelength of cyan light)
27. The projection display device according to claim 26.