JPH0195678A - Method and device for projection display - Google Patents

Abstract

PURPOSE:To project plural different pieces of video information by generating a first video information at a projection optical system with the use of a liquid crystal light valve, and simultaneously realizing the video of an electro-chromic device(ECD) at the projection optical system in the same optical system. CONSTITUTION:The video signal stored in a magnetic storing medium beforehand is inputted to a high illuminance CRT2, and the output light of the CRT2 is introduced from the photoconductive layer of a liquid crystal light valve(LCLV)3 provided by adhering to the phase plate of the CRT2, and a bias voltage is impressed to the LCLV3. On the other hand, white light generated from a xenon lamp 4 is time-division-selected, projected to a tungsten bronze system ECD91 before the incidence to a polarizing beam splitter(PBS)6 or after the reflection, made into the projecting light, which is timely and spatially modulated beforehand, and thereafter, when it makes incident from the liquid crystal layer side of the LCLV3, the outgoing light modulated by the video signal is projected and displayed on a screen. Thus, the video and the picture of the ECD with high luminance can be displayed with a simple mechanism.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method and display device for projecting and displaying an image using a liquid crystal light valve, and more specifically relates to a full-color image and an electrochromic device (hereinafter referred to as rEcD).
The present invention relates to a method and apparatus for projecting and displaying matrix-driven images (referred to as J).

[Summary of the Disclosure] This specification and drawings describe a method and a display device for projecting and displaying an image using a liquid crystal light valve, which simultaneously generate first image information in a projection optical system using a liquid crystal light valve; By allowing the ECD image to be realized on the projection optical system within the same optical system, multiple different image information, more specifically the video and the ECU image, can be transmitted alternately or in part or in full. This discloses a technique for superimposing and projecting images.

[Prior Art] In various presentations such as academic lectures and product announcements, when video images are projected and displayed to explain the images, call attention to them, or add other additional information, conventionally, It was common to stand in front of a projection display screen and point out the relevant location with a pointer. Alternatively, if it is possible to edit or process the video footage in advance, characters or symbols may be added or the colors of some parts of the video may be altered, but in this case, the original In order to preserve the image, both the original video and the edited video must be stored, which is uneconomical. In addition, with videos that have been edited and processed in this way, it is not possible to respond in accordance with the situation on the spot.Furthermore, the above-mentioned editing and processing work cannot be performed on videos that were shot or transmitted at the presentation venue, and as a result, There were drawbacks such as the fact that no additional information was added to the data.

[Problems to be Solved by the Invention] The present invention has been developed as a result of pursuing to eliminate the above-mentioned drawbacks of display methods and devices based on the prior art.

That is, an object of the present invention is to provide a method and a display device for displaying a plurality of pieces of video information using a simpler mechanism than those of the prior art. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and a display device for displaying high-brightness full-color video images and ECD images using a significantly simpler mechanism than those of the prior art.

Another object of the present invention is to display video information from a wide variety of video sources by simply providing an additional mechanism without using multiple types of display devices. An object of the present invention is to provide a method and a display device.

Yet another object of the present invention is to provide a method and display device for displaying video information from multiple video sources on the same screen using a single display device.

Still another object of the present invention is to add other information to the input video information and display it, or to select a temporal or spatial part of the input video information or a part of various attributes such as color. The object of the present invention is to provide a method and a display device for performing the selective display by providing an additional mechanism or changing a part of the inherent mechanism.

Still another object of the present invention is to provide a display device that can be used in a variety of applications as described above, and that is lightweight, compact, low-priced, and power-saving.

[Means for Solving the Problems] That is, the present invention relates to a method and apparatus for projecting and displaying a plurality of video information, and in this method, a method for projecting and displaying a plurality of video information using a liquid crystal light valve includes the following steps. of(
This is a projection display method characterized by using the steps A) to (G).

(A) Input multiple pieces of video information that change or do not change over time, with or without time division, output the multiple pieces of video information as irradiation light in a screen-sequential manner, and use the irradiation light as light to illuminate the liquid crystal display. (B) synchronizing a plurality of non-time-shared irradiation lights from a single or multiple light sources with the plurality of video information if the plurality of video information is time-shared; In other cases, each light source can be selected in a time-division manner without the need for synchronization, or multiple light sources can be synchronized as described above, or the projection light source system can be selectively turned on in a time-division manner without the need for synchronization. (C) A step of spatially modulating the irradiated light from the projection light source system using the irradiated light from the writing process in the liquid crystal light valve.

(D) A step of magnifying and projecting the modulated light from the liquid crystal light valve in a projection optical system; (E) A step of receiving and imaging the projection light from the projection optical system to display a desired projected image on a screen. (F) generating image information by matrix driving of the ECD on the optical path of the irradiation light from the projection light source system and/or the optical path of the modulated light from the liquid crystal light valve; (G) the image of the ECD; A step of projecting and displaying information in a superimposed manner or alternately with a part or all of the plurality of different video information.

The present invention is also a projection display device using a liquid crystal light valve, which is characterized by having the following mechanisms (a) to (e).

(a) Input multiple pieces of video information that change or do not change over time, with or without time division, output the multiple pieces of video information as irradiation light, and sequentially output the irradiation light. A writing light source system installed in a liquid crystal light valve.

(b) Synchronize multiple non-time-divided irradiation lights from a single or multiple light sources with the multiple video information if the multiple video information is time-divided; otherwise, synchronize (C) A projection light source system that selects each light source in a time-division manner or synchronizes multiple light sources as described above or selectively lights them in a time-division manner without the need for synchronization; (C) A projection light source system that uses irradiation light from a writing light source system; (d) a projection optical system that guides the irradiated light from the projection light source system to the liquid crystal light valve, magnifies and projects the modulated light from the liquid crystal light valve;

(e) An image provided on the optical path of the irradiated light from the projection light source system and/or the optical path of the modulated light from the liquid crystal light valve to generate image information of the EC port different from the plurality of image information. Source of information.

In particular, in the projection display method and display device of the present invention, the plurality of video information is divided into temporal segments R, G.
, B C (Hereinafter, red is denoted as R, m is denoted as a, and blue is denoted as B) This is image information for each color, and second image information different from this is generated by a slide film.

[Function] Hereinafter, the basic structure of the present invention will be explained in more detail with reference to the drawings.

FIG. 4 and FIG. 5 are schematic diagrams showing the configuration of the basic components of the display device of the present invention, and are 65th! J is a schematic diagram showing an example of a method of converting an input signal into a time-division video signal in FIG. 4; Hereinafter, a method for projecting and displaying a video image will first be described using FIGS. 4 and 6. However, as will be described later, the configuration shown in FIG. 5 may be used instead of the configuration shown in FIG. 4.

First, the input non-time-divided image signal 21 (-
As an example, a ROB signal is shown) is converted into a time-divided image signal 23 which is time-divided by the time division mechanism 1. This time division mechanism 1 may be constructed using a known technique. For example, as shown in FIG. 6, R' of the color signal 22 obtained by time-compressing each RGB signal every 1 field Cl7 (30 seconds) is used. , G', B' times signal, G', B'
Both signals are delayed by 1/3 field and 2/3 field relative to the R' signal to become the G", R' signals, and the R', G", and B# signals (these are called subfield signals). ), mutually distinguishable marker signals Ml,
M21 to M3 are attached and output as a time-division video signal 23 line-sequentially. On the other hand, the 1 time division mechanism 1 issues a synchronization signal 24 to the 1 time division color selection mechanism 5. This synchronization signal is
Most simply, the above mutually distinguishable marker signals M1
*M2. M3 is fine.

The time division video signal 23 output from the time division mechanism 1 is C
The time-division video signal 23 is input to the CRT 2.
Image information (subfield information) for each color that is time-divided according to the time is outputted as irradiation light 31 in a field-sequential manner.

In the case of this configuration, the signals input to the CRT 2 are line sequential as described above, and as described later, the liquid crystal light valve (hereinafter referred to as LCLV) 3 receives the irradiation light 31 from the CRT. Although the LCLV incident light 34 is modulated, it is not necessary or possible to transmit the color attribute of the irradiated light 31, so it is sufficient to use a monochrome device as the CRT 2.

However, a color CRT can also be used, in which case the time-division color signal 23 may be applied to each of the three color electron guns at the same time, and the irradiation light 31 from the CRT may be made achromatic.

Furthermore, regarding the mechanism for horizontally and vertically deflecting the electron beam in the CRT 2, it goes without saying that the electron beam is deflected in 1/3 of the time required for normal field image display in accordance with the subfield information for each color. Correspondingly, the luminescence of the phosphor is also subfield (1/180
It is necessary to define the phosphor material so that it effectively decays within (on the order of seconds).

In the above description, the field picture is used as a unit, but the same effect can be easily achieved even in a configuration where the frame picture is used as a unit. Further, the input signal may be an NTSC signal, in which case an appropriate circuit is provided in the time division mechanism l to directly output the time compressed signals R', G', B' or R', G. ", B' can also be obtained.

Next, the irradiated light 31 from the CRT 2 is guided to the photoconductive layer (not shown) side of the LCLV 3 to which a bias voltage has been applied in advance. This light guide is performed using a light guide, an example of which is an optical fiber plate. or, more simply, by bringing the phosphor screen of the CRT 2 into substantially close contact with the LCLV 3.The configuration shown in factor 5 is this latter method, but the former These arrangements, without excluding other methods or mechanisms, may substantially improve the spatial modulation resolution of the LCLV to that of the CRT.
It can be made to the same degree.

The bias voltage uses direct current or alternating current, but in the case of the below-mentioned liquid crystal, the bias voltage is 10 Hz to IMHz, preferably 1 kHz to 100 kHz, and more preferably 10 kHz to 100 kHz.
It is preferable to use an alternating current bias of kHz.

The conductivity of the photoconductive layer of the LCLV 3 changes depending on the intensity of the irradiated light from the CRT 2, and the voltage applied to each part on both sides of the liquid crystal cell of the LCLV changes accordingly. Since the optical properties of a liquid crystal cell change depending on the applied voltage, in the LCLV3 described above, the optical properties of the liquid crystal cell are different for each part C, and the LCLV incident light 34, which will be described later, is spatially modulated. do.

By providing a reflective layer between the photoconductive layer and the liquid crystal cell, the spatially modulated light, that is, the LCLV output modulated light 35, is reflected to the incident light side, and the polarizing beam splitter C (hereinafter referred to as PBS) 6, which will be described later, is It is emitted towards. By the way, the configuration and operation of the lc:LV have been described here only to those that are essential in a single configuration, and the LCLV of this configuration is different from the configuration and operation of the L(::LV) of the prior art. However, this does not mean that the LCLV of the present configuration is capable of using the configuration of the LCLV of the prior art almost as is.

In addition, many photoconductive materials can be used for the photoconductive layer in the LCLV with this configuration, among which cadmium sulfide, zinc sulfide, zinc oxide, selenium, tellurium selenide, a-silicon, and various organic The photoreceptor exhibits good performance.

In addition, as described later, as a liquid crystal cell of LCLV,
Materials and modes of operation must be selected that are capable of converting at least a portion, preferably all, of the S-polarized light into p-polarized light, ie liquid crystals capable of assuming a birefringent state. The operating modes used in such liquid crystal cells include hybrid field effect type (HFK type), strong galvanic type (FLC type), electric field controlled birefringence type (ECB type), and super twisted birefringence type (SBR type). (shape) etc.

On the other hand, the time-division color selection mechanism 5 that sequentially selects the three colors R, G, and B from the white light 32 emitted from the xenon lamp 4 in a time-division manner includes, for example, R, G, A mechanism that sequentially introduces H three-color filters into the optical path, more specifically, a disk in which n sets of the same color filters are sequentially arranged in the circumferential direction, at 60/sec.
Although the n-rotation mechanism is simple, the mechanism is not limited to this, and any known color selection mechanism can be used. For example, there is a mechanism that changes the transmittance of each color of R, G, and B by controlling the voltage applied to the piezoelectric material PLZT;
, G, and B colors are laminated perpendicularly to the optical path, and a mechanism is considered in which the colors are selected by sequentially applying voltage, and other techniques can also be used.

Furthermore, as a mechanism that functions as both a light source and a color selection mechanism, a mechanism that sequentially blinks R, G, and B three-color lamps or sequentially shuts off lighting using a shutter is also effective. Furthermore, a second light emitting diode may be used as the R, G, and B three-color light source in the same mechanism.

The time-divided selection light 33 thus time-divided is transmitted to the PBS.
6 to reflect only the S-polarized component of each color. This reflected light is transferred to an LCLV liquid crystal cell whose optical properties spatially change as the conductivity of the photoconductive layer changes.
It enters as LV incident light 34. This LCLV incident light 3
In this configuration, it is essential that the polarization direction is changed in order for the light beam 4 to be spatially modulated and emitted in the liquid crystal cell. That is, since the PBS 6 transmits the p-polarized light component and reflects the S-polarized light component, the LCLV output modulated light (hereinafter referred to as modulated light) 35 must have the p-polarized light component. , preferably most of the light, and more preferably all of the light, is a p-polarized light component, which increases the effect in carrying out the present invention. Therefore, L.C.
It is essential for the LV to exhibit one of the following effects.

(a) When the writing irradiation light 31 is dark, there is no emitted light 35, and when the irradiation light 31 is bright, the emitted light 35 is light containing p-polarized light. Or vice versa.

(a) When the irradiated light 31 is dark, the emitted light 35 is completely S-polarized, and when the irradiated light 31 is bright, the emitted light 35 is light containing a p-polarized component. Or vice versa.

(c) The ratio of the S-polarized light component to the p-polarized light component differs by more than a certain degree between when the irradiation light 31 is dark and when it is bright.

Among these, in case (c), when the p-polarized light component always exists to some extent, the projection screen will not become completely dark, so the contrast of the projected image will not be good, which is undesirable. In addition, in (4) and (o), when using LCLV which shows the effect when the brightness and darkness of the irradiation light 31 are opposite,
It is necessary to invert the time-division signal mentioned above to invert the brightness of the irradiation light 31. Furthermore, (a) is, for example, in LCLV exhibiting the action of (Il+),
This can be easily achieved by placing a p-direction polarizing plate between the liquid crystal cell and the reflective layer, making it an effective and basic LC.
LV is LCLV that exhibits the effect of (b). This LC
As LV, for example, U.S. Pat. No. 4,378,95
It is possible to use the one disclosed in No. 5. Suitable liquid crystals for use in this case are liquid crystals in a twisted nematic phase, as described in that patent, which are oriented to exhibit a hybrid field effect. This is, in other words, an orientation that primarily exhibits a twisted nematic effect when no electric field is applied to the liquid crystal cell, and can exhibit a birefringence effect when an electric field is applied.

Alternatively, the desired effect can be achieved by using, for example, a ferroelectric liquid crystal.

The modulated light 35 emitted from the LCLV in this manner has a p-polarized light component, passes through the PBS 6, and becomes PBS-transmitted light 41 containing only the p-polarized light component. This light is guided to the projection optical system 7 and irradiated onto the display screen 8 as projection light 42 to form an image. The projection optical system 7 can be widely used as an optical system that is essentially the same as disclosed or implemented in various projection display devices.The display screen 8 can also be used as it is for normal use. May be used.

In the above detailed description, the basic configuration of the present invention is an apparatus in which each mechanism up to the projection optical system 7 is incorporated, but the operation of this basic configuration is also realized by FIG. 5 described below. Ru.

Compared to the above configuration shown in FIG. 4, the configuration of FIG. 5 does not have the input signal time division mechanism 1 and therefore does not generate time division video signals, and on the other hand, time division color selection. It is characterized by two points: it has two mechanisms 5 and 5', and a synchronizing signal 24 is sent and received between both mechanisms 5 and 5'.

In this configuration, a non-time-divided image signal 21 is directly input to the CRT 2. CRT 2 is color CR
A full-color CRT output video 31a that is not time-divided according to the image signal 21 is outputted using T. This C
Immediately after the RT output, a time-divided color selection mechanism 5' similar to that described in detail in the previous embodiment, for example, a rotating disk on which color filters are sequentially arranged, is provided to select the time-divided colors. An output video 31b is obtained. L to which a voltage is applied in advance by the color output image 31b
The photoconductive layer of the CLV 3 is irradiated, and the time-division color selected LCLV is irradiated from the liquid crystal cell side of the LCLV by the actions of each part described in detail in the configuration of FIG. 4 above.
The incident light 34 is spatially modulated and output as modulated light 35.

At this time, it is essential to synchronize both the time-division color selection mechanisms 5' and 5 on the writing light source side and the projection light source side. This is achieved by issuing a synchronizing signal 24 from the circuit to the time-division color selection mechanisms 5 and 5'. In FIG. 6, the synchronizing signal 24 is shown to be sent from the time division color selection mechanism 5' to the time division color selection mechanism 5'.

In the configuration shown in FIG. 5, as described above, <LCLV3
The writing light source incident on the photoconductive layer changes color over time. In this case, for incidence of different colors of equal intensity, 2
Due to the wavelength dependence of the photoelectric conversion efficiency of the photoconductive layer, LC
The voltage applied to the liquid crystal cell of the LV changes, and the intensity of the projection light varies.However, this can be avoided by adjusting the transmittance of each color in the time-division color selection mechanism 5' for the writing light in advance. It can be resolved by

Further, according to this method, the voltage application to the liquid crystal cell of the LCLV can be made the same for each color, which is more effective in that the liquid crystal cell can be driven stably.

The configuration shown in FIG. 5 requires two time-division color selection mechanisms, and the presence of the mechanism applied to the writing light source system prevents the phosphor screen of the CRT 2 and the LCLV 3 from coming into substantial contact. For example, color selection mechanism 5' and LCL
By providing a light guide between the V3 and the LC
It is possible to effectively guide the writing light to the photoconductive layer of the LV, and it is possible to ensure the same spatial resolution as in the embodiments described above.

On the other hand, according to the display method and display device with a single-line configuration, the video signal input from the outside is not electrically processed.
In particular, without time compression and time division processing,
It can be converted into a projected display image, and the signal circuit system can be further simplified. - By adding an ECU to the basic configuration shown in FIGS. 4 to 6, it becomes possible to project and display additional video information according to the present invention.

1 to 3 are diagrams showing embodiments of the present invention.

The following will explain based on these. Of the basic configurations described above, an embodiment based on the configuration shown in FIG. 4 is shown here, but since the embodiment based on FIG. 5 is also possible in the same manner, it is omitted here.

FIG. 1 shows an example in which an ECD 91 is provided in the optical path of the time-division selection light 33.As will be described later, the ECD 91 having a configuration of 0 has at least S of the transmitted light by matrix drive.
- Modulating the intensity of the polarized light component.

With this configuration, when projecting the image of the ECD 91, the additional image information 25 is input to the ECD 91 while the image signal 21 is input as usual. Here, when the white light 32 from the xenon lamp is converted into time-division selection light 33 by the time-division selection mechanism 5 and enters the ECD 91, the intensities of the S-polarized light and the p-polarized light are modulated and become a video signal. PBS
6. At PBS 6, only the modulated S-polarized light is reflected towards LCLV3 and further to LCLVZ.
At that time, it is also spatially modulated in the liquid crystal cell of LCLV 3, and the p-polarized LCLV output modulated light 35
becomes.

Thereafter, the light passes through the PB 96 and is projected onto the display screen 8 by the projection optical system 7 .

On the display screen 8, the original image based on the image signal 21 and the additional image information 25 generated by the EGO 91 are displayed in a superimposed manner. Therefore, it is possible to partially hide the original image of the image signal 21 with the additional image information 25, or mark a specific part (cursor, underline, side point, arrow, etc.), and add it to the projection display based on the basic configuration. This makes it possible to give meaning to things.

Figure 2 shows that between LCLV3 and PBs6 (7), there is an ECD in the optical path of the LCLV incident light/output modulated light.
This is an example in which 92 is provided. The ECD with this configuration includes ■LCL
V modulates the incident light 34, i.e. S-polarized light, or ■L
At least one of the functions of modulating the CLV output modulated light 35, ie, p-polarized light, is required. That is, in the one-wire configuration, as in FIG. 1, in PBS 6, S
- only polarized light is reflected, resulting in LCLV incident light 34;
Further, when the LCLV incident light 34 is reflected and modulated by the LCLV 3, it becomes p-polarized LCLV output light 35.

Since an ECD normally does not have polarization characteristics, both the LCLV incident light 34 and the output light 35 are modulated in this configuration. At this time, as described later, ECD 92 is
By providing it in contact with LV3, the LCLV incident light 34
Each ray of the output light 35 is effectively a model, and the image of the additional image signal 22 is projected onto the display screen 8 as a single image superimposed on the original image of the image signal 21.

Furthermore, in this configuration, it is desirable to provide the ECD 92 as close to the LCLV 3 as possible. This is because the position of LCLV3 corresponds to the object point.

Figure 3 shows PB! 96 and the projection optical system 7, that is, P
In the 0-wire configuration, which is an example in which the ECD 93 is provided in the optical path of the BS transmitted light 41, the light incident on the ECD 93 has already been temporally and spatially modulated by the original video ζLCLV3 of the video signal 21. , and PBS 6 provides only p-polarized light. Therefore, the ECD 93 in this configuration can provide additional information if it is a liquid crystal cell that can modulate the intensity of the p-polarized light component.

The ECD used in the present invention is a known ECD that can be used as is. This is preferable from the viewpoint of contrast.

Further, matrix driving of the ECD is performed using an applied voltage (DC 1 to 5 V) depending on the electrode material and the properties of the electrolyte.

Furthermore, in the present invention, it is also possible to select EGO according to additional information and add a color. For example, when providing additional information with a blue color, tungsten bronze, ferrocyanide , viologen compounds, etc., if the color is red, use tetrathiafulvalene (TTF).
), anthraquinone, or anodized iridium hydroxide for black types may be used for the ECD.

Additionally, when adding additional information that changes rapidly,
It is also preferable to use all-solid EGO, etc., which has a quick response.

Various known methods can be used as the means for creating the additional information and the means for inputting it into the EGO as described above.

For example, there are methods in which pre-created character patterns (sentences) are read with a scanner, stored on a magnetic disk, and sequentially output. There is a method of accumulating, a method of writing handwritten characters on a tablet and displaying them superimposed on the original video, and a method of using a touch panel.
Characters such as cursor, underline, arrow, O mark etc.
, and move these characters up, down, left and right, and so on. In particular, the method of inputting information on the spot using a tablet or touch panel is a method of inputting and displaying extremely important information among the additional information of the present invention.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Examples 1 to 2 Using the apparatus shown in FIGS. 1 and 2, a projected display image to which additional information was added was realized in the following manner.

A video signal captured by a television camera and stored in a magnetic storage medium in advance was input to a high-brightness CRT 2. Same CR
The output light of T was introduced from the side of the photoconductive layer made of CdS of the LCLV3, which was provided in close contact with the face plate of the CRT. A bias voltage of 10 kHz was applied to the LCLV3.

On the other hand, the white light generated from the tooow xenon lamp is time-divisionally selected and irradiated onto the tungsten bronze ECU 91 or 92 before entering the PBS 6 or after being reflected to create projection light that has been temporally and spatially modulated in advance.
When the light entered from the liquid crystal layer side of No. 3, the outgoing light was modulated by the video signal and projected and displayed on the screen. The projected image has a resolution of 5 lines/C11 and a contrast of 15:1 on the screen, and is superimposed on this.
Bright blue-purple letters flashed on the screen.

Example 3 Using each of the apparatuses shown in FIG. 3, a projected display image to which additional information was added was realized in the same manner as in Example 1.2. However, an anthraquinone-based ECD was used. The projected image had a resolution of 5 lines/cts on the screen and a contrast of 16:1. Superimposed on this video, pale pink letters flashed clearly.

Example 4 Using the device shown in FIG. 4, it was connected to an ECD similar to that in Example 3 so that signals from the tablet could be displayed. When the additional information was projected and displayed in this manner, the handwritten comments input from the tablet were displayed superimposed on the projected image.

[Effects of the Invention] As explained in detail above, by using the projection display method and display device of the present invention, the following effects were obtained.

■Additional information could be added without reducing the brightness of the original image.

■ It has become possible to add additional information on the spot to the original video without having to perform editing work to add text information etc. in advance.

■ Additional information added to the original video can be prepared in advance independently of the original video, or can be created on the spot using an input device such as a tablet or touch panel, and can be added to the situation. It is now possible to add superimposition to the original video as needed.

■ Multiple images can be projected and displayed alternately without forcing the viewer to shift their line of sight, reducing viewer fatigue.

[Brief explanation of the drawing]

1 to 3 are schematic diagrams showing one embodiment of the display device of the present invention, and FIG. 4 and FIG. Figure 6 shows the fourth
FIG. 3 is a schematic diagram showing an example of a method of converting an input signal into a time-division video signal in the configuration shown in the figure. l...Time division mechanism for input signals, 2...Cathode ray tube (CRT), 3...Liquid crystal light pulp (LCLV), 4...Xenon lamp, 5.5'...Time division color Selection mechanism, 6... Polarizing beam splitter (PBS), 7... Projection optical system, 8... Display screen, 21... Image signal (field signal), 22... Time compressed color signal ( subfield signal). 23... Time-division video signal, 24... Synchronization signal, 25... Additional image signal, 31... Irradiation light, 31a... CRT output video not time-divided, 31
b...Time-divided color output image, 32--White light, 33--Time-divided selection light, 34-LCLV incident light. 35... LCLV output modulated light, 41... PBS transmitted light, 42... Projection light, 91-93... Electrochromic device (ECD)
.

Claims (8)

[Claims] (1) A method for projecting and displaying a plurality of images using a liquid crystal light valve, characterized in that the following steps (A) to (G) are used. (A) Input multiple pieces of video information that change or do not change over time, with or without time division, output the multiple pieces of video information as irradiation light in a screen-sequential manner, and use the irradiation light as light to illuminate the liquid crystal display. (B) synchronizing a plurality of non-time-shared irradiation lights from a single or multiple light sources with the plurality of video information if the plurality of video information is time-shared; In other cases, each light source can be selected in a time-division manner without the need for synchronization, or multiple light sources can be synchronized as described above, or the projection light source system can be selectively turned on in a time-division manner without the need for synchronization. (C) spatially modulating the irradiation light from the projection light source system in the liquid crystal light valve with the irradiation light from the writing process; (D) expanding the modulated light from the liquid crystal light valve in the projection optical system; (E) receiving and imaging the projection light from the projection optical system to display a desired projected image on a screen; (F) on the optical path of the irradiation light from the projection light source system; and/or
or (G) generating video information by matrix driving an electrochromic element on the optical path of the modulated light from the liquid crystal light valve; The process of projecting and displaying parts or all of them superimposed or alternately. (2) The projection display method according to claim 1, wherein the plurality of pieces of video information are color-separated video information. (3) The projection display method according to claim 1, wherein the plurality of irradiation lights are color-separated irradiation lights. (4) The projection display method according to claim 1, wherein the desired projected image is a full-color image. (5) A projection display device using a liquid crystal light valve, characterized by comprising the following mechanisms (a) to (e). (a) Input multiple pieces of video information that change over time or do not change over time, with or without time division, output the multiple pieces of video information as irradiation light sequentially, and apply the irradiation light to a liquid crystal display. a writing light source system introduced into the bulb; (b) synchronizing a plurality of non-time-shared irradiation lights from a single or multiple light sources with the plurality of video information when the plurality of video information is time-shared; In other cases, a projection light source system that performs time-division selection without the need for synchronization, or a projection light source system that synchronizes multiple light sources as described above or lights up each time-division selection without the need for synchronization; (c) a writing light source system; a liquid crystal light valve that spatially modulates the irradiated light from the projection light source system with the irradiated light from the projection light source system; (e) an optical path of the irradiation light from the projection light source system, and/or
Alternatively, a video information source is provided on an optical path of modulated light from a liquid crystal light valve to generate video information by driving a matrix of electrochromic elements different from the plurality of video information. (6) The display device according to claim 5, wherein the plurality of pieces of video information are color-separated video information. (7) The display device according to claim 5, wherein the plurality of irradiation lights are color-separated irradiation lights. (8) The display device according to claim 5, wherein the desired projected image is a full-color image.