JPH0196696A - Projection display method and apparatus - Google Patents

Abstract

PURPOSE: To give additional information on the spot without spoiling the luminance of original video or performing editing process operation by generating 1st video information by a projection optical system by using a liquid crystal light valve and actualizing video of a liquid crystal cell in the same optical system by the projection optical system. CONSTITUTION: The method and display device which projects and displays an image by using the liquid crystal light valve 3 makes the projection optical system 7 to generate the 1st video information by using the liquid crystal light valve 3. At the same time, the projection optical system 7 is enabled to actualize the video of the liquid crystal cell 91 in the same optical system. Consequently, different pieces of video information, concretely, images of video and the liquid crystal cell can be projected alternately or partially or entirely, one over the other.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method and a display device for projecting and displaying an image using a liquid crystal light valve, and more specifically, a method for projecting and displaying a full-color image and an image by matrix driving of a liquid crystal cell, and a method thereof. Regarding equipment. [Summary of the Disclosure] The present specification and drawings relate to a method and display device for projecting and displaying an image using a liquid crystal light valve. By producing the first image information in the projection optical system using a liquid crystal light valve and at the same time realizing the image of the liquid crystal cell in the projection optical system within the same optical system, a plurality of different image information, More specifically, the present invention discloses a technique for projecting video and liquid crystal cell images alternately, or by overlapping some or all of them.

[Conventional technology]

When video images are projected and displayed at various presentations such as academic lectures and product announcements; when explaining the image, calling attention to it, or adding other information, conventionally, projection It was common to stand in front of a display screen and point to 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 the video that has been edited and processed in this way, it is not possible to respond to the situation on the spot, and furthermore, the video that was shot or transmitted during the presentation cannot be edited and processed. As a result, there were drawbacks such as no additional information being added. [Problems to be Solved by the Invention] The present invention was discovered 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 for displaying a plurality of pieces of video information using a mechanism simpler than that of the prior art.
The purpose of this invention is to provide a display device. In particular, 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 images of liquid crystal cells using a significantly simpler mechanism than those of the prior art. Another object that has not yet been discovered is to display video information from a wide variety of video sources without using multiple types of display devices and by simply providing an additional mechanism. It is an object of the present invention to provide a method and a display device for displaying video information from multiple video sources on the same screen using a single display device. Still another object of the invention is to display input video information by adding other information, or to display input video information in a temporal and spatial manner. To provide a method and a display device for selectively displaying a part or a part of various attributes such as color by providing an additional mechanism or changing a part of an inherent mechanism. There is a particular thing. 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, either time-divided or not, output the multiple pieces of video information as irradiation light sequentially, and use the irradiation light as a liquid crystal display panel. (B) 'It-' or a plurality of non-time-divided irradiation lights from multiple light sources, if the plurality of image information is time-divided, synchronize with the plurality of pH image information. In other cases, the irradiation light is transmitted from the projection light source system to the liquid crystal display by time-division selection without the need for synchronization, or by synchronizing multiple light sources as described above, or by time-division selection lighting by each without the need for synchronization. Process to be introduced into light valves. (C) In the liquid crystal light valve, - a step of spatially modulating the irradiation light from the projection light source system by the irradiation light from the writing step; (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) producing video information by driving a matrix of liquid crystal cells on the optical path of the irradiated light from the projection light source system or on its extension, and/or on the optical path of the modulated light from the liquid crystal light valve or on its extension; (G) A step of superimposing or alternately projecting and displaying the image information of the liquid crystal cell with some or all of the plurality of different image information. In addition, the device is a projection display device using a liquid crystal light valve, and is characterized by having the following mechanisms (a> to (a)): (a) Changes over time; or a writing light source system that inputs a plurality of pieces of unchanging video information in time division or without time division, outputs the plurality of video information as irradiation light sequentially, and introduces the irradiation light into 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 lights them up 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 illumination light from the projection light source system to the liquid crystal light valve, and magnifies and projects the modulated light from the liquid crystal light valve. (e) Producing video information of a liquid crystal cell different from the plurality of video information on the optical path of the irradiated light from the projection light source system or an extension thereof, and/or on the optical path of the modulated light from the liquid crystal light valve or an extension thereof. In particular, in the projection display method and display device of the present invention, the plurality of video information is temporally divided into R, G,
, B (hereinafter, red is referred to as R1, green is referred to as G, and blue is referred to as B). Second image information different from this is generated by matrix driving of the liquid crystal cell. [Function] The basic configuration of the present invention will be explained in more detail below with reference to one drawing. 5 and 6 are schematic diagrams showing the configuration of the essential components of the display device of the present invention, and FIG. 7 shows an example of a method for converting the input signal into a time-division video signal in FIG. 5. It is a schematic diagram. Hereinafter, a method for projecting and displaying a video image will be described first with reference to FIGS. 5 and 7. However, as will be described later, the configuration shown in FIG. 6 may be used instead of the configuration shown in FIG. 5. First, the input non-time-divided image signal 21 (-
As an example, an RGB signal is shown) is converted into a time-divided image signal 23 which is time-divided by a time division mechanism 1. This time division mechanism l may be constructed using a known technique, for example, l field (1/60 second) as shown in FIG.
For each RGB signal, the R', G', and B' signals of the color signal 22 are time-compressed, and the G', B'
Both signals are delayed by 1/3 field and 2/3 field relative to the R' signal, respectively, to produce G'' and B' signals, and the R', G', and B'' signals (these are called subfield signals). marker signals MI that are distinguishable from each other
+M2+M'3 is added to line-sequentially time-division video signal 2
Output as 3. On the other hand, the time division mechanism 1 issues a synchronization signal 24 to the time division color selection mechanism 5. Most simply, this synchronization signal is the mutually distinguishable marker signal M1. N2. N3 is fine. Time division video signal 23 outputted from the qm structure is
The information is input to the CRT 2, and the CRT 2 is time-divided according to the time-division video signal 23 and outputs video information (subfield information) for each left color sequentially as irradiation light 31. In the case of this configuration, the signals input to the CRT 2 are line sequential as described above, and as will be described later. Liquid crystal light valve (hereinafter referred to as LCLV) 3 is a CRT
It modulates the LCLV incident light 34 by receiving the irradiated light 31 from the CRT 2, but it is not necessary or possible to transmit the color attributes of the irradiated light 31, so it is sufficient to use monochrome equipment as the CRT 2. It is. 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 accordance with the subfield information for each color at the 173 times of normal field image display. Correspondingly, the luminescence of the phosphor is also subfield (1/180
It is necessary to specify the phosphor material so that it decays within a few 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'. 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. The configuration shown in FIG. 5 may be achieved by using a light guide such as a fiber plate, or more simply by bringing the fluorescent screen of the CRT 2 into substantially close contact with the LCLV 3. Although this latter method does not exclude other methods or mechanisms including the former method, these configurations make the spatial modulation resolution of LCLV substantially comparable to that of CRT. Direct current or alternating current is used as the bias voltage, but in the ↑N liquid crystal described below, the bias voltage is 10 Hz to IMHz, preferably 1 kHz to 100 kHz, and more preferably 10 kHz.
It is preferable to use an AC bias of Hz. 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 differ depending on each part, and the LCLV incident light 34, which will be described later, is spatially modulated. . 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 directed to a polarizing beam splitter (hereinafter referred to as PBS) 6, which will be described later. It is emitted towards. By the way, here, the structure and function of LCLV are as follows:
The description is limited to those essential to this configuration, and does not indicate that the LCLV of this configuration is different from the configuration and operation of the LCL'V of the prior art, or that it lacks any part thereof. No, rather LI of this configuration
CLV is characterized in that the configuration of conventional LCLV can be used 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. In other words, it is a liquid crystal that can assume a birefringent state. The operating modes used in such liquid crystal cells include hybrid field effect type (JJFE type), ferroelectric type (FLC type), electric field controlled birefringence type (ECB type), and super twisted birefringence effect type (SBE type). ), etc. On the other hand, from the white light 32 emitted from the xenon lamp 4, a time-division color selection mechanism 5 sequentially selects three colors, R, G, and H, in a time-division manner. The time-division color selection mechanism 5 is, for example, a mechanism that sequentially introduces three color filters of R, G, and B into the optical path, and more specifically, a disk in which n sets of the same color filters are sequentially arranged in the circumferential direction. , 60 per second
/n rotation mechanism is simple, but the mechanism is not limited to this and any known color selection mechanism can be used. For example, a mechanism that changes the transmittance of each color of R, G, and B by controlling the voltage applied to the piezoelectric material PLZT. A possible mechanism is to stack electrochromic materials that produce R, G, and B colors perpendicular to the optical path and select colors by sequentially applying voltage, and other techniques are also available. Furthermore, as a mechanism that combines the interaction between the light source and the color selection mechanism, a mechanism that sequentially blinks the R, G, and B three-color lamps or sequentially shuts off the lighting with a shutter is also effective. Furthermore, a 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 sent to the LICLV liquid crystal cell whose optical properties change spatially as the conductivity of the photoconductive layer changes.
The light is incident as GLV incident light 34. In order for this LCLV incident light 34 to be spatially modulated in the liquid crystal cell and emitted, it is essential in this configuration that the polarization direction is changed. 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
It is essential for CLV 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 (c), if a certain amount of p-polarized light component always exists, the projection screen will not become completely dark, so the contrast of the projected image will not be good, which is undesirable; When using LCLV which shows the effect when the brightness and darkness of the irradiation light 31 is opposite in CI+),
It is necessary to invert the time-division signal mentioned above to invert the brightness of the irradiation light 31. Furthermore, (a) can be easily realized by placing a p-direction polarizing plate between the liquid crystal cell and the reflective layer in an LGLV exhibiting the effect of (0), so it is an effective and basic LCLV.
is the LCLV showing the effect of (El). This LCL
For example, U.S. Patent No. 4.378.955
It is possible to use the method disclosed in No. 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 component, passes through the PBs 8, and becomes PBS transmitted light 41 having only the p-polarized 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 a device incorporating each mechanism up to the projection optical system 7, but the operation of this basic configuration can also be realized by FIG. 6 described below. Ru. Compared to the above-described configuration shown in FIG. 5, the configuration of FIG. 6 does not have a time division mechanism for input signals, 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, the image signal 21 that is not time-divided is directly input to the CRT 2. CRT-2 is color CR
A full-color CRT output video 31a that is not time-divided is output according to the image signal 21 using the 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 CLV3 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. 5 above.
The incident light 34 is spatially modulated and output as modulated light 35. At this time, both pupil division color selection mechanisms 5. on the writing light source side and the projection light source side. It is essential to synchronize the time-shared color selection mechanisms 5 and 5' from one to the other.
Alternatively, the time-shared color selection mechanisms 5 and 5' may be
This is achieved by issuing a synchronization signal 24 to In FIG. 7, a synchronization signal 24 is shown to be issued from the time division color selection mechanism 5' to the time division color selection mechanism 5'. . In the configuration shown in FIG. 6, as described above, LCLV3
The writing light source incident on the photoconductive layer changes color over time. In this case, for the incidence of different colors of equal intensity,
Due to the wavelength dependence of the photoelectric conversion efficiency of the photoconductive layer, LCL
The voltage applied to the liquid crystal cell of V changes, and the intensity of the projection light varies.However, this can be done 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 '' Also, according to this method, it is possible to apply the same voltage to the liquid crystal cell of the LCLV for each color, which is more effective in terms of stably driving the liquid crystal cell. Two divided color selection mechanisms are required, 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.
By providing a light guide between LC and
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 having the 13-line configuration, it is possible to convert a video signal input from the outside into a projection display video without electrically processing it, and in particular without performing time compression or time division processing. The signal circuit system is further simplified. As described above, by adding a liquid crystal cell to the basic configuration shown in FIGS. 5 to 7, it becomes possible to project and display additional image information according to the present invention. 1 to 4 are diagrams showing embodiments of the present invention. The following will explain based on these. It should be noted that, among the above-mentioned basic configurations, an embodiment based on the configuration shown in FIG. 5 is shown here, but since an embodiment based on FIG. 6 is also possible in the same manner, it will be omitted here. FIG. 1 shows an example in which a liquid crystal cell 91 is provided in the optical path of the time-division selection light 33.The liquid crystal cell 91 having a zero-cell configuration is configured to have at least S of the transmitted light by matrix driving, as described later.
- Modulating the intensity of the polarized light component. For this purpose, both the FLC type and EGO type modes that exhibit a birefringence effect can be used, and the SBE type mode can also be used. Twisted nematic (TN) mode can also be used, but since it rotates the polarization plane of both S-polarized light and p-polarized light, a polarizer is placed in front of the liquid crystal cell 91, and the p-polarized light is It is necessary to introduce only polarized light into the liquid crystal cell 91. In addition, a phase change (PC) mode (transmission-scattering) using cholesteric liquid crystal and a guest-host (GH) mode (blue-colorless) using nematic liquid crystal can be used. With this configuration, when projecting the image of the liquid crystal cell 91, the image signal 2! While inputting , the additional image information 25 is input to the liquid crystal cell 91. Here, when the white light 32 from the xenon lamp is converted into time-division selection light 33 by the time-division color selection a structure 5 and enters the liquid crystal cell 91, the intensity of the S-polarized light is modulated and becomes a video signal, which is sent to the PBS 6. incident on . That is, in the liquid crystal cell 91, by emitting S-polarized light from non-operating pixels and emitting p-polarized light from operating pixels,
It performs modulation. In PBS6, only the S-polarized light is reflected, which heads toward LCLV3 and is further reflected by the reflector inside the LCLV S. At this time, it is also spatially modulated in the liquid crystal cell of LCLV3 and becomes p-polarized LCLV output modulated light 35. . Thereafter, the light passes through the PBS 6 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 liquid crystal cell 91 are displayed in a superimposed manner. Therefore, it is possible to partially hide the original image of one image value number 21 with additional image information 25, or mark a specific part (cursor, underline, side point, arrow, etc.), and it is possible to make projection display using the basic configuration possible. It becomes possible to give additional meaning.・ In Figure 2, between LCLV3 and PBS6 (7), immediately t+L
In a liquid crystal cell having a zero-cell configuration, which is an example in which a liquid crystal cell 92 is provided in the optical path of cLV incident light/output modulated light,
At least one of the functions of modulating the output modulated light 35, ie, p-polarized light, is required. That is, in this configuration, as in FIG. 1, only the S-polarized light is reflected at the PBS 6 and becomes the LICLV incident light 34, and when the LCLV incident light 34 is reflected and modulated by the LCLV 3, it becomes the p-polarized LCLV. The output light becomes emitted light 35. here,
If the liquid crystal cell 92 has a function of modulating S-polarized light,
If the LCLV incident light 34 and the liquid crystal cell 92 have the ability to modulate the p-polarized light, the LCLV output light 35 can be modulated into an image of the additional image signal 25. As a result, the image of the additional image signal 25 can be superimposed on the original image of the image signal 21 and projected onto the display screen 8. Almost all of the modes described above can be used in the liquid crystal cell 92 of this configuration. Further, in this configuration, it is desirable to provide the liquid crystal cell 92 as close to the LCLV3 as possible. This is LCLV
This is because position 3 corresponds to the object point. FIG. 3 shows that between the PBS 6 and the projection optical system 7, that is, the
In a single configuration, which is an example in which a liquid crystal cell 93 is provided in the optical path of the BS transmitted light 41, the light incident on the liquid crystal cell 93 has already been temporally and spatially added to the original image of the video signal 21 by the LCLV 3. It is modulated and is only p-polarized by PBS 6. Therefore, the liquid crystal cell 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. Those that meet this condition include EG
Almost all modes of liquid crystal cells such as O type and FLC type can be used. FIG. 4 shows an example in which a liquid crystal cell 94 is provided outside the basic configuration shown in FIG. That is, among the light emitted from the xenon lamp and made into the time-division selection light 33 by the time-division color selection mechanism 5, the PBS
In this configuration, a liquid crystal cell 94 and a reflection plate 95 are provided on the optical path of p-polarized light transmitted through the light source 6. This liquid crystal cell has a function of converting a part of the p-polarized light into 8-polarized light and emitting it. Liquid crystal cells of each mode of HF2 type, FLC type, ECB type, and SBR type meet this condition. As a result, the p-polarized light transmitted through the PBS 8 is converted into S-polarized light corresponding to the image of the additional image signal 25 by the action of the liquid crystal cell 94 and the reflection plate 95. This light is then reflected by the PBS 6 and the projection optical system 7
The image signal 2! is displayed on the display screen 8. By using a projection display device with a zero-line configuration that projects images overlappingly with the original image, it becomes possible to add additional information without losing any of the brightness of the original image. In any of the above cases of FIGS. 1 to 4, it is sufficient to drive the matrix of the additional information liquid crystal cell at the field frequency (60 Hz). Further, additional information is shown in black in the configurations of FIGS. 1 to 3, and is shown in white in FIG. 4. In addition, if the movement of additional information is small, FLC with memory
It is also advantageous to use the PC phase (ch). On the other hand, if it is desired to add color to the additional information, driving may be performed at a subfield frequency of 180 Hz in accordance with the color selection of the projection light. Various publicly known methods can be used as the means for creating the additional information and the means for inputting it into the liquid crystal cell as described above. For example, there is a method in which character patterns (text) created in advance 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.
This method involves outputting characters such as a cursor, underline, arrow, O mark, etc. to a liquid crystal cell, and moving these characters vertically, horizontally, and the like. 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. [Example] Hereinafter, the present invention will be explained in more detail by showing an example, but the present invention is not limited thereto. Example 1 Using the apparatus shown in FIG. 1, a projected display image to which additional information was added was realized in the following manner. A video signal photographed by a television camera was input to a high-brightness CRT 2 as a time-division video signal 23 by a time-division mechanism 1. The output light of the CRT was introduced from the photoconductive layer side made of CdJ of the LCLV, which was provided in close contact with the face plate of the CRT. A bias voltage of 10 kHz was applied to the LCLV. On the other hand, the white light generated from the tooow xenon lamp is time-divisionally selected and irradiated onto the additional information liquid crystal cell 91 made of ferroelectric liquid crystal to produce projection light that has been temporally and spatially modulated in advance. Reflected with PBS, LCLV
When the light entered from the liquid crystal layer side of No. 3, the output light was modulated by the video signal and projected and displayed on the screen. The projected image has a screen resolution of 5 lines/C■ and 1
It had a contrast of 7:1, and flashing black characters were superimposed on this. Examples 2 to 3 Using the apparatuses shown in FIGS. 2 and 3, projection display images with additional information added were realized in the same manner as in Example 1. However, the ECB mode was used for the liquid crystal cell. The projected image showed a resolution of 5 lines/C intestine on the screen, and the contrast was 18:1. Superimposed on this video were seven gray letters blinking. Example 4 Using the apparatus shown in FIG. 4, a projected display image with additional information added was realized in the same manner as in Example 1, except that the HFE mode was used for the liquid crystal cell. The projected image is
It showed a resolution of 5 lines/C fold on the screen and a contrast of 20:l. Superimposed on this video, gray letters were displayed. Example 5 Using the apparatus shown in FIG. 4, a projected display image to which additional information was added was realized in the same manner as in Example 1. However, the liquid crystal cell 94 was driven in FLC mode at a subfield frequency (180 Hz). In the projected image, green and red characters were displayed intermittently blinking in response to the signal sent to the liquid crystal cell 94. Example 6 In a device similar to Example 5, a liquid crystal cell was driven in synchronization with red projection light and was connected to the liquid crystal cell so as to display signals from a tablet. When the additional information was projected and displayed in this manner, the handwritten comment input from the tablet was 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 4 are schematic diagrams showing one embodiment of the display device of the present invention, FIG. 5 and FIG. 6 are schematic diagrams showing the configuration of the basic components of the display device of the present invention, and FIG. The figure shows the fifth
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. 1... Time division mechanism for input signals. 2...Cathode ray tube (CRT), 3...Liquid crystal light valve (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 that is not time-divided, 31
b...Time-divided color output video. 32...White light, 33...Time division selective light. 34-LCLV incident light. 35...LCLV output modulated light, 41...PBS transmitted light. 42...Projection light, 91-94...Liquid crystal cell, 95...Reflector,・

Claims (2)

[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; a step of projecting; (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) an optical path of the irradiation light from the projection light source system or an extension thereof; and/or on the optical path of the modulated light from the liquid crystal light valve or on its extension, generating video information by driving a matrix of liquid crystal cells; A process of projecting and displaying part or all of multiple pieces of video information overlappingly or alternately. (2) 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) The plurality of image information is placed on the optical path of the irradiated light from the projection light source system or on its extension, and/or on the optical path of the modulated light from the liquid crystal light valve or on its extension. A video information source provided to generate video information by driving a matrix of different liquid crystal cells.