JPH01149088A - Projection display and display device - Google Patents

Abstract

PURPOSE: To project plural sets of different video information alternately or while overlapping them by generating one independent set of plural pieces of video information at a projection optical system while using a 1st liquid crystal light valve(LCLV) and simultaneously providing the other independent set of plural pieces of video information at a projection optical system inside the same optical system while using a 2nd LCLV. CONSTITUTION: A non-time-divided image signal 21 is converted to a time division image signal 23 time-divided by a time division mechanism 1, and inputted to a CRT 2 and the video information for each time-divided color is plane- sequentially outputted as irradiation light 31. An LCLV 3 receives the irradiation light 31 from the CRT and modulates LCLV incident light 34 and LCLV emitted modulated light 35 passes through a polarized beam splitter(PBS) 6 and forms only the image of a p-polarized component on a display screen 8. Besides, a 2nd CRT 2' and LCLV 3' are provided on the optical path of p-polarized light transmitted through the PBS 6, the image signal is converted to a time division video signal 23' by a time division mechanism 1', an s-polarized component is reflected on the PBS 6, and the 2nd video information is displayed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a plurality of liquid crystal light valves to project and display images.
The present invention relates to a display method and display device, and more particularly to a method and device for projecting and displaying two sets of mutually independent full-color images.

[Summary of the Disclosure] This specification and drawings describe a method and a display device for projecting and displaying an image using a plurality of liquid crystal light valves, in which a set of independent video information is displayed using a first liquid crystal light valve. By using a second liquid crystal light valve to generate a plurality of independent image information in the projection optical system within the same optical system using a second liquid crystal light valve, The present invention discloses a technique for projecting a plurality of sets of different video information, more specifically, video images, alternately or partially or completely superimposed.

[Prior Art] Conventionally, in various presentations such as academic lectures and product announcements, when projecting and displaying multiple video information sources such as video images and computer text and graphic output, it is necessary to use display devices and It was customary to have two or more sets of display screens. Furthermore, when using a known direct projection type CRT display or liquid crystal light valve, the problem has sometimes been dealt with by appropriately switching the input to the second device.

[Problems to be Solved by the Invention] However, when multiple sets of display devices are used, the devices occupy a large amount of space, and the images move between two display screens, making it difficult for viewers to see. This method had drawbacks such as forcing unnecessary movement of the viewpoint. In addition, in the case of multiple inputs to a single device, for example, the characteristics of the signals are different between video images and computer outputs, so it is necessary to prepare two types of interfaces and have a mechanism to match the signals, etc. There were drawbacks such as a complicated mechanism. Furthermore, in the conventional example described above, it is virtually impossible to add additional information, such as displaying a computer output (characters, graphics) superimposed on a video image.

The present invention was discovered as a result of a search 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 two sets of mutually independent video information using a simpler mechanism than those of the prior art. Among other things, it is an object of the present invention to provide a method and a display device for displaying a plurality of mutually independent high-brightness full-color video images by a significantly simpler mechanism than in the prior art.

Another object of the present invention is to display video information from a wide variety of video sonis 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] The present invention relates to a method and apparatus for projecting and displaying two sets of mutually independent plurality of video information, and in the method of the first invention, a plurality of liquid crystal light valves are used. This projection display method is characterized by using the following steps (A) to (F).

(A) Input two sets of mutually independent video information that change or do not change over time, with or without time division, and input the two sets of video information into the first and second sets.
(B) two sets of mutually independent writing steps in which the first and second irradiation lights are respectively outputted as irradiation light in a plane-sequential manner, and the first and second irradiation lights are introduced into the first and second liquid crystal light valves;
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, and without the need for synchronization in other cases. , the first and second projection light source systems are selected in a time-division manner, or synchronize multiple light sources as described above, or are selectively turned on in a time-division manner without the need for synchronization.
(C) In the first and second liquid crystal light valves, the first and second irradiation lights from the writing process are used to introduce the irradiation light from the projection light source system into the first and second liquid crystal light valves, respectively. (D) enlarging and projecting the first and second modulated lights from the first and second liquid crystal light valves in the projection optical system; (E) receiving and imaging the projection light from the projection optical system to display a desired projection image on a screen; (F) converting the second modulated light into a part of the first modulated light; Or the process of projecting and displaying them all overlappingly or alternately.

Further, in the device according to the second invention, in the projection display device using a plurality of liquid crystal light valves, the following (a)
This is a display device characterized by having the mechanisms of ) to (d).

(a) Input two sets of mutually independent video information that change or do not change over time, either time-divided or not, and use the two sets of video information as irradiation light, respectively, frame-sequentially. two sets of multiple writing light source systems that output light to a liquid crystal light valve and introduce the irradiation light to a liquid crystal light valve, respectively;

(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 a plurality of light sources as described above, or selectively turns on each light source in a time-division manner without the need for synchronization; (c) irradiation light from the two sets of writing light source systems; first and second liquid crystal light valves for spatially modulating first and second illumination light from a single or multiple projection light source systems;

(d) guiding first and second illumination lights from the projection light source system to first and second liquid crystal light valves, respectively, and modulating the first and second light from the first and second liquid crystal light valves; A projection optical system that magnifies and projects light.

In particular, in the projection display method and display device of the present invention, the plurality of pieces of video information are temporally divided R, G,
, B (hereinafter referred to as R9 for red, G for green, and B for blue) is image information for each color.

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

4 and 5 are schematic diagrams showing the configuration of the basic parts of the display device of the present invention, and FIG.
FIG. 2 is a schematic diagram showing an example of a method of converting an input signal into a time-division video signal.

Below, we will first describe a method for projecting and displaying video images using Figures 4 and 8.
The configuration shown in FIG. 5 may be used instead of the configuration shown in the figure.

First, the input non-time-divided image signal 21 (-
) is shown as an example of an RGB signal, and 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. ', G', B' double the signal, G', B
'Both signals are delayed by 1/3 field and 2/3 field with respect to R' signal to obtain G' and B'' signals, and R', G', and B'' signals (these are subfield signals ), mutually distinguishable marker signals Ml,
M2. M3 is added and outputted as a time-division video signal 23 line-sequentially. On the other hand, the time division mechanism 1 issues a synchronization signal 24 to the time division color selection mechanism 5. This synchronization signal is
Most simply, the above mutually distinguishable marker signals II
s 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 inputted 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 and outputs the LCLV. Although the incident light 34 is modulated, it is not necessary or possible to transmit the color attributes of the irradiated light 31, so it is sufficient to use a monochrome device as the CRT 2.

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 compression signals R', G', B'.
Alternatively, it is also possible to obtain R', G', B''.

Irradiation light 31 from the CRT 2 is incident on the photoconductive layer (not shown) side of the LCLV 3 to which a bias voltage has been applied in advance. 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 above LCLV3, the optical properties of the liquid crystal cell differ depending on each part, and the LCLV described later
The incident light 34 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 is reflected by the polarizing beam splitter (hereinafter referred to as PBS) 6, which will be described later. It is emitted in the direction. By the way, the configuration and operation of the LCLV have been described here only to those essential for a single configuration, and the LCLV of this configuration is different from the configuration and operation of the LCLV of the prior art. This does not indicate that the LCLV of this configuration is lacking or that some of them are missing.
is characterized in that the configuration of the conventional LCLV can be used almost as is.

On the other hand, the time-division color selection mechanism 5 that sequentially selects the three colors R, G, and H from the white light 32 emitted from the xenon lamp 4 by the time-division color selection mechanism 5 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 80/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, 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 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 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. For example, suitable to use in this case are:
These are hybrid field effect liquid crystal cells and ferroelectric liquid crystal cells.

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 the optical system 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 description, the device in which each mechanism up to the projection optical system 7 is incorporated is the basic configuration of the present invention.

On the other hand, FIG. 5 shows another basic configuration of the present invention, in which the zero-line configuration is characterized in that the time-division color selection mechanism 5 is activated after passing through the PBS 6.

The other mechanisms are similar to the configuration shown in FIG. 5, and the same reference numerals indicate equivalent parts.

Now, FIGS. 1 to 3 are diagrams showing an embodiment of the present invention. The following will be explained based on these.

FIG. 1 is a diagram showing an embodiment based on the basic configuration of FIG. A second image display is performed by adding an S-polarized light component when spatially modulating the p-polarized light, and the S-polarized light component is reflected by the PBS 6 and introduced into the projection optical system 7. . This makes it possible to utilize the p-polarized light component, which was not utilized in the basic configuration of FIG. 4, and to project and display a second image that is independent of the first image.

The projection display of this aspect can be realized, for example, by the time-division video signal generation method shown in FIG. That is, CRT2'
The time-division video signal 23' input to the CRT 2 is generated in the same manner as the time-division video signal 23 input to the CRT 2.

At this time, since the time-division color selection mechanism 5 is single, CR
The color signals input to T2 and T2' must be synchronized, and for this purpose, the synchronization signal 2 is used as the timing.
4' is emitted from the input signal time division mechanism 1 to the same mechanism 1'. As a result, this mode in which two mutually independent time division mechanisms are collectively controlled is particularly effective when two mutually independent signals have the same characteristics. This embodiment is a diagram showing an embodiment based on the basic configuration of the figure.The second (1) CRT 2', LCL
V3' and a time-division color selection mechanism 5' are provided.
(1) Time sharing is done completely independently of CRT2 and LCLV3.

The feature is that you can also select colors. This mode is also suitable for projecting and displaying two sets of images that are independent of each other, but is especially suitable for combinations that do not require strong synchronization of color selection, such as moving images and still images, or for combinations such as video images and computer graphics. It is particularly effective when used in combinations where the characteristics of the signals are originally different from each other.

The time-division video signal generation method applied to this aspect is as follows.
As shown in FIG. When the method shown in FIG. 6 is used, all images are displayed in the same color order, similar to the method shown in FIG. 1, so it is the simplest method. On the other hand, the method shown in FIG. 7 is an example of a method in which the input to the second CRT 2' is performed independently, and is a case where only the order of the R2O and B color lights is changed. Since the second time-division video signal 23' does not need to be synchronized with the signal 23, optimal signal processing can be performed based on the characteristics of the original signal 21'.

FIG. 3 shows a modification of the embodiment shown in FIG. 2, in which the time division mechanism l performs the synchronization control all at once. The time-division video signal generation method corresponding to this is shown in FIGS. 6 and 7, in which 23 and 23' can be input in different color orders.

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

Example 1 Using the apparatus shown in FIG. 1, projection display of two types of images was realized by the following method.

Two types of video signals taken by a television camera are divided into time division video signals 23 and 23 by time division mechanisms 1 and 1', respectively.
' and input these to the high-intensity OR〒2゜2'. The output light of the same CRT is transmitted through LCLV3 and 3', which are provided in close contact with the face plate of the same CRT.
was introduced from the side of the photoconductive layer made of CdS. Same LCL
A bias voltage of 10 KHz was applied to each V.

On the other hand, the white light 32 generated from the tooow xenon lamp 4 is time-divisionally selected, and its S-polarized component is reflected by the PBS 6 and sent from the liquid crystal layer side of the LCLV 3, and the p-polarized component is transmitted through the PBS 6 and sent to the LCLV 3. The light was incident from the liquid crystal layer side of '. Since the video signals 21 and 21' are independent of each other, the synchronizing signal 24' is provided with a switching mechanism to alternately display the time-division video signals 23 and 23', resulting in a resolution of 5 lines/c on the screen.
m, contrast) 18:l images were acquired continuously.

Example 2 Using the apparatus shown in FIG. 3, a video image signal 21 was input to the time division mechanism 1, and a signal 21' from a computer was input to the time division mechanism 1'. The signal 21' is converted into a subfield signal by the time division mechanism 1'.

While projecting and displaying the time-division video signal 23, marks and characters previously stored in the memory of the computer were recalled according to the screen, converted to a time-division video signal 23', superimposed, and displayed for projection. A video image with explanatory text (caption) and marks for emphasis was projected and displayed.

Example 3 The same signal processing as in Example 2 was performed using the apparatus shown in FIG. At this time, the quality of the additional information can be freely changed, for example, when superimposing captions, the quality of the additional information can be changed, such as projecting in white without selecting any color or projecting with only a single color selected. Ta.

[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.

■It was possible to display two types of mutually independent images alternately at high brightness.

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

■Video information with different characteristics could be displayed alternately or overlappingly on a single screen.

-By preprogramming a computer and calling up information stored in memory at any time, it was possible to add additional information to video images according to the situation.

■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 embodiments of the projection display device of the present invention, FIG. 4 and FIG. 5 are schematic diagrams showing the configuration of the basic components of the display device of the present invention, and FIGS. FIG. 8 is a schematic diagram showing an example of a method of converting an input signal into a time-division video signal in the present invention. 1.1': Time division mechanism for input signals 2.2': Cathode ray tube (CRT) 3.3': Liquid crystal light valve (LGLV) 4: Xenon lamp 5.5': Time division color selection mechanism 6: Polarized beam Splitter (PBS) 7: Projection optical system 8: Display screen 21: Image signal (field signal) 22: Time-compressed color signal (subfield signal) 23, 23': Time-division video signal 24, 24', 24'' : Sync signal

Claims (13)

[Claims] (1) A method for projecting and displaying images using a plurality of liquid crystal light valves, characterized in that the following steps (A) to (F) are used. (A) Input two sets of mutually independent video information that change or do not change over time, with or without time division, and input the two sets of video information into the first and second sets.
two sets of mutually independent writing steps in which each of the first and second irradiation lights is outputted in a field-sequential manner as irradiation light, and the first and second irradiation lights are introduced into the first and second liquid crystal light valves, respectively; (B) single or multiple writing steps; If the multiple video information is time-divided, the plurality of non-time-divided irradiation lights from the light source are synchronized with the video information, and in other cases, time-division selection is performed without the need for synchronization. Alternatively, the first and second irradiation lights are introduced into the first and second liquid crystal light valves, respectively, from a projection light source system that selectively lights up the plurality of light sources in a time-division manner without the need for synchronization or synchronization as described above. (C) spatially modulating the first and second irradiation lights from the projection light source system in the first and second liquid crystal light valves using the first and second irradiation lights from the writing process, respectively; D) magnifying and projecting the first and second modulated light from the first and second liquid crystal light valves in the projection optical system; (E) receiving and imaging the projection light from the projection optical system; (F) displaying the desired projected image on the screen;
The step of projecting and displaying the modulated light of the first modulated light by superimposing or alternately with a part or all of the first modulated light. (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) The projection display method according to claim 1, wherein the first and second irradiation lights from the projection light source system are colored lights time-divided in the same order. (6) The projection display method according to claim 1, wherein the first and second irradiation lights from the projection light source system are colored lights that are time-divided in different orders. (7) The projection display method according to claim 5 or 6, wherein the time-divided colored lights are red, green, and blue. (8) A projection display device using a plurality of liquid crystal light valves, characterized by comprising the following mechanisms (a) to (d). (a) Input two sets of mutually independent video information that change or do not change over time, either time-divided or not, and use the two sets of video information as irradiation light, respectively, frame-sequentially. (b) two sets of multiple writing light source systems that output the irradiated light to a liquid crystal light valve and respectively introduce the irradiated light into the liquid crystal light valve; If the video information is time-divided, it is synchronized with the video information, and in other cases, each time-division selection is made without the need for synchronization, or multiple light sources are synchronized as described above, or each light source is individually selected without the need for synchronization. (c) a projection light source system that selectively lights up in a time division manner; (d) guiding first and second illumination lights from the projection light source system to the first and second liquid crystal light valves, respectively; a projection optical system that magnifies and projects the first and second modulated lights from the . (9) The display device according to claim 8, wherein the plurality of pieces of video information are color-separated video information. (10) The display device according to claim 8, wherein the plurality of irradiation lights are color-separated irradiation lights. (11) The display device according to claim 8, wherein the first and second irradiation lights from the projection light source system are colored lights time-divided in the same order. (12) The display device according to claim 8, wherein the first and second irradiation lights from the projection light source system are colored lights time-divided in different orders. (13) The display device according to claim 11 or 12, wherein the time-divided colored lights are red, green, and blue.