JPH0619495B2 - Stereoscopic image scope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention provides a screen of a video display device in which a screen for the left eye and a screen for the right eye are switched and displayed for each field, and displays the binocular parallax of a human. The present invention relates to a stereoscopic video scope for viewing as a stereoscopic screen.

[Prior Art] Humans have a fused visual effect in which an image having binocular parallax visually recognized by the left and right eyes can be recognized as an integrated optical image having a stereoscopic effect.

As a stereoscopic image technology for artificially creating such a human stereoscopic function, a so-called alternative system as shown in FIG. 5 is known.

The conventional alternative method will be described below with reference to FIG.

On the CRT 1, the left-eye image 2 and the right-eye image 3 are set to be displayed alternately for each field, for example.

1 shows a state in which the image 3 for the right eye is displayed on the CRT 1. At this time, the right shutter 6 of the shutter device 4 having an electro-optical shutter function is opened and the left shutter 5 is closed. 2 is C
The state where the image 2 for the left eye is displayed on the RT1 is shown. At this time, the left shutter 5 of the shutter device 4 is opened and the right shutter 6 is closed.

When a person wears such a shutter device 4, the CRT 1
By visually recognizing, the human left eye can see only the left eye image 2 and the right eye can see only the right eye image 3.
Then, switching the video for each field of the CRT1,
By synchronizing the opening and closing operations of the left and right shutters 5 and 6 in the shutter device 4 with each other, a stereoscopic image can be viewed.

FIG. 6 is a diagram showing the principle of a liquid crystal shutter as an example of the shutter device 4 used in the above-mentioned conventional alternative system. Referring to FIG. 6, the first polarizing plate 7 and the second polarizing plate 8 are arranged in parallel, and their polarization planes are orthogonal to each other.

The liquid crystal cell 9 inserted between the first polarizing plate 7 and the second polarizing plate 8 is capable of changing the polarization direction of transmitted light. In this example, liquid crystal molecules 10 are provided in the liquid crystal cell 9.
It is shown that there is a twist nematic effect unit model that considers the behavior of liquid crystal substances such as.

The liquid crystal cell 9 has a front surface and a rear surface, respectively.
The transparent electrode plates 11 are attached and sandwiched by both electrode plates 11.

The drive voltage source 12 applies a drive voltage to the transparent electrode plate 11 when the switch 13 is closed. As shown in FIG. 6A, in the state where the driving voltage is not applied between the transparent electrode plates 11, the liquid crystal molecules 10 of the liquid crystal cell 9 are arranged in the direction as shown in the figure, and the first polarized light is generated. The light transmitted through the plate 7 reaches the second polarizing plate 8 without changing its polarization plane. However, since the polarization plane of the second polarizing plate 8 is orthogonal to that of the first polarizing plate 7,
The light reaching the polarizing plate 8 cannot pass through the second polarizing plate 8, and the light transmittance becomes the minimum (almost 0).

On the other hand, as shown in FIG. 6 (b), the switch 13 is turned on,
When a driving voltage is applied between the transparent electrode plates 11, the liquid crystal cell 9
An electric field is generated inside, and the liquid crystal molecules 10 undergo a twisted molecular orientation of 90 °. Thereby, the light transmitted through the first polarizing plate 7 is
When passing through the liquid crystal cell 9, its polarization plane is rotated by 90 ° due to the influence of 90 ° twisted molecular orientation. As a result, the light passing through the liquid crystal cell 9 becomes a light whose polarization plane coincides with the polarization plane of the second polarizing plate 8 and passes through the polarizing plate 8 as it is. Therefore, in this state, the light transmittance becomes maximum.

[Problems to be Solved by the Invention] However, in the stereoscopic image scope using the above-described conventional alternative method, the opening / closing operation of the shutter device 4 is switched in synchronization with the image switching for each field of the CRT 1. However, since the change in the ambient brightness of the stereoscopic image scope is not considered at all, when the ambient brightness changes, such as when external light enters the stereoscopic image scope when viewing the stereoscopic image, There was a drawback that it became difficult to see stereoscopic images.

Therefore, an object of the present invention is to provide a stereoscopic image scope in which the brightness around the stereoscopic image scope is detected and the change in the brightness does not affect the visibility of the stereoscopic image.

[Means for Solving the Problems] Briefly stated, the present invention is, in a stereoscopic image scope, an ambient light amount detecting means for detecting ambient brightness, and a left shutter in response to an output of the ambient light amount detecting means. And a transmittance adjusting means for adjusting the respective light transmittances when the right shutter is opened.

[Operation] Since the ambient light amount detecting means detects the ambient brightness and the light transmittances of the left shutter and the right shutter are automatically adjusted based on the detection result, regardless of the ambient brightness change. , A stereoscopic image that is always easy to see is output.

[Embodiment] FIG. 1 is a configuration block diagram of a stereoscopic image scope according to an embodiment of the present invention.

With reference to FIG. 1, a stereoscopic image scope according to an embodiment of the present invention includes a left shutter 5, a right shutter 6, and a left shutter 5 and a right shutter 6 for detecting brightness around the stereoscopic image scope. It comprises a light quantity detector 21 provided between the shutter 6 and a drive circuit 14 for opening and closing both the left and right shutters 5, 6. The drive circuit 14 is a vertical synchronizing signal of the CRT 1 for displaying a stereoscopic image. It operates in synchronization with.

FIG. 3 is a signal timing diagram for explaining the operation of the block diagram of FIG.

First, the overall schematic operation will be described with reference to FIGS. 1 and 3. On the CRT 1, as in the conventional device, a stereoscopic image is switched and displayed for each field. And synchronized with the field switching cycle A signal (see FIG. 3A) is output and applied to the switch control circuit 16 of the drive circuit 14.

The switch control circuit 16, as shown in FIG. A switch control signal for the switch 19 is created based on the signal,
This controls the switching of the switch 19.

Therefore, the switch 19 closes between the terminals bx-ax and by-ay as shown in FIG. 1 when the control signal of the switch control circuit 16 (see FIG. 3 (b)) is "high level". Open the left shutter 5 and the control signal is "low level".
In the case of, the terminals bx-axr and by-ayr are closed and the right shutter 6 is opened.

After that, the switches 19 are alternately switched based on the control signal from the switch control circuit 16, and the left shutter 5
Alternatively, the right shutter 6 is alternately opened and closed.

The feature of this embodiment is that the left shutter 5 and the right shutter 6 are provided.
However, not only is the switch control circuit 16 alternately switched to open and block the light, but the light transmittance when the light is opened is automatically adjusted according to the ambient brightness.

Hereinafter, this point will be described in detail. In the following description, the left shutter 5 and the right shutter 6 have the same basic configuration and operation, so the left shutter 5 will be described.

The left shutter 5 has the same structure as that of the conventional example described in FIG.
The structure includes a transparent electrode plate 11 ′ and a liquid crystal cell 9. Here, for convenience of explanation, the first and second polarizing plates 7 and 8 (see FIG. 6) are omitted, but the actual left shutter 5 also includes these polarizing plates.

The structural feature of the left shutter 5 is that the transparent electrode plate 11 'is
The X electrodes and the Y electrodes are respectively arranged in a matrix as shown in FIG.
X electrodes X ₁ to X _n and Y electrodes Y ₁ to Y _n of the n sheets arranged in a matrix, respectively, by considering cross-talk, are arranged sufficiently closely. In the transparent electrodes arranged in such a matrix, by designating any X electrode and Y electrode, the designated X electrodes are formed.
A voltage is applied only to the intersections of the electrodes and the Y electrodes, and the liquid crystal molecules 10 (see FIG. 6) corresponding to the intersections are arranged in a predetermined direction.

That is, since the left shutter 5 according to this embodiment has the transparent electrode plates 11 'arranged in a matrix, the scanning signal XL for applying a voltage to the X electrode and the Y electrode of the transparent electrode plate 11'. , YL, the number of points at which a voltage is applied to the transparent electrode plate 11 'and its density distribution can be variously changed.

Returning to FIG. 1, the light amount detector 21 detects the brightness around the stereoscopic image scope and outputs a detection voltage correlated with the brightness. The detected voltage is amplified to a required level by the amplifier circuit 15 and input to the matrix drive circuit 17.

On the other hand, the matrix drive circuit 17 is supplied with clock signals Ckx and Cky from the oscillator circuit 20 as shown in FIGS. 3 (c) and 3 (e).

In the matrix drive circuit 17, the clock signals Ckx and Cky supplied from the oscillation circuit 20 are thinned out in correlation with the magnitude of the detection voltage supplied from the amplifier circuit 15, and the scanning signal X
ck and Yck are created and given to the level conversion circuit 18.

More specifically, for example, when a voltage is applied to the point X ₂ Y ₂ shown in FIG.
As shown in (f), the scanning signals Xck and Yck are generated from the clock signals Ckx and Cky, respectively. When the intersection point XkYi of the matrix-shaped transparent electrodes is designated as described above, the number of points designated by the detection voltage applied to the matrix driving circuit 17 is large (that is, the brighter the surroundings), and the detection voltage is small (that is, the detection voltage is small). The number of designated points increases (the darker the surroundings are), and the density distribution of the designated points becomes uniform on the electrode 11 '.

The scan signal Xck output from the matrix drive circuit 17,
Yck is converted into a signal of a level sufficient to drive the shutter in the level conversion circuit 18, and the scanning signal X is sent to the left shutter 5 or the right shutter 6 via the switch 19.
Given as L, YL or XR, YR.

Therefore, when the left and right shutters 5 and 6 are opened, the light transmittance changes according to the change in ambient brightness.

FIG. 4 is a diagram showing the correlation between the light transmittances of the left and right shutters 5 and 6 and the ambient brightness, that is, the magnitude of the detection voltage detected by the light amount detector 21.

The shutters 5 and 6 of this embodiment, as shown in FIG.
The lighter the surrounding brightness, the smaller the light transmittance.

After all, according to this embodiment, the light transmittance when the shutter is opened can be controlled to an appropriate transmittance in accordance with the brightness around the stereoscopic image scope so that the stereoscopic image is easy to see.

[Effects of the Invention] As described above, according to the present invention, the total transmittance of the stereoscopic image scope is appropriately controlled based on the change in the ambient brightness. Regardless of this, it is possible to provide a device that allows easy viewing of stereoscopic images.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a stereoscopic video scope according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the configuration of the transparent electrode provided in the shutter of one embodiment of the present invention. FIG. 3 is a signal timing diagram for explaining the operation of the block diagram of FIG. Fourth
The figure shows the correlation between the ambient brightness and the overall transmittance of the shutter. FIG. 5 is a schematic block diagram of a conventional stereoscopic stereoscopic image scope. FIG. 6 is a diagram showing the principle of a liquid crystal shutter used in the stereoscopic image scope of FIG. In the figure, 5 is a left shutter, 6 is a right shutter, 9 is a liquid crystal cell, 11 'is a transparent electrode plate arranged in a matrix, 14 is a drive circuit, and 19 is a switch.

Claims (1)

[Claims] 1. A stereoscopic image scope capable of viewing a screen of a video display device in which a left-eye screen and a right-eye screen are switched and displayed for each field as a stereoscopic image by utilizing human's binocular parallax. The liquid crystal cell and a plurality of electrodes arranged in a matrix form a left shutter that controls light reaching the human left eye, and the liquid crystal cell and a plurality of electrodes arranged in a matrix form In a device including a right shutter that controls light reaching the right eye and a shutter control unit that alternately opens or closes the left shutter and the right shutter in synchronization with screen switching for each field, the ambient brightness Ambient light amount detection means for detecting the depth, in response to the output of the ambient light amount detection means, based on the scanning signal for scanning the plurality of electrodes arranged in a matrix, By applying a predetermined voltage to a portion of the plurality of electrodes of Kihidari and right shutters,
A stereoscopic image scope, comprising: a transmissivity adjusting means for adjusting a transmissivity of light transmitted through each shutter when the left shutter and the right shutter are opened.