JPS62204226A - Stereoscopic television device - Google Patents

Abstract

PURPOSE:To remove visual influence of the opening/closing operation of shutters by shifting control signals for right and left switching shutters from a synchronizing signal for video display by an optional time. CONSTITUTION:The titled device is provided with a pair of optical shutter means corresponding to right and left eyes which execute light shielding operation complementarily after a prescribed delay time from a driving signal and an optical shutter control means for inputting a switching signal and supplying the driving signal to the optical shutter means prior to the approximately prescribed delay time. The shutter control circuit 13 consists of a field deciding circuit 13a for inputting a vertical synchronizing signal V and a horizontal synchronizing signal H and deciding a right or left image in accordance with the phase difference of respective signals V, H, a counter circuit 13b, a signal generating circuit 13c, and a driving circuit 13d supplying control signals Gl, Gr. Consequently, visual influence due to the delay of operation of the shutters for alternately observing right and left images can be minimized.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a stereoscopic television device.

[Technical background of the invention] As one of the means for recognizing the image of a subject three-dimensionally,
For example, PLZT (PeadLantha), which is a light shielding element,
num Zirconate T +tanate
) There is a method of using the element for stereoscopic vision, for example, in a glasses part.

FIG. 4 is an explanatory diagram showing the glasses portion of a stereoscopic television apparatus that recognizes a stereoscopic image of a subject using this PLZT element.

In the figure, reference numerals 1a and lb are optical shutters installed in the left and right eyes of the glasses, respectively. Optical shutters 1a, 1b
Since they have the same configuration, one optical shutter 1a will be explained. A PLZT element 4 is inserted between two polarizing plates 2 and 3, and these are brought into close contact with each other to constitute the optical shutter 1a.

The shutter drive means 5 alternately applies voltages to the optical shutters la and 1b configured in this manner in synchronization with switching signals for the left image and stone image of the subject that are alternately displayed on the television screen field by field or frame by frame. Supply, PLZT
The light transmittance of the elements 4, 4 is alternately switched to optically open and close both the optical shutters 1a, 1b.

FIG. 5 shows a schematic configuration diagram of a general stereoscopic television apparatus. The input decoded video signal S is converted into a video signal by the synchronization separation circuit 6 and is converted into a vertical synchronization signal V.

It is separated into a horizontal synchronizing signal H. These, V and H are respectively video amplification circuits 7. The signal is applied to a cathode ray tube 10 via a vertical deflection circuit 8 and a horizontal deflection circuit 9.

On the other hand, the shutter control device 11 inputs the horizontal and vertical synchronizing signals H and V, determines whether the field is a right image or a left image, and provides control signals Gr and Ql to the spectacle shutter 12. The shutter 12 is controlled by these control signals to close the right side during the period when the left image is displayed, and the left side during the period when the right image is displayed, so that the right eye and the left eye respectively close the right side. Only the image and the left image can be seen, and as a result, the image displayed on the cathode ray tube 10 can be recognized three-dimensionally.

[Problems with the background art] In a normal television system, the switching cycle for one field is approximately 1/60 seconds, but in order to perform stereoscopic viewing,
One set of left and right images is recognized as one image, so the period is 1/3 twice as long.
It becomes 0 seconds and I feel a flicker. Therefore, in order to avoid flickering in 3D television, it is necessary to
The video and shutter must be switched at twice the speed or faster, and in this case a delay in shutter operation becomes a problem. FIG. 6 shows a timing diagram of each signal in FIG. 5.

(1) is the vertical synchronization signal V, and (2) is the video signal.

(3) and (4) are the left and right shutter control signals Gl, respectively.
, Gr, (5) and (6) indicate the light transmittance of 31.3 r for the left and right shutters, respectively. Normal vertical synchronization signal V
Since this signal is a trigger for field switching, this signal is used as a trigger to generate a shutter control signal Gl.

(3r is generated. However, the actual shutter operation is 3r for this shutter control signal G1.Q'r.
As shown in 1.3r, there is a delay, and even with the fastest operating chiral smetic C liquid crystal, it takes about 0.5 msec to start operation and about 1.0 msec to complete operation. It takes. Therefore, if the display cycle of one field is shortened, for example, if it is displayed at twice the normal frequency, the image display will start approximately 0.8 to 0.9 msec after trigger V, so B + in Fig. 6 As shown by the dotted lines of , B r, the shutter switching is not completed in the first part of the display, that is, the part above the cathode ray tube displaying the image, so that normal stereoscopic image recognition is not possible.

[Object of the Invention] The present invention has been made in view of the above circumstances, and provides a method for shifting a control signal for the shutter by an arbitrary time with respect to a synchronization signal for displaying images in a left-right switching shutter of a 3D television device. Therefore, it is an object of the present invention to provide a stereoscopic television device in which the opening and closing operations of the shutter are not visually affected by stabilizing the operation of the shutter at all times during the display period.

[Summary of the Invention] In order to achieve the above-mentioned object, in the present invention, optical shutters provided corresponding to the right eye and the left eye are connected to a right image and a left image of a subject displayed on a television screen. In a 3D television device that enables the image of a subject to be recognized in 3D by opening and closing alternately in synchronization with the switching signal of
a pair of optical shutter means corresponding to the right eye and the left eye that operate to block light in a complementary manner after a predetermined delay time in response to the drive signal; The apparatus is characterized by comprising an optical shutter control means for supplying a signal to the optical shutter means.

[Embodiments of the Invention] FIG. 1 shows a specific configuration example of a shutter control circuit according to the invention, and FIG. 3 shows the timing of signals generated by the circuit shown in FIG. 1. The configuration in Figure 1 is similar to Figure 5, which shows the general configuration of a 3D television device.
This circuit is connected in place of the shutter control circuit 11 in the figure, and the other configurations are the same.

In FIG. 1, 13a is a field determination circuit;
A vertical synchronization signal V and a horizontal synchronization signal H are input, and it is determined whether it is a left or right image based on the phase difference between each signal V and H, and a trigger pulse V is applied only before the image signal of a stone statue starts, for example.
Generates 2. 13b is a counter circuit that starts counting up using this trigger pulse V2 as a reset signal, and outputs the count (direct) to an n-bit signal line as a binary code. 13c is a counter circuit that outputs a predetermined binary code from the counter circuit 13b. When the address arrives, it is recognized as address data and stored in the built-in ROM (Read 0nl).
yMemory), and thereby the two output terminals Q1. JHI in Q2, ill
These signal generation circuits are comprised of, for example, flip-flop circuits that perform switching in a complementary manner. 13d is Ql of the signal generation circuit 13c.

This is a drive circuit that supplies each output of Q2 as control signals G l and G r for driving the eyeglass shutter.

Next, the operation of an embodiment of the apparatus having the above configuration will be explained in FIGS. 1 and 2.
This will be explained with reference to FIGS. 3 and 5.

Field determination circuit 1
3a determines whether it is a stone image field or a left image field based on the phase difference between the respective synchronization signals, and generates a signal (2) that generates a pulse only before the stone image image signal starts. Then, this signal v2 causes the counter circuit 13b to
is reset and starts counting up in accordance with the input clock signal CK. The clock signal CK is a synchronization signal that is sufficiently faster than the vertical synchronization signal (2), and for example, the horizontal synchronization signal H may be used in common. That is, the counted value indicates the time from the frame synchronization signal, and the value is input to the signal generation circuit 13c. By the way, shutters such as liquid crystals have delay characteristics as shown in Figure 2, and To
There is a time lag in the opening/closing operation by n and Toff. Therefore, the counter circuit 13 is sent to the ROM in the signal generation circuit 13c.
The contents of the ROM in the signal generation circuit 13c are written in such a way that the count value from b is input as address data and the switching signal is generated earlier by the Ton and Toff times measured in advance.

As a result, as shown by the timing in FIG. 3, the shutter switching period falls within the blanking period between display periods. That is, as shown in FIG. 5, the stone image supplied from the synchronization separation circuit 6 during the odd field period of the vertical synchronization signal can be observed at the right shutter where the light transmittance 3r reaches the J Hi l level exactly during this odd period. , and the left image supplied from the sync separation circuit 6 in the next even field period is exactly this e
It can be observed with the left shutter where the light transmittance B1 reaches the LOW' level during the ven period.

As described above, if the shutter control according to the present invention is performed, switching within the vertical retrace period can be achieved by optimizing the switching timing even for shutters whose operation delay characteristics are slower than the vertical retrace time. It is possible to perform stereoscopic recognition over the entire displayed image. Therefore, there is no need to use an expensive liquid crystal with an extremely high operating speed, and furthermore, there is no need to add a special circuit to improve the operating speed.

It should be noted that the present invention is not limited to the above embodiment,
Various modifications can be made without changing the gist. For example, in the above embodiment, the vertical synchronization signal was used as the switching signal for left and right images, but if there is a device that shortens the switching cycle to prevent screen flickering, the switching cycle may be shortened. A shutter drive signal may also be output. Further, the display fields for the right image and the left image may be either odd or even. Furthermore, although glasses are used as the shutter in the explanation, the shutter is not limited to this, and any shutter may be used as long as it has the same function. Furthermore, the shutter control circuit is not limited to the circuit elements shown in FIG. 1, but may be any other structure as long as it has a similar function.

[Effects of the Invention] According to the present invention as described above, it is possible to provide a stereoscopic television apparatus in which the visual influence caused by the delay in shutter operation for alternately observing left and right images is minimized.

[Brief explanation of drawings]

FIG. 1 shows the configuration of the shutter control circuit according to the present invention, FIG. 2 is a diagram for explaining the operation delay of the liquid crystal shutter, and FIG. 3 shows the operation of the configuration of the present invention shown in FIG. 1. 4 is an explanatory diagram showing the optical shutter of a conventional 3D television device, FIG. 5 is a schematic configuration diagram of a general 3D television device, and FIG. 6 is a diagram of a conventional 3D television device. This is a time chart. 10... Braun tube, 12... Glasses shutter 13
...Shutter control circuit

Claims (1)

[Claims] By alternately opening and closing optical shutters provided for the right and left eyes in synchronization with switching signals for the right and left images of the subject displayed on the TV screen, a three-dimensional image of the subject is created. In a stereoscopic television device that can be recognized, a pair of optical shutter means are provided corresponding to the right eye and a left eye, and the switching signal is inputted to the optical shutter means, which are provided in a pair corresponding to the right eye and the left eye, and operate to block light in a complementary manner after a predetermined delay time with respect to the drive signal. and optical shutter control means for supplying a drive signal to the optical shutter means approximately the predetermined delay time in advance.