JPS62254594A - Stereoscopic picture display method and its device - Google Patents

Abstract

PURPOSE:To realize the display of a three dimensional stereoscopic picture without depending on a viewing angle or position by alternately feeding right and left pictures in time division to the right and left eyes. CONSTITUTION:In a picture display device 11, the left picture 12 viewed by the right eye and the right picture 12 viewed by the left eye are alternately displayed in time division at a prescribed timing. In both light shielding films 14, 15 of glasses 8, when the left picture 12 is displayed on the screen of the picture display device 11, the light shielding film 14 of a left window interrupts an incident light to the left eye 1 and the picture display device 11 is viewed only by the right eye 2. As for the right picture 13, the light shielding film 15 of the right window of the glasses 8 interrupts an incident light to the right eye 2 and the right picture 13 displayed on the picture display device 11 is viewed only by the left eye 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a stereoscopic image display method and apparatus suitable for stereoscopic television and the like.

[Prior Art] Originally, in order for humans to recognize three-dimensional stereoscopic images, there must be parallax between the images formed on the retinas of the left and right eyes.

This phenomenon will be explained with reference to FIG. 1θ and FIG. In FIG. 10, 1 and 2 indicate the left and right eyes of a human being, respectively, and 3 indicates a three-dimensional three-dimensional object, such as a cylinder, which is to be recognized by the left and right eyes 1 and 2. Also, the broken lines 4 and 5 indicate left eye 1. It represents the range of vision of the right eye 2. At this time, the left and right eyes 1 and 2 see two-dimensional images (planar images) whose positions are shifted from each other in the horizontal direction as shown in FIG. 11.

That is, what is important in recognizing a three-dimensional stereoscopic image in FIG. 11 is the positional relationship of the image of the subject 3. Visibility 4. Due to the difference of 5°, the left eye 1 has an object image 6
looks to the right, and to the right eye 2 it looks to the left. This deviation in the image formation positional relationship is generally referred to as parallax, and this parallax is a factor that causes humans to perceive it as a three-dimensional space.

Therefore, in order to display a three-dimensional stereoscopic image, it is technically most important to successfully create the above-mentioned parallax on the display screen of the image display device. For this purpose, conventionally, for example, the 12th
A stereoscopic display method as shown in the figure has been provided. 12th
In the figure, reference numeral 8 indicates glasses, for example, blue filters are used on the left and right (left frame) 9 of the glasses 8, and the 8 windows of the glasses 8 (
Right frame) Use a red filter for 10. On the other hand, if the left image 12 of the object is displayed in blue and the left image 13 of the object is displayed in red at the same time on the screen of the image display device 11 for displaying a three-dimensional image, the left eye 1 sees the left image through the left and right blue filters 9. 12 is not recognized, only the right image 13 is recognized, and conversely, only the left image 12 is recognized for the right eye 2 viewing through the red filter of the 8-window 10. As a result, parallax occurs and humans perceive a three-dimensional image.

However, since such conventional display methods use color filters, it is not possible to stereoscopically view ordinary natural color images (multicolor, natural color images). Therefore, the following method has been adopted to create parallax in color images as well as in monochrome images. That is, the left and right 9.8 windows 10 of the glasses 8 are each configured with a polarizing plate, and the angles of the polarization axes of the left and right polarizing plates are shifted perpendicularly, so that on the screen of the 10-man image display device 11, the left and right windows are Images polarized according to the respective polarization axes of the polarizing plates are simultaneously displayed at parallax positions. In this way, since the axes of the left and right polarizing plates are perpendicular to each other, left eye 1 and right eye 2 can select separate left and right images, creating parallax between color images, and creating a three-dimensional color image. can be recognized.

[Problems to be Solved by the Invention] However, in such a conventional three-dimensional image display method, a complicated mechanism is required for sending polarized left and right images on the image display device side, and recognition If you tilt your eye, the left and right images will be visible to both eyes at the same time, eliminating parallax, so there is a serious drawback in that the axis of the stereoscopic eye must be fixed.

Therefore, the present invention creates a color image parallax by sending left and right images to the left and right eyes separately in a time-sharing manner, thereby creating a three-dimensional three-dimensional image without depending on the viewing angle and with a simple configuration. It is an object of the present invention to provide a stereoscopic image display method capable of displaying images and a device therefor.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides an image display means that alternately outputs and displays images taken of the same subject with each field of view of both eyes; Use glasses that have a function of alternately blocking incident light to each eye, and when the right image taken in the field of view of the left eye is displayed on the image display means, the glasses block the incident light to the left eye. Then, when the left image taken in the field of view of the right eye is displayed on the image display means, the glasses are used to block the incident light to the right eye, and the left and right images are displayed separately to the left and right eyes in a time-sharing manner. The system is characterized by the ability to recognize a three-dimensional image by creating a parallax between the left and right sides of the displayed image using the afterimage effect of the eyes.

In another aspect of the present invention, there is provided a pair of glasses having an image display means for alternately outputting and displaying images of the same subject photographed with each field of view of both eyes, and a function of alternately blocking incident light to both eyes. and a synchronizing means for synchronizing the shut-off timing of the glasses and the display timing of the image display means.

[Function] According to the present invention, the left and right images necessary for three-dimensional image recognition are separately and alternately sent to the left and right eyes in a time-sharing manner to create color image parallax. Therefore, it is possible to realize a three-dimensional stereoscopic image display with a simple configuration and independent of the viewing angle or position.

[Example] The present invention will be described in detail below with reference to the drawings.

First, the basic configuration of the present invention will be explained with reference to FIGS. 1(A) and 2(B) and FIG.

In FIGS. 1A and 1B, reference numerals 14 and 15 indicate left and right light shielding films provided on the glasses 8. The image display device 11 displays a left image 12 that can be seen with the right eye and a right image 13 that can be seen with the left eye alternately at predetermined timing in a time-sharing manner. In both light blocking films 14 and 15 of the glasses 8, when the left image 12 is displayed on the screen of the image display device 11, the light blocking film [14] of the left window blocks the incident light to the left eye 1, and only the right eye 2 The user looks at the image display device 11.

This state is shown in FIG. 1 (8). On the other hand, as for the right image 13, as shown in Fig. 1(B), Fig. 1(A)
Contrary to the operation shown in , the light blocking film 15 of the 8 windows of the glasses 8 blocks the incident light to the right eye 2, and the right image 13 displayed on the image display device 11 is viewed only with the left eye 1. FIG. 2 shows the display operation on the time axis t. A in this figure shows how the image display device 11 displays separate left and right images alternately in a time-sharing manner. Here, "right" in the figure indicates that the right screen is displayed, and "left" indicates that the left screen is displayed. The left image 13 is displayed on the right photographing screen, and the right image 12 is displayed on the left photographing screen. In this figure, B indicates the opening/closing timing of the right light shielding film 15, and C in this figure indicates the opening/closing timing of the left light shielding film 1i14, which is assumed to be open at the "H level" and closed at the "L" level. By setting the opening/closing time interval td to, for example, several tens of milliseconds or less, flickering of the image can be eliminated.

As described above, in the present invention, the left and right output display images 12 and 13 that are output alternately in a time-sharing manner are controlled by the left and right light shielding films 14 and 14 that open and close in synchronization with the output. Since the IS is used to time-divide the signals to the left and right eyes 1.2, the signals are sent to the left and right eyes 1.2 separately.
2 parallax can be easily and accurately created, which is fundamentally different from conventional technology that uses conventional color filters and polarizing filters, and because it does not output left and right images at the same time, it is possible to create a three-dimensional effect even if you tilt your eyes. does not change, and a three-dimensional stereoscopic image with natural color display can be recognized without fixing the eye axis in a predetermined direction.

A. Overall configuration FIG. 3 shows a schematic configuration of an embodiment of the present invention. In Figure 3, 16 is a standing tree 9, a three-dimensional subject such as a person or a car, 17
18 is a left imaging camera having a field of view of a human's left eye (left eyeball) 1; 18 is a right imaging camera having a field of view of a human's right eye (right eyeball) 2; and 19 is an analog switch circuit. The analog switch circuit 19 switches and outputs the image signal R output from the left imaging camera 17 and the image signal R output from the right imaging camera 18 in synchronization with the switching synchronization signal 21 of the left and right image switching synchronization signal oscillator 20. 22 is an image signal selectively outputted alternately from the analog switch circuit 19;
This is an image signal amplification circuit that amplifies R and supplies it to an image display device 11 such as a CRT or a liquid crystal display.

An oscillator 20 generates an image switching synchronization signal 21 and an opening/closing synchronization signal 23 in synchronization with the frame synchronization signal. The opening/closing synchronization signal 23 is sent as is to the light shielding film 15 on the right side, and at the same time is inverted by the phase inversion circuit 24, and the inverted opening/closing synchronization signal 24 is sent to the light shielding film 14 on the left side. Subject 1
When the image signal from the leftmost camera 17 that has taken an image of 6 is being displayed on the image display device 11 through the analog switch circuit 19, the light blocking film 14 in front of the left eye 1 opens,
When the light shielding film 15 of the right eye 2 is closed and the image signal of the right imaging camera 18 is being displayed, synchronization signals 21, 23, and 25 are generated so that the operation is reversed.

B,! ? l] To explain the operation next, first, the subject 16 is photographed with separate left and right imaging cameras 17 and 18 to obtain three-dimensional stereoscopic image information and R, and then a time interval of several tens of ms according to the frame time is taken. Then, the left and right image signals R are switched by the analog switch circuit 1g and sent to the image signal amplification circuit 22. As a result, in the image display device 11, the above-mentioned FIG. 1(A),
As shown in (B), the left and right imaging cameras 1 are
The images selected in 7.18 will be displayed alternately. On the other hand, the light shields @14 and 15 attached to the windows of the glasses are left and right opening/closing synchronization signals (image switching signals) 23
．． 25 opens and closes the incident optical path. Assuming that the operation of this blocking film follows the timing chart shown in FIG. Only the images selected by the right imaging camera 18 will be sent.

Further, since the image switching time is set as fast as several tens of milliseconds as described above, the human eye perceives a series of flickering-free images due to the afterimage effect. Here, if a commonly used color television cathode ray tube or the like is used as the image display device 11, a three-dimensional color image can be easily and easily displayed. Furthermore, since the present invention separates the left and right images on a time-sharing basis, the drawbacks of the conventional polarizing plate method, such as the left and right images appearing overlapping even if the position of the human eye is slightly tilted with respect to the image display device, do not occur. do not have.

C0 Light-shielding Film Next, one example of the structure of the light-shielding films 14 and 15 used in the eyeglasses 8 in the above-described embodiment of the present invention will be described with reference to FIGS. 4 to 7.

Figures 4(^) and 4(B) show the principle of a liquid crystal light shielding film that can open and close the optical path using an external voltage. In this figure, 26 is the incident light incident on the glasses, 27 is a linear polarizing plate, 28 is a transparent electrode, 29 is a twisted nematic mode (TN mode) liquid crystal, and 30 is placed perpendicular to the polarization axis of the linear polarizing plate 27. and 31 is the transmitted light that enters directly into the eyeball 1.2. The light blocking film with the structure shown in this figure is currently widely used, and as a liquid crystal, N
It is common to use p type. The opening/closing response speed of this type is 10n+s to 50m5.

FIG. 4(A) shows the alignment structure of liquid crystal molecules when the voltage between the two electrodes 28 is zero.

As is well known, in the optical properties of Ch liquid crystal (cholesteric liquid crystal), when the relationship between the helical pitch P of the orientation of liquid crystal molecules and the wavelength λ of light is P>λ, optical rotation is exhibited.

In this case, the twist angle is approximately 90 degrees and the optical rotation angle is also the same. Therefore, when the liquid crystal 29 is sandwiched between the polarizing plate 27 and the analyzing plate 30 at an angle of 90 degrees to each other as shown in FIG. 4(A), light can be transmitted in a state where the voltage is zero. On the other hand, when a voltage is applied, as shown in Figure 4 (B), if the voltage is above the threshold, the molecules of the liquid crystal 29 stand almost vertically in the center between the two plates 27 and 30, and therefore lose their optical rotation ability. I almost lose it. As a result, the light is blocked by the analyzer plate 30 and does not reach the eyeball 1.2.

FIG. 5 shows experimentally investigated light-shielding characteristics of the light-shielding film of the TN mode cell shown in FIGS. 4(A) and 4(B). When handling color images as in the present invention, sufficient light-shielding properties must be obtained in the visible region. As is clear from this figure, the light blocking film of this example has a wavelength of 4
It can be seen that the light transmittance when a voltage of 7 V is applied in the visible range of 00 nm to 700 nm is 4% or less at the maximum, and it is understood that a practically sufficient light shielding property can be obtained.

Moreover, FIG. 6(A) shows the relationship between the applied voltage and the light transmittance in the light blocking film shown in FIG. 4(A) and CB). In this experimental example, it can be seen that when the applied voltage is zero (off), the light transmittance is about 33%, and when the applied voltage is 6 V or more (on), the light transmittance is about 3%.

FIG. 6(B) shows the psychological brightness of the light shielding film having the characteristics shown in FIG. 6(A) with respect to transmitted light. Figure 6 (A) and Figure 6 (
The difference in the characteristic curve from B) is due to the fact that the human eye becomes accustomed to the darkness, or due to the linearity of psychological brightness, and the psychological brightness differs from the physical absolute amount Y. It's for a reason.

Experimental results have confirmed that the psychological brightness is about 52% when the applied voltage is off and about 15% when the applied voltage is on.

D. Spectacle window FIG. 7 shows an example of the configuration of a spectacle window using the principle of the liquid crystal light blocking film shown in FIGS. 4(A) and 4(B). In the case of a liquid crystal light blocking film, the light in the direction perpendicular to the light blocking film is efficiently opened and closed, so as shown in this figure, the left and right light blocking films 14 are formed approximately spherically around the eyeball 1.2. .15 constitutes.

Control signals for opening and closing the optical paths of the light shielding films 14 and 15 are supplied via signal lines 23L and '25L connected as shown in the figure, using the common line 32 as a common ground. A voltage of 6 V or more is applied to the signal lines 23L and 25L, respectively, when the light is interrupted.

E. As for the synchronization signal image display system, the current television image signal processing system can be applied as is. Furthermore, regarding the signal system for synchronizing the glasses side and the image display side, it is not necessary to connect the oscillator 21 and the light shielding film 14, 15 with a signal line as shown in Fig. 3, and for example, as shown in Fig. 8. As shown in FIG. 1, the opening/closing synchronization signal is transmitted by light or radio waves from the oscillator 21 built into the image display device 11 side, and the connection cord for transmitting the synchronization signal can be removed by providing the receiving device on the glasses side 8. .

As an example, in FIG.
6 shows a signal transmission system in which light is received and a synchronization signal is obtained. First, using the open/close synchronizing signal 23 of the left/right image switching synchronizing signal oscillator 20,
Ift Keying) The light emitting diode 34 is frequency modulated by the modulation circuit 33. The frequency modulation is, for example,
In the display of the left image, the frequency is 1200 Hz, and in the right image, it is 24001 (z).The light beam (modulated light) 35 from the light emitting diode 34 is received by the photodiode 36 attached to the glasses 8, etc., and the modulated component of the light is is extracted by the detection circuit 37 to obtain opening/closing signals of the light shielding films 14 and 15.

Since the liquid crystal constituting the light blocking films 14 and 15 has high impedance, it has the characteristic that an extremely small amount of electric power is required for light blocking. Therefore, by configuring the electric circuit on the side of the glasses 8 with a low power consumption circuit such as an OMO5-IC, it is possible to realize glasses that are small and convenient to carry. Eliminating the communication line (communication code) for synchronization from the glasses 8 is extremely important in ensuring the degree of freedom on the viewing side.

Although the above-described embodiments of the present invention are applied to a display device such as a three-dimensional television, the present invention is not limited to this, and can also be applied to a three-dimensional movie, where the left and right display as shown in FIG. 8 is synchronized with the projection frames. By using switching glasses,
realizable.

[Effects of the Invention] As explained above, according to the present invention, the left and right images required for three-dimensional image recognition are sent alternately to the left and right eyes separately and in a time-sharing manner. The effect of realizing a three-dimensional three-dimensional image display with a simple configuration is achieved without depending on the viewing angle or position.

[Brief explanation of drawings]

Figures 1 (A) and (B) are perspective views showing the basic configuration of the present invention, Figure 2 is a timing chart showing the principle of the invention, and Figure 3 is a circuit diagram showing the schematic configuration of an embodiment of the present invention. , Fig. 4(A) and CB) are perspective views showing the principle of the liquid crystal light blocking film of the embodiment of the present invention, and Fig. 5 is a waveform diagram showing the light transmission characteristics of the liquid crystal light blocking film of the embodiment of the present invention. , FIG. 6(8), (B) is a waveform diagram showing the characteristics of the liquid crystal light shielding film according to the embodiment of the present invention with respect to applied voltage, FIG. 7 is a plan view showing the structure of the spectacle window of the embodiment of the present invention, Fig. 8 is a perspective view showing an example of a synchronization signal transmission method according to an embodiment of the present invention, Fig. 9 is a circuit diagram showing an example of a circuit realizing the transmission method of Fig. 8, and Fig. 10 is a three-dimensional stereoscopic image. FIG. 11 is a plan view showing the principle of recognition; FIG. 11 is an explanatory diagram showing the difference in the position of left-eye and right-eye images; and FIG. 12 is a perspective view showing a conventional three-dimensional display method. 1... Left eyeball, 2... Right eyeball, 3... Subject, 4... Left eye field of view, 5... Right eye field of view, 6... Two-dimensional image of the subject seen from left eyeball, 7...-
Two-dimensional image of the subject seen from the right eyeball, 8... Glasses, 9, lO... Windows of left and right glasses, 11... Image display device, 12, 13... Right image and left image, 14, 15...
・Light blocking film for left window and right window, 16... Subject, 17, 18... Left and right imaging cameras, 19.
...Analog switch circuit, 20...Image switching synchronization signal oscillator, 21...Switching synchronization signal, 22...Amplification circuit 23.25...Opening/closing synchronization signal, 24...Phase inversion circuit, 26. ...Incoming light, 27...Polarizing plate, 28...Electrode, 29...Liquid crystal, 30...Analysis plate, 31...Transmitted light, 32...Common ground, 33...FS A modulation circuit, 34...Light emitting diode, 35...Light from the light emitting diode, 36... Photodiode for light reception, 37... Synchronous signal detection circuit. Agent Patent Attorney Yoshi Tani - Kito B, Sumimoto Sekiha, 411 Figure 1 < = Light transmittance (%) to Lolly (A) Luminance Y Applied voltage V (B) Psychometric quantity Brightness L* Actually, I'm the best in the world"! Characteristics of the Shizuki odor and Namigata map shown in Figure 6 - 11 Fumitotanba Figure 8 Transmission method Shiba realization 13th Hoofi 11 River and Hoo times 9th Figure 9 Figure 3''J' A plan view showing the principle of formation of a single-eye elephant and a t-embryo.A plan view showing the relationship between the left and right eyes of a Nitto-eye elephant.
Figure 1 shows how to display the original tree in the conventional 3' map.
figure

Claims (1)

[Scope of Claims] 1) Image display means for alternately outputting and displaying images of the same subject photographed with each field of view of both eyes, and a function of alternately blocking incident light to each of the eyes for each monocular. When the right image taken in the field of view of the left eye is displayed on the image display means, the glasses are used to block incident light to the left eye, and then the left image taken in the field of view of the right eye is displayed. When an image is displayed on the image display means, the glasses block the incident light to the right eye, and the left and right images are sent separately to the left and right eyes in a time-sharing manner, so that the afterimage effect of the eyes can affect the displayed image. A stereoscopic image display method characterized by creating left and right parallax and recognizing a stereoscopic image. 2) Image display means for alternately outputting and displaying images of the same subject taken with each field of view of both eyes, glasses having a function of alternately blocking incident light to both eyes, and blocking of the glasses. A stereoscopic image display device comprising: synchronization means for synchronizing the display time of the image display means with the display time of the image display means. 3) In the device according to claim 2, in the glasses, each of the transmission windows to the both eyes is constituted by a liquid crystal light blocking film, and the molecular orientation of the liquid crystal in the liquid crystal light blocking film is electrically controlled. A three-dimensional image display device characterized in that the transmitted light to both eyes is alternately blocked. 4) In the device according to claim 2 or 3, the synchronizing means includes a light emitting element provided on the image display means side and a light receiving element provided on the eyeglasses side, and A stereoscopic image display device characterized in that a light emitting element and the light receiving element are synchronized by optical communication.