JPH0519388A - Three-dimensional display - Google Patents

Abstract

PURPOSE:To reduce the size of a device as compared with the display size of a reproduced image by decreasing the differences between a display effective space and a screen movement space and to realize an excellent visual feeling to the reproduced image by obtaining an observation position which is close to the display of the reproduced image and high in degree of freedom and further eliminating the need for the plane correction of the reproduced image. CONSTITUTION:The three-dimensional display has a screen 3 which moves at a high speed and a drawing means (circuit system and optical system) which scans the relevant screen 3 for drawing and forms a three-dimensional image within the movement distance of the screen 3 in the section of an afterimage drawn instantaneously on the screen 3; and the screen 3 is moved straight reciprocally by a crank mechanism composed of a wheel 4, a rod 5, and a motor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional display which reproduces a stereoscopic image in space by moving a screen.

[0002]

2. Description of the Related Art Recently, 360
A three-dimensional display has been proposed that allows you to view a stereoscopic video from anywhere.

A conventional three-dimensional display is a method of obtaining a three-dimensional image by moving a semitransparent screen which is scanned by a laser beam to display an image at a high speed as shown in FIG. A semitransparent blade serving as a screen is attached to the shaft 61a and rotated. Then, a three-dimensional image is displayed in the cylindrical space 62 in which the blade moves.

That is, the laser light L from the laser light source 63 is supplied to the intensity modulator 65 based on the synchronizing signal S from the synchronizing circuit 64.
By performing amplitude modulation in synchronization with the rotation of the motor 61 and applying the amplitude-modulated laser light L to the rotating blade, it is possible to illuminate any point in the cylindrical space 62 formed by the blade rotating. , This enables the display of stereoscopic moving images (NIKKEI ELEC
TRONICS 1990.9.3 (no.508) N
(See page 104 of E-Report). In the figure, 66 is a scanning means for deflecting the laser light in the XY directions.

In another example, as shown in FIG. 8, a so-called Archimedean spiral (r = aθ + b, a: proportional constant, b) where a radius r changes linearly with respect to a central angle θ on a disk 71. : Minimum radius), draw a strip plate along it, and use it as the screen segments 72a and 72b.

That is, when the disk 71 rotates at a constant speed,
Due to the nature of the Archimedes spiral, the positions of the segments 72a and 72b viewed from the point A in the figure change so that the distance decreases linearly with respect to the depth direction (Z direction), and instantaneously return to the original position. Therefore, if a part of the segments 72a and 72b is used as a screen, it can be regarded as a screen that moves in the depth direction at high speed in synchronization with the rotation of the disk 71.

Then, as in the example of FIG. 7, the laser light L from the laser light source 63 is fed to the synchronizing signal S from the synchronizing circuit 64.
Based on the above, amplitude modulation is performed by the intensity modulator 65 in synchronization with the rotation of the motor 61, and the amplitude-modulated laser light L is applied to the rotating segments 72a and 72b.
It is possible to display a stereoscopic moving image on a screen that moves in a pseudo direction at a high speed (see the 1990 21st Imaging Technology Conference P209 to P212 “Movable screen three-dimensional display”).

[0008]

By the way, a common feature of the above-mentioned conventional three-dimensional displays is that a part of the circumference of the screen which is rotating at high speed is cut out and used as an image display area. is there. The following are the two main drawbacks associated with this method.

First, since only a part of the circumference of rotation is used as the image display area, there is a drawback that the device itself becomes very large with respect to the size of the effective display space. For example, in the example shown in FIG. 7, the display space is a cube having a side of 10 cm, but as the space 63 in which the screen moves, a cylindrical space having a diameter of 50 cm and a height of 10 cm is required. Further, it is impossible to observe the screen from the movement space 63, which is one of the factors that limit the observation position.

Another point is that the reproduced image is distorted because the screen does not move in parallel. Therefore, in the case of the conventional device, calculation processing for correcting this distortion is required. However, the accuracy of this calculation process is limited, and there is the inconvenience that the planar and straight lines are unnatural even in the reproduced image after the calculation process.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the difference between the effective display space and the screen movement space, and the device for the display size of a reproduced image. In addition to being able to miniaturize itself, it allows a highly flexible observation position close to the reproduced image being displayed, and also eliminates the need for plane correction of the reproduced image, resulting in a good visual feeling of the reproduced image. It is to provide a three-dimensional display that can be realized.

[0012]

The present invention has a screen 3 that moves at a high speed, and drawing means (circuit system and optical system) that scans the screen 3 to draw an image. In a three-dimensional display that forms a three-dimensional image within the movement distance of the screen 3 by using the drawn afterimage as a cross section, the screen 3 is configured to linearly move back and forth.

[0013]

According to the above-described structure of the present invention, since the screen 3 is linearly moved back and forth, almost the entire surface of the screen 3 can be used as an image display area. Therefore, the difference between the effective display space and the screen movement space can be reduced, the device itself can be downsized with respect to the display size of the reproduced image, and the degree of freedom in approaching the displayed reproduced image is high. The observation position becomes possible.
Further, since the screen 3 moves in parallel, it is not necessary to correct the plane of the reproduced image, and the visual feeling of the reproduced image becomes good.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1A is a plan view showing a three-dimensional display according to this embodiment, FIG. 1B is a front view thereof, and FIG. 1C is a side view thereof.

Since the three-dimensional display is the same as the conventional three-dimensional display in that the laser is scanned in synchronization with the screen to obtain a three-dimensional image by utilizing the afterimage effect, the three-dimensional display is basically the same. Details of the configuration of the light source, the intensity modulator, the synchronizing circuit, etc. are omitted.

As shown in the figure, this three-dimensional display is constructed by mounting a base 2 on six legs 1 and mounting main components constituting the three-dimensional display on the base 2. There is.

The main components of this three-dimensional display include a disk-shaped screen 3, a wheel 4, a rod 5 and a motor 6.

The screen 3 is supported on the guide rail 7 by the linear motion slider 8 and is capable of smooth linear motion. The guide rail 7 is laterally mounted between two support plates 9a and 9b provided upright on the base 2. Therefore, the screen 3 linearly moves in parallel with the surface of the base 2. Further, an opening 10 having a diameter slightly smaller than the diameter of the screen 3 is provided in the central portion of the supporting plates 9a and 9b, and the opening 10 on the front surface transmits the laser light to the screen 3 so as to irradiate the screen 3. It is used as a hole, and the opening (not shown) on the rear surface is used as an insertion hole for the rod 5.

The wheel 4 includes a motor 6 and a gear box 1
1 is connected via the gear box 11 and is rotated by the driving force of the motor 6 which is decelerated by the gear box 11. Rod 5
Are the screen 3 and the wheel 4 and the bearing 12 respectively.
The rotary motion of the wheel 4 is smoothly converted into the linear reciprocating motion of the screen 3.

In this example, the rotation of the motor 6 is decelerated by the 1/6 gear box 11 and a direct current of about 10 V is applied to the motor 6, so that the wheel 4 rotates at about 600 rpm.
The screen 3 is converted into a reciprocating linear motion of about 10 Hz.

An encoder 13 is connected to the motor 6, and the position of the screen 3 is detected in addition to the optical marking (not shown) of the wheel 4 being detected by an origin sensor 14 provided on the base 2. And the motion is detected. Laser scanning is synchronized with a detection signal from the origin sensor 14. In this case, it is desirable that the output pulse cycle of the encoder 13 matches the displacement speed of the screen 3. Then, the surface of the screen 3 opposite to the surface on which the rod 5 is attached is irradiated with the scanned laser light to display a stereoscopic image in the moving space of the screen 3.

Rubber feet 15 for slip prevention are attached to the six legs 1, and a rubber sheet is attached to each portion between the screen 3 and the linear motion slider 8 to prevent vibration and sliding noise. ing.

Next, an example of a circuit system that controls the three-dimensional display will be described with reference to the block diagram of FIG.
Before that, the principle of displaying, for example, a sphere in the moving space of the screen will be described with reference to FIG.

First, the horizontal and vertical directions within the screen 3 are defined as XY coordinates, and the direction perpendicular to the screen 3 surface, that is, the screen movement direction is defined as Z coordinate. Then, when a sine wave (a sine wave and a cosine wave) whose phases are shifted from each other by π / 2 is input to an XY scanner that scans laser light in the X and Y directions, a Lissajous figure of a circle is obtained as shown in FIG. appear.

Next, when the screen 3 is swept in the Z direction, a spiral three-dimensional image is observed due to the afterimage effect, as shown in FIG. 3B.

Then, as shown in FIG. 3C, a semicircular modulation is applied to the radius of the spiral, that is, the amplitude of the sine wave. As a result, the spiral afterimage is observed as a three-dimensional image of a sphere as shown in FIG. 3D. X and Y of this stereoscopic image
The position of the sphere can be changed by adding an offset in the direction or adjusting the timing of modulation on the Z axis.

Next, an example of the circuit system will be described with reference to FIG.

For example, a direct current of 10 V from the motor power source 21 is applied to drive the motor 6 to rotate, and an encoder signal p from the encoder 13 accompanying the rotational driving of the motor 6 is shaped / divided by the clock shaping / dividing circuit 22. Then, for example, 12
A clock pulse c of 8 pulses / cycle is created. Further, each time the wheel 4 rotates half a turn, the origin sensor 14 outputs an origin pulse S _{0, which} is input to the synchronization counter 23.

In this example, an optical marking is provided on the wheel 4 so that the origin pulse S ₀ is output each time the screen 3 reaches the top / bottom dead center. The top dead center indicates the point when the screen 3 reaches the foremost end on the support plate 9a side, and the bottom dead center indicates the point when the screen reaches the rearmost end on the support plate 9b side.

On the other hand, the pattern memory 25 is connected to the computer 24 connected to this circuit system, and the computer 24 writes the offset value α and the color change pattern Pc for each cycle as data D in the pattern memory 25. Then, the offset value α is supplied from the pattern memory 25 to the asynchronous counter 26 for each cycle, and at the same time, the color change pattern Pc is supplied to the color selection circuit 27.

The synchronous counter 23 sets the input cycle of the origin pulse S ₀ from the origin sensor 14 as one cycle, and the clock pulse c from the clock shaping frequency dividing circuit 22 is set for each cycle.
Is counted 64 times, and a synchronizing signal S ₁ is generated. This synchronizing signal S ₁ is supplied to the enable circuit 28 at the subsequent stage. The origin pulse S ₀ constitutes a reset pulse of the synchronization counter 23, and the content of the synchronization counter 23 is reset to 0 based on the input of the origin pulse S ₀ .

The asynchronous counter 26 sets the clock pulse c from the clock shaping / dividing circuit 22 to 64 ± α depending on the setting.
When the number of times is counted and the predetermined number of pulses is counted, the asynchronous signal S
₂ is supplied to the enable processing circuit 28.

The enable processing circuit 28 prevents the generation of an unnatural image near the top / bottom dead center based on the synchronous signal S ₁ from the synchronous counter 23 and the asynchronous signal S ₂ from the asynchronous counter 26 (for example, upper side).・ Pause the movement of the stereoscopic image near bottom dead center).

For example, the synchronous signal S ₁ from the synchronous counter 23 and the asynchronous signal S ₂ from the asynchronous counter 26 are compared, and when the asynchronous signal is input within a predetermined interval from the top / bottom dead center, that is, As shown in FIG. 4, when the input timing interval t of the synchronous signal S ₁ and the asynchronous signal S ₂ is narrower than the predetermined interval T, the asynchronous signal S ₂ is set at the timing after the predetermined interval T from the input timing of the synchronous signal S _1. Fixed,
It is output as the control signal Sc. The asynchronous signal S ₂ input at a timing larger than the predetermined interval T is directly output as the control signal Sc without performing the above processing. Therefore, in terms of image, the movement of the stereoscopic image is temporarily stopped near the top and bottom dead centers.

The color selection circuit 27 creates a drive signal S based on the color change pattern Pc from the pattern memory 25 and the stereoscopic image generation control signal Sc from the enable processing circuit 28. Selective scanner (driver)
Control 29.

The arbitrary waveform generating circuit 30 generates a semicircular pulse signal Sw having a cross section of a sphere in synchronism with the output timing of the control signal Sc from the enable processing circuit 28, and the function generator 31 in the subsequent stage generates the pulse signal Sw. Supply.

The function generator 31 opens the gate according to the control signal from the enable processing circuit Sc to generate a sine wave, and the internal VCA (amplitude control by voltage) function allows the semi-circle from the arbitrary waveform generation circuit 30. The pulse signal Sw is applied to the control terminal to modulate the sine wave. That is, the generation timing of the control signal Sw from the arbitrary waveform generation circuit 29 shifts every cycle due to the shift of the offset value α, whereby the stereoscopic image moving speed in the Z direction (screen moving direction) is controlled. ..

The modulated sine wave signal from the function generator 31 is supplied to the XY offset circuit 32 as the X signal Sx and also input to the phase shift circuit 33. This phase shift circuit 33 obtains a Y signal Sy in which the phase of the X signal Sx is shifted by π / 2 and supplies it to the XY offset circuit 32.

The XY offset circuit 32 adds the offset signal d as a position to each of the input X signal Sx and Y signal Sy, and XY is added based on the added signal Sa.
The scanner (driver) 34 is controlled. This offset signal d is created by the computer 24 every cycle,
It is input to the XY offset circuit 32.

Although not shown in the figure, a sound effect generation circuit for generating a sound effect synchronized with the three-dimensional image of the sphere may be added.

Next, the optical system of the three-dimensional display according to this example will be described with reference to FIG.

As shown in the figure, this optical system includes a laser light source 41, a color selection scanner 29 as a control unit, and XY.
It is composed of a scanner 34 and a selection slit plate 42, a slit focus lens 43 for correction, a collimator lens 44 and a mirror 45.

The laser light source 41 is composed of a red He-Ne laser light source 41a and a green He-Ne laser light source 41b. The laser beams La and Lb from the laser light sources 41a and 41b depend on their respective positional relationships and the mirror 45. Is incident on the color selection scanner 29 with a slight angle. Note that if this angle is too large, it will affect the operating speed of the color selection scanner 29.

On the other hand, the slit focus lens 43 and the selection slit plate 42 are sequentially arranged on the emission side of the color selection scanner 29. When the color selection scanner 29 is operated by the color selection signal S from the color selection circuit 27, the laser beams La and Lb from the color selection scanner 29 are normally prevented from passing through the slit 46 of the selection slit plate 42. First, the slit 46 and the scanner driver are adjusted so that the laser light La or Lb passes through the slit 46. The focus of the slit focus lens 43 is adjusted to the slit 46 to enhance the selectivity.

Next, for example, the arrangement position of the XY scanner 34 is determined so that the laser beam La or Lb which has passed through the slit 46 is incident on the XY scanner 34. Then, the laser beam La scanned by the XY scanner 34
Alternatively, Lb is applied to the screen 3 through the collimator lens 44. The collimator lens 44 is provided in the XY scanner 3 in order to avoid the influence of the position of the screen 3.
4 has the effect of making the diffused laser light La or Lb parallel.

As described above, each of the laser light sources 41a and 41a
By irradiating the laser beams La and Lb from b to the screen 3 which reciprocates linearly by the crank mechanism shown in FIG. 1 by the circuit system and the optical system shown above,
A three-dimensional image of a sphere is displayed in the moving space of the screen 3.

The screen 3 preferably has high reflectance, high diffusivity and high uniformity. That is, if the reflectance is low, the stereoscopic image becomes dark. On the contrary, when the reflectance is high, the entire screen 3 appears to be shining unless attention is paid to the direction of the ambient light, so that it is necessary to take measures such as shading. Further, if the diffusivity is low and non-uniform, the sharpness of the image will differ depending on the direction of the position to be observed. In this example, therefore, white thick paper or the like having a fine surface is used as the screen 3.

As described above, according to this embodiment, the screen 3 is linearly moved back and forth by the crank mechanism including the wheel 4, the rod 5 and the motor 6, so that almost the entire surface of the screen 3 is used as an image display area. can do. Therefore, the difference between the display effective space and the screen movement space can be reduced, and the device itself can be downsized with respect to the display size of the reproduced image.
An observation position having a high degree of freedom, which is close to the displayed reproduced image, is possible. Further, since the screen 3 moves in parallel to the base, there is no need for plane correction of the reproduced image, and the reproduced image has a good visual feeling.

Although the screen 3 is made of white cardboard in the above-described embodiment, the screen 3 may be a semi-transparent thin screen (for example, an acrylic plate) having a diffusive property.
It may be configured with. In this case, it is possible to observe not only from the oblique side of the laser irradiation direction but also from the rear side.

Although the XY scanner 34 is used as the laser beam scanning means, it can be replaced with a high speed scanner such as an AOD (acousto-optic deflector). In this case, improvement in resolution and reproduction of a complicated stereoscopic image are expected.

Further, in the above example, the laser beams La and Lb from the two-color He-Ne laser light sources 41a and 41b are selectively switched and used, but the laser intensity of each of them is set to AOM (acousto-optic modulator). ), The mixed color can be displayed. Also, RGB display is possible by adding and controlling a blue laser.

The laser beam scanning control and color selection control may be performed directly by a computer. In this case, an arbitrary stereoscopic image can be displayed.

In the above-mentioned embodiment, the screen 3 is made to reciprocate linearly by the rod 5 rotatably attached to the wheel 4. However, as shown in FIG. 6, the screen 3 has a V-shaped guide surface. The screen 3 may be slidably attached to the screen rail 51, and the screen 3 may be linearly reciprocated via a crank slider 52 that is rotatably connected to a wheel 4 that is driven by a motor 6. In this figure, the guide rail 7 and the linear slider 8 shown in FIG. 1 are omitted.

According to the other embodiment described above, the screen rail 51 enables smooth linear movement. Also,
Since the rotary motion of the wheel 4 can be directly converted into the reciprocating linear motion of the screen 3 via the crank slider 52, the motion converting means such as the rod 5 is unnecessary. Therefore, the size of the three-dimensional display can be reduced accordingly. Further, since there are no accessories other than the lower part of the screen 3, it is possible to make a three-dimensional display capable of omnidirectional observation with a semitransparent screen.

[0055]

According to the three-dimensional display of the present invention, the difference between the effective display space and the screen movement space can be reduced, and the device itself can be downsized with respect to the display size of the reproduced image. The observation position with a high degree of freedom that is close to the reproduced image being displayed becomes possible, and the need for plane correction of the reproduced image is eliminated, and a good visual feeling of the reproduced image can be realized.

[Brief description of drawings]

FIG. 1A is a plan view showing the configuration of a three-dimensional display according to this embodiment. B is the front view. C is a side view thereof.

FIG. 2 is a block diagram showing a circuit system of the three-dimensional display according to this embodiment.

FIG. 3 is an explanatory diagram showing the principle of the three-dimensional display according to this embodiment.

FIG. 4 is a waveform diagram showing signal processing in the enable processing circuit according to the present embodiment.

FIG. 5 is a configuration diagram showing an optical system of the three-dimensional display according to the present embodiment.

FIG. 6A is a plan view showing the configuration of a three-dimensional display according to another embodiment. B is the front view. C is a side view thereof.

FIG. 7 is a configuration diagram showing a three-dimensional display according to a conventional example.

FIG. 8 is a configuration diagram showing a three-dimensional display according to another conventional example.

[Explanation of symbols]

 1 Leg 2 Base 3 Screen 4 Wheel 5 Rod 6 Motor 7 Guide Rail 8 Linear Slider 9a, 9b Support Plate 11 Gear Box 13 Encoder 14 Origin Sensor

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[Procedure amendment]

[Submission date] September 17, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction content]

The screen 3 preferably has high reflectance, high diffusivity, and high uniformity.
That is, if the reflectance is low, the stereoscopic image becomes dark. However, on the contrary, if the reflectance is high, pay attention to the direction of the ambient light,
Since the entire screen 3 looks shiny, it is necessary to take measures such as shading. Further, if the diffusivity is low and non-uniform, the definition of the image will differ depending on the direction of the observation position. Therefore, in this example, the screen 3 is an aluminum screen.
As a surface treatment of 3, stick white white paper with fine surface
did.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction content]

In the above embodiment, an opaque aluminum plate is used.
Although the screen 3 is made of white cardboard, the screen 3 may be made of, for example, a translucent thin screen having diffusivity (for example, an acrylic plate).
In this case, it is possible to observe not only from the oblique side of the laser irradiation direction but also from the rear side.

[Procedure amendment 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0053

[Correction method] Change

[Correction content]

[0053] In the above embodiment, although the screen 3 so as to reciprocate by a rod 5 which is rotatably mounted to the wheel 4, and other, as shown in FIG. 6, sliding the screen 3 to the scan clean rail 51 The screen 3 may be reciprocally linearly moved via a crank slider 52 that is movably attached and is rotatably connected to the wheel 4 that is rotated by the drive of the motor 6. This
In the case of, the guide rail 7 and the linear motion slider 8 shown in FIG.
Is structurally unnecessary.

Claims (1)

Claim: What is claimed is: 1. A screen having a high-speed moving screen and a drawing means for scanning the screen for drawing, and a moving distance of the screen with an afterimage instantaneously drawn on the screen as a cross section. A three-dimensional display for forming a three-dimensional image in the inside, wherein the screen moves back and forth in a straight line.