JPH0927970A - Video image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a size of a video image to be observed depending on a forward/ backward position of a head of a video image viewer. SOLUTION: A stereoscopic camera 1 is provided with image pickup zoom lenses 12L, 12R, and an HMD 2 is provided with an acceleration sensor 24. An acceleration in the forward/backward direction sensed by the acceleration sensor 24 is integrated twice by an integration circuit 41 to sense a position of a head of a viewer with an HMD 2 mounted thereon and a zoom arithmetic circuit 42 sets a focal distance of the zoom lenses 12L, 12R depending on the forward/backward position of the head. A size of a video image displayed on LCDs 22L, 22R of the HMD 2 is changed depending on the focal distance of the zoom lenses 12L, 12R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying an image, and more particularly to an image display device for changing the size of an image to be observed in accordance with the front and back position of the observer's head. .

[0002]

2. Description of the Related Art In recent years, display devices are becoming widespread which change the displayed image according to the direction of the observer to give the observer a realistic sensation as if they were in the image being displayed. For example, in Japanese Patent Laid-Open No. 3-56923, in a stereoscopic device that displays an image captured by a stereoscopic camera on a head-mounted display (hereinafter, referred to as HMD), the capturing direction of the stereoscopic camera corresponds to the direction of the HMD. It has been proposed to display the image according to the direction of the observer's head by controlling the display. With such a stereoscopic device, an observer can observe an image in a desired direction simply by changing the direction of the head.

It has been widely practiced in the past to use a camera equipped with a zoom lens to manually adjust the focal length of the lens to shoot an image in a desired range.

[0004]

In the above-mentioned stereoscopic device, the image capturing direction changes and the image range displayed on the HMD changes, but it is not possible to set the display image to the size desired by the user. Can not.

It is possible to provide a camera having a zoom lens in this stereoscopic device to make the photographing range variable, but in that case, the focal length of the zoom lens is adjusted by manual operation, and the HMD is used. The wearer needs to be near the camera, which significantly impairs the portability and operability of the HMD.

An object of the present invention is to provide an image display device capable of setting the size of an image to be observed in accordance with the front and back position of the head of an image observer.

[0007]

In order to achieve the above object, according to the present invention, a display device for displaying an image and a head of an observer observing the image displayed on the display device are provided in an image display device. A head position detecting means for detecting the position in the front-back direction,
And a control unit that changes the size of the image observed by the observer according to the position detected by the head position detection unit.

Specifically, a camera having a photographing lens composed of a zoom lens is provided, and an image photographed by this camera is displayed on a display element, and the control means detects the position detected by the head position detecting means. By changing the focal length of the taking lens according to the above, the size of the image displayed on the display element is changed to change the size of the image observed by the observer.

Further, the control means is provided with an eyepiece lens which is composed of a zoom lens and is arranged between the display element and the observer's eye to guide the image light of the display element to the observer's eye. The size of the image observed by the observer may be changed by changing the focal length of the eyepiece according to the position detected by the means.

The control means, when the position detected by the head position detecting means is before the predetermined reference position,
The image observed by the observer is enlarged, and the image observed by the observer is reduced when the position detected by the head position detecting means is behind the reference position.

Further, the control means changes the size of the image observed by the observer in a one-to-one correspondence with the distance between the position detected by the head position detection means and the predetermined reference position. The size of the image observed by the observer is changed.

The control means, when the position detected by the head position detecting means is before the first predetermined position,
The image observed by the observer when the image observed by the observer is continuously enlarged and the position detected by the head position detecting means is behind the second predetermined position behind the first predetermined position. To keep the size of the image observed by the observer unchanged when the position detected by the head position detecting means is between the first predetermined position and the second predetermined position. Good.

A mounting member for mounting on the observer's head is provided.

The head position detecting means includes an acceleration sensor for detecting acceleration and an acceleration detected by the acceleration sensor.
It is composed of an integrating circuit that performs integration, and the acceleration sensor and the display element are fixed to a common support member.

Further, the control means comprises an operation means for outputting to the control means a signal for instructing to change the size of the image observed by the observer when the observer manually operates.
When the signal is received, the size of the image observed by the observer is changed according to the signal regardless of the position detected by the head position detecting means.

Further, the control means is provided with operation means for outputting to the control means a signal instructing to change the size of the image observed by the observer when the observer manually operates the control means. At this time, the size of the image observed by the observer may be changed from the size of the image observed by the observer at that time in accordance with the signal.

[0017]

Operation: A display element for displaying an image, a head position detecting means for detecting the front-back position of the head of an observer observing the image displayed on the display element, and the size of the image observed by the observer. In a video display device configured to include a control unit that changes the position according to the position detected by the head position detection unit, when the observer moves the head back and forth, the position is detected by the head position detection unit. To be done. Since the control means changes the size of the image observed by the observer according to the detected head position, the size of the image observed by the observer is linked to the movement of the observer's head in the front-back direction. Change.

A camera having a photographing lens composed of a zoom lens is provided, and an image photographed by this camera is displayed on the display element, and the control means is responsive to the position detected by the head position detecting means. In the configuration in which the size of the image displayed on the display element is changed by changing the focal length of the image, the size of the image captured by the observer changes depending on the head position. Change. When the control unit sets the focal length of the taking lens short, a wide range is shot, so individual subjects in the image are small, and when the focal length is set long, a narrow range is shot. Grows. Since the image thus captured is displayed on the display element, the observer observes the image whose size changes according to the position of the head.

Further, the control means is provided with an eyepiece lens which is composed of a zoom lens and which is disposed between the display element and the observer's eye and guides the image light of the display element to the observer's eye. By changing the focal length of the eyepiece according to the position detected by the means, in the configuration that changes the size of the image observed by the observer, the size of the image displayed on the display element does not change, The size of the virtual image projected on the observer's eye via the eyepiece changes depending on the position of the observer's head. When the control means sets the focal length of the eyepiece to be short, the wide range of the display element is projected onto the observer's eye to reduce the individual images in the image, and when the focal length is set to long, the display is The individual images are large because a small area of the element is projected onto the eye.

The control means, when the position detected by the head position detecting means is before the predetermined reference position,
When the image observed by the observer is enlarged and the image detected by the head position detecting means is behind the reference position and the image observed by the observer is reduced, the observer moves his head forward. A large image is observed when the head is moved, and a small image is observed when the head is moved backward.

The control means changes the size of the image observed by the observer in a one-to-one correspondence with the distance between the position detected by the head position detection means and a predetermined reference position. When the size of the image observed by the observer is changed,
As the observer moves his head forward or backward,
The size of the observed image changes continuously. That is,
If there is a slight change in the front-back direction in the position of the head, the change is reflected in the size of the image observed by the observer.

The control means, when the position detected by the head position detecting means is before the first predetermined position,
The image observed by the observer when the image observed by the observer is continuously enlarged and the position detected by the head position detecting means is behind the second predetermined position behind the first predetermined position. Is kept small and the size of the image observed by the observer is not changed when the position detected by the head position detecting means is between the first predetermined position and the second predetermined position. Even if the observer moves his / her head within the range between the first predetermined position and the second predetermined position, the size of the observed image does not change. The image continues to expand in a state where the head is positioned further forward than the first predetermined position, and the expansion of the image stops when the head is returned to an intermediate position between the first predetermined position and the second predetermined position. It will be kept at its current size. The image continues to shrink when the head is positioned further back than the second predetermined position, and when the head is returned to an intermediate position between the first predetermined position and the second predetermined position, the reduction of the image stops. It will be kept at its current size.

In the structure provided with the mounting member for mounting on the observer's head, the display device can be mounted on the head and can be used as a so-called HMD.

The head position detecting means uses an acceleration sensor for detecting acceleration and an acceleration detected by the acceleration sensor.
With the integration circuit that integrates twice, the acceleration corresponding to the second derivative of the position is directly detected, the velocity is obtained by integrating this once, and the position is obtained by further integrating the velocity. If the acceleration sensor and the display element are fixed to a common support member, the position of the display element will be detected, and in a display device in which the display element moves with the head, the observer will see a change in the position of the head. The size of the observed image changes.

Further, the control means includes an operation means for outputting to the control means a signal instructing to change the size of the image observed by the observer when the observer manually operates the control means.
When the signal is received, regardless of the position detected by the head position detecting means, the size of the image observed by the observer is changed according to the received signal. The size is specified by a manual operation using the operation means, in addition to being automatically changed according to the change in the position of the head in the front-rear direction. The size of the image observed by the observer is reflected in the size instruction by the manual operation in preference to the front-back position of the head.

Further, the control means is provided with operation means for outputting to the control means a signal instructing to change the size of the image observed by the observer when the observer manually operates the control means. At that time, in the configuration in which the size of the image observed by the observer is changed from the size of the image observed by the observer at that time, the size of the image observed by the observer is It is also designated by manual operation using the operation means. The image observed by the observer, which is set to a size corresponding to the position of the head in the front-rear direction, is further enlarged or reduced by a manual operation to change the size.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A video display device of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of the first embodiment.
The video display device includes a stereoscopic camera 1, an HMD 2, an operation board 3 and a control box 4.

The stereoscopic camera 1 includes a carriage 10 having wheels.
And the left and right cameras 11L and 11R fixed thereon, and can freely move back and forth and change direction to the left and right. Subject Obj with left and right cameras 11L and 11R
By capturing, a left and right video image with parallax is generated. Each of the left and right cameras 11L and 11R is provided with a zoom lens as a photographing lens, and the size of the photographing range can be changed by adjusting the focal length of the zoom lens.

The HMD 2 presents the left and right images photographed by the stereoscopic camera 1 in front of the eyes of the observer wearing the HMD 2, and gives the observer a stereoscopic image of the object Obj. The operation board 3 includes an operation lever 31, an operation dial 32 and a switch 33.
, Which are manually operated by the observer. Control box 4 is stereo camera 1, HMD
2. The stereoscopic camera 1 is connected to the operation board 3 and transmits the video signal from the stereoscopic camera 1 to the HMD 2 and receives the signals from the HMD 2 and the operation board 3 to control the stereoscopic camera 1.

FIG. 2 shows the configuration of each part and the flow of signals. The left and right cameras 11L and 11R of the stereoscopic camera 1 have CCDs 13L and 13R as image pickup devices, respectively, and the CCD 13L and 13R receive light from a subject that passes through the zoom lenses 12L and 12R to perform shooting. . The stereoscopic camera 1 further includes the left and right image processing circuits 14L and 14R, the distance detection circuit 15, the focus adjustment motor 16 for adjusting the focus positions of the zoom lenses 12L and 12R, the zoom lenses 12L and 1L.
A zoom adjusting motor 17 for adjusting the 2R focal length and a motor 18 for moving the carriage are provided.

The CCDs 13L and 13R convert the received light into electric signals and output them to the left and right image processing circuits 14L and 14R. The image processing circuits 14L and 14R convert the signals from the CCDs 13L and 13R into image signals and give them to the HMD 2, and also output the signals of predetermined portions of the CCDs 13L and 13R to the distance detection circuit 15. The distance detection circuit 15 detects the positions of the left and right images of the subject from the left and right signals, and detects the amount of focus shift and the distance to the subject based on the shift of the positions of the left and right images. The distance detection circuit 15 drives the focus adjustment motor 16 in accordance with the detected focus shift amount to adjust the focus positions of the zoom lenses 12L and 12R, and forms the light from the subject on the light receiving surfaces of the CCDs 13L and 13R. .

The zoom adjusting motor 17 is driven by a control signal from the control box 4 to change the focal lengths of the zoom lenses 12L and 12R. The camera moving motor 18 is driven by a control signal from the control box 4 to rotate the wheels to move the stereoscopic camera 1 forward, backward, or turn left or right.

The HMD 2 is a liquid crystal display device (LC
D) 22L, 22R, left and right LCD drive circuits 21L, 21R for driving these, left and right eyepieces 23L, 23R, an acceleration sensor 24, and a horizontal sensor 25. In addition, a mounting member 26 for mounting on the observer's head
(FIG. 1). Video processing circuit 1 of stereoscopic camera 1
Left and right video signals from 4L and 14R are left and right respectively.
The LCD drive circuits 21L and 21R are input to the CD drive circuits 21L and 21R, and the LCD drive circuits 21L and 21R display left and right images carried by the input signals on the left and right LCDs 22L and 22R, respectively.

Eyepieces 23L and 23R are LCD 22L,
The image light of 22R is guided to the left and right eyeballs EL and ER of the observer.
The eyepieces 23L and 23R have fixed focal lengths and LC
The images of D22L and 22R are set to be enlarged and visible. By observing the image through the eyepieces 23L and 23R, the observer observes the virtual image of the image displayed on the LCD 22L and 22R. Left and right eyepieces 2
The optical axes of 3L and 23R are set to be parallel.

The acceleration sensor 24 detects the acceleration caused by the front-back movement of the head of the observer wearing the HMD 2. As the acceleration sensor 24, a piezoresistive acceleration sensor including a piezoresistor having a property that electric resistance changes when strain is applied, and a weight body that causes distortion in the piezoresistance when force is applied To use. The piezo resistance type acceleration sensor outputs a voltage having a magnitude proportional to the magnitude of the applied acceleration, and can detect the magnitude and direction of the acceleration.

The acceleration sensor 24 has an eyepiece lens 23.
It is arranged so as to detect accelerations in the directions along the optical axes of L and 23R. Here, the direction from the observer's eyeballs EL, ER to the eyepieces 23L, 23R is defined as the positive direction, and the opposite direction is defined as the negative direction. The acceleration sensor 24 outputs a positive voltage by positive acceleration and a negative voltage by negative acceleration.

As a result, a positive voltage is output when the observer wearing the HMD 2 starts to move his / her head forward from the front, and a negative voltage is output when the viewer starts moving backward. . In addition, a positive or negative voltage is output when accelerating or decelerating while moving forward. The output when accelerating or decelerating while moving backward is the opposite.

The horizontal sensor 25 detects the tilt of the HMD 2 in the front-rear direction and outputs a signal indicating the direction and size of the tilt. As shown in FIG. 6, the horizontal sensor 25 is composed of an encoder plate 25a having a weight 25c at the bottom and on which a black and white pattern is radially printed, and two photo reflectors 25b each having a light emitting element and a light receiving element. There is. The white portion of the encoder plate 25a reflects light and the black portion absorbs light. The photo reflector 25b emits light toward the encoder plate 25a to detect reflected light, and outputs an H level or L level voltage depending on whether light is detected or not.

The photo reflector 25b is fixed to the HMD 2, and the encoder plate 25a is rotatably attached to the HMD 2 with the center of the black and white pattern as the center of rotation. The rotation axis is set perpendicular to the optical axes of the eyepiece lenses 23L and 23R. When the HMD 2 tilts forward or backward, the photo reflector 25b tilts together with the HMD 2, but the encoder plate 25a having the weight 25c is always kept in a constant direction with respect to the gravity direction. Therefore, the photo reflector 25b rotates with respect to the encoder plate 25a, the light detected by the light receiving element becomes intermittent, and the output voltage of the photo reflector 25b becomes a pulse. The magnitude of the inclination of the HMD 2 is detected from the pulse number. The two photo reflectors 25b are arranged with respect to the encoder plate 25a so that the phases of the output pulses of the two photo reflectors 25 are shifted from each other, and the direction of the inclination of the HMD 2 is detected from the phase difference.

The control box 4 includes an integrating circuit 4
1. Zoom calculation circuit 42 and camera movement calculation circuit 43
Is built-in. The integration circuit 41 includes an acceleration sensor 2
The output voltage of 4 and the output voltage of the horizontal sensor 25 are input. The integrating circuit 41 detects the tilt of the HMD 2 in the front-rear direction based on the output of the horizontal sensor 25, and corrects the output of the acceleration sensor 24 according to the detected tilt to obtain the horizontal acceleration component. As a result, the longitudinal acceleration of the head is obtained regardless of the vertical orientation of the head of the HMD2 wearer.

The integrator circuit 41 integrates the longitudinal acceleration thus obtained twice. The velocity is obtained by integrating the acceleration once, and the moving distance D is obtained by further integrating the velocity. The front-back position of the head at the start of acceleration detection is P0, and the head position at the time of acceleration detection is P
Then, the moving distance D becomes P-P0. When the head is located in front of the acceleration detection start, D has a positive value, and when the head is located behind the acceleration detection start, D has a negative value. The integration circuit 41 outputs a signal representing the movement distance D to the zoom calculation circuit 42.

The zoom calculation circuit 42 determines the size of the shooting range based on the signals from the integration circuit 41 and the operation dial 32 of the operation board 3, and sets the focus to be set for the corresponding zoom lenses 12L and 12R. The distance is calculated and the control signal is sent to the zoom adjusting motor 17 of the stereoscopic camera 1.
Give to. When the zoom calculation circuit 42 determines the shooting range based on the output from the integration circuit 41, the size of the shooting range is linked to the front-back position of the head of the observer wearing the HMD 2. The method of determining the size of the shooting range will be described in detail later.

The camera movement calculation circuit 43 is provided on the operation board 3
In response to a signal from the operation lever 31, the control signal for moving the stereoscopic camera 1 in the front-rear direction or changing the direction is generated and output to the camera movement motor 18.

The operation lever 31 of the operation board 3 operates the movement of the stereoscopic camera 1. The observer tilts the movement operation lever 31 forward, backward, leftward and rightward to move the stereo camera
Can be remotely operated to move and shoot in any direction.

The operation dial 32 is for changing the size of the photographing range. As described above, the output of the zoom operation dial 32 is input to the zoom calculation circuit 42. By rotating the zoom operation dial 32, the observer can manually set the photographing range to a desired size.

The switch 33 is for setting whether or not the size of the photographing range and the front-back position of the head are interlocked. When the interlock switch 33 is ON, the integration circuit 41
Performs acceleration integration and outputs a signal indicating the moving distance D to the zoom calculation circuit 42.

In the image display device thus configured, the size of the photographing range can be set in accordance with the position of the observer's head in the front-back direction, and the size of the photographing range can also be set manually. Can be set. The image captured by the stereoscopic camera 1 is the entire range of the LCD 22L of the HMD2,
Since it is displayed on 22R, changing the size of the photographing range changes the size of the image observed by the observer.

FIG. 7 shows an example of the change in position of the observer's head in the front-back direction. Here, the state where the observer stays at a fixed position, for example, when the observer is sitting on a chair, is shown. (A) is a normal state in which the upper body is upright and faces the front, and (b) is a state in which the head is moved forward by leaning the upper body. (C) is a state in which the head is moved rearward from (a) by pulling the upper body. Examples of display images of the HMD 2 corresponding to the states of (a) to (c) of FIG. 7 are shown in (a) to (c) of FIG. 8, respectively. When the head is in the front, the image of the subject is reduced and the displayed subject image is large, and when the head is in the back, the image of the subject is enlarged and the image is displayed is small. Even when the observer does not stay at a fixed position but moves forward or backward, the head position is detected from the acceleration, and the size of the imaging range changes.

In the present invention, the size of the photographing range is set by the following two methods. In the first method, the size of the photographing range is not changed when the observer's head is in the position within the predetermined range, and the photographing range is narrowed at a constant ratio when the observer's head is in front of the predetermined range. Then, when it is behind the predetermined range, the shooting range is continuously widened at a constant rate. The size setting of the imaging range based on the head position can be corrected by manual operation using the zoom operation dial 32.

The flow of control processing by this method is shown in the flowchart of FIG. After the control is started, the initialization process is first performed. That is, the integration circuit 41 is initialized, and the first integrated value, that is, the head moving speed, and the second integrated value, that is, the head moving distance D are set to 0 (step # 10).
5). At that time, the observer keeps his / her head still so that acceleration does not occur. Further, the focal lengths of the zoom lenses 12L and 12R of the stereoscopic camera 1 are set to predetermined values, and the size of the photographing range is set to the standard size (# 110).

After the initialization processing, steps # 115 to #
Repeat the process cycle up to 165. The cycle of this repetition is set to 50 msec. First, operation board 3
It is determined whether or not the zoom operation dial 32 has been operated (# 115, # 125). When the operation dial 32 is rotated in the direction to instruct zoom up,
When the focal lengths of the zoom lenses 12L and 12R are increased, zoom-up is performed (# 120). When the zoom lenses 12L and 12R are rotated in the direction instructing zoom-down, the focal length is shortened and zoom-down is performed (# 130). The rate of change in the size of the shooting range at this time is set so as to correspond to the rotation amount of the operation dial 32.

When the zoom operation dial 32 is not operated, the setting state of the interlock switch 33 is determined (#
135). # 165 when the interlock switch 33 is OFF
When it is set to ON, the integration circuit 41 integrates the acceleration in the horizontal front-rear direction to detect the moving distance D in the front-rear direction of the head (# 140). Next, the detected moving distance D is set to a predetermined positive value D1.
Compare with When the moving distance D is larger than D1,
When the focal lengths of the zoom lenses 12L and 12R are increased to zoom in (# 150), and D is D1 or less,
The moving distance D is compared with a predetermined negative value D2. When the moving distance D is smaller than D2, the focal length is shortened to zoom down (# 160). D is D
When it is 2 or more, zoom operation is not performed (# 16
5).

In this embodiment, D1 is +15 cm,
D2 is set to -15 cm, and after the control is started, zoom-up is performed when the observer's head moves forward by more than 15 cm, and zoom-down is performed when it moves backward by more than 15 cm. . Head movement distance D is ± 15c
When it is within m, the zoom operation is not performed, and the size of the shooting range at that time is maintained.

The focal lengths of the zoom lenses 12L and 12R are adjusted in steps # 150 and # 160 so that the rate of change in the size of the photographing range is constant.
Specifically, the display image is set to be enlarged or reduced at a rate of 7% per second. Therefore, about 10
In a second, the display image is doubled or reduced to 1/2.

The zoom processing in steps # 120, # 130, # 150, and # 160 is stopped for a predetermined time and then stopped at # 165. Zoom operation dial 32
Is continuously operated, or when the interlocking switch 33 is set to ON and the head is moving forward or backward by more than 15 cm, the cycle of # 115 to # 165 is repeated to capture an image. The range changes continuously. Further, when the zoom operation dial 32 is being operated, steps # 140 to # 160 are not executed,
The shooting range size setting by manual operation has priority over the shooting range size setting linked to the head position.

According to this method, the observer can make the observed image a desired size by simply moving the upper body forward or backward while staying at a fixed position. When the upper body is returned to the normal position, the size of the image is maintained.
Therefore, the size of the observed image can be set by an extremely natural operation. Further, for example, by enlarging or reducing the observation image by moving one step forward or backward, it is possible to observe an image of a desired size by retracting or advancing and returning to the original position. . The rate of change in image size when D1, D2 and the head position exceed D1, D2 is not limited to the above values, and other values may be used to facilitate the use of the HMD2. It can be set to.

A second method of setting the size of the photographing range will be described. According to this method, the size of the photographing range is made to correspond to the moving distance D of the head one to one. The flow of this control processing is shown in the flowchart of FIG.

After the control is started, the initialization process is first performed. The integration circuit 41 is initialized, and the first integrated value, that is, the head moving speed, and the second integrated value, that is, the head moving distance D are set to 0 (step # 205). At that time, the observer keeps his / her head still so that acceleration does not occur. Further, the focal lengths of the zoom lenses 12L and 12R of the stereoscopic camera 1 are set to predetermined values, and the size of the photographing range is set to the standard size (# 210).

After the initialization processing, steps # 215 to #
Repeat the process cycle up to 250. The cycle of this repetition is set to 50 msec. First, the integration circuit 41
The horizontal longitudinal acceleration is integrated by and the amount of change ΔD in the moving distance of the head after the previous cycle is detected (# 21
5). Then, the setting state of the interlocking switch 33 of the operation board 3 is determined (# 220). Interlock switch 33 is ON
When set to, the amount of change ΔD is added to the movement distance D in the previous cycle to update the head movement distance D (# 225). When the interlock switch 33 is OFF, the moving distance D is not updated.

Next, it is determined whether or not the zoom operation dial 32 is operated (# 230, # 240), and when the operation dial 32 is rotated in the direction instructing the zoom-up, the moving distance D is set to a predetermined value. The positive value A of is added (# 235). On the contrary, when the zoom lens is rotated in the direction instructing to zoom down, the predetermined value A is subtracted from the moving distance D (# 245). When the dial 32 is not operated, the moving distance D is not changed.

After that, the zoom lens 12 of the stereoscopic camera 1
Adjust the focal lengths of L and 12R to perform zoom processing (# 2
50). This zoom processing is controlled by the zoom calculation circuit 42. Here, the zoom calculation circuit 42 narrows the shooting range as the movement distance D increases, and the movement distance D
The focal lengths of the zoom lenses 12L and 12R and the movement distances D are made to correspond to each other in a one-to-one manner so that the smaller the value becomes, the wider the photographing range becomes. If the moving distance D is the same as in the previous cycle, the focal length is not changed and the size of the shooting range is not changed.
When the moving distance D is 0, the focal length is step # 210.
This is the value used for initialization in.

The relationship between the focal length and the moving distance D of the head may be set such that the size of the photographing range is a linear function of the moving distance D, or the focal length is the moving distance D. You may set so that it may become a linear function of. Further, any function form may be used as long as the size of the shooting range monotonically increases as the moving distance D increases.

When the size of the photographing range is set by the second method, the observer can observe an image of a size corresponding to the moving distance of the head in the front-back direction. When observing at a fixed position, it is possible to continuously observe an image of a desired size by moving the upper body forward or backward and maintaining that state. Further, by moving forward or backward by an appropriate distance and staying at that position, it is possible to similarly continuously observe an image of a desired size. It is also possible to manually adjust the size of the image to be observed by operating the zoom operation dial 32.

In the control processing according to the first and second methods, the zoom calculation circuit 42 causes the zoom lens 12 to operate.
The focal length adjustment is set only within the focal length settable range of L and 12R, and the stereoscopic camera 1 is not damaged even if the moving distance D of the head becomes any value. Further, the operation board 3 is provided with a changeover switch (not shown), and the first and second control methods can be selected by the changeover operation.

Although a piezoresistive type acceleration sensor is used as the acceleration sensor 24 here, a magnetic sensor utilizing that the current flowing through the quadrature coil changes when the quadrature coil is moved in a magnetic field is used. Good. However, in that case, the use place of the HMD 2 is limited.

The configuration of the video display device of the second embodiment is shown in FIG.
Shown in In this embodiment, the stereoscopic camera 1 includes lenses 71L and 71R having fixed focal lengths as photographing lenses, and the HMD 2 includes zoom lenses 72L and 72R as eyepieces. Accordingly, the HMD 2 has a zoom adjusting motor 73.
The zoom calculation circuit 74 of the control box 4 controls the zoom lens 7 via the zoom adjustment motor 73.
It is set to adjust the focal length of 2L and 72R. The other structure is the same as that of the first embodiment, and the duplicated description will be omitted.

The image display device having this structure is used in the stereoscopic camera 1
Although the size of the shooting range is always constant, and therefore the size of the image displayed on the HMD 2 is also constant, the size of the image given to the observer's eye is changed by changing the focal length of the eyepiece. Can be made. The zoom lenses 72L and 72R are L when the focal length is the shortest.
The entire area of the display panel surface of the CD 21L, 21R is observed, and the central portion of the display panel surface of the LCD 21L, 21R is enlarged and observed as the focal length becomes longer.

In this embodiment as well, the acceleration detected by the acceleration sensor 24 of the HMD 2 is integrated by the integration circuit 41 to detect the moving distance D of the head. The zoom calculation circuit 74 adjusts the focal lengths of the zoom lenses 72L and 72R according to the moving distance D. The control processing of the focal length adjustment is based on the first or second method described in the first embodiment. That is, the size of the observation image is not changed when the front-back position of the observer's head is within the predetermined range, and is continuously increased at a constant rate when the front side of the observer exceeds the predetermined range and exceeds the predetermined range. It is possible to use a method in which the size of the observed image is made to correspond to the moving distance D of the head in a one-to-one manner, and a method in which the size of the observed image is continuously reduced at a constant rate when the vehicle is behind.

Although the present invention has been described above with reference to two embodiments, the video display device of the present invention is not limited to the camera and the HM.
The configuration is not limited to the combination of D. For example, instead of the stereoscopic camera 1 of the first embodiment, a computer may be used to generate left and right images. In that case, the size of the image generated by the computer is calculated by the zoom calculation circuit 42.
Controlled by the output of. Alternatively, a video image generated by a computer may be recorded, and the recorded video image may be displayed on the HMD 2 of the second embodiment to form an observation image of a desired size during observation.

As shown in FIG. 9A, the camera 1a
The present invention can also be implemented in a configuration in which a video image captured by the device is observed on the handheld display device 2a. In this case, for example, the taking lens of the camera 1a is a zoom lens, and the display device 2a is provided with an acceleration sensor and a horizontal sensor. The forward and backward movements of the observer or the bending and stretching of the arm are detected by the acceleration sensor, and the focal length of the camera is adjusted according to the moving distance of the display device 2a in the front-back direction.

The present invention can also be applied to the hand-held video camera 5 as shown in FIG. 9 (b).
The video camera 5 is provided with a photographing zoom lens, an acceleration sensor, a horizontal sensor, a video recording medium and a monitor display element, and the size of the photographing range is changed according to the forward and backward movement of the photographer. In this case, the size of the image displayed on the display element also changes with the recorded image.

Since the display device 2a of FIG. 9A and the video camera 5 of FIG. 9B are hand-held, a tilt in the front-back direction occurs, but in the present invention, the horizontal sensor detects the magnitude and direction of the tilt. To do. As a result, the component of the gravitational acceleration can be removed from the acceleration detected by the acceleration sensor to detect the horizontal acceleration. Therefore, the size of the observed image can be set based on the true amount of forward and backward movement of the display device 2a and the video camera 5.

[0073]

According to the image display device of the present invention, the observer can easily change the size of the image to be observed by merely moving the head back and forth. Sitting on a chair in a natural posture or standing upright in a natural posture, leaning forward from these postures with the head positioned forward, and pulling the upper body to move the head Since the size of the image to be observed can be changed according to each state when the is positioned rearward, the observer can change the size of the image to be observed simply by changing the posture naturally. You can do it, and you don't need to be particularly aware of enlarging or reducing the image.

Further, as the observer moves forward or backward, the position of the head changes, and the size of the image changes. Therefore, when observing an image while walking, like a display device for a monitor such as a video camera, the size of the image to be observed can be changed according to the distance moved forward or backward.

According to the image display device of the second aspect, since the width of the photographing range varies depending on the front and back position of the head of the observer, the above effect is surely achieved even if the display range of the display element is constant. It is possible to prevent deterioration of the image quality that is exhibited and the observed image becomes rough.

According to the image display device of claim 3, when the virtual image of the image on the display element is projected onto the observer's eye,
Since the size of the virtual image changes depending on the front-back position of the observer's head, the above-described effect is reliably exhibited even when the range of the image displayed on the display element is constant. Furthermore, when a plurality of observers use the image display devices to observe the same image, the individual observer does not affect the other observers at all and displays the image of the desired size. Can be observed.

In the image display device according to the fourth aspect, a large image can be observed when the head position is in the front, and a small image can be observed when the head position is in the rear. Enlargement and reduction correspond to the observer's natural movement. That is, the image to be observed is enlarged by the change in the posture of leaning forward or the change of the position of moving forward, and the image to be observed is reduced by the change of the posture of pulling the upper body or the change in position. Therefore, extremely natural image observation can be performed.

In the image display device according to the fifth aspect, since the observed image has a size corresponding to the distance between the position of the head and the reference position, the observer can change the posture of leaning forward or backward. An image of a desired size can be easily observed by adjusting the degree or the walking distance of forward or backward.

According to the image display device of the sixth aspect, the observer is in a range between the first predetermined position and the second predetermined position,
The head can be moved freely without changing the size of the image to be observed. When you want to observe a large image at a certain position, you can lean forward so that your head is positioned ahead of the first predetermined position. In this state, the image will gradually become larger, and the image will be at the desired size. At that time, the head may be returned between the first predetermined position and the second predetermined position. On the contrary, when a small image is desired to be observed, the upper body may be pulled so that the head is located rearward of the second predetermined position. In this state, the image gradually becomes smaller, and thus the desired size is obtained. At this time, the head is moved to the first predetermined position and the second position.
It is sufficient to return it between the predetermined positions of. Therefore, an image of a desired size can be observed in a comfortable posture. Even when observing an image while walking, the image can be observed in a certain size in a free place within a range not exceeding the first and second predetermined positions.

In the image display device according to the seventh aspect, the image display device can be used as an HMD and the size of the image to be observed can be set by the position of the head in the front-back direction without manual operation, so that both hands can be freely used for other purposes. Can be used, H
It is possible to fully utilize the portability and operability that are the features of MD.

According to the image display device of the eighth aspect, since the position of the head in the front-rear direction is detected by integrating the detected acceleration, it is not necessary to provide means for detecting the head position outside. . Therefore, a small-sized image display device can be obtained, and the place of use is not limited, and the device can be used at any place, which is particularly effective when the observer moves by walking or the like. Further, since the acceleration sensor moves together with the display element, it is not only a display device of a type worn on the head but also a display device of a type that an observer holds in front of his / her hand and observes an image while walking. Even at this time, the size of the image to be observed can be changed according to the change in the position of the head.

In the image display device according to the ninth aspect, the size of the image to be observed can be set by the manual operation, and the designation by the manual operation is set to the size of the image to be observed with priority over the position of the head. Since it is reflected, the observer can observe an image of a desired size in any posture and place.
In particular, it is effective when the position of the observer is limited or when it is desired to observe an image having a size exceeding the range where the observer can lean forward or backward.

In the image display device of the tenth aspect, the size of the image to be observed can be changed manually from the size set according to the position of the head. Therefore, even when there is a limit to the walking range and the range where the person leans forward and backward, the observer can observe an image of a desired size.

[Brief description of drawings]

FIG. 1 is an external view showing a schematic configuration of a video display device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a video display device according to a first embodiment.

FIG. 3 is a block diagram showing a configuration of a video display device according to a second embodiment.

FIG. 4 is a flowchart showing a first method of controlling the size of an observed image according to the present invention.

FIG. 5 is a flowchart showing a second method of controlling the size of an observed image according to the present invention.

FIG. 6 is a diagram showing a configuration of a horizontal sensor.

FIG. 7 is a diagram showing movement of the observer's upper body in the front-back direction.

FIG. 8 is a diagram showing an example of changes in the size of an observed image.

FIG. 9 is an external view showing another configuration of the video display device of the present invention.

[Explanation of symbols]

1 Stereoscopic camera 2 HMD 3 Operation board 4 Control box 11L, 11R Camera 12L, 12R Zoom lens (shooting lens) 13L, 13R CCD 14L, 14R Image processing circuit 15 Distance detection circuit 16 Focus adjustment motor 17 Zoom adjustment motor 18 Camera movement motor 21L, 21R LCD drive circuit 22L, 22R LCD (display element) 23L, 23R eyepiece lens 24 acceleration sensor (head position detecting means) 25 horizontal sensor 25a encoder plate 25b photoreflector 26 mounting member 31 moving operation lever 32 zoom operation dial ( Operation means) 33 Interlocking switch 41 Integration circuit (head position detection means) 42 Zoom calculation circuit (control means) 43 Camera movement calculation circuit 71L, 71R Shooting lens 72L, 72R Zoom lens (eyepiece lens) 3 zoom adjustment motor 74 zoom operation circuit (control means)

Claims (10)

[Claims] 1. A display element for displaying an image, a head position detecting means for detecting a position in the front-rear direction of a head of an observer who observes the image displayed on the display element, and the observer observes the image. An image display device, comprising: a control unit that changes the size of the image according to the position detected by the head position detection unit. 2. A camera having a photographing lens composed of a zoom lens is provided, wherein the display element displays an image photographed by the camera, and the control means is located at a position detected by the head position detecting means. The size of the image displayed on the display element is changed by changing the focal length of the photographing lens in accordance therewith, thereby changing the size of the image observed by the observer. The image display device described. 3. An eyepiece lens comprising a zoom lens, the eyepiece lens being disposed between the display element and an observer's eye to guide the image light of the display element to the observer's eye. The image display according to claim 1, wherein the size of the image observed by the observer is changed by changing the focal length of the eyepiece lens according to the position detected by the head position detecting means. apparatus. 4. The head means for detecting a head position, wherein the controller enlarges an image observed by an observer when the position detected by the head position detector is before a predetermined reference position. The image display device according to claim 1, wherein an image observed by an observer is reduced when the position detected by is behind the reference position. 5. The control means changes the size of the image observed by the observer in a one-to-one correspondence with the distance between the position detected by the head position detection means and a predetermined reference position. The image display device according to claim 1, wherein the size of the image observed by the observer is changed. 6. The control means continues to increase an image observed by an observer when the position detected by the head position detecting means is before the first predetermined position, and the head position is determined. When the position detected by the detection means is behind the second predetermined position behind the first predetermined position, the image observed by the observer is kept small and detected by the head position detection means. The image display device according to claim 1, wherein the size of an image observed by an observer is not changed when the determined position is between the first predetermined position and the second predetermined position. . 7. The image display device according to claim 1, further comprising a mounting member for mounting on an observer's head. 8. The head position detecting means comprises an acceleration sensor for detecting acceleration and an integrating circuit for integrating twice the acceleration detected by the acceleration sensor, and the acceleration sensor and the display element are a common support member. The image display device according to claim 1, wherein the image display device is fixed to the image display device. 9. When the observer performs a manual operation, the observer is provided with operation means for outputting a signal instructing to change the size of the image observed by the observer, and the control means is adapted to output the signal. The image display according to claim 1, wherein when received, the size of the image observed by the observer is changed according to the signal regardless of the position detected by the head position detecting means. apparatus. 10. An operation means for outputting to the control means a signal instructing to change the size of an image observed by the observer when the observer manually operates the control means, and the control means outputs the signal. The image according to claim 1, wherein when received, the size of the image observed by the observer is changed from the size of the image observed by the observer at that time according to the signal. Display device.