JP2001016619A - Image pickup device, its convergence distance decision method, storage medium and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device that automates convergence control so as to relieve a load of a photographer at photographing and to photograph a natural stereoscopic video image. SOLUTION: When a viewer inputs a screen size S and a view distance L (S11), the image pickup device obtains values Ft, Fo within a permissible fusional image range on the basis of the screen size S and a view distance L, an image size C, a base length l, and focal distance (f) through a geometrical calculation and obtains distances Zt, Zo within before-/after-photographing available ranges with respect to a convergence distance on the basis of the obtained values Ft, Fo within the permissible fusional image range (S15). The device obtains an object distance range form object distances Z1, Z2, Z3 detected by a range finding unit 8 (S17), and the device compares the distances Zt, Zo within the before-/after-photographing available ranges with object distances Zmin, Zmax and decides the convergence distance Y so that the object distances Zmin, Zmax are set within the photographing available range (Zt, Zo) (S18). Mirrors 107, 112 are driven until a mirror angle corresponding to the decided convergence distance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device for capturing left and right parallax images, a method of determining a convergence distance, a storage medium, and an optical device.

[0002]

2. Description of the Related Art In recent years, various types of stereoscopic image display devices have been proposed for displaying images taken by an image pickup device such as a video camera or an electronic still camera of this type. Conventionally, in a stereoscopic image display device in which left and right parallax images are displayed on a monitor, and an observer observes them with liquid crystal shutter glasses, the state of the left and right liquid crystals of the liquid crystal shutter glasses is synchronized with a video signal. Even if the image for the right eye and the image for the left eye are displayed alternately on the monitor, the observer always observes the image for the right eye for the right eye and the image for the left eye for the left eye. And an image with depth is observed. In other words, while the right-eye image is displayed on the monitor, the right liquid crystal is transmitted and the left liquid crystal is not transmitted, while while the left-eye image is displayed on the monitor. The liquid crystal for the right eye is non-transmitting, and the liquid crystal for the left eye is transmitting.

In recent years, head-mounted and eyeglass-type displays, so-called head-mounted displays, have been developed. In these displays, similarly, the image for the right eye is displayed on the right eye and the image for the left eye is displayed. By displaying an image selectively with the left eye, it is possible to observe a stereoscopic image with depth.

Further, by combining a liquid crystal display with a lenticular sheet having a predetermined pitch or a mask having openings and non-openings formed in a predetermined pattern, directivity is given to the light from the liquid crystal display. By matching the image pattern to be displayed on the display, the right eye can see the right eye image, the left eye can see the left eye image, and the observer can see the deep image. You.

Conventionally, these display images have been taken by a twin-lens camera having two lenses.
Was common. A camera that does not require two lenses has also been proposed (Japanese Patent Publication No. 8-27499,
Shooting device for stereoscopic television). This camera has two liquid crystal shutters, a total reflection mirror and a half mirror, and alternately captures left and right parallax images through one lens.

In a twin-lens camera, a lens that captures left and right images in a time-division manner needs to adjust the parallax of the left and right images at the time of shooting, that is, so-called convergence adjustment. It was common to be done.

[0007]

However, the above-mentioned conventional twin-lens camera shoots an image for the right eye and an image for the left eye for each lens. Differences, for example, magnification, deviation of the optical axis, color, brightness, distortion, differences in performance such as image plane tilt,
When it occurs between two lenses, when observing a stereoscopic image,
Since you may feel tired or unable to fuse, it is necessary to increase the precision of the parts to match the performance of both lenses, or if the performance is not achieved only with the precision of the parts, adjustment will be required, Furthermore, special measures such as electrical correction of the image had to be taken to absorb the difference in performance.

Further, in the case of a zoom lens, it is necessary to interlock the zooming operation of the two right and left lenses in a state in which these performances are matched at the time of zooming, so that the cost is high, the production is troublesome, and the mass productivity is reduced. It was poor.

[0009] Further, in order to observe an image photographed by a twin-lens camera, two monitors are required as they are, which is not practical. Further, when recording these two videos, it is necessary to record the two video signals in a synchronized state, and a special recording device for this is required.

In order to avoid this, it has been considered to convert two video signals into one video signal. For this purpose, a special method for alternately displaying and recording left and right parallax images is considered. Needed a converter.

Therefore, the twin-lens camera is very large and expensive because the camera itself is larger than a normal single-lens camera and the entire system requires special equipment as described above. The lack of mobility made it difficult to spread the word to the world.

On the other hand, in the camera proposed in Japanese Patent Publication No. Hei 8-27499, the optical paths of the right and left parallax images are coupled to each other by a half mirror and guided to a lens. There is a problem that the amount of light is halved when an image is incident. Further, in the configuration of this camera, the optical path lengths of the left and right parallax images are different in principle, resulting in a difference in magnification between the left and right images. This means
When observing an image photographed with this configuration, there is a problem in that it causes fatigue, cannot be fused, and cannot be stereoscopically viewed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small, low-cost imaging device capable of capturing high-quality stereoscopic images with high mobility and expandability, a method of determining a convergence distance, a storage medium, and an optical device. I do.

Further, the present invention provides an image pickup apparatus capable of reducing a burden on a photographer at the time of photographing and automating a natural stereoscopic image by automating convergence control, a method for determining a convergence distance, a storage medium, and a storage medium. It is another object to provide an optical device.

[0015]

According to a first aspect of the present invention, there is provided an image pickup apparatus comprising: an image pickup means for picking up an image; and an optical system for forming an image on the image pickup means. A pair of shutters arranged symmetrically with respect to the optical axis of the optical system and transmitting the left and right parallax images in a time-division manner, and arranged symmetrically with respect to the optical axis of the optical system and transmitting through the pair of shutters. A pair of mirrors for reflecting the left and right parallax images and guiding the parallax images to the optical system, display means for displaying an image taken by the imaging means, input means for inputting information relating to the display means, Convergence distance determining means for determining the convergence distance between the pair of mirrors based on the information obtained, and driving means for driving the pair of mirrors so that the convergence distance is determined.

According to a second aspect of the present invention, in the imaging apparatus of the first aspect, the imaging apparatus comprises a detachable optical unit and a photographing unit, wherein the optical unit includes the pair of shutters, the pair of mirrors, and the optical unit. A photographing unit including the image pickup unit and the display unit.

According to a third aspect of the present invention, there is provided the imaging apparatus according to the first or second aspect, further comprising subject distance information detecting means for detecting a subject distance, wherein the information on the display means includes a screen size, The viewing distance from the approximate position of the observer's eye to the display position, wherein the convergence distance determining means is the screen size, the viewing distance, the size of the imaging means, the focal length of the optical system, the parallax image. Calculating means for calculating a photographable range based on the optical axis interval and the human pupil interval, and determining the convergence distance based on the calculated photographable range and the detected subject distance. I do.

In the image pickup apparatus according to the fourth aspect, the third aspect is provided.
The convergence distance determining means may determine the convergence distance such that at least a part of the detected subject distance is included in the calculated photographable range.

In the image pickup apparatus according to the fifth aspect, the first aspect is as follows.
The input device may include a display screen and a switch for inputting information displayed on the display screen.

In the image pickup apparatus according to the sixth aspect, the fifth aspect is provided.
In the imaging apparatus according to the above, the display screen may also be used as a screen of the display unit on which an image captured by the imaging unit is displayed.

According to a seventh aspect of the present invention, there is provided a method of determining a convergence distance of an image pickup apparatus, wherein a camera for photographing an image, an optical system for forming an image on the camera, and a symmetrical optical axis of the optical system. A pair of shutters that transmit the left and right parallax images in a time-division manner, and are disposed symmetrically with respect to the optical axis of the optical system, and reflect the left and right parallax images transmitted through the pair of shutters to the optical system. A convergence distance determination of an imaging device that includes a pair of guiding mirrors, a monitor that displays an image captured by the camera, and a distance measurement unit that detects a subject distance, and drives the pair of mirrors to the determined convergence distance. Detecting a subject distance, inputting a screen size and a viewing distance from an approximate position of an observer's eye to a display position as information related to the monitor; and Calculating the photographable range based on the size and viewing distance, the monitor size, the focal length of the optical system, the optical axis interval of the parallax image and the human pupil interval, and the calculated photographable range and Determining the convergence distance based on the detected subject distance.

A storage medium according to claim 8 is a camera for taking an image, an optical system for forming an image on the camera,
A pair of shutters arranged symmetrically with respect to the optical axis of the optical system and transmitting the left and right parallax images in a time-division manner, and arranged symmetrically with respect to the optical axis of the optical system and transmitted through the pair of shutters. A pair of mirrors that reflect the left and right parallax images and guide the optical system to the optical system, a monitor that displays an image captured by the camera, and a distance measurement unit that detects a subject distance, including a determined convergence distance The storage medium, which is executed by a computer that controls an imaging device that drives the pair of mirrors and stores a program that determines the convergence distance, includes a procedure for detecting a subject distance, and information about the monitor, Inputting the screen size and the viewing distance from the approximate position of the observer's eye to the display position, and inputting the screen size and the viewing distance; A procedure for calculating a photographable range based on a monitor size, a focal length of the optical system, an optical axis interval of the parallax image and a human pupil interval, and calculating the photographable range and the detected subject distance. Based on
Determining the convergence distance.

An optical device according to a ninth aspect is an optical system for forming an image on the image pickup means, and a pair of optical systems arranged symmetrically with respect to the optical axis of the optical system and transmitting the left and right parallax images in a time-division manner. And a pair of mirrors arranged symmetrically with respect to the optical axis of the optical system, for reflecting left and right parallax images transmitted through the pair of shutters and guiding the parallax images to the optical system, Display means for displaying the displayed image, input means for inputting information about the display means, convergence distance determination means for determining the convergence distance of the pair of mirrors based on the input information, and the determined convergence Driving means for driving the pair of mirrors so as to be at a distance.

The optical device according to the tenth aspect is the ninth aspect.
The optical device according to claim 1, further comprising subject distance information detecting means for detecting a subject distance, wherein the information about the display means is a screen size, a viewing distance from a substantially approximate position of an observer's eye to a display position, and the convergence. Distance determining means, the screen size, the viewing distance, the size of the imaging means,
The focal length of the optical system, based on the optical axis interval of the parallax image and the human pupil interval, comprising a calculating means for calculating a photographable range, based on the calculated photographable range and the detected subject distance, The convergence distance is determined.

In the optical device according to the eleventh aspect, in the optical device according to the tenth aspect, the convergence distance determining means includes at least a part of the detected subject distance within the calculated photographable range. In such a case, the convergence distance is determined.

According to a twelfth aspect of the present invention, in the optical device according to the ninth aspect, the input means has a display screen and a switch for inputting information displayed on the display screen.

According to a thirteenth aspect of the present invention, in the optical device according to the twelfth aspect, the display screen also serves as a screen of the display means on which an image photographed by the imaging means is displayed. I do.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an imaging apparatus, a convergence distance determining method thereof, a storage medium and an optical apparatus according to the present invention will be described. The imaging device according to the present embodiment is applied to a stereoscopic video imaging device. FIG. 1 is a diagram showing a basic configuration of a stereoscopic video photographing apparatus. In the figure, reference numeral 1 denotes an interchangeable lens unit (simply referred to as a lens unit),
0, a liquid crystal control circuit 123, an IG driver 124, motor drivers 125 and 126, a lens microcomputer 127 for controlling them, a video input terminal (Line in) 128,
Input unit 21, standardized lens mount (not shown)
And a contact block (not shown).

Reference numeral 2 denotes a camera body, and a three-plate type imaging unit 20
0 and the imaging elements 201 and 20 constituting the imaging unit 200
Amplifiers 204, 20 connected corresponding to 2, 203
5, 206; a signal processing circuit 207 connected to the amplifiers 204, 205, 206; a camera microcomputer 208 connected to the signal processing circuit 207;
And a video output terminal (Line out) 209 connected to a zoom switch and an AF switch (not shown)
, An electronic viewfinder (EVF) 3, a standardized camera mount (not shown), and a contact block (not shown).

This camera mount has a structure detachable from the lens mount of the lens unit 1. By attaching the lens mount to the camera mount, the contact block of the lens unit 1 and the contact block of the camera body 2 are brought into contact with each other, and the signals indicated by arrow 7 in the figure can be exchanged.

That is, the lens microcomputer 127 and the camera microcomputer 208 communicate predetermined data according to a predetermined protocol. The power supply from the camera body 2 to the lens unit 1 is performed via the contact blocks of the camera body 2 and the lens unit 1, respectively.

Reference numeral 100 denotes a photographing optical system;
Reference numeral 2 denotes a total reflection mirror that is rotatable around a predetermined axis, and is driven by driving units 9 and 11, respectively. In the present embodiment, a stepping motor is used for the driving units 9 and 11. The driving units 9 and 11 are not limited to the step motor, but may be a DC motor or an ultrasonic motor.

Drivers 10 and 12 receive control signals from the lens microcomputer 127 and send drive signals to the drive units (step motors) 9 and 11. Lens microcomputer 127
Detects the rotation angle of the step motor by counting the number of steps of the step motors 9 and 11. When a DC motor or an ultrasonic motor is used, the rotation angle of the mirror can be detected by separately providing an encoder for detecting the rotation angle of the mirror. In addition, by driving the step motors 9 and 10, the mirrors 107 and 112 rotate around a predetermined axis to change the directions of the optical axes 4 and 5.
In the present embodiment, the rotation center of the mirror is the optical axis 4,
A rotation axis is a straight line passing through the vicinity of the point where the mirror 5 and the mirrors 107 and 112 intersect and perpendicular to the paper surface, that is, the vertical direction of the screen. Further, the optical axes 4 and 5 of the left and right images are substantially in the same plane, and substantially intersect at a predetermined position including the point at infinity (hereinafter, referred to as “infinity”).
Congestion).

As described above, the mirrors 107 and 112 are rotatable around a predetermined axis, and the positions of convergence can be changed by rotating each other. It is indispensable to change the convergence position in order to capture a natural stereoscopic image.

The optical axes 4, 5 and the mirrors 107, 112
In the present embodiment, the interval between the intersections with the reflection surface (hereinafter, referred to as a base line length) is not particularly limited, but is around 63 mm. This is set near 63 mm, which is the average human pupil distance, in order to capture a natural stereoscopic image.

Reference numeral 8 denotes a subject distance detection unit (distance measuring unit) for measuring a distance by triangulation. FIG.
FIG. 4 is a diagram showing a measurement principle by triangulation. The distance measuring unit 8 includes a light emitting lens, a light receiving lens, and an IR
It has an ED, a line sensor (sensor array) having a plurality of light receiving units in a line, and a calculating unit (not shown) for calculating an object distance L by receiving an output from the line sensor. I
The light emitted from the RED is reflected by the subject, collected by the light receiving lens L and the light receiving lens R, and forms an image on the line sensor L and the line sensor R. At this time, depending on where on each line sensor the light is received, that is, by calculating the difference (X1-Xr), the known light receiving lenses L,
The focal length fj of R and the distance between the light receiving lenses L and R (base line length)
From B, the subject distance L can be obtained by the calculation unit.

In the present embodiment, the subject distance information is calculated by triangulation. However, the subject distance information can be obtained from the position information of each lens group of the photographing optical system. May be obtained.

Reference numerals 108, 113, and 115 denote one or more lens units having a negative refractive power. 116, 11
Reference numerals 7 and 119 denote one or more lens units having a positive refractive power. A prism 110 has a total reflection mirror surface on the surface 109 and the surface 111. 101, 103, 10
Reference numerals 4 and 106 denote polarizing plates. 102 and 105 are liquid crystal elements having a shutter function.

By combining the polarizing plates 101 and 103 with the liquid crystal element 102 and applying an electric field to the liquid crystal, the luminous flux is transmitted.
It becomes a state of non-transmission. The same applies to the case where the polarizing plates 104 and 106 and the liquid crystal element 105 are combined. In this embodiment, FLC (ferroelectric liquid crystal) is used as a liquid crystal element, but the present invention is not limited to this, and TN, S
It is also possible to use liquid crystal such as TN. Further, the polarizing plates 101 and 103 and the polarizing plates 104 and 106 may be fixed to the liquid crystal elements 102 and 105 by bonding or the like, or may be separately arranged.

Reference numeral 114 denotes a stop as a light amount adjusting means. In the present embodiment, by disposing the stop on the object side,
It has been realized to reduce the effective light flux system of the front lens.
120 is an IG meter, 121 and 122 are step motors. Reference numerals 108, 113, and 115 are fixed lens groups. Reference numeral 116 denotes a variator lens. 117 is a compensator lens. Reference numeral 119 denotes a movable lens group having a focusing function.

In this embodiment, the lenses 116 and 117 are movably arranged in the optical axis direction in a mechanically interlocked manner by a cam cylinder 118.
18 is rotationally driven. The method of driving the lenses 116 and 117 is not limited to this, and the lenses 116 and 117 may be individually driven without using a cam barrel. The step motor 122 is connected to the lens 11
9 is driven. These drives are not limited to step motors, but may be electromagnetic motors such as DC motors, fixed motors such as ultrasonic motors, solid motors such as ultrasonic motors, and electrostatic motors. Not done.

The positions of the lenses 116, 117, and 119 in the optical axis direction are detected by counting the driving pulses for driving the step motor, thereby converting the positions of the lenses. still,
The means for detecting the position of the lens is not particularly limited to the one that counts the driving pulses of the step motor,
An optical type such as a variable resistance type, a capacitance type, a PSD (position detecting element), and an IRED (infrared light emitting diode) may be used.

The IG meter 120 controls the light amount by driving the diaphragm 114. Further, an ND filter (not shown) is arranged in the photographing optical system 1. The zoom type is a rear focus zoom type. That is, the lenses 116, 1
Reference numerals 17 and 119 denote lens microcomputers 127 when zooming.
Thus, the driving is controlled in conjunction with a predetermined relationship. still,
The zoom type is not particularly limited to this.

On the other hand, in the camera body 2, the signal processing circuit 207 has a camera signal processing circuit 207a and an AF signal processing circuit 207b. Camera signal processing circuit 20
7a is output as a video signal, and the output of the camera microcomputer 208 is output to the lens microcomputer 12 of the lens unit 1.
7 is supplied.

In the three-plate imaging unit 200, a first prism,
The incident light imaged by the imaging optical system 100 is color-separated into three primary colors by a second prism and a third prism (hereinafter, referred to as color separation prisms). The red component of the three primary colors is imaged on the image sensor 201, and the green component is the image of the image sensor 20.
2, and the blue component is formed on the image sensor 203. The subject images formed on the respective image pickup devices 201, 202, and 203 are each subjected to photoelectric conversion and supplied as electric signals to the corresponding amplifiers 204, 205, and 206.

Each electric signal amplified to an optimum signal level by each of the amplifiers 204, 205, and 206 is converted into a standard television signal by a camera signal processor 207a and output as a video signal. It is supplied to the processing circuit 207b. AF signal processing circuit 20
7b generates an AF evaluation value signal using the signals of the three primary colors from the amplifiers 204, 205, and 206.

The camera microcomputer 208 executes the AF signal processing circuit 20 by using a data read program stored in advance.
The AF evaluation value signal generated in 7b is read and transferred to the lens microcomputer 127. The lens microcomputer 127 drives and controls the lens 119 based on the transferred AF evaluation value signal to perform focusing.

FIG. 3 is a block diagram showing the electrical configuration of the lens microcomputer 127. The lens microcomputer 127 includes a well-known CPU 151, a ROM 152, a RAM 153, an I / O
O interface (IF) 154, communication I / F15
5, a configuration in which a counter 156 and the like are connected via a bus 157.

Next, the left and right parallax images are captured by the image sensor 200.
Will be described. Video output terminal 209 of camera body 2 and video input terminal 1 of lens unit 1
28 is connected by a cable 129, and a captured video signal is input to the liquid crystal control circuit 123.

The video signal is an NTSC interlace signal. Therefore, 60 video signals are output per second. These video signals are synchronized by a vertical synchronization signal and a horizontal synchronization signal. The vertical synchronizing signal is superimposed on the head of the 60 video signals. FIG. 4 is a timing chart showing signal waveforms of various parts of the liquid crystal control circuit 123. FIG. 5 is a block diagram showing a configuration of the liquid crystal control circuit 123.

The liquid crystal control circuit 123 separates a vertical synchronizing signal every 1/60 second from the input video signal. Further, an odd / even signal for determining whether the field is an odd field or an even field is generated from the input video signal.

Whether the odd field or the even field is distinguished is that the vertical synchronizing signal coincides with the edge of the horizontal synchronizing signal (odd field) or is delayed by 1 / 2H (H is the horizontal synchronizing cycle) (even field). Can be done with

Next, a left-eye liquid crystal drive signal and a right-eye liquid crystal drive signal are generated and output from the vertical synchronization signal and the odd / even signals, respectively.

The left and right liquid crystal drive signals are drive signals for picking up left and right parallax images by the image pickup unit (CCD) 200 alternately in a time-sharing manner. The liquid crystal shutter corresponding to the parallax image is in a transmissive state, and the other liquid crystal shutter is in a non-transmissive state.

As shown in FIG. 4, if the liquid crystal for the right eye is opaque when the positive voltage is applied and the light is opaque when the negative voltage is applied, the left eye is opaque while the liquid crystal for the right eye is opaque. A liquid crystal driving signal is supplied to the liquid crystals 102 and 105 so that the liquid crystal for transmission is transmitted and the liquid crystal for right eye is not transmitted while the liquid crystal for right eye is transmitted.

The liquid crystal 1 is driven alternately in this manner.
02 is non-transparent, an image transmitted through the liquid crystal 105 is captured by the imaging unit (CCD) 200, and while the liquid crystal 105 is non-transparent, an image transmitted through the liquid crystal 102 is captured by the imaging unit (CCD) 20.
0 is imaged.

In this embodiment, since even / odd field signals are included as information, a video signal for the left eye is captured in the odd field, and a video signal for the right eye is captured in the even field. By such an operation, the parallax image for the left eye and the parallax image for the right eye are alternately picked up by the image pickup unit (CCD) 200 for 30 images per second, 30 images per second.

Since the timing of reading from the image pickup section (CCD) 200 is also synchronized with this, the parallax image for the left eye and the parallax image for the right eye are alternately converted into a video signal as a video signal.
7 is output.

The method of vertical synchronization separation and the method of field detection are known techniques, and are not particularly limited. In the present embodiment, the video signal is input to the liquid crystal control circuit 123 via the cable 129. However, in the data communication between the lens microcomputer 127 and the camera microcomputer 208, the vertical synchronization signal information and the even / odd field information are transmitted. You may communicate.

In FIG. 4, the right-eye liquid crystal drive signal and the left-eye liquid crystal drive signal fall and rise in synchronization with the fall of the vertical synchronizing signal. The falling and rising of the liquid crystal driving signal and the liquid crystal driving signal for the left eye correspond to the vertical blanking period (20) of the video signal.
H).

In this embodiment, the left-eye video signal is picked up in the odd-numbered field and the right-eye video signal is picked up in the even-numbered field. , And a left-eye video signal may be captured in the even field.

Further, in this embodiment, a monocular EVF is used. Since the left and right parallax images are alternately displayed in the video signal in time series, the left and right parallax images are observed as a double image by the EVF. This can be avoided by displaying the left and right parallax images on a separate display unit from the time-division video signal. For example, it is realized by using a so-called HMD having this function. Therefore, an HMD may be used as the EVF. Further, a function of displaying only one side signal may be added to the EVF.

FIG. 6 is a flowchart showing the congestion control processing procedure. This processing program is executed by the lens microcomputer 12.
7, and is also executed by the CPU 151 in the lens microcomputer 127.

When the lens microcomputer 127 starts the convergence control, the lens microcomputer 127 determines the convergence distance of the mirror only when the change in the subject distance is equal to or more than a predetermined value and for a predetermined time or more in order to eliminate the influence of noise or the like. Then, the following processing is performed.

That is, the main subject distance Lk is detected by the distance measuring unit 8 (step S1). It is determined whether or not the absolute value of the difference between the detected main subject distance Lk and the previously updated main subject distance Lref is larger than a predetermined value ΔL (step S2). Here, the predetermined value ΔL is set to a value within a range of a subject distance that can be fused without difficulty due to the current convergence.

The absolute value of the difference between the main subject distances is a predetermined value ΔL.
If the following is true, that is, if the detected change in the main subject distance is small, the counter 1 in the lens microcomputer 127
The value k of 56 is reset to "1" (step S3), and the process returns to step S1. Here, the value k of the counter is
It is used to measure the time during which a large change in subject distance continues.

On the other hand, when the absolute value of the difference between the subject distances is larger than the predetermined value ΔL, that is, when the detected change in the subject distance is large, the counter value k is increased by “1” (step S4). Then, it is determined whether or not the value k of the counter has become larger than the predetermined value n (step S).
5). Here, the predetermined value n is a value corresponding to a time set for eliminating a change in the main subject distance due to noise or the like, and is set to a multiple of the field frequency in the present embodiment. If the counter value k is not larger than the predetermined value n, the process returns to step S1.

On the other hand, if the value k of the counter is larger than the predetermined value n, the main object distance Lk detected this time is updated to the object distance Lref to be referenced next (step S6).
Then, the value k of the counter is reset to "1" (step S7).

Thereafter, the convergence distance is determined (step S
8). The process of determining the convergence distance will be described later.
Then, the lens microcomputer 127 sends a signal to the drivers 10 and 12 until the mirror angle corresponding to the determined convergence distance is reached, and the drivers 10 and 12 drive the mirrors 107 and 112 in the directions of arrows 13 and 15 (step S9). . As a result, the optical axes 4 and 5 rotate in the directions of arrows 14 and 16 to cause convergence.

FIG. 7 is a flowchart showing the procedure for determining the convergence distance in step S8. First, a screen (display) size S of a display device for displaying a stereoscopic image photographed by an observer and a viewing distance L from a position of a schematic eye of the observer to a position at which an image is displayed are represented by: An input is made by the input unit 21 (step S11). In the present embodiment, a menu screen is displayed on the EVF 3 with an electronic switch or the like, and the screen size and the viewing distance are input thereto, or by selecting from the displayed numbers.
Determine the screen size and viewing distance and set the lens microcomputer 1
Send to 27. This input method is not particularly limited, as long as the screen size and the viewing distance can be input, and a numerical value may be directly input.

The values Δt and Δo of the permissible diopter range (permissible observation range) with respect to the input viewing distance L are calculated (step S12). The values Δt and Δo of the permissible diopter range are obtained by equations (1) and (2), respectively.

Δt = C1 × (1 / L) + C2 (1) Δo = C3 × (1 / L) + C4 (2) where C1, C2, C3, and C4 are predetermined constants. .

Instead of calculating using the equations (1) and (2), a table of the permissible diopter range or permissible range for the viewing distance L is stored in the ROM 152, and the viewing distance L is input. At that time, the information may be read from this table.

The image size C of the image pickup device, the base line length (interval of the optical axis of the parallax image) 1, and the human pupil interval IPD are stored in ROM1.
The current focal length f of the lens is obtained from the zoom information (step S13).

Here, the values Ft and Fo of the permissible fusion range, which are the range in which a person can reasonably view stereoscopically, are determined by the screen size S,
Viewing distance L, image size C, base length l, focal length f
Can be obtained by a geometric calculation. That is,
When the values Δt and Δo of the permissible diopter range are obtained in step S12, the amount of parallax between the left and right images on the display screen is obtained. Therefore, the values Ft and Fo of the permissible fusion range are expressed by formulas ( It is determined from 3) and (4) (step S14).

Ft = C × (IPD−Δt × L) / C5 × 1 × S × f (3) Fo = C × (IPD−Δo × L) / C5 × 1 × S × f (4) Here, C5 is a predetermined constant.

From the values Ft and Fo of the permissible fusion range, the distances Zt and Zo of the permissible photographing range (capturable range) before and after with respect to the convergence distance Y are obtained by equations (5) and (6) (step S15).

1 / Zt = 1 / Y−Ft (5) 1 / Zo = 1 / Y−Fo (6) Here, Zt is a distance closer to the front than the convergence distance Y, and Zo
Is a distance in the depth direction than the convergence distance Y.

Subsequently, the object distances Z1, Z2, Z3 are detected by the distance measuring unit 8 (step S16). A subject distance range is obtained from the detected subject distances Z1, Z2, Z3 (step S17). The distance in the front direction is Zm
in, and the distance in the depth direction is Zmax.

Further, the distances Zt and Zo in the photographable range are compared with the object distances Zmin and Zmax, and a convergence distance Y such that the object distances Zmin and Zmax fall within the photographable range (Zt and Zo) is obtained. In the present embodiment, when the range of the subject distances Zmin and Zmax is smaller than or equal to the distances Zt and Zo of the photographable range, the photographing range (Z
The convergence distance is determined so that the range of the subject distances Zmin and Zmax is in the middle of (t, Zo) (step S1).
8).

When the range of the subject distances Zmin, Zmax is larger than the photographable range (Zt, Zo), the subject distance at the center of the screen is set to the convergence distance, but is not limited to this. Subject distance Zmin, Zm
The convergence distance Y may be obtained such that the photographable range (Zt, Zo) is located in the middle of the range of ax. Further, the convergence distance may be obtained such that the subject distance Zmin and the distance Zt in the front direction of the photographable range are the same, or the subject distance Zmax may be the same as the distance Zo in the depth direction of the photographable range. , The convergence distance may be obtained.

With the series of processes described above, when the photographer inputs the screen size and the viewing distance, the optimum convergence distance can be determined according to the observation conditions. As described above, by automating the convergence control, the burden on the photographer when photographing is reduced, and a high-quality stereoscopic video with less fatigue can be photographed.

Further, the parallax image on the left and right can be photographed with one lens without the need for two lenses, thereby realizing the miniaturization and low cost of the apparatus, and the individual difference between the left and right lenses. The influence can be eliminated, and a high-quality stereoscopic video can be captured with a simple configuration.

Further, by disposing the mirror and the liquid crystal shutter symmetrically with respect to the optical axis of the lens, it is possible to make the optical path lengths of the left and right parallax images to the subject equal, thereby providing a magnification difference between the left and right images. , And high-quality stereoscopic video can be shot.

Further, since the left and right parallax images can be photographed by one imaging device through the photographing optical system, an unnecessary electric circuit is not required, and the size and cost of the apparatus can be reduced.

Further, it can be provided as one lens unit of the interchangeable lens system. In other words, the camera unit does not need to have any special parts for capturing a stereoscopic image, and a normal two-dimensional lens unit can be used in the same camera unit. Therefore, scalability is high and user merit is great. In addition, a plurality of lens units for capturing stereoscopic images having different specifications such as focal lengths can be used by the same camera.

It is needless to say that the present invention can be applied to a case where the present invention is achieved by supplying a program to an image pickup apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the present invention into an imaging device, the device can enjoy the effects of the present invention.

FIG. 8 is a diagram showing a memory map of the ROM 152 as a storage medium. The ROM 152 stores a convergence control processing program module shown in the flowchart of FIG. 6, a convergence distance determination processing program module shown in the flowchart of FIG. 7, an image size C, a base line length 1, an pupil distance IPD, and the like. The storage medium for supplying the program module is not limited to the ROM, and may be, for example, a floppy disk, a hard disk, a nonvolatile memory card, or the like.

[0089]

According to the present invention, it is possible to provide an imaging apparatus which is small in size, low in cost, has high mobility and expandability, and can capture high-quality stereoscopic images.

Further, by automating the convergence control, the burden on the photographer at the time of photographing is reduced, and natural stereoscopic video photographing is enabled.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a basic configuration of a three-dimensional video photographing apparatus.

FIG. 2 is a diagram illustrating a measurement principle by triangulation.

FIG. 3 is a block diagram illustrating an electrical configuration of a lens microcomputer 127.

FIG. 4 is a timing chart showing signal waveforms of various parts of the liquid crystal control circuit 123.

FIG. 5 is a block diagram illustrating a configuration of a liquid crystal control circuit 123.

FIG. 6 is a flowchart illustrating a congestion control processing procedure.

FIG. 7 is a flowchart showing a convergence distance determination processing procedure in step S8.

FIG. 8 is a diagram showing a memory map of a ROM 152 as a storage medium.

[Explanation of symbols]

 Reference Signs List 1 lens unit 2 camera unit 3 electronic viewfinder (EVF) 8 distance measuring unit 21 input unit 102, 105 liquid crystal shutter 127 lens microcomputer 151 CPU 152 ROM 200 imaging unit 201, 202, 203 imaging device 208 camera microcomputer

Claims (13)

[Claims] 1. An image capturing means for capturing an image, an optical system for forming an image on the image capturing means, and symmetrically disposed with respect to an optical axis of the optical system, so that left and right parallax images are transmitted in a time-division manner. A pair of shutters, a pair of mirrors arranged symmetrically with respect to the optical axis of the optical system, and a pair of mirrors that reflect right and left parallax images transmitted through the pair of shutters and guide the parallax images to the optical system, and photographed by the imaging unit. Display means for displaying the displayed image; input means for inputting information about the display means; convergence distance determination means for determining a convergence distance between the pair of mirrors based on the input information; A driving unit for driving the pair of mirrors so as to have a convergence distance. 2. An optical unit comprising a detachable optical unit and a photographing unit, wherein the optical unit includes the pair of shutters, the pair of mirrors, the optical system, and the driving unit, and the photographing unit includes the imaging unit. The imaging apparatus according to claim 1, further comprising: the display unit. 3. An object distance information detecting means for detecting an object distance, wherein the information relating to the display means is a screen size and a viewing distance from an approximate position of an observer's eye to a display position; The determining unit calculates a photographable range based on the screen size, the viewing distance, the size of the imaging unit, a focal length of the optical system, an optical axis interval of the parallax image, and a human pupil interval. 3. The imaging apparatus according to claim 1, wherein the convergence distance is determined based on the calculated photographable range and the detected subject distance. 4. The convergence distance determining unit determines the convergence distance such that at least a part of the detected subject distance is included in the calculated photographable range. 3. The imaging device according to 3. 5. The imaging apparatus according to claim 1, wherein the input unit includes a display screen and a switch for inputting information displayed on the display screen. 6. The imaging apparatus according to claim 5, wherein the display screen also serves as a screen of the display unit on which an image captured by the imaging unit is displayed. 7. A camera for photographing an image, an optical system for forming an image on the camera, and a pair of optical systems arranged symmetrically with respect to the optical axis of the optical system for transmitting left and right parallax images in a time-division manner. A shutter, a pair of mirrors arranged symmetrically with respect to the optical axis of the optical system, and a pair of mirrors that reflect left and right parallax images transmitted through the pair of shutters and guide the parallax images to the optical system, and an image captured by the camera A convergence distance determination method for an imaging device that drives the pair of mirrors to the determined convergence distance, the method comprising: Inputting the screen size, and the viewing distance from the approximate position of the observer's eye to the display position, as the information about the input screen size and the viewing distance, the monitor size, Calculating a photographable range based on a focal length of the optical system, an optical axis interval of the parallax image, and a human pupil interval; and calculating the convergence based on the calculated photographable range and the detected subject distance. Determining a distance. 8. A camera for taking an image, an optical system for forming an image on the camera, and a pair of symmetrically disposed optical axes of the optical system for transmitting left and right parallax images in a time-division manner. A shutter, a pair of mirrors arranged symmetrically with respect to the optical axis of the optical system, and a pair of mirrors that reflect left and right parallax images transmitted through the pair of shutters and guide the parallax images to the optical system, and an image captured by the camera And a distance measurement unit that detects a subject distance, is executed by a computer that controls an imaging device that drives the pair of mirrors at the determined convergence distance, and stores a program that determines the convergence distance. In the storage medium, the program includes: a procedure for detecting a subject distance; and information on the monitor, from a screen size and a position of a viewer's eye to a display position. In the procedure of inputting the viewing distance in, and based on the input screen size and viewing distance, the size of the monitor, the focal length of the optical system, the optical axis interval of the parallax image and the human pupil interval, A storage medium comprising: a step of calculating a photographable range; and a step of determining the convergence distance based on the calculated photographable range and the detected subject distance. 9. An optical system for forming an image on an image pickup means, a pair of shutters symmetrically arranged with respect to an optical axis of the optical system, and transmitting time-division left and right parallax images, A pair of mirrors that are arranged symmetrically with respect to the optical axis and reflect left and right parallax images transmitted through the pair of shutters and guide the parallax images to the optical system, and a display unit that displays an image captured by the imaging unit. Input means for inputting information about the display means; convergence distance determining means for determining a convergence distance of the pair of mirrors based on the input information; and the pair of convergence distances so as to be the determined convergence distance. An optical device comprising: driving means for driving a mirror. 10. An object distance information detecting means for detecting an object distance, wherein the information relating to the display means is a screen size and a viewing distance from an approximate position of an observer's eye to a display position; The determining unit calculates a photographable range based on the screen size, the viewing distance, the size of the imaging unit, a focal length of the optical system, an optical axis interval of the parallax image, and a human pupil interval. The optical apparatus according to claim 9, wherein the convergence distance is determined based on the calculated photographable range and the detected subject distance. 11. The convergence distance determining unit determines the convergence distance such that at least a part of the detected subject distance is included in the calculated photographable range. 11. The optical device according to 10. 12. The optical apparatus according to claim 9, wherein said input means has a display screen and a switch for inputting information displayed on said display screen. 13. The optical apparatus according to claim 12, wherein the display screen also serves as a screen of the display unit on which an image captured by the imaging unit is displayed.