JP4740477B2 - Stereoscopic imaging adapter lens and stereoscopic imaging system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the stereoisomers relates to an image capturing relates especially close photographable stereo imaging to telephoto shooting from stereoscopic imaging adapter lens and three-dimensional imaging system.
[0002]
[Prior art]
Photography is effectively used as a method for converting a three-dimensional object in a plane. On the other hand, there is also a demand for stereoscopic display of a three-dimensional object, and a stereo camera has been manufactured as a technique for this. In a general stereo camera, a method is used in which a subject to be photographed is photographed from two directions and those images are simultaneously viewed through a viewer. Also, this type of stereo camera is known in which focus adjustment is performed at the time of shooting using a focus function of an objective optical system. In addition, lenticular type stereoscopic photographs in which an image that is visible depending on the direction when the observation direction is changed are also known.
[0003]
[Problems to be solved by the invention]
In a conventional stereo camera, when photographing an object to be photographed from the left and right directions, the position and focus of each of the left and right images must be matched. However, since it is not possible to focus on an arbitrary distance, in general, the left and right optical axes are focused only on a specific distance, and other distances are when the observer peeks at the viewer. The technique of forcibly fusing was taken. In addition, the range in which the image can be fused is defined as an imaging range. The stereoscopic image created in this way has problems such as unnatural perspective and inconspicuousness, and increased observer fatigue.
[0004]
As a countermeasure against these problems, for example, Japanese Patent Laid-Open No. 2000-152282 discloses a method of correcting according to the shooting distance by shaking the left and right shooting system mirrors according to the shooting distance. However, since this method swings the left and right movable mirrors in conjunction with each other, a plurality of movable mirrors are required, and the interlocking mechanism needs to be complicated and configured with high accuracy. Moreover, it can only be applied to a specific lens and has low versatility. It is also difficult to correct when the stereoscopic effect becomes too large during close-up photography.
[0005]
When a general photographer performs the above-described stereo shooting, a dedicated stereo camera must be purchased. That is, in the past, stereo photography could only be realized with a dedicated camera, so ordinary people could not enjoy stereo photography easily. In addition, the conventional stereo camera has problems such as zoom shooting, super telephoto shooting, and close-up photography.
[0006]
An object of the present invention is to provide a stereoscopic image capturing adapter lens and a stereoscopic image capturing system capable of capturing a stereoscopic image using a general camera.
[0007]
[Means for Solving the Problems]
In order to solve the problem and achieve the object, the adapter lens and stereoscopic image capturing system of the present invention are configured as follows.
[0008]
(1) The adapter lens for three-dimensional image photographing of the present invention is a three-dimensional image photographing adapter lens that is attached to the front surface of a photographing lens that is provided on the photographing device and that is focused at infinity, and injects a subject luminous flux. The first optical system and the subject light beam emitted from the first optical system are divided into a plurality of light beams so as to form right and left images by the imaging device of the photographing apparatus, and each optical path of the divided light beams is deflected The first optical system is an afocal emission optical system that emits subject light as a parallel light beam, and is divided into right and left images by the second optical system. has a focus lens for performing adjustment of the focus, the images based on the plurality of light beams, formed on the imaging surface of the imaging device as a parallax image.
[0009]
(2) three-dimensional image photographing adapter lens of the present invention is an adapter lens according to (1), before Symbol first optical system, that further having a variable magnification optical system.
[0011]
( 3 ) The adapter lens for stereoscopic image photographing of the present invention is the adapter lens described in the above (1) or ( 2), and the second optical system is a prism.
[0012]
( 4 ) The adapter lens for stereoscopic image photographing of the present invention is the adapter lens described in ( 3) above, and the prism of the second optical system is an achromatic prism.
[0013]
( 5 ) The three-dimensional image photographing system of the present invention is a three-dimensional image photographing system comprising a three-dimensional image photographing adapter lens and a photographing device that attaches the adapter lens to the photographing lens and performs three-dimensional image photographing. Includes a first optical system that enters a subject light beam, and a second optical system that divides the subject light beam emitted from the first optical system into a plurality of light beams and deflects each optical path of the divided light beams. The first optical system is an afocal emission optical system that emits subject light as a parallel light beam , and forms each image based on the plurality of light fluxes as a parallax image on the imaging surface of the photographing apparatus. There, emitted from the by a second optical system having a focus lens for performing adjustment of the focus before being split into left and right images, the imaging device, the mounted adapter lens A plurality of images based on the light beam, an imaging optical system for forming on the imaging surface as the parallax images, the setting means comprises a setting unit, the setting the photographing optical system to a predetermined state, the imaging optical system Set the focus position to infinity.
[0015]
( 6 ) The stereoscopic image photographing system of the present invention is the system described in ( 5 ) above, and the setting unit further sets the magnification ratio of the photographing optical system to a predetermined magnification.
[0018]
As a result of taking the above-mentioned means, the following effects are obtained.
[0019]
(1) According to the adapter lens for stereoscopic image shooting of the present invention, it is possible to perform stereoscopic image shooting using a general camera that is not a dedicated camera for stereo shooting.
[0020]
(2) According to the stereoscopic image capturing adapter lens of the present invention, it is possible to capture a plurality of parallax images whose magnification does not change.
[0021]
(3) According to the adapter lens for stereoscopic image photography of the present invention, when the first optical system is focused at infinity, it becomes an afocal emission optical system, and a part of the optical system is moved from this state. Thus, it is possible to focus on a short distance.
[0022]
(4) According to the adapter lens for three-dimensional image photographing of the present invention, when the photographing region is widened and the image is enlarged or reduced, a unique three-dimensional effect of the photographing object can be obtained.
[0023]
(5) According to the adapter lens for stereoscopic image photographing of the present invention, the splitting and deflection of the subject luminous flux can be adjusted by appropriately replacing the prism. Further, since the light beam is split and deflected by the same prism, the adapter lens can be miniaturized.
[0024]
(6) According to the stereoscopic image capturing system of the present invention, it is possible to perform stereoscopic image capturing by mounting an adapter lens using a general capturing device. In addition, optimal stereoscopic shooting can be performed at a predetermined zoom position.
[0025]
(7) According to the adapter lens for stereoscopic image photographing of the present invention, the aberration (mainly color) is suppressed by the prism of the prism unit.
[0026]
(8) According to the stereoscopic image capturing system of the present invention, the focal length is determined according to the second optical system to be attached.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0030]
(First embodiment)
FIG. 1 is a diagram showing a configuration of a photographing system of a stereoscopic image photographing system (stereo camera) according to the first embodiment of the present invention. FIG. 2 is a diagram showing an image photographed by this stereoscopic image photographing system.
[0031]
The imaging system of FIG. 1 includes a lens unit 1, a prism unit 2, and a camera 3 in order from the object side that is the subject. The lens unit 1 includes an afocal light emission optical system 11 that converts a light beam from an object point as a subject into an afocal light beam. The afocal emission optical system 11 includes a focus lens 12 that moves in a direction for focusing. When the focus lens 12 is moved and the optical axes 21L and 21R of the left and right images of the subject are parallel on the incident side, an afocal optical system is obtained. Further, when the afocal light emission optical system 11 is provided with a zoom lens 13 including a zoom function, the photographing area is expanded.
[0032]
The prism unit 2 includes a two-divided deflection (deflection) prism 20. The two-divided deflection prism 20 has a shape that is plane-symmetric with respect to a plane that includes the optical axis S and is perpendicular to the plane of FIG. The two-divided declination prism 20 is a prism that bends light rays parallel to the optical axis S in a direction approaching the optical axis S at a specific angle within the plane of FIG. The declination of the two-divided declination prism 20 is determined by the lens 32 in the camera 3. When the two-divided declination prism 20 is a prism made of a single material, the distance may appear to be different depending on the color even if the subject is the same distance due to the difference in declination for each color (wavelength). In order to avoid this, it is preferable to use an achromatic prism having no difference in declination depending on color (wavelength) as the two-divided declination prism 20.
[0033]
The camera 3 captures an image 4 as shown in FIG. The image 4 includes left and right images 4L and 4R with parallax. The camera 3 includes an aperture stop 31, a lens 32, and an image sensor 33. When the focus lens 12 is moved at the time of photographing, each light beam passing through the center of the aperture stop 31 and the centers of the left and right parallax images 4L and 4R is incident on the incident side of the two-divided deflection prism 20 on the optical axis. Set to be parallel to S. The light beams passing through the centers of the left and right images are a left image optical axis 21L and a right image optical axis 21R, respectively. At this time, the focus position of the camera 3 is infinite. If the lens 31 of the camera 3 is a zoom lens, the focal length is determined according to the prism 20 to be attached. Therefore, when the prism 20 is attached, information on the focal length is transmitted to the camera 3 electrically or mechanically, and the focal length is obtained. The zoom lens of the camera 3 is moved.
[0034]
In this stereoscopic image photographing system, the lens 32 of the camera 3 is a set, but the two-divided declination prism 20 can be regarded as if there are two optical systems having the optical axes 21L and 21R of the left and right images as optical axes. . That is, the prism unit 2 and the camera 3 form an imaging unit. It can be said that the optical axes 21L and 21R of the left and right images and the optical axis S of the lens unit 1 as the objective optical system are in the same plane.
[0035]
The lens unit 1 and the prism unit 2 may be integrated, but changing the declination angle of the two-divided declination prism 20 (particularly when the angle of view becomes narrow) does not lead to deterioration of the imaging performance of the lens unit 1. In many cases, it is cheaper to make a system if it is systemized. That is, the lens unit 1 and the prism unit 2 serve as adapter lenses that can be mounted on the front surface of a general camera photographing lens. When this adapter lens is mounted on a general camera, stereo shooting is performed, and when it is not mounted, normal shooting is performed. Of course, this adapter lens and a general camera can be integrated into a camera dedicated to stereo photography.
[0036]
Further, when the two-divided declination prism 20 is a prism whose declination can be freely changed, the zoom lens of the camera 3 is moved in conjunction with the declination to focus on the object side intersection of the left and right image optical axes 21L and 21R. Control to match.
[0037]
FIG. 3 is a block diagram showing a configuration of the electronic camera according to the first embodiment. The electronic camera shown in FIG. 3 includes the photographing system shown in FIG. 1. In FIG. 3, the same parts as those shown in FIG.
[0038]
As shown in FIG. 3, the bus 120 includes a main CPU 140, an imaging circuit 151, an AE processing unit 121, an AF processing unit 122, an image processing circuit 123, a nonvolatile memory 124, a built-in memory 125, a compression / decompression unit 126, and a removable memory. 127, an LCD driver 131 is connected. An input unit 141, a speaker 142, a focus control unit 161, a zoom control unit 162, and an imaging circuit 151 are connected to the main CPU 140.
[0039]
A motor (step motor) 171 that drives the focus lens 12 is connected to the focus control unit 161, and a motor (step motor) 172 that drives the zoom lens 13 is connected to the zoom control unit 162. The image pickup circuit 151 is connected to an image pickup element 33 made of a CCD, and the LCD display 131 is connected to the LCD driver 131.
[0040]
In FIG. 3, each optical image of the subject that has passed through the lens through the afocal emission optical system 11 and the two-divided declination prism 20 is converted into an electrical signal by the imaging device 33, and these electrical signals are converted into analog signals by the imaging circuit 151. After being converted into an image signal, A / D conversion is performed. These digital image signals (hereinafter also referred to as “image information”) are temporarily stored in the volatile built-in memory 125. The built-in memory 125 is composed of a high-speed SDRAM (Synchronous Dynamic Random Access Memory), for example, and is also used as an image temporary storage memory and a work area for image processing.
[0041]
The image processing circuit 123 performs processing such as conversion of color information of image information temporarily stored in the built-in memory 125, conversion of the number of pixels, and the like. The image information subjected to various image processing by the image processing circuit 123 is JPEG-compressed by the compression / decompression unit 126, for example, and recorded in the removable memory 127 such as smart media. When displaying a captured image, the image information after image processing is displayed on the LCD 132 for image display via the LCD driver 131.
[0042]
When displaying an image recorded in the detachable memory 127, the image information read from the detachable memory 127 is expanded by the compression / decompression unit 126 and predetermined image processing is performed by the image processing circuit 123. After that, an image is displayed on the image display LCD 132 as in the case of shooting.
[0043]
The main CPU 140 reads the basic control program for the electronic camera from the nonvolatile memory 124 such as a flash memory, and controls the entire electronic camera. The main CPU 140 receives an input from the input unit 141 and performs control according to the input. The input unit 141 has a release button (shutter button) or the like (not shown). Further, the main CPU 140 generates a sound such as a warning from the speaker 142. Further, the main CPU 140 controls a power supply unit (not shown) to perform power management for the entire electronic camera.
[0044]
The main CPU 140 controls the drive of the focus lens 12 via the focus control unit 161 and the motor 171, controls the drive of the zoom lens 13 via the zoom control unit 162 and the motor 172, and performs element shutter control on the imaging circuit 15. To do.
[0045]
The main CPU 140 calculates the magnification of the zoom lens 13 from the number of steps when the motor 162 is driven (open loop). The main CPU 140 calculates the zoom magnification of each optical system in response to a zoom instruction from the input unit 141 by the photographer, and gives the number of steps corresponding to the magnification to the motor 172 via the zoom control unit 162 for control. To do.
[0046]
When the electronic camera shown in FIG. 3 has a trimming function, the main CPU 140 converts a single piece of captured image data (the left and right images are integrated as in the image 4) to a predetermined length and width respectively. The image data is trimmed to obtain two image data. Then, the main CPU 140 records each image data divided into two in the removable memory 127 as an image file individually.
[0047]
When the electronic camera shown in FIG. 3 does not have a trimming function, the main CPU 140 records the left and right images in the removable memory 127 as an integrated image. Thereafter, the recorded image is subjected to processing such as right and left division by an appropriate image processing software.
[0048]
Further, the main CPU 140 detects whether or not the adapter lens including the lens unit 1 and the prism unit 2 is attached to the camera 3 by determining the right and left identity of the captured image. That is, when the left and right images in one captured image are substantially the same, the adapter lens is attached to the camera 3, and when they are not substantially the same, it is detected that they are not attached. Further, a movable pin (in conjunction with a switch) may be provided near the tip of the taking lens barrel of the camera 3 to detect whether or not the adapter lens is attached by turning on / off the movable pin. In addition, a function for detecting the attachment of the adapter lens may not be provided, and a message to that effect may be input from the input unit 141 when the photographer wears it.
[0049]
As described above, according to the first embodiment, it is possible to perform stereoscopic image shooting using a general camera that is not a dedicated camera for stereo shooting. From two images with parallax, a viewer or the like can be obtained. A stereo photograph can be obtained for observation.
[0050]
(Second Embodiment)
FIG. 4 is a diagram showing a configuration of a photographing system of a stereoscopic image photographing system (stereo camera) according to the second embodiment of the present invention. In FIG. 4, the same parts as those in FIG. FIG. 5 is a diagram showing an image photographed by this stereoscopic image photographing system.
[0051]
The imaging system in FIG. 4 includes a prism unit 2 ′ instead of the prism unit 2 shown in FIG. 1, and the other configurations are the same as those in FIG.
[0052]
The prism unit 2 ′ is provided with a three-divided declination (deflection) prism 20 ′. The three-divided declination prism 20 ′ has a shape that is plane-symmetric with respect to a plane that includes the optical axis S and that is perpendicular to the plane of FIG. The three-divided declination prism 20 ′ is a direction in which a light beam parallel to the optical axis S approaches the optical axis S at a specific angle in the plane of FIG. Bend to. Further, the three-divided declination prism 20 ′ transmits the light near the optical axis S without bending the direction. Similarly to the two-divided declination prism 20, an achromatic prism having no difference in declination due to color (wavelength) may be used for the three-divided declination prism 20 ′.
[0053]
The camera 3 captures an image 5 as shown in FIG. The image 5 includes left and right images 5L and 5R having a parallax and a center image 5M. By moving the focus lens 12 at the time of shooting, each light beam passing through the center of the aperture stop 31 and the centers of the left and right parallax images 5L and 5R and the center of the image 5M is divided into three-division declination prisms 20 ′. Is set to be parallel to the optical axis S on the incident side. The light beams passing through the centers of the left and right images are referred to as the left image optical axis 21L and the right image optical axis 21R, respectively, and the light beams passing through the center of the central image are referred to as the central optical axis 21M. At this time, the focus position of the camera 3 is infinite. The case where the lens 31 of the camera 3 is a zoom lens is the same as in the first embodiment.
[0054]
In this stereoscopic image capturing system, the lens 32 of the camera 3 is a set, but the optical axes 21L, 21M, and 21R of the left image, the center image, and the right image are set as the optical axes by the three-divided declination prism 20 ′. It can be seen that there are three optical systems. That is, the prism unit 2 ′ and the camera 3 form an image forming unit. It can be said that the optical axes 21L, 21M, and 21R and the optical axis S of the lens unit 1 that is the objective optical system are in the same plane. In addition, it is also possible to obtain four or more images with parallax using a declination prism with four or more divisions instead of the three-division declination prism 20 ′.
[0055]
The configuration of the electronic camera according to the second embodiment is the same as that of the first embodiment. In addition, the lens unit 1 and the prism unit 2 ′ can be systemized as in the first embodiment.
[0056]
As described above, according to the second embodiment, stereoscopic images can be captured using a general camera that is not a dedicated camera for stereo shooting, and observation can be performed from three or more images with parallax. When the direction is changed, a lenticular-type stereoscopic photograph is obtained in which the image that can be seen changes depending on the direction. Also, unlike the case of a screen consisting of two left and right images, one image is arranged at the center of the screen, so that the center image can be used for AE / AF whose detection area is the center of the screen.
[0057]
In addition, this invention is not limited only to said each embodiment, In the range which does not change a summary, it can deform | transform suitably and can implement. The present invention is applicable to a silver salt camera, a still image electronic camera, a video camera, and the like.
[0058]
【The invention's effect】
According to the present invention, it is possible to provide a stereoscopic image capturing adapter lens and a stereoscopic image capturing system capable of capturing a stereoscopic image using a general camera.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a photographing system of a stereoscopic image photographing system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an image photographed by the stereoscopic image photographing system according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of the electronic camera according to the first embodiment of the invention.
FIG. 4 is a diagram illustrating a configuration of a photographing system of a stereoscopic image photographing system according to a second embodiment of the present invention.
FIG. 5 is a diagram showing an image photographed by a stereoscopic image photographing system according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Lens unit 2, 2 '... Prism unit 3 ... Camera 11 ... Afocal light emission optical system 12 ... Focus lens 13 ... Zoom lens 20 ... 2 division | segmentation declination prism 20' ... 3 division | segmentation declination prism 31 ... Aperture stop 32 ... Lens 33 ... Image sensor 4, 5 ... Image 120 ... Bus 121 ... AE processing unit 122 ... AF processing unit 123 ... Image processing circuit 124 ... Non-volatile memory 125 ... Built-in memory 126 ... Compression / decompression unit 127 ... Detachable memory 131 ... LCD Driver 132 ... LCD display unit 140 ... Main CPU
141 ... Input unit 142 ... Speaker 151 ... Imaging circuit 161 ... Focus control unit 162 ... Zoom control units 171, 172 ... Motor

Claims (6)

An adapter lens for stereoscopic image shooting that is attached to the front surface of a photographic lens that has a focal position at infinity provided on the photographic device,
A first optical system for entering a subject luminous flux;
A second optical system that divides a subject light beam emitted from the first optical system into a plurality of light beams so as to form left and right images by an imaging element of the photographing apparatus, and deflects each optical path of the divided light beams; With
It said first optical system is an afocal injection optical system which emits object light as a parallel light beam, a focus lens for performing adjustment of the focus before being split into left and right image by the second optical system Have
An adapter lens for stereoscopic image shooting, wherein each image based on the plurality of light beams is formed as a parallax image on an imaging surface of the imaging device.   The adapter lens for stereoscopic image photography according to claim 1, wherein the first optical system further includes a variable magnification optical system. The adapter lens for stereoscopic image photography according to claim 1, wherein the second optical system is a prism . The adapter lens for stereoscopic image photography according to claim 3, wherein the prism of the second optical system is an achromatic prism. A stereoscopic image photographing system comprising a stereoscopic image photographing adapter lens and a photographing device for attaching the adapter lens to photograph a stereoscopic image,
  The adapter lens is
  A first optical system for entering a subject luminous flux;
  A second optical system that divides the subject light beam emitted from the first optical system into a plurality of light beams and deflects each optical path of the divided light beams;
  Each image based on the plurality of light beams is formed as a parallax image on the imaging surface of the photographing apparatus, and the first optical system is an afocal emission optical system that emits subject light as a parallel light beam, and the second A focus lens for adjusting the focus before being divided into left and right images by the optical system of
  The imaging device
  An imaging optical system for forming each image based on a plurality of light beams emitted from the mounted adapter lens on the imaging surface as a parallax image,
  Setting means for setting the photographing optical system to a predetermined state.
  The stereoscopic image photographing system characterized in that the setting means sets the focal position of the photographing optical system to infinity. The stereoscopic image photographing system according to claim 5, wherein the setting unit further sets a magnification ratio of the photographing optical system to a predetermined magnification .

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