JP2010056865A - Image capturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously capture right eye information and left eye information to a single CCD in a single image sensor, and also to generate two right and left image data which are separately read out to form a solid image. <P>SOLUTION: An imaging unit 30 of a 3D camera 10 includes: a first photographing optical system 33 including a photographing lens 12 provided removably with a first polarizing plate 31 having a polarizing axis in a vertical direction and two mirrors 32; a first shutter 34; a second photographing optical system 37 including a photographing lens 13 with a second polarizing plate 35 having the polarizing axis in a second direction perpendicular to a first direction and two mirrors 36; a second shutter 38; and a CCD 40. The CCD 40 includes: a first photodetector with a polarizing plate having the polarizing axis in a vertical direction; and a second photodetector with the polarizing plate having the polarizing axis in a lateral direction, and reads out image information of a subject image formed by the two photographing optical systems separately upon solid photographing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that generates left and right image data for forming a stereoscopic image by forming subject images from two imaging optical systems on one imaging element.

A stereoscopic imaging apparatus that captures a stereoscopic image generates a stereoscopic image based on parallax between right eye information and left eye information of a subject image. In one of the methods, the right eye information and the left eye information are separated into separate imaging optical systems. There is a method of taking in and forming an image on one image sensor. Various methods for capturing the right eye information and the left eye information have been proposed. For example, in Patent Document 1 below, a lenticular lens is disposed immediately in front of the image sensor so that the image formation point at which the two imaging optical systems form an image through the lenticular lens is shifted by a ½ pixel pitch on the image sensor. The stereoscopic imaging apparatus is configured to displace the imaging element at a predetermined period so that two imaging points are alternately positioned on each pixel. In Patent Document 2 below, photographing light from two photographing optical systems having a mechanical shutter is imaged on one image pickup device by a half mirror, and the mechanical shutter is alternately opened to alternately display right eye information and left eye information. An imaging apparatus that sequentially captures and forms a stereoscopic image is described.
Japanese Patent Laid-Open No. 06-311535 JP-A-11-285026

  However, the subject image capturing methods disclosed in Patent Documents 1 and 2 are methods that alternately capture left and right information, and are not strictly images of the same timing. In addition, there is a problem of an increase in cost and space, such as a drive device that moves the lenticular lens or a half mirror that divides the photographing light.

  In view of the above problems, the present invention takes two right and left image data to form a stereoscopic image by capturing right-eye information and left-eye information at the same timing in one imaging element at the time of stereoscopic imaging without using a lenticular lens or a half mirror. An imaging apparatus that can generate and provide a high-quality image by acquiring double image information during normal shooting is proposed.

  An imaging apparatus according to the present invention includes a first imaging optical system in which a first polarizing plate having a polarization axis in a first direction is provided on an optical path, and a polarization axis in a second direction orthogonal to the first direction. A second imaging optical system having a second polarizing plate on the optical path, a first light receiving element having a polarizing plate having a polarization axis in the first direction, and a polarizing plate having a polarization axis in the second direction And the same number of second light-receiving elements arranged in a grid pattern, and imaging elements on which the respective subject images of the first photographing optical system and the second photographing optical system are formed, Image data is read from the image sensor and two left and right image data forming a stereoscopic image are generated.

  In the first light receiving element and the second light receiving element, four pieces including red, green, and blue arranged adjacently in a square form one set, and the first light receiving element and the second light receiving element are formed in one set unit. The two light receiving elements are preferably arranged alternately. Alternatively, in the imaging device, the first light receiving elements and the second light receiving elements, which are arranged in a Bayer array in a square lattice pattern, are arranged at positions shifted by a half pitch from each other at an angle of 45 °, and are arranged in a checkered pattern as a whole. It is good to do so.

  The imaging apparatus includes a shooting mode selection unit that can select either a stereoscopic shooting mode or a normal shooting mode, a first shutter that blocks an optical path of the first shooting optical system, and an optical path of the second shooting optical system. A second shutter that shields light, and the first polarizing plate is provided so as to be movable back and forth on the optical path of the first photographing optical system, and when the normal photographing mode is selected by the photographing mode selecting means, The subject image is photographed in a state where the first polarizing plate is retracted from the optical path of the first photographing optical system and the second shutter is held at a position that blocks the optical path of the second photographing optical system. It is good to make it.

  In the imaging apparatus, the first and second imaging optical systems have autofocus means, and when the autofocus means detects that the distance to the subject is longer than a predetermined distance, The normal shooting mode may be automatically selected.

  The imaging apparatus may include a third shutter immediately before the imaging element, and after the imaging element is shielded from light by the third shutter, image data may be read from all the light receiving elements.

  The first and second shutters may be controlled to be opened and closed at the same timing so that a subject image is taken.

  An imaging apparatus according to the present invention includes a left and right photographing optical system provided with two types of polarizing plates having polarization axes orthogonal to each other, and a light receiving element in which the two types of polarizing plates are alternately arranged, and a lenticular lens and a half. Without providing mirrors, left and right captured image information can be captured at the same timing and read out separately to generate two left and right image data to form a stereoscopic image, and twice as much image information during normal shooting It is possible to provide a high-quality image having

  As shown in FIGS. 1 and 2, a 3D camera (imaging device) 10 according to the present invention has two imaging lenses 12 and 13, a strobe light emitting unit 14, and a finder objective on the front surface of a substantially rectangular parallelepiped camera body 11. A power button 16 and a shutter button 17 are provided on the upper surface of the camera body 11. An LCD panel 18 as display means for displaying an image is provided on the back surface of the camera body 11, and the surface of the LCD panel 18 is a touch panel. An operation icon displayed on the LCD panel 18 can be operated by touching the touch panel using a user's finger or an attached operation pen (not shown). In addition to this, the viewfinder eyepiece window 19, a shooting / playback switching button 20 for switching between the shooting mode and the playback mode, a feed button 21 for sending to the next frame and a return button 22 for returning to the previous frame on the playback screen, and swinging up and down for imaging From a menu displayed on the LCD panel 18, a zoom operation button 23 for zooming the lenses 12 and 13, a shooting mode selection button (shooting mode selection means) 24 for switching between the normal shooting mode and the stereoscopic shooting mode, and other shooting conditions are displayed. Three operation buttons 25 are provided for selecting and deciding and for saving and erasing captured images. The shooting mode selected by the shooting mode selection button 24 is displayed on the LCD panel 18. Further, a slot (not shown) in which a memory card 27 in which image data is stored is detachably loaded is provided on the bottom surface of the camera body 11, and the captured image data is written and stored in the memory card 27. Is done.

  As shown in FIG. 3, the imaging unit 30 of the 3D camera 10 includes a photographing lens 12 in which a first polarizing plate 31 having a polarization axis in the vertical direction (first direction) is detachably provided, and two mirrors. 32, a first shutter 34 that opens and closes the optical path of the first imaging optical system 33, and a polarization axis in the horizontal direction (second direction) perpendicular to the vertical direction. A second photographing optical system 37 comprising a photographing lens 13 provided with a second polarizing plate 35 and two mirrors 36; a second shutter 38 for opening and closing the optical path of the second photographing optical system 37; A CCD (imaging device) 40 on which subject images of the first photographing optical system 33 and the second photographing optical system 37 are simultaneously formed. The photographing lenses 12 and 13 are provided with a diaphragm device 64.

  As shown in FIG. 4, in the CCD 40, a polarizing plate 43 having a polarization axis in the vertical direction and a polarizing plate 44 having a polarization axis in the horizontal direction are arranged in a checkered pattern, and as shown in FIG. A polarizing plate 43 is provided in front of the diode 45, and the second light receiving element 42 is provided with a polarizing plate 44 in front of the photodiode 45. As shown in FIG. 6, the first light receiving elements 41 are all provided with a polarizing plate 43 and are arranged in a Bayer array in a square lattice shape. Further, as shown in FIG. 7, the second light receiving elements 42 are all provided with a polarizing plate 44 and are arranged in a Bayer array in a square lattice shape. The first light receiving element and the second light receiving element are arranged with a half pitch offset from each other at an angle of 45 °, and have a checkered arrangement as shown in FIG.

  As shown in FIG. 8, the CCD 40 includes a grid of four first sets of Bayer arrayed first light receiving elements and one set of four second light receiving elements that are also Bayer arranged alternately. It may be arranged in a shape.

  Returning to FIG. When the stereoscopic shooting mode is selected by the shooting mode selection button 24, the first shutter 34 and the second shutter 38 are opened and closed with the first polarizing plate 31 inserted in the first shooting optical system 33. Both the subject images from the first photographing optical system 33 and the second photographing optical system 37 are formed on the CCD 40. Photographing light from the first photographing optical system 33 is received only by the first light receiving element 41, and photographing light from the second shutter 38 is received only by the second light receiving element 42.

  As shown in FIG. 9, when the normal shooting mode is selected, only the first shutter 34 is driven to open and close, the second shutter 38 is not driven, and shooting is performed only by the first shooting optical system 33. . At this time, since the first photographing optical system 33 is in a state in which the first polarizing plate 31 is retracted from the optical path, the photographing light by the first photographing optical system 33 receives the first light receiving element 41 and the second light receiving light of the CCD 40. Light is received by both of the elements 42.

  As shown in FIG. 10, the electrical configuration of the 3D camera 10 includes the CCD 40, CPU 50, CDS (correlated double sampling circuit) 51, AMP (amplifier circuit) 52, A / D converter 53, and image signal processing circuit 54. A compression / decompression processing circuit 55, an AE / AF processing circuit (autofocus means) 56, a ROM 57, a RAM 58, an SDRAM 59, an LCD driver 61 for controlling the LCD panel 18 and a media controller 62 are connected to the data bus 60. The CPU 50 reads the sequence program stored in the ROM 57 into the RAM 58, which is a work memory, and executes it. The imaging signal output from the CCD 40 is input to the CDS 51 and output as R (red), G (green), and B (blue) image data that accurately correspond to the amount of charge accumulated in each light receiving element of the CCD 40. The image data output from the CDS 51 is amplified by the AMP 52 and converted into digital image data by the A / D converter 53. The image data output from the A / D converter 53 is temporarily stored in the SDRAM 59 via the data bus 60. The image signal processing circuit 54 reads the image data from the SDRAM 59, performs various image processing such as gradation conversion and γ correction processing, and records the image data in the SDRAM 59 again. The image data temporarily stored in the SDRAM 59 is converted into an analog composite signal by the LCD driver 61 and displayed on the LCD panel 18. The SDRAM 59 has a plurality of memory areas for storing a plurality of images, and can write to the other while reading from one. The compression / decompression processing circuit 55 performs image compression on the image data subjected to the image processing by the image signal processing circuit 54 in a predetermined compression format (for example, JPEG format). The compressed image data is stored in the memory card 27 via the media controller 62.

  The CPU 50 includes a motor driver 63 that controls a stepping motor (not shown) that performs focus adjustment and zooming of the photographing lenses 12 and 13, and an aperture driver that controls a diaphragm device 64 incorporated in the photographing lenses 12 and 13. 65, a polarizing plate driving device 66 that inserts and removes the first polarizing plate 31 on the optical path, a shutter driver 67 that controls opening and closing of the first and second shutters 34 and 38, and light emission of the strobe light emitting unit 14. A strobe circuit 68 to be controlled is connected. Further, operation signals of the shutter button 17 and the shooting mode selection button 24 are input to the CPU 50. The imaging lenses 12 and 13 form a subject image on the light receiving surface of the CCD 40 disposed behind. Whether or not the image formed on the CCD 40 is in focus is detected by the AE / AF processing circuit 56. If the image is not in focus, the CPU 50 issues a command to the motor driver 63 to detect the image pickup lenses 12 and 13. Focusing is performed. At this time, it is confirmed whether the focus position is within a short distance range suitable for stereoscopic photography or a long distance not suitable for stereoscopic photography. If it is confirmed that the subject position is a long distance that is not suitable for stereoscopic shooting when the stereoscopic shooting mode is selected by the shooting mode selection button 24, the CPU 50 issues an instruction to change to the normal shooting mode, The normal shooting mode is automatically set.

  Next, according to the flowchart shown in FIG. 11, the imaging procedure and operation for generating two left and right image data for forming a stereoscopic image by the 3D camera 10 according to the present invention will be described. The power button 16 is turned on, the shooting mode is selected with the shooting / playback switching button 20, and the shooting mode selection button 24 is pressed to set the stereoscopic shooting mode. The first shutter 34 and the second shutter 38 which are mechanical shutters are opened when the power button 16 is turned on. Light from the subject is imaged on the CCD 40 by the first and second imaging optical systems 33 and 37, and the imaged image is periodically captured and displayed as a through image on the LCD panel. A description of the through image and its display is omitted. When the subject image is formed on the CCD 40, the AE / AF processing circuit 56 measures the focus positions of the first and second photographing lenses 12 and 13, and is not suitable for a short distance range suitable for a stereoscopic image and a stereoscopic image. Comparison with a threshold value that divides the long-distance range is performed. When the measured value indicates a short distance range smaller than the threshold value, it is confirmed that the first and second polarizing plates 31 and 35 are inserted on the respective optical paths, and are inserted when they are not inserted. The Thereafter, the camera enters a standby state until a release signal is generated by pressing the shutter button 17. On the other hand, when the measured value indicates a long distance range that is larger than the threshold value, a switching signal is output from the CPU 50 and the mode is automatically shifted to the normal photographing mode. The transition to the normal shooting mode is displayed on the LCD panel 18. Or, instead of automatically shifting to the normal shooting mode, a message indicating that it is preferable to display the message is displayed on the LCD 18 panel to prompt the photographer to select the normal shooting mode. good.

  When the shutter button 17 is pressed, accumulation of image light in the CCD 40 is newly started, and the first shutter 34 and the second shutter 38 are closed according to an instruction from the CPU 50 after a predetermined time (see FIG. 12). Thereafter, reading of an image from the CCD 40 is started and finished after a predetermined time. Since the light passing through the first photographing optical system 33 is polarized in the vertical direction by the polarizing plate 31, charges are accumulated in the first light receiving element 41 provided with the polarizing plate 43 in the same vertical direction. Charges are not accumulated in the second light receiving element 42 provided with the horizontal polarizing plate 44. Similarly, since the light passing through the second imaging optical system 37 is polarized in the lateral direction by the polarizing plate 35, electric charges are accumulated in the second light receiving element 42 provided with the same lateral polarizing plate 44. However, no charge is accumulated in the first light receiving element 41 provided with the vertical polarizing plate 43. Thereby, the subject image by the first photographing optical system 33 is accumulated only in the first light receiving element 41, and the subject image by the second photographing optical system 37 is accumulated only in the second light receiving element 42. Reading of images from the first light receiving element 41 and the second light receiving element 42 is performed separately and stored in the SDRAM 59 as separate images. The subject images taken by the two photographing optical systems 33 and 37 simultaneously photographed in this way are imaged on one CCD 40 and the charge is taken in, but the charge is taken out separately and stored as another image.

  Next, a case where the normal shooting mode is selected will be described with reference to the flowchart shown in FIG. A part of the description common to the stereoscopic shooting mode is omitted. When the normal shooting mode is selected, the opening of the first shutter 34 is confirmed, and the second shutter 38 is closed. Subsequently, the first polarizing plate 31 is retracted from the optical path of the photographic lens 12 and is moved to the retracted position when it is not retracted. Light from the subject is focused on the CCD 40 only by the first imaging optical system 33. When the shutter button 17 is pressed, image light is newly accumulated in the CCD 40, and the first shutter 34 is closed after a predetermined time. Since the light passing through the first imaging optical system 33 does not pass through the polarizing plate, charges are accumulated in both the first light receiving element 41 and the second light receiving element 42. Thereafter, reading of an image from all the light receiving elements is started and finished after a predetermined time. Thus, in the normal shooting mode, the image data includes twice as many pixels as in the stereoscopic shooting mode, and a high-quality image can be obtained.

  In the embodiment, the CCD 40 in which the first light receiving element and the second light receiving element are shifted by a half pitch at an angle of 45 ° and the check pattern is arranged as a whole, or the first light receiving element and the second light receiving element are grouped in groups of four. Although CCDs arranged in a lattice pattern alternately in one set unit are used, the present invention is not limited to this, and half of the photodiodes 45 may be luminance diodes that acquire only colorless luminance information, and the rest may be Bayer arrays. In addition, a set of four elements may be red, green, blue, and a luminance diode.

  In the above embodiment, when the accumulation of image light in the CCD 40 reaches a predetermined amount, the first shutter 34 and the second shutter 38 are closed at the same time so that the exposure amounts by the two optical systems are the same. As described above, the third shutter 71 may be provided immediately before the CCD 40, and the third shutter 71 may be closed to obtain an appropriate exposure amount. In this case, there is no problem even if the first shutter 34 is omitted.

  In the above-described embodiment, the polarizing plate 35 of the second imaging optical system 37 is fixed. However, like the polarizing plate 31, the polarizing plate 35 may be provided so as to be movable forward and backward. The diaphragm device 64 is not necessarily provided, and there is no problem even if it is not provided.

It is a perspective view which shows the external appearance of the 3D camera by this invention. It is a perspective view which shows the external appearance which looked at the 3D camera from the back side. It is a schematic diagram which shows the structure of the imaging unit of 3D camera. It is a schematic diagram which shows the arrangement | sequence of the light receiving element of CCD. It is a schematic diagram which shows the cross section of the light receiving element of CCD. It is a schematic diagram which shows the arrangement | sequence of a 1st light receiving element. It is a schematic diagram which shows the arrangement | sequence of a 2nd light receiving element. It is a schematic diagram which shows the polarizing plate arrangement | sequence and color arrangement | sequence of another CCD. It is a schematic diagram which shows the structure of the imaging unit at the time of imaging | photography mode. It is a block diagram which shows the electric constitution of 3D camera. It is a flowchart which shows the stereo imaging | photography procedure of a 3D camera. It is a figure which shows the time chart of a shutter. It is a flowchart which shows the normal imaging | photography procedure of 3D camera. It is a schematic diagram which shows the structure of another imaging unit.

Explanation of symbols

10 3D camera (imaging device)
12, 13 Shooting lens 24 Shooting mode selection button (shooting shooting mode selection means)
DESCRIPTION OF SYMBOLS 30 Imaging unit 31 1st polarizing plate 32,36 Mirror 33 1st imaging | photography optical system 34 1st shutter 35 2nd polarizing plate 37 2nd imaging | photography optical system 38 2nd shutter 40 CCD (imaging element)
41 1st light receiving element 42 2nd light receiving element 43,44 Polarizing plate 45 Photodiode 50 CPU
56 AE / AF processing circuit (autofocus means)
71 Third shutter

Claims (7)

A first imaging optical system in which a first polarizing plate having a polarization axis in a first direction is provided on the optical path;
A second imaging optical system in which a second polarizing plate having a polarization axis in a second direction orthogonal to the first direction is provided on the optical path;
The same number of first light receiving elements provided with polarizing plates having polarization axes in the first direction and second light receiving elements provided with polarizing plates having polarization axes in the second direction are alternately arranged in a lattice pattern. An imaging element on which subject images of the first imaging optical system and the second imaging optical system are simultaneously formed,
An image pickup apparatus that reads out image data from the image pickup device and generates left and right image data forming a stereoscopic image.   In the first light receiving element and the second light receiving element, four pieces including red, green, and blue arranged adjacently in a square form one set, and the first light receiving element and the second light receiving element are formed in one set unit. 2. The imaging apparatus according to claim 1, wherein the two light receiving elements are alternately arranged.   In the imaging device, the first light receiving device and the second light receiving device, which are arranged in a Bayer array in a square lattice pattern, are arranged at positions shifted by a half pitch from each other at an angle of 45 °, and are arranged in a checkerboard as a whole. The imaging apparatus according to claim 1, wherein: Shooting mode selection means that can select either the stereoscopic shooting mode or the normal shooting mode, a first shutter that opens and closes the optical path of the first shooting optical system, and a second shutter that opens and closes the optical path of the second shooting optical system And the first polarizing plate is provided so as to freely advance and retract on the optical path of the first photographing optical system,
When the normal photographing mode is selected by the photographing mode selecting means, the first polarizing plate is retracted from the optical path of the first photographing optical system and the second shutter is an optical path of the second photographing optical system. The imaging apparatus according to claim 1, wherein a subject image is captured in a state where the image is held at a position where the light is shielded.   The first and second photographing optical systems include autofocus means, and when the autofocus means detects that the distance to the subject is longer than a predetermined distance, the normal photographing mode is automatically set. The imaging apparatus according to claim 4, wherein the imaging apparatus is selected.   6. The imaging according to claim 1, further comprising a third shutter immediately before the imaging element, wherein image data is read from all the light receiving elements after the imaging element is shielded from light by the third shutter. apparatus. 4. The image pickup apparatus according to claim 1, wherein the first shutter and the second shutter are controlled to be opened and closed at the same timing to shoot a subject image.

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