JP2013097079A - Stereoscopic photographing device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the structure of the optical system of a stereoscopic photographing device and the structure of a drive unit and to provide an electronic apparatus that has a thin, small stereoscopic photographing device.SOLUTION: The stereoscopic photographing apparatus comprises: two light incident parts configured to take in subject images at different parallaxes; a polarization combining part configured such that the two subject images taken in the light incident part, which are different from each other in polarization, are combined on one optical axis; an optical system arranged on the optical axis; a drive unit configured to drive the optical system; and a polarization separating part configured to separate subject images from the optical system into individual polarization. The optical axis is arranged apart from the middles of the two light incident parts. The drive unit is arranged so as to be opposite to the optical axis with respect to the middles of the two light incident parts.

Description

  The present invention relates to a polarization-combining stereo camera capable of taking still images or moving images in stereo, and in particular, a polarization-combining stereo camera that can combine two polarized images of the same subject and obtain two polarized images again through an optical system. In particular, the present invention relates to a portable information terminal that is an electronic device and a small three-dimensional image capturing device built in a mobile phone.

  As a method of displaying a subject on a display in three dimensions, it has been proposed to take a subject image from two different directions and generate a stereo image. Further, as one method for measuring the distance to the subject, a stereo image of the subject is generated, and the distance to the subject is measured from the deviation of the subject using the principle of triangulation.

There are the following general methods for taking a stereo image.
(1) One that uses two cameras.
(2) A camera that shoots with the imaging element of the camera divided in half using a pair of reflecting means on the left and right.

  In the method of using two cameras of (1), two cameras having exactly the same characteristics are required. In particular, it is necessary to attach the two cameras, that is, to perform optical axis alignment with high accuracy. Also, a mechanism for capturing video in synchronization with an external signal is required for the two cameras. For example, in the one described in Patent Document 1, the left and right cameras are each provided with a positioning device arranged on a jig, and using a reference point and a reference horizontal line provided on a white plate arranged in parallel with the jig, The camera's optical axis and horizontal angle are adjusted.

  Further, as a method of using (2) a pair of reflecting means on the left and right sides and dividing the camera's imaging element in half and using the left and right imaging elements, for example, two subject light incident windows are used. A stereo adapter is attached to a camera capable of taking a stereo image, and a stereo format screen is divided into two to expose the right-eye and left-eye photos side by side (see Patent Document 2), or the camera's image sensor is arranged horizontally (horizontal). (Direction) When the image is divided in half, the left and right fields of view are narrowed. Therefore, the optical path of the two left and right imaging lenses is compressed in the left and right direction using a rotating mirror and a curved (convex) mirror. There is known a stereo adapter and a stereo image imaging device (see Patent Document 3) in which the aspect ratio is the same as when the image is expanded by processing and imaged using the entire imaging device.

  However, if the image sensor is divided into left and right in this way, the left and right optical axes for capturing the same subject (subject) are different (physically separated), so the lens distortion is eliminated. In addition to the need to correct the captured left and right images, the field of view in the left and right direction of the captured image is narrowed. To avoid this, for example, complicated correction means as described in Patent Document 3 Is required. In addition, since the left and right images are picked up by half of the image pickup device, there is a problem that the images become rough as compared with the case of picking up using the whole pixels.

  In addition, as Patent Document 4, it is conceivable to capture a P-polarized image as an image for the right eye and an S-polarized image as an image for the left eye, and take an image with a difference in polarization. When the glass window is projected, the reflected light is well reflected and the reflected light is not easily reflected in the P-polarized light. Therefore, even if the same image is captured in the P-polarized image and the S-polarized image, the left and right images are different. Even if two images are combined, it is difficult to recognize as a stereoscopic image.

Japanese Patent Laid-Open No. 7-229736 Japanese Unexamined Patent Publication No. 7-77747 JP 2003-140280 A JP-A 64-54438

  The present invention has been made to solve the problems of the conventional method for capturing a stereo image, and its purpose is to capture an image once divided into left and right by a stereo adapter with the entire imaging pixels of the camera. By forming a single image, the problem of dividing the conventional imaging pixel into left and right is solved, and by allowing the left and right images to be easily divided from there, the conventional optical system This is to make it possible to easily obtain a stereo image free from blurring and distortion without requiring correction or correction of a captured image.

  The stereoscopic imaging apparatus of the present invention includes two light incident units that capture subject images with different parallaxes, and a polarization combining unit that combines the two subject images captured by the light incident units as different polarizations on one optical axis. A stereoscopic photographing apparatus comprising: an optical system disposed on the optical axis; a drive unit that drives the optical system; and a polarization separation unit that separates a subject image from the optical system into each polarized light. The drive unit is disposed on the opposite side of the optical axis with respect to the center of the two light incident portions.

  The optical system includes a zoom lens and a focus lens, and the drive unit drives the first lens holder that holds the zoom lens, the second lens holder that holds the focus lens, and the first lens holder. And a second drive system for driving the second lens holder.

  The drive unit is characterized in that the first drive system and the second drive system are arranged in parallel with the optical axis.

  The second lens holder includes a frame portion that holds the lens, a holder arm that extends from the frame portion, and a screwing portion that is provided at an end portion of the holder arm. The screwing part is screwed to the lead screw of the second drive system across the system.

In addition, the holder arm is formed wider than the screwing portion. The electronic apparatus of the present invention includes any one of the three-dimensional imaging devices described above.

  According to the present invention, since a stereoscopic image having a parallax without blurring can be obtained with one camera, two cameras having exactly the same characteristics as in the case of using two cameras as in the past are used. There is no need to prepare a stand, and there is no need for adjustment work such as mounting of two cameras, that is, alignment of the optical axes, and a synchronization mechanism of the two cameras.

  In addition, according to the present invention, it is possible to provide an electronic apparatus equipped with a thin and small stereoscopic imaging device by optimizing the structure of the optical system and drive unit of the stereoscopic imaging device.

1 is a schematic diagram of a stereoscopic imaging apparatus according to an embodiment of the present invention. It is the top view and perspective view explaining the three-dimensional imaging device which concerns on embodiment of this invention. It is a perspective view of the other three-dimensional imaging device of this invention. It is a figure of the other polarization separation part of this invention. It is a figure of the other polarization separation part of this invention. It is a figure of the other polarization separation part of this invention. It is a front top view of the three-dimensional imaging device of this invention. It is a disassembled perspective view of the three-dimensional imaging device of this invention. It is a perspective view of the lens holder used for the three-dimensional imaging device of this invention. It is a block diagram explaining the structure of an image processing apparatus. It is the Example which mounted the stereoscopic imaging device which concerns on embodiment of this invention in the electronic device.

<Embodiment 1>
An embodiment of the present invention will be described with reference to the drawings. The stereoscopic imaging apparatus according to the present embodiment shifts the phase of an image light beam of the same subject with the same parallax having the parallax corresponding to the difference in distance between the two incident surfaces by λ / 2. In this way, they are combined as image beams with different polarizations, photographed with one camera optical system, separated again into two image beams due to the difference in polarization, and imaged on the corresponding image sensors to form two images on the left and right To do. The configuration will be specifically described below.

FIG. 1 is a conceptual diagram schematically showing a polarization combining type stereoscopic photographing apparatus according to an embodiment of the present invention. That is, the polarization-combining stereoscopic imaging apparatus roughly includes two light incident portions 10 and 12 that capture an image of the subject 0 as light rays α1 and α2 with different parallaxes, and an image incident from the light incident portion 10. The phase of the S-polarized component of the light beam α1 and the S-polarized component of the image light beam α2 incident from the light incident part 12 are shifted by λ / 2 to form P-polarized light, and then combined so that the optical axes of the light beam α1 and the light beam α2 match. A polarization combiner 2 that guides the camera optical system 3, a camera optical system 3 that emits a combined image so that the combined image light beam is imaged on the image sensor at a desired magnification, and camera optics. The formed image emitted from the system 3 is imaged (photoelectrically converted) after being separated from the polarization separation unit 4 that separates the formed image in the direction of the two imaging sensors (elements) 5 and 6 according to the difference in polarization, and then A / D converted. Image processing to form an image from the obtained digital image data It consists of location 7.

  In the above embodiment, in consideration of the influence of reflected light, the phase of the S-polarized component of the image beam α1 incident from the light incident unit 10 and the phase of the S-polarized component of the image beam α2 incident from the light incident unit 12 are λ. / 2 is synthesized as P-polarized light, but when the influence of reflected light is suppressed, the P-polarized component of the image light beam α1 incident from the light incident unit 10 and the P of the image light beam α2 incident from the light incident unit 12 are used. The phase of the polarization component may be shifted by λ / 2 and synthesized as the S polarization component. In that case, the first polarization separation film 13 ′ positioned in the polarization beam combiner 2 shown in FIG. 2 reflects the P-polarized light and transmits the S-polarized light.

  2A and 2B are diagrams schematically showing a specific embodiment of the polarization combining type stereoscopic photographing apparatus 1, in which FIG. 2A shows a plan view and FIG. 2B shows a perspective view. The polarization beam combining unit 2 includes lenses 10 and 12 that are light incident portions and a first prism 13 when viewed from the light incident side.

  The first prism 13 bends and propagates the image incident from the lens, and reflects the first polarized light and transmits the other polarized light (for example, reflects the S polarized light and transmits the P polarized light). The polarization separation film 13 ′. Further, a λ / 4 film (λ / 4 sheet, λ / 4 phase difference sheet) 17 (λ is a visible wavelength region, λ = 450 nm to 700 nm) and an image are formed on the opposite side of the side facing the camera optical system unit 3. A reflecting mirror 18 is disposed as a reflecting surface for reflection.

  Next, the image rays α1 and α2 will be described with reference to FIG. The image ray α1 is indicated by a solid line, and α2 is indicated by a broken line. Light rays α1 and α2 incident on the lenses 10 and 12 from the Z direction are reflected in the direction of the first polarization separation film 13 ′ by the prism portion below. Here, the case where the first polarization separation film 13 ′ is a polarization separation film that reflects S-polarized light and transmits P-polarized light will be described. Of the light α1 incident on the first polarization separation film 13 ′ from the lens 10 side, the polarized image light beam composed of the S-polarized component is reflected and travels in the direction of the camera optical system unit 3 in the −Y direction. On the other hand, the polarized image light beam composed of the P-polarized component in the light beam α2 is transmitted through the first polarization separation film 13 ′ and does not contribute to the image formation because it is not directed toward the camera optical system unit 3. That is, the light ray α1 indicated by the solid line is composed of P-polarized light and S-polarized light from the lens 10 to the polarization separation film 13 ′, but the light ray α1 is only S-polarized light from the polarization separation film 13 ′ to the camera optical system unit 3. Consists of.

  Also, the polarized image light beam composed of the S-polarized component of the light beam α2 incident on the first polarization separation film 13 ′ from the lens 12 side is reflected in the Y direction and transmitted through the λ / 4 sheet 17, for example, to the right The light is converted into circularly polarized light and further reflected by the reflecting mirror 18 to become counterclockwise circularly polarized light, and again transmitted through the λ / 4 sheet 17 to become P polarized light. The polarized image light beam that has become P-polarized light passes through the first polarization separation film 13 ′ and is emitted in the direction of the camera optical system unit 3.

  Of the image light incident on the first polarization separation film 13 ′ from the lens 12 side, the polarization image light composed of the P-polarized component is transmitted through the first polarization separation film 13 ′ and directed toward the camera optical system unit 3. It does not contribute to image formation. That is, the light ray α2 indicated by the broken line is composed of P-polarized light and S-polarized light from the lens 12 to the polarization separation film 13 ′, and the S-polarized light reflected by the polarization separation film 13 ′ is transmitted through the λ / 4 sheet 17 and reflected. Reflected by the mirror 18 and again transmitted through the λ / 4 sheet 17, it becomes P-polarized light, and is transmitted through the polarization separation film 13 ′. From the polarization separation film 13 ′, the light α 2 is P-polarized light. Consist only of.

  Further, in terms of optical characteristics, it is desirable that the optical path lengths of the image light beam emitted from the lens 10 side in the direction of the camera optical system unit 3 and the image light beam emitted from the lens 12 side in the direction of the camera optical system unit 3 are the same. The prism length on the lens 10 side is made longer than that on the lens 12 side, and the optical path length is made uniform. That is, the S-polarized light of the image light beam α2 incident from the lens 12 side is reflected by the polarization separation film 13 ′, and then passes through the reflection separation film 13 ′ through the λ / 4 sheet 17 and the reflection mirror 18 to become P-polarization. The prism length on the lens 10 side is lengthened by the amount of the optical path length until this time.

  2A has a configuration in which a λ / 4 sheet 17 and a reflection mirror 18 are provided on the lens 12 side in order to change the S-polarized light of the image light α2 to P-polarized light. As another configuration, the polarization separation film 13 ′ reflects P-polarized light and transmits S-polarized light, and a λ / 2 sheet having the S-polarized light of the image light α 1 on the lens 10 side as P-polarized light is the polarization separation film 13. The polarized image light beam that has become P-polarized light of the image light beam α1 is reflected by the polarization separation film 13 ′ and directed toward the camera optical system unit 3, while the image light beam α2 on the lens 12 side is reflected by the reflection mirror 18. The light is incident on the camera optical system unit 3 from the direction of the light, the P-polarized light is reflected by the polarization separation film 13 ′ and is directed in a direction different from the direction of the camera optical system unit 3, and the S-polarized light is directed to the camera optical system unit 3. It does not matter.

  The relationship between the P-polarized light and the S-polarized light described so far may be reversed for the P-polarized light and the S-polarized light including the configuration of the polarization separation film 13 ′ and the like. In addition, the lenses 10 and 12 in the light incident part are easy to obtain optical characteristics of the camera optical system part 3 described later, or can reduce the diameter of the light beam propagating through the polarization combining part 2, but the assembling property is improved. In addition, it is possible to eliminate the lenses 10 and 12 as the light incident portions in order to reduce the cost by reducing the number of parts and reduce the thickness of the apparatus.

  With the above method, two images captured from the lens 10 side and the lens 12 side can be combined on one optical axis and emitted to the camera optical system unit 3. In addition, although the difference between P-polarized light and S-polarized light is used for image synthesis, all the captured images are S-polarized images, and the phase of one of the S-polarized images is shifted by 1 / 2λ inside the apparatus. Therefore, no difference in the image due to the difference in polarization occurs between the two images such as the water surface, the reflected light of the glass, and the display screen of the liquid crystal. Even when it is made, an image without a sense of incongruity can be obtained.

  As the characteristics of the first polarization separation film 13 ′, the visible light wavelength band λ (450 nm to 700 nm) is used, and the P-polarized light transmittance 80 is in the range of 45 ± 10 degrees incident on the first polarization separation film 13 ′. % Or more and S-polarized reflectance of 80% or more are desirable.

  Further, in order to further remove the P-polarized light emitted to the camera optical system unit 3, a polarizing sheet 9 may be disposed on either side of the lenses 10 and 12 as shown in FIG. FIG. 3A shows the polarizing sheet 9 placed in front of the lenses 10 and 12, and FIG. 3B shows the polarizing sheet 9 placed after the lenses 10 and 12. As a result, the P-polarized image can be removed and the ratio of the S-polarized image can be increased at the stage of incidence on the first prism 13, so that a difference in image due to the difference in polarization does not occur, and a three-dimensional image is generated. If this is the case, an image with no sense of incompatibility can be obtained. If the polarizing sheet 9 is disposed after the lenses 10 and 12, the light is collected by the lens and the incident angle of the light to the polarizing sheet 9 can be narrowed. More effective.

  Furthermore, a polarization correction sheet 11 may be disposed before and after the lenses 10 and 12 of the subject image capturing unit. The polarization correction sheet 11 converts the phase of the linearly polarized light component including the polarization component of the S-polarized light component or the P-polarized light component (especially, water surface, reflected light of glass, liquid crystal display screen, etc.) to a circularly polarized light component by shifting it by λ / 4. And has a function of correcting a difference in appearance due to polarization deviation. Further, a polarizing sheet 9 that transmits only the S-polarized light may be added behind it in order to reduce crosstalk during polarization synthesis. As a result, even if the changed separation characteristics of the polarization separation film 13 ′ in the subsequent stage are not sufficient, the light from α1 is mixed as P-polarized light and the light from α2 is mixed as S-polarized light at the time of polarization synthesis, thereby degrading the 3D image as crosstalk. Can be prevented.

  In addition, in order to suppress stray light that degrades the 3D image, it is also possible to perform sanitization or frosted glass processing on the surface of the first prism 13 excluding a portion through which the light rays α1 and α2 pass. When stray light generated by scattering on the edge of the lens or on the reflection surface is emitted to the camera optical system unit 3 and formed on the imaging sensors 5 and 6, the 3D image is degraded. Stray light other than the light rays α1 and α2 can be suppressed. In addition, by increasing the distance in the X direction between the lenses 10 and 12 and the camera optical system unit 3, stray light entering the camera optical system unit 3 through the lens can be suppressed.

  Next, the camera optical system unit 3 is composed of a plurality of lens groups 8, and is a zoom optical system that can change the focal length by driving some of these lens groups 8. For this reason, the two types of input polarized images are simultaneously zoomed and focused by this set of zoom lens units, and the influence of the aberration of the optical system acts on the two images in the same way. The difference between the images does not occur, and the cost of the imaging system is the highest, and the effect of cost reduction and size minimization is great for the camera optical system part that is affected by the size increase.

Two types of polarized image light beams emitted from the camera optical system unit 3 are incident on the polarization separation unit 4, and the second prism 4 ′ (for example, PBS polarizing beam splitter Polarizing Beam).
Splitter) separates the original P-polarized image and S-polarized image and forms them on the image sensor 5. At this time, the characteristic of the second prism 4 ′ is that the visible light wavelength band λ (450 nm to 700 nm), the P polarization transmittance is 80% or more in the range of the incident angle 45 ± 10 degrees to the second polarization separation film 4 ″, S The polarization reflectance is preferably 80% or more. Further, by arranging the polarizing sheet 9 between the second polarization separation film 4 ″ and the imaging sensors 5 and 6, crosstalk at the time of polarization separation can be reduced.

  4 shows an example in which a polarizing sheet 9 is disposed between the second polarization separation film 4 ″ and the image sensors 5 and 6 in order to reduce crosstalk during polarization separation. For example, the polarization separation film 4 The stray light is blocked by disposing the polarizing sheet 9 that transmits S-polarized light between the image sensor 5 and the polarizing sheet 9 that transmits the P-polarized light between the polarizing separation film 4 and the image sensor 6. In other words, the light rays incident from the lenses 10 and 13 can be neatly subdivided and imaged on the sensors.

  FIGS. 5A to 5E show other examples of the polarized light separation unit 4 having a layout in which the interval between the image sensors 5 is widened to facilitate the arrangement. 5A to 5C, the shape of the second prism 4 ′ is made different, and the incident angle of the light to the second polarization separation film 4 ″ is made smaller than 45 degrees so that the interval between the image sensors 5 is increased. The second prism 4 ′ in FIG.5 (d) has a second polarization separation film 4 "that reflects S-polarized light and transmits P-polarized light, and λ / The four sheets 17 and the reflection mirror 18 are arranged. Of the image incident from the direction of the camera optical system unit 3, the S-polarized component is reflected by the second polarization separation film 4 "and directed to the image sensor 5, and the P-polarized component is transmitted through the second polarization separation film 4". By passing through the λ / 4 sheet, it is converted into, for example, clockwise circularly polarized light, and further reflected by the reflecting mirror 18 to become counterclockwise circularly polarized light, and again through the λ / 4 sheet, it becomes S polarized light. The S-polarized image reflects off the polarization separation film 4 ″ and enters the image sensor 6. In addition, it is desirable that the optical path lengths of the images incident on the image sensors 5 and 6 are the same because of optical characteristics. The second prism 4 'on the sensor 5 side is lengthened to make the optical path length uniform.

  The second prism 4 ′ in FIG. 5E includes a second polarization separation film 4 ″ that reflects S-polarized light and transmits P-polarized light, a λ / 4 sheet 17 and a reflecting mirror 18 on the side perpendicular to the direction of the camera optical system 3. Of the image incident from the direction of the camera optical system 3, the P-polarized light component passes through the second polarization separation film 4 ″ and travels toward the image sensor 6, and the S-polarized light component is the second polarization separation film. By reflecting 4 ″ and transmitting through the λ / 4 sheet, for example, it is converted into clockwise circularly polarized light, and further reflected by the reflecting mirror 18 to become counterclockwise circularly polarized light, and again transmitted through the λ / 4 sheet. The P-polarized image passes through the second polarization separation film 4 ″ and enters the image sensor 5. In addition, in view of optical characteristics, it is desirable that the optical path lengths of the images incident on the imaging sensors 5 and 6 are the same, and the second prism 4 ′ on the imaging sensor 6 side is lengthened to make the optical path lengths uniform.

  As another example of the polarization separation unit 4, as shown in FIG. 6, a polarization element 20 for transmitting P-polarized light and a changing element for transmitting S-polarized light are alternately arranged at positions corresponding to the respective pixels 21 of the imaging sensor 6. The polarizing plate 22 is configured to separate the P and S polarized light from the camera optical system unit 3. As a result, it is not necessary to use only one image sensor 6, the assembling property is improved, the cost can be reduced, a large optical element such as a prism is not required, and the apparatus can be miniaturized. The optical performance is improved.

  The imaging sensors 5 and 6 include, for example, an imaging element (sensor) such as a CCD image sensor or a CMOS image sensor, a sample hold circuit, an A / D converter, and the like, and imaging based on the P-polarized and S-polarized separated images. Image data is generated based on the output of the element. In addition, the camera device has a built-in memory that records information related to the image taken by itself, and performs image processing using a general-purpose interface capable of transferring images at high speed, such as a bidirectional parallel interface or a SCSI interface, or USB (Universal Series Bus). It is connected to the computer of the device 7.

<Embodiment 2>
Next, the stereoscopic imaging apparatus according to the second embodiment will be described with reference to FIGS. The stereoscopic imaging apparatus of the second embodiment embodies the zoom optical system described in the stereoscopic imaging apparatus of the first embodiment, and the same reference numerals are given to the same configurations as those of the stereoscopic imaging apparatus of the first embodiment. doing.

  FIG. 7 is a front view showing the structure of a stereoscopic imaging apparatus that is Embodiment 2 of the present invention. FIG. 8 is an exploded perspective view of the stereoscopic photographing apparatus.

  As shown in FIG. 7, the stereoscopic imaging apparatus according to the second embodiment includes two light incident units 10 and 12 that capture subject images with different parallaxes, and two subject images captured by the light incident units 10 and 12, respectively. A polarization combining unit 2 for combining different polarizations on one optical axis AA, a camera optical system 3 having a plurality of lens groups arranged on the optical axis AA, and a drive for driving the camera optical system 3 The unit 40 includes a polarization separation unit 4 that separates a subject image from the camera optical system 3 into each polarized light, and two imaging elements 5 and 6 that capture the separated subject image.

  As shown in FIGS. 7 and 8, in the light incident portions 10 and 12, the lenses 10b and 12b incorporated in the lens holders 10a and 12a are arranged with a center interval of 20 mm, for example, and the respective lenses 10b and 12b are arranged. To capture the subject image as rays α1, α2 with different parallaxes.

  The polarization beam combiner 2 includes a first prism 13, a λ / 4 film 17 disposed on the outside of the first prism 13, a reflection mirror 18, a cover that blocks unnecessary external light, and a first prism It is comprised from the lens arrange | positioned at 13 image surface sides. The polarization combining unit 2 extracts the s-polarized component from the light beam α1 captured from the light incident unit 10 and the p-polarized component from the light beam α2 captured from the light incident unit 12, as in the stereoscopic imaging device of the first embodiment. And the s-polarized light of the light α1 and the p-polarized light of the light α2 are emitted to the camera optical system 3 as the combined light A1.

  Here, because of optical characteristics, it is desirable that the optical path length from the light incident portion 10 to the camera optical system 3 and the optical path length from the light incident portion 12 to the camera optical system 3 are the same, the light incident portion 10 side. The optical path length is made uniform by making the prism length longer than that of the light incident portion 12 side. Therefore, as shown in FIG. 7, the optical axis AA of the combined light A1 emitted from the polarization combining unit 2 is from the center BB of the light incident unit 10 and the light incident unit 12 to the light incident unit 12 side. Since they are shifted, the optical axis of the camera optical system 3 is also shifted to the light incident part 12 side so as to be aligned with the optical axis A-A.

  The combined light A1 combined by the polarization combining unit 2 is emitted on the optical axis A-A, zoomed to a desired magnification by the camera optical system 3, and the combined light A2 that has been zoomed is incident on the polarization separation unit 4. To do.

  As shown in FIG. 8, the polarization separation unit 4 includes a lens 4a, a second prism 4 ', and a cover 4b that shields unnecessary external light. The lens 4a corrects coma and astigmatism generated during zooming of the camera optical system 3. The second prism 4 ′ has a polarizing film similarly to the polarization separation film 13 ′ of the polarization combining unit 2, and again separates the s-polarized component and the p-polarized component from the zoom-adjusted combined light A2, and By reflecting the polarization component and bending the optical axis by 90 degrees, the light rays α1 and α2 are imaged on the imaging elements 5 and 6, respectively, and an image for obtaining a stereoscopic image of the subject is generated.

  The three-dimensional imaging device 1 includes a housing 51, a top plate 52, and a bottom plate 53, and the light incident units 10 and 12 and the polarization combining unit 2 are installed outside the housing 51. The camera optical system 3, the drive unit 40, the polarization separation unit 4, and the imaging elements 5 and 6 are installed inside the housing 51, and the top plate 52 and the bottom plate 53 are attached and enclosed in the housing 51. The housing 51 is provided with photo interrupters 54a and 54b for detecting the lens position of the camera optical system 3.

  Next, the camera optical system 3 and the drive unit 40, which are features in the stereoscopic imaging apparatus 1 of the present invention, will be described in detail.

  The camera optical system 3 has a configuration in which a plurality of lens groups are arranged in the direction of the optical axis AA of the combined light A1, and as shown in FIG. 8, a diaphragm 33, zoom lenses 34 and 35, And a zoom and focus lens 36.

  The drive unit 40 drives the first lens holder 41 that holds the zoom lenses 34 and 35, the second lens holder 42 that holds the zoom and focus lens 36, and the first lens holder 41. A first drive system 43 and a second drive system 44 for driving the second lens holder 42 are provided.

  The first lens holder 41 and the second lens holder 42 move along the optical axis A-A direction by the guide shafts 47a, 47b, 47c and the springs 48a, 48b combined with the guide shafts 47a, 47b. So that it is regulated.

  The drive unit 40 drives the first lens holder 41 and the second lens holder 42 to change the positions of the lenses 34 to 36 of the camera optical system 3 in the direction of the optical axis AA, thereby combining light. A1 is scaled at a desired magnification.

  The first drive system 43 of the drive unit 40 includes a lead screw 46a connected to the step motor 45a. The female screw integrally formed or incorporated in the first lens holder 41 and the male screw of the lead screw 46a. The screws are screwed together, and the first lens holder 41 is driven in the direction of the optical axis AA by the rotation of the lead screw 46a.

  Similar to the first drive system 43, the second drive system 44 also has a lead screw 46 b connected to the step motor 45 b, and is a female screw integrally formed or incorporated in the second lens holder 42. And the male screw of the lead screw 46b are screwed together, and the second lens holder 42 is driven in the direction of the optical axis AA by the rotation of the lead screw 46b.

  The first drive system 43 and the second drive system 44 are unitized in a state of being adjacent to each other, and the flexible wirings 49 connected to the respective step motors 45a and 45b are combined into one. The number of parts is reduced and the invasion of garbage is prevented.

  Here, how to arrange the camera optical system 3 and the drive unit 40 is important in order to reduce the size and thickness of the stereoscopic photographing apparatus 1. The stereoscopic imaging device 1 needs a predetermined interval between the light incident unit 10 and the light incident unit 12 in order to perform stereoscopic imaging. For this reason, the three-dimensional imaging device 1 can be minimized by disposing the camera optical system 3 and the drive unit 40 inside the distance between the light incident part 10 and the light incident part 12.

  In the three-dimensional imaging device 1 of the present invention, the camera optical system 3 is arranged with the optical axis A-A shifted to the light incident portion 12 side, and the space on the light incident portion 10 side is wider. By disposing the drive unit 40 that requires more space than the optical system 3 on the light incident unit 10 side, the camera optical system 3 and the drive unit 40 can be accommodated between the light incident unit 10 and the light incident unit 12. .

  In addition, the first drive system 43 and the second drive system 44 of the drive unit 40 are arranged in parallel with the optical axis of the camera optical system 3, thereby reducing the size of the zoom mechanism including the camera optical system 3 and the drive unit 40. Furthermore, it can be thinned by arranging it in a planar shape.

  FIG. 9 is a perspective view showing the second lens holder 42 in detail. The second lens holder 42 includes a frame portion 42 a that holds the lens 36, bearing portions 42 b and 42 c into which the guide shaft 47 b is inserted, a bearing portion 42 d into which the guide shaft 47 c is inserted, and a second drive system 44. A holder arm 42e extending to the side, and a screwing portion 42f formed with a female screw to be screwed to the male screw of the lead screw 46b at the tip of the holder arm 42e.

  The second lens holder 42 is regulated by two axes of a guide shaft 47b and a guide shaft 47c so that the second lens holder 42 does not rotate and shift from the optical axis AA. Further, by receiving the guide shaft 47b at the two bearing portions 42b and 42c, the second lens holder 42 is twisted in the direction of the arrow in the XY plane by the force applied to the screwing portion 42f, and the guide shaft 47b and the bearing portion It prevents that the slidability of 42b and 42c falls. In order to further prevent the second lens holder 42 from being twisted, it is desirable to provide a wide interval between the bearing portions 42b and 42c.

  The first lens holder 41 has the same configuration as that of the second lens holder 42. However, the holder arm 42e of the second lens holder 42 has a screwing portion 42f straddling the lead screw 46a to the lead screw 46b. Since it is screwed, the shape is longer than that of the first lens holder 41.

When the holder arm 42e deflects longer, it becomes likely to occur twisting at a screwing portion 42f, the equation of the second moment about the Y-axis of the holder arm ^{42e (C × B 3/12} ), the width of the holder arm 42e It is desirable to increase B. The width of the screwing portion 42f is preferably smaller than the width B of the holder arm 42e so as not to interfere with the portions other than the lead screw 46b.

  Further, the combination of the first lens holder 41 and the first drive system 43, and the second lens holder 42 and the second drive system 44 can be switched, but the first lens holder 41 Since the plurality of lenses 34 and 35 are held and become heavier than the second lens holder 42, it is preferable to arrange the first lens holder 41 and the first drive system 43 close to each other as in the present embodiment. The first lens holder 41 can be driven without being twisted.

<Embodiment 3>
Next, an electronic device equipped with the stereoscopic imaging apparatus of the present invention will be described with reference to FIGS. Since the configuration of the stereoscopic imaging apparatus is the same as that of the first embodiment or the second embodiment, the same reference numerals are given and the detailed description and drawings are omitted. FIG. 10 is a block diagram illustrating the structure of the image processing apparatus 7.

  The image processing apparatus 7 includes a CPU 71 having a function of executing arithmetic processing and outputting an instruction, a ROM 72 storing a program for causing the CPU 71 to execute a procedure for image processing, and the processing operation of the CPU. Therefore, a computer 70 including a RAM 73 for temporarily storing the above-described program read from the ROM 72, data necessary for processing of the CPU, and the like, an input unit 74 for inputting data, commands, and the like, A display unit 75 for displaying the output of the CPU and storage means (not shown) for storing image data as necessary are provided.

  In the above configuration, the incident images α1 and α2 that have passed through each of the light incident units 10 and 12 pass through the polarization combining unit 2, the camera optical system unit 3, and the polarization separation unit 4, respectively, on the image sensor, respectively with P-polarized light and S An image separated into polarized light is formed. The P and S polarized images are slightly shifted from each other according to the parallax of the light incident portions 10 and 12.

  The image is converted into an electrical signal by the image sensor, A / D converted, then entered into a built-in image signal processing circuit, subjected to processing such as shading correction and γ correction, and then recorded in the built-in memory. The image data recorded in the built-in memory is input to the image processing device 7 in response to an image data request from the image processing device 3. The image data input to the image processing device 7 is formed into two stereo images by the computer 70. The computer 70 of the image processing device 7 can also calculate, for example, the distance to the subject from the two images obtained in this way, and output it to an output device (not shown).

  FIG. 11 shows an embodiment when the polarization combining type stereoscopic photographing apparatus 1 of the present invention is incorporated in a casing of an electronic device such as a mobile phone, a pocket movie, or a digital camera. In the electronic apparatus of FIG. 11A, the light incident units 10 and 12 are arranged on a plane composed of the polarization combining unit 2, the camera optical system unit 3, and the polarization separation unit 4 as in the stereoscopic imaging apparatus of the embodiment of FIG. FIG. 11B shows an example of mounting when arranged on the orthogonal side, and the electronic apparatus of FIG. 11B includes a light combining unit 10 and a polarization combining unit 2 and a camera optical system as shown in FIG. 4 shows an example of mounting in the case where the unit 3 and the polarization separation unit 4 are arranged in a plane direction.

  In addition, the stereoscopic imaging apparatus of the present invention can make the distance measurement possible by further providing a configuration necessary for distance measurement and mounting the structure on an electronic apparatus. The distance measurement by the polarization combining type stereo camera is performed based on the already known triangulation principle. By performing arithmetic processing based on the principle of triangulation for each small area divided on the image, the distance to the object included in the small area can be obtained.

  The stereoscopic photographing apparatus according to the present invention can be widely applied to all photographing apparatuses such as a digital still camera. In addition, the present invention can be applied to a small photographing device suitable for carrying. Specifically, it is mounted on a portable information terminal or a mobile phone.

DESCRIPTION OF SYMBOLS 1 Polarization composition type | formula three-dimensional imaging device 2 Polarization composition part 3 Camera optical system part 4 Polarization separation part 4 '2nd prism 4''Polarization separation film 5,6 Image sensor 7 Image processing apparatus 9 Polarizing sheet 10, 12 Light incident part DESCRIPTION OF SYMBOLS 11 Polarization correction sheet | seat 13 1st prism 13 'Polarization separation film 41 1st lens holder 42 2nd lens holder 43 1st drive system 44 2nd drive system 45 Step motor 46 Lead screw 70 Computer 71 CPU
72 ROM
73 RAM
74 Input unit 75 Display unit

Claims (6)

Two light incident parts for capturing subject images with different parallaxes;
A polarization beam combining unit that combines the two object images captured by the light incident unit as different polarized lights on one optical axis;
An optical system disposed on the optical axis;
A drive unit for driving the optical system;
A stereoscopic photographing device including a polarization separation unit that separates a subject image from the optical system into each polarized light;
The optical axis is arranged shifted from the center of the two light incident portions,
The stereoscopic photographing apparatus, wherein the drive unit is disposed on the opposite side of the optical axis with respect to the center of the two light incident portions. The optical system includes a zoom lens and a focus lens,
The drive unit includes a first lens holder that holds the zoom lens, a second lens holder that holds the focus lens,
The stereoscopic photographing apparatus according to claim 1, further comprising: a first drive system that drives the first lens holder; and a second drive system that drives the second lens holder.   The stereoscopic imaging apparatus according to claim 2, wherein the driving unit includes the first driving system and the second driving system arranged in parallel with the optical axis. The second lens holder is
A frame for holding the lens;
A holder arm extending from the frame,
A threaded portion provided at an end of the holder arm,
The stereoscopic photographing apparatus according to claim 3, wherein the holder arm straddles the first driving system and causes the screwing portion to be screwed to a lead screw of the second driving system.   The stereoscopic photographing apparatus according to claim 4, wherein the holder arm is formed wider than the screwing portion.   An electronic apparatus comprising the three-dimensional imaging device according to any one of claims 1 to 5.