JP4490756B2 - Stereo imaging device - Google Patents

Description

  The present invention relates to a stereoscopic image capturing apparatus that captures an integral photography stereoscopic image.

  In general, an integral photography method (IP method, Integral Photography) is known as one of three-dimensional image methods capable of freely observing a three-dimensional image from an arbitrary viewpoint of an observer (for example, Patent Document 1). reference).

  Three-dimensional image capturing (IP image capturing) in the three-dimensional image capturing apparatus disclosed in Patent Document 1 will be described with reference to FIGS. 6 to 8, and three-dimensional image display (IP image display) will be described with reference to FIG. The description will be given with reference.

  FIG. 6 is a schematic diagram of a stereoscopic image capturing apparatus disclosed in Patent Document 1. As shown in FIG. 6, the stereoscopic image pickup apparatus 101 includes a concave lens plate 103 in which five concave lenses 103a to 103e are arranged in a plane, an imaging lens and a photographic film, and focuses on the concave lens plate 103. And (in focus) the imaging camera 105, and H indicates a subject. In order to simplify the description, the number of concave lenses 103a to 103e in the concave lens plate 103 is five. However, in reality, several thousand to several tens of thousands of concave lenses are used for the concave lens plate 103. Yes.

  In this stereoscopic image pickup apparatus 101, the subject H is picked up by the image pickup camera 105 through the concave lens plate 103. An image captured (acquired) by the imaging camera 105 is denoted as an element image G, and this element image G is shown in FIG. As shown in FIG. 7, the element image G is obtained by imaging the subject H on the concave lenses 103 a to 103 e of the concave lens plate 103. More specifically, in the concave lens 103a, the subject H is imaged at the rightmost position (uppermost in FIG. 6) with respect to the center of the lens, and the concave lens 103b is positioned on the right side (upper in FIG. 6) with respect to the center of the lens. The subject H is imaged at the position, the subject H is imaged at the center (middle in FIG. 6) of the concave lens 103c, and the subject is positioned at the left side (lower in FIG. 6) of the concave lens 103d. H is imaged, and the object H is imaged at the position on the leftmost side (lowermost in FIG. 6) with respect to the center of the lens in the concave lens 103e.

  In FIG. 6, the subject H is arranged in front of the concave lens plate 103 (the opposite side where the imaging camera 105 is arranged). However, as described in detail in Non-Patent Document 1, in the IP method, when the subject H is arranged in front of the concave lens plate 103, a reproduced image (image Z) of the subject H appears near the concave lens plate 103. Further, it is said that the resolution of the stereoscopic image to be reproduced is relatively better when the position of the subject H is adjusted.

  Therefore, it is practically configured as a stereoscopic image capturing apparatus 101A as shown in FIG. In this stereoscopic image capturing apparatus 101 </ b> A, a convex lens 107 that adjusts the direction of light rays after passing through the concave lens plate 103 is disposed between the concave lens plate 103 and the imaging camera 105.

Next, stereoscopic image display (IP image display by an IP display) will be described with reference to FIG.
FIG. 9 is a schematic diagram of an IP display. As shown in FIG. 9, the IP display 109 is composed of a convex lens plate 111 having convex lenses arranged in a plane and a display element 113 such as a transmission type photographic film. R indicates a stereoscopic image, and this stereoscopic image R is observed from the observation direction indicated by the arrow. In a general IP display, when a convex lens is used at the time of image capturing and display, it is necessary to convert the captured element image into point symmetry. However, if a concave lens is used at the time of imaging, the captured element image can be used at the time of display without being converted into point symmetry.

  That is, the IP display 109 displays the element image G captured (acquired) by the imaging camera 105 of the stereoscopic image capturing apparatus 101 (101A) described with reference to FIGS. 6 to 8 on the display element 113, When viewed from the observation direction through the convex lens plate 111 (observation), the stereoscopic image R is raised at the position where the subject H exists.

JP 2000-308091 (paragraphs 0014 and 0015, FIG. 1) Journal of the Optical Society of America, Vol. 15, no. 8, p. 2059-2065, 1998

  However, although it is described in the stereoscopic image capturing apparatus 101 (Patent Document 1) using the conventional concave lens plate 103 that the captured element image G can be directly input to the IP display, when the concave lens plate 103 is used, The element image G of the subject H existing at the depth position is generated as a virtual image, and in order to capture the element image G that has passed through the concave lens plate 103, the imaging camera 105 including an imaging lens and a photographic film is used. The element image G was reprojected by the imaging lens. For this reason, there is a problem that the IP display 109 that displays a three-dimensional image cannot be directly input unless it passes through an imaging lens.

  Accordingly, an object of the present invention is to solve the above-described problem and provide a stereoscopic image capturing apparatus that can directly input to an IP display that displays a stereoscopic image.

  In order to solve the above-described problem, a stereoscopic image capturing apparatus according to claim 1 is a stereoscopic image capturing apparatus that captures an integral photography stereoscopic image, and includes a concave lens plate, an objective lens, and an imaging unit. It was set as the structure provided.

  According to such a configuration, the stereoscopic image capturing apparatus allows the objective lens to be freely arranged at a position for adjusting the distance from the subject to be imaged to the concave lens plate in which the concave lenses are arranged in an array. The light (substance light) that has passed through the plate is imaged as an element image including the subject by the imaging means. That is, the objective lens can be freely arranged, and the light passing through the concave lens plate is imaged while adjusting the distance from the subject. In addition, since an imaging lens to be re-projected is not required in the imaging unit as in the prior art, it is possible to directly input an element image captured by the imaging unit directly to the IP display.

  In addition to preparing several types of objective lenses having different curvatures and making them interchangeable, it is also possible to provide objective lens position adjusting means for adjusting the position of the objective lens.

  The stereoscopic image capturing apparatus according to claim 2 is the stereoscopic image capturing apparatus according to claim 1, wherein a shielding plate that prevents interference of the light between the concave lenses is interposed between the concave lens plate and the imaging unit. It is characterized by making it.

  According to such a configuration, in the stereoscopic image capturing apparatus, interference of light that has passed through the concave lens is prevented by the shielding plate.

  The stereoscopic image capturing apparatus according to claim 3 is the stereoscopic image capturing apparatus according to claim 1 or 2, wherein the imaging unit is a photoelectric conversion element that converts the light into an electrical signal. .

  According to such a configuration, since the photographing unit is configured by the photoelectric conversion element, the stereoscopic image capturing apparatus can easily obtain an element image that becomes a stereoscopic image at low cost.

  According to the first aspect of the present invention, the objective lens can be arranged freely, the light passing through the concave lens plate is picked up by the image pickup means while adjusting the distance, and the image is reprojected by the image pickup means. Since it is not necessary to prepare a lens, it is possible to directly input the element image captured by the imaging unit directly to the IP display.

  According to the second aspect of the present invention, the shielding plate prevents interference of light that has passed through the concave lenses of the concave lens plate, so that the stereoscopic image when the element image captured by the imaging unit is reproduced is a multiple image. Can be prevented.

  According to the third aspect of the present invention, it is possible to easily obtain an element image to be a stereoscopic image at low cost by the imaging means configured by the photoelectric conversion element.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
<Configuration of stereoscopic imaging device>
FIG. 1 is a schematic diagram of a stereoscopic image capturing apparatus. As shown in FIG. 1, the stereoscopic image capturing apparatus 1 is for capturing a stereoscopic image of a subject H, and includes a concave lens plate 3, an objective lens 5, and an imaging unit 7. In FIG. 1, a symbol H indicates a subject, and a symbol Z indicates an image of the subject H.

  The concave lens plate 3 has a plurality (five) of concave lenses 3a to 3e arranged in an array on the same plane. The concave lens plate 3 is disposed between the objective lens 5 and the imaging means 7 so as to face each other. Each concave lens 3 a to 3 e constituting the concave lens plate 3 generates an element image that is an image Z of the subject H incident through the objective lens 5.

  The objective lens 5 is disposed between the concave lens plate 3 and the subject H to be imaged, and adjusts the distance from the subject H to the concave lens plate 3. The objective lens 5 is configured to move in parallel in the optical axis direction between the concave lens plate 3 and the subject H by a moving means (not shown). Incidentally, the aperture of the objective lens 5 has a size that allows light to enter all the concave lenses 3 a to 3 e constituting the concave lens plate 3.

  The objective lens 5 is composed of a single convex lens. In addition to the single convex lens, the objective lens 5 includes a single concave lens, a refractive index distribution lens, a diffraction grating, or a combination of any of these optical elements. In this case, it is sufficient that the focal length of the convex lens is shorter than the focal length of the concave lenses 3 a to 3 e, and the objective lens 5 has the same function as that of one convex lens, so a real image of the subject H is generated in the vicinity of the concave lens plate 3. To do.

  When the focal length of the objective lens 5 is f0, the distance from the subject H to the principal point of the objective lens 5 is L21, and the distance from the principal point of the objective lens 5 to the image Z of the subject H is L22, the following formula (1) ) Can represent these relationships.

  L22 = f0 · L21 / (L21 + f0) (1)

  Therefore, in the stereoscopic image pickup apparatus 1, the image Z of the subject H is generated at the position of the distance L22 from the objective lens 5, so that the concave lens plate 3 is placed at the position of the distance L11 from the image Z so that the image Z is focused. If the image pickup means 7 is arranged at a distance L12 from the concave lens plate 3, an element image with good resolution can be obtained for the subject H. Then, a stereoscopic image can be generated by inputting the element image captured by the stereoscopic image capturing apparatus 1 to the conventional IP display 109 (see FIG. 9) described in the background art.

  The image pickup means 7 picks up element images (images Z) generated by the concave lenses 3 a to 3 e of the concave lens plate 3. In this embodiment, the imaging means 7 is composed of a photographic film. Here, the element image by each concave lens 3a-3e imaged with the imaging means 7 is shown in FIG.

  As shown in FIG. 2, in the element image, only the black portion at the lower end portion of the image Z of the subject H is captured on the concave lens 3a, and the black and white portion near the lower end of the image Z of the subject H is captured on the concave lens 3b. The middle lens of the image H of the subject H and the white portions on both sides thereof are imaged on the concave lens 3c, and the black and white portion near the upper end of the image Z of the subject H is captured on the concave lens 3d. The concave lens 3e captures only the black portion at the lower end of the image H of the subject H.

  Here, when the focal length of the concave lenses 3a to 3e is fc and the distance from the concave lenses 3a to 3e (concave lens plate 3) to the image Z of the subject H (image Z of the subject H by the objective lens 5) is L11, the image Z The element image is generated at a distance L12 from the concave lenses 3a to 3e. The relationship between the focal length fc, the distance L11, and the distance L12 is expressed by the following formula (2). Moreover, the state of the concave lens 3c and the element image is shown in FIG.

  L12 = fc · L11 / (L11 + fc) (2)

  As shown in FIG. 3, an image Z by the subject H is generated at a distance L11 from the concave lens 3c, and an element image of the image Z is generated at a distance L12. That is, the imaging means 7 is arranged at a distance L12 from the concave lens 3c (concave lens plate 3).

  In addition to the photographic film, the image pickup means 7 may be configured by a photoelectric conversion element that converts an element image based on the image Z of the subject H that is incident light into an electric signal. The photoelectric conversion element is, for example, a CCD (Charge Coupled Device).

  As shown in FIG. 4, a shielding plate 9 is provided between the concave lens plate 3 and the imaging unit 7 to prevent interference of light passing through the concave lenses 3 a to 3 e. That is, the shielding plate 9 is interposed between the concave lens plate 3 in which the concave lenses 3a to 3e are arranged (arranged) and the imaging means 7, and passes through the adjacent concave lenses 3a to 3e, that is, the subject. The element image by the image Z of H is prevented from interfering. If there is interference between element images obtained from the adjacent concave lenses 3a to 3e, a stereoscopic image generated using these element images becomes a multiple image. The shielding plate 9 can prevent a stereoscopic image from becoming a multiple image.

Returning to FIG. 1, the description of the configuration of the stereoscopic image capturing apparatus 1 will be continued.
According to the three-dimensional image pickup apparatus 1, the image pickup means 7 constituted by a photographic film or the like is disposed behind the concave lens plate 3 after passing through the concave lenses 3 a to 3 e constituting the concave lens plate 3. Since it is configured, it is not necessary to use a reprojection lens arranged in a conventional stereoscopic image capturing apparatus in order to project onto the image capturing means 7 that is an image capturing medium, and the captured elemental image is directly used as an IP display. Can be entered.

  Further, according to the stereoscopic image capturing apparatus 1, by configuring the imaging unit 7 with a photographic film or a photoelectric conversion element, an element image that becomes a stereoscopic image can be easily obtained at a low cost.

  Furthermore, according to the stereoscopic image capturing apparatus 1, since the interference of the light that has passed through the concave lenses 3a to 3e of the concave lens plate 3 is prevented by the shielding plate 9, the element image captured by the imaging unit 7 is reproduced. It is possible to prevent the stereoscopic image from becoming a multiple image.

  In this stereoscopic image capturing apparatus 1, the focal lengths fc of the concave lenses 3a to 3e of the concave lens plate 3 are set so that one subject H is in focus, but exist at a plurality of different depths. The focal length fc of the concave lenses 3a to 3e may be set so that the subject (not shown) is in focus. For example, a concave lens plate may be configured in which every other concave lens having focal lengths fc and fc ′ (not shown) is arranged so that subjects with different depths are in focus.

  In this stereoscopic image capturing apparatus 1, the example in which the concave lens plate 3 is configured by the five concave lenses 3 a to 3 e has been described. However, in reality, the concave lens plate 3 includes an optical element group using tens of thousands of optical elements. The shielding plate 9 (optical shielding plate) may be arranged so as to correspond to this optical element group.

<Operation of stereoscopic imaging device>
Next, the operation of the stereoscopic image capturing apparatus 1 will be described with reference to the flowchart shown in FIG. 5 (see FIG. 1 as appropriate).
First, in the stereoscopic image capturing apparatus 1, the distance from the subject H to the concave lens plate 3 is adjusted in advance by the objective lens 5 (step S1).

  Then, the stereoscopic image capturing apparatus 1 passes the light from the subject H, that is, the image Z of the subject H, through the objective lens 5 to the concave lens plate 3 (step S2). Then, the stereoscopic image capturing apparatus 1 captures an element image by the light (image Z of the subject H) that has passed through the concave lens plate 3 by the image capturing unit 7 (step S3).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the present embodiment, it is possible to regard each process by each configuration of the stereoscopic image capturing apparatus 1 as a stereoscopic image capturing method that is regarded as a method of capturing a stereoscopic image. In this case, the same effect as that of the stereoscopic image capturing apparatus 1 can be obtained.

1 is a schematic diagram of a stereoscopic image capturing apparatus according to an embodiment of the present invention. It is a figure explaining the example of the element image imaged with the stereo image imaging device shown in FIG. It is a figure explaining the relationship between the image which passed the concave lens, and an element image. It is the schematic diagram which showed the shielding board. 2 is a flowchart illustrating an operation of the stereoscopic image capturing apparatus illustrated in FIG. 1. It is a schematic diagram of the conventional stereo image imaging device. It is a figure explaining the example of the element image imaged with the conventional stereo image imaging device. It is a schematic diagram of another conventional stereoscopic image capturing device. It is a schematic diagram of the conventional IP display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stereoscopic image pickup device 3 Concave lens plate 3a-3e Concave lens 5 Objective lens 7 Imaging means 9 Shielding plate

Claims (3)

A stereoscopic image capturing apparatus that captures an integral photography stereoscopic image,
A concave lens plate in which a plurality of concave lenses are arranged in an array on the same plane;
An objective lens disposed between the concave lens plate and a subject to be imaged;
Moving means for moving the objective lens in the optical axis direction;
Imaging means for imaging light that has passed through the concave lens plate as an element image of the subject;
A stereoscopic image pickup apparatus comprising:   The stereoscopic image capturing apparatus according to claim 1, wherein a shielding plate that prevents interference of the light between the concave lenses is interposed between the concave lens plate and the imaging unit.   The stereoscopic image capturing apparatus according to claim 1, wherein the imaging unit is a photoelectric conversion element that converts the light into an electrical signal.

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