JP2011150068A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify adjustment of photographing with minimized restrictions on layout. <P>SOLUTION: A three-dimensional digital camera includes: a first photographic lens and a second photographic lens to take in first photographing light and second photographing light; an imaging device to convert the photographing light into an electrical signal; an imaging optical system to form an image on the imaging device with the photographing light; a first optical path to guide the first photographing light to the imaging optical system; a second optical path to guide the second photographing light to the imaging optical system; and an imaging controller configured to alternately switch a first photographing state in which the image is formed on the imaging device by making the first optical path open in a state where the second optical path is intercepted, and guiding the first photographing light to the imaging optical system, and a second photographing state in which the image is formed on the imaging device by making the second optical path open in a state where the first optical path is intercepted, and guiding the second photographing light to the imaging optical system, to control the imaging device, and to convert the first photographing light into the electrical signal in the first photographing state and convert the second photographing light into the electrical signal in the second photographing state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a digital camera having two photographing lenses.

Recently, there is an increasing demand for digital cameras capable of taking 3D images. In order to obtain a three-dimensional photographed image with such a three-dimensional digital camera, it is necessary to photograph two photographed images simultaneously with two lenses separated by a distance corresponding to the distance of the human eye.
As a general three-dimensional digital camera capable of photographing a three-dimensional image, a three-dimensional digital camera including two imaging units including an imaging element and a photographing lens is known (for example, see Patent Document 1). .

  Moreover, not only a three-dimensional digital camera but also a digital camera having two imaging systems exists (see, for example, Patent Documents 2 and 3).

JP 2002-300388 A JP 2006-081089 A Japanese Patent Laid-Open No. 2008-075511

  In a conventional 3D digital camera, it is necessary to arrange two identical lens groups in the horizontal direction. However, since the two lens groups occupy most of the camera, there is a problem that the layout is restricted. . In addition, since each lens is individually controlled, for example, when the zoom function is realized by the lens, deviation in adjustment of magnification and angle of view is likely to occur. In addition, it is necessary to consider variations in individual parts of the lens and the image sensor, assembling variations, operation variations, and the like.

  FIG. 6 shows an example of an imaging system of a conventional three-dimensional digital camera. The conventional imaging system includes left and right front lens 110a and 110b, first shutter 112a and 112b, second shutter 113a and 113b, left and right zoom lens groups 103a and 103b, left and right focus lenses 104a and 104b, left and right. Imaging elements 107a and 107b and left and right prisms 114a and 114b. The left and right front lens 110a and 110b are arranged at a distance of about 60 mm, which corresponds to the distance between the left and right eyes of a human. Behind each of the front lens 110a and 110b, two pieces of photographing light collected by the front lens 110a and 110b are reflected at an angle of 90 ° and guided to the zoom lens groups 103a and 103b, the focus lenses 104a and 104b, and the like. Prisms 114a and 114b are arranged (see FIG. 6 (2)). Since the zoom lens groups 103a and 103b and the focus lenses 104a and 104b have optical axes 141 and 142, respectively, and are provided as movable lenses, two images are simultaneously captured using the left and right imaging elements 107a and 107b. In some cases, if these lenses do not move exactly the same, a difference occurs in the angle of view and magnification. In addition, there is a problem in that, for example, if the time for focusing is shifted, the shooting may be hindered. Further, this type of problem is not limited to a three-dimensional digital camera, but generally exists in a digital camera having a plurality of photographing lenses.

  The present invention has been made in view of the above-described conventional problems, and is a three-dimensional digital camera that minimizes the adjustment of the angle of view, magnification, focus, and the like of an optical system at the time of shooting while minimizing layout restrictions. The purpose is to provide.

  A three-dimensional digital camera according to a first aspect of the present invention includes a first photographing lens that takes in first photographing light, a second photographing lens that takes in second photographing light, and converts the photographing light into an electrical signal. An image pickup device, an image pickup optical system that forms image light on the image pickup device, a first optical path that guides the first image pickup light to the image pickup optical system, and the second image pickup light to the image pickup optical system A first optical path to be guided, and a first optical path that is opened in a state where the second optical path is blocked, the first imaging light is guided to the imaging optical system, and a first image is formed on the imaging element A shooting state; a second shooting state in which the second optical path is opened in a state where the first optical path is blocked, the second shooting light is guided to the imaging optical system, and an image is formed on the imaging element; Are alternately switched and the image sensor is controlled so that in the first shooting state, The first photographing light, in the second shooting state is characterized by comprising an imaging control unit for converting the second photographing light into electrical signals.

  The three-dimensional digital camera according to the second aspect of the present invention further includes an elongated cylindrical portion in which the first optical path and the second optical path extend, and the cylindrical portion has one end portion. In addition, the first photographing light is reflected at a 90 ° angle to guide the first photographing light toward the inside of the cylindrical portion, and the second photographing light is provided at the other end portion at a 90 ° angle. A second reflecting portion that is reflected by the light and guided in an inner direction of the cylindrical portion, and the first photographing light and the second photographing that are incident between the first reflecting portion and the second reflecting portion. A spectroscopic unit that reflects light at an angle of 90 ° and guides the light to the imaging optical system.

  In the three-dimensional digital camera according to the third aspect of the present invention, the spectroscopic section first converts the S wave polarization component contained in the first reflected light from the first reflection section into a P wave polarization component. A birefringent surface, a second birefringent surface for phase-converting an S wave polarization component contained in the second reflected light from the second reflecting portion into a P wave polarization component, and the first birefringence surface And a prism block in the shape of a rectangular parallelepiped having a plane perpendicular to the first reflected light and the second reflected light, and a center of the prism block, A third birefringent surface that is provided perpendicular to the first reflected light and the second reflected light and that converts the S wave polarization component contained in the transmitted light to be transmitted into a P wave polarization component; The prism block is a surface inclined at an angle of 45 ° with respect to the first reflected light, The first reflected light incident through the birefringent surface is reflected at an angle of 90 ° and guided to the imaging optical system, and transmitted through the first birefringent surface and incident. A first spectral plane comprising: a first spectral plane that transmits a P-wave polarization component included in the first reflected light and reflects the S-wave polarization component at an angle of 90 ° to guide the imaging optical system. A reflective surface and a surface inclined at an angle of 45 ° with respect to the second reflected light, and the second reflected light incident through the second birefringent surface at an angle of 90 °. A P-wave polarization component contained in the second reflection surface that is reflected and guided to the imaging optical system and the second reflection light that is transmitted through and incident on the second birefringence surface is transmitted, and an S-wave polarization is transmitted. And a second spectral reflecting surface that reflects the component at an angle of 90 ° and guides the component to the imaging optical system. The reflection surface and the second spectral reflection surface intersect at right angles, the first reflection surface and the second reflection surface are formed above the formed intersection line, and the first spectral surface is below The second spectroscopic surface is formed.

  In the three-dimensional digital camera according to the fourth aspect of the present invention, the prism block has a first prism having a surface perpendicular to the first reflected light, and is perpendicular to the second reflected light. A second prism having a surface and having a top line abutting the top line of the first prism; and an upper right angle defined by the first prism and the top line and surface of the second prism. An upper first prism and an upper second prism disposed in a triangular prism-shaped space, the upper first prism having a surface inclined at an angle of 45 ° with respect to the first reflected light; An upper second prism having a surface inclined at an angle of 45 ° with respect to the second reflected light, and a lower portion defined by a top line and a surface of the first prism and the second prism. The lower first arranged in the space of the shape of a right triangular prism A lower first prism having a surface inclined at an angle of 45 ° with respect to the first reflected light, and an angle of 45 ° with respect to the second reflected light. A lower second prism having an inclined surface, and the third birefringent surface includes the upper first prism, the upper second prism, the lower first prism, and the lower second prism. 2 is provided perpendicular to the first optical path and the second optical path at a boundary surface between the first prism and the upper first prism. An optical reflecting surface formed at a boundary, wherein the first spectroscopic surface is formed by a boundary surface between the lower second prism and the second prism, and the second reflecting surface is the first reflecting surface. Formed at the boundary between the second prism and the upper second prism It is an optical reflecting surface, and the second spectroscopic surface is formed by a boundary surface between the lower first prism and the first prism.

  When the three-dimensional digital camera according to the fifth aspect of the present invention switches from the first shooting state to the second shooting state or from the second shooting state to the first shooting state, the The imaging element is characterized by sweeping out accumulated charges.

  A three-dimensional digital camera according to a sixth aspect of the present invention is characterized in that the imaging optical system includes a zoom lens and a focus lens.

  According to the present invention, it is possible to provide a three-dimensional digital camera that minimizes the adjustment of the angle of view, the magnification, the focus, and the like of the optical system at the time of shooting while minimizing layout constraints.

1 is an external view of a three-dimensional digital camera according to an embodiment of the present invention. FIG. 2 is a block diagram for explaining a configuration of a control circuit of the three-dimensional digital camera of FIG. 1. It is sectional drawing which shows the structure of the imaging system of the three-dimensional digital camera of FIG. It is sectional drawing explaining the relationship between the prism block of the three-dimensional digital camera of FIG. 1, and imaging | photography light. It is sectional drawing explaining the relationship between the prism block of the three-dimensional digital camera of FIG. 1, and imaging | photography light. It is sectional drawing which shows an example of the imaging system of the conventional three-dimensional digital camera.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an external appearance of a digital camera 1 that constitutes a three-dimensional digital camera according to an embodiment of the present invention, and FIG. 1 (1) is a front view of the digital camera 1, and FIG. (2) is a rear view of the digital camera 1.

  As shown in FIG. 1 (1), the three-dimensional digital camera 1 has two front lens 10a constituting the imaging system 2 (see FIG. 2) on the front side of the housing 5 of the three-dimensional digital camera 1. 10b. Further, as shown in FIG. 1B, on the back surface of the housing 5 of the three-dimensional digital camera 1, a cursor key 8, a display monitor 11, and a zoom key 16 (W (wide angle) button 16a, T (telephoto)) are provided. A button 16b), a mode setting dial 19 for determining shooting conditions, and the like are provided. A shutter key 17 and a power button 18 are provided on the upper surface of the housing 5 of the three-dimensional digital camera 1, and a side portion of the housing 5 is connected to an external device such as a personal computer (hereinafter referred to as a personal computer) or a modem. A USB terminal connection unit used when connecting to a USB cable is provided.

  FIG. 2 is a block diagram for explaining the configuration of the control circuit of the three-dimensional digital camera 1 according to the embodiment of the present invention.

  The three-dimensional digital camera 1 includes an imaging system 2, a display monitor 11, a shutter control unit 21, a lens control unit 22, a shutter drive unit 24, a lens drive unit 25, a timing generation unit 29, a signal processing unit 30, an image processing unit 31, A display processing unit 32, a recording unit 34, an operation unit 36, and a camera control unit 37 are provided. The camera control unit 37 includes a shutter control unit 21 and a lens control unit 22. The shutter control unit 21 constitutes an imaging control unit according to the present embodiment.

  The imaging system 2 includes a first front lens 10a, a second front lens 10b, first shutters 12a and 12b, second shutters 13a and 13b, a prism block 14, zoom lenses 3A and 3B, and a focus lens 4. The image sensor 7 is included. The first shutters 12 a and 12 b, the second shutters 13 a and 13 b, and the prism block 14 are formed inside a cylindrical portion 23 provided in the housing 5 of the three-dimensional digital camera 1. The zoom lenses 3A and 3B and the focus lens 4 constitute the imaging optical system according to the present embodiment. The prism block 14 constitutes a spectroscopic unit according to the present embodiment.

  The first front lens 10a and the second front lens 10b are arranged at a distance close to the distance between human eyes (about 60 mm), and the first front lens 10a has an optical axis 41. The second front lens 10b has an optical axis 42 (see FIG. 3 (1)).

  The first shutter 12a, 12b and the second shutter 13a, 13b are disposed in the cylindrical portion 23, and are photographed light from the first front lens 10a or photographed from the second front lens 10b. Is shut off or opened. Specifically, the first shutters 12a and 12b function as mechanical shutters that block or open the photographing light from the first front lens 10a by being opened and closed by being driven by the shutter driving unit 24. The second shutters 13a and 13b function as mechanical shutters that block or open the photographing light from the second front lens 10b by being opened and closed by being driven by the shutter driving unit 24.

  The prism block 14 is composed of a plurality of prisms disposed in the cylindrical portion 23, and the first front lens 10a according to the opening and closing of the first shutters 12a and 12b and the second shutters 13a and 13b. The imaging light from the second front lens 10 b is selectively guided to the zoom lens group 3, the focus lens 4, and the image sensor 7. In order to facilitate understanding, in FIG. 2, the photographic light guided from the first front lens 10a and the second front lens 10b to the zoom lens group 3, the focus lens 4, and the image sensor 7 are respectively luminous flux 41L and Shown as 42L.

  The zoom lens group 3 includes zoom lenses 3A and 3B, and is driven forward and backward by the lens driving unit 25 along the directions of the light beams 41L and 42L. Optical zoom adjustment of the imaging system 2 is performed by driving the zoom lens group 3 forward and backward.

  The focus lens 4 is driven forward and backward along the direction of the light beams 41L and 42L by the lens driving unit 25. The focus adjustment of the imaging system 2 is performed by driving the focus lens 4 forward and backward.

  The imaging device 7 photoelectrically converts light and darkness of the subject image formed on the imaging surface into an amount of electric charge (hereinafter referred to as “imaging charge”), sequentially reads the accumulated imaging charge, and converts it into an electrical signal. Convert. The image sensor 7 also has an electronic shutter function for accumulating imaging charges and sweeping the accumulated imaging charges based on the control of the shutter control unit 21. As will be described later, in the present embodiment, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or the like having a short time required for sweeping out charges is preferable as the image sensor 7.

  The shutter control unit 21 drives the shutter drive unit 24 based on the operation signal input from the operation unit 36, and opens and closes the first shutter 12a, 12b and the second shutter 13a, 13b. The shutter control unit 21 also controls an electronic shutter function that sweeps out imaging charges accumulated in the imaging element 7 in accordance with opening and closing of the first shutters 12a and 12b and the second shutters 13a and 13b.

  The lens control unit 22 drives the lens driving unit 25 based on the operation signal input from the operation unit 36 to drive the zoom lens group 3 and the focus lens 4.

  The signal processing unit 30 performs predetermined signal processing (for example, color interpolation processing, γ correction processing, white balance processing, shading correction processing, etc.) after converting the analog imaging signal into a digital signal. The timing generation unit 29 generates a read timing signal for an image pickup signal read from the image sensor 7.

  The image processing unit 31 converts the format of the image data input from the signal processing unit 30 into a predetermined data format, or gives the image data to the display processing unit 32. The display processing unit 32 generates a video signal using the image data and sends it to the display monitor 11.

  The display monitor 11 is configured by a liquid crystal display panel or the like, and displays an image or the like based on a video signal input from the display processing unit 32. The display image is recorded in the recording unit 34, a live view image that is sequentially captured by the image sensor 7 before the still image capturing instruction, a still image that is captured by the image sensor 7 after the still image capturing instruction, and a moving image at the time of moving image capturing. There are replay images based on existing image data. These images can be displayed on the display monitor 11 by electrically changing the display angle of view (electronic zoom) by operating the operation unit 36.

  The recording unit 34 is configured by a removable memory card or the like. In the shooting mode, the recording unit 34 records the image data whose format has been converted by the image processing unit 31. In the reproduction mode, the image data recorded in the recording unit 34 is read and sent to the image processing unit 31. The image processing unit 31 generates a video signal for displaying a reproduced image. Note that the three-dimensional digital camera 1 is configured to be able to select each of a still image shooting mode and a moving image shooting mode, and audio data may be recorded during moving image shooting.

  The operation unit 36 includes a zoom key 16, a shutter key 17, a power button 18, a mode setting dial 19, a release (half press switch, full press switch) switch, and the like, and generates an operation signal based on an operation condition corresponding to each operation. To the camera control unit 37. Thereby, for example, when the zoom key 16 is operated by the operator, a predetermined magnification (for example, 1 to 12 times) is set as the imaging condition, and is set when the shutter key 17 is pressed. An operation signal for photographing based on the conditions is sent to the camera control unit 37.

  The camera control unit 37 is configured to include a CPU, a ROM storing a control program executed by the CPU, and a work RAM (not shown), and outputs a command to each block according to an operation signal input from the operation unit 36. And control the camera operation.

<Description of imaging system>
FIG. 3 is a sectional view showing the structure of the imaging system 2 of the three-dimensional digital camera 1 according to the embodiment of the present invention. FIG. 3 (1) is a top sectional view of the three-dimensional digital camera 1. 3 (2) is a front sectional view of the three-dimensional digital camera 1, and FIG. 3 (3) is a side sectional view of the three-dimensional digital camera 1. FIG.

  The prism block 14 is composed of a plurality of prisms disposed in the cylindrical portion 23. In the optical path between the first front lens 10a and the second front lens 10b, the prism block 14 includes the first front lens 10a. The first prism surface 14a formed at an angle of 45 ° with respect to the optical axis 41, and the second prism formed at an angle of 45 ° with respect to the optical axis 42 of the second front lens 10b. The optical axis 42A reflected by the second prism surface 14b and the third prism surface 14c formed at an angle of 45 ° with respect to the light of the optical axis 41A reflected by the surface 14b and the first prism surface 14a. The fourth prism surface 14d is formed at an angle inclined by 45 ° with respect to the light. The 1st prism surface 14a and the 2nd prism surface 14b comprise the 1st reflective part and 2nd reflective part which concern on this Embodiment, respectively.

  The first prism surface 14a reflects the imaging light from the first front lens 10a at an angle of 90 ° and guides it to the inside of the cylindrical portion 23, and the second prism surface 14b It is designed so that the photographing light from the ball lens 10 b is reflected at an angle of 90 ° and guided toward the inside of the cylindrical portion 23.

  The third prism surface 14c reflects the photographic light reflected by the first prism surface 14a at an angle of 90 °, and guides it to the zoom lens group 3, the focus lens 4, and the image sensor 7 to provide a fourth prism. The surface 14d is designed to reflect the photographing light reflected by the second prism surface 14b at an angle of 90 ° and guide it to the zoom lens group 3, the focus lens 4, and the image sensor 7.

  As shown in FIG. 3 (1), the light including the optical axis 41 incident on the front lens 10a is reflected by the prism surface 14a of the prism block 14 and travels through the cylindrical portion 23. Further, as shown in FIG. ), The light is reflected by the prism surface 14c and travels toward the image sensor 7 provided inside the housing 5 of the three-dimensional digital camera 1.

  Similarly, light including the optical axis 42 incident on the front lens 10b is reflected by the prism surface 14b of the prism block 14 and travels through the cylindrical portion 23 (see FIG. 3 (1)), and further, the prism surface 14d. Reflected toward the image sensor 7 provided inside the housing 5 of the three-dimensional digital camera 1 (see FIG. 3B).

The cylindrical portion 23 is formed with a first optical path through which reflected light from the prism surface 14a travels and a second optical path through which reflected light from the prism surface 14b travels. The first optical axis 41 included in the first optical path and the second optical axis 42 included in the second optical path have different directions but extend on the same straight line. In other words, the first optical path and the second optical path have different directions but extend on the same straight line.
When the shutter key 17 is pressed, an operation signal for shooting based on the set magnification is sent to the camera control unit 37, and the first front lens 10 a and the first lens are controlled based on the control of the shutter control unit 21. The first shutters 12a and 12b and the second shutters 13a and 13b disposed in the optical path between the second front lens 10b alternately open and close. Therefore, for taking a picture, only one of the light including the optical axis 41 incident on the first front lens 10a and the light including the optical axis 42 incident on the second front lens 10b is a tube. The light enters the corresponding prism surface among the prism surfaces 14 c and 14 d formed on the shape portion 23. The light incident on one of the prism surfaces 14c and 14d in this way is reflected, guided to the zoom lens group 3, and imaged on the image sensor 7 by the focus lens 4, and the image sensor 7 Thus, an imaging charge of the subject image is generated by photoelectric conversion. The prism surface 14c constitutes the first spectral reflection surface according to the present embodiment, and the prism surface 14d constitutes the second spectral reflection surface according to the present embodiment.

  Here, the image pickup device 7 also executes an electronic shutter function for accumulating the image pickup charge of the image pickup device 7 and sweeping out the accumulated image pickup charge based on the control of the shutter control unit 21. That is, based on the control of the shutter control unit 21, the imaging charges accumulated in the imaging element 7 are swept out and subsequently incident upon opening and closing of the first shutters 12a and 12b and the second shutters 13a and 13b. The light of the subject image is immediately photoelectrically converted and accumulated as an imaging charge.

  Referring to FIG. 3 together with FIG. 1, the three-dimensional digital camera 1 according to the present embodiment transmits the photographing light from the two front lens 10 a and 10 b to the shutters 12 and 13 via the prism block 14. The operation of selectively guiding the zoom lens group 3 and the focus lens 4 according to opening and closing to form an image on the image sensor 7 and imaging the image will be described.

  First, when the first shutters 12a and 12b are opened and the second shutters 13a and 13b are closed, the photographing light 41A incident from the first front lens 10a and reflected by the prism surface 14a is converted into the first shutter. 12a and 12b, reflected by the prism surface 14c, guided to the zoom lens group 3 as a light beam 41B, imaged on the image sensor 7 by the focus lens 4, and subject to photoelectric conversion by the image sensor 7 An imaging charge of the image is generated (see FIG. 3 (3)). On the other hand, the photographing light 42A incident from the second front lens 10b and reflected by the prism surface 14b is blocked by the second shutters 13a and 13b, and is applied to the zoom lens group 3, the focus lens 4 and the image sensor 7. There is no guidance.

When the first shutters 12a and 12b are closed and the second shutters 13a and 13b are opened, the photographing light 41A incident from the first front lens 10a and reflected by the prism surface 14a is the first It is blocked by the shutters 12a and 12b and is not guided to the zoom lens group 3, the focus lens 4 and the image sensor 7. On the other hand, the photographing light 42A incident from the second front lens 10b and reflected by the prism surface 14b passes through the second shutters 13a and 13b, is reflected by the prism surface 14d, and zooms as a light beam 42B. The light is guided to the lens group 3 and imaged on the image pickup device 7 by the focus lens 4, and photoelectric conversion is performed by the image pickup device 7 to generate an image pickup charge of the subject image (see FIG. 3 (3)).
<Configuration of prism block>

  Next, with reference to FIG. 4 and FIG. 5, the principle in which photographing light is guided to the zoom lens group 3 and the focus lens 4 by the prism surfaces 14 c and 14 d of the prism block 14 according to the present embodiment will be described.

As shown in FIG. 4, the prism block 14 forming the prism surface 14 c and the prism surface 14 d includes a first prism 14 ₁ , a second prism 14 ₂ , a third prism 14 ₃ , a fourth prism 14 ₄ , It has a rectangular parallelepiped shape including a surface perpendicular to the reflected light 41A and 42A, which is composed of a total of six prisms having a substantially right triangular prism shape, with the fifth prism 14 ₅ and the sixth prism 14 ₆ in total. Functions as a beam splitter. The first prism 14 ₁ and the second prism 14 ₂ are substantially the same size, and the third prism 14 _3, a fourth prism 14 _4, a prism 14 ₅ of the fifth, the passing mark 6 prisms 14 _{6 is} also substantially the same size. An air layer is provided between each prism.

Having a surface perpendicular to the first prism 14 ₁ photographic light 41A reflected by the prism surface 14a. The second prism 14 ₂ has a surface perpendicular to the photographing light 42A reflected by the prism surface 14b (see FIG. 5). The first prism 14 ₁ of the top line and the second prism 14 _{and second} top line are arranged opposite the first prism 14 ₁ of the top line and the second prism 14 _{and second} top line mutually contact, the top and bottom by first prism 14 ₁ and the second prism 14 _{and second} top line surface, right angle triangular prism space shape defined.

In the space of a right triangular prism shape formed on the top, and the third prism 14 ₃ with an angle with inclined surface at 45 ° to the reflected imaging light 41A in the prism surface 14a, reflected by the prism surface 14b a fourth prism 14 ₄ is disposed with a surface inclined at an angle of 45 ° with respect to imaging light 42A which is (see Fig. 5). The third prism 14 _3, the upper first prism according to the present embodiment, the fourth prism 14 _4, constituting the upper second prism according to the present embodiment.

In the space of a right triangular prism shape formed in a lower portion, a fifth prism 14 ₅ having an angle with inclined surface at 45 ° to the reflected imaging light 41A in the prism surface 14a, reflected by the prism surface 14b a prism 14 ₆ sixth is arranged having an inclined surface at an angle of 45 ° with respect to imaging light 42A which is (see Fig. 5). Prism 14 ₅ of the 5, the lower first prism according to the present embodiment, the prism 14 ₆ sixth, constituting the lower second prism according to the present embodiment.

  The photographing light incident from the first front lens 10a and the second front lens 10b has all polarization components randomly, and includes a P wave polarization component (hereinafter referred to as “P wave”) and an S wave polarization component. (Hereinafter referred to as “S wave”).

With respect to the first prism 14 _1, photographic light 41A-T, which is reflected by the prism surface 14a, the side where the 41A-B is incident, the first phase difference plate 15a for changing the polarization direction of the light is disposed When the photographing lights 41A-T and 41A-B from the prism surface 14a pass, the reflected light is polarized so that the P wave included in the reflected light is phase-converted to S wave and the S wave is phase converted to P wave. . The first phase difference plate 15a may be formed adhered to first prism 14 _1. The first retardation plate 15a constitutes the first birefringent surface according to the present embodiment.

  When light passes through an interface of 45 ° or more, the P wave is easily transmitted and the S wave is easily reflected. For this reason, the photographic light reflected by the prism surface 14a contains many S waves. The first phase difference plate 15a functions to phase-convert S waves, which are contained in a large amount of photographing light reflected by the prism surface 14a, into P waves. As a result, most of the polarization component of the photographing light that has passed through the first retardation plate 15a becomes a P wave.

Third prism 14 _3, the fifth prism 14 ₅ and the fourth prism 14 _4, between the prism 14 ₆ sixth, second retardation plate 15b is disposed, the third prism 14 _3, the light from the prism 14 ₅ of the fifth pass, P wave contained in the light in the S wave light so S wave is phase converted to P-wave is polarized. The second phase difference plate 15b, the third prism 14 _3, not only the light from the prism 14 ₅ of the fifth, fourth prism 14 _4, the light from the prism 14 ₆ sixth pass At the same time, the light is polarized so that the P wave included in the light is phase-converted into an S wave and the S wave is converted into a P wave. The second retardation plate 15b may be formed by being attached to any one of the third prism 14 ₃ , the fifth prism 14 ₅ , the fourth prism 14 ₄ , and the sixth prism 14 _6. Good. The second retardation plate 15b constitutes a third birefringent surface according to the present embodiment.

The second prism 14 _2, on the side where photographic light from the prism surface 14b is incident is disposed third retardation plate 15c is abundant in reflected imaging light in the prism surface 14b It functions to phase-convert S wave to P wave. The photographing light reflected by the prism surface 14b includes a lot of S waves. As a result, most of the polarization component of the photographing light that has passed through the third phase difference plate 15c is a P wave. Third retardation plate 15c may be formed adhered to second prism 14 _2. The third retardation plate 15c constitutes the second birefringent surface according to the present embodiment.

Further, upper half of the prism surface 14c that is defined between the first prism 14 ₁ and the third prism 14 _3, at least either one metal of the first prism 14 ₁ and the third prism 14 ₃ etc. It is a reflective surface formed by vapor deposition. For this reason, when the light 41A reflected by the prism surface 14a is incident, the light 41A is reflected at an angle of 90 ° and guided to the zoom lens group 3, the focus lens 4, and the image sensor 7. The upper half of the prism surface 14c constitutes the first reflecting surface according to the present embodiment.

Similarly, the upper half of the second prism 14 ₂ and the prism surface 14d defined by the fourth prism 14 _4, at least either one metal of the second prism 14 ₂ and the fourth prism 14 ₄ When the photographic light reflected by the prism surface 14b is incident, it is reflected at an angle of 90 ° and guided to the zoom lens group 3, the focus lens 4 and the image sensor 7. Work. The upper half of the prism surface 14d constitutes the second reflecting surface according to the present embodiment.

Lower half of the prism surface 14d defined by the prism 14 ₅ of the first prism 14 ₁ and the 5, P-wave is transmitted, S-wave serves to reflection at an angle of 90 °. The lower half of the prism surface 14d constitutes the second spectral surface according to the present embodiment.

Similarly, the second prism 14 _2, also the lower half of the prism surface 14c that is defined by the prism 14 ₆ of the 6, P-wave is transmitted, S-wave serves to reflection at an angle of 90 °. The lower half of the prism surface 14d constitutes the first spectral surface according to the present embodiment.

  For this reason, as shown in FIG. 4, among the light incident from the first front lens 10a and reflected by the prism surface 14a, the light 41A-T toward the upper half of the prism surface 14c is in the first position. When the light passes through the phase difference plate 15a and enters the upper half of the prism surface 14c, it is reflected at an angle of 90 ° and guided to the zoom lens group 3, the focus lens 4 and the image sensor 7 as 42A-T.

  Of the light incident from the first front lens 10a and reflected by the prism surface 14a, most of the light 41A-B directed to the lower half of the prism surface 14c is an S wave. When it passes through the phase difference plate 15a, it becomes a P wave. For this reason, when it enters the lower half of the prism surface 14d, it passes through the prism surface 14d. Subsequently, since it is converted into an S wave when it passes through the second retardation plate 15b, when it enters the lower half of the prism surface 14c, it is reflected by the prism surface 14c at an angle of 90 °, and the zoom lens group 3, It is guided to the focus lens 4 and the image sensor 7 as 41A-B.

  Similarly, as shown in FIG. 5, among the light incident from the second front lens 10b and reflected by the prism surface 14b, the light 42A-T toward the upper half of the prism surface 14d is in the third position. When the light passes through the phase difference plate 15c and enters the upper half of the prism surface 14d, it is reflected at an angle of 90 ° and guided to the zoom lens group 3, the focus lens 4 and the image sensor 7 as 42A-T.

Of the light incident from the second front lens 10b and reflected by the prism surface 14b, most of the light 42A-B directed to the lower half of the prism surface 14d is an S wave. When it passes through the phase difference plate 15c, it becomes a P wave. For this reason, when it enters the lower half of the prism surface 14c, it passes through the prism surface 14c. Subsequently, when the light enters the second phase difference plate 15b, the phase is converted into an S wave. When the light enters the lower half of the prism surface 14d, it is reflected by the prism surface 14d at an angle of 90 °, and the zoom lens group 3, It is guided to the focus lens 4 and the image sensor 7 as 42A-B.
<Operation when the shutter is pressed>

Hereinafter, the operation of the imaging process executed by the three-dimensional digital camera 1 when the operator presses the shutter key 17 will be described.
When it is detected by the operation signal from the operation unit 36 that the operator has pressed the shutter key 17, the shutter control unit 21 controls the shutter drive unit 24 so that the second shutters 13a and 13b are closed. The photographing light incident from the second front lens 10b and reflected by the prism surface 14b is kept blocked by the second shutters 13a and 13b. At the same time, the shutter control unit 21 opens the first shutters 12a and 12b, and only the photographing light incident from the first front lens 10a and reflected by the prism surface 14a is transmitted to the zoom lens group 3 by the prism surface 14c. Then, the image is guided to the focus lens 4 and the image sensor 7 to form a subject image on the image sensor 7. Further, the shutter control unit 21 controls the image pickup device 7 to accumulate the subject image formed on the image pickup device 7 as an image pickup charge in the image pickup device 7, and then sends it to the signal processing unit 30 as an image pickup signal. The imaging charge accumulated in the imaging element 7 is quickly swept out (see FIGS. 3 (2) and 3 (3)).

  Subsequently, the shutter control unit 21 closes the first shutters 12a and 12b and blocks the photographing light incident from the first front lens 10a and reflected by the prism surface 14a by the first shutters 12a and 12b. Keep it in the same state. At the same time, the shutter control unit 21 opens the second shutters 13a and 13b, and only the photographic light incident from the second front lens 10b and reflected by the prism surface 14b is transmitted to the zoom lens group 3 by the prism surface 14d. Then, the light is guided to the focus lens 4 and a subject image is formed on the image sensor 7. Further, the shutter control unit 21 controls the image pickup device 7 to accumulate the subject image formed on the image pickup device 7 as an image pickup charge in the image pickup device 7, and then sends it to the signal processing unit 30 as an image pickup signal (see FIG. 3 (2) and FIG. 3 (3)).

  As described above, according to the present embodiment, the shutter control unit 21 only presses the first shutters 12a and 12b while keeping the second shutters 13a and 13b closed by pressing the shutter key 17 once. , And only the photographing light incident from the first front lens 10a is imaged on the image sensor 7. Further, the shutter control unit 21 sends out the imaging charge accumulated in the imaging device 7 as an imaging signal, and then quickly sweeps out the imaging charge. Subsequently, the shutter control unit 21 opens only the second shutters 13a and 13b while keeping the first shutters 12a and 12b closed, and images the photographing light incident from the second front lens 10b. The image is formed on the element 7 as a subject image, and is quickly sent out as an image pickup signal from the image pickup element 7. For this reason, even in a three-dimensional digital camera having two front lens 10a and 10b, the zoom lens group 3 and the focus lens 4 can be shared among the lens groups that occupy most of the camera. As a result, the size can be reduced with minimum layout constraints. A conventional three-dimensional digital camera includes a zoom lens group and a focus lens group for each of the left and right front lens. For this reason, the aberrations and distortion errors of the respective lenses differ between the left and right zoom lens groups and the focus lens group, so that it is necessary to perform image superimposition and aberration correction processing separately. However, even if the three-dimensional digital camera according to the present embodiment is a three-dimensional digital camera having two front lens 10a and 10b, the zoom lens group 3 and the focus lens 4 can be shared and used. The same processing can be performed for image superposition and aberration correction.

  Further, since the first shutter lenses 12a and 12b functioning as a mechanical shutter and the second shutters 13a and 13b are provided between the two front lens 10a and 10b, the zoom lens group 3, and the focus lens 4, the first shutter 12a and 13b are provided. By alternately opening and closing the one shutter 12a, 12b and the second shutter 13a, 13b, a single imaging element 7 can perform a total of two imaging operations for the left eye and the right eye.

  Comparing the time when the first shutters 12a and 12b and the second shutters 13a and 13b open and close alternately with the time when the CMOS image sensor that constitutes the image sensor 7 takes in the imaging charge, the first shutter 12a and 12b and the time when the second shutters 13a and 13b are alternately opened and closed are overwhelmingly slower. Therefore, the shortest time for capturing the subject images incident on the first front lens 10a and the second front lens 10b is the first shutter 12a, 12b and the second shutter 13a, 13b. Is equivalent to the time for alternately opening and closing. For this reason, the shutter control unit 21 needs to open and close the second shutters 13a and 13b immediately after the first shutters 12a and 12b are opened and closed. Shooting can be performed.

  In addition, since the CMOS image sensor directly reads out the voltage from the exposure region, the time required for sweeping out the imaging charge is shorter than that of a CCD (Charge Coupled Device) image sensor. In particular, when the subject is moving, it is preferable that the two images of the left-eye image and the right-eye image are captured at as short an interval as possible. Therefore, in the present embodiment, it is preferable to use a CMOS image sensor as the image sensor 7.

  The present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above-described embodiment, an example in which the present invention is applied to a three-dimensional digital camera has been described. However, a configuration that shares an image sensor with a partial imaging optical system according to the present invention is only the above-described three-dimensional digital camera. In other words, the present invention is generally applicable to a digital camera having two photographing lenses.

DESCRIPTION OF SYMBOLS 1 Digital camera 3A, 3B Zoom lens 4 Focus lens 5 Case 7 Imaging device 10a, 10b Front lens 12, 13 Shutter 14 Prism block 15a, 15b, 15c Phase plate 21 Shutter control part 22 Lens control part 24 Shutter drive part Reference Signs List 25 lens driving unit 30 signal processing unit 31 image processing unit 32 display processing unit 34 recording unit 36 operation unit 37 camera control unit

Claims (6)

A first photographing lens for taking in first photographing light;
A second photographic lens for taking in second photographic light;
An image sensor that converts imaging light into an electrical signal;
An imaging optical system that forms an image of imaging light on the imaging device;
A first optical path for guiding the first imaging light to the imaging optical system;
A second optical path for guiding the second imaging light to the imaging optical system;
A first imaging state in which the first optical path is opened in a state in which the second optical path is blocked, the first imaging light is guided to the imaging optical system, and an image is formed on the imaging element; The second optical path is opened in a state where the optical path is blocked, the second imaging light is guided to the imaging optical system, and alternately switched to a second imaging state in which the imaging element is imaged, An imaging control unit that controls the imaging element to convert the first imaging light in the first imaging state and the second imaging light in the second imaging state into an electrical signal. 3D digital camera. Furthermore, it comprises an elongated cylindrical portion in which the first optical path and the second optical path extend,
The cylindrical portion has a first reflecting portion that reflects the first imaging light at an angle of 90 ° and guides the cylindrical imaging portion toward the inside of the cylindrical portion at one end portion;
A second reflecting portion that reflects the second photographing light at an angle of 90 ° and guides the second photographing light toward the inside of the cylindrical portion on the other end;
A spectroscopic unit that reflects incident first imaging light and second imaging light at an angle of 90 ° between the first reflecting unit and the second reflecting unit and guides the imaging light to the imaging optical system; The three-dimensional digital camera according to claim 1. The spectroscopic unit is
A first birefringent surface for phase-converting an S-wave polarization component contained in the first reflected light from the first reflection section into a P-wave polarization component;
A second birefringent surface that phase-converts the S-wave polarization component contained in the second reflected light from the second reflection section into a P-wave polarization component;
A prism block in the shape of a rectangular parallelepiped, which is disposed between the first birefringent surface and the second birefringent surface and has a surface perpendicular to the first reflected light and the second reflected light;
A third phase which is provided perpendicular to the first reflected light and the second reflected light in the center of the prism block and which converts the S wave polarization component contained in the transmitted light to be transmitted into a P wave polarization component. Including a birefringent surface,
The prism block is
The surface is inclined at an angle of 45 ° with respect to the first reflected light, and the first reflected light transmitted through the first birefringent surface and reflected at an angle of 90 ° is reflected on the surface. The first reflection surface guided to the imaging optical system and the P-wave polarization component included in the first reflection light incident through the first birefringence surface are transmitted, and the S-wave polarization component is 90 °. A first spectral reflecting surface that is reflected at an angle of and guided to the imaging optical system, and
The surface is inclined at an angle of 45 ° with respect to the second reflected light, and the second reflected light incident through the second birefringent surface is reflected at an angle of 90 ° to The P-wave polarization component included in the second reflection surface that is guided to the imaging optical system and the second reflection light that is transmitted through the second birefringence surface is transmitted, and the S-wave polarization component is 90 °. A second spectral reflection surface that is reflected at an angle of and guided to the imaging optical system, and
The first spectral reflection surface and the second spectral reflection surface intersect at right angles, the first reflection surface and the second reflection surface are formed above the formed intersection line, and the first spectral reflection surface and the second reflection surface are formed below. The three-dimensional digital camera according to claim 2, wherein one spectral plane and the second spectral plane are formed. The prism block is
A first prism having a surface perpendicular to the first reflected light;
A second prism having a surface perpendicular to the second reflected light and having a top line in contact with the top line of the first prism;
An upper first prism and an upper second prism disposed in a space in the shape of an upper right triangular prism defined by the top line and the surface of the first prism and the second prism,
An upper first prism having a surface inclined at an angle of 45 ° with respect to the first reflected light;
An upper second prism having a surface inclined at an angle of 45 ° with respect to the second reflected light;
A lower first prism and a lower second prism disposed in a space in the shape of a lower right triangular prism defined by a top line and a surface of the first prism and the second prism,
A lower first prism having a surface inclined at an angle of 45 ° with respect to the first reflected light;
A lower second prism having a surface inclined at an angle of 45 ° with respect to the second reflected light,
The third birefringent surface is formed on the boundary surface between the upper first prism and the upper second prism, the lower first prism and the lower second prism, and the first optical path and the first prism. Provided perpendicular to the two optical paths,
The first reflecting surface is an optical reflecting surface formed at a boundary portion between the first prism and the upper first prism,
The first spectral surface is formed by a boundary surface between the lower second prism and the second prism,
The second reflecting surface is an optical reflecting surface formed at a boundary portion between the second prism and the upper second prism,
The three-dimensional digital camera according to claim 3, wherein the second spectral surface is formed by a boundary surface between the lower first prism and the first prism.   The imaging device sweeps out the accumulated charge at any time when switching from the first imaging state to the second imaging state or from the second imaging state to the first imaging state. The three-dimensional digital camera according to 1. The three-dimensional digital camera according to claim 1, wherein the imaging optical system includes a zoom lens and a focus lens.

Images