JP4549255B2 - Solid-state imaging device and resolution conversion device - Google Patents

Description

  The present invention relates to a solid-state imaging device such as a video camera, a video camera with an electronic still function, and an electronic still camera, and more particularly to a solid-state imaging device capable of performing pixel-shifted imaging (hereinafter referred to as pixel shift) in order to increase the resolution of an imaging device. The present invention relates to a resolution conversion apparatus that performs imaging by shifting pixels in front of a solid-state imaging device.

  Conventionally, there is a camera of a type in which a conversion device is arranged in front of an imaging device such as a teleconversion lens to change the imaging state. Similarly, a conversion device is arranged in front of the imaging device to achieve high resolution. There was no solid-state imaging device such as an electronic still camera that made it possible.

  In general, as a method for increasing the resolution of a solid-state imaging device, there is a pixel shift (hereinafter referred to as pixel shift) imaging method. All of this pixel shift function is built into the solid-state image pickup device body. Whether this function is added to an image pickup apparatus that does not have a pixel shift shooting function or an image pickup apparatus that has a pixel shift shooting function, There is a problem that the device becomes expensive with modification. Further, there is a problem that the apparatus becomes large with the modification and the compactness at the time of normal photographing is lost.

  An object of the present invention is to solve the conventional problems as described above. The object of the present invention is to easily capture a captured image without increasing the cost of the apparatus and without losing the compactness during normal shooting. It is an object of the present invention to provide a solid-state imaging device and a resolution conversion device that can increase resolution.

In order to solve the above-mentioned problems, the present invention comprises means described in 1) and 2) below. That is,
1) In a solid-state imaging device having a function of synthesizing a captured image in a normal mode and a captured image in a shift mode taken with a pixel shift function, the incident light and the lens arranged in front of the lens of the solid-state imaging device A conversion device having a pixel shift element that shifts the optical axis by changing the angle of light emitted to the light source, and the pixel shift element comprises a composite prism formed by combining two or more shape-fixed prisms, and Means for rotating at least one of the compound prisms by a rotation angle corresponding to the angle of the prism on a surface substantially perpendicular to the optical axis, and the prism direction of the prism in the normal mode and the prism direction in the shift mode. The prism when the rotation angle between the prism direction is 90 degrees or less and the rotation angle of the prism is 1/2 The solid-state imaging device, wherein the direction perpendicular to the direction is constituted the prism so that the pixel shift direction of light incident on the lens.
2) A resolution conversion device comprising a pixel shift element in a housing that can shift the optical axis by changing the angle of incident light and emitted light, and the pixel shift element is two or more. And a means for rotating at least one of the composite prisms by a rotation angle corresponding to the angle of the prism on a surface substantially perpendicular to the optical axis. When capturing a captured image in the normal mode and a captured image in the shift mode with the prism, a rotation angle between the prism direction of the prism in the normal mode and the prism direction of the prism in the shift mode is 90 degrees or less. The pixel shift method of light incident on the lens is a partial rotation and the direction perpendicular to the prism direction when the rotation angle of the prism is ½ Resolution conversion apparatus characterized by being configured the prism so as to be.

  According to the solid-state imaging device and the resolution conversion device of the present invention, it is possible to easily increase the resolution of a captured image without making the device expensive and without losing compactness.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration according to the first embodiment of the solid-state imaging device of the present invention. A pixel shift adapter 2 is disposed in front of the lens 11 of the digital still camera (DSC) 1. This pixel shift adapter 2 includes a pixel shift element (glass or plastic prism) 21 and is detachably disposed in front of the lens 11 described above. 2f is a front view of the pixel shift adapter 2, and a switching button 22 for manually switching the rotation direction of the prism 21 is attached.

  Next, the operation of this embodiment will be described. After fixing the digital still camera 1, (1) the pixel shift adapter 2 is disposed in front of the lens 11 of the digital still camera 1. (2) The switching button 22 of the pixel shift adapter 2 is switched to set, for example, the normal mode, and (3) shooting A is performed in the normal mode. (4) The switching button 22 is switched to change the rotation angle direction of the prism 21 to change to the shift mode and perform photographing B.

  Here, when the switching button 22 described above is switched, the prism 21 rotates around the optical axis as shown in FIG. In the normal mode, the direction of the prism 21 is the A direction, but in the shift mode, the direction is the B direction. If the shift amount at that time is displayed as a vector, S = S2-S1 as shown in FIG. Thus, when the prism 21 is rotated around the optical axis, the subject is imaged on the CCD 12 with a deviation of 0.0115 degrees, for example, as shown in FIG. The prism may be rotated in the in-plane direction perpendicular to the optical axis, and the center of rotation can be other than the optical axis. For example, when the rotation angle is small, a protrusion may be provided at a position facing the switching button, and the protrusion may be rotated around this point.

  FIG. 5A shows a subject image obtained by two shootings of shooting A in normal mode and shooting B in shift mode, and both subjects are shifted by 2.44 μm in the direction of arrow S, for example. When these two subject images are combined, 3.2 million pixels have the same resolution as the 12.8 million pixel image shown in FIG.

  FIG. 5C shows a screen A for shooting mode A in normal mode and a screen B for shooting mode B in shift mode. By combining these screens, the screen becomes as shown in FIG. The resolution can be improved as described above.

  The relationship between the shift amount (angle) of the optical axis and the shift amount (distance) of the subject image on the solid-state image sensor is determined by the focal length of the lens. Therefore, in the case of a zoom lens, it can be used in the entire zoom area by changing the rotation angle of the prism in accordance with the focal length. One method is to widen the rotation angle of the switching button and provide a scale and a stopper according to the focal length.

  Various composite images can be obtained by changing the amount in the shift direction. For example, shifting in the horizontal direction increases the horizontal resolution. This can be achieved by adding a mechanism for rotating the entire pixel shift function unit. Further, if the shift amount is divided and sequentially shifted to be resolved and synthesized, the resolution is improved several times.

  FIG. 6 is a diagram showing the structure of the prism 21 which is a pixel shift element. The prism 21 may be a single unit as shown in FIG. 6 (a), or may be a composite prism formed by combining two prisms having a minute angle as shown in FIGS. 6 (b) and 6 (c). When a composite prism is used, the angle of the prism alone can be increased, and it is possible to easily produce a prism having a small angle, which is difficult with a single prism, and to eliminate chromatic aberration.

  In such a composite prism, the shift amount may be changed by rotating integrally during pixel shift, but the shift amount can also be changed by rotating a part of the composite prism. In this case, as shown in FIG. 6 (c), two identically shaped prisms can be rotated by 180 degrees, and when the part is rotated, if the angle of one prism is increased, the prism is rotated. The corner can be reduced.

  According to the present embodiment, a high-quality image of, for example, 12.8 million pixels can be obtained inexpensively and easily. In addition, since the pixel shift adapter 2 is placed in front of the digital still camera 1, the digital still camera 1 does not lose its compactness during normal shooting. If the digital still camera 1 has a pixel shift function, an ultra high-quality still image equivalent to 25.6 million pixels can be obtained at a low cost by combining it with this. It can also be applied to compact VHS-C and DVC still images.

  In the above embodiment, the pixel shift adapter 2 that is separate from the digital still camera 1 is arranged in front of the digital still camera 1. However, as shown in FIG. The digital still camera 1 can be mounted, and the pixel shift adapter 2 can be reliably arranged at a predetermined position in front of the digital still camera 1. Moreover, as shown in FIG.7 (b), there also exists a structure made into a separate type separate body.

  FIG. 8 shows an embodiment in which the pixel shift adapter 2 is attached to the digital still camera 1 to increase the resolution. A manual selection mode button 15 for selecting the normal mode and the high resolution mode is provided on the digital still camera 1. It is provided and operability can be improved. As the high resolution mode, a function that can be combined at a favorite time can be added by adding an electrical marking to the photographed image.

  FIG. 9 is similar to the embodiment shown in FIG. 8, but in this example, when the pixel shift adapter 2 is attached to the digital still camera 1, the switch 16 is automatically pressed by the adapter 2 to automatically enter the high resolution mode. Therefore, the operability can be further improved as compared with the embodiment of FIG.

  Further, in the above embodiment, the switching button 22 for changing the pixel shift amount is configured to be manually rotated as shown in FIG. 10A, but is configured to be electrically rotated as shown in FIG. 10B. As a result, operability can be improved. Furthermore, as shown in FIG. 10C, the operability can be further improved by controlling the electric pixel shift operation by the operation on the main body side of the digital still camera 1. For example, in the case of a zoom lens, the amount of rotation can be controlled according to the focal length of the lens.

  FIG. 11 is a diagram showing a configuration according to the second embodiment of the solid-state imaging device of the present invention. In this example, a pixel shift adapter 2 is integrally attached to the digital still camera 1 as shown in FIG. 11A, and a prism 21 serving as a pixel shift element is connected to the pixel shift adapter 2 in FIG. ) Is detachably mounted as shown in FIG.

  Next, the operation of this embodiment will be described. When performing normal photographing, photographing is performed with the pixel shift element (prism) 21 removed from the pixel shift adapter 2. When you want to perform high-resolution photography, first shoot in the normal mode with the pixel shift element (prism) 21 removed from the pixel shift adapter 2, and then attach the pixel shift element 21 to the pixel shift adapter 2. Take the subject again in shift mode.

  After that, by synthesizing the two captured images, a high-resolution captured image can be obtained, which has the same effect as the first embodiment shown in FIG. In particular, since this example has a simple configuration, high-resolution imaging can be performed at a lower cost.

  FIG. 12 is a diagram showing a configuration according to the third embodiment of the solid-state imaging device of the present invention. In this example, a pixel shift adapter 2 using a mirror 24 as a pixel shift element is provided in front of the lens 11 of the digital still camera 1. The pixel shift adapter 2 has a switch button 22 for switching between the normal mode and the shift mode.

  Next, the operation of this embodiment will be described with reference to FIG. The mirror 24 is disposed at a predetermined angle (45 degrees) in front of the lens 11. The inclination of the mirror 24 is changed by rotating the switching button 22. As a result, the mirror 24 is tilted by 0.0115 degrees compared to the normal mode, so that the image on the CCD 12 is shifted as if the subject is shifted from 100A to 100B. Although there is an effect similar to that of the first embodiment, since the mirror 24 is used as the pixel shift element, a high-quality image free from chromatic aberration can be obtained. Even if the mirror is rotated in an in-plane direction slightly inclined with respect to the mirror 24, the same effect can be obtained.

  FIG. 14 is a diagram showing a configuration according to a fourth embodiment of the solid-state imaging device of the present invention. A pixel shift adapter 2 using a parallel plate 25 made of plastic or the like as a pixel shift element is disposed in front of the lens 11 and the collimator lens 13 of the digital still camera 1. The pixel shift adapter 2 has a switch button 22 that operates the pixel shift mechanism 27 to tilt the parallel plate 25 with respect to the optical axis.

  Next, the operation of this embodiment will be described with reference to FIG. By turning the switching button 22, the pixel shift mechanism 27 is moved to A or B, and the parallel plate 25 at the normal shooting position is moved to the shift shooting position (broken line in the figure), thereby tilting 2.36 degrees. As a result, the image on the CCD 12 is shifted as if the subject is shifted from 100A to 100B, so that the pixel shift photographing can be performed, and there is an effect similar to that of the first embodiment. Since the parallel plate 25 is used, a high quality image with little chromatic aberration can be obtained. The same processing can be obtained even if the parallel plate is rotated in an in-plane direction slightly inclined with respect to the parallel plate.

  FIG. 16 is a diagram showing a configuration according to the fifth embodiment of the solid-state imaging device of the present invention. This example has a configuration in which a pixel shift adapter 2 to which two pixel shift elements 21-1 and 21-2 arranged in parallel with each other can be mounted in front of the lens 11 of the digital still camera 1. .

  Next, the operation of this embodiment will be described. First, shooting A is performed in the normal mode of the pixel shift elements 21-1, 21-2, and shooting B is performed in the shift mode of 21-1. Next, the photographing C is performed in the 21-1 normal, 21-2 shift mode, and the photographing D is performed in the 21-1, 21-2 shift mode. As a result, as shown in FIG. 17, the subject is displaced as A, B, C, and D, so that a screen A, B, C, and D as shown in FIG. When these are combined, an ultra-high resolution screen as shown in FIG. 18B is obtained.

  As a result, in the present embodiment, it is possible to easily and inexpensively perform shooting with higher resolution than in the above-described embodiment.

  FIG. 19 is a diagram showing a configuration according to the sixth embodiment of the solid-state imaging device of the present invention.

  In the example of FIG. 19A, a pixel shift adapter 2 is attached to a digital still camera 1 that does not have a normal pixel shift photographing function, and a personal computer 3 is connected to the digital still camera 1.

  In this case as well, one image is taken in the normal mode and one image is taken in the shift mode to obtain two images. The compositing function for synthesizing these two images to create a high-resolution image is a digital still. Not in camera 1. Therefore, the above-mentioned two images are sent from the digital still camera 1 to the personal computer 3, and the composition is performed by the composition software and the personal computer 3, so that a high-resolution image is obtained.

  Similarly, FIG. 19B shows a configuration for causing the composite software and the printer 4 to perform two shot images.

  According to the present embodiment, even with a digital still camera 1 that does not have a normal pixel shift function, if a separate pixel shift adapter 2 and a personal computer 3 or a printer 4 are provided, high-resolution imaging can be easily performed. it can.

It is the figure which showed the structure which concerns on 1st Embodiment of the solid-state imaging device of this invention. It is a figure explaining the rotation operation | movement of the prism shown in FIG. It is a figure explaining the shift amount of the prism shown in FIG. It is a figure explaining the pixel shift imaging operation by the apparatus of FIG. It is a figure explaining the principle which can obtain a high-resolution picked-up image using the pixel shift adapter of the apparatus shown in FIG. It is the figure which showed the structural example of the prism which is a pixel shift element shown in FIG. It is the figure which showed the Example of the pixel shift adapter shown in FIG. FIG. 6 is a diagram illustrating another example of the pixel shift adapter illustrated in FIG. 1. FIG. 6 is a view showing still another embodiment of the pixel shift adapter shown in FIG. 1. It is the figure which showed the example of an operation structure of the switch button shown in FIG. It is the figure which showed the structure which concerns on 2nd Embodiment of the solid-state imaging device of this invention. It is the figure which showed the structure which concerns on 3rd Embodiment of the solid-state imaging device of this invention. It is a figure explaining the pixel shift operation | movement by the mirror shown in FIG. It is the figure which showed the structure which concerns on 4th Embodiment of the solid-state imaging device of this invention. It is a figure explaining the pixel shift operation | movement by the parallel plate shown in FIG. It is the figure which showed the structure which concerns on 5th Embodiment of the solid-state imaging device of this invention. FIG. 16 is a diagram for explaining subject displacement when pixel shift photographing is performed with the apparatus of FIG. 15. FIG. 16 is a diagram for explaining a principle that a captured image when a pixel shift photographing is performed with the apparatus of FIG. It is the figure which showed the structure which concerns on 6th Embodiment of the solid-state imaging device of this invention.

Explanation of symbols

1 Digital Still Camera 2 Pixel Shift Adapter 3 Personal Computer 4 Printer 11 Lens 12 CCD
13 Collimator Lens 15 Selection Mode Button 16 Switch 21 Prism 21-1, 21-2 Pixel Shift Element 22 Switch Button 24 Mirror 25 Parallel Plate 27 Pixel Shift Mechanism 201 Pedestal

Claims (2)

In a solid-state imaging device having a function of synthesizing a captured image in a normal mode and a captured image in a shift mode captured with a pixel shift function,
A conversion device including a pixel shift element that is disposed in front of a lens of the solid-state imaging device and changes an angle of incident light and light emitted to the lens to shift an optical axis;
The pixel shift element is composed of a composite prism formed by combining two or more shape-fixed prisms, and at least one of the composite prisms has a rotation angle corresponding to the angle of the prism on a plane substantially perpendicular to the optical axis. Means for rotating only,
The prism direction when the rotation angle between the prism direction of the prism in the normal mode and the prism direction of the prism in the shift mode is a partial rotation of 90 degrees or less and the rotation angle of the prism is ½ A solid-state imaging device, wherein the prism is configured such that a direction perpendicular to the pixel is a pixel shift direction of light incident on the lens. A resolution conversion apparatus comprising a pixel shift element capable of shifting an optical axis by changing an angle of incident light and emitted light in a housing,
The pixel shift element is composed of a composite prism formed by combining two or more shape-fixed prisms, and at least one of the composite prisms has a rotation angle corresponding to the angle of the prism on a plane substantially perpendicular to the optical axis. Has means to rotate only,
When capturing a captured image in the normal mode and a captured image in the shift mode with the prism, a rotation angle between the prism direction of the prism in the normal mode and the prism direction of the prism in the shift mode is 90 degrees or less. The resolution is characterized in that the prism is configured such that it is a partial rotation and the direction perpendicular to the prism direction when the rotation angle of the prism is ½ is the pixel shift direction of the light incident on the lens. Conversion device.

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