JPH07222038A - Image pickup device - Google Patents

Abstract

PURPOSE:To obtain high definition image information by providing an aperture having an opening at a specified position in a 1st optical system movably, thereby preventing incidence of flare. CONSTITUTION:An aperture 11 is provided in the vicinity of a pupil of a 1st optical system 1. The aperture 11 has an operature opening 11A nearly around a center of one pupil area among plural pupil areas of the pupil of the 1st optical system 1. The image of an object is formed onto an area A on a primary image forming face 21 with luminous flux passing through the aperture opening 11A in the 1st optical system 1. The image formed on the area 21A is formed again on a plane of an image pickup element 31A provided to a secondary image forming plane by a lens system 3A of a 3rd optical system 3 through the 2nd optical system 2. The aperture 11 is driven by an aperture motor 13 to form an image of the object onto a face of image pickup elements 31D-31B sequentially by lens systems 3D-3B of the 3rd optical system 3. Then the picture information from the four image pickup elements 31A-31D is synthesized to obtain the total object image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and more particularly, to easily obtain high resolution image information by using a plurality of image pickup elements having a limited number of pixels without increasing the number of pixels of the image pickup element. In addition, the present invention relates to an image pickup apparatus suitable for, for example, a small video camera or a still video camera, in which appropriate exposure control can be performed by a diaphragm provided in the first optical system.

[0002]

2. Description of the Related Art In recent years, solid-state area sensors (image sensors in which pixels are two-dimensionally arranged) as image pickup devices used in image pickup devices such as small video cameras and still video cameras have high pixel counts and low prices. It can be made smaller and smaller, and is used in many imaging devices.

The number of pixels of an image pickup device which is currently put into practical use is about 400,000, which has a resolution equivalent to that of a television of the current standard such as NTSC. However, for example, when the input image is displayed on a large screen image, hard copy or computer graphic,
The roughness of the pixels becomes noticeable, and it is difficult to output as a high-definition image.

Recently, a solid-state area sensor of 2 million pixels for HDTV is being developed. However,
Even with this number of pixels, the resolution is not sufficient to be used as an input for super-large screen display. The number of pixels of the current area sensor is not always sufficient to obtain an image with higher resolution (high resolution).

Conventionally, as a method of obtaining a high-definition image using an image pickup device, there is a method of obtaining a high-resolution image by increasing the pixel density of the image pickup device and increasing the number of pixels.

Generally, when the pixel area is reduced in order to increase the pixel density, the output signal becomes small and the S / N ratio deteriorates. Considering this decrease in the S / N ratio, the number of pixels of 2 million is almost the limit, and it is very difficult to further increase the number of pixels and improve the resolution under the present circumstances.

Therefore, various methods for obtaining a high-definition image without increasing the number of pixels have been proposed. For example, Japanese Patent Publication No. 50-13052 and Japanese Patent Publication No. 59-189.
No. 09, Japanese Patent Publication No. 59-43035, and the like propose a method using pixel shifting.

In this pixel shift method, an optical element for splitting a light beam based on a subject image on the image plane side of the image pickup optical system,
For example, by disposing a dichroic prism, a half mirror, or the like, and imaging the light beams divided by the optical element with a plurality of solid-state area sensors arranged by shifting the position by a half pitch of pixels or less, a high resolution image can be obtained. I'm getting an image.

Further, in Japanese Patent Laid-Open No. 4-286480, one or more optical path splitting means is arranged behind the imaging lens, the optical path splitting means divides the subject image into a plurality of divided subject images. An image is formed on each of a plurality of solid-state area sensor surfaces arranged at image forming plane positions, and the entire subject image is taken by interpolating areas that cannot be picked up by sensors at other image forming positions. Has obtained a high resolution image.

Further, in Japanese Patent Laid-Open No. 63-193678, a wedge-shaped deflecting member is arranged in the optical path of the photographing optical system, and the movement of the image caused by the rotation of the deflecting member is periodically picked up by an image pickup element. Therefore, image information of more than the number of pixels is obtained.

Further, in Japanese Patent Application Laid-Open No. 60-250789, a subject image formed by a photographing optical system is separated into a plurality of images by a secondary imaging optical system, and the separated plurality of images are respectively separated by a plurality of image pickup devices. A high-resolution image is obtained by forming an image on a surface and synthesizing and outputting image pickup signals from the plurality of image pickup elements.

[0012]

The method using pixel shifting as a method for obtaining a high-definition image has a problem in that it is necessary to take images while shifting in order to increase the resolution.

In the method proposed in Japanese Patent Laid-Open No. 4-286480, a high resolution image can be obtained by increasing the number of divisions of the optical path innumerably. For that purpose, the back focus of the taking lens is used. Had to be extremely long, and there was a problem that the size of the entire apparatus was increased. Therefore, in practice, the two-plate type or the three-plate type is the limit even if a 3P prism or the like is used.

Further, the method proposed in Japanese Patent Laid-Open No. 63-193678 is not suitable for a moving image because an image of one frame is combined by taking a plurality of times, and even if it is a still image, it is an output image. There was a problem that it took too much time to obtain.

Further, in the method proposed in Japanese Patent Laid-Open No. 60-250789, a light beam splitting mirror as a light beam splitting means is arranged so as to be slightly shifted from the primary image forming plane so that a boundary portion of an image is formed. Although pixel loss is prevented, there is a problem in that the structure is very difficult due to problems such as the thickness of the light beam separation mirror and the pupil of the off-axis light beam. In addition, the number of pixels increases at most about 2 to 3 times, which makes it difficult to obtain a high-resolution image.

According to the present invention, a plurality of image pickup devices having a limited number of pixels are used to appropriately set the arrangement of the image pickup devices and the respective optical elements constituting the image pickup system when forming a subject image on each image pickup device. Further, by providing a diaphragm having an appropriate opening in the first optical system, it is possible to prevent the incidence of flare or the like that adversely affects the image forming light flux and to easily provide high-definition image information. To aim.

[0017]

The image pickup apparatus of the present invention comprises: (1-a) Forming a subject image on a predetermined image forming plane by the first optical system, which is on the optical axis of the first optical system. And a plurality of lens systems having an optical axis outside the optical axis of the first optical system and arranged behind the second optical system. When re-imaging a part of the subject image formed on the planned image forming surface with the third optical system which is provided on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems , The second optical system has the pupils of the plurality of lens systems of the third optical system and the pupils of the first optical system in a substantially conjugate relationship, and each of the plurality of lens systems is the first optical system. Is an image pickup device that uses light fluxes from a plurality of regions of the pupil and obtains high-definition image information by using image information obtained by the plurality of image pickup elements. The first optical system in the first optical system.
The optical system is characterized in that a diaphragm having a diaphragm opening whose center is approximately the center of one of the plurality of pupil areas of the optical system is provided so that the diaphragm opening can be displaced.

(1-b) A subject image is formed on a planned image forming surface by the first optical system, and a second image is arranged on the optical axis of the first optical system and near the planned image forming surface. The planned image forming plane is formed by an optical system and a third optical system having an optical axis outside the optical axis of the first optical system and having a plurality of lens systems arranged behind the second optical system. When a part of the subject image formed on the second optical system is re-imaged on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems, the second optical system causes the third optical system to operate. The pupils of the plurality of lens systems of the system and the pupils of the first optical system have a substantially conjugate relationship, and the plurality of lens systems respectively use light fluxes from a plurality of regions of the pupil of the first optical system. An image pickup device for obtaining high-definition image information by using image information obtained by the plurality of image pickup elements, wherein the first optical system includes the first optical system. At least one of the plurality of pupil areas of
It is characterized in that a diaphragm having a diaphragm opening including two pupil regions is provided so that the diaphragm opening can be displaced.

(1-c) A subject image is formed on the planned image forming plane by the first optical system, and a second image is arranged on the optical axis of the first optical system and near the planned image forming plane. The planned image forming plane is formed by an optical system and a third optical system having an optical axis outside the optical axis of the first optical system and having a plurality of lens systems arranged behind the second optical system. When a part of the subject image formed on the second optical system is re-imaged on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems, the second optical system causes the third optical system to operate. The pupils of the plurality of lens systems of the system and the pupils of the first optical system have a substantially conjugate relationship, and the plurality of lens systems respectively use light fluxes from a plurality of regions of the pupil of the first optical system. An image pickup device for obtaining high-definition image information by using image information obtained by the plurality of image pickup elements, wherein the first optical system includes the first optical system. It is characterized in that a diaphragm having a plurality of aperture openings and substantially centered on the center of each pupil regions of a plurality of pupil areas.

[0020]

Embodiment 1 FIG. 1 is a perspective view of an essential part of Embodiment 1 of the present invention, and FIG.
FIG. 3 is a schematic view of a main part of a part of the optical system of Example 1 of the present invention.

In the figure, reference numeral 1 denotes a first optical system, which forms a subject image on a primary image forming surface (planned image forming surface) 21.

Reference numeral 11 denotes a diaphragm, which is a pupil 1 of the first optical system 1.
It is provided near the a position. The diaphragm 11 has a diaphragm opening 11A having a center of at least one pupil region 202a among a plurality of pupil regions (pupil diameters) obtained by dividing the pupil 1a of the first optical system 1 by each element described later. The diaphragm motor 13 serving as a driving unit is configured to be rotatable clockwise as indicated by an arrow A in the figure. In the state of FIG. 1, the diaphragm 11 is provided near the position of the pupil area 202a of FIG.
The aperture opening 11A is set to be located.

The size of the diaphragm opening 11A of the diaphragm 11 in this embodiment is variable by a diaphragm mechanism (not shown) so that it can be changed to a predetermined diaphragm value. .

Reference numeral 2 denotes a second optical system composed of a field lens or the like, which is arranged on the optical axis of the first optical system 1 and in the vicinity of the primary image plane 21 and The light flux from the subject image formed on the image plane 21 is condensed and guided to the subsequent lens system.

A third optical system 3 has four lens systems, namely, a 31st lens system 3A, a 32nd lens system 3B, a 33rd lens system 3C, and a 33rd lens system 3D.

The four lens systems 3A, 3B, 3C and 3D have an optical axis outside the optical axis of the first optical system 1 and the second optical system 2
It is located behind.

Reference numeral 31 denotes an image pickup means, for example, four image pickup elements 31A, 31B, 31 which are solid-state area sensors.
C, 31D, each having four lens systems 3A, 3B, 3
They are arranged on the C and 3D image planes. The four image pickup devices 3
1A, 31B, 31C and 31D are image pickup devices 31A, 31B and 31 from the optical axis 100 of the first optical system 1.
It is arranged so that the distances to the centers of C and 31D are equal.

Four lens systems (3A, 3A) of the third optical system
B, 3C, 3D) divides the subject image on the primary imaging surface 21 formed by the first optical system 1 into a plurality of regions, and the subject images in the respective regions are respectively associated with the image pickup devices 31A, 31B, 31.
The image is re-formed on the C and 31D planes.

In this embodiment, the second optical system 2 comprises a plurality of lens systems 3A, 3B, 3C, which form the third optical system 3.
The 3D pupils are each imaged in the pupil 1a region of the first optical system 1. As a result, the first optical system 1
Pupil region is divided into a plurality of pupil regions. Aperture 1 in FIG.
The first diaphragm aperture 11A has an aperture shape including one pupil region 202a of the plurality of pupil regions of the first optical system 1.

In this embodiment, first the first optical system 1
Then, the subject 200 is imaged as an image 203a on the region 21A on the primary imaging surface 21 by the light flux that has passed through the aperture opening 11A of the aperture 11. The image 20 formed in the area 21A
3a is re-imaged as an image 204a through the second optical system 2 by the lens system 3A of the third optical system 3 on the surface of the image pickup device 31A provided on the secondary imaging surface.

At this time, the light is blocked by the diaphragm 11 and the light flux does not enter the lens systems 3B, 3C and 3D of the third optical system 3. Therefore, no subject image is formed on each of the image pickup devices 31B, 31C, 31D corresponding to the lens systems 3B, 3C, 3D.

In the present embodiment, when the image pickup of the subject image in the area 21A is completed, the diaphragm 11 is sequentially rotated clockwise by the diaphragm motor 13 as indicated by an arrow A in the figure, so that each area 21D,
The subject images are sequentially formed on 21C and 21B, and the subject images at this time are formed by the plurality of lens systems 3 of the third optical system 3.
The image pickup devices 31D, 31C,
An image is formed on the surface 31B.

The four image pickup devices 31A, 31B, 3
The image information from 1C and 31D is used for synthesis by a signal processing system (synthesis processing system) described later to obtain an entire subject image.

In this embodiment, the sum of the plurality of divided images formed by the third optical system 3 is configured to include the entire area of the subject image formed by the first optical system 1. That is, the adjacent divided images are configured to overlap each other with pixels at the boundary portion so that no inconvenience occurs at the image boundary portion.

Next, the image processing method of this embodiment will be described with reference to FIG. FIG. 3 is a block diagram of essential parts of a signal processing system of the image pickup apparatus of this embodiment.

In this embodiment, the electric signals from the image pickup devices 31A to 31D shown in the figure are sampled and held by the sample and hold circuits (S / H circuits) 51A to 51D, and the analog-digital conversion circuits (A / D conversion circuit)
The analog signals are converted into digital signals by 52A to 52D and stored in the memories (storage circuits) 53A to 53D. Then, each memory 53A to
Information is read from 53D and is combined by the image combining processing circuit 54 to obtain a high resolution image.

As described above, in this embodiment, each element of the image pickup apparatus is properly set, and the rotatable diaphragm 11 is provided near the position of the pupil 1a of the first optical system 1 to appropriately set the exposure range. This makes it possible to obtain high-definition image information and effectively prevent adverse effects such as unnecessary flare on the imaging light flux.

FIG. 4 is a perspective view of a main part of the second embodiment of the present invention, and FIG. 5 is a cross-sectional view of a part of an optical system of the second embodiment of the present invention. 4 and 5, the same elements as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

This embodiment is different from the first embodiment described above in that a plurality of pupil regions 202a of the pupil 1a of the first optical system 1 are
In the vicinity of the positions of 202b, 202c, 202d, a plurality of aperture openings 41A, 41B, 41 having substantially the centers of the respective pupil regions 202a, 202b, 202c, 202d as their centers.
A diaphragm 41 having C and 41D is provided, and the pupil region 202
A subject image 202a, 202b, 202c, 202d formed by the light flux passing through a, 202b, 202c, 202d is re-imaged on each of the plurality of image pickup devices 31A, 31B, 31C, 31D, and at the same time, a region of the subject image is imaged. (Exposure). Other configurations and optical functions are substantially the same as those in the first embodiment,
This produces the same effect.

That is, in this embodiment, as shown in FIG. 5, the aperture opening 41A (41) of the aperture 41 in the first optical system 1 is used.
In the drawing of the subject image 200, the upper half of the image 200a (200b) with respect to the optical axis 100 is 1 by the light flux that has passed through B).
An image 203a (203b) is formed on the next image forming surface 21, and the image 203a (203b) is passed through the second optical system 2 to form a secondary image forming surface by the lens system 3A (3B) of the third optical system 3. Image 204 on the image sensor 31A (31B) surface provided in
The image is re-formed as a (204b).

Further, the subject image 20 is formed by the light flux that has passed through the aperture opening 41D (41C) of the aperture 41 in the first optical system 1.
Image 200d of the lower half with respect to the optical axis 100 on the drawing of 0
An image 203d (203c) of (200c) is formed on the primary imaging plane 21.
c), and the image 203d (203c) is passed through the second optical system 2 and the lens system 3D (3D of the third optical system 3
Image pickup device 31D (31
An image 204d (204c) is re-imaged on the surface C).

The four image pickup devices 31A, 31B, 3
The image information from 1C and 31D is combined by the signal processing system to synthesize the entire subject image [image 204a + image 204b + image 20].
0c + image 204d] is obtained.

In this embodiment, as described above, the optical axis of the third optical system 3 does not coincide with the optical axis 100 of the first optical system 1, and for example, the image 204a formed on the secondary image plane is formed. Is an image of the image 203a formed on the primary imaging surface 21 when viewed obliquely, and therefore the center position of the pupil region 202a of the first optical system 1 is displaced from the optical axis 100.

Therefore, the plurality of pupil regions 2 of the first optical system 1
The positions of 02a, 202b, 202c, and 202d are the upper half of the subject images 200a (2
00b) and the lower half of the subject image 200d (200c) have different pupil area centers with respect to the optical axis 100. Therefore, in the present embodiment, a plurality of diaphragm apertures are provided and the diaphragm 1 is provided.
Make up one.

However, these pupil regions 202a, 202
When the centers of b, 202c and 202d are close to each other and a part of the pupil regions 202a, 202b, 202c and 202d overlap each other, it is not always necessary to provide a plurality of diaphragm openings, and for example, the embodiment shown in FIG. As shown in FIG. 3, the diaphragm opening 51A is provided with respect to the diaphragm 51 as shown in FIG.
Even if it is formed so as to include 02b, 202c, and 202d, the same effect as that of the above-described embodiment can be obtained.

Further, in each of the above embodiments, the entire screen of the subject image is divided into four parts, and the respective divided images are combined by the signal processing system (combining processing system) to obtain one high resolution image. I got an image, but I made up the third optical system. 4
The number of pixels can be substantially increased by arbitrarily increasing the number of one lens system and the number of image pickup devices corresponding to the lens system, whereby an image with higher resolution can be obtained.

Further, in the case of a still image, a higher resolution image can be obtained by using it together with the above-mentioned conventional pixel shifting method.

[0048]

As described above, according to the present invention, each element of the image pickup apparatus is appropriately configured, and a diaphragm having an appropriate configuration is provided in the first optical system, so that an image pickup element having a limited number of pixels can be realized. A high-resolution image can be obtained by using it, without limiting the back focus of the photographic optical system, etc., and a high-resolution image that does not cause any inconvenience at the boundary between images can be obtained. On the other hand, it is possible to achieve an imaging device that can prevent image deterioration such as flare.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a part of an optical system according to Example 1 of the present invention.

FIG. 3 is a block diagram of a main part of a signal processing unit according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a main part of a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part of a part of an optical system according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a diaphragm according to a third embodiment of the present invention.

[Explanation of symbols]

1 1st optical system 2 2nd optical system 3 3rd optical system 11, 41, 51 diaphragm 11A, 41A, 41B, 41C, 41D, 51A diaphragm opening part 13 drive means (motor) 21 1st imaging surface 31 image pickup means 3A, 3B, 3C, 3D lens system 31A, 31B, 31C, 31D image pickup element 51A, 51B, 51C, 51D sample hold circuit 53A, 53B, 53C, 53D A / D conversion circuit 55A, 55B, 55C, 55D Memory 53 Image synthesis processing circuit 58 Image processing circuit

Claims (3)

[Claims] 1. A second optical system which forms a subject image on a planned image forming plane by the first optical system, and is arranged on the optical axis of the first optical system and near the planned image forming plane. , A third optical system having an optical axis outside the optical axis of the first optical system and having a plurality of lens systems arranged behind the second optical system, is formed on the planned image forming surface. When the part of the subject image is re-imaged on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems, the second optical system is the plurality of the third optical systems. Of the lens system and the pupil of the first optical system have a substantially conjugate relationship, and the plurality of lens systems respectively use light fluxes from a plurality of regions of the pupil of the first optical system. An image pickup apparatus for obtaining high-definition image information by using image information obtained by the image pickup device, wherein a plurality of the first optical systems are provided in the first optical system. A diaphragm having a diaphragm opening which is substantially centered on the center of one pupil area of the pupil region, the imaging apparatus characterized by restrictor opening is provided to allow transition. 2. A second optical system which forms a subject image on a planned image forming plane by the first optical system and is arranged on the optical axis of the first optical system and near the planned image forming plane. , A third optical system having an optical axis outside the optical axis of the first optical system and having a plurality of lens systems arranged behind the second optical system, is formed on the planned image forming surface. When the part of the subject image is re-imaged on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems, the second optical system is the plurality of the third optical systems. Of the lens system and the pupil of the first optical system have a substantially conjugate relationship, and the plurality of lens systems respectively use light fluxes from a plurality of regions of the pupil of the first optical system. An image pickup apparatus for obtaining high-definition image information by using image information obtained by the image pickup device, wherein a plurality of the first optical systems are provided in the first optical system. A diaphragm having an aperture portion including at least one pupil area of the pupil region, the imaging apparatus characterized by restrictor opening is provided to allow transition. 3. A second optical system which forms a subject image on a planned image forming plane by the first optical system and is arranged on the optical axis of the first optical system and near the planned image forming plane. , A third optical system having an optical axis outside the optical axis of the first optical system and having a plurality of lens systems arranged behind the second optical system, is formed on the planned image forming surface. When the part of the subject image is re-imaged on the plurality of image pickup devices of the image pickup means having a plurality of image pickup devices corresponding to the plurality of lens systems, the second optical system is the plurality of the third optical systems. Of the lens system and the pupil of the first optical system have a substantially conjugate relationship, and the plurality of lens systems respectively use light fluxes from a plurality of regions of the pupil of the first optical system. An image pickup apparatus for obtaining high-definition image information by using image information obtained by the image pickup device, wherein a plurality of the first optical systems are provided in the first optical system. Imaging apparatus characterized in that a diaphragm having a plurality of throttle openings is substantially centered on the center of each pupil area of the pupil region.