JP3513194B2 - Imaging device - Google Patents

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 a high resolution image information easily obtained 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. The present invention relates to an image pickup apparatus suitable for, for example, a small video camera or a still video camera.

[0002]

2. Description of the Related Art In recent years, solid-state area sensors (image sensors in which pixels are two-dimensionally arrayed) used as image pickup devices in image pickup devices have become capable of increasing the number of pixels, lowering their prices, and further reducing their size. Therefore, it has been widely applied to home-use compact video cameras, still video cameras, and the like, and sufficient image quality has been obtained in televisions of current standards such as NTSC.

FIG. 16 is a schematic view of a main part in the vicinity of an image pickup element of a conventional single plate type image pickup apparatus.

In the figure, 101 is a taking lens and 102
Is an optical filter, and is composed of, for example, a low-pass filter or a near-infrared light cut filter. Reference numeral 103 denotes a solid-state image sensor, which is composed of, for example, an area sensor, and a color filter having a filter array as shown in FIGS. 17 and 18 is provided on the surface of the image sensor 103. In the figure, an output signal (image information) obtained by the image sensor 103 is processed by a signal processing circuit (not shown), and thereby a colorized video signal is obtained and color reproduction is performed.

In order to obtain an output signal (image information) with a higher resolution than that of a single-plate type image pickup device, a two-plate type or three-plate type image pickup device as shown in FIGS. 19 and 20 is required. .

In FIGS. 19 and 20, 101 is a taking lens and 102 is an optical filter, which is composed of, for example, a low-pass filter or a near infrared light cut filter. Reference numeral 104 denotes a dichroic prism (or half mirror) as color separation means, which separates the incident light into two color lights in FIG. 19 and separates the incident light into three color lights in FIG. There is. 103A, 10
Reference numerals 3B and 103C are solid-state image pickup devices, each of which is composed of, for example, an area sensor and is provided on the exit surface of each prism.

In these image pickup devices, an output signal (image information) obtained from each solid-state image pickup element 103A, 103B, 103C is processed by a signal processing circuit (not shown) to obtain a colorized video signal. Color reproduction is performed.

[0008]

However, although the number of pixels of the image pickup device has been increasing in recent years in the conventional single-plate type image pickup device, its resolution is limited by the number of pixels of the solid-state image pickup device. It is difficult to reduce the cost because it is not possible to obtain an image with a resolution of 2) and the image pickup device with a high number of pixels is very expensive.

On the other hand, in a two-plate type or three-plate type image pickup device, since an optical member such as a dichroic prism or a half mirror is used as a color separation means, the back focus of the photographing lens becomes extremely long and the entire device is miniaturized. There was a problem that could not be achieved. Further, these optical members are expensive, and thus it is difficult to reduce the cost.

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 a subject image is formed on each image pickup device. Another object of the present invention is to provide an image pickup apparatus in which a filter having a predetermined spectral characteristic is provided on each image pickup element surface so that high-definition image information (color image) can be easily obtained.

[0011]

According to a first aspect of the present invention, there is provided an image pickup apparatus, wherein a first optical system forms a subject image on a predetermined image formation plane, and the image is formed on the optical axis of the first optical system. The second optical system arranged near the planned image forming surface and the third optical system arranged on the optical axis of the first optical system and behind the second optical system form the planned image formation. All of the subject images formed on the surface are re-imaged on the first image pickup means, have an optical axis outside the optical axis of the first optical system, and are arranged behind the second optical system. Part of the subject image formed on the planned image forming surface by the optical system of FIG. 2 is re-imaged on the second image pickup means, and the image information obtained by the first image pickup means and the second image pickup means is used. to an imaging apparatus to obtain a high-definition image information, it provided a filter having a predetermined spectral characteristic onto an imaging device surface of the first, respectively on the imaging device surface of the second The spectral characteristics and the predetermined spectral characteristics
It is characterized in that a filter having a plurality of different regions is provided .

According to a second aspect of the present invention, in the first aspect, the fourth optical system has a plurality of lens systems.
The second image pickup means has a plurality of image pickup elements corresponding to the plurality of lens systems. According to a third aspect of the present invention, in the second aspect, the plurality of lens systems of the fourth optical system divides the subject image formed by the first optical system into a plurality of regions, and the subject images of the respective regions are divided. Is imaged on the surface of the corresponding image pickup device. According to a fourth aspect of the invention, in the second or third aspect of the invention, the third optical system and the plurality of lens systems of the fourth optical system have different imaging magnifications. According to a fifth aspect of the present invention, in the second, third or fourth aspect of the present invention, a plurality of image signals in the high frequency region are formed by using the output signal from the first image pickup means to form the second image pickup means. It is characterized in that a video signal in a low frequency band is formed by using an output signal from the image pickup device. The invention of claim 6 is the same as the invention of claim 2, 3, 4 or 5,
Form a luminance signal using the output signal from the image pickup means of
It is characterized in that the color signals are formed by using the output signals from the plurality of image pickup devices constituting the second image pickup means. According to a seventh aspect of the present invention, in the invention according to any one of the second to sixth aspects, a filter having a plurality of regions having different spectral characteristics is provided on a plurality of image pickup device surfaces forming the second image pickup unit. Is characterized by. According to the invention of claim 8 in the invention of claim 1, on the surface of the first imaging means.
A feature is that a filter having a spectral characteristic corresponding to color light used as a luminance signal is provided. The invention of claim 9 is characterized in that, in the invention of claim 1, a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first imaging means. According to a tenth aspect of the present invention, in the invention according to any one of the second to ninth aspects, the number of pixels of the first image pickup means is larger than the number of pixels of a plurality of image pickup elements forming the second image pickup means. It is characterized by that.

According to the eleventh aspect of the present invention, an image pickup device forms a subject image on a planned image forming surface by the first optical system, and is located on the optical axis of the first optical system and near the planned image forming surface. Second placed
And the third optical system arranged on the optical axis of the first optical system and behind the second optical system, all the subject images formed on the planned image forming surface are The image is re-imaged on the first image pickup means, has an optical axis outside the optical axis of the first optical system, and is formed on the planned image forming surface by the fourth optical system arranged behind the second optical system. All the formed subject images are re-imaged on the second image pickup means, and high-definition image information is obtained by using image information obtained by the first image pickup means and the second image pickup means. a an imaging device, provided with a filter having a predetermined spectral characteristic onto an imaging device surface of the first, it on an imaging device surface of the second
A plurality of regions, each of which has a spectral characteristic different from the predetermined spectral characteristic.
The feature is that a filter having a region is provided .

In a twelfth aspect of the present invention based on the eleventh aspect, the fourth optical system has one or a plurality of lens systems, and the second image pickup means has the one or a plurality of lenses. It is characterized by having one or more image pickup devices corresponding to the system. According to a thirteenth aspect of the present invention, in the twelfth aspect of the present invention, the one or more lens systems of the fourth optical system cover the entire area of the subject image formed by the first optical system on the corresponding image pickup element surface. It is characterized by forming an image. According to a fourteenth aspect of the invention, in the twelfth or thirteenth aspect of the invention, the third optical system and the one or more lens systems of the fourth optical system have different imaging magnifications. The invention of claim 15 relates to claims 12 and 1.
In the invention of 3 or 14, an output signal from the first image pickup means is used to form a video signal in a high frequency range, and an output signal from one or a plurality of image pickup elements constituting the second image pickup means is formed. It is characterized in that a video signal in a low frequency range is formed by using it. The invention of claim 16 is claim 12, 1
In the invention of 3, 14, or 15, an output signal from the first image pickup means is used to form a luminance signal, and an output signal from one or a plurality of image pickup elements forming the second image pickup means is used. The feature is that the color signal is formed by
According to a seventeenth aspect of the present invention, in the invention according to any one of the twelfth to sixteenth aspects, there is provided a filter having a plurality of regions having different spectral characteristics on one or a plurality of image pickup device surfaces forming the second image pickup means. The feature is that it is provided. According to an eighteenth aspect of the present invention, in the eleventh aspect of the invention, a filter having a light-splitting characteristic corresponding to color light used as a luminance signal is provided on the surface of the first image pickup means. The invention of claim 19 is characterized in that, in the invention of claim 11, a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first imaging means. Claim 20
In the invention of any one of claims 12 to 19, the number of pixels of the first image pickup means is larger than the number of pixels of one or a plurality of image pickup elements forming the second image pickup means. It is characterized by that.

According to a twenty-first aspect of the present invention, an image pickup apparatus forms an image of a subject on a planned image forming plane by the first optical system, and has the same optical axis as the first optical system arranged near the planned image forming plane. Object image formed on the planned image formation plane by the second optical system and the third optical system that is arranged behind the second optical system and has the optical axes of the first optical system and the first optical system aligned with each other. Are imaged on the surface of the first image pickup means, and a plurality of areas obtained by dividing the subject image formed on the planned image formation surface have an optical axis different from the optical axis of the first optical system. A fourth optical system having one or a plurality of lens systems and arranged behind the second optical system
An image is formed on each of the one or more image sensor surfaces of the second image capturing means having one or more image sensor elements corresponding to one or more optical systems, and image information from the plurality of image sensor elements is formed. An image pickup apparatus for synthesizing to obtain image information about an entire subject image, wherein a filter having a predetermined spectral characteristic is provided on the surface of the first image pickup means to constitute the second image pickup means. Alternatively, each spectral feature can be
That has a plurality of regions whose characteristics differ from the predetermined spectral characteristics.
It is characterized by having a filter .

In a twenty-second aspect of the invention according to the twenty-first aspect, the third optical system and one or a plurality of lens systems forming the fourth optical system have different imaging magnifications. I am trying. The invention of claim 23 is claim 21.
In the invention described above, a high-frequency video signal is formed by using the output signal from the first image pickup means, and a low-frequency signal is generated by using output signals from one or a plurality of image pickup elements forming the second image pickup means. It is characterized in that a video signal in the frequency range is formed. The invention of claim 24 is the same as the invention of claim 21,
A luminance signal is formed by using an output signal from the first image pickup means, and a color signal is formed by using an output signal from one or a plurality of image pickup elements constituting the second image pickup means. I am trying. According to a twenty-fifth aspect of the present invention, in the twenty-first aspect, as a luminance signal on the surface of the first image pickup means
It is characterized in that a filter having a spectral characteristic corresponding to the color light used is provided. The invention of claim 26 is characterized in that, in the invention of claim 21, a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first imaging means. According to a twenty-seventh aspect of the present invention, in the twenty-first aspect, the number of pixels of the first image pickup means is larger than the number of pixels of one or a plurality of image pickup elements forming the second image pickup means. There is.

[0017]

FIG. 1 is a sectional view of the essential parts of an optical system according to the first embodiment of the present invention, and FIG. 2 is a perspective view of the essential parts of the first embodiment 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 2 denotes a second optical system, which is the first optical system 1.
Of the subject image formed on the primary image forming surface 21 and is guided to the subsequent lens system. .

Reference numeral 3 denotes a third optical system, and the first optical system 1
It is arranged on the optical axis of, and behind the second optical system 2 (on the image plane side). That is, the optical axis of the third optical system 3, the optical axis of the first optical system 1, and the optical axis of the second optical system 2 coincide with each other.

Reference numeral 31 denotes a first image pickup means (main image pickup means), which is arranged on the image forming surface behind the third optical system 3 and is composed of, for example, a solid area sensor. In this embodiment, as shown in FIG. 3A, a green (G) color filter having a spectral characteristic requiring visually high resolution is provided on the surface of the first image pickup means 31.

The entire area of the subject image formed on the primary image plane 21 by the first optical system 1 is recombined on the surface of the first image pickup means 31 by the second optical system 2 and the third optical system 3. I'm making you image.

Reference numeral 4 denotes a fourth optical system, which has four lens systems: a 41st lens system 4A, a 42nd lens system 4B, a 43rd lens system 4C, and a 44th lens system 4D.

The four lens systems 4A, 4B, 4C and 4D 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 41 denotes a second image pickup means (sub-image pickup means), which is, for example, four image pickup elements 4 including solid-state area sensors.
1A, 41B, 41C, 41D, which are arranged on the image planes of the four lens systems 4A, 4B, 4C, 4D, respectively.
In this embodiment, four image pickup devices 41A, 41B, 41C,
As shown in FIG. 3B, red (R) color and blue (B) having spectral characteristics that do not require high resolution visually on the surface 41D.
A color filter is provided in which color filters are alternately arranged in the main scanning direction (horizontal direction in the drawing) and the sub-scanning direction (vertical direction in the drawing).

The four lens systems of the fourth optical system 4 (4A,
4B, 4C, 4D) divides the subject image on the primary image forming 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 image pickup devices 41A, 41B, 41.
The image is re-formed on the C and 41D planes.

In this embodiment, the number of pixels of the image pickup device of the first image pickup device 31 is larger than the number of pixels of the plurality of image pickup devices 41A, 41B, 41C and 41D which constitute the second image pickup device 41. As described below, the first
A plurality of image pickup elements 41A, 41 forming a second image pickup means 41 by forming a high frequency image signal by the image pickup means 31 of
B, 41C, and 41D form a low-frequency video signal.

In the second embodiment, in the second optical system 2, the pupil 1a of the first optical system 1 and the pupil 3a of the third optical system 3 are substantially conjugate with each other as shown by the optical path 32 of the solid line in the figure. I am trying. Further, as shown by an optical path 42 indicated by a broken line in the drawing, a plurality of lens systems 4A, 4B, 4C, 4D which constitute the fourth optical system 4 are formed.
The pupils 4A1, 4B1, 4C1 and 4D1 are imaged in the vicinity of the divided pupil regions of the first optical system 1, respectively.

Four lens systems (4A, 4B, 4C, 4D) of the third optical system 3 and the fourth optical system 4 in this embodiment.
The image forming magnifications of and are different from each other, which effectively aligns the pupil image formation.

In this embodiment, as shown in FIG.
The subject image is formed on the primary image forming surface 21 by the optical system 1, and the subject image is formed on the surface of the first imaging means 31 by the third optical system 3 through the second optical system 2. The entire area of is imaged. Further, the four lens systems 4A, 4B, 4C, and 4D of the fourth optical system 4 divide the subject image formed on the primary image-forming surface 21 into four regions, and divide the subject image of each region into the second region. The four image pickup devices 41A, 41B, 41C and 41D constituting the image pickup means 41 are imaged respectively.

A plurality of image pickup elements 41A, 41B, 41 constituting the first image pickup means 31 and the second image pickup means 41.
A color image signal is obtained by a signal processing system, which will be described later, using the output signals (image information) from C and 41D to perform color reproduction.

Next, the image processing method of this embodiment will be described with reference to FIG. This figure is a block diagram of the essential parts of the video signal processing unit (signal processing system) of the image pickup apparatus of this embodiment.

In the figure, 31, 41A, 41B, 41
C and 41D are image pickup devices, and these image pickup devices 3
1, 41A, 41B, 41C, 41D on the surface of FIG.
The color filters shown in are provided respectively.

In the present embodiment, the entire subject image formed on the first image pickup means 31 is output from the image pickup means 31 as an electric signal (G signal), and a sample hold circuit (S / H circuit) 51 performs sample hold. Then, the analog-digital conversion circuit (A / D conversion circuit) 52 converts the analog signal into a digital signal, which is stored in the memory (storage circuit) 53.

Further, a subject image formed by area-dividing the four image pickup devices 41A, 41B, 41C and 41D forming the second image pickup means 41 into the respective image pickup devices 41A, 41B,
41C and 41D output as electric signals (R and B signals are alternately output), and sample and hold circuits (S / H circuits) 54A to 54H sample and hold at the timings of the R and B signals, respectively. , R signal and B signal are separated. Then, each signal is converted from an analog signal to a digital signal by each analog-digital conversion circuit (A / D conversion circuit) 55A to 55H, and each memory (storage circuit) 5
6A to 56H.

The G signal stored in the memory 53 is input to the luminance signal processing circuit 57 and the color signal processing circuit 58. Further, the information is read out from each of the memories 56A to 56H and input to the color signal processing circuit 58 in such an order that the R signal and the B signal stored in each of the memories 56A to 56H are divided into areas and stored in the entire screen. Luminance signal processing circuit 57
Then, the G signal is subjected to necessary signal processing as a luminance signal, for example, automatic gain control (AGC) and gamma correction, and output as a luminance signal.

The color signal processing circuit 58 performs processing such as AGC, gamma correction, and white balance adjustment on the input R, G, and B signals, performs matrix processing, and outputs color difference signals. . Then, a color video signal is obtained using these signals to perform color reproduction.

Each output signal of the luminance signal and the color difference signal may be converted from a digital signal to an analog signal by a digital-analog conversion circuit (D / A conversion circuit) as necessary, or may be output. It may be converted into a composite video signal by the encoder circuit and output.

In this embodiment, since the luminance signal is formed by using the signal obtained from the first image pickup means 31 having a high number of pixels, it is possible to achieve higher resolution than the conventional image pickup apparatus.

Since the required wavelength band for the color signal is narrow, the four image pickup elements 41A, 41A, which constitute the second image pickup means 41 having a smaller number of pixels than the first image pickup means 31,
By using the output signals from 41B, 41C, and 41D, different from the conventional multi-plate type image pickup device,
High resolution can be achieved without using a plurality of expensive high-pixel-number image pickup elements when using multiple boards.

Further, since it is possible to perform multiple plates and colorization without using an expensive optical member such as a dichroic prism or a half mirror as the color separation means, there is no restriction on the back focus of the taking lens.

In the present embodiment, the plurality of image pickup elements 41 constituting the first image pickup means 31 and the second image pickup means 41.
The arrangement of the color filters provided on the A, 41B, 41C, and 41D surfaces is not limited to the filter arrangement shown in FIG. 3, and, for example, as shown in FIGS. 5, 6, 7, and 8, a luminance signal component, The present invention can be applied in the same manner as in the above-described first embodiment with any filter arrangement as long as a color signal component is obtained.

That is, in FIG. 5, the first image pickup means 31
A G (green) color filter is provided on the surface, and a red (R) color filter and a blue (B) color filter are provided on the surface of the second imaging unit 41 (41A to 41D) in the main scanning direction (horizontal direction in the drawing). The color filters are arranged alternately. In FIG. 6, a yellow (Y) color filter is provided on the surface of the first image pickup means 31, and red (R) color and blue (B) color are provided on the surface of the second image pickup means 41 (41A to 41D). A color filter is provided in which the filters are alternately arranged in the main scanning direction and the sub scanning direction (vertical direction in the drawing). In FIG. 7, a yellow (Y) color filter is provided on the surface of the first image pickup means 31, and a red (R) color and a blue (B) color are provided on the surface of the second image pickup means 41 (41A to 41D). A color filter is provided in which the filters are arranged alternately in the main scanning direction. Also, in FIG. 8, the first
A white (W) color filter is provided on the surface of the image pickup means 31 of
Red (R) on the surface of the second imaging means 41 (41A to 41D)
A color filter is provided in which color, green (G), and blue (B) filters are alternately arranged in the main scanning direction.

In particular, with the filter arrangement shown in FIG. 8, for example, when a high-resolution image is not required, the first image pickup means 31 alone can be used for image pickup.

In the present embodiment, the fourth optical system is 4
Although the number of lens systems is one, the number is not limited to four, and any number can be used as long as the entire area of the subject image can be divided by a plurality of lens systems and photographed. In particular, if the fourth optical system 4 is composed of five or more lens systems, higher resolution can be achieved.

FIG. 9 is a sectional view of the essential parts of an optical system according to the second embodiment of the present invention, and FIG. 10 is a perspective view of the essential parts of the second embodiment of the present invention.
In the figure, the same elements as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

The difference of this embodiment from the above-mentioned first embodiment is that the fourth optical system 4 is composed of two lens systems 4A and 4B, and the second lens systems 4A and 4B are respectively provided with a second optical system. The image pickup devices 41A and 41B as the image pickup means 41 are arranged respectively, and a red (R) color filter is provided on the surface of the image pickup device 41A as shown in FIG.
A blue (B) color filter is provided on the surface, and the entire area of the subject image formed on the primary imaging surface 21 is re-imaged on the surfaces of the two image pickup devices 41A and 41B, respectively, and the two image pickup devices are formed. By using the signals from 41A and 41B and the signal from the first image pickup means 31 arranged on the image plane of the third optical system 3, a color image signal is obtained by the signal processing system and color reproduction is performed. is there. Other configurations and optical functions are substantially the same as those in the first embodiment.

That is, in the present embodiment, the second optical system 2
Is configured so that the pupil 1a of the first optical system 1 and the pupil 3a of the third optical system 3 are substantially conjugate with each other as indicated by the optical path 32 of the solid line in the figure, and the optical path 42 of the dashed line in the figure 4th as shown
Of the two lens systems 4A and 4B that form the optical system 4 of FIG.
A1 and 4B1 are formed in the vicinity of the pupil area of the first optical system 1, respectively.

Then, as shown in FIG. 10, the first optical system 1
The subject image is formed on the primary imaging plane 21 by means of the second optical system 2 and the third optical system 3 causes the entire area of the subject image to be formed on the surface of the first image pickup means 31. Imaged. In addition, the two lens systems 4A and 4B of the fourth optical system 4
The object image formed on the primary image forming surface 21 is formed on the surfaces of the two image pickup devices 41A and 41B forming the second image pickup means 41, respectively. Then, using the output signals (image information) obtained by the two image pickup devices 41A and 41B forming the first image pickup unit 31 and the second image pickup unit 41, a color image signal is obtained by a signal processing system described later and color is obtained. It is reproduced.

Next, the image processing method of this embodiment will be described with reference to FIG. This figure is a block diagram of the essential parts of the video signal processing unit (signal processing system) of the image pickup apparatus of this embodiment.

In the figure, reference numerals 31, 41A and 41B denote image pickup elements, and these image pickup elements 31, 41A and 41B.
The color filters shown in FIG. 11 are provided on the surface B, respectively.

In this embodiment, the entire image of the subject formed on the first image pickup means 31 is output from the image pickup element 31 as an electric signal (G signal), and a sample hold circuit (S / H circuit) 51 performs sample hold. Then, the analog-digital conversion circuit (A / D conversion circuit) 52 converts the analog signal into a digital signal, which is stored in the memory (storage circuit) 53.

Further, all the subject images formed on the two image pickup devices 41A and 41B constituting the second image pickup means 41 are supplied as electric signals (R signal and B signal) from the image pickup devices 41A and 41B.
Each sample and hold circuit (S / H circuit)
54A and 54B sample hold, each analog-
Digital signals are converted into digital signals by digital conversion circuits (A / D conversion circuits) 55A and 55B and stored in respective memories (storage circuits) 56A and 56B.

The G signal stored in the memory 53 is input to the luminance signal processing circuit 57 and the color signal processing circuit 58. The R and B signals stored in the memories 56A and 56B are read from the memories 56A and 56B and input to the color signal processing circuit 58. The brightness signal processing circuit 57 performs necessary signal processing on the G signal as a brightness signal, such as automatic gain control (AGC) and gamma correction, and outputs the brightness signal.

The color signal processing circuit 58 performs processing such as AGC, gamma correction, and white balance adjustment on the input R, G, and B signals, performs matrix processing, and outputs color difference signals. . Then, a color video signal is obtained using these signals to perform color reproduction.

In this embodiment, as in the first embodiment, the luminance signal is formed by using the signal obtained from the first image pickup means 31 having a large number of pixels, so that the resolution is higher than that of the conventional image pickup apparatus. Can be achieved.

Further, since the required wavelength band for the color signal is narrow, the two image pickup devices 41A, 41A, which constitute the second image pickup device 41 having a smaller number of pixels than the first image pickup device 31,
By using the output signal obtained from 41B, it is possible to improve the resolution without using a plurality of expensive high-pixel-number image pickup elements when the number of boards is increased, unlike the conventional multi-plate type image pickup apparatus. Can be planned.

Further, since it is possible to perform multi-plate and colorization without using an expensive optical member such as a dichroic prism or a half mirror as the color separation means, there is no limitation on the back focus of the taking lens.

Further, in the circuit configuration of the color signal processing system in the present embodiment, the number of pixels of the image pickup device is smaller than the number of pixels of the image pickup device used in the conventional image pickup apparatus, so that the storage capacity of the memory is small, for example. Further, since the driving frequency of the S / H circuit and the A / D conversion circuit can be small, the circuit configuration can be made easy, and further, the current consumption is small.

In the present embodiment, the arrangement of the color filters provided on each image pickup element surface is not limited to the filter arrangement shown in FIG. 11, and, for example, as shown in FIG. 13, there are luminance signal components and color signal components. If it is obtained, the present invention can be applied to any filter arrangement as in the above-mentioned embodiment.

That is, in FIG. 13, the first image pickup means 3
A yellow (Y) color filter is provided on one surface, a red (R) color filter is provided on the image pickup element 41A surface of the second image pickup means 41, and an image pickup element 41B surface of the second image pickup means 41 is provided. A blue (B) color filter is provided on the above, and thereby the same effect as that of the above-described embodiment is obtained.

FIG. 14 is an explanatory view showing the arrangement of the color filters provided on the surfaces of the first image pickup means 31 and the second image pickup means 41 according to the third embodiment of the present invention.

This embodiment is an invention obtained by further improving the above-mentioned second embodiment. That is, the different point from the above-described second embodiment is that the fourth optical system 4 is composed of one lens system 4A, and the image pickup element 41A as the second image pickup means is arranged on the image forming surface of the one lens system 4A. 14B on the surface of the image pickup element 41A.
As shown in FIG. 5, a color filter is provided in which red (R) color filters and blue (B) color filters are alternately arranged in the main scanning direction and the sub scanning direction. As described above, the present invention can be applied in the same manner as the above-described second embodiment by configuring the fourth optical system 4 and the number of image pickup elements arranged corresponding to the fourth optical system 4 to be one. Other configurations and optical functions are substantially the same as those in the second embodiment.

Next, the image processing method of this embodiment will be described with reference to FIG. This figure is a block diagram of the essential parts of the video signal processing unit (signal processing system) of the image pickup apparatus of this embodiment.

In the figure, reference numerals 31 and 41A denote image pickup devices, and the color filters shown in FIG. 14 are provided on the surfaces of the image pickup devices 31 and 41A, respectively.

In this embodiment, the subject image formed on the first image pickup means 31 is outputted from the image pickup device 31 as an electric signal (G signal), and the sample hold circuit (S / H circuit) 51 is outputted.
The sample is held by, and the analog-digital conversion circuit (A / D conversion circuit) 52 converts the analog signal into a digital signal, which is stored in the memory (storage circuit) 53.

Further, the subject image formed on the second image pickup means 41 is outputted from the image pickup element 41A as an electric signal (an R signal and a B signal are alternately outputted), and each sample hold circuit (S / H) is outputted. (Circuits) 54A and 54B sample and hold at the timings of the R signal and the B signal, respectively, to separate them into the R signal and the B signal. Then, each signal is converted from an analog signal to a digital signal by analog-digital conversion circuits (A / D conversion circuits) 55A and 55B, and each memory (storage circuit) is converted.
It is stored in 56A and 56B. Then, the G signal stored in the memory 53 is input to the luminance signal processing circuit 57 and the color signal processing circuit 58.

The R and B signals stored in the memories 56A and 56B are read out from the memories 56A and 56B and input to the color signal processing circuit 58. The brightness signal processing circuit 57 performs necessary signal processing on the G signal as a brightness signal, such as automatic gain control (AGC) and gamma correction, and outputs the brightness signal.

The color signal processing circuit 58 performs processing such as AGC, gamma correction, and white balance adjustment on the input R, G, and B signals, performs matrix processing, and outputs color difference signals. . Then, a color video signal is obtained using these signals to perform color reproduction.

In this embodiment, the number of image pickup elements constituting the second image pickup means 41 is smaller than that of the second embodiment, and therefore, the power consumption can be reduced. .

The arrangement of the color filters provided on the surface of each image pickup device in this embodiment is not limited to the arrangement shown in FIG. 14, but may be as shown in FIGS. 5, 6, 7, and 8, for example. The present invention can be applied to any filter arrangement as long as the luminance signal component and the chrominance signal component are obtained, in the same manner as the above-described embodiment.

[0072]

According to the present invention, each element of the image pickup apparatus is appropriately configured as described above, and the high frequency of the object image is obtained by the first image pickup means having a large number of pixels arranged on the image forming plane of the third optical system. By capturing the low-frequency component of the subject image with the second image capturing unit having a smaller number of pixels than the first image capturing unit disposed on the image forming surface of the fourth optical system, the high frequency component of the subject image is expensive. High resolution can be easily achieved without using multiple image sensors with the number of pixels, and there is no need to use expensive optical members such as dichroic prisms and half mirrors, and the back focus of the shooting optical system is limited. Also disappears.

Furthermore, in the circuit configuration of the color signal processing system, the number of pixels of the image pickup device is smaller than the number of pixels of the image pickup device used in the conventional image pickup apparatus, so that the capacity of the memory can be reduced or the S / H circuit can be used. Since the driving frequency of the A / D conversion circuit and the A / D conversion circuit can be small, the circuit configuration can be facilitated, and an image pickup device that can reduce current consumption can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of an optical system according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a main part of a signal processing unit according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the first embodiment of the present invention.

FIG. 9 is a schematic view of a main part of an optical system according to a second embodiment of the present invention.

FIG. 10 is a perspective view of essential parts of Embodiment 2 of the present invention.

FIG. 11 is an explanatory diagram showing an array of color filters provided on the surfaces of the first and second image pickup means according to the second embodiment of the present invention.

FIG. 12 is a block diagram of essential parts of a signal processing unit according to a second embodiment of the present invention.

FIG. 13 is an explanatory diagram showing an arrangement of color filters provided on the first and second image pickup means surfaces of the second embodiment of the present invention.

FIG. 14 is an explanatory diagram showing an array of color filters provided on the first and second image pickup means surfaces of the third embodiment of the present invention.

FIG. 15 is a block diagram of a main part of a signal processing unit according to a third embodiment of the present invention.

FIG. 16 is a schematic view of a main part of a conventional imaging device.

FIG. 17 is an explanatory diagram showing an array of color filters provided on an image pickup element surface of a conventional image pickup apparatus.

FIG. 18 is an explanatory diagram showing an array of color filters provided on the image pickup element surface of a conventional image pickup apparatus.

FIG. 19 is a schematic view of a main part of a conventional two-plate type imaging device.

FIG. 20 is a schematic view of a main part of a conventional three-plate type imaging device.

[Explanation of symbols]

1 First optical system 2 Second optical system 3 Third optical system 4th optical system 21 First image plane 31 First imaging means 41 Second image pickup means 4A, 4B, 4C, 4D lens system 41A, 41B, 41C, 41D Imaging means 51, 52A, 52B sample and hold circuit 53 Analog-digital conversion circuit 54, 55A, 55B memory 56 Luminance signal processing circuit 57 Color signal processing circuit

Claims (27)

(57) [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 first image pickup means for all the subject images formed on the planned image forming surface by the third optical system arranged on the optical axis of the first optical system and behind the second optical system. Image formed on the planned image forming plane by the fourth optical system which is re-imaged on the optical axis and has an optical axis outside the optical axis of the first optical system, and which is arranged behind the second optical system. Device for re-imaging a part of the image on the second image pickup means and obtaining high-definition image information by using image information obtained by the first image pickup means and the second image pickup means In addition, a filter having a predetermined spectral characteristic is provided on the surface of the first image pickup means, and each spectral feature is provided on the surface of the second image pickup means.
That has a plurality of regions whose characteristics differ from the predetermined spectral characteristics.
An imaging device having a filter . 2. The fourth optical system has a plurality of lens systems, and the second image pickup means has a plurality of image pickup devices corresponding to the plurality of lens systems. The image pickup apparatus according to claim 1. 3. The plurality of lens systems of the fourth optical system are arranged on the corresponding image pickup device surfaces of the subject images of the respective regions when the subject image formed by the first optical system is divided into a plurality of regions. The image pickup apparatus according to claim 2, wherein the image is formed on the image. 4. The image pickup apparatus according to claim 2, wherein the third optical system and the plurality of lens systems of the fourth optical system have different imaging magnifications. 5. An image signal in a high frequency band is formed using an output signal from the first image pickup device, and a low frequency band is formed using output signals from a plurality of image pickup devices constituting the second image pickup device. 3. The video signal according to claim 2 is formed.
The imaging device according to 3 or 4. 6. A luminance signal is formed by using an output signal from the first image pickup means, and a color signal is formed by using output signals from a plurality of image pickup elements which form the second image pickup means. The image pickup apparatus according to claim 2, 3, 4, or 5. 7. The filter according to claim 2, wherein a filter having a plurality of regions having different spectral characteristics is provided on a plurality of image pickup device surfaces forming the second image pickup means. Imaging device. 8. A luminance signal is provided on the surface of the first image pickup means.
The image pickup apparatus according to claim 1, further comprising a filter having a spectral characteristic corresponding to the color light used as the light source. 9. The image pickup apparatus according to claim 1, wherein a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first image pickup means. 10. The number of pixels of the first image pickup means is larger than the number of pixels of a plurality of image pickup elements forming the second image pickup means. The imaging device according to. 11. 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 element disposed on the optical axis of the first optical system and behind the second optical system.
Of the subject image formed on the planned image forming surface with the optical system of FIG. A fourth optical system arranged behind the optical system reimages all of the subject image formed on the planned image forming surface on the second image pickup means, and the first image pickup means and the second image pickup means. An image pickup device for obtaining high-definition image information by using image information obtained by the method, comprising: providing a filter having a predetermined spectral characteristic on the surface of the first image pickup means; Each spectral feature on the instrument surface
That has a plurality of regions whose characteristics differ from the predetermined spectral characteristics.
An image pickup device comprising a filter . 12. The fourth optical system has one or a plurality of lens systems, and the second image pickup means has one or a plurality of image pickup elements corresponding to the one or a plurality of lens systems. The imaging device according to claim 11, further comprising: 13. The one or more lens systems of the fourth optical system form an entire area of a subject image formed by the first optical system on a corresponding image pickup element surface. The imaging device according to claim 12. 14. The image pickup apparatus according to claim 12, wherein the third optical system and one or a plurality of lens systems of the fourth optical system have different imaging magnifications. 15. An image signal in a high frequency range is formed using an output signal from the first image pickup means, and an output signal from one or a plurality of image pickup elements forming the second image pickup means is used. The image pickup apparatus according to claim 2, 3 or 4, wherein a video signal in a low frequency range is formed. 16. A luminance signal is formed by using an output signal from the first image pickup means, and a color signal is formed by using an output signal from one or a plurality of image pickup elements forming the second image pickup means. It is formed, The claim 12, 13, 14 characterized by the above-mentioned.
Alternatively, the image pickup device according to item 15. 17. A filter having a plurality of regions having different spectral characteristics is provided on the surface of one or a plurality of image pickup devices constituting the second image pickup means.
17. The imaging device according to any one of 1 to 16. 18. A luminance signal on the surface of the first image pickup means
The image pickup apparatus according to claim 11, further comprising a filter having a spectral characteristic corresponding to the color light to be used . 19. The image pickup apparatus according to claim 11, wherein a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first image pickup means. 20. The number of pixels of the first image pickup means is larger than the number of pixels of one or a plurality of image pickup elements forming the second image pickup means. The image pickup apparatus according to item 1. 21. An object image is formed on a planned image forming surface by a first optical system, and a second optical system having the same optical axis as that of the first optical system arranged near the planned image forming surface is provided. The first image pickup means includes all of the subject image formed on the planned image forming plane by the third optical system which is arranged behind the second optical system and whose optical axis is aligned with that of the first optical system. While focusing on the surface,
The second optical system having a plurality of regions obtained by dividing the subject image formed on the planned image forming surface and having one or a plurality of lens systems having an optical axis different from the optical axis of the first optical system. By a fourth optical system disposed behind the image pickup device of the second image pickup means having one or a plurality of image pickup devices corresponding to the one or a plurality of optical systems, respectively. An image pickup device for forming an image and synthesizing image information from the plurality of image pickup elements to obtain image information about an entire subject image, wherein a filter having a predetermined spectral characteristic is provided on the surface of the first image pickup means. Provided on the surface of one or a plurality of image pickup devices constituting the second image pickup means, and each of the spectral characteristics has a predetermined spectral
An image pickup apparatus comprising a filter having a plurality of regions different from each other . 22. The image pickup apparatus according to claim 21, wherein the third optical system and one or a plurality of lens systems forming the fourth optical system have different imaging magnifications. 23. An image signal in a high frequency range is formed using an output signal from the first image pickup means, and an output signal from one or a plurality of image pickup elements forming the second image pickup means is used. 22. The image pickup device according to claim 21, wherein a video signal in a low frequency range is formed. 24. A luminance signal is formed by using an output signal from the first image pickup means, and a color signal is formed by using an output signal from one or a plurality of image pickup elements constituting the second image pickup means. The imaging device according to claim 21, wherein the imaging device is formed. 25. A luminance signal is provided on the surface of the first image pickup means.
22. The image pickup apparatus according to claim 21, further comprising a filter having a spectral characteristic corresponding to the color light to be used . 26. The image pickup apparatus according to claim 21, wherein a filter having a spectral characteristic of a green light characteristic is provided on the surface of the first image pickup means. 27. The image pickup apparatus according to claim 21, wherein the number of pixels of the first image pickup means is larger than the number of pixels of one or a plurality of image pickup elements forming the second image pickup means. .