JP2001352481A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that attains focus adjustment with high accuracy for attaining high image quality. SOLUTION: The imaging device is provided with a focus adjustment means, that adjusts the focal state of an image-forming optical system, an object information detection means (#5) that detects object information at least either of an object color and a spatial frequency, and a focal point adjustment amount calculating means (#6) that calculates a focus adjustment quantity for adjusting the image-forming optical system into an optimum focal state, on the basis of information relating to a distance up to an object and the object information, and the focus adjustment amount calculated by the focal point adjustment amount calculating means drives the focus adjustment means for adjusting the focus (#7).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device such as an electronic camera.

[0002]

2. Description of the Related Art In recent years, video equipment such as an electronic camera has made remarkable progress, and various improvements have been made, such as digitization of signal processing.

FIG. 6 is a block diagram showing an electric configuration of a conventional electronic camera. In FIG. 6, reference numeral 100 denotes an electronic camera, and 101 denotes a recording medium such as a memory card.

In the electronic camera 100, reference numeral 1 denotes an imaging lens capable of adjusting a focal length and an angle of view, 2 denotes an aperture / shutter which has both an aperture function and a shutter function, and 3 denotes a photographing lens 1.
And a mechanical drive circuit of the aperture / shutter 2.

[0005] Reference numeral 4 denotes an image sensor for converting reflected light from a subject into an electric signal; 5, a timing signal generator (TG) for generating a timing signal required to operate the image sensor 4; and 6, a timing signal generator. An image pickup device driving circuit for amplifying a signal from the image pickup device to a level at which an image pickup signal can be driven;
A pre-processing circuit provided with a (double correlation sampling) circuit and an AGC (auto gain control) circuit.
A converter 9 is a video signal processing circuit having a memory for temporarily storing the A / D-converted digital signal and a circuit for processing the signal, 10 is a system control CPU, and 11 is a connection between the electronic camera 100 and the recording medium 101. This is a recording medium interface (I / F).

Reference numeral 12 denotes an operation unit for the photographer to control the start of photographing by the camera, more specifically, a release switch, which can be operated in two stages, a first stroke SW1 and a second stroke SW2. Reference numeral 13 denotes an operation display unit for displaying a display for assisting operation and displaying the state of the camera. 14 is a photographing lens 1
A distance measuring circuit for measuring the distance between the electronic camera 100 and the subject for focus adjustment, and a photometric sensor 15 for measuring the brightness of the subject.

FIG. 7 is a flowchart showing the operation of the electronic camera 100 having the above configuration.

Operation section (release switch) by photographer
When the 12 first stroke SW1 is turned on,
The system control CPU 10 starts the operation of the distance measuring sensor 14 and captures its output. Then, a focus adjustment amount is calculated based on the output of the distance measuring circuit 14 (# 201 to # 20).
3) driving the focus adjustment device (not shown) via the mechanical drive circuit 3 to move the focus adjustment lens of the photographing lens 1;
The focus state is set (# 204). When the movement of the lens is completed, the state is set to the AF_LOCK state, and thereafter, the focus adjustment device is not driven (# 205).

Thereafter, the system control CPU 10 keeps taking in the output of the photometric sensor 15 until the second stroke SW2 of the operation unit 12 is turned on by the photographer (# 206, # 207).

When it is detected that the second stroke SW2 is turned on, the brightness of the subject is detected from the output of the photometric sensor 15, and the aperture value and shutter speed corresponding to the detected value are calculated (# 208). Then, the aperture and the timing signal generating circuit 5 are calculated based on the calculated exposure condition.
The electronic shutter timing is set, the image sensor 4 is exposed, and the output of the image sensor 1 is read (# 209).

Next, the read image output is subjected to signal processing such as CDS processing and gain control in the preprocessing circuit 7. At this time, since the gain of the gain control circuit is determined by the sensitivity of the image sensor 1, it is set when the electronic camera is manufactured. The output of the preprocessing circuit 7 is converted into a digital signal by the A / D converter 8 and
Is input to As a result, the exposure condition is reconfirmed from the imaging output by the video signal processing circuit 9 and the system control CPU 10, and an error from the proper exposure is detected to change the setting of the shutter speed (# 209). Then, the image sensor 1 is exposed again according to the changed exposure condition, and its output is read. The output of the image sensor 1 is converted into a digital signal, and after being converted into a specific format by the video signal processing circuit 9, a captured image signal is recorded on the recording medium 101 via the recording medium I / F 13 (# 211).

[0012]

As described above, in a conventional electronic camera, a distance to a subject is measured by using a distance measuring circuit in order to focus the photographing lens, and the focusing of the photographing lens is performed. That is, a typical focusing operation is performed. In general, the best photographing position of the photographing lens differs depending on the color of the subject and the spatial frequency. Therefore, adjusting the focus position of the taking lens at the distance measured by the distance measurement circuit can focus on the standard focus position, but requires more precise focusing such as an imaging device with higher resolution. The best image cannot be obtained with an electronic camera.

[0013] Products such as camcorders have been realized to realize the function only by the image pickup device without using the distance measuring circuit, but it is necessary to minimize the release time lag at the time of release as in an electronic camera. The performance of the product with the defect has not been achieved.

[0014] Further, an imaging device capable of changing the resolution by selecting a mode is known. In such an imaging device, when the same focus adjustment is performed in each mode, the best focus is set depending on the spatial frequency of the subject. Since the positions are different, the focus adjustment accuracy becomes insufficient. In other words, when the accuracy of focus adjustment is suitable for an object having a low spatial frequency in the low resolution mode, the focus adjustment performance becomes insufficient when shooting an object having a high spatial frequency in the high resolution mode.

(Object of the Invention) It is an object of the present invention to provide an image pickup apparatus that enables highly accurate focus adjustment and obtains high image quality.

[0016]

In order to achieve the above object, the invention according to claim 1 comprises a focus adjusting means for adjusting a focus state of an imaging optical system, and at least one of a color and a spatial frequency of a subject. Subject information detecting means for detecting such subject information; and a focus adjustment amount calculation for calculating a focus adjustment amount for adjusting the imaging optical system to an optimum focus state based on information on a distance to the subject and the subject information. Means,
According to another aspect of the present invention, there is provided an imaging apparatus that performs focus adjustment by driving the focus adjustment unit based on the focus adjustment amount calculated by the focus adjustment amount determination unit.

According to another aspect of the present invention, there is provided a photographing means having an imaging optical system for photographing an optical image, a distance detecting means for detecting a distance to a subject, and A focus adjusting means for adjusting a focus state of the means; a subject information detecting means for detecting at least one subject information of a subject and a spatial frequency; and an optimal focusing state based on the subject distance information and the subject information. A focus adjustment amount calculating unit that calculates a focus adjustment amount for adjusting the imaging optical system, and drives the focus adjustment unit based on the focus adjustment amount calculated by the focus adjustment amount determination unit to perform focus adjustment. It is an imaging device.

According to another aspect of the present invention, there is provided an image forming optical system for forming an optical image on a photoelectric conversion element for converting an optical image into an electric signal; A focus shift amount detecting means for detecting a focus shift amount of a system, a focus adjusting means for adjusting a focus state of the imaging optical system, a subject information detecting means for detecting subject information, and the focus shift amount information and the subject information. A focus adjustment amount calculating unit that calculates a focus adjustment amount that adjusts the imaging optical system to an optimal focusing state based on the shooting information information, and a focus adjustment amount calculated by the focus adjustment amount determination unit. According to another aspect of the present invention, there is provided an imaging apparatus that drives the focus adjustment unit to perform focus adjustment.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a block diagram showing an electric configuration of an electronic camera according to a first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes an electronic camera, and 101 denotes a recording medium such as a memory card.

In the electronic camera 100, reference numeral 1 denotes a photographic lens capable of adjusting a focal length and an angle of view, 2 denotes an aperture / shutter which has both an aperture function and a shutter function, and 3 denotes a photographic lens 1.
And a mechanical drive circuit of the aperture / shutter 2.

Reference numeral 4 denotes an image sensor for converting reflected light from an object into an electric signal; 5, a timing signal generator (TG) for generating a timing signal required for operating the image sensor 4; and 6, a timing signal generator. An image sensor driving circuit for amplifying the signal from 5 to a level at which the image signal can be driven; 7, a pre-processing circuit having a CDS circuit and an AGC circuit for removing output noise of the image sensor 4; , A video signal processing circuit having a memory for temporarily storing the A / D converted digital signal and a circuit for processing the signal, 10 a system control CPU, 11 an electronic camera 1
A recording medium interface (I / F) for connecting the recording medium 101 to the recording medium 101.

Reference numeral 12 denotes an operation unit for the photographer to control the start of photographing by the camera, more specifically, a release switch, which can be operated in two stages, a first stroke SW1 and a second stroke SW2. Reference numeral 13 denotes an operation display unit for displaying a display for assisting operation and displaying the state of the camera. 14 is a photographing lens 1
A distance measuring circuit for measuring the distance between the electronic camera 100 and the subject for focus adjustment, and a photometric sensor 15 for measuring the brightness of the subject.

Reference numeral 16 denotes a lens information storage device for storing information on the photographing lens 1. In general, the best focus position of a photographic lens differs depending on the spatial frequency of the subject, and the best focus position also differs depending on the color of the subject, that is, the wavelength, due to the remaining chromatic aberration. Therefore,
The lens information storage device 16 stores the shift amount of the best focus position due to the difference in the subject of the mounted photographing lens 1. In the first embodiment of the present invention, when an object is present from close to infinity, the difference between each optical paraxial focus position and the best focus position according to the spatial frequency and color of the object is stored. Then, an object distance measured by the distance measuring circuit 14 and a correction amount corresponding to the object information are read out from the lens information storage device 16 and corrected at the time of focusing operation, thereby enabling extremely accurate focusing. ing.

FIG. 2 is a flowchart showing the operation of the electronic camera 100 having the above configuration.

When the first stroke SW1 of the operation unit 12 is turned on by the photographer (# 1), the system control CPU 10 starts the operation of the distance measuring circuit 14 and captures its output (# 2). Then, the focus adjustment amount is calculated from the output of the distance measurement circuit 14 (# 3), and the focus adjustment device (not shown) is driven via the mechanical drive circuit 3 to move the focus adjustment lens of the photographing lens 1; This is set as a first focus state (# 4).

In this state, the output of the image sensor 1 is read out,
Object information such as the color and the spatial frequency of the object is detected (# 5). Then, based on the subject distance obtained by the distance measuring circuit 14 and the subject information, the information in the lens information storage device 16 storing the characteristics of the photographing lens 1 is illuminated to determine the correction amount of the focus adjustment (# 6). . Next, the focus adjustment lens of the photographing lens 1 is driven via the mechanical drive circuit 3 based on the correction amount to adjust the focus, and the second focus state is set. When the focus adjustment is completed, AF_LOC
In the K state, the focus adjustment device is not driven thereafter (#
7).

In a series of focusing operations, if the subject information can be detected before the first focusing state, that is, if the defocus amount is small from the beginning,
It is also possible to omit the first focusing operation. Further, the subject information read out from the image sensor 1 does not need to be the entire image capturing screen, but may be only the information of the main subject portion to be focused.

Thereafter, until the photographer turns on the second stroke SW2 of the operation unit 12, the system control CPU 10 keeps taking in the output of the photometric sensor 15 (# 8, # 9).

When it is detected that the second stroke SW2 has been turned on, the brightness of the subject is detected from the output of the photometric sensor 15, and the aperture value and shutter speed corresponding to the detected value are calculated (# 10). Then, the aperture and the electronic shutter timing of the timing signal generation circuit 5 are set according to the calculated exposure condition, the image sensor 4 is exposed, and the output of the image sensor 1 is read (# 11).

Next, the pre-processing circuit 7 performs signal processing such as CDS processing and gain control on the read image pickup output. At this time, since the gain of the gain control circuit is determined by the sensitivity of the image sensor 1, it is set when the electronic camera is manufactured. The output of the preprocessing circuit 7 is converted into a digital signal by the A / D converter 8 and
Is input to As a result, the exposure condition is reconfirmed from the imaging output by the video signal processing circuit 9 and the system control CPU 10, and an error from the proper exposure is detected to change the setting of the shutter speed (# 12). Then, the image sensor 1 is exposed again according to the changed exposure condition, and its output is read. The output of the image sensor 1 is converted into a digital signal,
After the video signal processing circuit 9 performs a conversion process into a specific format, a captured image signal is recorded on the recording medium 101 via the recording medium I / F 13 (# 13).

According to the first embodiment, subject information such as the spatial frequency and color (wavelength) of the subject is obtained from the output of the image pickup device 4, and the photographic lens 1 is obtained based on the subject information and subject distance information. Lens information storage device 16 storing characteristics
By comparing the information in the box to determine the amount of correction for focus adjustment,
Since focus adjustment is performed according to the corrected focus adjustment amount, more accurate focus adjustment can be performed. Therefore, it is possible to obtain high image quality without impairing the release lime lag, even for an electronic camera that requires the release time lag to be as short as possible.

Further, even if the electronic camera having the above configuration can change the resolution by selecting a mode, correction of a focus adjustment amount suitable for a desired resolution is performed when performing the focus adjustment. Thus, the same effect can be obtained regardless of the resolution at that time.

(Second Embodiment) FIG. 3 is a block diagram showing an electric configuration of an electronic camera according to a second embodiment of the present invention. In FIG.
Reference numeral 01 denotes a recording medium such as a memory card.

In the electronic camera 100, reference numeral 1 denotes a photographing lens capable of adjusting a focal length and an angle of view, 2 denotes a diaphragm / shutter which has both a diaphragm function and a shutter function, and 3 denotes a photographing lens 1.
And a mechanical drive circuit of the aperture / shutter 2.

Reference numeral 4 denotes an image sensor for converting reflected light from an object into an electric signal; 5, a timing signal generator (TG) for generating a timing signal required for operating the image sensor 4; and 6, a timing signal generator. An image sensor driving circuit for amplifying the signal from 5 to a level at which the image signal can be driven; 7, a pre-processing circuit having a CDS circuit and an AGC circuit for removing output noise of the image sensor 4; , A video signal processing circuit having a memory for temporarily storing the A / D converted digital signal and a circuit for processing the signal, 10 a system control CPU, 11 an electronic camera 1
A recording medium interface (I / F) for connecting the recording medium 101 to the recording medium 101.

Reference numeral 12 denotes an operation unit for the photographer to control the start of photographing by the camera, more specifically, a release switch, which can be operated in two stages, a first stroke SW1 and a second stroke SW2. Reference numeral 13 denotes an operation display unit for displaying a display for assisting operation and displaying the state of the camera. 14 is the electronic camera 1
This is a distance measuring circuit that measures the distance between 00 and a subject, and any form can be used as long as the distance to the subject can be measured. For example, the distance to the subject may be measured by detecting the state of the focusing lens after the focusing operation, and the distance may be measured independently of the photographing lens 1 using the principle of triangulation. It may be a device. A photometric sensor 15 measures the brightness of the subject.

Reference numeral 16 denotes a lens information storage device for storing information on the photographing lens 1. In general, the best focus position of a photographic lens differs depending on the spatial frequency of the subject, and the best focus position also differs depending on the color of the subject, that is, the wavelength, due to the remaining chromatic aberration. Therefore,
The lens information storage device 16 stores the shift amount of the best focus position due to the difference of the subject of the mounted photographing lens. In the second embodiment, when an object is present from close to infinity, the difference between the optical paraxial focus position and the best focus position based on the spatial frequency and color of the object is stored. The distance information obtained from the output of the distance measuring circuit 14 and the correction amount corresponding to the subject information are read out from the lens information storage device 16 and corrected at the time of focusing operation, thereby enabling extremely accurate focusing. I have to.

Reference numeral 17 denotes a focus detection device for detecting the focus adjustment state of the photographic lens 1, and any mechanism may be used as long as the mechanism can measure the defocus amount. For example, as a generally well-known example, two light beams that pass through two different pupils of a photographing lens system are taken out and guided to a secondary imaging optical system, and the defocus amount is set to a value corresponding to a distance between two images that can be obtained here. A method of detecting the difference may be used.

FIG. 4 is a flowchart showing the operation of the electronic camera 100 having the above configuration.

When the first stroke SW1 of the operation unit 12 is turned on by the photographer (# 21), the system control CPU 10 starts the operation of the focus detection device 17 and captures its output (# 22). And the system control CP
U10 calculates the focus adjustment amount from the output of the focus detection device 17 (# 23), drives the focus adjustment device (not shown) via the mechanical drive circuit 3, and moves the focus adjustment lens of the photographing lens 1, This is set as a first focus state (# 24).

In this state, the output of the image sensor 1 is read out,
Object information such as the color and the spatial frequency of the object is detected (# 25). Thereafter, the distance to the subject is measured by the subject distance measuring device, that is, the distance measuring circuit 14 (# 2)
6). Then, based on the subject information and the subject distance information, the information of the lens information storage device 16 storing the characteristics of the photographing lens is illuminated to determine the correction amount of the focus adjustment (#
27). Based on this correction amount and the defocus information obtained from the focus detection device 17, the focus adjustment device of the photographing lens 1 is driven via the mechanical drive circuit 3 to perform focus adjustment, and the second focus state is set. When the focus adjustment is completed, AF_
In the LOCK state, the focus adjusting device is not driven thereafter (# 28).

In a series of focusing operations, if the subject information can be detected before the first focusing state, that is, if the defocus amount is small from the beginning, the first focusing operation is performed. Can be omitted. Further, the subject information read from the image sensor 1 does not need to be the entire screen of the photographing.
Only the information of the main subject portion to be focused may be used.

Subsequent operations (# 30 to # 34) are the same as those in the first embodiment (# 9 to # 13 in FIG. 2), and a description thereof will be omitted.

In the second embodiment, the focus detecting device and the distance measuring circuit (device) are provided. However, the image capturing device has a means for the photographer to input information on the subject distance in advance such as a short distance mode. If it is a device or a shooting lens,
It is also possible to omit the distance measuring circuit. Also, as a characteristic of the photographing lens, the distance measuring device can be omitted even when the focus correction value due to the subject distance has little fluctuation.

According to the second embodiment, subject information such as the spatial frequency and color (wavelength) of the subject is obtained from the image pickup device 4, and the characteristics of the photographing lens 1 are determined based on the subject information and the subject distance information. Is compared with the information in the lens information storage device 16 in which the focus adjustment is determined, the focus adjustment is determined, and the focus adjustment is performed in accordance with the focus adjustment amount obtained by correcting the defocus information obtained from the focus detection device 17. Therefore, more accurate focus adjustment can be performed. Therefore, it is possible to obtain high image quality without impairing the release lime lag, even for an electronic camera that requires the release time lag to be as short as possible.

Further, even if the electronic camera having the above configuration can change the resolution by selecting a mode, correction of the focus adjustment amount suitable for a desired resolution is performed when performing the focus adjustment. Thus, the same effect can be obtained regardless of the resolution at that time.

(Third Embodiment) FIG. 5 is a block diagram showing an electric configuration of an electronic camera according to a second embodiment of the present invention. In FIG.
Reference numeral 01 denotes a recording medium such as a memory card, and reference numeral 102 denotes a detachable photographing lens, which has a built-in lens information recording device.

In the electronic camera 100, reference numeral 1 denotes a photographing lens capable of adjusting a focal length and an angle of view, 2 denotes a diaphragm / shutter which has both a diaphragm function and a shutter function, and 3 denotes a photographing lens 1.
And a mechanical drive circuit of the aperture / shutter 2.

Reference numeral 4 denotes an image sensor for converting reflected light from a subject into an electric signal; 5, a timing signal generator (TG) for generating a timing signal required for operating the image sensor 4; and 6, a timing signal generator. An image sensor driving circuit for amplifying the signal from 5 to a level at which the image signal can be driven; 7, a pre-processing circuit having a CDS circuit and an AGC circuit for removing output noise of the image sensor 4; , A video signal processing circuit having a memory for temporarily storing the A / D converted digital signal and a circuit for processing the signal, 10 a system control CPU, 11 an electronic camera 1
A recording medium interface (I / F) for connecting the recording medium 101 to the recording medium 101.

Reference numeral 12 denotes an operation unit for the photographer to control the start of photographing by the camera, more specifically, a release switch, which can be operated in two stages, a first stroke SW1 and a second stroke SW2. Reference numeral 13 denotes an operation display unit for displaying a display for assisting operation and displaying the state of the camera. 14 is the electronic camera 1
A distance measuring circuit that measures the distance between 00 and the subject, and 15 is a photometric sensor that measures the brightness of the subject.

A detachable lens information storage device built in the taking lens 102 stores correction information of the focus of the lens. In general, the best focus position of the shooting lens differs depending on the spatial frequency of the subject,
Also, the best focus position differs depending on the color of the subject, that is, the wavelength, due to the remaining chromatic aberration. In view of this, the lens information storage device stores the shift amount of the best focus position due to the difference in the subject of the mounted photographic lens. In the third embodiment, the difference between the optical paraxial focus position when the subject is present from close to infinity and the best focus position according to the spatial frequency and color of the subject is stored.

The operation of the electronic camera having the above configuration is the same as that of the first embodiment (FIG. 2), and the effect is the same, so that the description is omitted here.

(Modification) In each of the above embodiments,
Although an example in which the present invention is applied to an electronic camera is shown, the present invention is not limited to this. As long as the camera includes a device for detecting subject information, the present invention can be applied to a conventional camera using a silver halide film as a medium. It is possible to apply.

Further, even in the case of an electronic camera, for example, color information of a subject may be obtained from a photometric sensor or the like, instead of obtaining the subject information from the image sensor. In addition, it can be said that a photometric sensor divided into a large number can detect a spatial frequency component of a subject.

Also, when the subject information is detected and the spatial frequency of the subject is high and high-precision focusing accuracy is required, the system control CPU 10 adjusts the focus of the photographing lens 1 via the mechanical drive circuit 3. It is only necessary to improve the focus adjustment accuracy by subdividing the pitch of the object, and conversely, when there are features such as a low spatial frequency of the subject and fast movement,
The system control CPU 10 can increase the focus adjustment speed by making the adjustment pitch for adjusting the focus of the photographing lens 1 via the mechanical drive circuit 3 high, thereby improving the followability to the subject.

[0057]

As described above, according to the first, ninth, or tenth aspect of the present invention, it is possible to provide an imaging apparatus that enables highly accurate focus adjustment and obtains high image quality. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electrical configuration of an electronic camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a main part of the electronic camera of FIG.

FIG. 3 is a block diagram illustrating an electrical configuration of an electronic camera according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of a main part of the electronic camera of FIG. 3;

FIG. 5 is a block diagram illustrating an electrical configuration of an electronic camera according to a third embodiment of the present invention.

FIG. 6 is a block diagram illustrating an electrical configuration of a conventional electronic camera.

FIG. 7 is a flowchart showing an operation of a main part of the electronic camera of FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photographing lens 4 image sensor 9 video signal processing circuit 10 system control CPU 14 distance measuring circuit 16 lens information storage device 17 focus detection device 101 storage medium 102 photographing lens having lens information storage device

Claims (10)

[Claims] A focus adjustment unit that adjusts a focus state of the imaging optical system; a subject information detection unit that detects subject information of at least one of a subject color and a spatial frequency; information on a distance to the subject; A focus adjustment amount calculation unit that calculates a focus adjustment amount that adjusts the imaging optical system to an optimal focus state based on subject information, wherein the focus adjustment amount calculated by the focus adjustment amount determination unit is: An imaging apparatus, wherein a focus adjustment unit is driven to perform focus adjustment. 2. The imaging apparatus according to claim 1, wherein the subject information detection means obtains the subject information from an output of an image sensor or a photometric sensor. 3. The information on the distance to the subject is as follows:
The photographing apparatus according to claim 1, wherein the information is subject distance information obtained by a distance measuring unit. 4. The information on the distance to the subject is as follows:
The photographing apparatus according to claim 1, wherein the amount is a defocus amount of the imaging optical system. 5. The focus adjustment amount calculation means includes a storage means for storing information on a focus position of the imaging optical system and a best focus position based on a color and a spatial frequency of a subject, which are stored in advance. The imaging apparatus according to claim 1, wherein the focus adjustment amount is calculated based on information stored in the storage unit and the subject information. 6. The apparatus according to claim 1, wherein said focus adjustment amount calculation means switches a drive pitch of said imaging optical system by said focus adjustment means based on a spatial frequency of a subject. Imaging device. 7. The method according to claim 1, wherein the focus adjustment amount calculating means obtains a subject speed from a spatial frequency of the subject, and switches a driving pitch of the imaging optical system by the focus adjusting means based on the subject speed. Item 6. The imaging device according to any one of Items 1 to 5. 8. The imaging apparatus according to claim 1, further comprising a resolution changing unit for changing a resolution of the image quality. 9. A photographing means having an imaging optical system for photographing an optical image, a distance detecting means for detecting a distance to a subject, a focus adjusting means for adjusting a focus state of the photographing means, and a space between the subject and the subject. Subject information detecting means for detecting at least one of subject information of a frequency; and focus adjustment for calculating a focus adjustment amount for adjusting the imaging optical system to an optimum focus state based on the subject distance information and the subject information. An imaging apparatus comprising: an amount calculation unit; and driving the focus adjustment unit to perform focus adjustment based on the focus adjustment amount calculated by the focus adjustment amount determination unit. 10. An imaging optical system for forming an optical image on a photoelectric conversion element for converting an optical image into an electric signal, a defocus amount detecting means for detecting a defocus amount of the imaging optical system, and Focus adjusting means for adjusting the focus state of the imaging optical system; subject information detecting means for detecting subject information; and the imaging optics in an optimum focusing state based on the defocus amount information and the subject information information. A focus adjustment amount calculating means for calculating a focus adjustment amount for adjusting a system, wherein the focus adjustment means is driven by the focus adjustment amount calculated by the focus adjustment amount determination means to perform focus adjustment. Imaging device.