JPH0965194A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a still image with high resolution by synthesizing each image with high resolution in the meridional direction and the sagittal direction. SOLUTION: When a photographing mode switch means 10 is a still image photographing mode, an image is detected by a zoom location detection means 4. For the optimum focusing defocus positional information on the optical axis at a zoom location, each information on each optimum focusing defocus location in the meridional direction and the sagittal direction outside an optical axis is further read from a focusing characteristic storage means 15. By the information, the focus lens of an image formation means 1 is moved and controlled in an optical axis direction by a lens location control means 5, an image is formed on an image pickup means 2, the image is photographed, and the parts corresponding to the one frame of each image are stored in image storage means 11, 12 and 13. The images stored in the image storage means 11, 12 and 13 are composited by an image compositing means 14, the image of the one frame is formed, and still images with high resolution in the both of the meridional direction and the sagittal direction can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing device suitable for a video camera.

[0002]

2. Description of the Related Art An outline of a conventional photographing apparatus such as a video camera of this type is constructed as shown in a block diagram of FIG. In FIG. 5, reference numeral 1 is an image forming means for optically forming an image of a subject, 2 is an image forming means for converting an optical image into an electric signal,
Reference numeral 3 is a camera signal processing means for performing basic signal processing of an electric signal, 4 is a zoom position detecting means for detecting zoom position information of the image forming means 1, and 5 is based on information of a focusing characteristic storing means described later. Lens position control means for controlling the movement of the focus lens in the components of the image forming means 1 in the optical axis direction,
Reference numeral 6 denotes a focusing characteristic storage unit that stores the optimum focusing defocus position on the optical axis of the image forming unit 1.

FIG. 6 (a) is on the optical axis (at the center of the photographed image).
An example of the MTF-defocus characteristic of the image forming means in FIG.
FIG. 6B shows the MT of the image forming means outside the optical axis (peripheral part of the captured image).
It is a figure which shows the example of F-defocus characteristic. In FIG. 6A, A is the optimum in-focus defocus position which is the peak point of the MTF-defocus characteristic curve on the optical axis. Further, in the MTF-defocus characteristic of FIG. 6, the vertical axis represents MTF.
(Modulation Transfer Function) value, and the horizontal axis indicates the amount of deviation in the optical axis direction from the defocus position, that is, the in-focus position on the optical axis. In FIG. 6B, B is the optimum in-focus defocus position that is the peak point of the MTF-defocus characteristic curve in the meridional direction outside the optical axis, and C is the M in the sagittal direction.
It is the optimum in-focus defocus position that is the peak point of the TF-defocus characteristic curve.

The MTF-defocus characteristic on the optical axis is the same in both the meridional direction and the sagittal direction (see FIG. 6A), but the MTF-defocus characteristic outside the optical axis is shown by a solid line. There is a difference between the characteristic in the meridional direction and the characteristic in the sagittal direction indicated by the broken line (see FIG. 6B). This is due to the optical characteristics of the image forming means 1, but it is a phenomenon that occurs inevitably with the downsizing and widening of the lens.

The operation of the conventional photographing apparatus will be described below. The optical image obtained by the image forming means 1 for optically forming the light from the subject is converted into an electric signal by the image pickup means 2, and the camera signal processing means 3 performs basic signal processing such as gamma correction and gain correction for photographing. Signals are sent to the signal processing unit of the device body. At this time, the zoom position information of the image forming unit 1 is detected by the zoom position detecting unit 4, and the information of the optimum focus defocus position A (see FIG. 6) on the optical axis at the detected zoom position is used as the focus characteristic storage unit 6. Then, based on the information, the lens position control means 5 controls the movement of the focus lens in the components of the image forming means 1 to form an image on the image pickup means 2 in an optimally focused state.

[0006]

However, in the photographing apparatus having such a configuration, the focusing characteristic on the optical axis is read out from the focusing characteristic storage means based on the information detected by the zoom position detecting means. The lens position control means controls the movement of the focus lens in the components of the image forming means so as to form an image on the image pickup means in an optimally focused state. At this time, the focus characteristic stored in the focus characteristic storage means stores information on the defocus position at which the highest MTF value on the optical axis is obtained. Therefore, as shown in FIG.
Outside the optical axis, it is impossible to obtain the highest MTF value in the meridional direction and the MTF value in the sagittal direction at the defocus position, and it is not possible to correspond to a high-quality image with high resolution when shooting a still image. There was a problem.

The present invention solves the above-mentioned problems of the prior art. When capturing a still image, the images having the highest resolution in the meridional direction and the sagittal direction are combined so that both the meridional direction and the sagittal direction are combined. It is an object of the present invention to provide a photographing device which can obtain images with high resolution, and manually switches images with high resolution in the meridional direction or the sagittal direction to combine them, if necessary, and is useful for image effects.

[0008]

To achieve this object, the present invention provides an image forming means for optically forming an image of light from a subject, and an optical image formed by the image forming means as an electric signal. An image pickup means for converting, a signal processing means for processing an electric signal, a photographing mode switching means for switching between a moving image photographing mode and a still image photographing mode, an optimum focusing defocus position on the optical axis of the image forming means, And a focusing characteristic storage unit that stores the optimal focusing defocus positions in the meridional direction and the sagittal direction off the optical axis, a detection unit that detects zoom position information of the image forming unit, and a combination that the output of the detection unit indicates. A lens position control means for changing a predetermined image forming position by moving a predetermined component of the image forming means in the optical axis direction based on the information of the focus characteristic storing means, an image storing means for storing images, and an image combining for combining a plurality of images. With means It is characterized in.

Further, an image forming means for optically forming an image of light from a subject, an image pickup means for converting an optical image formed by the image forming means into an electric signal, and a signal processing means for processing the electric signal. , A shooting mode switching means for switching between a moving image shooting mode and a still image shooting mode, an optimum focusing defocus position on the optical axis of the image forming means, and optimum focusing defocus positions in the meridional direction and the sagittal direction outside the optical axis. Focusing characteristic storing means for storing the focus position, detecting means for detecting zoom position information of the image forming means, and information of the focusing characteristic storing means indicated by the output of the detecting means moves the image pickup means in the optical axis direction. An image pickup position control unit for changing the image position, an image storage unit for storing images, and an image combination unit for combining a plurality of images are provided.

Further, there is provided a manual image switching means for manually switching the output of the images photographed at the optimum focus defocus positions in the meridional direction and the sagittal direction stored in the image storage means.

[0011]

According to the above-mentioned structure, when the still image photographing mode is switched by the photographing mode changeover switch, the image photographed in the optimum focusing defocus position where the resolution becomes highest on the optical axis in the image storage means, Three types of images, each of which is an image taken at each of the optimal in-focus defocus positions where the resolution in the meridional direction and the sagittal direction are highest off-axis, are stored, and these images are combined by the image combining means to increase the resolution. Obtain a high quality still image.

Further, by manually switching the images stored in the image storage means, a still image effectively representing an image having a high resolution in the meridional direction or an image having a high resolution in the sagittal direction is obtained.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the schematic arrangement of an image pickup apparatus according to the first embodiment of the present invention. Here, the same effects as those described in FIG. 5 of the conventional example are denoted by the same reference numerals, and the same applies to each of the following drawings. In FIG. 1, 1 is an image forming unit, 2 is an image pickup unit, 3 is a camera signal processing unit, 4 is a zoom position detecting unit, 5 is a lens position control unit, and 10 is a shooting mode for switching between a moving image shooting mode and a still image shooting mode. Switching means, 11,
Reference numerals 12 and 13 denote image storage means for storing one frame of an image, 14 denotes an image synthesizing means for synthesizing the images stored in the image storage means 11, 12, and 13, and 15 denotes an optical axis of the image forming means 1. It is a focusing characteristic storage unit that stores the most suitable focusing defocus position and the optimal focusing defocus positions in the meridional direction and the sagittal direction off the optical axis.

According to the first embodiment, the zoom position detecting means 4 is used when the photographing mode switching means 10 is in the moving image photographing mode.
The zoom position is detected by, the optimum focus defocus position A on the optical axis at the zoom position is read from the focus characteristic storage means 15, and the lens position control means 5 causes the image forming means based on the read information. The focus lens in the first component is controlled to move in the direction of the optical axis, and an image is formed on the image pickup means 2 for photographing.

Further, when the photographing mode switching means 10 is in the still image photographing mode, the zoom position detecting means 4 detects the zoom position, and first, at that zoom position, the optimum focusing defocus position A on the optical axis (see FIG. ) Is read from the focusing characteristic storage means 15, and the lens position control means 5 controls the movement of the focus lens of the image forming means 1 in the optical axis direction based on the read information, and the image is displayed on the image pickup means 2. An image is formed and photographed, and one frame is stored in the image storage means 11.

Next, the optimum focus defocus position B (see FIG. 6B) in the meridional direction off the optical axis is read from the focus characteristic storage means 15, and the lens position control means 5 reads it based on the information. The focus lens of the image forming means 1 is controlled to move in the optical axis direction, an image is formed on the image pickup means 2 and photographed, and one frame is stored in the image storage means 12.

Similarly, also in the sagittal direction, an image photographed based on the information of the optimum focusing defocus position C in the sagittal direction outside the optical axis stored in the focusing characteristic storage means 15 (see FIG. 6B). Is stored in the image storage means 13 for one frame.

The images stored in the image storing means 11, 12, 13 are combined by the image combining means 14 to form one frame image. By combining the captured images in this way, a still image with high resolution can be obtained in both the meridional direction and the sagittal direction.

Next, FIG. 2 is a block diagram showing a schematic structure of a photographing apparatus according to the second embodiment of the present invention. In FIG. 2, 1 is an image forming unit, 2 is an image pickup unit, 3 is a camera signal processing unit, 4 is a zoom position detecting unit, 10 is a photographing mode switching unit, 11, 12 and 13 are image storing units, and 14 is an image synthesizing unit. Reference numeral 15 is a focusing characteristic storage means, and 16 is an image pickup position control means for controlling the position of the image pickup means 2 in the optical axis direction based on the information of the focus characteristic storage means 15.

In the second embodiment, the lens position control means 5 in the structure described in the first embodiment is replaced by the image pickup position control means 16.
In place of the above, other configurations are the same. In the moving image shooting mode, the information on the optimum in-focus defocus position A on the optical axis at the detected zoom position is read out from the focus characteristic storage means 15, and the image pickup position control means 16 is based on the information.
The movement of the position in the optical axis direction is controlled to form an image on the image pickup means 2, and the image is taken.

Further, in the still image photographing mode, information on the optimum in-focus defocus position A on the optical axis at the detected zoom position is read out from the focusing characteristic storage means 15, and based on the information, the imaging position control means 16 is used for optical The position in the axial direction is moved to form an image on the image pickup means 2 and an image is taken, and one frame is stored in the image storage means 11. Further, the optimum focusing defocus position B in the meridional direction off the optical axis from the focusing characteristic storage means 15
Information is read out, an image is formed on the image pickup means 2 based on the information, and an image is taken, and one frame is stored in the image storage means 12. Similarly, an image photographed based on the information of the optimum focusing defocus position C in the sagittal direction of the focusing characteristic storage means 15 is stored in the image storage means 13 for one frame. The images stored in the image storage means 11, 12, 13 are combined by the image combining means 14 to form one frame image. Similar to the first embodiment, a still image with high resolution can be obtained in both the meridional direction and the sagittal direction.

FIG. 3 is a block diagram showing a configuration example of the image synthesizing means in the first and second embodiments. In FIG. 3, 11, 12, and 13 are image storage means, 14 is an image synthesizing means, and 17 is an image operation means for performing a logical product operation on the three images stored in the image storage means 11, 12, and 13.

Now, the image storage means has 910 horizontal pixels,
A pixel signal is expressed in 256 gradations in a frame memory in which the number of vertical pixels is 525 and one pixel is quantized by 8 bits. Further, the image photographed at the optimum focus defocus position on the optical axis is stored in the image storage means 11, and the image shot at the optimum focus defocus position in the meridional direction off the optical axis is stored in the image storage means.
An image photographed at an optimal focus defocus position in the sagittal direction is stored in the image storage means 13. According to this image synthesizing means, the image storing means indicated by an arbitrary address
1 is obtained by logically ANDing each address value of 11, 12, and 13 by the image calculation means 17 and repeating the operation for the number of pixels.
A composite image for frames can be obtained.

FIG. 4 is a block diagram showing the schematic arrangement of a photographing apparatus according to the third embodiment of the present invention. In FIG. 4, 1 is an image forming unit, 2 is an image pickup unit, 3 is a camera signal processing unit, 4 is a zoom position detecting unit, 5 is a lens position control unit, 10 is a photographing mode switching unit, and 11, 12 and 13 are images. A storage means, 14 is an image synthesizing means, 15 is a focusing characteristic storage means, and 18 is a manual image switching means for manually switching between a high resolution image in the meridional direction and a high resolution image in the sagittal direction.

In the third embodiment, the manual image switching means 18 is provided in the structure of the first embodiment, and the image storage means 1 is used for shooting in the moving image shooting mode and shooting in the still image shooting mode.
The operation is the same until the images are stored in 1, 12, and 13. In the still image shooting mode, the images stored in the image storage unit 12 and the image storage unit 13 can be arbitrarily switched and output by the manual image switching unit 18, and the selected image and the image stored in the image storage unit 11 can be output. By synthesizing the image by the image synthesizing means 14, an image having a high resolution only in the meridional direction or an image having a high resolution only in the sagittal direction can be obtained.

Even if the manual image switching means 18 described in the third embodiment is provided in the structure of the second embodiment, the same effect can be obtained.

[0027]

As described above, according to the present invention,
When the still image shooting mode is switched by the shooting mode changeover switch, the optimum focusing defocus position where the MTF value on the optical axis becomes highest in the image storage means and the MTF values in the meridional direction and the sagittal direction outside the optical axis become the highest. The optimum focusing defocus position to be increased and the image forming position are controlled by the lens position control means or the imaging position control means, three types of images are stored, and these images are synthesized by the image synthesizing means. A still image with high resolution can be obtained in both the direction and the sagittal direction.

Further, by the manual image switching means for switching the output of the image stored in the image storage means, a still image having a high resolution in the meridional direction or a still image having a high resolution in the sagittal direction can be obtained, and the image effect can be obtained. This has the effect of being useful for expressing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a photographing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of an image pickup apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration example of image synthesizing means in the first and second embodiments.

FIG. 4 is a block diagram showing a schematic configuration of a photographing device according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a conventional imaging device.

FIG. 6A shows an example of the MTF-defocus characteristic of the image forming means on the optical axis (the center portion of the captured image), and FIG.
It is a figure which shows the example of the MTF-defocus characteristic of the imaging means in (a peripheral part of a picked-up image).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Imaging means, 2 ... Imaging means, 3 ... Camera signal processing means, 4 ... Zoom position detection means, 5 ... Lens position control means, 6,15 ... Focus characteristic storage means, 10 ... Shooting mode switching means, 11 , 12, 13 ... Image storing means, 14 ... Image combining means, 16 ... Imaging position controlling means, 17 ... Image computing means, 18 ... Manual image switching means.

Claims (3)

[Claims] 1. An image forming means for optically forming an image of light from a subject, an image forming means for converting an optical image formed by the image forming means into an electric signal, and a signal processing for processing the electric signal. Means, a shooting mode switching means for switching between a moving image shooting mode and a still image shooting mode, an optimum focusing defocus position on the optical axis of the image forming means, and a meridional direction and a sagittal direction outside the optical axis. Focusing characteristic storage means for storing the most suitable focus defocus position, detecting means for detecting zoom position information of the image forming means, and the image formation by the information of the focusing characteristic storage means indicated by the output of the detecting means. A lens position control means for moving a predetermined constituent member of the means in the optical axis direction to change the image forming position; an image storage means for storing an image;
An image taking apparatus comprising: an image synthesizing unit that synthesizes a plurality of the images. 2. An image forming means for optically forming an image of light from a subject, an image forming means for converting an optical image formed by the image forming means into an electric signal, and a signal processing for processing the electric signal. Means, a shooting mode switching means for switching between a moving image shooting mode and a still image shooting mode, an optimum focusing defocus position on the optical axis of the image forming means, and a meridional direction and a sagittal direction outside the optical axis. Focusing characteristic storage means for storing the most suitable focus defocus position, detecting means for detecting zoom position information of the image forming means, and the image pickup means by the information of the focusing characteristic storage means indicated by the output of the detecting means. An image pickup apparatus comprising: an image pickup position control means for changing the image forming position by moving the lens in the optical axis direction; an image storage means for storing images; and an image synthesizing means for synthesizing a plurality of the images. 3. A manual image switching means for manually switching the output of an image photographed at each optimal focus defocus position in the meridional direction and the sagittal direction stored in the image storage means. 2. The photographing device according to 2.