JPH09222554A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform focusing decision and focusing suitable for an image pickup element in a camera for taking a photograph by using two kinds of image pickup elements. SOLUTION: Light is divided into two by a half mirror C04, and the photograph is taken by the use of silver salt film C08 and a CCD C21. 1st and 2nd defocusing amount torelances corresponding to the depth of focus of the film C08 and the CCD C21 are set. The defocusing amount with respect to the film C08 is detected by a focusing state detection part C02 and an arithmetic control part L06, and focusing or non-focusing is decided according to whether or not the detected defocusing amount is within the 1st tolerance at the time of taking the photograph by the use of film C08 and whether or not it is within the 2nd tolerance at the time of taking the photograph by the use of the CCD. Focusing is performed at high speed at the time of taking the photograph by the use of the film C08 and at low speed at the time of taking the photograph by the use of the CCD C21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera that splits light transmitted through a photographing lens to perform photographing with a silver salt film and video recording with a photoelectric conversion element, and more specifically, to a silver salt film and a photoelectric conversion element. The present invention relates to a camera in which the focus determination criteria are set differently.

[0002]

2. Description of the Related Art Light from an object to be photographed that has passed through a photographing lens is divided into two parts, one of the divided lights is guided to a silver salt film, and the other is guided to a photoelectric conversion element (CCD) to take a picture and video. A camera that does is proposed. Such a camera has both the characteristics of still image shooting using a silver halide film and the characteristics of moving picture shooting with a video camera, as well as new characteristics by recording moving pictures and still pictures using the same light. Be prepared.

For example, it becomes possible to shoot a still image on a silver salt film while shooting a moving image. The still image obtained here records the light transmitted through the common photographing lens, and thus completely matches the angle of the moving image. Moreover, since the silver salt film has extremely high resolution, the still image thus obtained has a much higher image quality than the image obtained by the still video or the still image of the moving image.

Further, as used in a general video camera, it is possible to combine a CCD for video shooting with a display device, for example, a liquid crystal display device (LCD) to use it as a finder. With the camera with the above configuration,
This finder can be used not only as a finder for video shooting but also as a finder for still image shooting on a silver salt film. Moreover, by configuring the LCD so that the recorded video signal is given, it becomes possible to confirm the angle after photographing on the silver salt film.

[0005]

However, as described above, since the image resolutions of the CCD and the silver salt film are greatly different, the image formed on the CCD and the image formed on the silver salt film are required. There is a difference in the degree of focusing. Although it is desirable that the CCD image has a high degree of focusing, the CCD has a relatively coarse pixel arrangement, and therefore a high degree of focusing beyond the upper limit of resolution due to the pixel arrangement interval is not necessary. Furthermore, in moving image shooting, even if the degree of focusing of the image of each frame is somewhat low, it is easy for an observer to recognize that the image is a clear image. In video shooting with a CCD, it suffices to obtain a degree of focus enough to satisfy the highest resolution.

On the other hand, since the silver salt film has a high resolution and provides a still image, it is necessary to make the degree of focus of the image formed on the film extremely high. If the degree of focus is low, the characteristics of the silver salt film cannot be utilized.
When shooting on a silver salt film, it is desirable to quickly achieve a high degree of focus.

In a camera used for different purposes such as still image shooting and moving image shooting by using different image pickup devices such as a silver salt film and a CCD, focus determination is set according to the image pickup device and the image is determined. It is necessary to set the time required for focusing on the image pickup device according to the image pickup device and the shooting application.

An object of the present invention is to make a focus determination suitable for each photographing means in a camera having two photographing means, and further to set a focusing achievement time suitable for each photographing means. To aim.

[0009]

In order to achieve the above object, in the present invention, the light from the object to be photographed is divided into the first light flux and the second light flux.
Light splitting means for splitting into a light flux, a first shooting means for receiving a first light flux and shooting an image of the light flux, and a second shooting means for receiving a second light flux and shooting an image of the light flux. And the first
A camera having at least one image forming position adjusting means for adjusting the image forming positions of the second light beam and the second light beam,
At least one imaging state detecting means for detecting the amount of deviation of the image of the first light flux from the in-focus state of the image pickup means or the amount of deviation of the image of the second light flux from the in-focus state of the second image pickup means. And a shift amount detected by the image formation state detection means, and whether or not the image of the first light flux in the first image pickup means is in focus is determined based on the first determination criterion. Focus determination means for determining whether or not the image of the second light flux in the second image capturing means is in focus according to the determination criterion, and when the image is captured by the first image capturing means, The first control means for controlling the image forming position adjusting means to adjust the image forming position of the first light flux so that it is determined to be in the in-focus state, and the second image capturing means alone,
A second control unit is provided to control the image forming position adjusting unit to adjust the image forming position of the second light flux so that the in-focus state is determined by the focus determining unit. Shooting by the first shooting unit and shooting by the second shooting unit may be performed separately or simultaneously.

In this configuration, the image forming state detecting means detects the deviation of the first light flux or the second light flux from the in-focus state, the focus determining means determines whether or not the focus is achieved, and the control means is used. The control of the image forming position adjusting means and the adjustment of the image forming positions of the first light flux and the second light flux by the image forming position adjusting means are repeated. The focus determination means determines whether or not the image of the first light flux is in focus using the first determination criterion,
It is determined whether or not the image of the second light flux is in focus by using the second determination criterion. If the first determination criterion is stricter than the second determination criterion, then when the first determination criterion determines that the image of the first light flux is in focus, the image of the second light flux also The in-focus state is reached, and the first and second photographing means both photograph sharp images. When it is determined by the second determination criterion that the image of the second light flux is in focus, the second image capturing unit captures a clear image. At this time, the image of the first light flux is not always in focus, and the image captured by the first image capturing unit is not necessarily clear.

In the above structure, the first determination criterion and the second determination criterion of the focus determination means are set corresponding to the focal depths of the first photographing means and the second photographing means, respectively. When the determination reference is set in this way, focus determination suitable for the image pickup device of each image pickup means is performed, and it is possible to avoid waste of adjusting the image formation position with high accuracy.

Further, the image forming position adjusting means is operated in a first mode for adjusting the image forming positions of the first light flux and the second light beam at a high speed and a second mode for adjusting the image formation position at a low speed. The high speed and the low speed mentioned here are relative. The first mode is suitable for the case where quick shooting is required, such as shooting a still image. The second mode is suitable for reflecting a change in the image formation state on an image, such as shooting a moving image.

Specifically, the first photographing means performs photographing by exposing the silver halide film to the first light flux, and the second photographing means converts the second light flux into a video signal by a photoelectric conversion element. Shoot by doing. At this time, the image-forming position adjusting means operates in the first mode when performing the image capturing by the first image capturing means, and operates in the second mode when performing the image capturing by the second image capturing means. To do. Therefore, the image-forming position is adjusted at high speed when shooting with a silver salt film, and the image-forming position is adjusted at low speed when shooting with a photoelectric conversion element.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a camera of the present invention is shown in FIG. In this camera 1, the camera body C and the taking lens L are separately configured, and various interchangeable lenses can be attached to the camera body C. Here, as an example, a case where a zoom lens is mounted as the taking lens L is shown.

The camera 1 splits the light that has passed through the taking lens L and is incident into two light fluxes, guides one light flux to the silver salt film to expose the silver salt film for recording, and the other light flux. To a CCD to record a video signal. The camera body C is provided with a display device, and displays the video signal generated from the output of the CCD, so that the CCD and the display device also function as a finder. Prior to the description of each component of the camera 1, the camera 1
The outline of the function and operation of is explained.

<Photographing Mode> The camera 1 performs photographing in any of the following three modes. PH mode: Only shooting with a silver salt film is performed. MV mode: Only shooting with CCD is performed. PM mode: A silver salt film and a CCD are simultaneously photographed.

<Exposure control mode> Silver salt film and C
CD exposure is controlled in the following four modes. A mode: Priority is given to the set aperture value, and the shutter speed is adjusted. S mode: The set shutter speed is prioritized and the aperture value is adjusted. P mode: Adjust the aperture value and shutter speed according to a predetermined program line. M mode: Uses the set aperture value and shutter speed.

<Focus control mode> Silver salt film and C
The adjustment of the image forming position in photographing with a CD, that is, the focus adjustment is performed in the following two modes. AF mode: Automatic focus adjustment. MF mode: manual focus adjustment.

<Video Recording / Reproducing Mode> Video signals are recorded and reproduced in the following modes. V mode: The recorded video signal is reproduced as an image. SV mode: Capture and record still video.

In addition, a next-generation silver halide film in which a magnetic medium is applied to the outside of the light-sensitive area to record photographing information on the magnetic medium is used as an object for editing the recorded photographing information. It also has a mode. The focal length of the zoom lens is adjusted by a power zoom system in which a zoom lens group is driven by a motor.

Next, each component of the camera 1 will be described with reference to FIG. 1. Members provided in the camera body C are denoted by reference symbols beginning with C, and members provided in the taking lens L are shown. A code starting with L is attached.

On the outer surface of the fixed lens barrel L13 of the taking lens L, operating rings L01 and L03 rotating in the circumferential direction are provided. These are operated and rotated by the user. An encoder L02 for detecting rotation of the operation ring L01 is provided inside the operation ring L01, and an encoder L0 for detecting rotation of the operation ring L03 is provided inside the operation ring 03.
4 are provided. The operation ring L01 is for adjusting the focal position of the photographing lens L, and the operation ring L03 is for adjusting the focal length.

Reference numeral L05 is a focal length detector for detecting the set focal length of the taking lens L. L07 is a zoom motor for changing the focal length of the taking lens, L08
Is a zoom motor monitor that detects the rotation state of the zoom motor L07. L09 is a focus motor for adjusting the focus position, L11 is a diaphragm, L12 is a diaphragm L
Aperture controller for opening and closing 11, AF for focus adjustment by L10
It is an AF / MF changeover switch operated by the user to switch between the mode and the MF mode. Reference numeral L06 denotes an arithmetic control unit for controlling the focal length, focal position, and aperture adjustment of the photographing lens L, which is constituted by a microcomputer (hereinafter, also referred to as a lens microcomputer).

When the AF / MF selector switch L10 is set to the MF mode side and the operating ring L01 for adjusting the focus position is operated, the rotation thereof is caused by the encoder L02.
Detected and transmitted to the calculation control unit L06. The arithmetic control unit L06 arithmetically processes the detection output of the encoder L02, and drives the focus motor L09 based on the result to perform focus adjustment. When the operation ring L03 for adjusting the focal length is operated, the rotation thereof is reflected by the encoder L0.
4 and is transmitted to the arithmetic control unit L06. The arithmetic control unit L06 arithmetically processes the output of the encoder L04 and drives the zoom motor L07 on the basis of the result to perform zoom adjustment. The arithmetic control unit L06 also applies a control signal to the diaphragm control unit L12 to control the opening / closing of the diaphragm L11 and regulates the light flux passing through the taking lens L. Information for controlling the aperture is provided from the camera body C to the arithmetic control unit L.
06.

A flash & light F can be mounted on the top of the camera body C. Flash & Light F
Can emit flash light and continuously emit quantitative light, and irradiate a subject for a short time or a long time. Both are used for the purpose of compensating for the insufficient light quantity of the subject, but mainly flash light is used for photographing with a silver halide film and quantitative light is used for photographing with a CCD. The light emission of the flash & light F is controlled by a built-in control unit F01.

The camera body C is provided with an arithmetic and control unit (hereinafter, also referred to as a main microcomputer) C01 composed of a microcomputer for controlling the camera body. The main microcomputer C01 communicates not only with the main body but also with the lens microcomputer L06 via the communication contact C30, communicates with the flash & light control unit F01 via the communication contact C20, and obtains information necessary for the photographing operation. Acquisition and control instructions.

Specifically, from the lens microcomputer L06,
The lens obtains fixed information specific to the taking lens L, such as the open aperture value and the longest and shortest focal lengths, and information on the current setting conditions such as an AF / MF switch, focal length, and focal position. Microcomputer L06
, Information on conditions to be set in photographing, such as an aperture value and a focus position, is provided. Flash & light control unit F
In addition to the fixed information including the maximum and minimum irradiation angles, information necessary for controlling the operation of each light emission such as completion of light emission preparation is obtained from the control unit F01. And a signal instructing start and stop of light emission.

In the camera body C, C04 is a half mirror, which splits the light passing through the taking lens L into transmitted light and reflected light, and uses a silver halide film for the first photographing section and a CCD for the first photographing section. 2 lead to the shooting department. C07 is a shutter, C06 is a drive unit of the shutter C07, C09
Is a film supply unit that supplies the silver salt film C08, and these constitute a first photographing unit.

C05 is a movable total reflection mirror provided behind the half mirror C04 (hereinafter, also referred to as a sub mirror), and reflects the light transmitted through the half mirror C04 downward. The sub-mirror C05 is operated by a mechanism (not shown) when the first imaging unit performs imaging.
The light flux from 04 to the film C08 is retracted to a position that does not block it.

Below the sub-mirror C05, there is provided a focus state detection section (hereinafter also referred to as an AF module) C02 including a line sensor. The distance from the sub mirror C05 to the AF module C02 is set to be substantially equal to the distance from the sub mirror C05 to the film C08, and the light receiving surface of the AF module C02 is on a surface substantially equivalent to the film C08. The AF module C02 detects the in-focus state in the first imaging unit.

Reference numeral C03 denotes a light receiving element which constitutes a photometric / light adjusting section for detecting the brightness of the normal subject and the brightness of the subject illuminated by the emission of the flash & light F (hereinafter also referred to as AE sensor). The shutter C07 or the film C08 is arranged so as to detect reflected light. The outputs of the AF module C02 and the AE sensor C03 are given to the main microcomputer C01 and used for focus control and exposure control, respectively.

When the shutter release button (not shown) is operated when the photographing mode is set to PH or PM mode for photographing with a silver halide film, the main microcomputer C01 causes the sub-mirror C05 to move after the focusing control described later. The shutter C07 is opened and the shutter drive unit C06 is given a control signal to open the shutter C07. When the time corresponding to the set shutter speed has elapsed, the main microcomputer C01 gives a control signal to the shutter drive unit C06 to close the shutter C07 and restore the sub-mirror C05. During this time, the silver salt film C0 is exposed by the light transmitted through the taking lens L and the half mirror C04.
8 is exposed and a picture is taken. After closing the shutter, the main microcomputer C01 gives a control signal to the film supply section C09 to feed one frame of the silver salt film C08 to prepare for the next photographing.

A condenser lens C10 and a total reflection mirror C11 are provided above the half mirror C04, and the light reflected by the half mirror C04 is thinned by the condenser lens C10, and then the mirror C1.
1 is guided to the rear side of the camera body. C13 is ND
It is a filter and is configured so that the light transmittance can be changed from total transmission to several steps. This light transmittance is set by the ND filter control unit C15.

C14 is a relay optical system having a movable lens and a diaphragm C18. The first imaging unit and the later-described second
Although the photographing areas of the photographing units are different, the photographing angle of view of both photographing units is made substantially equal by the relay optical system C14.
C19 is a control unit of the relay optical system C14, and includes a drive unit that moves the movable lens of the relay optical system and sets the diaphragm C18, and a detection unit that detects the position of the movable lens and the size of the diaphragm that is set. Become.

C16 is an optical low pass filter, C17
Is an IR (infrared) cut filter, C21 is a CCD that is an image sensor, and C23 is a CCD that drives the image sensor C21.
The driving unit, C22 is an imaging processing unit (hereinafter, also referred to as an A / D converter) that samples the analog output of the imaging device C21 and further converts it into a digital signal, and C24 is A.
An image processing unit that processes the output of the / D converter C22 and converts it into an image signal, and these constitute a second imaging unit.

The ND filter C13 and the diaphragm C18 of the relay optical system C14 described above are different in sensitivity between the silver salt film as an image pickup element and the CCD, and the condenser lens C10 per unit area of the amount of light guided to the second photographing section. It is provided to correct the increase caused by the relay optical system C14. In any case, it is possible to reduce the amount of light guided to the second imaging unit. When the light flux is regulated by the diaphragm C18 to reduce the light amount, the depth of field of the second photographing unit becomes deep. On the other hand, ND filter C1
When the light is absorbed and attenuated by 3, the depth of field of the second photographing unit is not affected. In consideration of the influence on the image due to such a difference in characteristics, the ND filter C13
And the diaphragm C18 can be appropriately selected, or both can be used in combination.

As a medium for recording the image of the second photographing section, a magnetic medium such as a magnetic tape or a magnetic disc, an optical medium such as a digital video disc (DVD) or a mini disc (MD), or a flash memory or the like. Various things such as a semiconductor storage medium can be used. Here, a magnetic tape C28 is used as a recording medium so that a home VTR device can easily view and view an image.

C26 is a magnetic head for writing and reading the magnetic tape C28, C36 is a drive unit for the magnetic tape C28, and C25 is a recording / reproducing unit for encoding and decoding image signals. The image signal of the image processing section C24 is recorded on the magnetic tape C28 via the magnetic head C26 by the recording / reproducing section C25, and the image signal recorded on the magnetic tape C28 is read by the magnetic head C26 and reproduced by the recording / reproducing section C25. Is done. C27 is a display unit that displays an image (hereinafter, also referred to as EVF), and is composed of a color liquid crystal display device (LCD). The display unit C27 functions as a finder monitor when the second imaging unit is performing imaging, and the display unit C27 functions as a reproduction monitor when an image on the magnetic tape C28 is being reproduced.

Reference numeral C31 is a voice processing unit for processing the voice collected by the microphone C34 provided at the front of the camera body. The audio signal output from the audio processing unit C31 is supplied to the recording / reproducing unit C25, and is recorded on the magnetic tape C28 together with the image signal from the image processing unit C24. C33
Is a speaker, which outputs a reproduced sound when the image on the magnetic tape C28 is reproduced. A power supply unit C29 supplies power to the camera body C, the taking lens L, and the flash & light F.

The COP is an operation unit, and is composed of operation members such as buttons, levers, and switches. The user operates the members of the operation unit COP to set the shooting mode, the exposure control mode, and the video recording / reproducing mode, and information necessary for shooting in the set mode, such as exposure control, is set to S.
Input the shutter speed in mode. The shutter release button provided on the operation unit COP is a signal S1ON for starting automatic focus adjustment in the first stroke.
Is output, and a signal S2ON for starting shooting by the first shooting unit with a deeper second stroke is output.
C35 is a display unit for displaying the state of the camera, which is an LCD
Consisting of The display unit C35 displays information about the camera such as the set mode and the remaining power of the power supply unit C29.

C32 is a connector section for connecting to an external device, and includes a main microcomputer C01 and an image processing section C2.
4, and the audio processing unit C31 is connected to another electronic device. It is possible to externally supply control information to the main microcomputer C01 through the connector section C32 to control the operation of the camera, and supply image signals and audio signals to external devices. In addition, the audio processing unit C31 can record the audio signal given from the external device on the magnetic tape C28 instead of or superimposed on the audio signal from the microphone C34.

When the main switch provided in the operation section COP is operated and power supply is started, the main microcomputer C01
Sends a control signal to the CCD drive unit C23 to cause the image sensor C
The light reception by 21 is started. This output signal is provided to an image processing unit C24 via an A / D converter C22 and is converted into an image signal. The output signal of the image processing unit C24 is supplied to the image display unit C27, and the image is displayed in color.

Light reception by the image pickup device C21 and image display portion C
The image display by 27 is always performed while the power is supplied regardless of the setting of the photographing mode. Therefore, the user must take a still image on a silver salt film or a CCD.
In shooting a moving image by, the shooting angle can be set while observing the image displayed on the image display unit C27. When the shooting mode is set to the MV or PM mode, the output signal of the image processing unit C24 is the operation unit C.
In response to a recording operation from the OP, it is also given to the recording / reproducing section C25 and recorded on the magnetic tape C28.

When the PM mode is set in which the silver salt film photographing and the CCD photographing are performed at the same time, as described above, in response to the operation of the shutter release button, the first
Photographing is performed by the photographing unit of. During this period, the recording of the moving image on the magnetic tape C28 by the second photographing unit is continued regardless of the operation of the shutter release button. Therefore,
A part of the continuous image recorded on the magnetic tape is recorded on the silver salt film as a still image.

The initial operation of the camera at the start of power supply will be described. When the supply of electric power is started by operating the main switch, the main microcomputer C01 tries to communicate with the lens microcomputer L06 and determines whether or not the taking lens L is attached. When the taking lens L is not attached, a warning to that effect is displayed on the display section C35. When the taking lens L is attached, the following processing is performed.

Information specific to the taking lens L, that is, the maximum aperture value, the minimum aperture value, the maximum focal length, and the minimum focal length is acquired from the lens microcomputer L06. AF / M
The setting status of the F changeover switch L10 is obtained. A control signal for instructing initialization is given to the lens microcomputer L06 to set the taking lens L to the initial state. In response to this command, the lens microcomputer L06 responds to the zoom motor L0.
7 to set the focal length to the minimum or maximum, to drive the focus motor L09 to set the focus position to infinity or the closest end, and to set the aperture L1 via the aperture controller L12.
Release 1. The ND filter C13 is set to full transmission through the ND filter control unit C15. The diaphragm C18 is opened via the relay optical system controller C19. The image pickup device C21 is driven via the CCD drive unit C23, and the light reception and image signal generation in the second image pickup unit are started. The settings of various operation members of the operation unit COP and the stored default values are read out and displayed on the display unit C35.

With this initial setting, preparations for recording a still image on the silver salt film by the first photographing section and recording a moving image by the second photographing section are completed. Hereinafter, the setting is changed according to the input from the operation unit COP or the setting change of the AF / MF changeover switch L10, and the image is taken by the first photographing unit, the second photographing unit, or both.

The in-focus state is detected by the phase difference detection method which is a well-known technique for the first photographing section. For this purpose, the AF module C02 includes at least one pair of sensors including a line sensor and an imaging lens (not shown). The main microcomputer C01 determines the defocus amount DF by comparing the distance between the two images formed on these line sensors with the reference distance at the time of perfect focusing, and is the defocus amount DF within the allowable range? Depending on whether or not it is determined whether or not it is in focus. When it is determined to be in focus, the taking lens L is not driven.

On the other hand, when it is determined that the object is out of focus, the drive amount of the focus motor L09 is calculated from the obtained defocus amount DF and the focal length of the photographing lens L at that time, and the motor L09 is driven via the lens microcomputer L06. Then, the photographing lens L is focused. After the driving of the motor L09 is completed, the defocus amount DF is obtained again to determine whether the focus is achieved or not, and the focusing is repeated until the focus is achieved.

Focusing and non-focusing are determined by whether or not the defocus amount DF is within the allowable range as described above, but in the present invention, the size of the allowable range is 2 depending on the photographing mode. It is set in stages. Specifically, a relatively small first allowable range is set for the PH mode in which only silver halide film is used for shooting, and a relatively large second allowable range is set for the MV mode in which only CCD is used for shooting. The range is set. In the PM mode in which both the silver salt film and the CCD are used for shooting, the first permission is allowed after the signal S1ON (half-press signal of the release button) for instructing shooting with the silver salt film is issued until the shooting ends Judgment is made according to the range, and the other allowable period during which the image is taken only by the CCD is judged according to the second allowable range.

When a light beam to be imaged at one point on the plane is imaged in front of or behind the plane due to imperfect setting of the focal position, the image on the plane is blurred and becomes a circular image instead of a point image. . When an image is formed from an infinite number of continuous points as in a photograph, even if each point is slightly blurred and becomes a circular image, it is not recognized by the human eye as a blurred image. The upper limit for appreciating the size of a circular image is called the permissible circle of confusion, and the shift amount of the focal position corresponding to the permissible circle of confusion is called the depth of focus.

In the case of photographs using a 135-format silver salt film, the diameter δg of the circle of permissible circle of confusion is generally 33 μm.
It is said that it is about. The spacing between silver salt particles in the silver salt film is much smaller than this value, and it is possible to faithfully reflect the setting of the focus position with higher accuracy. However, when the accuracy exceeds a certain level, the human eye cannot recognize the difference in accuracy. On the other hand, the arrangement of CCD pixels is large,
In a device used as an image pickup device, it is generally about several μm or more. The CCD cannot reflect the setting of a highly accurate focus position that is equal to or smaller than the pixel arrangement interval, and an excessively accurate focus position setting is meaningless.

A still image is exclusively taken with the silver salt film, and a moving image is mainly taken with the CCD. The ability of the human eye to discriminate between two adjacent points is high in stationary images but significantly diminished in moving images. Therefore, it is meaningless to set the focus position with extremely high accuracy when shooting a moving image.

For this reason, in the present invention, the first
The allowable range of the defocus amount DF is set to be different between when the image is captured by the image capturing unit and when the image is captured only by the second image capturing unit. In other words, the first allowable range and the second allowable range are set in consideration of the required depth of focus.

First defocus amount DF of defocus amount DF
The 1st and 2nd permissible range DF2 is defined by Formula (1) and Formula (2). (Note that DF is the converted value on the film surface) DF1 = FNo1 × δg (1) DF2 = FNo2 × δv × (1 / β) ² (2) where FNo1 is the aperture value of the taking lens L at the time of shooting. , FNo2
Is a diaphragm value of the diaphragm C18 of the relay optical system C14 at the time of photographing. δg and δv are silver salt film and CC, respectively.
It is the diameter of the permissible circle of confusion of D, and β is the magnification of the relay optical system C14. For example, if the screen of the film is reduced to 1/4, β = 1/4. The reciprocal of (1 / β) is a converted value on the film surface. The diameter δv of the permissible circle of confusion of the CCD is set to be about one digit larger than the diameter δg of the permissible circle of confusion of the silver salt film.
2 is larger than the first allowable range DF1.

The magnification of the relay optical system (1
The square term of / β) is the first term as in the camera of the present embodiment.
This is a term necessary for converting the defocus amount DF when the defocus amount DF of the image capturing unit is detected and used for determining the in-focus state of the second image capturing unit. In the configuration that directly detects the defocus amount of the second imaging unit, this (1 /
The square term of β) is not necessary.

In order to directly detect the defocus amount of the second image pickup section, a focus detection section such as an AF module C02 having a pair of line sensor and imaging lens is provided on the equivalent surface of the image pickup element C21. It may be installed. Alternatively, the defocus amount of the second image capturing section can be directly detected as follows.

The movable lens of the relay optical system C14 is moved back and forth from the set position, and the image pickup device C
The image signal from the image processing unit C24 corresponding to the predetermined partial area 21 is monitored, and the contrast change is detected. When the contrast becomes maximum, the in-focus state is perfect, but the defocus amount is obtained from the difference between the position of the movable lens at that time and the set position.

This method based on the contrast detection method is
Although the accuracy of the detected defocus amount is slightly inferior to that of the phase difference detection method, it can be said that it is suitable because a highly accurate in-focus is not required in photographing by CCD. Also,
There is no need to newly add a focus detection unit, and the configuration of the camera does not become complicated.

When shooting a still image on a silver salt film, quick shooting is required so that a photo opportunity is not missed. For this reason, it is necessary to perform focusing quickly when out of focus. On the other hand, when shooting a moving image with a CCD, fast shooting is not required, and if focusing is performed too fast, on the contrary, the image may be unsightly due to a rapid change from the out-of-focus state to the in-focus state. Furthermore, in video recording,
In some cases, a technique called focus-in is used in which the subject is intentionally out of focus and gradually focused to enhance the image effect. Therefore, a slow focusing is desirable in photographing with a CCD.

Therefore, in the present invention, in the AF mode, the focus motor L09 is driven at two speeds according to the photographing mode. P shooting with only silver salt film
The focus motor L09 is rotated at a relatively high first speed in the H mode and at a relatively low second speed in the MV mode in which shooting is performed only by the CCD. In the PM mode in which both the silver salt film and the CCD are used for shooting, at the first speed from the time when the signal S2ON is issued until the shooting of the silver salt film is completed, the other speed is at the second speed. To drive.

FIG. 5 shows an example of controlling the focus speed. Curve A represents the first drive speed in the PH and PM modes, and curve B represents the second drive speed in the MV and PM modes. Here, the maximum value of the second speed is approximately half the maximum value of the first speed, and it is necessary to drive the same amount (the areas under the curves in the figure are equal in the curves A and B). The time is about half the second speed at the first speed. The second speed may have a smaller value. In addition,
The focus motor L09 is gradually stopped at the low second speed, and is gradually stopped at the high first speed.

The control in focusing will be described with reference to the flowcharts of FIGS. FIG. 2 shows a control process in the PH mode in which shooting is performed only by the first shooting unit. When the shutter release button is pressed in PH mode and the signal S1ON is output (step #
5), the main microcomputer C01 calculates the defocus amount DF from the output of the AF module C02 (# 10). The defocus amount DF is compared with the first allowable range DF1 according to the equation (1) (# 15) to determine whether or not the focus is achieved. When not in focus, the drive amount of the focus motor C09 is calculated from the defocus amount DF and the value of the aperture L11 at that time (# 20), and the focus motor C09 is driven by the calculated amount (# 25). The drive speed at this time is a high speed first speed.

When it is determined in # 15 that the object is in focus,
It is determined whether or not the shutter release button is further pressed and the signal S2ON is output (# 30). Signal S2ON
If is not output, the process returns to # 10 and the above process is repeated. When the S2ON signal is output, the sub-mirror C
05 is retracted (# 35), the shutter C07 is opened, and the silver salt film C08 is exposed (# 40). After the exposure is completed, the sub-mirror C05 is returned (# 45), and the film C08 is fed by one frame (# 50) to prepare for the next shooting.

FIG. 3 shows the control processing in the MV mode in which shooting is performed only by the second shooting section. As mentioned above, the second image capturing section is irrespective of the setting of the image capturing mode.
The reflected light of the half mirror C04 is always received. MV
When the mode is set and a recording start instruction is given by operating the operation section COP, the main microcomputer C01 gives an instruction to the recording / reproducing section C25 to start recording an image signal and an audio signal on the magnetic tape C28 (step # 105).
Next, it is determined whether or not there is a recording end instruction from the operation unit COP (# 110).

When there is no end instruction, the AF module C
The defocus amount DF is calculated from the output of 02 (# 11
5) Then, the defocus amount DF is compared with the second allowable range DF2 according to the equation (2) (# 120) to determine whether or not the focus is achieved. If in focus, the process returns to # 110 and is repeated. When out of focus, the drive amount of the focus motor C09 is calculated from the defocus amount DF and the value of the aperture L11 at that time (# 125), and the focus motor C09 is driven by the calculated amount (# 130). The drive speed at this time is the second speed which is a low speed. Then # 110
And the above process is repeated. In addition, (# 105, # 1
The focusing operation (# 115 to # 130) may be continuously performed regardless of whether the recording in 10) is started or ended.

FIG. 4 shows the control processing in the PM mode in which both the first photographing section and the second photographing section perform photographing. When a recording start instruction is given by operating the operation section COP, the main microcomputer C01 gives an instruction to the recording / reproducing section C25 to start recording an image signal and an audio signal on the magnetic tape C28 (step # 205). Then, it is determined whether or not there is a recording end instruction from the operation unit COP (# 2
10) When the end instruction is given, the shooting recording by the second shooting unit is ended. When there is no end instruction, it is determined whether or not the shutter release button has been operated and the signal S1ON has been output (# 215).

When there is no signal S1ON, the defocus amount DF is calculated from the output of the AF module C02 (#
220), comparing this with the second allowable range DF2 (#
225), it is determined whether or not it is in focus. If in focus, the process returns to # 210. Focus motor C when out of focus
The drive amount of 09 is calculated (# 230), the second low speed is driven (# 235), and the process returns to # 210.

At # 215, when the signal S1ON instructing recording on the silver salt film is output, A
The defocus amount DF is calculated from the output of the F module C02 (# 240), and this defocus amount DF is compared with the first allowable range DF1 (# 245) to determine whether or not the focus is achieved. When not in focus, the drive amount of the focus motor C09 is calculated (# 250), and the focus motor C09 is driven by the calculated amount at the high first speed (# 255). After that, the process returns to # 240 and the calculation of the defocus amount and the focus determination are repeated.

When it is determined that the focus is achieved in # 245, S2 is ON.
Is determined (# 257), and if S2ON, the submirror C
The retreat of 05 (# 260), the exposure of the silver salt film C08 (# 265), the return of the sub-mirror (# 270), and the single frame feeding of the film (# 275) are sequentially performed, and the process returns to # 210. The processing of steps # 260 to # 275 is a photographing processing on the silver salt film by the first photographing unit, and during this period, the magnetic tape C2 of the photographed image of the CCD of the second photographing unit is also in the meantime.
The record for 8 continues. Further, similarly to FIG. 3, the focusing operation in the second allowable range may be continuously performed.

The camera of the present embodiment, which is subjected to focus determination and focusing control as described above, can quickly shoot a still image using a silver salt film, and the image becomes clear. Further, in photographing with a CCD, a non-focused subject slowly becomes clear, so that it is possible to photograph a natural moving image without sudden changes in the image.

Generally, the power consumption of the motor is large at high speed driving and small at low speed driving. In the focusing control described above, since the focus motor C09 is driven at a low speed when shooting a moving image for a relatively long time, the power supply unit C
The power consumption of 29 is suppressed.

In the present embodiment, focusing of both the first and second photographing sections is performed by adjusting the focal position of the photographing lens L, but focusing of the second photographing section is performed by relay optics. It may be performed by adjusting the focus position of the system C14. As described above, the relay optical system C14 includes a movable lens, and the position thereof can be changed by the drive unit of the relay optical system control unit C19. Based on the detected defocus amount DF, the main microcomputer C01 controls the relay optical system control unit C19 to adjust the position of the movable lens, so that the focusing of the second imaging unit can be easily performed. Since the movable lens of the relay optical system C14 is lighter than the taking lens L, it consumes less power.

Further, in the above structure, the light is split by the half mirror C04, but instead of this, a movable total reflection mirror such as a flip-up type may be used. However, when using a movable total reflection mirror,
Since light is guided to only one of the image capturing unit and the second image capturing unit, simultaneous image capturing cannot be performed in a strict sense, and a time difference occurs in image capturing between both image capturing units by the time required to move the mirror. Further, if the image is taken with a silver salt film while the image is taken with the CCD, the image taken with the CCD is interrupted in a short time. Such a problem does not occur in the configuration using the half mirror C04, and it is preferable to use the half mirror for dividing the light flux.

[0075]

When the camera of the present invention is used, it is possible to determine whether or not the image to be photographed is in focus according to the photographing means. Therefore, two photographing means using different types of image pickup elements can be used. It is easy to use. Further, when one of the image capturing means is configured to capture a still image exclusively and the other image capturing means is configured to capture a moving image only, the criterion for determining whether or not the object is in focus is to use a still image or a moving image. It can be set according to.

According to the second aspect of the present invention, the criterion for determining the in-focus state is set in correspondence with the depth of focus of the photographing means, so that it is unnecessary when two different photographing elements are used for the two photographing means. The strict determination criterion does not delay the arrival time to the focused state, and the insufficient determination criterion does not determine that the subject is in the focused state although the subject is not in focus. Therefore, it is possible to capture an image with a sufficient degree of definition according to the unique resolution of the imaging means.

According to the third aspect of the present invention, the image forming position can be adjusted at high speed or at low speed according to the purpose of each photographing means or the criterion for determining the in-focus state. When adjusted at high speed, each of the captured images will be sharp. This is suitable for intermittent shooting. When adjusting at a low speed, the change in the imaging state can be reflected in the image. If you use this when shooting continuously like a movie,
The expression of the captured image will be rich.

With the camera according to the fourth aspect, it is possible to shoot a still image with a silver salt film and a moving image with a photoelectric conversion element, and it is possible to adjust the imaging position suitable for each shooting. . When shooting on a silver salt film, the image forming position is quickly adjusted, so that a clear still image can be taken without losing a photo opportunity. When shooting with a photoelectric conversion element,
Since the image forming position is slowly adjusted, a sudden change in the image forming state does not appear in successive images, and a natural moving image can be taken. In addition, the power consumption required for adjusting the image forming position in photographing by the photoelectric conversion element is small, and a long-time moving image can be photographed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a camera according to an embodiment of the present invention.

FIG. 2 is a flowchart showing control of focusing when photographing with a silver salt film.

FIG. 3 is a flowchart showing control of focusing when photographing with a CCD.

FIG. 4 is a flowchart showing control of focusing when photographing with a silver salt film and a CCD.

FIG. 5 is a diagram showing two speeds of focusing.

[Explanation of symbols]

C camera main body C01 arithmetic control unit (imaging state detection means, focus determination means, first control means, second control means) C02 focusing state detection unit (imaging state detection means) C04 half mirror (light splitting means) C05 Sub-mirror C07 Shutter C08 Silver salt film (first photographing means) C09 Film supply section C10 Condenser lens C13 ND filter C14 Relay optical system C18 Relay diaphragm C19 Relay optical system control section C21 CCD (Second position) C23 CCD drive unit C24 Image processing unit C25 Recording / playback unit C27 Image display unit C28 Magnetic tape C31 Audio processing unit COP operation unit L Photographing lens L05 Focal length detection unit L06 Calculation control unit (control means) L07 Zoom motor L09 Focus motor (imaging position Section means) L11 aperture F flash and light DF1 first defocus amount permissible range (first criterion) DF2 second defocus amount permissible range (second criterion)

Claims (4)

[Claims] 1. A light splitting means for splitting light from a subject to be photographed into a first light flux and a second light flux, and a first photographing means for receiving the first light flux and photographing an image of the light flux. It has a second photographing means for receiving the second luminous flux and photographing an image of the luminous flux, and at least one image forming position adjusting means for adjusting the image forming positions of the first luminous flux and the second luminous flux. Regarding a camera, a deviation amount from an in-focus state of an image of the first light flux in the first photographing means or a deviation amount from an in-focus state of an image of the second light flux in the second photographing means is detected. And a shift amount detected by the image formation state detection means, and an image of the first light flux in the first image pickup means is focused according to a first determination criterion. It is judged whether or not it is in the state, and according to the second judgment criterion The focus determination means for determining whether or not the image of the second light flux in the second imaging means is in focus, and the focus determination means for focusing by the first imaging means. The first control means for controlling the image-forming position adjusting means to adjust the image-forming position of the first light flux so as to be determined to be in the state; A second control unit for controlling the image forming position adjusting unit to adjust the image forming position of the second light flux so that the in-focus state is determined by the focus determining unit. A camera to do. 2. The first determination criterion and the second determination criterion of the focus determination means are set corresponding to the depths of focus of the first photographing means and the second photographing means, respectively. The camera according to claim 1, wherein the camera is a camera. 3. The image forming position adjusting means operates in a first mode in which the image forming positions of the first light flux and the second light beam are adjusted at a high speed and a second mode in which the image formation position is adjusted at a low speed. The camera according to claim 1, wherein: 4. The first photographing means performs photographing by exposing a silver salt film to the first light flux, and the second photographing means converts the second light flux into a video signal by a photoelectric conversion element. When performing image capturing by converting, the image forming position adjusting unit operates in the first mode when performing image capturing by the first image capturing unit, and when performing image capturing by the second image capturing unit. The camera according to claim 3, wherein the camera operates in the second mode.