JPH11352391A - Autofocusing camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phase difference detecting system autofocusing camera capable of surely detecting a focusing state by using AF(autofocusing) auxiliary light in macro-photographing and rapidly performing focusing. SOLUTION: An auxiliary light emitting device 42 emitting AF auxiliary light is incorporated in a macro-flashing device 40 attached to a photographing lens 30 so as to emit the auxiliary light when it is required for the macro- photographing. When the focusing state is not detected even when the auxiliary light is emitted, detection is tried while driving a focus lens for focusing 31 in order to find out a position where it can be detected, and the auxiliary light is emitted also in the midst of driving the lens 31. When it is made detectable, the lens 31 is driven in accordance with the detected result in order to focus the lens 31, and the focusing state is detected by emitting the auxiliary light even in the midst of driving the lens 31 so as to control the driving in accordance with the detected result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autofocus camera using a phase difference detection method, and more particularly, to a macro flash device for illuminating a short-distance subject, which is provided with an auxiliary light emitting device for emitting auxiliary light for detection mounted on a taking lens. It relates to an autofocus camera built in.

[0002]

2. Description of the Related Art Some autofocus (AF) cameras that automatically focus a photographing lens on a subject adopt a phase difference detection method as a method for detecting a focus state of the photographing lens with respect to the subject. The phase difference detection method is
One or more pairs of image detection sensors, such as line sensors, are disposed near a surface equivalent to an imaging surface on which an imaging device such as a silver halide film or a photoelectric conversion device is disposed, and light transmitted through a photographing lens. Of the different parts of the light beam to different sensors,
The shift of the focus of the photographing lens is detected from the shift of the position of the subject image on the paired sensors.

In this type of autofocus camera,
The amount of deviation detected by repeating the operation of detecting the direction and amount of defocus and driving the focus lens for focusing included in the photographing lens in the detected direction by a distance corresponding to the detected amount. And finally focus the taking lens on the subject.

In order to detect the displacement of the object image on the paired sensors, it is necessary to find out which part of the images of both sensors corresponds to which part, which is based on the brightness of the image on the sensors. That is, the comparison is performed by comparing contrast distribution patterns. Therefore, when the subject does not have sufficient contrast, the position of the subject image on the sensor cannot be determined, and focus adjustment cannot be performed. Even when the subject has a sufficient contrast, if the focus of the photographing lens is largely out of focus, the image is blurred on the sensor and the contrast is lost, making it difficult to adjust the focus.

When the contrast of the image on the sensor is insufficient and the displacement of the image cannot be detected, the focus lens is moved at a constant speed while monitoring the contrast of the sensor to provide a detectable contrast. Find the position of This operation is called a low contrast scan.

In the low-contrast scan, it is not known at that time whether the focus is in front of or far from the subject, and how much the focus is out of focus. Done on a range. For example, the focus lens is first moved from its current position to the near end corresponding to the latest shooting distance, and then to the infinity end corresponding to the furthest (infinity) shooting distance. Thus, even if the focus of the photographing lens is greatly deviated from the in-focus position, it is possible to detect the displacement.

[0007] In order to assist the detection of the positional shift of the image, an AF auxiliary light of a predetermined pattern is applied to the subject. In such a camera, an auxiliary light emitting device that emits AF auxiliary light is built in the camera body, or is incorporated in a flash device for illuminating a subject when photographing in a dark environment or in a backlight condition and performing proper exposure. ,
It can be attached to the camera body as needed. Some cameras use both AF auxiliary light and low contrast scanning.

In macro photography for photographing a subject located at a short distance, a dedicated macro flash device is mounted on the tip of the photographing lens to illuminate the subject instead of a flash device used for normal photography. It has also been proposed to incorporate an auxiliary light emitting device for emitting AF auxiliary light in the macro flash device. The AF auxiliary light from the auxiliary light emitting device built into the camera body or the auxiliary light emitting device built into the normal flash device is difficult to function in macro photography because part of it is blocked by the lens barrel of the taking lens. The AF auxiliary light from the flash device functions reliably without being interrupted.

FIG. 25 shows a configuration of a conventional autofocus camera in which an auxiliary light emitting device is built in a macro flash device.
26. The camera 5 in FIG. 25 has an AF actuator 14 for driving the focus lens 31 of the photographing lens 30 in the camera body 10, and transmits a driving force to the focus lens 31 via a lens driving system 33. The taking lens 30 is detachable from the camera body 10 and has a lens ROM storing various information unique to the lens.
32 are provided.

A macro flash device 40 is mounted near the tip of the taking lens 30. The macro flash device 40 is detachable, and is mounted as needed when performing macro photography. When the macro flash device 40 is mounted, the macro flash control device 50 is mounted on the upper part of the camera body 10. The macro flash control device 50 is directly connected to the camera body 10, and is connected to the macro flash device 40 by a cable 51.

The macro flash device 40 is provided with a flash unit 41 for illuminating a subject and an auxiliary light emitting unit 42 for emitting AF auxiliary light. The macro flash control device 50 includes a light emission control unit 43 that controls light emission of the flash unit 41 and the auxiliary light emission unit 42, a power supply 46 that supplies power for light emission, and calculations such as calculation of a light emission amount of the flash unit 41. A flash CPU 44 for performing the entire operation and controlling the entire macro flash control device 50 is provided. A control signal and power for instructing start and stop of light emission are given from the macro flash control device 50 to the macro flash device 40 via the cable 51. FIG.
5, a thick line connecting the macro flash control device 50 and the macro flash device 40 represents a power supply line, and a thin line represents a signal line.

The camera body 10 is an AF sensor module comprising a flip-up main mirror 11, a sub-mirror 12 attached to the main mirror 11, a CCD sensor 13a for performing photoelectric conversion, and an optical system 13b for guiding light reflected by the sub-mirror 12. 13, AF actuator 14
An AF encoder 15 for detecting the amount of drive of the camera, an AFCPU 1 for detecting the focus state of the photographing lens 30 by a phase difference detection method based on the output of the CCD sensor 13a, and controlling the focus adjustment of the photographing lens 30 via the AF actuator 14.
6, and a camera CPU 17 for controlling the overall operation of the camera except for focusing. The camera CPU 17 reads information from the lens ROM 32, and provides information related to focus adjustment such as a focal length and a minimum shooting distance to the AF CPU 16, and the AF CPU 16 uses the information for focus adjustment control.

In addition, the camera body 10 includes a photometric module 1 for detecting the brightness of a subject for exposure control.
8. Light control module 19 that outputs a signal indicating that the amount of light guided to photographic film 9 at the time of flash photography has reached a predetermined amount, auxiliary light emitting unit 21 that emits AF auxiliary light, and information on the focus state of photographic lens 30 A for displaying
An F display unit 22 is also provided.

The camera 6 shown in FIG.
The configuration is such that an AF actuator 14 for driving the AF actuator 1 is provided on the photographing lens 30 itself.
An AF encoder 15 for detecting the amount of drive of No. 4 is also provided on the taking lens 30. The taking lens 30 is an AF
A lens CPU 34 for controlling the driving of the focus lens 31 by the actuator 14 and communicating with the camera body 10, and a termination switch 3 for detecting that the focus lens 31 is located at the near end and the infinity end, respectively.
5a and 35b, and a PF encoder 36 for detecting rotation of an operation ring (not shown) operated at the time of power focus (PF) for performing focus adjustment in accordance with manual operation.

The camera CPU 17 communicates with the lens CPU 34 and transmits the output from the CCD sensor 13a of the AF sensor module 13 to the AF CPU 16. A
The FCPU 16 detects the focus state of the photographing lens 30 by a phase difference detection method based on the output of the CCD sensor 13a, and outputs the detection result to the lens CPU via the camera CPU 17.
34 to control the focus adjustment of the taking lens 30.
Other parts of the camera body 10 and the macro flash device 4
The configuration and function of the macro flash control device 50 are the same as those of the camera 5.

In these cameras 5 and 6, when the contrast of the image on the CCD sensor 13a is low and the focus state cannot be detected, the AF CPU 16 controls the camera body 1
0, the AF auxiliary light is emitted from the auxiliary light emitting unit 21 incorporated in the macro flash unit 40, or a signal is sent to the camera CPU 17 to instruct the auxiliary light emitting unit 42 of the macro flash unit 40 to emit the AF auxiliary light. The focus state is detected using the AF auxiliary light.

If the focus state cannot be detected by using the AF auxiliary light, a low contrast scan is performed. 27 and 28 show the relationship between the driving of the focus lens and the processing related to the detection of the focus state in the low contrast scan.
In these figures, the horizontal axis represents time, and the vertical axis represents FIG.
In FIG. 28, the drive speed of the focus lens is shown, and in FIG. 28, the position of the focus lens is shown. The low-contrast scan is performed first toward the near end and then toward the infinite end, but the focus lens is driven at a constant speed except for a period immediately after the start of driving.

Reference numeral I denotes photoelectric conversion by the CCD sensor, reference numeral D denotes an output from the CCD sensor of electric charges accumulated by photoelectric conversion, reference numeral F denotes detection of a focus state by the AFCPU,
The symbol S indicates detection of the setting of switches (not shown) by the camera CPU and communication with the lens CPU, and the symbol L indicates emission of AF auxiliary light. These processes are performed during the illustrated period.

A based on the photoelectric conversion I and the output D of the stored charge
The focus state detection F by the FCPU is also performed while the focus lens is being driven by the low contrast scan. However, the emission L of the AF auxiliary light during the photoelectric conversion I is before the start of the low contrast scan and when the focus lens is at the near end. Or only when it is at the infinite end and stopped.

FIG. 29 shows the relationship between the drive of the focus lens and the processing for detecting the focus state after the focus state can be detected by using the AF auxiliary light. FIG.
In FIG. 9, the horizontal axis represents time, the vertical axis represents the driving speed of the focus lens, and the symbols attached to the horizontal axis are as described above. First, an amount by which the focus lens should be driven is calculated from the detection result using the AF auxiliary light, and the focus lens is driven by the calculated amount. Next, after the focus lens is stopped, the focus state detection F accompanying the emission of the AF auxiliary light L is performed again, and the amount to drive the focus lens is calculated from the detection result. Then, the focus lens is driven by the calculated amount, and the focus adjustment ends.

[0021]

In order to successfully detect the focus state using the AF auxiliary light, the subject needs to be within a detectable distance range at the time when the AF auxiliary light is emitted. is there. However, as described above, in the conventional camera, the AF auxiliary light used in combination with the low contrast scan is emitted only before the start of the scan and when the focus lens is stopped at the near end or the infinity end, so that the focus state cannot be detected. The possible distance range is limited to three.

The position of the focus lens before the start of scanning is unspecified, and the detectable distance range at this initial position is not necessarily the detectable distance range when the focus lens is located at the near end or infinity end. Do not overlap. An example of the distance range in which the focus state can be detected is indicated by an arrow R in FIG. In this example, the detectable distance range at the initial position and the detectable distance range at the near end do not overlap, and an undetectable distance range RU exists between them.

Even if the low-contrast scan and the AF auxiliary light are used together, if the subject is in the undetectable distance range RU, the focus state cannot be detected naturally. Especially,
In the case of macro photography in which a subject located at a short distance is photographed, the detectable distance range greatly changes with a slight change in the position of the focus lens, so that the subject is not located within the detectable distance range. Is easy to occur,
In many cases, the focus cannot be adjusted.

In the conventional camera, when the focus state can be detected by using the AF auxiliary light, as described above, the focus lens is driven to bring the photographing lens closer to the in-focus state, and the focus lens is moved. In the stopped state, the focus state using the AF auxiliary light is detected again. However, the accuracy of the initial detection is low, and particularly in macro photography, since the change in the focus state with respect to the change in the position of the focus lens is large, it is easy for the focus lens to be excessively driven or the driving amount is insufficient before re-detection, Focus adjustment could not be performed quickly.

Further, in the conventional camera, which one of the auxiliary light emitting portion built in the camera body and the auxiliary light emitting portion built in the macro flash device emits light is determined based on the brightness of the subject. Sometimes, the auxiliary light emitting unit built in the camera body emits light. For this reason, the AF auxiliary light may be partially blocked by the photographing lens and the macro flash device during macro shooting. In addition to using the auxiliary flash unit in the macro flash device, the AF auxiliary light is not fully utilized, and the macro flash device is mounted. Doing so sometimes hinders focus adjustment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is an autofocus camera of a phase difference detection system capable of reliably detecting a focus state using AF auxiliary light in macro photography and quickly adjusting the focus. The purpose is to provide. It is another object of the present invention to provide an autofocus camera that effectively utilizes a light emitting device for AF auxiliary light built in a macro flash device.

[0027]

In order to achieve the above object, the present invention provides an autofocus camera for detecting the focus state of a photographic lens by a phase difference detection method, which illuminates an object at a short distance. An imaging device that includes a macro flash device and has a built-in auxiliary light emitting device that emits auxiliary light for assisting detection of a focus state when the focus state cannot be detected. The focus adjusting lens is driven while trying to detect a focus state in order to find the position of the focus adjusting lens of the lens, and the auxiliary light emitting device emits auxiliary light during the driving.

This camera performs a low-contrast scan when the focus state cannot be detected, and emits AF auxiliary light from an auxiliary light emitting device built in the macro flash device during the low-contrast scan. This A
If the subject is within the distance range where the focus state can be detected when the F auxiliary light is emitted, the low contrast scan can be ended. The necessity of the AF auxiliary light may be determined by detecting the normal focus state before the start of the low contrast scan.

In macro photography, a slight change in the position of the focus adjustment lens, that is, the focus lens greatly changes the distance range in which the focus state can be detected.
When the focus state cannot be detected by one light emission, the AF auxiliary light is emitted any number of times while scanning continues, and the distance range in which the focus state can be detected for each light emission can be partially overlapped. As a result, the subject enters a detectable distance range at any time of light emission,
It is possible to prevent a situation in which the subject enters a detectable distance range and goes out of the range during a period in which no auxiliary light is emitted. Therefore, it is possible to reliably detect the focus state even in macro shooting.

The driving speed when driving the focusing lens while trying to detect the focus state is switched to a low speed after a predetermined amount of driving or after the focusing lens reaches a predetermined position, and after the switching, The auxiliary light may be emitted from the auxiliary light emitting device for the first time. The ratio of the change in the distance range in which the focus state can be detected to the change in the position of the focus lens increases as the focus lens approaches the near end, but when the focus lens is driven toward the near end in a low contrast scan. If the drive speed is switched to a low speed after a predetermined amount of drive or after the focus lens has reached a predetermined position, the distance at which the focus state can be detected while the light emission interval of the AF auxiliary light is kept substantially constant. Ranges can be reliably overlapped. If the AF auxiliary light is emitted before the start of the low-contrast scan, the detection of the focus state during the high-speed driving at the beginning of the scan does not fail.

Further, during low contrast scan, an image flows on the focus state detecting sensor due to movement of the focus lens, so that it is more difficult to detect the focus state than when the focus lens is stationary. However, by switching the driving speed to a low speed, the flow of the image on the sensor can be reduced, and the detection of the focus state can be more reliably performed.

In order to achieve the above object, the present invention also provides an autofocus camera for detecting a focus state of a photographing lens by a phase difference detection method, comprising a macro flash device for illuminating a subject at a short distance. When the macro flash device has a built-in auxiliary light emitting device that emits auxiliary light to assist in detection of the focus state, after detecting the focus state, the photographing is performed while detecting the focus state in order to focus the shooting lens. The focus adjusting lens of the lens is driven, and the auxiliary light is emitted from the auxiliary light emitting device during the driving.

In this camera, when the focus state can be detected, the detection of the focus state and the driving of the focus lens based on the detection result are repeated to gradually bring the photographing lens closer to the in-focus state. Emit. Since the focus state can be detected while the focus lens is being driven by the AF auxiliary light, the drive of the focus lens can be more appropriately controlled, and the time required for focusing the photographing lens can be reduced.

When the focus state is detected, the driving amount of the focus adjusting lens required to bring the photographing lens into focus is calculated, and the auxiliary light is emitted from the auxiliary light emitting device only after the calculated driving amount becomes equal to or less than a predetermined value. You may make it emit. It is not necessary to perform the re-detection of the focus state immediately after the drive of the focus lens is started, and it is sufficient to start the drive after the drive amount reaches a focus position after the drive to some extent. It just needs to emit light.

It is preferable that the macro flash device be detachable from the taking lens.

In order to achieve the above object, the present invention further provides an autofocus camera for detecting a focus state of a photographing lens by a phase difference detection method, wherein the autofocus camera emits an auxiliary light for assisting the focus state detection. A second auxiliary light emitting device that can attach a macro flash device, which incorporates the first auxiliary light emitting device, for illuminating a subject at a short distance to a photographing lens and emits auxiliary light for assisting detection of a focus state. When the macro flash device is mounted, the first auxiliary light-emitting device emits auxiliary light prior to the second auxiliary light-emitting device when the macro flash device is mounted.

The macro flash device is mounted when photographing a subject located at a short distance, and the AF auxiliary light emitted from the auxiliary light emitting device built in or mounted on the camera body is used for photographing a lens or a macro flash device. May be partially obstructed. At the time of macro shooting, the auxiliary light emitting device built in the macro flash device emits AF auxiliary light in preference to these auxiliary light emitting devices, so that A
The F auxiliary light can be reliably used for detecting the focus state.

[0038]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a schematic configuration of a camera 1 according to the first embodiment. The camera 1 is an autofocus camera based on a phase difference detection method, and includes a camera body 10, a photographing lens 30, and a macro flash device 40. The taking lens 30 is the camera body 1
The macro flash device 40 is detachable near the front end of the lens barrel of the photographing lens 30. The appearance of the camera 1 is shown in FIG.

The photographing lens 30 includes a focus lens 31 for focusing and a lens RO storing lens-specific information.
M32 is provided. The focus lens 31 is driven by a driving force provided from the camera body 10 via a lens driving system 33.

The macro flash device 40 is attached to the photographing lens 30 at the time of macro photography for photographing a subject located at a short distance, and includes a flash unit 41 for emitting flash light for illuminating the subject, and a focus state detection. And an auxiliary light emitting unit 42 that emits AF auxiliary light for assisting the camera. The macro flash device 40 also includes a light emission control unit 43 that controls light emission of the flash unit 41 and the auxiliary light emission unit 42, a macro flash device 4 that communicates with the camera body 10 and sets the light emission amount of the flash unit 30.
0 is provided with a flash CPU 44 for controlling the entirety of the flash memory.

FIG. 3 shows the appearance of the photographing lens 30 detached from the camera body 10 from obliquely rear, and FIG. 4 shows the appearance of the macro flash device 40 detached from the photographing lens 30 from obliquely rear. The mounting portion provided at the rear end of the photographing lens 30 for mounting on the camera body 10 has the photographing lens 30 attached thereto.
Are provided with several terminals 37 for electrical connection. Although not shown, the same number of terminals that are coupled to the terminals 37 when the photographing lens 30 is mounted are provided on the mount portion on the front surface of the camera body 10.

An outer peripheral surface of the photographing lens 30 near the front end of the lens barrel is provided with an engagement hole 38 for engaging and fixing with the macro flash device 40 and a number of holes for electrically connecting with the macro flash device 40. Terminals 39 are provided. These terminals 39 are connected to a part of the terminals 37 of the mount section by wiring arranged in the lens barrel. The remaining part of the terminal 37 is used for electrical connection between the camera body 10 and the photographing lens 30 itself, and is used for transmitting and receiving signals and supplying power from the camera body 10 to the photographing lens 30.

The macro flash device 40 has a shape surrounding the outer periphery of the taking lens 30,
1 is provided on substantially the entire front surface, and the auxiliary light emitting section 42 is provided on a part of the front surface. The macro flash device 40 includes an engagement claw 48 that engages with the engagement hole 38 of the photographing lens 30, and an engagement claw 48.
And a detach button 47 for releasing the engagement of the engagement hole 38 and several terminals 49 which are coupled to the terminal 39 when the terminal is attached to the taking lens 30. These terminals 49 are connected to the flash CPU 44 and the light emission control unit 43.

The photographing lens 3 attached to the camera body 10
By attaching the macro flash device 40 to the
The camera body 10 and the macro flash device 40 are automatically electrically connected via terminals 37, 39, and 49. With this configuration, a cable for connecting the camera body and the macro flash device, which has been conventionally required, becomes unnecessary, and it is not necessary to hold the macro flash unit 40 so as not to rotate.

The camera body 10 includes a flip-up main mirror 11, a sub-mirror 12 attached to the main mirror 11, a CCD sensor 13a for performing photoelectric conversion, and an optical element for guiding light from the photographing lens 30 reflected by the sub-mirror 12 to the main body. An AF sensor module 13 comprising a system 13b, an AF actuator 14 for supplying a driving force to a focus lens 31, an AF encoder 15 for detecting a driving amount of the AF actuator 14, and a photographing lens 30 by a phase difference detection method based on an output of the CCD sensor 13a. The AF CPU 16 detects the focus state of the camera and controls the focus adjustment of the photographing lens 30 via the AF actuator 14, and the camera CP controls the entire operation of the camera except the focus adjustment
U17 is provided.

The camera CPU 17 reads information from the lens ROM 32 and gives information relating to focus adjustment such as a focal length and a minimum photographing distance to the AF CPU 16.
6 uses the information for controlling the focus adjustment. Camera CP
U17 communicates with the light emission control unit 43 and the flash CPU 44 of the macro flash device 40 to control the emission of flash light and AF auxiliary light, and to emit light from a power supply (not shown) provided in the camera body 10. Power is supplied to the macro flash device 40. The transmission and reception of signals and the supply of electric power are performed by the terminals 37, 3,
9 and 49 are performed. In FIG. 1, a thick line connecting the camera body 10 and the macro flash device 40 represents a power supply line, and a thin line represents a signal line.

In addition, the camera body 10 includes a photometric module 1 for detecting the brightness of a subject for controlling exposure.
8. Light control module 19 that outputs a signal indicating that the amount of light guided to photographic film 9 at the time of flash photography has reached a predetermined amount, auxiliary light emitting unit 21 that emits AF auxiliary light, and information on the focus state of photographic lens 30 A for displaying
An F display unit 22 is also provided. When the brightness of the subject is insufficient and the macro flash device 40 is mounted, the camera CPU 17 causes the flash unit 41 to emit flash light.

Although not shown, a flash device for illuminating a subject in normal photographing other than macro photographing can be mounted on the upper portion of the camera body 10.
An AF auxiliary light can be emitted from an auxiliary light emitting unit built in the flash device. However, when the macro flash device 40 is mounted, the camera 1 takes precedence over the auxiliary light emitting unit built in the normal flash device and the auxiliary light emitting unit 21 built in the camera body 10 to give the macro flash device 40 The auxiliary light emitting section 42 emits light. Therefore, the AF auxiliary light is not blocked even in macro shooting.

FIG. 5 schematically shows the structure of a camera 2 according to the second embodiment. The camera 2 is also an autofocus camera based on the phase difference detection method, but differs from the camera 1 of the first embodiment in that an AF actuator 14 for driving the focus lens 31 of the photographing lens 30 is provided in the photographing lens 30. Different. An AF encoder 15 for detecting a driving amount of the AF actuator 14 is also provided on the photographing lens 30.

The photographing lens 30 includes the AF actuator 1
4 controls the driving of the focus lens 31 and communicates with the camera body 10; lens switches 34a and 35 for detecting that the focus lens 31 is located at the near end and the infinite end, respectively.
b, a PF encoder 36 for detecting rotation of an operation ring (not shown) operated at the time of power focusing.

The camera CPU 17 communicates with the lens CPU 34 and transmits the output from the CCD sensor 13a of the AF sensor module 13 to the AF CPU 16. A
The FCPU 16 detects the focus state of the photographing lens 30 by a phase difference detection method based on the output of the CCD sensor 13a, and outputs the detection result to the lens CPU via the camera CPU 17.
34 to control the focus adjustment of the taking lens 30.
Other parts of the camera body 10 and the macro flash device 4
0 and the configuration for electrical connection between the camera body 10 and the macro flash device 40 are the same as those of the camera 1 of the first embodiment.

FIG. 6 schematically shows the structure of a camera 3 according to the third embodiment. In the camera 3, communication units 23 and 45 are provided in the camera body 10 and the macro flash device 40 of the camera 1 of the first embodiment, respectively, so that they can communicate wirelessly. Shooting lens 3
0 and the aforementioned terminal 3 provided in the macro flash device 40.
Reference numerals 7, 39, and 49 are used only for supplying power for light emission.
As the wireless medium for communication, any one such as ultrasonic waves, light, radio waves, etc. can be used, and the communication units 23 and 45 are configured using a known technique according to the medium.

FIG. 7 schematically shows the structure of a camera 4 according to the fourth embodiment. In the camera 4, a power supply 46 is provided in the macro flash device 40 of the camera 1 of the first embodiment, and power is not supplied from the camera body 10 to the macro flash device 40. Terminal 3 provided on photographing lens 30 and macro flash device 40
7, 39 and 49 are used only for transmitting and receiving signals.

The focus adjustment of the cameras 1 to 4 in each of the above embodiments will be described. When receiving an instruction to start the focus adjustment, the cameras 1 to 4 try to detect the focus state without emitting the AF auxiliary light in a state where the focus lens 31 is stopped at the position at that time.

When the focus state can be detected, ordinary focus adjustment is performed. That is, the direction and the amount to drive the focus lens according to the detected focus shift are obtained, and the drive of the focus lens is started. Then, the detection of the focus state is repeated during driving, and the driving of the focus lens is adjusted according to the detection result, so that the photographing lens 30 is gradually brought into focus. When the detected shift amount becomes equal to or less than a predetermined focusing reference value, the focus lens is stopped,
The focus state is further detected for confirmation, and the focus lens is driven by a small amount as necessary, thereby ending the focus adjustment.

When the focus state cannot be detected, A
Attempt to detect the focus state using F auxiliary light. At this time,
It is determined whether or not the macro flash device 40 having the auxiliary light emitting unit 42 is mounted, and if it is mounted, it is determined that macro shooting is to be performed. Depending on the brightness of the subject,
AF of an auxiliary light emitting unit built in the camera body 10 or an auxiliary light emitting unit built in another flash device mounted on the camera body 10
Auxiliary light is used.

When it is possible to detect the focus state using the AF auxiliary light of the auxiliary light emitting unit other than the macro flash device 40, the focus lens is driven according to the detection result, and after the driving is completed, the focus is again used using the AF auxiliary light. Detect state.
By repeatedly driving the focus lens and detecting the focus state, the photographing lens gradually approaches the in-focus state, and when the detected amount of focus shift falls below the focus reference value, the focus lens is stopped and the focus is adjusted. To end.

FIG. 8 shows the relationship between the driving of the focus lens 31 and the processing for detecting the focus state when the focus state can be detected using the AF auxiliary light of the auxiliary light emitting section 42 built in the macro flash device 40. . In FIG. 8, the horizontal axis represents time, and the vertical axis represents the driving speed of the focus lens. Reference numeral I denotes photoelectric conversion by the CCD sensor 13a, reference numeral D denotes an output of charges accumulated by the photoelectric conversion from the CCD sensor 13a, reference numeral F denotes detection of a focus state by the AFCPU 16, and reference numeral S denotes setting of switches (not shown) by the camera CPU 17. Detection of the situation, communication with the photographing lens 30, symbol L
Represents light emission of the AF auxiliary light from the auxiliary light emitting section 42, and these processes are performed in the illustrated period.

First, the drive of the focus lens is started according to the detection result, and the detection F of the focus state accompanied by the emission L of the AF auxiliary light is repeated during the drive, and the drive of the focus lens is adjusted according to the detection result. . Then, the focus lens is stopped when the detected defocus amount becomes equal to or less than the focus reference value, and a focus state detection F accompanied by the emission of the AF auxiliary light L is performed for confirmation. The focus lens is driven by a very small amount to complete the focus adjustment.

Here, when the focus state is detected for the first time, the drive amount of the focus lens required for focusing the photographing lens is calculated, and the drive amount of the focus lens is already output by the output of the AF encoder 15 during the drive. The detected amount is measured, and the detection of the focus state from the second time onward using the AF auxiliary light is started only when the remaining drive amount becomes equal to or less than the predetermined value. In the second and subsequent focus state detections as well, the drive amount of the focus lens required to bring the photographing lens into focus is calculated, and if the remaining drive amount is equal to or less than a predetermined value, the focus state using AF auxiliary light is used. Continue to detect.

When the focus state cannot be detected by using the AF auxiliary light, a low contrast scan is performed using the AF auxiliary light. Also at this time, when the macro flash device 40 having the auxiliary light emitting section 42 is mounted, the AF auxiliary light is used with priority. The low contrast scan is performed first towards the near end and then towards the infinite end.

When using the AF auxiliary light of the auxiliary light emitting unit built in the camera body 10 or a normal flash device for low-contrast scan, an attempt is made to detect the focus state without emitting the AF auxiliary light while driving the focus lens.
When the focus lens reaches the near end or the infinity end, AF auxiliary light is emitted with the focus lens stopped to try to detect the focus state.

There are three modes for low-contrast scan using the AF auxiliary light of the auxiliary light emitting section 42 built in the macro flash device 40, and the camera user operates a selection switch provided on the camera body to select an arbitrary mode. Can be selected. In either mode,
An attempt is made to detect a focus state accompanied by emission of AF auxiliary light during driving of the focus lens.

FIGS. 9 and 10 show the relationship between the drive of the focus lens in the first mode and the processing related to the detection of the focus state. In these figures, the horizontal axis represents time, the vertical axis represents the drive speed of the focus lens in FIG. 9, and the position of the focus lens in FIG. Each symbol attached to the horizontal axis is as described above. In this mode, the focus lens is driven at a constant speed except for a period immediately after the start of driving. Then, the detection F of the focus state accompanied by the emission L of the AF auxiliary light is attempted at a substantially constant cycle immediately after the start of driving. AF even when the focus lens is located at the near end or infinity end
Attempt to detect the focus state F accompanied by the emission L of the auxiliary light.

The distance range in which the focus state at the focus lens position can be detected at each detection is indicated by an arrow R in FIG. The detectable distance range at the time of each detection partially overlaps with the detectable distance range at the time of the preceding and following detections, as indicated by reference numeral RD. Therefore, no matter where the subject is located from the latest shooting distance to the farthest (infinity) shooting distance,
The subject enters at least one detectable distance range, and the entire range becomes the detectable range of the focus state.
Therefore, the focus state can be reliably detected.

FIGS. 11 and 12 show the relationship between the driving of the focus lens in the second mode and the processing related to the detection of the focus state. In this mode, the focus lens is first driven at a high speed, and after a predetermined amount of drive or after the focus lens has approached the near end or infinity end to a predetermined distance, the drive speed is switched to a low speed. During driving, the focus state detection F is attempted at a substantially constant cycle, but the emission of the AF auxiliary light L is not performed before the switching of the speed, but is performed after the switching of the speed until the driving is restarted.

By appropriately setting the predetermined drive amount or the predetermined distance to the near end or infinity end according to the characteristics of the photographing lens such as the focal length, the speed switching is performed as shown by RD in FIG. The detectable distance range in the later first detection can partially overlap the detectable distance range in the preceding stop position. Therefore, the entire range from the latest shooting distance to the farthest shooting distance becomes a detectable range of the focus state, and the focus state can be reliably detected regardless of the distance to the subject. In addition, since the focus lens is driven at a low speed when the focus state accompanied by the emission of the AF auxiliary light is detected, the flow of the image on the CCD sensor is small, and the accuracy of the detected focus state is high.

FIGS. 13 and 14 show the relationship between the driving of the focus lens in the third mode and the processing relating to the detection of the focus state. In this mode, first, the drive toward the near end of the focus lens is performed at a high speed, and then the drive toward the infinity end is performed at a low speed. During driving, the focus state detection F is attempted at a substantially constant cycle, but the emission of the AF auxiliary light L is not performed during driving toward the near end, but is performed after the focus lens reaches the near end.

The detectable distance range at each detection during driving toward the infinite end partially overlaps with the detectable distance range at the time of detection before and after, and the entire range from the latest shooting distance to the farthest shooting distance is obtained. Is the detectable range of the focus state. Therefore, the focus state can be reliably detected regardless of the distance to the subject. In addition, the accuracy of the focus state detected due to the low-speed driving increases. In addition, since the focus state is detected during driving from the near end to the infinity end, regardless of the position of the focus lens before the start of the low contrast scan, the focus adjustment can be performed on the subject closest to the camera. It is possible.

In any of the first to third modes, when the focus state can be detected without the AF auxiliary light, normal focus adjustment is performed. When the focus state can be detected by emitting the AF auxiliary light, The focus adjustment using the AF auxiliary light is performed.

The flow of the focus adjustment operation of the cameras 1 to 4 will be specifically described with reference to the flowcharts of FIGS. FIG. 15 shows a schematic flow of the entire processing. The start of the focus adjustment operation is instructed by operating a shutter release button provided on the camera body.
When the shutter release button is half-pressed, it outputs a first signal for instructing photometry for focus adjustment and exposure control of a photographic lens, and when fully pressed, outputs a second signal for instructing exposure of a photographic film. It is set as follows.

First, it is determined whether or not the start of focus adjustment is instructed by the first signal (step # 5). If there is no instruction, the flag indicating that low contrast scan is being performed is released, and The flag indicating that the emission of the AF auxiliary light is prohibited is cleared, the flag indicating that the low contrast scan is prohibited is cleared (# 10), and the process waits for a start instruction. When the instruction is issued, it is determined whether or not the macro flash device 40 having the built-in auxiliary light emitting section 42 is mounted (# 15). Then, a process is performed to determine whether or not the AF auxiliary light is to be emitted, and to determine which auxiliary light emitting section is to emit light when the AF auxiliary light is emitted (# 20).

Next, it is determined whether or not to emit the AF auxiliary light with reference to the flag indicating whether or not to emit the AF auxiliary light which is set or canceled in step # 20 (# 2).
5) If it is to be emitted, emission of AF auxiliary light from the auxiliary light emitting unit determined in the process of step # 20 is started (# 3).
0). Then, integration of the CCD sensor 13a, that is, photoelectric conversion is performed for a predetermined time (# 35). After photoelectric conversion, AF
It is determined whether or not the auxiliary light is being emitted (# 40). If the auxiliary light is being emitted, the operation is stopped (# 45).

Thereafter, the charge accumulated by the photoelectric conversion, that is, the data representing the image on the CCD sensor is transferred to the AFCPU 16 (# 50), and a predetermined correlation operation for detecting the focus state is performed (# 55). Then, the defocus amount is calculated (# 60). Then, the drive of the focus lens is controlled based on the calculation result (# 65), and the process returns to step # 5 to repeat a series of processes.

The correlation calculation in step # 55 is a process of finding corresponding portions of two images on the CCD sensor, and is performed by a well-known phase difference detection method. Step # 65
When the focus state, that is, the shift can be detected, the lens drive control is an adjustment process for focusing on driving the focus lens so that the detected shift amount becomes small, and the focus state can be detected. If not, a low contrast scan is performed.

A series of processes of steps # 5 to # 65 are repeated as many times as long as the shutter release button is half-pressed and the first signal is given. Therefore, the detection of the focus state and the drive control of the focus lens are repeated at a substantially constant cycle. The determination as to whether or not to emit AF auxiliary light is made every time the focus state is detected.
Whether or not to use the F auxiliary light is appropriately switched. In the first detection, no AF auxiliary light is emitted.

FIG. 16 shows the flow of the AF auxiliary light emission determination process performed in step # 20. First, the flag indicating that the AF auxiliary light is emitted is released (step # 10).
5). Next, it is determined whether or not the emission of the AF auxiliary light is prohibited (# 110). When the light emission is prohibited, the process returns to step # 25 in FIG. 15 without performing any processing.

When the emission of the AF auxiliary light is not prohibited, the focus state can be detected without using the AF auxiliary light from the previous attempt to detect the focus state without using the AF auxiliary light. It is determined whether or not there is (# 115). If possible, the flag indicating that the emission of the AF auxiliary light is prohibited is set to “prohibited” (# 120), and the process returns to step # 25.

If the focus state cannot be detected without using the AF auxiliary light, it is determined whether or not the macro flash device 40 including the auxiliary light emitting section 42 is mounted (# 125). If this is the case, the auxiliary light emitting section is used with priority. If not, the process proceeds to a determination process as to whether or not to emit an auxiliary light emitting unit built in the camera body or another flash device (# 130).

When the macro flash device having the built-in auxiliary light emitting section is mounted, it is determined whether or not the focus lens is stopped (# 135). If it is stopped, a flag indicating the type of AF auxiliary light, that is, which auxiliary light emitting unit is to be emitted, is set to a built-in one in the macro flash device, and a flag indicating that the AF auxiliary light is emitted is set to “light emission”. (# 140). Then, the process returns to step # 25.

If the focus lens is not stopped,
That is, if the drive is being performed, it is determined whether or not the drive is a low contrast scan drive by referring to the flag (# 145). If the low-contrast scan is being driven, the process proceeds to a process of determining whether or not to emit the AF auxiliary light during the drive (# 150). If the drive is not a low-contrast scan drive, the drive is a normal drive for focusing the photographing lens. In this case, the process proceeds to a process of determining whether or not to emit the AF auxiliary light during the drive (# 15).
5).

According to the processing of steps # 115, # 125, and # 140, when the AF auxiliary light is necessary for detecting the focus state, and the macro flash device with the built-in auxiliary light emitting unit is mounted, the initial position of the low contrast scan is determined. While the focus lens is stopped at the near end and the infinite end, the AF auxiliary light is emitted from the auxiliary light emitting unit.

FIG. 17 shows the flow of the process of determining the general auxiliary light emission performed in step # 130. First, it is determined whether or not the focus lens is stopped (step # 20).
5) If not stopped, the process returns to step # 25 in FIG. Therefore, unless the macro flash device having the built-in auxiliary light emitting section is mounted, the AF auxiliary light is not emitted while the focus lens is being driven.

If the focus lens is stopped, AF
The flag indicating that the auxiliary light is emitted is set to “light emission” (# 210). Then, it is determined whether the brightness of the subject detected by the photometry module 18 or the output value of the CCD sensor 13a corresponding to the brightness is a predetermined brightness value (BV value), for example, 1 or more (# 215). It is determined whether or not a normal flash device with a built-in auxiliary light emitting unit is mounted (# 220). If the brightness of the subject is less than a predetermined brightness value and the normal flash device is mounted, Then, an auxiliary light emitting unit built in the flash device is set as an auxiliary light emitting unit to emit light (# 225), and in other cases, an auxiliary light emitting unit 21 built in the camera body is set as an auxiliary light emitting unit to emit light (# 230). After the setting, the process returns to step # 25.

FIG. 1 shows the flow of the light emission determination processing during the low contrast scan driving performed in step # 150 of FIG.
8 and FIG. FIG. 18 shows the processing used in the first mode. A built-in auxiliary flash unit that emits light is set in the macro flash device, a flag indicating that the AF auxiliary light is emitted is set to “light emission” (step # 305), and the process returns to step # 25 in FIG. Here, by setting the flag unconditionally, the first
In this mode, AF auxiliary light is emitted from the time when the driving of the focus lens is started.

FIG. 19 shows the processing used in the second mode and the third mode. First, it is determined whether the driving speed of the focus lens is low (step # 35).
5). If the drive speed is not low, no processing is performed. If the drive speed is low, a built-in auxiliary flash unit that emits light is set in the macro flash device, and the flag indicating that the AF auxiliary light is emitted is set to “light emission”. Set (Step # 3
60), and return to step # 25 in FIG.

Here, no processing is performed, so that the second
Before the speed change in the mode, and during driving in the near end direction in the third mode, the AF auxiliary light is not emitted, and the speed in the second mode is set by the setting in step # 360. After the switching, and at the time of driving in the infinite end direction in the third mode, AF auxiliary light is emitted.

FIG. 20 shows the flow of the process for determining the light emission during the normal driving performed in step # 155 of FIG. First, the remaining drive amount of the focus lens necessary for focusing the photographing lens is obtained (step # 405). The remaining drive amount is calculated from the calculated drive amount, that is, the value directly calculated from the defocus amount calculated in step # 60 of FIG. 15, and is the measured drive amount, that is, the actually measured value of the amount driven until the process is performed after photoelectric conversion. Is determined by subtracting The measurement of the drive amount is performed based on the output of the AF encoder 15.

Next, it is determined whether or not the remaining drive amount is equal to or less than a predetermined value A (# 410). The remaining drive amount is the predetermined value A
No processing is performed when the value exceeds the predetermined value A, and when the value is equal to or less than the predetermined value A, a built-in auxiliary flash unit that emits light is set in the macro flash device, and a flag indicating that the AF auxiliary light is emitted is set to “emit (Step # 41)
5) Return to step # 25 in FIG.

By this processing, when the focus lens is driven for focusing after the focus state is detected using the AF auxiliary light from the auxiliary light emitting section built in the macro flash device, the photographic lens is adjusted to a certain degree. The emission of the AF auxiliary light is restarted only when the focus is approached.

FIG. 21 shows the flow of the lens drive control process performed in step # 65 of FIG. First, step # 6
It is determined whether the focus state of 0 has been detected (step # 505). When detection was possible,
The flag indicating that low-contrast scanning is being performed is released, and the flag indicating that low-contrast scanning is prohibited is set to “prohibited” (# 510).
Then, the drive amount of the focus lens is calculated and calculated based on the shift amount calculated in step # 60, the position of the focus lens at that time, and the position of the focus lens at an intermediate time of the integration period of the CCD sensor. The focus lens is driven according to the driving amount (# 515),
It returns to step # 5 of FIG.

If the focus state cannot be detected in step # 505, it is determined whether low-contrast scan is prohibited (# 520). If the low-contrast scan is prohibited, the focus lens is not driven without driving. Step #
Return to 5. Step # 5 is set to prohibit scanning
10 and at the time of completion of scanning (to be described later) (# 575).
Once the focus detection is enabled or after the scan is completed, the low contrast scan is not performed.

If it is determined in step # 520 that the scanning has not been prohibited, it is determined whether low-contrast scanning has already been started (# 525). If not, the focus lens is moved toward the near end. Is started, and when the focus lens reaches the near end, a timer interrupt for stopping the lens drive is started (# 535). Then, a flag indicating that a low contrast scan is being performed is set (# 54).
0), and return to step # 5 in FIG. If the second mode is selected, prior to the start of driving in step # 535, an interrupt process for switching the driving speed to a low speed during driving is activated (# 530).

FIGS. 22 and 23 show the flow of interrupt processing for speed switching. FIG. 22 shows a process of switching the driving speed from high speed to low speed when the focus lens is driven by a predetermined amount after the start of the low contrast scan. The driving amount of the focus lens from the start of driving is measured based on the output of the AF encoder, and it is determined whether or not the measured driving amount is equal to or greater than a predetermined value B (step # 605).
If the measured drive amount is less than the predetermined value B, no processing is performed, and if the measured drive amount is equal to or more than the predetermined value B, the drive speed is switched to a low speed (# 6).
10).

FIG. 23 shows a process for switching the driving speed from a high speed to a low speed when the focus lens approaches a near end or an infinite end to a predetermined distance. The distance between the position of the focus lens at that time and the near end or infinity end is calculated, and it is determined whether or not the calculated distance is equal to or smaller than a predetermined value C (step # 655). If the calculated distance exceeds the predetermined value C, no processing is performed, and if the calculated distance is equal to or less than the predetermined value C, the driving speed is switched to a low speed (# 660).

FIG. 24 shows the flow of a timer interrupt process for stopping the drive upon detecting that the focus lens has reached the end. Whether or not the position of the focus lens has changed is detected based on the output of the AF encoder (step # 705). If the lens position has not changed, it is determined that the focus lens has reached the near end or the infinity end. , A
The lens driving by the F actuator 14 is stopped (#
710). If the lens position has changed, no processing is performed.

This process is necessary for the cameras 1, 3, and 4 of the first, third, and fourth embodiments that drive the focus lens from the camera body. In the camera 2 according to the second embodiment, in which the taking lens itself drives the focus lens, the lens CPU 34 stops driving based on the outputs of the end switches 35a and 35b, which is unnecessary.

Returning to FIG. 21, description of the lens drive control process will be continued. If the low-contrast scan has already been started in the determination in step # 525, it is determined whether or not the focus lens has stopped (# 545). If not, the process returns to step # 5 in FIG. Thus, the ongoing low contrast scan is continued.

If the focus lens has stopped, it is determined whether or not focus detection has been performed in the stopped state (# 550). If focus detection has not been performed, step # 5 is performed.
Return to As a result, the focus lens is kept at the stop position, that is, at the near end or the infinite end, and steps # 25 to # 6 are performed.
At 0, the focus detection at the stop position is attempted.

If the focus detection is being performed in the stopped state, it is determined whether or not the focus lens is located at the near end (# 555). When the focus lens is located at the near end, the low-contrast scan is not completed and the focus detection remains impossible. As in the case of driving to the end side, it detects that the focus lens has reached the infinite end, and activates a timer interrupt of FIG. 24 for stopping lens driving (# 565). Then, the process returns to step # 5.

When the second mode is selected, prior to the start of driving in step # 565, FIG. 22 or FIG. 23 for switching the driving speed to a low speed during driving.
Is started (# 560). If the third mode has been selected, step # 56
The drive speed of the focus lens started at 5 is set to a low speed.

If it is determined in step # 555 that the focus lens is not located at the near end, the focus lens is located at the infinite end. In addition, focus detection at the infinite end was not performed, and the low-contrast scan was unsuccessful. At this time, the focus lens is moved to a predetermined position where the focus state can be detected in a wide distance range (# 570). This predetermined position is determined according to the focal length of the taking lens. Thereafter, the flag indicating that low-contrast scanning is being performed is released, the flag indicating that low-contrast scanning is prohibited is set to “prohibited” (# 575), and the process returns to step # 5.

By the above control, the camera 1 of each embodiment
4 can surely detect the focus state of the taking lens with respect to the subject by low-contrast scanning even during macro shooting. Moreover, the focus of the photographing lens can be adjusted to the subject immediately after the focus state can be detected.

Although the present invention has been described by taking a camera for exposing a photographic film as an example, the present invention can be applied to a digital camera or a video camera that converts light into a digital signal or a video signal and records the converted signal. it can.

[0105]

According to the present invention, a low-contrast scan is performed when the focus state cannot be detected, and an AF auxiliary light is emitted from an auxiliary light-emitting device incorporated in a macro flash device during the low-contrast scan. By doing so, it is possible to reliably capture the subject within the distance range where the focus state can be detected during scanning,
Automatic adjustment of the focus of the taking lens can be easily performed even in macro shooting.

In particular, when the driving speed of the focus lens in the low-contrast scan is switched to a low speed halfway, and the AF auxiliary light is emitted for the first time after the switching, the light emission interval of the AF auxiliary light is kept substantially constant. It is possible to capture the subject within a distance range in which the focus state can be detected, and the control process for detecting the focus state becomes extremely easy. In addition, the flow of the image on the detection sensor can be reduced, and the detection of the focus state can be more easily and reliably performed.

In the present invention, when the focus state can be detected, the focus state is detected and the driving of the focus lens based on the detection result is repeated to gradually bring the photographing lens closer to the in-focus state. , The focus lens can be driven more appropriately, and the focus can be adjusted quickly.

In particular, when the focus state is detected, the drive amount of the focus lens required to bring the photographing lens into focus is calculated, and the auxiliary light is emitted from the auxiliary light emitting device only after the calculated drive amount becomes a predetermined value or less. AF
The auxiliary light can be used without waste.

If the macro flash device can be attached to and detached from the photographing lens, the macro flash device can be mounted only at the time of macro photographing, so that it does not hinder normal photographing, and the photographing lens becomes larger and heavier. can avoid.
In addition, the macro flash device can be shared by a plurality of photographing lenses.

According to the present invention, the A light from the auxiliary light emitting device built in the macro flash device detachable from the photographing lens can be used.
When both the F auxiliary light and the AF auxiliary light of the auxiliary light emitting device built in or attached to the camera body can be used, when the macro flash device is mounted, the AF auxiliary light of the auxiliary light emitting device built in the macro flash device is used. With the priority use, even during macro shooting, the AF auxiliary light is not emitted, and the focus state can be reliably detected.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a schematic configuration of a camera according to a first embodiment.

FIG. 2 is a perspective view showing the appearance of the camera.

FIG. 3 is a perspective view showing the appearance of a taking lens detached from a camera body of the camera.

FIG. 4 is a perspective view showing the appearance of a macro flash device in a state where the macro flash device is detached from a photographing lens of the camera.

FIG. 5 is a diagram schematically illustrating a schematic configuration of a camera according to a second embodiment.

FIG. 6 is a diagram schematically illustrating a schematic configuration of a camera according to a third embodiment.

FIG. 7 is a diagram schematically illustrating a schematic configuration of a camera according to a fourth embodiment.

FIG. 8 is a diagram illustrating a relationship between driving of a focus lens toward focusing of a camera and detection of a focus state in each embodiment.

FIG. 9 is a diagram illustrating a relationship between driving of a focus lens and detection of a focus state in a first mode of a low contrast scan of the camera of each embodiment.

FIG. 10 is another diagram illustrating a relationship between driving of a focus lens and detection of a focus state in a first mode of a low contrast scan of the camera of each embodiment.

FIG. 11 is a diagram illustrating a relationship between processing of driving a focus lens and detection of a focus state in a second mode of a low contrast scan of the camera of each embodiment.

FIG. 12 is another diagram showing the relationship between driving of the focus lens and detection of the focus state in the second mode of the low contrast scan of the camera of each embodiment.

FIG. 13 is a diagram showing a relationship between driving of a focus lens and detection of a focus state in a third mode of a low contrast scan of the camera of each embodiment.

FIG. 14 is another diagram showing the relationship between the driving of the focus lens and the process of detecting the focus state in the third mode of the low contrast scan of the camera of each embodiment.

FIG. 15 is a flowchart showing a schematic flow of the entire processing of the focus adjustment operation of the camera of each embodiment.

FIG. 16 is a flowchart illustrating a flow of a process of determining emission of AF auxiliary light of the camera according to each embodiment.

FIG. 17 is a flowchart showing the flow of processing for determining the emission of general AF auxiliary light of the camera of each embodiment.

FIG. 18 is a flowchart illustrating a flow of a process of determining emission of AF auxiliary light during low contrast scanning of the camera according to each embodiment.

FIG. 19 is a flowchart showing the flow of another process of determining the emission of AF auxiliary light during low contrast scanning by the camera of each embodiment.

FIG. 20 is a flowchart illustrating a flow of a process of determining emission of AF auxiliary light during normal driving of the camera according to each embodiment.

FIG. 21 is a flowchart illustrating a flow of processing of drive control of a focus lens of the camera according to each embodiment.

FIG. 22 is a flowchart illustrating a flow of an interrupt process for switching a driving speed of a focus lens during a low contrast scan of the camera of each embodiment.

FIG. 23 is a flowchart showing another interrupt processing flow for switching the driving speed of the focus lens during the low contrast scan of the camera of each embodiment.

FIG. 24 is a flowchart showing the flow of a timer interrupt process for stopping the drive by detecting that the focus lens of the camera according to each embodiment has reached the end.

FIG. 25 is a diagram schematically showing a schematic configuration of a conventional camera.

FIG. 26 is a view schematically showing a schematic configuration of another conventional camera.

FIG. 27 is a view showing a relationship between driving of a focus lens and detection of a focus state in a low contrast scan of a conventional camera.

FIG. 28 is another diagram showing a relationship between processing of driving a focus lens and detection of a focus state in a low contrast scan of a conventional camera.

FIG. 29 is a diagram showing a relationship between a conventional process of driving a focus lens toward focusing of a camera and detection of a focus state.

[Explanation of symbols]

 1, 2, 3, 4 Auto focus camera 9 Photo film 10 Camera body 11 Main mirror 12 Sub mirror 13 AF sensor module 13a CCD sensor 14 AF actuator 15 AF encoder 16 AFCPU 17 Camera CPU 18 Photometry module 19 Light control module 21 Auxiliary light emitting unit Reference Signs List 22 AF display unit 23 Communication unit 30 Shooting lens 31 Focus lens 32 Lens ROM 33 Lens drive system 34 Lens CPU 35a, 35b Termination switch 37 Terminal 38 Engagement hole 39 Terminal 40 Macro flash device 41 Flash unit 42 Auxiliary light emitting unit 43 Light emission control Unit 44 flash CPU 45 communication unit 46 power supply 47 release button 48 engagement claw 49 terminal

Claims (6)

[Claims] 1. An auto-focus camera for detecting a focus state of a photographing lens by a phase difference detection method, comprising a macro flash device for illuminating a subject at a short distance, and an auxiliary for assisting detection of a focus state. In a device in which an auxiliary light emitting device that emits light is built in the macro flash device, the focus state is determined in order to find the position of the focus adjustment lens of the photographing lens that allows the focus state to be detected when the focus state cannot be detected. An autofocus camera, wherein the focus adjusting lens is driven while trying to detect the auxiliary light, and auxiliary light is emitted from the auxiliary light emitting device during the driving. 2. The method according to claim 1, further comprising: switching a driving speed when driving the focusing lens while trying to detect a focus state to a low speed after a predetermined amount of driving or after the focusing lens reaches a predetermined position; The autofocus camera according to claim 1, wherein the auxiliary light is emitted from the auxiliary light emitting device only after the switching. 3. An auto-focus camera for detecting a focus state of a photographing lens by a phase difference detection method, comprising a macro flash device for illuminating a subject at a short distance, and an auxiliary for assisting detection of a focus state. In a device in which an auxiliary light emitting device that emits light is built in the macro flash device, after detecting a focus state, the focus adjustment lens of the photographing lens is driven while detecting the focus state to bring the photographing lens into focus. And an auxiliary light emitted from the auxiliary light emitting device during the driving thereof. 4. A drive amount of the focus adjustment lens required for focusing the photographing lens when a focus state is detected, and the auxiliary light emission is performed only after the calculated drive amount becomes a predetermined value or less. The autofocus camera according to claim 3, wherein the device emits auxiliary light. 5. The autofocus camera according to claim 1, wherein the macro flash device is detachable from the photographing lens. 6. An auto-focus camera for detecting a focus state of a photographic lens by a phase difference detection method, wherein the first auxiliary light-emitting device for emitting auxiliary light for assisting the focus state detection is provided. A macro flash device for illuminating a subject can be mounted on the taking lens, and a second auxiliary light emitting device that emits auxiliary light for assisting detection of a focus state can be built in or mounted on the camera body. An auto-focus camera, wherein when the macro flash device is mounted, the first auxiliary light emitting device emits auxiliary light prior to the second auxiliary light emitting device.