JP2590873B2 - Camera with focus detection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera provided with a focus detection device.

Conventional technology and its problems For example, in continuous shooting of a moving subject such as a sports photograph, in an AF-priority camera that cannot release a shutter until automatic focus adjustment (hereinafter referred to as AF) is completed, If the subject is out of focus, the release cannot be performed. Therefore, if the subject is slightly out of the frame, the photographing cannot be performed. However, in the continuous shooting mode, the shooting cycle is short, for example, 3 frames per second, 300 m per frame
It is about sec. Even if the subject moves fast in the horizontal direction, it may move out of the focus detection area during this 300 msec, but rarely moves out of the shooting area. Therefore, it is irrational that the shutter cannot be released even though the subject to be photographed can be captured. However, the conventional AF-priority camera has a drawback in that the shutter cannot be released in spite of the situation where shooting is possible as described above because the camera cannot be released when there is a focus shift.

Accordingly, the present invention provides a camera of the AF priority mode type or a camera in which the shooting mode is set to the AF priority mode, and which can perform a shutter release even when the focus cannot be detected or the defocus amount is large in the continuous shooting mode. It is the purpose.

Means for Solving the Problems In order to achieve the above object, a camera provided with a focus detection device according to the present invention calculates a focus position and focuses on a lens according to the calculation result. Means for setting to a focal position; control means for continuously performing a shooting operation and an automatic focus adjustment operation repeatedly at a predetermined cycle while the release button is continuously pressed; and The result of the focus detection calculation by the focus detection means when the camera is set to the continuous shooting mode when the camera is provided with automatic focus priority control means for controlling not to enter the release operation unless focusing is completed. An in-focus detection means for detecting whether focus detection is impossible and a defocus amount larger than a predetermined value, and a memory for storing information indicating that focusing was performed at the time of the previous release. The focus detection is not possible or the defocus amount is larger than a predetermined value by the in-focus detection means at the time of the current photographing, and the focus is determined at the time of the previous release. Means for permitting release without performing lens adjustment in the event that there is.

According to the configuration described above, even in the continuous shooting mode even when the camera is in the AF priority mode, the shutter can be released even if focusing is not completed. Therefore, when several subjects continuously enter the shooting frame, it is possible to take a picture even if the subject on the rear side is slightly in focus, and obtain a photograph as intended by the photographer. We can provide a camera that can do it.

Embodiment FIG. 28 is a graph for explaining the principle of the present invention,
The meaning of the vertical and horizontal axes is the same as in FIG. If it is determined that the tracking delay has occurred with respect to the subject based on the defocus amounts D ₅ and D ₆ at the time point P ₁ while the lens is stopped, the tracking is performed at the time point P ₁ by the calculation C ₆ at the time of the integration I _6. Correction is applied and the lens is Q ₁
Then, without stopping, move the lens further by the amount of correction WR to Q ₁
Bring it up. This correction amount WR will be described later,
The amount of movement when the subject moves in the direction of the optical axis of the photographing lens of the camera is taken as the amount of defocus on the film surface of the camera. This movement amount is obtained by converting it into a tilt per unit period TI of focus detection. In the case of FIG. 29, the next lens drive time is considered to be TI, and it is considered that it will catch up at the latest after time TI. If the time is longer than the correction amount WR at this time TI, the subject will need to drive the lens for a certain amount of time. You can say that you are catching up with the subject by coming. In this model, the movement of the subject is assumed to be a linear function based on the defocus amount on the film surface. However, in practice, for example, when the subject approaches the camera at a constant speed, the defocus amount Does not become a linear function but a higher-order function. In this case as well, even if the tracking correction is performed, the correction amount is insufficient. Note that this
Target correction position in the case of FIG. 28 is a middle point P ₃ of the integral I _8.

Since the middle point P ₀ of the integrating I ₆ to the end P ₁ of the operation C ₆ does not move the lens, tracking delay of the object is also occur during this time. It is necessary to consider the delay and the delay during the next driving of the lens (in this period, one cycle of integration and calculation is included). In other words, in the lens stop, when the follow delay is moving subject occurs, the correction through the integration I ₇ from the integration I ₆ in anticipation of movement of the object to the midpoint of the integration I ₈ at the P ₁ You need to call. That is, in this case, P ₁
You just have to add 2WR correction.

Because the midpoint of the integration I ₈ of this goal, as viewed from P _1, having substantially the same meaning as that of the point P ₂ the result of the next integration I ₇ comes out to target. Because the integration time is short here, it is assumed that P ₂ ≒ P ₃ . Here, while the calculation takes 50 msec, the integration is several msec or less.

FIG. 29, at P ₄ in the lens drive, showing a case where it is determined that the follow delay with respect to the subject based on the defocus amount of D ₃ and D ₄ occurs. In addition, the state in which the lens is driven while the tracking correction is continuously applied while tracking the subject in the tracking mode including the case where it is determined to enter the tracking mode while stopped is shown. . When the correction enters the tracking mode when P ₄ such drives the defocus amount by lens which is calculated based on data obtained by integrating I _3, without stopping the lens in Q ₁ be finished driving, further 2W
Move R minutes. Similar to FIG. 28, the correction target point is the midpoint of the integration I ₇ beside the P ₆ in which the result of calculation based on the data of the next integration I ₆ is obtained. This corresponds exactly to two cycles of the focus detection calculation from the midpoint of the detection integrated I ₄ made followers delay. This is to attempt to correct and drive a total of two cycles including one cycle taken until the present detection result is obtained within one cycle time when the next result is obtained.
In the following, the same operation is repeated, but if the lens drive cannot catch up, that is, if the drive count value to which the correction value is added during the follow-up mode is larger than the predetermined count value, the lens drive speed is switched. . In the figure, it is switched at the Q _2. Even if the drive speed is switched, the correction value and the target value are considered to be the same. If the driving direction is reversed according to the calculation result after catching up on the way, the tracking correction is not performed.

Next, a method of calculating the inclination per unit period TI of focus detection with respect to the movement of the subject in the camera optical axis direction will be described with reference to FIG.

In the figure, the unit focus detection cycle is defined as S _{1 to} S ₂ , S
₃ to S ₄ or T ₁ through T _3, a T ₁ '~T _3' and the like. These are continuous, and each time is regarded as the same, assuming that the same subject is viewed. A current position and calculating C _3.
The defocus amount obtained by the previous integration is LERR. Incidentally, this is the obtained is a time of T _3. The defocus amount obtained by this integration is defined as ERR. This is obtained at T ₃ ′.

The defocus amount corresponding to the moving amount of the subject per unit period, that is, the inclination WR, is obtained from the drawing as WR = ERR + ITI-LERR. Here, ITI is a lens movement amount from the previous integration to the current integration. The relative positions of the previous integration center of the lens is obtained as 1/2 of the sum of the relative positions of the integration start time T ₁ and the end time T ₂ of the lens. T ₁ and T ₂ are values obtained by converting the defocus amount LERR ′ at the time of S ₁ into a lens drive count number in the operation C ₁ and setting the value in the event counter. On the other hand, a focusing encoder is set on the lens, and when the lens moves, a pulse is output from the encoder. This signal is connected to the input of the event counter, and the event counter counts down each time a pulse comes. Therefore,
The amount of movement of the lens can be determined by reading the value of the event counter. These values are T ₁ and T ₂ . Therefore, (T ₁ + T ₂ ) / 2
= MIL finds the previous center.

Next, a case where the shutter is released during the AF operation in the following mode will be described with reference to FIG. In the present invention, the lens is driven even during the release time lag in order to improve the followability. That is, the lens is driven until the release signal is input and the exposure operation is started, for example, while the reflex mirror of the single-lens reflex camera is raised.
However, since the mirror is raised during this time, focus detection (integration and calculation) cannot be performed by the focus detection method of detecting focus by receiving light passing through the mirror. Therefore, the amount WS by which the subject moves while the mirror is moving up is calculated in advance. Assuming that the release time lag time is RTS, from the subject movement WR per unit focus detection time TI, WS = WR ×
RTS / TI. By using this WS as a tracking correction amount, the lens is moved and stopped before the exposure operation. Then, after the exposure of the film, the lowering of the mirror starts, and at the same time, the automatic winding of the film and the winding operation of shutter cocking are started. (It is not always necessary to perform automatic winding.) At this time, the camera is in the release priority mode in which the shutter release is prioritized over reaching the in-focus state, and before the camera is focused. Assume that the shutter has been released. The result of shooting is naturally blurred, but if the camera is in continuous shooting mode in which continuous shooting is performed, the second and subsequent photos should be in focus as much as possible. Therefore, during the lowering of the mirror (during this time, integration and calculation cannot be resumed until the mirror is stabilized at the lowering position). . In the figure, the lens is stopped when integration is restarted, but there is no problem if integration is performed while moving.

FIG. 1 is a block diagram of a camera control circuit used in an embodiment of the present invention. (1) a microcomputer (hereinafter referred to as a microcomputer) for controlling and calculating the sequence of a camera, and (2) opening and closing a shutter according to an exposure start / end signal from the microcomputer (1), and a mirror-up signal. Exposure control circuit for performing mirror-up and aperture control according to (1), (3) digitizes a signal corresponding to the luminance of the subject by a photometric circuit, and sends it to the microcomputer (1).
(4) is a film sensitivity automatic reading circuit which digitizes film sensitivity information and sends it to the microcomputer (1).
(5) is a one-frame winding circuit which drives the motor in response to a signal from the microcomputer (1) to wind the film by one frame, and stops driving the motor by turning on the one-frame winding detection switch (S9). (6) is a setting circuit for setting the aperture value and shutter speed, and (7) is ON / OF of the switch (S1).
A pulse generating circuit that generates one pulse in conjunction with F. (8) is an interface circuit provided between the CCD (9) used for focus detection and the microcomputer (1).
In accordance with a signal from the microcomputer (1), control such as start and end of charge accumulation of the CCD (9) and A / D conversion of data of the CCD (9) and output to the microcomputer (1) are performed.

(10) a motor control circuit for controlling a motor (M) for driving a focus adjustment optical system of a photographic lens (not shown) for focus adjustment based on a signal from the microcomputer (1);
(11) is an encoder that monitors the rotation of the motor (M), and generates 16 pulses each time the motor (M) makes one rotation. (12) is a lens circuit provided in the taking lens, and sends data unique to each lens to the microcomputer (1). (13) is an auxiliary light emitting device used at the time of focus detection. (14) is a display circuit for displaying a focus detection state, and (15) is a timer for generating a release signal at regular intervals in a continuous shooting mode in which shooting is continuously repeated. (E) is a power supply battery, which is a microcomputer (1), a switch described later, a reset resistor (RR), and a capacitor (C).
R) and the power supply transistor (Tr ₁ ). Power supply transistor (Tr ₁ ) for other circuits
Is supplied with the voltage of the battery.

Next, the switch will be described. (S1) is turned on by the first stroke of pressing a release button (not shown), and the microcomputer (1) executes a flow (AFS) described later by turning on the switch (S1) or turning off by releasing the release button. (S2) turns on when the release button is pressed down to the second stroke longer than the first stroke, and this ON causes the microcomputer (1) to execute a release flow described later with reference to FIG. 16 (a). (S3) is a switch that turns on when the mirror is up, and when the release member (not shown) is charged by winding the film by the one-frame winding mechanism, the switch (S3) turns off.
State. (S4) is a so-called one-shot mode in which the focus detection operation is stopped once the photographing lens reaches a focus state, and a so-called continuous mode in which focus detection is continued even once the focus state is reached. Switch to select. (S5) is an exposure mode setting switch, which outputs a 2-bit signal to the microcomputer (1) according to the set mode.
Sent to The exposure control mode of the camera according to the present embodiment includes a program mode (hereinafter referred to as P mode), an aperture priority mode (hereinafter referred to as A mode), a shutter speed priority mode (hereinafter referred to as S mode), and a manual mode (hereinafter referred to as M mode). There are four types.

(S6) is a release priority mode in which the shutter release is prioritized regardless of the focus state, and a focus priority mode in which release is permitted or prohibited depending on the focus state (hereinafter, referred to as "S6").
Switch to switch between AF priority mode) (S7)
Is an end detection switch for detecting that the lens driven at the time of focus detection has been driven to the latest or the farthest or infinity in-focus position. Is executed. (S8) is a changeover switch for switching between continuous shooting mode and one-frame shooting mode, (S9) is turned on when exposure is completed,
This is a one-frame winding detection switch that turns off when one-frame winding is completed.

In the above circuit configuration, when a battery is mounted on the camera, power is supplied to the reset resistor (RR) and the capacitor (CR), and the reset terminal (RE) of the microcomputer (1) is supplied.
A signal that changes from the “Low” level to the “High” level is input to the microcomputer (1).
SET). The microcomputer (1) first resets the flag and the output port to an initial state (# 5, # 10).
Next, turn off the auxiliary light emitting device (13), turn off the display,
The driving of the lens is stopped, when the film winding has not been completed by driving the motor, hoisting is turned OFF if completed transistor for feeding _{(Tr 1) (# 15~ #} 30). Then, the auxiliary light flag (auxiliary light F) for the auxiliary light emission is reset, the terminal (OP3) is set to "Low" level, and the microcomputer (1) stops (# 35, # 40). Step # 1 above
Steps 5 to # 40 are mainly effective when shifting from step # 55 described later.

When the release button is pushed down to the first stroke with the battery mounted, the switch (S1) is turned on, and the microcomputer (1) executes the flow from AFS in FIG. The microcomputer (1) first resets all the flags and turns on the power supply transistor (Tr ₁ ). As a result, power is supplied to each circuit, and at the same time, the photometric circuit (3) starts photometry. The microcomputer (1) determines whether or not the switch (S1) is ON. If the switch (S1) is OFF, the process proceeds to step # 15 to perform the above-described processing. If the switch (S1) is ON, the next focus detection and subsequent processing are performed. Execute the flow (# 55). When the switch (S1) is ON, it is determined whether or not the auxiliary light flag (auxiliary light F) is set. Proceeding to step # 70, if the auxiliary light flag is not set, skip step # 65 and proceed to step # 70 (# 60, # 65).

Next, the microcomputer (1) reads the time (TI) taken from the start of the integration at the time of the previous integration to the start of the current integration by the timer (TI), and then resets the timer (TI) to start. And start the integration (# 70 to #
78). In order to detect the relative position of the lens at this time, a value (CT1) of a counter (hereinafter, referred to as an event counter) indicating an amount to drive the lens until an in-focus state is read (# 8)
0). Next, a flag (long product F) indicating whether or not the mode is a long integration time mode is determined. If the flag is set, wait for 80 msec to elapse. Then, the auxiliary light emitting device (13) is turned off, and the process proceeds to step # 110 (# 85 to # 95). If the flag (long product F) is not set, the process proceeds to step # 110 when 20 msec has elapsed even when integration is completed or when integration is not completed (# 100, # 105). The integration is terminated when the amount of light incident on the light receiving element of the integration time control monitor provided near the CCD (9) becomes equal to or greater than a predetermined value. Is omitted.

In step # 110, the value of the event counter is read as (CT2) in order to know the relative position of the lens at the end of the integration. Further, the microcomputer (1) dumps the CCD data, and performs a focus detection calculation using the data (# 120, # 125). Next, with the value (MI) indicating the relative position of the lens at the previous integration center as MIL, the lens relative position at the start of integration (CT1) and the lens at the end of integration are determined to obtain the relative position of the lens at the current integration center. Divide the sum with the relative position (CT2) by 2 and set this value as MI (# 13
0, # 135). Next, an attempt is made to find the amount by which the lens has been driven between the previous integration center and the current integration center.
Not determined by L-MI.

The reason will be described with reference to the graph of FIG. In this graph, the horizontal axis represents time, and the vertical axis represents the movement amount of the movement (a) of the subject image and the movement (b) of the lens on the film surface. In this case, integration and calculation are performed while driving the lens. T ₁ , T ₁ ′, T ₁ ″ indicate the integration start time, T ₂ , T ₂ ′, T ₂ ″ indicate the integration end time, and T ₃ , T ₃ ′, T ₃ ″ indicate the calculation end time. , T ₁ ′ = T ₃ ″ and T ₁ = T ₃ ′. The reason for this is that the time required for focus detection is mostly spent on the above-described integration, data dump, and focus detection calculation (# 60 to # 125). As the MIL indicating the relative lens position at the center of the previous integration I ′, the value obtained by adding the value of the event counter indicating the lens position at the integration start time T ₁ ′ and the integration end time T ₂ ′ and dividing by 2 is entered. deep. End of operation C "
In the event counter of T ₁ ′, as a result of the operation C ″,
A value obtained by converting the defocus amount from the subject position RE1 into the number of movements of the encoder is input. This subject position RE1
Is a position indicating the amount of defocus from the image plane at the center of the integration I ″.

Next, MI indicating the relative position of the lens at the center of the current integration I includes the subject position RE
Enter the value obtained by converting the defocus amount from 2 to the number of encoder movements. Therefore, MIL, which indicates the relative position of the lens,
The MI has different scale values between the scale with the previous result as the origin and the scale with the current result as the origin. Even if this is simply MIL-MI, an accurate movement amount of the lens is not calculated. If the scales are not aligned, an accurate lens movement amount cannot be obtained.

Therefore, this correction amount is defined as DT. This value DT is a value of the event counter from the object position RE1 showing a lens position of the operation C 'end T _3' (CT3), and converts the operation result value DF2 'at this time the movement speed of the encoder value (LER
R). That is, DT = LER
Obtained by R-CT3. Then, the amount of lens movement (IT
I) can be obtained by subtracting the above DT from the relative position MI of the lens at the integration center this time and subtracting it from the MIL.
That is, it is obtained by ITI = MIL- (MI-DT). Microcomputer (1)
Then, this is performed in steps # 140 and # 145 of FIG.

Next, the microcomputer (1) inputs, from the lens circuit (12), data of the open aperture value Av ₀ and a coefficient value (hereinafter referred to as KL value) for converting the defocus amount into the number of pulses of the encoder. Data is read from the ROM of the lens circuit (12). First, the chip select terminal (CS) is set to the “High” level to output a signal indicating the start of data communication, and the variable N indicating the number of read data is set to 0, and a serial communication instruction is performed (# 155, # 160). According to this instruction, a clock is output from the terminal (SCK) of the microcomputer (1), and data is output from the lens circuit (12) bit by bit in synchronization with the rise of the clock. Then, in synchronization with the falling of this clock, the microcomputer (1) connects the terminal (SI
N), the data is read out and eight pulses are output, thereby completing one serial communication. This is performed twice, and the above two types of data are input from the lens circuit (12) (# 165, # 170). When the two types of data have been input, the terminal (CS) is set to the "Low" level to notify the lens circuit (12) of the end of the serial communication (# 175). Next, the process proceeds to a subroutine for exposure calculation (# 180).

This subroutine will be described with reference to FIG. First, the microcomputer (1) inputs the open metering value Bv ₀ from the measuring circuit (3) and the film sensitivity data Sv from the automatic film sensitivity reading circuit (4) (# 2000, # 2005). These data and the aperture value entered as described above
The exposure value Ev is calculated from Av ₀ (# 2010). Next, the exposure control mode is determined.
The aperture value Av is determined by halving Ev, and the aperture value Av is subtracted from the exposure value Ev to determine the shutter speed value Tv and return (# 2015 to # 2025). In the case of the A mode, the set aperture value Av is read, the set aperture value Av is subtracted from the exposure value Ev to obtain the shutter speed value Tv, and the process returns (# 2030 to # 20).
40). If the mode is the S mode, the set shutter speed value Tv is read, the set shutter speed value Tv is subtracted from the exposure value Ev to obtain the aperture value Av, and the process returns (# 2045 to # 2055). If it is not any of the above modes, that is, if the mode is the M mode, the set aperture value Av and shutter speed value Tv are read and the process returns (# 2060 to # 2065).

Returning to the flowchart of FIG. 2, if it is determined in step # 185 that the focus cannot be detected, the flow advances to step # 188 to reset the flag MVF. By resetting the flag MVF, shutter release is allowed even if large defocus or focus detection is impossible during continuous shooting. If it is determined in step # 185 that the focus cannot be detected, the process proceeds to step # 186. In step # 186, it is determined whether or not a continuous shooting flag indicating that continuous shooting is being performed is set. When the continuous shooting flag is not set, the flow proceeds to LOWCON to perform low contrast scanning for detecting the contrast of the subject while driving the lens. On the other hand, when the continuous shooting flag indicating that continuous shooting is set is set, a flag (MVF) indicating that the release is permitted and the tracking mode correction is prohibited during release is set without performing the low contrast scan, and CDINT
The flow proceeds to the step (1) to perform focus detection. The reason for this is that, in the present embodiment, in the continuous shooting mode and the AF priority mode, the first photographing is performed only when the subject is in focus before the release or when the subject is in focus during the release, and the subject is focused. Is suitable. If a currently moving subject is being photographed or the camera is slightly moved during continuous shooting, a desired subject may fall out of the range in which focus detection is performed, contrary to the intention of the photographer. Originally, the defocus amount should be relatively small or 0 during continuous shooting because the shooting interval is short, but in such a case, the focus detection of the camera may cause other subjects in the focus detection range to be detected. As a result of focus detection, focus detection may not be possible or large defocus may occur.In AF priority mode, release prohibition must be performed in accordance with this focus detection result, and in accordance with the focus detection result. It is not a good method to drive the lens. When the focus cannot be detected, the lens drive does not update the data of the defocus amount, and is driven according to the data of the result of the previous focus detection. If detectable,
Reset the low-con flag LCF indicating that focus cannot be detected,
Low light (the subject has low brightness below a certain value)
Is determined (# 185 to # 195). If it is not low light, the auxiliary light flag is reset in step # 200. If it is low light, step # 200 is skipped, and the process proceeds to step # 205. Read with a counter. Next, the number of pulses of the encoder is obtained by multiplying the defocus amount Δε obtained in this calculation by the conversion coefficient KL value. If this value is positive, the variable TD indicating the current direction is set to 1, and if this value is negative,
TD is set to 0 (# 205 to # 225).

Next, a subroutine for accuracy checking is entered. In the focus adjustment device used in the present embodiment, in the focus adjustment, an accuracy priority mode in which priority is given to focusing accuracy over time to reach the focusing state, and a speed at which the focusing state is reached than the accuracy is increased. It has a speed priority mode that prioritizes the operation. The speed of the lens control motor relating to this will be described later. In this subroutine, the above two modes are switched according to the type of lens or various conditions at the time of shooting. This can take various forms.

For example, as shown in FIG. 5 (a), in the continuous mode, the focus is often adjusted for a moving subject, so that the speed priority mode is set. In the one-shot mode, the focus is set on the still subject. Since adjustment is often performed, the mode is set to the accuracy priority mode. Alternatively, as shown in FIG. 5 (b), in the A mode, it is considered that it is often desired to accurately focus on a still subject such as a portrait, so the accuracy priority mode is set, and other exposure control is performed. In the mode, the speed priority mode is set. Alternatively, as shown in FIG. 5 (c), when the aperture value (F-number) to be controlled is smaller than 1.7, it is considered that the aperture value is often used for a portrait or the like. The speed priority mode is set in consideration of the fact that the depth of field of the lens is somewhat deeper. This limit F value may be arbitrarily selected as long as it is between F4 and 5.6. Further, as shown in FIG. 5 (d), when the KL value for converting the defocus amount into the number of encoder pulses is large, that is, in a lens in which the change amount of the defocus amount per pulse number is small, it takes time to adjust the focus. And the speed priority mode, and when the KL value is small, the opposite is true.
If the lens driving speed is too fast, accurate focus adjustment cannot be performed, and the mode is set to the precision priority mode. In the latter case, even in the accuracy priority mode, the focus is achieved with a small number of pulses.
The time required for focusing is relatively short.

In this embodiment, the flow is as shown in FIG. 5 (e) so as to include all the judgments in the above four cases, and the judgment states are shown in Table 1. Here, regarding the classification into the accuracy priority mode and the speed priority mode, the mode with the higher priority mode is the mode at that time. When the number of priority modes is the same, priority is given to the threshold value of the aperture value. This is because a lens having a small F-number has a very shallow depth of field, and is likely to be out of focus even with a slight shift.

Returning to FIG. 2, after finishing the accuracy check mode, it is detected whether or not the lens is stopped (# 235). This can be seen by detecting the drive signal to the motor. If the lens is stopped, the process proceeds to the MFZ routine; if not, the process proceeds to the IDOBUN routine.

First, the MFZ routine will be described with reference to FIG. To memory the defocus amount Δε to another variable Δε _1, focusing the number of zones pulse over the KL value to the amount of the in-focus zone ΔIF (40μ)
Ask for IFP. Next, the value of the amount of the lens moved from the integration center to the end of the calculation is set to a value CTC represented by the number of encoder pulses of 0 (# 240 to # 250). Next, it is determined whether or not ERR indicating the defocus amount Δε by the number of encoder pulses (hereinafter referred to as the number of defocus pulses) is 3 or less. The number ERR is set to the previous defocus pulse number LERR, the current defocus direction TD is set to the previous direction LD, and a focus flag (focus F) indicating focus is set to perform focus display (# 255). ~ # 275). Then, a flag (AFEF) indicating the end of the focus detection is set, and it is determined whether or not the mode is the continuous mode from the state of the switch (S4). from
The flow proceeds to the CDINT routine to perform focus detection again. If the microcomputer is in the one-shot mode, the microcomputer (1) does not perform focus detection after waiting for an interrupt.

In step # 255, if the defocus pulse number ERR exceeds 3, it is determined whether or not the focus flag (focus F) is set. If the focus flag is set, the defocus pulse number ERR is determined in advance. It is determined whether or not the number is within the focusing zone pulse number. If it is within the focusing zone, the process proceeds to the INFZ routine from step # 260 (# 290, # 295). Even if the focus flag (focus F) is not set in step # 290, the current defocus direction TD and the previous defocus direction LD are reversed, or even if they are not reversed, the near-zone If it is determined in the subroutine A that the vehicle is not within the near zone (NZF = 1), the flag (1STF) indicating that the vehicle has passed once is reset, and the process proceeds to step # 295 (# 370 to # 380).

The subroutine of the near zone A determination will be described with reference to FIG.

The microcomputer (1) first calculates the number of defocus pulses ERR as E
RR1 and determine whether or not the lens is stopped (# 3000, # 3000)
3005). If stopped, the process proceeds to step # 3015. If not stopped, the lens movement amount CTC from the integration center to the end of the calculation is subtracted from ERR1, and the process proceeds to step # 3015. In step # 3015, it is determined whether or not the following flag (following F) indicating the following mode is set. If it is set, the counter NZC indicating the near zone range is set to 63. If the mode is the non-follow-up mode (when the follow-up flag is reset), the near zone counter is set to 100 in the case of the speed priority mode, and the near zone counter is set to 120 in the case of the accuracy priority mode, and step # 3035
Proceed to (# 3015 to # 3030). In step # 3035, it is determined whether or not the defocus pulse number ERR1 is equal to or less than the set value NZC of the set near zone counter. If the count value of the near zone counter exceeds NZC, the near zone flag NZF is reset and the process returns (# 3035 to # 3045). Here, in the present embodiment, the range of the near zone is changed depending on whether the mode is the speed priority mode or the accuracy priority mode. However, in this case, a fixed value, for example, 100 may be used because it is not related to the speed control of the motor.

Returning to FIG. 6, when it is determined in step # 380 that the near zone flag (NFZ) has been set,
After this step, when the defocus amount increases for a moving subject, a flow for correcting the defocus amount will be shown, and such a case will be referred to as a following mode. In step # 385, it is determined whether or not the flag (1STF) indicating that the vehicle has passed once is set. When the flag (1STF) is not set, the flag (1STF) is set, the flag (following F) indicating the following mode is reset, and a following correction flag (following correction) indicating that the correction is further performed. F) is reset and the process proceeds to step # 300 (# 455, # 460, # 445). Step # 38
If the flag (1STF) indicating that the image has passed once at 5 is set, the previous defocus direction (LD) and the current defocus direction (TD) are determined.
That is, if the directional data is 1,0 or 0,1, the process proceeds to step # 460, and the tracking correction in the tracking correction mode is not performed.
If the previous defocus direction (LD) and the current direction (TD) are in the same direction, that is, if both data are 0, 0 or 1, the process proceeds to step # 400 and the follow flag (follow F) is set. Is determined (# 390 to # 400, # 450).
If the following flag is not set in step # 400, the previous defocus pulse number LEER is subtracted from the current defocus pulse number ERR to obtain WR (# 430).
If this value WR is larger than the predetermined amount AA, that is, if the defocus amount (the number of pulses) is large, the follow-up flag (follow-up F) is set, but in this embodiment, WR becomes a positive value twice. The correction is performed when the error occurs, so that the tracking correction flag (following correction flag) indicating the correction in the tracking mode is reset so that the correction is not performed for the first time (# 435, # 440, # 445). . The predetermined amount AA is a value determined in consideration of the noise component, and may be set to 0 if the configuration has no noise component. If the WR is equal to or less than AA, the defocus amount is not large, so that the flow proceeds to step # 460 without correction. When the tracking flag (following F) is set in step # 400, WR is obtained in the same manner as in step # 430, and whether or not this is larger than AA is determined. Since it is not necessary to perform the correction because it has caught up with, the process proceeds to step # 300 with WR as the correction amount set to 0 (# 405, # 410, # 425).

On the other hand, if it is determined in step # 410 that WR is larger than AA, the process proceeds to step # 415. In step # 415, the difference WR between the previous and current calculation results is set to be larger than the count value NZC of the near zone counter. It is determined whether the value is equal to or greater than the set value AX. The reason why the setting value AX is provided is as follows. In the following mode, that is, when the subject is moving, the subject may move out of the area provided for focus detection due to the movement of the subject. . This is because, if the subject deviates from this area, another object in the area will be in focus, and this is to be prevented. For this reason, when the correction amount WR is equal to or more than the set value AX, it means that a desired subject has deviated from the area, and thus the lens movement amount is not updated. That is, if the correction amount WR is equal to or larger than the set value AX in step # 415, the non-update flag (non-update F) for inhibiting the update of the lens movement amount is set, and the tracking correction flag is reset (# 425, # 445). On the other hand, if the correction amount WR is less than AX, the non-update flag is reset, the tracking correction flag is set (# 417 to # 419), and the routine proceeds to step # 300.

If the defocus amount Δε1 is not within the focusing zone in step # 295, the flow advances to step # 300 to reset the focusing flag (focus F) indicating the focusing state. Next, the current defocus pulse number ERR is set to the previous defocus pulse number LERR, and the current defocus direction (TD)
Is the previous direction (LD) (# 300, # 305). And
It is determined whether or not the tracking correction flag (following correction F) is set. When the flag is set, the tracking correction amount 2WR is added to the number of defocus pulses ERR to obtain a new defocus amount, and the process proceeds to step # 322. Go on (# 315, # 320).

In step # 322, it is determined whether or not a continuous shooting flag indicating that continuous shooting is being performed is set. If the flag has not been set, the process proceeds to step # 355. On the other hand, if the continuous shooting flag is set, step # 324
To determine whether or not the number of defocus pulses (ERR) is 1000 or more. Set the flag MVF and proceed to the CDINT flow. If the number of defocus pulses is less than 1000, the process proceeds to step # 335 to drive the lens. At this time, since the contents of the drive counter ENZCNT do not change, the lens is driven based on the result of the previous focus detection.

In step # 335, if the following flag (following F) is set, the process proceeds to the subroutine of operation III shown in FIG. In the subroutine of the operation III, first, it is determined whether the mode is the AF priority mode.
150 (msec), Td = 100 (ms in release priority mode)
ec) and proceeds to step # 2215. This Td is provided for driving the lens by that amount when the release button is pressed down to the second stroke and the lens drive amount is not 0 (focused state) when the release is possible. , Td = release time lag (50 msec) + TC (constant time). The release time lag is a value determined by the camera. On the other hand, TC is 100 msec in the AF priority mode, and 50 msec in the release priority mode.

The reason that this value TC is changed in each mode is generally AF
Since the priority mode is a mode used when it is desired to accurately focus on the subject, it is desirable to move the lens as much as possible so that the defocus amount becomes zero. Because it is. On the other hand, in the release priority mode, it is important that the release is made at the moment when the user wants to take a picture anyway, so the fixed time is shortened. Next step #
At 2215, the integration period TI is read, Td is divided by this time TI, the ratio R is obtained, and the correction amount WR is multiplied by R in order to obtain the moving amount WS of the object moving between Td on the image plane (# 2215). , # 2
220). Then, the defocus pulse number ERR is added to this value WS.
To obtain a new defocus pulse number ERRT (#
2225). Next, it is determined whether the camera is in the AF priority mode.In the AF priority mode, it is determined whether the number of defocus pulses ERRT is 148 or less and in the release priority mode, it is 100 or less. If there is, in the following mode, a following focus flag (following focus F) indicating that the in-focus state has been reached is set, and if it exceeds the set value, the following focus flag is reset and the routine returns. The above set values will be described in a release mode described later.

Then, the flow returns to step # 340 in FIG. 6, and it is determined whether or not the subject is within the following focusing zone by setting the above-mentioned following focusing flag. If within this zone, the flag AFEF indicating the end of focus detection is set. Then, the in-focus display is performed, and the flow proceeds to the flow of TINNZ (# 335 to # 350). If the tracking flag (following F) is not set in step # 335, or if the tracking flag is set but is not within the tracking focus zone in step # 340, the process proceeds to step # 355, and the defocus pulse number ERRT is set to a narrow value to be described later. It is determined whether it is within the focusing zone (# 355). If it is within the narrow focus zone, a narrow focus flag (narrow focus flag) is set and the process proceeds to step # 365. If it is not within the narrow focus zone, step # 360 is skipped and the process proceeds to step # 365. In step # 365, it is determined whether or not the defocus pulse number ERRT is within a display focusing zone described later. If it is not within the display focusing zone, the process proceeds to TINNZ without displaying. Here, the focusing zone will be described.

(1) Focusing zone (# 295) In a conventional area, if the driving amount of the lens required to reach the in-focus state once becomes 0 and the integration result in a state where the lens is stopped is this area, Indicates that the camera is in focus.

(2) Display focus zone (# 365) This is a range wider than the focus zone of (1) and within which the lens can be accurately moved into the focus zone during the release time lag after release. In this embodiment, , Pulse number
Defocus amount equivalent to 21 (depends on lens)
And Then, regardless of whether the lens is stopped or moving, if the defocus amount falls within this range, display is performed and release permission in the AF priority mode is performed.

(3) Tracking Focus Zone (Step # 340) The zone is the widest and indicates the range in which the focus display in the tracking mode and the release permission in the AF priority mode are performed. In the tracking mode, when the camera continues to follow the movement of the subject while driving the lens, the focusing state (the defocus amount is 0) may not be achieved. However, in the conventional AF priority mode, the release cannot be performed unless the lens is stopped. The following focus zone is provided to prevent this, and the size of this zone is set to a value that allows the lens to be driven during a release time lag plus a fixed time. This value will be described in detail later in the description of the release flow.

(4) Narrow focusing zone (# 355) This zone is almost the same as the focusing zone of (1).
The reason why this zone is provided is described below. When the lens is driven in this zone, the movement amount CTC of the lens that moves from the integration center to the end of the calculation is subtracted from the number of defocus pulses. Now, the number of defocus pulses is a value at the center of integration. However, the number of defocus pulses may not always be a value at the center of integration due to a change in light, hand shake, or electrical noise. Therefore, a correct defocus amount may not be obtained even if the lens movement amount is subtracted from the number of defocus pulses.
Even if the lens is driven and stopped by this defocus amount, the focusing state may not be achieved. In such a case, the lens must be moved again according to the result of the next focus detection. If a similar event occurs during this driving, the lens must be driven based on the result of the next focus detection. This zone is provided to prevent the lens from being stopped due to the detection of the in-focus state forever. Therefore, when the defocus amount falls within this narrow focusing zone, focus detection is not performed, and the lens is driven until the number of defocus pulses becomes zero.

On the other hand, in FIG. 2, when the lens is not stopped in step # 235, the flow proceeds to the IDOBUN flow shown in FIG.

In the flow of IDOBUN in FIG. 8, first, it is determined whether or not the currently calculated defocus direction is different from the previously calculated defocus direction (# 435). If the direction is reversed, the lens is stopped (step # 455), and the flow returns to CDINT from step # 55 onward in FIG. 2 to perform integration again. On the other hand, if the direction is not reversed in step # 435 in FIG. 8, the movement amount CTC of the lens moved from the integration center to the end of the calculation is obtained (# 435, # 440). Next, the procedure proceeds to a subroutine for determining near zone A, which will be described later.
If is set, the process proceeds to step # 460, and if not, the following flag is reset in step # 520 (# 445, # 450). In step # 460 and below, it is determined whether or not the previously calculated defocus direction (LD) and the currently calculated defocus direction (TD) are in the same direction. The driving amount ITI of the lens moved from the previous integration center to the current integration center is added to the pulse number ERR, and the previous defocus amount LERR is subtracted to obtain the correction amount WR (# 460 to # 470,
# 515).

Next, it is determined whether or not the follow-up flag (follow-up F) is set. If the follow-up flag is not set and the correction amount WR is equal to or more than the predetermined amount AA, the follow-up flag (follow-up F) and the follow-up correction The flag (follow-up correction F) is set, and the process proceeds to step # 300 in FIG. 6 (# 480 to # 49).
0).

On the other hand, if the correction amount WR is less than the predetermined amount AA in step # 480, the tracking correction flag (following correction F) is reset, and
The process proceeds to step # 300 (# 480, # 485). Step # 475
When the follow-up flag (follow-up F) is set, the correction amount WR is equal to the predetermined amount AX (count value of the near zone counter).
NZC) or more, and if it is more than a predetermined amount, it is determined that the subject has deviated from the focus detection area,
The non-update flag (non-update F) for inhibiting the update of the lens drive amount is set, the follow-up correction flag (follow-up correction F) is reset, and the routine proceeds to step # 300 (# 500, # 505, # 490).

Conversely, if the correction amount WR is less than the predetermined amount AX in step # 500, the non-update flag (non-update F) is reset, the follow-up correction flag (follow-up correction F) is set, and the process proceeds to step # 300 (# 500). , # 510, # 490).

Returning to FIG. 2, when it is determined in step # 185 that focus detection is impossible, the flow proceeds to the LOWCON flow of FIG. In the flow of LOWCON in Fig. 9, the microcomputer (1)
First determines whether the follow-up flag (follow-up F) is set, and if the follow-up flag (follow-up F) is set, sets the non-update flag (non-update F) (# 52).
0, # 525). Then, it is determined whether or not the flag FIF indicating that this is the first time to pass here is set, and when it is not set, that is, when this is the first time to pass here, this flag FIF is set. The variable N1 is set to 0, and the process proceeds to the CDINT flow of step # 55 and subsequent steps in FIG. 2 (# 5).
30, # 625, # 630).

In step # 530, when the flag FIF is set, 1 is added to the variable N1, and it is determined whether or not this value N1 is 2. If not, step # 55 in FIG. Proceed to the following flow of CDINT, and if it is 2, the follow-up flag (follow-up F) and the non-update flag (non-update F)
Are reset, and the process proceeds to step # 555 (# 535
~ # 550). Steps # 520 to # 550, # 625, and # 630 described above
In this case, if the subject deviates from the focus detection area in the tracking mode, the amount of defocus may suddenly increase or it may be determined that focus detection is not possible. Therefore, measures are taken against this. That is, if the focus can be detected even if the defocus amount suddenly increases, it means that the correction amount WR suddenly increases. In this case, the processing in steps # 500 to # 510 in FIG. doing.
On the other hand, when it is determined in step # 185 in FIG. 2 that the focus cannot be detected, the flow proceeds to the LOWCON flow in FIG. And
When it is determined that the focus cannot be detected in the tracking mode, that is, when the subject is out of the focus detection area, the normal focus detection impossible processing from step # 555 is not performed, and the lens is moved based on the previously calculated defocus amount. I'm going to drive. On the other hand, when the tracking flag is not set in step # 520, the flag FIF is reset, and the process proceeds to step # 555.

In step # 555 and below, count interruption, timer interruption, and ENTEVENT interruption described below are prohibited (# 555 to # 555).
557). Next, it is detected based on the output of the light receiving element provided near the photodiode of the CCD whether or not the cause of determining that the focus cannot be detected is that the luminance of the subject is too low (low light). If the cause of the focus detection failure is this low light, it is detected whether or not the auxiliary light emitting device (13) is mounted on the camera, and when the auxiliary light emitting device (13) is mounted, the auxiliary light emitting device (13) is detected. The mode is set to the light emission mode, and it is determined whether or not the auxiliary light flag (auxiliary light F) is set (# 560 to # 570). When the auxiliary light flag (auxiliary light F) is set in step # 570, that is, when the auxiliary light is emitted once but the focus cannot be detected due to the low light, the low contrast display indicating that the focus cannot be detected is displayed. Then, the microcomputer (1) waits for an interrupt to stop focus detection (# 570, # 585, # 590). Conversely, if the auxiliary light flag is not set in step # 570,
This flag (auxiliary light F) is set, and a long integration flag (long product F) indicating a mode with a longer integration time is set.
The flow proceeds to the flow CDINT after step # 55 in FIG. If it is determined in step # 555 that it is not low light, or if it is determined in step # 565 that the auxiliary light emitting device (13) is not mounted, low contrast display is performed (# 59).
Five). Then, a flag LBF indicating the lens retraction mode is determined, and if this flag LBF is not set, a command for controlling the lens retraction is instructed. After outputting the command to drive the motor for use, the flow proceeds to the focus detection flow CDINT of step # 55 and subsequent steps in FIG. 2 to perform focus detection (# 600, # 605, # 610, # 615).

Next, the flow of the lens drive control shown in FIGS. 10 to 13 will be described. First, the speed control of the lens driving motor according to the embodiment will be described. As for the type of motor speed, outside the near zone (out zone)
Speed, three speeds in the near zone, and five types of step drive. In each of the following modes, the priority mode for accuracy and the mode priority for non-follow mode, according to the number of defocus pulses at that time. Thus, the above five types of lens speed control are performed. These are shown in Table 2 and explained. The rotation speed of the motor is 20,000 rpm
(Out zone), 5,000rpm (near zone 1), 2,500r
pm (near zone 2), 1,000 rpm (near zone 3), and step drive. Of these, the step drive is used only in the non-follow-up mode in which accuracy is prioritized, and the lens control is performed with high accuracy.
The difference in the speed of the lens with respect to the number of defocus pulses in the near zone is faster as the speed up to focusing is required. The higher the speed of the motor, the lower the stopping accuracy tends to be. How these speed controls are performed in the sequence of the camera will be described below.

First, the flow of TINNZ shown in FIG. 10 will be described. In step # 630, the microcomputer (1) determines whether or not the lens is stopped. If the lens is not stopped, a flag (non-update F) indicating that the driving amount of the lens is not updated is set. Is determined, and if set, the process proceeds to step # 700 without updating the lens drive amount (# 630, # 635). If the lens is stopped in step # 630, the flow advances to step # 680 to proceed to a near zone determination subroutine for determining whether or not the vehicle is in the near zone. The near zone subroutine will be described with reference to FIG. In step # 2300 in FIG. 11, the microcomputer (1) determines whether or not the follow-up flag (follow-up F) is set. If the follow-up flag (follow-up F) is set, the count value NZC of the counter indicating the near zone range is set to 63. If the mode is the non-follow mode (when the follow flag is reset), the count value NZC of the near zone counter is set to 100 in the speed priority mode, and the count value NZC of the near zone counter is set in the accuracy priority mode. Set each to 120 and proceed to step # 2310 (# 2300, # 2305, # 2325 ~
# 2335). In step # 2310, the number of defocus pulses
Count value NZC of the near zone counter set by ERR
It is determined whether or not it is below, and if the count value of the near zone counter is less than NZC, a flag NZF indicating the near zone is set, and if the count value of the near zone counter is NZC or more, the near zone flag NZF is reset. Return (# 2310 to # 2320).

Then, returning to step # 685 in FIG. 10, it is determined whether or not the near zone flag NZF is set. If not, a value obtained by subtracting the count value NZC of the near zone counter from the defocus pulse number ERR Into the event counter EVENTCNT (# 685 to # 69)
0). This event counter EVENTCNT subtracts 1 each time a pulse is sent from the encoder (11) in FIG. 1, and executes an interrupt (INTEVENT) indicating near zone entry when the counter content becomes 0. belongs to. When the input to the event counter EVENTCNT is completed, the process proceeds to the event counter set (EVENTCNT set) subroutine in step # 695, and when the subroutine is completed, the process proceeds to step # 700. Call this subroutine the 10th
The description is shown at the upper right of the figure.

In this subroutine (EVENTCNT set), interruption (INTEVENT) by this event counter is permitted, and further, timer interruption and counter interruption (CNTR interruption) described later are prohibited, and the routine returns (# 2350 to # 2360).

In step # 635 of FIG. 10, when the non-update flag (non-update F) is not set, the movement amount CTC of the lens moved from the integration center to the end of the calculation is subtracted from the defocus pulse number ERR to actually The number of defocus pulses to be driven is set, and the process proceeds to the near zone determination subroutine shown in FIG. 11 (# 645, # 650). If the flag NZF indicating the near zone is not set in this subroutine, the count value NZC of the near zone counter is subtracted from the defocus pulse number ERR, and the process proceeds to the event counter set (EVENTCNT set) subroutine as the count value of the event counter EVENTCNT. Then, the process proceeds to step # 700 via this subroutine (# 655, # 670,
# 675). In step # 655 or step # 685, when the near zone flag NZF is set, the defocus pulse number ERR is set to the drive counter ENZCNT
, And proceeds to the timer I set subroutine shown in FIG. 14. After the subroutine ends, the process proceeds to step # 700 (# 660, # 665). In this subroutine, the motor speed with respect to the number of defocus pulses in the near zone is determined for each of the modes shown in Table 2 (tracking mode, speed priority in non-tracking mode, and precision priority). The speed control of the motor in the present embodiment is performed by turning on / off the energization of the motor depending on whether or not a pulse is transmitted from the encoder within a predetermined time, thereby keeping the motor speed constant, and changing the predetermined time. Changes the speed of the motor. The shorter the predetermined time, the higher the speed of the motor. The timer equivalent to 5000 revolutions per minute is A1, the timer equivalent to 2500 revolutions is A2, the timer equivalent to 1000 revolutions is A3, and A1 <A2 <A3 The relationship is

The details of the timer I set subroutine shown in step # 665 of FIG. 10 will be described with reference to FIG. 14. In steps # 2400 to # 2455, the motor speed is set so as to be as shown in Table 2. The set timer is set, and in steps # 2460 and # 2465, the count interruption and the timer interruption are permitted, respectively, and the routine returns. Where a ₂
= 61, a ₃ = 30, b ₁ = 31, b ₂ = 15, c ₁ = 79, c ₂ = 31. Flag indicating step drive mode in step # 2435
If STEPF is set, the process proceeds to step # 2470.
In step # 2470, it is determined whether the driving of the motor is stopped. If the driving is not stopped, the step driving flag ST indicating that the count interruption by the encoder pulse has been performed with the value of the driving counter to perform the step driving.
Judge whether PDRF is set and set this flag STPDRF
Is set, this flag STPDRF is reset and the timer is set to D1 (# 2470 to # 248
Five). On the other hand, if the motor is stopped or the step drive flag STPDRF is not set, this flag
Set STPDRF and set D2 to the timer (# 24
70, # 2475, # 2490, 2495). The drive time at this time is shorter, and D1 <D2.

Returning to FIG. 10, the motor is driven in step # 700. Then, it is determined whether or not the near zone flag NZF is set, and if not, the moving integration flag NIDF indicating that the integration is performed while moving the lens is set (# 705, # 745). Next, it is determined whether or not the motor is stopped. If the motor is stopped, the process proceeds to step # 735 after waiting a little for the rise time of the motor, and if not, the process immediately proceeds to step # 735 (# 750, # 7
55). In step # 735, it is determined whether or not the defocus pulse number ERR has entered the narrow focusing zone. If the number is within the narrow focusing zone, the microcomputer (1) moves the lens by the remaining defocus amount without performing integration. ) Is an interrupt waiting control, and if the zone is not the narrow focusing zone, the flow proceeds to the focus detection flow CDINT of step # 55 and subsequent steps in FIG. 2 (# 735, # 740). If the near zone flag NZF is set in step # 705, the flow proceeds to the flow of WNZ3, and first, the moving integration flag (NI
It is determined whether or not (DF) is set. If not, the process proceeds to step # 735 (# 710). On the other hand, if the moving integration flag (NIDF) is set in step # 710, the count value ENZCNT of the drive counter becomes the near zone 3
The process proceeds to a near zone 3 determination subroutine for determining whether or not the number is within the defocus pulse number (see Table 2).

The details of the near zone 3 determination subroutine will be described with reference to FIG. 15. First, it is determined whether or not the follow-up flag (follow-up F) is set. When the flag (follow-up F) is set, Drive counter count value
If ENZCNT is 15 or less, set the flag NZ3F indicating that it is within the near zone 3 and return. If ENZCNT exceeds 15, reset the flag NZ3F and return (#
2500 to # 2510, # 2535). Conversely, when the non-following mode is the speed priority mode, the flag NZ3F is set if the count value ENZCNT of the drive counter is 30 or less, and reset and return if it exceeds 30. Further, when the non-following mode is the accuracy priority mode, the flag NZ3F is set when the count value ENZCNT of the drive counter is 31 or less, and when the count value exceeds 31, the flag NZ3F is reset and the process returns.

Returning to FIG. 10, when the near-zone 3 flag NZ3F is not set in step # 715, that is, when the near-zone 3 area is not set, the process returns to step # 712, where the near-zone 3 area is set and the flag NZ3F is set. Resets the moving integration flag NIDF (#
720). Next, it is determined whether or not the follow-up flag (follow-up F) is set. If it is set, or if the follow-up flag (follow-up F) is not set and the speed priority mode is set, the process proceeds to step # 735. Go on (# 725,
# 727). If the mode is the accuracy priority mode, step # 727 is repeated until the lens stops (until the count value ENZCNT of the drive counter becomes 0). This is because the step integration in the accuracy priority mode cannot perform the moving integration correctly because the speed is not constant.

The above-described movement integration will be described with reference to FIG.
FIG. 21 shows the rotation speed of the motor on the vertical axis and the time on the horizontal axis. The upper part shows whether movement integration is possible depending on the state of the motor. In this embodiment, 20,0
Movement integration is prohibited until the vehicle enters the near zone 3 at the time of deceleration from 00 rpm, during step drive, and when the motor is stopped and accelerated to 20,000 rpm. This is because during these periods acceleration and deceleration are not always constant, so that the center of integration during movement is not clear, and it is considered that there are many errors in focus detection. On the other hand, when accelerating into or near the near zone, the focus detection error is about a few pulses in terms of the encoder pulse due to the originally low speed of the motor and the short time during acceleration. Integrating is not practical. Therefore, in this embodiment, the time required for the focus adjustment is shortened as much as possible by performing the movement integration as described above.

Next, returning to FIG. 10, the event counter interrupt INTEVENT shown in the lower right will be described. Event counter (EVENCN
T) subtracts 1 from the count value each time a pulse comes from the encoder (11). When the count value of the event counter becomes 0, the flow enters this interrupt INTEVENT. In this flow, first, INTEVE in step # 2550
Disables NT interrupts and releases RESF flag
If this flag RESF is set, 40 is added to the count value of the drive counter EVENCNT, and the process proceeds to a timer R set subroutine to be described later to control the rotation speed of the motor (# 2550, # 2555, # 2570, # 2575). If the flag RESF is not set in step # 2555 and the shutter is not being released, the count value of the near zone counter NZC is added to the count value of the drive counter ENZCNT, and the process proceeds to a timer I set subroutine described later. Then, the near zone flag NZF is set, and the flow proceeds to the flow of WNZ3 following step # 710 (# 2560 to # 2567).

Next, the counter interrupt (CNTR interrupt) shown in FIG. 12 will be described. This counter interrupt is controlled by the encoder (1
Executed every time a pulse is generated from 1). When entering this flow, the microcomputer (1) first sets the drive counter EVEN
The count value of CNT is decremented by one, and it is determined whether the count value of the drive counter ENZCNT has become 0 (# 800 to # 8)
05). And the count value of the drive counter EVENCNT is 0
If not, it is determined whether or not the step mode flag STEPF indicating the step drive is set (# 815),
When it is set, the process proceeds to step # 835. If the flag STEPF is not set in step # 815, the process proceeds to step # 820. If the mode is not the accuracy priority mode, or if the count value of the drive counter ENZCNT exceeds 6 even in the accuracy priority mode, the step driving is not performed. The process proceeds to step # 840. Here, a flag TIPA indicating that a timer interrupt has occurred before this counter interrupt
It is determined whether SF is set or not, and if it is set, this is reset and the routine returns. If the flag TIPASF is not set, the motor is turned off (# 845). On the other hand, if it is the accuracy priority mode in step # 820 and the count value of the drive counter ENZCNT is 6 or less, the process proceeds from step # 825 to step # 830, and the flag STEPF indicating the step mode is set.
Further, after setting the step drive flag STPDRF, the motor is turned off in step # 845 (# 830, # 835, # 84
Five). Next, it is determined whether or not the flag RESF indicating that the shutter has been released is set. If the flag is set, the process proceeds to a timer R set subroutine. If not, the process proceeds to a timer I set subroutine.
After the end of the subroutine, the program returns (# 850 to # 860).
The timer R set will be described at the time of release.

In step # 805, when the count value of the drive counter ENZCNT becomes 0, that is, when the lens has finished driving to the focal point, the motor is stopped, the step mode flag STEPF is reset, and the timer interrupt and the count interrupt are performed. Is prohibited (# 870 to # 880). When the release flag RESF is set, the process returns. When the release flag RESF is not set, the process proceeds to the DRVED flow described later (# 885).

In the DRVED flow, first, a flag 1STDF indicating that the flow has passed once when the count value of the drive counter ENZCNT becomes 0 in the one-shot mode
It is determined whether or not is set, and if it is set, the flow CD of focus detection after the second step # 55
Proceed to INT (# 895). This flag 1STDF in step # 895
If has not been set, the process proceeds to step # 900 to determine whether the mode is the continuous mode or the one-shot mode from the state of the switch (S4). The flag 1STDF indicating once passing is set and the flow proceeds to the focus detection flow CDINT (# 900, # 910, # 915). Step #
If the continuous mode is selected in 900, it is determined whether or not the tracking flag is set, and if it is set, the routine returns and the focus detection is continuously performed using the data at that time. If not set, the flow proceeds to the INFZ flow from step # 260 onward in FIG. 6 to control the focus display and the like (# 905).

FIG. 13 shows the flow of the timer interrupt. This timer interrupt is executed when no pulse is sent from the encoder within the time set in the timer 1 set routine. In FIG. 13, the microcomputer (1) determines a flag RESF in step # 950 and determines whether or not this timer interrupt has been performed during the release. If it is during release, the flow proceeds to a timer R set subroutine described below (# 950 to # 960). Next, the flag STEPF is determined to determine whether the mode is the step mode. If the mode is not the step mode, the flag TI indicating that the timer interrupt has been performed is determined.
Set PASF, energize the motor and return (#
965 to # 975). In the step mode, it is determined whether or not the flag STPDRF indicating that the step drive is performed is set.If the flag STPDRF is set, the motor is energized. Return (# 975, # 980, # 985).

When the release button is pressed down to the second stroke and the release switch (S2) is turned on while the focus detection and the focus adjustment are being performed, a signal that changes from "H" to "L" is sent to the microcomputer (1). Input to the terminal (INT2)
The release interrupt flow shown in FIG.
First, the microcomputer (1) determines whether or not film winding is completed, and if completed, inhibits the release interrupt and the AFS interrupt from step # 45 in FIG. 2 (a), respectively. Then, a release flag RESF indicating the release mode is set (# 1000 to # 1012).

If the winding of the film has not been completed in step # 1000, it is determined whether or not the release switch (S2) has been turned ON. When S2) is OFF, the flow proceeds to the CDINT flow from step # 55 in FIG.

When the release flag RESF is set in step # 1012, the interrupt INTEVENT for entering from the out zone to the near zone is prohibited in step # 1014.
At 16, it is determined whether the near zone flag NZF is set. When the near zone flag is not set in step # 1016, since the value is not set in the drive counter, the value obtained by adding the count value of the near zone counter NZC to the count value of the event counter EVENTCNT is counted by the drive counter Step # as value ENZCNT
Continue to 1025. In step # 1025, the state of the switch (S6) is detected to determine whether or not the mode is the AF priority mode. If the mode is the AF priority mode, the process proceeds to step # 1110. If the mode is the release priority mode, the process proceeds to step # 1030.

Next, in FIG. 16 (a), when the AF priority mode is set in step # 1025, the process proceeds to step # 1109, in which a flag (MVF) indicating release permission and tracking correction inhibition during release is prohibited.
Is set or not. If the flag is set, it is determined in step # 1110 whether or not a flag (REIF) indicating that the previous photographing was not possible to detect the focus or performed with a large defocus amount is set.

If the flag (REIF) is not set, it is assumed that the previous operation has been started and the release operation (shooting) has been started, the flag (REIF) is set in step # 1112, and the flow advances to step # 1190 to perform the current release. The above flag (REIF)
If is set, the process proceeds to step # 1170 to prohibit release for the above-described reason.

In step # 1109, flag MV indicating release permission
If F has not been set, the process proceeds to step # 1112, where it is determined whether or not a flag (AFEF) indicating the end of focus detection has been set. The flag (REIF) indicating that shooting is performed at the time of large defocus is reset, and the flow advances to step # 1115. On the other hand, if the flag (AFEF) indicating the end of the focus detection is not set, the process proceeds to step # 1170 to prohibit the release.

To begin with the description of the release priority mode, first, it is determined whether or not the following mode is set, based on whether a following flag (following F) is set. In the subroutine of this operation I, the release time lag (switch (S
2) Time from ON to actual exposure start)
During this period, the amount of movement of the subject is estimated, and the defocus amount is calculated as a value obtained by adding the amount of defocus up to this mode (release) to this amount. This subroutine is shown and described in FIG.

In the subroutine of the calculation I shown in FIG. 17, the movement of the subject during one cycle of the focus detection time, that is, the movement inclination (in terms of defocus amount) of the subject in the unit focus detection time in the optical axis direction is obtained. The moving amount (in terms of defocus amount) of the moving subject is obtained. That is, in step # 2600, the release time lag time RST is divided by the unit focus detection time TI to obtain the ratio R, and the moving amount WS during the release time lag is obtained by multiplying the subject moving amount WR per unit time by this ratio R. This is added to the count value of the drive counter ENZCNT, and the count value of the new drive counter ENZCNT is obtained and the process returns (# 2600 to # 2610).

Returning to FIG. 16 (a), if the tracking mode is not set in step # 1030, the subroutine of operation I is skipped and the process proceeds to step # 1036. Then, it is determined whether or not the count value of the drive counter ENZCNT is 3 or less. If the count value is 3 or less, it is determined that focusing is performed, the motor is stopped, and the process proceeds to step # 1190. Go on (# 113
6, # 1137). The flow after step # 1140 described below is to drive the lens during the release time lag when the release is permitted. Step #
At 1040, it is determined whether the count value of the drive counter ENZCNT is 13 or less. If the count value is 13 or less, a flag e1F for setting the motor speed to 1000 rpm is set, and a timer R (described later) is set.
Proceed to the set subroutine (# 1080, # 1090). If the count value of the drive counter ENZCNT is larger than 13 and equal to or smaller than 40, the process proceeds to the timer R set subroutine (# 1045, # 1
090). If the count value of the drive counter ENZCNT is larger than 40 and smaller than 66, the motor speed is set to 5000 rpm
The flag e2F is set, and the process proceeds to the timer R set subroutine (# 1050, # 1085, # 1090).

Here, the timer R set subroutine shown in FIG. 19 will be described. This is a routine for setting a timer for setting the speed of the motor, similarly to the subroutine of one timer set. First, it is determined in step # 2780 whether or not the camera is in the AF priority mode. If the mode is the AF priority mode, the flow advances to step # 2785. This will be described later. On the other hand, when the release priority mode is set, it is determined whether or not the flag e1F is set. If the flag e1F is set, the process proceeds to step # 2760 to set the timer 1 to A3 (1000 rpm).
Then, the timer interrupt and the count interrupt are permitted and the process returns (# 2765, 2770). If the flag e1F for setting 1000 rpm has not been set in step # 2705, it is determined in step # 2710 whether the flag e2F for setting 5000 rpm has been set. If the flag e1F has been set, the flow proceeds to step # 2800 It is determined whether the flag Fe2F for correcting the excessive amount α1 when the motor is stopped is set, and if the flag Fe2F is set, A1 is set to the timer 1 in step # 2830 (equivalent to 5000 rpm). Proceed to step # 2765. If the flag Fe2F is not set in step # 2800, step # 2805
The flag Fe2F is set in step # 2810. In step # 2810, the excess amount α1 is added to the count value of the drive counter ENZCNT to newly set the count value of the drive counter ENZCNT. . Explaining the overshoot amount, if the motor is stopped from 1000 rpm, the overshoot amount is negligibly small, but if the motor is stopped from 5000 rpm, the overshoot will be too large. This amount is almost specific to the rotation speed of the motor, and the variation for each lens is small. Therefore, if a certain value α1 is added to the count value of the drive counter ENZCNT, the lens can reach the in-focus position. The motor starts to stop, and the motor can be stopped properly when the lens reaches the focus position.

When the flags e1F and e2F are not set at both steps # 2705 and # 2710, it is determined at step # 2745 whether or not the count value of the drive counter ENZCNT exceeds 100.
If it exceeds, subtract 40 from the count value of drive counter ENZCNT, and count value of event counter EVENTC
Enter NT and set the event counter set (EVENTCNT
Set subroutine and return (# 273)
0, # 2735).

If the count value of the drive counter ENZCNT is 100 or less in step # 2745, the process proceeds to step # 2750. Here, it is determined whether the count value of the drive counter ENZCNT is greater than 14, and if it is greater than 14, the process proceeds to step # 2830. Set timer 1 to A1 (equivalent to 5000 rpm) and go to step # 276
Go to 5. In step # 2750, drive counter ENZCNT
If the count value is equal to or less than 14, the process proceeds to step # 2755 to determine whether the count value of the drive counter ENZCNT exceeds 4. When the count value of the drive counter ENZCNT is 14 or less and greater than 4, the timer 1 is set to A2 (equivalent to 2500 rpm) in step # 2850, and when the count value is 4 or less, the timer 1 is set to A3 (equivalent to 1000 rpm) in step # 2760. Then, in steps # 2765 and # 2770, the timer interrupt and the count interrupt are permitted, and the process returns.

Returning to FIG. 16 (a), when the count value of the drive counter ENZCNT exceeds 66 in step # 1050,
At 5000 rpm or less, the count value of the drive counter ENZCNT cannot be set to 0 (focus), so the release time lag is increased by a predetermined time (50 msec when not in the AF priority mode in this embodiment) and the motor is driven during this time. ing. However, in the continuous shooting mode indicating the continuous shooting mode, it is desired to perform shooting as quickly as possible, so that the lens is not driven until a predetermined time that is an increase in the time lag is provided. Therefore, in step # 1055, the switch (S
The state of 8) is detected to determine whether or not the camera is in the continuous shooting mode. If the camera is in the continuous shooting mode, the process proceeds to step # 1095.
On the other hand, when the mode is not the continuous shooting mode, the process proceeds from the step # 1055 to the step # 1060, and it is determined whether or not the mode is the tracking mode.
In the following mode, the subroutine of operation II is executed to calculate the amount of movement of the subject within the predetermined time set in step # 1065, and then the process proceeds to step # 1070. on the other hand,
If the tracking mode is not set in step # 1060, it is determined that the subject is stopped, and step # 1065 is performed.
Proceeding to step # 1070, the timer is set in the above-described timer R set subroutine in accordance with the count value of the drive counter ENZCNT, and after waiting for 50 msec, the lens is moved. (# 1060 to # 1075).

Next, the subroutine of the operation II in the step # 1065 will be described with reference to FIG. In this subroutine, first,
In step # 2650, it is determined whether or not the camera is in the AF priority mode. In the case of the AF priority mode, the time TC is set to 100 msec. In the case of the release priority mode, the time TC is set to 50 msec. The ratio R is obtained by dividing by TI, and in step # 2670, the defocus amount (count WR) of the object moving within the unit focus detection time is multiplied by this ratio R to obtain the tracking delay defocus amount WS until exposure. In step # 2675, WS is added to the count value of the drive counter ENZCNT, a new count value of the drive counter ENZCNT is obtained, and the process returns. In step # 1095, which proceeds from steps # 1055, # 1075, and # 1090, the motor speed is set to low speed (5000 rpm).
If the speed is not low speed (that is, 20,000 rpm), the motor does not stop immediately even if the motor stop signal is output, so the motor brake signal is output (# 1095). , # 1100). And
In steps # 1103 and # 1107, the count interrupt and the timer interrupt are prohibited, respectively, and the process proceeds to step # 1190. If the speed is low in step # 1095, go directly to step # 11
Go to 90. If the motor is an AF priority motor in step # 1025, it is determined whether or not a flag AFEF indicating the end of focus detection is set. If not, the release flag RESF is reset and the process returns (# 1110, # 1)
170).

In the present embodiment, even if the in-focus state is detected again after the end of the exposure, if the release button is kept pressed, the release is not performed, and if the release button is pressed again, the release is performed. The reset flag RESF is not reset. On the other hand, the release flag RESF is determined in the step following step # 250.
If you proceed to step 15, you can use the method of releasing immediately after focusing.

If the flag AFEF is set in step # 1110, it is determined in step # 1115 whether or not the mode is the tracking mode. If not, the process proceeds to step # 1190. In the following mode, the distance of the moving subject during the release time lag is calculated in the subroutine of the calculation I of step # 1120 (shown in FIG. 17), and the drive counter ENZCNT is calculated.
If the count value is not more than 13, the flag f1F for controlling the motor at 1000 rpm is set, the flow proceeds to a timer R set subroutine for setting a timer for controlling the speed of the motor, and the flow proceeds to step # 1190 ( # 1120, # 112
5, # 1175, # 1185). Drive counter E in step # 1125
If the count value of NZCNT is 21 or less, step # 1185
The routine proceeds to step # 1190 from the timer R set subroutine. Further, if the count value of the drive counter ENZCNT exceeds 21 in step # 1140, it is determined in step # 1145 whether or not the continuous shooting mode is set. If the continuous shooting mode, the release priority mode is used as described above. Then, it is determined that shooting should be performed immediately, and the process proceeds to step # 1190. If it is not the continuous shooting mode in step # 1145, since the AF priority mode is set, the lens is always brought to the in-focus position, so that control for moving the lens for a predetermined time (100 msec) is performed. In other words, the lens is brought to the in-focus position by taking 150 msec together with the release time lag (50 msec). Here, since the mode is the following mode, the process proceeds to the subroutine of the calculation II in step # 1150 to obtain the amount of defocus in which the subject moves during the 100 msec, and the count value of the necessary drive counter ENZCNT is obtained. Then, the process proceeds to a timer R set subroutine to control the speed of the motor based on this value and waits for 100 msec (# 1150 to # 116
Five).

Here, the case of the timer R set in the AF priority mode will be described with reference to FIG. In the case of the AF priority mode, the process proceeds from step # 2780 to step # 2785, and 1000rp
If the flag f1F indicating the m drive is set, the process proceeds to step # 2760 to set A3 (corresponding to 1000 rpm) in the timer 1. If the flag f1F is not set in step # 2785, the driving counter EN is set in step # 2790.
It is determined whether the count value of the ZCNT is 28 or less. If the count value is not 28 or less, a time A1 corresponding to 5000 rpm is set in the timer 1. Similarly, if the count value of the drive counter ENZCNT is 8 or less, the process proceeds from step # 2795 to step # 2760 to set the timer 1 to A3 and control the motor to 1000 rpm.
If it is larger than 28, the process proceeds from step # 2795 to step # 2850 to set timer 1 to A2 and set the motor to 2500
Control to rpm.

Table 3 shows the relationship between the motor rotation speed and the encoder pulse, and the time required for focusing, for each of the AF priority mode and the release priority mode.
It is. To briefly explain the relationship between the number of rotations and the pulse of this motor, in AF priority mode, this mode is selected so that the lens is released when the lens is in focus, so it is higher than the release priority mode Focusing accuracy is required, and the use time of 1000 rpm is extended to reduce stop errors due to motor inertia.

In the AF priority mode, a control method that constantly monitors the number of revolutions without adopting 20,000 rpm is used to improve the focusing accuracy.

On the other hand, in the release priority mode, focus detection accuracy is also required, but since exposure is required earlier than that, the setting time of the motor drive during release is shortened compared to the AF priority mode. I have.

Returning to FIG. 16 (a), in step # 1190, the auxiliary light emitting device (13) is turned off, and the display is turned off (# 11
90, # 1195). Next, a mirror-up start signal and an aperture control signal are output to the exposure control circuit to perform mirror-up and aperture control to a predetermined value Av, and wait for mirror-up to be completed (# 1200 to # 1210). During this time, if the mirror up of about 50 msec is completed, a motor stop signal is output,
Wait 10 msec for the motor to stop, prohibit interrupts, output an exposure start signal, and start running one curtain. (# 1215-1230). Then, the exposure time Tv is measured, and when it reaches a predetermined Tv, an exposure end signal is output and the system waits for the closing of two curtains (# 1235 to # 1240).

Next, proceeding to FIG. 6B, the microcomputer (1) outputs a one-frame winding start signal in step # 1243, and
Make the komamaki.

If it is determined in step # 1245 that the continuous shooting mode is not set, the terminal (op3) is set to the "L" level to disable the timer interrupt, and the continuous shooting flag is reset.
Continue to 1275. On the other hand, if it is determined that the mode is the continuous shooting mode, the terminal (op3) is set to the "H" level to interrupt the timer, the continuous shooting flag is set, and the flow advances to step # 1250.

Then, in step # 1245, it is determined whether or not the camera is in the continuous shooting mode. When the camera is not in the continuous shooting mode, the terminal (OP3) is set to "L" so that continuous shooting is not performed, and the process proceeds to step # 1275. On the other hand, when the continuous shooting mode is set, the terminal (OP3) is set to "H" level in step # 1247, and the timer circuit (1) shown in FIG.
5) Output the timer start signal. Next, when the focus flag is not set or the camera is not in the focus zone, the counter interrupt and the timer interrupt are enabled to drive the motor to drive only the remaining count of the drive counter ENZCNT. Drive and proceed to step # 1275 (# 1250, # 1
255, # 1265, # 1270). If AF is completed during this time and the camera is focused, step # 885 to step # 1275 in FIG.
And loops back to step # 1275. When the focus flag (focus F) is set and the focus is within the focus zone, the focus is displayed in step # 1260, and the process proceeds to step # 1275 to wait for the mirror to be lowered (#
1250 to # 1260, # 1275).

When the mirror down is completed, a signal to stop the motor for driving the lens is output, and this stops for 20 msec.
After waiting, the flags other than the follow-up flag and the continuous shooting flag are reset, the release interrupt is permitted, and the flow returns to the CDINT flow from step # 55 onward in FIG. 2 (# 1280 to # 1295). However, here, steps # 1280 and # 1285 are not always necessary, and it is possible to return to CDINT while driving the lens.

In the present embodiment, when the release button is continuously pressed while the continuous shooting mode is set, the terminal (OP3) goes high and the timer circuit (15) starts counting time. At a predetermined time, a signal that changes from "H" level to "L" level is input to the terminal (INT4) of the microcomputer (1). When this is input, the microcomputer (1) again
16 Start the interrupt from step # 1297 in Fig.
At step # 1297, an "L" level signal is output from the terminal (OP3) to stop the timer circuit (15), and the release flow from step # 1000 is similarly performed.

Next, the flow of the terminal interruption shown in FIG. 20 will be described. This is the process flow when scanning at low contrast, when the contrast of the subject is detected while driving the lens, and the end of the lens is reached without detecting a sufficient contrast level for focus detection. It is.
This end is detected by a switch (S
7) is provided, and this switch (S7) is turned on when the lens reaches either the end position of the closest position or the infinity position, and the terminal (INT3) of the microcomputer (1) is set to the “H” level. , The microcomputer (1) performs the flow of the termination interrupt shown in FIG. In this flow, first, the motor is stopped in step # 1350, and in step # 1355, it is determined whether the flag LBF for retracting the lens is set. If not set, the end is reached with the lens extended. Therefore, in step # 1360, this flag LBF is set and step # 136
Start the inversion drive at 5 and proceed to the CDINT flow in FIG.
If the flag LBF is set in step # 1355, it means that the lens has reached the end after one reciprocation, and it is impossible to detect the contrast.
At 70, the microcomputer (1) displays an impossibility.

Next, a modified example will be described. The contents of the modification are as follows.

1) In the release priority mode during release, eliminate 20,000 rpm of the motor and reduce stop error.

2) In the AF priority mode during release, if the count value of the drive counter ENZCNT does not become 0 within a predetermined time, release lock is performed.

3) In the AF priority mode and the precision priority mode during release, the motor speed is only 1000 rpm, release is possible only when the count value of the drive counter ENZCNT becomes 0, and release lock is performed when it does not become 0. To increase the focusing accuracy.

 A modified example accompanying the above change is shown and described in FIG.

First, in the change accompanying (1), steps # 1095 to # 1107 in FIG. 16A are deleted. This is 20,000rpm
This is because (high speed) disappears (see FIG. 22). This and steps # 1745 and # 27 in FIG.
30, # 2735 is deleted, and this is also deleted because the high speed mode is not in the release (not shown). Step # 255 in the INTEVENT flow
5, Delete # 2570 and # 2575.

Next, a change associated with (2) is that a drive counter ENZC is provided between step # 1150 and step # 1160 in FIG.
Step # 1155 for determining whether or not the NT count value exceeds 148 is inserted, and if it exceeds 148, step # 1170
And resets the release flag RESF and returns. Explaining this value 148 with reference to Table 3, since it takes 60 msec for the pulse number 28, 150 msec to 60 m
90msec after subtracting sec is the time that can be driven at 5000rpm,
The number of pulses that can be driven is 4/3 × 90 = 120.
Add up to 148.

The point that is changed according to (3) is that, after step # 1125 in FIG. 16 (a), a step of determining whether or not the mode is the precision priority mode is provided as step # 1130. Proceed to step # 1145 to prohibit the mode of 1000 rpm or more. Also, after step # 1150, step #
A determination step for determining whether or not the mode is the precision priority mode is provided as 1152. When the mode is the precision priority mode, the count value of the drive counter ENZCNT is 40 or less (150 msec × 4/15 (1000r
pm)), a step # 1153 for judging whether or not the flag is f40 is provided.
Then, the process proceeds to step # 1175 to perform the processing thereafter. If it exceeds 40, the release flag RESF is reset in step # 1170 and the routine returns. Step #
If it is not the accuracy priority mode in 1152, the process proceeds to step # 1155, and the subsequent flow is performed.

Effect of the Invention According to the above configuration, even if the camera is in the AF priority mode, in the continuous shooting mode, the continuous shooting of the second and subsequent frames is performed in the AF operation at the time of the previous release even if focusing is not completed. If the in-focus state is stored, the current shutter release becomes possible. Therefore, when several subjects continuously enter the shooting frame, it is possible to take a picture even if the subject on the rear side is slightly in focus, and obtain a photograph as intended by the photographer. We can provide a camera that can do it.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the apparatus shown in FIG. 1, FIG. 3 is a graph showing an offset of an event counter of a focus detection apparatus, and FIGS. FIG. 20 is a flowchart showing the operation of the apparatus shown in FIG. 1, FIG. 21 is a time chart showing the relationship between whether or not movement integration is possible and the drive control of the motor, and FIGS. 22 and 23 are flowcharts showing modified examples. FIGS. 24 and 25 are diagrams showing the principle of focus detection, FIGS. 26 and 27 are diagrams showing the principle of conventional tracking correction, and FIGS. 28 to 31 are diagrams of the tracking correction principle of the present invention. FIG. 1 ... microcomputer, 2 ... exposure control circuit, 3 ... photometry circuit, 10 ... motor control circuit, 11 ... encoder, 12 ...
... Lens circuit, 13 ... Auxiliary light generator, 15 ... Timer.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Otsuka 2-30 Azuchicho, Higashi-ku, Osaka City International Building Minolta Camera Co., Ltd. (56) References JP-A-61-261709 (JP, A) JP-A-61-258226 (JP, A) JP-A-57-72115 (JP, A) JP-A-57-142630 (JP, A)

Claims (1)

(57) [Claims] A focus detecting means for calculating and detecting a focus position; a means for setting a lens to a focus position in accordance with a result of the calculation; Control means for repeatedly executing the operation and the automatic focus adjustment operation at a predetermined cycle; and automatic focus priority control means for controlling the lens so as not to enter the release operation unless the focusing of the lens is completed even though the release operation is performed. In the camera equipped with, whether the focus detection is impossible as a result of the focus detection calculation by the focus detection means when the continuous shooting mode is set,
An in-focus detection means for detecting that the defocus amount is larger than a predetermined value; a storage means for storing that the in-focus state was at the time of the previous release; and Means for permitting release without performing lens adjustment when focus detection is not possible or when the defocus amount is larger than a predetermined value, and when focusing was performed during the previous release. A camera equipped with a focus detection device, comprising: