JPH0215214A - Automatic focusing camera - Google Patents

Abstract

PURPOSE:To prevent such trouble that follow-up correction is carried out unconditionally during continuous photographing to continuously take greatly unfocused pictures by setting follow-up correction in a continuous photographing mode under prescribed conditions and releasing the follow-up correction under other prescribed conditions. CONSTITUTION:A focus detecting means 1 detects the focusing state of a photographing lens, and outputs a defocus quantity DFO. A changing speed detecting means 2 detects the changing speed VHO of the defocus quantity due to the movement of the object, and based on the changing speed VHO, a following and correcting means 3 obtains the changing amount DELTADF of the defocus amount to correct the defocus quantity DFO. In the continuous photographing mode, the following and correcting means 3 does not operate unconditionally, and is made operable by a follow-up setting means 5 under the prescribed set conditions. Under prescribed release conditions, the following and correcting means 3 is made inoperable by a follow-up releasing means 6. As a result, greatly unfocused pictures are not taken continuously.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic focusing camera that drives a focusing lens toward an in-focus position according to focus detection results, and It is particularly suitable for cameras.

[Prior Art] In conventional automatic focusing cameras, the focusing accuracy when photographing a dynamic subject is lower than the focusing accuracy when photographing a still subject. This is because if the subject is moving, even if the lens is driven to the in-focus position at the time of the current focus detection and the shutter is released, the subject will shift out of focus until the shutter is released. Therefore, JP-A-60-
As disclosed in Japanese Patent No. 214325, it has been proposed to perform tracking correction in which the lens is driven in accordance with the speed of the subject when the subject is moving.

On the other hand, during the release operation, the release operation is performed continuously,
Autofocus cameras are commercially available that have a continuous shooting mode that can take multiple pictures per second.

In addition, in automatic goldfish cameras equipped with such a continuous shooting mode, focus detection is always performed during continuous shooting, so that the necessary focusing accuracy can be ensured even if the subject moves during continuous shooting. It has been proposed to use a continuous AP mode that continues to drive the lens toward the in-focus position based on the results.

[Problems to be Solved by the Invention] In an autofocus camera equipped with the above-described continuous shooting mode, if tracking correction for a dynamic subject is performed during autofocus adjustment during continuous shooting, it is possible to improve the focus on a dynamic subject that is shot continuously. It is thought that focusing accuracy can be improved.

However, if tracking correction is performed unconditionally during continuous shooting,
Under conditions where tracking accuracy cannot be obtained, the amount of defocus may actually increase, resulting in the inconvenience that many out-of-focus photographs are taken in succession.The present invention has been designed in consideration of these points. The purpose of this invention is to provide an automatic focusing camera that can perform tracking correction for a dynamic subject during continuous shooting only under appropriate conditions.

[Means for Solving the Problems] In the present invention, in order to solve the above problems, the first
As shown in the figure, in an autofocus camera that has a continuous shooting mode in which the release operation continues continuously during the release operation, focus detection detects the amount of defocus (defocus DFO) of the photographing lens with respect to the subject to be focused on. Means (1) and speed of change of defocus amount due to movement of subject V
A change rate detection means (2) for detecting HO, and a change amount ΔDF in the amount of defocus due to the movement of the subject are determined based on the output of the change rate detection means (2), and the focus detection result by the focus detection means (1) is determined. A tracking correction means (3) for correcting the focus, and a lens drive means (4) for driving the focus adjustment lens toward the in-focus position according to the focus detection result of the focus detection means (1).
), tracking setting means (5) for switching the tracking correction means (3) from a non-operating state to an operating state in continuous shooting mode;
The present invention is characterized by comprising tracking canceling means (6) for switching the tracking correction means (3) from an operating state to a non-operating state in the continuous shooting mode.

Note that the tracking canceling means (6) is the continuous shooting speed detecting means (7).
When the continuous shooting speed detected by It is desirable that the tracking correction means (3) be a means for switching from an operating state to a non-operating state when the direction is reversed.

However, FIG. 1 is an explanatory diagram showing the structure of the present invention functionally in a block form, and in the embodiments described later, the main part of the above structure is realized by a microcomputer program. To show a specific correspondence, the focus detection means (1) is #107 in FIG. The rate of change detection means (2) is located at #313 in Figure 1O, the tracking correction means (3) is located at #401 to #417 in Figure 12, and the lens driving means (4) is located at #113 in Figure 11. 359, follow-up setting means (
5) are #324 to #329 in FIG. 10, and the following cancellation means (6) is #3o7 in FIG. 10 and #340 in FIG. 11. #
344, the continuous shooting speed detection means (7) is #30 in FIG.
6 and photographing magnification detection means (8) correspond to #325 in the figure.

[Effect] Hereinafter, the operation of the present invention will be explained with reference to FIG.

The focus detection means (1) detects the focus state of the photographic lens with respect to the subject to be focused, and outputs the amount of defocus (defocus DFO). Here, defocus D
FO is a variable whose sign indicates the direction of defocus and whose absolute value indicates the magnitude of defocus.

The lens driving means (4) drives the focusing lens toward the in-focus position based on the defocus DFO (or its correction value) detected by the focus detecting means (1).

The rate of change detection means (2) detects the rate of change VI (◯) of the amount of defocus due to the movement of the subject.

Based on this rate of change V HO, follow-up correction means (3)
calculates the amount of change ΔDF in the amount of defocus due to the movement of the subject and corrects the defocus DFO.

In the present invention, the tracking correction means (3) does not operate unconditionally in continuous shooting modes 1 to 1, but under predetermined setting conditions, the tracking correction means (3) is controlled by the tracking setting means (5).
is in an operating state, and under a predetermined release condition, the following correction means (3) is brought into a non-operating state by the following release means (6).

First, the tracking setting means (5) switches the tracking correction means (3) from the non-operating state to the operating state (10th #329. #330. #335, #331 in the diagram
reference). However, if the change speed of the amount of defocus VI (O) is not within the predetermined range, it may be due to variations in the focus detection results or a change in the subject, so the tracking setting is not performed (#327 in the same figure). (See #328). Further, if the imaging magnification β detected by the imaging magnification detection means (8) is larger than the predetermined value, accurate tracking correction cannot be performed, so tracking setting is not performed (see #325 and #326 in the same figure). . As a result, when tracking correction is required, the tracking correction means (3) operates only when accurate tracking correction is possible.

Next, the tracking canceling means (6) is, for example, the continuous shooting speed detecting means (
If the continuous shooting speed detected in step 7) is slower than the predetermined speed, the tracking correction means (3) is switched from the active state to the non-active state ( (See #306 and #307 in Figure 10)
. Further, if the photographing magnification β detected by the photographing magnification detection means (8) is not within the predetermined range, accurate tracking correction cannot be performed, and therefore tracking is canceled (see #344 in FIG. 11). Furthermore, if the direction of the rate of change VHO detected by the rate of change detection means (2) is reversed, it is possible that the subject has suddenly stopped, the direction of movement has been reversed, or the photographer has panned the camera. Because it can be considered,
It is determined that it is not time to carry out tracking correction, and the tracking is canceled (see #340 in FIG. 11). This prevents inaccurate tracking correction or inappropriate tracking correction from being continued, and eliminates the inconvenience of continuously taking many out-of-focus photographs.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a single-lens reflex camera with interchangeable lenses, where 101 is a camera body and 102 is a zoom lens which is an example of an interchangeable lens (photographing lens). A main mirror 103 is composed of a reflecting part and a transmitting part. The light passing through the photographic lens is reflected by the reflecting part of the main mirror [03], and is then sent to the finder optical system (not shown).
While being guided to the
Leads to 4. Zabu mirror 104 is main mirror 103
The light that has passed through is reflected to the focus detection module 105.

FIG. 3 shows the camera body [0] viewed from the front. As mentioned above, ]0] is the main mirror of the camera body 10B, 105 is a focus detection module, and 106 is a mechanical unit 1 configured to automatically perform mirror up, exposure operation, film winding, and rewinding. Since these are not directly related to the present invention, their explanation will be omitted.

FIG. 4 shows a circuit diagram of a camera to which the present invention is applied. Reference numeral 201 is a camera control microcomputer that performs functions such as sequence control of the entire camera, exposure calculation control, and calculation control of AF 1 to focus (hereinafter abbreviated as AF). It is equipped with input/output terminals P1 to P, 21, etc. 202 is an AF distance measuring unit that measures the amount of defocus of a subject image, and includes a one-dimensional self-scanning image sensor (hereinafter abbreviated as CCD);
It consists of a driving section, an A/D conversion section, a reference power generation source for A/D conversion, etc. The image information obtained by this CCD is A
The data is taken into the CPU 201 via the F data bus 201a. 203 is a display unit consisting of a liquid crystal display (LCD) or a light emitting diode (LED);
Automatic exposure (hereinafter abbreviated as AE) sent from PU201
The display unit 203 displays information such as the shutter speed Tv, aperture value Av, in-focus/out-of-focus, and photographing mode, which are the calculation results. A lens data circuit 204 is provided inside each interchangeable lens 102 and stores the maximum aperture value, the minimum aperture value, the focal length, the extension amount conversion coefficient necessary for focus adjustment, and the like.
02 is attached to the camera body 101, the data is transmitted to the camera body 101 via an electrical contact provided near the attachment part. Reference numeral 205 denotes a photometry unit that measures the brightness Bv of the subject, and is composed of a photoelectric conversion element for light reception, an A/D conversion unit, a reference voltage source for A/D conversion, a data exchange unit with the CPU 201, etc., and receives commands from the CPU 201. The light passing through the photographic lens is measured according to the following. A film sensitivity reading section 206 automatically reads the sensitivity of the loaded film, and the film sensitivity on the film cassette is read through an electrical contact provided in the cassette chamber of the camera.

The display section 203, lens data circuit 204, photometry section 2
05, each piece of information from the film sensitivity reading unit 206 is input as a serial signal to the serial input/output unit 201c (abbreviated as serial I10 in the figure) via the serial data bus 201b. 207 is a sequence motor M4 for winding and rewinding the film, an AF motor M2 for driving the lens for AF, and a driver control unit for exciting various magnets required during exposure operation, and an output terminal P8 of the CPU 201. ~P1.6 is controlled by control output lines CMDO~CMD8. SW1～
SW3, SW5 to SW], and O are switches, one end of which is grounded, and the other end connected to input terminals P1 to P7, P2O, and P21, respectively. S
WI is a switch that turns ON when film charging starts and turns OFF when film charging is completed. SW2 is a switch that turns ON while mirror is up and turns OFF when mechanical charging is completed. SW3 is a switch that turns 0N10F multiple times during film running.
This is a switch that repeats F. SW5 is a photometry switch that is turned ON in the first step of pressing down a shutter button (not shown), and the CPU 201 outputs a signal to start photometry and distance measurement. While this switch SW5 is ON, if the lens is in an out-of-focus position as determined by distance measurement, the lens continues to be driven, and when it reaches the in-focus position, the lens stops driving. When the button is released and the switch SW5 is turned off, the driving of the lens is stopped.

SW6 is a release switch that is turned ON in the second step of pressing down the shutter button, and if this switch SW6 is turned ON when the release is possible, the CPU 20
1 commands the release operation t. Note that when the release switch SW6 is turned on, the photometry switch SW5 is configured to be kept in the on state. SW7 is a film detection switch provided in the film running path, and if there is a film at this film detection switch SW7, switch SW7 is activated.
is OFF, and turns ON when the film runs out.When rewinding, this switch SW7 changes from OFF to OFF.
If N, it indicates that the film is slightly out of the cartridge, and is used as a switch for determining the end of rewinding. SW8 is a cartridge detection switch provided near the electrical contact of the film sensitivity reading unit 206 provided in the cartridge chamber of the camera, and is turned on when a cartridge is placed in the cartridge chamber and the camera back is closed. , OF without a patrone room
It becomes F state. SW9 is a back cover opening/closing switch, which is turned ON when the back cover is completely closed. 5WIO is a multiple exposure mode changeover switch, and when it is turned on, the multiple exposure mode is set.

RESET is set by resistor R] to control power supply voltage -I-V
There is a reset terminal that is pulled up to pD, and after the power is turned on, it is charged via capacitor C1 or resistor R1,
It is set by the CPU 201 when the voltage changes from the "Lo11" level to the "HiHb" level. X is a crystal oscillator for providing a clock signal to the CPU 20].

Next, the driver control section 207 and each control section will be explained. ], CMg is Macunet 1 for holding shutter 1 curtain.
~, and when the control output line ICMGO reaches the "Lo4" level, magnets 1~] and CMg are energized and the shutter 1 curtain is held. 2CMg has a magnet for holding the second shutter curtain, and the control output line 2CMGO
When becomes I LO da II level, Makunet 1-2
CMg is energized, the second shutter curtain is held, and the first
This corresponds to the shutter speed or the time between when the curtain shutter is released and when the second curtain shutter is released.

FMgl, itm shadow lens aperture locking magnet I.
When the control output line PMGO reaches the "Lou+'" level, power is applied to the Macnet I-FMg and the aperture (
When the locking member is held and released, the aperture locking member operates to lock the aperture in a predetermined position. RMg is a magnet for release, and when the control output line RM G becomes "Lou+" for a certain period of time, the release member is unlocked, the aperture is narrowed down, and the mirror is raised.

Q1~QIO is Z-Kensmoke M1 and AF Momo-M
This is a 1-transistor for driving No. 2. This sequence motor M1 has two types of coils inside, and can obtain the characteristics of high 1 herk low speed rotation and low 1 to 1 herk high speed rotation, and can switch between both characteristics, and can also rotate in forward and reverse directions. 1 to transistors Q1 to Q6 are connected as possible. That is, the high-speed terminal I] of the sequence motor M1 is connected to the common connection point between I-ransistor Q and Q2, the low-speed side terminal is connected to the common connection point between transistors Q3 and Q4, and the remaining common terminal C is connected to the common connection point between transistors Q1 to Q5. and Q6 are respectively connected to the common connection point. 1 to transistor Q1 in Table 1
This shows whether the rotation state of the seek smoke M1 changes as shown in the on/off state of Q6.

Table 1 Note that in this embodiment, the high speed brake is not used, and only the low speed brake is used. Therefore, in the following explanation, the term "brake" refers to the low-speed brake SBR. Q7 to Q], O are transistors for driving the AF momo-M2, and are connected in a bridge configuration so that the AF momo-M2 can be rotated in forward and reverse directions. AF Momo-M2 is rotated forward to push the lens out, and reversed to retract the lens. O
M1 to M1-0 are control output lines for switching the respective transistors Q1 to Q10.

211,. 212 is an aperture encoder and an AF encoder consisting of a photo coupler, and an input signal line PT];
, PT2 are connected to the driver control section 207 through the driver control section 207. The aperture encoder 211 monitors the stroke of the aperture pre-seller 1 to the lever at the time of release, and the light emitted by the light emitting diode 2]1a is detected by the phototransistor at the time of release, and is input to the driver control unit 207 via the input signal line PTI. . After the waveform is shaped into a pulse by this driver control unit 207, it is passed through an output signal line FP to an input terminal P of the CPU 20.
], sent to 8. A. The F encoder 2]2 is for monitoring the rotational speed of the AF momo-M2 for driving the lens during AP, that is, the amount of movement of the lens, and the light emitted by the light emitting diodes 21 and 2a is sent to the transistor 23. 21) and is input to the driver control unit 207 via the input signal line PT2. After being waveform-shaped into a pulse by this driver control unit 207, the C
It is sent to input terminal P19 of PU201. This output signal line AFP is also connected to a counter 201d inside the CPU 201, and is used to monitor the extended position of the photographic lens. In other words, the counter 201d is cleared to 0 at the ω end of the lens, and by setting it to count up when driving in the side direction and count down when driving in the ω direction, the number of pulses delivered from the ω end of the lens can be determined at any time. You can get it. This AFP signal is sent to CPU2
It is also connected to the 01 interrupt terminal (not shown), and the AF
An interrupt is generated at the falling edge of the P signal. Also, CPU20
1 has a built-in timer 201e, and is configured to be able to read the time by counting an internal clock. Furthermore, the CPU 201 has a built-in so-called E2PROM 201f that can be electrically written to and read from and retains memory contents even when the power is turned off. Further, the CPU 201 includes an interrupt timer (not shown) that generates a timer interrupt when a set time has elapsed.

(Margin below) Table 2 In the table, H is "igb" level L means =IL　o, IT level.

Table 3 In the table, H is “’High° level”. L means 'Loiu' level.

CMDO to CMD8 are output terminals P8 to P of the CPU 201 to control the control unit 207], 6
It is a control output line output from CMIT)0,C
The MDI controls the control output lines RMGO and FMGO for controlling MacNel-R, M-BI, and FMg, respectively, and the CMD
2 According to CMDB, Macnet 1~], CM
g, 2CM8 control control output line] -CM GO, 2C
Control MGO. In addition, control output lines for driving the sequence motor M) ○M1 to ○ are set by CMD4 to CMD6.
Control M6, CMD7. AF motor M by CMDB
2 drive control output lines OM7 to OM] and O.

Table 2 shows the control of the sequence motor M, and Table 3 shows the control of the AF.
Control of motor M2 is not shown. In the table, H means "High" level and L means °'LOL11 level.

AMg is a lock releasing machine that shakes the film still.
and 1 to Runcisstar Q11. CP via resistor R2
It is connected to the output terminal P], 7 of U20]. 1-The connection point between the base of transistor Q11 and resistor R2 is resistor R.
Grounded via 3. Output terminal P of CPU 201
], 7 are normally in the "I-, o +u" level, and the transistor Q1-1 is in an off state, so that the magnets 1 to AM-B are not energized and hold the attracting piece by suction. In order to release the engagement between the winding stopper and the winding stopper lever, the CPU 20 output terminal P], 7 or "High" is connected.
When it becomes "h", electricity is energized to the McNell-AM and the adsorption force disappears.

Next, a series of release operations in this embodiment will be explained with reference to FIG. As shown in the figure, the release operation is roughly divided into four sequences: mirror up, exposure, mechanical charge, and film charge.

In the mirror-up sequence, 1. The main mirror is retracted, and the diaphragm of the photographic lens is unlocked to narrow the diaphragm. The exposure sequence is the 1st and 2nd act of the focal plane shutter.
The exposure time (shutter speed 1~) is controlled by controlling the curtain. In the mechanical charge sequence, the main mirror, submirror, photographic lens aperture, and shutter curtains 1 and 2 are energized by a splash for the next release.

In the film charging sequence, the film is advanced.

This will be explained in more detail below using timer 1. As already explained in FIG. 4, the switch SW6 has the following functions.
When the shutter button is pressed down two steps, it is turned on and the release operation is started. When the release operation starts, first, by setting the control output line RM GO to the "Lou+'" level, the release lens l□ RM g is energized, and the main mirror, which is biased by the spring, is locked. Release. As a result, the main mirror is retracted to the finder side, and the sub-mirror is also retracted in conjunction with the main mirror. Next, the control output line FMG
By setting O to "Lou+" level, the magnet FMg for locking the aperture is energized, and the aperture of the photographic lens, which is biased by the spring, is released from the lock. When the lock is released, the aperture starts, but the state of the aperture at this time is as explained in Fig. 4.
1 to transistor 211+1 to 1 to driver control unit 20
7, the waveform-shaped FP multiplied signal is sent to CPU2.
01 is input. The CPU 201 generates a number of FP multiplication signals corresponding to the aperture value based on a predetermined exposure calculation, sets the control output line FMGO to the "Higl+" level, stops the aperture, and sets the photographic lens to the desired aperture value. be done. Next, in order to perform the exposure operation, the control output line becomes 'Low' at the start of release], CM
One control output line 1cMG of GO2CMGO.

is the 'High' level.This causes one curtain of the focal plane shutter to run.After the exposure time according to the predetermined exposure calculation has elapsed, the other control output line 2CMG
By setting O to ``gh'' level, the two curtains of the focal plane shutter run and exposure control is performed.After exposure, a mechanical charge sequence begins.The mechanical charge sequence begins with the sequence motor M
Since high torque is required when starting 1, low speed mode FF
(L) and then, when a predetermined rotational speed is reached, the mode is switched to high-speed mode F(H) with low torque and high-speed rotation. As a result, the sequence motor M can be driven efficiently, and high-speed mechanical charging and film charging can be achieved.

By this rotation of the Z-ken smoke M1, the main mirror and the sub-mirror are lowered and biased by the spring, and at the same time, the aperture of the photographing lens and the first and second curtains of the focal plane shutter are also biased by the spring. When this mechanical charging is completed, as already explained, the switch SW2 is turned off as a mechanical charging completion signal. CPU
20] detects that the switch SW2 is turned off, it shifts to the film charging sequence. This releases the lock that fixes the film and starts winding the film. At this point, switch SW1 for monitoring film charge is turned on, and film winding is performed by sequence motor M1. When film winding for one frame is completed, switch SWI is turned to O.
It becomes an FF and is notified to the CPU 201. CP, U2
01 is a brake (not shown) in order to stop the sequence motor M when the OFF of the switch SWI is detected.
Multiply by This completes the release operation for one frame.

Next, the sequence in the continuous shooting mode in which the camera is continuously released while the switch SW6 is ON will be explained with reference to the time chart of FIG. 6, including the focus detection operation. The section ■ in FIG. 6 indicates the first frame of continuous shooting, and the section ■ indicates the second frame of continuous shooting. Section I of the first frame of continuous shooting is as explained in FIG. By the way, in order to perform focus detection, it is necessary that the main mirror and sub-mirror are lowered and stabilized. Therefore, the switch SW2 is turned OFF, and after the mechanical charging is completed and a period of time for mirror stabilization is waited, CCD integration is started. In this embodiment, this waiting time is set to 30 m5ec. In the figure, the part not shown by ■ is the integration time of the CCD, and the part not shown by Dl is the CCD.
It shows the data dump time for A/D converting the pixel data of and importing it into the memory of the CPU 201. When the pixel data of the CCD is taken into the CPU 201, reliability of defocus, defocus direction, and focus detection is determined by predetermined calculations. Since this focus detection calculation is not directly related to the present invention, a description thereof will be omitted. Now, when the first film charge is completed, the switch SW1 is turned OFF, and the sequence motor M is activated by the low speed brake S.
BR is applied.

At this point, the CPU 201 determines whether the switch SW6 is ON. If the switch SW6 is ON and the continuous shooting mode is set, then the second frame, which is indicated by section 3, starts to be released. In the case of this second frame, to release the film immediately after charging the film, in order to ensure that the film stops, wait for a while with the low speed brake SBR applied to the sequence motor M1, and press the release magnet RM.
g is energized. Now, if the result obtained in calculation 1 is that the camera is in focus, you can take an in-focus photo even if you release the camera next time with the photographic lens stopped, but if it is not in focus, you can continue to release the camera next time. For example, out-of-focus photos may be taken. In particular, when shooting in continuous shooting mode, there are many cases where the subject is moving and the defocus changes over time, so in calculation 1, the defocus due to the movement of the subject is Detect minutes. By performing this defocus drive while the mirror is up, it is possible to obtain an in-focus photograph even at the next release. A in Figure 6
The AF Momo-M2 column shows the driving state of the photographing lens by AF Momo-M2, and one line indicates the OFF state and the AFM
indicates that it is being driven in either direction.

To compensate for the defocus amount obtained as a result of calculation 1 or for the movement of the subject, the photographing lens is driven during mirror up in the next section (3). Furthermore, when the control output line RMGO is at the "Low" level, that is, when the release magnet RM is energized, the A
The power to F Momo-M2 is turned off. This is because the current flowing through the release magnet RMg is very large, and if the AF Momo-M2 is driven during this time, the A
To avoid problems such as the drive accuracy of F MOMO-M2 decreasing, or the current flowing through the release magnet h RM g decreasing, causing the mirror to be unlocked and not being able to raise the mirror. It is.

Thereafter, similarly to the first frame, the release is continued while the switch SW6 is ON.

Next, the operation of this embodiment will be explained using flowcharts 1 to 1 shown in FIG. 7 and subsequent figures. FIG. 7 is a flowchart when the photometry switch SW5 mentioned above is turned on.

When the switch SW5 is OFF, the camera is in a low power consumption mode, a so-called sleeve mode. switch SW5
When turned on, clock oscillation starts and is activated.

When the CPU 201 starts up, it sends a start signal and a clock to the peripheral IC at #1.01, and sets the boat's initial A.
Performs startup processing such as live performance. Next, in #102, the first BIJ of flannel, constants, etc. used in the program is performed. Subsequently, in #103, serial communication is performed with the switches of each part of the camera body, flash, lens, display element, etc. Furthermore, in order to discharge unnecessary charge from the CCD, which is the focus detection element, initialize it to #104.
It will be held at

Continuing, start focus detection FICD I NTA (# ),
05 onwards). First, prior to CCD integration,
At #106, the integration start time is input to the memory Tll of the CPU 20 from the timer and saved.

Similarly, the counter indicating the lens position mentioned above is set to -1~,
Save to Memory T]. Thereafter, in step #107, CCD integration is performed to obtain a signal level appropriate for focus detection. When the CCD integration is completed, the timer value is saved in the memory TM2 and the counter value is saved in the memory T2 in #108. Next, at #109, memory T
Save the value of memory TM in M L and safe (TM2-TMl)/2 in memory TM. TMI, TM2
indicate the integration start and end times, respectively, and (TM2
TMI)/2 means the time of the center of integration. That is,
#109 Then store the previous integration center time in the memory TML,
The current time at the center of the minute is saved in the memory TM. Similarly, regarding the counter value, the value of the memory MI is saved in the memory M I L at #]1-0, and (T2-TI>/2 is saved in the memory MI. As mentioned above, the counter value is the value of the lens position Tl
, T2 indicate the lens position at the start and end of integration, respectively, and (T1-TI, )/2 indicates the lens position at the center of integration. That is, in #Coni0, the previous lens position of the center of integration is saved in MII-, and the lens position of the current center of integration is saved in MI.

Next, in #111, each pixel data of the CCD is sent to the CPU2.
0 ]- Perform data stamping. With this CCD pixel data, #112
Save the value of memory DFO in memory LDF. At this point, focus detection by CCD integration in #]07 has not been performed, so the process in #]12 stores the previously detected focus DFO in the memory T.
-DF This means you are safe in F. In #113, focus detection calculation is performed based on the integration f, 2 CCD pixel data in #]07, and the defocus DFO and defocus direction of the photographing stamp as well as the reliability bat of focus detection are calculated. . Subsequently, serial communication and exposure calculation are performed at # here 4, and photometric values are displayed and each switch is sensed. For example, #107 to #3.1 /I
If the switch SW5 is turned off during this time, it is detected at #1]4, the display is turned off, the motor is turned off, etc., and the process shifts to sleeve layering again. When the serial communication and exposure calculation are completed, the process proceeds to #]15, and the Furano VLYF determines whether or not continuous shooting is currently being performed. The continuous shooting flag VLYF is set to 1 when the photographer selects continuous shooting mode 1 to 1 during the winding operation, which will be explained later. This #115 judgment indicates continuous shooting flag ■L Y F
If is 1, the flow branches to continuous shooting A, F (#30], ). The flowchart of continuous shooting AF) will be explained in detail later using FIG. 10.

Now, if the continuous shooting flag is V L Y F or 0, #11
The process proceeds to step 6, where it is determined whether or not the camera is in focus.

In this focus determination, if the reliability of the focus detection in #113 is higher than a predetermined value and the defocus DFO is smaller than a predetermined amount, it is determined that the focus is in focus. In this case, the predetermined amount is
It is set to 100μIn. Also, this value takes into account the depth of focus from the aperture value of the photographic lens set by exposure calculation, and is calculated as follows: 60 ttm + 8 X (2j!og2F
No+ 1. ) may also be set. Here, FNo is the F number of the aperture value.

In addition, this predetermined amount is the E2 of the CPU 20 described earlier.
It is written in PROM20 if. This makes it possible to write small values for users who want high precision, and large values for users who want feel and focusing time, allowing us to respond to users in detail.

If focus is determined in #116, proceed to #117,
Focus is displayed. After in-focus display, exposure recalculation and serial communication are performed. This is done in order to reflect the focus detection result in the exposure calculation. Thereafter, the process waits while performing serial communication in #120 until the ON state of the switch SW6 is detected in #119.

If it is determined in #116 that the focus is not in focus, #121
The process proceeds to the subsequent out-of-focus processing 0UTFS.

First, turn off the focus display in step #122, and then turn off the focus display in step #123.
In order to perform the next focus detection without driving M2,
The process branches to focus detection processing CD INTA after #105. If there is no low contrast, proceed to #124 and A
After starting the drive of F Momo-M2 and waiting until the drive is finished in #125, in order to perform the next focus detection, start the drive in #105.
The process advances to the subsequent focus detection process CD INTA. In #124, the defocus DFO is multiplied by the conversion coefficient KL obtained from the photographic lens to calculate the number of drive pulses ERRCNT for the AF momo-M2 described above.

In other words, the number of drive pulses ERR,CNT is ERRCNT
= Determined by DFOXIgL. At #125, the AFP signal for monitoring the rotation of AF Momo-M2 is detected for the number of drive pulses ERRCNT.
is driven. Note that this conversion coefficient KL varies depending on the focal length of each photographing lens, and is sent from the photographing sense through serial communication. Thereafter, the same process is repeated again until focus is determined in #105 to #116.

Next, a description will be given of the processing after the ON of the switch SW6 is detected in #119. In #126, it is determined whether the number of drive pulses ERRCNT is smaller than the constant NPI written in the E2PROM 201f mentioned above (#126>.
If the number is greater than I, a constant N is added to the drive pulse number ERRCNT.
Please reset the PI #127), drive pulse number ER, RC
If NT is smaller than the constant NPI, leave it as #1
Proceed to 28. In #128, it is determined whether the defocus DFO determined in focus in #116 is smaller than the constant DFCI. If DFO<DFCl, the process branches to release (#131) to immediately perform a release operation. If DFO≧DFC1, the process proceeds to #129, and it is determined whether the number of drive pulses ERRCNT is smaller than 4 pulses. If the drive pulse number ERRCNT is smaller than 4 pulses, the process immediately branches to release (#131). If the number of driving pulses ERRCNT is 4 pulses or more in #129, driving of the AF momo-M2 is started in #130. In the processes from #126 to #131, it is determined whether or not to drive the photographing lens during mirror up.

As already explained, in step #116, focus determination is performed based on whether the detected defocus is within a predetermined defocus range. If this focusing range is made very small, accuracy will increase, but it will take time to focus due to variations in focus detection, camera shake by the photographer, etc. Alternatively, problems such as small hunting of the photographic lens may occur. Furthermore, when the subject is a moving object, the detected defocus changes moment by moment, so no focus determination is made. For this reason, this focusing range is set to be wide enough to absorb variations in focus detection or changes in defocus due to changes in the subject. However, in this case, the defocus corresponding to the focusing range remains as an error. For this reason, this remaining defocus is used during mirror up to create an even more accurate autofocus camera. Also, in order to shorten the release time, the number of pulses that can be driven during mirror up is limited to a constant NPI #126. #127), if dimensional accuracy is ensured, then #128 and DFO<D
In the case of FCI, or if the number of drive pulses ERRCNT is less than 4 with #]2, the shutter is immediately released, taking into consideration the drive accuracy of the A and F motors M2.

Next, a series of release controls (#20 and subsequent steps) including mirror up, exposure time control, mechanical charge, and film winding will be explained using FIG. First, #202 does not indicate that power is being applied to the release pin 1-R, Mg, and sets 1 to the flag RMG○NF.
-C, #203 turns the power to AF Momo-M2 to 0FFL,
At #204, power is applied to the shutter shutter curtains 1 to RMg and the shutter curtain holding shutters lcMg and 2CMg. After that, after waiting for some time in #205, energize the release magnet RM g in #206, ○FFL, #
207 and clears the flag RMGONF to 0. this#
In step 204, through the process #206, the main mirror submirror is locked or released, and mirror-up is started. Also,
By processing #202, #203, and #207, MacNet 1
-While power is being applied to RMg, power to A and F motors M2 is prohibited. Specifically, the control of the AF Momo-M2 is performed by turning on the A and F motors M2 by a timer interrupt that occurs at predetermined time intervals, and braking by the AFP signal interrupt. Flag RMGON
When F is C, turning on of AF motor M2 and braking are both prohibited, and A and F motors M2 are turned off.

When the flag RM G ON F is reset, driving of the AF momo-M2 is automatically restarted by a timer interrupt. The above processing is for MacNet 1-R, Mg for release.
A large current is required to energize the camera. be exposed.

When the mirror-up is started, the magnets 1 to FMg for locking the aperture are energized in step #209.

As a result, the diaphragm of the photographic lens is unlocked and the aperture of the photographic lens is started. At #210, the pulse of the aperture encoder 21 described above is applied to the pulse 1, and when the pulse set by the exposure calculation is divided, at #211, the magnets 1 to FMg are de-energized and the aperture is fixed. After this, at #2] 2, press the release button)~RM
Wait for the predetermined time t1 to elapse from the energization to #2
Proceed to step 13. In #213, in order to prevent the photographic lens from being driven during exposure, turn off the power to the AF motor M2 to 0FFL, and then in #214 turn off the sequence motor M.
Make it FF. As described above, the sequence motor M1 is braked until it is turned off in #214 for the second and subsequent frames of continuous shooting.

#215: Magnet I for holding shutter 1 curtain
By turning off the power to CM g, one curtain of the focal plane shutter runs, waits for the shutter speed at #216, and energizes the magnet 2CMH for holding the second shutter curtain at #2]7. OFF and run the second curtain of the focal plane shutter. This completes the exposure. #2] 8. Then safe the timer value in the memory TIME1. #21
Then, in order to wait for the second curtain of the focal plane shutter to complete its travel, the process waits for a predetermined time L18 to elapse, and then moves to the winding routine (#220).

In the winding routine (not shown in Fig. 9), first, in #221, the sequence motor M1 is energized in low speed mode, and in #2
After waiting for a predetermined time until the rotational speed of the motor M1 increases in step #22, the high-speed motor is energized in step #223. As a result, mechanical charging progresses, and wait until switch SW2, which is the mechanical charging completion signal, turns OFF at #224.

When the switch SW2 is turned OFF and the mechanical charge sequence is completed, since the main mirror and the main mirror are in a down state, TTI-photometry is possible, and photometry is started at #225. In order to proceed to the film charge sequence, as described above, the stop release magnet A M g for stopping the film is energized for a predetermined time t6 (#226).

Then, for a given time. The process waits for a period of time (#227), and then moves to #228. This predetermined time tlo is set to 3Qmsec in this embodiment, and is a waiting time for stabilizing the submirror. In #228, it is determined whether or not continuous shooting mode is selected by the photographer. If it is continuous shooting mode, in #229, the continuous shooting flag VLYF indicating that continuous shooting is in progress is set to 1. After setting, focus detection processing C after #105 is performed in order to perform focus detection next time.
Proceed to DINTA (#230). On the other hand, when not in continuous shooting mode, switch SW6 turns OFF and #
After waiting at 231, focus detection processing C-
Proceed to DINTA.

The automatic focus adjustment operation during continuous shooting will be explained using the flowchart in FIG. #1 from #230 in Figure 9
After proceeding to the focus detection process CDINTA from 05 onwards, focus detection calculation and exposure calculation are performed as explained in FIG. 7, and the process branches to continuous shooting AF (#301) at #115. First, at #302, exposure calculation and serial communication based on the photometric values started at #225 in FIG. 9 are performed.

This makes it possible to always obtain appropriate exposure even if the subject brightness changes during continuous shooting. Subsequently, in #303, the process waits until the switch SW] is turned off. That is, focus detection during film charging is limited to one time. This is to prioritize the next release since this is a continuous shooting mode.

When the OFF of the switch SWI is detected, the film charging sequence is completed, and the brake is immediately applied to the Siegens motor M1 at #3o4. In #306, it is determined whether the time required to wind the film is longer than a predetermined time. Film winding time varies greatly depending on the tension of the film, power supply conditions, number of frames, etc. If it is determined in #3.6 that the film winding is slow, then in #307 the following mode flag TF and the first time following flag Tl5TF are reset. The following mode flag TF will be explained later, but when the subject is a moving object, it is set in the following mode to correct the movement of the subject. When it is determined in #306 that the film winding is slow, the continuous shooting interval is long and an error occurs in the correction for subject movement, so the tracking mode flag TF is reset.

In #308, it is determined whether the focus detection result is low contrast. If the contrast is not low, the process branches to #309 and the previous ignore flag LIF is reset. This previous ignore flag LIF is set when the next release is performed while ignoring low contrast during continuous shooting. Next, in #310, VHO is stored in VHI as the previous defocus speed (velocity at the image plane of the subject), and in #313, the current defocus speed VHO is stored in VHI.
seek.

The calculation of the defocus speed VHO in #313 is performed as follows. At the time of #313, the current focus detection result is stored as a defocus DFO. The previous focus detection result is saved in the memory LDF by the process #112 in FIG. Also, the lens position at the center of integration of the CCD that obtained the defocused DFO is:
Through the process #110 in FIG. 7, the lens position at the center of integration of the CCD at which the previous defocus LDF was calculated is saved in the memory MIL. As a result, the defocus change δDF caused by the movement of the subject is: δDF=DFC1-LDF-(MI~MIL)/KL・
...■ is calculated. DFO-LDF is the change in defocus, and (M I - M I L)/KL is the defocus due to the movement of the lens during that time. On the other hand, the time Δt required during that time can be determined by subtracting the previous integration center time from the current integration center time.

From the process #109 in FIG. 7, Δt=TM-TML...■ is calculated. From equations (1) and (2), the subject speed VHO is determined as VHO-δDF/Δt.

After finding the subject speed VHO in #313, #319/\
and proceed. - On the other hand, if it is determined in #308 that it is to go to low contrast 1 Hellas 1, the process proceeds to #311. #3
+-1, it is determined whether the previous ignored flag is L (F) or 1h) O. If it is cleared to 0, proceed to #312, set the previous ignored flag LIF to 1, and detect this time. 0 for defocus DFO, 0 for drive pulse number ERRCNT
Set. #3] In 1, the previous ignore flag LIF
If it is set to 1, the release routine of #314 OUTR.

Branch to V2 and set the follow mode flag TF at #315.
After resetting the following initial flag Tl5TF, which will be explained later, and clearing the continuous shooting flag VLYF in #317, the process jumps to 0UTFS in #121 of FIG. 7 (#318). Side” 2, #318 from #308
If low contrast is detected twice in a row during focus detection during continuous shooting, continuous shooting mode is canceled, release operation is prohibited, and the focus is restarted again according to the flowchart explained in Figure 7. If you don't rush the release, you will be prohibited.

As a result, in the case of a moving subject, even if the subject moves out of the focus frame during continuous shooting, or if there is a subject without contrast 1 to last, it is possible to take a picture at least once, resulting in so-called dramatic The chance of missing a moment is greatly reduced. However, the probability of significant defocusing is low. In particular, in continuous shooting mode 1', there are many cases where the photographer wants to prioritize the release, and the effect is great. Moreover, if low contrast (1 Hellas) is detected twice in a row, continuous shooting will be interrupted until the focus is refocused, so the release will not be continued with a large defocus. Even if the photographer inadvertently shoots an unintended subject, or if the front of the photographic lens is covered with a hand, the film will not be wasted. #3]2
Since this time the low contrast is set to 1, the number of defocus DFO 1 driving pulses ERRCNT is undefined. Therefore, each of these is set to O. Also,
Defocus speed V T (0 is not updated because it cannot be calculated.

That is, the previously detected defocus speed V H0 is used. Subsequently, in #319, it is determined whether the current tracking mode is selected. If the tracking mode flag TF has been reset and the tracking mode is not in effect, the process proceeds to #320 and the defocus speed V determined in #313 is determined.
Compare HO and constant VEI, and if VHO>VEI, set constant F Z to INFZ, which is the focusing range, in #321.
RE L], #322 if VHO≦VE]
Set the constant FZREL2 at . FZ
RE T-1 is set narrower than F Z REL 2. If the defocus speed V HO is small, the subject is stationary, and in this case the defocus change due to subject movement is small, so set a wide range and set the defocus speed V HO to a large value. in case of,
Since the defocus change is large, set a narrow focusing range. As a result, when the subject is stationary, the shooting lens does not have to be driven much, and stable and high-speed continuous shooting is possible. achieves high-precision continuous shooting with little tracking lag by using a narrow focusing range. Also, these constants VEI, FZRELI, P
Z RE L 2 is E2PROM20 in CPU20]
1f, and can be rewritten according to the photographer's preference. In #323, the focusing range INFZ set in #321 and #322 is compared with the currently detected defocus DFO. If it is smaller than the defocus DFO heating range INFZ, it is determined that the accuracy is sufficiently high, and the process proceeds to #37o, where it is determined whether the switch SW6 is ON or not. If the switch SW6 is ON, the photographer has requested the next release, and the process jumps to the next release (#371). That is, when accuracy is ensured, the next release is performed without performing mirror-up driving. If switch SW6 is ○FF, #
Cancellation processing after 372 ○ Branch to UTRv, #37B,
At #374, continuous shooting flag VLYF, tracking first flag T
After resetting l5TF, the process jumps to focus detection processing CD INTA after #1o5 in order to perform the next focus detection (#375).

On the other hand, in the judgment of #323, the currently detected defocus DFO
If the value is greater than or equal to the focusing range INFZ, the process advances to #324 to determine whether the photographic lens is driven or in tracking mode. In #324, it is determined whether the subject brightness is bright or dark. Specifically, the determination is made based on the integration time of the CCD and the gain multiplied by the output data, and if it is dark, the process branches to #333. If it is bright, the process proceeds to #325 and calculates the image magnification β of the subject. In #326, it is determined whether the image magnification β is larger than the constant B ET A LOCK. β> B E T A L O
In the case of CK, the process branches to #333. β≦BETA
In the case of LOCK, the process proceeds to #327, and it is determined whether the defocusing speed VHO is greater than the constant RVMIN. #333 if VHO≦RVMIN
If VHO>RVMIN, the process branches to #328. In #328, the defocus speed VHO is set to a constant R.
Compare with VMAX.

If VHO≧R, VMAX, branch to #333,
If VHO<RVMAX, the process advances to #329. #3
In step 29, it is determined whether the current and previous defocusing speeds ■HO and VHI determined in steps #31o and #313 are in the same direction or in opposite directions, and if they are in opposite directions, the process branches to #336. , if they are in the same direction, proceed to #330. In #330, the follow-up first flag T ], S T
Determine whether F is set to 1. If it is cleared to 0, branch to #335 and set to 1; if it is already set to 1, proceed to #331. The tracking mode flag TF is set to 1 and the process jumps to the tracking processing routine RN AFT I.

Through the processes from #323 to #332 described above, a tracking mode for correcting the change in defocus due to the movement of the subject is determined. In other words, if it is determined in #324 that the subject is dark, the CCD integration takes time and the noise component is large, so the defocus speed V HO cannot be determined accurately, so the tracking mode cannot be entered. . Also,#
If it is determined in step 326 that the image magnification is large, the tracking mode cannot be entered in the same way because the influence of camera shake of the photographer is large. If the defocus speed VHO is less than the constant RVMIN in #327, it is not possible to determine whether the defocus change is caused by fluctuations in focus detection or by movement of the subject, and in order to avoid erroneous correction, the camera is set to tracking mode. Can't enter. Even if the defocus changes due to the movement of the subject, the speed is slow, so the defocus changes are small and can be ignored even without correction.

When it is determined in #328 that VHO≧RVMAX,
The change in defocus is abnormally large and cannot be considered to be a movement of the subject; it is determined that the subject has changed, that is, the camera has been shaken, and the tracking mode cannot be entered. If the directions of the previous and current defocus speeds VHI and VHO are reversed in #329, it is thought that the focus detection is unstable or the subject is moving irregularly, and there is a high possibility that incorrect correction will be made. I can't enter it. Furthermore, #330, #331, #33
By performing the process 5, the tracking mode is entered when the determination conditions #323 to #329 are passed twice in succession. This makes it possible to reliably determine whether or not the subject is a moving object, and there is no risk of erroneous correction. Also, the constant BETAL
OCK, RVMIN, and RVMAX are written in the E2Pr (0M201f) built into the CPU 201. If the direction of the defocus speed VHO is reversed in #329, particularly unstable focus detection or subject movement is expected. Therefore, the release process 0UTRV3 after #336
In #337, the tracking mode flag TF, tracking initial flag T], STF, and continuous shooting flag VLYF are reset, and in order to perform the next focus detection, jump to focus detection processing CDINTA from #105 onwards (# 338). As a result, the next release is prohibited, and as explained in FIG. 7, the lens is driven until the lens is brought into focus again, so there is no need to worry about out-of-focus photography being performed.

If it is determined in #324, #326, #327, #328, and #330 that the process branches to #333, the currently detected defocus DFO is compared with the constant INFZEl. When DFO < INFZEI, the defocus is not very large and the reliability of focus detection is high, ensuring sufficient accuracy even if the photographing lens is driven by this differential 4-cus while the mirror is up and the next release is performed. When the mirror is turned up, the program branches to a drive routine RNMTR during mirror up. D
In the case of FO≧1 NFZE1, the defocus is large and if the next release is performed as it is, the accuracy may not be ensured, so the process jumps to the cancellation process UTRV2 (#334). By performing the processing in #333 and #334, when the defocus is small, high-precision automatic focusing and high-speed continuous shooting are achieved by driving the mirror up, and when the defocus is large, it is possible to perform a transformation inspection. Highly accurate automatic focusing is achieved by moving the lens out to focus. 5 Also, cancel processing from #334 ○UT RV
Defocus processing after 2. When entering UTFS &, the 7th
As explained in the figure, the differential DF obtained during continuous shooting this time
Since refocus detection is performed after driving the lens by 0 minutes, it is fast and accurate. Also, the constant T N FZEI is the CPU
2014) It is written in E2PROM201f,
It is possible to change the taste of the knee.

Now, the follow-up process RNAFTI executed by branching based on the determination in #319 or jumping from #332 will be explained with reference to FIG. First, in #340,
It is determined whether the directions of the current and previous defocusing speeds VHO and VHI are the same. If the direction is different, it may be because the subject suddenly stopped, changed direction, or shook the camera. In this case, #3
The process branches to step 41, jumps to canceling process UTRV3, cancels the tracking mode, and performs the automatic focusing operation again. This allows highly accurate focusing without making erroneous corrections even if the subject suddenly stops, changes direction, or shakes the camera.

If they are not in the same direction, proceed to #342 and (VH
Compare O+VH1, )/2 with a constant A VE S H. (VHO+VH], )/2 indicates i゛022 from the processing of #31o, and becomes a weighted average value. In the above equation, I7 indicates the number of loops, and V Hi does not indicate the previous speed.

That is, #342 is the weighted average value and constant AVES H
Compare with. The weighted average value is a constant A VE S I (
In the following cases, the weighted average value is reset for the defocus speed VHO in #343, and if it is greater than the constant A VE S H, the process directly proceeds to #344. In other words, in the case of slow speeds, stable correction is achieved by absorbing fluctuations in focus detection by performing weighted averaging, and in the case of a subject approaching at a constant speed, changes in defocus are Since it increases approximately in inverse proportion to the square of the distance, this achieves correction with good responsiveness and little follow-up delay at high speeds. In addition, the constants A and VESH are CPU
20] is written in the E2PROM20 if built in.

#344 Calculate the image magnification β and set the constant BETAL O
Compare with CK 2. As the image magnification increases, the effect of camera shake as mentioned above increases, so the canceling process 0UTRV2 is shifted in step #347, and the tracking mode 1~ is also exited. In addition, the constant BETAI−○CK2 is CPU20]1
)E2PROM20], written in f, constant B
It is set larger than ET A and LOCK. In #345, defocus speed V HO and constant RV
Compare OUT and determine the defocus speed VI (O or RVO
If the speed is within UTJ, J, the defocus speed is sufficiently slow and the process branches to #347 to avoid erroneous correction due to variations in focus detection. In #346, the defocus speed V HQ and the constant RV MA,X 2 are compared. Defocus speed V HO is R, V M A
If it is 2 or more, it is determined that the defocusing speed is very fast and even if follow-up correction is performed, the delay will be large and defocusing will occur, and the process branches to #347. #347 Jumps to cancellation processing ○UTRV2, cancels the tracking mode, prohibits release next time, and performs focus detection again. As a result, in the case of a very high-speed subject, the shutter release is prohibited, and it is possible to prevent the camera from taking a picture of a subject that is too slow to follow. #344~#
The H.346 processing prevents erroneous correction and achieves highly accurate correction.

Subsequently, follow-up correction calculation 1 is performed in #348 to calculate the number of drive pulses ERRCNT. This calculation will be explained in detail later using FIG. 12. In #34, the defocus MDF after tracking correction is compared with the constant INFZE2. If the defocus after tracking correction is large, the process branches to #350 and jumps to the cancellation process 0UTRV21 from #316 onwards (FIG. 10) in order to improve accuracy.

As a result, only the continuous shooting flag VLYF is cleared, the tracking mode is maintained, and the out-of-focus processing is shifted to 0UTFS. Constant INFZE2 is E2PROM2 of CPU201
It is written in 01f. Also, this constant INFZE
2 is set larger than the constant INFZE1 explained in #333. This is because tracking correction is performed, and unless the correction amount is large, the process cannot proceed to #351.

After #351, there is drive processing during mirror up, and #33
This is the branch from #3 or the flow from #349. First, in #352, it is determined whether the switch SW6 is ON. If switch SW6 is OFF, the next release is not requested, so the process branches to #363 and release processing 0 is performed.
Jump to UTRV. Subsequently, in #353, the number of driving pulses ERRCNT and the constant NPI are compared. As explained in FIG. 7, the constant NP1 is the number of pulses that can be driven during mirror up. If the number of drive pulses ERRCNT is less than or equal to the constant NPI, it is possible to drive during mirror up, and the process branches to #359.

If the number of driving pulses ERRCNT exceeds the constant NPI, driving is not possible only while the mirror is up, so a driving time is required before starting the next release. J, this A
The time required to drive the F motor M2 varies depending on power supply conditions, characteristics of the interchangeable lens, etc. Therefore, if the time until the next release start is fixed at 40m5ec, and the number of driving pulses ERRCNT is within 4Qmsec and the number of pulses that can be driven during the next mirror up (constant NP2), the AF
The motor M2 is driven, and if the number of drive pulses ERRCNT exceeds the constant NP2, refocusing is performed. As a result, tracking correction can be performed accurately for 40m5ec even in the moving object mode. Also, even if you wait 40m5ec,
The continuous shooting speed of 3 frames per second only needs to drop to 2.7 frames per second, and the deterioration of the continuous shooting feel is minimal. Furthermore, when the number of driving pulses ERRCNT exceeds the constant NP2, refocusing is detected, which solves the problem that the error associated with lens driving increases indefinitely.

If ERRCNT≦NPI in #353, the process advances to #354 and the tracking flag TF is determined. If it is tracking mode (TF=1) in #354, tracking correction calculation 2 for 40 m5ec is performed in #355, and if TF=0, #355 is skipped, and in both cases, the number of drive pulses ERRC is set in #356.
Compare NT with constant NP2. Drive pulse number ERRCN
If T exceeds the constant NP2, the process branches to #364 and jumps to release processing 0UTRV2. #349, #3
If the next release is to be performed by driving during mirror up without performing focus detection again in the determination in step 56, it is determined that the camera is in focus, and the focus display is maintained. Next, AF with #357
Start driving motor M2 and set 40 +n5e at #358.
Wait for time c. In #359, the drive of AF motor M2 is started in case it branches from #353, and in #3
The process advances to continuous shooting release processing RNRELESE after 60. Since continuous shooting is performed in #361, in order to completely stop the film, the camera waits for a predetermined time tl+, and then jumps to the next release. As is clear from the above explanation, in tracking mode, it is necessary to compensate for changes in defocus caused by the subject, so if the shooting lens is stopped,
The next release will not be performed.

Next, the follow-up correction calculations after #401 will be explained with reference to FIG. First, in #402, it is determined whether the current focus detection was low contrast. If the low contrast is not found, the time T for correction is determined in #403.

The time of the center of the current CCD integration is saved in the memory TM, and the value of the memory TM is subtracted from the current timer value TC, and the mirror-up time of 70m5ec is added.The deviation is calculated from the center of the current integration until the next exposure. Find the time. If the low contrast is 1 or higher, the process proceeds to #404, and the time T from the previous exposure time to the next exposure time is determined. As explained in FIG. 8, the previous exposure time is saved in the memory TIME1. Therefore, the value of memory TIME1 is subtracted from the current timer value TC and 7Q+
The addition deviation of n5ec is good. That is, #402 to #4
04, if it is not low contrast 1 Hellas 1~, the calculation is performed based on the current defocus DFO, and in the case of low contrast I/last, the calculation is performed assuming that the defocus was 0 at the previous exposure.

Next, in #405, set the defocus speed to V HO"1
The correction amount ΔDF is obtained by subtracting the time T obtained in step #403 or #404. Next, in #406, the defocus speed V HO and the constant V V H are compared. VH
O> V V H If the defocus speed is fast, #4
In step 07, it is determined whether the subject is approaching or far away, and if the subject is approaching, the correction amount ΔDF is multiplied by 1.25 (#408). This is because, as mentioned above, if the subject approaches in the optical axis direction at constant speed, the defocusing speed will increase in inverse proportion to the square of the subject distance.
When the speed becomes high, the time T obtained in #403 or #404 above
The defocus speed also increases during this time. In order to correct this error, the correction amount ΔDF is multiplied by 1.25.

When the subject is far away, the defocus speed becomes slow, so multiply the correction amount ΔDF by 0.75 (#40
9). Next, #4] 0 and this time detected defocus DFO
Check the direction of defocus speed V HO and if the direction is the same, the corrected defocus MDF is DFO +
ΔDF (#41.1). If the directions are different, the currently detected defocus DFO and correction amount Δ are determined in #412.
Compare with DF, and if DFO≦△DF, set ∆DF-DFO to corrected defocus MDF (#41
．． 3). If DFO>△DF, the photographing lens must be driven in the opposite direction to the defocus speed direction,
This means that a large defocus is detected in the direction opposite to the defocus speed direction. For this reason, assuming a backlash error due to reversal of the photographic lens or abnormal movement of the subject, stack initialization is performed in #414, and #
At /115, release processing ○ Proceeds to UTRV21 to prohibit the next release and perform refocusing detection. #41
], #4.1.3 When the corrected defocus MDF is found, in #416 the defocus is multiplied by a coefficient KL for converting the number of pulses, the number of drive pulses ERRCNT is set, and the process returns (#41. 7).

This allows for highly accurate correction even when the subject is moving at high speed, and can also be used for subjects that are approaching or moving away. Furthermore, as is clear from the explanation of FIG.
#308 to #3] Even when low contrast 1 Hellas 1 to 2 are ignored once, the correction for the movement of the subject is performed correctly.

Finally, timer interrupts and AFP interrupts will be explained.

FIG. 13 shows a timer interrupt processing routine for driving the AF momo-M2. The CPU 201 has a built-in interrupt timer (not shown) that generates a timer interrupt when a set time has elapsed. When a timer interrupt occurs, #5
At step 02, the interrupt timer 'IT' is reset. As a result, the interrupt timer T automatically generates a timer interrupt when the set time elapses after the current timer interrupt occurs.

Next, the flag RM G ON F is determined in #503, and if it is set, the release magnets I to RM are set.
Since current is being applied to g, AF Momo-M2 is turned off as described above (#505). If the flag RMGONF is reset to 1, #504 causes AF Momo-M,
energizes and returns (#506).

FIG. 14 shows an ARP interrupt processing routine that occurs when the AFP signal falls. When an A, FP interrupt occurs, first, the number of drive pulses ERRCNT is decremented by one in #602. In #603, the number of drive pulses ERRCNT is O.
Then, it is determined whether or not the driving of the A and F motors M2 has ended. Drive pulse number ERRCNT or O, A
If F Momo-M2 has not finished driving, #60
Proceed to step 4 and reset the interrupt timer IT. #60
At step 5, the flag RMGONF is checked. flag.

If RMGONF is set and the release magnet RM& is energized, the AF momo-M2 is turned off in #608. If the flag RMGONF has been reset, the brake is applied to AF Momo-M2 in #606, and the process returns (#607). On the other hand, if the driving of AF Momo-M2 is completed in the determination in #603, #6
The process branches to step #609, and the power supply to AF momo-M2 is turned off. Next, in #610 and #611, timer interrupts and AFP interrupts are inhibited, respectively, and the process returns (#6
07). As described above, the AF momo-M2 is driven by the timer interrupt and the AFP interrupt, and the AF momo-M2 is controlled to be OFF while the release magnet RMg is energized.

[Effects of the Invention] In the automatic focusing camera of the present invention, tracking correction is set under predetermined conditions during continuous shooting mode, and tracking correction is canceled under other predetermined conditions. This eliminates inaccurate tracking correction or inappropriate tracking correction, and compared to unconditionally performing tracking correction during continuous shooting mode, tracking correction can result in many out-of-focus photos. This has the effect of preventing inconveniences such as continuous shooting.

Note that if the tracking correction is canceled when the continuous shooting speed is slower than a predetermined speed or when the imaging magnification is not within the predetermined range, it is possible to prevent the tracking correction from being performed when the subject cannot be accurately tracked. In addition, if tracking correction is canceled when the rate of change in the amount of defocus is reversed, tracking correction can be applied when the subject suddenly stops or changes direction of movement, or when the photographer pans the camera. It is possible to prevent follow-up correction from being performed when it is not appropriate to do so.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a side view of a camera as an embodiment of the present invention, FIG. 3 is a front view of the same as the above, and FIG. 4 is a block circuit diagram of the same as the above. 5 and 6 are operation waveform diagrams of the same as above, and FIGS. 7 to 14 are flow charts showing the same operation as above. (1) is focus detection means, (2) is change speed detection means, (
3) is a tracking correction means, (4) is a lens driving means, and (5)
(6) is a follow-up setting means, (7) is a continuous shooting speed detection means, and (8) is an imaging magnification detection means.

Claims (4)

[Claims] (1) In an autofocus camera that has a continuous shooting mode that continues the release operation during the release operation, there is a focus detection means that detects the amount of defocus of the photographic lens with respect to the subject to be focused on, and a focus detection means that detects the amount of defocus of the photographing lens with respect to the subject to be focused, and a focus detection means that detects the amount of defocus of the photographic lens with respect to the subject to be focused on. a change rate detection means for detecting the change rate of the amount of deviation; and a tracking correction means for correcting the focus detection result by the focus detection means by determining the amount of change in the amount of focus deviation due to movement of the subject based on the output of the change rate detection means. , a lens driving means for driving a focus adjustment lens toward a focus position according to a focus detection result of the focus detection means; and a tracking setting means for switching the tracking correction means from a non-operating state to an operating state in continuous shooting mode. ,
An automatic focusing camera comprising: tracking canceling means for switching tracking correction means from an operating state to a non-operating state in continuous shooting mode. (2) Further comprising a continuous shooting speed detection means for detecting a continuous shooting speed, and the tracking canceling means activates the tracking correction means when the continuous shooting speed detected by the continuous shooting speed detection means is lower than a predetermined speed. 2. The automatic focusing camera according to claim 1, further comprising means for switching from a non-operating state to a non-operating state. (3) Further comprising a photographing magnification detection means for detecting a photographing magnification of the subject, and the tracking canceling means changes the following correction means from an operating state to a non-operating state when the photographing magnification detected by the photographing magnification detection means is not within a predetermined range. 2. The automatic focusing camera according to claim 1, further comprising means for switching the state. (4) The tracking canceling means is a means for switching the tracking correction means from an operating state to a non-operating state when the direction of the speed of change detected by the speed of change detection means is reversed. Autofocus camera as described.