JP2501189B2 - Automatic focus adjustment device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to an automatic focusing device for a camera.

2. Description of the Related Art Conventionally, various cameras having an automatic focusing device have been proposed.

Problems to be Solved by the Invention Here, as a method of using the automatic focusing apparatus, one-shot AF mode in which once the photographing lens reaches a focused state, the state is maintained and the movement of the subject thereafter is not followed If the subject moves even after reaching the in-focus state, the continuous AF mode in which the automatic focus adjustment is repeated following the movement can be considered. Even in combination with the shutter release timing, the AF priority mode does not allow the shutter release unless the shooting lens reaches the in-focus state after the automatic focus adjustment operation is completed, and the shutter release button regardless of the automatic focus adjustment operation. A release priority mode is conceivable in which the shutter is released in response to the depression of.
Also, in the case of shooting with a built-in or external device for automatically winding a film such as a motor drive device, the film winding is stopped for each frame even if the shutter release button is continuously pressed. (Single shooting mode) and continuous shooting mode (continuous shooting mode) in which the film is automatically rolled up one after another for continuous shooting as long as the shutter release button is kept pressed.
There is.

As an example of a combination of these various modes, a continuous AF mode is set by closing the switch S ₀ that is closed by touching the shutter release button with a finger. Switch S ₁ is closed to switch to the one-shot AF mode, and by further pressing the shutter release button to the second step, another switch S ₂ is closed and the taking lens has reached the in-focus state. If so, shutter release is performed and a configuration in AF priority mode is possible.

Considering the case of performing continuous shooting using the motor drive device in such a configuration, the switch S ₁ is kept closed in the continuous shooting mode, and thus the one-shot AF mode is set. However, if the subject is moving,
If the one-shot AF mode operation is performed after the shutter release is completed, the time required for distance measurement calculation will be short, and it will be immediately determined to be in focus. There is a high possibility that out-of-focus photos will be taken. Here, shooting in continuous shooting mode with a camera in AF priority mode is thought to be aimed at following a moving subject, so a photograph with out of focus may be taken. Is the least preferred.

Therefore, the present invention provides an automatic focus adjustment device that reduces the possibility that an out-of-focus photograph is taken in this way, and improves the followability with respect to a moving subject. With the goal.

In order to achieve the above object, the present invention provides a focus detecting means for detecting a focus state of a photographing lens, a focus adjusting means for driving the photographing lens according to a detection result of the focus detecting means, and a film. Film winding means capable of film winding during frame-by-frame single shooting and film winding during continuous film-winding, and film winding operation by the film winding means during single-shot and continuous shooting The setting means for each setting, the one-shot AF means that keeps the shooting lens once it reaches the in-focus state, and the shooting lens does not follow subsequent movements of the subject, and the shooting lens is in focus If the subject moves for focus adjustment after reaching the state, continuous shooting is performed by the continuous AF means that repeats the subject automatically When set, it is characterized by having control means for repeatedly performing focus adjustment by the continuous AF means during a period from the end of exposure to the start of exposure of the next frame.

Therefore, according to the present invention, even if the one-shot AF mode is set before the exposure operation is completed, the continuous AF mode is set after the exposure operation is completed. Therefore, it is possible to reduce the possibility that an out-of-focus photograph is taken.

Embodiment An outline of a camera system for automatic focusing according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, the interchangeable lens (LZ) is on the left side of the alternate long and short dash line, and the camera body (BD) is on the right side.
Connection terminals (JL1) to (JL5) mechanically via (107)
(JB1) to (JB5) are electrically connected. In this camera system, the subject light that has passed through the interchangeable lens (LZ) passes through the central semi-transmissive part of the reflection mirror (108) of the camera body (BD), is reflected by the sub mirror (109), and is reflected by the CCD image sensor ( The optical system is configured to be received by the FLM).

The interface circuit (112) drives the CCD image sensor (FLM) in the focus detection module (AFM) and C
It captures subject data from the CD image sensor (FLM) and sends this data to the AF controller (113). The AF controller (113) calculates the signal of the defocus amount | ΔL | that indicates the amount of deviation from the in-focus position and the defocus direction (front pin, rear pin) based on the signal from the CCD image sensor (FLM) To do. Motor (MO
1) is driven based on these signals, and its rotation is transmitted to the interchangeable lens (LZ) via the slip mechanism (SLP), drive mechanism (LDR), and camera body side clutch (107).
The slip mechanism (SLP) prevents the motor (MO1) from being overloaded by slipping when the driven part of the interchangeable lens (LZ) is subjected to a torque larger than a predetermined value. A transmission mechanism (105) is connected to the lens side clutch (106), and the lens system is moved in the optical axis direction via the transmission mechanism (105) to adjust the focus.

Furthermore, the encoder (ENC) for monitoring the drive amount of the interchangeable lens (LZ) is the drive mechanism (L) of the camera body (BD).
This encoder (ENC) outputs a number of pulses corresponding to the drive amount of the lens (FL).

Here, the number of rotations of the motor (MO1) is NM (rot), the number of pulses from the encoder (ENC) is N, the resolution of the encoder (ENC) is ρ (1 / rot), and the rotation axis of the motor (MO1) is the encoder. Set the reduction ratio of the mechanical transmission system up to the (ENC) mounting shaft to μ
P, the reduction ratio of the mechanical transmission system from the rotary shaft of the motor (MO1) to the camera body side clutch (107) is μB, and the reduction ratio of the mechanical transmission system from the lens side clutch (106) to the large gear (103) is μL. , LH (mm / rot) for the helicoid lead of the focus adjustment member (102) and Δd (mm) for the movement amount of the focusing lens (FL), N = ρ · μP · NM Δd = NM · μB · μL · LH That is, the relational expression of Δd = N · μB · μL·LH / (P · μP) …………………… (1) is obtained.

Further, the ratio of the amount of movement ΔL (mm) of the image plane when the lens is moved by Δd (mm) and the above Δd is expressed as Kop = Δd / ΔL ……………… (2) From equations (1) and (2), the relational expression of N = Kop · ΔL · ρ · μP / (μB · μL·LH) …………………… (3) is obtained. Here, if KL = Kop / (μL ・ LH) …………………… (4) KB = ρ ・ μP / μB ……………… (5), then N = KB ・ KL ・ΔL ………………………… (6) The relational expression of

In the equation (6), ΔL is a signal processing circuit (112)
From the defocus amount | ΔL | and a signal in the defocus direction.

Also, KB in the equation (5) is the reduction ratio μB in the camera body.
This data is fixedly determined according to
KB is held by the camera controller (111).

Here, from the camera main body side reading circuit (LDC) to the lens side lens circuit (LEC), power is supplied via terminals (JB1) (JL1) and synchronization clock is supplied via terminals (JB2) (JL2). A read start signal is sent to each pulse via terminals (JB3) (JL2). Further, the data KL is serially output from the lens circuit (LEC) to the reading circuit (LDC) via the terminals (JL4) (JB4). The terminals (LB5) (JL5) are common ground terminals.

When a read start signal is input via the terminals (JB3) (JL3), the lens circuit (LEC) synchronizes the KL data with the clock pulse input from the camera body via the terminals (JB2) (JL2). And outputs them in series to the reading circuit (LDC).
Then, the reading circuit (LDC) reads the serial data from the terminal and converts it into parallel data based on the same clock pulse as the clock pulse output to the terminal (JB2).

The camera controller (111) uses the data KL from the reading circuit (LDC) and the data KB inside the KL and KB =
K is calculated. The AF controller (113) obtains the defocus amount | ΔL | using the data of the subject image from the interface circuit (112), and this defocus amount | Δ
Based on L | and the data K from the camera controller (111), K · | ΔL | = N is calculated, and the number of pulses to be detected by the encoder (ENC) is calculated. The AF controller (113) rotates the motor (MO1) clockwise or counterclockwise through a motor driver circuit (114) according to a defocus direction signal obtained using the subject image data, and an encoder (EN
When the number of pulses equal to the value N calculated by the AF controller (113) is input from C), the focusing lens (FL)
Is determined to have moved by the amount of movement Δd to the in-focus position,
Stop the rotation of the motor (MO1).

In the above explanation, the data KB is fixedly stored on the camera body (BD) side, and the value of K = KL · KB is calculated by multiplying this data KB by the data KL from the lens. However, calculation of the K value Is not limited to the method described above. For example, if the interchangeable lens can be attached to any of several types of camera bodies with different KB values, the lens circuit (LEC) of the interchangeable lens (LZ)
To output the data of K1 = KL · KB1 corresponding to the camera body having a specific KB value according to the set focal length.
On the other hand, in the camera body of this specific model, the data KB in the camera controller (111) and the data K1 from the reading circuit (LDC) are not necessary to calculate the KL / KB, and the AF controller (1
13) and have a value KB2 (≠ KB1) different from the above specific KB value, when the above lens is mounted on another camera body, the KB2 / KB1 value in the camera controller (111) You may make it have data and perform the operation of K2 = K1 · KB2 / KB1 = KL · KB2 to obtain the value of KL · KB2.

In particular, in the case of a front group extension type interchangeable lens that performs focusing by moving only the front group in the optical axis direction, the value of Kop is Kop = (f1 / f) ² …………………… (7) f1 : It becomes the focal length of the focusing lens, and the KL value or K value for one interchangeable lens changes in a very wide range. In this case, the data KL or K stored in the lens is the exponent part data and the significant digit data (for example, in the case of 8-bit data, the upper 4 bits are the exponent portion and the lower 4 bits are the significant digit number). Divided into
If the lower 4 bits of the data read by the reading circuit (LDC) of the camera body are shifted by the exponent data and input to the camera controller (111), K
Even if the value of L or K changes significantly, it can be sufficiently coped with.

Next, in the present system, when the subject is dark and the focus detection device determines that the contrast is low, the subject is irradiated with auxiliary light for focus detection. In the present embodiment, this auxiliary light source is built into the flash device (FL) and attached to the accessory shoe (65) of the camera body (BD). Inside the flash unit (FL) is a flash discharge tube (4
0), fill light unit (62), fill light source light emitting diode (48), condenser lens (63), flash circuit (FL)
S) is incorporated. And the flash circuit (FL
The S) and the camera controller (111) are electrically connected to each other to exchange signals.

It should be noted that, in the above description with reference to FIG. 1, the device of the present invention is shown to be configured by a combination of rotary blocks in order to facilitate understanding of the overall function and operation of the present invention. Most of the functions of these circuit blocks are achieved by a microcomputer (hereinafter, referred to as a microcomputer), as described below.

FIG. 2 is a block diagram schematically showing a circuit in the camera of this embodiment.

In Fig. 2, (MNS) is a power switch, and (POR) is a power-on reset circuit that resets the AF microcomputer (MC1) and control microcomputer (MC2), which will be described later, according to the closing of the power switch (MNS). is there. (S1) is a switch that is closed by pressing the shutter release button one step (half-press), and the operation of photometry and automatic focus adjustment is started by this switch. (S2) is the shutter release button 2
The switch is closed by step-depressing (push-off), and the exposure operation is started by this closing. (S4) is a switch that is closed when the winding of the film is completed.

(MC2) is the camera controller (11
It works as 1), and is a microcomputer that controls the operation of the entire camera system in a sequence (hereinafter referred to as the control microcomputer). A switch (S1) is connected to the terminal (11), and switches (S2) (S4) are connected to the terminal (12) via an AND circuit. (OS
C) is an oscillator circuit for the operation. (MC1) functions as the AF controller (113) shown in FIG.
It is a microcomputer (hereinafter referred to as AF microcomputer) that controls the automatic focus adjustment operation in sequence. The calculated focus adjustment status is displayed LED (LEDL) (LEDM) (LED
It is displayed in the viewfinder by turning on one of R).

(SAF / M) is a switch for switching between automatic focus adjustment mode (hereinafter referred to as AF mode) and manual focus adjustment mode (hereinafter referred to as nonAF mode), which is AF when closed.
Mode, when it is open, it becomes nonAF mode, and its SAF
The / M signal is input to the terminal (PT6) of the control microcomputer (MC2). Here, the non-AF mode is provided with an FA mode in which the lens is not moved because the focus adjustment state is considered to be displayed, and a MANUAL mode in which the display is not performed. (SA / R)
Is the AF priority mode that performs shutter release after the completion of automatic focus adjustment and the switch (S2) even before the completion of automatic focus adjustment
When the shutter is closed, it is a switch that selectively switches between the shutter release priority mode in which the shutter is released according to the closing of the
AF priority mode, when released, it becomes release priority mode, and its SA / R signal is the control microcomputer (MC2) terminal (PT7)
Is input to

(SS / C) is continuous AF mode (Continuous A
F mode)) and single-shot AF mode (one shot A below)
It is a selector switch that selectively switches between the F mode). If this switch (SS / C) is opened, the camera will be in continuous AF mode, and automatic focus adjustment will continue even after the camera has reached the in-focus state. Then, when the switch (SS / C) is closed, the one-shot AF mode is set, and after the in-focus state is reached once, the automatic focusing device is locked. This switch (the signal from SS is input to the terminal (PT0) of the control microcomputer (MC2). ”(MDR2) is a driver circuit that controls the film winding and rewinding motor (MO2). (MC
The direction and amount of rotation of the motor (MO2) is controlled by the MM and MN signals from 2). Table 1 shows the relationship between the MM and MN signals and the operation of the motor (MO2).

(EDO) transmits to the control microcomputer (MC2) the manually selected mode among exposure control modes such as program mode / shutter speed priority mode / aperture priority mode / manual mode, and is required for exposure control in that mode. An exposure control setting circuit for transmitting information such as shutter speed, aperture value, film sensitivity, and exposure correction value to the control microcomputer (MC2). (BS1) and (BS2) are the data lines.

(LMC) is a photometric circuit, the ANI signal of which indicates a reference voltage for A / D conversion, and the VRI signal of which indicates an analog photometric signal, which are respectively the terminals (PT7) (PT
8) has been entered. (EXD) is the control microcomputer (MC2)
An exposure display circuit that displays the proper exposure value (shutter speed, aperture value, etc.) calculated in (BS3) is its data line. (EXC) is an exposure control circuit that controls exposure according to the proper exposure value (shutter speed, aperture value, etc.) calculated in the control microcomputer (MC2) and the set exposure value, and (BS4) is the data It is a line.

(FLS) indicates a circuit (hereinafter referred to as a flash circuit) in the electronic flash device attached to the camera.
S) is the terminal (ST
1) Connected to the camera side circuit by (ST2) (ST3) (ST4) (ST5) and (GND). This flash circuit (FL
The details of S) are shown in FIG.

FIG. 3 shows a flash circuit (FLS), in which (20) is a main switch, (22) is a power battery,
When the main switch (20) is closed, the voltage of the power supply battery (22) is boosted by the DC-DC converter (24) and supplied to the main capacitor (28) via the diode (26). (GND) is the ground terminal. Main capacitors (28)
The charging voltage of the battery is monitored by the charging monitoring circuit (30), and when the voltage reaches a predetermined amount, the charging completion detection circuit (3
2) outputs the charge completion signal, which is the AND circuit (3
It is transmitted to the terminal (ST2) via 4). On the camera side,
After receiving this charge completion signal, a light emission start signal is output via the terminal (ST1), which causes the trigger circuit (3
6) is triggered, the SCR (38) becomes conductive and the flash discharge tube (4
0) starts to emit light by the energy of the main capacitor (28). This light emission start signal is also input to the light emission start monitor circuit (42), and this light emission start monitor circuit (42)
When the light emission start signal is received, the AND circuit (34) is closed to prevent transmission of the charge completion signal to the terminal (ST2). When the camera's photometry circuit (LMC) detects that the correct exposure has been reached, the camera outputs a flash stop signal to the terminal (ST3), and the flash stop circuit (44) receives this flash stop signal. , Stop the light emission of the flash discharge tube (40).

(45) is closed to provide auxiliary illumination for detecting the focus adjustment state from the electronic flash device when the subject is dark.
AF assist light switch, when it is closed the terminal (ST5)
Outputs an AF auxiliary light OK signal indicating that illumination for focus detection by auxiliary light is possible. If the camera determines that this auxiliary light is required, the terminal (ST
An AF auxiliary light emission signal is input to 4), whereby the transistor (46) becomes conductive and the auxiliary light LED (48) emits light.

Returning to FIG. 2, (Sx) is a synchro switch of the camera, and (FLB) is a light emission control circuit for controlling the light emission time of the electronic flash device. (LEC) and (LDC) are the lens circuit inside the lens and the reading circuit inside the camera, respectively, as in FIG. 1, and when the lens is mounted on the camera, both circuits are connected to terminals (JB1) to (JB5) and (JL1) to (JL5) are connected to each other. In the figure, (VL) is the power supply, (RES) is the read start signal, (CL) is the clock pulse, (DATA) is the data,
(G) indicates ground respectively. A clock pulse is input to the reading circuit (LDC) from the control microcomputer (MC2) terminal (SCK), and the reading circuit (LDC) is output from the control microcomputer (MC2) terminal (TXD) serial data output. Lens data is serially input to that terminal (RXD) according to the signal.

(FLM) is the CCD image sensor shown in Fig. 1, (IF1)
Is an interface circuit for driving the sensor, (MDR1) corresponds to (114) in FIG. 1, and a driver circuit for controlling the drive of the lens driving motor (MO1), and (ENC) is an encoder similar to that in FIG. is there.

4 and 5 are flowcharts showing the operation of the control microcomputer (MC2) shown in FIG. The operation of the system shown in FIG. 2 will be described below with reference to this flowchart.
Before that, the names and contents of each flag used in this embodiment are shown in Tables 2 and 3.

In FIG. 4, when the switch (S1) is closed and an interrupt signal is input to the terminal (I1), the control microcomputer (MC2) starts its operation. First, in step S1, the release flag
Clear RLF. This flag is a flag used to distinguish between continuous shooting (hereinafter referred to as continuous shooting mode) and single-shot shooting (hereinafter referred to as single shooting mode) in the shooting modes of the camera. Here, the continuous shooting mode means the switch (S2)
When it is ON, it refers to the mode in which you can take pictures continuously, and single-shot mode refers to the mode in which one shot can be taken with one switch (S2) turned ON. Next, in S2, the AF microcomputer drive clock CK is supplied from the control microcomputer (MC2) terminal (Xout) to the AF microcomputer (MC1). Next, in S3, serial input / output operations are performed multiple times to capture multiple data from the lens circuit (LEC), and the conversion coefficient (KROM) required for automatic focus adjustment, the light from the auxiliary light source, and the visible light Focus position correction data (ΔI
R), backlash data (BKLSH), AF (automatic focus adjustment) or FA (focus adjustment status display), the open F value for AF (AFAV
0), lens attachment discrimination (LENSF), presence / absence of AF coupler axis (AFCF), whether the lens can detect focus (FAENL)
Save each signal in the memory of the control microcomputer (MC2).

In step S4, data from the exposure control value setting circuit (EDO) that outputs setting data for exposure control and the like is fetched. This includes data relating to exposure and whether to use single-shot or continuous-shot mode. Control microcomputer (MC2) for S5
Set the AFS signal output from the terminal (PT1) of to “Low”.
This is input to the interrupt terminal (INT1) of the AF microcomputer (MC1), and the AF microcomputer (MC1) starts operating at the falling edge of this signal. At the same time, IN from the terminal (PT2)
The REL signal is set to "High". This is the AF microcomputer (MC
It is input to the interrupt pin (INT2) of 1), but this interrupt does not occur because the interrupt is taken at the falling edge.

In the flowchart of FIG. 4, there may be a case where a loop is made from S5 to S10 and from S22 to S3. When passing S5 in the loop, the AFS signal falls and the INREL signal rises many times, but the AFS signal is already "Low" and the INREL signal is "Hig".
Since it is h ", the AF microcomputer (MC1) is not interrupted. When the operation of the AF microcomputer (MC1) starts, the setting data for the operation of the control microcomputer (MC2) and the AF microcomputer (MC1) and the data from the lens Data is sent serially.The control microcomputer (MC2) terminal (TX) is synchronized with the clock signal from the control microcomputer (MC2) terminal (SCK).
D) serially outputs 5 bytes of 8-bit data and the contents shown in Table 4 are output, and the AF microcomputer (MC1) terminal (T
XD) is input.

The control microcomputer (MC2) goes from the AF microcomputer (MC1) terminal (P11) to the control microcomputer (MC2) terminal (PT4) D
The TRQ signal is regarded as a signal of data request, and data output is started. In the control microcomputer (MC2), this DTRQ signal goes to "L" at S6.
Wait until it becomes "ow", and if it becomes "Low", proceed to S7 and send the data. AESIO of S7 makes data for determining the operation mode of the microcomputer to AF microcomputer (MC1) and sends the data serially However, it is shown as another routine in FIG.

At the beginning of the AESIO routine starting from step S29 in FIG. 5, first, the RAM of the fifth serial data of the control microcomputer (MC2) containing the signals AFFL, RDY, DR, AFC, FAEN is cleared. The FAEN signal is determined in S30, S31, and S32. First S
Look at the LENSF signal of the data coming from the lens circuit (LEC) at 30, and if LENSF = 0 indicates that there is no lens, the FAEN signal remains "0" and proceeds to S33. When the lens is attached and LENSF = 1, if the FAENL signal is “1”, that is, if the lens is focus-detectable, go to S32 and set the FAEN signal to “1”. If the FAENL signal is “0”, the FAEN signal is 0"
Will remain.

Next, in S33 to S35, the AFC signal is determined. Terminal at S33 (PT
Check the SAF / M signal input to 6). The SAF / M signal is a switch that decides whether or not to automatically adjust the focus of the camera lens from outside the camera. If it is "High", the AF mode Depending on the result, the mode for automatically adjusting the focus of the taking lens), and if it is "Low", it will be the non-AF mode. S33
If the SAF / M signal is “0” in, the AFC signal remains “0” in S36.
If it is "1", go to S34 and use the data A from the lens.
Watch the FCF signal. If the AFCF signal is "1" in S34, select the lens
Since there is a coupler axis for AF, set the AFC signal to "1" in S35. That is, when the lens has the coupler axis for AF and the operation switch (SAF / M) of the camera is closed to be on the AF side, the AFC signal becomes "1", and other than that, it is set to "0".

If the camera drive mode setting in S36 and S37 is continuous shooting mode, the DR signal is set to "1", and if it is single shooting mode, the DR signal remains "0". Next, in S38 and S39, the signal from the electronic flash device attached to the camera is checked, and if the electronic flash device is attached to the camera and the AF auxiliary light switch (45) is on, the flash circuit (FLS) The terminal (ST5) goes into the "High" state and enters the terminal (PT11). At S38, PT11 =
If it is "High", the AFFL signal is set to "1" in S39. This is a signal to the AF microcomputer (MC1) that the AF auxiliary light can be emitted. (Details will be described later.) Set the RDY signal in S40 and S41. When charging of the electronic flash device is completed, the terminal (ST2) of the flash circuit (FLS) goes to the "High" state, and this is input to the terminal (ST9). Go ahead and set the RDY signal to "1". This signal is also used at the time of focus detection using auxiliary light described below (hereinafter referred to as auxiliary light AF mode). The SCF signal is set in S42 and S43. Switch (SS /
If C) is closed, the signal input to the terminal (PT0) is "Low", so set SCF to "1".
If the switch (SS / C) is open, the terminal (ST0) is "High", and SCF remains "0". Then, in S44, the data sent from the lens is set in the serial transfer register to be sent to the AF microcomputer (MC1). In S45, the CSAF signal for starting serial transfer is set to "High". This is a response to the DTRQ signal of the serial transfer request from the AF microcomputer (MC1). When the CSAF signal becomes "High", the AF microcomputer (MC1) starts capturing serial data. Then, in S46, the 8-bit 5-byte data is transferred to the AF microcomputer (MC1). CS in S47
The AF signal is returned to "Low" to complete the serial transfer.

Next, returning to the main routine of FIG. 4, the process proceeds to the next step S8. Here, the ANI signal of the photometric output and the VRI signal of the reference voltage for A / D conversion are taken in from the photometric circuit (LMC), the photometric output is A / D converted, and prepared as data necessary for exposure calculation. . Next, in S9, the exposure calculation for the constant light and the flash light is performed. At the next S10, it is checked whether the terminal (12) of the control microcomputer (MC2) is "Low", and it is checked whether the release has been made. If the shutter is charged and the switch (S4) is ON, the release button is pressed in two steps and the switch (S2) is ON, the terminal (I
2) should be “Low”. Terminal (I2) is "H"
If it is "igh", it means that the release has not been done, so the operation proceeds to S25. At S25, the release flag RLF is cleared. If you are wearing a flash, go to S27 and display the flashlight shooting data on the display (E
XD), and if the charging completion signal is not received, the process proceeds to S28, in which the stationary light imaging data is sent to the display unit (EXD) for display, and the process proceeds to step S22. Then, in step S22, it is determined whether or not the terminal (I1) is "Low" while the switch (S1) remains closed, and if it is "Low", step
The process returns to S3 and the same operation as described above is repeated.

On the other hand, when it is determined in step S22 that the terminal (I1) is "High", the process proceeds to S23, and the operation of the AF microcomputer (MC1) is stopped. The way to stop is to interrupt the AF microcomputer (MC1) terminal (INT1) with the AFS signal. Start of AF microcomputer (MC1) by AFS signal and AF
In order to distinguish it from the interruption for stopping by the S signal, the stop interrupt is made to rise again in less than 50 μs after falling (see FIG. 17 (B)). If only the metering flow is interrupted from S26 to S28,
Since the AFS signal is “Low”, the stop signal is once “Hig
Release after "h", flow of release S11 ~ S21
When an interrupt occurs, the AFS signal is "High", so the stop signal falls. This interrupt causes the AF microcomputer (MC1) to enter stop mode and stop the automatic focus adjustment operation. In S24, the exposure display on the display (EXD) is turned off, and the control microcomputer (MC2) stops operating.

Next, if photometry is repeated and the flow is released while the flow is looping, the terminal (I2) becomes "Low". Then
After checking S10, proceed to S11. Next release flag
Check RLF and if it is "1", proceed to S26. This means that the release flag RLF is set to "1" in S21 to S22 if the shutter is released once in the single shooting mode, and the switch (S2) is turned on by pressing the release button two steps. As it is, it is not released again. Meanwhile, switch (S1)
When the switch (S2) is turned off while turning on, the process proceeds from step S10 to S25, and the release flag RLF is cleared. That is, when the switch (S2) is turned on again next time, the process proceeds from S11 to S12 and is released.

Next, in S12, the AF priority / release priority switching signal input to the terminal (PT7) is checked. Here, the AF priority mode is a mode in which the shutter is released only after focusing is completed by the automatic focus adjustment even if the switch (S2) is turned on.The release priority mode is the mode in which the focus is not adjusted during the automatic focus adjustment. In this mode, the switch (S2) is released whenever it is closed. In S12, SA / R signal is "Hig
If h "(SA / R = 1), it will be AF priority mode and proceed to S13.
Check AFE signal. This is the signal output from the AF microcomputer (MC1) terminal (P12).
Is a signal which becomes "High" when the focus is detected and it is determined that the focus is achieved. In S13, it is determined whether or not it is in focus. If it is in focus, the AFE signal is "1", the process proceeds to S14 and the release is started. If the AFE signal is "0" in S13, the process goes to S26 and the shutter is not released. On the other hand, if the release priority mode is set in S12, the process proceeds to S14 and is released. The SA / R signal checked in S12 is a signal according to the manual selection of the switch attached to the camera, but this is also linked to the self-timer switch (not shown) and the self-timer is activated. Then, even if there is a switch in the AF priority mode, it switches to the release priority mode.
During the self-timer, the release priority mode is set. When using the self-timer, a self-timer waiting time (not shown), for example, a 10-second waiting time is inserted between S14 and S15. Also, the switch (SA / R) provided on the camera body is connected to the terminal (ST7), but this switch is taken out of the camera body and used for an external controller (for example, a controllable back cover) or a remote controller. You can leave it to the receiver of the.

Next, in S14, an INREL signal indicating that the release has been made from the terminal (PT2) to the AF microcomputer (MC1) is issued. INREL signal is AF
It is input to the connection terminal (INT2) of the microcomputer (MC1),
The falling edge of this signal causes an interrupt, and the AF microcomputer (MC1) jumps to the release routine. Then, even if the lens is being driven during automatic focusing, the operation is stopped, the display is turned off, and the release is completed. In S14, in preparation for the end of the next release and the start of operation of the AF microcomputer (MC1), AFS
Keep the signal "High". Next, in step S15, it is determined whether or not the charge completion signal is input from the flash circuit (FLS) by looking at the terminal (PT9). Send to the exposure control circuit (EXC), and if the charging completion signal has not been input, the exposure control data for constant light is output in S17 in the exposure control circuit (EX
Send to C). Then, the exposure control operation is started in S18.

When the exposure control operation is completed, the film is automatically wound up in S19. Then, the release flag RLF described above in S20 and S21 is set to "1" in the single shooting mode, and the process proceeds to S22. Then, if the switch (S1) is still closed and the terminal (I1) of the control microcomputer (MC2) is "Low", the process moves to step S3 to capture the data, repeat the calculation / display operation, and close the switch (S1). If not, the control microcomputer (MC2) stops the operation after shifting to the above-mentioned step S23 and performing the same operation as described above. This concludes the description of the flow of the control microcomputer (MC2).

FIG. 6 shows the interface circuit (IF1) of this embodiment.
3 is a circuit diagram showing the details of FIG. The operation of this circuit will be described below.

When the control microcomputer (MC2) detects that the switch (S1) that is closed by pressing the shutter release button one step is ON, the AF microcomputer (MC1) adjusts the focus according to the signal from the control microcomputer (MC2). To start the operation.

First, the IOS signal from the AF microcomputer (MC1) is set to "Low", and the interface circuit (IF
The gate opens in the direction in which the signals of NBφ to NB3 are output toward 1). Then, the AF microcomputer (MC1) outputs a pulsed integration clear signal ICG to the CCD image sensor (FLM) as a signal of NB2, which causes the CCD image sensor (F
Each pixel of LM) is reset to the initial state and CCD
The output AGCOS of the brightness monitor circuit (MC) built in the image sensor is reset to the power supply voltage level. AF
At the same time, the microcomputer (MC1) receives a "Hig" from the terminal (NB5).
The shift pulse generation enable signal SHEN of h "level is output.
Then, at the same time as the integration clear signal ICG disappears, the integration of photocurrent starts in each pixel in the CCD image sensor (FLM), and at the same time, the output AGCOS of the brightness monitor circuit (MC) drops at a speed according to the brightness of the subject. To start, the reference signal output DOS from the reference signal generation circuit (RS) built into the CCD image sensor is kept at a constant reference level. The AGC controller (406) compares AGCOS with DOS, and controls the gain of the variable gain differential amplifier (408) according to how much AGCOS decreases with respect to DOS within a predetermined time (100 msec. During focus detection). To do. Further, when the AGC controller (406) detects that the AGCOS drops below a predetermined level with respect to DOS within a predetermined time after the integration clear signal ICG disappears, then the AGC controller outputs a "High" level TINT signal. This TINT signal is input to the shift pulse signal output circuit (410) through the AND circuit (AN) and the OR circuit (OR1), and in response thereto, the shift pulse SH is output from this circuit (410).
Also, the TINT signal passes as an NB4 signal through the OR circuit (OR2).
The signal is taken into the AF microcomputer (MC1) and the AF microcomputer (MC1) knows the completion of integration of the CCD image sensor by this signal. When this shift pulse SH is input to the CCD image sensor (FLM), the photocurrent integration by each pixel ends, and the charge according to this integration value is transferred in parallel to the corresponding cell of the CCD image sensor shift register. . On the other hand, based on the clock pulse CL from the AF microcomputer (MC1), the sensor drive pulse generation circuit (412) outputs two sensor drive pulses φ1 and φ2 with a phase difference of 180 °, and the CCD
Input to the image sensor (FLM). CCD image sensor (FLM) has φ
In synchronization with the rising edge of 1, the charge of each pixel of the CCD shift register is discharged serially from the end one by one, and the OS signal forming the image signal is sequentially output. This OS signal has a higher voltage as the incident light intensity to the corresponding pixel is lower, and the subtraction circuit (414) subtracts this from the above-mentioned reference signal DOS,
(DOS-OS) is output as a pixel signal. If the TINT signal is not output after the integration clear signal ICG disappears and a predetermined time elapses, the AF microcomputer (MC1) outputs "H" from the terminal (NBφ).
The igh "level shift pulse generation command signal SHM is output. Therefore, if the" High "level TINT signal is not output from the AGC controller (406) even after a lapse of a predetermined time after the integration clear signal ICG disappears, this shift In response to the pulse generation command signal SHM, the shift pulse generation circuit (41
0) generates the shift pulse SH.

On the other hand, in the above operation, the AF microcomputer (MC1) is the CCD
When the pixel signals corresponding to the 7th to 10th pixels of the image sensor are output, the sample hold signal S / H is output. This part of the CCD image sensor is covered with an aluminum mask for the purpose of eliminating dark output components.
The light-receiving pixel of the image sensor is a light-shielded portion. on the other hand. By the sample hold signal,
The peak hold circuit (416) holds the difference between the output OS and DOS corresponding to the aluminum mask part of the CCD image sensor, and thereafter, the difference output and the pixel signal are input to the variable gain amplifier (408). The variable gain amplifier (408) amplifies the difference between the pixel signal and its difference output with a gain controlled by the AGC controller (406), and the amplified output is A / D converted by the A / D converter (418). After that, it is taken into the AF microcomputer (MC1) as pixel signal data.

When the pixel signal data is captured, the AF microcomputer (MC
Signal IOS from 1) becomes "High", and NBφ to NB from the interface circuit (IF1) to the AF microcomputer (MC1)
The gate opens in the direction where the 3 signal is output. The A / D conversion of the A / D conversion circuit (418) is performed by 8 bits, but the upper 4 bits and the lower 4 bits are transferred to the AF microcomputer (MC1).
The switching timing of the upper and lower 4 bits is EOC
It is done by signals. The EOC signal is ORed with the TINT signal by the OR circuit (OR2) and input to the AF microcomputer (MC1) as the NB4 signal. AF microcomputer (MC1) is this NB
Depending on the timing of the “High” and “Low” states of the four signals
Pixel signal data will be fetched from NBφ to NB3.
Further, AGC data is also fetched from the NBφ to NB3 from the AGC controller (406) before the fetching of pixel signal data is started. This AGC data is
As will be described later, it is used as a judgment level. In addition, the Sφ signal output from the terminal (NB1) of the AF microcomputer (MC1) is used to initialize the CCD image sensor.
This is a signal for switching between normal operation for integrating the subject light.

After that, the AF microcomputer (MC1) sequentially stores this pixel signal data in the internal memory. When the data corresponding to all the pixels of the image sensor has been saved, it is used to defocus according to a predetermined program. And the direction thereof are calculated and displayed on the display circuit. On the other hand, the lens driving device is driven in accordance with the focus shift amount and the direction thereof to perform automatic focus adjustment of the photographing lens.

In the present embodiment, the integration of the CCD image sensor (FLM), the data dump, and the focus detection calculation are repeated to improve the accuracy.

7 to 16 are flowcharts showing the operation of the AF microcomputer (MC1). First, Tables 5-1, 2, and 3 show the flags used in this flowchart.

There are four entrances to start the operation of the AF microcomputer (MC1). That is, when the power is turned on, that is, when the RES signal arrives at the terminal (CLR1) of the AF microcomputer (MC1) in FIG. 2, “RESET” (step # 1 in FIG. 7), the terminal of the control microcomputer (MC2) ( "INT1S" (No. 1) starts when the AFS signal issued to start AF operation (automatic focus adjustment operation) or FA operation (focus detection operation) from PT1) is input to the terminal (INT1) of the AF microcomputer (MC1). AF from the terminal (PT2) of the control microcomputer (MC2)
"INT2S" (step # 27 in Fig. 8) and encoder (ENC) started when the INREL signal issued to the microcomputer (MC1) to notify it of the release is input to the terminal (INT2) of the AF microcomputer (MC1). These four are “INT3S” (step # 252 in FIG. 16) which starts when the PS signal from is input to the terminal (INT3) of the AF microcomputer (MC1). The main routine of the flow of the automatic focus adjustment operation starts from “INT1S” in step # 8 in FIG. 7 and passes through “AFSTART” in step # 33 in FIG. 9 and “CDINTS” in step # 44 in FIG. 11. Flow to "MAIN1" in step # 86 in FIG. From "MAIN1", it is roughly divided into three, starting from "LOWCON" at step # 165 in Fig. 13, when the contrast of the subject is low, and from "LSAVE" at step # 238 in Fig. 14 Auxiliary light AF mode that starts (a mode that illuminates the subject with the auxiliary light LED (48) to detect focus when it is dark and focus detection is not possible) and the flow of step # 91 in FIG. The flow is for normal AF mode, in which the contrast of the subject begins with "NLOC1" and is sufficiently high. As a subroutine, a flow for inputting and processing serial data from the control microcomputer (MC2) starting with “SIOSET” in step # 241 in FIG. 15 and a lens termination starting with “CKLOCK” in step # 196 in FIG. There is a flow for judging the position. The automatic focus adjustment operation (hereinafter referred to as AF operation) and the focus detection operation (hereinafter referred to as FA operation) in this embodiment will be described below based on this flowchart.

First, in response to the closing of the power switch (MNS), a reset signal RES is output from the power-on reset circuit (POR), and this control signal causes the control microcomputer (MC2) to move from a specific address. At the same time, the clock pulse CK is output from the terminal (Xout) of the control microcomputer (MC2). This is input to the terminal (Xin) of the AF microcomputer (MC1). When the reset signal RES is input to the terminal (CLR1) under the clock pulse CK from the control microcomputer (MC2), the AF microcomputer (MC1) starts from “RESET” in step # 1.
Step # 1 clears all flags (Tables 5-1, 2, 3) used in the flowchart. Each flag is set to "0" in the initial state. From step # 2, to stop the AF or FA operation from the control microcomputer (MC2) to the AF microcomputer (MC1),
Although a stop signal as will be described later is output, this step # 2 is also passed when this stop command is input.

In step # 2 (hereinafter “step” is omitted), the signal from the terminal (ST4) input to the terminal (P13) is brought to the “Low” state and the illumination by the auxiliary light LED (48) is turned off.
This is the switch (S
This is because when 1) is opened and the focus detection operation is stopped, the light emission is stopped. In # 3, the focus adjustment state display or the defocus direction display in the AF or FA operation is turned off.
Here, "High" is output to the terminals (P32) to (P30) and erased, but this is done by setting each terminal to the input mode. Even if the display is erased by this method, the output state being displayed is stored in the output port register, and the stored content can be displayed again by setting this port in the output mode. We will use this later.

In # 4, the lens is stopped. The brake is not applied here. This is because, while the AF microcomputer (MC2) is not operating, the lens is not braked so that it can be moved relatively easily by hand, and power saving is considered. The control of the lens motor drive signals MC, MR, MF, and MB that are input from the AF microcomputer (MC2) to the driver circuit (MDR1) are shown in Table 6 and the terminal (PO2).
By setting the signals MR, MF, and MB of ~ (PO0) to the "High" state, the electric brake is not applied and the motor (MO1) is de-energized and the lens stops.

In # 5, when a stop command is received from the control microcomputer (MC2) during the release operation or in the fill AF mode, the release flag (5th
Release F in Table 1 and auxiliary light mode flag (No. 5-2)
This is a step of clearing the auxiliary light mode F) in the table. #
6 is a control for determining an interrupt state for starting the next flow, and after the operation of the AF microcomputer (MC1) has stopped, INTIS of # 8 or I of # 28
Allowing a start from NT2S. However, in actuality, when the shutter release button (not shown) for the camera is pressed one step, the switch (S1) in FIG. 2 is closed and the control microcomputer (MC2) interrupts INT1. Switch (S2) is closed and IN
Since the release interrupt is applied to T2, the start of the next flow chart is "INT1S" of # 8.
become. At # 7, the AF microcomputer (MC1) enters stop mode. Stop mode means that the AF microcomputer (MC1) enters the power saving mode and stops operating. At this time, the status of each terminal is only "Low" for P13 and "High" for others, the LED for auxiliary light illumination (48) is off, and the LED for display (LEDL) (LE
DM) (LEDR) is off, the lens is in the stop state, and the interface circuit (IF1) is also in the stop state. In this state, the next control microcomputer (MC2)
Waiting for start of interrupt from pin to INT1.

Next, the second entrance # in the above-mentioned flowchart
Move on to the explanation of "INT1S" in 8. The interrupt start from this "INT1S" does not disable the interrupt during the entire flow of the AF microcomputer (MC1) and accepts the interrupt at any time. This entrance serves three interrupts. One is AF or FA operation start, the second is AF
Alternatively, the FA operation is stopped, and the third is the focus adjustment status display return operation immediately after release and the operation in continuous shooting mode. The distinction between these three is described. The first and the second are distinguished by the input signal to the terminal (INT1). That is, as shown in FIG. 17 (A), AF or AF is used to start FA operation.
S signal falls from "High" to "Low", "Low" is 50μs
It is necessary to continue above. To stop the AF or FA operation, the AFS signal changes from "High" to "Low" as shown in Fig. 17 (B).
After falling to, within 50μs from "Low" to "High"
Need to get up to. A flag is used to distinguish the third operation from the first normal AF or FA operation. When a release interrupt described later comes, the release flag (release F) is set in the flow during release, and it is distinguished by checking whether or not this flag is set at the start of the next "INT1S". These will be sequentially described from # 8. # 8, INT at start
Disable interrupts other than 1 and INT2. The event counter interrupt of INT3 and the internal interrupt of the timer that determines the blinking period of the display LED, which is not shown in the flowchart, are prohibited. # 9 is about to clear the used flag, but AFSINR from # 15
Among them, the two flags used as the previous states, that is, the scan prohibition flag (scan prohibition F in Table 5-1) and the previous low control flag (previous low control F in Table 5-1) are not cleared. The switch (S1) does not clear the scan prohibition flag even in continuous shooting mode.
As long as you do not turn off, once the contrast of the subject is sufficient for focus detection and you have been able to calculate the defocus amount, or once you have performed low contrast scan, as in the single shooting mode, This flag is left to prevent low contrast scanning. Also, the last time the low-con flag is not cleared is "AFSINR" which is the interrupt flow by the AFS signal after release starting from # 15. If the switch (S1) remains on after release, The focus detection calculation result display is not cleared in order to restore it. That is, during release, the LED defocus direction display is turned off once, and when the release operation is finished, it is displayed again.Therefore, it is necessary to determine whether the LED was blinking at low contrast. Leave the flag.

Wait for 50 μs in the next # 10 and see if the interrupt that entered "INT1S" was an AF or FA step interrupt.
I'm going to see it at 11. Here, the AF microcomputer pin (MC1) terminal (I
If the signal included in NT1) is as shown in FIG. 17 (A), the AFS signal is “Low”, so the process proceeds to # 12. If the signal is as shown in FIG. 17 (B), the AFS signal is Goes to "High" and goes to the # 2 stop mode process flow "STPMD" A
The operation of the F microcomputer (MC1) stops. In step # 12, it is determined whether to proceed to the interrupt flow "AFSINR" by the AFS signal after the release or by the interrupt of the first AFS signal. That is, if the release flag (release F) is on, #
If the release flag (release F) is not set, the process proceeds to "AFSINR" 15 and proceeds to the next step # 13. AF in # 13
Initialize each pin of the microcomputer (MC1).
That is, the auxiliary light emission terminal in auxiliary light AF mode (P13)
Only "Low" and other terminals "High". However, from the state that the AF microcomputer (MC1) has been in the stop mode until now, when coming to this step by the interrupt start, each pin remains the same state, that is, only the pin (P13) is "Low" and the others. Remains "High".

Next, in # 14, the scan prohibition flag and the previous low control flag which were not cleared in # 9 are cleared again. In # 401, the drive flag is cleared after the release. This flag is used in the continuous shooting mode, and is used in the focusing processing flow to determine whether the state is before release or after release during the continuous shooting mode. Since # 401 is a place where the vehicle passes before the release, the flag is cleared.
Then proceed to # 33 “AF START”. After that, the focus adjustment state is detected, the lens is driven according to the result,
The focus adjustment status is displayed. What is the focus adjustment status display?
Input signals LL and LR of LED (LEDL) (LEDM) (LEDR) are “H”
igh ", LM is to turn on the green LED when it is" Low ". If you see this display and close switch (S2), or (S1) and (S2) are closed, auto focus If the adjustment is done and the focusing operation is completed, the control microcomputer (MC
2) starts the release operation and at the same time AF microcomputer (MC1)
An interrupt signal INREL is output to notify that the shutter has been released. Since the AF microcomputer (MC1) receives this at the pin (INT2), it causes a release interrupt. This is the flow starting from "INT2S" in # 27 of FIG.

In # 27, interrupts other than INT1 and INT2 are disabled first.
Next, at # 28, the signal from the terminal (ST4) is set to "Low" to turn off the auxiliary light illumination. This is a step that is necessary only in the release priority mode and not necessary in the AF priority mode. This is because the focus adjustment is completed in the AF priority mode and the auxiliary light illumination is already off.
Similarly, # 29 is a step in which the lens motor (MO1) required only in the release priority mode is stopped. The motor (MO1) is not braked here. In the release priority mode, it is not always possible to release after the subject is in focus, and it is possible that the release may occur before that, so it was released while the lens was moving toward the in-focus position. At that time, rather than braking the motor (MO1) at that non-focus point to stop and release the lens, stop without braking, move the lens by some inertia, and at a place near the in-focus position at least This is because it is often the case that a better photograph can be taken with the release. At # 30, the focus adjustment status display or defocus direction display is turned off. This is because the mirror is raised and the inside of the viewfinder is completely black during the release with the single-lens reflex camera. This is because it is meaningless to display only the display here, and it is not preferable that unnecessary light is output inside the camera during film exposure.

Next, at # 31, the release flag (release F) is set to "1" and the release is left as a flag. And then #
At 32, INT1 or INT2 interrupt wait. When the release interrupt comes in succession, the process starts from "INT2S" of # 27 again. This is the case when the switch (S2) is repeatedly opened and closed with the switch (S1) in Fig. 2 closed.
It says that the lens is fixed at the in-focus position without being driven.
This is the same as repeating the release with the AF locked. After the switch (S2) is closed and released, the control microcomputer (MC
As shown in the flowchart in 2), the AFS signal enters the AF microcomputer (MC1) again and the INT1 interrupt occurs. Then, the flow from "INT1S" of # 8 proceeds to "AFSINR" of # 15 in Fig. 7 because "1" is set in the release flag (release F) this time. The steps from # 15 will be described later.

Fifth after closing the switch (S2) and releasing
When both switches (S2) (S1) are opened as shown in the flow in the figure, this time the AFS signal for stopping the AF microcomputer (MC1) enters the AF microcomputer (MC1) from the control microcomputer (MC2). , INT1 interrupt occurs. After that, the AF microcomputer (MC1) enters the stop mode by the above-mentioned flow and waits for the next interrupt again.

Here, the flow of interrupt start by the AFS signal after release will be described. The entrance is "INT1" of # 8 in Fig. 7.
However, since the release flag RLF is 1 this time, the process branches at # 12 and goes to "AFSINR" at # 15. Here, first, the release flag (release F) is reset because this flow has been passed. Since # 402 is a place where the vehicle passes after the release, the drive flag is set after the release. This flag will be used later in the focusing processing flow. Next, in # 16, serial data is input from the control microcomputer (MC2). The serial data is input here by the AF microcomputer (MC
This is to check whether the operation mode of 1) has been changed. The flow that comes to "AFSINR" starting from # 15 is the flow that comes after the release, but during this release or just before that, the operation mode, that is, AF mode / FA
If each mode of MANUAL mode or AF mode is switched to single shooting mode / continuous shooting mode, the operation must be changed according to the mode.

Step # 16 is a step for inputting information of this mode from the control microcomputer (MC2). This # 16 flows through the flow of "SIOSET" starting from # 241 in FIG. 15 in the subroutine. Here, each mode is checked and the mode flag is operated. First, in # 241, control microcomputer (MC2)
The DTRQ signal of the terminal (P11) is set to "Low" and the serial data is requested. Then the control microcomputer (MC2) becomes D
Looking at the TRQ signal, it sends serial data as shown in Table 4. On the AF microcomputer (MC1) side, this serial data is input at # 242 and the DTRQ signal is set to "High" at # 243.

The data sent by serial communication is the open F value for AF.
AFAV0, lens drive defocus amount-pulse count conversion coefficient KROM, auxiliary light AF correction data ΔIR, lens drive inversion backlash correction data BKLSH, auxiliary light OK
Signal AFFL, flash charge completion signal RDY, continuous shooting / single shooting mode signal DR, AF coupler axis attached lens signal AFC, FA possible /
There are 9 types of non-signal FAEN. When each information is sent by serial communication, it is saved in the RAM of the AF microcomputer (MC1),
If necessary, the contents of that RAM will be referenced.
The use of each information will be described later in the explanation of the flowchart.

 Check each mode from # 244.

In step # 244, the AF open F value AFAV0 is checked. The light receiving element for focus detection has a usable limit, and when the open F value of the lens is small, the incident light to the light receiving element for focus detection is eclipsed by the exit pupil, and correct focus detection calculation cannot be performed. Even if a single lens that makes focus detection impossible is not created, the focus detection limit F value may be exceeded depending on the combination of converter lenses and the like. For example, if the focus detection limit F value of the light receiving element for focus detection is 7.0, the open F value for AF is 5.6.
The lens is capable of focus detection, but if a double teleconverter is attached to it, the F value will be 11.2 and focus detection will be impossible. Here, the AF open F value is the F value when the diaphragm of the lens is not closed, but even in the case of a lens whose F value changes due to zooming or focusing, the light receiving element for focus detection is not cut off. Since this is information for determining that, if the F value changes due to zooming or focusing, the smallest open F value is included.

If the open F value AFAV0 for AF is larger than 7.0 in # 244, the process proceeds to # 251, where the AF mode flag (5-1
Table AF.F) is set to "1", and the FA mode flag (AF.F in Table 5-1) is also set to "1" at # 250 to set the MANUAL mode flag state. Return to # 16. If the open F value AFAV0 for AF is smaller than 7.0, it means that the lens can detect the focus for the F value, and the process proceeds to # 245.

In # 245, it is checked whether the AF mode has been set so far. If the AF mode flag is “0”, it means that the AF mode has been used up to now, and the process advances to # 246.
Check whether it is AL mode. # 246 is a step to check if there is an AF coupler axis. If the AFC signal is "1", there is an axis, so proceed in AF mode as it is,
"If there is no axis, it means that automatic focus adjustment is not possible, so proceed to # 247 and set" 1 "to the AF mode flag.
The coupler shaft is a shaft for transmitting power from the motor (MO1) in the camera body to the focusing mechanism of the lens.

In # 248 of FIG. 15, it is checked whether or not the lens can detect the focus. If the focus can be detected, the FA flag (FA.F) is set to “0” to enter the FA mode. If the focus cannot be detected, the FA flag is set to “1”.
Then, it is judged that the AF flag is "1" and the mode is MANUAL mode. When FAEN = "1", it means that the lens is attached to the camera body and the focus can be detected. Other than this, FAEN is "0". A lens that cannot detect focus is a lens such as a reflective telephoto lens that cannot detect focus even if the open F value for AF is small.
It is a special lens such as a shift lens or a vari-soft lens that has extremely large aberrations. In this subroutine, the change from FA mode to AF mode is not seen, but this will be seen in step # 86 of FIG. 11 later.

Now, the subroutine of FIG. 15 returns to proceed to the next step # 17. Check if it is in AF mode. If it is AF mode, step # 19. If it is not AF mode, #
At 18, it is checked whether the FA mode or not, and if it is not the FA mode, the process goes to the # 36 “MANUAL” flow.

In # 19, if the state before release is low contrast when looking at the state up to the previous time for display restoration, # 20
To restore the low contrast display. The low contrast display is a display in which both ends (LEDL) (LEDR) of the three LEDs (LEDL) (LEDM) (LEDR) for focus adjustment state display are blinked by repeatedly turning on and off at 2 Hz. If the contrast is not low, the focus adjustment state or the direction display is restored at # 21. The contents displayed before the release are saved in the display register, so the previous display is restored when the port is set to output mode.

In # 22, it is checked by the AF mode flag (AF.F) whether or not it is the AF mode. If it is not the AF mode but the FA mode, the process proceeds to "CDINTA" in # 39 to repeatedly perform the focus detection. Therefore, in the FA mode, if the switch (S1) in FIG. 2 is turned on after the release, the focus is continuously detected and displayed. In AF mode, whether the single shooting mode or continuous shooting mode is determined based on the DR signal in # 23, and if DR = 0, the AFE signal of the terminal (P12) is set to “High” in # 25 which is the single shooting mode. To This signal is for notifying the control microcomputer (MC2) that the automatic focus adjustment operation is completed and the focus is achieved and the release is possible.

When the shutter release button is pressed down to the second step, the control microcomputer (MC2)
If this signal is "High", release is permitted and "L"
If it is ow ", the release is not possible. That is, in the single-shot mode, after focusing and releasing once, keep pressing the release 1 step (switch (S1) ON),
If an interrupt such as the AFS signal does not come in, “AFSIN
Since the AFE signal becomes “High” in # 25 following the flow of “R”, if the subject position is changed as it is, the shutter can be released even in the out-of-focus state. At this time, the lens is not driven because the release interrupt or the AF microcomputer (MC1) stop interrupt is to be waited at # 26. This sequence can be called "AF lock".

On the other hand, in the continuous shooting mode, the process proceeds from # 23 to # 24. In # 24, the fill light mode flag is cleared and the “CDINT
Proceed to "A" to enter the next focus detection. That is, auxiliary light AF
The continuous shooting mode is also possible in the mode, and in this case,
Instead of entering the supplementary light mode from the beginning, the normal mode is restored once, and when the conditions of the supplementary light mode are satisfied, the supplementary light mode is entered again. This is because the subject may become bright and need not enter fill mode.

The flow starting from "AF START" in # 33 of Fig. 9 is # 14
Fly away from. In # 33, the subroutine "SIOS
ET "is called. When starting the operation of the AF microcomputer (MC1), the control microcomputer (MC2) receives various data to determine the operation mode. At this time, the decided mode is automatically written to the mode register RG in the AF microcomputer (MC1). This register RG is for checking whether the mode has been changed later. # 34, #
At 35, the operation mode is checked, and if it is neither AF mode nor FA mode but MANUAL mode, proceed to # 36.
In # 36, the driver circuit (MDR
1) Signals MR, MF, MB are all set to "High" to stop the lens motor (MO1). In # 37, INT1 and INT2
Stop interrupts other than the above and loop to # 33 to repeat.

If in AF or FA mode, proceed to # 38 to initialize the CCD image sensor (FLM) and warm up the sensor. The interface circuit (IF1) sets the IOS signal of the terminal (P20) to "Low" in # 39.
This is also to set the mode to input the signal from the AF microcomputer (MC1) and to integrate the output of the CCD image sensor (FLM). Then, proceed to # 44 in FIG.

Here, first, 1-cut shot flag (1- in Table 5-1
Cut shot F), that is, clear the flag indicating whether the integration time exceeds 50 ms. Terminal at # 45 (P12)
The AFE signal output from is set to "Low". I'm doing this here because it keeps looping even after focusing. This is a signal that becomes "High" when the AFE signal is in focus, so it is kept "Low" in preparation for the next calculation. Next, at # 46, the NB2 signal is output from the terminal (P23) to start the integration of the CCD image sensor (FLM). In step # 47, the lens drive pulse count value EVTCNT for correcting the lens movement amount during focus detection calculation and integration, which will be described later, is read and the memory T1 is read.
Save to. At # 48, half the maximum integration time of 100 ms of the CCD image sensor (FLM) is set to 50 ms. Ninth
In the figure, “CDINA” is parallel to “CDINA” starting from # 40
There is a "T" and there is another flow up to # 53, but this is a flow for a function called "convolution integration", and a description thereof will be given later.

Continue from # 48 to "TLNTφ" from # 55. In # 55, all interrupt routines are enabled. At # 56, check the NB4 signal coming into the terminal (P25), and
If it is w ", it is a signal that the CCD image sensor (FLM) has completed the integration according to the brightness of the subject, so the flow proceeds to" CDINT2 "in # 64. If it is "High", it means that the integration is continuing, so the process proceeds to # 57, and it is checked whether or not the maximum integration time initially set has elapsed. That is, # 48
Check whether 50 ms set in step 5, 40 ms set in step # 53, 50 ms in step # 61 or 150 ms in step # 62 set in the future, and if not, return to step # 56 and repeat the loop. If the maximum integration time has elapsed, proceed to # 58. 1-cut here
If the shot flag (1-cut shotF) is not "1", proceed to # 59 and set "1" to this flag. 1-cu when going to # 63
Since the t shot flag is "1", it is after passing # 59 or # 49. In # 60, it is checked whether the 200ms flag (200msF in Table 5-2) is "1". If it is not "1", the maximum integration time is usually 100ms. 50 ms of # 61
Set with and return to # 56 to check the NB4 signal. # 6
If the flag is 0 and the 200ms flag is "1" (this is set in a later flow, and the maximum integration time is set to 200ms only under special conditions), the integration set in # 48 is performed. Set the remaining 150ms of 50ms and return to # 56.
Check the signal.

If the output from the CCD image sensor (FLM) is obtained to a sufficient level, the process proceeds from # 56 to # 64. Here, even if the output is not sufficient, the integration must be completed if the maximum integration time has passed, and that time is when the process proceeds from # 58 to # 63. #
In 58, since the 1-cut shot flag is "1" this time, the program always advances to # 63, where the interface circuit (I21)
Output the forced integration stop signal NB0 to F1). And # 64
To "CDINT2". The steps from # 64 to # 67 are the flow of “convolution integration”, and the explanation will be given later.

In # 68, interrupts other than INT1 and INT2 are forbidden, but this is to prevent interrupts from entering the timing when data is taken in after this and to prevent timing errors. Since INT1 and INT2 interrupts start from the beginning of the main flow, do not disable them. # 69 is the ST of pin (P13) when the auxiliary light LED (48) has been illuminated during CCD integration so far.
4 The signal is turned "Low" and turned off. # 70 is for terminal (P20)
Interface circuit (IF1) with IOS signal set to "High"
Is switched to the data output mode. I.e.NB4-N
The B0 signal becomes a line for data transfer, and data can be sent from the interface circuit (IF1) to the AF microcomputer (MC1). 8-bit data is sent as data, but in 4-bit parallel from NB3 to NB0,
The data is sent in two steps, and when the timing is taken by NB4, the higher 4-bit data is sent when NB4 is "High", and the lower 4-bit data is sent when NB4 is "Low". AF microcomputer (MC
In 1), the data sent separately to the upper and lower layers is recreated and incorporated.

So, first, AF from the interface circuit (IF1)
The AGC data is sent to the microcomputer (MC1), which is one of the numerical values of the gain (1 time, 2 times, 4 times or 8 times) determined in the AGC controller (406) in FIG. 6 ( Less than,
(AGC data) is sent and AF is done at # 71 in Fig. 10.
Take it into the microcomputer (MC1). By the way, after the CCD image sensor (FLM) integration is completed, the timing at which these data come out is determined by the interface circuit (IF1), and AGC data must be taken in immediately after the integration is completed. AGC data is output for a certain period of time, and as soon as this is completed, pixel data of the CCD image sensor (FLM) is also sent at a certain timing. Just 72 hours after loading this AGC data, # 72
As described in, the lens drive pulse count value EVTCNT at the end of integration is read and stored in the memory T2. This corresponds to # 47 at the start of integration.

Immediately thereafter, the pixel data of the CCD image sensor (FLM) is input at # 73 and saved in the memory of the AF microcomputer (MC1). Next, # 74 is a subroutine for checking whether the driven lens hits the infinity end or the closest end while driving the lens, and if it hits the end (infinity end or the closest end), the lens drive motor. Step (MO1) or reverse drive.
The subroutine "CKLOCK" will be described later with reference to FIG. In # 75, data for driving the lens etc. is obtained by serial communication with the control microcomputer (MC2). Even though I received the data once in # 33, I am doing serial communication again here, because I do not pass through # 33 in the repeated loop, so if the conversion coefficient KROM for lens drive changes in the middle (depending on the lens Is changed depending on the focus state, zooming, etc.), and the data changes when the microcomputer operation mode changes, so "SIOSET" is provided in # 75 to see this repeatedly. Then, in # 76, focus detection calculation is performed using the CCD image sensor (FLM) data taken in in # 73. With respect to this method, the defocus amount DF is obtained by the method already proposed by the present applicant in Japanese Patent Laid-Open No. 59-126517, but since it is unrelated to the gist of the present invention, its explanation is omitted.

From # 77 to # 85, whether or not the brightness of the subject is lower than a predetermined level is checked to make a determination by looking at the level of AGC data. Here, when the brightness of the subject is below a predetermined level, it is called low light. At # 77, "1" is set in the low light flag (low light F in Table 5-2). #
In 78, if the electronic flash device is attached to the camera and the auxiliary light switch (44) is closed, the AFFL signal sent by serial communication is "1", so the process proceeds to # 80. That is, if the auxiliary light emission enabled state is set, a low light determination is made when the AGC data is 2 times, 4 times, or 8 times in the mode with the maximum integration time of 100 ms, and # 86
Go to “MAIN1” of No. and when the AGC data is 1 time, #
After passing 80, the low light flag is cleared to "0" at # 85 and the process goes to # 86. In the mode where the maximum integration time is 200 ms, all become low light and go from # 80 to # 86.

On the other hand, if the auxiliary light emission enabled state is not set, the process moves from # 78 to # 81. In the mode with the maximum integration time of 100 ms, when the AGC data is 4 times and 8 times, # 82, # 8
It goes through 3, # 86 and becomes low light judgment, and AGC data is 1
At the time of double and double, it moves from # 82 or # 83 to # 85 and clears the low light flag and goes to # 86. Maximum integration time
In the 200ms mode, when the AGC data is 2 times, 4 times, or 8 times, the low light judgment is made from # 84 to # 86 and the AGC is performed.
When the data is 1 time, the process goes from # 84 to # 85, clears the low light flag at # 85, and goes to # 86.

Here, the determination of low light when the auxiliary light emission enabled state is set is one step brighter than the determination of low light when not set. This is very effective in the case of giving up the automatic focus adjustment because the focus detection cannot be calculated if the subject has low contrast and low brightness. That is, if the auxiliary light emission enabled state is set, the focus detection in the auxiliary light non-use state is given up early, and the auxiliary light emission enabled state is entered immediately to immediately detect the focus. If is not set, the focus is detected only by outside light to the point where it can be removed, and if low contrast and low brightness are reached, the lens is retracted without automatic focus adjustment. In this embodiment, before giving up the focus detection, the lens is further extended or rescanned to perform a scan for reconstruction, and a method of searching for a position having contrast is adopted. About this
This will be described in the flow after "LOWCON" from # 165 in FIG.

In the present embodiment, the determination of the subject brightness is based on AGC data, but this may be based on the integration time. For example, among the flags used in this embodiment, if the integration time of the CCD image sensor (FLM) is 50 ms or more, it is 1-cut s.
You may use the hot flag.

Now, the "MAIN1" from # 86 in FIG. 11 will be described below. From here, the process of driving the lens will be explained. First, # 86 compares the serial data obtained in # 75 with the mode in which the AF microcomputer (MC1) has been operating so far, and if the mode has changed, restarts from "AF START" in # 33. That is, the contents of the register RG indicating the AF mode / FA mode / MANUAL mode set after the last serial communication # 33 and the single shooting / continuous shooting mode, and the focus detection mode flag (AF mode Flag, FA mode flag),
It is compared with the flag (DR) in the single shooting mode, and if there is a change, it means to proceed to # 33. Then, at # 33, a new mode is automatically written in the mode register RG. In # 87, it is checked whether or not the mode is the focus detection operation mode using the auxiliary light. If it is the mode using the auxiliary light (hereinafter referred to as auxiliary light AF mode), the focus of the auxiliary light in FIG. 14 is used. # 238 “LSAV of detection flow”
Enter "E". Note that the method of entering this fill-in AF mode is on condition that the subject is in a state of low contrast and low brightness. Therefore, enter from the low contrast flow starting from “LOWCON” in # 165 of FIG. become.

If it is not the auxiliary light AF mode in # 87, the current low-con flag (current low-con F in Table 5-1) is checked in # 88 to determine whether or not the result of focus detection calculation is low light. If there is, “165 LOW in FIG. 13
Move to "CON" flow. This time the low contrast flag that appears in # 88 is determined and set in # 76.
If the result of this calculation is not low contrast, the process proceeds to # 89 to check the AGC data input in # 71 of FIG. 10, and if the AGC data is 1 time, clear the 200 ms flag in # 90. This is because the maximum integration time is 20 when it is dark.
Although it is said that there is a 0ms mode state, if the AGC data is 1 time when in 200ms mode, it is not necessary to set it to 200ms mode. This is because the time is short. When integration time is 200ms and AGC data is 1 time, integration time is 100ms
Therefore, it can be seen that the pixel output is almost the same as when the AGC data is doubled, and it is disadvantageous when the integration time becomes long considering the movement of the subject and camera shake. If you can find the contrast of
The maximum integration time is 100ms.

The flow of "NLOC1" starting from # 91 is a flow when the contrast is found in the subject, and in # 91, the scan inhibition flag is set to "1". When the contrast of the subject is low, this is called low-con scan, in which the focus is detected while moving the focusing lens by looking for a position with high contrast. This sequence is prohibited while the sequence is closed). This is because, if you scan frequently, it will be difficult to use as an autofocus camera, and the contrast will be found once. Even if
It seems that there is a high probability that the contrast will be found again, and even if the next low contrast is reached, the effect will be adversely affected by the focus detection when the low contrast scan is started immediately.

Further, the reason why the scan is prohibited is that, in addition to this, there is a case where the scan is once completed with low contrast. The flow from # 92 to # 101 mainly shows the processing when a sufficient contrast is found during the low contrast scan. This is roughly divided into 2
There are some cases, and it is divided when the integration time of the CCD image sensor (FLM) exceeds 50 ms and when it is not.
When the contrast is found during low-con scanning when the subject is dark such that the integration time exceeds 50 ms, once the lens is completely stopped, focus detection is performed again, and the lens is moved to the in-focus position according to the result. Focus is not detected while the lens is moving. The reason is that when the lens is driven when the integration time becomes long, the image of the subject flows out, which adversely affects the defocus amount calculation. This is because if the integration time becomes long and the AGC magnification becomes large, the noise due to the dark output variation of the CCD image sensor (FLM) also becomes large, and if the image flows in this state, delicate focusing will be lost. .

Therefore, when the integration time exceeds 50 ms, the focus is not detected while moving the lens, and the focus is detected by the value only when the lens is stopped. This is called the 1-cut shot mode. A flag indicating that (1-cut shot flag in Table 5-1) is provided. This flag is already set at # 49 or # 59. Next, in the case of a bright subject whose integration time does not exceed 50 ms, if sufficient contrast is found during low-con scanning, then the focus detection is performed using that contrasted data without stopping the lens. The calculation is performed, and the lens is driven up to the resulting focal point. During this period, the focus detection calculation is repeated, and the lens drive amount up to the in-focus position is constantly refreshed for focusing. This is called the multi shot mode because the focus is repeatedly detected while the lens is being driven. When it comes to focus detection without stopping the lens during low contrast scanning, the lens position is different between the time when the CCD image sensor (FLM) is integrated and the time when the lens drive amount is obtained. For the preparation for correcting this movement, see “LO
It is performed in the "WCON" flow, and the movement amount is corrected using this. The idea about this movement correction is
Since it is described in Japanese Patent Laid-Open No. 59-68713, detailed description will be omitted here.

Next, it is possible that low contrast will be obtained even after the contrast is found during the low contrast scan and the operation of the multi shot mode is started. In this case, the result of low contrast is ignored, and the lens is driven to a position that is considered to be the in-focus point according to the drive amount set before the low contrast is obtained. Only the results with contrast are used for driving. The decision to get out of the low contrast state is
Check by checking the previous low control flag (previous low control F in Table 5-2). This flag is set in the "LOWCON" flow from # 165 in Fig. 13, and is set when the previous calculation result was low contrast. On the other hand, being in # 92 means that there was contrast in this result, so
If the low contrast flag was set to "1" last time at # 92, it means that the low contrast has been exited and the process proceeds to # 93. If the low contrast flag is "0" last time, the process proceeds from # 92 to # 102 as a place to pass when the focus is detected due to contrast from the beginning. At # 93, the focus adjustment status display is turned off. Until now, when the lens drive was in a low contrast state and the lens drive was stopped, a blinking display indicating that focus detection is not possible is displayed, but this is erased because the contrast appears. In # 94, if the 1-cut shot flag is set as described above, the lens must be stopped.
Proceed to 95, if the 1-cut shot flag is not on, leave the lens unstopped even during low contrast scanning,
Go to 101. At # 101, the previous low contrast flag, the per-scan flag (F per scan in Table 5-1) and the in-scan flag (F during scan in Table 5-1) are cleared. This is to reset the flag indicating the state when the low contrast scan has been completed once or during the scan. Of course, the scan prohibition flag is left without being reset.

# 95 comes when it is in the 1-cut shot mode state. Here, it is checked whether the low-con scan has come by looking at the scanning flag. If it is not scanning, proceed to # 101, go to the one that drives the lens according to the present calculation result, and if it is scanning, # 96,
At # 97, the lens driving motor (MO1) is de-energized and the brake is applied according to the signal pattern shown in Table 6. In order to remember the state in which the lens is stopped, the driving flag (driving F in Table 5-2) in # 98 is cleared. In # 99, wait 70 ms for the lens to completely stop, then in # 100 clear the same flag as in # 101, return to # 39 “CDINTA”, and start the next focus detection. As described above, the # 99 waiting time causes an image to flow if the lens is moving when the integration time of the sensor is long, and the problem is that even if the movement data is corrected to the integration data position during driving, Correct correction is difficult when a negative acceleration is applied. Therefore, if the next sensor integration is started after the lens is completely stopped, the focus shift of the focus detection calculation can be prevented.

Next, the flow for converting the defocus amount of the focus detection calculation result into the pulse count value for driving the lens "MPUL
There is an S ". In step # 102, the defocus range in which the lens is in focus within this range is set in the register FZW as the focusing zone. Note that here, the focus zone amount in the automatic focus adjustment state (AF mode) and the focus zone amount in the focus adjustment display state (FA mode) are distinguished,
Set a wider value in FA mode than in AF mode. # 103
From # 106, the flow is when the lens is stopped at the end, which is the case when the lens is hitting the end at infinity. The end flag of # 103 (end F in Table 5-2) is
It is made in the termination check subroutine before coming here. If the lens has stopped at the end, the process proceeds to step # 104, and the previous direction flag (previous direction F in Table 5-3) is checked to check in which direction the lens is about to move. If the lens is at the infinity end and is trying to drive to the infinity side further, proceed to # 105, check the end position flag (end position F in Table 5-2) to see if the end position is at the infinity end side. Looking at the closest end side, if it is at the infinity end side, proceed to # 106 and set the focusing zone to a large value of 255 μm. If the lens stop position is the closest end, # 10
Go to 7 Even if the lens is located at the infinity end position due to variations in focus detection data, this may result in the in-focus position being further toward the infinity end, and if a narrow focus zone is set. , At the infinity end, there is a possibility to move the lens toward the infinity side. or,
Furthermore, the position at which the lens is considered to be at the infinity end may actually stop the lens midway due to other external stress. In the present example, this is indistinguishable.

Therefore, if the detection result is that the lens is at the infinity end and the in-focus position is beyond the infinity end, first widen the focusing zone to 255 μm, and then the lens is inside the focusing zone. If so, the focus is displayed, and if this value is not within the focus zone, the focus detection is impossible (LED blinking display). If the lens is forcibly stopped by hand etc. while the lens is trying to move to the infinity side during automatic focus adjustment, the LED will blink if the lens stop position is not within the focus zone. That is. This display flow corresponds to # 120 to # 123.

On the other hand, if there is a lens at the closest end and it is detected that the subject is on the close side, or the lens is trying to move to the close side during automatic focus adjustment, the lens is forcibly stopped halfway. If the position is not within the in-focus zone, the display is made in the closest direction. The flow of this display is from # 147 to # 1 in FIG.
Hit 52. If the lens doesn't stop at infinity,
The focus zone moves to # 107 while keeping the numerical value set in # 102.

In # 107, it is checked based on the auxiliary light mode flag whether or not the auxiliary light AF mode is set, and if it is the auxiliary light AF mode, chromatic aberration correction is performed. Since the infrared light is used as the illumination light in the auxiliary light AF mode, the best focus position is displaced due to the difference in the light source during flash photography. Therefore, if the auxiliary light AF mode is set, this focus position shift amount must be corrected. As shown in Table 4, the correction data ΔIR according to this taking lens is sent from the control microcomputer (MC2) by serial communication. This is # 108, and the defocus amount DF that has been obtained so far
Correct for.

However, the correction data ΔIR is prepared assuming that auxiliary light of a certain wavelength, for example, a light source of 800 nm is used. However, the auxiliary light actually used is, for example, 700n
If the light source is m, it will be overcorrected. Therefore, 800
To convert the correction value of nm to the correction value of 700 nm, the correction value is halved. However, this is a condition when the surrounding brightness is pitch dark, and considering the usage conditions of the focus detection device used now, the surrounding brightness is often a little dark. Therefore, if the correction value is halved, the correction will still be overcorrected. Therefore, the optimum magnification for the apparatus of this embodiment is 1/4. Therefore, in # 300, ΔIR is multiplied by 1/4 and put back into ΔIR, and this value is used for correction. The correction formula can be expressed as follows.

DF = DF ₀ −ΔIR where DF is the defocus amount in auxiliary light mode, DF ₀
Is the defocus amount after correction.

Then, in # 109, the defocus amount is converted into a pulse count value for driving the lens. Since the coefficient for this conversion is also unique to each lens, the data KROM sent by serial communication is used like ΔIR. The defocus amount DF found is also multiplied by the conversion coefficient KROM to find the pulse count value DRCNT for driving the lens. Similarly, the focusing zone FZW is also multiplied by the data KROM and converted into the pulse count value FZC. The conversion into these pulse count values is described in detail in Japanese Patent Laid-Open No. 59-140408, and therefore omitted here.

Then, in # 110, it is determined based on the driving flag (driving F in Table 5-2) whether or not the automatic focus adjustment operation is currently being performed, and when the lens is driving, "IDO of # 131" is set.
BUN ”. When the lens is stopped, that is, when it first passes through the flow, when the focus position is confirmed after automatic focus adjustment is completed, or when in FA mode, the process proceeds to # 111. Here, the defocus amount DF when the lens is stopped is stored in the memory FERM. This value will be used later to determine whether to go to the loop for checking the in-focus position after the end of automatic focus adjustment or not according to this value. In the next step # 112, it is determined whether or not the FA mode is set based on the FA mode flag. If the FA mode is set, the flow branches to “FAP” from # 113. This is because the non-AF mode is the FA mode.

In # 113, it is judged whether or not the lens is in the focusing zone. Here, the lens drive pulse count value DRCNT and the focus zone pulse count value FZC are compared, but the defocus amount DF and the focus zone amount FZW may be compared. As a result, if there is a lens in the focus zone, focus display is performed at # 115. This is the terminal (P31) LM
This is done by setting the signal to "Low", leaving the LL and LR signals at "High", and turning on only the central LED (LEDM). If it is outside the focusing zone, the flow proceeds to # 114, where the direction in which the lens should be driven is shown. For example, in the lens extension direction, set the LL signal of the terminal (P32) to "Low" to turn on the left LED (LEDL), and in the lens extension direction, set the LR signal of the terminal (P30) to " Set to "Low" and light the right LED (LEDR). Then, for the next focus detection, the process loops to # 40 "CDINTA" in FIG.

If it is in AF mode in # 112, focus check in AF mode is performed in # 116. Lens drive pulse count value
If DRCNT is smaller than the focus zone pulse count value FZC, it means that focus is achieved, and the process branches from # 117 to "INFZ".
In # 117, the focus display is displayed as in # 115 in FA mode,
At # 118, set the AFE signal from the terminal (P12) to "High". The control microcomputer (MC2) is watching this signal, and if it becomes "High", it is considered that the automatic focus adjustment is completed. Then, in the AF priority mode, the release operation becomes possible only after the AFE signal becomes "High".

Next, at # 403, the flag SCF is checked. Flag SCF
If is “0”, it means continuous AF mode.
After focusing, the automatic focus adjustment continues. Therefore, it returns to the # 40 “CDINTA” from # 403 and immediately starts the next distance measuring operation. If the flag SCF is "0", it means the one-shot AF mode, so once the focus is reached, the automatic focus adjustment mechanism is locked (AF lock) and the process does not proceed to # 40. Once the subject is in focus, this AF lock keeps displaying the focus even if the focus position changes after that, and the lens is not driven again. As the processing for this, the interrupt of INT1 which is an AF stop instruction in # 119 or I
It goes around the loop of waiting for the release interrupt of NT2.

However, there is only one exception here. The processing is # 404 to # 406. This is for continuous shooting mode,
This is a problem especially in continuous shooting in AF priority mode, and the camera automatically starts film winding operation when the shutter is released after focusing.

On the other hand, the automatic focus adjustment mechanism is set so that it often ends before the winding is completed. If the subject is within the in-focus zone, the in-focus display will be displayed immediately and the AF will be locked. It is good if the distance between the subject and the camera is not changing, but if this distance is changing, if the AF lock is fast and the film winding is completed and shutter release is possible, The subject is out of the focusing zone, resulting in a defocused photograph. Therefore, in the present embodiment, only when in continuous shooting mode, when focus is reached after release, it is treated as continuous AF mode and looped to the next distance measurement.

However, this is only for the normal mode, and the principle is followed for the auxiliary light mode. Whether or not this is the auxiliary light mode is determined at # 404, and when in the auxiliary light mode, the interruption is waited at # 119.

In # 405, it is determined whether it is after the release or not. If it is before the release, the principle is followed in # 119. Then, in # 406, it is determined whether it is continuous shooting or single shooting. In the single shooting mode, since DR is "0", the process proceeds to # 119 and follows the principle. When DR is "1", it means continuous shooting mode, so at this time, the process loops to "CDINTA" of # 40.

When it is determined in # 116 that the object is out of the focusing zone, # 1
Go to 20. As described above, here, the end flag (the fifth flag
2 Check the end F) of the table and it is the end (# 120),
If the focus detection result of the previous direction flag was checked and the in-focus position of the focus detection result is at the infinity end side (# 121) and the lens stop position is at the infinity end (# 122), proceed to # 123 to drive the lens. If not, the two LEDs (LEDL) and (LEDR) on both sides will blink together to indicate that focus detection is not possible, and the interrupt will be waited at # 119, and the next focus detection will not be performed. In the case other than these conditions, the process proceeds to # 124.

From # 124 to # 130, the reversal check of the defocus direction is performed. That is, by comparing the defocus direction of the previous focus detection calculation result with the direction of the result calculated by this loop, if it is found that the defocus direction is reversed, correct the backlash of the lens drive system. That is. When driving the lens, a considerable amount of backlash is provided especially in the coupler portion of the driving force transmission shaft between the camera body and the lens. Therefore, if the lens driving direction is reversed due to a change in the distance to the subject, the lens will not move to the in-focus position determined by the calculation result due to the amount of rotation from the motor (MO1). Therefore, if the direction is reversed, the amount of backlash must be corrected. This backlash amount is unique to the taking lens and is obtained by serial communication from the control microcomputer (MC2) as shown in Table 4. However, when the previous defocus direction that appears here is the first loop after closing the switch (S1), remember that this is also the last lens drive direction in the previous sequence. ing. That is, switch (S
The memory is remembered even during the stop mode of the microcomputer (MC1) (MC2) before 1) is closed. Also, this backlash correction is not so correct as soon as the calculation result is reversed, and this correction is limited only when the lens is stopped. If the result is that the direction is reversed while driving the lens, just stop the lens and do not immediately perform the reverse driving of the lens. or,
Do not reset the direction flag last time. Therefore, the direction (current direction) obtained by the next focus detection calculation after stopping the lens is the direction that was obtained once before the lens was stopped, that is, the direction that was driving the lens. If it is reversed from (previous direction), it means that the backlash is corrected for the first time. This is because the dispersion of the calculation in the vicinity of the in-focus position is taken into consideration so that the lens does not hunt due to the error of the backlash amount.

The flow for these is # 124, which will be described later.
To # 130 and # 1 in FIG. 12 showing the flow during lens driving.
Achieved in combination with 34 to # 140. After checking the current direction flag (current direction F in Table 5-3) in # 124 and looking at the current defocus direction, # 125, # 126
Check the previous defocus direction with. Then, if the defocus direction is different between the previous time and this time, # 12
Go to 7 and # 128 respectively, and rewrite the previous direction flag. If it is the same direction, skip to “TINNZ” of # 141. In # 129, the backlash correction data BKLSH sent by serial communication is used as the lens drive pulse count value D
The RCNT is corrected, and in # 130, an inversion flag (inversion F in Table 5-2) indicating that the image has been inverted and the backlash has been corrected is set, and the process proceeds to # 141.

Next, based on FIG. 12, the flow of “IDOBUN” from # 131 when the lens branched from # 110 is being driven will be described. In # 131, it is checked whether or not the lens is hit at the end, and in # 132, the third event counter value EVTCNT for moving amount correction is read and stored in the register T3. Now you have all the data for the correction of the movement. That is, T1 at the start of sensor integration, T2 at the end of integration, and T3 at the end of focus detection calculation, using these three values, focus detection calculation based on pixel data obtained by integration during lens driving. The result,
The amount of movement of the lens is corrected until the lens driving amount is set after the actual calculation. When the amount of lens movement Tx during integration is calculated by the pulse count value, Tx
= T1-T2. Since the event counter is a subtraction count here, T1> T2 and Tx is positive. The lens movement amount Ty in the time required for focus detection calculation is
It is calculated as Ty = T2-T3. Assuming that the lens is moving at a constant speed, the intermediate position of the sensor integration time is represented as the point where the subject data was obtained. Tz = Tx / 2 + Ty The lens has moved by the amount of. Therefore, if Tz is subtracted from the count value DRCNT obtained by this calculation result,
It means that the movement amount has been corrected. Therefore, in # 133, DRCNT-Tz is newly replaced as DRCNT, and the value is set as the next lens drive pulse count value.

Steps # 134 to # 140 are the flow when the defocus direction is reversed during lens driving as described above. In # 134, the current direction flag is checked to see the current defocus direction. Then, the previous direction flag is checked to check the previous defocus direction, and if the direction is reversed, the process proceeds to # 137, and if not reversed, the process proceeds to # 141. #
In 137 and # 138, the lens drive motor (MO1) is de-energized and the brake is applied to stop it. In # 139, the driving flag indicating that the lens is being driven is cleared, and in # 140, wait 70 ms until the lens stops. Then proceed to # 39 “CDINTA”.

“TINNZ” starting from # 141 is a flow that merges from both when the lens is being driven and when it is stopped, and is a part where the lens drive pulse count value DRCNT is set and the lens is moved. The driving speed of the lens is a two-stage type in this embodiment, and it is set to switch between high speed when the lens is far away from the focus position and low speed near the focus position of the lens. . The part that controls the lens at low speed is called the near zone. In # 141, the lens drive pulse count value DRC
It is checked whether NT is within the pulse count value NZC of this near zone area. If the lens is within the near zone area, proceed to # 143, near zone flag (near zone in Table 5-2). F) is set. # 14
The MC signal from the terminal (PO3) is set to "Low" at 4 to drive the lens drive motor (MO1) at low speed as shown in Table 6. On the other hand, when outside the near zone,
Proceed to # 142 to set the MC signal to "High" to drive the lens drive motor (MO1) at high speed.

Although a part of the description has been made in the above from # 145 to # 152, it is a flow of processing when the lens is stopped at the terminal position. By the way, detecting that the lens is stopped at the end does not mean that there is a switch at the lens end position, as described in the subroutine from "CLOCK" in Fig. 14 below, and it is input from the interrupt port INT3. It is judged that the lens is stopped when the pulse from the motor drive amount monitor encoder (ENC) is not input for a certain period. It is judged that the fact that the lens is stopped even though the motor (MO1) is being driven means that it is hit at the end of the lens.
In the "K" subroutine, the motor drive is stopped and the end flag is set. With this method, even if the lens is not at the end, it will be forcibly stopped in the middle, or something will be caught in the lens, or the lens will stop for a moment (on the order of several 100 ms). However, it will be judged as the end.

In order to prevent such a thing, even if you see that the lens stopped at the end, try moving the lens again, and only after it is judged as the end by the "CLOCK" subroutine again,
It is said that it actually stops at the end. The flag to see this is the end 2nd flag (end 2F in Table 5-2).
Then, look at the end flag created in the "CLOCK" subroutine, and when it is "1", look at this end 2nd flag at # 146. Since this flag is "0" in the initial state, the process proceeds to # 150, and the terminal 2nd flag is set up.
The lens drive flow from 153 moves the lens. Then, when it comes to # 146 in the next loop, it is judged that the vehicle has stopped at the end for the first time, and the process proceeds to # 147.

In # 147, check the defocus direction this time,
Then, by checking the end position flags at # 148 and # 149, it is checked which side the end of the lens is hitting. That is, assuming that the current defocus state is the front focus (current direction flag = 1) and the lens position is at the infinity end, the lens must be moved further to the infinity side than the current infinity end. become. In this case, # 148
From # 40 to # 40, in the next loop from "CDINT", the focus zone is expanded and the focus is rechecked as described above.

This time the defocus state is the rear pin (this time direction flag =
0), and assuming that the lens position is the closest side (end position flag = 1) in # 149, the lens must be moved to the closer side. In this case, # 14
Proceed from 9 to # 152, and set the LL signal from the terminal (P32) to "Low".
Then, the direction indicator for instructing to move the lens to the closest side is turned on. Then leave the lens stopped,
The process goes to the next loop from # 40 and the focus detection is repeated. Then, if the position of the subject changes and the defocus direction is reversed, the process proceeds from # 147 to # 148 in the loop, passes through to # 151, clears the termination flag, and enters the lens drive loop from # 153. In this embodiment, the current direction flag is used to check the defocus direction of # 147, but the previous direction flag may be used. The lens does not follow and remains stopped even if it enters the focusable area of. In the case of one-shot AF mode, the latter method may be used, and in the case of continuous AF mode, it may be inconvenient unless the former.

In this latter case, once the low contrast state is reached, the end flag is cleared in the # 165 “LOWCON” flow of FIG. Entering, it means that automatic focus adjustment is possible. Next, if the lens is not at the end, or if it is at the end but trying to move in the opposite direction, # 153 in FIG.
Enter the lens drive flow from.

In # 153, all the focus adjustment status display LEDs are turned off.
This is based on the basic principle that the defocus direction is not displayed while the lens is being driven. When the lens is stopped, the center LED (LEDM) is lit when focusing to show the focus, and the LED (LED
L) (LEDR) is lit to indicate the defocus direction, and when the contrast is low, LED (LEDL) (LED
R) blinks. In # 154, the lens drive pulse count value DRCNT is set in the event counter EVTCNT and the termination check register MECNT. The value DRCNT set in the event counter EVTCNT is the interrupt pin (INT
When a pulse from encoder (ENC) is input to 3) and AF microcomputer (MC1) is interrupted, it is subtracted in this interrupt flow (INT3S in Fig. 16). Count value DRCNT
It is a mechanism that the lens is in focus when the lens is stopped when “0” is reached.

In # 155, the lens driving motor (MO1) is energized to start lens driving. This moves the lens according to the previous direction flag. That is, this flag remains as the lens driving direction so far. Because the previous direction flag, when the lens is stopped,
This is because the same content as the current direction flag is obtained by the flow from # 124 in FIG. If the previous direction flag is "0" (rear pin), the MF from the terminal (P01)
Set the signal to "Low" and extend the lens as shown in Table 6. If the previous direction flag is "1" (front pin), set the MR signal from the terminal (P00) to "Low" and extend the lens. Move in the direction. In # 156, the driving flag is checked to see if the lens has been driven so far. If it is driving (explained later, driving here means automatic focus adjustment outside the near zone. (Middle), loop to # 40 "CDINT" and start the next focus detection. If the lens has been stopped so far, the driving is started in # 155, so the driving flag is set in # 157. At # 158, the auxiliary light mode flag is checked to see if it is the auxiliary light AF mode. If it is the auxiliary light AF mode, the process branches to "L2SAVE" from # 231 in FIG. If it is not the auxiliary light AF mode, at # 159, the near zone flag is checked to see if the lens drive is within the near zone. If it is within the near zone, the process proceeds to [WSTOP] from # 160. # 160, #
The 161 simply repeats the end check at 100 ms intervals and does not return to the next focus detection loop. Then, it waits until the lens completely stops at the in-focus position, waits for the lens to stop, and then starts focus detection for in-focus confirmation. This is "WSTO
While turning the "P" loop, "INT3" of # 252 in Fig. 16
The "S" interrupt comes in and controls the lens.

The reason why focus detection is not performed while driving the lens in this near zone is as follows. First, the lens drive in the near zone has acceleration rather than constant speed. That is, the lens has a positive acceleration at the start of driving the lens and has a negative acceleration before the lens stop position. When entering the near zone from high speed driving and switching to low speed, it has negative acceleration. Here, originally, the near zone count amount NZC is determined based on the count value from high speed to when the motor (MO1) is de-energized and the movement of the lens stops. The motor (MO1) is constant speed. It is not an area for movement. Here, the fact that the speed is not constant means that even if the sensor is integrated while the motor is being driven, it cannot be represented as the point at which the subject data was obtained at the intermediate position of the integration time. Therefore,
Even if the correction for the movement amount as described above is made, the correction is not accurate and has a calculation error of the lens driving pulse.
Therefore, it is desirable not to integrate the sensor when the lens is not moving at a constant speed. Therefore, in this embodiment, focus detection is not performed during acceleration or deceleration.

Next, when it is determined in # 159 that the vehicle is out of the near zone, the process branches to # 162 and waits for 100 ms here. Since the lens is accelerating from the stopped state, it takes 100ms until the speed becomes constant.
I'm waiting for time. Then, the termination check is performed at # 163. The end check cycle may be too short or too long. If it is shorter than the encoder pulse interval according to the movement of the lens, it will be judged that it has stopped, and if it is too long, the durability of the drive system such as the motor, gear, clutch, etc., and reversal drive at the end Since there are problems such as the responsiveness of, the interval is set to several tens to 200 ms. Next, in # 164, it is checked whether the 1-cut shot mode is set by looking at the 1-cut shot flag. In the 1-cut shot mode, focus detection is not performed while driving the lens. So # 160
Go to "W STOP" to wait for the lens to stop, and then stop and perform focus detection for confirming focus. 1-cut
If it is not the shot mode, loop to # 39 “CDINTA” in FIG. The above is the main routine of automatic focus adjustment.

Next, the branch routine and the subroutine from FIG. 13 will be described. First of all, "LOW
The “CON” flow is a flow that branches from # 88 of the main routine of FIG. 11 when the focus detection calculation result is low contrast. First, in # 165, the terminal end is checked, and in # 166, the AF mode flag is checked to see whether or not the AF mode is set. If in AF mode, proceed to # 167, set the low contrast flag last time, and repeat the low and high LL and LR signals of the terminals (P32) and (P30) at the same time as the low contrast display at # 168. LED (LEDL) (LEDR)
Blinks. Then it immediately loops to the next focus detection. If it is not the AF mode, the process proceeds from # 166 to # 169 to check the driving flag to check whether the motor is driving. If it is driving, there are cases where low contrast scanning is being performed and cases where low contrast has been obtained during automatic focus adjustment, so the # 170 scanning flag is checked to distinguish this, and automatic If focus adjustment is in progress, the result of low contrast is ignored until the lens is stopped, as described above, so the process immediately proceeds to "CDINT" at # 40 to start the next focus detection. # 170 during low contrast scan
If you come to # 171, get out of the low contrast state at # 171 and adjust the event counter value T3 at the end of calculation to the maximum count value 65,000 to correct the movement amount during renormalization integration when starting automatic focus adjustment. Set to. (Details will be described later) Similarly, motor drive event count value
EVTCNT, end detection count value MECNT also has maximum count value 6
Set it to 5,000. Then loop to # 40 "CDINT".

When the lens is stopped and the contrast is low, the process proceeds from # 169 to # 172. Then, if the scan prohibition flag indicating prohibition of the low contrast scan is set, the process proceeds to # 173. It should be noted that the fact that the scan prohibition flag fluctuates indicates that the low-contrast scan has already ended once or that contrast has been generated.

Steps # 173 to # 175 and # 181 to # 183 are steps in which it is determined whether or not the auxiliary light AF mode is entered. The conditions to enter this auxiliary light AF mode are
First, it is in AF mode, the subject is in low contrast, the lens is stopped and the light is low, and the electronic flash device with auxiliary light illumination device in Fig. 3 is attached to the camera. Therefore, the AFFL signal indicating that the auxiliary light can be emitted has come, and the charging completion signal RDY has come, and the auxiliary light AF mode is entered only when all of these conditions are met. First, at # 173, the low light flag, at # 174, the auxiliary light OK signal AFFL,
Seeing the charge completion signal RDY at # 175, if all the conditions are "1", jump to "LLLED" from # 225 and enter auxiliary light AF mode. If these conditions are not met, the low light state is checked based on the low light flag in # 176.
If it is low light, double the maximum integration time of the sensor with # 177 at # 177. This is because if the integration time is 100 ms and the AGC is 8 times low contrast and low light, if the integration time is increased by one step, then low contrast does not occur and focus detection may be possible. However, since the error occurs when the focus is detected while driving the lens when the integration time is long, the maximum integration time is set to 200 ms mode only when the lens is stopped.

In # 178, the previous low contrast flag was set, in # 179, the LED (LEDL) (LEDR) indicating the low contrast state was displayed blinking, and in # 180, the near zone flag and renormalization integration flag (revolution integration F in Table 5-1). ), The inversion flag, the end flag, and the end 2nd flag are cleared, and # 40 “CDINT”
Loop to.

If the low contrast scan is not disabled in # 172, # 181
It branches to "SEARCH" from. The flow from # 181 to # 195 is a flow for starting the low contrast scan.
First, in steps # 181 to # 183, the conditions for entering the auxiliary light AF mode are determined in the same manner as the flow from # 173 to # 175.
If conditions are met, # 183 to # 225 “LLLED” is entered, and auxiliary light AF mode is entered. If it is a low light but the auxiliary light illuminator is not set and the AFFL signal is not "1", the process proceeds from # 281 to # 182 and # 184, where the maximum integration time of the sensor has already been reached. Check if it is in 200ms mode.

# 230 if not in maximum 200ms mode
To LL200, set the 200ms mode flag and
Loop to 39 "CDINTA". In # 184, if the mode is already in the maximum 200 ms mode and the contrast is low, or in # 181 it is low contrast but not low light, proceed to # 185 and proceed for 200 ms.
Clear the mode flag.

This is because the integration time is long during low contrast scan.
As mentioned above, the image of the subject tends to flow, and low contrast tends to occur, and even if there is contrast, if it is the maximum value of the integration time and the focus detection calculation time, stop the lens, There may be a lens with a large driving ratio that already exceeds the focusing range when the focus is detected again, so to prevent this, clear the 200ms mode flag and set the maximum integration time to 100ms. Is in the mode.

Next, in the flow from # 186 to # 190, the method for starting the scan of the lens when performing the low contrast scan is determined. When the subject is bright, the low contrast scan
Scanning starts from the direction found by the focus detection calculation. (# 188) Even if it is determined that the contrast is low and the defocus amount is not obtained, it may be obtained in the defocus direction. Therefore, scanning is performed according to the direction of the calculation result. If the area where the defocus amount is obtained during the low contrast scan comes, the automatic focus adjustment operation starts as described above. In the low contrast scan, if the lens is at one end, it is driven in reverse, and if it is at the opposite end, the scan ends. Whether the subject is dark or bright
1-cut sho which shows whether the integration time exceeds 50 ms at 186
It is checked using the t flag. For this, AGC data may be used, and the darkness may be 2 times or more, or 4 or 8 times or more. On the other hand, when it is dark, the process proceeds to # 187 to start the low contrast scan from the feeding direction. In this way, the final stop position at the end of the low-con scan ends with the lens retracted at the infinity end. This means that when the lens is capped, it will end in the retracted state, and the lens will be compact and convenient for storage in the camera case.

At this time, if the function of ending the lens by retracting the lens is emphasized instead of searching for the contrast, the process may proceed to # LLIGHT2 of # 189 without proceeding to # 187. That is, a scan-per-scan flag (F per scan) indicating that the low-conscan has hit the end once in # 189 is set.
At # 190, the MR signal is set to "Low" and low contrast scanning is started in the renormalization direction. When the lens hits the end at infinity, # 18
In the "ROTEM" from # 199 of FIG. 14 determined by the per-scan flag generated in 9, it is determined that the scan is completed, and the lens is stopped. Since this "LLIGHT2" is a modified example, # 189 and # 190 may be deleted.

In # 191, the low control flag is set to “1” last time, and in # 192, the scanning flag is set.

In # 193, the defocus amount FERM when the lens is stopped is set to a maximum value of 65,000. # 194, like T # 171, T
3. Set the maximum value of 65,000 in EVTCNT and MECNT. The display is turned off when driving the lens in # 195. Then, while scanning, the process returns to the next focus detection loop # 40.

Next is the end check subroutine "CKLOCK" in Fig. 14.
Let's move on to the explanation. In # 196, it is checked whether or not the lens is being driven by looking at the driving flag. If it is not driving, the end is not checked and the process returns. If the lens is being driven, proceed to # 197 to check the end. The end check register MECNT that was set to the same value as the lens drive pulse count value DRCNT during driving, and the event count value E that was set as the lens drive count value DRCNT
Compare with VTCNT. If the lens is moving, the value of EVTCNT is decremented by 1 each time it enters the pulse from the encoder (ENC), which is different from MECNT. If the lens does not move to the end, no pulse comes from the encoder (ENC), so the value of EVTCNT does not change and remains the same value as MECNT.

Therefore, if MECNT = EVTCNT in # 197, it is determined that the lens is stopped, and the flow branches to # 199 in the termination processing flow “ROTEM”. If MECNT ≠ EVTCNT, it is determined that the lens is moving, and the process proceeds to # 198.

In # 198, the value of EVTCNT is reset to MECNT to prepare for the next termination check. Then return.

In the termination processing flow "ROTEM" from # 199, the subroutine first branches off, so the stack pointer of the microcomputer is reset. # 1, INT1, INT2
Disable interrupts other than. Since it hits the end, the power is cut off to the motor (MO1) in # 201 and # 202, and the brake is applied. In # 203, the motor (MO1) is stopped, so the driving flag is cleared. If the previous direction flag is checked at # 204 and the previous direction flag is "0" (it is a rear pin and the lens is extended), it means that it is stopped at the closest end position at # 205, which means the end position. Set "1" in the flag. If the previous direction flag was "1" (it was the previous pin and the lens was retracted), the end position flag is cleared in the sense that it stopped at the infinite end position at # 206. In # 207, it is checked whether or not the end has been hit during the low contrast scan, and if it is in scanning, the process proceeds to # 208, and the end flag that the lens is stopped at the end is set.

In # 209, whether or not the auxiliary light AF mode is in the auxiliary light AF mode is further checked based on the auxiliary light mode flag. If it is in the auxiliary light AF mode, if the end is reached, focus detection by the first light emission is performed. Even if it does, it does not loop to the next focus detection, the LED blinks and the focus detection is abandoned. For auxiliary light AF mode, see “L” from # 225.
This will be described in detail in the “LLED” flow.

If the auxiliary light AF mode is not set in # 209, the process goes to the next focus detection loop "CDINTA" while keeping the lens at the end position.

In # 207, if the lens is at the end during the low contrast scan, proceed to # 210 to check whether the lens has hit the end during the scan, that is, whether it is going or returning. If there is, it is necessary to reverse the scanning direction and move, so the flow proceeds to # 217. In # 217, since it has come to the end this time, the per-scan flag is set. Next, in # 218, the previous direction flag (indicating the lens driving direction) is checked, and in # 219 and # 221, the directions are reset in the opposite directions. And # 220, # 2
The lens drive signal according to the direction to move next with 22
Set MR or MF to "Low". At this time, of course, the brake signal M
B is set to "High". This starts the inversion drive.
In # 223, FERM, T3, E
Reset VTCNT and MECNT to the maximum value of 65,000 respectively. In # 224, the driving flag is set to "1" and the process goes to the next focus detection loop "CDINTA".

On the other hand, if it has already hit the end once and is the second end, the process proceeds from # 210 to # 211. This time, the lens does not move because the low contrast scan is completed. # 211
Clears the per-scan flag that hits the end of the scan at, and clears the in-scan flag at # 212.
In # 213, if you scan once, it will not be done anymore,
Set the scan prohibition flag. In # 214, low contrast scan was performed, but no contrast was found and focus detection was impossible, so the LED blinks.

In # 215, check whether it is in auxiliary light AF mode,
If it is in the auxiliary light AF mode, the process goes to # 216, waits for an interrupt without going to the next focus detection, and ends as it is. If it is not the auxiliary light AF mode, focus detection is repeated at the end position after the end of scanning, so the process returns to "CDINTA" in # 39. The above is the end detection routine.

Next, the auxiliary light AF mode routine will be described. Auxiliary light
The AF mode is entered from the "LOW CON" routine shown in FIG. If the above conditions are met, the process proceeds from # 175 or # 183 to "LLLED" in # 225 and the auxiliary light AF mode flow is reached. In # 225 of FIG. 14, first, an auxiliary light AF mode flag indicating the auxiliary light AF mode is set. At # 226, the signal from the terminal (P13) to the terminal (ST4) is set to "High". The flash circuit (FLS) causes the auxiliary light LED (48) to start emitting light in response to this signal. In # 227, the LL and LR signals are set to "Lo" to notify the outside that the auxiliary light AF mode has been entered.
w "and turn on the LEDs (LEDL) (LEDR) on both sides. The lighting time is up to 45 until the next focus detection calculation ends.
It is standard to turn on for 0 ms. This is the total time when the # 229 waits for 200 ms, the calculation time for focus detection, and the maximum integration time is 200 ms, but if the subject is very close and bright, focus detection will be completed in 450 ms or less. To do. That is, this is also because the display is turned off while the lens is being driven. This display is only once when the auxiliary light AF mode is entered. On the other hand, the auxiliary light LED (48) emits light twice.
The auxiliary light AF mode sequence starts with the auxiliary light LED (4
8) emits light once and the CCD image sensor (F
Preliminary lighting for LM). This is to improve the responsiveness of the CCD image sensor (FLM). And
Mode with maximum integration time of 200 ms, C under fill illumination
Integrate CD. Then, the focus detection calculation is performed based on this data, and the lens is driven. During this time, focus detection is not performed. And after stopping the lens, the second LED for auxiliary light (48)
After a maximum of 450 ms, as in the first time, if the focus detection result is not within the focus zone, the lens is driven again to perform focus adjustment. This is the basic movement.
Here, it is necessary to distinguish whether the LED (48) for auxiliary light emits light for the first time or the second time. In order to distinguish this, an auxiliary light 1st flag (auxiliary light 1stF in Table 5-2) is provided. If "0" is entered in this flag, it indicates that the first light emission has occurred, and if "1" indicates that the second light emission has occurred. #
In 228, "0" is put in this flag. In # 229, 200 ms is waited as the preliminary illumination time of the sensor, and in # 230, the maximum integration time of the sensor is set to 200 ms. Auxiliary light A
In F mode, the integration time is usually 200ms. Then, it loops to "CDINTA" as in normal AF mode.

The flow proceeds from # 39 in FIG. 9 in the auxiliary light emitting state,
Turn off the auxiliary light at # 69 in Fig. 10. Similarly, focus detection is performed
13. The flow comes to # 87 in FIG. 13 and branches to the auxiliary light AF mode flow “LSAVE” in # 238 in FIG. This is the flow starting from # 238.

First, it is determined whether or not the focus detection in the auxiliary light AF mode is the first time, and if it is the first time, the process proceeds to # 239. Here, it is checked whether or not the focus detection calculation result has a low contrast. If the result is low contrast, the process proceeds to # 233, and the second auxiliary light emission starts. Just because the first auxiliary light emission caused low contrast, I don't give up immediately and try again. This is because in the case of an object near the low contrast limit, the first auxiliary light emission gives a preliminary light emission effect to the CCD sensor to increase its sensitivity, and automatic focus detection can be performed at the second light emission. Because there is a possibility. If # 239 is not low contrast, [NLOC1] in # 91 of Fig. 11
Go to the focus control drive flow. In this case, it passes through # 91 to # 102 in FIG. 11, and further to # 1 in FIG.
Driving is started at # 155 through 41, and the flow branches from # 158 to the auxiliary light AF mode flow "L2SAVE"(# 231 in FIG. 14).

In # 231 of FIG. 14, it is checked whether the emission of the auxiliary light is the first time based on the auxiliary light 1st flag, and if it is the first time, the process proceeds to # 232. Wait until the lens is driven by the count amount of the focus detection calculation result, and after the movement of the lens is stopped, the flow proceeds to the second auxiliary light emission flow # 233. # 233
Now, look at the fill light OK signal AFFL, and if it is "1" (OK),
At # 234, the second auxiliary light emission signal is output (that is, the signal at the terminal (ST4) is set to "High"). AFFL signal is “0”
In that case, since the auxiliary light illuminating device is turned off, the second light emission is not performed. In this embodiment, the auxiliary light AF mode is not released in this case, but it may be released.

The auxiliary light 1st flag is set at # 235 to indicate that the auxiliary light AF mode is for the second time. Then, as in the first time, wait for # 229 for 200ms, go through # 230, and go to "CDINTA" of # 39. A similar flow is followed in the second auxiliary light AF mode, from # 39 in FIG. 9 to # 44, # 68 in FIG.
If the auxiliary light AF mode is set at # 87 in FIG. 11, the process branches to “LZAVE” at # 238 in FIG. This time is the second auxiliary light AF mode, so proceed to # 240. If it is low contrast at # 240, if it is low contrast, proceed to # 211. Still again, with the lens stopped without stopping, the LEDs on both sides (LEDL) (L
EDR) is displayed blinking and the system is waiting for an interrupt.

If not low contrast, # 240 to # 9 in FIG. 11
Proceed to 1 to enter the lens drive flow. Then, the process branches to “L2SAVE” in the auxiliary light AF mode flow up to # 158 in FIG.

Since # 231 is the second auxiliary light AF mode, # 236
Proceed to and wait for the lens to stop like the first time. If it is not in the auxiliary light AF mode, focus detection for focus confirmation is then performed, but since the emission of auxiliary light is limited to two times, focus detection for confirmation is not performed. (In this embodiment, since the light is emitted up to twice, the following processing is performed without confirmation. However, the number of times of light emission is not limited, and light may be emitted until the focus is confirmed. This process checks the focus detection calculation value FERM when the lens is stopped. That is, if the defocus amount at the start of the second lens drive is less than 1 mm,
Considering the focus detection performance, it was judged that the lens could be brought into the focusing zone without sufficient confirmation of the focusing,
In step # 117 of Fig. 11, the flow for focusing is proceeded to "INFZ" to display the focus. If FERM is 1 mm or more, it means that the focus detection results for the first and second times are very different, and it is assumed that reliable focus detection could not be performed, so proceed to # 211 and leave the lens at the current position. LED on both sides (LEDL) (LED
R) blinks. The above is the auxiliary light AF mode routine. Limiting the emission of the auxiliary light LED (48) to two times is that power consumption and usage problems occur when the number of times of light emission is large, and focus detection error and backlash error occur when it is once. Therefore, 2 times are appropriate. Again 2
If the focus cannot be detected for the second time, the lens is not retracted. If you open the switch (S1) once and then close it again and try the auxiliary light AF mode again, This is because it is determined that there is a high possibility that the lens will start near the in-focus point and that the possibility of bringing the lens into the in-focus zone will increase.

Next, the event counter interrupt flow "IN
Enter the explanation about "T3S". This is an interrupt pin (INT
3) The lens drive control is performed using the pulse signal PS from the encoder (ENC) of the lens drive motor (MO1) that enters. The drive count value EVTCNT of the lens up to the in-focus position was obtained by focus detection calculation. The interrupt signal to INT3 constantly monitors the lens drive amount, and controls the lens moving speed and stop position. First, the drive count value EVTCNT is set in the event counter when the lens is driven. Then, the energization of the lens driving motor (MO1) is started. Then, the lens starts to move, a pulse is output from the encoder (ENC) and INT3 is interrupted. Then, the # 252 “INT3S” flow begins.

First, the # 1 pulse signal came in # 252.
Decrement the count value EVTCNT of the event counter by "1". Then, in # 253, it is checked whether or not this count value EVTCNT has counted a specified amount (that is, “0”). If EVTCNT becomes “0”, it means that the lens has come to the in-focus position, and the process proceeds to # 259. , Stop the drive of the motor (MO1).

If the count value EVTCNT of the event counter is not "0", the process proceeds to # 254, and it is checked whether or not the lens is in the near zone based on the near zone flag. If the near zone flag is not "1", proceed to # 255 to check whether the near zone has been entered by this pulse. If the count value EVTCNT of the event counter becomes smaller than the count value NZC of the near zone counter at # 255, it means that the vehicle has entered the near zone this time, and the process proceeds to # 256. If it is outside the near zone, "INT3
Return from the "S" interrupt flow to the main flow. On the other hand, in # 256, the near zone flag is set for the first time this time, so the near zone flag is set, and in # 257, the MC signal from the terminal (P03) is set to “Low”, and the drive of the motor (MO1) is switched to low speed. . Then, in # 258, the stack pointer of the interrupt flow is reset and the process proceeds to "WSTOP" in # 160 in FIG. 12 to wait for the lens to stop while checking the end.

That is, while looping through this "WSTOP" flow, "I
The interrupt of "NT3S" is input, the flow of # 252 to # 254, # 258 is repeated, and when the count value EVTCNT becomes "0", this loop is exited and the process proceeds to # 259. If it is in the near zone, it proceeds to # 160 “WSTOP” and does not return to the main flow because it does not detect the focus when the lens is not moving at a constant speed as described above. Since the lens decelerates, it is not a constant speed, so if it enters this area, focus detection is not performed while moving the lens.

Next, when the lens has moved by the drive pulse count value EVTCNT, the count value E is checked by # 253.
Since VTCNT becomes "0", proceed to # 259. Here, the lens driving motor (MO1) is de-energized, the brake is applied in # 260, the driving flag is cleared in # 261, the event counter interrupt is disabled in # 262, and the process is advanced to # 263. move on.
Here, it is checked whether or not the auxiliary light AF mode is in progress, and if it is in the auxiliary light AF mode, the process returns from this event counter interrupt. This return destination is # 232 in FIG. 14 as described in the auxiliary light AF mode flow.
Or # 236. If the auxiliary light AF mode is not set in # 236, the stack pointer is reset in # 264 and the process proceeds to # 265.

The flow from here is to determine whether or not to go to the focus detection for confirming whether the stop position of the lens is within the focusing zone after the focus adjustment driving. First, look at the DR signal sent from the control microcomputer (MC2) to check whether it is single shooting mode or continuous shooting mode.
If the DR signal is “0”, that is, the single shooting mode, # 267
Wait for 10ms, then the lens stops completely from low speed before entering the next focus detection loop. Then, if it is confirmed by the next focus detection that it is within the focus zone, that is, if the focus is checked in # 116 of the main flow of FIG. do. If the position where the lens is stopped is not within the focus zone, the lens driving routine is started again from # 120 in FIG. 11 and the same operation is repeated. This is the flow when confirming the focus. Next, in the continuous shooting mode, since the DR signal is "1", the process proceeds from # 265 to # 266 in FIG. Here, the defocus amount (FERM) when the lens is stopped (when the driving flag is "0") is checked. If this value is 500 μm or more, proceed to # 267. That is, in the continuous shooting mode, if the defocus amount before driving the lens is 500 μm or more,
This means checking the focus. FERM 500μ at # 266
If it is less than m, the process proceeds to # 268 to check whether or not the reversal flag is set. If the reversal flag is set, it means that the backlash has been corrected. Go to. If the reversal flag is not set at # 268, the flow goes to the focus display flow of "INFZ" at # 117. This is a method for increasing the lens drive speed to improve the followability to a moving subject in the continuous shooting mode. When automatic focus adjustment is performed from a position within 500 μm without correcting backlash. The system has a good linearity and goes to the in-focus display directly without performing focus detection for in-focus confirmation with the belief that the system is surely within the in-focus zone. In other cases, go to the focus confirmation and improve the focus accuracy. However, if the focus detection capability is further improved and there is almost no drive system error, the focus confirmation may not be necessary here. The above is the sequence of automatic focus adjustment.

Finally, the flow from # 40 to # 53 in FIG. 9 will be described. This is a flow related to so-called "renormalization integration", and details thereof are described in Japanese Patent Application No. 60-7179 previously filed by the applicant of the present application, and since they are not the gist of the present invention, they are omitted here. This "convolution integral" is
It starts from # 66 in Figure 10. When it is determined that the lens is being driven by checking the driving flag in # 65, it may or may not be in the “convolution integration” state, but the next integration is started in # 66, and the convolution integration flag (first The renormalization integral F) in Table 5-1 is established. Then, the top of the focus detection loop when "convolution integration" is required is set to "CDINT" of # 40 in FIG.

Now consider the case where the subject is dark. The integration mode is set at # 40 so that the integration end signal NB4 can be detected. Then, in # 42, it is checked whether or not the renormalization integration flag is set. If it is not, the renormalization integration mode is not set, so the flow proceeds to # 44. If the renormalization integration flag is set, the process proceeds to step # 43, where the integration end signal NB4 is checked to see if the integration has already been completed. If the integration has not ended, the process proceeds to “TINTC” in # 49, that is, the flow from “TINTC” is the renormalization state, and “CDINTS” from # 44 is for non-renormalization. 10th
In # 49 of the figure, the 1-cut shot flag is set to "1". At # 50
The AFE signal is set to "Low", and T1 'is corrected in preparation for movement correction in # 51 as described above. In # 53, the maximum remaining integration time of 40 ms is set, and the flow advances to # 55. The following is the flow of the main routine. The "convolution integration" has the effect of shortening the focus detection time in this way. AF
This concludes the explanation of the flow of the microcomputer (MC1).

Next, the first embodiment described above for the second embodiment of the present invention
Only the parts different from the embodiment will be described. In the first embodiment, the continuous AF mode is set to the continuous AF mode, which is indicated by # 403 in FIG. 11 of the flowchart.
It was shown in # 406. Therefore, in the second embodiment, FIG. 18 shows a flow chart as a replacement of # 403 to # 406 in FIG.

In FIG. 18, first, in # 410, it is determined whether or not the auxiliary light AF mode is set, and if it is the auxiliary light AF mode, the process proceeds to the interrupt waiting loop of # 414, which is a so-called AF locked state. If it is in auxiliary light AF mode at # 410, proceed to # 411 to determine whether the drive flag after release is "1". If not before release, proceed to # 413 and perform one-shot AF.
Whether the mode or the continuous AF mode is determined, if it is the one-shot AF mode, the operation proceeds to # 414 to enter the AF lock state, and if it is the continuous AF mode, the operation proceeds to # 39 to start the next distance measurement.

Then, after the release in the continuous shooting mode, the process proceeds from # 411 to # 412 and then to # 39 to enter the continuous AF mode. If not continuous shooting mode, proceed from # 412 to # 413,
When in continuous AF mode, it returns to # 39 and repeats distance measurement. Even with this configuration, it is possible to set the continuous AF mode after the release in the continuous shooting mode.

As described above in detail, the automatic focus adjusting device according to the present invention is a focus detecting means for detecting a focus state of a photographing lens, and a focus adjusting means for driving the photographing lens according to a detection result of the focus detecting means. And a film winding means capable of winding a film of one frame during single shooting and film winding during continuous shooting of continuously winding film, and the film winding means continuous shooting with the above single shooting. Setting means for setting the film winding operation at each time, one-shot AF means for holding the state once the photographing lens reaches the focused state, and the photographing lens does not follow the movement of the subject thereafter, If the subject moves after the shooting lens reaches the in-focus state, the continuous AF means that follows the subject and repeats automatic focus adjustment, and the above-mentioned When the continuous shooting is set by the setting means, it has a control means for repeatedly performing focus adjustment by the continuous AF means during a period from the end of exposure to the start of exposure of the next frame. With this configuration, during continuous shooting, if the subject moves after reaching the in-focus state during the period from the end of exposure to the start of exposure of the next frame, automatic focus adjustment is repeated following the subject. Therefore, the exposure operation can be performed with the focus deviation corrected as much as possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an entire camera system of an embodiment of the present invention, FIG. 2 is a block diagram showing its electric circuit, and FIG. 3 is a circuit diagram showing a flash circuit of its electronic flash device.
Figure 5 is a flow chart showing the operation of the control microcomputer.
FIG. 6 is a block diagram showing the interface circuit,
FIG. 7-16 is a flow chart showing the operation of the AF microcomputer, FIGS. 17 (A) and (B) are time charts showing the interrupt signal, and FIG. 18 is a flow chart showing another embodiment of the present invention. (LZ): Photography lens, (AFM) (FLM) (MC1) (112)
(113) (IF1): focus detection means, (113) (114) (MO
1) (SLP) (LDR) (ENC) (MC1): Focus adjustment means, (M
C2): One-shot AF method, (MDR2) (MO2): Automatic film winding method, (MC2): Continuous AF method

Claims (5)

(57) [Claims] 1. A focus detecting means for detecting a focus state of a photographing lens, a focus adjusting means for driving the photographing lens according to a detection result of the focus detecting means, and a film for single-shot film winding. Film winding means capable of winding and film winding at the time of continuous film winding, and setting means for setting the film winding means to the film winding operation at the time of single shooting and at the time of continuous shooting respectively. , Once the taking lens reaches the in-focus state, the state is maintained and the one-shot AF means in which the taking lens does not follow the movement of the subject thereafter, and the above-mentioned even after the taking lens reaches the in-focus state. When continuous shooting is set by the continuous AF means for repeatedly operating the focus adjustment means and the setting means, the next frame from the end of exposure An automatic focus adjusting device comprising: a control unit that repeatedly performs focus adjustment by the continuous AF unit until the exposure starts. 2. The continuous AF means is configured to hold the focus adjusting means in a stopped state when the exposure operation is started. Automatic focus adjustment device. 3. A one-shot AF mode in which the focus adjusting means is deactivated and the state is maintained once the taking lens reaches a focused state, and focus detection by the focus detecting means is repeated, and focus adjustment is performed according to the detection result. Mode setting means that can selectively switch between continuous AF mode that activates the means and one-shot when the one-shot AF mode is set
In addition to operating the AF means, it also activates the continuous AF means when the continuous AF mode is set, and even after the exposure operation is completed, the continuous AF means operates even if the one-shot AF mode is set. The automatic focus adjusting device according to claim 1, further comprising a control means for controlling the automatic focus adjusting device. 4. The automatic focus adjusting device according to claim 1, wherein the film winding means is detachable from the camera. 5. The automatic focus adjusting device according to claim 1, wherein the film winding means is built in the camera body.