JPH061289B2 - Automatic focus adjustment device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focus adjustment device capable of performing focus detection by stationary light and focus detection by emitting auxiliary light for illuminating a subject.

2. Description of the Related Art Conventionally, there is an automatic focus adjustment device which is configured to perform a focus detection operation repeatedly while driving a taking lens so as to improve accuracy and speed of an automatic focus adjustment operation, for example, Japanese Patent Laid-Open No. 56-78823 or It is described in JP-A-58-58508.
An apparatus for detecting focus by emitting auxiliary light for illuminating a subject is disclosed in, for example, Japanese Patent Laid-Open Nos. 55-11929 and 57-105.
No. 710, JP-A-58-132733 and the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, when the focus detection operation is repeatedly performed when the photographing lens is driven based on the focus detection result in the state where the auxiliary light is emitted, the following problems occur.

That is, focus detection with emission of auxiliary light is required when reliable detection result is not obtained in focus detection performed without emission of auxiliary light. Even if focus detection is repeated while driving the taking lens in such a situation, a reliable focus detection result will not be obtained.

An object of the present invention is to provide an automatic focus adjustment device that solves the above problems.

Means for Solving the Problems In order to solve the above problems, the automatic focus adjusting device of the present invention, in particular, controls the drive means based on the detection result of the focus detection means in a state in which auxiliary light is not emitted. When the photographing lens is driven, the focus detection means performs a detection operation even while the photographing lens is being driven, and the detection result is also used to control the driving means. "," Focus detection with auxiliary light emitted And a means for prohibiting the detection operation by the focus detection means while the photographing lens is being driven when the photographing means is driven by controlling the driving means based on the detection result of the means.

In other words, focus detection is performed during lens driving based on focus detection in a state in which auxiliary light is not emitted, but focus detection is prohibited during lens driving based on focus detection in a state in which auxiliary light is emitted. .

Embodiment FIG. 1 is a block diagram showing the basic configuration of the present invention. The manual operation unit (1) for operating the automatic focus adjusting device is manually operated to perform the automatic focus adjusting operation, and the terminal (2
0) outputs a "High" signal, and the sequence control circuit (2) performs the automatic focus adjustment operation as described below while the "High" signal is input from this terminal (20). . First, when the sequence control circuit (2) outputs a start signal from the terminal (21), the light emitting circuit (11) operates and the xenon tube (12) emits a predetermined amount of light. Of the light emitted from the xenon tube (12), only the light that has passed through the infrared filter (or near infrared filter) (13) is applied to the subject, and the light reflected by the subject passes through the taking lens (3). The light is received by the light receiving section (4).

When the start signal from the terminal (21) is input, the control / arithmetic circuit (5) causes the light receiving section (4) to start the light receiving operation. When the monitor output (not shown) from the light receiving unit (4) reaches a predetermined value, the light receiving operation is stopped and the output of each light receiving pixel in the light receiving unit (4) is captured. Then, the defocus amount and direction are calculated, and the lens movement amount data is calculated based on the defocus amount. The calculated defocus direction signal is output to the terminal (50) and the movement amount data is output to the terminal (52). Output. When this arithmetic operation is completed, a pulse is output to the terminal (51), the operation of the motor drive circuit (7) is started, and the motor (8) is rotated in the direction according to the direction signal from the terminal (50). Further, the movement amount data from the terminal (52) is preset in the down counter (10) by the pulse from the terminal (51).

When the motor (8) rotates, the lens (3) is moved by a known mechanism, and the encoder (9) outputs a pulse corresponding to the amount of movement of the lens. The down counter (10) counts down the preset data with the pulse from the encoder (9), and when the content of the down counter (10) becomes “0”, outputs a pulse from the terminal (25) to drive the motor. The operation of the circuit (7) is stopped, the rotation of the motor (8) is stopped, and the movement of the lens (3) is stopped. This means that the lens has moved by the planned amount of movement. In addition, the pulse from the terminal (25) of the down counter (10) is input to the sequence control circuit (2) and the start signal for starting the second measurement operation from the terminal (21) of the sequence control circuit (2). Is output. Then, when the second operation similar to that described above is performed and the pulse is again output from the terminal (25), the movement of the lens is stopped, and thereafter, even if the “High” signal is input from the terminal (20). No start signal is output from the terminal (21) and the automatic focus adjustment operation is stopped. That is, the coarse adjustment is performed by the first operation, and the fine adjustment to the accurate in-focus position is performed by the second operation. When the in-focus position is reached in the second operation, the terminal (27) becomes "High", and the in-focus display is performed on the display circuit (14).

Reference numeral (6) is means for determining whether or not the light intensity distribution of the subject image has a low contrast based on the output from the light receiving unit (4). When it is determined that the contrast is low in the first measurement and the terminal (23) becomes “High”, the operation of the motor drive circuit (7) is prohibited, and the second operation is performed from the terminal (21) of the control circuit (2). A start signal for starting the operation is output, and the second operation is started. When it is determined that the contrast is low in the second measurement, the movement of the lens (3) is prohibited as in the first measurement, and the next measurement operation is not performed. Then, in the second operation, the terminal (26) of the control circuit (2) is "High", and the display circuit (16) gives a warning display.

Regardless of the first and second operations, when it is determined that the calculated movement amount data is in the focusing area, the terminal (22) becomes “High” and the lens movement is performed from the terminal (51). The pulse to start is not output. As a result, the movement of the lens (3) is not started, the focus display is displayed by the display circuit (14), the control circuit (2) does not shift to the next operation, and the terminal (20) becomes "Hi".
It remains in this state for "gh".

(15) outputs a pulse to the terminal (24) if no pulse is output from the encoder (9) for a certain period of time. At this time, the lens (3) has reached the end, and the focusing operation is impossible. Therefore, the operation of the motor drive circuit (7) is stopped by the pulse from the terminal (24). At this time, if it is the first operation, the terminal (21) subsequently outputs a start signal for starting the second operation, and the second measurement operation is started. On the other hand, during the second operation, the terminal (2
When a pulse is output from 4), the movement of the lens (3) is stopped, and since the terminal (26) is "High", a warning is displayed by the display circuit (16) and the operation is stopped.

Further, when the terminal (26) is "High" during the second operation and the calculated movement amount data output from the terminal (52) is larger than the predetermined value, the terminal (29) is "High".
Therefore, the operation of the lens drive circuit (7) is prohibited.
As a result, the lens (3) is not moved, and only the warning is displayed by the display circuit (16). In this case, there is a malfunction in the first operation, and in the second operation, an accurate focus adjustment cannot be performed due to variations and the like, so only a warning is given.

When the above-mentioned warning is issued, the photographer once stops the operation so that the "High" signal is not output from the terminal (20), and changes the condition to output the "High" signal again. You can perform the operation.

An embodiment will be described below in which the preliminary irradiation of the electronic flash device according to the present invention is used as auxiliary light for automatic focus adjustment.

FIG. 2 is a circuit diagram showing an entire camera system using an electronic flash device to which the present invention is applied. In this figure, thick lines indicate signal lines of a plurality of bits. Light receiving part (F
MD) is composed of a CCD (Charge Coupled Device), and is provided with two rows of light receiving sections, and each of the light receiving section rows receives visible light including near-infrared light among subject light from the exit pupil of the photographing lens. Since various optical systems and the like of the light receiving section have been proposed, they are omitted. (COC) is the light receiving part (FM
It is a control circuit for controlling the operation of D). And (MC
O1) is a microcomputer for automatic focus adjustment, and (MCO2) is a microcomputer (hereinafter referred to as a microcomputer) for controlling the operation of the camera. First, the photometric operation by the circuit portion described above will be described.

When the terminal (O3) of the microcomputer (MCO1) becomes "High", a "High" pulse is output from the terminal (φR) of the control circuit (COC), the analog switch (AS2) becomes conductive, and the terminal (ANM) is turned on. Through this, a plurality of charge storage units of the CCD (FMD) are charged to the output voltage of the constant voltage source (E1). Then, when the terminal (φR) becomes “Low”, charges corresponding to the amount of light received by each light receiving unit are accumulated in the charge storage unit. At this time, a signal corresponding to the electric charge accumulated by the monitor light receiving portion (not shown) in the CCD of the light receiving portion (FMD) is transmitted to the terminal (A
NM), at which time the terminal (φR) is "Low"
Therefore, the analog switch (AS1) is conductive, and the output from the monitor light receiving section is given to the inverting input terminal of the comparator (AC1). The output voltage gradually decreases as the charge is accumulated. At this time, if the flash emission mode is not used, the terminal (O1) becomes “Low”, and the analog switch (AS
3) becomes conductive and the output voltage of the constant voltage source (E2) becomes
In the flash emission mode, the terminal (O1) is "High", the analog switch (AS4) is turned on, and the output voltage of the constant voltage source (E3) is applied to the non-inverting terminal of the comparator (AC1).

Monitor output from the terminal (ANM) is a constant voltage source (E2)
Or when the level of (E3) is reached, the comparator (AC
The output (STP1) of 1) is inverted to "High", and the transfer pulse is output from the terminal (φT) of the control circuit (COC). With this pulse, the accumulated charge in the charge accumulating portion corresponding to the amount of light received in each light receiving portion is transferred to the transfer gate,
Based on the transfer pulses (φ1), (φ2), and (φ3), signals of accumulated charge are sequentially supplied from the terminal (ANS) to the control circuit (CO
Sent to C). In the control circuit (COC), the terminal (AN
The signal sent from S) is sequentially A / D converted, a pulse is output to the terminal (ADE) each time one A / D conversion is completed, and the A / D converted data is output to the output terminal (ADD).
Output to.

Further, when the transfer pulse is not output from the terminal (φT) even after a lapse of a certain time after the start of charge accumulation, it means that the brightness of the subject is low. In this case, the pulse is output from the terminal (O2), When this pulse is input, the control circuit (COC) outputs the transfer pulse (φT) regardless of the output of the comparator (AC1).

When performing pre-irradiation with an electronic flash device, the terminal (O
1) becomes “High”, and the voltage from the constant voltage source (E3) is input to the non-inverting terminal of the comparator (AC1). The output potential of the constant voltage source (E3) is higher than the output potential of the constant voltage source (E2). Therefore, compared with the case where the amount of charge accumulated by the monitor is not pre-irradiated,
The transfer pulse (φT) is output at a small time point. This is because when pre-irradiation with flash light is performed, the intensity of the flash light changes abruptly, and the charge accumulation section overflows due to the response delay of the circuit, etc., making it impossible to measure the correct light intensity distribution. This is to prevent it from being lost.

As described above, the terminal (O3) is used to start the charge accumulation.
When "High", the one-shot circuit (OS1) outputs a pulse, and the pulse is the AND circuit (AN1).
Is output via the terminals (JB1) and (JF1) to the electronic flash device (FLC) as a light emission start signal. When the transfer pulse (φT) is not output even after a certain period of time, the pulse is output from the terminal (O2) to forcibly output the transfer pulse, and the charge storage operation is stopped. By the way, the fixed time for limiting the accumulation time is shorter than that when the preliminary irradiation is not performed. This is because the light emission time of the electronic flash device is short and it is not necessary to lengthen the integration time.

When the microcomputer (MCO2) reads data from the electronic flash device, the data contains a signal indicating whether or not preliminary irradiation is possible. Therefore, the microcomputer (MCO
In 2), when a signal indicating that preliminary irradiation is possible is input, the terminal (O16) is set to "High". The microcomputer (MCO1) determines that the operation in the pre-irradiation mode is possible if the terminal (i2) is "High", and the operation in the pre-irradiation mode is not possible if it is "Low". Is determined.

(MDR) is a circuit for driving a focus adjustment motor (MO). When the focus detection result is the front pin and the lens needs to be retracted, the terminal (O4) is the rear pin and the lens is moved. The terminal (O5) becomes "High" when it is necessary to feed it. The rotation of the motor (MO) is transmitted to the lens side (LE) via the lens driving unit (LD), and the focus of the lens is adjusted. In addition, the lens drive unit (L
The drive amount of D) is converted into a pulse signal by the encoder (ENC), and the pulse signal is converted by the microcomputer (MCO1).
Is input to the clock input terminal (CPI) of and the drive amount is counted. Further, the pulse from the encoder (ENC) is input to the motor drive circuit (MDR) and used as a reference signal for driving the motor (MO) so that the lens driving speed becomes constant.

(FDP) is a display unit that displays a focus adjustment state, and displays a front focus state, a focus state, a rear focus state, and a focus adjustment failure warning according to data from the output terminal (OP1) of the microcomputer.

The switch (SMB) shown in the upper right corner of the figure is the main switch, and (BB) is the power supply battery. From the power supply battery (BB), a microcomputer (MCO1), (MCO1), (MCO1) via the main switch (SMB) and the power supply line (+ E).
Power is directly supplied to CO2). The switch (S1) is a photometric switch that is closed at the first step of pressing the release button (not shown). When this switch (S1) is closed, the inverter (IN3), AND circuit (AN3), OR circuit An interrupt signal is input to the interrupt terminal (it) of the microcomputer (MCO2) via (OR4), and the microcomputer (MCO2)
Sets the terminal (O12) to "High" and the inverter (IN6)
The transistor (BT1) is made conductive via the power supply line (+ V), and the inverters (IN3) to (IN
6), power supply to circuits other than AND circuits (AN2), (AN3), OR circuit (OR4), microcomputer (MCO1), (MCO2) is started. Then, based on the start of power supply, a reset pulse is output from the power-on reset circuit (PO1), and the circuit supplied with power from the power supply line (+ V) is reset. Also, the terminal (O12) is "High".
And the AND circuit (AN3) is disabled, (AN
2) becomes the active state, and the interrupt signal from the switch (S1) is not input.

The switch (S2) is a release switch which is closed at the second step of pressing the release button, and the switch (S4) is opened when the exposure control operation is completed and closed when the charge of the exposure control mechanism (not shown) is completed. This is a reset switch. Therefore, when the release switch (S2) is closed in a state where the charge of the exposure control mechanism is completed and the reset switch (S4) is closed, the terminal (via the AND circuit (AN2) and the OR circuit (OR4) ( An interrupt signal is input to it).

(EDO) is a block for outputting the set exposure control data, and the setting data is sequentially read through the terminal (IP10) based on the read signal from the terminal (OP13). (LMC) is a photometric circuit, and the output of the photometric circuit (LMC) is input to the analog input terminal (ANI) for AD conversion. Further, the reference voltage in the photometric circuit (LMC) is input to the terminal (VRI) as the reference voltage for the DA converter of the microcomputer (MCO2). (EXD) is a display circuit for displaying the exposure control value and displays the exposure control value (that is, the aperture value to be controlled, the shutter speed value or a combination thereof) based on the display data from the terminal (OP14). (EX
C) is an exposure control circuit which controls the aperture and the exposure time based on the signal from the terminal (OP15). Also, the terminal (TIE) of the exposure control circuit (EXC) is set to "Hig
It becomes h ”, and the integration operation for controlling the flash emission amount at the time of shooting is enabled.

(LEB) is a circuit for reading data from the circuit (LEC) on the lens side. As described above, the transistor (B
When T1) becomes conductive, the power supply line (+ V) changes to the terminal (J
B11), (JL1) through lens side circuit (LEC)
Is supplied to. And microcomputer (MCO2)
When the terminal (O15) of is set to "High", the circuit (LEB) becomes operable, and further, the terminals (JB12), (JL
2) becomes “High”, and the circuit (LEC) on the lens side becomes operable. In the lens side circuit (LEC), a ROM in which exposure control data and automatic focus adjustment data unique to the interchangeable lens are fixedly stored at a plurality of addresses,
An address for sequentially specifying the ROM address based on the output of the code plate according to the set focal length in the case of a zoom lens for the clock pulse that inputs the address of this ROM through terminals (JB13) and (JL3) Designating means,
The data output from the ROM in parallel is output to the terminal (JB1
3), based on the clock pulse input via (JL3), the terminals (JL4), (JB1
4) through parallel-serial conversion means for outputting via.

The data fixedly stored in the ROM include check data for confirming the lens device commonly provided for all interchangeable lenses, open aperture value data, maximum aperture value data, open metering error data. , Focal length data, aperture variation data according to the focal length set by the zoom lens, and the like. Furthermore, a conversion coefficient (KD) for converting the defocus amount detected by the focus detection device into the drive amount of the lens, the near infrared light so as to prevent the subject from feeling dazzling during preliminary irradiation by the electronic flash device. In order to correct the difference in focus position between near infrared light and visible light, that is, the difference between the defocus amount and the focus detection by irradiating the light (that is, the defocus amount measured by the near infrared light is visible. Data (for correcting the defocus amount by light) (IRD), when the driving direction of the lens is changed from one direction to the other direction, the fitting backlash between the drive shaft on the camera side and the driven shaft on the lens side The extra drive amount when it is necessary to drive the drive axis by extra, that is, the backlash data (B
LD) etc.

Eight clock pulses are output from the terminal (SCP) of the microcomputer (MCO2), and the lens side circuit (LE
In C), every time 8 clock pulses are input, RO
The address of M is updated, and the data fixedly stored at the designated address is sequentially output in series based on the clock pulse and sequentially read from the serial input / output terminal (SIO) of the microcomputer (MCO2).

(FLB) is an electronic flash device control circuit, and (FLC)
Is a circuit in an electronic flash device to which the present invention is applied. A specific example of the circuit (FLC) in the electronic flash device is shown in FIG. 3, and the operation using the electronic flash device will be described below in conjunction with FIG. In FIG. 3, (BF) is a power supply battery of the electronic flash device, and (SMF) is a main switch. (DD) is a booster circuit, and the booster circuit (DD) 2
The high voltage terminal on the next winding side is connected to the main capacitor (C2) via the diode (D1), and the main capacitor (C2) is charged by the voltage from the high voltage terminal. Also, 2
The low voltage terminal of the next winding is connected to the capacitor (C1) via the diode (D2), and the capacitor (C1) is charged by the output voltage thereof. When the main switch (SMF) is closed, the transistors (BT2), (BT3) become conductive, and the boosted output from the voltage stabilization circuit (CV) or the output of the power supply battery (BF) via the diode (D3) is generated. Power is supplied to the power supply line (VF) through the transistor (BT3). Electric power is supplied from the power supply line (VF) to all circuits whose power supply path is not shown in FIG. When power supply from the power supply line (VF) is started, a reset signal is output from the power-on reset circuit (PO2), and the digital circuit section is reset.
The switch (SOF) is a switch that opens and closes in phase with the main switch (SMF). And resistance (R
1) to (R4) are resistors for dividing the charging voltage of the main capacitor (C2), and (VC) is a constant voltage source. The potential at the connection point between the resistors (R1) and (R2) is the constant voltage source (V
The output "High" next to the exceed the potential of C) a comparator (AC ₂ 1), when it becomes the output input signal is "High", the to the lowest voltage required for the xenon tube (XE1) emits light Means that the capacitor (C2) has been charged, and when the light emission start signal is input, the xenon tube (XE2)
Light emission is started. When the potential of the connection point of the resistors (R2) and (R3) is exceed the output potential of the constant voltage source (VC), the output of the comparator (AC ₂ 2) becomes "High". In this case, the voltage of the main capacitor (C2) has been charged to a voltage necessary for the amount of light emitted from the xenon tube (XE2) to reach the nominal amount of light emission, and a charge completion signal is sent to the camera body. At the same time, the display circuit (CDP) displays the completion of charging. When the potential at the connection point of the resistor (R3) and (R4) is exceed the output potential of the constant voltage source (VC) output of the comparator (AC ₂ 3) it becomes "High". At this time, the main capacitor (C2) is charged to a value necessary for the xenon tube (XE2) for photographing to emit light at a nominal value and for the xenon tube (XE1) for preliminary irradiation to emit a predetermined amount of light twice. This signal is sent to the camera side as a preliminary irradiation enable signal. The switch (SS) is a switch that can be manually switched. If this switch (SS) is connected to the terminal (EN), the preliminary irradiation enable signal is sent to the camera side, but the terminal (DEN)
If it is connected to, the input to the terminal (PCH) is always "Lo
w ”and the preliminary irradiation enable signal is not sent to the camera side, the camera does not enter the preliminary irradiation mode, and the OR circuit (OR
The output of 20) remains "Low" and does not emit light.

(TR1) and (TR2) are xenon tubes (XE1),
(XE2) trigger and thyristor (SC1), (S
Trigger circuit for conducting C2), (ST1), (ST
2) is a stop circuit that makes the thyristors (SC1) and (SC2) non-conductive and stops the light emission of the xenon tubes (XE1) and (XE2). In addition, xenon tube (XE
1) is for pre-irradiation, and a filter (FLT) that transmits near infrared rays and cuts visible light having a shorter wavelength than near infrared rays is provided at the light emission position of this xenon tube (XE1). , When the preliminary irradiation is performed, the subject person does not feel dazzled.

In FIG. 2, when the terminal (O13) of the microcomputer (MCO2) becomes "High", data can be exchanged between the camera and the electronic flash device. Then, the microcomputer (MCO
When a pulse having a width of 50 μsec is output from the terminal (O14) of 2), this pulse is sent to the electronic flash device via the terminals (JB2) and (JF2). With this pulse, the mode discriminating circuit (FMS) in FIG. 3 discriminates that it is in the mode for transferring data from the electronic flash device to the camera, and the terminal (DO
Set M) to "High". Then, the data output circuit (DOU) in FIG. 3 becomes operable. When a clock pulse is output from the clock pulse output terminal (SCP) of the microcomputer (MCO2), this clock pulse is output to the terminal of the data output circuit (DOU) of FIG. 3 via the terminals (JB2) and (JF2). (SCP), and a power supply signal indicating that power is being supplied by the electronic flash device based on this clock pulse, and a terminal (PCH) indicating that the electronic flash device is ready for preliminary irradiation. signal,
A charge completion signal to the terminal (CHC) and a signal to the terminal (FDC) indicating whether or not the dimming operation has been performed are sequentially output from the terminal (SOU), and the terminals (JF3) and (JB3).
Is sent to the camera side via. Other data to be sent include, for example, data of maximum and minimum light emission amounts of the electronic flash device, aperture value set by the electronic flash device, bounce state, and data indicating whether or not a multi-flash is used. Then, when the data transfer is completed, a pulse is output from the terminal (r2), the mode discriminator (FMS) enters the initial state via the OR circuit (OR12), and the terminal (DOM) is "Low".
become.

Next, when a pulse having a width of 100 μsec is output from the terminal (O14), the mode discrimination circuit (FMS) causes the terminal (DIM) to be “Hi”.
gh ”. Then the data input circuit (DIN) becomes active. And the camera microcomputer (MCO2)
Outputs a clock pulse from a terminal (SCP), and outputs data such as an aperture value for flash photography, exposure time, film sensitivity, and shooting distance from the terminal (SIO) based on this clock pulse. This data is sent through the terminals (JB3) and (JF3) to the data input circuit (DI
N). Then, a display based on the read data is displayed on the display circuit (DSP).

Microcomputer (MCO2) to start exposure control operation
Output a pulse of 150 μsec width from the terminal (O14). Then, the mode discrimination circuit (FMS) sets the terminal (FLM) to "Hi".
gh ”. This activates the light emission control circuit (FLC) to perform light emission control. The front curtain of the focal plane shutter of the camera is completed and the X contact (S
When X) is closed, the light emission start signal is input from the terminals (JB4) and (JF4) to the terminal (STA), and the terminal (α1)
Emits a light emission start signal. At the same time, the terminal (α3) is inverted from “High” to “Low” and this signal is sent to the camera side through the terminals (JF3) and (JB3). On the camera side, when the terminal (JB3) becomes "Low", the photometric integration circuit (not shown) in the circuit (FLB) is reflected from the subject illuminated by the flash light and the aperture of the taking lens (not shown). When the integrated amount reaches the analog value corresponding to the film sensitivity from the analog output terminal (ANO), the terminal (JB
A pulse for stopping light emission is output to 2). This pulse is input to the terminal (STP) of the light emission control circuit (FLC) via the terminal (JF2). Then, a light emission stop signal is output from the terminal (α2) and the light emission of the xenon tube (XE2) is stopped. The light emission stop signal from the terminal (α2) is also sent to the display circuit (FDP), and the X contact (SX) is opened when the exposure control operation is completed. Based on this signal, the X contact (SX) is opened. The terminal (df) stays at "Hi" for a certain time after opening.
gh ”, indicating that the dimming operation has been performed during this period. This signal is also sent to the camera side via the data output circuit (DOU). Also, the X contact (SX) is opened. Then, a pulse is output from the terminal (r3), the mode discrimination circuit (FMS) is reset via the OR circuit (OR12), and the terminal (FLM) becomes "Low".

In the pre-irradiation mode, when the terminal (O) of the microcomputer (MCO1) is in the "High" state and a "High" signal is output from the terminal (O3) to start the accumulation, the one-yacht circuit (OS1) outputs a pulse. Is output and this pulse is output from the AND circuit (AN1). This pulse is input to the AND circuit (AN20) of FIG. 3 through terminals (JB1) and (JF1). In this case, D output of the flip-flop (DF21) is turned to "High", the comparator have become the output is "High" of the (AC ₂ 3), the output of the OR circuit (OR20) is because "High", and The pulse input to the circuit (AN20) is an AND circuit (AN20).
Is output from. This pulse is a trigger circuit (TR1)
Then, the preliminary irradiation with the xenon tube (XE1) is started. Then, the pulse from the AND circuit (AN20) sets the D flip-flop (RF20), so that the reset state of the counter (CO6) is released and the counter (CO6) is released.
6) starts counting. Then, when a certain period of time has elapsed from the start of counting, the terminal (f1) of the decoder (DE6) becomes "High", and a pulse is output from the one-shot circuit (OS22). This pulse is a light emission stop circuit (S
It is sent to T1) and the preliminary irradiation of the xenon tube (XE1) is stopped. Further, when the terminal (f1) becomes "High", the flip-flop (RF20) is reset via the OR circuit (OR22), the counter (CO6) is reset, and the terminal (f1) becomes "Low". The output pulse of the AND circuit (AN20) is the D flip-flop (DF2
The output of 0) is sent to the clock pulse input terminal the comparator (AC ₂ 3) of "High" is latched, Q output of the D flip-flop (DF20) becomes "High".

Even with the charging voltage of the main capacitor (C2) is lowered placed in the output is "Low" of the comparator (AC ₂ 3) when the second time pulse is outputted from the AND circuit (AN20), first-time emission D flip-flop (DF20)
Since the Q output of is high, the OR circuit (OR2
The output of 0) is "High", and the AND circuit (AN2
A pulse is output from 0). Then, the pulse causes the same light emitting operation as described above. Further, the Q output of the D flip-flop (DF21) becomes "High" by this pulse. Then, a pulse is output from the one-shot circuit (OS20), a pulse is output from the one-shot circuit (OS21) at the falling edge of this pulse, and the D flip-flops (DF20) and (DF21) are reset to return to the initial state.

FIG. 4 is a flowchart showing the operation of the microcomputer (MCO2) shown in FIG. The operation of the system shown in FIG. 2 will be described below with reference to this flowchart. When the photometric switch (S1) is closed and an interrupt signal is input to the terminal (it), the microcomputer (MCO2) starts its operation. First, it is determined whether the flag LMF is "1". This flag LMF
Is 1 if the exposure control data has been calculated, but since the calculation has not been performed when the photometry switch (S1) is closed and an interrupt signal is input, the flag is set. LMF is "0", and the process shifts in step S2. In the step of S2, the terminal (O12) is set to "High" to make the transistor (BT1) conductive and the power supply line (+ V).
Power supply is started via. Next, the serial input / output operation is performed a plurality of times to capture a plurality of data from the lens circuit (LEC), and the conversion coefficient (KD) required for automatic focus adjustment is input to the terminal (OP10) to the near infrared light. Outputs the correction data (IRD) of the in-focus position between the light and visible light to the terminal (OP11) and the backlash data (BLD) to the terminal (OP12), and inputs it to the microcomputer (MCO1) for automatic focus adjustment (MCO1). IP
2), (IP3), (IP4). Then, the output terminal (O10) is set to "High". This signal is sent to the microcomputer (M
The signal is input to the interrupt terminal (it2) of CO1), and when this signal is output, the microcomputer (MCO1) starts its operation.

In step S8, a block (ED
O), and then serial input / output operation to serially capture the data from the electronic flash device.
Then, the terminal (O16) is set to "High" if a signal capable of preliminary irradiation is input, and is set to "Low" if not input. Then, the photometric output from the photometric circuit (LMC) is AD converted. All the data required for the exposure calculation has been imported.

Next, exposure calculation for stationary light photography and flash light photography is performed to set the flag LMF to "1" to enable interruption. In step S15, serial input / output operation is performed to send data to the electronic flash device. In step S16, it is determined whether or not the power supply signal is read from the electronic flash device. If the power supply signal is read, the flash light shooting data is displayed, and if not, the stationary light shooting data is displayed on the display unit (EXD). Then, the process proceeds to step S27. Then, in step S27, it is determined whether or not the terminal (i12) is "High" while the photometric switch (S1) remains closed. If it is "High", the process returns to step S3 and the same as above. Repeat the operation. On the other hand, if it is determined in step S27 that the terminal (i12) is "Low",
The terminal (O10) is set to "Low" to stop the automatic focus adjustment operation, the flag LMF is set to "0", and the terminal (O12) is set to "Lo".
As w ″, the transistor (BT1) is made non-conductive to stop the power supply from the power supply line (+ V), and the display unit (EX
The display of D) is turned off and the microcomputer (MCO2) stops its operation.

When an interrupt signal is input while the exposure control data is calculated, the process proceeds to step S20, the terminal (O10) is set to "Low" and the automatic focus adjustment operation is stopped. Then, it is determined whether or not the power supply signal is input from the electronic flash device,
If the power supply signal is input, data for flash light photography is sent to the exposure control unit (EXC), and if not, data for steady light photography is sent. Next, in step S24, it is determined whether or not the operation for automatic focus adjustment has completely stopped and the terminal (i11) is at "Low". If not, it waits until it becomes "Low". . This is to prevent the exposure control operation from starting during the movement of the taking lens.

When the terminal (i11) becomes "Low", the exposure control circuit (EX
The exposure control operation by C) is performed, and the microcomputer (MCO
2) is the reset switch (S
Wait until 4) is opened and the terminal (i10) becomes "Low". When the terminal (i10) becomes "Low", it is determined in step S27 whether or not the photometric switch (S1) is closed. The display operation is repeated, and if the photometric switch (S1) is not closed, the microcomputer (MCO2) stops the operation after proceeding to step S28 and performing the same operation as described above.

FIGS. 5-1 to 5-3 are flowcharts showing the operation for automatic focus adjustment by the microcomputer (MCO1). The operation for automatic focus adjustment of the circuit of FIG. 2 will be described below with reference to FIGS. 5-1 to 5-3. Microcomputer (MCO
When the terminal (O10) of 2) becomes "High" to start the automatic focus adjustment operation, an interrupt signal is input to the terminal (it2),
The operation of the microcomputer (MCO1) starts. First, in step # 1, the microcomputer (MCO2) informs the terminal (O7) that the automatic focus adjustment operation is being performed.
gh ”. Then, the terminal (O3) is set to“ High ”and the control circuit (COC) controls the CCD of the light receiving unit (FMD).
To start the charge storage operation.

In step # 3, the content of the counter COR that counts an external or internal clock in the microcomputer (MCO1) is set in the register ECR1. As will be described later, this is data necessary for calculating the amount of movement of the lens during focus detection in order to perform focus detection while moving the taking lens, and is not necessary at the time of the first measurement. The counter COR and the register ECR are microcomputers (MC
O1), and in the following description, the counters, registers, etc., in which the reference numerals are not enclosed in parentheses are those in the microcomputer. Interruption is possible in step # 4, and the process proceeds to step # 5. In step # 5, it is determined whether the flag FLF is "1". This flag is set to "1" when the preliminary irradiation by the flash is performed, and is set to "0" when the measurement using only the stationary light is performed. During the first measurement, the preliminary irradiation is not necessarily performed, the flag FLF is "0", and the process proceeds to step # 6.

In step # 6, a fixed value Ka is set in the timer register TIR1. Next, the counter C is set in the register ECR4.
The contents of OR are set, and the fixed value K1 is set in the timer register TIR2. And the timer register TIR
The operation of subtracting "1" from the content of 2 and determining whether the content of the register TIR2 is "0" is repeated and waits for a fixed time. After a certain amount of time, #
In step 11, it is determined whether the input terminal (i3) is "Low". If it is "Low", the signal to stop the automatic focus adjustment operation is input from the microcomputer (MCO2) as described above. Therefore, the operation for stopping the automatic focus adjustment operation starting from step # 210 is performed. On the other hand, if the terminal (i3) is "High", it is determined in step # 12 whether the flag FPF is "1". This flag FP
F is "1" when the motor (MO) is stopped as in the first measurement. Therefore, the flag F
If the PF is "1" and the motor (MO) is stopped, # 12
From the step of # 15 to the step of # 15, “1” is subtracted from the register TIR1 in which the fixed value Ka is set in the step of # 6 to determine whether the content of TIR1 becomes “0”. If it is not "0", the process returns to step # 7 and the same operation is repeated. When the output of the comparator (AC1) in FIG. 2 is inverted to "High" while this operation is repeated, the terminal (φ of the control circuit (COC)
A transfer pulse is output from T), this pulse is input to the interrupt terminal (it1), and the microcomputer (MCO1) starts the operation from step # 25. If it is determined in step # 16 that the content of the register TIR1 has become "0", a pulse is output to the terminal (O2) in step # 21 to force the accumulation operation as described above. Stop, flag T
The OF is set to "1" to end the operation and wait for the interrupt signal to the terminal (it1). Here, the time from when the accumulation operation is started in step # 2 to when it is determined in step # 16 that the content of the register TIR1 is “0” is a fixed time, and the accumulation time is The above does not become long.

Flag FP when the motor (MO) is operating
F has become "0", and the contents of the counter COR are set in the register ECR5 in steps # 12 to # 13. Then, the process proceeds to step # 14. In this step of # 13, the contents of the register ECR4 in which the contents of the counter COR are set in the step of # 7 and this register E
Compare with the contents of CR5. A certain time has passed between steps # 7 and # 13, and if the lens does not move during this time, no clock pulse is input from the encoder (ENC) and (ECR4) = (ECR5). ing. Therefore, even if the motor (MO) is driven, the lens has reached the end position (infinity position or closest position) and the lens has stopped moving. In this case, the flag LSF (“0” during normal focusing operation, a low contrast signal indicating that the contrast of the subject image is low is output, and “1” is output when a lens position that is not low contrast is scanned. If the value is "1", the scan is in low contrast and the process proceeds to step # 158. If the value is "0", the normal focusing operation is in progress and the process proceeds to step # 63. Transition.

If the flag FLF is "1" in step # 5, the flash light is pre-illuminated, and the process proceeds to step # 17. At this time, a fixed value Kf is set in the register TIR1, "1" is subtracted from the register TIR1, and it is determined whether the terminal (i3) is "Low", and "Hig
If it is "h", it is determined whether the content of TIR1 is "0". If it is not "0", the operation of returning to step # 18 is repeated, and the content of TIR1 is "0" at step # 20.
If so, the process proceeds to step # 21 and the above operation is performed. In the pre-irradiation mode, the limitation of the storage time is much shorter than that in the stationary light mode. It is configured this way for the following reasons. Light in the near-infrared region is used as the pre-illumination light so that the human being, who is the subject, does not feel dazzling. On the other hand, when pre-irradiation is not performed, it is measured with the constant light, but the constant light is generally white light. Therefore, when both lights are mixed and measured, the effect of chromatic aberration on the defocus amount cannot be corrected unless the mixing ratio is known. Therefore, in the pre-irradiation mode, the longest accumulation time is set to be almost equal to the flash emission time so that the chromatic aberration can be accurately corrected in order to prevent the stationary light component from being measured as much as possible. . Further, in the pre-irradiation mode, the motor (MO) is not driven during the measurement, so that the end detection operation of whether the lens has reached the end is not performed.

When a transfer pulse is output from the terminal (φT) of the control circuit (COC) and an interrupt signal is input to the terminal (it1), the operation from step # 25 is started. In step # 25, an interrupt is possible and the terminal (O3) is set to "Low", and the counter C
The contents of OR are fetched in the register ECR2. This is data for correcting an error due to the movement of the lens when the lens is moved during measurement. Next, when the A / D converted data of the received light amount of each light receiving unit output from the control circuit (COC) is sequentially taken in, and the A / D converted data corresponding to all the light receiving units is taken in, the process proceeds to step # 29. To do. In step # 29, it is determined whether the flag FLF is "1",
If it is not "1", it is determined whether the flag TOF is "1". The flag TOF becomes "1" in step # 22 when the storage time has reached the limited time. Therefore, when the FLF is “0” and the TOF is “1”, the brightness is low in the constant light mode, the flag LLF is set to “1” in step # 31, and otherwise the flag LLF is set in step # 32. Set it to "0", and set the flag TOF to "0" in # 33.
To In step # 34, the degree of correlation between the two rows of light receiving portions is obtained based on the output from the light receiving portion (FMD), and the defocus amount and the defocus direction are calculated from this correlation degree. This calculation may be performed, for example, as proposed in US Pat. No. 4,333,007. This calculated defocus amount is | LD |
When LD> 0, it is a front pin, and when LD <0, it is a rear pin.

In step # 35, it is determined whether or not the flag FLF is "1", and when the FLF is "0" and the measurement is performed with the constant light (visible light), the calculated data LD is directly set to the correct value LDt and FLF is set. If is “1”, it means the pre-irradiation mode. At this time, since the measurement with near infrared light is performed, the difference between the focus position with visible light and the focus position with near infrared light is measured. That is, in order to correct only IRD, LD-IRD is calculated and this calculated value is set as the correct defocus amount LDt. Although the data sent from the lens is used as it is as the data IRD, for example, the lens stores correction data for a specific wavelength, data of the wavelength of the preliminary irradiation light source is obtained, and this wavelength is used. The correction data may be converted into data corresponding to, and the defocus amount may be corrected by the converted correction data.

In # 38, determine whether the terminal (i3) is "Low" and
If “w”, the process proceeds to step # 210 as described above.
On the other hand, if the terminal (i3) is “High”, then it is determined whether or not the measurement data has low contrast.
The determination of the low contrast may be made by determining the total sum of absolute values of the output differences between the adjacent light receiving units in each light receiving unit of the light receiving element array, and when the total is less than or equal to a predetermined value, the low contrast is determined. In the case of low contrast, since the defocus amount is calculated by comparing the light distribution states of the two rows of light receiving elements, the calculated defocus amount is not reliable. Therefore, when the low contrast is determined, the process proceeds to step # 110 to perform the low contrast operation. If it is determined in step # 39 that the contrast is not low, the flag LCF is determined in step # 40.
It is determined whether 1 is "1". And the flag LCF
If 1 is "1", the previous measurement value has low contrast, and in this case, the flag FLF is "1" in step # 41.
Determine whether or not. If the flag FLF is "1", the preliminary irradiation by the flash is performed in this measurement, so the operation from step # 170 is performed. On the other hand, if the flag FLF is "0", the previous measurement has low contrast, and the current measurement has sufficient contrast without preliminary irradiation. At this time, the flags LCF1, LCF2, SEF1, SEF2, LSF are set to "0", and it is determined whether the TIF is "1" or "1".
If not, the operation from # 50 is performed. In this case, the measured value was low contrast, and the measured value was not low contrast during the measurement while moving the lens until the measured value was not low contrast (hereinafter referred to as low contrast scan mode). This is the case, and at this time, the operation moves to move the lens based on the defocus amount from step # 50. If the flag TIF is "1" in the step # 43, the lens is scanned in the low-con scan mode over the entire area, and the lens is stopped for a certain period of time when a measurement value other than low contrast is not obtained during this period. This is the case where the measurement is repeated until then (hereinafter referred to as the low-con stopped mode). In this case, since the counter COR is in the mode (timer mode) for counting the internal clock of the microcomputer (MCO1), the event count mode (encoder (EN
The clock pulse from C) is set to the mode), the flag FPF is set to "1", and the TIF is set to "0".
To step # 50 and step # 50
The same operation is performed as when the measured value of the second time is not low contrast.

When the flag LCF1 is "0" in the step of # 40, or when the flag TIF is "0" in the step of # 43 described above, or when the step of # 46, the process shifts to the step of # 50. In step # 50, the defocus amount LDt is multiplied by the conversion coefficient KD to calculate the lens movement amount ND. Next, LID is data in a range that can be regarded as in-focus, and by multiplying this by a conversion coefficient KD, the amount I of movement of the lens in the in-focus region is calculated.
Calculate FD. In the step of # 52, it is determined whether the flag FPF is "1", and if it is "1", # 75, "0".
If so, move to step # 53. Therefore, if the motor (MO) is driven, the process proceeds to step # 53, and if the motor (MO) is not driven, the process proceeds to step # 75.

In the step of # 53, the register ECR that captures the contents of the counter COR at the start of charge accumulation in the light receiving unit (FMD)
The amount τ of movement of the lens during charge accumulation is calculated by obtaining the difference τ between 1 and the register ECR2 that has loaded the contents of the counter COR at the end of accumulation. Then, the contents of the counter COR at this point are set in the register ECR3, the difference t between the registers ECR2 and ECR3 is obtained, and the movement amount t of the lens during the defocus amount calculation is calculated. Then, assuming that the calculated defocus amount is a value based on the measurement value in the middle of the movement of the lens during the accumulation time, the lens moves by τ / 2 + t from the time when the calculated lens movement amount ND is measured. In step # 56,
| ND | − (τ / 2 + t) = NDc is calculated to correct the movement amount. In step # 57, the corrected movement amount data | NDc | is compared with the in-focus area data IFD. If | NDc | IFD, it means that the in-focus area is entered. Transition to terminal (O
4) and (O5) are set to "Low" to stop the motor (MO), the flags IFF and FPF are set to "1", and the process returns to step # 2 to perform confirmation measurement.

When it is determined in step # 57 that | NDc |> IFD, the process proceeds to step # 61, where the contents of the counter COR are set in the register ECR3, and at the time of step # 27, the contents of the counter COR are set. The contents of the register ECR2 are compared. When it is determined that (ECR2) = (ECR3), the lens has reached the end, and in steps # 63, the terminals (O4) and (O5) are set to “Low” to turn on the motor (MO). The rotation is stopped, the flags ENF and FPF are set to "1", the process returns to step # 2, and the measurement is performed again.

When it is determined in step # 62 that (ECR2) ≠ (ECR3), it is determined in step # 66 whether the correction data NDc has a negative value. If it is a negative value, the correction amount (τ / 2 + t) is larger than the calculated movement amount | ND |, which means that the lens has passed the in-focus position. Therefore, in this case, the process proceeds to the step of # 71 and the terminals (O4) and (O5) are set to "Low" to stop the rotation of the motor (MO), and the flags SCF and FPF are set to "1" to the step of # 2. Make a measurement to confirm the return.

If it is determined in step # 66 that NDc> 0, then it is determined in step # 67 whether the lens driving direction is the retraction direction (ND> 0). Then, if ND> 0, it is determined whether the flag SIF is "1" at step # 68, and if ND <0 (feeding direction), at step # 69. This flag SIF is "1" if the moving direction of the lens at this point is the retracting direction, and "0" if it is the retracting direction. Therefore, the flag SIF is “0” in the step # 68, or the flag SIF is in the step # 69.
If “1” is, it means that the moving direction of the lens at this point and the calculated moving direction of the lens are reversed, and the process proceeds to step # 71 described above to stop the motor (MO), The flags SCF and FPF are set to "1", and the process returns to step # 2 to perform measurement for confirmation. On the other hand, if the direction is not reversed, the data NDc calculated in the step # 56 is set in the counter COR, the process returns to the step # 2, and the next measurement is performed.

In step # 52, when the flag FPF is "1", the motor (MO) is stopped and the measurement is performed without preliminary irradiation. In this case, it is first determined whether or not it is | ND | IFD, and if it is | ND | IFD, the in-focus display is performed in step # 76, and the operation proceeds to step # 211 described later. Stop. On the other hand, |
If ND |> IFD, the process proceeds to step # 80 in FIG. In steps # 80 to # 82, flags IFF and S
It is determined whether CF and FNF are "1". These flags are "1" when the moving lens is once stopped and the measurement for confirmation is performed as described above, and at this time, the process proceeds to step # 84. In steps # 84 to # 86, it is determined whether the direction in which the lens has been driven by that time and the direction obtained by this measurement are the same as in steps # 67 to # 69 described above. If it is reversed, the flag SIF is reversed in steps # 84 and # 88, and the backlash data (BLD) is added to the data of the movement amount | ND | in the step # 91.
The value obtained by adding is set in the counter COR, and the process proceeds to step # 96. On the other hand, when the directions are the same, it is determined in step # 89 whether the flag FNF is "1".
If the flag ENF is "1", it means that the lens has reached the end as described above. At this time, since the lens cannot be driven in the calculated direction, a warning is displayed. The operation is stopped by moving to step # 211 described later. On the other hand, if the flag ENF is "0", the movement amount data | ND |
Set to R and move to step # 96.

When the flags ENF, SCR and IFF are all "0", the moving direction is determined in step # 92. If ND> 0, the flag SIF is set to "1", and if ND <0, the SIF is set to "0".
In step # 95, the calculated movement amount data is set in the counter COR, and the process proceeds to step # 96.

In step # 96, the event count mode is set and the data set in the counter COR is subtracted by the clock pulse input from the encoder (ENC), and then the terminal (O4) is set according to the moving direction. Or (O
5) Set "High" to start the rotation of the motor (MO), set the flags FPF, IFF, SCF, ENF to "0", and display the front pin or the rear pin according to the contents of the flag SIF. Then, the process returns to step # 2 and the next measurement operation is performed.

When it is determined in step # 39 that the measurement result has low contrast, the process proceeds to step # 110. In step # 110, it is determined whether the flag FPF is "1". If "1", it means the first measurement, and the process proceeds to step # 111. In step # 111, it is determined whether the flag LLF is "1". This flag LLF is # 29-
As described in step # 33, this flag is "1" when the subject brightness is low.
If F is “1”, the process proceeds to step # 114, and if “0”, the process proceeds to step # 121.

In step # 114, it is determined whether the terminal (i2) is "High". If the terminal (i2) is "Low", it is determined in step # 115 whether the flag SEF2 is "1". As will be described later, this flag SEF2 is a flag that becomes "1" when the lens scans the entire area in the low contrast scan mode. Therefore, if it is "1", the process shifts to step # 144 and shifts to the low-con converter stop mode described later. On the other hand, if the flag SEF2 is "0", the mode shifts to the low contrast scan mode from # 121.

When it is determined in step # 114 that the terminal (i2) is "High", the process shifts to the preliminary irradiation mode from step # 116.
In the step of # 116, the flag FLF is set to "1", then the terminal (O1) is set to "High", the flag FPF is set to "0", the flags LCF1 and FFF are set to "1", and the process returns to the step of # 2. Then, as described above, the measurement operation for performing the preliminary irradiation is performed.

If the flag LLF is "0" in the step of # 111 or the flag SEF2 is "0" in the step of # 115, # 1
The operation shifts to step 21 and the operation of the low-con scan mode is started. First, the flags LCF1, LCF2, and LSF are set to "1", then it is determined which defocus direction is calculated, and the flag SIF is determined according to the determined direction.
Is set to "1" or "0" and the lens is moved in that direction. Then, a warning is displayed, the flag FPF is set to "0", the interrupt signal is not accepted when the content of the counter COR becomes "0", the process returns to step # 2, and the next measurement is performed. Let

If the flag FPF is "0" in step # 110, # 140
Then, it is determined whether the flag FLF is "1". If the flag FLF is "1", it means that the measurement result in the preliminary irradiation mode is low contrast. At this time, the terminal (O1) is set to "Low"
Go to step # 200 in FIG. Then, in step # 200, it is determined whether the flag FFF is "1", and if the flag FFF is "1", it means that the first measurement is performed in the preliminary irradiation mode. At this time, the flag FFF is set to "1". Then, the terminal (O1) is set to "High" and the process returns to step # 2 to perform the operation in the second preliminary irradiation mode. On the other hand, if the flag FFF is "0" in the step # 200, it means that the second measurement is performed in the preliminary irradiation mode. At this time, the warning is displayed and the operation shifts to the step # 211 to stop the operation. To do.

If the flag FLF is "0" in the step # 140, then it is determined whether the flag TIF is "1" in the step # 142. If the flag TIF is "1", the low contrast stop mode is set, and the process returns to step # 2 to perform the next measurement. If the flag TIF is "0" in step # 142, then it is determined in step # 143 whether the flag SEF2 is "1". If it is "1", it means that only the measured value of the low contrast is obtained even if the lens scans the whole area in the low contrast scan mode. At this time, the operation of the low contrast stop mode from # 144 is started. .

In step # 144, the fixed data T1 is stored in the counter COR.
Is set to switch to the timer mode in which the contents of the counter COR are subtracted by the clock pulse inside the microcomputer (MCO1), the flag TIF is set to "1", the counter interrupt is enabled, and the process returns to step # 2 to perform the measurement. Let In this mode, the measurement is repeated with the lens stopped for a certain period of time, and if a measurement value that is not low contrast is obtained during this time, the lens is driven by the movement amount data based on this measurement value and the low contrast measurement is performed for a certain period of time. When only the value is obtained, the same operation as the first measurement is performed again.

If it is determined in step # 143 that the flag SEF2 is "0", then in step # 150 the flag LCF1 is set.
It is determined whether is "1". And when it is not "1", the measured value up to the previous time is not low contrast,
This is the case when the contrast suddenly becomes low in this measurement. In this case, the process proceeds to step # 151 and the flag LC
F1 is set to "1", LCF2 is set to "0", and terminals (O4),
(O5) is set to "Low" to stop the operation of the motor (MO), the flag FPF is set to "1", and the process returns to # 2 to repeat the measurement. In step # 150, the flag LCF1 is "1".
Then, in step # 155, it is determined whether the flag LCF2 is "1". If the flag LCF2 is "0", the previous measurement value suddenly becomes low contrast, and the current measurement value obtained by re-measurement also has low contrast. Therefore, in this case, the operation for starting the low contrast scan mode is performed from step # 121.

If the flag LCF2 is "1" in step # 155, the operation is in the low-conscan mode. in this case,#
In step 156, the contents of the counter COR are registered in the register EC.
In step # 157, it is determined whether or not the contents of the register ECR2, which has been set in R3 and the contents of the counter COR have been fetched in step # 27, match. If they do not match, the lens has not reached the end, so the procedure returns to step # 2 to perform the measurement operation. Meanwhile, the register ECR2
If the contents of ECR3 and ECR3 match, the lens has reached the end, and the drive of the motor (MO) is stopped in step # 158. Then, in step # 159, the flag S
It is determined whether EF1 is "1", and if it is "1", the lens has reached one end, and therefore the lens has reached both ends and the entire area has been operated. Become. Therefore, at this time, the flag SEF2 is set to "1", the process proceeds to step # 114, whether or not the preliminary irradiation is possible from the flash is confirmed, and if the preliminary irradiation is possible, the preliminary irradiation mode is changed to the preliminary irradiation. If is not possible, it shifts to the low contrast stop mode.

If the flag SEF1 is "0" in the step of # 159, it means that the lens reaches the end for the first time in the low-con scan mode. In this case, the flag SIF is inverted and the rotation direction of the motor (MO) is also inverted. Set SEF1 to "1" and return to step # 2 to perform measurement.

If the flag FLF is "1" in step # 41, it means that the result of measurement in the preliminary irradiation mode is not low contrast. At this time, the process proceeds to step # 170 in Fig. 5-3. In step # 170, set terminal (O1) to "L".
ow ”, and the lens movement amount ND and the focusing region IFD are calculated from the defocus amount data LDt and the focusing region data obtained in the step # 37 and the conversion coefficient KD. Then, the step # 173. When │ND│IFD, the focus is displayed, the flag FFF is set to "0", and the process proceeds to step # 211 to end the operation.

If it is determined in step # 173 that | ND |> IFD, the process proceeds to step # 180, where | ND | is set in the counter COR, the event count mode is set, and the counter interrupt is enabled. Then, it is determined whether or not the flag FFF is "1", and if it is "1", it means that the first measurement is performed in the preliminary irradiation mode. At this time, the process directly proceeds to step # 188. On the other hand, if FFF is “0”, 2
The second measurement is when the measurement is performed. In this case, the process proceeds to step # 178 and the data LN near the focus is obtained.
The data NFD of the neighboring area is calculated by multiplying D by the conversion coefficient KD. Then, in step # 179, it is determined whether or not | ND | NFD.

When | ND |> NFD, it is considered that normal operation is not performed in the first focusing operation or the second measurement result is poor in reliability. Furthermore, it is difficult to accurately move the lens to the in-focus position with only one movement of the lens due to variations in the conversion coefficient, and it is considered that the in-focus operation cannot be performed basically. Therefore, in this case, a warning is issued in step # 201, the process proceeds to step # 211 and the operation is stopped.

If it is determined in step # 179 that | ND | NFD is set, it is considered that normal control operation is possible. Therefore, the moving direction is determined next, and whether the moving direction is reversed from the previous time. To determine. Then, if it is determined that it is reversed, | ND | + BLD is calculated to correct the movement amount data | ND | by the amount of backlash data, and this data is reset to the counter COR. On the other hand, if it is not inverted, the data set in step # 180 remains as it is and the process proceeds to step # 188. Then, the direction of movement is determined, a signal corresponding to that direction is set in the flag SIF, and the motor (MO) is rotated in the determined direction.

Next, after setting the contents of the counter COR in the register ECR2 and waiting for a certain period of time, it is determined whether or not the terminal (i3) is "Low", and when the (i3) is "High", the contents of the counter COR are set in the register ECR3. Set to. And #
At step 197, it is determined whether the contents of the registers ECR2 and ECR3 match. And (ECR2)
If ≠ (ECR3), the contents of ECR3 are set to ECR2 and the process returns to step # 194. Therefore, in the preliminary irradiation mode, when data is obtained by measurement, the lens is driven based on this data, but the measurement operation is not performed during this driving. When the lens moves by the calculated amount of movement, a counter interrupt is applied and the lens is stopped, as will be described later, and if it is the first time, the operation moves to the second time, and if it is the second time, the focus display is performed. Stop the operation. Also,#
When it is detected in step 197 that the lens has reached the end, the terminals (O4) and (O5) are set to "Low" to stop the motor. Then, in step # 200, the flag FFF is set.
If it is "1", it is the first measurement, so set FFF to "0" and set the terminal (O1) to "High".
Then, the procedure returns to step # 2 and the second preliminary irradiation mode measurement is performed. On the other hand, FFF in step # 200
If it is determined that is “0”, the lens has reached the end by the second operation at this time, and in this case, a warning is displayed and the process proceeds to step # 211 to perform the operation. Stop.

When the content of the counter COR becomes "0", the counter is interrupted and the operation from step # 230 is performed. In step # 230, it is determined whether the flag TIF is "1".
When the value is "1", the constant time has elapsed in the low contrast stop mode, and only the measured value of the low contrast is obtained during this period. At this time, it is possible to interrupt and the flags TIF and SEF are set.
1, SEF2, LCF1, LCF2, LSF are set to "0", the flag FPF is set to "1", the event count mode is set, and the process returns to step # 2. Therefore, the measurement is performed in the same state as the first measurement.

When the flag TIF is "0" in step # 230, it means that the movement amount of the lens has moved by the output movement amount. In this case, the motor (MO) is stopped to enable the interrupt. Then, in step # 235, it is determined whether the flag FLF is "1". If it is "1", it means the pre-irradiation mode, and the process proceeds to step # 238. In the step of # 238, it is determined whether the flag FFF is "1", and if it is "0", it means that the second focusing operation in the preliminary irradiation mode is completed, and after the focusing display is performed, the step of # 211. Move to. On the other hand, if the flag FFF is "1", it means that the first focusing operation has been completed in the preliminary irradiation mode.
The flag FFF is set to "0" and the terminal (O1) is set to "High" to return to the step # 2 to perform the second focusing operation.

If the flag FLF is "0" in the step of # 235, the preliminary irradiation is not performed, a measured value which is not low contrast is obtained, and the lens is moved by the calculated moving amount. At this time, the flags IFF and FPF are set to "1" and #
Return to step 2 and ask for confirmation measurements.

In the steps # 11, # 19, # 38, and # 195, the terminal (i3) goes to “L”.
If it is determined that it has become "ow", interrupts are disabled in step 210, and then the event count mode is set.
Go to step 213. On the other hand, # 76, # 90, # 175,
When the operation is completed in steps # 201 and # 239, #
Interruption is disabled in step 211, and terminal (i3) is "Low".
Wait for When the terminal (i3) becomes “Low”, the process proceeds to step # 213. In step # 213, the terminals (O4) and (O5) are set to "Low" and the motor (MO)
Stop and then turn off the display. And the terminal (O
1), (O2), (O3), and (O7) are set to "Low" to stop the operation of the circuit for automatic focus adjustment. And F
All flags except PF and SIF are set to "0" to set the flag FPF to "1". Next, the counter CO
The contents of R are set in the register ECR2, and after waiting for a fixed time, the contents of the counter COR are set in the register ECR3. Then, it is determined whether or not (ECR2) = (ECR3), and if (ECR2) ≠ (ECR3), the contents of the register ECR3 are set in the register ECR2 #
Return to step 219. And (ECR2) = (ECR
If it is 3), the movement of the lens is completely stopped, so the terminal (O7) is set to "Low" to indicate that the microcomputer (MCO2) may start the exposure control operation. , And the microcomputer (MC
O1) stops the operation.

In the above embodiment, when it is determined that the in-focus state is obtained in step # 75 when not in the preliminary irradiation mode,
After that, even if a signal (high signal to the terminal (i3)) to continue the automatic focus adjustment operation is input from the microcomputer (MCO2), the automatic focus adjustment operation is not performed and the operation is stopped. However, as shown in the parentheses after the step # 76 in FIG. 5A, the step may return to the step # 2. In this way, even if the subject is once in focus, if the subject deviates from the focus, the automatic focus adjustment operation is executed again. Also, # 89 in Fig. 5-2
Even if the flag ENF is "1" in the step, that is, if the lens reaches the end position and the lens cannot move, the process may return to the step # 2 to perform the measurement again. In this way, the lens starts moving again when a signal in the direction in which the lens can be moved is obtained. Even in the case of the modification as described above, the measurement is limited to twice in the preliminary irradiation mode.

A modified example of the above-described embodiment will be described below. First,
In the electronic flash device, the emission energy of the xenon tube for photographing and pre-irradiation was supplied by the electric charge charged in the common May condenser (C2), but another condenser was used for pre-irradiation. You may use it. In this case, the pre-irradiation enable signal may be output when the charging voltage of the separately provided capacitor reaches a predetermined value. Further, in this case, if the capacity of the capacitor is increased to increase the number of times of preliminary light emission, the automatic focus adjustment operation can be speeded up by performing the measurement while moving the lens as in the normal mode. .

Further, in the embodiment, in the electronic flash device, the xenon tube for photographing and the pre-irradiation were respectively provided exclusively, but a common xenon tube is used, and a filter that cuts visible light and transmits near infrared light is used. The filter may be inserted before the xenon tube during the preliminary irradiation and the filter may be removed during the photographing.

Further, in the embodiment, the pre-irradiation mode is set when the low contrast and the low light are used. However, the low light is not included in the determination requirement, and the pre-irradiation mode is set when the low contrast is set. Good. In this case, the preliminary irradiation has a strong purpose of increasing the contrast of the subject.

Further, the light emission of the preliminary irradiation may be stopped by providing a photometric circuit on the flash side and stopping the light emission by the output of the photometric circuit.

Further, the camera body is provided with a determination means for determining whether or not the flash is directly connected, and if it is determined that the flash is not directly connected (when connected by a cable or the like), the preliminary irradiation mode is not set. You may do it. Furthermore, the cable has terminals (JB1) and (JB1).
It suffices not to provide a conducting portion for connecting to F1).

Further, a circuit for receiving the light emission start signal of the preliminary irradiation is provided only when the preliminary irradiation enable signal is output on the electronic flash device side, but this circuit is not always necessary.

This is because the camera determines whether the preliminary irradiation enable signal is input, and only when it is determined that the preliminary irradiation enable signal is input, the light emission start signal is output twice, and the preliminary irradiation enable signal is input. This is because the light emission start signal is not output when the determination is not made. So if you omit it,
AND circuit (AN20), OR circuit (OR20), (OR2
1), D flip-flop (DF20), (DF21),
The one-shot circuits (OS20) and (OS21) are not required, and the terminal (JF1) is directly connected to the set terminal of the flip-flop (RF20) and the trigger circuit (TR1). Also, in order to make the amount of light emission constant during preliminary irradiation,
Although the light emission time is made constant, the light emission amount may be directly monitored, or the electricity amount for light emission may be directly monitored to make the light emission amount constant.

When it is determined that the lens cannot be moved to the in-focus position after performing the operation twice in the preliminary irradiation mode, the operation is performed from the terminal (O10) of the microcomputer (MCO2) in this embodiment. Although the automatic focus adjustment operation is stopped even if the "High" signal for performing the operation is output, if it is determined that the focus position cannot be moved in the preliminary irradiation mode, The operation from the beginning or the operation in the low contrast scan mode or the low contrast stop mode may be performed again.

The preliminary irradiation enable signal was sent from the terminal (JF3) as one of serial data, but the terminal (JF1)
Alternatively, it may be directly sent to the microcomputer (MCO1). Further, the pre-irradiation enable signal may not be specially prepared, and it may be possible to switch to the pre-irradiation mode when a power supply signal or a charging signal is input from the electronic flash light emitting device.

Although the electronic flash light emitting device attached to the camera is used as the light source for preliminary irradiation, a light emitting diode or the like built in the camera may be used in addition to this, or a light source other than the electronic flash light emitting device may be used in the camera. The electronic flash light emitting device may be attached to the camera, or the electronic flash light emitting device may be incorporated in the camera for use.

The present invention is premised on an automatic focus adjustment device of the type that detects the amount of defocus, but it can also be applied to a type in which the lens is moved to the position where the contrast becomes maximum. The number of times must be limited to more than 2.

Further, if the constant light is used as the light source for the preliminary illumination, the lighting time of the light source may be limited.

In addition, in this embodiment, one focus detection element having a spectral sensitivity from the visible region to the near infrared region is used to perform the measurement with only the stationary light and the preliminary irradiation measurement with the flash having the energy in the near infrared region. However, two types of focus detection element having sensitivity only in the visible range and focus detection element having sensitivity only in the near infrared range may be prepared and used by switching according to the measurement mode. You may make it use only one focus detection element which has a sensitivity only. In this case, it is not necessary to cut the integration time in the pre-irradiation light mode in a short time.If the light quantity is insufficient due to the pre-irradiation, the integration time is extended as it is and the stationary light component is additionally integrated. But it doesn't matter. Further, in this case, if the sensitivity of the focus detection element is set to the infrared region instead of the near infrared, the light source also becomes infrared, and there is an effect that a person does not feel that the preliminary irradiation is performed.

In the above-mentioned embodiment, the measurement by the preliminary irradiation is limited to two times, but as long as the power condition of the flash permits, it is set to three.
Needless to say, it is possible to limit the number of times to a predetermined number such as four times or four times.

Further, when the integration time reaches the limit value in the first operation or when the measured value is low contrast, the light amount of the second preliminary irradiation may be increased.

Effect According to the automatic focus adjustment device of the present invention, focus detection is performed during lens driving based on focus detection in a state where auxiliary light is not emitted, but a lens based on focus detection in a state where auxiliary light is emitted Focus detection is prohibited during driving. That is,
Optimal operation can be performed in each case.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a circuit diagram showing the entire camera system to which the present invention is applied, and FIG. 3 is a circuit showing a specific example of the flash unit (FLC) of FIG. Figures 4 and 5 show the microcomputer (MCO
Flowchart showing operation 2), 5-1, 5-2,
FIG. 5-3 is a flowchart showing the operation of the microcomputer (MCO1) shown in FIG. Photographing lens → 3 Drive means → 8 Focus detection means → 4.5 Light emitting means → 11/12/13 First control means → # 50 to 62 to 73 to 2 Second control means to # 170 to 193

Continuation of front page (56) Reference JP-A-48-53717 (JP, A) JP-A-54-126023 (JP, A) JP-A-58-132733 (JP, A) JP-A-58-58508 (JP , A) JP 59-195605 (JP, A)

Claims (1)

[Claims] 1. A photographing lens and a driving hand for driving a focusing lens in the photographing lens.
And the subject image formed by the shooting lens.
Focus detecting means for detecting the focus of the photographing lens relating to the object
And the light emission means that emits the auxiliary light that illuminates the subject, and the detection results of the focus detection means when the auxiliary light is not emitted.
When driving the shooting lens by controlling the driving means based on
If the shooting lens is driven, the focus detection means detects
This detection result is also used for the control of the driving means.
The control result and the focus detection result when the auxiliary light is emitted
When driving the photographing lens by controlling the driving means based on
Is the detection movement by the focus detection means while the shooting lens is being driven.
An automatic focus adjusting device comprising: a second control means for prohibiting a work.