JPS6052812A - Automatic focusing device with backlash correction - Google Patents

Abstract

PURPOSE:To improve accuracy by preparing the data corresponding to the error of backlash and adding the correction corresponding to the error to the extent of movement of a driving motor or a focusing optical system when the driving direction of said motor or optical system changes. CONSTITUTION:The data K on the coefft. of conversion read in a read circuit LEB is fed to a multiplier circuit 40. The circuit 40 calculates the extent N of driving of a driving motor MO by multiplying the defocusing rate ¦DELTAL¦ inputted from an arithmetic processing circuit 34 by the data K. The latest data of the data on the defocusing direction outputted intermittently from the circuit 34 is stored in the 1st storage circuit 46 and the data of the previous time is stored in the 2nd storage circuit 48. A comparator circuit 50 compares the contents of the 1st and the 2nd storage circuits. A correction circuit 44 outputs the output from the circuit 40 as it is when there is no change in the driving direction of the motor MO and said circuit outputs the data N' obtd. by adding the data BLD on the correction rate of backlash from the circuit LEB to the output data from the circuit 40 when the driving direction is inverted.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to photoelectric measurement and electrical measurement of the amount of deviation of the position of a subject image formed by a lens J with respect to a planned focal plane, that is, the amount of deviation of the so-called pin h. Based on the results, the amount of drive of the drive motor for driving the focusing optical system (optical system that is moved for focus adjustment) of the photographic lens is calculated. The present invention relates to a device that controls a drive motor to adjust the focus of a single closest lens.

BACKGROUND TECHNOLOGY Conventionally, a stone-carved lens is formed by photoelectrically detecting the light intensity of the subject light that has passed through a photogenic lens or the distribution of incident light m on a planned focal plane, and applying predetermined arithmetic processing to the detection results. Based on this data, drive the drive motor,
The applicant of the present application has proposed a device for adjusting the focus by driving the focusing optical system of the photographic lens via a transmission mechanism connected to this motor, in 44 B715'l-f332b'71 and the like.

In such devices, backlash exists between elements such as gears and connecting members involved in transmission in the transmission system from the drive motor to the focusing optical system, and it is necessary to eliminate this backlash. is impossible. When performing focus adjustment via such a transmission mechanism, there is no problem if the focusing optical system reaches the in-focus position while the drive motor is rotating in one direction and its drive is stopped. , due to some reason, the focusing optical system has passed the focusing position and the drive motor has to be reversed. When returning the focusing optical system, the focusing optical system has to go back and forth until it reaches the focusing position. When moving, an error equivalent to backlash occurs when the driving direction is reversed. That is,
The focusing optical system is driven less than the planned drive m for a certain amount of rotation of the drive motor by the amount of backlash. As a result, when the focusing optical system of the lens is moved and focus detection (detection of the amount of deviation of the subject image position from the expected focal plane) is repeated, and the focusing optical system reaches the in-focus position, The focusing optical system repeats reciprocating motion near the focusing position, and it takes a long time for the focusing optical system to reach the focusing position. Also, focus detection is performed with the focusing optical system stationary, and based on the result, the focusing optical system is moved to the vicinity of the focus position and coarse adjustment is performed, and then focus detection is performed again, and the result is When finely adjusting the position of the focusing optical system based on
If the driving direction of the focusing optical system changes between adjustment and fine adjustment,
An error occurs in the amount of adjustment during fine adjustment. Also, when adjusting the focus based on focus detection only once, after focusing on one subject, when focusing on another subject,
If the moving direction of the focusing optical system changes, an error will occur in the second adjustment amount.

An object of the present invention is to provide a device that can perform automatic focus adjustment with high precision and without being affected by the above-mentioned backlash caused by i15 in the transmission system.

[First step in achieving this objective, in the present invention, data corresponding to the error caused by backlash is prepared, and when the drive direction of the drive motor or focusing optical system changes, the amount of drive motor drive is A correction corresponding to the error is added to the data.

It is a -1-row tatami diagram showing a specific supplementary selection of the connection part d31=) in the example.

33 in FIG. 1, the left side of the two-dot chain line shows the interchangeable photographing lens, and the right side shows the configuration of the camera body. The photographic lens (10) is equipped with a photographic lens optical system and an aperture structure. A transmission mechanism (12) is provided that transmits the driving force from the camera side via the lens side connecting member (14)'. Also, a photographic lens (1
0), as described below, includes U■ widest aperture value, minimum aperture value, and focal length 1! ! 11. Differential 4 detected inside the camera body
- Coefficients for converting n1 data into lens drive f, IJ, etc. A memory circuit that permanently stores data for exposure and automatic focus adjustment specific to a shadow lens, and related circuits (LEC ) is provided. This storage circuit also stores backlash data according to the present invention, that is, information on the power transmission mechanism from the drive unit in the camera described in 1 to the focusing optical system of the darkest lens 61. Data for correcting the drive amount when the drive motor's drive force is reversed due to backlash is also stored.

On the other hand, the camera body (20) is constructed as a negative-eye reflex camera, and the subject light that has passed through the photographic lens optical system is reflected by the movable mirror (22) before photographing. The center part of the mirror (22) is a semi-transparent mirror, and the subject light that passes through the semi-transparent mirror is reflected by the auxiliary mirror (30).
The light enters the focus detection light receiving element array (32) provided at the inner bottom of the camera body (20). The output from this light-receiving element array is sent to an arithmetic processing circuit (34), and the arithmetic processing circuit (34) performs predetermined arithmetic processing on the output of the light-receiving element array. Subject image 4i1. m relative to the planned focal plane (5
) That is, calculate the defocus amount and the defocus direction whether the deviation is in front of, behind, or without deviation from the expected focal plane, that is, whether the front bin is in focus, the back focus is in focus, or the defocus direction is in focus.

The photographing lens circuit (LEC) is connected to the terminal (J) on the lens side.
It is connected to the reading circuit (LEB) via terminals (JB11) to (JL114) on the camera body side that are in contact with these terminals (Ll) to LIL4), respectively.

The circuit (LEC) is supplied with power from the camera body via the terminal 11B11) (Jl 1), and is connected to the terminal (JB12) (Jl 1).
The memory data is serially sent out from the terminals (Jl4) and (J[314]) in synchronization with the clock pulse sent through the terminals (Jl3) and (JB1).
3) This is for Harisera 1-.

Among the photographic lens data read by the reading circuit (LEB), the conversion coefficient data is sent to the multiplication circuit (40) through the signal path (36), and the multiplication circuit (40) is connected to the arithmetic processing circuit (34). ) is inputted via the signal path (38) by the conversion coefficient data K, and the subject image is focused until it is focused on the planned focal plane (that is, brought into focus). Drive amount N of the drive motor (MO) required to move the optical system (=K・1Δml)
Calculate the data. Further, the backlash correction amount data BLD read by the reading circuit (LEB) is sent to the correction circuit (44) through the signal path (42).

Defocus direction data D from the arithmetic processing circuit (34)
D connects the motor drive circuit (M
DR') and also to the first storage circuit (46) through the signal path (48B). When the first storage circuit (46) receives new defocus direction data DD, it transfers the data stored up to that point to the second storage circuit (48) and stores the new data. That is, among the defocus direction data intermittently output from the arithmetic processing circuit (34), the latest one is stored in the first storage circuit, and the previous one is stored in the second storage circuit. Note that when the defocus direction data is in focus (shift 10), the contents up to that point are maintained in both storage circuits.

The comparison circuit (50) compares the contents of the first and second storage circuits, provides an output according to the comparison result to the correction circuit, and controls its operation. That is, when the contents of both storage circuits are equal, that is, when there is no change in the drive direction of the drive motor < MO, the correction circuit (44) uses the multiplication circuit (40
), and when the contents of both memory circuits are different, that is, when the driving direction of the drive motor (MO) is reversed, the correction circuit applies the output data from the multiplication circuit (40) to the reading circuit ( Data N' (=N+BLD) including backlash correction amount data BLD from LEB) is output.

(MO) is a drive motor for focus adjustment, and its driving force is transmitted through the slip mechanism (54) and the camera side transmission mechanism (5G
), camera side connecting member (5B), lens side connecting member (1
4) and the lens side transmission +14114 (12) to the focusing optical system. Slip II ffj (54
), for example, when a large load is applied to the transmission mechanism, such as when the focusing & optical system is stopped at the infinity focusing position or the closest distance focusing position, the load is applied to the drive motor (
This is to prevent slippage from reaching the MO), and it is designed to slip if a load above a certain level is applied to the output side. An encoder is applied to a suitable part of the camera-side transmission mechanism (56) at a later stage (output side) than the slip mechanism (54), that is, a part that has a primary relationship with the movement of the focusing optical system. (ENC) is connected, and the encoder outputs a number of pulses according to the amount of movement of the focusing optical system. Here, each output of the multiplication circuit (40) and the correction circuit (44) is designed to be data of the same unit or dimension as the output of the encoder (ENC), and the event counter (52) is configured to output data of the same unit or dimension as the output of the encoder (ENC). 4
The output of 4) is sent to the cell. The motor drive circuit (M
DR) drives the drive motor (MO>, the encoder (ENC) outputs pulses according to its rotation, and the event counter (52) inputs preset data to the pulse input from the encoder (ENC). When the content thereof becomes zero, a motor stop signal is given to the motor drive circuit (MDR) via the signal path (53) to stop the drive motor (MO).

Figures 2 and 3 show the camera and lens side transmission mechanism (56
) (12) shows a specific example of a connecting mechanism that connects. The lens-side connecting member is formed on the contact surface (16) at the rear end of the photographic lens barrel and faces the connecting hole. The camera side connection part +4 (58) is connected to the drive shaft (6) of the camera body.
2) and acts on the linking lever (64), the bayonet seat plate (68)
It is biased so that it protrudes from. Photography lens (10
) is attached to the camera body (20) using a bayonet mount, and when it is attached, the contact surface (16) of the photographic lens is first aligned with the mount seat 4f of the camera body.
fi (68), the camera-side connecting member (58) and the positioning pin (70) are retracted against the coil spring (66), and then the photographing lens (10) is brought into contact with the camera body (20).
), the camera-side connecting member (58) faces the connecting hole on the contact surface of the photographic lens, the positioning pin (70) faces the positioning hole (72), and the coil springs (66) fits into those holes by the urging force of (66), and the camera side connecting part IJ (58) is removed from the lens side connecting part (66).
14). Note that the two connecting members (58) and (14) may not mesh well depending on their relative angle relationship, but the camera side connecting member (58) is connected to the gear (7).
4) (76), driven via a drive shaft (62);
By at most half a rotation, the two connecting members are in a positional relationship in which they engage with each other.゛Here, as shown in FIGS. 3(A) and 3(B), it is necessary to provide an adjustment (α) in the meshing part of this connecting member so that the connection between the two can be performed smoothly, and this adjustment (α) The amount of backlash caused by
This is the main cause of backlash in the transmission system from the drive motor (MO) to the focusing optical system.

FIG. 4 is a circuit diagram showing an entire camera system using an electronic flash device to which the present invention is applied, and in this figure, thick lines indicate multi-bit signal lines. Light reception m (
FMD) t, tccD (Ct+aroeQ up
The photodetector includes two light-receiving section rows, each of which receives visible light including near-infrared light from the subject light from the exit pupil of the photographic lens. Note that various optical systems and the like for the light receiving section have been proposed, so they are omitted. (COC) is this light receiving port/computer (hereinafter referred to as a microcomputer). First, the photometry operation by the circuit portion described above will be explained.

The terminal (03) of the microcomputer (MGO1) is Ht o hI
When it becomes I, a pulse of PATO + igi 11 is output from the terminal (φ1<) of the control circuit (COC), the analog switch (As 2) becomes conductive, and multiple signals of the COD (FMD) are connected via the terminal (ANM). The charge storage section is connected to a constant voltage source (E
The battery is charged to the output voltage of l). Then, when the terminal (φR) becomes "LOW", charges corresponding to the light reception Φ of each light receiving section are accumulated in the charge storage section. At this time, the light receiving section (F
A signal corresponding to the accumulated charge by the monitor photoreceptor (not shown) in the CCD of the MD is output from the terminal (ANM). At this time, the terminal (φR) is "LOW", so the analog switch ( As 1) is conducting,
The output from the monitor light receiving section is the comparator (AC1)
is applied to the inverting input terminal of As charge accumulates, the output voltage gradually decreases. At this time, if the mode is not to emit flash, the terminal (01) is “
When the analog switch (As3) becomes conductive and the output voltage of the constant voltage source (E2) becomes LOW, the output voltage of the constant voltage source (E2) becomes LOW.If the mode is for flash emission, the terminal (01) becomes ``I''ig.
At tl'', the analog switch (As4) becomes conductive and the output voltage of the constant voltage source (E3) is applied to the non-inverting terminal of the comparator (AC1).

Monitor output from terminal (ANM) is constant voltage source (E2)
Or when the level of (E3) is reached, the comparator (AC1
) output (STP 1) is “” l-l right −”
, and a transfer pulse is output from the terminal (φd) of the control circuit (COC). By this pulse, the accumulated charge in the charge storage section corresponding to the amount of light received in each light receiving section is transferred to the transfer gate, and the transfer pulses (φ1), (φ2),
(φ3), the accumulated charge signal is sequentially transmitted to the terminal (ANS
> is sent to the control circuit (COC). Control circuit (CO
In C), the signals sent from the terminal (ANS) are sequentially A
-D conversion, and outputs a pulse to the terminal (ADE>) every time one AD conversion is completed, and outputs the A-D converted data to the output terminal (ADD).

Also, even if a certain period of time has elapsed since charge accumulation started, the terminal (
When the transfer pulse is not output from the terminal (φT), the brightness of the object is low. In this case, the pulse is output from the terminal (02). When this pulse is input, the control circuit (COC) outputs the signal from the comparator (AC1). ) outputs a transfer pulse (φ1°) regardless of the output.

When performing preliminary irradiation with an electronic flash device, connect the terminal <01
) becomes ′= Hi, hI), and the comparator (AC1
The voltage from the constant voltage source (E3) is input to the non-inverting terminal of >. The output potential of this constant voltage source (E3) is the constant voltage source (E3).
It is higher than the output potential of 2). Therefore, the transfer pulse (φT) is output at a time when the charge accumulation h1 by the monitor part is smaller than that in the case where preliminary irradiation is not performed. This is because when performing preliminary irradiation with flash light, the intensity of the flash light changes rapidly, and the charge storage section overflows due to circuit response delays, making it impossible to measure the light intensity distribution correctly. This is to prevent it from being put away.

Terminal (03) to start charge accumulation as described above.
becomes “'l-1-1i”, the one-shot circuit (O
81), the pulse is output through the AND circuit (AN 1), and the terminals (JBl) and (J
FI) is sent to an electronic flash device (FLC) as a light emission start signal. Transfer pulse (φ
1-) is not output, output a pulse from terminal (02) (forcibly output a transfer pulse and stop the charge accumulation operation. By the way, preliminary irradiation is performed for a certain period of time to limit the accumulation time. The time is shorter than when no flash is used.This is because the electronic flash device has a short light emission time and there is no need to keep the integration time long.

When the microcomputer (MCO2) reads data from the electronic flash device, this data includes a signal indicating whether preliminary irradiation is possible. Therefore, microcomputer (MCO)
2), when a signal indicating that preliminary irradiation is possible is input, the terminal (
016) to "14 igh". Microcomputer (M
CO1) determines that if the terminal (12) is "'l-1iUh", it is possible to operate in the pre-irradiation mode, and if it is "'LOW", it is possible to operate in the pre-irradiation mode. Determine that it is impossible.

(MDR) is a circuit that drives the focus adjustment motor (MO), and when the focus detection result is the front bin and it is necessary to retract the lens, the terminal (04) is the final bin and the lens is retracted. When it is necessary to feed out the terminal (05)
l-1;gh''.

The rotation of the motor (MO) is transmitted to the lens side (LE) via the lens drive section (LD), and the focus of the lens is adjusted. Further, the drive amount of the lens drive unit (LD) is converted into a pulse signal by an encoder (ENC), and this pulse signal is input to a clock input terminal (CPI) of a microcomputer (MCOL) to count the drive amount. Also,
Pulses from the encoder (ENC) are input to the motor drive circuit (MDR) and are used as reference signals for driving the motor (MO) so that the lens drive speed is constant.

(FDP)” is a display section that displays the focus adjustment state,
Depending on the data from the output terminal (OP1) of the microcomputer, the front bin status, in-focus status, rear bin status, and focus adjustment failure warning are displayed.

The switch (SMB) shown in the upper right corner of the figure is the main switch, and (BB> is the power battery. From this power battery (BB), the main switch (SMB) and the power line (+F) are connected. Microcontroller (MCO1), (M
CO2,) is directly supplied with electricity. Switch (SL)
is a photometry switch that is closed when the release button (not shown) is pressed in the first step, and when this switch (Sl) is opened, the light is transmitted through the inverter (IN3), AND circuit (AN3), and OR circuit (OR4). An interrupt signal is input to the interrupt terminal (it) of the microcontroller (MCO2), and the microcontroller (MCO2)
2), the terminal (012) is set to "+-++oM', the transistor (BT1) is made conductive via the inverter (IN6), and the inverter (I
N3) ~ (IN6), AND circuit (AN 2), (AN
3), OR circuit (OR4), microcomputer (MCO1), (
Start supplying power to circuits other than MCO2). Based on this start of power supply, the power-on reset circuit (PO1
), a reset pulse is output from the power supply line (10■)
The circuit that is powered by the power source is reset. Also, the terminal (0
12) becomes "l-1ight", the AND circuit (AN3> becomes disabled, AN2) becomes active, and no interrupt signal from the switch (Sl) is input.

The switch (S2) is a release switch that is opened at the second step of pressing the release button, and (S4) is a release switch that is opened at the second step when the release button is pressed.
It will be released when the drawing of the rabbit is completed, and the exposure system T11 drawing (
(not shown) is opened when charging is completed.
It's a switch. Therefore, when the exposure control mechanism is fully charged and the release switch (S2) is closed with the reset switch (S4) open, the AND circuit (A
An interrupt signal is input to the terminal (it) via the OR circuit <0R4).

(EDO) is a block that outputs set exposure control data, and the setting data is sequentially read through the terminal (IPlo) based on a read signal from the terminal (OP 13). (LMC) is a photometric circuit, and the output of the photometric circuit (LMC) is input to an analog input terminal (ANI) for AD conversion. Also, as a reference voltage for the D-A converter of the microcomputer (MCO2), the reference voltage in the photometry circuit (LMC) is input to the terminal (VRI>.(EXD) is a display circuit that displays the exposure control I value. displays the exposure control value (i.e., the aperture value, shutter speed value, or a combination thereof to be controlled) based on the display data from the terminal (CPI4). (EXC) is an exposure control circuit;
15) The aperture and exposure time are controlled based on the signals from 15). In addition, the terminal (TIE) of the exposure control circuit (EXC) is set to 11 and 11'' from the time of shutter release until a certain period of time has elapsed after the trailing curtain starts running, and is used as an integral for controlling the amount of flash light emitted during shooting. Enable operation.

(LEB) is a circuit for reading data from the lens side circuit (LEC). As mentioned above, the transistor (B
When TI) becomes conductive, the terminal (J
BII), LJL 1) to the lens side circuit (LE
G) is supplied with power. And microcomputer (MCO)
When the terminal (015) of 2) becomes "l-1iOh", the circuit (LEB) becomes operational, and furthermore, the terminal (JB
12) , ('JL 2) becomes "High", and the lens side circuit (LEC) also becomes operable. In the lens side circuit (LEC), there is a ROM that fixedly stores data for exposure control and autofocus vA adjustment specific to this interchangeable lens at multiple addresses, and the addresses of this ROM are connected to terminals LIB13) and (JL3). ), if it is a zoom lens, the clock pulses are outputted in parallel from the ROM to an address specifying means that sequentially specifies the address of the ROM based on the output of the code plate according to the set focal length. Parallel-to-serial conversion means for sequentially outputting data one pit at a time via terminals (JL4'>, (JB14)) based on clock pulses input via terminals (JB13), (JL3); It is equipped with

The data fixedly stored in the ROM includes check data for confirming lens attachment, which is common to all interchangeable lenses, aperture value data, maximum aperture value data, and aperture metering error. data, focal length data, data on aperture change m according to the set focal length of a zoom lens, etc. Furthermore, a conversion coefficient (KD>) is used to convert the amount of defocus detected by the focus detection device into the amount of lens drive. In order to correct the difference in focus position between near-infrared light and visible light, that is, the difference in defocus M, when performing focus detection by irradiating near-infrared light (in other words, Data (IRQ) that compensates for the amount of defocus caused by light, when the driving direction of the lens is changed from one direction to the other, the fitting play between the driving shaft on the camera side and the driven shaft on the lens side. When the drive shaft needs to be driven extra by
LD) etc.

Eight clock pulses are output from the terminal (SCP) of the microcomputer (M-CO2), and the circuit on the lens side (L
IEC), every time 8 clock pulses are input,
The address of the ROM is updated, and the data fixedly stored at the specified address is output in series based on the vine pulse, and read out from the serial input/output terminal (SIO) of the microcontroller (MCO2) in sequence. go.

(FLB) is an electronic flash device control circuit, (FLC)
is a circuit in an electronic flash device to which this invention is applied. A specific example of the circuit (FLC) in the electronic flash device is shown in FIG. 5, and the operation of using the electronic flash device will be described below in conjunction with FIG. In FIG. 5, (BF) is a power supply battery for the electronic flash device, and (SMF') is a main switch.

(DD) is a booster circuit, and the high voltage terminal on the secondary winding side of the booster circuit (DD) is connected to the main capacitor (C2) via a diode (Dl), and the voltage from the high voltage terminal is applied to the main capacitor (C2). C2) is charged. In addition, the low voltage terminal of the secondary winding is connected to the capacitor (cl) via the diode (D2), and the output voltage is connected to the capacitor (Cl).
) is charged. When the main switch (SMF) is closed, the transistors (BT2) and (BT3) become conductive, and the boosted output from the voltage stabilization circuit (GV) or the power supply battery (BF) via the diode (D3) is activated. The output is fed to the power supply line (VF) via the transistor (BT3). Power is supplied from this power supply line (VF) to all circuits whose power supply paths are not shown in FIG. When power supply via the power supply line (VF) starts, a reset signal is output from the power-on reseller 1 to circuit (PO2), and the digital circuit unit reset operation is performed. The switch (SOF) is a switch that is opened and closed in the same phase in conjunction with the main switch (SMF). Resistors (R1) to (R4) are resistors that divide the charging voltage of the main capacitor (C2), and (VC) is a constant voltage source. The potential at the connection point of resistors (R1) and (R2) is set by a constant voltage source (
When the potential exceeds the potential of the xenon tube (VC), the output of the comparator (AC21) becomes “I Hi, l, II.
The capacitor (C2) is charged to the minimum voltage required for XE 1) to emit light, and when light emission start No. 18 is input, xenon I (XE2) starts emitting light.

The potential at the connection point of resistors (R2) and (R3) is constant voltage source (V
C), the comparator (AC22
) becomes "I-1ight". in this case,
The voltage of the main capacitor (C2) has been charged to the voltage required for the amount of light emitted by the xenon @ (XE 2) to reach the nominal light emission m, and a charging completion signal is sent to the camera body and the display circuit ( CDP) displays the completion of charging.

The potential at the connection point of resistors (R3) and (R4) is constant voltage source (V
When the output potential of C) is exceeded, the comparator (AC23)
The output becomes "'t11g1ll. At this time, the xenon tube for photography (XE 2) emits light by the nominal value, and the xenon tube for preliminary illumination (XE 1) emits light by the predetermined amount.
Main capacitor (C2) up to the value required to emit light twice.
This signal is sent to the camera as a preliminary irradiation enable signal. Note that the switch (ss) is a switch that can be changed manually, and this switch (8
8) is sent to the camera side, but if it is connected to the terminal (DEN), the input to the terminal (PCI-1> is always "
LOW”, 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 (
Since the output of OR20) remains 'LOW', no light is emitted.

(TR1) and (TR2) are Kihinon tubes (XE 1
), (XE 2) (7) l-IJ car and trigger circuit that conducts the Hisairisk (SC1) and (SC2), (ST1) and (ST'2) are each connected to a thyristor (S
Xenon tube (XE
1) This is a stop circuit that stops the light emission of (XE 2). In addition, the xenon tube (XE 1) is for preliminary irradiation, and the light emission position of this xenon tube (XE 1) is equipped with a filter that transmits near infrared light and cuts visible light with a shorter wavelength than near infrared light. ('FLT) is installed so that the subject does not feel dazzled when performing preliminary irradiation.

In Figure 4, the terminal (013) of the microcomputer (MCO2)
When the value becomes ")-light", data can be exchanged between the camera and the electronic flash device. Then, 50μsec I1 from the terminal (014) of the microcomputer (MCO2)
When pulse 3 is output, terminal LJB 2), L
This pulse is an electronic flash via JF 2)! ! i1δ. With this pulse, mode discrimination port 1 (,
EMS) determines that the mode is to transfer data from the electronic flash device to the camera and connects the terminal (D OM> to “).
li (lh”).Then, the data output circuit in Figure 5 (
DOtJ) becomes operational. And the microcomputer (
When a clock pulse is output from the clock pulse output terminal (SOP) of MCO2>, this O-clock pulse is outputted to the terminal (SCP) of the data output circuit (DOLJ) in FIG. 5 via the terminals LIB2) and (JF2). ), and based on this clock pulse, a power supply signal indicating that power is being supplied to the electronic flash device, and a power supply signal to the terminal (PCH) indicating that the electronic flash device is ready for preliminary irradiation. A signal, a charge completion signal to the terminal (CHC), and a signal to the terminal (FDC) indicating whether the dimming operation has been performed are sequentially output from the terminal (Sou), and the terminal (JF3).

(JB3) and is sent to the camera side. Other data to be sent includes, for example, the maximum and minimum light output data of the electronic flash device, the aperture value set on the electronic flash device,
There is data indicating the bounce status, whether multiple flashes are used, etc. When the data transfer is completed, the terminal (“2
), a pulse is output from C through the OR circuit (OR12)
The mode discrimination circuit (F'MS) is in the initial state and the terminal (1) OM) becomes "LOW'".

Next, when a pulse with a width of 100 μsec is output from the terminal (014), the mode discrimination circuit (FMS) selects the terminal (DIM
) to "l-1i0h". Then, the data puff 3 circuit (CDIN) becomes active. The microcomputer (MCO2) in the camera body outputs a clock pulse from the terminal (SCP), and also outputs the aperture value for flash photography, exposure time, film sensitivity, shooting distance l1f1 from the terminal (310) based on the Otsuk pulse. Output data such as. This data is read into the data input circuit (DIN>) via the terminals (JB3>, (JF3). Then, a display based on the read data is displayed on the display circuit (DSP).

When starting the exposure control operation, use the microcomputer (MCO2)
A pulse with a width of 150 μSec is output from the terminal (014). Then, the mode discrimination circuit (FM'S) selects the terminal (FL
M) to "')l 1jllll".

This causes the light emission control circuit (FLC) to become active and perform light emission control. When the front curtain of the camera's focal plane shutter completes travel and the X contact (SX) is closed, the terminal LJB4) is closed.

A light emission start signal is input from (JF4) to the terminal (STA), and a light emission start signal is output from the terminal (α1). Also, at the same time as this, the terminal (C3) is “from Highll = c
This signal is inverted to o w 1' and is sent to the terminal (JF3),
(JB3) and is sent to the camera side. On the camera side, when the terminal 11B3) becomes “LOW”, the circuit (FLB
) integrates the amount of light that is reflected from the subject illuminated by the flash light and passes through the aperture of the photographic lens (not shown), and the integrated amount is output to the analog output terminal (ANO). ), a pulse for stopping light emission is output to the terminal (JB2). This pulse is sent to the terminal (S T P ) of the light emission control circuit (FLC) via the terminal (Jl=2).
is input. When this happens, a light emission stop signal is output from the terminal (C2), and the light emission of xenon@(XE2) is stopped. The light emission stop signal from the terminal (C2) is also sent to the display circuit (FDP>), and when the exposure control operation is completed,
The contact (SX) is opened, but based on this signal, the terminal (IN) becomes “HilJ” for a certain period of time after the X contact (SX) is opened.
ll'', and during this time it is displayed that the dimming operation has been performed.Furthermore, this signal is sent to the data output circuit (DOU').
It is also sent to the 7J Mera side via. In addition, the X contact (SX
) is opened, a pulse is output from the terminal (r3),
The mode discrimination circuit (FMS) is connected via the OR circuit (OR12).
) is reset and the terminal (FLM) becomes "LOW".

Preliminary ((＾In the irradiation mode, the terminal (01) of the microcomputer (MCO1) is in the state of “l Fly igh-1” and the terminal (
03) from "to start j" l-1ight
''' signal is output, the one-shot circuit (O8
A pulse is output from 1) and this pulse is sent to the AND circuit (
Output from AN 1>. This pulse is applied to the terminal (JB
1), the AND circuit (A
N20). At this time, the Q output of the D flip-flop (DF21) becomes ')high,' the output of the comparator (AC23) becomes 'Higb,' and the output of the OR circuit (OR20) becomes 'H+g+.
1°', the pulse input to the AND circuit (AN20>) is output from the AND circuit (AN20). This pulse is sent to the trigger circuit (TR1) and the xenon tube (
Preliminary irradiation with XE 1) begins. And the pulse from the AND circuit (AN20) is the flip-flop (RF
20), the reset state of the counter (Go 6) is released and the counter (COO) starts counting.

Then, when a certain period of time has elapsed after the start of counting, the terminal (fl) of the decoder (DE6> becomes High I+ and a pulse is output from the one-shot circuit (O822). This pulse is sent to the light emission stop circuit (ST1). is sent to stop the preliminary irradiation of the xenon tube (XE 1). Also, when the terminal (fl) becomes ")light'", the flip 70 tube (RF20) is reset via the OR circuit (OR22). , the counter (COO) goes into a reset state, and the terminal (fl) becomes ``LOW''. In addition, the output pulse of the AND circuit (AN 20) is sent to the clock pulse input terminal of the D flip-flop (DF20), the output of "*-+igh I" of the comparator (AC3) is latched, and the output pulse of the D flip-flop 7U block is latched. (DF20) Q
The output becomes Hi o hII.

When the second pulse is output from the AND circuit (AN20), even if the charging voltage of the main capacitor (C2) decreases and the output of the comparator (AC3) becomes "'LOW," the -th light emission will occur. At this point, the D flip-flop (
Since the Q output of D F 20) is "C-1ipH", the output of the OR circuit (OR20) is "@igl+"
A pulse is output from the second circuit (AN20).The pulse causes the same light emitting operation as described above.Also, this pulse causes the Q output of the D flip-flop (DF21) to be output. l-l
1 (111”).Then the one-shot circuit (OS
A pulse is output from 20), and at the fall of this pulse, a pulse is output from the one-shot circuit (0821), and the D flip-flops (DF20) and (DF21) are reset to return to the initial state.

FIG. 6 is a flowchart 1 to 1 showing the operation of the microcomputer (MCO2) in FIG. 4. The operation of the system shown in FIG. 4 will be explained below based on this flowchart. When the photometry switch (Sl) is closed and an interrupt signal is input to the terminal (i[), the microcomputer (MCO2) starts operating. First, it is determined whether the flag LMF is "1". This flag Lm
F is 1'' if the exposure control data has been calculated, but when the metering switch (Sl) is closed and the interrupt signal is input, the calculation has not been performed yet. The flag LMF is '0'' and the process moves to step S2. In step S2, connect the terminal (012) to ')lig
h”, the transistor (B-1-1> is turned on and power supply is started via the power supply line (+■).Next, serial input/output operation is performed multiple times to connect multiple lines from the lens circuit (LEC). After importing the data, the conversion coefficient (KD) necessary for automatic focus adjustment is sent to the terminal (OP 10), and the data for correction of the focusing position of near-infrared light and visible light (Ir<o> is sent to the terminal (OPll), backlash data (BLD) is output to the terminal (OR14), and the input terminals (IP2), (IP3),
Send to (IP 4). Then, set the output terminal (010) to ``to1high''.This signal is sent to the microcomputer (MCO1).
The microcomputer (MCO1) starts operating when this signal is output.

In step S8, a block (ED
data from the electronic flash device is taken in in series by performing a serial input/output operation.

If a signal that enables preliminary irradiation is input, the terminal (
01G) to "")-1igb°', and if it has not been input, change it to OW°'. Next, the photometric circuit (ILM)
A-to-D conversion is performed on the photometric output from C). With the above, all the data necessary for exposure calculations has been imported.

Next, exposure calculations for ambient light photography and flash light photography are performed, and the flag LMF is set to "1°" to enable interrupts.In step 315, serial input/output operations are performed to send data to the electronic flash device. In step 816, it is determined whether or not a power supply signal has been read from the electronic flash device, and if the power supply signal has been read, data for flash light photography is displayed, and if not, data for ambient light photography is displayed on the display. (EXD) - (Proceeds to step 827. Then, in step 827, it is determined whether the terminal (i12) is set to "Htgh" with the photometry switch (Sl) left open, and it is determined that the terminal (i12) is set to "H+gll". If so, return to step S3 and repeat the same operation as described above.Meanwhile, in step 327, the terminal (i12) is set to "LOW".
If it is determined that the
Stop the automatic focus wJ adjustment operation as "LOW", set the flag and MF to "0", and set the terminal (012) as "LOW"
”, the transistor ([3-r 1) is made non-conductive and the power supply from the power line (→-■) is stopped, and the display section (
EXD) disappears and the microcomputer (MCO2) stops operating.

When an interrupt signal is input with the exposure control data calculated, the process moves to step 320 and the terminal (010) is connected.
LOW” to stop the automatic focus adjustment operation.

Then, it is determined whether or not a power supply signal is input from the electronic flash device. The data is sent to the exposure control unit (EXC).Next, in step 324, it is determined whether the automatic focus adjustment operation has completely stopped and the terminal (ill) has become LOW. If not, 10%
It has become vII. This is to prevent the exposure control operation from starting while the photographing lens is moving.

m child < ill ) When the power becomes “Low”, it will be exposed.
Exposure control operation is performed by the control circuit ([EXC),
The microcomputer (MCO2) waits until the exposure control 11 operation is completed, the reset switch (S4) is opened, and the terminal (ilO) becomes "LOW".
When it becomes "l-OW", it is determined in step 827 whether the photometry switch (Sl) is open, and if it is open, the process moves to step S3 (previous), data is fetched, and the display/display operation is performed. Repeat, press the photometry switch (Sl)
) is not closed, the process moves to step 328 described above and the 10 microcontrollers (MCO2
) will stop working.

7-1 to 7-3 are flowcharts showing the operation for automatic focus adjustment by the microcomputer (MCO1). Below, based on Figures 7-1 to 7-3, the construction of the circuit in Figure 4 is explained.
#The operation for J quasi-point adjustment will be explained. Microcomputer (MC)
When the terminal <o io> of O2) becomes "g1iIJh" to start the automatic focus adjustment operation, an interrupt signal is input to the terminal (it2), and the operation of the microcomputer (MCO1) becomes &f
l start. First, in step #1, the terminal (07) is set to ')li(lh) in order to transmit to the microcomputer (MCO2) that the automatic focus adjustment operation is being performed.
The terminal (03) is set to “1-1-1i” and the control circuit (CO
C>, the charge accumulation operation by COD of the light receiving section (FMD) is started.

In step #3, the contents of a counter COR that counts an external or internal clock in the microcomputer (MCO1) are set in a register ECR1.

As will be described later, this data is necessary for calculating the amount of movement of the lens during focus detection in order to perform focus detection while moving the photographic lens, and is not necessary during the first measurement. In addition, counter C0R1 register EC
R is inside the microcomputer (MCO1), and in the following explanation, counters, registers, etc. that are not marked in parentheses are inside the microcomputer.In step #4, interrupts are possible. As such, move on to step #5.#
In step 5, it is determined whether the flag FLF is 441 II. This flag is set to "1°' when preliminary flash illumination is performed, and J:
When all J determination is performed, it is 110 II. During the first measurement, preliminary irradiation is not always performed and the flag FLF is set to "Q11" and #
Move to step 6.

In step #6, a fixed value Ka is set in the timer register TIR1. Next, register ECR4 has counter C.
The contents of the OR are set, and a fixed value of 1 is set in the timer register TlR2.

Then, 1'' is subtracted from the contents of the timer register TIR2, and the operation of determining whether the contents of the register TIR2 is 0'' is repeated and waits for a certain period of time. After a certain period of time has elapsed, in step #11 it is determined whether or not the heka terminal (i3) is "LOW", and if it is "LOW", the microcomputer (MCO2) is activated as described above. Since a signal to stop the automatic focus adjustment operation is input from , the operation to stop the automatic focus adjustment operation starting from step #210 is performed. On the other hand, if the terminal (i3) is "I-I igb", it is determined in step #12 whether the flag FPF is P1'''. ) is stopped, it is 111 II -). Therefore, if the flag FPF is 1pa and the motor (MO) is stopped, steps #12 to #15
Move on to step #6, and fix it in step #6 (subtract °゛1'' from the register TIRI where direct Ka is set,
Determine whether the content of TIR1 has become II OII, and if it is not 0'', return to step #7 and repeat the same operation.
The output of the comparator (ACl) in the figure is 'l-I 1g
11”, the control circuit (COC) terminal (φT
) outputs a transfer pulse, and this pulse is output from the interrupt terminal (
ill) and the microcomputer (MCO1) starts operation from step #25. Additionally, if it is determined in step #16 that the contents of register TIR1 have become O'', a pulse is output to the terminal (02) in step #21 to forcibly stop the accumulation operation as described above. The u1 flag TOF is set to '1'', the operation is completed, and the terminal (itl
) waits for an interrupt signal. After starting the accumulation operation in step #2, register T is stored in step #16.
The time until it is determined that the content of IR-1 is OII is 1 or more at a certain time, and the accumulation time is not made longer than this.

Flag F is set when the motor (MO) is being driven.
PI= is 00', and the process moves from step #12 to step #13. In step #13, the contents of counter COR are set in register ECR'5.
Then, in step #14, the contents of register ECR4, where the contents of counter COR were set in step #7, are compared with the contents of this register ECR5. #7
A certain amount of time has passed between step #13 and
If the lens does not move during this time, the encoder (ENC)
) is not inputting zero pulse (ECR4)
= (ECR5). Therefore, the motor (M
Even if O> is being driven, the lens has reached the end position (infinity position or R-near position) and is no longer moving. In this case, the flag LSF (low contrast 1- last signal indicating that the contrast of the subject image is low is output during normal focusing operation, and when scanning a lens position that is not low contrast l- is “1”), and if it is “1”, it is 1.
1-Fun 1 to Last scanning is in progress and the process moves to step #158; if it is LIOII, normal focusing operation is in progress and the process moves to step #63. □ If the 7-lag FLF is 1'' in step #5, it is the mode for preliminary flash light irradiation, and the process moves to step #17. At this time, set the fixed value Kf in register TIR1 and register Subtract “1” from TIR1, determine whether the terminal (13) is “OW”, and
')light", it is determined whether the contents of TIRI are "pa0".

If it is not 0'', the operation returns to step #18 and is repeated, and when the content of TIR1 becomes 0'' in step #20, the process moves to step #21 and the above-described operation is performed. During this pre-illumination tIJ'fX- mode, the limit on the storage time is much shorter than in the constant light mode. This is configured as J: for the following reasons. Light in the near-infrared region is used for the preliminary illumination light so that the human subject will not feel dazzled. On the other hand, when preliminary irradiation is not performed, measurement is performed using constant light, which is generally white light. Therefore, when measuring a mixture of both lights, it becomes impossible to correct the influence of chromatic aberration on the amount of defocus unless the mixing ratio is known.

Therefore, in the preliminary illumination mode, in order to prevent the steady light component from being measured as much as possible, the maximum accumulation time is set to be approximately equal to the flash emission time, allowing accurate chromatic aberration correction. . Mlc1 preview @
In the irradiation mode, the motor (MO) is not driven during measurement, so the lens reaches the end and 1. : Termination detection operation is not performed.

When a transfer pulse is output from the terminal (φT) of the control circuit (C'OC) and an interrupt signal is input to the terminal (itl),
The operation starts from step 25.

In step #25, interrupts are enabled and the terminal (03) is connected to J.
Set to L 0WI- and take in the contents of counter COR to register ECR2. Tore is data for correcting errors caused by lens movement when the lens is moved during measurement. Next, data obtained by A-D converting the amount of light received by each light-receiving section output from the control circuit (COC) is sequentially fetched, and when the A-D conversion data corresponding to all the light-receiving sections is fetched, #2
Move to step 9. In step #29, it is determined whether the flag FLF is "1°", and if it is not "1'°, it is determined whether the flag TOF is 1".Flag TO
F is #2 when the accumulation time reaches the limited time
It becomes "1" in step 2. Therefore, FLF is “0”
When the TOF is II II, it means that the brightness is low in the constant light mode, and the flag LLF is set to "1" in step #31. Otherwise, the flag LL is set to "1" in step #32.
F is set to 0'', and in #33, the flag TOF is set to '0''. In #34, the degree of correlation between the two rows of light receiving sections is calculated based on the output from the light receiving section (1=MD), and the defocus amount and defocus direction are calculated from this degree of correlation. This implementation may be implemented, for example, as proposed in US Pat. No. 1,133,007. This calculated defocus amount is ILDI, and when LD>0, the front bin is used, and when LD<0, the rear bin is used.

In step #35, it is determined whether the flag FLF is "Pa1" or not, and if FLF is "0" and the measurement is performed using steady light (visible light), the calculated data LD is directly used as the correct value LDt. , if FLF is ``'1pa, it is the preliminary irradiation mode, and at this time, measurement is being performed with near-infrared light, so the focus position of visible light and the focus position of near-infrared light are In order to correct by which difference, i.e., IRD, LD-IRD
Calculate this value to determine the correct defocus amount LD.
Let it be t. The data IRD uses the data sent from the lens as is, but for example, the lens stores correction data for a specific wavelength, and sets the data of the wavelength of the preliminary irradiation light source to 14 for this wavelength. corresponding to lζ
The correction data may be converted into data, and the defocus amount may be corrected using the modified correction data.

In #38, it is determined whether the terminal (i3) is "low", and if it is "low", the process moves to step #210 as described above. On the other hand, terminal (i3) is +-+ 111 degrees.

If so, next, it is determined whether the measurement data indicates loaf l-last. This low contrast determination is performed by calculating the sum of the absolute values of the output differences between adjacent light receiving parts in each light receiving part of the light receiving element array, and when this sum is less than a predetermined value, low contrast I/Rath 1 is determined. Just shift it. In addition, since the defocus m is calculated by comparing the light distribution states of the two light receiving element rows when changing from low contrast 1 to last 1, the calculated defocus amount has poor reliability. Therefore, when low contrast is determined, the process moves to step #110 and the low contrast 1-last operation is performed.

If it is determined in step #39 that it is not low contrast 1, a flag is flagged in step #40 and CF 1 is set to low contrast 1.
”.Then, the flag LCFI is “1”.
”, the previous measurement value is low contrast, and then in step #41 it is determined whether the flag F' L F is "1". Then, if the flag FLF is 1111+
In this case, since preliminary irradiation with a flash was performed in the current measurement, the operation from step #17o is performed. On the other hand, if the flag FLF is "0", the previous measurement was low contrast] and the current measurement had sufficient contrast even without preliminary irradiation. At this time, 75ri LCF 1.1cF 2. S'E, F 1゜SEP 2.1SF to "O",! :L, TIF
It is determined whether or not it is "at 1", and if it is not at 1 ++, the same operation as #5o is performed. In this case, the measured value is low-contrast, and while the lens is being moved until a measured value that is not low-contrast is obtained (hereinafter referred to as low-contrast mode), the 0-
This is a case where a measured value other than contrast is obtained, and in this case, the operation shifts to the operation of moving the lens based on the defocus amount from step #5o. Also, #43
If the flag TIF is "1'' in the step, the lens is scanned over the entire area in low contrast scan mode, and if no measurement value that is not low contrast is obtained during this period, the lens is stopped for a certain period of time and the measurement is performed. is repeated (hereinafter referred to as low control stop mode).In this case, the counter COR is in the seventh mode (timer mode) that clocks the internal clock of the mine T1 (MCO1). Event count mode (clock pulse from encoder (ENC) is clocked 1-"tJ
mode) and set the flag FPF to "1",
TIF is set to "0" and the process moves to step #50, then steps 4j from #5(), and the same operation as in the case where the first measured value is not low contrast i- is performed.

When the 7-lag LCF 1 is 0'' in step #40, or when the flag -1'IF is 0'' in step #43, or from step #46, #50
Move to the next step. In step #50, the defocus amount LDt is multiplied by the conversion coefficient KO to calculate the lens movement mN.
Calculate D. Next, l-11) is data in a range that can be considered to be in focus, and is multiplied by a conversion coefficient KD to calculate the movement mIFD of the lens in the in-focus area. In step #52, it is determined whether the flag FPF is 11111 or not.
If the motor (MO) is 1", it moves to step #75; if it is "O", it moves to step #53. Therefore, if the motor (MO) is driven, it moves to step #53; if the motor (MO) is not driven, it moves to step #53. Move to step #75.

In step #53, the register EC which has taken in the contents of the counter COR at the start of the charge accumulation reconnaissance of the light receiving unit (FMD)
Retrieve R1 and the contents of counter COR at the end of accumulation.
By calculating the difference τ between υ and the register ECR2, the amount of movement τ of the lens during charge accumulation is calculated. Then, the content of the counter COR at this point is set in the register ECR3, and the amount of movement of the lens during defocusing is calculated based on Xt between the registers ECR2 and EC:R3. Then, assuming that the calculated defocus m is a value based on the measured value at the middle of the lens movement during the accumulation time, from the time when the calculated lens movement fftND was measured, τ/2 + (
Therefore, in step #56, the amount of movement is corrected by calculating INDI-(τ/2÷t)-=NDC. In step #57, this corrected movement data INI)cl of 8 m is compared with the data IFD of the focus area, and if INDcl<IFD, it has entered the focus area, and the process proceeds to step #58. Shift and connect terminals (04) and (05) to 'I L, 'o
%vII C motor (MO) is stopped and flag I
Set FF, FP, and F to 1111+, return to step #2, and perform measurement for confirmation.

#5Tty) When it is determined that 1NDe l>IFD in step #61, the contents of counter COR are set in register ECR3, and the contents of counter COR are set at step #27. Compare the contents of register ECR2.

When it is determined that (ECR2) = (ECR3), the lens has reached the end, and #6
In step 3, connect terminals (04) and (05) to "LO"
W” to stop the rotation of the motor (MO>), set the flags ENF and FPF to “1”, and return to step #2.
Measure again.

#62 (7) Stellafuchi (ECR2) ≠ (ECR3)
If it is determined that the correction data NDc is a negative value, it is determined in step #6G whether the correction data NDc is a negative value or not. If the value is negative, it means that the correction m(τ/2+t) is larger than the calculated movement amount INDI, and this means that the lens has passed the in-focus position. Therefore,
In this case, move to step #71 and connect the terminal (04).
, (05) is set to "l-ow" to stop the rotation of the motor (MO), flags SCF and FPF are set to '1', and the process returns to step #2 to perform confirmation measurements.

If it is determined in step #66 that NDc>o, then in step #67 it is determined whether the driving direction of the lens is the renormalization direction (N D >, O).

And if ND>O, #68, ND<0 <IA')
If the moving direction of the lens at this point is the retraction direction, it is determined whether the flag SIF is 1'' in step #69.
``'', if it is in the feeding direction, it is ``0''. Therefore, if the 7 lag SIF is ``OII'' in step #68 or the flag SIF is 1 in step #69, then the lens at this point is The moving direction and the calculated moving direction of the lens are reversed, so proceed to step #11 described above, stop the motor (MO), and set the flag SC.
F.

Set FPF to “1” and return to step #2 Mf KW
Perform measurements for On the other hand, the direction is reversed ()
If so, the data NDc sieved in step #5G is set in the counter COR, and the process returns to step #2 to perform the next measurement.

This is a case where the motor (MO) is stopped and measurement is performed without preliminary irradiation when the flag F P l = reaches °°1'' in step #52.In this case, first, INDI≦
Determine whether it is IFD and determine whether INDI≦I
If it is FD, focus display will be performed in step #76, and steps #80 to #82 (7) in step #211 mentioned above will be displayed.
7' The ENF is on the 77th IFF, SC.
Determine whether it is set to 1".

These flags are set to 1'' when the moving lens is temporarily stopped and measurements are taken for M1 recognition as described above.
, and at this time, proceed to step #84.
Ru. Steps #84 to #86 include steps #67 to #6 mentioned above.
Similar to step 9, determine whether the direction in which the lens was driven up to that point matches the direction obtained by the current measurement, and if it is reversed, select #84.1.
In step 88, the flag STF is inverted, and in step #91, the value obtained by adding the backlash data (BLD> to the data of the movement amount INDI) is set in the counter COR, and the process moves to step #9G.Meanwhile, the direction If they match, 7 lag ENF is set in step #89 11
Determine whether it is 1 or not. If the flag ENF is "1", the lens has reached the end as described above, and in this case, the lens cannot be driven in the calculated direction, so a warning is displayed. The process moves to step #211, which will be described later, and the operation is stopped. on the other hand,
If the flag ENF is 110 II, set the movement amount data l'NO+ to the counter C0Rk in step #95.
Proceed to step 96.

Flag ENF, Sc+=, IFF U” 0
”, determine the moving direction in step #92, and
If D>O, flag SIF is set to "1", N D<
If it is 0, set SIF to “0”, set the calculated movement amount data in the counter COR in step #95, and execute #96.
Move to the next step.

In step #9G, the mode is set to event 1-count mode, in which the data set in the counter COt< is subtracted using the clock pulse input from the encoder (ENC), and then the terminal (04) or (05) is "t-1ight" and 'C motor (
MO) starts rotating, flags FPF, IFF, 'S
CF and ENF are set to 0'', the front bin or the back bin is displayed according to the contents of the flag SIF, and the process returns to step #2 to perform the next measurement operation.

If it is determined in step #39 that the measurement result is low contrast, the process moves to step #110. #
In step 110, it is determined whether the flag FPF is 1'°, and if it is '1'°, it is the first measurement, and #
The process moves to step 111.

In step #111, it is determined whether the flag LLF is "1". As explained in steps #29 to #33, this flag LLF is set to 1 when the subject brightness is low.
”, and this flag LLF is
”, proceed to step #114; if “0”, proceed to step #121.

In step #114, the terminal (12) is "' l-l
If the terminal (12) is '1-ow', it is determined in step #115 whether the flag SEI:2 is '1'. This flag SEF 2 will be described later, but it is a flag that becomes 1" when the entire area of the lens is scanned in the loaf scan mode. Therefore, if it is "1'°, #144
The process moves to step , and the process moves to a low control stop mode, which will be described later. On the other hand, if the flag SEF2 is 0'', the process shifts to the low contrast scan mode from #121.

In step #114, the terminal (12) is “)l igl,
If it is determined that the mode is II, the mode shifts to the preliminary irradiation mode from #116. In step #116, flag F
, set LF to “1”, then set terminal (01) to l-1ig
h t+, flag FPF °l Q II, flag LCF1. Set FFF to '1°° and return to step #2. Then, as described above, a measurement operation for performing preliminary irradiation is performed.

When the flag LLF is 0" in step #111 or when 7lag SIN:2 is "0" in step #115, the process moves to step #121 and starts the operation of the loaf scan mode. First, the flag LLF is set to "0". LCF 1.LCF
2. Set LSF to "1", then determine which direction the determined defocus direction is, and depending on the determined direction, set the flag S I F to #I II or '0', and move the lens to that direction. Then, the five notices are displayed, the flag F P F is set to "0", and the counter Co is set to "0".
When the content of R becomes 1101+, the interrupt signal is not accepted and the process returns to step #2 to perform the next measurement.

If the flag FPF is "Os" in step ttiio, move to step #140 and determine whether flag FLF is 1'. If flags FL and F are LL 1 II, the measurement result in preliminary irradiation mode. has shifted to low contrast J
Ru. Then, at step #200, the flag FFF is “
If the flag "1:F is 1", it means that the first measurement was performed with the preliminary illumination. ” Then, turn the terminal (ol) on to 1Bg1. It is set to "it" and returns to step #2 to perform the second preliminary irradiation mode operation. On the other hand, the flag FFF is 0″ at step #200.
If so, it means that the second measurement has been performed in the preliminary irradiation mode, and a warning is then displayed and the process moves to step #211 to stop the operation.

If the 7 lag F'LF is "OII" in the step #140, then the flag TIF is "1" in the step #142.
′′ Determine whether or not. And flag TIF is “1”
If so, it is loaf stop mode and #2 step SEF
Determine whether 2 is “1” or not. If it is “1”, it means that only low contrast measurement values were obtained even if the lens scanned the entire area in low contrast scan mode. starts the low control stop mode operation from #144.

In step #144, 1211 constant data T1 is set in the counter COf<, and the mode is switched to a timer mode in which the contents of the counter COR are decremented by the internal clock pulse of the microcomputer (MCOl), and the flag TfF is set to 1 "1". enables the counter interrupt and returns to step #2 to perform the measurement.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 period, this measurement value is Transfer based on 111
The lens is driven by the data of m, and if only the low contrast 1-last measurement value is obtained for a certain period of time, the 1st Fi
Perform the same operation as the first measurement.

#143(7)7. Terafuchi flag SEF 2 is'
When it is determined that there is a flag LCF1, it is determined in step #15o whether the flag LCF1 is 1''. If it is not Pa 1'', the previous measurement value was not low contrast, and the current measurement suddenly became low contrast 4T. At this point, move to step #151, set flag LCF 1 to "1", and set LCF1 to "1".
CF 2 “O”! :L/, terminal (04).

(05) ``LOW'' Niji T'E-tar (MO)
(7) Stop the operation, set the flag FPF to '1', and return to #2 to start the process again. If the flag LCF 1 is '1' in step #15o, then the flag is flagged in step #155 and it is determined whether CF2 is '1' or not. If flag LCF2 is l*011, the previous measurement value suddenly changed. The contrast becomes low, and the current measurement value obtained by redoing the measurement is also a low contrast case.Therefore, in this case, the above-described low contrast skillen mode starting operation from step #121 is performed.

When the 7-lag LCF 2 is 1111 in step #155, the low contrast scan mode is being operated.

In this case, the contents of the counter COR are set in the register ECR3 in step #156, and the process proceeds to step #21. If they do not match, the lens has not reached the end, so the process returns to step #2 and performs the measurement operation. On the other hand, if the contents of registers ECR2 and ECR3 match, it is determined whether the lens has reached the end or not. Both ends are reached and the entire area is manipulated/
It's going to happen. Therefore, in this case, flag SEF 2 is set to (
Set to L 111, move to step #114, perform T11 confirmation to see if preliminary irradiation is possible from the flash, and if preliminary irradiation is possible, move to preliminary irradiation mode, and if preliminary irradiation is not possible, proceed to step #114. Transition to stop 0-mo-1-'.

If the flag SEF 1 is "0" in step #159, it means that the lens has reached the end for the first time in low contrast scan mode, and in this case, the flag SIF is reversed and the rotation direction of the motor (MO) is also reversed. flag SEF 1
Set the value to 1''' and return to step #2 to perform the measurement.

In step #41, the flag F L F is ``1''.
1) is set to "LOW", and the ND and focusing area IFD are separated in step #37. If INDI≦IFD is satisfied in step #173, an in-focus display is performed, and the flag FFF is set to "0" to proceed to step #211, where the operation ends.

If it is determined that INDI>IFD in step #173, the process moves to #180 and INDI is set to counter COR.
Set to event count mode and enable counter interrupts. Then, it is determined whether the flag FFF is "1" or not, and if it is "1", it means that the first measurement was carried out in the preliminary irradiation mode, and in this case, #188
Proceed directly to step . On the other hand, FFF is '°0
If it is ``, then the second measurement has been performed.1.In this case, the process moves to step ``#178,'' and it is determined whether the near-focus (NFD) is reached.

If I ND I >NFC, it is considered that either the first focusing operation was not performed normally or the second measurement result is unreliable. Furthermore, due to variations in conversion coefficients, etc., it is difficult to accurately move the lens to the in-focus position with just one movement! There are 11 positions, so basically it is considered that the focusing operation cannot be performed.

Therefore, in this case, a warning is issued in the old step #2, and the process moves to step #211 to stop the operation.

#179)7. Terra 7r l ND l (, N FD
It is considered that normal control operation is possible when it is determined that there is a toner, so next, the direction of movement is determined.
Determine whether the turn and direction of movement are reversed. And when it is determined that it is reversed, I ND I +
Perform the BLD operation to correct the movement amount data INDI by the amount of backlash data [), and reset this data to the counter COR. On the other hand, if it is not reversed, #18o
Assuming the data set in step #18
Move to 8. Then, the moving direction is determined and a signal corresponding to that direction is set in the flag SIF to control the motor (MO).
is determined and rotated in the 1c direction.

Next, it is determined whether the contents of the counter COR are registered. If (EcR2)≠(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 through measurement, the lens is driven based on this data, but no measurement operation is performed during this driving. Zoshi τ
When the lens moves by the amount of movement a, a counter interrupt is generated and the lens is stopped +L as described later. If it is the 111th time, it will move to the second operation, and if it is the second time, the focus will be displayed. to stop the operation. Also, the lens reaches the end at step #197! Here and F F r=1'
’, and then determine “1 i 11 (Since this is the first measurement from i, set FFF to 0’° and set terminal (01) to +
-+ i9h n and returns to step #2 to perform the second measurement in the secondary copper mode.

On the other hand, if it is determined in step #200 that F F F is "0°," then the second operation means that the lens has reached the end, and in this case, a warning is displayed. Then, the process moves to step #211, and the operation is stopped.

When the contents of the counter COR reach #OII, a counter interrupt is generated and the operation starts from step #230. #
In step 230, it is determined whether the flag TIF is 1''. If it is II 1 II, a certain period of time has elapsed in the low contrast stop mode and only the measured value of this frontage-con can be obtained. In this case, , interrupt enabled flag TIF, SEF 1゜5EF2.1-C12 1
．． LCF 2. Set LSF to 0'' and set flag F
Set PF to '1'' and set #2 as event count mode.
Go back to step. Therefore, the measurement is performed under the same conditions as the first measurement.

If flag TIF is #011 in step #230, move the lens! 1i It is determined whether the movement FLF is '1'' by the movement amount outputted by IIID.

If so, it is the preliminary irradiation mode and the process moves to step #238. At step #238, flag FFF is “1”
If it is “0”, it is 2 in preliminary irradiation mode.
This means that the second focusing operation has been completed, and after a focus display is performed, the process moves to step #211. On the other hand, flag FF
If F is 1'', it means that the first focusing operation has been completed in the n irradiation mode, and the flag FFF is set to ``0'', the terminal (01) is set to ``thigh'', and the process returns to step #2. Perform a second focusing operation.

If the 7-lag FLF is "0'' in step #235, preliminary irradiation is not performed and measurement m that is not low contrast I.
'J b<obtained, and this is the case where the number lunz moves by the calculated movement m. At this time, the flags IFF and FPF are set to 1111+, and the process returns to step #2 to perform a measurement for confirmation.

#11. #19. #38. # When it is determined in step 195 that the terminal (i3) has become "LOW", interrupts are disabled in step #210, and then the process goes to event count mode and moves to step #213. do. On the other hand, #76, #90. #175. #
201° When the operation is completed in step #239, interrupts are disabled in step #211 and the terminal (i3
) becomes “110., II. Then, the terminal (i
3) becomes "Low", the process moves to step #213.

#213 No. Step Terminal (04), 10.5>
Set it to “Low” to stop the motor (MO) and then turn off the display. and terminal (01).

(02), (0'3), (07) "low"
As a result, the operation of the automatic focus adjustment circuit is stopped. And 0° for all flags except FPF and SIF.

is set, and the flag FPF is set to "'1"'. next,
Set the contents of counter COR to register ECR2, wait for a certain period of time, and then write the contents of counter COR to register ECR2.
Set it to R3. Then, it is determined whether (ECR2) = (ECR3) or not (ECR2>≠(ECR2)
3) then set the contents of register ECR3 to register E'CIj
After setting it to 2, return to step #219. And (E
cR2) = (ECR3), the lens movement has completely stopped, so the microcontroller < M
To indicate that the exposure control operation may be started with CO2), the terminal (07) is set to L 0W11, and the microcomputer (MC01) stops its operation as an interrupt is possible.

In the above embodiment, #75 is used when not in the preliminary irradiation mode.
When it is determined that the focus state is reached in step , the microcomputer (MCO2) sends a signal ('''l-l 1g1 to terminal (i3)) to continue automatic focus adjustment operation.
” signal) is input, so that the automatic black water
You may return to step 2. If you shift like this, once the subject is in focus, the 7 lag ENF will be “1”.
'', that is, when the lens reaches the end position and cannot be moved, you may return to step #2 and perform the measurement again. In this way, the lens cannot be moved. If a signal in the direction in which it is possible is obtained, the lens will start moving again.In the case of deformation as described above, measurements are limited to three days in the preliminary irradiation mode.

Although one embodiment of the present invention has been described above, the present invention is not limited thereto. For example, in the above embodiment, on the premise that the amount of backlash is different for each interchangeable lens, backlash correction amount data is stored for each interchangeable lens, read out on the camera body side, and motor drive vJffi data is stored. had given corrections. However, the main cause of backlash is play in the interlocking part of the connection between the interchangeable lens and the camera body, and by managing the dimensional accuracy of the parts, this can be maintained at a constant value regardless of the interchangeable lens. can be managed. Therefore, variations in the backlash of the various interchangeable lenses within the interchangeable lens are ignored, and the backlash of the various interchangeable lenses scheduled for use is added to the backlash (fixed value) caused by the play between the connecting members. A constant correction value corresponding to darkness, which is the minimum or average value of the amount and the backlash of the transmission mechanism on the camera body side (fixed value), is commonly approximated for all interchangeable lenses, and this constant correction value data is On the camera side,
For example, it may be set in advance in the correction circuit so that Jj < or input to the correction circuit. If J: is used, there is no need to store backlash compensation 1Effi data on the interchangeable lens side or read it on the camera body, which simplifies signal processing.

Furthermore, when an intermediary member such as a rear inverter is interposed between the photographic lens and the camera body, there are two connecting portions: one between the camera body and the intermediary member, and one between the intermediary member and the photographic lens. In such a case, the backlash correction data may be output from the intermediary member as well, and data obtained by adding the backlash correction data of both the R shadow lens and the intermediary member may be transmitted to the camera. In this case, the backlash correction data of the photographic lens is input from the photographic lens to the intermediary member, and the intermediary member-specific backlash correction data is added to this data within the intermediary member so that it is not sent to the camera side. Zuba J: Yes. Such li 11 or addition of BL data in the intermediary member is described in, for example, Japanese Patent Application No. 11358-6277 previously filed by the applicant of the present application.
The method proposed in No. 9 may be used. Furthermore, if the camera body has a fixed value that is common to all interchangeable lenses as backlash correction amount data, a signal indicating the presence of the intermediate member can be transmitted from the intermediate member to the camera body. When the camera body receives such a signal, it doubles the fixed value of the backlash correction amount data stored in advance on the camera side, and uses the doubled value as the backlash correction amount data. good.

Furthermore, instead of detecting the change in the drive direction of the drive motor in the electric circuit as in the above embodiment, the change in the drive direction of the drive motor is detected by controlling the movement of any mechanical element in the transmitters B and 5 or the focusing optical system using a switch or the like. May be detected.

Historically, the camera used in the embodiment is an eye reflex camera with interchangeable lenses, but it goes without saying that it may be a camera that does not have interchangeable lenses, or it may be a camera other than an eye reflex camera. stomach.

According to the present invention as described above, the focusing optical system of the photographing lens is automatically driven by the drive motor via the transmission mechanism based on the automatically detected defocusing and direction signals. When J3 is in the focus vAllil device and the drive direction of the focusing optical system by the drive motor changes, the drive amount data of the drive motor is corrected by the amount of backlash in the transmission I geometry, so the time to reach focus due to backlash will be reduced. Automatic focus adjustment can be performed quickly and with high precision without affecting the focus or focus rate.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of an embodiment of the present invention, FIG. ) is a front view of the main part of the connecting part l in J3 in Fig. 2, and Fig. 3 (13) is the line B of Fig. 3 (A>
- Cut along B! ! 4 is a circuit diagram showing the entire camera system using the present invention, and FIG. 5 is a circuit diagram showing the entire camera system using the present invention.
1 circuit diagram showing a specific example of the electronic flash light emitting 'jA hJ circuit shown in the figure. FIG. 6 is a flowchart 1-1 showing the operation of the microcomputer (MCO2) in FIG. 4. Figure 3 is flowboo 1 showing the operation of the microcomputer (MCO1) in Figure 4.
・-1-. 10: Linear lens, 20: Camera body, 12.56: Transmission mechanism, 14. ! i8: Connecting member, 32: Focus detection light receiving element, MO=Focus detection drive motor, BLD
: Packlash correction amount data, 44: Correction circuit, 50
: Instant action direction change detection circuit Applicant: Minolta Camera Co., Ltd.

Claims (1)

[Scope of Claims] 1. Detection means for detecting a deviation of the subject image position formed by the photographic lens with respect to a planned focal plane, and a focusing optical system of the photographic lens based on the detection result of the detection means. an arithmetic circuit that calculates the drive amount of the focus adjustment drive motor necessary to drive the focus adjustment drive motor to the desired position; a drive control circuit that controls the drive motor based on data on the drive amount calculated by the arithmetic circuit; A transmission mechanism that transmits the driving force of the motor to the focusing optical system of the photographic lens, an output circuit that outputs data on backlash in the transmission mechanism, and a direction detection circuit that detects a change in the driving direction by the drive motor. , an automatic focus 11 section 1L2 comprising a correction circuit for correcting the drive amount data by the backlash ω data of the output circuit in response to a drive direction change detection signal from the direction detection circuit; the photographing lens is an interchangeable lens; A patent claim in which the camera body is equipped with a detection means, an arithmetic circuit, a drive motor, a direction detection circuit, and a correction circuit, and each interchangeable lens is equipped with an output circuit that outputs backlash data specific to the interchangeable lens. 3. The photographing lens is an interchangeable lens, the output circuit is provided in the camera body, and the transmission IJ! mechanism is connected to the camera side mechanism and the lens side mechanism. A patent claim configured to output data according to the sum of a backlash value due to play in connecting parts, an approximate lens-side mechanism backlash value common to the entire interchangeable lens, and a backlash value in a camera-side mechanism. The automatic focus adjustment device according to item 1.