JPH0812317B2 - Camera with autofocus device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a camera having an autofocus device that drives a lens according to a defocus amount up to an object.

<Prior Art> Conventionally, as a method of photographing a subject at a plurality of different positions in a state in which each subject is in focus, a method in which a lens is in focus at a position between a plurality of subjects and The camera is set to the narrowed state, and the aperture that covers each subject is determined by the depth of field while checking the state of each subject.

For this reason, the shooting under the above circumstances is greatly affected by the experience of the photographer and the like, is unsuitable for amateurs, and has a high probability of failure.

<Objective> The present invention has been made in view of the above matters, and as its configuration, includes a light receiving circuit that receives a light flux from a subject incident through a photographing lens, and a measurement field of view based on an output of the light receiving circuit. A focus detection circuit that obtains a defocus amount for a subject captured by the camera, a drive circuit that drives the photographing lens based on the defocus amount from the focus detection circuit, an operating member, and the measurement at the time of operating the operating member. A first circuit for focusing the photographing lens on the first subject by the drive circuit based on the defocus amount obtained by the focus detection circuit for the first subject captured in the visual field. The second subject which is captured in the measurement field of view at the time of operating the operation member after moving the taking lens to the first position while moving to the position. Control means for moving the taking lens by the drive circuit to a position where the defocus amount of the first subject image and the second subject image is internally divided based on the defocus amount obtained by the point detection circuit. Is provided so that the photographer can visually confirm whether or not the above-described processing symmetry is surely performed with respect to the subject, and then quickly defocuses the defocus between the desired two subject images. A camera for moving a photographing lens to a position is provided.

<Example> Before describing an example of the present invention, the principle of the present invention will be described.

Considering the subjects A and B at two different positions, in order for both subjects to be in focus, first, the lens should be approximately at the center of the two subjects, that is, the defocus amounts for the two subjects match. Focus on various positions. In this state, since the defocus amounts of the subjects A and B are approximately the same, if the aperture at this time is set to be within the depth with respect to both the subjects, it is assumed that both the subjects A and B are in focus. Become.

Further, since the depth of field is obtained by dividing the amount of differential focus from the focus surface by the circle of least confusion, the aperture value at this time is determined.

In the present invention, for the subject A, B in the autofocus device to determine the defocus amount the defocus of the two objects match, move the lens to this position,
Further, by dividing the amount of the coincident differential focus by the circle of least confusion, the aperture value is obtained and both subjects are brought into focus.

 Next, examples of the present invention will be described.

FIG. 1 is a circuit diagram showing an embodiment of a camera having a lens driving device according to the present invention.

In the figure, SPC is a light receiving element for TTL open photometry, DI is a diode, AMP1 is a well-known photometry circuit that is an operational amplifier, and outputs an Apex BV0 as its output. VR1 is a variable resistor for setting the film sensitivity and sends out S0 of the apex. VR2 is a variable resistor that sets the open aperture value (AV0 of the apex) of the mounted lens. The outputs of these variable resistors VR1 and VR2 and the photometric circuit output are input to the amplifier ADD1 that constitutes the adder, and the amplifier ADD1 From BV0 + SV + AV0 = BV + SV = EV
Is sent.

AD1 is the output of the above-mentioned amplifier ADD1 (EV of Apex)
The output of the AD conversion circuit for conversion is input to the PE port of the micro computer UCOM (hereinafter referred to as the microcomputer).

AD2 is an AD conversion circuit that AD-converts the output of the variable resistor VR2 and transmits it to the PF port of the microcomputer UCOM. VR3 is a variable resistor that sets the minimum aperture value (minimum aperture value on the aperture side) AVL of the mounted lens, and the output of the resistor VR3 is a digital value via the AD conversion circuit AD3.
Tell the PG port of.

SWMD is a mode setting operation member for setting camera shooting mode (shutter priority, aperture priority, program) information.
Tell the PA port. SWTV is a shutter time setting member for setting shutter time information, and SWAV is an aperture setting member for setting aperture value information.
The AV value is input to the PC and PB ports of the microcomputer UCOM.

DA1 is a DA conversion circuit for converting the control aperture value information sent from the PH port of the microcomputer UCOM to analog (voltage), and the output from the circuit DA1 is input to the amplifier AMP2 that constitutes the subtraction circuit, and the amplifier The calculation with AV0 set in the resistor VR2 is performed by AMP2, and the number of aperture stages (ΔAV of the apex) is obtained as the output.

The DRAV has a start magnet MG1 and a stop magnet MG2 for aperture control, and the output of the amplifier AMP2 ΔAV
This is a diaphragm control circuit that controls the diaphragm on the basis of. EXPAND
ER is a real-time expansion circuit for expanding the control shutter time information TV output from the PJ port of the microcomputer UCOM, transmitting the information to the shutter control circuit DRTV, and performing the shutter time control. The shutter control circuit has a front-curtain magnet MG3 and a rear-curtain magnet MG4. By operating each magnet, a not-shown shutter front-curtain and rear-curtain are driven.

The DRAV and DRTV of the above control circuit are activated by a signal from the PI port of the microcomputer UCOM, and start diaphragm and shutter control.

disp1 is a display that digitally displays the shutter time value and aperture value output from the PK port of the microcomputer UCOM, for example, on a 7-segment liquid crystal display.
1 flashes the display value of the aperture with a signal from the AVBLINK port of the microcomputer UCOM.

disp2 is the array display shown in FIG. In the array display, CP1 to CP24 are comparator arrays that selectively generate outputs based on the depth information disp (K) output from the PL port of the microcomputer UCOM. LDA is a display driver array for selectively driving the LEDs D1 to D24 based on the outputs of the comparators CP1 to CP24.
The LEDs D1 to D24 are arranged on the display plate to indicate the scale SCALE to which FNO of the aperture is attached, and display the aperture value according to the depth information.

SW1 is a switch that is turned on in a first operation state of a shutter button (not shown), SW2 is a switch that is turned on in a second operation state of the button, and SWdep is turned on by pressing a first operation button (not shown). And SWCLK are switches which are turned on by pressing a second operation button (not shown), and these switches are input to the PD port of the microcomputer UCOM.

DR1 is a motor driver which is connected to the PN port of the microcomputer UCOM and operates the motor MT1 in response to a signal from the port to drive a shutter charge and a film winding mechanism. SWCHG is a detection switch that works together with the above mechanism and turns on when the mechanical charge is completed and turns off when the shutter running is completed.
It is connected to the PM port. AFS is a focus detection circuit that calculates the defocus amount until focusing based on the signal from the autofocus sensor that receives the light flux image incident through the taking lens L1, and the output of the circuit is the PP port of the microcomputer UCOM. Reportedly.

Each of the above circuit elements is provided on the camera side, and elements to be described later are disposed on the lens side mounted on the camera, and information communication is performed between the camera and the lens.

On the lens side, a zoom brush ZMB and a code pattern board COD1 are provided with a zoom information forming circuit for forming a digital value according to the lens zoom position, and the zoom information from the circuit is converted by the zoom encoder ZOOM. After that, it is transmitted to the PQ port of the camera-side microcomputer UCOM via the communication controller CONCOM.

CNT is the communication controller C from the PQ port of the microcomputer UCOM.
An up-down counter that sets the lens drive amount information input via ONCOM, and CONMT is a motor control circuit that determines the lens drive direction (forward or reverse direction) based on the drive direction signal output together with the lens drive amount information. Then, the circuit transmits a teaching direction signal to the counter CNT to determine the up or down mode of the counter. DR2 drives the motor MT2 in the direction determined by the motor control circuit CONMT.
Is a motor drive circuit that drives the lens 11
Moves in the optical axis direction by a mechanism linked to MT2. LP1 is a comb-shaped pattern that moves in conjunction with the movement of the lens L1, and this pattern turns on and off the contact piece LP2 by movement, and the contact piece LP2
Then, a pulse is sent out each time the lens moves by a unit length.

Next, the operation of the embodiment shown in FIG. 1 will be described based on the program flow chart shown in FIGS. The program is stored in the ROM incorporated in the microcomputer UCOM, and each number indicates a program step.

First, when the power supply (not shown) is turned on and the power supply to the microcomputer UCOM is turned on, the power-up is cleared in step 1, and thereafter the operation is performed in the following step order.

Step 2: A signal for turning off the display circuits disp1 and disp2 is sent from the PK and PL ports of the microcomputer UCOM, and the display circuits disp1 and disp2 are turned off.

Step 3: Switch SWdep to the memory inside the microcomputer
Zero is set as the information n on the number of times of pressing, and zero is set as the aperture value AVdep in depth priority described later. In this step 3, the number of times n the switch SWdep is pressed and the aperture value AVdep in depth priority are initialized.

Step 4: Switch SW1, at PV port of microcomputer UCOM
The state of SW2 is detected, and the result of the detection is switch SW1.
Or, if SW2 is on, proceed to step 5, SW1 and SW2
When is off, proceed to step 12.

Now, the shutter button is operated and the switch SW1 or SW2
Is on, step 5 is executed.

Step 5: The ranging subroutines of steps 67 to 69 are called and the ranging subroutine is performed.

In the distance measurement subroutine, steps 67 and below are executed.

Step 68: The focus detection circuit AFD is driven based on the image which drives the focus detection circuit AFD and enters the sensor AFS through the lens L1.
The amount of defocus Xnow calculated in the PP of microcomputer UCOM
Enter through the port.

Also, the zoom information from the zoom information forming circuit is input to the PQ port of the microcomputer UCOM via the controller CONCOM.

Step 69: End the ranging subroutine and return to the main routine. Therefore, the process proceeds to step 6.

Step 6: The lens drive amount MV is obtained from the defocus amount Xnow obtained in the distance measuring subroutine. The lens drive amount MV is determined based on the defocus amount Xnow and the zoom information.

Step 7: The lens drive routine of steps 70 to 72 is read. As a result, steps 70 to 72 are performed.

Step 71: The lens drive amount signal MV is transmitted from the PQ port of the microcomputer UCOM, and the lens drive amount signal MV is transmitted to the pulse counter CNT via the communication controller CONCOM. At this time, the drive amount signal MV and the signal indicating the drive direction are also displayed on the PQ.
The motor control circuit CONMT sent from the port determines forward / reverse rotation for the motor based on the signal.

Further, the signal determines the up or down mode for the counter CNT. Also, the motor control circuit CONMT transmits a drive signal to the motor drive circuit DR2, and the motor MT2 rotates in the direction determined by the drive direction signal,
The lens L1 is moved in the optical axis direction. This movement in the optical axis direction is converted into a pulse by the comb-shaped pattern interlocking with the lens L1 and the contact piece LP2 and transmitted to the counter CNT, and the count operation is performed, and the count value matches the set lens drive amount MV. At that time, a coincidence signal is sent from the counter CNT, which causes the motor control circuit CONMT to stop the driving of the motor MT2 by the motor drive circuit DR2. With the above operation, the lens is driven by the above-mentioned drive amount MV to be in a focused state.

The coincidence signal is transmitted to the microcomputer UCOM via the communication controller CONCOM, and the process returns to the main routine in step 72 and step 8 is executed.

Step 8: Call the photometric routine of steps 64-66, and steps 64-66 are executed.

In steps 64-66, the output of the AD conversion circuit AD1, namely EV
The value is input from the PE port of the microcomputer UCOM, and the process proceeds to the main routine, that is, step 9.

Step 9: The calculation display 1 routine of steps 44 to 56 is called, and steps 44 to 46 are executed.

Step 45: It is determined whether or not the number n of times the switch SWdep is pressed is n ≧ 2. If the switch SWdep has not been depressed even once, n = 0 and the step moves to step 48.

Step 48: Read the mode information to the PA port of the microcomputer UCOM, and if the mode set by the mode setting operation member SWMD is aperture priority, step 47; if shutter priority, step 50; or program mode. If so, execute step 49.

At step 47, the AV value (AVSET) set by the aperture setting member SWAV input to the PB port of the microcomputer UCOM is read, and at step 51 the EV value obtained by the photometric routine and the calculated EVSET value EV -AVSET = TV is done. In step 49, an AV value that uniquely corresponds to the EV value obtained in the photometry routine is selected based on the AV value table corresponding to the program diagram built in the microcomputer UCOM. The TV value is obtained by calculating the selected AV value and the EV value.

At step 50, the TV value (TVSET) set by the shutter speed setting member SWTV input to the PC port of the microcomputer UCOM is read, and at step 52, the EV value obtained by the photometric routine is calculated EV −TVSET = AV is done.

The TV and AV values for control according to the shooting mode set in the above steps 48 to 52 are obtained, and in step 53, these TV and AV values are transmitted from the PK port of UCOM to the display disp1 and controlled. The shutter speed and aperture value are displayed. In step 54, the control AV value is
The voltage is transmitted to the DA conversion circuit DA1 via the PH port, and a voltage corresponding to the AV value is output. Further, for the above control at step 55
TV value is expanded in real time through PJ port of microcomputer UCOM
It is transmitted to EXPANDER and returns to the main routine at step 56, that is, step 10.

Step 10: The state of the switch SW2 at the PD port of the microcomputer UCOM is detected, and when the switch SW2 is on, the process proceeds to step 11, and when it is off, the process proceeds to step 3.

As described above, when the shutter button is in the first operation state and SW1 is on and SW2 is off, the above steps 3 to 10 are repeatedly executed and the lens is always moved to the in-focus position and selected based on the result of the immediate distance. The shutter speed and aperture value in the mode are displayed.

If the shutter button is shifted to the second operation state during the above process, this is detected in step 10 and step 11 is executed, and the sequence routine of steps 57 to 63 is called.

In the routine, in step 58, a signal is sent from the PI port of the microcomputer UCOM and the diaphragm control circuit DRAV operates. The diaphragm control circuit DRAV actuates the magnet MG1 to drive an unillustrated diaphragm regulating member and output ΔAV of the amplifier AMP2.
When the aperture is restricted by the aperture regulating member, the magnet MG2 is operated to stop the driving of the aperture regulating member.

As described above, the DA conversion circuit DA1 outputs a voltage corresponding to the control aperture value AV, and this voltage is transmitted to the amplifier AMP2, so the output of the amplifier AMP2 shows a ΔAV value according to the control aperture value AV. Therefore, the aperture becomes the control AV value by the above operation.

Also, after this, the shutter control circuit DRTV magnet MG
3, the shutter front curtain starts running, and at the same time the front curtain runs, the real-time expansion circuit EXPANDER operates and starts the timekeeping operation. As described above, the control TV is included in the circuit EXPANDER.
A value has been input, and the circuit extends the TV value to generate an output after the time is counted, and activates the magnet MG4 to drive the rear curtain of the shutter. With the above, control of the aperture and the shutter speed is performed. At step 59, the state of the switch SWCHG is detected, and the switch SWCHG is turned off to allow the shift to step 60.

Since the switch SWCHG is configured to be turned off upon completion of the travel of the rear curtain of the shutter, the process proceeds to step 60 after the exposure operation is completed. In step 60, the microcomputer UCOM
A drive signal is transmitted from the PN port. Drive circuit DR
1 operates and the mechanical charge mechanism is driven by the motor MT1 to execute the shutter charge, the aperture charge, and the film feeding operation. When the charge operation is completed, the switch SWCHG is turned on. Therefore, the completion of the charge operation is detected in step 61, and when the charge operation is detected, the stop signal is sent from the PN port of the microcomputer UCOM in step 62 to drive circuit DR1. Becomes inoperable, the drive of the motor MT1 is stopped, and at step 63, the process returns to the main routine. In the above steps 1 to 11, a series of normal operation control of the camera is performed.

Next, the operation when the switch SWdep is pressed will be described.

If the shutter button is not operated after the power supply to the camera is turned on, the process proceeds to step 12 at step 4 and the steps after step 12 are executed.

Step 12: Switch SWdep status is PV of microcomputer UCOM
When the switch SWdep is read at the port and the switch SWdep is on, the process proceeds to step 13.

Now, if the first operation button is pressed while the distance measuring field is aligned with the subject A in FIG. 5, the switch SWdep is turned on, so steps 13 to 15 are executed. Steps 13 to 15 are the same as steps 5 to 7 described above, and the lens shifts to the in-focus position based on the distance measurement result.

Step 16: Set the number n of times the switch SWdep is pressed to 1, and set the current depth information disp (0) and the first switch SW.
Depth information at subject distance obtained by pressing dep disp
Set to 0 in (1).

Step 17: The display 2 routine of steps 73 to 75 is called, and steps 73 to 75 are executed.

At steps 73 to 75, the depth information corresponding to the current depth information disp (0) and the depth information disp (n) at each pressing of the switch SWdisp is displayed on the display device disp2.

Since n = 1 is set in step 16 and disp (0) and disp (1) are set to 0, disp (n) is
It becomes disp (1), and disp (0) and disp (1) = 0 are displayed.

This information disp (0) and disp (1) are stored in the microcomputer UCOM.
It is transmitted to the display disp2 via the PL port.

The display disp2 is configured as shown in FIG. 2, and the information disp (0), disp from the PL port of the microcomputer UCOM is displayed.
(1) = 0 is detected by the comparator array, a tribar based on the detection result is selected, and the corresponding dot is turned on. Since the information disp (0) and disp (1) are now 0,
The comparator CP12 generates a detection output and lights the dot D12 corresponding to the scale F1.

When this display 2 routine is completed, the process proceeds to step 18.

Step 18: In this step, the switch SWdep is detected again, and when the switch SWdep is off, the process proceeds to step 19, and when it is on, the process proceeds to step 27.

Now, it is assumed that the switch SWdep is held in the off state after the switch SWdep is turned on for the first time.

In this state, the above-described photometric routine is executed in step 19 to obtain the defocus amount Xnow. As described above, in steps 13 to 15, the lens moves to the position corresponding to the subject in the distance measuring field when the switch SWdep is pressed, so the defocus amount here is the first switch SWdep.
With respect to the lens position that is in focus with respect to the object at the time of pressing, the amount of defocus to the object currently being framed is obtained. After the defocus amount for the current object is obtained in this way, step 20 is executed.

Step 20: Here, a calculation is performed in which the defocus amount Xnow based on the distance measurement result is divided by the minimum circle of confusion = 35 μm.

Since the depth of field is obtained by dividing the amount of defocus and the circle of least confusion, the lens is switched by this calculation.
The depth information required to bring the current subject position into focus while the SWdep is held in focus with respect to the subject position when pressed is calculated as the current depth information disp (0). , The calculation result is set.

Step 21: Execute the above display 2 routine. As a result, the depth information disp (0) and disp (1) are displayed.

Since the depth information disp (0) is obtained in step 20 and disp (1) is 0, the dot of the display disp2 is the FHo corresponding to the depth information obtained in step 20 above. Turn on the dot and F1 dot.

Now, the subject position is 2m when the switch SWdep is turned on for the first time, and the subject is 3m when the distance is measured by step 19 thereafter. The defocus amount at this time is 450 μm.
Then, as depth information, disp (0) ≈12.8
Becomes Therefore, in this case, the comparator CP in FIG.
4 generates detection output, turns on dot D4, and keeps the lens position in focus for a subject of 2 m for 3 m
FN required to keep even the subject in focus
Show that o is 16.

Thereafter, the photometry and calculation display 1 routine is executed in steps 22 and 23, and the aperture and shutter time based on the photometry value at that time are displayed.

Step 24: The state of the switch SWCLR is detected, and it is detected whether or not the second operation button is pressed. If the second operation button is pressed and the switch SWCLR is turned on, the process proceeds to step 2; The above operation after step 2 is executed again. The second operation button is a clear button. Pressing this button inhibits depth display and returns to the normal operation mode. If the second operation button is not pressed, the process proceeds to step 25.

Step 25: The current zoom information from the zoom information forming circuit is transmitted to the PQ port of the microcomputer UCOM via the communication controller CONCOM, and whether or not the current zoom information matches the previous zoom information detected earlier. Detection is performed. When it is determined as a result of this detection that they do not coincide with each other, that is, when the zoom ratio is changed in the above-described operation process, the process proceeds to step 2, and the normal operation mode is restored.

Since the depth of field changes depending on the zoom ratio, if the zoom ratio changes in the process of obtaining depth information in the above series of operations, the depth information display on the display disp2 will not be appropriate. Therefore, in the present invention, the change in the zoom ratio is detected and the mode is shifted to the normal mode as described above.

When the zoom ratio is not changed, the operation state of the switch SW2 is detected at step 26, and when the switch SW2 is off, the process returns to step 18. So once the switch
After SWdep is turned on, switch SWdep and switch SW
2.If SWCLR is off and the zoom ratio is not changed, steps 18 to 26 are repeatedly executed and the focus state is kept for the subject at the time of pressing the switch SWdep for the first time. The FNo for keeping the current subject position in focus is repeatedly displayed on the display disp2.

Further, in this state, the operation shifts to step 11 for setting the shutter button to the second operation state, and the photographing is performed by the above sequence routine. The exposure at this time is controlled based on the shutter and aperture information obtained in steps 22 and 23 immediately before the shutter button is brought into the second operation state.

Next, a case will be described in which the switch SWdep is once pressed and then released, and then the switch SWdep is pressed again.

In this case, the pressing of the switch SWdep is detected in the step 18 in the process of repeating the steps 18 to 26, and therefore the step shifts to 27 and thereafter, and the steps after 27 are executed.

Step 27: Add 1 to the information n on the number of times of pressing the switch SWdep. This is the second press of the switch SWdep,
By pressing the switch SWdep for the first time, n = by step 16
Since it is set to 1, n = 2.

Step 28: The above photometric routine is executed. Thereby, the second switch SW for the lens that is in focus with respect to the subject position when the first switch SWdep is pressed is provided.
The defocus amount Xnow for achieving the in-focus state with respect to the subject position when dep is pressed is obtained.

Step 29: Execute X (n) = Xnow + XT. (X
(N): Defocus amount XT obtained when the switch SWdep is pressed n times: Defocus amount that is uniform for each subject) Since XT is set to 0 at step 16, the calculation result X (2 ) = Xnow.

Is calculated.

Now, since n = 2, the above XP is (X (1) + X
(2)) / 2, and since X (1) is set to 0 in step 16, XP becomes X (2) / 2 = Xnow / 2.

In this calculation, the amount of movement of the lens to an intermediate position between the current lens position and the lens position for bringing the subject position into focus when the switch SWdep is pressed this time, that is, the defocus amount is obtained. . In other words, the subject position when the switch SWdep is pressed for the first time and the current switch SWd
An intermediate position from the position of the subject when ep is pressed is determined.

Therefore, for example, as shown in FIG. 5, the subject A at the time of the first switch SWdep band is at the position of 2 m, and the next switch SWdep
When the object B of 5 m is placed in the distance measuring field when the button is pressed, the differential focus amount Xnow = X (2) from the state where the object A is in focus to the object B is obtained in step 29, At step 30, the defocus amount XP to a position where the defocus amount is half of this defocus amount, that is, the defocus amount is uniform between the subjects A and B and to the subjects A and B is obtained. Now, in the above case, the defocus amount Xn for the subject B
If ow = X (2) is 805 μm, XP is 805/2 = 40
3 μm.

Step 31: XP-XT is performed to obtain the lens drive amount MV. Since XT is set to 0, the lens drive amount information MV is
XP, and in the above case, MV is 403 μm. In this case, the drive amount MV for XP-XT is obtained from the zoom information.

Step 32: The above lens driving routine is executed, whereby the lens moves from the state of focusing on the subject A to the subjects A and B.
Intermediate position 3.08m with a uniform defocus amount of 403μm
Move to the position.

 Step 33: Set XT = XP.

Step 34: disp (K) = {X (K) -XT} / 35 μm
Calculate with (K = i, n). Since n = 2 now, the depth information disp for bringing the switch SWdep into the n-th subject position of the switch with respect to the current lens position
(1) = X (1) -XP / 35 μm, disp (2) = X (2)
-XP / 35μm is required.

As mentioned above, X (1) is zero, X (2) is 805, and XP is 403.
Therefore, disp (1) =-11.5, disp (2) = + 11.5
Becomes

 Step 35: The display 2 routine is executed.

As a result, the comparators CP4 and CP21 in FIG. 2 are activated and the dots D4 and D21 of the display array are lit up, and the aperture FNo at this time is displayed.

Step 36: The maximum absolute value of the depth information disp (K) for the subject for each time obtained in step 34 is set as the control aperture FNodep in this mode. Di in the above case
The sp (2) = 11.5 is the aperture FNodep.

Step 37: Convert the above-mentioned aperture FNodep into the AV value of the apex to obtain AVdep.

Step 38: Compare the above AVdep with the minimum aperture AVL (Apex) of the lens. If AVdep> AVL, that is, if AVdep is smaller than AVL, set the value of AVdep to this minimum aperture AVL at step 40. .

When AVL ≧ AVdep, the process proceeds to step 39, where AVdep <A
When V0 is determined and AVdep <AV0, that is, when AVdep is further open than AV0, the value of AVdep is set to the limit value AV0.

 When AVdep <AV0, the process proceeds to step 43.

For the above steps 38 to 42, it is judged whether or not AVL ≧ AVdep ≧ AV0. In this case, at step 43, the microcomputer UCOM
After turning off the AVBLINK terminal, the process proceeds to step 18.

When AVdep> AVL, AVdep is set to AVL which is the limit value, and in step 41, the terminal AVBLINK is turned on, and the process proceeds to upper step 18. At this time, if the switch SWdep is off, steps 19 to 23 are executed again. With this, the depth information disp when the switch SWdep is pressed each time
(1) disp (2) and depth information according to the defocus amount for the current subject position obtained in step 19
disp (0) is displayed on the display device disp2 in the display 2 routine. As above, disp (1) disp (2) is +, -11.5
Therefore, the dots D4 and D21 in FIG.
FNo = FNodep is also displayed to keep B in focus, and a defocusing for focusing the current subject position from the lens where the defocusing amount is uniform for both subjects A and B. Depth information to keep this current subject in focus based on the amount disp
The dot indicating the FNo corresponding to (0) is lit.

In the calculation display 1 routine at this time, since n = 2, step 46 is executed, the above AVdep is set as the AV value, and steps 51 to 56 are executed thereafter.

Accordingly, in this case, the display 1 displays the above AVdep as an aperture value regardless of the setting mode, and the TV value obtained by EV-AVdep = TV based on the EV value at this time is defined as shutter time. indicate.

At this time, when AVdep is> AVL, the display value is in accordance with the AVL, and since the terminal AVBLINK is turned on in step 41, the aperture value is displayed in a blinking manner, and both the objects A and B are in focus. Warn that you will not be filmed. Also AV
When dep <AV0, AVdep is set to AV0. In this case, since AV0 has a deeper depth, it is not configured to blink the aperture value.

As described above, after the subjects A and B are both framed while the aperture value AVdep for displaying the subjects A and B in focus is displayed, the shutter button is in the second operation state. This is determined at step 26 to shift to, and the sequence routine is executed at step 11, and the above-mentioned sequence routine is executed, whereby the aperture is controlled on the basis of the AVdep, and the subject A and B are both focused. Shooting will be done.

The above operation is the operation when the switch SWdep is pressed twice.When the switch SWdep is pressed twice or more, similarly, the AVdep for bringing each subject into focus is obtained, and this is displayed. At the same time as the aperture control.

<Effect> As described above, according to the present invention, the lens is moved to a position where the operation subject of the operation member for the first time is in focus, and the lens is moved to the subject at this time by the next operation of the operation member. Since the lens is moved to a position that internally divides the amount of defocus to the lens, it is possible to quickly move the lens to a position where each subject is in focus and confirm the focus state for each subject through the pre-finder before shooting. It can be done.

In the embodiment, the defocus amount for each subject is made uniform, but the defocus amount may be set to 10 for the infinite subject and 7 for the closest subject.

In this case, the aperture value may be obtained by dividing the close-side defocus amount by the circle of least confusion or by dividing the infinite side defocus amount by the minimum circle of confusion.

Further, in the embodiment, the indicator is made to blink when the calculated aperture value is outside the limit of the small aperture, but instead of this, a dedicated element for warning may be provided, and this may be warned by sound. Of course, the warning form may be any one.

Further, in the embodiment, the defocus amount is divided by the circle of least confusion, but this value can be arbitrarily adjusted to make the focus state loose or severe.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a camera adopting the lens driving device according to the present invention, and FIG. 2 is a display device di shown in FIG.
Circuit diagram showing one embodiment of sp2, FIG. 3, FIG.
(F) is a flowchart showing a program built in the microcomputer UCOM of FIG. 1, and FIG. 5 is an explanatory diagram showing a view of a viewfinder of the camera of FIG. UCOM: Microcomputer AFD: Focus detection circuit disp2: Display

Claims (1)

[Claims] 1. A focus detection circuit comprising a light receiving circuit for receiving a light flux from a subject incident through a photographing lens, and for obtaining a defocus amount for the subject caught in the measurement visual field based on the output of the light receiving circuit. A drive circuit for driving the photographing lens based on a defocus amount from the focus detection circuit, an operation member, and the focus detection for a first subject captured in the measurement field of view when the operation member is operated. Based on the defocus amount obtained by the circuit, the drive circuit moves the photographing lens to the first position where the first subject is brought into focus and moves to the first position of the photographing lens. Based on the defocus amount obtained by the focus detection circuit for the second object captured in the measurement visual field at the time of operating the operation member after An autofocus device comprising a control means for moving the photographing lens by the drive circuit to a position where the defocus amount between the image of the object and the image of the second object is internally divided. Camera with.