JPH06100763B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an aperture determination device.

<Prior Art> Conventionally, as a method for shooting a subject at a plurality of different positions in a state in which each subject is in focus, the camera is narrowed down and the object scene is checked while checking the state of each subject. The brightness determines the aperture that covers 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.

<Purpose> The present invention has been made in view of the above matters, and a focus detection circuit that obtains a defocus amount for a subject captured in a measurement visual field, and a first subject and a second subject captured in the measurement visual field. On the other hand, a drive circuit that moves the imaging optical system to a position that internally divides the defocus amount between the first subject and the second subject based on the defocus amount obtained by the focus detection circuit; Aperture calculation circuit for determining an aperture value for keeping the first subject and the second subject within the depth according to the defocus amount between the subject and the second subject, and the calculated aperture value is on the small aperture side. Discriminating circuit for discriminating whether or not the aperture is smaller than the limit aperture value, and the aperture value calculated by the aperture calculating circuit when the discriminator circuit does not discriminate the aperture value smaller than the limit aperture value. First and second subject within depth When the aperture value is set to the photographic aperture value as the aperture value that can be set, and the determination aperture value is determined to be smaller than the limit aperture value, the first subject and the second By determining that it is impossible to bring the subject within the depth, it is possible to issue a warning or the like, and the above object is achieved.

<Example> The principle of the present invention will be described before describing an example of the present invention.

Considering subjects A and B at two different positions, in order to bring both subjects into focus, first,
The lens is focused at about the center of both subjects, that is, at a position where the defocus amounts for both subjects match.
In this state, the amount of differential focus of subjects A and B is approximately the same, so if the apertures at this time are set so that they are within the depth of both subjects, it will be said that both 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 subjects A and B, the autofocus device obtains the defocus amount in which the defocuses of the two subjects match, and the aperture value is obtained by dividing this amount by the circle of least confusion. Both are designed so that they are in focus. When the calculated aperture value at this time is outside the limit value of the aperture, the above-mentioned object cannot be achieved. However, when the calculated aperture value exceeds the limit value on the open aperture side, The aperture value has a deeper depth than the calculated aperture value, and there is no problem even if it is controlled with the open aperture value, but if it is outside the limit value of the small aperture value, controlling with this limit value will make the depth shallow. It will be. Therefore, in the present invention, when the small aperture value is out of the limit, the warning can be given.
Next, examples of the present invention will be described.

FIG. 1 is a circuit diagram showing an embodiment of an aperture determination device according to the present invention.

In the figure, SPC is a light receiving element for TTL open photometry, DI is a diode, and AMP1 is an operational amplifier, which is a known photometry circuit, and outputs BV0 of the apex as its output. VR1 is a variable resistor for film sensitivity setting and sends 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 an AD conversion circuit that AD-converts the output of the above-mentioned amplifier ADD1 (EV of Apex) and its output is a microcomputer UC
It is input to the PE port of the OM (hereafter 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 the shooting mode (shutter priority, aperture priority, program) information of the camera.
Tell the PA port. SWTV is a shutter time setting member that sets the shutter time information, and SWAV is an aperture setting member that sets the 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 into analog (voltage). The output from the circuit DA1 is an amplifier A that constitutes a subtraction circuit.
It is input to MP2, and is calculated with AV0 set in the resistor VR2 by the amplifier AMP2, and the number of diaphragm stages (ΔAV of the apex) is obtained as the output.

DRAV is an aperture control circuit which has a start magnet MG1 and a stop magnet MG2 for aperture control, and controls the aperture based on the output ΔAV of the amplifier AMP2. EXPANDER
Expands the control shutter time information TV output from the PJ port of the microcomputer UCOM and transmits it to the shutter control circuit DRTV,
This is a real-time expansion circuit for controlling the shutter time control. The shutter control circuit is a magnet MG for the front curtain.
3 and the trailing-curtain magnet MG4 are operated, and the shutter leading and trailing shutters (not shown) are run by operating each magnet.

The control circuits DRAV and DRTV are operated by a signal from the PI port of the microcomputer UCOM to start the 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.
Blinks the aperture display value with a signal from the AVB LINK 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 which selectively drives the LEDs D1 to D24 to be lit by the outputs of the comparators CP1 to CP24. The LE
Indicate the scale SCALE on DD1 to D24 on the display plate with the FNO of the aperture, and display the aperture value according to the depth information.

SW1 is a switch that is turned on when the shutter button (not shown) is in the first operation state, SW2 is a switch that is turned on when the button is in the second operation state, and SWdep is turned on when the first operation button (not shown) is pressed. SWCLK and SWCLK are switches that 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 the shutter charge and the film winding mechanism. The SWCHG is a detection switch that is turned on when the mechanical charge is completed in conjunction with the above mechanism and is turned off when the shutter running is completed. The switch is connected to the PM port of the microcomputer UCOM. 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 the elements described later are arranged on the lens side mounted to 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 a communication controller C from the PQ port of the microcomputer UCOM
CONMT is a motor control that determines the lens drive direction (forward or reverse direction) by the drive direction signal output together with the lens drive amount information, which is the up / down counter in which the lens drive amount information input via ONCOM is set. In the circuit, the circuit transmits the direction signal to the counter CNT and determines the up or down mode of the counter. DR2 is the motor M in the direction determined by the motor control circuit CONMT.
In the motor drive circuit that drives T2, the lens L1 moves in the optical axis direction by a mechanism that works in conjunction with the motor MT2. LP1 is a comb-shaped pattern that moves in conjunction with the movement of the lens L1,
The pattern moves to turn on and off the contact piece LP2,
A pulse is sent from P2 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: Display circuit d from PK, PL port of microcomputer UCOM d
A signal to turn off isp1 and disp2 is sent and the display circuit
disp1 and disp2 turn off.

Step 3: Zero is set in the memory inside the microcomputer as information n of the number of times the switch SWdep is pressed, 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, SW at PV port of microcomputer UCOM
The state 2 is detected, and as a result of the detection, the process proceeds to step 5 when the switch SW1 or SW2 is on, and proceeds to step 12 when SW1 and SW2 are off.

Now, assuming that the shutter button is operated and the switch SW1 or SW2 is turned 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 measuring subroutine, steps 67 and below are executed.

Step 68: The focus detection circuit AFD is driven to input the defocus amount Xnow obtained by the focus detection circuit AFD based on the image incident on the sensor AFS via the lens L1 via the PP port of the microcomputer UCOM.

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 differential focus amount Xnow and the zoom information.

Step 7: Read out the lens driving routine in steps 70 to 72. As a result, steps 70 to 72 are executed.

Step 71: The lens drive amount signal MV is sent 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, a signal indicating the driving direction is also sent from the PQ port together with the driving amount signal MV, and the motor control circuit CONMT determines the forward / reverse rotation with respect to the motor based on the signal.

Further, the signal determines the up or down mode for the counter CNT. Further, the motor control circuit CONMT transmits a drive signal to the motor drive circuit DR2, the motor MT2 rotates in the direction determined by the drive direction signal, and moves the lens L1 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, counting operation is performed, and the count value is the set lens drive
When it coincides with MV, 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 drive amount MV to be in the focused state.

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

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

In steps 64-66, the output of the AD conversion circuit AD1, that is, the EV 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 56 are executed.

Step 45: It is judged whether or not the number n of times the switch SWdep is pressed is n ≧ 2. Assuming that the switch SWdep has not been pressed once, n = 0, so the step shifts to 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
Calculation with AVSET value EV-AVSET = TV is performed.

Further, in step 49, an AV value uniquely corresponding 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, and in step 51, the AV value is selected. The selected AV value and the above EV value are calculated.
TV value is required.

Also, in step 50, the TV value (TV value set by the shutter time setting member SWTV input to the PC port of the microcomputer UCOM
(SET) is read, and EV-TVSET = AV is calculated in step 52 with the EV value obtained in the photometric routine.

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.
Further, in step 54, the control AV value is transmitted to the DA conversion circuit DA1 via the PH port of the microcomputer UCOM, and a voltage corresponding to the AV value is output. Further, at step 55, the control TV value is transferred to the real-time expansion circuit EXPA via the PJ port of the microcomputer UCOM.
It is transmitted to NDER, and at step 56, it returns to the X in-routine, that is, step 10.

Step 10: Switch S in PD port of microcomputer UCOM
When the state of W2 is detected and the switch SW2 is on, the process proceeds to step 11, and when it is off, the process proceeds to step 3.

From the above, the shutter button is in the first operation state,
When SW1 is on and SW2 is off, steps 3 to 10 are repeatedly executed, and the lens always moves to the in-focus position based on the distance measurement result, and the shutter time and aperture value in the selected mode are displayed.

When the shutter button is shifted to the second operation state during the above process, this is detected at step 10, step 11 is executed, and the sequence routine of steps 57-63 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 a diaphragm regulating member (not shown), and at the same time, the output ΔAV of the amplifier AMP2 activates the magnet MG2 when the diaphragm is regulated by the diaphragm regulating member to drive the diaphragm regulating member. To stop.

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. Therefore, the output of the amplifier AMP2 corresponds to the control aperture value AV.
The AV value is shown, and the aperture becomes the control AV value in the above operation.

Further, after this, the magnet MG3 of the shutter control circuit DRTV operates, the front curtain of the shutter starts running, and at the same time as the running of the front curtain, the real-time extension circuit EXPANDER operates and starts timing operation. The control TV value is input to the circuit EXPANDER as described above, and the circuit generates a timed output of the time when the TV value is extended and operates the magnet MG4 to drive the rear curtain of the shutter. With the above, control of the aperture and the shutter speed is performed. In step 59, the state of the switch SWCHG is detected, and the switch SWCHG is turned off to allow the shift to step 60.

The switch SWCHG is configured to be turned off when the traveling of the shutter rear curtain is completed, and therefore the process proceeds to step 60 after the exposure operation is completed. In step 60, the microcomputer UCOM PN
Send a drive signal from the port. With this, the drive circuit DR1
Is activated 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 steps 1 to 11 described above, 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 has not been operated after the power of the camera has been turned on, the process proceeds to step 12 in step 4 and the steps after step 12 are executed.

Step 12: The state of the switch SWdep is read by the PV port of the microcomputer UCOM, and when the step SWdep is on, the process proceeds to step 13.

Now, if the first operation button is pressed with the distance measuring field of view of the subject A in FIG. 5 being pressed, the switch SWdep is turned on, so steps 13 to 15 are executed. The steps 13 to 15 are the same as the steps 5 to 7 described above, whereby the lens moves to the in-focus position based on the distance measurement result.

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

Step 17: Call the display 2 routine of steps 73 to 75 and execute steps 73 to 75.

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.

In step 16, n = 1 is set, and disp (0) and
Since disp (1) is set to 0, disp (n) is di
sp (1) is displayed, and disp (0) and disp (1) = 0 are displayed.

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

The display disp2 is configured as shown in FIG. 2, and the information disp (0), disp (1) from the PL port of the microcomputer UCOM is displayed.
= 0 is detected by the comparator array, the triber 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 step shifts to 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, at steps 13 to 15, the lens shifts to the position corresponding to the subject in the distance measuring field when the switch SWdep is pressed, so the defocus amount here is compared to the subject when the switch SWdep is pressed for the first time. Thus, the amount of differential focus up to the subject currently being framed with respect to the lens position in focus. In this way, step 20 is executed after the differential focus amount for the current subject is obtained.

Step 20: Here, an operation 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 differential focus and the circle of least confusion, the switch SW
Depth information necessary to bring the current subject position into focus while dep is held in focus with respect to the subject position when pressed is calculated.
This calculation result is set as sp (0).

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 corresponds to the depth information obtained in step 20.
Turn on the FNo and F1 dots.

The subject position is now 2 when the first switch SWdep is turned on.
m, and when the distance measured by step 19 is 3
If it is at the position of m and the defocus amount at this time is 450 μm, the depth information is disp (0) ≈12.8. Therefore, in this case, the comparator CP4 in Fig. 2 generates the detection output, turns on the dot D4, and keeps the lens position in focus for the 2m subject, keeping the 3m subject in focus. FNo required to bring the product into a closed state is 1
Show that it is 6.

After that, 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: If the state of the switch SWCLR is detected and it is detected whether or not the second operation button is pressed, and if the second operation button is pressed and the switch SWCLR is turned on, the process proceeds to step 2 above. The above-mentioned operations after step 2 are executed again. The second operation button is a clear button, and pressing this button prohibits the 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 the current zoom information matches the previous zoom information detected before that. Detection is done. 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 shifts to step 2 to return to the normal operation mode.

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 again. Therefore, switch SW once
After dep is turned on, switch SW dep 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, when the shutter button is set to the second operation state, the process proceeds to step 11, 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: Step SWdep push count information n +
Do 1 Now, it is the second press of the step SWdep, and n = 1 by the step 16 when the first step SWdep is pressed.
Therefore, n = 2.

Step 28: The above photometry routine is executed. As a result, the second switch SW for the lens in focus on the subject position when the first switch SWdep is pressed
The defocus amount Xnow for obtaining 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 obtained when the switch SWdep is pressed n times XT: Defocus amount that is uniform for each subject) Since XT is set to 0 in step 16, the above,
The calculation result X (2) = Xnow.

Since n = 2 now, 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.

By this calculation, the amount of movement of the lens to the intermediate position between the current lens position and the lens position for focusing on the subject position 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 SWdep
The intermediate position with respect to the subject position when is pressed is obtained.

Therefore, for example, as shown in FIG. 5, the subject A when the switch SWdep is pressed for the first time is at the position of 2 m, and when the subject B of 5 m is put in the distance measuring field when the switch SWdep is pressed next time, the subject A is selected at step 29. A defocus amount Xnow = X (2) from the focused state until the subject B is focused is obtained, and at step 30, half of this defocus amount, that is, between the subjects A and B, and the subject A. , B, the differential focus amount XP to the position where the uniform differential focus amount is obtained.
Now, in the above case, the differential focus amount Xnow = for the subject B
If X (2) is 805 μm, XP is 805/2 = 403 μ
m.

Step 31: XP-XT is performed to obtain the lens drive amount MV. 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 shifts from the state of focusing on the subject A to the position of the intermediate position 3.08 m from the subject A, B to the uniform defocus amount of 403 μm.

Step 33: XT = XP.

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

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

Step 35: The above 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: Depth information obtained in step 34 The maximum absolute value of disp (K) for the object at each time is set as the control aperture FNodep in this mode. Disp in the above case
(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 and AVdep <AV0
When AVdep <AV0, that is, when AVdep is more open than AV0, the value of AVdep is set to the limit value AV0.

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

In the above steps 38 to 42, it is determined whether or not AVL ≧ AVdep ≧ AV0. In this case, in step 43, the microcomputer UCOM AV
Turn off the BLINK terminal and then proceed 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, dots D4 and D21 in FIG.
FNo = FNodep is also displayed to keep B in focus, and a defocusing to focus 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.

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

Therefore, in this case, the AVdep is displayed as the aperture value on the display unit 1 regardless of the setting mode.
EV-AVdep = TV value obtained by V value is displayed as the shutter time.

At this time, when AVdep is> AVL, the display value corresponds to AVL, and since the terminal AVBLINK is turned on at step 41, the aperture value blinks and both subjects A and B are in focus. Warn that you will not be photographed. AVde again
When p <AV0, AVdep is set to AV0. In this case, AVdep
Has a deeper depth, so 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. If it is moved to step 26, this is determined in step 26, and the processing proceeds to step 11, and the above sequence routine is executed. With this, the aperture is controlled based on the AVdep, and both the subjects A and B are in focus. Will be filmed.

The above operation is the operation when the step SWdep is pressed twice, but when the SWdep is pressed twice or more, similarly, the AVdep for keeping the respective subjects in focus is obtained and displayed. It will also be used for aperture control.

As described above, according to the present invention, the aperture that automatically brings the different subjects into focus is automatically calculated, so that even a beginner can easily perform focusing with different subjects. It is possible to do.

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.

<Effect> As described above, in the present invention, the lens is moved to a position that internally divides the defocus amount between the first and second subjects, and at that time, the defocus amount between the first and second subjects is further increased. Depending on the, the aperture is calculated by setting the aperture that sets the first and second subjects within the depth, so it is possible to shoot with the first and second subjects at different positions both within the depth. In addition, when the calculated aperture is smaller than the limit aperture, it is determined that it is impossible to shoot both the first and second subjects within the depth. It is possible to give a warning to the photographer whether or not it is within the depth.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a camera adopting an aperture control device according to the present invention, and FIG. 2 is a display disp shown in FIG.
2 is a circuit diagram showing an embodiment of FIG. 2, FIG. 3 and FIG.
(F) is a flow chart showing a program incorporated in the microcomputer UCOM of FIG. 1, and FIG. 5 is an explanatory diagram showing a finder field of view of the camera of FIG. UCOM: Microcomputer AFD: Focus detection circuit disp2: Display

Claims (1)

[Claims] 1. A focus detection circuit for obtaining a defocus amount for a subject captured in a measurement visual field, and a focus detection circuit for a first subject and a second subject captured in the measurement visual field. Drive circuit that moves the imaging optical system to a position that internally divides the defocus amount between the first subject and the second subject based on the defocus amount, and the defocus between the first subject and the second subject. An aperture calculation circuit that obtains an aperture value for keeping the first subject and the second subject within the depth according to the focus amount, and whether the calculated aperture value is smaller than the limit aperture value on the small aperture side. And a discriminating circuit that discriminates the aperture value calculated by the aperture calculating circuit when the aperture value is not smaller than the limit aperture value by the determining circuit. Taken as an aperture value that can be within In addition, it is impossible to set the first subject and the second subject within the depth when it is determined by the determination circuit that the calculated aperture is smaller than the limit aperture value. A camera characterized by being determined to be present.