JPS59140426A - Motor control device of lens interchangeable automatic focusing camera - Google Patents

Abstract

PURPOSE:To execute automatic focusing of a lens by making a lens side which is capable of automatic focusing have an information regarding a moving extent to a unit rotation of a motor, and varying a constant by its data in a controlling circuit side. CONSTITUTION:An analog video signal of a sensor 33 is inputted to an input terminal M0 of an interface circuit 101, converted to a digital value by an A/D converter, and inputted to a CPU 102. The CPU 102 generates a feed amount of a lens, an operation of EXT, and also a control signal based on its operation result. An input terminal M1 of the interface circuit 101 is connected to a power source VDD through a resistance R1. The lens side is provided with a device for inputting an information related to a lead, etc. of its lens to a camera body. When an interchangeable lens is installed to the camera body, this resistance R2 is connected to the resistance R1 of the camera body side. Voltage Vin=[R2/(R1 +R2)] X VDD is applied to the input terminal M1 of the interface circuit 101. The CPU 102 obtains a coefficient K of a moving extent of a lens to a standard lens from said information, and utilizes it for automatic focusing of its lens.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a camera that is equipped with a control circuit such as a microprocessor (hereinafter referred to as CPU), and uses signals from the CPU to control a motor that drives the lens of the camera. The present invention relates to a lens drive motor control device that enables automatic focus adjustment of a lens.

The motor movement amount and direction from the current position of the standard lens attached to the camera to the in-focus position can be detected from the output of the distance measurement sensor, and a control element measurement value can be output.

The principle will be explained with reference to FIGS. 1, 2, and 3. FIG. 1 is a schematic diagram showing the positional relationship between a sensor and a lens of an automatic focus detection system. FIG. 2 is a graph showing the output of the sensor of the system.

Focusing on the luminous flux B, which is divided into two in the horizontal direction around the optical axis of the lens 30, passes through different parts of the periphery of the exit pupil, and enters the sensor 33. As shown in FIG. 3, the sensor 33 is formed of a CCD and a lenslet group (a small lens group corresponding to each pair of elements of the CCD), and is arranged at a position optically equivalent to the film surface.

The elements of group A are ao+al, a2. ~am,B
The elements of the group are bo, bl, b2. ~bm, and elements with corresponding subscripts form a pair,
Each pair is associated with a lenslet.

The luminous flux A and the luminous flux B are directed from the focal position of the lens 30 to the optical axis direction (
1 and 2 when paying attention to each element of the CCD of groups A and B of the sensor 33.
A spatial phase difference ΔX shown in the figure will occur.

The effective f value of the microlens on the entire surface of the sensor 33:
If r=2.8, the angle at which each element of the sensor faces the exit pupil of the photographing lens is related to the value of f=2.8.

When the f-number of the photographic lens is large, the exit pupil is faced at an angle corresponding to f4. The f value setting of this sensor 33 is set electrically high to the terminal input of the sensor 33.

Determined by adding with a low signal.

Therefore, the photographer may perform a switching operation manually and apply a signal to the sensor 33, or the switching may be performed automatically using a signal piece on the photographing lens side.

On the other hand, the position of the sensor 33 and the amount of deviation from the imaging point of the photographing lens (extension error ΔZ) and the first
The relationship between the deviation (ΔX) of the luminous fluxes A and B shown in the figures and FIG. 2 is expressed by the following equation.

ΔZ=k (Δx/f2.8) ・・・−・−・11
Since ΔX can be calculated from the video signals of each sensor of the A and B groups of the proportional constant sensor 33 using an arithmetic expression, the amount of ΔZ can be obtained from equation (1).

Once the amount of ΔZ is determined, the lens can be adjusted to ΔZ using a motor etc.
Automatic focus adjustment can be performed by driving the lens.

The structure of such a coupler, which has already been proposed by the inventors of the present application, will be explained with reference to FIG.

The drive motor 1 is a motor used for both lens focusing drive and camera operation drive. The rotation of pinion 2, which is the output shaft of motor 1 (7), passes through reduction gear train 3 and gear 4.
The transmission is transmitted to the 5th gear, which is driven by the 5th gear. In this Kura-Sochi gear 5, an electromagnetic Kura-nochi 6 moves up and down in the figure in response to a control signal to switch power transmission. In the figure, the clutch gear 5 is connected to the gear 7, and the driving force from the motor 1 is transmitted to the gear 7 and the gear 8.
The signal is transmitted to the camera drive mechanism 9 via the . The camera drive mechanism 9 has a well-known configuration for winding the film outside the shirt and for mirror-driving the shirt release, and should be understood as a part for performing electric camera operations other than AF (automatic focusing). When a signal is connected to the electromagnetic clutch 6 in the state shown in this figure, the clutch gear 5 is moved downward,
The clutch gear 5 is separated from the gear 7 and the lens drive gear 12
The driving force from the motor 1 is switched to the lens driving system. A switch 10 is a switch that detects that the clutch gear 5 is in the upper state in the figure, and a switch 11
is a clutch position detection switch that detects that the clutch is on the lower side.These switches form a clutch information sensor that detects and outputs the state of the clutch. The rotation of the lens drive gear 12 is transmitted to the coupling 34 of the camera mount via the gears 13 to 20, and then to the coupling 24 on the lens side. The main lens 30 is connected to a lens-side camp ring 24 via a helicoid 26, and is moved forward and backward by the rotation of the gear 25. The main lens 30
The light beam that has passed through passes through the translucent part at the center of the mirror 31, which also serves as the finder optical path, and the optical path is changed by the auxiliary mirror 32, and then reaches the distance measurement sensor 3 installed at the bottom of the mirror box.
It is guided by 3.

The output of the ranging sensor 33 is output from the CPU mounted on the camera.
The amount of rotation of the motor required to move the lens by the amount of ΔZ, more precisely the number of output pulses (N) of the encoder corresponding to the rotation of the motor, is calculated by ΔZ.
is output as

The encoder converts the amount of rotation of gear 20 in the lens drive system into gear 21 . It is taken out to a perforated disk 28 via a gear 22, and the rotation of this disk 28 is detected by an LED 29 and a phototransistor 27.

The CPU stops the motor 1 when the number of output pulses from the encoder reaches the number (N), performs another measurement using the distance measuring sensor 33, and returns the focus when it is confirmed that the desired movement has been performed. Generates an output confirming completion of adjustment.

This method is based on the premise that the amount of lens extension relative to the amount of rotation of the motor 1 is constant.

Therefore, generally speaking, this method cannot necessarily be applied if the lens changes. Due to the lens structure, it is difficult to make the amount of lens extension constant for all lenses. This problem will be further explained.

Since the rotation angle (θ+1) of the helicoid drive gear 25 and the rotation angle (θE) of the encoder 28 are in a proportional relationship, the following equation holds true.

θll=to, xθE (2) θH:
Helicoid rotation angle θE: 1 to the encoder rotation angle: The proportionality constant θH is determined by the rotation angle of the lens-side coupler and the gear ratio between the coupler and the helicoid.

If the number of pulse signals generated in the photocoupler by the rotation of the encoder 28 is (Nc), then (Nc) is also proportional to θ■.

θH=2 XNp ・・・・・・・・・(3)(
k2: proportionality constant) The lead of the helicoid 26 is the lens 3 that moves for focusing.
The mass of the member on the 0 side is determined by the amount of delivery.

Furthermore, since the rotation angle of the helicoid 26 is restricted, it is necessary to provide a large lead for a telephoto lens or a macro lens that has a large extension amount.

When the lead is increased, the lens driving torque on the coupler 34.24 axis increases. Since there is a restriction on the output torque of the motor 1, a problem arises in such a case. Therefore, in such a case, the pinion gear 25 of the coupler shaft and the helicoid 2
It is also necessary to consider changing the gear ratio between gears 6 and 6 to absorb the increase in lens drive torque due to the increase in lead, and to push the torque on the coupler shaft below a certain level.

Therefore, kl is the gear ratio in the lens and the helicoid 26
This is a mechanical setting value determined by the lead etc.

The aforementioned lens extension amount ΔZ (EXT) is closely related to the lead of the helicoid 26.

Now, the rotation angle of the photographic lens with respect to the optical axis is θL.

If the amount of feed (i.e. lead) when rotated 360° is LD, then EXT=LD
LD X (θH/360')・ ・ ・ ・ ・
・ ・ ・ ・(4) (R3: proportionality constant) It is expressed as follows.

From equations (3) and (4), EXT=2 Xk3XLD X (Nc/360'
)...(5) In the end, the lens extension amount IXT) is proportional to the lead (LD) and the number of pulses detected (NC).

Once the amount of extension of the photographic lens to the in-focus position has been calculated from the video signal of the sensor 33, the motor 1 is rotated to extend the lens 30. At this time, the number of pulses Nc is measured, and if it reaches a predetermined value, the motor 1 is stopped.

If the lead of the photographic lens 30 is different, for example if the lead becomes larger, the predetermined number of pulses must be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problem and provide a motor control device for a lens exchangeable automatic focusing camera that can obtain lead-related information from the lens side and smoothly adjust the focus even when a different lens is attached. It's about doing.

In order to achieve the above object, a motor control device for a lens exchangeable automatic focusing camera according to the present invention calculates the amount of motor movement (N ) and a direction and outputs a control element measurement value; a motor drive circuit that drives a lens drive motor in forward and reverse rotation; and a movement amount detection device that detects a rotation amount (NC) of the motor. Said (N)
When the difference between and (Nc) reaches within the allowable range (No), a control signal to stop the motor is output to the motor drive circuit, a new (N) is obtained from the distance measuring circuit, and the new (N) is In a motor control device for an automatic focusing camera with interchangeable lenses, the motor control device is configured of a control circuit that outputs a control signal to the motor drive circuit until the motor reaches within the above (No). providing a signal generating device corresponding to a feed ratio (K) with respect to the standard lens, and providing means for transmitting the (K) to the control circuit when the interchangeable lens is attached to the interchangeable lens and the camera body; The control circuit calculates (Nc/K), and the difference between (N) and (Nc/K) is within the tolerance range (No/K).
K), outputs a control signal to the motor drive circuit to stop the motor, and outputs a control signal to the motor drive circuit to stop the motor when the distance measurement circuit reaches the distance
The control circuit includes a control circuit that outputs a control signal to the motor drive circuit until the new (N) reaches the (NO/K).

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 5 is a block diagram showing an embodiment of a motor control device for an automatic focusing camera with interchangeable lenses according to the present invention.

In Figure 5, the bonding surface of the camera body and lens is indicated by the broken line 1.
It is indicated by 00. Corresponding parts in FIG. 4 are also marked with broken lines.

The interface circuit 101 has a built-in A/D converter having multi-channel input terminals. The analog video signal from the sensor 33 described above is inputted to the input terminal MO of the interface circuit 101, converted into a digital quantity by an A/D converter, and then taken into the CPU 102.

The CPU 102 is a control circuit that calculates the aforementioned EXT (=ΔZ) and generates control signals based on the calculation results.

The CPU 102 is connected to the pulses from the encoder 103 described earlier with reference to FIG. 4, and obtains information on the actual drive amount (Nc) of the motor l.

Further, the lens is provided with a limit switch for detecting the limit of lens driving, and a signal indicating the lens driving state is connected to the port P28 of the CPUIO2.

A signal indicating whether automatic focus adjustment mode or manual focus adjustment mode is selected is connected to ports 1-P27 of CPUI O2.

The clutch drive circuit 104 is a drive circuit for driving the clutch drive electromagnet 6 described above in connection with FIG.
It is operated by a control signal from the PU 102.

The display circuit 105 is a circuit that displays the degree of focus adjustment, and is used as an auxiliary means (focusing) when a lens that cannot automatically adjust the focus is attached to this camera.
(aid) etc.

The motor drive circuit 106 is a circuit that drives the motor 1 using a control signal from the CPU 102.

This motor drive circuit 106 can rotate the motor 1 in forward and reverse directions, and can drive it at full speed and at very low speed.

The direction of rotation of the motor is determined by changing the direction of the current flowing through the motor. Further, full-speed driving is performed by supplying continuous current, and slow-speed driving is performed by supplying intermittent current, as shown in FIG.

Next, the lens read information is sent to the CPU 10 on the camera body side.
The circuit incorporated in 2 will be explained.

The input terminal M of the interface circuit 101 is a resistor R1.
It is connected to the power supply VDD through.

A device is provided on the lens side for inputting information related to the lead of the lens to the camera body.

A resistor R8 is inserted into the standard lens for automatic focusing of this camera, and when the standard lens for automatic focusing is attached to the camera body, the resistor Ro is connected to the resistor R1 on the camera body side.

At this time, the input terminal M of the interface circuit 101,
The voltage Vin is given by the following equation.

Vin= (Ro/(R+ +Ro)) xV
DD is applied.

The CPU 102 replaces ΔZ with the actual driving amount of the motor 1 (the number of output pulses of the encoder 103) when the standard lens is attached and outputs it.

(5) Equation 2. 3. If LD is data related to a standard lens, the motor movement amount (N) output by the CPU 102 is N-Δ
Zx (360°) / (3xLD to k2x)...
(6) is given by.

Therefore, when a standard lens for focus adjustment is attached, by driving the motor 1 until the number of output pulses Nc of the encoder 103 corresponding to N is obtained,
Automatic focus adjustment as described above becomes possible. The camera control shown in FIG. 4 described above is based on this principle.

In the present invention, in order to distinguish between a standard lens for focus adjustment and other lenses for automatic focus adjustment that have different leads from this lens, lead information of the lens is also incorporated into the CPUI O2 on the camera body side for the standard lens. The resistor R8 is pre-installed on the standard lens.

Standard, that is, the input terminal M of the interface circuit 101
When the voltage Vin of 1 is (Ro/(R++Ro))XVDD, control is performed by considering that N and Nc correspond to 1:1.

The amount of movement of the lens corresponding to NC=1 is taken as a reference unit.

Any other autofocus one-cycle lens has the above-mentioned Nc=1
If the amount of movement of the lens corresponding to is twice the reference unit, the lens is provided with another resistor R2 on the lens side that can transmit the K to the camera body side.

A lens with a large focal length increases the weight of the lens itself, and also requires a large lead due to constraints on the rotation angle of the helicoid, which increases the lens driving torque TI on the coupler axis.

The drive torque Tc on the coupler shaft of the small motor on the body side is restricted to a certain value. Tc>T to drive the lens
7! Must be. Therefore, by incorporating a reduction gear between the coupler shaft on the lens side and the helicoid mechanism, it is possible to reduce the torque "TJ" on the coupler shaft.

In this case, it is necessary to increase the rotation speed of the coupler shaft by the ratio of the reduction gear.

If the lens feed amount per unit rotation amount of the motor is smaller than that of a standard lens, the above value will be smaller than 1.

The CPU 102 reads this value and determines the value of the above.

When this lens is attached to the camera body, this tLH>'
cR2 is connected to resistor R2 on the camera body side.

Voltage Vi of input terminal Ml of interface circuit 101
A different voltage from the above expressed by the following equation is connected to n.

Vin=(R2/(R1+R2))xVDD is applied.

The CPU 02 obtains K from the information and uses it for automatic focusing of the lens.

Further, the automatic focusing lens is provided with a switch that indicates the limit position of lens drive (infinity position and close limit position).

To facilitate understanding, we will first explain the control circuit (CPU) when the standard lens for focus adjustment is attached.
) 102 focus adjustment program will be explained.

As mentioned above, when the standard lens is attached, the voltage Vln of the input terminal M of the interface circuit 101 is (Ro/(R+ +Ro))XVDD, so N and Nc have a one-to-one correspondence. Think and control.

The following program corresponds to the program shown in FIG. 9 when N=1.

FIG. 7 schematically shows the relationship between predetermined constants for automatic focus adjustment.

(Step 700) of the program shown in FIG. 8 is based on the information regarding Δ2 connected from the sensor 33 via the interface circuit 101, and the distance (N) and direction from the current position of the lens attached to the camera to the in-focus position. This is a step to support

(Step 701) is a step for determining which mode the camera is set to. When it is confirmed in this step that the automatic focus adjustment mode (AP) has been selected, the next step is entered.

If automatic focus adjustment mode is not selected, skip the execution of the automatic focus adjustment mode program described below and select A.
E (automatic exposure adjustment) mode is executed.

(Step 702) is a step of determining whether the predicted movement amount (N) is within the allowable limit (No) or exceeds (No).

This (No) is a numerical value used to judge the autofocus joint result, and the movement amount (N) is within the allowable limit (NO), (
If N)≦(No), there is no need to perform focus adjustment, so the camera skips the automatic focus adjustment described below and enters the automatic exposure adjustment (AF) step.

This condition is an extremely rare condition that occurs when the current position of the lens coincidentally corresponds to the subject distance. The above-mentioned condition will not be established in the trial.

(Step 703) is the step where (N)≦(No)
This is a step to prepare for automatic focus adjustment, which is executed when it is confirmed that the condition is not satisfied.

In this step, the LED 629 of the photocoupler constituting the movement amount detection device is turned on.

(Step 704) In this step, the predicted value (N
) is larger than (N m ). (N
m) is an inherent constant, which is 9 to 3 of the total moving area of the lens.
It is an arbitrary value of about 1/2.

Please refer to FIG.

The amount of movement (N) indicated by the predicted value is compared with a constant value (Nm), and if the amount of movement (N) is large (step 705
), and set the movement amount (N) indicated by the predicted value to a constant value (N
If the amount of movement (N) is small compared to step 708), the process proceeds to step 708).

(Step 705) is a step in which the lens motor is fully driven, and a continuous drive control signal is supplied to the drive circuit.

(Step 706) During the entire driving period, the control circuit (CPU
) 600 receives a pulse corresponding to the movement of the lens from the movement amount detection device, and the control circuit calculates the integrated value of the pulse (
Find (Nv) = (N) (Nc) using this (NY)
and the number of seats (Nstop).

The constant (Nstop) is large enough to be compared with the constant value (Nm) described above, and in this embodiment, the relationship (Nm)>(Nstop)>(No) is given.

Note that (No) is a constant indicating an allowable limit.

(Step 707) In the above (Step 706), (NY
) ≠ (N s stop), then check the state of the limit switch in step 707, and if (NV) ≠ (N stop) and the limit switch is not on, (Nv) = The loop of (step 705), (step 706), (step 707), and (step 705) is continued until either the condition (Nstop) or the limit switch is on is satisfied.

(Step 713) In the above (Step 706), (Nv)
When establishment of = (Nstop) is detected, a stop control signal is connected to the motor drive circuit in this step.

In step 714, the LED 629 of the photocoupler constituting the movement amount detection device is cleared.

Subsequently, the above-mentioned (step 700) (step 701)
(Step 702) is executed.

(Step 700), the adjustment result is the new (N)
is loaded. If the camera mode is (AF) in (step 701), that is, if the mode has not changed, in the next step (step 702), the new (
N) is determined.

If this new (N) is less than or equal to (No.sub.2), it is assumed that the desired control has been completed by the focus adjustment, and the step of automatic exposure adjustment (AE) is entered.

When (N) exceeds (No), the above (step 703)
) (step 704) is executed.

Normally, the new (N) obtained by re-measuring the distance in step 701 is smaller than the previous (N), so (N) <('Nm
) holds true.

(Step 708) is (N) in the above (Step 704).
A step executed when < (Nm) is established, that is, when the predicted movement amount (N) is small,
An intermittent signal shown in FIG. 9 is supplied to the motor drive circuit to drive the motor at a low speed.

(Step 709) compares (N) - (Nc), that is, the remaining movement amount (NY) with the allowable limit value (No), and
v)≦(No), as described above (step 7).
13).

(Step 710) is the step in which (NV)≦(No
) does not hold, always check the state of the limit switch to ensure that the limit switch is not on and (NV
)≦(No) (step 710)
(Step 708) A loop of (Step 709) and (Step 710) is executed, and when (NV)≦(NO) is established, the above-mentioned (Step 713) is executed.

Next, regarding the above (NV), (Nv)≦(N.

) is not satisfied in the above (step 710), and in the above-mentioned (step 707), the limit switch is turned on before (Nv) = (Nstop) is not satisfied. Explain the operation.

(Step 711) When the limit switch is turned on in the above-mentioned (step 71O) or (step 707), a signal to stop driving the motor is sent in this step to stop the motor.

(Step 712) is a step of generating a control signal to slightly drive the motor in the opposite direction after stopping the motor in the previous step. , and executes the steps after step 709) to complete the focus adjustment.

The program shown in FIG. 9 is a program that can be applied to all lenses that are equipped with information output means for the amount of movement.

(Step 700) (Step 701) of the program shown in FIG. 9 is the same as described above.

(Step 800) is from the interface circuit to the CPU.
This step is a step of calculating the feed ratio (K) of the interchangeable lens attached to the camera when the motor of the interchangeable lens attached to the camera rotates by a unit amount with respect to the standard lens from the data read in step 102, and changing constants used in the program. .

(Step 702) means that the amount of movement (N) is within the allowable limit (N
This is a step of determining whether it is within (No./K) or exceeds (No./K).

As mentioned above, this (No) is a value used to judge the automatic focus adjustment result with a standard lens, but when the amount of extension is doubled, it is set to 1/K, and the error in the adjustment result between lenses is set to 1/K. Align.

If the predicted movement amount (N) is (N)≦(No/K), there is no need to adjust the focus, so the camera can skip the automatic focus adjustment described below and perform automatic exposure adjustment (A
Enter step F).

(Step 703) is the step in which (N)≦(No/
This is a step to prepare for automatic focus adjustment, which is executed when it is confirmed that K) is not satisfied.

In this step, the LED 629 of the photocoupler constituting the movement amount detection device is turned on.

(Step 704) In this step, the predicted value (N
) is larger than (Nm/K). (N
m) is an inherent constant, which is 9 of the total moving area of the standard lens.
This is an arbitrary value of ~1/3, but if the so-called lead is doubled, it must be set to (Nm/K).

The amount of movement (N) indicated by the predicted value is compared with a constant value (Nm/K), and if the amount of movement (N) is large (step 7
05), the amount of movement (N) indicated by the predicted value is compared with a constant value (N m /K), and if the amount of movement (N) is small, the process proceeds to (step 708).

(Step 705) is a step in which the lens motor is fully driven, and a continuous drive control signal is supplied to the drive circuit.

(Step 706) During the entire driving period, the control circuit (CPU
) 600 receives a pulse corresponding to the movement of the lens from the movement amount detection device, and the control circuit calculates the integrated value of the pulse (
Using (Nc/K), (Nv) = (N) - (Nc/K)
Find this (NV) and the constant (N 5top/K )
Compare with.

The constant (Nstop) is large enough to be compared with the constant value (Nm) mentioned above, and for a standard lens, (Nm) > (
It was mentioned above that the relationship of Nstop)>(No) is given.

(Step 707) In the above (Step 706), (Nv
)≠(Nstop/K), always check the state of the limit switch in step 707, and if (Nv)≠(Ns stop) and the limit switch is not on, (NV) =(N 5top/
(Step 7゜5) (Step 70
6) (Step 707) Continue execution of the loop of (Step 705).

(Step 713) In the above (Step 706), (Nv)
"' When establishment of (Nstop/K) is detected, a stop control signal is connected to the motor drive circuit in this step.

In step 714, the LED 629 of the photocoupler constituting the movement amount detection device is cleared.

Subsequently, the above-mentioned (step 700) (step 701)
(Step 702) is executed.

(Step 700), the adjustment result is the new (N)
is loaded. Then, if the camera mode is (AF) in (step ?01), that is, if the mode has not changed, in the next (step 702), the new (
N) is determined.

If this new (N) is less than or equal to (No/K), it is assumed that the desired control has been completed by the focus adjustment, and the automatic exposure adjustment (AE) step is entered.

When (N) exceeds (No/K), the above (step 7)
0'3) (step 704) is executed.

Normally, the new (N) obtained by re-measurement in (step 701) is smaller than the previous (N), so in (step 704) (N) < (N
m/K) holds true.

(Step 708) is (N) in the above (Step 704).
< This step is executed when (Nm/K) is established, that is, when the predicted movement amount (N) is small, and is shown in FIG. 9 in order to cause the motor drive circuit to drive the motor at a low speed. An intermittent signal is provided.

(Step 709) compares (N) (Nc/K), that is, the remaining movement amount (NV) with the allowable limit value (No/K), and if (Nv)≦(No/K) is satisfied, as described above. (step 713).

(Step 710) is the step in which (NV)≦(No
) does not hold, the city checks the state of the limit switch and confirms that the limit switch is not on and (Nv
)≦(No/K) does not hold (step 710
) (Step 708) (Step 709) (Step 7
10) is executed, and when (Nv)≦(No/K) is established, the above-mentioned (step 713) is executed.

Next, regarding the above (Nv), (NV)≦(N.

/K) is not satisfied when the limit switch is turned on in the above (step 71o), and in the above (step 707), (Nv) = (Nstop/K)
We will explain the operation when the limit switch is turned on before .

(Step 711) When the limit switch is turned on in step 71o or step 707 as described above, a signal to stop driving the motor is sent in this step to stop the motor.

(Step 712) is a step of generating a control signal to slightly drive the motor in the opposite direction after stopping the motor in the previous step. After this step, the process returns to the previously described (Step 708) and the motor is started again. , and executes the steps after step 709) to complete the focus adjustment.

Although the above description of the operation relates to an autofocusing lens, when a conventional lens (interchangeable lens before autofocusing cameras were designed) is inserted into the body, the display on the display device 105 can be used to Focus can be adjusted manually.

Since such a lens does not have a portion corresponding to R8 or R2, the voltage Vin at the M1 input terminal of the interface circuit IO1 is equal to VDI), and the voltage Vin at the M1 input terminal of the interface circuit IO1 is equal to VDI).
2, information that a conventional lens is attached is input.

The automatic focus adjustment described above is not performed. However, since the distance measurement sensor 33 can be operated, the camera user can manually adjust the focus using the display of the distance measurement results.

As explained above, according to the present invention, since the lens capable of automatic focus adjustment is provided with information regarding the amount of movement per unit rotation of the motor, the control circuit side changes the constant based on the data to adjust the lens. Automatic focus adjustment is possible.

If the constants are not changed, a delay in adjustment time due to overfeeding or insufficient feed is expected, and it will be difficult to uniformly adjust all lenses.

That is, according to the present invention, by automatically changing the constants of the same program, it is possible to smoothly perform automatic focusing of various lenses.

Various modifications can be made to the embodiments described in detail above within the scope of the present invention.

An example is shown in which a resistance is provided on the lens side as a signal generating device corresponding to the feed ratio (K) with respect to the standard lens when the motor rotates a unit amount on the interchangeable lens. ) It is also possible to prepare pins of different lengths corresponding to the lenses, and to transmit information by changing the resistance on the body side when the lens is attached.

In addition, although the above embodiments have shown examples of motors that are built into the camera body and are used to drive the lens and other drives, there is a motor that is built into the camera body and is used to drive the lens and other drives. Of course, it can also be used to control motors.

Only a control circuit is provided inside the camera body, and manual focus adjustment is performed using that circuit.

For automatic focus adjustment, it is also possible to adopt a configuration in which a device with a built-in motor is coupled to the camera.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the positional relationship between a sensor and a lens. FIG. 2 is a graph showing the output of the sensor. FIG. 3 is a graph illustrating the relationship between the structure of the sensor and light incident on the sensor. FIG. 4 is a schematic diagram for explaining an example of an automatic focusing camera previously proposed by the inventors of the present invention. FIG. 5 is a schematic diagram showing an embodiment of a motor control device for an automatic focusing camera with interchangeable lenses according to the present invention. FIG. 6 is a waveform diagram for explaining motor drive output. FIG. 7 is a graph showing the relationship between constants for control. FIG. 8 is a flowchart showing a motor drive program when a standard lens is attached. FIG. 9 is a flowchart showing a motor drive program when lenses with different feed speeds are attached. 1...Motor 30...Standard lens 33...Distance sensor 101...Interface circuit 102...CPU 103...Encoder 104...Clutch drive circuit 105... ...Display device 106...Motor drive circuit patent applicant Yashika Co., Ltd. Agent Patent attorney Inoro Hisute Itoko? 1ili
, j] 3rd store: 1numa Fl] April 1959 v Branch Patent Office Official Kazuto Wakasugi
1. Indication of matter A'1 1981 Patent Application No. 15089 2. Name of the invention Lens exchange automatic! Odor control camera motor; 1ill+
ilr device 3, relationship with non-considerations for hli correction z1\permission I 褥4, agent G, l+Ii correction of ta) Elephant Contents of specification and drawing amendment (Patent application 15089-1989) fll
``If the r value is large, use f4'' in the 1st row of the statement box 4.
If the 1F value is large, correct it to R4. (2) Figures 1 to 3 on page 5, line 9 of the specification to Figure 1 and 4.
Correct to. (3) [θII=kzXNp・
...(3)" to "θtl="k2xNc..."
...(3)". (4) Change “as if pressed” to 1 on page 9, line 12 of the specification.
Correct it to "hold it down." (5) rEXT= from line 1 to line 4 of page 10 of the specification
LD X (θL/36(1')=R3XLD X (
θ11 /, 360°)・ ・ ・ ・ ・ ・ ・
・(4) (R3 biproportionality constant)
rEXT=LD x (θL/360')=3 x
LD X (/711/360')・・・・
・ ・ ・ ・ ・ (4) (R3: proportionality constant)
”. (6) Correct "Signal" on page 13, line 13 of the specification to "limit signal terminal". (7) “What we can do” on page 19, line 16 of the specification
Correct "to be". (8) Correct [Automatic Exposure Adjustment (AF) J] to [Automatic Exposure Adjustment (AE) J] in lines 8 to 9 of page 20 of the specification. (9) rLED62 on page 20, line 18 of the book
Correct 9j to rLED29J. α0) From page 21, line 13 to line 14 of the specification, ``The control circuit (CPU) during the entire drive period 6'00J is corrected to the control circuit (CPU) during the entire drive period (CPU) 102J.'' (11) [Photocoupler LED 629J on page 22, line 18 of the specification is corrected to [photocoupler LED 29J. (12) "Figure 9" on page 23, line 19 of the specification is changed to "
Figure 6 is corrected. (13) rLED629 on page 26, line 16 of the specification
" is corrected to rLED29j. (14) Correct “the control circuit (CPU) 600 during the entire drive period” from line 12 to line 13 of page 27 of the specification to “control circuit (CPU) 102j during the entire drive period”. (I5) Book III, page 28, line 16, II, E
Correct D629j to rLED29J. (16) Change “Figure 9” on page 29, line 17 of the specification to “
Figure 6 is corrected. (17) Figures 3(n) and 5 of the attached drawings are amended to the attached Figures 3(n) and 5, respectively. that's all

Claims (1)

[Claims] (1) A distance measurement circuit that detects the motor movement amount (N) and direction from the current position of the standard lens attached to the camera to the in-focus position from the output of the distance measurement sensor and outputs a control element measurement value, and the lens. A motor drive circuit that drives the drive motor in forward and reverse rotation, a movement amount detection device that detects the amount of rotation (Nc) of the motor, and a difference between (N) and (Nc) that is within an allowable range (
When it reaches within the range (No), it outputs a control signal to the motor drive circuit to stop the motor, obtains a new (N) from the distance measurement circuit, and continues the process until the new (N) reaches within the range (No). In a motor control device for an automatic focusing camera with interchangeable lenses, which is configured with a control circuit that outputs a control signal to a motor drive circuit, the ratio of feed to the standard lens when the motor rotates a unit amount to the interchangeable lens is determined. (K) is provided with a corresponding signal generating device, and means is provided for transmitting the signal (K) to the control circuit when the interchangeable lens is attached to the interchangeable lens and camera body, and the control circuit is configured to (Nc/ K), and calculate the above (N) and (Nc/'
outputting a control signal to the motor drive circuit to stop the motor when the difference in K) reaches an allowable range (No/K);
Obtain new (N) from the distance measuring circuit and obtain the new (N)
1. A motor control device for an automatic focusing camera with interchangeable lenses, comprising a control circuit that outputs a control signal to the motor drive circuit until the number reaches the number (No/K).