JPH07104474B2 - Optical device having power focus device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention converts a manual focusing operation in a camera or an interchangeable lens thereof into an electric signal or the like, and drives and controls a power source such as a motor by the electric signal or the like. Thus, the present invention relates to an optical apparatus having a power focus device configured to drive the focusing lens to follow the focusing operation faithfully.

[Background of the Invention] Many recent cameras and their interchangeable lenses are equipped with an autofocus device (hereinafter abbreviated as AF), and such cameras and interchangeable lenses operate the human eye and hand. Since it is very easy to use because it does not require the focusing operation by and, the number of customers with AF cameras is increasing.

However, in addition to the drawback of using an AF-equipped camera or an interchangeable lens with AF, you may not be able to intentionally take a blurred picture, and the shutter will not operate until the subject is in focus, so it will be a moment. Since there is a drawback that it is easy to miss the shooting opportunity of, it is necessary to take a moment of shooting opportunity even if the person who wants to take a variety of pictures using various shooting techniques or the focus is slightly blurred For those who have it, the camera with AF and the interchangeable lens with AF are rather difficult to use. Therefore, when shooting a photograph that does not require precise focus on a specific subject or a photograph that is intentionally blurred, traditionally only manual operation is used to focus. Interchangeable lenses and cameras have been used, but under various shooting conditions, it becomes necessary to use AF to take a picture in focus, or a manual focus mechanism (hereinafter abbreviated as MF). It may be necessary to intentionally take a blurred picture using
It was desirable to be able to perform autofocus operation and manual focus operation with the interchangeable lens of the stand.

Against this background, interchangeable lenses that can perform both autofocus operation and manual focus operation have been manufactured. In this known interchangeable lens, the lens is driven by a motor during autofocus, and the lens is manually driven by switching the clutch during manual focus. Therefore, autofocus shooting and manual focus shooting are possible. Therefore, it is possible to deal with various shooting situations.

However, in this known interchangeable lens, since a dog clutch is used for switching between AF and MF, there is a possibility that the lens may move due to a mechanical shock generated at the time of clutch switching and a meshing tolerance of the clutch. However, there is also a drawback that the operation of switching the clutch is complicated. Also, in manual focus operation,
Since the lens is driven by hand, the lens driving speed is slower than the autofocus operation, and a considerable operating force is required, which is difficult to use.

Therefore, in order to solve the above problems existing in the known interchangeable lens, a so-called power focus device that drives the lens by a motor even during the manual focus operation is provided.
It has been proposed to mount it on an interchangeable lens together with AF, and some proposals have also been made for the power focus device.

Among the proposals relating to the power focus device, there is a proposal that a button switch is used instead of a conventionally known focus ring (focus ring), and a lens at the time of manual focus operation depending on a rotation angle of a ring-shaped rotary switch that works in conjunction with the focus ring. There is a proposal to change the driving speed.

However, the former proposal has a drawback in that the button switch and the conventionally known focus ring have very different operation methods, which makes it difficult to use, and the latter proposal does not allow the lens to move even if the hand operation is stopped. Without stopping,
At this time, in order to stop the movement of the lens, it is necessary to return the rotary switch to the neutral position, so that the operability is poor, and there is a drawback that precise focusing is impossible. Therefore, it was difficult to put the power focus apparatus proposed by the above proposals into practical use. Therefore, in order to make the power focus device practical, it is necessary to configure the manually operated operation member so that it can be operated by exactly the same operation as the conventional focus ring, and the movement of the device for driving the lens. It is necessary to be configured to follow the movement of the hand without significantly delaying it.

[Object of the Invention]

An object of the present invention is to provide an optical device having a power focus device which does not have the drawbacks inherent in the above-mentioned conventional proposals, is practical and has good operability, and is capable of precise focusing. is there.

[Outline of Invention]

An optical device having a power focus device according to the present invention is operative in association with rotation of a focus operating member that is rotationally operated, a lens driving drive source that drives a focusing lens, and the rotation of the focus operating member, and that depends on the amount of rotation. Signal generation means for generating an electric signal, rotation direction detection means for detecting the rotation direction of the focus operation member from the electric signal, rotation amount detection means for detecting the rotation amount of the focus operation member from the electric signal, A drive direction setting unit that sets the drive direction of the lens drive source based on the detection result of the rotation direction detection unit, and a drive amount of the lens drive source based on the detection result of the rotation amount detection unit. The drive amount setting means to be set, the drive direction set in the drive direction setting means, and the drive amount set in the drive amount setting means Drive source control means for controlling the lens drive source according to the drive amount, and the focus operating member drives the drive source in the second direction when the lens drive source is driven in the first direction. And a reversing means for driving the drive source in the second direction regardless of the setting in the drive amount setting means.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a focusing device in a camera or an interchangeable lens equipped with a power focusing device 100 and AF.

In FIG. 1, reference numeral 100 denotes a power focus device of the present invention. The device 100 includes a focus ring 1 that is rotated by fingers and an operation amount required for a focus operation according to the rotation operation of the focus ring 1. And the manual focus calculation circuit 2 for calculating
Source 4 such as a motor for driving in the direction (optical axis direction)
And a drive control circuit 5 for controlling the drive source 4. The drive control circuit 5 also serves as a drive control circuit for AF. An AF calculation circuit 98 is connected to the circuit 5, and an output signal of a known AF sensor 99 is input to the AF calculation circuit 98.

FIG. 2 is a block diagram of the control system showing the functions of the main parts in one embodiment of the power focus device of the present invention, and FIG. 3 is an actual electrical diagram of the power focus device shown in FIG. It shows the configuration.

In FIG. 2, 1 is a focus ring which is rotated by a human finger, 6 is a first pulse generating means for generating a pulse signal in conjunction with the focus ring 1, and 3 is provided in a lens barrel of a camera or the like. The focusing lens 4 and the lens 3
A drive source such as a motor for driving the focus ring 1 according to a pulse signal generated from the first pulse generating means 6.
Focus ring rotation direction detecting means for detecting the rotation direction of the focus ring, 8 is a focus ring rotation amount detecting means for detecting the rotation amount (rotation angle) of the focus ring 1 from the pulse signal, and 9 is a focus ring rotation direction detecting means 7. The detected rotation direction is the drive direction of the drive source 4 (rotation direction)
The drive direction setting means 10 is set as the drive amount setting means, and the drive amount setting means 10 stores the rotation amount detected by the focus ring rotation amount detecting means 8 and sets the corresponding drive amount (rotation angle) as the drive amount of the drive source 4. Reference numeral 11 is a second pulse generating means for generating a pulse signal proportional to the movement of the driving source 4 or lens 3, and 12 is a pulse generating speed for detecting the generation speed of the pulse signal generated by the first pulse generating means 6. Detecting means, 13 is drive speed setting means for setting the drive speed of the drive source 4 according to the pulse speed detected by the pulse generation speed detecting means 12, and 14 is drive direction setting means 7, drive amount setting means 8 and drive speed. Drive source control means for controlling the applied current, voltage or pulse cycle to the drive source 4 according to the set value set by the setting means 13,
When the pulse signal is not generated from the pulse generating means 6 even if a predetermined time has elapsed, 15 is an immediate stop that resets the drive amount setting means 10 to set the set value to zero and generates a signal to stop the drive source 4. Means, 16 is a drive direction detecting means 7
An immediate reversing means for resetting the driving amount setting means 10 to return the set value in the means 10 to zero and generating a signal for driving the driving source 4 in the reverse direction when the driving direction detected in the direction changes. is there.

In the drive amount setting means 10, the stored value, that is, the set value is sequentially subtracted by the number of pulses generated from the second pulse generating means 11, and the drive source 4 is stopped by the drive source control means 14 when the set value becomes zero. .

The drive amount setting in the drive amount setting means 10 is performed according to the detection value of the focus ring rotation amount detecting means 8, but the drive amount setting is broken by the output of the immediate stopping means 15 and the output of the immediate reversing means 16, The drive source 4 is immediately stopped or reversed.

The immediate reversing means 16 drives the drive amount setting means only when the detection value of the focus ring rotation direction detecting means 7 and the setting value of the driving direction setting means 9 differ within a predetermined time.
Set the drive amount setting value at 10 to zero (that is, drive source 4
Has a function of temporarily stopping).

In FIG. 2, a block A surrounded by an alternate long and short dash line is a portion corresponding to the power focus device 100 shown in FIG. 1, and the block A has a manual focus arithmetic circuit 2 and a drive control circuit shown in FIG. A configuration corresponding to 5 is included. Note that, in FIG. 2, the dotted line, the alternate long and short dash line, and the double solid line indicate mechanical connection.

FIG. 3 is a diagram showing an example of an actual electrical configuration for realizing the control system shown in FIG. In the figure, 30 is MPU
(That is, a microprocessor unit), 31 is a counter, 32 is a reset circuit, 33 is a D / A converter, 34 is a voltage follower, 35 to 38 are transistors for switching the current to the drive source 4 (that is, a motor), and 11A is a first A pulse generating switch constituting the second pulse generating means 11 shown in FIG. 2 and 6A and 6B are two pulse generating switches constituting the first pulse generating means 6 shown in FIG.
In FIG. 3, R indicates resistance, and the dotted line indicates mechanical connection.

The function of block B surrounded by the two-dot chain line in Fig. 2 is MPU30.
And a counter 31 and a reset circuit 22. On the other hand, the drive source control means 14 and the first
The function corresponding to the drive control circuit 5 in the figure is a part of MPU30 and D.
It is realized by a configuration including an / A converter 33, a voltage follower 34, and transistors 35 to 38.

4 and 5 show the pulse generating switch shown in FIG.
6 shows an embodiment relating to 6A and 6B and a pulse generation switch 11A.

In FIG. 4, reference numeral 39 denotes a first helicoid cylinder of a lens barrel of a camera (or a lens barrel of an interchangeable lens), and the first helicoid cylinder 39 is rotatably supported by a lens barrel body or the like. There is. A lens 3 attached to a second helicoid cylinder (not shown) (supported so as to be rotatable and movable in the optical axis direction with respect to the lens barrel body) at an inner diameter position of the first helicoid cylinder 39.
The lens 3 is accommodated in the axial direction relative to the first helicoid cylinder 39 when the first helicoid cylinder 39 is rotated by screwing the first helicoid cylinder 39 and the second helicoid cylinder 39 together. It is possible to move. Teeth 39a are formed on the outer peripheral surface of the first helicoid cylinder 39, and the first helicoid cylinder itself is configured as a ring gear.
A gear train 40 for rotating the first helicoid cylinder 39 by meshing with the teeth 39a of the first helicoid cylinder 39 is arranged outside the first helicoid cylinder 39, and the gear train 40 includes the first helicoid cylinder 39. The rotation is transmitted from the drive source 4 arranged outside the.

The focus ring 1 shown in FIG.
A ring 41 is mounted on the outer side of the helicoid cylinder 39 so as to be relatively rotatable, and a ring 41 that rotates integrally with the focus ring 1 is fitted on the first helicoid cylinder 39. A conductor pattern 42 is formed on the outer peripheral surface of the ring 41 as shown in FIGS. 4 and 5, and the conductor pattern 42 is grounded as shown in FIG. The conductor pattern 42 is formed with two pattern portions 42a and 42b arranged along the circumferential direction of the ring 41 so as to be offset from each other by a half pitch. Outside the outer peripheral surface of the ring 41, sliding contact pieces 43 and 44 of the two pulse generating switches 6A and 6B, which are supported in a stationary state by a supporting member (a fixed tube of the lens barrel body) not shown, are arranged, The contact piece 43 of the pulse generation switch 6A is positioned so as to contact the pattern portion 42a, and the contact piece 44 of the pulse generation switch 6B is positioned so as to contact the pattern portion 42b.

Therefore, when the ring 41 is rotated in the direction of the arrow f _{1 in} FIG. 5, the circuit connected to the two contact pieces 43 and 44 has a sixth
As shown in the figure, pulse signals having phases shifted from each other by a half pitch are generated. In FIGS. 5 and 6, the contact piece
When 43 and 44 are on the line a in FIG. 5, the voltage of the pulse signals p ₁ and p ₂ generated in the pulse generating switches 6A and 6B is 6th.
The value on the line a in the figure is obtained, and when the contacts 43 and 44 are on the line b in FIG. 5, the voltage of the pulse signal generated in the pulse generating switches 6A and 6B is the value on the line b in FIG.

Since the two pulse signals p ₁ and p ₂ are different in phase by half pitch, the rotation direction of the ring 41 can be detected by comparing the number of pulses or the phase of both pulse signals within a predetermined time.

On the other hand, as shown in FIG. 4, on the outer peripheral surface of the first helicoid cylinder 39, a conductor pattern 45 composed of a pattern portion of only one kind is formed, and the conductor pattern 45 is also the conductor pattern 42.
It is grounded as well. And this conductor pattern 45
A pulse generating switch 11A having a contact piece 46 that comes into contact with is provided outside the first helicoid cylinder 39. Since only one kind of pulse signal is generated from the pulse generation switch 11A, the pulse signal represents the rotation amount of the first helicoid cylinder 39 (that is, the movement amount of the lens 3), but the rotation direction is detected from the pulse signal. You cannot do it.

Next, first, the operation of the power focus device of the present embodiment will be described mainly with reference to FIG.

The photographer first rotationally operates the focus ring 1 in the first direction with his / her own finger, whereby the ring 41 (see FIG. 4) integrated with the focus ring 1 is, for example, the arrow f _{1 in} FIG.
It is supposed to be rotated in the direction of. As a result, the two pulse generating switches 6A and 6B (FIG. 4) constituting the first pulse generating means 6 (FIG. 2) have two different phases as shown in FIG. Pulse signals p ₁ and p ₂ are generated, and these pulse signals are applied to the focus ring rotation direction detection means 7, focus ring rotation amount detection means 8 and pulse generation speed detection means 12, respectively, and at the same time to the immediate stop means 15. Is applied. As a result, the focus ring rotation direction detection means 7 detects the rotation direction of the focus ring 1 by comparing the pulse numbers of the two types of pulse signals p ₁ and p ₂ , and the focus ring rotation amount detection means 8 detects the focus ring 1 Is detected.

On the other hand, the pulse generation speed detection means 12 detects the rotation speed of the focus ring 1.

Also, the pulse signal is an immediate stopping means having a timer circuit.
Since it is also applied to 15, the operation of the timer circuit in the immediate stopping means 15 is started.

The focus ring rotation direction detection means 7, the focus ring rotation amount detection means 8 and the pulse generation speed detection means
In the actual configuration of FIG. 3, the instant stop means 15 and the like 12 and the like are all constituted by various registers in the MPU 30, a built-in timer and a counter 31.

When the values such as the focus ring rotation direction, the focus ring rotation amount, and the pulse generation speed are detected from the pulse signal generated by the rotation operation of the focus ring 1 as described above, the drive direction setting means 9 drives the drive source 4 to drive the drive source 4. The drive direction of the drive source 4 is set in the drive amount setting means 10, and the drive speed of the drive source 4 is set in the drive speed setting means 13. Then, signals representing these set values are applied to the drive source control means 14, and the drive source control means 14 drives the drive source 4 based on these set values.

On the other hand, when the rotation direction of the focus ring 1 is detected by the focus ring rotation direction detection means 7, the output corresponding to the rotation direction is input to the immediate reversing means 16 by the output of the detection means 7. In this case, since the same direction as the detection direction in the detection means 7 is set in the drive direction setting means 9 by the detection means 7, the output of the drive direction setting means 9 and the output of the detection means 7 are applied. Instant reversal means 16
Therefore, the output for making the set value in the drive amount setting means 10 zero does not occur.

When the drive source 4 is driven, the rotation of the drive source 4 is decelerated and transmitted to the first helicoid cylinder 39 via the gear train 40 in FIG. 4, and the first helicoid cylinder 39 is rotated. When the first helicoid cylinder 39 is rotated, the second helicoid cylinder 39 (not shown), which is in threaded relation with the first helicoid cylinder 39, moves in the axial direction, and the lens 3 moves toward, for example, the tip side of the first helicoid cylinder 39. It is rolled out. When the first helicoid cylinder 39 rotates, the conductor pattern 45 formed on the outer peripheral surface of the first helicoid cylinder 39 moves in the circumferential direction.
A pulse signal representing the amount of rotation of the first helicoid cylinder 39 (that is, the amount of movement of the lens 3) is generated in the pulse generation switch 11A having the contact piece 46 in contact with 45, and this pulse signal is the drive amount setting means 10 Be fed back to. The driving amount setting means 10 uses the driving amount detection signal fed back from the second pulse generating means 11 as described above to set an initial setting value (that is, an initial setting drive based on the detection value detected by the focus ring rotation amount detecting means 8). Amount) is sequentially subtracted, and the drive source 4 is stopped by the drive source control means 14 when the initial set value becomes zero.

When the focus ring 1 is first operated in the forward direction and then in the reverse direction, the phases of the pulse signals p ₁ and p ₂ generated from the pulse generation switches 6A and 6B are also reversed, and the focus ring rotation direction detecting means 7 has a focus ring. In the normal rotation of 1, an output signal of, for example, +1 is generated as the rotation direction, and subsequently, an output signal of, for example, -1, is generated in accordance with the reverse rotation of the focus ring 1. For this reason, the focus ring rotation direction detecting means 7 to -1 is added to the immediate reversing means 16.
Input signal from the drive direction setting means 9 and the input signal of +1 from the drive direction setting means 9 in the previous operation of the focus ring.
A signal for setting the set amount at 10 to zero is output. As a result, the set amount in the drive amount setting means 10 becomes zero, and the drive source control means 14 immediately stops the drive of the drive source 4.
Immediately thereafter, the drive is started based on the newly set drive direction and drive amount, and the drive source 4 is reversed.

On the other hand, the first pulse signal generated by the rotation operation of the focus ring 1 is generated from the pulse generating means 6, and while the drive source 4 and the lens 3 are being driven according to the pulse signal, a predetermined time has elapsed from the time of the first pulse generation. If the subsequent pulse does not occur even after the lapse of time, the timer of the immediate stop means 15 times up, and a signal for causing the set value of the drive amount setting means 10 to be zero is generated from the means 15, whereby the drive amount Setting means 10
Is set to zero and the drive source 4 is immediately stopped. Therefore, the drive source 4 does not rotate for a relatively long time after stopping the rotation operation of the focus ring,
The drive source 4 immediately follows the operation of the focus ring 1.

FIG. 7 is a flow chart of a program for operating the MPU 30 in the actual device shown in FIG.

The operation of the apparatus of FIG. 3 will be described below with reference to FIGS. 3 and 7.

When the power is turned on from a power supply (not shown), the reset circuit 32 outputs a low level for a certain period and resets the MPU 30. After that, the reset circuit rises to high level and MP
U30 starts executing the program in order from (1) below.

(1) Output 1 (high level) from output port P20 to P23. As a result, the transistors 37 and 35 are turned off and the transistors 38 and 36 are turned on to drop both ends of the motor 4 to the ground and apply the power-generating brake.

(2) Set 0 to the timer TIMER in the MPU. The timer TIMER has the function of incrementing the value by 1 at regular intervals.

(3) Clear the registers MP, MDIR, EDIR, OLDSW. M
P, EP, MDIR, EDIR, OLDSW are registers in MPU1.

(4) Output 1 to port P24 and clear the value of counter 31.

(5) Wait for the time while the value of the counter 31 is reset.

(6) Output 0 to port P24 and return counter 31 to the countable state.

(7) The contents of counter 31 are read from port PORT0 and stored in register EP. Unless the focus ring is rotated, the switches 6A and 6B do not change, so the counter 31
Since the value of has been cleared in (4), EP is 0. (8)-(10) clears the value of the counter 31 as in (4)-(6).

(11) Determine EP = 0. Since EP = 0 now, branch to (35).

(35) Set 0 to the focus ring rotation direction register EDIR.

(24) Determine the value of the motor rotation direction register MDIR,
Since it was cleared to 0 in (3), it branches to (37).

(37) Clear the registers MDIR and MP.

(38) Apply the brake to the motor 4 as in (1). Then return to (7). Therefore, while the focus ring is not rotating, (7)-(8)-(9)-(1
0)-(11)-(35)-(36)-(24)-(37)-(3
Repeat 8). Meanwhile, the motor 4 maintains the braking state.

Now, if you rotate the focus ring in this state,
The switches 6A and 6B are turned on and off to generate the signals p ₁ and p _{2 as} shown in FIG. 6, and each time the switches 6A and 6B are turned on, the signals p ₁ and p ₂ become high level, so that the value of the counter 31 is incremented. To go. Therefore, the EP value input in (7) becomes positive. Once the value of the counter 31 is read, it is reset from (8) to (10), so it is not read twice. Since EP = 0 is discriminated in (11) and they are not equal (12)
Branch to.

(12) EP> 0 is discriminated, and the process branches to (13).

(13) +1 to focus ring rotation direction register EDIR
To store.

(16) EP / TIMER from output port 3 to D / A converter 33
Is output. That is, a voltage proportional to the pulse amount per unit time divided by the time taken to change the pulse of the focus ring appears at the output of the voltage follower 34.

(17) Determine the value of the register MDIR. Since it was cleared in (3), skip to (22).

(22) Store the EP value in the motor movement amount register MP.

(23) Store the value of EDIR in the motor rotation direction register MDIR.

(24) The value of MDIR is determined. Since it is not 0, the process branches to (25).

(25) MP value is discriminated. Since it is not 0, go to (26). (26) MDIR value is discriminated. Since it is +1, go to (27). (27) Output 0 to P20 and P21, output 1 to P22 and P23, By turning on the transistors 38 and 35 and turning off the transistors 37 and 36, current flows from the voltage follower 34 to the transistor 35, the motor 4, and the transistor 38 to drive the motor 4 and move the taking lens 3 toward the infinite end.

(29) Determine the status of switch 11A. If it is on, go to (30). (30) Set register OLDSW to 0 and return to (7). If the focus ring is not rotated as it is, the counter 31 remains 0 (7)-(8)-(9)-(10).
-(11)-(35)-(36)-(24)-(25)-(26)-
Repeat the loop of (27)-(29)-(30). Of these, the photographic lens 3 is moved to a desired position by driving the motor 4, and the switch 11A is turned off to branch to (31) at (29).

(31) Determine the status of register OLDSW. Since it is set to 0 in (30), decrement the value of (32) MP to (32).

(33) Set 1 to OLDSW. After that, at the branch of (31), go to (32) and come to (33). (7)-(8)-(9)
-(10)-(11)-(35)-(36)-(24)-(25)-
Switch the loop of (26)-(27)-(31)-(34) to switch 11
Repeat while A is off. Therefore, in the routines (29) to (34), the value of the register MP is decremented by 1 each time the switch 11A rises from ON to OFF. When the above loop is executed, MP = 0 soon becomes, and at (25), it branches to (37) and brakes the motor 4. In this way, the taking lens 3 can be electrically driven by the same amount as the rotation pulse of the focus ring.

Next, a case where the focus ring is continuously rotated while the motor is being driven will be described.

From the braking state to the energized state, the above-mentioned (7)-(8)-(9)-(10)-(11)-(12)-
(13)-(16)-(17)-(22)-(23)-(24)-
It is the same as the loop of (27)-(29)-(30), but the positive value is set to EP because the focus ring is rotated when the value of the counter 3 is read the second time. (12)-(1
3)-(16) is controlled in the same way as the previous time and branches to (18) at (17).

(18) Compare the values of the focus ring rotation direction register EDIR and the motor rotation direction register MDIR. If they are in the same direction, branch to (19).

(19) Add the newly added pulse EP to the motor movement pulse register MP.

Since the same control as that described above is performed thereafter, the photographing lens can be moved according to the rotation amount of the focus ring that has been continuously moved. Further, when the focus ring is rotated backward, the value of the counter 31 becomes negative, so that the process branches to 14 in (12).

(14) -1 to the focus ring rotation direction register EDIR
Set to indicate that it is a reverse rotation.

(15) Change the EP value to the absolute value. From (16) to (2
The control in 5) is performed in exactly the same way as during normal rotation. Since MDIR is set to -1 in (26), go to (28).

(28) Outputs 1 to ports P20 and P21 and 0 to P22 and P23.
Therefore, a current flows from the voltage follower 34 to the transistor 37, the motor 4, and the transistor 36 to move the taking lens 3 toward the closest end. After that, the reverse direction can be controlled in the same manner.

Next, the case where the focus ring is rotated in reverse while the motor 4 is being driven will be described. If the focus ring is reversed, the motor 4 will feel very unnatural unless it follows the driving direction. When the focus ring is reversed, the value of the counter 31 and the sign of EP are reversed. Therefore, at (18), the registers MDIR and EDIR become unequal and branch to (20).

(20) Set the previous value in the lens movement amount register MP to the EP value.

(21) Change the rotation direction of the motor 4 to a new direction.
In this way, the rotation of the motor 4 can be reversed in response to the reverse rotation of the focus ring. Also, it is unnatural that the motor keeps moving for a while even if the focus ring stops rotating. Therefore, if the value of the counter 31 remains 0 for a certain time T after the timer TIMER is set to 0 in (2) or (16), it is judged as a time-out in (36) and the process branches to (37) and the motor is branched. By applying a brake to 4, you can bring your sensation closer to the conventional manual focusing.

In the above-described embodiment, there are provided a first pulse generating means for generating a pulse signal in synchronization with the rotation operation of the focus ring and a second pulse generating means for generating a pulse signal in synchronization with the rotation of the first helicoid cylinder. Although it is constructed as a sliding contact type switch means, it goes without saying that the pulse generating means may be constituted by a non-contact type converter such as a photoelectric type, a magnetic sensitive type and a capacitance type. Further, as the drive source 4, not only known electric motors but also various actuators whose rotation or movement can be electrically controlled can be used.

〔The invention's effect〕

In the optical device having the power focus device of the present invention shown in the above examples, the same rotary operation member as the conventional manual focus device is used as the focus operation member,
Further, since the lens driving drive source is controlled according to the rotation direction and the rotation amount of the focus operating member, the operation of the focus operating member and the actual driving of the focusing lens are sensuously matched, and the conventional manual focus It is possible to obtain a feeling of operation similar to that of the device. In particular, the lens driving source properly follows the reverse rotation of the focus operating member, and the focusing lens can also perform the reverse movement as the operator wishes.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a camera or an interchangeable lens equipped with a power focus device and an auto focus device of the present invention, and FIG. 2 is a configuration of a control system in an embodiment of the power focus device of the present invention. The block diagram shown in FIG. 3, FIG. 3 is a diagram showing an example of the actual electrical configuration of the embodiment shown in FIG. 2, and FIG. 4 is the focus ring in the embodiment shown in FIG. 2 and FIG. FIG. 5 is a perspective view showing an example of pulse generating means related to the lens barrel and an example of a lens driving mechanism, FIG. 5 is one plan view of the pulse generating means shown in FIG. 4, and FIG. 6 is FIG. FIG. 7 is a diagram showing the phase and waveform of the pulse signal generated in the pulse generating means shown in FIG. 7, and FIG. 7 is a flow chart for explaining the operation of the MPU 30 of FIG. 1 ... Focus ring 2 ... Manual focus calculation circuit 3 ... Lens, 4 ... Lens drive source 5 ... Drive control circuit 6 ... First pulse generation means 6A and 6B ... Pulse generation switch 7 ... Focus Ring rotation direction detection means 8 ... Focus ring rotation amount detection means 9 ... Drive direction setting means, 10 ... Drive amount setting means 11 ... Second pulse generation means 11A ... Pulse generation switch 12 ... Pulse generation speed Detecting means 13 …… Drive speed setting means 14 …… Drive source control means, 15 …… Immediate stop means 16 …… Instant reversal means, 30 …… MPU 31 …… Counter, 32 …… Reset circuit 33 …… D / A Transducer, 34 …… Voltage follower 35〜38 …… Transistor 39 …… First helicoid cylinder 40 …… Gear train, 41 …… Rings 42,45 …… Conductor pattern 43,44,46 …… Sliding contact

Claims (1)

[Claims] 1. A focus operation member that is rotated, a lens driving drive source that drives a focusing lens, and a signal generation that interlocks with the rotation of the focus operation member and generates an electric signal according to the amount of rotation. Means, a rotation direction detecting means for detecting a rotation direction of the focus operating member from the electric signal, a rotation amount detecting means for detecting a rotation amount of the focus operating member from the electric signal, and a detection in the rotation direction detecting means. Drive direction setting means for setting the drive direction of the lens driving drive source based on the result, and drive amount setting means for setting the drive amount of the lens driving drive source based on the detection result of the rotation amount detecting means. Controlling the lens drive source according to the drive direction set by the drive direction setting means and the drive amount set by the drive amount setting means. When the lens driving drive source is driven in the first direction and the focus operating member is rotationally operated so as to drive the drive source in the second direction, An optical apparatus having a power focus device, comprising: a reversing unit that drives the drive source in the second direction regardless of the setting in the drive amount setting unit.