JPS6389823A - Power focusing device - Google Patents

Abstract

PURPOSE:To attain accurate and rapid focusing by immediately reversing a lens driving source when a focus ring is rotated in a 2nd direction at the time of driving the lens driving source in a 1st direction. CONSTITUTION:When the focus ring 1 is forward rotated at first and then reversed, the phase of a pulse signal outputted from a pulse generating means 6 is also reversed. A focus ring rotational direction detecting means 6 outputs '+1' output signal at the time of forward rotation of the ring 1, and generates '-1' output signal in accordance with the revere of the ring 1. Since the '-1' signal outputted from the means 7 and the '+1' signal outputted from a driving direction setting means 9 based upon the preceding operation of the ring 1 are inputted to an immediate inverting means 16, the means 16 outputs a signal for turning a set value of an extent of driving setting means 10 to zero. A driving source control means 14 receiving the '0' signal from the means 10 immediately stops the driving of a ring driving source 4. Since the driving source 4 is reversed based on a newly set up driving direction, focusing can be attained without being delayed from the movement of the ring 1.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] This invention converts a manual focusing operation in a camera or its interchangeable lens into an electrical signal, etc., and uses the electrical signal, etc. to drive and control a power source such as a motor. The present invention relates to a power focusing device configured to drive a focusing lens to faithfully follow the focusing operation.

[Background of the invention]

Many recent cameras and their interchangeable lenses are equipped with an auto7 focus device (hereinafter abbreviated as AF), and such cameras and interchangeable lenses rely on the human eye and hand for focusing. The demand for cameras with AF is increasing because they are very easy to use as they do not require any operations.

However, AF-equipped cameras and AF-equipped interchangeable lenses have the disadvantage that you cannot intentionally take out-of-focus photos even if you want to, and the shutter does not operate until the subject is in focus, so the shutter does not operate for a moment. However, there are people who want to take a variety of photos using various shooting techniques, and people who want to capture a momentary photo opportunity even if it is slightly out of focus. For people who own cameras, AF-equipped cameras and AF-equipped interchangeable lenses can become difficult-to-use photographic equipment. Therefore, when taking photos that do not require a specific subject to be strictly in focus or photos that are intentionally out of focus, it is conventional to use the traditional method of manually adjusting the focus. Interchangeable lenses and cameras have been used, but in various shooting situations, it has become necessary to use AF to take a focused photo, or a manual focus mechanism (hereinafter abbreviated as MP). In some cases, it may be necessary to take intentionally out-of-focus photos using the
Second, it was desirable to be able to perform al-focus operations.

Against this background, interchangeable lenses that can perform both autofocus and manual focus operations have been manufactured. This known interchangeable lens is configured so that the lens is driven by a motor during autofocus, and the lens is driven manually by switching the clutch during runny al focus, so it can be used for both autofocus photography and manual/alternative photography. 7 Orcus photography can be performed, and therefore, various photography situations can be handled.

However, since this known interchangeable lens uses a dog clutch to switch between AF and MF, there is a risk that the lens may move due to the mechanical shock that occurs when switching the clutch and the mesh tolerance of the clutch. Another drawback was that the clutch switching operation was complicated. In addition, in manual focus operation, since the lens is driven by hand, the lens drive speed is slower than in autofocus operation, and it requires an operating force of about 100 to 200 yen, making it difficult to use.

Therefore, in order to solve the above-mentioned problems with the known interchangeable lenses, it has been proposed to mount a so-called power focus device, which drives the lens with a motor even during manual focus operation, on the interchangeable lens together with AF. , etc. Several proposals have also been made regarding the wharf orcus device.

Among the proposals regarding the power focus device, there is a proposal to use a button switch in place of the conventionally known focus ring, and a proposal to use a button switch in place of the conventionally known focus ring, and a rotation angle of a ring-shaped rotary switch that interlocks with the focus ring to improve manual focus operation. There is a proposal to change the lens drive speed in .

However, the former proposal has the disadvantage that the operation method is very different between the button switch and the conventionally known focus ring, making it difficult to use, and the latter proposal also has the disadvantage that the lens cannot be moved even if the hand operation is stopped. without stopping,
At this time, in order to stop the lens movement, it is necessary to return the rotary switch to the neutral position, which has disadvantages in that it is not easy to display and precise focusing is impossible. Therefore, it has been difficult to put the power focus devices according to both of the above proposals into practical use. Therefore, in order to make the Tsukwarf Orcus device practical, it is necessary that the manually operated operating member be configured so that it can be operated in exactly the same way as a conventional focus ring, and that the device that drives the lens be moved. It is necessary that the device be configured to follow the movement of the hand without significant delay.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a power focusing device that is practical, easy to operate, and capable of precise focusing without having the drawbacks inherent in the conventional proposals as described above.

[Summary of the invention]

The four-wharf focus device according to the present invention includes a focus ring that is rotated by hand, a focus generating means that generates a pulse signal in conjunction with the focus ring, and a focus that detects the rotational direction of the focus ring from the pulse signal. A ring rotation direction detection means, a focus ring rotation amount detection means for detecting the rotation amount of the focus ring from the nose signal, and a drive direction of the lens drive source based on the detection result of the focus ring rotation direction detection means. drive direction setting means for setting the amount of movement of the lens drive source based on the detection result detected by the focus ring rotation amount detection means; If the focus ring is rotated in the second direction while the focus ring is being driven in the second direction, the setting in the drive direction setting means is changed, the previously set amount in the drive amount setting means is discarded, and the lens drive source is changed. The present invention is characterized by comprising an immediate reversing means for immediately reversing the rotation.

The Tsukwarf Orcus device of the present invention uses the focus ring used in conventional MF as the manual focus operating member, so it has the advantage of being extremely easy to use, and also has the above-mentioned instant reversal means. Therefore, even when the focus ring is suddenly reversed, the lens driving source has the advantage of following the movement of the focus ring without delay.

[Embodiments of the invention]

The present invention will be described in detail 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 Zukwarf focus device of the present invention. A manual focus calculation circuit 2 that calculates the amount of operation, etc., a drive source 4 such as a motor for driving the focusing lens 3 in the direction of arrow f (optical axis direction), and a drive control circuit that controls the drive source 4. 5 is included. The drive control circuit 5 also serves as a drive control circuit for AF, and an AP calculation circuit 98 is connected to the circuit 5, and a known AF sensor 99 is connected to the AP calculation circuit 98.
The output signal of is input.

FIG. 2 is a block diagram showing the main functions of the control system in an embodiment of the Zwharf Orcus device of the present invention, and FIG. This shows the success of the target.

In FIG. 2, 1 is a focus ring that is rotated by a person's fingers, 6 is a first pulse generating means that generates a dulse signal in conjunction with the focus ring 1, and 3 is a lens barrel of a camera, etc. 4 is a drive source such as a motor for driving the lens 3; 7 is a focus ring 10 that is driven by a 9-noise signal generated from the first nolus generating means 6; Focus ring rotation direction detection means 8 detects the rotation direction of the focus ring 10 from the pulse signal; focus ring rotation amount detection means 9 detects the rotation amount (rotation angle) of the focus ring 10 from the pulse signal; 9 focus ring rotation direction detection means 7;
Drive direction setting means sets the rotation direction detected by as the drive direction (rotation direction) of the drive source 4, and 10 stores the rotation amount detected by the focus ring rotation amount detection means 8, and also stores the corresponding drive amount. (rotation angle) as the drive amount of the drive source 4;
Reference numeral 11 denotes a second norm generating means that generates a pulse signal proportional to the movement of the driving source 4 or the lens 3, and 12 denotes a first pulse signal.
Pulse generation speed detection means 13 detects the generation speed of the Norse signal generated from the Noyalse signal generation means 6, and 13 sets the drive speed of the drive source 4 according to the Norse speed detected by the pulse generation speed detection means 12. Drive speed setting means 14 is a drive source that controls the applied current, voltage, pulse cycle, etc. to the drive source 4 according to the set values set in the drive direction setting means 7, the drive amount setting means 8, and the drive speed setting means 13. The control means 15 resets the drive amount setting means 10 to make the set value zero and generates a signal to stop the drive source 4 when a pulse signal is not generated from the pulse generation means 6 even after a predetermined time has elapsed. Immediate stop means 16 resets the drive amount setting means 10 to return the set value in the means 10 to zero when the drive direction detected by the drive direction detection means 7 changes, and also causes the drive source 4 to reverse direction. instantaneous inverting means for generating a signal to drive the signal.

In the drive amount setting means 10, the stored value, that is, the set value, is sequentially subtracted according to the number of pulses generated from the second pulse generating means 11, and when the set value becomes zero, the drive source control means 1
4, the drive source 4 is stopped.

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

The instant reversal means 16 causes the drive amount setting value in the drive amount setting means 10 to be set to zero only when the detection value in the focus ring rotation direction detection means 7 and the setting value in the drive direction setting means 9 are different within a predetermined time ( It has a function to temporarily stop the drive source 4.

In FIG. 2, block A surrounded by a dashed line is a part corresponding to the power focus device 100 shown in FIG. A configuration corresponding to circuit 5 is included.

In addition, in FIG. 2, dotted lines, dashed-dotted lines, and double solid lines indicate mechanical connections.

FIG. 3 is a diagram showing an example of an actual electrical configuration for realizing the control system shown in FIG. 2. In the same figure, 30 is M
PU (i.e. 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 drive sources 4 (
In other words, the transistor 11A for switching the current to the motor) is the second normality generating means 11 shown in FIG.
Pulse generating switches 6A and 6B forming the first pulse generating means 6 shown in FIG.
pulse generating switches. In addition, in FIG. 3, R represents resistance, and dotted lines represent mechanical connections.

The function of block B surrounded by a two-dot chain line in Fig. 2 is the MPU
30, a counter 31, and a reset circuit 32. On the other hand, the functions corresponding to the drive source control means 14 in FIG. 2 and the drive control circuit 5 in FIG.
It is realized by a configuration consisting of a part of the PU 30, a D/A converter 33, a voltage follower 34, and transistors 35 to 38.

4 and 5 show an embodiment of the pulse generation switches 6A and 6B and the pulse generation switch 11A shown in FIG. 3.

In FIG. 4, numeral 39 is a first helicoid tube of a camera lens barrel (or an interchangeable lens barrel), and the first helicoid tube 39 is supported by the lens barrel body etc. so that it can only rotate. It looks like this.

The lens 3 attached to a second helicoid tube (not shown) (supported so as to be rotatable and movable in the optical axis direction with respect to the lens barrel body) is accommodated at the inner diameter position of the first helicoid tube 39. Due to the screw engagement between the first helicoid tube 39 and the second helicoid tube, the lens 3 is moved along the axial direction relative to the first helicoid tube 39 when the first helicoid tube 39 rotates. It is possible to move around. Teeth 39m are formed on the outer peripheral surface of the first helicoid cylinder 39. ri, 1st
The helicoid tube itself is configured as a ring gear. A gear train 40 for rotating the first helicoid cylinder 39 by meshing with the teeth 391A of the first helicoid cylinder 39,
Rotation is transmitted to this gear train 40 from a drive source 4 arranged outside the first helicoid cylinder 39.

The focus ring 1 shown in FIG.
A ring 41 is fitted on the first helicoid tube 39 so as to be relatively rotatable on the outside of the helicoid tube 39, and rotates integrally with the focus ring 1. A conductor pattern 42 is completely formed on the outer peripheral surface of the ring 41 as shown in FIGS. 4 and 5, and the conductor notch 42 is grounded as shown in FIG. The conductor pattern 42 has two pattern portions 42& and 42b aligned along the circumferential direction of the ring 410 and shifted by a half pitch from each other.
is formed. Sliding contact pieces 43 and 44 of two pulse generation switches 6A and 6B, which are supported in a stationary state by a support member (not shown) (fixed barrel of the lens barrel main body), are arranged on the outside of the outer peripheral surface of the ring 41 ( The contact piece 43 of the pulse generation switch 6A is positioned at a position where it contacts the 9-turn portion 42m, and the contact piece 44 of the pulse generation switch 6B is positioned at a position where it comes into contact with the 4-turn portion 42b.

Therefore, when the ring 41 is rotated in the direction of the arrow f1 in FIG. 5, the circuit connected to the two contact pieces 43 and 44 receives pulse signals whose phases are shifted by half a pitch from each other as shown in FIG. will occur. In FIGS. 5 and 6, when the contact pieces 43 and 44 are on the line shown in FIG.
The voltages of i and Pz are the values on the a line in Figure 6, and the contact piece 4
3 and 44 are on the line in FIG. 5, the voltage of the pulse signal generated at the pulse generating switches 6A and 6B becomes a value on the line b in FIG. 6.

Both 14 Luz signal p! Since the phases of and p are different by half a pitch, the direction of rotation 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.
5 is formed, and nine turns 45 of the conductor are also grounded like the conductor pattern 42. An arm pulse generating switch IIA having a contact piece 46 in contact with the conductor pattern 45 is provided outside the first helicoid cylinder 39. Since only the unique arm pulse signal is generated from these 11 t4 pulse generation switches, this pulse signal represents the amount of rotation of the first helicoid tube 39 (that is, the amount of movement of the lens 3), but the direction of rotation is cannot be detected from the pulse signal.

Next, first, the operation of the power focusing device of this embodiment will be explained with reference mainly to FIG.

The photographer first rotates the focus ring 1 in the first direction with his or her finger, and as a result, the ring 41 (see FIG. 4), which is integrated with the shift focus ring 1, moves in the direction of the arrow f1 in FIG. 5, for example. Suppose it is rotated. As a result, the first No. 4
As shown in FIG. 6, two kinds of gussets with different phases are generated from the two lasing generating switches 6 and 6B (FIG. 4) constituting the lasing generating means 6 (FIG. 2). Signals pI and pl are generated, and these signals are applied to the focus ring rotation direction detection means 7, the focus ring rotation amount detection means 8, and the pulse generation speed detection means 12, respectively, and are also applied to the immediate stop means 15 at the same time. be done. As a result, the focus ring rotation direction detection means 7 detects two types of nose signals p1 and p! The rotation direction of the focus ring 10 is detected from the comparison of the number of rotations, and the rotation amount of the focus ring 1 is detected by the focus ring rotation amount detection means 8.

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

Further, the knee thickness signal is also applied to the instant stop means 15 having a timer circuit, so that the timer circuit in the instant stop means 15 starts operating.

Note that the focus ring rotation direction detection means 7, the focus ring rotation amount detection means 8, the norse generation speed detection means 12, the immediate stop means 15, etc. are all registered in the MPU 30 in the actual configuration shown in FIG. and a built-in timer and counter 31.

As described above, when values such as the focus ring rotation direction, focus ring rotation amount, and /4 pulse generation speed are detected from the pulse signal generated by rotating the focus ring 10 times, the drive direction setting means 9 sets the drive source 4 to the drive direction setting means 9. In addition, the drive amount 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. 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 rotational direction of the focus ring 1 is detected by the focus ring rotational direction detection means 7, an input corresponding to the rotational direction is also input to the immediate reversal means 16 based on 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 for the drive direction setting means 9 by the detection means 7, the output of the drive direction setting means 9 and the detection means 7
The instantaneous reversing means 16 to which the output is applied does not produce an output that makes the set value in the drive amount setting means 10 zero.

When the drive source 4 is driven, the rotation of the drive source 40 is transmitted through the gear train 40 to the first helicoid cylinder 39 at a reduced speed in FIG. 4, and the first helicoid cylinder 39 is rotated. 1st
When the helicoid tube 39 is rotated, the first helicoid tube 3
A second helicoid tube (not shown) in a screwed relationship with 9 moves in the axial direction, and the lens 3 becomes, for example, the first helicoid tube 39.
It is pulled out towards the tip side. Furthermore, when the first helicoid tube 39 rotates, the conductor pattern 45 formed on the outer peripheral surface of the first helicoid tube 39 moves in the circumferential direction. An A/lus 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 generating switch IIA, and this pulse signal is sent to the drive amount setting means 10.
will be given feedback. The drive amount setting means 10 uses the drive amount detection signal fed back as described above from the second pulse generation means 11 to set the initial setting value (that is, the initial setting drive based on the detection value detected by the focus ring rotation amount detection means 8). When the initial setting value becomes zero, the drive source 4 is stopped by the drive source control means 14.

When the focus ring 1 is first operated in the forward direction and then subsequently operated in the reverse direction, the /4 pulse generation switches 6A and 6B are activated.
The Norse signals p1 and p! generated from The phase of is also reversed,
The focus ring rotation direction detecting means 7 generates an output signal of, for example, +1 as the rotation direction when the focus ring 1 rotates in the forward direction, and subsequently generates an output signal of, for example, -1 as the focus ring 1 rotates in the reverse direction. Therefore, an input signal of -1 is input to the immediate reversing means 16 from the focus ring rotation direction detection means 7, and a +1 input signal is input from the drive direction setting means 9 during the previous focus ring operation.
Since the instantaneous inverting means 16 receives the input signal, the instantaneous reversing means 16 outputs a signal that makes the set amount in the drive amount setting means 10 zero. As a result, the set amount in the drive amount setting means 10 becomes zero, and the driving of the drive source 4 is immediately stopped by the drive source control means 14. Thereafter, the drive source 4 is immediately driven based on the newly set drive direction and drive amount. is started, and the drive source 4 is reversed.

On the other hand, the first noyal pulse signal accompanying the rotational operation of the focus ring 1 is generated from the noyal pulse generating means 6, and while the drive source 4 and lens 3 are being driven in accordance with the pulse signal, the first /4' If a subsequent Noculus does not occur even after a predetermined period of time has elapsed from the time of occurrence, the timer of the immediate stop means 15 times up, and a signal is generated from the means 15 to set the set value of the drive amount setting means 10 to zero, This is υ,
The set value of 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 the rotation operation of the focus ring is stopped, and the drive source 4 immediately follows the operation of the focus ring I.

Figure 7 shows MPU 3 in the actual device shown in Figure 3.
1 is a flowchart of a program that operates 0.

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

When a power supply (not shown) or a stain source is turned on, the reset circuit 32 is activated.
outputs a low level signal for a certain period of time and resets the MPU 30. Thereafter, the reset circuit rises to a high level, and the MPU 30 starts executing programs in order from (1) below.

(1) Output 1 (high level) from output port P20 to P23. As a result, transistors 37 and 35 are turned off and transistors 38 and 36 are turned on, thereby grounding both ends of the motor 40 and applying a dynamic brake.

(2) Set the MPU internal tether-q-TIMERVCO.

The timer TIMER has a function of incrementing the value by 1 at regular intervals.

(3) Vcy, /MP, MDIR, ED
Clear IR and 0LDSW. MP, EP
, MDIR, EDIR.

0LDSW is a register within MPU 1.

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

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

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

(7), p-) Read the contents of the FORTO counter 31 and store them in the register IP. Switch 6A unless the focus ring is rotated.

Since 6B does not change, the value of the counter 31 remains cleared at (4), so EP is 0. (8)-
αQ clears the value of the counter 31 similarly to (4)-(6).

Determine α and EP=O, and since Ep=o now, branch to (35).

(35) Enter O in the focus ring rotation direction register EDIR.

(c) Determine the value of the motor rotation direction register MDIR, and since it is cleared to O in (3), branch to (37).

Clear registers MDIR and MP.

(38) Apply the brake to motor 4 in the same way as in (1). Then return to (7). Therefore, while the focus ring is fully rotated, (7) - (s) - (9)
-αQ-α溌-(35) -C3B") -(Next)-(
Execute (g) - (a) repeatedly. During this time, the motor 4 maintains the brake state.

Now, if you rotate the focus ring in this state,
Switches 6A and 6B are turned on and off to produce a signal P as shown in FIG.
It ps is generated, and the signals p1 and p go to high level each time the switches 6A and 6B are turned on, so the value of the counter 31 is incremented. Therefore (7
), the value of EP input is positive. -degree counter 31
When the value of is read, it is reset by αO from (8), so it will not be read twice. A gp-o determination is made at α, and since they are not equal, the process branches to (6).

(2) Determine EP)O and branch to (To).

(2) Store +1 in the focus ring rotation direction register EDIR.

α One output port 3 to D/A converter 33
Output TIMER. In other words, a voltage proportional to the amount of noculus per unit time divided by the time taken to change the noculus of the focus ring is applied to the output of the voltage follower 34.

a21 Determine the value of register MD IH. Since it was cleared in (3), go to (a).

) Store the value of the motor movement amount register MPKEP.

(To) KDI in motor rotation direction register MDIH
Store the value of R.

(c) Determine the value of MDIR, and since it is not O, branch to (c).

(b) Determine the value of MP, since it is not O, go to (c) (c)
Determine the value of MD I H, it is +1, so go to (b) @ P
2O, output O to P21, output 1 to P22゜P23,
Turn on transistor 38.35, transistor 37.3
6 is turned off, current flows from the voltage 7 follower 34 to the transistor 35, motor 4, and transistor 38 to drive the motor 4 and move the photographic lens I#3 toward the infinite end.

翰 Determine the state of switch IIA, if it is currently on, go to Zeng (7) Set register 0LDSW to O and return to (7).

If the 7 orcus ring is not rotated as it is, the counter 31 will be in the O position (7) - (8) - (9)
-α0-a and -(35)-(33)-(c)-(c)-
Repeat the loop of (c) - ni) - Kanichi (g). Eventually, the photographic lens 3 will move to the desired position due to the drive of the motor 4, and the switch IIA will be turned off (31).
Branch to.

(31) Determine the state of register 0LDSW. Since it is set to 0 at (to), go to (32) and decrement the value of MP.

(33) Set 0LDSW to 1. From then on (31)
At the (7) branch, go to (33) instead of going to (32). (
7) -(s) -(9)-αku(b)-(35)
-(35)-(c)-(c)-(g)-ri-(31)
- Repeat the loop (34) while switch IIA is off.

Therefore, in the routine from (to) to (34), each time the switch 11A rises from on to off, the register M
The value of P is subtracted by 1.

When the above loop is executed, MP=O (
At a), branch to (37) and apply the brake to motor 4. In this way, the photographing lens 3 can be electrically driven by an amount equal to the rotation pulse of the focus ring.

Next, the case where the focus ring continues to be rotated while the motor is being driven will be explained.

Until the state changes from the brake state to the energized state, as explained previously (7) - (8) - (9) - (10-α and -)
-〇-α→-aノ-ni)-ni)-(to)-(b)-4-
This is the same as the loop in (g), but since the focus ring is turned when reading the value of counter 3 for the second time, a positive value is set to EP. (2)=(2)-α· is controlled in the same way as before, and branches to IFj when it reaches 0.

(1 o'clock: Compare the values of the focus ring rotation direction register EDIR and the motor rotation direction register MDIH, and if they are in the same direction, branch to (to).

(To) Add the newly increased pulse EP to the motor movement pulse register MPKi.

Since the control is thereafter performed in the same manner as described above, the photographing lens can be moved in accordance with the amount of rotation of the focus ring that continues to be moved. Also, if the focus ring is turned in the opposite direction, the value of the counter 31 will be negative, so α■ will be 14.
Branch to.

α→ Focus ring rotation direction register EDIR -
Set to 1 to indicate reversal.

Edge Convert the EP value to an absolute value. From now on α・kara (c)
Control is performed in exactly the same way as during forward rotation. MD in Kan
Since IR is set to -1, go to (c).

1, P at the terminal and port P2O, P21
22.

Outputs O to P23. Therefore, current flows from the voltage follower 34 to the transistor 37, motor 4, and transistor 36, moving the photographing lens 3 toward the near end. Thereafter, the reverse direction can also be controlled in exactly the same manner.

Next, a case will be described in which the focus ring is reversed while the motor 4 is being driven. When the focus ring is reversed, it will feel very unnatural if the motor 4 does not follow the driving direction. When the focus ring is reversed, the value of the counter 31 and the sign of EP are reversed.

Therefore, the registers MDIR and EDIR are no longer equal in the α barrel, and a branch is made to the register.

翰 Discard the previous value of the lens movement amount register MP and set it to the value of EP.

Gume: Change the rotation direction of motor 4 to the new direction.

In this way, the rotation of the motor 4 can also be reversed in response to the reverse rotation of the focus ring.

It also feels unnatural that the motor continues to run for a while even after the focus ring has stopped rotating. Therefore, if the value of the counter 31 remains O for a certain period of time T after the 0 → output timer TIMER is set to O, it will be judged as a timeout with 015).
By branching to 7) and applying a brake to the motor 4, it is possible to bring the sense of focus closer to that of conventional manual focusing.

In the above embodiment, the first seven-arm pulse generating means generates a pulse signal in conjunction with the rotation of the focus ring, and the second pulse generator generates a pulse signal in conjunction with the rotation of the first helicoid strip. Although the f-pulse generating means is constructed as a sliding contact type switch means, the normal pulse generating means may be constructed from a non-contact converter such as a photoelectric type, a magnetic sensitive type, a capacitance type, etc. Of course. Furthermore, it is also possible to use various actuators whose rotation or movement can be controlled electrically, rather than the known electric motor.

〔Effect of the invention〕

The power focus device of the present invention shown in the above embodiments has the following features: (1) It is easy to use because it uses the same rotary operation type focus ring as the conventional manual focus device as the manual focus operation member; (11) Focus is easy to use; The lens drive source immediately follows the rotation of the ring when it is reversed or the operation is stopped. Effects such as control can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of a camera or an interchangeable lens equipped with a power focus device and an autofocus device of the present invention, and FIG. 2 is a diagram showing the configuration of a control system in an embodiment of the power focus device of the present invention. The block diagram shown in FIG. 3 is a diagram showing an example of the actual electrical configuration of the embodiment shown in FIG. 2, and FIG. FIG. 5 is a plan view of one of the pulse generating means shown in FIG. 4, and FIG. FIG. 7 is a flow chart for explaining the operation of the MPU 30 shown in FIG. 3. 1... Focus ring 2... Manual focus calculation circuit 3... Lens 4... Lens drive source 5... Drive control circuit 6... First pulse generating means 6A and 6B... Noculus Generation switch 7...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... Arm pulse generation speed detection means 13... Drive speed setting means 14... Drive source control means 15. ... Immediate stop means 16
... Immediate reversal means 30...→0U31... Counter 32... Reset circuit 33... D/A converter 34... Voltage followers 35 to 38... Transistor 39... To the first Recoid cylinder 40...Gear train 41...Ring 42.45
...Conductor pattern 43, 44, 46...Sliding contact piece Koji Shinbe; -11th figure 1 figure 3 figure 4 figure 5 figure 6

Claims (1)

[Claims] A focus ring that is rotated by hand, a lens drive drive source that drives a focusing lens, a pulse generating means that is linked to the rotation of the focus ring and generates a pulse signal according to a rotation angle, and the pulse signal focus ring rotation direction detection means for detecting the rotation direction of the focus ring from the pulse signal; focus ring rotation amount detection means for detecting the rotation amount of the focus ring from the pulse signal; drive direction setting means for setting the drive direction of the lens drive drive source based on the drive direction, and the detection results of the focus ring rotation amount detection means are stored, and the stored value is set as the drive amount of the lens drive drive source. a drive amount setting means; a drive source control means for controlling the lens drive drive source according to the drive direction set in the drive direction setting means and the drive amount set in the drive amount setting means; and the lens drive source. If the focus ring is rotated in the second direction while being driven in the first direction, the settings in the drive direction setting means are changed and the previous memory and the previous set value in the drive amount setting means are changed. A power focus device comprising immediate reversing means for immediately reversing the lens driving source at the same time as discarding the driving amount setting means and resetting the driving amount setting means.