JPS6389825A - Power focusing device - Google Patents

Abstract

PURPOSE:To attain accurate focusing operation by converting the rotation of a focus ring into a pulse signal, detecting the rotational amount of the focus ring from the pulse signal and controlling a lens driving source on the basis of the detected value. CONSTITUTION:When a photographer rotates the focus ring 1, a pulse generating means 6 generates a pulse signal interlocking with the ring 1. The pulse signal is inputted to a focus ring rotational amount detecting means 8 to detect the rotational amount of the ring 1. An extent of driving setting means 10 sets up the driving variable of the lens driving source 4 based on the detected value and impresses a signal indicating the set value to a driving source control means 14 and the driving source 4 is controlled based on the impressed signal. Since the rotation of the ring 1 is converted into a pulse signal, the rotational variable of the ring 1 is detected as a digital value and the driving source 4 is controlled based on the detected value, the driving source 4 can be driven so as to faithfully follow the ring 1 and accurate and rapid focusing operation can be attained.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present 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 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 by controlling the focusing lens.

[Background of the invention]

Many modern cameras and their interchangeable lenses are equipped with autofocus devices (hereinafter abbreviated as AF), and such cameras and interchangeable lenses require human eyes and hands to perform focusing operations. The demand for cameras with AF is increasing because they are very easy to use and do not require AF.

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. The drawback is that it is easy to miss photo opportunities, so there are people who want to take a variety of photos using gentle photography techniques, and people who want to capture a momentary photo opportunity even if the focus is somewhat obscured. For those who need it, cameras with A/F/and interchangeable lenses with AF have become difficult to use photographic equipment. Therefore, when taking photographs that do not require strict focus on a specific subject or photographs that are intentionally out of focus, it is conventional to manually adjust the focus using only manual operations. interchangeable lenses and cameras have been used,
In various shooting situations, it may be necessary to use AF to take a photograph that is in focus, or use a manual focus mechanism (hereinafter abbreviated as MF) to take an intentionally out-of-focus photograph. Therefore, it is desirable to be able to perform both autofocus and manual focus operations with a single interchangeable lens.

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 during autofocus, the lens is driven by a motor, and during manual focus, the lens is driven manually by switching the clutch. Therefore, it is possible to deal with various shooting situations.

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 error in the clutch's meshing. Another drawback was that the clutch switching operation was complicated. Further, in manual focus operation, since the lens is driven by hand, the lens drive speed is slower than in autofocus operation, and a considerable amount of operating force is required, 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 on the interchangeable lens together with AF, which drives the lens with a motor even during manual focusing. Furthermore, several proposals have been made regarding the f-warf orcus device.

Among the proposals regarding the nuclear/arm wharf orcus device, there is a proposal to use a methane switch instead of the conventionally known focus ring, and a proposal to improve the rotation angle of a ring-shaped rotary switch that works with the focus ring during manual focus operation. There is a proposal to change the lens drive speed.

However, the former proposal has the disadvantage that the methane switch and the conventionally known focus ring have very different operating methods, making it difficult to use, and the latter proposal has the disadvantage that the lens does not move even if the hand is stopped. does not stop,
At this time, in order to stop the lens movement, it is necessary to return the rotary switch to the neutral position e, which has disadvantages in that operability is poor 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 a power focus 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 the focus ring of a conventional MP, and that a device that drives the lens be used. It is necessary that the movement of the hand be configured so that it can immediately respond to and faithfully follow the movement of the hand.

OBJECT OF THE INVENTION It is an object of the present invention 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. That's true.

[Summary of the invention]

The No. 9 wharf focus device according to the present invention includes a focus ring that is rotated by hand, a pulse generating means that generates a /4' pulse signal in conjunction with the focus ring, and a rotation direction of the focus ring that is determined from the pulse signal. A focus ring rotation direction detection means for detecting a rotation direction of the focus ring, a focus ring rotation position detection means for detecting a rotation amount of the focus ring from the reference pulse signal, and a focus ring rotation direction detection means for detecting the rotation direction of the focus ring based on the detection result of the focus ring rotation direction detection means. drive direction setting means for setting the drive direction of the focus ring, and drive amount setting means for setting and storing the drive amount of the lens drive source based on the detection result detected by the focus ring rotation amount detection means. It is characterized by the fact that

The power focus device of the present invention uses the focus ring used in conventional MF as a manual focus operation member, so it has the advantage of being extremely easy to use. Since the lens drive source is configured to detect the rotation amount of the focus ring as a digital quantity based on the notarus signal and to control the lens drive source based on the detected value, the lens drive source can be driven to faithfully follow the focus ring. It has the advantage of being able to perform precise and high-speed focusing operations.

[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 the first @, 100 is a power focus device of the present invention, and the device 100 includes a focus ring 1 that is rotated with a finger, and operations necessary for a focus operation in accordance with the rotation operation of the focus ring 1. A manual focus calculation circuit 2 that calculates the amount, 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 5 that controls the drive source 4. and are included. The drive control circuit 5 also serves as a drive control circuit for AF, and an AF calculation circuit 98 is connected to the circuit 5, and a known AF' sensor 99 is connected to the AF 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 9-wharf orcus device of the present invention, and FIG. 3 is a diagram showing the actual power focus device shown in FIG. 2. This shows the electrical configuration.

In FIG. 2, 1 is a focus ring that is rotatably operated by a person's fingers, 6 is a first pulse generating means that generates a pulse signal in conjunction with the focus ring 1, and 3 is provided in a lens barrel of a camera, etc. 4 is the lens 3 for focusing.
7 is a drive source such as a motor that drives the shift focus ring 1 by a pulse signal generated from the first pulse generating means 6.
Focus ring rotation direction detection means 8 detects the rotation amount (rotation angle) of the focus ring 10 from the reference signal; 9 focus ring rotation direction detection means 7; Drive direction setting means 10 sets the rotation direction detected by the drive source 4 as the drive direction (rotation direction); Drive amount setting means 11 sets the drive amount of the drive source 4, second pulse generation means 11 generates a pulse signal proportional to the movement of the drive source 4 or the lens 3, and 12 generates a pulse signal generated from the first pulse generation means 6. Ta/
? Pulse generation speed detection means for detecting the pulse signal generation speed, 13 a 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 detection means 12, and 14 a drive direction setting means. 7 and drive source control means 15 for controlling the applied current or voltage, pulse period, etc. to the drive source 4 according to the set values set in the drive amount setting means 8 and the drive speed setting means 13;
When a pulse signal is not generated from the pulse generating means 6 even after a predetermined period of time has elapsed, the drive amount setting means 10 is reset to make the set value zero and a signal is generated to stop the drive source 4. Means 16 returns the set value in the drive amount setting means 10 to zero when the drive direction detected by the drive direction detection means 7 changes, and also returns the set value to the drive source 4.
"t" is an immediate inverting means that generates a signal to drive in the opposite direction.

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

The drive amount setting in the drive amount setting means 10 is performed according to the detected value of the seven-orbit ring rotation amount detection means 8, but the drive amount setting is canceled by the output of the immediate stop means 15 and the output of the immediate reversal means 16. Otherwise, the drive source 4 is immediately stopped or reversed.

The instant reversal means 16 sets the drive amount set value in the drive amount setting means 10 to zero only when the detected value in the seven-occasion ring rotation direction detection means 7 and the set 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, a block A surrounded by a dashed line corresponds to the Power 7 orcus device 100 shown in FIG. 1, and the block A includes the manual focus calculation circuit 2 shown in FIG. A configuration corresponding to the control 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 (
(i.e., a transistor for switching the current to the motor), lIA is a pulse generation switch constituting the second pulse generation means 11 shown in FIG. 2, and 6A and 6B are the first /4' These are two pulse generating switches that constitute the pulse generating means 6. 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 7 lowerer 34, and transistors 35 to 38.

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

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

A 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. When the first helicoid tube 39 and the second helicoid tube are screwed together, the lens 3 is moved in the optical axis direction relative to the first helicoid tube 39 when the first helicoid tube 39 rotates. You can adjust the focus by moving the lens along the Teeth 39m are formed on the outer peripheral surface of the first helicoid tube 39, and the first helicoid tube itself is configured as a ring gear. Teeth 39a of the first helicoid cylinder 39
A gear train 40 is disposed outside the first helicoid cylinder 39 and engages with the gear train 40 to rotate the first helicoid cylinder 39. Rotation is transmitted from a drive source 4 located at.

The focus ring 1 shown in FIG.
A ring 41 is fitted onto the first helicoid tube 39 so as to be relatively rotatable thereto (on the outer diameter side of the helicoid tube 39 ) and rotates integrally with the focus ring 1 . Four conductor turns 42 are formed on the outer peripheral surface of the ring 41, as shown in FIGS. 4 and 45, and the conductor turns 42 are grounded as shown in FIG. The conductor pattern 42 has two pattern portions 42a and 4 arranged along the circumferential direction of the ring 41, shifted by a half pitch from each other.
2b is formed. On the outside of the outer peripheral surface of the ring 41, sliding contact pieces 43 and 44 of two pulse generating switches 6A and 6B, which are supported in a stationary state by a support member (not shown) (fixed tube of the lens barrel body), are arranged. The contact pieces 43 of the six pulse generation switches are positioned to contact the pattern portion 42a, and the contact pieces 44 of the Noyalus generation switch 6B are positioned to contact the pattern portion 42b.

Therefore, when the ring 41 is rotated in the direction of the arrow f1 in FIG. 5, the nine circuits connected to the two contact pieces 43 and 44 receive pulse signals whose phases are shifted by half a pitch from each other as shown in FIG. will occur. 5 and 6, when the contact pieces 43 and 44 are on the line a in FIG. 5, the pulse signal p1 generated in the pulse generating switches 6A and 6B is
The voltage of Pt and Pt is the value on line a in Fig. 6, and the contact piece 43
and 44 are on the line in FIG. 5, the voltage of the pulse signal generated at the pulse generation switches 6A and 6B becomes a value on the line b in FIG. 6.

Both pulse signals p1 and p! Since the phases of the two pulse signals differ 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 the conductor pattern 45 is also grounded like the conductor pattern 42. An i4 pulse generation switch IIA having a contact piece 46 that contacts this conductive pattern 45 is provided outside the first helicoid 39. Since only one type of pulse signal is generated from this pulse generation switch IIA, the pulse signal is the first one.
Although it represents the amount of rotation of the helicoid cylinder 39 (that is, the amount of movement of the lens 3), the direction of rotation 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 fingers, and as a result, the ring 41 (see FIG. 4), which is integrated with the υ focus ring 1, moves in the direction of the arrow fl in FIG. 5, for example. Suppose it is rotated. As a result, the first /4
As shown in FIG. 6, two types of pulse signals p1 having mutually different phases are output from the two arm pulse generating switches 6A and 6B (FIG. 4) constituting the pulse generating means 6 (FIG. 2). and pg are generated, and these pulse 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. As a result, the focus ring rotation direction detection means 7 detects the rotation direction of the focus ring 10 by comparing the number of pulses of the two types of nose signals pl and p snow, and the focus ring rotation amount detection means 8 detects the rotation direction of the focus ring 10. The amount of rotation is detected.

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

Further, since the arm pulse signal is also applied to the instant stop means 15 having a timer circuit, the operation of the timer circuit within the instant stop means 15 is started.

Note that the focus ring rotation direction detection means 7, the focus ring rotation amount detection means 8 and 9, the pulse generation speed detection means 12, the immediate stop means 15, etc. are all included in the MPU 30 in the actual configuration shown in FIG. It is composed of a register, a built-in timer, and a counter 31.

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

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 4 is transmitted through the gear train 40 to the first helicoid tube 39 at a reduced speed in FIG. 4, and the first helicoid tube 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 ejected towards the tip side. Further, when the first helicoid tube 39 rotates, the conductor pattern 45 formed on the outer circumferential surface of the first helicoid tube 39 moves in the circumferential direction. A pulse signal representing the amount of rotation of the first helicoid tubes 3 and 9 (that is, the amount of movement of the lens 3) is generated in the pulse generation 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 sets the initial setting value (that is, the detection value detected by the focus ring rotation amount detection means 8) based on the drive amount detection signal fed back as described above from the second pulse generation means 11. When the initial setting value becomes zero, the driving source control means 14 controls the driving source 4.
to stop.

When the focus ring 1 is first operated in the forward direction and then subsequently operated in the reverse direction, the pulse generation switches 6A and 6B generate noise. The phases of the pulse signals p1 and p are also reversed,
The focus ring rotation direction detection 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, the instant reversal means 16 receives an input signal of -1 from the focus ring rotation direction detection means 7, and also receives a +1 input signal from the drive direction setting means 9 in 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 Noculus signal associated with the rotational operation of the focus ring 1 is generated from the pulse generating means 6, and while the drive source 4 and lens 3 are being driven according to the pulse signal, a predetermined period of time from the time of the first pulse generation is generated. If the subsequent pulse does not occur even after the elapse of time, the timer circuit in the immediate stop means 15 times out, and a signal is generated from the means 15 to zero the set value of the drive amount setting means 10. Yosi,
The set value of the drive amount setting means 1o 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 1.

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 goes high and the MPU 30 starts executing the program from (1) below.

(1) Output? - Outputs 1 (/S level) from P20 to P23. This results in a transistor of 37.35
is off, transistors 38 and 36 are on, grounding both ends of the motor 4, and applying a dynamic brake.

(2) Set timer TI■ in the MPU to O.

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

(3) Regis p M P , MDIR, EDIR, 0
Clear LDSW. MP, EP, MDIR,
EDIR.

0LDSW is a register in MPU l.

(4) Output 1 to date 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) Read the contents of the counter 31 from PORTO and store it in the register EP. 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 set to O. (8)-
00 clears the value of the counter 31 similarly to (4)-(6).

Determine α1J gp=o, because now EP=O (3
Branch to 5).

05) Focus ring rotation direction register EDIR is 0
Insert.

(c) Determine the value of the motor rotation direction register MDIR, and since it was cleared to 0 in (3), branch to (3'7).

(37) 1/ Clear registers DIR and MPi.

(38) Apply the brake to motor 4 in the same way as in (1). Then return to (7). Therefore, while the focus ring is not rotating, (7) - (8) - (9)
−αQ−α■−(35) −(36) −(24) −
Repeat steps (37) to (38). 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.
t I pz is generated, and each time the switches 6A and 6B are turned on, the signals PI and p! becomes high level, so the value of the counter 31 is incremented. Therefore (7
) will be positive. -degree counter 31
When the value of is read, it is reset by αQ from (8), so it will not be read twice. (11) EP=
A 0 determination is made and since they are not equal, the process branches to (6).

(6) Determine EP)O and branch to (6).

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

α→ EP from output boat 3 to D/A converter 33
/ Outputs IMER. The voltage proportional to the amount of pulses per unit time divided by the time it takes to change the pulse of the focus ring and the focus ring is the voltage follower 3.
You will be able to see the output of 4.

a) Determine the register MD I RO value, and since it was cleared in (3), go to (a).

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

Motor rotation direction register MDIRK Stores the value of EDIR.

(c) Determine the value of MDIH. Since it is not 0, branch to (c).

(c) Determine the value of MP, since it is not O, go to (c) fi
Determine the value of MDIR, it is +1, so go to (B) (B) P
2O, output 0 to P21, output 1 to P22゜P23,
Turn on transistor 38.35, transistor 37.3
By turning off the lens 6, current flows from the voltage follower 34 to the transistor 35, motor 4, and transistor 38, driving the motor 4 and moving the photographing lens 3 toward the infinite end.

Determine the status of switch IIA, if it is currently on (
(1) Set register 0LDSW to 0 and return to (7).

If the focus ring is not rotated as it is, the counter 31 will be blank (7) - (s) - (9)
-C10-αme-(35) -(A)-(C)-(E)
- to) - (b) - Repeat the loop of Kanichi (1). Eventually, the photographing lens 3 is moved to a desired position by the drive of the motor 4, the switch IIA is turned off, and the process branches to (31) at w.

(31) Determine the state of register 0LDSW. Since it is set to O in (1), go to (32). (32) Decrement the value of MP. (33) Set 0LDSW to 1. From then on (31)
At the branch, it does not go to (32) but comes to (33). (7)
-(8) -(9)-〇〇-α■-(35)-vortex)-(
The loop of c)-(i)-(1)-(3υ-(34)) is repeated while the switch 11A is off.

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

As the above loop is executed, MP=0 and Kashi (
At c), 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 radius 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 brake state changes to the energized state, the previously explained (7) - (8) - (9) - α1 - α car (2) -
(6) - αQ - α car) - ni) - (c) - (goods) - Same as Kanichiso's loop, but when reading the value of KARA/RI3 for the second time, turn the IC47 orcus ring. Therefore, a positive value is set to EP. (6) - (to) - α0 is controlled in the same way as the previous time and branches to α Enoki with α force.

0→Compare the values of the focus ring rotation direction register EDIR and the motor single rotation direction register MDIR, and if they are in the same direction, branch to (to).

The newly increased brightness pulse EP is added to the α1-e-tar moving pulse register MP.

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 you turn the focus ring in the opposite direction, the value of counter 31 will be negative, so (6) will be 1.
Branch to 4.

CI4 Focus ring rotation direction register EDIH
Set -1 to indicate a reversal.

(g) Convert the EP value to an absolute value. From then on, from αQ (2
) is controlled in exactly the same way as in normal rotation. Since MDIR is set to -1 in (c), go to (c).

Outputs 1 to P2O, P21, and O to P22° and P23. Therefore, a current flows from the voltage follower 34 to the transformer 37, motor 4, and transistor 36 to move the photographing lens 3 toward the close 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 (at 111S register MD I R and EDI
Since R is no longer equal, the process branches to (1).

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

Yay, change the rotation direction of motor 4 to a 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 0 for a certain period of time T after the timer TIMER is set to 0 in (2) or ←Q, it will be judged as a timeout in 06).37
) and brakes motor 4, it is possible to bring the sense of focus closer to that of conventional manual focusing.

In the above embodiment, the first pulse generating means generates the Noculus signal in conjunction with the rotation of the focus ring, and the second pulse generates the Noculus signal in conjunction with the rotation of the first helicoid tube. Although the pulse generating means is constructed as a sliding contact type switch means, the pulse generating means may be a photoelectric type,
It goes without saying that a non-contact type transducer such as a magnetic sensitive type, a capacitance type, etc. may be used. Furthermore, it goes without saying that the drive source 4 may be any actuator 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 when the ring is reversed or the operation is stopped. (] iD 7 The rotation of the orcus ring is converted into a pulse signal, and the lens drive source is controlled by calculation using a digital signal, so it is highly accurate. 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 perspective view showing an example of a noyalus generating means and an example of a lens drive mechanism related to the first helicoid tube and the first helicoid tube. FIG. 5 is a plan view of one of the noyalus generating means shown in FIG. The diagram shows the pulse generation means shown in FIG. FIG. 7 is a flowchart for explaining the operation of the MPU 30 in FIG. 3, which shows the phase and waveform of the pulse signal. 1...Focus ring 2...Manual focus axoog3...Lens 4...Lens drive source 5...Drive control circuit 6...First pulse generating means 6A and 6B.../? Lust 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 /4' Luss Generating means 11A...NoJ? Pulse generation switch 12...Pulse generation speed detection means 13...Drive speed setting means 14...Drive source control means 15...Immediate stop means 16
... Immediate reversal means 30... MPU31... Counter 32... Reset circuit 33... D/A converter 34... Voltage 7 Lowers 35-38... Transistor 39... First Helicoid cylinder 40...Gear train 41...Ring 42145
...Conductor pattern 43, 44, 46...Sliding contact piece Fig. 1 Fig. 3

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 Focus ring rotation direction detection means for detecting the rotation direction of the focus ring from a signal; focus ring rotation amount detection means for detecting the rotation amount of the focus ring from the pulse signal; and detection results in the focus ring rotation direction detection means. drive direction setting means for setting the drive direction of the lens drive drive source based on the drive direction; and drive amount setting means for setting the drive amount of the lens drive drive source based on the detection result of the focus ring rotation amount detection means. and a drive source control means for controlling the lens driving 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. focus device.