JP2013161000A - Photographing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photographing apparatus capable of performing lens driving with excellent responsibility while securing energy saving.SOLUTION: Movable lens frames 53, 54 provided with lens groups G3, G4 constituting a zoom optical system are connected so as to be movable by stepping motors 44a, 44b, and are coupled by an energizing spring 55 where a force amount for energization varies according to a distance between the lens groups G3, G4. A control unit performs speed control when the lens groups G3, G4 are driven by the stepping motors 44a, 44b according to the distance between the lens groups.

Description

The present invention relates to an imaging apparatus that performs imaging using a movable optical system such as a zoom lens.

Conventionally, various imaging apparatuses that perform imaging using a movable optical system such as a zoom optical system have been proposed.
For example, Japanese Patent Laid-Open No. 2001-124976 discloses a plurality of detection means at a plurality of locations in the optical axis direction, the first optical element, and the first optical element so that the first optical element arranged in the optical axis direction can be detected. The first optical element is selectively detected by one of the plurality of detection means according to the distance from the second optical element, and the first optical element is detected by each detection means. An imaging apparatus is disclosed that includes control means for controlling the driving of the first optical element with reference to the position.

JP 2001-124976 A

However, in the conventional example of the above publication, it is difficult to perform control to increase the speed and set the target or designated position while achieving energy saving in the photographing optical system including a movable optical system such as a zoom optical system. Become.
A plurality of lens groups constituting a photographing optical system having a movable optical system such as a zoom optical system may be a heavy load when moved. For this reason, if the lens group is simply moved at a high speed close to the maximum in response to the instruction operation, the energy consumption increases, and it is necessary to replace the battery before the shooting time desired by the user. Therefore, the convenience for the user is reduced.
Further, if the driving is performed assuming the maximum load, not only the high-speed performance is impaired, but also the energy consumption increases, causing noise and vibration, and wasting power consumption. The actuator becomes larger and it becomes difficult to reduce the size of the product.

Therefore, when the movable optical system is driven, it is driven at a high speed when the load is small, and when the load is large, it is possible to achieve energy saving while suppressing energy consumption (in a state where energy saving can be achieved). It is desired to drive with good responsiveness. In addition, by independently driving multiple lens groups that require accurate position adjustment, correct position control is more important in order to bring out the performance as designed, ensuring position accuracy and ensuring that each group collides. It is important to have a design that is hard to break and a safe design. This consideration is even more important when the product is downsized.
The present invention has been made in view of the above-described points, and an object of the present invention is to provide a photographing apparatus capable of performing lens driving control that is small and highly accurate and has good responsiveness.

  An imaging apparatus according to an aspect of the present invention includes an imaging optical system including a movable optical system that is movable in the optical axis direction in cooperation with each position of a first lens group and a second lens group. A biasing spring that connects the first lens group and the second lens group, and a change in the force of the biasing spring that changes according to the distance between the first lens group and the second lens group. A plurality of encoders for detecting the positions of the first lens group and the second lens group for detection, and driving to move the first lens group and the second lens group to the respective positions. A plurality of actuators, and a control unit that performs speed control when each of the first lens group and the second lens group 2 is moved by the plurality of actuators according to output results of the plurality of encoders. .

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which can perform lens drive control with small and highly accurate and favorable responsiveness can be provided.

FIG. 1 is a diagram illustrating an overall configuration of a photographing apparatus according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the position of each lens group when focusing on infinity by each lens group constituting the photographing optical system along the optical axis direction. FIG. 3 is a diagram showing a schematic configuration of a plurality of encoders for detecting the position of a lens group constituting the photographing optical system, a plurality of actuators, a linear encoder for detecting the position of the movable frame, a photo interrupter for detecting in a region, and the like. FIG. 4 is a diagram illustrating a detection operation by the photo interrupter in FIG. 3 and a detection operation in which of a plurality of regions by two photo interrupters is present. FIG. 5 is a view showing a schematic characteristic of changing the speed at which the zoom lens is moved according to the amount of extension of the spring. FIG. 6 is a flowchart showing the processing contents of camera control. 7A is a flowchart showing a processing procedure of ring control corresponding to the ring shift operation in FIG. FIG. 7B is a flowchart showing the processing contents of ring rotation control corresponding to the ring rotation operation in FIG. 6. FIG. 8A is a flowchart showing processing details of lens drive control. FIG. 8B is a flowchart showing the processing contents for driving two lens groups constituting the zoom lens when the power is OFF. FIG. 9 is a diagram showing a movable region of two lens groups constituting the zoom lens. FIG. 10 is a flowchart showing a processing content for setting two lens groups constituting the zoom lens at a predetermined lens position after resetting. FIG. 11 is a view showing the contents of a speed table referred to in the case of the processing contents of FIG. 12 is an explanatory diagram of the operation of FIG. FIG. 13 is a flowchart showing the processing contents for driving two lens groups constituting the zoom lens to a zoom designated position. FIG. 14 is a diagram showing the contents of a speed table referred to in the process of FIG. FIG. 15 is an explanatory diagram of the operation of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, the camera 1 according to the first embodiment constituting the photographing apparatus of the present invention has a photographing lens unit 2 provided with a photographing optical system 20 in a lens barrel 25 for photographing a subject, and this photographing. A lens body 2 has a camera body portion (hereinafter simply referred to as a body portion) 3 to which the lens portion 2 is detachably mounted.
In the main body 3, an image pickup device 4 having a photoelectric conversion function for converting an optical image formed on the image pickup surface into an electric signal, such as a CMOS sensor, is disposed in the vicinity of the image forming position on the optical axis of the photographing optical system 20. Thus, the imaging unit 5 that performs imaging with the imaging element 4 is formed.
The main body unit 3 includes a signal processing & control unit 6 that performs signal processing on the imaging unit 5 and overall control of the camera 1. The signal processing & control unit 6 is constituted by a CPU, for example.

In addition, the main body 3 touches a display unit 7 that displays an image captured by the imaging unit 5 and a recording unit 8 that records the captured image and a captured image by a shooting operation (release operation). A touch panel 9 that performs adjustment of alignment, selection of operation items, and the like, and an operation unit 11 that performs various operations such as a release operation by a release button 11a are provided.
In addition, the main body 3 includes an operation determination unit 12 that performs determination on the operation of the operation unit 11, a clock unit 13 that measures time and performs time management, and an object captured from an image captured by the imaging unit 5. The face detection unit 14 for detecting the face part, the communication unit 15 for bidirectional communication with the photographing lens unit 2, and the communication unit 16 for bidirectional communication with the accessory when the accessory is used. And having.

The signal processing & control unit 6 functions as a display image generation unit that drives the image sensor 4 and performs signal processing on the output signal of the image sensor to generate an image to be displayed on the display unit 7.
Further, when an instruction operation for focusing is performed, the signal processing & control unit 6 detects the contrast of the captured image from the output signal of the image sensor and determines the highest contrast as the in-focus (focus) state. It has the function of the contrast determination part 6a to perform.
Further, the signal processing & control unit 6 includes a moving image compression unit 6b that compresses a moving image. When an instruction operation for shooting and recording a moving image is performed while the moving image is displayed on the display unit 7, the moving image compressed by the moving image compression unit 6 b is recorded in the recording unit 8.
In addition, the signal processing & control unit 6 includes a still image compression unit that compresses still images. When a moving image is displayed on the display unit 7 and an instruction operation for recording a still image is performed, the still image compressed by the still image compression unit is recorded in the recording unit 8.

The photographic lens unit 2 includes a photographic optical system 20 as will be described later, and the photographic optical system 20 forms a zoom optical system capable of zooming in a focused state as a movable optical system movable in the optical axis direction. A zoom lens 21 is included.
As shown in FIG. 2, the photographing optical system 20 includes five lens groups sequentially arranged on the optical axis from the object side to the image pickup surface (image plane) I of the image pickup device 4 (from the position close to the object). It is composed of G1-G5. In the present embodiment, the lens group G1-G5 is described in the G1-G5 lens group notation.
The positions of the G1 lens group and the G5 lens group in the G1-G5 lens group are fixed. Three G2, G3, and G4 lens groups disposed between the G1 and G5 lens groups form a movable optical system. In this embodiment, the structure is reduced in size.

Specifically, the G2 lens group forms a focus lens that is moved to set a focus (in-focus) state by focusing, and a zoom lens 21 that changes the magnification in the focus state of the G3 and G4 lens groups. Form. Therefore, the G3 lens group and the G4 lens group become the first lens group and the second lens group constituting the zoom lens 21 in the movable optical system.
The photographic lens unit 2 includes a control unit 22 that controls the operation of each unit of the photographic lens unit 2, and an operation ring (hereinafter simply referred to as a ring) for performing aperture, focusing, and zoom operations of the photographic lens unit 2. The ring operation unit 24 provided with 23 is provided.
The ring operation unit 24 is slidably provided on a cylindrical lens barrel 25 that forms an outer cylinder of the photographing lens unit 2. The user can change the mode to be described later by sliding the ring operation unit 24. In the lens barrel 25 of the photographic lens unit 2, five groups of lenses G <b> 1 to G <b> 5 constituting the photographic optical system 20, the control unit 22, and the like are arranged.

In addition, the photographing lens unit 2 includes a communication unit 26 that performs bidirectional communication with the signal processing & control unit 6 of the main body unit 3 via the communication unit 15 of the main body unit 3. Therefore, when it is described that the control operation in the camera 1 described below is performed by the signal processing & control unit 6, for example, the control unit 22 can perform the control operation by performing communication using the communication units 15 and 26. The signal processing & control unit 6 can also perform the control operation performed by the unit 22.
The user rotates the ring 23 to mechanically move the G3 length group forming the zoom lens 21 constituting the photographing optical system 20 in the direction of the optical axis to perform photographing by manual zooming or to rotate the ring 23. It is possible to perform photographing by electric zoom that electrically drives the zoom lens 21 in response to the rotation operation and macro photographing at a macro position that focuses on a close distance of the subject.
In this way, the mode is changed from one mode to another mode in the three modes of the manual zoom mode as the first mode, the electric zoom mode as the second mode, and the macro mode as the third mode. You can shoot in the selected mode.

The control unit 22 includes a mode change control unit 22e that controls the mode change.
Further, the photographing lens unit 2 performs the sliding movement when the ring operating unit 24 provided with the ring 23 slides (shifts) in the direction of the central axis (optical axis) of the lens barrel 25 as indicated by reference numeral C in FIG. A slide determination unit 31 for determination is provided. In addition, the slide determination part 31 which determines (detects) the shift of the ring operation part 24 is comprised using a mechanical switch, for example.
In addition, the slide determination unit 31 outputs a signal for determining a mode change operation by turning on / off the plurality of, more specifically, three mechanical switches. For this reason, the ring operation unit 24 and the slide determination unit 31 or the slide determination unit 31 that are slidable and movable form a mode change unit that changes the mode such as the manual zoom mode. The mode change control unit 22e receives a signal for determining the mode change and performs a control operation corresponding to the mode change.

In addition, it is not limited to the configuration using a mechanical switch that changes the mode by turning on / off according to the shift position of the ring operation unit 24, but from one mode to another by operating a mode change button or a mode selection button provided with the number of modes. It is also possible to adopt a configuration in which the mode can be changed to, or any one mode can be selected.
In addition, when the ring 23 is rotated around the central axis (optical axis) of the lens barrel 25 as indicated by the symbol D in FIG. 1, the photographing lens unit 2 includes a rotation determination unit 32 that determines the rotation. Have. In addition, the rotation determination part 32 is comprised by the blade | wing which rotates with the ring 23, for example, and the encoder which detects the rotation position.
The taking lens unit 2 also determines (detects) each group position determination unit 33 that determines (detects) each lens group position of the G2-G4 lens group that constitutes the movable optical system, and an initial position of each lens group. It includes an initial position determination unit 34 and each group drive unit (or also referred to as a drive unit) 35 as an actuator that drives each lens group.

As shown in FIG. 3, each group position determination unit 33 is an encoder (specifically, a magnetoresistive effect sensor (MR sensor) using a magnetoresistive effect element) that detects the position (within the movable region) of the G2 lens group. 40), an encoder (specifically, linear encoder 41) for detecting the absolute position (within the movable region) of the G3 lens group, and a plurality of (in the specific example, divided) movable regions of the G4 lens group. It is composed of a plurality of encoders (specifically, photointerrupters (abbreviated as PI) 42a and 42b) that form an area determination unit that determines in which of the four areas.
The initial position determination unit 34 detects the initial positions of the G2, G3, and G4 lens groups using the MR sensor 40, the linear encoder 41, and PIs 42a and 42b.
The slide determination unit 31, the rotation determination unit 32, each group position determination unit 33, and the initial position determination unit 34 in FIG. 1 output the determination results to the control unit 22, and the control unit 22 determines each group based on these determination results. The drive by the drive unit 35 is controlled.

Further, each group driving unit 35 constituting a plurality of actuators includes a voice coil motor (abbreviated as VCM) 43 for driving the lens group G2 and stepping motors for driving the lens groups G3 and G4, respectively, as shown in FIG. (Abbreviated as SM) 44a, 44b.
As shown in FIG. 1, the control unit 22 includes a focus control unit 22 a that controls the focusing of the photographing optical system 20 and a zoom control unit 22 b that controls the zoom lens 21. Further, the control unit 22 includes a speed control unit 22 c that controls the speed (movement speed) of moving the lens groups G <b> 3 and G <b> 4 constituting the zoom lens 21 via each group driving unit 35.
When the speed control unit 22c controls the speed, for example, the speed control unit 22c is referred to information in a speed table 22g as a speed information storage unit provided in the control unit 22. The speed table 22g may be provided outside the control unit 22.

In the present embodiment, when the manual zoom mode is changed to another mode, the control unit 22 includes a reset unit 22d that resets the positions of the G3 and G4 lens groups and performs control corresponding to the mode change. In other words, in response to the mode change, the control unit 22 (the reset unit 22d) sets the G3 and G4 lens groups to a predetermined position that becomes known, and sets the G3 and G4 lenses to the target positions in the changed mode. It has a function of a setting unit that allows the group to be driven smoothly.
In addition, as will be described later, the control unit 22 is an encoder and actuator that controls position detection by a plurality of encoders (MR sensor 40, linear encoder 41, PI 42a, 42b) and each group driving unit 35 constituting a plurality of actuators. It has the function of a control unit (abbreviated as E / N & AC control unit in FIG. 1) 22f.
FIG. 2 is a cross-sectional view showing the position of each lens group constituting the photographing optical system 20 in the present embodiment and arranged along the optical axis direction. FIGS. 2A to 2D show the positions of the lens groups in the electric zoom mode as the second mode, and FIG. 2E shows the macro mode as the third mode. In FIG. 2, the outline of the zoom range is indicated by a thick arrow, and the approximate position of the focus lens and the approximate position of the zoom lens are indicated by dotted lines.

2A shows the wide-angle end or wide end (W inf or W) when focusing on infinity (when focusing on infinity), and FIG. 2B shows the intermediate state when focusing on infinity (S inf Or Sp1), FIG. 2C shows a state in which the G3 lens group is disposed at the same position as the G3 lens group in the third mode in the second mode (M1 or Sp2). 2D shows the telephoto end or telephoto end (T inf or T) at the time of focusing on infinity, and FIG. 2E shows the predetermined state (M2 or macro) in the third mode.
In the second mode shown in FIG. 2C, the G3 lens group is disposed at the same position as the G3 lens group in the third mode in the infinite focus state is an intermediate focal length state ( This corresponds to a state during zooming from the telephoto end (FIG. 2D) to FIG.
In this embodiment, the photographing optical system 20 includes, in order from the object side to the image side, a negative refractive power G1 lens group (object side lens group), a negative refractive power G2 lens group (focus lens), and a positive refractive power G3 lens. Group, a negative refractive power G4 lens group, and a positive refractive power G5 lens group.

In the second mode, when zooming from the wide end to the tele end, the G1 lens group is fixed, the G2 lens group moves along a convex locus on the image side, and the G3 third lens group moves only on the object side. The G4 lens group moves only to the object side, and the G5 lens group is fixed. That is, as shown in FIG. 2, in the present embodiment, the control unit 22 divides the G3 lens group as the first lens group and the G4 lens group as the second lens group constituting the zoom lens 21 into a wide angle (wide angle). When zooming from the farthest distance to the closest distance is performed during zooming from telephoto (telephoto) to telephoto (telephoto), control is performed so as to move together so that the position changes in the same direction (object side).
Focusing is performed by moving the G2 lens group in the optical axis direction, and focusing operation from a long distance to a short distance is performed by extending the G2 lens group to the object side.
When the mode is switched to the third mode shown in FIG. 2E, the G2, G3, and G4 lens groups move to predetermined positions in the movable range in the second mode.
In the example shown in FIG. 2 (E), the G2 lens group moves to the position at the time of focusing on the tele end at infinity in the second mode shown in FIG. 2 (D).
The G3 lens group moves to a predetermined position between the intermediate state shown in FIG. 2B and the tele end state shown in FIG.

The G4 lens group moves to the image side relative to the relative position with the G2 lens group in the second mode. Then, by setting the lens group position in FIG. 2 (E), an aberration correction state in which the aberration at the macro position can be substantially eliminated is set.
FIG. 2 shows the moving direction with respect to the lens group arrangement at the time of focusing on the tele end at infinity in the second mode, but when the mode becomes the third mode at the lens position at the wide end. Each of the G2, G3, and G4 lens groups moves to the object side and is disposed at a predetermined position.
Focusing in the third mode is performed by moving the G2 lens group in the optical axis direction. Focusing to a short distance is performed by moving the G2 lens group to the object side, and focusing to a long distance is performed by moving the G2 lens group to the image side.

  The lens group data (surface data, aspheric data, various data 1, various data 2) in the case of FIG. 2 is as follows. The surface data includes, for each surface number, the curvature radius r of each lens surface (optical surface), the surface interval d, the refractive index nd of each lens (optical medium) with respect to the d-line (587.6 nm), and each lens ( The Abbe number νd for the d-line of the optical medium) is shown. In the surface data, an asterisk * added to the right side of the surface number indicates that the lens surface is aspherical, and ∞ described in the curvature radius r indicates infinite. Note that the unit of data relating to the distance, such as the radius of curvature r and the surface interval d, is millimeter (mm) unless otherwise specified. The same applies to the data described in the various data 1 and 2.

In addition, the aspheric data shows data related to the lens surface having an aspheric shape in the surface data. The aspherical shape is expressed by the following equation, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.
x = (y ² / r) [1+ {1− (1 + K) · (y / r) ² } ^1/2 ]
+ A4y ⁴ + A6y ⁶ + A8y ⁸ + A10y ¹⁰ + A12y ¹² +.
Here, r is a paraxial radius of curvature, K is a conical coefficient, and A4, A6, A8, A10, and A12 are fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients. The symbol E in the lens group data indicates that the subsequent numerical value is a power index having a base of 10. The zoom data includes a focal length, an F number (Fno), a half angle of view, a variable surface interval d, and a radius ER of the aperture stop. In addition, the imaging magnifications MG and NA are indicated in the second mode (M2) data.
The various data 2 indicate the focal length, back focus air conversion length, optical total length, image height, focal length, half angle of view, shooting distance, and shooting magnification in the macro mode.

Lens group data surface number rd nd νd
1 45.2207 2.1400 1.77250 49.60
2 16.3269 5.1200
3 * 41.8793 1.5000 1.58313 59.38
4 * 14.4691 3.8500
5 23.9939 3.8000 1.80810 22.76
6 103.8698 d6 (variable)
7 -24.8418 1.2000 1.74100 52.64
8 -100.0000 d8 (variable)
9 * 14.0498 4.3000 1.58313 59.38
10 * -31.7996 1.3000
11 (Aperture) ∞ 1.9000
12 179.0098 1.0000 1.83400 37.16
13 10.8826 5.0000 1.49700 81.54
14 -18.9390 d14 (variable)
15 128.8505 1.0000 1.83481 42.71
16 15.2795 1.5800
17 * 37.2148 2.0000 1.53071 55.69
18 * 57.5081 d18 (variable)
19 -75.0639 2.4800 1.75211 25.05
20 -23.7233 d20 (variable)
Image plane (imaging plane) ∞
Aspheric data 3rd surface
K = 1.2447
A4 = 2.0075E-5
A6 = 2.7611E-7
A8 = 2.4894E-10
A10 = 3.5331E-12
A12 = −9.3037E-15
4th page
K = 1.0662
A4 = 2.1822E-5
A6 = −3.0982E−7
A8 = 1.77595E-9
A10 = 1.9840E-11
A12 = −5.0306E-14
9th page
K = 0
A4 = -3.8287E-5
A6 = -4.3941E-8
A8 = 1.5034E-10
A10 = 1.3526E-11
10th page
K = 0
A4 = 6.6094E-5
A6 = -2.9345E-8
A8 = -1.6201E-9
A10 = 3.6897E-11
17th page
K = −82.6051
A4 = 2.9743E-4
A6 = −7.3765 E-6
A8 = 9.2595E-8
A10 = −8.7606E−10
18th page
K = −271.4873
A4 = 2.8604E-4
A6 = −6.8173E-6
A8 = 8.5146E-8
A10 = −7.3142E−10

Various data 1
Focal length W-S-M1-T = 12.2-24.5-44.4-49.0
Fno W-S-M1-T = 3.6-5.2-6.1-6.5
Half angle of view W-S-M1-T = 44.9-23.8-13.5-12.
W inf (W) S inf (Sp1) M1 (Sp2) T inf (T)
d0 (Subject) ∞ ∞ ∞ ∞
d6 6.64460 9.32450 7.17320 5.91140
d8 30.06750 12.35030 2.51040 1.55590
d14 3.81420 7.93550 17.62220 19.75130
d18 6.81620 17.73200 20.03650 20.12370
ER 5.17564 5.38054 5.38054 6.41796

M2
d0 (subject) 110.72054
d6 5.91140
d8 3.34967
d9 0.40000
d14 20.00066
d18 17.68053
ER 6.41796
MG -0.35000
NA 0.028

Various data 2
G1 focal length -41.219
G2 focal length -44.911
G3 focal length 18.399
G4 focal length -23.276
G5 focal length 45.180
Back focus air equivalent length 14.600
Optical total length (common to WT) 100.111
Image height 10.815

Macro mode Focal length = 40.5
Macro mode Half angle of view = 13.4
In macro mode Shooting distance = 110.7 (distance from object to first surface)
Macro mode Shooting magnification = -0.35

3A and 3B show the configuration of the photographing optical system 20, the encoder that detects the position of the movable optical system in the photographing optical system 20, and the drive unit that drives the movable optical system.

A VCM 43 is attached to a fixed frame 51 fixed to the lens barrel 25, a G2 lens group is attached to a movable lens frame 52 attached to a movable base of the VCM 43, and the G2 lens group is attached to the movable lens frame 52 by the VCM 43. At the same time, it is driven to move in the optical axis direction. The position of the G2 lens group attached to the movable lens frame 52 is detected by the MR sensor 40 described above.
Further, the rotation shafts (drive shafts) of stepping motors (abbreviated as SM) 44a and 44b attached to the fixed frame 51 are connected to feed screws, respectively, and the movable lens frames 53 and 54 screwed to the feed screws have G3. , G4 lens group is attached.
Then, by rotating the SM 44a (44b) with a drive pulse, the G3 (G4) lens group can be driven to move in the optical axis direction together with the movable lens frame 53 (54) screwed to each feed screw. it can.

When one drive pulse is applied to the SMs 44a and 44b, the amount of movement of the SMs 44a and 44b to move the G3 and G4 lens groups in the optical axis direction by one drive pulse is determined by the pitch of the feed screw.
The G3 lens group is a mechanism that can move along the optical axis by a ring operation of the user. Therefore, it is necessary to detect the absolute position of the G3 lens group and cause the G4 lens group to follow the zoom position that the user wants to set. The G3 lens group position changed by this user operation is detected by the linear encoder 41 here. In addition, the position of the G4 lens group (position in units of divided areas) is a PI 42a that performs a binary (H, L level value) determination on the movement of the convex piece 54a provided on the movable lens frame 54 in the optical axis direction. , 42b. The PIs 42a and 42b are arranged at two locations along the direction parallel to the optical axis of the fixed frame 51.
After the G4 lens group detects one known lens position among the known reference positions Pr1, Pr2, and Pr3 detected by the PIs 42a and 42b described in FIG. Each position including the position including the moving distance for moving the G4 lens group to the target position side by the number of pulses, the position in the middle of moving, and the like are managed.

In addition, after the position of the G3 lens group is detected by the linear encoder 41, the position including the moving distance for moving the G3 lens group by the number of drive pulses for driving the SM 44a by the control unit 22, or the position during the movement, etc. Managed.
For example, if the distance from the current lens position to the target lens position is D1, and the amount of movement to move the G3 (G4) lens group together with the movable lens frame 53 (54) per drive pulse is m, the control unit 22 applies a drive pulse number Np divided by D1 / m to SM44a (M44b), and SM44a (M44b) drives the G3 (G4) lens group to a target lens position.
In the present embodiment, the movable lens frames 53 and 54 are fixed to the end portions of the urging spring 55, and thus the movable lens frames 53 and 54 are connected by the urging spring 55. For example, as shown in FIG. 3B, the urging spring 55 urges both lens groups in a direction in which both lens groups are attracted with a small amount of force when the distance between the G3-G4 lens groups is small.

Further, as shown in FIG. 3A, when the distance between the G3-G4 lens groups is large and the urging spring 55 is greatly extended, both lens groups are urged in a direction in which they are drawn with a large force.
By urging both lens groups in a predetermined direction (opposite each other) in this manner, the G3 and G4 lens groups are moved (driven) in the optical axis direction by the SMs 44a and 44b using a lead screw. It is possible to control the position with high accuracy by suppressing the generation.
FIG. 4A shows one PI 44a and convex piece 54a. In the PI 42a, a small light emitting hole E by a light emitting element and a small light receiving hole P by a light receiving element are arranged at positions facing each other at a predetermined interval, and a light shielding convex piece 54a is indicated by an arrow between both holes. Arranged to be movable in the direction.

In the state of FIG. 4A, the light receiving element receives light from the light emitting element (referred to as a transmission state). In the state of FIG. 4A, when the convex piece 54a moves to the left side, the convex piece 54a enters a light shielding state in which light emitted from the light emission hole E by the light emitting element is shielded.
Therefore, the approximate position of the convex piece 54a can be detected by determining the light receiving / blocking state of light by the light receiving element.
In this embodiment, as shown in FIGS. 3A and 3B, by arranging the PIs 42a and 42b at two locations, four movable areas of the G4 lens group can be detected by the PIs 42a and 42b. Divide into regions R1-R4. FIG. 4B shows four regions R1-R4 that can be detected by the PIs 42a and 42b.
Each of the output levels of the PIs 42a and 42b is set so that the transmission state is L level and the light shielding state is H level. Each group position determination unit 33 determines the position of the G4 lens group based on the output levels of the PIs 42a and 42b.

Specifically, both output levels are L, L level, L, H level, H, H level, H, L level (the position of the convex piece 54a corresponding to the position of the G4 lens group is in the movable region). It is determined (detected) which region in each of the regions R1-R4 exists (each group position determination unit 33). Therefore, each group position determination unit 33 has a function of an area determination unit that determines an area where the G4 lens group exists.
Although the relationship between transmission and light shielding is not illustrated precisely, when the G4 lens group moves from the wide side to the tele side as shown in FIGS. 3A to 3B, the light shielding state of the PI changes. , R1 to R4 can be determined.
Each group position determination unit 33 can also detect positions where the output levels of the PIs 42a and 42b change from the L level to the H level or vice versa as the known reference positions Pr1, Pr2, and Pr3. Yes.
Further, in the present embodiment, as shown in FIG. 9, the movable region of the G3 lens group is also divided into a plurality of regions and managed by the control unit 22.
Specifically, the movable region of the G3 lens group is divided into eight regions Ra-Rh, and the speed controller 22c determines the distance between both regions between the region where the G4 lens group exists and the region where the G3 lens group exists. In accordance with (distance in region unit), speed control is performed when the G4 lens group and the G3 lens group are driven by the SMs 44b and 44a, respectively. At this time, the sizes (distances) of the eight regions Ra-Rh do not have to be the same, and the drive required to move from one end to the other end in the movable region of the G3 lens group according to the required control speed. By using a value obtained by appropriately dividing the number of pulses, the control unit 22 manages in which region the G3 lens group exists.
Further, the current position of the G3 lens group is managed by the number of drive pulses that have driven the G3 lens group. Regarding the G4 lens group, the current position of the G4 lens group can be managed by the number of drive pulses that have driven the G4 lens group. In the present embodiment, the description will be made on the case of eight regions of Ra-Rh. However, the present invention is not limited to the case of eight regions, and can be similarly applied to the case of a plurality of regions other than eight.

As shown in FIG. 3, the G3 lens group and the G4 lens group are connected by a biasing spring 55. Accordingly, the content of speed control according to the distance between the areas of both lens groups corresponds to the amount of extension of the biasing spring 55.
Then, the speed control unit 22c controls the speed when the G3 and G4 lens groups are driven by the SMs 44a and 44b according to the amount of force corresponding to the extension amount of the biasing spring 55 (in other words, the distance between the areas of both lens groups). I do. The speed control unit 22c changes the speed at which the G3 and G4 lens groups are driven (moved) by changing the period for outputting the drive pulse number Np described above.
As shown in FIG. 9, the movable region of the G3 lens group and the movable region of the G4 lens group have overlapping regions that are partially overlapped. For this reason, in this embodiment, when the initial position (initial region) of the G3 and G4 lens groups is not fixed as will be described later, both lens groups are separated from the overlapping region (separated from the overlapping region). When the position of both lens groups is fixed by the retraction, or after setting to the determined position, it is linked to the specified position (target position) side. Adopting driving control action.

The speed controller 22c changes the driving (moving) speed according to the extension of the biasing spring 55 as shown in FIG. As shown in FIG. 5, when the extension of the biasing spring 55 is small, that is, when the biasing force is small, the speed is increased and the G3 lens group and the G4 lens group are driven to the zoom designated position side. Also, when the biasing spring 55 is extended, that is, when the biasing force is large, the speed is decreased and the G3 lens group and the G4 lens group are driven to the zoom designation position side.
The speed table 22g takes into account the magnitude (drive load) for driving the G3 and G4 lens groups by the SMs 44a and 44b as actuators in the case of a force corresponding to the extension amount of the biasing spring 55, The driving speed is set. FIG. 5 shows that when the extension amount of the urging spring 55 is the smallest, the speed at which the G3 and G4 lens groups are driven is maximum (Vmax).

In the present embodiment, by driving the G3 and G4 lens groups constituting the zoom lens 21 in this way, when the biasing force of the biasing spring 55 is small, the driving speed is increased. Then, the G3 lens group and the G4 lens group are driven to the target zoom designation position side, and the G3 lens group and the G4 lens group can be set to the zoom designation position at high speed (in a short time).
On the other hand, if the biasing force of the biasing spring 55 is large, increasing the speed results in a large energy consumption. Therefore, in the present embodiment, the energy consumption is reduced so that the energy consumption is not large. While controlling, the speed is controlled so as to achieve a speed close to the optimum (the speed is made as high as possible while the energy consumption is suppressed).
The control unit 22 (the speed control unit 22c) is energized from position information based on detection by the linear encoder 41 as the first encoder and position information detected by the PIs 42a and 42b as the second encoder. The smaller the force corresponding to the expansion / contraction amount of the spring 55, the G3 lens group as the first lens group and the G4 lens group as the second lens group are used as the first and second stepping motors. The SM 44a and 44b are controlled to move at high speed.
By controlling the drive as described above, the present embodiment can perform lens drive control with high accuracy and good responsiveness even when the size is reduced while ensuring energy saving.

As described above, when the biasing force of the biasing spring 55 is large, driving the G3 lens group and the G4 lens group at a speed (lower than the maximum movable speed) allows the SMs 44a and 44b to move. The lens driving control system by driving is prevented or reduced so that the lens can be driven with high accuracy. Further, by performing such lens driving, it is possible to reduce the generation of noise.
In the manual zoom mode, the position of the G3 lens group that moves in conjunction with the manual movement amount of the ring operation unit 24 is detected by the linear encoder 41. Further, in conjunction with this movement, the G4 lens group is driven by the SM 44b under the control of the control unit 22 so as to be at the lens position constituting the zoom lens.

In the electric zoom mode, the G3 and G4 lens groups are driven by the SMs 44a and 44b, respectively, under the control of the control unit 22 corresponding to the operation amount of the ring operation unit 24. The initial position detection (positioning) of the G3 lens group is performed by the linear encoder 41. After the position of the G3 lens group is detected, the position (and movement distance) of the G3 lens group is determined by the number of drive pulses that drive the SM 44a. ) Is managed.
As will be described later, when the mode is changed from the manual zoom mode to the electric zoom mode, the lens position for detecting the position of the G4 lens group is reset.

  The camera 1 forming the photographing apparatus of the present embodiment having such a configuration cooperates with the positions of the G3 lens group as the first lens group and the G4 lens group as the second lens group in the optical axis direction. A photographic optical system 20 having a movable optical system that can be moved, a biasing spring 55 that connects the first lens group and the second lens group, the first lens group, and the second lens. A linear encoder 41 as a plurality of encoders for detecting the positions of the first lens group and the second lens group in order to detect a change in the force of the biasing spring 55 that changes in accordance with the distance between the groups. And PI 44a, 44b, SM 44a, 44b as a plurality of actuators for driving the first lens group and the second lens group to move to the respective positions, and output results of the plurality of encoders. Characterized in that it comprises a and a speed control section 22c serving as a control unit for controlling the speed for moving the first lens group and the second lens group 2, respectively by the plurality of actuators.

Next, the operation of this embodiment will be described. FIG. 6 shows an example of the processing contents of the camera control of this embodiment.
When the power source of the camera 1 is turned on and each part of the camera 1 is in an operating state, in the first step S1, the signal processing & control unit 6 determines whether or not it is in the shooting mode. When the shooting mode is selected by the user, in step S2, the signal processing & control unit 6 outputs the moving image of the subject observed in the shooting mode to the display unit 7 and displays the through image on the display unit 7. Is done.
In the next step S <b> 3, the control unit 22 determines whether or not the ring operation unit 24 has been shifted through the slide determination unit 31. If it is determined that the ring operation unit 24 has been shifted, in step S4, the control unit 22 performs ring control corresponding to the shift operation, and proceeds to the next step S5.

If it is determined in step S3 that the shift operation is not performed, the process proceeds to step S5. In step S5, the control unit 22 determines whether the ring 23 is rotated through the rotation determination unit 32. When the ring 23 is rotated, in step S6, the control unit 22 performs ring rotation control corresponding to the ring rotation, and proceeds to the next step S7.
In step S7, the signal processing & control unit 6 determines whether or not a still image shooting operation has been performed. If a still image shooting operation has been performed, in the next step S8, the still image is shot and recorded. A still image is recorded in the unit 8. After step S8, the process returns to step S1.
If a still image shooting operation is not performed in step S7, the signal processing & control unit 6 determines in step S9 whether a moving image shooting operation has been performed.

When a moving image shooting operation is performed, in the next step S10, moving image shooting starts, and the signal processing & control unit 6 starts moving image shooting processing. In the next step S <b> 11, the signal processing & control unit 6 determines whether or not an operation for ending moving image shooting has been performed. When an operation for ending the moving image shooting is performed, in the next step S12, the signal processing & control unit 6 ends the moving image shooting process, and records the moving image from the start of shooting to the end of shooting in the recording unit 8. Then, the process returns to step S1.
If it is determined in step S11 that the moving image shooting is not terminated, in step S13, the control unit 22 determines whether or not the ring operation unit 24 is shifted through the slide determination unit 31.

If it is determined that the ring operation unit 24 has been shifted, in step S14, the control unit 22 performs ring control corresponding to the shift operation, and proceeds to the next step S15.
If it is determined in step S13 that the shift operation is not performed, the process proceeds to step S15. In step S15, the control unit 22 determines whether or not the ring 23 is rotated through the rotation determination unit 32.
When the ring 23 is rotated, in step S16, the control unit 22 performs ring rotation control corresponding to the ring rotation, and proceeds to the next step S11. If no operation for shooting a moving image is performed in step S9, the process returns to step S1.

If the shooting mode is not selected in step S1, the signal processing & control unit 6 determines in step S17 whether or not the playback mode is selected.
If the playback mode is selected, the signal processing & control unit 6 controls the display unit 7 to display a list of files recorded in the recording unit 8 in step S18.
In step S <b> 19, the signal processing & control unit 6 determines whether one file is selected from the files displayed as a list by the user.
If a file is selected, the signal processing & control unit 6 reproduces the file (selected file) in the next step S20, and proceeds to the next step S21. In step S <b> 21, the signal processing & control unit 6 determines whether or not the reproduction of the selected file is finished. If not finished, the process returns to step S <b> 20.

On the other hand, when the reproduction of the selected file is finished, the process returns to step S18. If no file is selected in step S19, the signal processing & control unit 6 determines in step S22 whether or not a reproduction end operation has been performed. If no reproduction end operation has been performed, the process returns to step S18. On the other hand, if an operation to end reproduction is performed, the process returns to step S1.
If the reproduction mode is not selected in step S17, the signal processing & control unit 6 determines in step S23 whether or not an instruction operation for turning off the power has been performed. In the case of an instruction operation for turning on not turning off the power, the control unit 22 turns on the lens power in step S24. The lens power source is a power source for driving the movable optical system (G2-G4 lens group). In the next step S25, the signal processing & control unit 6 sets the G3 and G4 lens groups to the lens initial position A, and returns to the processing in step S1. Details of the case where the lens power is ON will be described with reference to FIG. 8A.

On the other hand, if the power is OFF in the next step S23, the control unit 22 sets the G3 and G4 lens groups to the lens initial position B in step S26. In the next step S27, the signal processing & control unit 6 turns off the lens power and returns to the processing in step S1. Details of the case where the lens power is OFF will be described with reference to FIG. 8B.
FIG. 7A shows the processing content of the ring shift control in steps S4 and S14 in FIG. The user can change the mode as described below by shifting the ring operation unit 24 in the optical axis direction. Further, in the present embodiment, the control unit 22 (the mode change control unit 22e) corresponds to the mode change from the manual zoom mode as the G3 lens group and the second lens group as the first lens group. The G4 lens group is set to a predetermined lens position.
In the first step S31, the control unit 22 determines whether or not the ring shift is an operation on the macro side.
If the shift is an operation on the macro side, in step S32, the control unit 22 determines whether or not the mode is changed from manual zoom.

If the mode is changed from manual zoom, the control unit 22 resets the lens positions of the G3 and G4 lens groups in step S33. In other words, during manual zooming, the G3 lens group moves mechanically in conjunction with the ring 23 that is manually operated, and the G4 lens group forms a zoom lens by the SM 44b in response to the canonical movement of the G3 lens group. Driven by. The lens position of the G3 lens group can be detected by the linear encoder 41.
Accordingly, when the mode is changed to the macro side, the lens position is reset as an initial position in order to perform position control (drive pulse management) by the drive pulse of the SM 44a. That is, here, the control based on the linear encoder is switched to the (drive) pulse control by the stepping motor (SM44a). Such pulse control is more accurate and enables high-speed position control. When the control method changes in this way, the control is started after clarifying the reference position of each control (that is, after the initial position is set by the reset operation) to ensure accuracy. In particular, in the open loop control in which the position is determined by inputting a pulse to the stepping motor, the control from the reference initial position is important. Therefore, the reset operation is indispensable when the mode is switched or the power is turned on.

After the position of the G4 lens group is also determined by resetting the lens position in step S33, the control unit 22 drives the G3 and G4 lens groups to the macro position in the next step S34. If the determination in step S32 is not a mode change from manual zoom (a mode change from electric zoom), the process proceeds to step S34 without performing step S33. By performing the process of step S34, the process of FIG. 7A is completed, and the process proceeds to the next process (step S5 or S15) of FIG.
If the macro-side ring shift is not performed in step S31, the control unit 22 determines in step S35 whether or not the operation is a manual zoom-side ring shift operation.

In the case of ring shift on the manual zoom side, in the next step S36, the control unit 22 determines whether or not the mode is changed from the macro side (to the manual zoom side). In the case of a mode change from the macro side, zoom driving is performed by manually moving the G3 lens group to the lens position determined by the mechanical ring shift amount from the macro position in the next step S37 (macro → normal position in FIG. 7A). Drive), and the process of FIG.
When the mode is not changed from the macro side in step S36 (that is, when the mode is changed from the electric zoom), if the user performs a manual zoom operation, the G3 lens group is mechanically moved. Depending on how it is moved and the position of the G4 lens group at that time, the G3 lens group may move rapidly and hit the G4 lens group. Therefore, in the present embodiment, control of the lens position reset B for retracting the G4 lens group is performed in step S41. This is because the G4 lens group is moved to the wide side and retracted, and when there is a sufficient distance from the G3 lens group, the position control is executed following the G3 lens group, but the position with the G3 lens group is detected. If it is determined that it is too close, after the G4 lens group is retracted to the area where the movement of the G3 lens group is restricted (end retreat position), the tracking control for following the G3 lens group is entered. Is. In this way, when preparation for following the G3 lens group is completed, the processing in FIG. 7A is terminated.
Depending on the design, when the lens group position changes greatly (15 mm in the example of this embodiment), such as a high magnification zoom, this retracted position is a very limited area at the end of the movable range (this embodiment) In this example, there is only about 2 mm), and if the initial position is determined by always retracting to this limited end retracted position, it takes time to determine the initial position, and rapid imaging control cannot be performed. Therefore, in this embodiment, in addition to position detection indicating the end retreat position, a photo interrupter for determining a further reference position is provided, so that a reset position is provided even during retraction, and high-speed and high-precision lens drive control is performed. Made possible.

If the manual zoom side is not set in step S35, the control unit 22 determines in step S38 whether the mode is changed from the macro side. When the mode is not changed from the macro side (when the mode is changed from the manual zoom side), in step S40, the control unit 22 resets the lens position of the (G3) G4 lens group, and then ends the process of FIG. 7A. To do. On the other hand, when the mode is changed from the macro side in step S38, in step S40, the control unit 22 drives the normal position from the macro position by pulse management corresponding to the ring (electric zoom ring) operation during electric zoom. To end the process of FIG. 7A.
FIG. 7B shows the processing content of the ring rotation control in step S6 or S16 in FIG. In first step S51, the control unit 22 determines whether or not the macro ring rotation operation (macro side ring rotation operation).

In the case of the macro ring rotation operation, in step S52, the control unit 22 performs a focusing process for the G2 lens group corresponding to the operation. Thereafter, the process in FIG. 7B is terminated, and the process proceeds to the next step S7 or S11 in FIG.
If it is not a macro ring rotation operation in step S51, the control unit 22 determines in step S53 whether or not it is a manual zoom ring rotation operation.
In the case of determining the manual zoom ring rotation operation, in step S54, the G3 lens group is mechanically manually moved by the manual zoom ring rotation operation by the user.
Further, in step S55, the control unit 22 determines the zoom position of the G4 lens group in accordance with the movement amount moved in the optical axis direction by the rotation amount of the G3 lens group in step S54, and the G4 lens is set at the zoom position. After controlling the driving by the SM 44b to drive the group, the processing in FIG. 7B is terminated.

If the ring rotation operation for manual zooming is not performed in step S53, the control unit 22 performs zoom control of the G3 lens group and the G4 lens group in step S56 in accordance with the direction of the ring rotation operation, and then, as shown in FIG. 7B. The process ends.
8A and 8B show the processing contents related to steps S23 to S27 in FIG.
FIG. 8A shows the details of lens drive control processing for the G3 and G4 lens groups. FIG. 8B shows the control contents when the power-off operation is performed.
When the lens drive control is started as shown in FIG. 8A, in the first step S61, the control unit 22 waits for the lens power supply to be turned from OFF to ON. When the lens power is turned on, in step S62, the control unit 22 resets the G3 lens group and the G4 lens group at the same time. Details of the reset process will be described with reference to FIG.

In the next step S63, the control unit 22 determines whether or not the zoom position is designated from the main body unit 3. If the zoom position is designated, in the next step S64, the control unit 22 drives the G3 lens group and the G4 lens group simultaneously to the zoom designated position as the designated zoom position, thereby driving the lens in FIG. 8A. End the control.
This zoom designation position corresponds to the lens initial position A set in step S24 in FIG. Note that the user can designate the zoom designation position when the lens power is turned on by operating the operation unit 11 in the main body 3.
If the zoom position is not designated in step S63, the G3 lens group and the G4 lens group are simultaneously driven to a wide zoom designated position close to the wide end, and the lens drive control in FIG. 8 is terminated. The wide zoom designation position corresponds to the lens initial position B in step S26 in FIG.

FIG. 8B shows the control contents when the power is turned off in FIG.
When this process is started, in the first step S71, the control unit 22 determines whether or not the power-off operation is performed in the macro mode. In the macro mode, in step S71, the control unit 22 performs drive control so as to move the G3 and G4 lens groups to a reset position (Sp2 state position in FIG. 2) close to the macro position. Terminate the process.
In this case, when the power is turned on next time, the reset position can be determined (detected) in a short time, and then the movement (drive) to the target lens position can be performed smoothly.
In step S71, when the mode is other than the macro mode, in step S73, the control unit 22 determines whether or not the power-off operation is performed in the manual zoom mode.

In the case of the manual zoom mode, the process of FIG. 8B is terminated without performing electrical control according to the user's operation.
On the other hand, if it is determined in step S73 that the power OFF operation has not been performed in the manual zoom mode, in step S74, the control unit 22 determines whether there is an instruction to reset the lens position from the main body unit 3.
It should be noted that the user operates the operation unit 11 of the main body unit 3 to change the position of the G3 and G4 lens groups when the power is turned off (in other words, the lens position that is initially set when the power is turned on next) to the current position. You can specify (select) nearby. If the user desires to take a picture with the composition currently being taken, it is preferable to instruct the lens position reset from the main body 3 side. The signal processing & control unit 6 of the main body unit 3 sends the information to the control unit 22 when there is an instruction to reset the lens position by the user, and the control unit 22 makes the determination in step S74 based on this information.

It should be noted that the user does not have to give an instruction to reset the lens position when he / she wants to perform normal shooting with which the subject can be easily confirmed at a wide angle.
If there is an instruction to reset the lens position as described above, in step S75, the control unit 22 drives the G4 lens group to the tele side of the PI closer to the current position, and detects the G4 lens group as the current encoder. Control is performed so as to drive to the tele-side end of one of the regions Ra-Rh (abbreviated as encoder region in FIG. 8B), and the processing in FIG. 8B ends.
In this case, when the power is turned on next time, the lens is set to a reference position close to or close to the reference position when the power is turned off. Can do. Even if the power of the actuator is lost when the power is turned off in this state, and the lens position is shifted due to a spring or gravity, there is a detection mechanism nearby, and quick initialization is possible.

On the other hand, if there is no instruction to reset the lens position in step S74, in step S76, the control unit 22 performs control to drive the G3 and G4 lens groups to a reset position close to the wide end, and the process in FIG. .
In this case, when the power is turned on next time, since the G3 and G4 lens groups are close to the reference position, the G3 and G4 lens groups are moved to the wide position in a short time, and the user can easily confirm the subject at a wide angle. Normal shooting can be performed in the state.
FIG. 10 shows the processing content of resetting the G3 and G4 lens groups in FIG. 8A.

  When the reset process is started, in the first step S81, the control unit 22 determines the moving speed when the G3 and G4 lens groups are first retracted (to determine the initial position). Reference 22g. FIG. 11 shows the contents of the speed table 22g that is referred to when moving for evacuation.

The speed table 22g is also referred to for the following resetting. However, in the present embodiment, the value of the speed V1-V8 in the speed table 22g that is referred to for evacuation is referred to for resetting so that the difference in moving distance is large and the distance difference can be moved at high speed. It is set to a large value compared to the case where it is done. As described above, since different speed tables are used depending on the situation, it is possible to perform an optimal control that balances the speed and accuracy according to the situation. At this time, when a stepping motor is used as an actuator, 1-2 phase driving or microstep driving may be properly used. In other words, the resetting is performed by micro-step driving that allows small control although the torque is small, and at the time of evacuation, the 1-2 phase driving that has high accuracy but large torque is used.
In the next step S82, the control unit 22 controls the driving of the SM 44a so that the G3 lens group is retracted to a predetermined position using the detection information of the linear encoder 41 in the tele (telephoto) direction. This predetermined position is a boundary position where the movable lens frame 53 to which the G3 lens group is attached moves to the tele side (object side) and is mechanically restricted by the fixed frame 51 (for example, in the movable region in FIG. 9). Near the end of the region Ra).

In step S83, the control unit 22 controls the driving of the SM 44b so as to retract the G4 lens group in the wide (wide angle) direction while referring to the detection information of the PIs 42a and 42b. Note that steps S82 and S83 may be performed simultaneously.
The retreat speed table 22g is for determining the speed when the G3 and G4 lens groups are moved in a direction that does not collide, and the control unit 22 overlaps the G3 and G4 lens groups shown in FIG. Control is made to move in a direction away from the overlapping region.
For example, when the G3 lens group is located in the area Rf and the G4 lens group is located in the area R2, the G3 lens group and the G4 lens group are separated from each other at a speed V1 from the retreat speed table 22g. The control unit 22 controls to drive the SMs 44a and 44b so as to move. The speed V1 in this case is the maximum speed at which the movement is performed at the highest speed in FIG. As the speed V1-V8 is smaller, the speed is larger, and V8 is the lowest speed. The control unit 22 performs control according to the characteristics shown in FIG.

FIG. 12A shows how the G4 lens group moves in step S83. When the G4 lens group was present in the region R1, it was moved to the region R2, and when the G4 lens group was present in the region R2, it was moved to the region R3, and the G4 lens group was present in the region R3. In this case, it is moved to the region R4 side.
After the evacuation process is completed by the processes of steps S81 to S83 in FIG. 10, the control for driving the G3 and G4 lens groups to move to a predetermined reset position is performed by the processes after step S84.
In step S84, the control unit 22 refers to the speed table 22g for resetting in order to determine the moving speed when moving to a predetermined position for resetting.

In step S85, the control unit 22 controls the reset driving while referring to the detection information of the PIs 42a and 42b with the G4 lens group in the tele direction. And it drives to the reference position (predetermined position) used as known lens positions, such as Pr1, Pr2, and Pr3.
In step S86, the control unit 22 uses the detection information of the linear encoder 41 to control the reset driving for setting the G3 lens group to a predetermined position, and ends the process of FIG.
The predetermined position in this case is a reference position for enabling the G3 lens group to perform pulse control (pulse management) with the number of drive pulses by the SM 44a. After setting to a predetermined position where pulse management can be performed by the linear encoder 41, the G3 lens group can be driven to a target lens position at high speed with the number of drive pulses applied to the SM 44a.
Strictly speaking, in this embodiment, since the G3 lens group is interlocked with the movement of the user's hand in this embodiment, only the G4 lens group is reset for pulse management, but FIG. Shown.

As a supplementary explanation, the linear encoder 41 requires an A / D converter or the like (not shown), takes time to detect the absolute position, and consumes a large amount of energy when used constantly. For this reason, in this embodiment, the linear encoder 41 is always used only in the manual zoom mode.
However, in other modes, the linear encoder 41 is used only when the absolute lens position needs to be detected, and the lens position is normally managed when the G3 lens group is driven with the number of drive pulses. Do. By doing in this way, this embodiment can perform an energy-saving and high-speed lens drive.
FIG. 12B shows how the G4 lens group is moved by the process of step S85.

When the G4 lens group is present in the region R4, it is moved to the region R3 side. When the G4 lens group is present in the region R3, it is moved to the region R2 side, and the G4 lens group is present in the region R2. In this case, it is moved to the region R1 side.
FIG. 13 shows the processing contents of the zoom designated position driving in step S64 or S65 in FIG.
When this process is started, in the first step S91, the control unit 22 refers to the speed table 22g in order to determine the moving speed when moving the G3 and G4 lens groups to the zoom designated position. FIG. 14 shows the contents of the speed table 22g referred to in this case.
In this case, the value of speed Vi ′ (i = 1-8) is set to a large value corresponding to the case where the movement distance difference is large.

In the next step S92, the control unit 22 controls the driving of the SMs 44a and 44b so as to move the G3 and G4 lens groups to the target zoom designation position region side.
In the next step S93, the control unit 22 determines whether or not the target zoom designation position has been reached. If the target zoom designation position has not been reached, the process returns to step S91.
In this way, when the G3 and G4 lens groups reach the target zoom designation position, the processing in FIG. 13 ends. FIG. 15 shows how the G4 lens group is moved by the process of FIG.
FIG. 15A shows the operation contents when the G4 lens group is moved from the state in the tele-side region R1 to the target zoom position at the wide end.

In this case, the moving speed (driving speed) for the G4 lens group in the region R1 is determined by referring to the speed table 22g, and the G4 lens group moves toward the target position at the determined speed. When the G4 lens group is in the region R1, the control unit 22 performs control so as to move at the same speed.
When the G4 lens group moves from the region R1 to the region R2 across the boundary between the region R1 and the region R2, the control unit 22 moves the G4 lens group from the region R1 to the region R2 due to the output change of the PIs 42a and 42b. Detect that. And the control part 22 changes to the speed corresponding to area | region R2 with reference to the speed table 22g.
As shown in FIG. 15A, every time the area where the G4 lens group exists changes, the control unit 22 refers to the speed table 22g and changes the speed corresponding to that area to set the target position. Take control.

FIG. 15B shows the operation contents when the G4 lens group is moved from the state in the tele-side region R1 to the target zoom end position at the tele end.
In this case, the G4 lens group is set to the target position with the speed in the speed table referred to in the region R1.
FIG. 15C shows the operation contents when the G4 lens group is moved from the state in the region R3 closer to the wide to the target zoom end designated zoom position.
In this case, the moving speed for the G4 lens group in the region R3 is determined from the contents of the speed table 22g, and the G4 lens group moves in the target direction at the determined speed. When the G4 lens group is in the region R3, the control unit 22 controls to move at the same speed.

When the G4 lens group moves from the region R3 to the region R2 beyond the boundary between the region R3 and the region R2, the control unit 22 detects that the G4 lens group has moved to the region R2 due to the output change of the PIs 42a and 42b. To do. And the control part 22 changes to the speed corresponding to area | region R2 with reference to the speed table 22g. As shown in FIG. 15C, every time the area where the G4 lens group is present changes, the control unit 22 refers to the speed table 22g and changes the speed corresponding to the area while changing the G4 lens group to the target. Control to set the position. At this time, the speed is changed while referring to the position of the G3 lens group.
According to the present embodiment that performs the operation as described above, it is possible to provide a photographing apparatus capable of performing lens driving control that is small and highly accurate and has good responsiveness while ensuring energy saving.
In other words, in this embodiment, when the first and second lens groups constituting the zoom lens 21 are driven by the first and second actuators (specifically, SM 44a and 44b), both lens groups are When the driving load to drive is large, the lens is driven so as to drive as fast as possible in the state while suppressing the energy consumption, so that the lens driving with good responsiveness is ensured while ensuring energy saving. Can do.

Further, according to the present embodiment, the period of the driving pulse for the SMs 44a and 44b constituting the first and second actuators is changed corresponding to the magnitude of the driving load (at least when the driving load is large, the period is changed). Therefore, the lens can be driven with high accuracy while suppressing the step-out.
In the electric zoom mode in the present embodiment, when the positions of the first and second lens groups are determined, the target lens is determined from the current lens position by the number of drive pulses applied to the SMs 44a and 44b. Since it is driven (moved) to the position, it can be driven to the target lens position at high speed.
Further, according to the present embodiment, even when a part of the movable area of the first and second lens groups overlaps, the first and second lens groups do not collide when the power is turned on. , It can be driven to the target lens position. Further, according to the present embodiment, the first and second lens groups can be driven in cooperation (simultaneously in parallel), so that the target lens position can be achieved at higher speed (short time). Each can be set.

The control operation performed by the control unit 22 in the photographing lens unit 2 described above may be performed by the signal processing & control unit 6 in the main body unit 3. Further, the control unit 22 may have some of the functions of the signal processing & control unit 6.
In the above description, the case where the photographing lens unit 2 and the main body unit 3 are detachable has been described. However, the present invention is also applicable to a case where the photographing lens unit 2 and the main body unit 3 are integrated. be able to. In such a case, the signal processing & control unit 6 may have the function of the control unit 22 without providing the communication units 15 and 26.
In the above-described embodiment, the position detection of whether the G4 lens group is in any of the four regions R1-R4 or the known reference positions Pr1-Pr3 using the two PIs 42a and 42b. However, three or more PIs may be used. By increasing the number of PIs, the number of known reference positions can be increased, and the accuracy of position detection in units of areas can be further improved.

In the above-described embodiment, the case where the G3 and G4 lens groups are moved in the target direction with reference to the speed table 22g as the speed information storage unit has been described. It is not limited to this case, and it may be controlled to move at different speeds.
Further, for example, a force amount detection unit such as a strain sensor for detecting the force amount of the biasing spring 55 is mounted, and the G3 and G4 lens groups are targeted from the current position to the target position side according to the detection value of the force amount detection unit. You may make it control the speed when moving to. This case is not limited to the case where both lens groups are controlled to move at the same speed.
Regarding the flowcharts in the claims, the specification, and the drawings, even if “next” or the like is used for convenience, it does not mean that it is essential to carry out the processing in that order. . Further, each step constituting these flowcharts may be omitted as appropriate for a portion that does not affect the essence of the invention.

The present invention includes the following technical idea. That is, in order to prevent two lens groups from colliding with each other, it has a detection unit (photo interrupter) for detecting the retracted position of at least one lens group, and it is necessary to consider the collision of the two lenses at the retracted position. Do different controls for not. For this purpose, a determination unit capable of determining the retracted position is provided. Here, it is indicated by PI.
In addition, when the lens group position changes greatly, such as in a high-magnification zoom, this retracted position has only a very limited area (about 2 mm in this case) at the end of the movable range, and this limited end retracted position. If the initial position is always retracted until the initial position is reached, it takes time to locate the initial position, and rapid imaging control cannot be performed. Therefore, as in the present invention, in addition to the position detection indicating the end retreat position, a position determination unit such as a photo interrupter for determining a further reference position enables high-speed and high-precision lens control. be able to.
Therefore, when the lens group is moved using a small motor, for example, when the lens group moves over a long distance exceeding 10 mm, for example, a predetermined value that prevents the user from missing a photo opportunity from the relationship between the stop accuracy due to inertia and the energy consumption. Although it is generally difficult to reset in time, accurate and quick lens control can be performed without using the retracted position at the end of the movable portion as a reference. From this point of view, when imitating the present invention, the design is such that a plurality of detection units such as photo interrupters are provided in order to detect movement of the same lens group.
Further, in the case of a photographing apparatus that has a lens group (here, a G3 lens group) that can be moved by mechanically connecting the mechanism manually and another lens group that moves in accordance with the lens group, and that controls the position by an actuator. As in the present invention, performing appropriate retraction driving and reference positioning driving according to the position of each lens group is extremely effective in improving responsiveness, safety, resistance to breakage, and simple downsizing of the device configuration. It is a meaningful and important improvement.

  DESCRIPTION OF SYMBOLS 1 ... Camera, 2 ... Shooting lens part, 3 ... Main body part, 4 ... Image pick-up element, 5 ... Imaging part, 6 ... Signal processing & control part, 7 ... Display part, 8 ... Recording part, 11 ... Operation part, 15, DESCRIPTION OF SYMBOLS 26 ... Communication part, 20 ... Imaging optical system, 21 ... Zoom lens, 22 ... Control part, 22a ... Focus control part, 22b ... Zoom control part, 22c ... Speed control part, 22d ... Reset part, 22e ... Mode change control part , 22g ... speed table, 23 ... ring, 24 ... ring operation part, 25 ... lens barrel, 31 ... slide judgment part, 32 ... rotation judgment part, 33 ... group position judgment part, 34 ... initial position judgment part, 35 ... Each group drive unit, 40 ... MR sensor, 41 ... linear encoder, 42a, 42b ... PI (photo interrupter), 43 ... VCM, 44a, 44b ... SM (stepping motor), 51 ... fixed frame, 52, 53, 54 ... Movable lens , 55 ... biasing spring, G1-G5 ... lens group,

Claims (13)

A photographing optical system including a movable optical system capable of moving in the optical axis direction in cooperation with each position of the first lens group and the second lens group;
A biasing spring connecting the first lens group and the second lens group;
Positions of the first lens group and the second lens group in order to detect a change in the amount of force of the biasing spring that changes according to the distance between the first lens group and the second lens group. Multiple encoders to detect
A plurality of actuators for driving the first lens group and the second lens group to move to respective positions;
A control unit for performing speed control when moving the first lens group and the second lens group 2 by the plurality of actuators according to the output results of the plurality of encoders;
An imaging apparatus comprising: The movable optical system forms a zoom optical system,
The controller controls the first lens group and the second lens group constituting the zoom optical system in the same direction when zooming from the farthest distance to the closest distance when zooming from wide angle to telephoto. The photographing apparatus according to claim 1, wherein the photographing device is controlled to move in cooperation so that the position of the photographing device changes.   The first lens group and the second lens group are disposed between two lens groups that are fixedly disposed at a position closest to the object and a position farthest from which constitutes the photographing optical system, and The photographing apparatus according to claim 1, wherein the photographing apparatus is arranged to be movable in the optical axis direction of the photographing optical system. The plurality of encoders, for the first lens group, a first encoder that detects an absolute position in a first movable region as a movable region of the first lens group;
A second encoder composed of two or more pluralities for detecting in which of the three or more plural regions obtained by dividing the second movable region as the movable region of the second lens group; The imaging apparatus according to claim 2, comprising:   5. The plurality of actuators are configured by first and second stepping motors that drive the first lens group and the second lens group, respectively, with drive pulses. Shooting device.   The control unit sets a movement distance when the first lens group is moved based on information on the absolute position detected by the first encoder to a driving pulse for driving the first stepping motor. The imaging apparatus according to claim 5, wherein the imaging apparatus is managed by a number.   From the position information based on the detection by the first encoder and the position information detected by the second encoder, the control unit increases the amount of force corresponding to the amount of expansion / contraction of the biasing spring. 5. The photographing apparatus according to claim 4, wherein the first lens group and the second lens group are controlled to move at high speed by the plurality of actuators.   From the position information based on the detection by the first encoder and the position information detected by the second encoder, the control unit increases the amount of force corresponding to the amount of expansion / contraction of the biasing spring. 7. The photographing apparatus according to claim 6, wherein the first lens group and the second lens group are controlled to move at high speed by the first and second stepping motors. The first lens group and the second lens group are set as targets corresponding to the plurality of areas obtained by dividing the first movable area and the plurality of areas obtained by dividing the second movable area. A speed information storage unit that stores information on the speed when moving to the position side,
The control unit is configured to detect the first and the second in accordance with the speed information stored in the speed information storage unit from the position information based on the detection by the first encoder and the position information detected by the second encoder. 9. The photographing apparatus according to claim 8, wherein the driving of the second stepping motor is controlled.   Furthermore, an electric zoom mode for electrically driving the first lens group and the second lens group, a manual zoom mode for mechanically moving the first lens group by a manual movement amount by a user, and the first From one mode to another mode in a plurality of modes that are at least two or more in a macro mode in which one lens group and the second lens group are driven to focus at a macro position at a close distance from the subject. 6. The photographing apparatus according to claim 5, further comprising a mode changing unit that changes the direction.   11. The control unit according to claim 10, wherein the control unit sets the first lens group and the second lens group to predetermined lens positions in response to a mode change from the manual zoom mode. The imaging device described. In the manual zoom mode, the control unit corresponds to the second lens group in response to detection of the position of the first lens group by the first encoder corresponding to the amount of movement of the manual zoom by the user. Controlling the driving operation of the second stepping motor to move to
In the electric zoom mode, after the initial position of the first lens group is calculated by the first encoder, the number of drive pulses corresponding to the operation amount by the user is applied to the first stepping motor. 11. The photographing apparatus according to claim 10, wherein control is performed to move the first lens group to a target lens position. The first movable area and the second movable area have overlapping areas that partially overlap,
In an initial state in which the power source for driving the zoom optical system is turned on, the control unit sets the first lens group and the second lens group to the target lens positions when the first lens group and the second lens group are set to target lens positions. 3. The control according to claim 2, wherein the plurality of actuators are driven so as to retract the second lens group and the second lens group in a direction opposite to the overlapping region, and then driven to the predetermined lens position. The imaging device described.

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