JP3894683B2 - Zoom lens device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
Using the rotation of a single motor, at least two lens groups are zoomed while changing the distance between the lens groups, and then the front lens group is moved and focused in the zoomed state. The present invention relates to a zoom lens device.
[0002]
[Prior art]
Japanese Patent Publication No. 6-100707 proposes a zoom lens that performs a zooming operation and a focusing operation using a common driving means. This zoom lens is composed of a zoom ring, two lens groups, a motor for rotating the zoom ring, and the like. A zooming operation is performed by relatively moving the two lens groups on the inner periphery of the zoom ring. A first cam groove and a second cam groove for performing a focusing operation by moving the lens group so as to draw a locus different from the first cam groove are provided. The second cam grooves are alternately provided on the extension line of the first cam groove, and the focusing position for each zooming position is determined according to the rotation angle of the zoom ring that is rotated by driving the motor.
[0003]
[Problems to be solved by the invention]
  In the former zoom lens, the first zooming position, the focusing range at the first zooming position, the second zooming position, the focusing range at the second zooming position, and so on in that order. Thus, the cam groove is composed of a cam groove obtained by combining the first cam groove for zooming and the second cam groove for focusing.The zoom position is set in advance for each step between the wide end and the tele end, and the focusing amount corresponding to the subject distance is different for each zoom position. Therefore, in order to recognize the zoom position at that time, the absolute rotation position of the cylinder that rotates during zooming is detected. In the conventional means for detecting the absolute rotational position using a known code, the signal part for inputting either one of the binary signals is converted into a binary signal for each rotational position of the rotating cylinder corresponding to the zoom position. Since the conductor pattern members arranged in the radial direction so that the code consisting of any one of the combinations is different, when newly increasing the zoom position between the wide end and the tele end, In order to create a code corresponding to the magnification position to be increased, it is necessary to newly arrange signal portions in the radial direction, and there is a drawback that the shape of the conductor pattern member becomes large in the radial direction.
[0004]
  The present invention has been made in view of the above circumstances,The means for detecting the absolute rotation position of the teaching tube that rotates during zooming can be made compact.An object is to provide a zoom lens device.
[0005]
[Means for Solving the Problems]
  In order to achieve the above object, in the zoom lens device of the present invention,A cylindrical barrel; there is no relative movement in the optical axis direction with respect to the barrel at the time of zooming, and it rotates with respect to the barrel and is housed in accordance with this rotation. An inner barrel that moves the lens group in the direction of the optical axis; and a rotational position detecting means for detecting a rotational position of the inner barrel corresponding to a plurality of zooming positions set in advance in a zooming range from the wide end to the telephoto end. The rotation position detecting means is fixed to one of the lens barrel and the inner lens barrel; and the rotation position detecting means is fixed to the other and the rotation position corresponding to the zoom position is set to the inner mirror. First and second pattern members that alternately give two types of signals to the signal generating means each time the cylinder passes.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
  As shown in FIGS. 1 to 4, the zoom lens device 10 of the present invention isGroupThis is a mechanically-corrected two-group zoom lens composed of a holding cylinder 11, a rectilinear guide cylinder 12, a rear group cam cylinder 13, a rear group support cylinder 14, a rotary cylinder 15, a fixed cylinder 16, and the like, and is a single motor. By rotating the rotary cylinder 15 using the rotation of the lens 17, the front lens group 18 and the rear lens group 19 are moved in the direction of the optical axis 20 while changing the distance between the lens groups, thereby changing the magnification. Thereafter, focusing is performed by moving the front lens group 18 and the rear lens group 19 in the direction of the optical axis 20 so as to be between the lens groups different from the change at the time of zooming.
[0007]
The rotating cylinder 15 is provided with a male helicoid screw 21 and a gear portion 22 formed so as to protrude between the threads of the male helicoid screw 21 on the outer periphery. Drive of the motor 17 is transmitted to the gear portion 22 via the cylindrical gear 23. A female helicoid screw 25 provided on the inner periphery of the fixed cylinder 16 is screwed into the male helicoid screw 21. The rotating cylinder 15 moves in the direction of the optical axis 20 while rotating with respect to the fixed cylinder 16 according to the lead of the male helicoid screw 21 and the female helicoid screw 25. A female helicoid screw 26 is formed on the inner surface of the rotating cylinder 15. A male helicoid screw 27 provided on the outer periphery of the front group support cylinder 11 is screwed into the female helicoid screw 26.
[0008]
A front group lens 18 and a shutter mechanism 28 are fixed to the front group support cylinder 11 in order from the object side. A rectilinear guide groove 29 parallel to the optical axis 20 is formed on the inner periphery of the front group support cylinder 11. A first guide protrusion 30 provided on the outer peripheral front end side of the rectilinear guide tube 12 is engaged with the rectilinear guide groove 29. The front group support cylinder 11 moves straight in the direction of the optical axis 20 with respect to the rotary cylinder 15 according to the leads of the helicoid screws 26 and 27 by the rotation stop of the linear guide cylinder 12 by the rotation of the rotary cylinder 15.
[0009]
The straight guide tube 12 is provided with a second guide protrusion 32 on the outer peripheral rear end side. The second guide protrusion 32 is rotatably engaged with an annular groove 33 provided along the rotation direction around the optical axis 20 on the inner periphery of the rotary cylinder 15. The rectilinear guide tube 12 moves in the direction of the optical axis 20 together with the rotating tube 15 in a state where the rotation is stopped inside the rotating tube 15.
[0010]
  The rear group cam cylinder 13 is provided with a flange portion 35 at the outer peripheral rear end. The flange portion 35 is rotatably engaged with a groove 36 provided in an annular shape along the rotation direction around the optical axis 20 on the inner periphery of the linear guide tube 12. The rear group cam cylinder 13 is rotatably supported by the rectilinear guide cylinder 12. The rear group cam cylinder 13 is formed with a cam opening 38 having a cam surface. A cam follower 39 provided on the rear group support cylinder 14 is engaged with the cam opening 38. These cam followers 39 are engaged with a rectilinear guide opening 40 provided in parallel to the optical axis 20 in the rectilinear guide cylinder 12 through the cam opening 38. These cam openings 38, cam followersWa-39 and the rectilinear guide opening 40 are respectively provided at three divided positions in the rotation direction around the optical axis 20. 2 to 4, reference numeral 41 denotes a film surface, and reference numeral 42 denotes a front cover.
[0011]
The rear end surface 43 of the rotary cylinder 15 is formed with a notch 44 in a part of the rotation direction around the optical axis 20. As shown in detail in FIG. 5, the notch 44 is engaged with a bent tip of an L-shaped arm 46 provided on the rear end face 45 of the rear group cam cylinder 13. The arm 46 is engaged with play in the circumferential direction around the optical axis 20 inside the notch 44. The play between the notch 44 and the arm 46 is an idling region where the rotation of the rear group cam cylinder 13 is stopped, and the notch 44 and the arm 46 constitute the linkage portion having the idling region of the present invention. is doing. At the time of zooming, the motor 17 rotates the rotating cylinder 15 and further rotates the rear group cam cylinder 13 beyond the idling range. At the time of focusing, the motor 17 rotates the rotary cylinder 15 in the idling region. The arrow direction shown in FIG. 5 indicates the direction in which the rotating cylinder 15 rotates when the motor 17 is driven in the tele end direction.
[0012]
The rear group cam cylinder 13 is configured to rotate the rotating cylinder 15 by pressing the arm 46 on one of the two walls 44 a and 44 b along the rotation direction around the optical axis 20 in the notch 44. The force is transmitted and rotated with respect to the straight guide tube 12. In FIG. 5, a wall 44a for transmitting the rotation of the rotary cylinder 15 in the tele end direction to the rear group cam cylinder 13 is a tele-direction rotation transmission wall, and the opposite side is a wide-direction rotation transmission wall 44b. A rear group lens 19 is supported on the rear group support cylinder 14.
[0013]
At the time of zooming, the rear group cam cylinder 13 is rotated together with the rotary cylinder 15 in the same direction as the rotary cylinder 15, so that the front group lens 18 combines the displacement of the rotary cylinder 15 and the displacement of the front group support cylinder 11 to form the optical axis. The rear group lens 19 moves in the direction of the optical axis 20 by combining the displacement of the rotary cylinder 15 and the displacement of the cam in the cam opening 38. Since the rear group cam cylinder 13 does not rotate during focusing, the front group lens 18 moves in the direction of the optical axis 20 by the combination of the displacement of the rotary cylinder 15 and the displacement of the front group support cylinder 11, and the rear group lens. 19 moves in the direction of the optical axis 20 by the displacement of the rotary cylinder 15.
[0014]
A conductor pattern member 48 is attached to the rear end surface of the rectilinear guide tube 12. A slider 49 is attached to the rear end face 45 of the rear group cam cylinder 13. The slider 49 has two brushes 49 a and 49 b that slide on the conductor pattern member 48. As shown in FIG. 6, the conductor pattern member 48 is provided with a ground pattern 50, a first pattern 51, a second pattern 52, and a retracted position pattern 53. The brushes 49a and 49b are electrically connected to each other. The ground pattern 50 is connected to the ground, and along the locus on which the brush 49b slides when the rear group cam cylinder 13 rotates in accordance with the magnification between the retracted position and the telephoto end. It is formed in a band shape.
[0015]
The first pattern 51 and the second pattern 52 are arranged in two rows along the rotation direction of the rear group cam cylinder 13. A predetermined voltage is applied to the first pattern 51 and the second pattern 52 from the signal detection unit 55, and the rear-group cam cylinder 13 is changed according to the magnification between the wide end and the tele end. A plurality of zooming stop position signal portions 56 are arranged for each of the rotational positions Z1 to Z8 of the rear group cam cylinder 13 corresponding to the zooming position on the trajectory of the brush 49a sliding when. Yes. These signal portions 56 are the even-numbered signal portions 56 in the first pattern 51 and the odd-numbered signal portions 56 when the signal portion 56 provided at the rotational position of the rear-group cam cylinder 13 at the wide end Z1 is first. A second signal unit 56 is provided in the second pattern 52. Therefore, the brush 49a slides alternately on the signal portion 56 in the odd-numbered order and the even-numbered order by scaling in one direction. In the present embodiment, the position of Z8 shown in FIG. 6 is the rotational position of the rear group cam cylinder 13 at the telephoto end.
[0016]
The retractable position pattern 53 itself forms a signal part, and the rear group cam is directed toward the wide end rather than the signal part 56 provided at the rotational position of the rear group cam cylinder 13 at the wide end Z1. The rotation position of the rear cylinder cam cylinder 13 depends on the retracted position by pulling up a constant voltage from the signal detection unit 55, which is arranged on the side closer to the rotation direction of the cylinder 13 and on the sliding locus of the brush 49a. The brush 49a comes into contact with the signal detection unit 55 at a point in time when it reaches the position, and outputs a low level signal.
[0017]
The signal detection unit 55 inputs a binary signal corresponding to the presence or absence of the signal units 53 and 56 of the first pattern 51, the second pattern 52, and the retracted position pattern 53 to the controller 60. The binary signal includes a signal portion “1” (high level) input when there is no signal portion, that is, the brush 49 a is not in contact with the signal portions 53 and 56, and a signal portion is present, that is, the brush 49 a is the signal portion 53. , 56 is a “0” (low level) signal. Hereinafter, a signal obtained from the first pattern 51 is an output signal A, a signal obtained from the second pattern 52 is an output signal B, and a signal obtained from the retractable position signal unit 53 is an output signal Hp. A signal that changes from a low level signal to a low level signal will be described as a falling signal, and vice versa.
[0018]
The motor 17 is connected to the controller 60 via a driver 61. A rotary encoder 62 is provided on the output shaft of the motor 17. The rotary encoder 62 detects the rotation angle of the motor 17 and feeds it back to the controller 60. The controller 60 reads the rotation angle of the motor 17 and controls the stop of driving of the motor by focusing driving or the like.
[0019]
The controller 60 drives the motor 17 in response to an operation of a zoom button provided in the zoom operation unit 63. The zoom button includes a tele-side zoom button for continuously changing the focal length toward the telephoto end and a wide-side zoom button for changing toward the wide side.
[0020]
A ROM 64 and a RAM 65 are connected to the controller 60. The ROM 64 stores a program for controlling the camera in which the zoom lens device 10 is incorporated. The program has a flow chart as shown in FIG. 7, and includes a tele end direction drive and wide end direction drive program for controlling the driving of the motor 17 in accordance with a zooming operation (FIGS. 8 and 8). 9), a focus driving program (FIG. 10) for driving the zoom lens apparatus 10 from the zoom position to the focus position corresponding to the subject distance after the shutter release, and the zoom lens apparatus 10 is changed from the focus position after the exposure is completed. A standby drive program for returning to the double position (see FIG. 11), an error processing program for detecting whether or not the rotational position of the rear group cam cylinder 13 has shifted, and for returning to the original magnification position when shifted (FIG. 12). See).
[0021]
Each time the controller 60 sequentially detects the output signal A and the falling signal of the output signal B obtained at the time of zooming, the controller 60 determines the zooming position at that time, for example, “Z1 (wide position), Z2, Z3, Z4. -It is specified which of "Z8 (tele position)". At the time of zooming from the tele end to the wide end, the zooming position can be specified by the difference in the rotation direction of the motor 17. The specified zoom position is rewritten and stored in the RAM 65 each time.
[0022]
The tele end direction driving and wide end direction driving programs correspond to the even or odd number of the signal unit 56 corresponding to the immediately preceding magnification position after completion of the scaling operation, that is, the immediately preceding magnification position. By determining whether or not the output signal obtained from the signal section is the output signal A, the drive control of the motor 17 is configured by two different flows.
[0023]
The focus drive program also controls the drive of the motor 17 by determining whether the signal unit 56 corresponding to the zoom position at that time is even or odd, that is, whether the output signal A is obtained from the signal unit. Are composed of two different flows.
[0024]
In the standby drive program, since the brush 49a is in a state of being detached from the signal portion 56 of the first pattern 51 or the second pattern 52 after focusing, this is also applied to the signal portion 56 corresponding to the zoom position at that time. In this control, the motor 17 is driven by determining whether the signal unit 56 corresponding to the original zoom position is an even number or an odd number, that is, whether the output signal obtained from the signal unit 56 is the output signal A or not. It consists of two flows with different controls.
[0025]
The error processing program is executed at regular intervals during a standby state in which operations such as zooming, focusing, exposure, and film feeding are not performed. During standby, the brush 49a is in contact with any one of the signal units 56. However, there is a risk that the rotational position of the rear group cam cylinder 13 that is driven and transmitted via the idling region is shifted due to the disturbance force applied to the lens barrel.
[0026]
In the error processing program, the binary signal of the output signal A or the output signal B input at that time is read to determine whether or not the rotational position of the rear group cam cylinder 13 is deviated. In this case, the drive of the motor 17 is controlled so that the rear group cam cylinder 13 is returned to the rotational position corresponding to the original zoom position. In this control, the drive control of the motor 17 differs depending on whether the signal unit 56 corresponding to the original magnification position is an even number or an odd number, that is, whether the output signal obtained from the signal unit 56 is the output signal A or not. It consists of a flow.
[0027]
The controller 60 controls the drive of the motor 17 so that the zoom lens device 10 is zoomed from the retracted position to the wide end in response to the power switch 66 being turned on. In this control, after driving the motor 17 in the tele end direction, the output signal A is monitored, and the drive of the motor 17 is stopped by obtaining the falling signal of the output signal A. As a result, the brush 49a comes into contact with the first signal portion 56 of the second pattern 52, and the arm 46 is in contact with the tele-direction rotation transmission wall 44a at the cutout portion 44 of the rotary cylinder 15.
[0028]
In the camera of the present embodiment, the lens stop position when zooming to an arbitrary zooming position differs depending on the idling region when zooming from the wide end side and zooming from the tele end side. In the standby state, when the brush 49a comes into contact with the signal portion 56 of the first pattern 51 or the second pattern 52, the arm 46 always comes into contact with the tele-direction rotation transmission wall 44a of the notch portion 44. The above-mentioned program is assembled.
[0029]
  In this embodiment, since the amount of movement of the front group and rear group lenses 18 and 19 is different for each zoom position even at the same subject distance at the time of focusing, the motor drive parameter corresponding to the lens movement amount for each subject distance is used.LuzAre prepared for each zoom position and stored in the ROM 64. These motor drive parametersLuzAre all the amount of rotation within the idling zone.
[0030]
  The operation of the above configuration will be described with reference to FIGS. The initial state of the zoom lens device is in the retracted position shown in FIG. 2, and is located in the signal portion 56 at the rotational position of the rear group cam cylinder 13 when the brush 49a is in the retracted position. The controller 60 drives the motor 17 with a rotation amount exceeding the idling region in the tele end direction in response to the power switch 66 being turned on. This drive is transmitted to the rotary cylinder 15 and the rotary cylinder 15Is transmitted in the direction of the optical axis 20 with respect to the fixed cylinder 16 according to the leads of the helicoid screws 21 and 25 by the transmission of the rotational drive. Further, when the rotary cylinder 15 rotates, the front group support cylinder 11 moves in the direction of the optical axis 20 with respect to the rotary cylinder 15 according to the leads of the helicoid screws 26 and 27 by the action of the linear guide of the linear guide cylinder 12. . As a result, the front group lens 18 moves in the direction of the optical axis 20 by a combined displacement of the displacement of the rotary cylinder 15 and the displacement of the front group support cylinder 11.
[0031]
The rectilinear guide cylinder 12, the rear group cam cylinder 13, and the rear group support cylinder 14 move in the direction of the optical axis 20 together with the rotary cylinder 15. The rotational drive of the rotary cylinder 15 is transmitted to the rear group cam cylinder 13 by the tele-direction rotation transmission wall 44a pushing the arm 46 in the rotation direction about the optical axis 20. The rear group cam cylinder 13 rotates inside the rotary cylinder 15, thereby moving the rear group support cylinder 14 in the direction of the optical axis 20 relative to the rotary cylinder 15 by the cam displacement of the cam opening 38. As a result, the rear group lens 19 moves in the direction of the optical axis 20 due to the displacement of the cam of the cam opening 38 in addition to the displacement of the rotary cylinder 15, and the distance between the rear group lens 19 and the front group lens 18 is changed.
[0032]
When the rear group cam cylinder 13 rotates, the slider 49 slides along the row of the signal portions 56 provided in the linear guide cylinder 12 and the ground pattern 50. During this time, the controller 60 monitors the output signal B, and stops driving the motor 17 when it obtains the first falling signal of the output signal B. As a result, the rear group cam cylinder 13 is in a rotational position where the brush 49 a contacts the first signal portion 56 of the second pattern 52. The controller 60 specifies that the zoom position is the wide end when the first falling signal of the output signal B is obtained, and stores this information in the RAM 65. Thereby, even if the controller 60 detects a zooming operation toward the wide end next, the current zooming position is at the wide end, so that this operation can be invalidated.
[0033]
When a power scaling operation is performed toward the tele end after the power is turned on, the controller 60 executes the tele direction driving program shown in FIG. Thereby, the motor 17 is driven in the tele end direction with the rotation amount exceeding the idling range, and the output signal is monitored during the driving.
[0034]
Each time the brush 49a passes through the signal portion 56 at the rotational position “Z2, Z3, Z4...”, The controller 60 sequentially outputs the falling signal and the rising signal in the order of the output signal A and the output signal B. Is input. Each time one of the signals is obtained, the controller 60 rewrites the information on the zoom position stored in the RAM 65. Therefore, the RAM 65 always stores information on the magnification position immediately before the magnification operation is completed. Therefore, in response to the completion of the magnification operation at the magnification operation unit 63, the controller 60 reads the information on the magnification position written in the RAM 65, and for example, the signal unit 56 corresponding to the read magnification ratio is an even number. In the case of “Z2”, processing is performed along the flow on the left side shown in FIG. That is, the controller 60 continues to drive the motor 17 after the zooming operation, and stops driving the motor 17 when a falling signal of the output signal B is detected thereafter. As a result, the brush 49a is in contact with the “Z3” signal portion of the second pattern. At this time, the arm 46 is in contact with the telescopic rotation transmission wall 44 a of the notch 44.
[0035]
  When the magnification operation is performed in the wide end direction, the wide direction drive program is executed. In this program, if the motor 17 is simply reversed, the arm 46 is in contact with the wide-direction rotation transmission wall 44b on the opposite side of the tele-direction rotation transmission wall 44a, and the magnification operation is performed in the tele end direction. Compared to when the lens is moved, the lens stop position is shifted by the amount corresponding to the idling region. Therefore, in this wide end direction drive program, when the zooming operation is completed, the motor 17 continues to be driven in the wide end direction, and the rotation position of the rear group cam cylinder 13 is determined.,The driving of the motor 17 is temporarily stopped when the brush 49a reaches the position where it has passed the signal unit 56 corresponding to the magnification position. Thereafter, the motor 17 is moved to the position where the brush 49a contacts the previous signal unit 56 in the tele end direction.,Drive with a rotation amount exceeding the idling range. As a result, regardless of the direction of zooming in either the wide end or the tele end, the form of the linkage portion is the tele-direction rotation transmission wall 4.4Therefore, the arm 46 is in contact with a, and the lens stop position can be made the same.
[0036]
FIG. 13 shows the amount of displacement of the front group and rear group lenses 18 and 19 in the direction of the optical axis 20 with respect to the rotation amount of the motor 17. The front group lens 18 moves along a straight line A shown in the figure by zooming drive, and the rear group lens 19 moves along a curve B. These lens groups 18 and 19 stop at any one of the zoom positions (Z1 to Z8). Note that the zoom position can be set at any position on the zoom locus without limitation.
[0037]
  When the shutter button 67 is half-pressed, the controller 60 operates the photometry mechanism 68 and the distance measurement mechanism 69. Information on subject brightness and subject distance obtained from the photometry mechanism 68 and the distance measurement mechanism 69 is stored in the RAM 65. The controller 60 executes the focusing drive program by performing the full pressing operation of the shutter button 67 as it is. As shown in FIG. 10, the in-focus driving program reads the current output signal and identifies whether the low level signal is obtained from the output signal A or B. For example, when a low level signal is obtained from the output signal B, FIG.RightWhen a low level signal is obtained from the output signal A,leftProcess along the flow.
[0038]
  In the flow, first, to the position where the rising signal of the output signal A or B is detected, TeThe motor 17 is driven in the end direction, and when the rising signal is detected, the motor 17 is driven in the same direction by a predetermined pulse and then stopped. In the standby state at the zooming position, the arm 46 is in contact with the tele-direction rotation transmission wall 44a. Therefore, when the motor 17 is driven in the tele end direction by focusing driving, the driving of the rotary cylinder 15 is immediately performed. The brush 49 a is transmitted to the cylinder 13 together with the rotation of the rear group cam cylinder 13, and the brush 49 a is detached from the signal portion 56. When the brush 49a is detached, a rising signal is input to the controller 60. After receiving this signal, the motor 17 is driven in the same direction by a fixed pulse, and then the driving is stopped. As a result, the brush 49a is moved from the signal unit 56 corresponding to the zoom position at that time.FIG.To the position rotated by a predetermined angle in the direction of the arrow shown in FIG. At this time, the telescopic rotation transmission wall 44a is in contact with the arm 46.
[0039]
  Thereafter, the controller 60 reads out the subject distance, and reads out from the RAM 65 a motor drive pulse based on the current zoom position and subject distance. Thereafter, the motor 17 is driven in the wide end direction with the rotation amount in the idling region, the pulses obtained from the rotary encoder 62 are counted during this driving, and the count value is read out from the motor drive pulse value.OneAt that time, the driving of the motor 17 is stopped. Since the driving pulse of the motor 17 at the time of focusing is the amount of rotation within the idling region, the arm 46 is separated from the telescopic rotation transmission wall 44a of the notch after the focusing operation. Of course, the arm 46 isDoFurther, the brush 49a remains in a state shifted from the signal portion 56 in the tele end direction because the rotation is in the idling region.
[0040]
The movement of the zoom lens apparatus 10 at the time of focusing is shown in FIG. 14 because the motor 17 is first driven in the tele end direction by the rotation amount exceeding the idling region and then driven in the wide direction by the rotation amount in the idling region. As described above, when the lens is first driven in the telephoto end direction, the front group and rear group lenses 18 and 19 move from the zoom position Zn to the position indicated by the dotted line C through the zoom loci A and B, and then idle. Since the front group lens 18 moves to the G1 through the zooming locus A because it rotates in the wide end direction with the amount of rotation within the area, the rear group lens 19 moves by the amount of displacement of the rotary cylinder 15. Therefore, unlike the zooming locus B which is the combined displacement of the rotating cylinder 15 and the cam of the cam opening 38, the moving path moves to the point G2 through the displacement locus D of the rotating cylinder 15. As a result, the front group and rear group lenses 18 and 19 are moved at intervals different from those at the time of zooming to focus on the subject distance at that time. Here, focusing is performed in a direction in which the object is focused from close to infinity. Note that, depending on the control method, an operation of focusing from infinity to the closest position can be performed.
[0041]
After the focus drive program is executed, the exposure control program is executed. With this program, the controller 60 operates the shutter mechanism in accordance with the subject brightness and the sensitivity of the photographic film.
[0042]
After the exposure is completed, the controller 60 executes a standby drive program. After the exposure is completed, the front group and rear group lenses 18 and 19 remain moved to the in-focus position corresponding to the subject distance at that time. Accordingly, since the brush 49a is separated from the signal unit 56 corresponding to the current magnification position and the arm 46 is separated from the telescopic rotation transmission wall 44a, the standby magnification program uses the original magnification position. Control to return to.
[0043]
When this program is executed, whether the signal unit 56 corresponding to the original magnification position is an even number or odd number, that is, whether or not the output signal A is obtained from the signal unit 56 corresponding to the original magnification position. to decide. One of the two flows is selected based on the determination result, and the controller 60 processes based on the selected flow.
[0044]
  The controller 60 first drives the motor 17 in the wide end direction by the amount of rotation exceeding the idling range. This drive is performed when the signal unit 56 corresponding to the original magnification position is activated.FallingSignal and standingRiseAfter detecting the signals in order, it is driven for a fixed pulse and then stopped. Therefore, by this driving, the rear group cam cylinder 13 is rotated to the rotation position where the brush 49a has passed the signal portion 56 corresponding to the original magnification position. Thereafter, the controller 60 drives the motor 17 in the tele end direction with a rotation amount exceeding the idling region until a falling signal from the signal unit 56 corresponding to the original zoom position is detected. As a result, the brush 49a comes into contact with the signal portion 56 corresponding to the original magnification position, and the tele-direction rotation transmission wall 44a comes into contact with the arm 46.
[0045]
When execution of the standby drive program is completed, film feeding is performed, and a new shooting frame is set in the aperture of the camera. This prepares for the next shooting.
[0046]
  During the waiting period when the above-mentioned program is not being executed,For error handlingThe program is executed. When this is executed, first, the controller 60 reads the signal level of the output signal A or the output signal B obtained at the time of execution, and determines whether or not the signal is a low level signal. After the zooming operation and after executing the standby drive program, the brush 49a is always in contact with the signal unit 56, so that a low level signal should be obtained from the output signal A or the output signal B. However, when an external force, vibration, or the like is applied to the lens barrel, the rear group cam barrel 13 may idle in the idling region. In this case, there is no problem if the brush 49a is idling to the extent that it does not come off from the signal unit 56, but if idling to the extent that it is disengaged, there is a possibility that it will be out of focus when the focusing drive program is executed as it is. In the idling direction of the rear group cam cylinder 13, since the rotating cylinder 15 does not rotate, the arm 46 is rotated in the wide direction rotation transmission wall 44.bThe direction of rotation toward the. Accordingly, the brush 49a is displaced from the signal portion 56 along the rotational direction of the rear group cam cylinder 13 in the tele direction.
[0047]
For this reason, when a low level signal cannot be obtained from the output signal A or the output signal B, the motor has a rotation amount exceeding the idling region in the wide end direction until it passes through the signal unit 56 corresponding to the original zoom position. 17 is driven, and the drive of the motor 17 is stopped after driving for a predetermined pulse after passing through the signal unit 56 corresponding to the original zoom position. Thereafter, when the motor 17 is driven in the tele end direction with a rotation amount exceeding the idling region and the falling signal of the original signal unit 56 is obtained, the driving of the motor 17 is stopped. Thereby, the rear group cam cylinder 13 can be returned to the rotation position where the arm 46 is in contact with the tele-direction rotation transmission wall 44a and the brush 49a is in contact with the signal portion 56 corresponding to the original zoom position.
[0048]
When the power switch 66 is turned off, the controller 60 drives the motor 17 in the wide end direction with a rotation amount exceeding the idling region. During this time, the controller 60 monitors the output signal Hp. When the zoom lens device 10 is retracted to the retracted position, the brush 49a contacts the retracted position pattern 53. At this time, the output signal Hp is input to the controller 60 via the signal detection unit 55, and when receiving this, the controller 60 stops driving the motor 17.
[0049]
  Embodiment aboveThe straight guide tube 12 described in the above corresponds to the lens barrel of the present invention, and the rear group cam tube 13 described in the above embodiment corresponds to the inner lens barrel of the present invention. The slider 49 corresponds to the signal generating means of the present invention. Furthermore, the controller 60, the standby drive control program, the error processing program, and the like described in the above embodiment constitute the phase identification means, monitoring means, standby drive control means, and error processing control means of the present invention. .
[0050]
The zoom lens device 10 of the above embodiment has a structure in which focusing is performed by moving the front lens group 19 and the rear lens group 19 by giving rotation within the idling region. A structure in which focusing is performed by moving only the front lens group by giving rotation within the region may be adopted. In this case, instead of the two-stage protruding structure of the rotating cylinder 15 and the front group supporting cylinder 11, a one-stage protruding structure in which only the front group supporting cylinder 11 protrudes, that is, a helicoid between the rotating cylinder 15 and the fixed cylinder 16 is used. The screws 21 and 25 may be omitted and the rotary cylinder 15 may be configured not to advance or retract in the direction of the optical axis 20. According to this, by giving rotation within the idling region to the rotary cylinder 15, only the front group lens 18 moves along the zooming locus while the rear group lens 19 is stopped, and accordingly, at the time of zooming, Since they are at different intervals, focusing can be performed.
[0051]
Alternatively, a zoom lens structure may be used in which focusing is performed by moving only the rear lens group 19 by applying rotation within the idling range. In this case, the zoom lens apparatus includes a rotating cylinder, a front group support cylinder, a front group lens, a rear group lens, and an idling region. The rotating cylinder is driven by a motor. The front group support cylinder moves the front group lens in the optical axis direction in conjunction with the displacement of the rotary cylinder. The rear lens group moves in the optical axis direction within the rotating cylinder in conjunction with the displacement of the rotating cylinder. The idling region is provided in a link portion between the rotating cylinder and the front group supporting cylinder, and allows displacement of only the rotating cylinder within a certain range. At the time of zooming, the rotating cylinder is driven so as to be displaced beyond the idling region. Thereby, the front group lens and the rear group lens move in the optical axis direction while changing the distance between them. Further, at the time of focusing, the motor is driven so that the rotating cylinder is displaced within the idling region. As a result, only the rear group lens moves along the zoom locus while the position of the front group lens is stopped, and the distance between the front group and the rear group lens is different from that at the time of zooming. it can.
[0052]
Moreover, in the said Example, the conductor pattern member 48 which outputs a two-phase signal shifted | deviated from the signal part of the 1st and 2nd patterns 51 and 52 for every rotation position of the rear-group cam cylinder according to a magnification position. Used. For this reason, in the means for detecting the absolute rotational position using a conventionally known code, the signal part for inputting any one of the binary signals is set for each rotational position of the rotating cylinder according to the magnification position. Since the conductor pattern members arranged in the radial direction are used so that the code consisting of either one of the binary signals is different, the zoom position is newly increased between the wide end and the tele end. In order to create a code corresponding to the newly increased magnification position, it is necessary to newly arrange the signal portions in the radial direction, and there is a drawback that the shape of the conductor pattern member becomes large in the radial direction. On the other hand, in the above embodiment, the first and second patterns 51 and 52 are provided side by side, and the signal portions 56 need only be alternately added in the facing direction, so that the lens barrel can be made compact.
[0053]
In the above-described embodiment, the focusing drive is performed in response to the full-pressing operation of the shutter button 67, but may be performed in response to the half-pressing operation of the shutter button 67. In this case, only exposure control is performed in response to the full pressing operation of the shutter button 67.
[0054]
In the above embodiment, the number of zoom positions is eight, but the number is not specified in the present invention. When a zooming position is added between the wide end and the telephoto end, the stop positions of the front group and rear group lenses 18 and 19 can be taken without limitation on the zooming trajectories A and B shown in FIG. Further, the signal portions 56 may be alternately added to the rotation position of the rear group cam cylinder 13 corresponding to the newly added zoom position on the first and second patterns 51 and 52.
[0055]
  Further, in the above embodiment, the rotational position detecting means is a contact type detecting means using the slider 49 and the conductor pattern member 48, but it may be a non-contact type. In this case, instead of the conductor pattern member 48, the rear group cam cylinder 13 has two rows in the rotation direction, and each row has the rear group.forCam cylinder 15The rear group cam cylinder 13 is provided in place of the slider 49 by using a member provided with holes in an arrangement shifted for each rotation position, and detecting two holes in each row. According to this, since it is a non-contact type, the durability is improved as compared with the contact type, and even if the rotation speed of the rotary cylinder 13 is increased, it can be reliably detected, and high-speed zooming becomes possible.
[0056]
Further, although the signal portions 56 of the first and second patterns 51 and 52 are arranged along the rotation direction around the optical axis 20, they may be arranged linearly. In this case, the first and the first patterns in which the signal portions are linearly arranged are attached on the outer periphery of the rear group cam cylinder 13 along the rotation direction, and the slider is attached to the inner surface of the linear guide cylinder 12. Should be provided. According to this, since the rotational position detecting means can be incorporated between the lens barrels, the length along the direction of the optical axis 20 of the zoom lens device 10 can be made compact.
[0057]
【The invention's effect】
  As described above, in the zoom lens device of the present invention,The signal generating means fixed to one of the lens barrel or the inner lens barrel and the two types of signals are alternately supplied to the signal generating means each time the inner lens barrel passes through the rotational position corresponding to the magnification changing position. Since the first and second pattern members are provided, the zooming and focusing are performed using the drive of one driving source, and many zooming positions are provided between the wide end and the tele end. A stable operation can be performed while having it. Also,In the zoom lens device of the present invention, the driven side to which the drive of the motor is transmitted via the idling regionOf lens groupsSince the displacement position is detected, it is possible to reliably detect the inconvenience that the rotational position of the driven lens group idles in the idling region.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an outline of a zoom lens device.
FIG. 2 is a cross-sectional view showing a state of a retracted position of the zoom lens device.
FIG. 3 is a cross-sectional view showing a state of a wide end of the zoom lens device.
FIG. 4 is a cross-sectional view illustrating a tele end state of the zoom lens device.
FIG. 5 is an explanatory view showing the relationship between the notch and the arm and the relationship between the conductor pattern member and the slider, as viewed from the film surface side.
FIG. 6 is an explanatory view schematically showing a relationship between a slider and a conductor pattern member.
FIG. 7 is a flowchart showing a main program for controlling the zoom lens apparatus.
FIG. 8 is a flowchart showing a tele direction drive program executed when a zooming operation is performed in the tele end direction.
FIG. 9 is a flowchart showing a wide direction drive program executed when a scaling operation is performed in the wide end direction.
FIG. 10 is a flowchart showing a focusing drive program executed at the time of focusing.
FIG. 11 is a flowchart showing a standby drive program executed after completion of exposure.
FIG. 12 is a flowchart showing an error processing program executed during standby.
FIG. 13 is a graph showing the movement of the front group and rear group lenses in the optical axis direction with respect to the motor rotation amount during zooming.
FIG. 14 is a graph showing lens movement during focusing.
[Explanation of symbols]
11 Front support tube
12 Straight guide cylinder
13 Cam cylinder for rear group
14 Rear group support cylinder
15 Rotating cylinder
16 Fixed cylinder
17 Motor
38 Cam opening
48 Conductor pattern members
49 Slider
50 Grounding pattern
51 1st pattern
52 2nd pattern
56 Signal section

Claims (5)

A lens barrel and a lens group which is provided inside thereof and does not move relative to the lens barrel in the optical axis direction at the time of zooming, and rotates with respect to the lens barrel and is accommodated therein in accordance with the rotation. An inner lens barrel that moves in the direction of the optical axis, and a rotational position detection means that detects a rotational position of the inner lens barrel in accordance with a plurality of magnification positions preset in a magnification range from the wide end to the telephoto end. In the provided zoom lens device,
The rotational position detecting means is
Signal generating means fixed to one of the lens barrel or the inner lens barrel;
A first and a second pattern member fixed to the other, each of which alternately gives two types of signals to the signal generating means each time the inner lens barrel passes through a rotational position corresponding to the zoom position. A zoom lens apparatus characterized by comprising: The first pattern member has a first signal portion that gives an A signal to the signal generating means arranged in a line on the rotation trajectory of the inner barrel, and the second pattern member has the signal A second signal section that gives a B signal different from the A signal to the generating means is arranged in a row so as to enter one by one between the first signal sections on the rotation locus. The zoom lens apparatus according to claim 1. The signal generating means and the first and second pattern members are provided on the end surface of the inner barrel and the end surface of the barrel, respectively.
3. The zoom lens device according to claim 2, wherein the first and second signal units are arranged so as to protrude from opposite sides of the lens barrel in the radial direction so as to face each other on the rotation locus. A rotating cylinder that houses the lens barrel and rotates about the optical axis with respect to the lens barrel by inputting a drive of a single motor;
A front lens group that moves in the direction of the optical axis in accordance with the rotation of the rotating cylinder;
A link portion provided at a link portion between the rotary barrel and the inner barrel, and transmitting the rotation of the rotary barrel to the inner barrel beyond an idling region that allows rotation of only the rotary barrel;
After rotating the rotating cylinder beyond the idling range, the front lens group and the lens group are moved in the optical axis direction while changing the distance between them, and then the zooming is performed within the idling range. 4. Focusing is performed by moving the front lens group and the lens group in the optical axis direction so as to have a lens interval different from that at the time of zooming. Zoom lens device. A phase identifying means for identifying which of the two-phase signals obtained from the first and second patterns is the signal detected by the rotational position detecting means after completing the zooming operation;
In accordance with the identification of the phase identification means, after the photographing operation is completed, the linkage form in the linkage part is a fixed form in which the idling region is linked to any one of the rotation directions of the rotating cylinder. The driving direction of the motor is switched, and the driving of the motor is stopped after the inner barrel is rotated to a rotation position where any one of the two-phase signals obtained from the first and second patterns is generated. Standby drive control means;
Monitoring means for monitoring whether any one of the two-phase signals is obtained at regular intervals during non-operation when the zooming and focusing operations are not performed;
When the monitoring means detects that any one of the two-phase signals is not obtained, the motor is driven in a direction different from the direction in which the linkage portion is in a fixed form. The inner lens barrel is rotated to a rotational position beyond the signal section that outputs a signal having the same phase as that identified by the phase identification means, and then the motor is driven in reverse to identify again by the phase identification means. When the signal having the same phase as that detected is detected, the motor is stopped, and the rotation position of the inner lens barrel is rotated according to the original magnification position in a state where the linkage portion is in a fixed form. position Error handling control means to return to
The zoom lens apparatus according to claim 4, further comprising:

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