JP2006030767A - Lens device, imaging system and interchangeable lens system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that there is possibility that the deterioration of the starting characteristic of focusing, the deterioration of stopping accuracy thereof, overshoot or erroneous stop occurs because grease used to stabilize control characteristic is not uniform in the driving range of a linear actuator. <P>SOLUTION: In the lens device and the imaging system having a control means for performing driving control of focusing and zooming, the control means finishes the initial operation of focusing at least after detecting the finish of the initial operation of zooming. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens apparatus having a lens, an imaging system such as a video camera and a digital camera, and an interchangeable lens system.

For example, Japanese Patent No. 3177931 has been proposed as an initial movement operation of a lens apparatus and an imaging system using a linear motor for driving a lens, as a method of detecting the origin position by colliding with the mechanical end of the lens as a method of detecting the origin of the linear actuator. Yes.
Japanese Patent No. 3177931

  In recent years, in a lens apparatus, an imaging system, and an interchangeable lens system, it has been required to improve the overall performance of the lens apparatus and the imaging system while increasing the number of pixels of an imaging element and improving the image quality. Since linearization and high performance have always been issues, linear actuators are widely used for focusing. This is because the linear actuator can be driven at a higher speed than conventional DC motors and stepping motors.

  However, the controllability of linear actuators is closely related to mechanical friction, and viscous materials such as grease are generally used to stabilize the friction and stabilize the control characteristics. Although it is desirable that this grease is uniform over the entire driving range of the linear actuator, there is no guarantee that it will be uniform depending on the environment, time, storage posture, and the like. Therefore, the friction varies depending on the position. For example, when grease is accumulated as compared with a uniform state, the friction is large and the friction is easy to stop, but it is difficult to start during driving. On the contrary, when the grease is small and the friction is small, it is easy to start at the time of driving, but there is a problem that overshooting at the time of stopping tends to occur and oscillation occurs.

  Therefore, when the lens device and the imaging system are functioning in this state, the focus start / stop accuracy is poor, the overshoot is not conspicuous, the focus is not achieved, and the blur is stopped. , You can go back and forth without stopping forever.

  Moreover, when the linear actuator in an interchangeable lens system is used, it has the same subject.

  Furthermore, in the lens apparatus, the imaging system, and the interchangeable lens system, there is a problem in that it is desirable to avoid losing a photographing opportunity as much as possible by high-speed activation after power-on.

  In order to solve the above problems, in the present invention, a lens that forms a subject image on an imaging surface, a focus that performs focus adjustment, a linear actuator driving unit that drives the focus, a zoom that changes a focus magnification, A driving unit that drives the zoom, and a control unit that performs driving control of the focus and zoom; the control unit ends the initial operation of the focus and the lens system that can detect the end of the initial operation of the focus and the imaging system; A lens apparatus and an imaging system are provided which are performed after detecting the above.

  A lens that forms an object image on the imaging surface; a focus that performs focus adjustment; a linear actuator driving unit that drives the focus; a zoom that changes a focus magnification; and a driving unit that drives the zoom; Provided is a lens device and an imaging system having control means for performing drive control of focus and zoom, wherein the control means performs at least the end of the initial focus operation after detecting the end of the initial zoom operation. .

  In the above description, the control unit provides a lens apparatus and an imaging system that drive the linear actuator while detecting the end of the initial operation other than the focus.

  Further, in the interchangeable lens system, the interchangeable lens includes a lens that forms a subject image on the imaging surface, a focus that performs focus adjustment, a linear actuator driving unit that drives the focus, a zoom that changes the focus magnification, and the zoom A camera control unit having a communication function for communicating with the lens, and an image sensor. The lens control means performs the initial focus operation after the completion of other initial operations of the detectable interchangeable lens other than the focus and the detection of the camera initial operation end information from the camera control means. An interchangeable lens system is provided.

  As described above, according to the present invention, the lens for forming the subject image on the imaging surface, the focus for adjusting the focus, the linear actuator driving means for driving the focus, the zoom for changing the focus magnification, A driving unit that drives the zoom, and a control unit that performs driving control of the focus and zoom, and the control unit terminates the initial operation of the focus and the initial operation of the lens system and the imaging system capable of detecting other than the focus. A lens apparatus and an imaging system, which are performed after detecting the image, or in the interchangeable lens system, the interchangeable lens is a lens that forms a subject image on the imaging surface, and a focus that performs focus adjustment. A linear actuator driving means for driving the focus, a zoom for changing the focus magnification, and driving the zoom. A camera control unit having a communication function for communicating with the lens, and an imaging device. The lens control means is characterized in that the initial operation of the focus is completed after completion of other initial operations of the interchangeable lens that can be detected other than the focus and detection of camera initial operation end information from the camera control means. By providing an interchangeable lens system, the friction that has a close relationship with the controllability of the linear actuator is stabilized, and in a driving range that is not necessarily guaranteed to be uniform depending on the environment, time, storage posture, etc. If the friction is large compared to the above, it will be easy to stop, but it will be difficult to drive. Issues such as overshoot easy it is possible to realize that do without lengthening the initial operation end time.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an imaging apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an optical system, which includes a four-group rear focus zoom lens (hereinafter referred to as an RFZ lens) including four lens groups. That is, the RFZ lens 1 includes a first lens group (hereinafter referred to as a front lens) 101 that is a fixed lens group, a second lens (hereinafter referred to as a variator) 102 that is a moving lens group and has a variable power function, and a fixed lens group. A third lens group (hereinafter referred to as afocal) 103 that is a lens group, a moving lens group that is a focus function, and a function as a compensator that corrects fluctuations in the image plane position due to a zooming operation. 4 lens groups (hereinafter referred to as a focus lens).

  2 is a photoelectric conversion element such as a CCD, 3 is a diaphragm for adjusting the amount of light incident on the photoelectric conversion element 2, 4 is a diaphragm drive unit for changing the aperture of the diaphragm 3, and 5 is a position of the diaphragm 3. An aperture position detector 6 for detecting the aperture (aperture amount) of the aperture 3 based on an output signal of the aperture position detector 5, and a controller 7 for comprehensively controlling the imaging operation of the imaging apparatus. It is.

  The control unit 7 includes a microcomputer, and includes a CPU, a ROM, and a RAM (not shown). The CPU controls various operations such as movement control of the variator 102 and the focus compensator 104 while using the RAM as a work area or the like according to a control program stored in the ROM.

  Reference numeral 8 denotes a stepping motor for moving the zoom lens 102 and is driven by the motor driver 10. The zoom lens 9 performs an initial operation for detecting a position when the power is turned on. A linear actuator for moving the focus lens 104, driven by the driver 11, and detected by a position detection means and a detection circuit 18 using 17 MR elements, for example. This focus lens also performs an initial operation for detecting a position when the power is turned on. Reference numeral 12 denotes an amplifier for amplifying the output signal of the photoelectric conversion element 2, and reference numeral 13 denotes a process circuit for converting the amplified signal into a video signal such as an NTSC video signal. The AF control means 14 in the control means 7 performs AF by the AF control means 14. A signal is also output. As an automatic focusing method using this video signal, various methods such as a hill climbing method have been proposed (Japanese Patent Laid-Open No. Sho 62-103616).

  The purpose of this embodiment is to focus on its high-speed drive during initial operations in the lens apparatus and imaging system so that the drive characteristics of the linear actuator can be controlled in the best possible state. The linear actuator is driven during the initial operation from start to start and function, and by continuing, the viscosity of the grease used in the linear actuator is made uniform over the entire linear actuator drive range, achieving uniform drive characteristics There is to make it.

  The controllability of linear actuators is closely related to mechanical friction, and viscous materials such as grease are generally used to stabilize the friction and stabilize control characteristics. Although it is desirable that this grease is uniform over the entire driving range of the linear actuator, there is no guarantee that it will be uniform depending on the environment, time, storage posture, and the like. Therefore, the friction varies depending on the position, and when the friction is large compared to the uniform state, it is easy to stop, but it is difficult to drive, and conversely, if the friction is small, it is easy to drive, but overshoot is easy to stop. There are challenges.

  FIG. 2 shows the variation of the drive characteristics of the linear actuator with and without the grease as pulse response characteristics.

  In the figure, A represents a good state, B represents a state where there is a lot of grease or is accumulated, and C represents a state where the grease is insufficient or missing.

  While a smoothly follows the drive and stop commands, b not only takes a reaction time for the drive commands, but also the stop position with respect to the drive position has errors and deviations. In addition, although c has good responsiveness to the drive command, it repeatedly overshoots until it stops, and it takes much time to reach the target stop position.

  In this way, it can be easily imagined that the driving range partially becomes a state such as b or c depending on the environment, time, storage posture, etc., and the driving range of FIG. It is unlikely that the grease is in good condition.

  Therefore, when the lens device and the imaging device are functioning in this state, the AF start / stop accuracy is poor in the case of b, and the overshoot is conspicuous in the case of c, or both are in focus. Not only does it happen, but it can cause blurring or a phenomenon such as going back and forth without stopping forever.

  Therefore, in order to make the lens apparatus and the image pickup system function as much as possible after the state shown in FIG. In addition, in order to avoid extending the initial operation time from when the power is turned on, in this embodiment, the linear actuator is driven until the end of another initial operation is detected, and the viscosity is made as uniform as possible. It is something to try.

  FIG. 3 shows the flow.

  When power is turned on in 301, functions that require various initial operations in the lens apparatus and the imaging system, such as a zoom lens, a CCD, and a focus lens, are started in 302. In 303, the end of focus origin position detection is determined, and if it has not been completed, it is continued. If it has been completed, the end state of another initial operation is detected in 304. If there is an unfinished one, focus drive is performed at 305. At this time, it is preferable that the drive reciprocates the entire drive range. Returning to 305, if all other detectable initial operations have been completed, the focus drive is stopped at 306, and the initial focus operation is completed.

  As described above, according to this embodiment, the viscosity of the grease that is made uniform over the driving range of the linear actuator can be realized without extending the initial operation end time as much as possible.

  In this embodiment, the zoom is a stepping motor and the focus is a linear motor. However, this may be a linear motor and the focus is a stepping motor. If either the focus or zoom uses a linear actuator, this It goes without saying that the intended effect of the embodiment can be obtained.

  Furthermore, when both the focus and zoom use a linear actuator, after the origin check operation of each of focus and zoom, if the initial operations other than those are not completed, each is driven as in this embodiment, It can be easily imagined that the initial operations of focus and zoom may be terminated after the end is detected.

(Second Embodiment)
FIG. 4 is a block diagram showing a schematic configuration of an imaging apparatus according to the second embodiment of the present invention, which is an interchangeable lens system. In FIG. 1, reference numeral 1 denotes an optical system, which includes a four-group rear focus zoom lens (hereinafter referred to as an RFZ lens) including four lens groups. That is, the RFZ lens 1 includes a first lens group (hereinafter referred to as a front lens) 101 that is a fixed lens group, a second lens (hereinafter referred to as a variator) 102 that is a moving lens group and has a variable power function, and a fixed lens group. A third lens group (hereinafter referred to as afocal) 103 that is a lens group, a moving lens group that is a focus function, and a function as a compensator that corrects fluctuations in the image plane position due to a zooming operation. 4 lens groups (hereinafter referred to as a focus lens).

  2 is a photoelectric conversion element such as a CCD, 3 is a diaphragm for adjusting the amount of light incident on the photoelectric conversion element 2, 4 is a diaphragm drive unit for changing the aperture of the diaphragm 3, and 5 is a position of the diaphragm 3. An aperture position detector 6 for detecting the aperture (aperture amount) of the aperture 3 based on an output signal of the aperture position detector 5, and a controller 7 for comprehensively controlling the imaging operation of the imaging apparatus. It is.

  The control unit 7 includes a microcomputer, and includes a CPU, a ROM, and a RAM (not shown). The CPU controls various operations such as movement control of the variator 102 and the focus compensator 104 while using the RAM as a work area or the like according to a control program stored in the ROM.

  The camera control unit 17 of the camera unit communicates the output of the process circuit 13 that generates a focusing signal for AF, the output for the diaphragm operation, and the like to the lens unit control unit 7 via the camera contact 18 and the lens contact 19. I do. The lens unit control means 7 performs AF and diaphragm operations based on the information, and each control means can transmit and receive such as sending the zoom position focus position, the diaphragm position, etc. to the camera unit control means.

  The camera control means 17 has a function of sending to the lens control means 7 by communication that the initial operation of the image pickup device 2 or a recording unit (not shown) is completed, or that the camera unit can output an image. The camera control means 17 also obtains the initial operation end information or the image output permission information from the lens means 7 and outputs a camera image.

  The purpose of this embodiment is the same as that of the first embodiment, and an embodiment in which the configuration is an interchangeable lens system will be described.

  FIG. 5 shows a control flow of the lens control means 7.

  When the power is turned on in 501, functions that require various initial operations, such as a zoom lens, a CCD, and a focus lens, are started in 502. At 503, the end of focus origin position detection is determined. If it has not been completed, it is continued. If it has been completed, the lens control means 7 and the camera control means 17 communicate with each other. At 505, the other initial operations of the lens unit are completed. The initial operation end state is detected from the initial operation end information of the camera. If there is something that has not been completed, focus drive is performed at 506. At this time, it is preferable that the drive reciprocates the entire drive range. Returning to 504, if all the initial operations that can be detected are completed in 505, the focus drive is stopped in 507, the initial focus operation is terminated, and in 508, the lens control means transmits initial operation end information to the control means to the camera. .

  In this embodiment, the zoom is a stepping motor and the focus is a linear motor. However, this may be a linear motor and the focus is a stepping motor. If either the focus or zoom uses a linear actuator, this It goes without saying that the intended effect of the embodiment can be obtained.

  Furthermore, when both the focus and zoom use a linear actuator, after the origin check operation of each of focus and zoom, if the initial operations other than those are not completed, each is driven as in this embodiment, It can be easily imagined that the initial operations of focus and zoom may be terminated after the end is detected.

A first embodiment is shown. The figure for description of the 1st example. The flowchart for description of a 1st Example. The figure for description of the 2nd example. The flowchart for description of a 2nd Example.

Claims (6)

  A lens for forming a subject image on an imaging surface, a focus for focus adjustment, a linear actuator driving means for driving the focus, a zoom for changing a focus magnification, a driving means for driving the zoom, and the focus Control means for performing drive control of the zoom, wherein the control means performs the initial operation end of the focus after detecting the end of the initial operation of the lens apparatus and the imaging system other than the focus. A lens apparatus and an imaging system.   A lens for forming a subject image on the imaging surface, a focus for focus adjustment, a linear actuator driving means for driving the focus, a zoom for changing a focus magnification, a driving means for driving the zoom, the focus, A lens apparatus and an imaging system, comprising: a control unit that performs zoom drive control, wherein the control unit performs at least the end of the initial focus operation after detecting the end of the initial zoom operation.   The first and second aspects are characterized in that the control means drives the linear actuator while detecting the end of the initial operation other than focusing.   In an interchangeable lens system, an interchangeable lens is a lens that forms a subject image on an imaging surface, a focus that performs focus adjustment, a linear actuator driving means that drives the focus, a zoom that changes a focus magnification, and the zoom that drives the zoom. A camera control unit having a communication function for communicating with the lens, and an imaging device. The lens control means is characterized in that the initial operation of the focus is completed after completion of other initial operations of the interchangeable lens that can be detected other than the focus and detection of camera initial operation end information from the camera control means. Interchangeable lens system.   In a lens apparatus and an imaging system having a focus lens and a zoom lens, and having one linear actuator as a focus or zoom drive means, the end of the initial focus or zoom operation driven by the linear actuator A lens apparatus and an imaging system, which are performed after detecting the end of an initial operation of a detectable lens apparatus and an imaging system other than a unit driven by an actuator.   Lens device and imaging system in which both focus and zoom are driven by a linear actuator End of the initial operation of focus and zoom driven by a linear actuator in an interchangeable lens system is the initial operation of other detectable lens devices and imaging systems A lens apparatus and an imaging system, which are performed after detecting the end of the above.

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