JP5038176B2 - Optical equipment - Google Patents

Description

  The present invention relates to an optical apparatus such as a lens apparatus or an imaging apparatus that controls a control target operation such as zoom or focus based on a signal output in response to an operation of an operation member.

  Some lens devices and imaging devices can electrically control optical adjustment operations such as zoom, focus, and diaphragm according to operation of an operation member. In this case, the operation direction and the operation amount of the operation member are detected based on a change in a signal (position signal) indicating the position of the operation member generated using an output signal from a sensor such as an MR (magnetoresistive) element. The

  The MR (magnetoresistive) element outputs a plurality of sine-wave signals having different phases that change periodically according to changes in the operation position of the operation member. Then, the position of the operation member can be obtained by taking out a linearly changing portion from these phase signals and performing an interpolation operation to generate one linearly changing position signal.

  At this time, a method for improving the discontinuity of the joint of the position signal created by the interpolation operation and the linearity of the change of the position signal by aligning the amplitudes and reference positions of the signals of the plurality of phases by gain adjustment and offset adjustment. Is known (see Patent Document 1).

  However, when the position (operation direction or operation amount) of the operation member is detected using a sensor such as an MR element as described above, the sensor output may fluctuate due to a change in temperature at which the optical device is used. In this case, even if the operation member is not operated, the value of the position signal generated from the signals of the plurality of phases changes, and the optical adjustment operation is performed.

  On the other hand, as disclosed in Patent Document 1, an optical adjustment operation due to a temperature change is performed by performing gain offset correction or taking the average of two detected relative position data. It is also possible to avoid this.

  However, when a temperature change occurs in a state where the operation member is stopped in the vicinity of the joint of the position signal at the time of interpolation, a change in the interpolation due to a change in sensor output accompanying this change is disclosed in Patent Document 1. Even if this method is used, a large change may occur in the position signal. As a result, the optical adjustment operation is performed even if the operation member is not operated.

In order to solve such a problem, in general, a threshold value that can sufficiently cover the fluctuation of the sensor output (the fluctuation of the position signal) due to the temperature change is set. Then, only when the position signal changes beyond the threshold value compared with the position signal detected last time, it is determined that the operation member has been operated, and the optical adjustment operation is performed (the previous and current position signals). The amount of operation is the operation amount).
JP 2004-61459 A

  However, when the threshold value as described above is set, even if the position signal changes due to the operation member being operated, the optical adjustment operation is not performed unless the change amount exceeds the threshold value. This hinders high resolution of the optical adjustment operation.

  On the other hand, when the threshold value is decreased, it is repeatedly determined that the operation member is operated even though the operation member is not operated as described above. As a result, minute optical adjustment operations are frequently performed, and unsightly images are taken.

  According to the present invention, it is possible to avoid the operation of the control target due to the fluctuation of the interpolation value accompanying the temperature change without setting a large threshold for the change amount of the sensor output (that is, the position signal), and An optical apparatus capable of controlling operation with high resolution is provided.

An optical apparatus according to an aspect of the present invention includes an operation unit capable of operation, and a signal output that outputs a plurality of phase signals that change periodically according to changes in the operation position of the operation unit. Means, position detection means for calculating position information corresponding to the operation position of the operation means by interpolating the signals of the plurality of phases, and acquiring the position information at a predetermined period and controlling based on a change in the position information Control means for operating the target, and the control means operates the control target on condition that the position information continuously changes in the same direction for a predetermined number of times or more , and the predetermined period is the control period. The means is characterized in that it is at least twice as fast as the control cycle for controlling the operation of the controlled object .

  According to the present invention, since the control target is operated on condition that the position information continuously changes in the same direction for a predetermined number of times or more, the position according to the temperature change can be obtained without increasing the threshold for the change amount of the position information. It is possible to avoid that the control target is operated due to a change in information. In addition, the operation of the control target can be controlled with high resolution through the operation of the operation means.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration of a lens-integrated video camera (hereinafter simply referred to as a video camera) as an optical apparatus (imaging device) according to an embodiment of the present invention.

The video camera has a so-called rear focus type imaging optical system. Light from a subject is movable in a fixed lens 102, a variable magnification lens (hereinafter referred to as a zoom lens) 103 that can move in the optical axis direction, an iris 104 that performs a light amount adjustment operation, a fixed lens 105, and the optical axis direction. A subject image is formed on the image sensor 107 through the focus lens 106. The image sensor 107 is a photoelectric conversion element such as a CCD sensor or a CMOS sensor, and converts a subject image into an electrical signal. The zoom lens 103, the iris 104, and the focus lens 106 are optical adjustment members included in the imaging optical system.

  An electrical signal (imaging signal) from the image sensor 107 is subjected to processing such as signal amplification by the camera signal processing unit 108 and input to the video signal processing unit 109. The video signal processing unit 109 performs processing such as color correction and white balance on the input imaging signal to generate a video signal. The video signal is displayed on a display (not shown), recorded on a recording medium such as a magnetic tape, a semiconductor memory, or an optical disk, or output to the outside.

In the rear focus type imaging optical system, it is necessary to move the focus lens 106 in order to correct the image plane variation accompanying the variation while moving the zoom lens 103 in the optical axis direction and performing zooming. In the video camera of this embodiment, the microcomputer (control means) 112 controls the positional relationship between the zoom lens 103 and the focus lens 106 according to the subject distance in accordance with the zoom cam data shown in FIG.

  Specifically, the microcomputer 112 detects the positions of the zoom lens 103 and the focus lens 106 using the zoom lens position detection unit 113 and the focus lens position detection unit 114, respectively. Then, the zoom lens 103 and the focus lens 106 are moved while maintaining the positional relationship according to the zoom cam data of FIG. 3 in response to the zoom operation ring (operation means) 117 that can be continuously rotated by the user. Move. The zoom lens 103 and the focus lens 106 are moved by the operation of the zoom lens driving unit 115 and the focus lens driving unit 116 that have received a driving signal (control signal) from the microcomputer 112, respectively. This zoom operation is also called computer zoom.

  In addition, the video camera is provided with an operation amount detection unit (position detection means) 118 for detecting an operation (operation direction and operation amount) of the zoom operation ring 117.

  FIG. 4 shows a cross section of the zoom operation ring 117 shown in FIG. The zoom operation ring 117 includes an operation unit 401 that is rotatably attached to the outer periphery of a lens barrel (not shown) that houses the imaging optical system.

  When the user rotates the operation unit 401 of the zoom operation ring 117 in the clockwise direction in the figure, the gear 403 engaged with the gear unit 402 formed on the inner periphery of the operation unit 401 is opposite to the operation unit 401. Rotate in the direction. The gear 403 rotates by an amount corresponding to the gear ratio between the gear unit 402 and the gear 403 with respect to the operation amount of the operation unit 401.

  FIG. 5 shows a specific configuration example of the MR sensor unit 201 as a signal output unit included in the operation amount detection unit 118. In this figure, when the gear 403 rotates, the shaft 504 that fixes the gear 403 also rotates, and the rotation is input to the rotary MR sensor 505.

  Although not shown, the rotary MR sensor 505 is magnetized alternately with S and N in the circumferential direction and rotates in conjunction with the rotation of the shaft 504, and is separated from the magnet drum by a certain distance. And arranged magnetic resistance. When the magnetic drum rotates in a state where a predetermined voltage is applied to the magnetic resistance, that is, in accordance with the change in the operation position of the zoom operation ring 117, the rotational MR sensor 505 has different phases from each other that periodically change. A multi-phase signal (detection signal) is output. In this embodiment, the case where a two-phase detection signal is output is used. However, the detection signal may be a plurality of phases such as three phases or four phases.

  Here, the case where the rotary MR sensor 505 is used will be described. However, a magnet in which S and N are alternately magnetized is attached to the inner periphery of the zoom operation ring 117, and the magnet is positioned at a certain distance from the magnet. Similarly, a plurality of phases of detection signals can be obtained even if a magnetic resistance is arranged.

  As shown in FIG. 8, the two-phase detection signals (S-phase signal and C-phase signal) from the rotary MR sensor 505 are like sine waves depending on the change in the operation position (rotation amount) of the zoom operation ring 117. Change. The phase difference between the S-phase signal and the C-phase signal at this time is determined by the magnetization pitch of the magnet drum and the distance of the magnetic resistance with respect to the magnet drum. In this embodiment, the S phase signal and the C phase signal have a phase difference of 90 °. The S phase signal means a signal having a sin waveform, and the C phase signal means a signal having a cos waveform.

  FIG. 2 shows the configuration of the operation amount detection unit 118. The operation amount detection unit 118 interpolates the S phase signal and the C phase signal, and generates position information corresponding to the operation position of the zoom operation ring 117. Hereinafter, the configuration and operation of the operation amount detection unit 118 will be described more specifically.

  The output signals (S-phase signal and C-phase signal) of the MR sensor 201 are amplified by the amplifier 202 into an electric signal having an appropriate magnitude. The amplified S-phase signal and C-phase signal are converted from an analog signal to a digital signal at a predetermined sampling timing by the sample hold circuit 203 and the ADC 204. The digital signal is adjusted by the gain offset adjustment unit 205 to have an appropriate gain and offset, and is input to the phase shift / inversion signal generation unit 206.

  The phase shift / inversion signal generation unit 206 generates eight signals including a signal shifted in phase and an inverted signal with respect to the S phase signal and the C phase signal from the input S phase signal and C phase signal. . The eight signals are sent to the sub position calculation unit 208.

  The sub position calculation unit 208 determines the phases of the eight signals based on the input signal (determines whether plus or minus), and calculates a sub position as a rough position (region).

  The output of the phase shift / inversion signal generation unit 206 is also sent to the main position calculation unit 207. The main position calculation unit 207 selects an appropriate signal based on the phase determination result from the linear portions of the eight signals, and calculates the value as the main position.

  Then, the position corresponding to the operation position of the zoom operation ring 117 is obtained by combining the main position calculated by the main position calculation unit 207 and the sub position calculated by the sub position calculation unit 208 by the combining position calculation unit 209. Information is calculated.

  The position information of the zoom operation ring 117 calculated in this way is sent to the microcomputer 112 as control means. The microcomputer 112 samples (detects) the position information at a predetermined cycle, and compares the value of the position information detected at the previous sampling timing with the value of the position information detected at the current sampling timing. The operation direction of the zoom operation ring 117 can be determined by determining whether the value of the current position information has increased or decreased with respect to the value of the previous position information. Further, the operation amount of the zoom operation ring 117 can be obtained by calculating the difference between the current position information value and the previous position information value.

  In this embodiment, the case where the operation amount detection unit 118 is provided separately from the microcomputer 112 has been described. However, the configuration (or function) of the operation amount detection unit 118 excluding the MR sensor 201 is included in the microcomputer 112. You may have it. In this case, the microcomputer 112 functions as position detection means and control means, and generates position information (composite position) corresponding to the operation position of the zoom operation ring 117 according to the procedure shown in the flowchart of FIG. This operation is executed according to a computer program stored in the internal memory of the microcomputer 112.

  In S (step) 601, the microcomputer 112 captures digital signals of the S phase signal and the C phase signal that are output signals from the MR sensor 201. In step S603, the microcomputer 112 performs appropriate gain adjustment and offset adjustment on the S phase signal (denoted as S in FIG. 6) and the C phase signal (denoted as C in FIG. 6). Turn into.

  Next, in S604, the microcomputer 112 calculates a 45 ° phase advance signal HS for the S phase signal and a 45 ° phase delay signal HC for the C phase signal. Furthermore, in S606, an S phase signal, a C phase signal, a phase advance signal HS, and an inverted signal of the phase advance signal HC are calculated. As a result, the eight signals described above are generated.

  In step S <b> 607, the microcomputer 112 determines the phases of the eight signals, and calculates a rough sub position of the zoom operation ring 117 based on the determination result. In step S609, an appropriate signal is selected from the eight signals based on the phase determination result, and the value is calculated as the main position of the zoom operation ring 117.

  Subsequently, in S610, the microcomputer 112 combines the calculated main position and sub position to finally obtain position information (composite position) corresponding to the operation position of the zoom operation ring 117.

  In step S611, the microcomputer 112 returns to step S601. The microcomputer 112 detects (updates) position information of the zoom operation ring 117 at the predetermined cycle by repeating the above processing at the predetermined cycle.

  An ideal change when the zoom operation ring 117 is operated, that is, a change in position information (composite position) when there is no change in output from the MR sensor 201 due to a change in the operating environment temperature or internal temperature of the video camera. As shown in FIG. The signal used to calculate the position information of the zoom operation ring 117 is switched from the interpolation signal A → B → C by the processing in the composite position calculation unit 209 (or S610) as the operation amount of the zoom operation ring 117 changes. . In an ideal state, the interpolated signals A, B, and C are joined together without shifting from each other.

  However, when the output from the MR sensor 201 fluctuates due to changes in the operating environment temperature or internal temperature of the video camera, for example, as shown in FIG. 10, a gap (gap) occurs at the joint between the interpolation signals A and B. There is. In this case, if the operation position of the zoom operation ring 117 happens to be near the joint between the interpolation signals A and B, position information is calculated based on the interpolation signal A due to fluctuations in the output from the MR sensor 201, The position information changes abruptly, for example, based on the insertion signal B. For this reason, the microcomputer 112 erroneously recognizes that the zoom operation ring 117 has been operated.

  Here, the change in the position information due to such a shift of the joint of the interpolation signal (shift due to the switching of the interpolation) basically does not occur twice in the same direction, and the increase / decrease direction. The next change after changing in one direction occurs in the opposite direction. In this embodiment, this characteristic is used to avoid erroneous recognition that the zoom operation ring 117 has been operated.

  The flowchart of FIG. 7 shows the operation of the microcomputer 112 for avoiding erroneous recognition that the zoom operation ring 117 has been operated. This operation is executed according to a computer program stored in the internal memory of the microcomputer 112.

  When the process starts in S701, in S702, the microcomputer 112 calculates the position information (composite position) of the zoom operation ring 117 described above. Thereby, the current position of the zoom operation ring 117 is acquired.

  In step S <b> 703, the microcomputer 112 calculates a difference between the current position of the zoom operation ring 117 and the previously acquired position, and determines whether the difference is larger than a specified value (threshold value). If it is larger than the specified value, the process proceeds to S705, and if it is smaller than the specified value, the process proceeds to S704.

  In S704, the microcomputer 112 sets the operation flag to False. In step S710, the current position information is updated to the previous position information. As a result, the zoom operation ring 117 is treated as being not operated from the previous time. From S710, the process returns to S702 via S711 and S701, and S704 and S710 are repeated until the position information changes beyond the specified value.

  On the other hand, in S705, the microcomputer 112 sets the operation flag to True in order to confirm whether or not the previous position information has changed beyond the specified value with respect to the previous position information. It is determined whether or not. If the operation flag is not set to True, the process proceeds to S706, and the direction in which the current position information has changed with respect to the previous position information (current change direction) is stored. Then, True is set in the operation flag, and the process proceeds to S710.

If the operation flag is set to True, the process advances to step S707, and the microcomputer 112 determines that the current change direction is the direction in which the previous position information has changed from the previous position information (previous time). It is determined whether or not the change direction is the same. If the current change direction is different from the previous change direction, the process proceeds to S708, the current change direction is stored, the operation flag is set to True, and the process proceeds to S710. In this way, if the position information changes only once more than the specified value, the zoom operation ring 117 is not treated as being operated, and the operations of the zoom lens 103 and the focus lens 106 that are the control targets are prohibited. .

On the other hand, if the current change direction is the same as the previous change direction, that is, if the position information has continuously changed in the same direction a predetermined number of times (twice in this embodiment), the process proceeds to S709. In step S <b> 709, the microcomputer 112 outputs a drive signal to the zoom lens driving unit 115 and the focus lens driving unit 116 according to the operation direction and operation amount of the zoom operation ring 117. That is, the zoom lens 103 and the focus lens 106 that are the control targets are operated.

  Thus, on the condition that the position information continuously changes in the same direction for a predetermined number of times or more, the current position information change is not due to the change in the output from the MR sensor 201 due to the temperature change, but the zoom operation. It is assumed that the ring 117 is operated. Accordingly, it is possible to avoid erroneous recognition that the zoom operation ring 117 has been operated without increasing the specified value used in S703, and to perform a zoom operation (optical adjustment operation) unintended by the user. Can be prevented. By setting the specified value to be as small as possible, the operation amount that the operation of the zoom operation ring 117 is treated as effective in S709 can be reduced, and the resolution of zoom operation control can be increased.

  From S709, the microcomputer 112 stores the current change direction, sets the operation flag to True, and proceeds to S710.

  In this embodiment, the detection period (predetermined period) of the position information of the zoom operation ring 117 by the microcomputer 112 is set to 1 KHz, for example. On the other hand, the cycle (control cycle) for controlling the zoom operation in accordance with the operation of the zoom operation ring 117 (change in position information) is set to 60 Hz, for example. Thus, even if the zoom operation is executed under the conditions described in S707 by increasing the detection cycle of the position information at least twice as long as the control cycle based on the position information, the zoom for the operation of the zoom operation ring 117 can be performed. There is almost no delay in operation.

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

  For example, the lens integrated video camera has been described in the above embodiment, but the present invention can also be applied to other optical devices such as an interchangeable lens. Further, the present invention is not limited to optical devices for performing these imaging operations, but also to various optical devices that control the operation of the control target by detecting the operation of the operation member by interpolating a plurality of phase signals from the sensor. Can also be applied.

  Further, the “predetermined number of times” in the condition that the position information continuously changes in the same direction for a predetermined number of times or more is not limited to two times, and may be three or more times. Furthermore, you may provide the frequency change part (frequency change means) for enabling a user to change this predetermined frequency arbitrarily.

In the above-described embodiment, the case where the zoom lens and the focus lens are operated (zoom operation) according to the operation of the zoom operation ring has been described. It can also be applied to the case where the operation of) is performed.

  Furthermore, the present invention is not limited to an optical apparatus such as an imaging device having an optical adjustment unit or an interchangeable lens, and can be widely applied to various types of optical apparatuses for controlling the operation to be controlled according to the operation of the operation member.

1 is a block diagram illustrating a configuration of a video camera that is an embodiment of the present invention. The block diagram which shows the structure of the operation amount detection part in an Example. The figure which shows the positional relationship (cam data) of the zoom lens and focus lens in zoom operation | movement. Sectional drawing of the zoom operation ring in an Example. The figure which shows MR sensor in an Example. The flowchart which shows the operation | movement in an Example. The flowchart which shows the operation | movement in an Example. The figure which shows the S phase signal and C phase signal which are output from MR sensor. The figure which shows the change of ideal positional information. The figure which shows the change of the positional information when the output from MR sensor fluctuates by temperature change.

Explanation of symbols

103 zoom lens 105 focus lens 107 image sensor 112 microcomputer 118 operation amount detection unit 201 MR sensor

Claims (5)

Operation means capable of operation;
Signal output means for outputting signals of a plurality of phases with different phases that change periodically according to changes in the operation position of the operation means;
Position detecting means for interpolating the signals of the plurality of phases to calculate position information corresponding to the operation position of the operating means;
Control means for acquiring the position information at a predetermined period and operating a control object based on a change in the position information;
The control means operates the control object on the condition that the position information continuously changes in the same direction for a predetermined number of times ,
The optical apparatus according to claim 1, wherein the predetermined period is twice or more faster than a control period in which the control unit controls the operation of the control target . The optical apparatus according to claim 1, wherein the control target is an optical adjustment member included in an optical system of the optical apparatus. The operation means is a zoom operation ring for driving a zoom lens and a focus lens by a rotation operation,
The optical apparatus according to claim 1, wherein the control target is a zoom lens and a focus lens. The operation means is a diaphragm operation member for driving the diaphragm by a rotation operation,
The optical apparatus according to claim 1, wherein the control target is a diaphragm. The optical device according to any one of claims 1 to 4, characterized in that it has a number changing means capable of changing the predetermined number of times.