Control device, control method, and computer program

Abstract

To provide a control device capable of highly accurate position control.SOLUTION: A control device comprises first target position generation means that generates a first target position being a movement target of a first drive member on the basis of a target velocity of the first drive member, first control means that controls a position of the first drive member so as to follow the first target position, second target position generation means that generates a second target position being a movement target of a second drive member in accordance with an actual position of the first drive member or the first target position, and second control means that controls a position of the second drive member so as to follow the second target position.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a control device, a control method, a computer program, etc. [Background technology]

[0002] One known method for controlling a multi-group zoom lens is to set a movement target for another lens based on the movement locus of one reference lens, and then control the lens. A method for controlling lenses based on the position and speed information of each lens corresponding to the focal length has been proposed. Patent Document 2 also proposes a method for controlling lenses by taking into account position information of the lens itself and other lenses, and estimated disturbances. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-134408 [Patent Document 2] Japanese Patent Application Publication No. 8-327876 Summary of the Invention [Problem to be solved by the invention]

[0004] However, lens speed can be disturbed by external disturbances such as jitter, which disturbs the movement trajectory of the reference lens. This then disturbs the movement of other lenses that have movement targets set based on this movement trajectory. Furthermore, in addition to this disturbance of the reference lens, speed disturbances due to disturbances caused by the other lenses themselves are superimposed, resulting in even greater disturbances, which in turn deteriorates zoom tracking performance and causes noise.

[0005] In contrast, Patent Document 1 controls the lens position and speed linked to the focal length, but does not consider speed variations due to jitter or disturbance. Also, Patent Document 2 controls each lens taking into consideration its own and other lens position information and estimated disturbance, but jitter and disturbance are difficult to estimate because they change from moment to moment depending not only on individual differences but also on the environment.

[0006] An object of the present invention is to solve the above-mentioned problems and to provide a control device capable of highly accurate position control. [Means for solving the problem]

[0007] A control device according to one aspect of the present invention includes: a first target position generating means for generating a first target position to be a movement target of the first driving member based on a target speed of the first driving member; a first control means for controlling the position of the first drive member so that the first drive member follows the first target position; a second target position generating means for generating a second target position to be a movement target of a second driving member in accordance with the actual position of the first driving member or the first target position; a second control means for controlling the position of the second drive member so that the second drive member follows the second target position; The present invention is characterized by having the following. [Effects of the Invention]

[0008] According to the present invention, a control device capable of highly accurate position control can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of the configuration of a lens barrel according to an embodiment of the present invention. [Figure 2] 1A and 1B are diagrams showing an example of a schematic configuration of a motor unit according to an embodiment of the present invention. [Figure 3] 1 is a functional block diagram showing an example of the configuration of a lens control system according to an embodiment of the present invention. [Figure 4] 10A to 10E are diagrams illustrating an example of processing performed by the encoder 305 according to an embodiment of the present invention. [Figure 5] 10A to 10C and 10E to 10I are diagrams showing the processing flow of the lead angle / power rate control unit 308 and the drive waveform generation unit 309 in the embodiment of the present invention. [Figure 6] FIG. 4 is a diagram illustrating an example of the relationship between an advance angle and a motor rotation speed according to an embodiment of the present invention. [Figure 7] 10 is a flowchart illustrating an example of processing by an advance angle / power rate control unit 308 according to the embodiment of the present invention. [Figure 8] 10 is a flowchart illustrating an example of a target advance angle / power rate selection process in step S710. [Figure 9] 10 is a flowchart illustrating an example of processing by an advance angle / power rate control unit in step S711. [Figure 10] 10 is a flowchart illustrating an example of a target position counter value generation process for the first zoom lens 102 according to the embodiment of the present invention. [Figure 11] 10 is a flowchart illustrating an example of a target position counter value generation process for the second zoom lens 103 according to the embodiment of the present invention. [Figure 12] 2 is a diagram showing an example of the positional relationship between a first zoom lens 102 and a second zoom lens 103 according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. In each drawing, the same members or elements are designated by the same reference numerals, and duplicate descriptions will be omitted or simplified.

[0011] Fig. 1 is a diagram showing an example of the configuration of a lens barrel according to an embodiment of the present invention. The lens barrel shown in Fig. 1 constitutes an imaging optical system and includes, in order from the subject side (left side of the figure), a fixed lens 101, a first zoom lens 102, and a second zoom lens 103. Note that the lens barrel of this embodiment also includes a focus lens (not shown). The first zoom lens 102 and the second zoom lens 103 function as a first drive member and a second drive member, respectively.

[0012] Reference numeral 102a denotes a first motor unit for performing zooming by moving the first zoom lens 102 in the optical axis direction. Reference numeral 103a denotes a second motor unit for assisting zooming by the first zoom lens 102 by moving the second zoom lens 103 in the optical axis direction in conjunction with a change in the position of the first zoom lens 102.

[0013] Next, Figures 2(A) and (B) are diagrams showing an example of the schematic configuration of a motor unit according to an embodiment of the present invention. The motor units shown in Figures 2(A) and (B) are installed in each lens, and correspond to a first motor unit and a second motor unit for independently driving each lens. In other words, multiple motor units are configured to drive each of the multiple lenses that make up the photographic lens.

[0014] 2A, reference numeral 201 denotes a stepping motor, 202 denotes a rotating shaft of the stepping motor 201, and 203 denotes a rack. The rotating shaft 202 is a lead screw, and while meshing with the rack 203, a lens 204 connected to the rack 203 moves in the direction of the optical axis in response to the rotation of the rotating shaft 202.

[0015] The reference position of the lens is determined by the configuration of a PI (photo interrupter) 205 arranged on a fixed member (not shown) and a light shielding plate 206 provided on the lens. The PI 205 is composed of a light emitting section and a light receiving section, and when the light shielding plate 206 enters between the light emitting section and the light receiving section as the lens 204 moves, the detection signal of the PI 205 switches from High to Low.

[0016] This switching position is set as the reference position of the lens. 207 is a cylindrical rotational phase detection magnet attached to the rotating shaft 202, which detects the rotational phase of the stepping motor 201 in combination with rotational phase detection hall sensors 208 and 209. In the following, rotational phase detection hall sensor 208 will be referred to as Hall-Ch0, and 209 will be referred to as Hall-Ch1.

[0017] 2(B) is a diagram illustrating the arrangement of the rotation phase detection magnet 207 and the rotation phase detection hall sensors 208 and 209 when the stepping motor 201 has 10 poles. The rotation phase detection magnet 207 is configured with a 10-pole magnet to match the number of poles of the motor.

[0018] The poles are evenly spaced over a mechanical angle of 36°. Rotation phase detection Hall sensors 208 and 209 are placed on an extension of the 18° mechanical angle of rotation phase detection magnet 207. With this configuration, each Hall sensor detects two types of sine waves with a phase difference of 90° according to the rotation of the motor.

[0019] Next, Fig. 3 is a functional block diagram showing an example configuration of a lens control system according to an embodiment of the present invention. Note that this system is configured to control the motor units provided in each lens in conjunction with one another. Note that some of the functional blocks shown in Fig. 3 are realized by causing a CPU or other device serving as a computer (not shown) included in the lens control system to execute a computer program stored in a memory (not shown) serving as a storage medium.

[0020] However, some or all of these functions may be implemented by hardware, which may be a dedicated circuit (ASIC) or a processor (reconfigurable processor, DSP).

[0021] 3 may not be contained in the same housing, but may be configured as separate devices connected to each other via signal paths. The above explanation regarding FIG. 3 also applies to FIG. 8.

[0022] In Fig. 3, blocks with the same numbers as in Fig. 2 are the same members. The two-phase Hall signals detected by Hall-Ch0 and Hall-Ch1 are amplified by amplifier circuits 301 and 302, respectively. The amplified two-phase Hall signals are quantized by an AD converter 304 in a motor control device 303, and encoded by an encoder 305 to calculate a position detection counter value.

[0023] 3 shows a configuration in which the motor control device 303 controls one set of motor units consisting of 201, 204, 205, 207-209, 301, 302, and 310. However, in this embodiment, a single motor control device 303 is configured to control multiple sets of motor units. However, a motor control device 303 may be provided for each motor unit.

[0024] The motor control device 303 has a built-in CPU or the like as a computer, and functions as a control means that controls the operation of each part of the entire motor control device based on a computer program stored in a memory that serves as a storage medium.

[0025] The encoder 305 generates a position detection counter value that indicates the position information of the lens 204, which is a member connected to the motor. In this embodiment, an example is described in which the position detection counter value is calculated using a Hall sensor, but the present invention is not limited to this. Instead of the Hall sensor, a photointerrupter and a slit rotating plate may be used to calculate the position detection counter value from rotation detection pulses.

[0026] A target position setting unit 306 sets a target position of the lens and generates a target position counter value for controlling each lens at a target speed and target position. That is, the target position setting unit 306 generates a target position counter value so that the first zoom lens 102 reaches the target zoom speed.

[0027] Here, the target position setting unit 306 functions as a first target position generating means that generates a first target position that serves as a movement target for the first driving member based on the target speed of the first zoom lens as the first driving member.

[0028] Similarly, for the second zoom lens 104, the target position setting unit 306 generates a target position counter value in conjunction with the movement of the first zoom lens 102 so that the second zoom lens 104 moves along a predetermined locus.

[0029] Therefore, the target position setting unit 306 also functions as a second target position generating unit that generates a second target position to be a movement target of the second zoom lens serving as the second driving member. As will be described later, in this embodiment, the second target position is generated in accordance with the actual position or the first target position of the first driving member.

[0030] The same coordinate origin is set for the position detection counter value and the target position counter value by a coordinate origin setting unit 307, and the coordinates are aligned. 308 is a lead angle / power rate control unit that sets a target lead angle and generates a drive counter value by adding the target lead angle to the position detection counter value. Furthermore, the lead angle / power rate control unit 308 performs feedback control of the lead angle and amplitude of the drive waveform by setting the power rate so that the lens moves in accordance with the target position counter value.

[0031] Here, lead angle / power rate control unit 308 functions as a control means that controls the rotational speed and rotational position of the motor based on the target lead angle. Also, lead angle / power rate control unit 308 as a control means controls at least one of the target lead angle and drive voltage (power rate) set for the motor.

[0032] That is, the lead angle / power rate control unit 308 functions as a first control means for executing a first control step of controlling the position of the first driving member so that it follows the first target position, and also functions as a second control means for executing a second control step of controlling the position of the second driving member so that it follows the second target position.

[0033] Reference numeral 309 denotes a drive waveform generation unit, which generates a drive counter value by adding a target lead angle to the position detection counter value, performs SIN / COS conversion on the generated drive counter value, and further generates a two-phase drive waveform whose amplitude is adjusted according to the power rate.

[0034] It should be noted that open control is performed during this period because feedback control is not possible until the coordinate origin is set by the coordinate origin setting unit 307. In this case, the lead angle / power rate control unit 308 sets the target position counter value obtained from the target position setting unit 306 as the drive counter value, and also sets a power rate for open control to open control the drive waveform.

[0035] The drive waveform generated by the drive waveform generation unit 309 is supplied to the motor driver 310 as, for example, a PWM signal, and is converted by the motor driver 310 into a motor drive signal that is supplied to the stepping motor 201. The drive waveform may be supplied to the motor driver 310 after undergoing AD conversion processing, or may be supplied as drive waveform information from a communication port.

[0036] The processing of the encoder 305 will now be described in detail with reference to Fig. 4. Figs. 4(A) to 4(E) are diagrams showing an example of processing by the encoder 305 in an embodiment of the present invention. Note that, in accordance with the configuration of Fig. 2(B), an example will be described in which the stepping motor 201 has 10 poles and the rotation phase detection magnet 207 is also a cylindrical magnet with 10 poles.

[0037] 4(A) shows the magnet 207 for detecting the rotational phase of the motor, and (B) and (C) show the waveforms of the Hall signals detected by Hall-Ch0 and Hall-Ch1, respectively. The configuration shown in FIG. 2(B) provides the Hall signals as sine waves (Sin waves) and cosine waves (Cos waves) that are 90° out of phase with each other.

[0038] The encoder 305 performs an arctangent operation (tan ) using (B) and (C), which are the sine wave and cosine wave signals quantized by the AD converter 304. -1 (Sin / Cos)) to calculate phase information from 0 to 360°.

[0039] (D) shows the calculated phase information, which is integrated to calculate the position detection counter value (E) indicating the amount of motor rotation. This rotation amount information can be converted into lens position information by multiplying it by the lead screw pitch.

[0040] Therefore, the motor rotation amount information calculated by the encoder 305 is treated as a lens position detection counter value. The encoder 305 functions as an encoding means that executes an encoding step that detects the rotation state of the motor and converts it into actual position information. Also, although the phase information has been described here as information from 0 to 360°, this is determined by the resolution of the position detection counter value and is not limited to this.

[0041] Next, a detailed description will be given of the processing of the coordinate origin setting unit 307. When the motor control device 303 is powered on, it first executes a sequence for setting the coordinate origin of the lens.

[0042] That is, the lens is driven to search for the lens position where the detection signal of PI205 described in Fig. 2 switches from High to Low, and this searched switching position is set as the coordinate origin, and the position detection counter value and target position counter value are initialized to predetermined values. This aligns the coordinates of both, making it possible to control the lens position.

[0043] 5(A) to (C) and (E) to (I) are diagrams showing an example of processing by the lead angle / power rate control unit 308 and the drive waveform generation unit 309 in an embodiment of the present invention. Note that since Fig. 5(A), (B), (C), and (E) are the same as the signals explained with the same reference numerals in Fig. 4, their explanation will be omitted here. (F) indicates the target position counter value. As mentioned above, the target lead angle and power rate are calculated so that the position detection counter value (E) follows the target position counter value (F).

[0044] In the following description, an example is taken where the target lead angle is 90°. The lead angle / power rate control unit 308 generates a drive counter value (G) by superimposing the target lead angle of 90° on the position detection counter value (E).

[0045] The position detection counter value (E) is a counter value obtained by integrating phase information from 0 to 360°, and the drive counter value (G) similarly has phase information from 0 to 360°. Therefore, the drive waveform generation unit 309 performs SIN and COS conversion on this drive counter value (G) to generate a two-phase A-phase drive waveform (sine wave) (H) and a B-phase drive waveform (cosine wave) (I) that are phase-shifted by the advance angle relative to the motor rotation phase.

[0046] The drive waveform generation unit 309 generates an offset position counter value by adding a target lead angle as an offset value to the position detection counter value, and controls the motor based on the offset position counter value and the target position counter value. Note that the offset position counter value is determined based on the position detection counter value and the target lead angle, and the target lead angle is set based on the target position counter value and the position detection counter value.

[0047] Furthermore, the power rate of these drive waveforms is set so as to achieve the target amplitude, and the waveforms are output to the motor driver 310. Here, the phase information has been described as information of 0 to 360°, but this is determined by the resolution of the position detection counter value (E), and is not limited to this.

[0048] FIG. 6 is a diagram showing an example of the relationship between the advance angle and the motor rotation speed according to an embodiment of the present invention. In FIG. 6, the relationship between the advance angle and the motor rotation speed is shown for examples of power rates PR1% and PR2% (PR1 < PR2). Here, PR1% is, for example, 50%, and PR2% is, for example, 60%. The power rate adjusts the amplitude of the drive waveform. For example, a power rate of 60% generates a waveform so as to suppress the amplitude of the drive waveform to 60%.

[0049] In FIG. 6, it can be seen that in region R1, the motor rotation speed increases in proportion to the increase in the advance angle. However, when the advance angle is further increased, the motor rotation speed gradually saturates with respect to the advance angle, and the motor reaches region R2. When the advance angle is further increased beyond the saturation point SP1, the motor enters region R3 where the motor rotation speed decreases.

[0050] Also, the larger the power rate, the steeper the slope of the advance angle vs. motor rotation speed in region R1, and the saturation point SP1 shifts toward the larger advance angle. The relationship between the advance angle and the speed is a proportional relationship within the range of region R1. That is, the relationship between the advance angle and the speed can be expressed by the following equation (1).

[0051] Speed = Advance angle × γ + β ··· Equation (1) However, γ is the slope and β is the intercept.

[0052] Therefore, the relationship between the advance angle and the rotation speed is measured in advance, and based on the measurement data, the slope γ, the intercept β of Equation (1), and region R1, which is the effective region of Equation (1) corresponding to region R1, are stored as an advance angle vs. speed table.

[0053] Here, a plurality of advance angle vs. speed tables are stored for each power rate so that they can be selected according to the target speed. Also, the smaller power rate is preferentially selected. Here, the relationship between the advance angle and the speed is described by Equation (1), but the correspondence information between the rotation speed of the motor and the advance angle may be table data in which the relationship between the advance angle and the speed is stored in advance.

[0054] 7 is a flowchart illustrating an example of processing by the lead angle / power rate control unit 308 according to an embodiment of the present invention. Note that the operation of each step in the flowchart in FIG. 7 is performed sequentially by a CPU or the like serving as a computer in the motor control device 303 executing a computer program stored in memory.

[0055] 3, the coordinates of the position detection counter value and the target position counter value are aligned by setting the same coordinate origin in the coordinate origin setting unit 307. However, since feedback control is not possible until the coordinate origin is set in the coordinate origin setting unit 307, open control is performed during this period.

[0056] Therefore, the lead angle / power rate control unit 308 switches its control method to open control during initialization driving and to feedback control once initialization driving is complete. That is, in step S700, it is determined whether initialization driving has been completed, and if the determination in step S700 is No, the process proceeds to step S701, where open control is selected.

[0057] When open control is selected in step S701, the target position counter value is set as the drive counter value in step S702. Next, in step S703, it is determined whether detection and setting of the coordinate origin has been completed in the coordinate origin setting unit 307. If the determination in step S703 is No, the process returns to step S702, and the processes of steps S702 and S703 are repeated.

[0058] If it is determined in step S703 that the setting of the coordinate origin has been completed, the process proceeds to step S704, where the initialization drive is completed, and in step S705, feedback control is selected, the process returns to step S700, and the flow of FIG. 7 is repeatedly executed.

[0059] On the other hand, if it is determined in step S700 that the initialization driving has been completed, the process proceeds to step S710, where a target advance angle / power rate selection process is performed, and then speed control is performed in step S711. Thereafter, the process returns to step S700, and the flow of FIG. 7 is repeatedly executed.

[0060] Fig. 8 is a flowchart illustrating an example of the target advance angle / power rate selection process in step S710. Note that the operation of each step in the flowchart in Fig. 8 is performed sequentially by a CPU or the like serving as a computer in motor control device 303 executing a computer program stored in memory.

[0061] First, in step S800, the advance angle / power rate control unit 308 determines whether the target speed has been updated. If the target speed has been updated, the process proceeds to step S801, where it is determined whether the vehicle is currently stopped. If it is determined in step S801 that the vehicle is currently stopped, the process calculates an initial target advance angle and power rate from the target speed in step S802, i.e., selects the calculated initial target advance angle and power rate, and ends the flow of FIG. 8.

[0062] If the answer is No in step S800 or step S801, the current advance angle and power rate are not changed, that is, the current advance angle and power rate are selected, and the flow of FIG. 8 ends.

[0063] The target speed is calculated from the deviation D1 between the current position and the target position and the target time t1 required to move to the target position using the following equation (2). Target speed = deviation Dl / target time t1 Equation (2)

[0064] 9 is a flowchart illustrating an example of the processing performed by the lead angle / power rate control unit in step S711. Note that the operation of each step in the flowchart in FIG. 9 is performed sequentially by a CPU or the like serving as a computer in the motor control device 303 executing a computer program stored in memory.

[0065] In the flowchart of FIG. 9, feedback control of the lead angle and power rate of the drive waveform is performed using the target lead angle and power rate selected in the target lead angle / power rate selection process in step S710.

[0066] That is, first, in step S900, a drive counter value is generated by adding a target lead angle to the position detection counter value. Next, in step S901, the slope of the target position counter value is set to the target speed, and the slope of the position detection counter value is set to the actual speed. Here, step S901 functions as a first control step that controls the position of the first drive member so that it follows the first target position.

[0067] In step S902, it is determined whether the speed difference, which is the difference between the target speed set in step S901 and the actual speed, is equal to or less than a predetermined threshold value D2. If step S902 returns No, that is, if it is determined that there is a speed difference greater than D2, the process proceeds to step S903, where an advance angle / power rate search process is executed to find the target advance angle and power rate.

[0068] Next, the process proceeds to step S904, where the target advance angle is added to the position detection counter value to generate a drive counter value, and then the flow of Fig. 9 ends. On the other hand, if the determination in step S902 is Yes, the speed is not changed and the flow of Fig. 9 ends.

[0069] Fig. 10 is a flowchart illustrating an example of target position counter value generation processing for the first zoom lens 102 according to an embodiment of the present invention. Note that the operations of the steps in the flowchart in Fig. 10 are performed sequentially by a CPU or the like serving as a computer of the motor control device 303 executing a computer program stored in memory. Note that the processing in Fig. 10 is repeatedly executed by the target position setting unit 306 separately from the flow shown in Fig. 7.

[0070] First, in step S1000, the target position setting unit 306 acquires the target speed of the first zoom lens 102. In this embodiment, a designated zoom speed from among a plurality of predetermined zoom speeds is acquired as the target speed.

[0071] Next, the process proceeds to step S1001, where a target position counter value for the first zoom lens 102 is generated from the target speed of the first zoom lens 102 acquired in step S1000.

[0072] Here, step S1001 functions as a first target position generation step for generating a first target position to be a movement target of the first driving member (first zoom lens) based on the target speed of the first driving member. After that, the process returns to step S1000, and the flow of FIG. 10 is repeatedly executed.

[0073] 11 is a flowchart illustrating an example of a target position determination process for the second zoom lens 103 according to an embodiment of the present invention. Note that the operation of each step in the flowchart in FIG. 11 is performed sequentially by a CPU or the like serving as a computer of the motor control device 303 executing a computer program stored in a memory.

[0074] The flow in Fig. 11 shows an example of a processing flow that is performed based on the target position counter value generated in step S1001 in Fig. 10. The processing in Fig. 11 is executed separately from the flow shown in Fig. 7, and is repeatedly executed by the target position setting unit 306 together with the flow in Fig. 10.

[0075] First, in step S1100, the difference between the target position counter value and the actual position counter value of the first zoom lens 102 is calculated. Next, in step S1101, it is determined whether the calculated difference is equal to or smaller than a threshold value D3. The threshold value D3 is calculated from the allowable circle of confusion and the amount of influence that the second zoom lens 103 has on the in-focus position. However, it may also be determined based on, for example, an image magnification obtained from optical information.

[0076] If it is determined in step S1101 that the difference is equal to or smaller than the threshold value D3, then in step S1102, a target position counter value for the second zoom lens 103 is generated from the target position counter value (first target position) for the first zoom lens 102. That is, in step S1102, when the difference between the first target position and the actual position of the first driving member is equal to or smaller than the threshold value, the target position setting unit 306 generates the second target position based on the first target position. Then, the process returns to step S1000 in Fig. 10, and the flow in Fig. 10 is executed again.

[0077] Fig. 12 is a diagram showing an example of the positional relationship between the first zoom lens 102 and the second zoom lens 103 according to an embodiment of the present invention. In Fig. 12, 1200 indicates an example of the positional relationship between the first zoom lens 102 and the second zoom lens 103 determined from optical design information for obtaining a desired angle of view.

[0078] That is, 1200 indicates the position of the second zoom lens 103 on the vertical axis corresponding to the position of the first zoom lens 102 shown on the horizontal axis. In this embodiment, the positional relationship shown in FIG. 12 is stored in advance in memory as, for example, table data or a function formula.

[0079] Therefore, in step S1102, for example, the target position 1202 of the second zoom lens corresponding to the target position 1201 of the first zoom lens 102 can be obtained based on the table data or function formula of the positional relationship as shown in Figure 12 stored in memory.

[0080] On the other hand, if it is determined in step S1101 that the position difference is greater than the threshold value D3, the process proceeds to step S1103. In step S1103, a target position 1204 of the second zoom lens 103 is determined from the actual position 1203 of the zoom lens 102 based on the table data or function of the positional relationship as shown in FIG.

[0081] That is, in step S1103, when the difference between the first target position and the actual position of the first driving member is greater than the threshold value, the target position setting unit 306 generates a second target position based on the actual position of the first driving member. After that, the process returns to step S1000 in Fig. 10, and the flow in Fig. 10 to Fig. 11 is executed again.

[0082] Here, in steps S1102 and S1103, the target position setting unit 306 functions as a second target position generation step in which a second target position that serves as a movement target for the second driving member is generated in accordance with the actual position or the first target position of the first driving member.

[0083] As described above, in the embodiment of the present invention, the target position counter value of the first zoom lens 102 is generated from the zoom speed, as shown in Fig. 10. Furthermore, the target position counter value of the second zoom lens is generated from the actual position or target position counter value (first target position) of the first zoom lens 102, as shown in Fig. 11. Therefore, it is possible to realize linked drive with reduced speed disturbance.

[0084] Furthermore, according to the above embodiment, each lens is controlled without being affected by variations in the speed of other lenses, thereby controlling the lenses at ideal positions, reducing noise and improving zoom tracking accuracy.

[0085] The present invention has been described above in detail based on its preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications and combinations of the above embodiments are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0086] For example, in the above embodiment, the first driving member is a first zoom lens that performs zooming by moving in the optical axis direction, and the second driving member is a second zoom lens that assists zooming in conjunction with the first lens. However, the first driving member and the second driving member do not have to be zoom lenses, and may be, for example, a first lens and a second lens, respectively.

[0087] It may also be used to generate a target position for a focus lens that corrects changes in focus position in response to movement of a zoom lens. That is, the first lens may be a first zoom lens that performs zooming by moving in the optical axis direction, and the second lens may be a focus lens that corrects movement of the focus position in conjunction with the first lens.

[0088] Furthermore, the control device of the above embodiment may be applied to the control of a pan / tilt-capable camera platform, an automobile, a robot arm, etc. In other words, the drive member to be driven by the control device of the above embodiment is not limited to a lens, and may be anything. In that case, the first drive member and the second drive member are each drive members to be driven separately.

[0089] The present invention also includes those that realize the functions of the above embodiments using, for example, at least one processor such as a CPU, memory, or circuit (for example, ASIC). Also, multiple processors may be used to perform distributed processing.

[0090] In order to realize some or all of the control in the above embodiments, a computer program that realizes the functions of the above embodiments may be supplied to a motor control device or the like via a network or various storage media. The computer (or CPU, MPU, etc.) in the motor control device or the like may then read and execute the program. In this case, the program and the storage medium storing the program constitute the present invention. The present invention also includes the following combinations.

[0091] (Configuration 1) A control device comprising: a first target position generating means for generating a first target position to be a movement target of a first driving member based on a target speed of the first driving member; a first control means for controlling the position of the first driving member so that it follows the first target position; a second target position generating means for generating a second target position to be a movement target of a second driving member in accordance with the actual position of the first driving member or the first target position; and a second control means for controlling the position of the second driving member so that it follows the second target position.

[0092] (Configuration 2) The control device according to Configuration 1, wherein the second target position generating means generates the second target position based on the actual position when a difference between the first target position and the actual position of the first driving member is greater than a threshold value.

[0093] (Configuration 3) The control device according to configuration 1 or 2, characterized in that the second target position generation means generates the second target position based on the first target position when a difference between the first target position and the actual position of the first driving member is equal to or less than a threshold value.

[0094] (Configuration 4) A control device described in any one of configurations 1 to 3, characterized in that the first driving member is a first lens, and the second driving member is a second lens different from the first lens.

[0095] (Configuration 5) The control device described in Configuration 4, wherein the first lens is a first zoom lens that performs zooming by moving in the optical axis direction, and the second lens is a second zoom lens that assists zooming in conjunction with the first lens.

[0096] (Configuration 6) The control device described in Configuration 4, characterized in that the first lens is a first zoom lens that performs zooming by moving in the optical axis direction, and the second lens is a focus lens that corrects movement of the focal position in conjunction with the first lens.

[0097] (Method) A control method comprising: a first target position generation step of generating a first target position to be a movement target of a first driving member based on a target speed of the first driving member; a first control step of controlling the position of the first driving member to follow the first target position; a second target position generation step of generating a second target position to be a movement target of a second driving member in accordance with the actual position of the first driving member or the first target position; and a second control step of controlling the position of the second driving member to follow the second target position.

[0098] (Program) A computer program for controlling each means of the control device according to any one of configurations 1 to 6 by a computer. [Explanation of symbols]

[0099] 101...Fixed lens 102...The first zoom lens 103...Second zoom lens 201...Stepping motor 202...Rotation axis 203... Rack 204...Moving member 205...PI (Photointerrupter) 206... Shade 207...Phase detection magnet 208...Hall sensor (Hall-Ch0) 209...Hall sensor (Hall-Ch1) 303...Motor control device 304 AD converter 305...Encoder 306‥‥Target position setting section 307. Coordinate origin setting section 308...Advance angle / power rate control section 309...Drive waveform generation unit 310...Motor driver

Claims

1. a first target position generating means for generating a first target position to be a movement target of the first driving member based on a target speed of the first driving member; a first control means for controlling the position of the first drive member so that the first drive member follows the first target position; a second target position generating means for generating a second target position to be a movement target of a second driving member in accordance with the actual position of the first driving member or the first target position; a second control means for controlling the position of the second drive member so that the second drive member follows the second target position; A control device comprising:

2. 2. The control device according to claim 1, wherein the second target position generating means generates the second target position based on the actual position when a difference between the first target position and the actual position of the first drive member is greater than a threshold value.

3. 2. The control device according to claim 1, wherein the second target position generating means generates the second target position based on the first target position when a difference between the first target position and the actual position of the first drive member is equal to or smaller than a threshold value.

4. the first driving member is a first lens; 2. The control device according to claim 1, wherein the second driving member is a second lens different from the first lens.

5. the first lens is a first zoom lens that performs zooming by moving in the optical axis direction, 5. The control device according to claim 4, wherein the second lens is a second zoom lens that assists zooming in conjunction with the first lens.

6. the first lens is a first zoom lens that performs zooming by moving in the optical axis direction, 5. The control device according to claim 4, wherein the second lens is a focus lens that corrects movement of a focal position in conjunction with the first lens.

7. a first target position generating step of generating a first target position to be a movement target of the first driving member based on a target speed of the first driving member; a first control step of controlling the position of the first drive member so that the first drive member follows the first target position; a second target position generating step of generating a second target position to be a movement target of a second driving member in accordance with the actual position of the first driving member or the first target position; a second control step of controlling the position of the second drive member so that the second drive member follows the second target position; A control method comprising:

8. A computer program for controlling each means of the control device according to any one of claims 1 to 6 by a computer.

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