Imaging device

Abstract

This imaging device comprises: a camera head in which a pitch axis, a yaw axis, and a roll axis are set; a turning mechanism which pans and tilts the camera head; a gyro sensor which is mounted on the camera head and detects angular velocities about the pitch axis, the yaw axis, and the roll axis; and a control unit which performs vibration correction of a captured image on the basis of the angular velocities detected by the gyro sensor. The control unit converts the rotational angle or rotational velocity of the camera head into the angular velocity of each of the pitch axis, the yaw axis, and the roll axis to acquire a turning operation-derived component. For each of the pitch axis, the yaw axis, and the roll axis, the control unit calculates a vibration-derived component by subtracting the turning operation-derived component from the angular velocity detected by the gyro sensor. The control unit performs the vibration correction of the captured image on the basis of the vibration-derived components.

Description

Imaging device

[0001] The present disclosure relates to an imaging device.

[0002] For example, Patent Document 1 discloses an imaging device having a pan function and a tilt function.

[0003] Japanese Patent Application Laid-Open No. 2005-283274

[0004] Incidentally, in the case of the imaging device described in Patent Document 1, there is a possibility of "image blur" occurring due to vibrations transmitted to the imaging device from the outside, or due to vibrations of the camera head caused by panning or tilting the camera. "Image blur" refers to a state in which the subject appears blurred in the captured image, i.e., the subject appears with unclear contours.

[0005] Therefore, an object of the present disclosure is to suppress image blur in an imaging device having a pan function and a tilt function.

[0006] In order to solve the above-described problems, according to one aspect of the present disclosure, there is provided an imaging device comprising: a camera head having a pitch axis, a yaw axis, and a roll axis; a rotation mechanism for panning and tilting the camera head; a rotation drive unit for driving the rotation mechanism; an image sensor mounted on the camera head and having a light receiving surface orthogonal to an imaging direction; a gyro sensor mounted on the camera head for detecting angular velocities around the pitch axis, the yaw axis, and the roll axis; and a control unit for performing vibration correction of a captured image based on the angular velocities detected by the gyro sensor, wherein the control unit converts the rotation angle or rotation speed of the camera head rotated by the rotation mechanism into angular velocities around the pitch axis, the yaw axis, and the roll axis, respectively, to obtain a rotation motion-derived component; calculates a vibration-derived component by subtracting the rotation motion-derived component from the angular velocities detected by the gyro sensor for each of the pitch axis, the yaw axis, and the roll axis; and performs vibration correction of the captured image based on the vibration-derived component.

[0007] According to the present disclosure, it is possible to suppress image blur in an imaging device having a pan function and a tilt function.

[0008] a perspective view of an imaging device according to an embodiment of the present disclosure; a front view and partial perspective view of the imaging device; a cross-sectional view of a pan direction rotation unit; an enlarged view of area A shown in FIG. 3; a diagram showing an example of a light receiving surface of a first scale of a first rotary encoder; a diagram showing an example of a light receiving surface of a second scale of a second rotary encoder; a block diagram showing a control system of the imaging device related to a first rotation angle detection device; a conceptual diagram of two errors included in an absolute rotation angle detected based on output signals of a first and second sensors; a flowchart showing the flow of a first process executed by a control unit; a diagram showing an example of an output signal of a first sensor; a diagram showing an example of an output signal of a first phase calculation unit of the control unit; a diagram showing an example of an output signal of a first interpolation output accumulation unit; 12. Flowchart showing the flow of a third process executed by the control unit. Diagram for explaining setting of an interpolated cumulative value of a first sensor based on a second sensor. Flowchart showing the flow of a fourth process executed by the control unit. Conceptual diagram of linearity correction. Block diagram showing a control system related to vibration correction in an imaging device. Flowchart of a process for calculating angular velocity around each axis of a camera head caused by a rotation operation. Flowchart of a process for vibration correction. Block diagram showing a control system related to vibration correction in an imaging device according to another embodiment. Flowchart of a process for calculating angular velocity around each axis of a camera head caused by a rotation operation in an imaging device according to another embodiment.

[0009] Hereinafter, embodiments will be described with reference to the drawings. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in independent claims will be described as optional components.

[0010] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Furthermore, in each figure, substantially the same configuration is assigned the same reference numeral, and duplicate explanations may be omitted or simplified. Furthermore, even when the same object is illustrated in each figure, the scale may be changed for convenience.

[0011] Furthermore, in this specification, terms indicating the relationship between elements, such as coincidence, equality, and parallelism, terms indicating the shape of elements, such as plate-like and rectangular, as well as numerical values ​​and numerical ranges, are not expressions that only express the strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] FIG. 1 is a perspective view of an imaging device according to an embodiment of the present disclosure, and FIG. 2 is a front view and a partial perspective view of the imaging device.

[0014] 1 and 2 , an imaging device 10 according to this embodiment has a pan function and a tilt function. Specifically, the imaging device 10 includes a camera head 12 that captures images, an arm 14 that rotatably supports the camera head 12, and a base 16 that rotatably supports the arm 14. A rotation center line CA of the arm 14 extends in a direction perpendicular to the extension direction of a rotation center line CB of the camera head 12. The camera head 12 pans when the arm 14 rotates about the rotation center line CA relative to the base 16. The camera head 12 tilts when the camera head 12 rotates about the rotation center line CB relative to the arm 14.

[0015] As shown in FIG. 2, the imaging device 10 includes a first rotation angle detection device 20A for detecting the absolute rotation angle of the arm 14 that pans relative to the base 16, and a second rotation angle detection device 20B for detecting the absolute rotation angle of the camera head 12 that tilts relative to the arm 14.

[0016] 3 is a cross-sectional view of the first rotation angle detection device, and FIG. 4 is an enlarged view of an area A shown in FIG.

[0017] The first rotation angle detection device 20A includes first and second bearings 24, 26 that support a rotation shaft 22 connected to the arm 14, and first and second rotary encoders 28, 30. The second rotation angle detection device 20B is substantially the same as the first rotation angle detection device 20A except that the rotation shaft of the object of rotation angle detection is connected to the camera head 12, and therefore a description thereof will be omitted.

[0018] The rotation shaft 22 is a member that extends in the direction of the rotation center line CA and rotates around the rotation center line CA. In this embodiment, the rotation shaft 22 also serves as a drive shaft that rotates the arm 14, as will be described in detail later.

[0019] The first and second bearings 24, 26 support the rotary shaft 22 rotatably about the rotation center line CA. The first and second bearings 24, 26 are arranged at an interval in the direction in which the rotary shaft 22 extends.

[0020] The first and second rotary encoders 28 and 30 are optical rotary encoders for detecting the rotation angle of the rotary shaft 22 .

[0021] The first rotary encoder 28 includes a first scale 32 attached to the rotary shaft 22, and a first sensor 34. The first scale 32 is an annular substrate through which the rotary shaft 22 passes and is supported by the rotary shaft 22. This causes the first scale 32 to rotate together with the rotary shaft 22. The first sensor 34 is an optical sensor composed of, for example, a light-emitting element and a light-receiving element, and irradiates light toward the first scale 32 and receives light reflected from the first scale 32.

[0022] The second rotary encoder 30 includes a second scale 36 attached to the rotary shaft 22, and a second sensor 38. The second scale 36 is an annular substrate through which the rotary shaft 22 passes and is supported by the rotary shaft 22. This causes the second scale 36 to rotate together with the rotary shaft 22. The second sensor 38 is an optical sensor composed of, for example, a light-emitting element and a light-receiving element, and irradiates light toward the second scale 36 and receives light reflected from the second scale 36.

[0023] The first and second scales 32 and 36 are made from a circular substrate such as polyethylene terephthalate, and have light receiving surfaces 32 a and 36 a that receive light from the first and second sensors 34 and 38 , respectively.

[0024] Fig. 5 is a diagram showing an example of a light receiving surface of a first scale of a first rotary encoder, and Fig. 6 is a diagram showing an example of a light receiving surface of a second scale of a second rotary encoder.

[0025] As shown in Figures 5 and 6, a plurality of reflective portions R are provided on the light receiving surfaces 32a, 36a of the first and second scales 32, 36, respectively, aligned at intervals in the circumferential direction CD (i.e., the rotation direction of the rotary shaft 22). Note that in Figures 5 and 6, the reflective portions R are indicated by hatching, and non-reflective portions that are not reflective portions R are indicated by white paint. The reflective portions R are provided on the substrate by evaporating a highly reflective material, for example, a metal material such as aluminum, onto the substrate. The non-reflective portions are provided on the substrate by applying a low-reflective material, for example, an ink with low reflectivity, to the substrate.

[0026] 5 and 6, a reflection pattern formed by a plurality of reflection portions R arranged in the circumferential direction CD is formed on the first and second light receiving surfaces 32a, 36a of the first and second scales 32, 36. Specifically, the first and second scales 32, 36 have reflection patterns that are different from each other.

[0027] 5, the first light receiving surface 32a of the first scale 32 has a periodic pattern. Specifically, the first light receiving surface 32a has a plurality of reflective portions R that are periodically arranged in the circumferential direction CD. That is, on the first scale 32, the distance between adjacent reflective portions R is constant. Therefore, the first rotary encoder 28 that uses the first scale 32 is an encoder for detecting a so-called relative rotation angle (amount of rotation).

[0028] As shown in FIG. 6 , the second light receiving surface 36a of the second scale 36 has a non-periodic pattern. Specifically, the second light receiving surface 36a has a plurality of pattern areas PA(0) to PA(5) divided into areas aligned in the circumferential direction CD. The example second scale 36 shown in FIG. 6 has a pattern area PA(0) in an angular range of 0° to 60°, a pattern area PA(1) in an angular range of 60° to 120°, a pattern area PA(2) in an angular range of 120° to 180°, a pattern area PA(3) in an angular range of 180° to 240°, a pattern area PA(4) in an angular range of 240° to 300°, and a pattern area PA(5) in an angular range of 300° to 360°.

[0029] Each pattern area has a different reflection pattern. Specifically, in the reflection pattern of each pattern area, multiple reflection portions R are arranged non-periodically in the circumferential direction CD so as to differ from the other pattern areas. That is, in the second scale 36, the distance between adjacent reflection portions R is not constant. Therefore, the second scale 36 is an encoder for detecting a so-called absolute rotation angle. Note that the number of pattern areas each having a different reflection pattern is not limited to six. The higher the required resolution, the greater the number of pattern areas. For example, the resolution of the second rotary encoder 30 can be increased by dividing the light receiving surface into multiple regions arranged in the radial direction and then dividing each region into multiple pattern areas arranged in the circumferential direction.

[0030] The first sensor 34 emits light toward the light-receiving surface 32a of the first scale 32 and receives the light reflected by the reflecting portions R of the light-receiving surface 32a. Based on this received light, the first sensor 34 detects the reflecting portions R. Based on the count number of the detected reflecting portions R and the angle between adjacent reflecting portions R, the relative rotation angle of the rotary shaft 22, i.e., the amount of rotation, can be determined.

[0031] The second sensor 38 emits light toward the light-receiving surface 36a of the second scale 36 and receives the light reflected by the reflecting portions R of the light-receiving surface 32a. The reflecting portions R are detected based on this received light. Furthermore, a pattern area is detected (identified) based on the detection timing of each of the multiple reflecting portions R when the rotation shaft 22 is rotated. The absolute rotation angle of the rotation shaft 22, i.e., the absolute angle range, can be determined based on the detected pattern area.

[0032] The reason for using the first rotary encoder 28 for detecting the relative rotation angle and the second rotary encoder 30 for detecting the absolute rotation angle is to detect the absolute rotation angle of the rotating shaft 22 with high resolution in a short time without increasing the size of the imaging device 10.

[0033] To explain, it is possible to detect the absolute rotation angle of the camera head 12 with high resolution using only the first rotary encoder 28. For example, this is possible by providing a reflective portion indicating the origin, a so-called Z phase. However, for example, when the power of the imaging device 10 is turned off and then restarted, a time-consuming return-to-origin operation must be performed. For example, there are cases where the rotation shaft 22 needs to be rotated one full rotation. Therefore, the absolute rotation angle of the rotation shaft 22 cannot be detected in a short time using only the first rotary encoder 28.

[0034] Furthermore, by increasing the number of pattern areas with different reflection patterns on the light receiving surface 36a of the second scale 36 of the second rotary encoder 30, the absolute angle range of the pattern areas can be reduced, i.e., the resolution of the detected rotation angle of the second rotary encoder can be improved. This makes it possible to detect the absolute rotation angle of the rotating shaft 22 with high resolution. However, increasing the number of pattern areas increases the size of the second scale 36, which in turn increases the size of the first rotation angle detection device 20A. As a result, the imaging device 10 also increases in size.

[0035] Therefore, in this embodiment, a first rotary encoder 28 for detecting the relative rotation angle (amount of rotation) and a second rotary encoder 30 for detecting the absolute rotation angle (absolute rotation angle range) are used in combination. For example, the absolute rotation angle of the rotating shaft 22 at restart is determined by first rotating the rotating shaft 22 until the second sensor 38 of the second rotary encoder 30 detects the origin of one of the multiple pattern areas (e.g., the boundary of the pattern area). The number of reflective portions R detected by the first sensor 34 of the first rotary encoder 28 is counted until this origin is detected. As a result, the absolute rotation angle of the rotating shaft 22 at restart can be detected with high resolution based on the absolute rotation angle corresponding to the origin of the pattern area detected by the second sensor 38 and the relative rotation angle (amount of rotation) corresponding to the count number of reflective portions R detected by the first sensor 34. In this case, the rotating shaft 22 only needs to be rotated by the angle range of the pattern area at most, and the absolute rotation angle of the rotating shaft 22 can be determined in a short time.

[0036] Naturally, in this case, the resolution of the first rotary encoder 28 needs to be higher than the resolution (i.e., the rotation angle range of the pattern area) of the second rotary encoder 30. In other words, the angle between adjacent reflective portions R on the first scale 32 of the first rotary encoder 28 needs to be smaller than the rotation angle range of the pattern area on the second scale 36 of the second rotary encoder 30.

[0037] In order to detect the absolute rotation angle of the rotating shaft 22 with high accuracy using the two rotary encoders 28, 30 in this manner, the first and second scales 32, 36 are disposed between the first and second bearings 24, 26 in the extension direction of the rotating shaft 22, as shown in Figures 3 and 4. With this arrangement, the first and second bearings 24, 26 function as sealing members that prevent dust from approaching the first and second scales 32, 36. This prevents dust from adhering to the first and second light receiving surfaces 32a, 36a of the first and second scales 32, 36. As a result, the first and second sensors 34, 38 can normally receive light reflected from the reflecting portions R of the first and second scales 32, 36, maintaining the accuracy with which the first and second rotary encoders 28, 30 detect the rotation angle of the rotating shaft 22.

[0038] Furthermore, in this embodiment, the first and second scales 32, 36 are provided on the rotating shaft 22 so that the first and second light receiving surfaces 32a, 36a face each other across a gap in the extension direction of the rotating shaft 22. That is, the first light receiving surface 32a of the first scale 32 does not face the first bearing 24. At the same time, the second light receiving surface 36a of the second scale 36 does not face the second bearing 26. This further prevents dust from adhering to the first and second light receiving surfaces 32a, 36a of the first and second scales 32, 36.

[0039] Furthermore, in this embodiment, the first and second sensors 34, 38 are disposed between the first and second light receiving surfaces 32a, 36a of the first and second scales 32, 36, which face each other at a distance. As a result, the first scale 32 is present between the first sensor 34 and the first bearing 24, and the presence of the first scale 32 prevents dust from adhering to the first sensor 34. Similarly, the second scale 36 is present between the second sensor 38 and the second bearing 26, and the presence of the second scale 36 prevents dust from adhering to the second sensor 38. By preventing dust from adhering to the first and second sensors 34, 38, the first and second sensors 34, 38 can normally emit light to predetermined positions on the first and second scales 32, 36 and can normally receive light reflected from the first and second scales 32, 36.

[0040] Furthermore, in this embodiment, the first and second sensors 34, 38 are mounted on a sensor substrate 40 that is disposed between the light receiving surfaces 32a, 36a of the first and second scales 32, 36. Specifically, the first sensor 34 is provided on a first surface 40a of the sensor substrate 40 that faces the first light receiving surface 32a of the first scale 32 across a gap. The second sensor 38 is provided on a second surface 40b of the sensor substrate 40 that faces the second light receiving surface 36a of the second scale 36 across a gap. This eliminates the need to provide the first and second sensors 34, 38 on separate sensor substrates. As a result, the first rotation angle detection device 20A is more compact than if a sensor substrate were provided for each of the first and second sensors 34, 38.

[0041] So far, we have explained the structure of the imaging device 10, particularly the first rotation angle detection device 20 A. From here, we will explain the control system related to the first rotation angle detection device 20 A of the imaging device 10.

[0042] FIG. 7 is a block diagram showing a control system of an imaging device related to the first rotation angle detection device.

[0043] 7 shows a control system of the imaging device associated with the first rotation angle detection device 20 A. The control system associated with the second rotation angle detection device 20 B is substantially the same as the control system associated with the first rotation angle detection device 20 A, and therefore a description thereof will be omitted.

[0044] In this embodiment, the imaging device 10 includes a motor 102 that rotates a rotating shaft 22 connected to the arm 14, a reduction mechanism 104 that drives and connects the motor 102 and the rotating shaft 22, a drive circuit 106 that controls the rotation of the motor 102, and a control unit 200 that controls the drive circuit 106.

[0045] In this embodiment, the control unit 200 is configured, for example, with a circuit board, at least one processor mounted on the circuit board, and a storage device such as a memory mounted on the circuit board. The processor operates in accordance with a program stored in the storage device, causing the processor to perform various functions, such as a first phase calculation unit 202 described later.

[0046] The control unit 200 causes the drive circuit 106 to rotate the motor 102, whereby the rotation of the motor 102 is transmitted to the rotating shaft 22 via the speed reducer 104. The rotation angle of the rotating shaft 22 is detected by the first and second rotary encoders 28, 30. The first rotary encoder 28 outputs a signal corresponding to the detection timing of the reflective portion R to the control unit 200. The second rotary encoder 30 also outputs a signal corresponding to the pattern area to the control unit 200. The control unit 200 detects (calculates) the absolute rotation angle of the rotating shaft 22, as described above, based on the output signal from the first sensor 34 of the first rotary encoder 28 and the output signal from the second sensor 38 of the second rotary encoder 30.

[0047] Furthermore, in this embodiment, the imaging device 10 is configured to correct the absolute rotation angle of the rotating shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38 of the first and second rotary encoders 28, 30. This is because the calculated absolute rotation angle may contain two errors.

[0048] FIG. 8 is a conceptual diagram showing two errors contained in the absolute rotation angle detected based on the output signals of the first and second sensors.

[0049] As shown in Figure 8(a), there may be a case where linearity does not exist between the actual absolute rotation angle of the rotation shaft 22 and the absolute rotation angle of the rotation shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38. Furthermore, as shown in Figure 8(b), when viewed in the extension direction of the rotation shaft 22, the origin of, for example, pattern area PA(0) of the actual second scale 36 may be shifted from the position where it should be on the first scale 32 (naturally, the origins of the other pattern areas are also shifted).

[0050] These phenomena are caused by a coaxial error between the first scale 32 of the first rotary encoder 28 and the second scale 36 of the second rotary encoder 30. The "coaxial error" referred to here refers to a deviation of the centers C1, C2 of the first and second scales 32, 36 from the rotation center line CA of the rotary shaft 22, which is caused by manufacturing errors within the tolerances of the first and second scales 32, 36 and the rotary shaft 22, as well as assembly errors therein. The dashed line in Figure 8(a) indicates the case where there is linearity between the actual absolute rotation angle and the detected absolute rotation angle.

[0051] Due to such coaxial error, the absolute rotation angle of the rotating shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38 contains a linearity error and a phase error as errors with respect to the actual absolute rotation angle of the rotating shaft 22. That is, the deviation between the solid line and the broken line shown in Figure 8(a) corresponds to the linearity error, and the deviation of the origin shown in Figure 8(b) corresponds to the phase error.

[0052] In order to reduce such linearity error and phase error, the absolute rotation angle of the rotary shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38 is corrected. The control by the control unit 200 for this purpose will now be described.

[0053] 9 is a flowchart showing the flow of a first process executed by the control unit. The first process is an initial adjustment process for correcting a phase error included in the absolute rotation angle of the rotating shaft 22 detected based on the output signals of the first and second sensors 34, 38. The coaxial error differs among the multiple imaging devices 10 produced. Therefore, the imaging device 10 is configured to be able to appropriately correct the absolute rotation angle of the rotating shaft 22.

[0054] 9, first, in step S1, the control unit 200 causes the drive circuit 106 to drive the motor 102. As a result, the motor 102 rotates the rotary shaft 22 via the speed reducer mechanism 104.

[0055] In the next step S2, the control unit 200 detects the phase difference between the first sensor 34 and the second sensor 38. To do so, the control unit 200 acquires the output signal of the first sensor 34 and the output signal of the second sensor 38.

[0056] Specifically, first, the first phase calculation unit 202 in the control unit 200 acquires the output signal of the first sensor 34 .

[0057] Fig. 10A shows an example of an output signal from the first sensor. Fig. 10B shows an example of an output signal from the first phase calculation unit of the control unit. Fig. 10C shows an example of an output signal from the first interpolation output accumulator. Fig. 11 is a diagram showing the phase relationship between the output signal from the first sensor and the output signals from the second sensor.

[0058] The first phase calculation unit 202 acquires the two-phase sinusoidal waveform signals with a phase shift of 90° shown in Fig. 10A from the first sensor 34, performs phase calculation (arctangent calculation) on the acquired signals, and outputs a sawtooth waveform signal shown in Fig. 10B.

[0059] As shown in Figure 11, the phase difference detection unit 204 of the control unit 200 acquires the value of the output signal of the first phase calculation unit 202 shown in Figure 10B each time the signal value output from the second sensor 38 changes from a LOW level to a HIGH level, thereby detecting the phase difference between the output signal of the first sensor 34 and the output signal of the second sensor 38, i.e., the phase difference between the first scale 32 and the second scale 36.

[0060] The first interpolation output accumulation unit 206 of the control unit 200 acquires the periodic change in the value of the output signal of the first phase calculation unit 202 shown in Figure 10B as a period counter 206a, acquires the value of the output signal of the first phase calculation unit 202 as an interpolation counter 206b, and outputs the interpolation accumulation value of the first sensor 34 shown by the solid line in Figure 10C.

[0061] In step S3, the phase difference detection unit 204 acquires the absolute rotation angle value detected by the absolute rotation angle acquisition unit 208 based on the output signal of the second sensor 38. Note that the absolute rotation angle value is a position value (an identification number that distinguishes between the multiple pattern areas) corresponding to the acquired information, which is acquired at the timing generated by the acquisition timing generation unit 210 based on the output value of the phase difference detection unit 204 for each bit information (information that identifies each of the multiple pattern areas) indicated by the output signal of the second sensor 38 shown in FIG.

[0062] Note that the output signals of the first sensor 34 and the second sensor 38 shown in Fig. 11 are simplified for ease of understanding, and therefore do not correspond to the first and second scales 32, 36 illustrated in Figs.

[0063] In step S4, the phase difference between the first scale 32 and the second scale 36 corresponding to the absolute rotation angle value acquired in step S3, i.e., the value of the phase difference (phase difference value) between the interpolated cumulative value of the first sensor 34 acquired in step S2 and the absolute rotation angle value of the second sensor 38 acquired in step S3, is stored in the control storage unit 212. This phase difference value will be used in the third process described later. Also, FIG. 11 shows a case where the phase difference between the interpolated cumulative value of the first sensor 34 and the absolute rotation angle value of the second sensor 38 is zero ( FIG. 11( a) ) and a case where the phase difference is 200 degrees ( FIG. 11( b) ).

[0064] The control unit 200 repeatedly executes the processes of steps S1 to S4 described above over the entire 360° rotation angle of the rotating shaft 22 (step S5). As a result, the phase difference between the first scale 32 and the second scale 36 caused by the coaxial error of each of the first scale 32 and the second scale 36 is stored in the control memory unit 212 as a phase difference corresponding to the absolute rotation angle value detectable by the second scale 36. This stored phase difference makes it possible to correct the phase error included in the absolute rotation angle of the rotating shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38.

[0065] FIG. 12 is a flowchart showing the flow of the second process executed by the control unit.

[0066] The second process is an initial adjustment process for correcting the linearity error contained in the absolute rotation angle of the rotary shaft 22 detected (calculated) based on the output signals of the first and second sensors 34 and 38 .

[0067] 12, the control unit 200 includes a linearity error detection unit 214 and a second interpolation output accumulator 216. The control memory unit 212 stores linearity reference waveform data.

[0068] In this embodiment, as shown in FIG. 7 , the linearity reference waveform data is calculated based on the rotation angle of the rotating shaft 108, which rotates at a rotation speed 100 times or more faster than that of the rotating shaft 22. The rotating shaft 108 is directly connected to the motor 102 and is drivingly connected to the rotating shaft 22 via a speed reducer 104. Similarly to the first rotary encoder 28, a third rotary encoder is provided for detecting the relative rotation angle of the rotating shaft 108. A third scale 110 of the third rotary encoder is attached to the rotating shaft 108. A third sensor 112 for detecting the relative rotation angle of the third scale 110 outputs a detection signal similar to that of the first sensor 34 to a second phase calculation unit 218. The second phase calculation unit 218 performs calculation processing similar to that of the first phase calculation unit 202 on the detection signal acquired from the third sensor 112 and outputs the processing result to a second interpolation output accumulator 216. The second interpolation output accumulator 216 performs the same processing as the first interpolation output accumulator 206 on the output from the second phase calculator 218 to obtain waveform data. The waveform data is stored in the control memory 212 as linearity reference waveform data.

[0069] Additionally, since the rotating shaft 108 rotates at a speed 100 times or more faster than the rotating shaft 22, the linearity error is smaller than that of the rotating shaft 22. Therefore, the waveform data output from the second interpolation output accumulator 216 is substantially linear waveform data and can be used as linearity reference waveform data. Note that the third rotary encoder may be optical or magnetic, similar to the first rotary encoder 28.

[0070] 12, in step S10, the control unit 200 causes the drive circuit 106 to drive the motor 102. As a result, the motor 102 rotates the rotary shaft 22 via the reduction mechanism 104.

[0071] In subsequent steps S11 and S12, the linearity error detector 214 of the control unit 200 extracts an interpolation count value from the information output by the first interpolation output accumulator 206. Here, the interpolation count value is the value of the sawtooth waveform signal shown in FIG. 10B (the value obtained as a result of the sawtooth changing stepwise as discrete values). The linearity error detector 214 also detects the timing at which the interpolation value is equal to or greater than the maximum interpolation value divided by 2.

[0072] Fig. 13 is a diagram for providing additional explanation of the second process shown in Fig. 12. The maximum interpolated value is the peak value within one cycle of the waveform signal shown in Fig. 10B. That is, as shown in Fig. 13, the timing at which the interpolated value ≥ maximum interpolated value ÷ 2 is satisfied is the timing at which the latter half of the slope appears within one cycle of the waveform signal shown in Fig. 10B.

[0073] During the continuation of the rotation of the rotary shaft 22, at the timing detected in step S12, in step S13 the linearity error detection unit 214 acquires the output values ​​of the first and second interpolation output accumulators 206, 216. Then, in step S14, the linearity error detection unit 214 detects the timing at which the interpolation value < the maximum interpolation value divided by 2. That is, this is the timing at which the first half of the slope appears in one cycle of the waveform signal shown in FIG. 10B .

[0074] In steps S15 and S16, the linearity error detection unit 214 acquires the output value (interpolated cumulative value) of the first interpolation output accumulator 206 and the output value (interpolated cumulative value) of the second interpolation output accumulator 216 at the sample immediately before the timing detected in step S14 as a linearity correction value corresponding to the interpolated count value and stores it in the control memory unit 212.

[0075] The processes from step S11 to step S16 are repeatedly executed until the linear correction values ​​are acquired and stored over the entire circumference of the first scale 32 (step S17).

[0076] This makes it possible to correct the linearity error contained in the absolute rotation angle of the rotating shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38, which is caused by the coaxial error of the first scale 32.

[0077] Next, a third process will be described for determining, without reproducibility error, the value of the absolute rotation angle, which is the output value from the angle detection value output unit 220 of the control unit 200 during initial operation when the imaging device 10 is powered on and started up. In other words, the third process is a process for reducing phase errors.

[0078] 14 is a flowchart showing the flow of the third process executed by the control unit 200. To execute the third process, the control unit 200 has an interpolated cumulative value linearity corrector 222, an interpolated cumulative value setter 224, and a drive controller 226 in addition to the angle detection value output unit 220.

[0079] The angle detection value output unit 220 outputs the final value of the absolute rotation angle of the rotating shaft 22. That is, it outputs a value obtained by performing linearity correction and phase correction on the absolute rotation angle of the rotating shaft 22 detected (calculated) based on the output signals of the first and second sensors 34, 38. The absolute rotation angle of the rotating shaft 22 after linearity correction output from the interpolated accumulated value linearity correction unit 222 is output to the drive control unit 226. The interpolated accumulated value linearity correction unit 222 corrects (linearity correction) the output value (interpolated accumulated value) of the first interpolated output accumulator 206 so as to reduce the above-mentioned linearity error. The details of this linearity correction will be described later.

[0080] 14, in step S20, the control unit 200 causes the drive circuit 106 to drive the motor 102. As a result, the motor 102 rotates the rotary shaft 22 via the reduction mechanism 104.

[0081] In step S21, the interpolation cumulative value setting unit 224 acquires, from the absolute rotation angle acquisition unit 208, the absolute rotation angle value calculated by the absolute rotation angle acquisition unit 208 based on the output signal of the second sensor 38. Note that the absolute rotation angle value is a position value (an identification number that distinguishes between multiple pattern areas) corresponding to the acquired information, which is acquired at the timing generated by the acquisition timing generation unit 210 based on the output value of the phase difference detection unit 204 for each bit information (information that identifies each of the multiple pattern areas) indicated by the output signal of the second sensor 38 shown in FIG.

[0082] In step S22, the interpolation cumulative value setting unit 224 reads from the control memory unit 212 the phase difference value between the first scale 32 and the second scale 36 that was stored in the control memory unit 212 in step S4 of the first processing shown in Figure 9 and corresponds to the absolute rotation angle value acquired in step S21.

[0083] In step S23, the interpolation accumulation value setting unit 224 determines a period count value from the absolute rotation angle value obtained in step S22, using the value obtained by adding the phase difference value read from the control memory unit 212 in step S22 to the output of the first phase calculation unit as the acquisition timing. For example, if the phase difference of the first scale 32 relative to the second scale 36 is −200 degrees, the absolute value of the period count value is determined at the position where the phase difference is −200 degrees compared to 0 degrees. The period count value is a value obtained by counting the number of periods of the interpolation counter shown in FIG. 10C , and is set in the period counter of the first interpolation output accumulator 206 as the output of the interpolation accumulation value setting unit 224 calculated by the third process, thereby determining the absolute value of the angle detection value output unit 220.

[0084] FIG. 15 is a diagram for explaining setting of the interpolated cumulative value of the first sensor based on the second sensor.

[0085] 15(a) shows a case where there is no phase difference (phase difference value is zero) between the first scale 32 and the second scale 36, and as a result, there is no phase difference between the absolute rotation angle of the rotating shaft detected based on the phase difference calculation output of the first sensor 34 and the output signal of the second sensor 38, and the absolute value of the period count value is determined near the center of the phase difference calculation output of the first sensor 34. Also, FIG. 15(b) shows a case where the phase difference is −200 degrees, and as a result, the absolute value of the period count value is determined near a position shifted −200 degrees from the first sensor 34.

[0086] In step S24, the interpolation accumulation value setting unit 224 determines the final absolute rotation angle value to be output by the angle detection value output unit 220 by setting the period count value determined in step S23 to the period counter 206a of the first interpolation output accumulation unit 206.

[0087] This makes it possible to determine, without reproducibility error, the output value output by the angle detection value output unit 220 of the control unit 220 in the initial operation when the power supply of the imaging device 10 is turned on, i.e., the absolute rotation angle of the rotation shaft 22 after linearity correction output from the interpolated cumulative value linearity correction unit 222. As a result, it is possible to obtain an absolute rotation angle with reduced phase error.

[0088] Next, we will explain the correction of the linearity error contained in the absolute rotation angle of the rotating shaft 22 output by the angle detection value output unit 220, which is caused by the coaxial error of the first scale 32, i.e., the linearity correction performed by the interpolated cumulative value linearity correction unit 222.

[0089] Fig. 16 is a flowchart showing the flow of a fourth process executed by the control unit. The fourth process is a process executed by an interpolated accumulated value linearity correction unit 222 that corrects (linearity correction) the output value (interpolated accumulated value) of the first interpolated output accumulator 206 so as to reduce the above-mentioned linearity error. Fig. 17 is a conceptual diagram of the linearity correction.

[0090] The interpolation cumulative value linearity correction unit 222 corrects the linearity of the output (interpolated cumulative value) of the first interpolation output accumulation unit 206 using the linearity correction value corresponding to the interpolation count value of the first interpolation output accumulation unit 206 stored in the control memory unit 212 in step S16 of the second processing shown in Figure 12.

[0091] 16, in step S30, the interpolation accumulated value linearity correction unit 222 acquires the output value from the first interpolation output accumulator 206. Specifically, the interpolation accumulated value linearity correction unit 222 acquires the period count value and the interpolation count value.

[0092] Next, in step S31, the interpolated accumulated value linearity correction unit 222 reads out a linearity correction value corresponding to the interpolated count value acquired in step S30 from the control storage unit 212. That is, the interpolated accumulated value linearity correction unit 222 acquires, as the linearity correction value, the output value (interpolated accumulated value) of the first interpolated output accumulator 206 and the output value (interpolated accumulated value) of the second interpolated output accumulator 216 corresponding to the interpolated count value.

[0093] In the next step S32, the interpolation cumulative value linearity correction unit 222 corrects the current output value (interpolated cumulative value) output from the first interpolation output accumulator 206 in accordance with the current interpolation count value. Specifically, the current output value output from the first interpolation output accumulator 206 is corrected by multiplying it by a correction gain. The current correction gain can be expressed by Equation 1.

[0094] In Equation 1, n is the current period count value. X is the current interpolation count value. Gn is the current correction gain corresponding to the current period count value n. Yn is the output value of the first interpolation output accumulator 206 corresponding to the current period count value n, which was read out from the control memory unit 212 in step S31. Rn is the output value of the second interpolation output accumulator 216 corresponding to the current period count value n, which was read out from the control memory unit 212 in step S31s. Note that Equation 1 for calculating the correction gain Gn is used when the maximum value of the interpolation counter is 2048.

[0095] In step S32, based on the output value (interpolated accumulated value) of the first interpolated output accumulator 206 that has been linearly corrected in step S31, the angle detection value output unit 220 outputs the corrected final absolute rotation angle of the rotating shaft 22.

[0096] Furthermore, in this embodiment, the imaging device 10 is configured to perform vibration correction to prevent the creation of a captured image in which the subject appears blurred, i.e., to suppress "image blur." The term "image blur" as used herein refers to "image blur" caused by external vibrations transmitted to the imaging device, or "image blur" caused by camera head vibrations caused by panning and tilting the camera. Furthermore, "image blur" refers to a state in which the subject appears blurred in the captured image, i.e., the subject appears with unclear contours.

[0097] FIG. 18 is a block diagram showing a control system related to vibration correction in the imaging device.

[0098] 18, the imaging device 10 includes an imaging element 300, a lens unit 302, and a gyro sensor 304 in its camera head 12. The imaging device 10 also includes a rotation mechanism 306 that pans and tilts the camera head 12.

[0099] The rotation mechanism 306 referred to here is a mechanism including the rotating shaft 22, the reduction mechanism 104, and the motor 106 connected to the arm 14 shown in FIG. 7, a rotating shaft connected to the camera head 12, a motor that rotates and drives the rotating shaft, and a reduction mechanism that drives and connects the motor and the rotating shaft.

[0100] The image sensor 300 is mounted on the camera head 12 and receives light from a subject on its light-receiving surface and converts the received light into a corresponding electrical signal. The electrical signal from the image sensor 300 is output to an image processing unit 308 of the control unit 200. The image processing unit 308 creates a corresponding captured image (image data) based on the electrical signal. As described above, the control unit 200 is composed of, for example, a circuit board, at least one processor mounted on the circuit board, and a storage device such as a memory mounted on the circuit board. The processor operates in accordance with a program stored in the storage device, thereby performing various functions, such as the image processing unit 308 and the drive control unit 315 described below.

[0101] The lens unit 302 is mounted on the camera head 12 so as to be positioned in front of the image sensor 300 and is composed of multiple lenses. Light that passes through the lens unit 302 is incident on the light receiving surface of the image sensor 300. The lens unit 302 includes an anti-vibration lens 310 that can be tilted with respect to the imaging direction F shown in FIG. 1 for vibration correction. The imaging direction F is a direction perpendicular to the light receiving surface of the image sensor 300. The image capturing device 10 also includes an anti-vibration lens driver 312, such as an actuator, that changes the attitude of the anti-vibration lens 310 with respect to the imaging direction F. The anti-vibration lens driver 312 appropriately changes the attitude of the anti-vibration lens 310 in response to vibrations applied to the image capturing device 10, thereby obtaining a captured image in which the subject is not blurred.

[0102] The gyro sensor 304 is mounted on the camera head 12 to detect vibrations of the camera head 12. A pitch axis, a yaw axis, and a roll axis are set in advance in the camera head 12. The roll axis extends parallel to the imaging direction F. The yaw axis extends parallel to the rotation center line CA of the camera head 12. The pitch axis extends parallel to the rotation center line CB of the camera head 12. The gyro sensor 304 detects angular velocities ωy, ωp, and ωr around the pitch axis, yaw axis, and roll axis of the camera head 12 as vibrations.

[0103] The turning mechanism 306 is controlled by a drive control unit 315 via a turning drive unit 314. The turning drive unit 314 here includes the drive circuit 106 shown in FIG.

[0104] From here, the vibration correction performed by the imaging device 10 will be described.

[0105] First, the angular velocities ωy, ωp, ωr around the yaw axis, pitch axis, and roll axis of the camera head 12 detected by the gyro sensor 304 include vibration-derived components ωy1, ωp1, ωr1 caused by vibrations transmitted to the imaging device 10 from the outside, and rotation-movement-derived components ωy2, ωp2, ωr2 caused by the rotation of the imaging device 10 (panning and tilting).

[0106] To perform vibration correction, it is necessary to use only the vibration-derived components ωy1, ωp1, and ωr1 contained in the angular velocities ωy, ωp, and ωr about the yaw axis, pitch axis, and roll axis detected by the gyro sensor 304. In other words, if vibration correction (attitude control of the vibration-proof lens 310) is performed using the angular velocities ωy, ωp, and ωr about each axis detected by the gyro sensor 304 as they are, an unnatural captured image may be obtained. Therefore, in this embodiment, the imaging device 10 is configured to perform vibration correction using the angular velocities ωy1, ωp1, and ωr1 obtained after removing the turning motion-derived components ωy2, ωp2, and ωr2 from the angular velocities ωy, ωp, and ωr about each axis detected by the gyro sensor 304. The components and directions for this purpose are described below.

[0107] FIG. 19 is a flowchart of a process for calculating the angular velocity around each axis of the camera head caused by a turning operation.

[0108] First, in step S40, the drive control unit 315 of the control unit 200 determines drive command information for the rotation mechanism 306. The drive command information is, for example, the rotation angle and rotation speed of the pan operation of the camera head 12. If a change occurs in the command speed and command angle from the drive control unit 315, the process proceeds to the next step.

[0109] In step S41, the drive control unit 315 of the control unit 200 performs a speed profile calculation (acceleration / deceleration calculation) corresponding to the command speed and command angle, and calculates a command angular speed at the current time.

[0110] In step S42, the drive control unit 315 of the control unit 200 outputs the command angular velocity calculated in step S41 to the turning drive unit 314. The turning drive unit 314 controls the turning mechanism 306 so that the turning mechanism 306 performs an operation corresponding to the command angular velocity.

[0111] In step S43, the drive control unit 315 of the control unit 200 outputs the command angular velocity calculated in step S41 to the angular velocity conversion unit 316.

[0112] In step S44, the angular velocity conversion unit 316 of the control unit 200 converts the command angular velocity acquired from the drive control unit 315 in step S43 into angular velocities ωy2, ωp2, and ωr2 about the yaw axis, pitch axis, and roll axis of the camera head 12. For example, if the command angular velocity is the angular velocity of a pan operation (i.e., the angular velocity about the rotation center line CA), the angular velocity is converted into angular velocities ωy2, ωp2, and ωr2 about the yaw axis, pitch axis, and roll axis of the camera head 12.

[0113] In step S45, it is determined whether the camera head 12 has reached the commanded speed or angle. If the commanded speed or angle has not been reached, the processes from step S42 to step S44 are repeated.

[0114] Next, the vibration correction process will be described.

[0115] FIG. 20 is a flowchart of the vibration correction process.

[0116] As shown in FIG. 20, in step S50, the turning angular velocity compensation unit 318 of the control unit 200 acquires the angular velocities ωy, ωp, and ωr of the camera head 12 about the yaw axis, pitch axis, and roll axis detected by the gyro sensor 304.

[0117] In step S51, the rotation angular velocity compensation unit 318 of the control unit 200 acquires from the angular velocity conversion unit 316 the angular velocities ωy2, ωp2, and ωr2 around the yaw axis, pitch axis, and roll axis of the camera head 12 that were converted from the command angular velocity by the angular velocity conversion unit 316 in step S44 shown in FIG. 19.

[0118] In step S52, the turning angular velocity compensation unit 318 of the control unit 200 subtracts the angular velocities ωy2, ωp2, and ωr2 about the yaw axis, pitch axis, and roll axis of the camera head 12, which were obtained in step S51 and converted from the command angular velocity by the angular velocity conversion unit 316, from the angular velocities ωy, ωp, and ωr about the yaw axis, pitch axis, and roll axis of the camera head 12, which were obtained in step S50 and detected by the gyro sensor 304. As a result of this subtraction, vibration-derived components ωy1, ωp1, and ωr1 contained in the angular velocities ωy, ωp, and ωr about the yaw axis, pitch axis, and roll axis detected by the gyro sensor 304 are extracted.

[0119] In step S53, the vibration correction angle calculation unit 320 of the control unit 200 acquires the vibration-derived components ωy1, ωp1, and ωr1 of the angular velocities ωy, ωp, and ωr extracted by the turning angular velocity compensation unit 318 in step S52, and calculates a shake correction value.

[0120] In step S54, vibration correction control is executed based on the shake correction value calculated in step S53. Specifically, the vibration-proof lens driver 312 changes the attitude of the vibration-proof lens 310 based on the shake correction value. That is, the vibration-proof lens driver 312 changes the attitude of the vibration-proof lens 310 in response to vibrations transmitted from the outside to the imaging device 10 so that the image of the subject that has passed through the vibration-proof lens 310 is formed on the light-receiving surface of the image sensor 300 without shaking. This makes it possible to obtain a captured image in which the subject is not blurred.

[0121] Note that vibration correction of a captured image can be achieved by methods other than changing the orientation of the vibration-proof lens. For example, the image sensor 300 may be displaced in a direction perpendicular to the optical axis of the lens unit 302 via an actuator or the like in response to vibrations transmitted from outside to the image capture device 10. For example, if the light receiving surface of the image sensor 300 perpendicular to the imaging direction F is sectional, the camera head 12 may be equipped with a first actuator that shifts (translates) the image sensor 300 in the longitudinal direction of the light receiving surface and a second actuator that shifts (translates) the image capture device 300 in the lateral direction of the light receiving surface. The control unit 200 then controls the first and second actuators to shift the image sensor 300 by an amount based on the vibration-derived components ωy1, ωp1, and ωr1 so that the subject appears blur-free in the captured image. Instead of these mechanical vibration correction methods, electronic vibration correction may be performed to correct the captured image itself, in which the subject appears blurred.

[0122] Furthermore, in the present embodiment, the rotational movement-derived components ωy2, ωp2, and ωr2 contained in the angular velocities ωy, ωp, and ωr about the yaw axis, pitch axis, and roll axis of the camera head 12 detected by the gyro sensor 304 are calculated by converting the command angular velocity shown in Fig. 19. The rotational movement-derived components ωy2, ωp2, and ωr2 can also be calculated by another method.

[0123] Fig. 21 is a block diagram showing a control system related to vibration correction in an image pickup apparatus according to another embodiment, and Fig. 22 is a flowchart showing a process for calculating angular velocities around each axis of a camera head caused by a rotational movement in an image pickup apparatus according to another embodiment.

[0124] As shown in Fig. 21, the control system of an imaging device according to another embodiment is generally the same as the control system of imaging device 10 according to the above-described embodiment shown in Fig. 18. Furthermore, the process for calculating the angular velocity around each axis of the camera head caused by a turning operation according to another embodiment is also generally the same as the process shown in Fig. 19. Therefore, the other embodiment will be described, focusing on the differences.

[0125] 21 , an imaging device according to another embodiment includes a rotation angle detection unit 322 that detects the rotation angle of a rotation mechanism 306, and an angular velocity calculation unit 324 that calculates an angular velocity based on the rotation angle detected by the rotation angle detection unit 322. Note that the rotation angle detection unit 322 referred to here is the encoder of each of the first and second rotation angle detection devices 20A and 20B shown in FIG.

[0126] As shown in FIG. 22, the processing from steps S60 to S62 is the same as the processing from steps S40 to S42 of the processing shown in FIG. 19 according to the above embodiment.

[0127] In step S63 , the rotation angle detection unit 322 detects the rotation angle of the camera head 12 .

[0128] In step S64, the angular velocity calculation unit 324 of the control unit 200 calculates the angular velocity from the amount of change per unit time in the rotation angle of the camera head 12 detected by the rotation angle detection unit 322 in step S63.

[0129] In step S65, the angular velocity conversion unit 316 of the control unit 200 converts the angular velocities calculated by the angular velocity calculation unit 324 in step S64 into angular velocities ωy2, ωp2, and ωr2 around the respective axes of the camera head 12.

[0130] The process of step S66 is the same as the process of step S45 of the process shown in FIG. 19 according to the above embodiment.

[0131] According to the present embodiment described above, it is possible to suppress image blur in an imaging device equipped with pan and tilt functions. Specifically, it is possible to suppress image blur caused by vibrations transmitted to the imaging device from the outside and image blur caused by vibrations of the camera head caused by panning and tilting movements.

[0132] Although the embodiments of the present disclosure have been described above with reference to the above-mentioned embodiments, the embodiments of the present disclosure are not limited to these.

[0133] For example, in the above-described embodiment, the first and second rotary encoders 28, 30 are optical and reflective encoders. That is, the first and second scales 32, 36 reflect light from the first and second sensors 34, 38 toward the first and second sensors 34, 38. However, the embodiments of the present disclosure are not limited to this. For example, the first and second rotary encoders may be optical and transmissive encoders. That is, the multiple reflective portions in the first and second scales are replaced with slits, and the first and second sensors are composed of a light-emitting element that emits light toward the first and second scales and a light-receiving element that receives light that has passed through the multiple slits in the first and second scales.

[0134] In other words, an imaging device according to an embodiment of the present disclosure is, in a broad sense, an imaging device comprising: a camera head having a pitch axis, a yaw axis, and a roll axis; a rotation mechanism for panning and tilting the camera head; a rotation drive unit for driving the rotation mechanism; an imaging element mounted on the camera head and having a light receiving surface perpendicular to an imaging direction; a gyro sensor mounted on the camera head for detecting angular velocities around the pitch axis, the yaw axis, and the roll axis; and a control unit for performing vibration correction of a captured image based on the angular velocities detected by the gyro sensor, wherein the control unit converts the rotation angle or rotation speed of the camera head rotated by the rotation mechanism into angular velocities around the pitch axis, the yaw axis, and the roll axis to obtain a rotation motion-derived component, subtracts the rotation motion-derived component from the angular velocities detected by the gyro sensor for each of the pitch axis, the yaw axis, and the roll axis to calculate a vibration-derived component, and performs vibration correction of the captured image based on the vibration-derived component.

[0135] As described above, the above-described embodiments have been described as examples of the technology of the present disclosure. For this purpose, drawings and detailed descriptions are provided. Therefore, the components described in the drawings and detailed descriptions may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the above-described technology. Therefore, the fact that these non-essential components are described in the drawings or detailed descriptions should not be interpreted as immediately indicating that these non-essential components are essential.

[0136] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. can be made within the scope of the claims or their equivalents.

[0137] The present disclosure is applicable to an imaging device having a pan function and a tilt function.

Claims

1. An imaging device comprising: a camera head having set pitch, yaw, and roll axes; a rotation mechanism for panning and tilting the camera head; a rotation drive unit for driving the rotation mechanism; an image sensor mounted on the camera head and having a light receiving surface perpendicular to the imaging direction; a gyro sensor mounted on the camera head for detecting angular velocities around the pitch, yaw, and roll axes; and a control unit for performing vibration correction of captured images based on the angular velocities detected by the gyro sensor, wherein the control unit converts the rotation angle or rotation speed of the camera head rotated by the rotation mechanism into angular velocities around the pitch, yaw, and roll axes to obtain components derived from rotational motion; calculates vibration-derived components for each of the pitch, yaw, and roll axes by subtracting the rotational motion-derived components from the angular velocities detected by the gyro sensor; and performs vibration correction of captured images based on the vibration-derived components.

2. The imaging device of claim 1, wherein the control unit acquires the rotational motion-derived component by converting the command angular velocity output to the rotation drive unit into angular velocities for the pitch axis, the yaw axis, and the roll axis.

3. The imaging device of claim 1, further comprising: a first encoder that detects the rotation angle of the panning operation of the camera head; and a second encoder that detects the rotation angle of the tilting operation of the camera head, wherein the control unit acquires the component derived from the rotational operation by converting the rotation angles detected by the first and second encoders into angular velocities of the pitch axis, the yaw axis, and the roll axis, respectively.

4. The imaging device according to claim 1, further comprising: an anti-vibration lens mounted on the camera head so as to be positioned in front of the imaging element; and an anti-vibration lens drive unit that changes the attitude of the anti-vibration lens, wherein the control unit changes the attitude of the anti-vibration lens based on the vibration-derived component.

5. The imaging device according to claim 1, further comprising an actuator mounted on the camera head for shifting the imaging element in a direction perpendicular to the imaging direction, the actuator shifting the imaging element by an amount of shift based on the vibration-derived component.

6. The imaging device according to claim 1, wherein the roll axis extends parallel to the imaging direction, the yaw axis extends parallel to the rotation center line of the camera head during panning, and the pitch axis extends parallel to the rotation center line of the camera head during tilting.

Images