Imaging apparatus

Abstract

To provide an imaging apparatus capable of suppressing the image disturbance when the orientation of an imaging unit is changed.SOLUTION: An imaging apparatus 1 comprises: a base 20; a housing 22 that is fixed on the base; a first rotation drive mechanism that rotates the base about a base rotation axis P; an imaging unit 24 that is accommodated in the housing and includes an imaging element therein; a connecting part 26 that connects the imaging unit to the housing so that the imaging unit can rotate about at least a first unit rotation axis inside the housing; and a driving part 42 that moves the imaging unit inside the housing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an imaging device. [Background technology]

[0002] Conventionally, cameras have been known that have the function of changing the orientation of the imaging unit horizontally (pan) and vertically (tilt) (see, for example, Patent Document 1). In recent years, pan and tilt functions have become increasingly required for cameras used in meetings and presentations, and for security purposes, in particular, to track and capture a subject or switch between subjects. To achieve such pan and tilt functions, it is common to rotate the imaging unit by driving a stepping motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4521941 specification Summary of the Invention [Problem to be solved by the invention]

[0004] However, when such a stepping motor starts or completes its operation, backlash can occur due to the resolution and detent torque of the stepping motor, which can cause image blurring and distortion when a panning or tilting operation starts or completes.

[0005] The present invention has been made in consideration of the problems of the conventional technology, and has an object to provide an imaging device that can suppress image distortion when the orientation of the imaging unit is changed. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an imaging device capable of suppressing image distortion when changing the orientation of an imaging unit. The imaging device includes a base, a housing fixed on the base, a first rotation drive mechanism that rotates the base about a first base rotation axis, an imaging unit accommodated inside the housing and including an imaging element, a connection part that connects the imaging unit to the housing so that the imaging unit can rotate inside the housing about at least the first unit rotation axis, and a drive part that moves the imaging unit inside the housing. [Effects of the Invention]

[0007] According to the present invention, the imaging unit can be rotated relative to the housing around the first unit rotation axis so as to cancel out displacement of the imaging unit within the housing caused by changing the orientation of the imaging unit, thereby preventing distortion of images captured by the imaging unit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view schematically showing an imaging device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a front view schematically showing the imaging device shown in FIG. [Figure 3] FIG. 3 is a partial cross-sectional plan view schematically showing the housing of the imaging device shown in FIG. 2 and its internal structure. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of an imaging device according to the present invention will be described in detail below with reference to FIGS. 1 to 3. In FIGS. 1 to 3, identical or corresponding components are denoted by the same reference numerals, and redundant description will be omitted. In addition, in FIGS. 1 to 3, the scale and dimensions of each component may be exaggerated, and some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used merely to distinguish components from one another, and do not represent a particular order or ranking.

[0010] FIG. 1 is a plan view schematically illustrating an imaging device 1 according to one embodiment of the present invention, and FIG. 2 is a front view. As shown in FIGS. 1 and 2, the imaging device 1 includes a base 2, a rotation stage 3 mounted on the base 2 so as to be rotatable about an axis P, and a stepping motor 4 for rotating the rotation stage 3. A worm gear 5 is attached to the rotation axis of the stepping motor 4. A rotor 7 is mounted on the base 2 so as to be rotatable about an axis 6. Gears (not shown) are provided on the outer peripheries of the rotation stage 3 and the rotor 7, respectively, and the gear of the rotation stage 3 and the gear of the rotor 7 mesh with each other. The gear of the rotor 7 also meshes with the worm gear 5. Therefore, when the stepping motor 4 is driven, the rotation stage 3 rotates about the axis P via the worm gear 5 and the rotor 7, as shown by the arrow in FIG. 1.

[0011] As shown in Fig. 2, the rotation stage 3 is provided with a pair of support walls 10, 11 extending from the rotation stage 3 in the +Z direction. These support walls 10, 11 are provided with shaft holes (not shown), into which a shaft 15 extending in the X direction is inserted. The shaft 15 is rotatable relative to the support walls 10, 11. The support wall 10 is also provided with another shaft hole, into which a shaft 18 extending in the X direction is inserted. A two-stage gear including two gears 21, 23 is attached to this shaft 18.

[0012] A rectangular plate-shaped base 20 is attached to the shaft 15, and this base 20 is disposed between the support walls 10 and 11. A housing 22 is fixed to this base 20. As described above, the base 20 can be rotated about the axis P by rotating the rotary stage 3 by driving the stepping motor 4. In this way, the stepping motor 4, worm gear 5, rotor 7, and rotary stage 3 in this embodiment function as a first rotation drive mechanism that rotates the base 20 about the axis P (first base rotation axis).

[0013] A stepping motor 30 is provided on the rotary stage 3, and a gear 31 is attached to the rotary shaft of the stepping motor 30. The gear 31 meshes with a double-gear gear 21. A gear 16 is attached to the shaft 15, and a double-gear gear 23 meshes with the gear 16. Therefore, when the stepping motor 30 is driven, the shaft 15 and the base 20 rotate about the axis Q via the gear 31, the double gear (gears 21 and 23), and the gear 16. In this way, the stepping motor 30, the gear 31, the double gear (gears 21 and 23), and the gear 16 in this embodiment function as a second rotation drive mechanism that rotates the base 20 about the axis Q (second base rotation axis).

[0014] 3 is a partial cross-sectional plan view schematically showing the housing 22 and its internal structure. As shown in FIG. 3, an imaging unit 24 including a lens and an imaging element is housed inside the housing 22, and the imaging unit 24 is connected to the housing 22 by a connecting portion 26.

[0015] The connection portion 26, which may take the form of a gimbal frame, connects the imaging unit 24 to the housing 22 so that the imaging unit 24 can rotate within the housing 22 around one or more unit rotation axes. In this embodiment, the connection portion 26 includes a connection frame 27, a first bearing 28A that connects the connection frame 27 to the housing 22 so that the imaging unit 24 can rotate around a first unit rotation axis (e.g., the X-axis), and a second bearing 28B that connects the imaging unit 24 to the connection frame 27 so that the imaging unit 24 can rotate around a second unit rotation axis (e.g., the Z-axis). The first unit rotation axis and the second unit rotation axis are preferably perpendicular to each other. The connection portion 26 allows the imaging unit 24 to be held within the housing 22 so that the imaging unit 24 can rotate around the first unit rotation axis and / or the second unit rotation axis. While the second bearing 28B is shown in FIG. 3 for simplification, the actual second bearing 28B is provided in a location not shown in FIG. 3.

[0016] The imaging device 1 also has a first drive unit 42 that moves the imaging unit 24 inside the housing 22 along a first drive direction (e.g., the Y direction). The first drive unit 42 is, for example, a voice coil motor, and includes a yoke 51 and a magnet 52 disposed on one side of the imaging unit 24, and a coil 53 disposed inside the housing 22. The magnet 52 has, for example, different magnetic poles in the Y direction, and the coil 53 is disposed in a position facing the yoke 51 and the magnet 52. A magnetic sensor 58 that detects changes in the magnetic field caused by the magnet 52 is disposed inside the coil 53, and the output of the magnetic sensor 58 is used to detect the position (posture) of the imaging unit 24. For example, a Hall element utilizing the Hall effect or an MR element utilizing the magnetoresistance effect can be used as such a magnetic sensor.

[0017] In addition to the first drive section 42, the imaging device 1 has a second drive section (not shown) that moves the imaging unit 24 along a second drive direction (e.g., the Y direction). The configuration of this second drive section is similar to that of the first drive section 42, but it is provided, for example, on a side surface adjacent to the side surface of the imaging unit 24 on which the first drive section 42 is provided. A magnetic sensor similar to the magnetic sensor 58 is also provided inside the coil of this second drive section.

[0018] By energizing the coil 53 of the first drive unit 42, a force along the first drive direction is applied to the imaging unit 24 by the magnetic field generated by the coil 53 and the magnet 52. Similarly, by energizing the coil of the second drive unit, a force along the second drive direction is applied to the imaging unit 24 by the magnetic field generated by the coil and the magnet. In this embodiment, the imaging unit 24 is held by the connection unit 26 so as to be rotatable about the first unit rotation axis and the second unit rotation axis. Therefore, by driving the first drive unit 42 and the second drive unit to apply a force to the imaging unit 24, the imaging unit 24 can be rotated about the first unit rotation axis and the second unit rotation axis.

[0019] 1, a first sensor 60 that detects the acceleration or angular velocity of the base 20 is provided on the base 20. Furthermore, as shown in Fig. 3, a second sensor 62 that detects the acceleration or angular velocity of the imaging unit 24 is provided inside the imaging unit 24. These sensors 60, 62 may be an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, or the like.

[0020] As shown in FIG. 1, the imaging device 1 includes a control unit 70 that controls the operation of the stepping motors 4, 30, the first drive unit 42, and the second drive unit, and this control unit 70 is connected to the stepping motors 4, 30, the first drive unit 42, the second drive unit, the magnetic sensor 58 in the first drive unit 42, the magnetic sensor in the second drive unit, and sensors 60, 62.

[0021] The control unit 70 can perform a panning operation on the imaging unit 24 on the base 20 by driving the stepping motor 4 and rotating the rotary stage 3 about the axis P. The control unit 70 can also perform a tilting operation on the imaging unit 24 on the base 20 by driving the stepping motor 30 and rotating the shaft 15 about the axis Q.

[0022] When performing a panning or tilting operation (in other words, changing the orientation of the imaging unit 24), the control unit 70 receives output signals from the sensors 60, 62 and controls the energization of the coils of the first drive unit 42 and the second drive unit based on the acceleration or angular velocity of the imaging unit 24, and rotates the imaging unit 24 about the first unit rotation axis and / or the second unit rotation axis relative to the housing 22 so as to cancel out displacement of the imaging unit 24 within the housing 22 caused by the panning or tilting operation. This makes it possible to prevent distortion in images captured by the imaging unit 24.

[0023] Furthermore, the control unit 70 may receive output signals from the magnetic sensor 58 (third sensor) in the first drive unit 42 and the magnetic sensor (third sensor) in the second drive unit to detect the position (attitude) of the imaging unit 24, and control the first drive unit 42 and the second drive unit in consideration of the current attitude of the imaging unit 24. This allows for more precise control of the movement of the imaging unit 24, thereby more effectively suppressing image distortion.

[0024] The imaging device 1 in this embodiment includes two rotation drive mechanisms that rotate the base 20, but may include only one of the rotation drive mechanisms. Also, the sensor 62 may be omitted, and the first drive unit 42 and the second drive unit may be controlled based on the acceleration or angular velocity of the base 20 detected by the sensor 60.

[0025] When the base 20 is rotated around two base rotation axes by two rotation drive mechanisms as in this embodiment, in order to cancel out displacement of the imaging unit 24 due to rotation around these base rotation axes, the imaging unit 24 needs to be held rotatably around the two unit rotation axes by the connection part 26, but the two base rotation axes and the two unit rotation axes do not necessarily need to be parallel to each other. On the other hand, when the imaging device 1 includes only one rotation drive mechanism and the connection part 26 holds the imaging unit 24 rotatably around one unit rotation axis, it is preferable that the base rotation axis and the unit rotation axis of the rotation drive mechanism be parallel to each other in order to effectively suppress image distortion.

[0026] As described above, the imaging device according to the present invention can employ the following configuration. [Configuration 1] With the base, a housing fixed on the base; a first rotation drive mechanism that rotates the base around a first base rotation axis; an imaging unit accommodated inside the housing and including an imaging element therein; a connection portion that connects the imaging unit to the housing so that the imaging unit can rotate around at least a first unit rotation axis inside the housing; a drive unit that moves the imaging unit inside the housing; An imaging device comprising:

[0027] [Configuration 2] a first sensor that detects an acceleration or angular velocity of the base; a control unit configured to control operation of the drive unit based on an output of the first sensor; The imaging device of configuration 1 further comprises:

[0028] [Configuration 3] Further, a second sensor is provided to detect an acceleration or an angular velocity of the imaging unit. The control unit is configured to control the operation of the drive unit based on outputs of the first sensor and the second sensor. Imaging device of configuration 2.

[0029] [Configuration 4] a third sensor configured to detect a position of the imaging unit relative to the housing; the control unit is configured to control the operation of the drive unit based on outputs of the first sensor, the second sensor, and the third sensor. Imaging device of configuration 3.

[0030] [Configuration 5] 5. The imaging device of any one of configurations 1 to 4, further comprising a second rotation drive mechanism that rotates the base about a second base rotation axis different from the first base rotation axis.

[0031] [Configuration 6] 6. The imaging device of any one of configurations 1 to 5, wherein the connection portion is configured so that the imaging unit can rotate inside the housing about a second unit rotation axis that is perpendicular to the first unit rotation axis.

[0032] [Configuration 7] 7. The imaging device according to claim 1, wherein the first base rotation axis and the first unit rotation axis are parallel to each other.

[0033] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0034] 1. Imaging device 3 Rotation stage 4 stepping motors 20 base 22 Housing 24 Imaging unit 26 Connection 30 Stepping motor 42 drive unit (first drive unit) 51 York 52 Magnet 53 Coil 58 Magnetic sensor (third sensor) 60 Sensor (First Sensor) 62 Sensor (Second Sensor) 70 Control Unit P axis (first base rotation axis) Q axis (second base rotation axis)

Claims

1. With the base, a housing fixed on the base; a first rotation drive mechanism that rotates the base around a first base rotation axis; an imaging unit accommodated inside the housing and including an imaging element therein; a connection portion that connects the imaging unit to the housing so that the imaging unit can rotate about at least a first unit rotation axis inside the housing; a drive unit that moves the imaging unit inside the housing; An imaging device comprising:

2. a first sensor for detecting an acceleration or angular velocity of the base; a control unit configured to control operation of the drive unit based on an output of the first sensor; The imaging device of claim 1 further comprising:

3. a second sensor for detecting an acceleration or an angular velocity of the imaging unit; the control unit is configured to control the operation of the drive unit based on outputs of the first sensor and the second sensor. The imaging device according to claim 2 .

4. a third sensor for detecting a position of the imaging unit relative to the housing; the control unit is configured to control the operation of the drive unit based on outputs of the first sensor, the second sensor, and the third sensor. The imaging device according to claim 3 .

5. The imaging device according to claim 1 , further comprising a second rotation drive mechanism that rotates the base about a second base rotation axis different from the first base rotation axis.

6. The imaging device according to claim 1 , wherein the connection portion is configured so that the imaging unit can rotate inside the housing about a second unit rotation axis that is perpendicular to the first unit rotation axis.

7. The imaging device according to claim 1 , wherein the first base rotation axis and the first unit rotation axis are parallel to each other.

Images