Imaging unit and imaging device

Abstract

The present invention provides an imaging device that eliminates the need for center of gravity adjustment when changing the imaging unit's orientation between horizontal and vertical shooting positions. [Solution] The imaging unit 103 has a lens section 109 and an imaging sensor 108, and has a first screw hole 105a for fixing it to the mounting base 102 in a horizontal position, and a second screw hole 105b for fixing it in a vertical position, which is rotated 90 degrees counterclockwise around the imaging optical axis from the horizontal position. When the center of gravity of the imaging unit 103 in the horizontal position is the first center of gravity, the center of gravity in the vertical position is the second center of gravity, the point obtained by rotating the first center of gravity 90 degrees clockwise is the first virtual point, and the point obtained by rotating the first center of gravity 90 degrees counterclockwise is the second virtual point, on the projection plane viewed from the direction of the imaging optical axis with the imaging optical axis horizontal, the distance between the first center of gravity and the second center of gravity is smaller than the distance between the first center of gravity and the first virtual point, and also smaller than the distance between the first virtual point and the second virtual point.

Description

Technical Field

[0001] The present invention relates to an imaging unit and an imaging device.

Background Art

[0002] An imaging sensor mounted on an imaging device such as a digital camera or a digital video camera generally has a rectangular shape in which the length of one opposing side is longer than the length of the other opposing side. Video shooting with such an imaging device is generally performed in "horizontal shooting" for shooting a landscape-oriented video.

[0003] However, in recent years, smartphones have become widespread, and "vertical shooting" for shooting portrait-oriented videos is widely performed on smartphones. Affected by this, for an imaging device capable of panning and tilting rotation of an imaging unit by driving an actuator, a configuration that can selectively perform horizontal shooting and vertical shooting has been demanded.

[0004] As an example of a configuration for such a requirement, there is a configuration that enables the attachment of an imaging unit to a pan-tilt rotating table to be changed between a horizontal shooting posture and a vertical shooting posture. In such a configuration, if the center of gravity position of the imaging unit moves before and after the posture change, problems such as a change in the driving load of the actuator for performing pan-tilt rotation and an increase in power consumption, and inhibition of smooth driving will occur.

[0005] Therefore, particularly in an imaging device that performs tilt rotation including rotation in a direction against gravity, it is important to keep the distance between the tilt rotation axis and the center of gravity of the imaging unit within a certain range. Therefore, as a method for adjusting the center of gravity of an imaging unit in an imaging device capable of pan rotation and tilt rotation, a center of gravity adjustment mechanism in which a counterweight movable in three axial directions is arranged has been proposed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] In the center of gravity adjustment mechanism disclosed in Patent Document 1, it is necessary to adjust the center of gravity each time the orientation in which the imaging unit is mounted on the pan-tilt rotating table is changed.

[0008] This invention has been made in view of these circumstances, and aims to provide a technology that eliminates the need for center of gravity adjustment when changing the imaging unit between a horizontal and vertical shooting position in an imaging device capable of panning and tilting the imaging unit. [Means for solving the problem]

[0009] The imaging unit according to the present invention is an imaging unit having a lens and an imaging sensor, and comprises a first fixing means for fixing it in a first orientation at a predetermined position, and a second fixing means for fixing it in the predetermined position in a second orientation obtained by rotating the first orientation by 90 degrees in a first direction about the imaging optical axis of the imaging unit, wherein the center of gravity of the imaging unit in the first orientation is the first center of gravity, the center of gravity in the second orientation is the second center of gravity, the point obtained by rotating the first center of gravity by 90 degrees in a second direction opposite to the first direction about the imaging optical axis is the first virtual point, and the point obtained by rotating the first center of gravity by 90 degrees in the first direction about the imaging optical axis is the second virtual point, and on a projection plane viewed from the imaging optical axis direction of the imaging unit with the imaging optical axis parallel to the horizontal direction, the distance between the first center of gravity and the second center of gravity is smaller than the distance between the first center of gravity and the first virtual point, and also smaller than the distance between the first virtual point and the second virtual point. [Effects of the Invention]

[0010] According to the present invention, in an imaging device in which the imaging unit is capable of panning and tilting, it becomes unnecessary to adjust the center of gravity when changing the imaging unit between a horizontal and vertical shooting position. [Brief explanation of the drawing]

[0011] [Figure 1] This is an external perspective view of the PTZ camera according to the first embodiment. [Figure 2] Figure 1 is a block diagram showing the system configuration of the PTZ camera. [Figure 3] Figure 1 is a perspective view of the imaging unit that makes up the PTZ camera. [Figure 4] This is a front view of the imaging module that makes up the PTZ camera. [Figure 5] Figure 4 is a front view illustrating the center of gravity of the imaging module. [Figure 6] Figure 5 shows the relationship between the center of gravity and heavy objects in the imaging module. [Figure 7] This is an exploded perspective view of the imaging unit that makes up a PTZ camera. [Figure 8] This figure shows the configuration and characteristics of the examples and comparative examples. [Figure 9] This is an external perspective view of the PTZ camera according to the second embodiment. [Figure 10] Figure 9 is a perspective view of the imaging unit and lens unit of the PTZ camera. [Figure 11] Figure 9 is an exploded perspective view of the imaging unit that makes up the PTZ camera. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The imaging device according to the present invention is configured to be able to rotate independently in the pan and tilt directions, and is equipped with a zoom-driving lens. In the following description, this will be referred to as a "PTZ camera".

[0013] <First Embodiment> Figure 1 is an external perspective view of a PTZ camera 101 according to the first embodiment. The PTZ camera 101 has an imaging module 104, a head unit 106 that holds the imaging module 104, and a base unit 107 that is fixed during installation. The imaging module 104 has an imaging unit 103 and a fixing base 102 that holds the imaging unit 103. The imaging unit 103 is fixed (screwed) to the fixing base 102 with a screw 105. Note that the fixing of the imaging unit 103 to the fixing base 102 is not limited to screwing, and may be performed by, for example, a slide lock mechanism or a clamp mechanism.

[0014] The head unit 106 and the base unit 107 are configured as a pan-tilt rotation unit that pan-tilt rotates the imaging module 104. That is, the head unit 106 is a tilt rotation unit that holds the fixing base 102 so as to be tilt-rotatable. Therefore, the imaging module 104 fixed to the fixing base 102 can be tilt-rotated with respect to the head unit 106 integrally with the fixing base 102. The base unit 107 is a pan rotation unit that holds the head unit 106 so as to be pan-rotatable. Thereby, the imaging module 104, the fixing base 102, and the head unit 106 are integrated and can be pan-rotated with respect to the base unit 107.

[0015] Figure 1 shows a state where the PTZ camera 101 is in the home position. Here, the X-axis (X direction), Y-axis (Y direction), and Z-axis (Z direction) shown in Figure 1 are defined. The tilt rotation axis of the imaging module 104 is defined as the X-axis, and the pan rotation axis of the imaging module 104 is defined as the Y-axis. That is, the rotation of the imaging module 104 around the X-axis (with the X-axis as the rotation center axis) is tilt rotation, and the rotation around the Y-axis is pan rotation.

[0016] When the PTZ camera 101 is in the home position, an axis orthogonal to the X-axis and the Y-axis is defined as the Z-axis. Regardless of the pan rotation angle and tilt rotation angle of the imaging module 104, the X-axis and the Y-axis are orthogonal to each other, and the X-axis and the Z-axis are also orthogonal to each other. However, the angle formed by the Z-axis and the Y-axis changes depending on the tilt angle of the imaging module 104. When the PTZ camera 101 is in the home position as shown in FIG. 1, the Z-axis and the Y-axis are orthogonal to each other, and the Z-axis coincides with the imaging optical axis of the imaging unit 103.

[0017] Regarding the X direction, Y direction, and Z direction, the direction in which the arrow in FIG. 1 points is defined as the positive direction. In the following description, it is denoted as “+X direction” or “+X side”, etc., and the opposite side (negative direction) is denoted as “-X direction” or “-X side”, etc., respectively. Also, in the state where the PTZ camera is in the home position, the +Z side is defined as the “front side” of the PTZ camera 101, and the opposite side of the front side is defined as the “back side”. In the state when the PTZ camera 101 is viewed from the front side, the “right side”, “left side”, “upper side” and “lower side” of the PTZ camera 101 are defined. That is, the +X side is defined as the right side, the -X side is defined as the left side, the +Y side is defined as the upper side, and the -Y side is defined as the lower side, respectively.

[0018] FIG. 2 is a block diagram showing the system configuration of the PTZ camera 101. The imaging unit 103 constituting the imaging module 104 includes an imaging sensor 108, a lens unit 109, and a video generation unit 113. The lens unit 109 forms an incident light on the imaging surface of the imaging sensor 108. The imaging sensor 108 is, for example, a CMOS sensor, which converts an optical image formed on the imaging surface into an electrical signal and transmits it to the video generation unit 113. The video generation unit 113 generates video data from the electrical signal transmitted from the imaging sensor 108.

[0019] The head unit 106 has a tilt motor 117c, and the tilt rotation of the fixed base 102 (imaging module 104) is performed via a speed reduction mechanism (not shown) by driving the tilt motor 117c.

[0020] The base unit 107 includes a pan motor 117b, a lens drive unit 116a, a tilt drive unit 116c, a pan drive unit 116b, a system control unit 110, a video output terminal 151, an operation input terminal 154, a power supply terminal 156, and a storage medium 158.

[0021] The system control unit 110 is a so-called microcomputer that executes a predetermined program to comprehensively control the operation of each part of the PTZ camera 101. The pan drive unit 116b drives the pan motor 117b according to a command from the system control unit 110, and the pan rotation of the head unit 106 is performed via a reduction mechanism (not shown) by the drive of the pan motor 117b. At this time, the imaging module 104 rotates integrally with the head unit 106. The lens drive unit 116a changes the zoom magnification, focus, and aperture settings of the lens unit 109 according to a command from the system control unit 110. The tilt drive unit 116c drives the tilt motor 117c according to a command from the system control unit 110.

[0022] The video data generated by the video generation unit 113 is transferred to the system control unit 110, and then output from the video output terminal 151 to the video display device 161 connected to the video output terminal 151. The video display device 161 can be an electronic device such as a smartphone with an LCD monitor or LCD panel. The user of the PTZ camera 101 can confirm the subject by displaying the video captured by the PTZ camera 101 on the video display device 161. The communication between the video output terminal 151 and the video display device 161 may be wired or wireless.

[0023] An operating device 162 is connected to the operation input terminal 154, and an operation command corresponding to the operation performed by the operating device 162 is transmitted to the system control unit 110. The system control unit 110 then transmits commands to the lens drive unit 116a, the pan drive unit 116b, and the tilt drive unit 116c in response to the operation command, thereby operating the PTZ camera 101. The operating device 162 can be, for example, an information processing device such as a smartphone or a tablet PC. These information processing devices function as an operating device 162 by launching a predetermined application for operating the PTZ camera 101. The operating device 162 may also be a dedicated input terminal (controller). The communication connection between the operation input terminal 154 and the operating device 162 can be wired or wireless.

[0024] A power supply 164 is connected to the power supply terminal 156, and power is supplied from the power supply 164 to the lens drive unit 116a, pan drive unit 116b, and tilt drive unit 116c via the power supply terminal 156 and the system control unit 110. The power supply 164 can be a commercial power supply (AC / DC adapter) or a battery, and in the case of a battery, it can be built into the base unit 107.

[0025] The storage medium 158 is detachable from the base unit 107 and stores captured video data. However, the storage medium 158 is not always necessary. If the PTZ camera 101 does not have the storage medium 158, it can be configured so that captured video data is transmitted to an external storage device via a communication unit (not shown) and stored there. Instead of the detachable storage medium 158 on the base unit 107, the video display device 161 may have a storage medium that stores video data transmitted from the video output terminal 151.

[0026] Next, we will explain how to change the horizontal shooting orientation (first orientation) and vertical shooting orientation (second orientation) of the PTZ camera 101, or in other words, how to reattach the imaging unit 103 to the mounting base 102 in the PTZ camera.

[0027] Figure 3(a) is a perspective view of the imaging unit 103 viewed from the front and diagonally below, and Figure 3(b) is a perspective view of the imaging unit 103 viewed from the rear and diagonally below. A tally 111 is provided on the front of the imaging unit 103 to inform the subject (person) whether or not imaging is in progress. The tally 111 lights up in a predetermined color (e.g., red or green) when imaging is in progress and turns off when not imaging. The imaging unit 103 is also provided with a first screw hole 105a and a second screw hole 105b on each of its -Y and -X sides at positions that are 90 degrees relative to the imaging optical axis. Screw grooves are formed in the first screw hole 105a and the second screw hole 105b, respectively. A cable 112 for transmitting lens drive control signals and images is routed from the back of the imaging unit 103.

[0028] Figure 4(a) is a front view showing the imaging module 104 in a horizontal orientation, and Figure 4(b) is a front view showing the imaging module 104 in a vertical orientation. In Figure 4, the imaging sensor 108, which is mounted inside the imaging unit 103, is shown by a dashed line. The imaging sensor 108 has a rectangular imaging surface, with a pair of long sides parallel to the tilt rotation axis (X-axis) in the horizontal orientation, and a pair of short sides parallel to the tilt rotation axis in the vertical orientation. The X-axis, which is the tilt rotation axis, and the Y-axis, which is the pan axis, intersect at the center of the imaging sensor 108 on the projection plane viewed from the direction of the imaging optical axis.

[0029] The PTZ camera 101 is characterized by its ability to be used in either a horizontal or vertical orientation. The operation to change the orientation of the PTZ camera 101 is often performed when the PTZ camera 101 is in its home position. Therefore, in the following description, the PTZ camera 101 will be described as being in its home position. Also, for the sake of explanation, the X-axis will be assumed to be parallel to the horizontal direction and the Y-axis to be parallel to the vertical direction.

[0030] As shown in Figure 4(a), in the horizontal orientation, the imaging unit 103 is fixed to the mounting base 102 by screwing a screw 105 into the first screw hole 105a (see Figure 3(a)). By positioning the imaging module 104 in the horizontal orientation, it is possible to capture a horizontally elongated image where the longer side of the imaging sensor 108 is parallel to the horizontal direction.

[0031] Viewing the imaging unit 103 from the front, the imaging unit 103 in the horizontal position is temporarily removed from the mounting base 102, rotated 90 degrees counterclockwise (first direction) around the imaging optical axis, and then reattached to the mounting base 102. As a result, the imaging module 104 is in the vertical position as shown in Figure 4(b). In the vertical position, the imaging unit 103 is fixed to the mounting base 102 by screwing the screw 105 into the second screw hole 105b (see Figure 3(a)). By positioning the imaging module 104 in the vertical position, it is possible to capture a vertically elongated image in which the shorter side of the imaging sensor 108 is parallel to the horizontal direction.

[0032] Installation personnel and users can easily determine whether the PTZ camera 101 is in a horizontal or vertical shooting position by checking whether the tally 111 is on the +Y side (upper side) or the -X side (left side) when viewing the PTZ camera 101 from the subject side (+Z side). In both horizontal and vertical shooting positions, the cable 112 can be routed through the inside of the tilt rotation axis portion 102a of the mounting base 102 to the head portion 106.

[0033] When the orientation of the imaging unit 103 is switched between a horizontal and a vertical shooting orientation, the system control unit 110 switches the control mode for the horizontal shooting orientation (horizontal shooting mode) and the control mode for the vertical shooting orientation (vertical shooting mode) to correspond to the orientation. For example, when the system control unit 110 displays video being shot in a horizontal shooting orientation on a horizontally oriented video display device 161, it displays the video so that the long side of the imaging sensor 108 is parallel to the long side of the display screen, that is, it displays the video to roughly the entire screen. On the other hand, when the system control unit 110 displays video being shot in a vertical shooting orientation on a horizontally oriented video display device 161, it provides non-display areas on the left and right sides of the display screen, and displays the captured video in a vertical orientation in the center so that the long side of the imaging sensor 108 is parallel to the short side of the display screen. In the case of a vertically oriented video display device 161, conversely, when shooting in a horizontal shooting orientation, non-display areas are provided at the top and bottom of the display screen and the video is displayed in the center, while when shooting in a vertical shooting orientation, the video is displayed to roughly the entire screen. Furthermore, the system control unit 110 adds information to the video data of the captured video indicating whether it was shot in a horizontal or vertical orientation. This makes it possible to play back the captured video on the video display device 161 in a manner that matches the aspect ratio of the display screen of the video display device 161.

[0034] Switching between horizontal and vertical shooting modes may be performed, for example, by the user changing the settings via the control unit 162. Alternatively, a gyro sensor may be attached to the imaging unit 103, and the system control unit 110 may automatically switch the control mode based on the direction of gravity detected by the gyro sensor.

[0035] Next, the relationship between the center of gravity of the imaging module 104 in a horizontal orientation and the center of gravity of the imaging module 104 in a vertical orientation will be explained. Figure 5(a) is a front view illustrating the center of gravity of the imaging module 104 in a horizontal orientation. Figure 5(b) is a front view illustrating the center of gravity of the imaging module 104 in a vertical orientation. In Figures 5(a) and (b), the installation positions of the imaging sensor 108, which is located inside the imaging unit 103 that constitutes the imaging module 104, and the first heavy object 121 and the second heavy object 122, which greatly affect the center of gravity of the imaging module 104, are shown by dashed lines. The first heavy object 121 and the second heavy object 122 are relatively large in mass among the structures arranged inside the imaging unit 103. In the following explanation, the terms "heavy objects 121, 122" will be used as appropriate to refer to the first heavy object 121 and the second heavy object 122.

[0036] In an XY coordinate system with the center of the imaging sensor 108 as the origin, the first center of gravity 131 of the imaging module 104 in a horizontal orientation is located in the fourth quadrant, at a distance of Y131 from the Y axis towards the -Y side, as shown in Figure 5(a). On the other hand, the second center of gravity 132 of the imaging module 104 in a vertical orientation is located in the second quadrant, at a distance of Y132 from the X axis, which is the tilt rotation axis, towards the -Y side, as shown in Figure 5(b).

[0037] Figure 5(b) shows the first virtual point 131a, obtained by rotating the first centroid 131 90 degrees clockwise (second direction) around the origin of the XY coordinate system (imaging optical axis). Also in Figure 5(b), the second virtual point 131b is obtained by rotating the first centroid 131 90 degrees counterclockwise (first direction) around the origin of the XY coordinate system (imaging optical axis). The first virtual point 131a and the second virtual point 131b are located at distances Y131a and Y131b from the X axis, respectively.

[0038] Since the distances Y131, 132, Y131a, and Y131b are distances from the X-axis, all shall take positive values regardless of the +Y direction or -Y direction. At this time, the positional relationships of the first centroid 131, the second centroid 132, the first virtual point 131a, and the second virtual point 131b are as follows. That is, by changing from the horizontal shooting posture to the vertical shooting posture, the centroid of the imaging module 104 moves from the first centroid 131 to the second centroid 132. If the amount of movement in the Y-axis direction at this time (the distance between the first centroid 131 and the second centroid 132 in the gravitational direction) is 'D1', the amount of movement D1 is an absolute value, and D1 = |Y131 - Y132|. Also, since the first virtual point 131a is a point obtained by geometrically rotating the first centroid 131 by 90 degrees around the optical axis, if the amount of movement in the Y-axis direction due to this rotational movement is 'D2', then D2 = |Y131 - Y131a|. Similarly, if the amount of movement in the Y-axis direction from the first centroid 131 to the second virtual point 131b is D3, it is represented by |Y131 + Y131b|.

[0039] The feature of this embodiment is that when the posture of the imaging module 104 is changed between the horizontal shooting posture and the vertical shooting posture, the amount of movement of the centroid of the imaging module 104 in the Y direction is smaller than the amount of movement when the imaging module 104 is rotated by 90 degrees geometrically around the imaging optical axis. That is, it is characterized in that the centroid position of the imaging module 104 is designed so that the relationship D1 < D2 and D1 < D3 holds. Thereby, even when switching between the horizontal shooting posture and the vertical shooting posture, the distance from the tilt rotation axis (X-axis) to the centroid does not change significantly. Therefore, the variation in the load on the tilt motor 117c due to the change in posture is small, and it is not necessary for the installer to perform a centroid adjustment operation every time the posture is changed.

[0040] Now, in this embodiment, the centroid position is designed as described above using the heavy objects 121 and 122. Next, the heavy objects 121 and 122 and their arrangement will be described.

[0041] Figure 6(a) is a front view showing the relationship between the main components and the center of gravity when the imaging module 104 is in a horizontal orientation. Figure 6(b) is a front view showing the relationship between the main components and the center of gravity when the imaging module 104 is in a vertical orientation. In Figure 6, as in Figure 5, the installation positions of the imaging sensor 108 and the heavy objects 121 and 122 inside the imaging unit 103 are shown by dashed lines.

[0042] The first centroid 131 and distance Y131 in Figure 6(a), and the second centroid 132 and first virtual point 131a in Figure 6(b) are the same as those shown in Figures 5(a) and (b). The centroid G121 of the first heavy object 121 is assumed to be on the Y axis in the XY coordinate system, and the centroid G122 of the second heavy object 122 is assumed to be on the X axis in the XY coordinate system. The distance in the Y direction from the X axis to the centroid G121 is 'H121', and the distance in the X direction from the Y axis to the centroid G122 is 'H122', and both are assumed to be positive values. Figure 6(a) shows the centroid G102 of the imaging module 104 in the XY coordinate system without heavy objects 121 and 122. The centroid G102 is assumed to be on the Y axis, and the distance in the Y direction from the X axis to the centroid G102 is 'H102'.

[0043] Here, the arrangement of the heavy objects 121 and 122 in the imaging unit 103 will be described. Figure 7(a) is an exploded perspective view of the imaging unit 103. The imaging unit 103 includes a lens unit 201, a bottom cover 202, a top cover 203, a front cover 204, a sensor board 205, an image processing board 206, a tally board 207, and heavy objects 121 and 122.

[0044] The lens unit 201 is constructed by arranging a group of lenses that collect light from the subject side and an actuator that drives the lens group inside an outer wall made of metal. An image sensor 108 (not shown) is mounted on the front of the sensor substrate 205. An LED is mounted on the tally substrate 207, and the subject (person) can see the on / off state of the LED through the light guide part 204L provided on the front cover 204. The first weight 121 is a weight placed between the top surface of the lens unit 201 and the top cover 203. The second weight 122 is a weight placed between the side surface of the lens unit 201 and the inner surface of the top cover 203 and the bottom cover 202. The weights 121 and 122 are preferably heavy objects with a large mass within the small space in which they can be placed, such as dense metal objects, for example, die-cast zinc can be used.

[0045] Figures 7(b) and 7(c) are exploded perspective views showing the group of components forming the exterior of the imaging unit 103 (hereinafter referred to as the "exterior component group") and the main body located inside the exterior, respectively. The fixing direction of the main body to the exterior component group differs between Figures 7(b) and 7(c). That is, in Figure 7(b), the heavy objects 121 and 122 are fixed to the lens unit 201 by screws (not shown), but the fixing of the heavy objects 121 and 122 is not limited to the use of screws, and may also be done using double-sided tape or adhesive. In Figure 7(c), the first heavy object 121 is fixed to the back surface of the top cover 203, and the second heavy object 122 is fixed to the side surface of the lens unit 201. The fixing method is not particularly limited, and screws, double-sided tape, adhesive, etc., can be used. The imaging unit 103 is assembled by first fixing the heavy components 121 and 122, then fixing the bottom cover 202 and top cover 203 to the lens unit 201, and finally fixing the front cover 204 to the bottom cover 202 and top cover 203.

[0046] A bottom hole 201a is formed on the bottom surface of the lens unit 201 at a position opposite to the first screw hole 105a provided in the bottom cover 202. Additionally, a side hole (not shown) is formed on the side surface of the lens unit 201 at a position opposite to the second screw hole 105b provided in the bottom cover 202a or the top cover 203. When the imaging unit 103 is screwed to the mounting base 102 with a screw 105 in a horizontal orientation, the tip of the screw 105 fits into the bottom hole 201a, allowing the imaging unit 103 to be stably fixed to the mounting base 102. The same applies when the imaging unit 103 is screwed to the mounting base 102 in a vertical orientation.

[0047] Alternatively, the first screw hole 105a and the second screw hole 105b may be formed as straight holes without screw grooves, while the bottom hole 201a and the side hole may be formed as screw holes with screw grooves that engage with the screw 105. In this case, for example, when the imaging unit 103 is screwed to the mounting base 102 in a horizontal position using the screw 105, the screw 105 engages with the bottom hole 201a, thereby stably fixing the imaging unit 103 to the mounting base 102. The same applies when the imaging unit 103 is screwed to the mounting base 102 in a vertical position.

[0048] As described above, when the imaging unit 103 is fixed to the mounting base 102 by the screw 105, the heavy objects 121 and 122 are positioned on the surface of the lens unit 201 opposite to the surface where it is fixed to the mounting base 102. As a result, in the horizontal shooting position, the mounting base 102 and the first heavy object 121 are positioned opposite each other across the tilt rotation axis in the imaging module 104. In the vertical shooting position, the mounting base 102 and the second heavy object 122 are positioned opposite each other across the tilt rotation axis in the imaging module 104. In other words, the center of gravity of the imaging module 104 is less likely to move away from the tilt rotation axis.

[0049] Furthermore, it is desirable that the heavy objects 121 and 122 be positioned so as to coincide with the tilt rotation axis on the projection plane viewed from the Y direction, which is the axial direction of the pan rotation axis. This allows the center of gravity of the imaging unit 103 to be positioned near the tilt rotation axis in the direction of the imaging optical axis, thereby reducing the drive load on the tilt drive unit 116c during tilt rotation.

[0050] Furthermore, the heavy objects 121 and 122 are not limited to weights specifically designed for adjusting the center of gravity of the imaging module 104, but may also be relatively large structures among those placed inside the imaging unit 103. For example, filter switching units, lens drive units, signal transmission cables for control signals and video signals, etc., can be used as heavy objects, as long as they can adjust the center of gravity of the imaging module 104.

[0051] Next, examples and comparative examples of the present invention will be described. Figure 8 is a table showing the configurations of Examples 1 and 2 and Comparative Example 1. The center of gravity G102 (see Figure 6(a)) and the mass at the center of gravity G102 are the same for Examples 1 and 2 and Comparative Example 1. Also, the distance H102 from the X-axis to the center of gravity G102 is 60 mm, and the mass m102 at the center of gravity G102 is 550 g.

[0052] In Example 1, in a horizontal shooting position, the distance H121 from the X-axis to the center of gravity G121 of the first heavy object 121 was set to 40 mm, and the mass m121 at the center of gravity G121 was set to 450 g. Similarly, the distance H122 from the Y-axis to the center of gravity G122 of the second heavy object 122 was set to 40 mm, and the mass m122 at the center of gravity G122 was set to 450 g. As a result, the distance Y131 from the X-axis to the first center of gravity 131 is 10.3 mm. In Example 1, when the shooting position is changed to a vertical shooting position, the distance Y132 from the X-axis to the second center of gravity 132 is 10.3 mm, and the distance Y131a from the X-axis to the first virtual point 131a is 12.4 mm.

[0053] In Example 2, in the horizontal shooting posture, the distance H121 from the X-axis to the center of gravity G121 of the first weight 121 was 35 mm, and the mass m121 at the center of gravity G121 was 550 g. Also, the distance H122 from the Y-axis to the center of gravity G122 of the second weight 122 was 50 mm, and the mass m122 at the center of gravity G122 was 600 g. As a result, the distance Y131 from the X-axis to the first center of gravity 131 became 8.1 mm. In Example 2, when changing to the vertical shooting posture, the distance Y132 from the X-axis to the second center of gravity 132 was 1.8 mm, and the distance Y131a from the X-axis to the first virtual point 131a was 17.6 mm.

[0054] In Comparative Example 1, in the horizontal shooting posture, the distance H121 from the X-axis to the center of gravity G121 of the first weight 121 was 40 mm, and the mass m121 at the center of gravity G121 was 550 g. Also, the distance H122 from the Y-axis to the center of gravity G122 of the second weight 122 was 40 mm, and the mass m122 at the center of gravity G122 was 100 g. As a result, the distance Y131 from the X-axis to the first center of gravity 131 became 9.2 mm. In Comparative Example 1, when changing to the vertical shooting posture, the distance Y132 from the X-axis to the second center of gravity 132 was 24.2 mm, and the distance Y131a from the X-axis to the first virtual point 131a was 3.3 mm.

[0055] In the table of FIG. 8 summarizing the above, the movement amount D1 in the Y-axis direction from the first center of gravity 131 to the second center of gravity 132 and the movement amount D2 in the Y-axis direction from the first center of gravity 131 to the first virtual point 131a when changing from the horizontal shooting posture to the vertical shooting posture are shown. In the evaluation column, a circle (〇) is marked when the relationship D1 < D2 is satisfied, and a cross (×) is marked when the relationship D1 ≥ D2 is satisfied. It can be seen that in the examples, it is a circle, and in the comparative examples, it is a cross. That is, in the examples, the movement amount of the center of gravity in the Y direction when changing from the horizontal shooting posture to the vertical shooting posture is smaller than the movement amount when geometrically rotated 90 degrees around the optical axis, and it can be said that the fluctuation of the load on the tilt motor 117c due to the change in posture is small.

[0056] <Second Embodiment> Figure 9(a) is a perspective view of the PTZ camera 301 according to the second embodiment, viewed from diagonally above and in a sideways orientation. For the sake of explanation, as shown in Figure 9(a), the same XYZ axes as those defined for the PTZ camera 101 according to the first embodiment are defined for the PTZ camera 301.

[0057] In the first embodiment, the PTZ camera 101 has an imaging unit 103 that includes a lens unit 109 and an imaging sensor 108. In contrast, the imaging unit of the PTZ camera 301 in the second embodiment has a configuration that allows the lens device to be attached to and detached from the sensor unit equipped with the imaging sensor.

[0058] The PTZ camera 301 includes an imaging module 304, a head portion 306 that holds the imaging module 304, and a base portion 307 that is fixed when installed. The imaging module 304 corresponds to the imaging module 104 of the PTZ camera 101 according to the first embodiment, and generally includes an imaging unit 310 and a mounting base 302 to which the imaging unit 310 is fixed. The imaging unit 310 includes a lens device 315 and a sensor unit 303. The lens device 315 is detachable from the mount portion (not shown) of the sensor unit 303 by a known configuration such as a bayonet engagement. The user of the PTZ camera 301 can take pictures by attaching the lens device 315 with a focal length suitable for the purpose of shooting as needed.

[0059] Figure 9(b) is a perspective view of the PTZ camera 301 viewed from the front and diagonally below, and, as in Figure 9(a), the PTZ camera 301 is in a side-viewing position. The sensor unit 303 is fixed to the mounting base 302 by a screw 305. The mounting base 302 has an elongated hole 302L formed therein with the Z direction as its longitudinal direction, and the mounting position of the screw 305 is variable in the Z direction within the range of the length of the elongated hole 302L. By moving the fixing position of the sensor unit 303 in the direction of the imaging optical axis according to the lens device 315, the center of gravity position of the imaging unit 310 can be adjusted in the direction of the imaging optical axis. This makes it possible to suppress fluctuations in the drive load of the pan motor 117b and maintain high pan rotation performance. Note that the method of fixing the sensor unit 303 to the mounting base 302 is not limited to fixing by a screw 305, as long as the sensor unit 303 can be moved in the direction of the imaging optical axis, and fixing methods using a slide lock mechanism or clamp mechanism may also be used.

[0060] The head unit 306 and the base unit 307 are equivalent to the head unit 106 and base unit 107 of the PTZ camera 101, respectively. That is, the head unit 306 holds the fixed base 302 so that it can tilt and rotate, and the imaging module 304 can tilt and rotate relative to the head unit 306. The base unit 307 holds the head unit 306 so that it can pan and rotate, and the imaging module 304 and the head unit 306 can pan and rotate integrally with respect to the base unit 307. The system configuration of the PTZ camera 301 is the same as the system configuration of the PTZ camera 101 according to the first embodiment (Figure 2), except that the lens device 315 includes the lens unit 109, and therefore the explanation is omitted.

[0061] Figure 10(a) is a perspective view of the sensor unit 303 and lens device 315 viewed from the front and diagonally below, and Figure 10(b) is a perspective view of the sensor unit 303 and lens device 315 viewed from the rear and diagonally below. The sensor unit 303 is provided with a first screw hole 305a and a second screw hole 305b at positions that are 90 degrees relative to each other around the imaging optical axis. More specifically, the first screw hole 305a and the second screw hole 305b are provided on the -Y side and -X side of the sensor unit 303, respectively, when the imaging module 104 is in a side-view position. A cable 312 for transmitting lens drive control signals and images is routed from the back of the sensor unit 303. The cable 312 runs between the side of the sensor unit 303 and the tilt rotation axis of the fixed base 302 to the head unit 306.

[0062] The sensor unit 303 has an imaging sensor (not shown) with a rectangular shape when viewed from the direction of the imaging optical axis. The sensor unit 303 is fixed to the mounting base 302 using the first screw hole 305a and is in a horizontal position, and the sensor unit 303 is fixed to the mounting base 302 using the second screw hole 305b and is in a vertical position.

[0063] The relationship between the center of gravity positions of the imaging module 304 in the horizontal and vertical orientations of the PTZ camera 301 is the same as in the first embodiment. That is, a heavy object is placed inside the sensor unit 303, so that the distance from the tilt rotation axis (X axis) to the center of gravity does not change significantly even when the orientation is changed. The definition of a heavy object is the same as in the first embodiment.

[0064] Figure 11(a) is an exploded perspective view of the sensor unit 303. The sensor unit 303 includes a circuit board unit 323, a front cover 320, a rear cover 324, a first heavy object 321, and a second heavy object 322. As in the description of the first embodiment, the terms "heavy objects 321, 322" will be used as appropriate to refer to the first heavy object 321 and the second heavy object 322.

[0065] The front cover 320 has a lens mount 320a, a first screw hole 305a, and a second screw hole 305b formed therein. The circuit board unit 323 includes an image sensor 108 and an image processing board that generates an image signal from the electrical signal output from the image sensor 108.

[0066] Figure 11(b) is an exploded perspective view of the sensor unit 303 with the weights 321, 322 and the circuit board unit 323 fixed to the front cover 320. The circuit board unit 323 is fixed to the front cover 320 with screws (not shown). The weights 321 and 322 are weights specifically designed for adjusting the center of gravity, and are placed between the circuit board unit 323 and the frame portion of the front cover 320 (the +Y side and +X side walls in the side-view orientation), and are fixed to the front cover 320 with screws (not shown). The rear cover 324 is fixed to the front cover 320 with screws (not shown).

[0067] Furthermore, the weights 321 and 322 are not limited to weights specifically designed for adjusting the center of gravity. The weights 321 and 322 can be relatively large components from the internal structure of the sensor unit 303, and can be selected in consideration of the surrounding configuration of the circuit board unit 323 inside the sensor unit 303. For example, the weights 321 and 322 may be mechanisms related to imaging performance, such as filter switching mechanisms, or cables that transmit control signals and video signals. The change in the center of gravity when changing the orientation between vertical and horizontal shooting orientations is the same as in the first embodiment, and therefore will not be explained.

[0068] Even with the interchangeable-lens PTZ camera 301, by minimizing the shift in the center of gravity when changing orientation between horizontal and vertical shooting positions, it is possible to suppress fluctuations in the drive load of the tilt motor 117c and maintain high tilt rotation performance.

[0069] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various forms that do not depart from the spirit of the invention are also included in the present invention. Furthermore, each of the embodiments described above is merely one embodiment of the present invention, and it is possible to combine each embodiment as appropriate.

[0070] This embodiment includes the following configuration. (Configuration 1) An imaging unit having a lens and an imaging sensor, comprising: a first fixing means for fixing in a first orientation at a predetermined position; and a second fixing means for fixing in the predetermined position in a second orientation obtained by rotating the first orientation by 90 degrees in a first direction about the imaging optical axis of the imaging unit, wherein the center of gravity of the imaging unit in the first orientation is the first center of gravity, the center of gravity in the second orientation is the second center of gravity, the point obtained by rotating the first center of gravity by 90 degrees in a second direction opposite to the first direction about the imaging optical axis is the first virtual point, and the point obtained by rotating the first center of gravity by 90 degrees in the first direction about the imaging optical axis is the second virtual point, and on a projection plane viewed from the imaging optical axis direction of the imaging unit with the imaging optical axis parallel to the horizontal direction, the distance between the first center of gravity and the second center of gravity is smaller than the distance between the first center of gravity and the first virtual point, and also smaller than the distance between the first virtual point and the second virtual point. (Configuration 2) The imaging unit according to Configuration 1, characterized in that a weight is placed inside the imaging unit to adjust the positions of the first center of gravity and the second center of gravity. (Configuration 3) The imaging unit according to Configuration 2, characterized in that the weight is a weight made of a metal member. (Configuration 4) The imaging unit according to Configuration 2, characterized in that the heavy object is a filter switching unit, a lens drive unit, or a signal transmission cable. (Configuration 5) The aforementioned heavy object consists of two parts: a first heavy object and a second heavy object. The imaging unit according to any one of configurations 2 to 4, characterized in that, on the projection plane when the imaging unit is viewed from the direction of the imaging optical axis, the first weight and the first fixing means face each other across the imaging optical axis, and the second weight and the second fixing means face each other across the imaging optical axis. (Configuration 6) An imaging apparatus characterized by comprising: an imaging unit as described in Configuration 5; a fixed base as the predetermined position on which the imaging unit is fixed; and a tilt rotation unit that holds the fixed base so as to be tiltable and rotatable. (Configuration 7) The imaging apparatus according to Configuration 6, characterized in that, on the projection plane when the imaging unit is viewed from the direction of the imaging optical axis, the first weight and the first fixing means are facing each other with the tilt rotation axis in between, or the second weight and the second fixing means are facing each other. (Configuration 8) The imaging apparatus according to Configuration 6 or 7, characterized in that the tilt rotation axis overlaps with the first heavy object or the second heavy object on the projection plane when viewing the imaging unit from a direction perpendicular to the imaging optical axis and tilt rotation axis of the imaging unit. (Configuration 9) The imaging device according to any one of Configurations 6 to 8, wherein the imaging unit comprises a lens device having the lens, and a sensor unit having the imaging sensor, the first fixing means and the second fixing means, the lens device being detachable from the sensor unit, and the sensor unit being fixed to the fixing base. (Configuration 10) The imaging apparatus according to Configuration 9, characterized in that it has an adjustment means for adjusting the mounting position of the imaging unit with respect to the fixed base in the direction of the imaging optical axis of the imaging unit. (Configuration 11) An imaging apparatus according to any one of Configurations 6 to 10, characterized in that it has a pan rotation unit that holds the tilt rotation unit in a pan rotation manner. (Configuration 12) An imaging unit equipped with an imaging sensor having a rectangular imaging surface, which is mounted on a tilt-rotation unit, comprising: a first fixing means for fixing the imaging unit to the tilt-rotation unit in a first orientation in which the long side of the imaging surface is parallel to the tilt-rotation axis; and a second fixing means for fixing the imaging unit to the tilt-rotation unit in a second orientation in which the short side of the imaging surface is parallel to the tilt-rotation axis, wherein the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the orientation of the imaging unit is changed between the first orientation and the second orientation, with the imaging optical axis of the imaging unit parallel to the horizontal direction, is smaller than the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the imaging unit is rotated 90 degrees around the imaging optical axis. (Configuration 13) An imaging device comprising: an imaging unit having a lens and an image sensor; a tilt-rotating unit that holds the imaging unit so as to be tiltable; and a pan-rotating unit that holds the tilt-rotating unit so as to be pan-rotating, wherein the imaging unit has a first fixing means for fixing it to the tilt-rotating unit in a first posture; and a second fixing means for fixing the imaging unit to the tilt-rotating unit in a second posture obtained by rotating the imaging unit in the first posture by 90 degrees in a first direction around the imaging optical axis of the imaging unit, wherein the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the posture of the imaging unit is changed between the first posture and the second posture, with the imaging optical axis of the imaging unit parallel to the horizontal direction, is smaller than the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the imaging unit is rotated by 90 degrees around the imaging optical axis. [Explanation of Symbols]

[0071] 101,301 PTZ cameras 102,302 Fixed stand 103,310 imaging units 106,306 Head section 108 imaging sensors 121,321 First heavy object 122,322 Second heavy object 303 Sensor Unit 315 Lens device

Claims

1. An imaging unit having a lens and an imaging sensor, A first fixing means for fixing in a predetermined position in a first posture, The system includes a second fixing means for fixing the first orientation in a predetermined position in a second orientation obtained by rotating the first orientation by 90 degrees in the first direction around the imaging optical axis of the imaging unit, An imaging unit characterized in that, with the imaging unit's center of gravity in the first orientation being the first center of gravity, the center of gravity in the second orientation being the second center of gravity, the point obtained by rotating the first center of gravity by 90 degrees in a second direction opposite to the first direction around the imaging optical axis being the first virtual point, and the point obtained by rotating the first center of gravity by 90 degrees in the first direction around the imaging optical axis being the second virtual point, and on a projection plane viewed from the imaging optical axis direction of the imaging unit with the imaging optical axis parallel to the horizontal direction, the distance between the first center of gravity and the second center of gravity is smaller than the distance between the first center of gravity and the first virtual point, and also smaller than the distance between the first virtual point and the second virtual point.

2. The imaging unit according to claim 1, characterized in that a weight for adjusting the positions of the first center of gravity and the second center of gravity is arranged inside the imaging unit.

3. The imaging unit according to claim 2, characterized in that the aforementioned weight is a weight made of a metal member.

4. The imaging unit according to claim 2, characterized in that the aforementioned heavy object is a filter switching unit, a lens drive unit, or a signal transmission cable.

5. The aforementioned heavy object consists of two parts: a first heavy object and a second heavy object. The imaging unit according to any one of claims 2 to 4, characterized in that, on the projection plane when the imaging unit is viewed from the direction of the imaging optical axis, the first weight and the first fixing means face each other across the imaging optical axis, and the second weight and the second fixing means face each other across the imaging optical axis.

6. The imaging unit according to claim 5, A fixing base which is the predetermined position on which the imaging unit is fixed, An imaging apparatus characterized by having a tilt rotation unit that holds the aforementioned fixed base in a tiltable and rotatable manner.

7. The imaging apparatus according to claim 6, characterized in that, on the projection plane when the imaging unit is viewed from the direction of the imaging optical axis, the first weight and the first fixing means are facing each other with the tilt rotation axis in between, or the second weight and the second fixing means are facing each other.

8. The imaging apparatus according to claim 6, characterized in that, on a projection plane viewed from a direction perpendicular to the imaging optical axis and tilt rotation axis of the imaging unit, the tilt rotation axis coincides with the first heavy object or the second heavy object.

9. The imaging unit is A lens device having the aforementioned lens, The sensor unit comprises the imaging sensor, the first fixing means and the second fixing means, The lens device is detachable from the sensor unit. The imaging device according to claim 6, characterized in that the sensor unit is fixed to the fixed base.

10. The imaging apparatus according to claim 9, further comprising an adjustment means for adjusting the mounting position of the imaging unit with respect to the fixed base in the direction of the imaging optical axis of the imaging unit.

11. The imaging apparatus according to claim 6, further comprising a pan rotation unit that holds the tilt rotation unit in a pan rotation manner.

12. An imaging unit equipped with an imaging sensor having a rectangular imaging surface, which is mounted on a tilt rotation unit, A first fixing means for fixing the image sensor to the tilt rotation unit in a first orientation in which the long side of the image sensor is parallel to the tilt rotation axis, The device includes a second fixing means for fixing the imaging surface to the tilt rotation unit in a second orientation in which the shorter side of the imaging surface is parallel to the tilt rotation axis, An imaging unit characterized in that, with the imaging optical axis of the imaging unit parallel to the horizontal direction, the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the orientation of the imaging unit is changed between the first orientation and the second orientation is smaller than the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the imaging unit is rotated 90 degrees around the imaging optical axis.

13. An imaging unit having a lens and an image sensor, A tilt rotation unit that holds the imaging unit so that it can be tilted and rotated, An imaging apparatus having a pan rotation unit that holds the tilt rotation unit so as to be pan rotatable, The imaging unit is A first fixing means for fixing the tilt rotation unit in a first position, The system includes a second fixing means for fixing the imaging unit in a second position, which is obtained by rotating the imaging unit in the first position by 90 degrees in the first direction around the imaging optical axis of the imaging unit, to the tilt rotation unit. An imaging apparatus characterized in that, with the imaging optical axis of the imaging unit parallel to the horizontal direction, the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the orientation of the imaging unit is changed between the first orientation and the second orientation is smaller than the amount of movement of the center of gravity of the imaging unit in the direction of gravity when the imaging unit is rotated 90 degrees around the imaging optical axis.

Images