Camera, posture change detection and posture restoration thereof

A device for detecting posture change of a operation part in a camera and a method for restoring posture are disclosed. The device may include a photo interrupter and a photoelectric baffle structure including a plurality of baffle pieces fixed on a base. The baffle pieces may include a first baffle piece and remaining second baffle pieces of a length specification different from that of the first baffle piece, and there is a gap between two adjacent baffle pieces. An output signal from the photo interrupter changes according to the aligning relationship between the photo interrupter and the baffle pieces. One of the photoelectric baffle structure and the photo interrupter may follow the motion of an operation part of the camera while the other one remains unmoved, so that a posture change of the operation part may be detected based on the output signal from the photo interrupter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Chinese Patent Application No. 201510090171.2, filed on Feb. 27, 2015, and Chinese Patent Application No. 201520118159.3, filed on Feb. 27, 2015, the entire contents of both of which are hereby incorporated by reference for all purposes.

BACKGROUND

The disclosure relates to a camera, particularly relates to a device for detecting posture change of a camera and a posture restoration for the camera.

A user may direct a camera towards a specific monitoring position by rotating an operation part of the camera. However, the operation part also may be rotated due to shake or other reasons such that the camera cannot achieve expected monitoring, which degrades user experience for the camera.

DETAILED DESCRIPTION

FIG. 1Ais a perspective view schematically showing a photoelectric baffle structure of a device for detecting posture change according to an example of the disclosure.FIG. 1Bis a top view of the photoelectric baffle structure illustrated inFIG. 1A. As illustrated inFIG. 1AandFIG. 1B, a photoelectric baffle structure100may include a base110, a first cylinder120and a plurality of baffle pieces130. One end of the first cylinder120is fixed on a side end surface of the base110. The plurality of baffle pieces130are fixed on an annular end surface of the other end of the first cylinder120, and there is a gap133between every two adjacent baffle pieces130. According to another example, the plurality of baffle pieces130may be directly fixed on the base110, as illustrated inFIG. 1C.

The plurality of baffle pieces130may include a first baffle piece131and second baffle pieces132. Further, as illustrated inFIG. 1B, the base110may be provided thereon with a central hole111and a plurality of mounting holes112which are evenly arranged circumferentially with respect to the central hole111. The photoelectric baffle structure100may be mounted to a camera through the mounting holes112.

As illustrated inFIG. 2andFIG. 3, the device for detecting posture change may further include a photo interrupter200. When the device is mounted to the camera, one of the photoelectric baffle structure100and the photo interrupter200may follow the motion of an operation part300of the camera while the other may remain unmoved. The “operation part300” may be explained as a functional component of the camera for the rotation of a lens. For example, the operation part300may be a lens310or a stepping motor (not shown) which may drive the lens310to rotate horizontally by using a vertical rotation axis320, and so on.

Referring toFIG. 2, the “follow the motion of the operation part300of the camera” may be understood as: the photoelectric baffle structure100may rotate simultaneously, by the same angle, and in the same direction as the operation part300, and thus, they both may remain stationary relative to each other. For example, when the lens310is driven to rotate horizontally by the stepping motor310, the photoelectric baffle structure100may simultaneously rotate by the same angle in the same direction as the lens310.

Similarly, the “remain unmoved” may be understood as: when the operation part300rotates, the absolute position of the photo interrupter200may be unchanged. For example, as illustrated inFIG. 2, when the operation part300and the photoelectric baffle structure100rotate synchronously around the vertical rotation axis320, the photo interrupter200may remain unmoved. Therefore, a relative motion may occur between the photoelectric baffle structure100and the photo interrupter200, so that a posture change of the operation part300may be detected based on the change of the output signal from the photo interrupter200caused by the relative motion.

In another example, the photo interrupter200may follow the motion of the operation part300while the photoelectric baffle structure100remains unmoved, and its redundant description is omitted here.

As illustrated inFIG. 2, the photo interrupter200may be provided thereon with a trench210which coordinates with the photoelectric baffle structure100. One side of the trench210corresponds to a light transmitter220and the other side corresponds to an optic sensor230. In order to secure the coordination between the photo interrupter200and the baffle pieces130on the photoelectric baffle structure100, the cross section projection of each baffle piece130may be an arc segment, for example, on the annular end surface of the first cylinder120or on the base110, as illustrated inFIG. 3. Thus, it can prevent collision or friction of the baffle pieces130with both lateral sides of the trench210on the photo interrupter200during the motion of the baffle pieces130. However, the cross section of each baffle piece130may be in other shapes besides an arc segment, so long as the baffle piece130may enter into the trench210to block light transmitted from the light transmitter220.

When light transmitted from the light transmitter220reaches the optic sensor230, an output signal from the photo interrupter200may be of a first level such as a high level. When light transmitted from the light transmitter220is blocked by any one of the baffle pieces130on the photoelectric baffle structure100and cannot reach the optic sensor230, the output signal from the photo interrupter200may be of a second level such as a low level. Thus, when the photoelectric baffle structure100rotates along with the operation part300, the output signal from the photo interrupter200may be of the first level or the second level. The level of the output signal from the photo interrupter200may change according to the aligning relationship between the photo interrupter200and the baffle pieces on the photoelectric baffle structure100.

According to another example, besides the level of the output signal, it may adopt other attributes of the output signal such as frequency, which may change according to the aligning relationship between the photo interrupter200and the baffle pieces on the photoelectric baffle structure100.

In this way, when the output signal from the photo interrupter200is changed, it indicates that the aligning relationship between the photo interrupter200and the baffle pieces on the photoelectric baffle structure100may have changed. Thus, the posture of the operation part300may be viewed to have changed. The posture change may be due to control of the user, or due to an unexpected external force. For example, the posture of the operation part of the camera may be changed when the mounting rack of the camera gets hit accidentally.

By provision of a plurality of baffle pieces130on the photoelectric baffle structure100, it may detect whether the posture of the operation part300of the camera has changed according to change of the output signal from the photo interrupter200. And when determining the posture change of the operation part300is not caused by the user's instructions, a posture restoration operation described hereinafter may be performed to eliminate the impact from an unexpected external force on the monitoring of the camera as possible.

To facilitate determining and controlling the posture of the operation part300, an initial posture may be pre-defined, such as in which the lens of the camera is directed toward the right front direction. And each posture of the operation part300may be recorded as a relative positional relationship with respect to the initial posture. Therefore, by setting the baffle pieces130on the photoelectric baffle structure100to have different specifications, for example, a baffle piece131which corresponds to the initial posture has a first length specification, and remaining baffle pieces132all have a second length specification, it may determine the initial posture by searching for the first baffle piece131. For example, as illustrated inFIG. 3, when the photo interrupter200is aligned with the edge of one side of the first baffle piece131, the operation part300can be viewed as in the initial posture.

As illustrated inFIG. 1B, the first baffle piece131has a downward projection length longer than that of the second baffle piece132. However, the downward projection length of the first baffle piece131may also be shorter than that of the second baffle piece132, as long as there is difference in length specification between the first baffle piece131and the second baffle piece132.

Further, the detection precision for relative motion between the photo interrupter200and the photoelectric baffle structure100may be improved by increasing the number or density of the second baffle pieces132, so that the detection precision for posture change of the operation part of the camera can be improved. Further, all the second baffle pieces132may be arranged evenly so as to ensure that the detection precision is the same or similar no matter when the operation part300rotates to have any posture. For example, as illustrated inFIG. 1B, suppose that the first baffle piece131corresponds to a first arc segment121of the annular end surface, and all the second baffle pieces132correspond to remaining second arc segments122, all the second baffle pieces132may be arranged corresponding to the second arc segments122in an equal space from each other.

According to an example, the gap between every two adjacent baffle pieces may have the same length specification as that of the second baffle piece132. In this case, since the gap between every two adjacent baffle pieces is equal in length specification to the second baffle piece132, manufacturing of the photoelectric baffle structure100may be easy and the calculation complexity in position detection based on the photoelectric baffle structure100may be also simplified.

According to one aspect of the disclosure, a camera is provided which may include an operation part and the above-described device for detecting posture change. When the operation part rotates around a vertical rotation axis or a horizontal rotation axis, one of a photoelectric baffle structure and a photo interrupter of the device for detecting posture change may follow the motion of the operation part while the other one may remain unmoved. Thus, a relative motion may occur between the photo interrupter and the photoelectric baffle structure, so that the posture of the operation part can be detected according to the aligning relationship between the photo interrupter and the baffle pieces on the photoelectric baffle structure.

According to another example, the camera may include an operation part and two devices for detecting posture change. When the operation part rotates around a vertical rotation axis, one of a photoelectric baffle structure and a photo interrupter of the first device for detecting posture change may follow the motion of the operation part while the other one may remain unmoved. Thus, a relative motion may occur between the photo interrupter and the photoelectric baffle structure of the first device, so that posture change of the operation part in the horizontal plane may be detected according to the aligning relationship between the photo interrupter and the baffle pieces on the photoelectric baffle structure of the first device. When the operation part rotates around a horizontal rotation axis, one of a photoelectric baffle structure and a photo interrupter of the second device for detecting posture change may follow the motion of the operation part while the other one may remain unmoved. Thus a relative motion may occur between the photo interrupter and the photoelectric baffle structure of the second device, so that posture change of the operation part in the vertical plane can be detected according to the aligning relationship between the photo interrupter and the baffle pieces on the photoelectric baffle structure of the second device.

FIG. 5illustrates a flowchart for a method for restoring posture of an operation part in a camera according to an example of the disclosure. As illustrated inFIG. 5, the method may include the following blocks510˜530.

At block510, it may determine that the operation part of the camera has changed from a first posture into a second posture when a change of an output signal from the photo interrupter in the camera is detected.

As describe above, the output signal from the photo interrupter may be set as a detection condition for detecting posture change of the operation part, and further determination may be made on whether the posture change occurs in response to the user's instruction. If the posture change is determined not to occur in response to the user's instruction, the camera may be determined to have an undesired posture change influencing the camera monitoring.

At block520, the operation part of the camera may be adjusted from the second posture into a preset initial posture when the posture change of the operation part does not relate to the user's instruction. In the initial posture, the photo interrupter may be aligned with the edge at one side of the first baffle piece on the photoelectric baffle structure.

According to the implementation of the photoelectric baffle structure, the operation part of the camera may be adjusted into the initial posture in various ways.

According to an example, suppose that an arc segment corresponding to the first baffle piece on the photoelectric baffle structure may have a length L and an arc segment corresponding to the second baffle piece may have a length h, wherein L>h. If the photo interrupter rotates at a constant rotation speed with respect to the photoelectric baffle structure under control of the motor, and the blocking time in which the photo interrupter is blocked by the first baffle piece is t1and the blocking time in which the photo interrupter is blocked by the second baffle piece is t2, it can be ascertained that t1>t2, as illustrated inFIG. 6. In this case, since the photo interrupter may output a signal with a constant level such as a low level signal when blocked by the baffle piece, the length specification of the baffle piece blocking the photo interrupter may be determined according to the lasting time during which the photo interrupter outputs the signal with a constant level every time. For example, if the lasting time matches with the length of the arc segment corresponding to the first baffle piece and the rotation speed of the photoelectric baffle structure with respect to the photo interrupter, i.e., the lasting time t0=arc segment length L/rotation speed v, then it may be determined that it is the first baffle piece which blocks the photo interrupter.

Further, the edge at one side of the first baffle piece may be preset as a zero-point position. For example, when the first baffle piece is found, the photo interrupter may be aligned with the zero-point position by rotation of the photoelectric baffle structure with respect to the photo interrupter, so that the operation part of the camera may be adjusted into the initial posture.

According to another example, suppose that an arc segment corresponding to the first baffle piece on the photoelectric baffle structure has a length L, an arc segment corresponding to the second baffle piece has a length h, and an arc segment corresponding to the interval between the adjacent baffle pieces has a length h, wherein L=2 h. In this case, initialization of the posture may be performed through a method including the following blocks.

At block521, the photo interrupter may be caused to align with the edge of any baffle piece on the photoelectric baffle structure by rotation of the photoelectric baffle structure with respect to the photo interrupter.

At block522, the photoelectric baffle structure may be caused to rotate by a distance h/2 in a preset direction with respect to the photo interrupter.

At block523, the photoelectric baffle structure may be caused to rotate by a distance h in the preset direction with respect to the photo interrupter, and it may be determined whether the output signal from the photo interrupter has changed during the rotation.

If the output signal from the photo interrupter has not changed during the time in which the photoelectric baffle structure rotates by a distance h relative to the photo interrupter, it may indicate that the photo interrupter2has aligned with the first baffle piece131on the photoelectric baffle structure1. At this time, the photo interrupter2may be caused to align with the zero-point position which is the edge at one side of the first baffle piece131by rotation of the photoelectric baffle structure1with respect to the photo interrupter2, so that the operation part3of the camera may be adjusted into the initial posture.

If the output signal from the photo interrupter has any change, the process may return and repeat block323until the first baffle piece131is found.

At block524, the photo interrupter2may be caused to align with the zero-point position which is the edge at one side of the first baffle piece131by rotation of the photoelectric baffle structure1with respect to the photo interrupter2.

For example, as illustrated inFIG. 7, in block521, the photo interrupter2may be aligned with the left side (illustrated as position a) of the second baffle piece132. Then, suppose that the photoelectric baffle structure1moves leftwards relative to the photo interrupter2, after block522, the photo interrupter2may be aligned with the central position (illustrated as position b inFIG. 7) of the second baffle piece132. Then, after block523, the photo interrupter2may be aligned with the central position (illustrated as position c inFIG. 7) of the gap133on the right side of the second baffle piece132, during which the output signal from the photo interrupter2has changed from a low level into a high level.

As another example, as illustrated inFIG. 8, in block521, the photo interrupter2may be aligned with the left side (illustrated as position a inFIG. 8) of the first baffle piece131. Then, suppose that the photoelectric baffle structure1moves leftwards relative to the photo interrupter2, after block522, the photo interrupter2may be aligned with a position (illustrated as position b inFIG. 8) having a distance h/2 from the left side of the first baffle piece131. Then, after block523, the photo interrupter2may be aligned with a position (illustrated as position c inFIG. 8) having a distance 1.5 h from the left side of the first baffle piece131, during which the output signal from the photo interrupter2remains unchanged, that is, to maintain a low level.

As yet another example, as illustrated inFIG. 9, in block521, the photo interrupter2may be aligned with the left side (illustrated as position a) of the first baffle piece131(or the second baffle piece132). Then suppose that the photoelectric baffle structure1moves rightwards relative to the photo interrupter2, after block522, the photo interrupter2may be aligned with the central position(illustrated as position b) of the gap133on the left side of the first baffle piece131. Then, after block523, the photo interrupter2may be aligned with the central position (illustrated as position c) of the second baffle piece132′ on the left side of the gap133, during which the output signal from the photo interrupter2has changed from a high level into a low level.

At block530, the operation part may be adjusted from the initial posture into the first posture according to a pre-recorded relative positional relationship between the first posture and the initial posture.

In this example, the relative positional relationship may be stored into the local storage space of the camera or cloud storage, wherein the relative positional relationship may include the rotation direction and the rotation angle between the first posture and the initial posture, such as “rotate by 32° clockwise in a horizontal direction”.

Further, as illustrated inFIG. 4, the photoelectric baffle structure100may also include a second cylinder140. One end of the second cylinder140may be fixed on one side end surface of the base110. The second cylinder140may be positioned inside the first cylinder120. There may be an annular gap between the outer wall of the second cylinder140and the inner wall of the first cylinder120to facilitate electrical connection between components. The outer wall of the second cylinder140and the inner wall of the first cylinder120may be connected though a plurality of reinforcing ribs141which are evenly arranged circumferentially in the annular gap, so as to reinforce the mechanical connection between the second cylinder140and the first cylinder120. Further, the inner wall of the second cylinder140and the inner end surface of the base110may be connected through a plurality of ribbed plates142which are evenly arranged circumferentially, so as to reinforce the mechanical connection between the second cylinder140and the base.

FIG. 10schematically illustrates a hardware structure of a device for restoring posture of an operation part in a camera according to an example of the disclosure. Referring toFIG. 10, in the aspect of hardware, the device may include a processor1010, an internal bus1020, a network interface1050, an internal memory1030and non-volatile storage medium1040, and may further include other hardware. The processor1010may read and execute corresponding machine executable instructions from the non-volatile storage medium1040into the internal memory1030. In the aspect of logic, the machine executable instructions may correspond to control logic for camera posture restoration. Besides the software implementation, the disclosure may include other implementations such as logic devices or combination of software and hardware, etc. For example, the executing subject in the process illustrated inFIG. 5may be not limited to the processor1010illustrated inFIG. 10and may be hardware or logic devices.

Referring toFIG. 11, in software implementation, the control logic1100for camera posture restoration may functionally include the following modules.

A detecting unit1110may determine that an operation part of the camera has changed from a first posture into a second posture when a change of an output signal from the photo interrupter in the camera is detected.

An initializing unit1120may adjust the operation part of the camera from the second posture into a preset initial posture when determining that the posture change of the operation part does not relate to the user's instruction, wherein, when the operation part is in the initial posture, the photo interrupter is aligned with the edge of one side of a first baffle piece on the photoelectric baffle structure.

A restoring unit1130may adjust the operation part from the initial posture into the first posture according to a pre-recorded relative positional relationship between the first posture and the initial posture and.

According to an example, the initializing unit1120may be used to: control the photoelectric baffle structure to rotate with respect to the photo interrupter at a constant rotation speed; record the lasting time during which the photo interrupter continuously outputs a signal with a constant level; when the lasting time matches with the length of an arc segment corresponding to the first baffle piece and the rotation speed of the photoelectric baffle structure with respect to the photo interrupter, determine that the photo interrupter is aligned with the first baffle piece; and rotate the photoelectric baffle structure with respect to the photo interrupter such that the photo interrupter is aligned with the edge of one side of the first baffle piece.

According to another example, in case that the length of an arc segment corresponding to the second baffle piece on the photoelectric baffle structure is a preset length, the length of the gap between adjacent baffle pieces on the photoelectric baffle structure is the preset length, and the length of an arc segment corresponding to the first baffle piece is twice the preset length, the initializing unit1120may be used to: rotate the photoelectric baffle structure with respect to the photo interrupter, so that the photo interrupter is aligned with an edge of any one of the baffle pieces on the photoelectric baffle structure; rotate the photoelectric baffle structure by a half of the preset length in a preset direction with respect to the photo interrupter; rotate the photoelectric baffle structure by the preset length in a preset direction with respect to the photo interrupter, and determine whether the output signal from the photo interrupter has changed during the rotation of the preset length, and when any change occurs, continue to rotate the photoelectric baffle structure by the preset length in the preset direction with respect to the photo interrupter until the output signal from the photo interrupter does not change during a rotation of the preset length; and when the output signal from the photo interrupter does not change during a rotation of the preset length, determine that the photo interrupter is aligned with the first baffle piece, and rotate the photoelectric baffle structure with respect to the photo interrupter such that the photo interrupter is aligned with the edge of one side of the first baffle piece.

The above are only preferred examples of the present disclosure is not intended to limit the disclosure within the spirit and principles of the present disclosure, any changes made, equivalent replacement, or improvement in the protection of the present disclosure should contain within the range.

The methods, processes and units described herein may be implemented by hardware (including hardware logic circuitry), software or firmware or a combination thereof. The term ‘processor’ is to be interpreted broadly to include a processing unit, ASIC, logic unit, or programmable gate array etc. The processes, methods and functional units may all be performed by the one or more processors; reference in this disclosure or the claims to a ‘processor’ should thus be interpreted to mean ‘one or more processors’.

Further, the processes, methods and functional units described in this disclosure may be implemented in the form of a computer software product. The computer software product is stored in a storage medium and comprises a plurality of instructions for making a processor to implement the methods recited in the examples of the present disclosure.

The figures are only illustrations of an example, wherein the units or procedure shown in the figures are not necessarily essential for implementing the present disclosure. Those skilled in the art will understand that the units in the device in the example can be arranged in the device in the examples as described, or can be alternatively located in one or more devices different from that in the examples. The units in the examples described can be combined into one module or further divided into a plurality of sub-units.

Although the flowcharts described show a specific order of execution, the order of execution may differ from that which is depicted. For example, the order of execution of two or more blocks may be changed relative to the order shown. Also, two or more blocks shown in succession may be executed concurrently or with partial concurrence. All such variations are within the scope of the present disclosure.