Lens control system

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a lens control system, and more particularly to a lens control system in which a person other than the cameraman can correct the focusing of a television lens by the cameraman.

【0002】

[Conventional technology]

In broadcasting TV camera / lens systems, especially systems for high-definition TVs, it is difficult to check the best focus with the small viewfinder used by the cameraman, so defocusing is confirmed with a large monitor or TV receiver. There is. For this reason, conventionally, there is known a system in which a person other than the cameraman (focusman) can perform focus correction in the camera control unit (CCU) for focusing by the cameraman. According to this system, Focusman checks the focus while looking at the image on a large monitor, and if focusing by the photographer is not appropriate, he can focus accurately by his own operation without giving instructions to the photographer. Can be done.

【0003】

[Problems to be Solved by the Invention]

However, in the system in which the focus correction can be performed by a person other than the cameraman as described above, the focus position actually set with respect to the focus target position instructed by the focus operation of the cameraman is instructed by the focus correction. Since the shift is made by the amount of correction, if this correction is not canceled, there will be a range in which the focus cannot be adjusted near the near end or the infinity end by the focus operation of the photographer. For this reason, it is necessary to perform an operation to cancel the focus correction (set the correction amount to 0), but the operation for canceling the focus correction is complicated, and the focus position moves by canceling the focus correction, which makes the user feel uncomfortable. There was a problem that

【0004】

The present invention has been made in view of such circumstances, and when a photographer makes a correction to focusing by another person, the correction can be canceled without a special canceling operation and without a sense of discomfort. An object of the present invention is to provide a lens control system capable of providing a lens control system.

【0005】

[Means for solving problems]

In order to achieve the above object, the invention according to claim 1 is a focus position indicating means for instructing a focus target position of a photographing lens and a correction amount for correcting the focus target position instructed by the focus position indicating means. By driving the focus lens with a motor, the focus correction amount indicating means for instructing the focus correction amount, the focus target position correction means for correcting the focus target position based on the focus target position and the correction amount, and the photographing lens. In a lens control system including a focus position control means for controlling a focus position so as to be a focus target position corrected by the focus target position correction means, the focus target position correction means is provided by the focus position indicating means. When the instructed focus target position is changing, the correction amount is gradually reduced along with the change in the focus target position to correct the focus target position.

【0006】

According to the present invention, the focus target position indicated by the focus position indicating means based on the focus operation of the cameraman or the like is indicated by the focus correction amount indicating means based on the operation of another person other than the cameraman such as the focus man. When the focus target position is changed by the focus position indicating means when the correction amount is corrected, the correction amount is gradually reduced to correct the focus target position as the focus target position changes. Therefore, while the camera is performing the focus operation, the correction amount is finally set to 0, and the focus position of the photographing lens is set to the focus target position indicated by the focus position indicating means. Therefore, the correction is released without any special release operation and without a sense of discomfort.

【0007】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the lens control system according to the present invention will be described in detail with reference to the accompanying drawings.

【0008】

FIG. 1 is a block diagram showing a configuration related to focus control and zoom control of the lens control system according to the present invention. The lens control system shown in the figure is mainly composed of a lens device 10, a camera head 12, a camera control unit (CCU) 14, and the like. The lens device 10 and the camera head 12 are mechanically and electrically connected, and the image formed by the optical system of the lens device 10 including the focus lens (group) F, the zoom lens (group) Z, etc. is the camera head. It is converted into an electric signal (image signal) by 12 image sensors. Further, the lens device 10 has a built-in control system that drives the focus lens F and the zoom lens Z and controls the focus and zoom of the optical system as described later.

【0009】

The CCU 14 is a camera control device connected to the camera head 12 by a cable, acquires an image signal from the camera head 12 and performs various signal processing, and also controls various optical systems of the camera head 12 and the lens device 10. I do. In the present embodiment, the focus of the lens device 10 is controlled in particular.

【0010】

As shown in the figure, a focus controller 20 and a zoom controller 22 are connected to the lens device 10, and an operating member (for example, a rotary operating member called a focus knob) arranged on the focus controller 20 is used by a photographer. When is operated, the focus operation value corresponding to the operation amount is output as a focus control signal. When the photographer operates an operation member (for example, a rotary operation member called a thumb ring) arranged on the zoom controller 22, a zoom operation value corresponding to the operation amount is output as a zoom control signal. Here, the focus operation value of the focus control signal shall indicate the focus target position, and the zoom operation value of the zoom control signal shall indicate the zoom target speed. The focus control signal and the zoom control signal output from the focus controller 20 and the zoom controller 22 are input to the CPU 26 via the A / D converter 24 in the lens device 10.

【0011】

The CPU 26 determines a focus command value indicating the focus target position and a zoom command value indicating the zoom target speed as described later, and drives the focus lens F and the zoom lens Z based on these focus command values and the zoom command values. Controls the focus and zoom of the optical system.

【0012】

Regarding the zoom command value, the CPU 26 uses the zoom operation value of the zoom control signal given from the zoom controller 22 as the zoom command value. Then, the zoom command value is output to the zoom amplifier 32 via the D / A converter 30. The zoom amplifier 32 drives the zoom motor 34 at a rotation speed (including elements in the rotation direction) according to the zoom command value. As a result, the power of the zoom motor 34 is transmitted to the zoom lens Z via the power transmission mechanism 36 such as a gear, and the zoom lens Z moves in the optical axis direction at a speed corresponding to the rotation speed of the zoom motor 34. Therefore, the zoom speed is controlled to be the zoom command value, that is, the zoom target speed indicated by the zoom operation value. The CPU 26 acquires the current zoom position from the position sensor 28, and when the zoom lens Z approaches the telephoto end or the wide end, it imposes a certain limit on the zoom command value and forcibly decelerates the zoom speed. Processing is being performed.

【0013】

The method of determining the focus command value differs depending on whether or not the focus correction in the CCU 14 is enabled as described later. However, when the focus command value is determined as described later, the CPU 26 sets the focus command value as the focus target position. And. Then, the difference between the focus command value and the current focus position acquired from the position sensor 38 is obtained, and the value corresponding to the difference, that is, the focus target speed according to the difference between the current focus position and the focus target position is obtained. The indicated value is output to the focus amplifier 40 via the D / A converter 30. The focus amplifier 40 drives the focus motor 42 at a rotation speed (including an element in the rotation direction) corresponding to a value indicating the focus target speed. As a result, the power of the focus motor 42 is transmitted to the focus lens F via the power transmission mechanism 44 such as a gear, and the focus lens F moves in the optical axis direction at a speed corresponding to the rotation speed of the focus motor 42. Therefore, feedback control is performed so that the focus position of the optical system becomes the focus target position indicated by the focus command value.

【0014】

Here, whether or not to enable the focus correction in the CCU 14 can be selected by the user by the focus correction switch 46. The CPU 26 detects the on / off state of the focus correction switch 46, and when it detects that the focus correction switch 46 is off, that is, when disabling the focus correction in the CCU 14, it is given by the focus controller 20. The focus operation value of the focus control signal is set as the above-mentioned focus command value. As a result, the focus position of the optical system is controlled based only on the focus operation of the photographer on the focus controller 20.

【0015】

On the other hand, when it is detected that the focus correction switch 46 is on, that is, when the focus correction in the CCU 14 is enabled, the CPU 26 serially communicates the focus operation value of the focus control signal given by the focus controller 20. It transmits to CCU 14 via interface (SCI) 48 and camera head 12. On the other hand, the corrected focus operation value is transmitted from the CCU 14 as a focus control signal via the camera head 12, and the CPU 26 acquires the corrected focus operation value via the SCI 48 and obtains the focus command value. And. The corrected focus operation value given by the CCU 14 is the sum of the correction amount adjusted by the CCU 14 to the focus operation value from the focus controller 20 as described later, and this focus operation value is used as the focus command value. By doing so, the focus position of the optical system is controlled based on the focus operation of the cameraman in the focus controller 20 and the focus correction operation by a person other than the cameraman (focus man) in the CCU 14.

【0016】

As shown in the figure, the CCU 14 has a built-in CPU 50, and the CPU 50 acquires the focus operation value (of the photographer) of the focus controller 20 transmitted from the lens device 10 via the SCI 52 as described above.

【0017】

On the other hand, a focus correction operation means 54 for a person other than the cameraman (focus man) to correct the focus position is connected to the CCU 14, and the focus man connects the operation member arranged in the focus correction operation means 54. When the operation (focus correction operation) is performed, a correction signal indicating the correction amount when correcting the focus position based on the operation amount is given to the CPU 50. The CPU 50 acquires a correction amount from the correction signal, and adds the correction amount to the focus operation value acquired from the lens device 10. Then, the value obtained as a result (corrected focus operation value) is transmitted to the lens device 10 as a focus control signal via the SCI 52 and the camera head 12. As a result, the focus target position instructed by the focus operation of the cameraman is corrected by the focus correction operation of the focus man.

【0018】

Further, the CPU 50 is corrected to be added to the focus operation value of the focus controller 20 when the focus operation value of the focus controller 20 given by the lens device 10 is changed, that is, when the photographer is performing the focus operation. Gradually reduce the amount. As a result, the corrected focus operation value transmitted from the CCU 14 to the lens device 10 gradually approaches the focus operation value of the focus controller 20 while the photographer is performing the focus operation, and finally. Matches the focus operation value of the focus controller 20. Therefore, even if the focus target position indicated by the focus operation value of the focus controller 20 and the actually set focus position do not match due to the focus correction operation performed by the focus man, it is special. The focus target position indicated by the focus operation value of the focus controller 20 and the actual focus position come to match while the photographer is performing the focus operation without performing the correction release operation, and the nearest end or the actual focus position is matched. The problem that the focus cannot be adjusted by the focus controller 20 near the infinity end is reduced. Further, by gradually reducing the correction amount, such a correction cancellation process is performed without a sense of discomfort.

【0019】

Next, the processing procedure of the CPU 26 of the lens device 10 and the CPU 50 of the CCU 14 will be described with reference to the flowcharts of FIGS. 2 and 3. First, the processing procedure of the CPU 50 of the CCU 14 will be described with reference to the flowchart of FIG. The CPU 50 reads the focus operation value (of the photographer) of the focus controller 20 from the lens device 10 (step S10). Then, it is determined whether or not there is a focus operation in the focus controller 20 (step S12). If it is determined to be NO, it is determined whether or not the focus correction flag is on (step S14). Further, when it is determined as NO, that is, in the initial case where it is determined as NO in the determination in step S12, the focus operation value at the start of the correction operation is stored (step S16). Then, the focus correction flag is turned on (step S18), and the process returns to step S10.

【0020】

On the other hand, if YES is determined in step S14, the correction amount of the focus correction operation is read from the focus correction operation means 54 (step S20). Next, the correction amount is added to the focus operation value stored in step S16, and the result value is used as the focus operation value (step S22). Then, the corrected focus operation value is transmitted to the lens device 10 as a focus control signal (step S24), and the process returns to step S10.

【0021】

When it is determined in the determination process of step S12 that NO, that is, there is no focus operation in the focus controller 20, the focus correction flag is turned off (step S26). Then, the correction amount added to the focus operation value at the present time is reduced by a certain amount according to the focus operation amount (change amount of the focus operation value) (step S28). Next, the reduced correction amount is added to the focus operation value of the photographer, and the value is used as the focus operation value (corrected focus operation value) (step S30). The focus operation value thus obtained is transmitted to the lens device 10 as a focus control signal (step S24), and the process returns to step S10. When the correction amount is reduced in step S28, the focus correction operation means 54 does not match the correction amount output to the CCU 14, so in order to prevent this (especially when the focus operation is switched from with or without). To prevent the correction amount recognized in step S20 from being inconsistent with the correction amount immediately before the focus operation is switched to Yes) The correction amount output by the focus correction operation means 54 is also the correction amount to be added to the focus operation value. The process for reducing the number may be performed in the focus correction operation means 54 or in the CPU 50. The relationship between the focus operation amount and the correction amount reduction may be non-linear. When the focus operation amount is small, it is recognized as being finely adjusted, and at that time, a threshold value such as not reducing the correction amount may be set.

【0022】

Next, the processing procedure of the CPU 26 of the lens device 10 will be described with reference to the flowchart of FIG. The CPU 26 reads the focus operation value (of the photographer) of the focus controller 20 (step S40). Then, it is determined whether or not the focus correction switch 46 is on (step S42). If NO is determined, the focus operation value of the photographer is used as the focus command value (step S44). Then, the difference between the focus command value and the current focus position is obtained, the value corresponding to the difference is output to the D / A converter 30 (step S52), and the process returns to step S40.

【0023】

On the other hand, if YES, the photographer's focus operation value is transmitted to CCU14 (step S46). Then, the corrected focus operation value is received from the CCU 14 (step S48), and the corrected focus operation value is used as the focus command value (step S50). Then, the difference between the focus command value and the current focus position is obtained, the value corresponding to the difference is output to the D / A converter 30 (step S52), and the process returns to step S40.

【0024】

As described above, in the above embodiment, the process of correcting the focus operation value of the focus controller 20 is performed by the CCU 14, but this process is performed by the CPU 26 of the lens device 10 by acquiring the correction amount from the CCU 14. May be good.

【0025】

[Effect of the invention]

As described above, according to the lens control system according to the present invention, the focus target position indicated by the focus position indicating means based on the focus operation of the cameraman or the like can be operated by another person other than the cameraman such as the focus man. When the focus correction amount is corrected by the correction amount instructed by the focus correction amount indicating means based on the above, and the focus target position instructed by the focus position instructing means is changing, the correction amount is gradually increased as the focus target position changes. Since the focus target position is corrected by decreasing the amount, the correction amount finally becomes 0 while the camera is performing the focus operation, and the focus position of the photographing lens is the focus target position indicated by the focus position indicating means. Will be set to. Therefore, the correction is released without any special release operation and without a sense of discomfort.

[Simple explanation of drawings]

[Figure 1]

FIG. 1 is a block diagram showing a configuration related to focus control and zoom control of the lens control system according to the present invention.

[Figure 2]

FIG. 2 is a flowchart showing the processing procedure of the CPU of the CCU.

[Fig. 3]

FIG. 3 is a flowchart showing the processing procedure of the CPU of the lens device.

[Explanation of symbols]

10 ... lens device, 12 ... camera head, 14 ... camera control unit (CCU), 20 ... focus controller, 26, 50 ... CPU, 42 ... focus motor, 46 .. .Focus correction switch, 54 ... Focus correction operation means, F ... Focus lens (group)