JP2756266B2 - Camera system or interchangeable lens in camera system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera system such as a video camera and a still camera, or an interchangeable lens in the camera system.

[Conventional technology and its problems]

Conventionally, the third interchangeable lens for video camera systems
The one shown in the figure is known.

That is, an imaging optical system includes the focusing lens L1, the zoom lens L2, and the relay lens (not shown).

A distance ring 101 having a cam portion on the outer periphery is fixed to a front cylinder 106 holding the focusing system lens L1 with a mounting screw 102. The front cylinder 106 is connected to the outer periphery of the fixed cylinder 103 by a helicoid screw. The output gear 105a of the motor 105 fixed to the structural member 104 attached to the fixed cylinder 103 and the distance ring 10
When the outer peripheral gear 101a meshes with the
The front tube 106 rotates integrally with the lens, and is guided by the helicoid screw to move the focusing lens L1 back and forth in the optical axis direction. FIG. 4-1 is an enlarged view of the meshing portion of the output gear 105a of the motor 105 and the outer peripheral gear 101a of the distance ring 101 in the interchangeable lens having such a configuration. Fourth
When the output gear 105a rotates counterclockwise in the state of FIG. 2 and as a result, when the driven outer peripheral gear 101a receives the transmission clockwise, the output gear 105a As shown in FIG. 4-3, there is a delay by the backlash b (flush) of the gear and the time required for stopping the output gear 105a until the outer peripheral gear 101a moves following the movement. The longer the response delay, the more likely the problem will occur.

[Means for solving the problem]

The present invention solves the problem of backlash of a driven member driven by a motor on the interchangeable lens side by driving a motor in the interchangeable lens by a command from a computer provided on the camera body side and driven by a coupling member. In an interchangeable lens in a camera system for driving members, a timer unit for setting a predetermined time necessary for absorbing backlash or a detecting unit for detecting a driving state of a driven member is provided, and a previous rotation direction of the motor is provided. On the other hand, when the current rotation direction is the reverse direction, a specific signal is supplied for a time set by the timer means or until the detection means detects that the driven member has moved. Communication means to communicate the camera to the computer of the camera body, and inform the camera body that backlash removal is in operation, and To provide an interchangeable lens or camera system that solves the above problem.

〔Example〕

The overall schematic circuit configuration of the embodiment will be described with reference to FIG. The camera body is on the right side and the lens is on the left side with respect to the one-dot broken line in the center of the drawing. The light of the subject 1 is condensed on the image sensor 3 such as a CCD by the optical system 2. The output is converted into a television signal by the camera signal processing circuit 4 and output.

On the other hand, the television signal is used for various automatic adjustment mechanisms such as a well-known AWB (automatic white balance) circuit 5, an AF circuit 6, and an AE circuit 7 (automatic exposure control).

Control circuits 5, 6, 7 as control signal sources for the automatic adjustment mechanism
Thus, each control signal is output. The control signal of the AWB circuit 5 for adjusting the color balance of the camera signal processing is transmitted to the processing circuit 4
And the remaining control signals are input to the camera microcomputer 9.

A zoom switch 8 for setting the focal length of the optical system 2
Is also input to the camera microcomputer 9.

The data communication path 13 is connected to the lens microcomputer 14, and all communication data is received by the lens microcomputer 14 once.

Various control signals C1, C2, C3 input to the camera microcomputer 9
Is processed according to a program stored in a ROM in the camera microcomputer 9, and information related to the lens side is supplied to the lens microcomputer 14 via the data communication path 13.

Reference numeral 28 denotes a zoom motor, which is a drive source for controlling the movement of a lens related to the zoom operation in the optical system 2 in the optical axis direction. The zoom motor 28 is driven by the lens microcomputer 14 receiving the operation signal (C ₃ ) of the zoom switch 8 via the camera microcomputer 9 and operating the driver 25. Reference numeral 29 denotes an AE motor, which is a drive source for controlling opening and closing of the aperture in the optical system 2. The motor 29 is driven by the camera microcomputer 9 receiving a control signal (C ₂ ) of the AE circuit 7, performing an operation for obtaining an appropriate aperture value, issuing a drive command to the lens microcomputer 14, and based on this command. This is performed by the lens microcomputer 14 operating the driver 26. Reference numeral 30 denotes an AF motor, which is a lens related to focusing in the optical system 2 (for example, the focusing lens shown in FIG. 3).
L1) is a drive source (for example, the motor 105 in FIG. 3) for controlling the movement of the lens in the optical axis direction. The AF motor 30 is driven by the camera microcomputer 9 receiving the control signal (C ₁ ) of the A circuit 6, performing an operation for obtaining the focusing direction and the defocus amount, and issuing a drive command to the lens microcomputer 14. This is performed by the lens microcomputer 14 operating the driver 27 based on this command.

Reference numeral 31 denotes a zoom encoder which detects the movement of the lens related to the zoom operation by using a code plate or a pulse plate, and supplies the detected information to the lens microcomputer 14. Reference numeral 32 denotes an aperture encoder which detects the movement of a movable member of the aperture and supplies the detection information to the lens microcomputer 14. Reference numeral 33 denotes an AF encoder for reading the movement of a lens (focusing system lens L1) related to focusing by pulse reading (for example, forming a reflection or non-reflection stripe pattern on the outer periphery of the distance ring 101 in FIG. 3). A detector comprising a light-transmitting / light-receiving element of an optical type is disposed on the inner diameter side of the structural member 104 opposed thereto, and the detection information is supplied to the lens microcomputer 14. Note that the encoder 33 is configured to be able to determine the movement of the lens related to focusing in both directions, that is, the movement to the closest side and the movement to the infinity side. Of course, encoder 33
The signal supplied from the to the lens microcomputer 14 also includes information on the lens moving direction related to the focusing.

The control of the motors 28, 29, 30 by the lens microcomputer 14 controls the rotation direction, drive / stop, speed, and the like. Data transmission from the lens microcomputer 14 to the camera microcomputer 9 is output as time-division serial data.

Next, the operation of the lens microcomputer 14 according to the point of the embodiment will be described based on the flowchart of FIG.

[Step 1] In response to a command from the camera microcomputer 9, the motor 2 on the lens side
This flow starts when the rotation control of 8, 29 or 30 is performed.

[Step 2] A control command to the lens side is received from the camera microcomputer 9 of the camera body, and the command is decoded.

[Step 3] The flow is separated depending on whether the moving direction immediately before the lens-side motor 28, 29 or 30 is forward rotation (+ end point) or reverse rotation (one end point). If the rotation is forward, the procedure proceeds to step 3, and if the rotation is reverse, the procedure proceeds to step 7. .

In this step, when a command relating to the rotation of the lens-side motor 28, 29 or 30 is issued from the camera microcomputer 9 this time, it is determined in which direction the drive gear of the output transmission system of the motor meshes with the driven gear. . That is, in FIG. 4, it means that the subsequent flow is separated depending on whether the state is as shown in FIG. 4-2 or the state shown in FIG. 4-3.

[Step 4] In the state immediately before the present command, the lens-side motors 28 and 29
Alternatively, the flag of “REVERSE” is “0” if the driving direction of 30 is normal rotation, and “1” is set if the driving direction is reverse. Therefore, in this step, when the “REVERSE” flag is “0”, the command of the camera microcomputer 9 is switched in the reverse direction this time (the driving direction of the motor and the received command are reversed). If this is the case, the process proceeds to step 5; otherwise, the process proceeds to step 6 when the current motor driving direction and the present command are in the same forward direction.

[Step 5] The flag of “REVERSE” is set to “1”, and the process proceeds to Step 10.

[Step 6] Step 12 END with the "REVERSE" flag set to "0"
Proceed to.

[Step 7] Here, when the “REVERSE” flag is “1”, the command from the camera microcomputer 9 proceeds to Step 8 when the command is in the reverse direction, which is the same direction as the previous command. When the present command is in the forward direction with respect to the reverse direction which is the motor driving direction, the process proceeds to step 9.

[Step 8] END of step 12 with "REVERSE" flag set to "1"
Proceed to.

[Step 9] The flag of “REVERSE” is set to “0”, and the process proceeds to Step 10.

[Step 10] A Busy signal is sent to the camera microcomputer 9. This Busy
The signal is used to inform the camera body that the driven transmission system has not been driven by the gear backlash or the like when the motor 28, 29 or 30 on the lens side is driven in the direction opposite to the previous direction. is there. The camera body is this Busy
Upon receiving the signal, the camera microcomputer 9 takes measures such as interrupting another routine and temporarily stopping transmission with the lens microcomputer 14, for example.

[Step 11] The driven transmission system has started to move based on the driving in the driving direction of the motor 28, 29 or 30 by the encoder 31, 32 or 33, that is, no detection pulse has yet been output in a state where the backlash has been absorbed. In this case, return to Step 10
The generation of the sy signal is continued. On the other hand, when the detection pulse is output, the process proceeds to step 12 to determine END.

The embodiment using the flow chart of FIG.
Although the absorption of the backlash has been confirmed based on the output pulses of 1, 32 or 33, the generation of the Busy signal can be controlled simply by a preset time. The operation of the other system will be described with reference to the flowchart of FIG.

Steps 1 to 9 are the same as those in the flowchart of FIG.

[Step 20] In this step, when the lens-side motor 28, 29 or 30 is driven in the direction opposite to the previous one, the timer means in which the timer time set slightly longer than the time lag caused by the backlash is started.

[Step 21] A Busy signal is transmitted to the camera microcomputer 9.

[Step 22] When the timer time of the timer means reaches the set value, the process proceeds to step 12 to determine END. When the timer time has not yet reached, the process returns to step 21 to continue outputting the Busy signal.

In the above-mentioned embodiment, what is effective in the operation of the flow chart of FIG. 2 is not only to inform the camera microcomputer 9 of the time relating to the absorption of the backlash, but also, for example, to quickly stop the moving motor. In the case of reverse rotation, the busy signal can be transmitted as the time lag in the command from the camera microcomputer 9 for the time related to the stop, and the change in the time lag due to the speed of the motor can also be handled.

Note that, also in the flowchart of FIG.
In the setting of the timer time of the timer means in 20, based on the information on the motor stop, information on the motor speed,
By changing the timer time, the same effect as in the case of FIG. 2 can be obtained.

〔The invention's effect〕

The present invention is directed to a camera body side for a time lag state such as absorption of a splash generated due to a rotation direction of a motor for a time set by a timer means or until a movement of a driven member is detected by a detection means provided in a lens. Can be transmitted as a specific signal, thereby eliminating system problems.

[Brief description of the drawings]

FIG. 1 is a schematic configuration circuit diagram of a camera system as an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the circuit shown in FIG. FIG. 3 is a sectional view showing a configuration of a general interchangeable lens. FIG. 4-1, FIG. 4-2, and FIG. 4-3 are explanatory diagrams in which main parts of FIG. 3 are enlarged. FIG. 5 is a flow chart as another embodiment. 9 Camera microcomputer 14 Lens microcomputer 28, 29, 30 Lens motor 31, 32, 33 Encoder

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Claims (2)

(57) [Claims] 1. An interchangeable lens in a camera system that drives a motor in an interchangeable lens according to a command from a computer provided on the camera body side and drives a driven member via a connecting member, to absorb backlash. Timer means for setting a predetermined time, or a detecting means for detecting the driving state of the driven member is provided, and when the current rotation direction is opposite to the previous rotation direction of the motor, Communication means for communicating a specific signal to a computer of the camera body for a time set by the timer means or until the movement of the driven member is detected by the detection means is provided. Interchangeable lens in a camera system. 2. A camera system comprising a camera body having a built-in computer and an interchangeable lens mountable to the camera body, wherein communication means for communicating between the computer in the camera body and the interchangeable lens is provided. A motor driven by a command from a computer of the camera body input via the communication means, a driven member driven via a connecting member by a driving force of the motor, and a predetermined time required for absorbing backlash Timer means for setting, or a detecting means for detecting the driving state of the driven member is provided, and when the current rotation direction is opposite to the previous rotation direction of the motor, the timer means A specific signal is transmitted through the communication unit during a set time or until the movement of the driven member is detected by the detection unit. A camera system characterized by communicating with a computer of the camera body.