1. Field of the Invention
The present invention relates to an image taking system in which multiple operating apparatuses are connected, and driving of a movable optical member is controlled according to commanding signals from the multiple operating apparatuses. The present invention also relates to the operating apparatus.
2. Description of the Related Art
Conventionally, many models of broadcast image taking systems are configured to have operating apparatuses for operating focusing and zooming as other systems which are separate from a lens system. This is to allow selecting an optimum operating unit in various image taking situations. For example, as described in Japanese Patent Application Laid-Open No. H08-334674, some operating apparatuses are provided with a shot switch for moving the zoom position and the focus position to positions stored in advance, in addition to the zoom thumb ring and the focus knob used for moving the zoom position and the focus position, respectively, in synchronization with operations thereof. Further, in the case of such an image taking system that the lens system and the camera system are detachable, an operation commanding signal may be input also from the camera system as described in Japanese Patent Application Laid-Open No. 2000-032304.
Further, Japanese Patent Application Laid-Open No. 2003-149535 discloses the uniaxial two-operation type controller and the zoom and focus operating apparatuses.
Further, in recent years, for the purpose of 3D image taking, there has been a demand that multiple lenses be operated by the same operating apparatus, as described in Japanese Patent Application Laid-Open No. H09-133852.
In Japanese Patent Application Laid-Open No. H09-133852, in order to reduce an error in zoom position between the left and right lens systems used for the 3D image taking, the driving speed is adjusted based on a difference value obtained from the position information of the respective lens systems. However, due to a delay time of the position information, a process of high accuracy is required.
As operation commanding signals to be generated by the operating apparatuses, there are a position command which specifies the target positions of zoom and focus lenses (also referred to as position control) and a speed command which specifies the moving direction and the moving speed (also referred to as speed control). When multiple lenses are to be moved to substantially the same positions, it has an advantage to give an operation command through the position commanding control. Thus, some zoom operating apparatuses are configured to convert the speed command of the operating apparatus into the position command and then, output the command to the lens system.
In the case where the zoom operating apparatus transmits the position command, there are the following problems.
For example, the following case is assumed. That is, the focus operating apparatus provided with the zoom shot switch function as in Japanese Patent Application Laid-Open No. H08-334674 and the position command zoom operating apparatus are connected to the lens apparatus. In this case, the zoom position commanding signal is transmitted from the position command zoom operating apparatus at constant periods, and hence, even if the zoom shot command is transmitted once, the zoom shot command is then canceled due to the zoom position commanding signal transmitted thereafter. In short, there is a problem that the zoom driving cannot be effected by means of the zoom shot switch.
Japanese Patent Application Laid-Open No. 2000-032304 discloses a changeover between the speed commands provided from the camera system and the operating apparatus, which is performed by making a judgment regarding a neutral level of the commanding values. However, this technique cannot be applied to the changeover of the position commanding signals.
Further, Japanese Patent Application Laid-Open No. 2003-149535 discloses the provision of an operation apparatus changing switch so as to allow the operation to be changed over between the uniaxial two-operation type controller giving the zoom position command and the zoom operating apparatus giving the zoom speed command, and also discloses that either the uniaxial two-operation type controller or the zoom operating apparatus which is operated is selected. However, performing the changeover by using the changeover switch is troublesome to an operator, and also, in order to automatically select the operated operating apparatus, the configuration of the lens apparatus needs to be changed.