Description:
BACKGROUND OF THE INVENTION
1.Field of the Invention
The invention relates to a color television camera for battery operation.
2.Description of the Prior Art
In battery-operated portable color television cameras, the prevailing problem is essentially one of energy supply, since the ratio of battery weight to possible length of operation of the camera ought to be minimized. This minimization can generally be helped by use of suitable circuit technology, but there are certain limits to what can be accomplished by this means.
SUMMARY OF THE INVENTION
The invention therefore provides a color television camera by means of which an additional extension of the possible time of operation can be obtained.
According to the invention, a switching device is provided in a color television camera, preferably for battery operation, whereby the camera can be switched optionally from normal operation to test operation or stand-by operation. In this test operation or standby operation, an operating voltage is fed only to the circuit sections necessary for the production of a black-and-white signal and for the operational manipulation.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be explained in detail with the aid of an embodiment shown in the sole FIGURE wherein only those parts of a color television camera are shown which are essential for the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For generating a color picture signal, three picture taking or pick-up tubes are provided. Tube 1 is provided for white light, tube 2 is provided for red light, and tube 3 is provided for blue light. Corresponding amplifiers 6, 7, and 8 are provided to amplify the video signals from tubes 1, 2 and 3. Furthermore, the auxiliary circuits 9, which may include telephony, lens control such as focusing, and a view finder, are mounted in the camera. A battery 10 is provided for use as an energy supply and is preferably also mounted in the camera.
According to the invention, a switching device 11 is provided which consists of a switch 12 and a switch 13, each with three contacts a, b, c. The contacts 12a and 13aare without connection to other elements, such that, in this position of switches 12 and 13, the television camera is switched off. Contact 13b of switch 13 is likewise without connection, while contact 12b of switch 12, together with contacts 12c and 13c of switches 12 and 13 are connected to battery 10.
In the center (illustrated) positions 12b and 13b of switches 12 and 13, used for test operations or standby, the white channel with picture-taking tube 1 and amplifier 6, together with auxiliary circuits 9, are therefore connected to the voltage supply of the battery, whereas color channels for red and blue are out of operation. In the normal operation mode, (switch position c), all channels of the camera are connected to battery 10. While in normal operation mode of the camera, a color picture signal is produced, but in the test operation mode, the camera produces only a black-and-white signal which is fed to the master control panel and to the cameraman as a view-finding signal.
Because substantially fewer circuits are in operation in test operation mode, large reduction from the normal operation levels of the camera results. This reduction leads to an extension of the time of operation in test or standby, which may be doubled or tripled.
With this black-and-white operation it is possible to test most focusings. At the few focusings at which a color picture must be produced in the test operation, too, this is possible by actuation of the switching device mounted on the television camera. The auxiliary circuits include those needed for maintaining black-and-white operation and those needed for manipulation of the camera itself.