JPS593072B2 - television system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a configuration in which a television camera such as a rear confirmation television of a vehicle and a monitor television are connected by a multi-core cable, and deflection current, low voltage and high voltage power, etc. of the television camera are supplied from the monitor television section. The present invention relates to a television system in which a plurality of television cameras are switched and used, and a monitor television 15 receives composite video signals having other synchronization signals.

In general, in simple television systems such as vehicle rear confirmation televisions, door cameras, and simple monitoring devices, in order to make the television camera part small, lightweight, or inexpensive, a monitor television 1 and a television camera are used as shown in Figures 1a and 20. 3 are connected with a multi-core cable 2, and all necessary deflection current, power, etc. for the TV camera 3 are supplied from the monitor TV 1, and the TV camera 3
The circuit is often configured to have only a video amplification circuit25.

Below, we will specifically explain the case of a vehicle rear confirmation television. Fig. 1a shows a vehicle rear confirmation television having such a configuration, in which adjustment-related functions are built into the monitor television 1, and the first FIG. b shows a case where the adjustment-related functions are separated from the monitor television 5 to the control section 4 by 30 minutes. Figure 1 a, b
The configuration is selected depending on whether the monitor televisions 1 and 5 are installed near the driver's seat.

A block diagram of the configuration of such a simple television system is shown in FIG. The rectangular wave oscillated by the 31.5KH2 oscillation circuit 6 is extracted as horizontal and vertical deflection pulses of 15.75KH2 and 60H2 by the i and Π1 frequency dividing circuits (using ICs, etc.), and the pulses are output to each drive circuit 8,
11 causes the horizontal and vertical output circuits 9 and 12 to operate.

Reference numerals 13 and 10 are horizontal and vertical deflection coils of the picture tubes of the monitor televisions 1 and 5, and coil assemblies 22 and 23 of the picture tube 24 of the television camera 3 are connected in parallel to these through the multicore cable 2. A camera deflection current synchronized with the deflection current is supplied.

Reference numeral 16 denotes a monitor video amplification circuit, which amplifies the video signal from the television camera 39 and video amplification circuit 26 and applies it to the picture tube of the monitor television.

14 is a variable resistor, and 15 is a variable coil.

17 and 18 are the voltage G2 (generally about 1fC 300V) which is the accelerating electrode of the image pickup tube and the voltage G which is the focus electrode.
3 (generally about 250), and is normally used by rectifying and stabilizing the pulses on the secondary side of the flyback transformers of the monitor televisions 1 and 5.

Reference numerals 19 and 20 are circuits for generating a negative voltage of G1, which is the beam current control electrode of the image pickup tube of the television camera 3, and this voltage is also normally used by rectifying the flyback pulse.

21 is a low voltage power supply stabilizing circuit, and usually a series regulator or a switching regulator is used.

This output voltage (usually about 11.5 V) is also supplied to the television camera 3VC and is used as a power source for the video amplification circuit, the heater of the image pickup tube, and the coil assembly focus coil (not shown). Deflection circuits can perform interlacing, but more commonly, horizontal deflection systems have horizontal oscillation circuits, and vertical deflection systems have power synchronization or vertical oscillation circuits and are random. Many of them are interlaced. In a simple television camera as shown in Figures 1 and 2, if you want to install multiple television cameras and use them by switching, and also receive a composite video signal including a synchronization signal, Problems with switching synchronization when receiving composite video signals, and when receiving images from multiple television cameras, the circuits become complicated and expensive because there are many switching circuits for the voltage supplied to the television cameras as shown in Figure 2. There is a problem.

If the monitor television is configured with a monitor-type circuit that can receive composite video signals, and if the television camera is configured so that the television camera video output is a composite video signal with a synchronization signal, it is as simple as switching the video signal. However, the configuration of the television camera is complicated, the shape is large, and the price is high. FIG. 3 is an example of a vehicle television camera and fare display system. 1 is a monitor television of a television camera installed near the driver's seat.

Reference numeral 27 denotes an adapter section that receives and switches signals from the television camera 3, the television camera 28 for confirming boarding/exiting steps, and the digital fare display signal generator 30.

29 is a cable, and 31 is a color monitor television set for displaying fares installed in the passenger seats of the train.

This television system displays fares for buses that operate on multiple sections with different fares on the driver's seat TV monitor 1 and the passenger seat TV 31, and also allows the driver's seat TV monitor 1 to check the rear and steps. It can be done.

The reason behind the demand for such devices is that with the conventional fare display system, it is not possible to easily change the displayed content, so the same bus cannot be operated on routes with different fares, or the display can be changed when fares are revised. Therefore, there were disadvantages such as a large amount of cost and time. Digital fare display signal generator 3 in Figure 3
Regarding 0, the content of the charge display signal is displayed by an IC memory, and that part is a pack type and can be easily replaced. Furthermore, the contents of the 1C memory can be easily erased or replaced with new contents. On the other hand, equipment that performs safety confirmation using the rear confirmation television camera 3 and monitor television 1 of conventional vehicles has become quite popular on buses.

On the other hand, there was also a request to conduct safety checks such as jumping into vehicle entrances and exits (steps). There is also a growing demand for television cameras to be used to confirm the safety of passengers who jump into the entrance and exit just before departure, and to confirm the safety of the area around the entrance and exit and the rear wheels of the vehicle. When operating different demands as one system via the television as described above, the above-mentioned problems regarding the configuration of the vehicle camera system may occur.

゛The present invention provides a television system that uses a plurality of television cameras by switching between a composite video signal having a synchronizing signal of the digital part of the charge display signal generator and a synchronization signal of the digital section of the charge display signal generator, while retaining the basic structure of the conventional components regarding such a camera system. It's about systems. FIG. 4 shows an example of the configuration of the present invention when there are two television cameras.

Note that the same parts as in FIG. 1 are given the same numbers and will be explained. 1 is a monitor TV, 27 is an adapter part, 3 is a TV camera at the rear of the vehicle, 28 is a TV camera at the entrance/exit,
30 is a digital charge display signal generating section.

Of course, a configuration in which some of the circuits included in the adapter section 27 are inserted into the monitor television 1 is also possible. Reference numeral 36 denotes a switching circuit such as a manual switch or a relay, and is a switching circuit for receiving the fee display image and for receiving the image from the television cameras 3 and 28.

The illustrated state of the switching circuits 36a, b, c, and d shown in FIG. 4 (when the switch is in the upper position) is a charge display image receiving state. Contacts A and B of the switching circuit 36 switch the synchronizing signal between charge display and television camera reception.

In the case of charge display, the signal output (composite video signal with synchronization signal) of the digital charge display signal generation section 30 is sent to the synchronization separation circuit 3.
2, only the synchronizing signal is separated, and the quadratic oscillation circuit 33 and the AFC and horizontal oscillation circuits 34 and 35 are synchronized. In the case of television camera reception, if there is no synchronizing signal, random interlace will occur, and vertical oscillation will be free oscillation at a frequency considerably lower than 60 Hz, making flickering noticeable. For this reason, interlacing is also performed when receiving images from a TV camera, and in order to obtain flicker-free images, 3.
The output of the 1.5KHz oscillation circuit 6 is divided by Σ, -% by the circuit 7.
A signal corresponding to an interlacable synchronization signal of 15.75 KHz and 60 Hz is created by using this method, and the TV camera deflection is switched to be synchronized with this signal. Next, the switching circuit 36
c and c of the switching circuit 37 are for switching video signals.

Numerals 38 and 18 are variable resistors for setting the focus voltages of the two television cameras 3 and 28.

The contact point d of the switching circuit 36 is connected to the acceleration voltage G2 of the image pickup tube at 300°C.
This is a V switching circuit, and when the fare is displayed, the image pickup tube G2 voltage is not applied and no beam current flows. Further, in the case of television camera image reception, voltage is applied to the two television cameras 3 and 28VC at the same time. In this example, the configuration is such that the G2 voltage is cut off to cut off the beam current of the image pickup tube.
A similar effect can be obtained even if the G1 voltage is significantly switched in the negative direction. 25 is a cathode resistor, 39 and 20 are variable resistors for setting G and voltage of the image pickup tube 24, and 40 and 41 are
is the camera horizontal deflection current applying capacitor.

(This is because the G1 voltage and camera horizontal deflection voltage are superimposed.)
When using this configuration for a vehicle, the switching circuits 36, 3
By using a relay at 7, it is possible to receive images from the television cameras 3 and 28 in conjunction with the back gear switch and step door switch of the vehicle. It is also possible to make the rear TV camera 3 work preferentially in conjunction with the back gear switch. In this example, in the case of TV camera reception, the two TV cameras are working together, but in the system shown in Figure 3, the toll is displayed during normal driving, and only when the vehicle is backing up, the rear TV camera is activated. 3 and temporarily operate the TV camera 28 at the entrance/exit when the entrance/exit door opens, so there is no problem with the service life. However, it is of course possible to adopt a configuration in which only the television camera in the image receiving state is in operation and no beam current flows through the other television camera image pickup tubes.
As explained above, according to the present invention, a plurality of television cameras are operated, images from these television cameras are displayed on a monitor television, and a composite video signal from another image generating means is received on the monitor television. In a system for displaying images, the plurality of television cameras are configured so that deflection current and other voltages are always supplied in parallel from the monitor television side, and only the synchronization signal and video signal are switched, so fewer switching circuits are required. Also, the television camera has the same configuration as the conventional simple television camera, and can be made smaller, lighter, and less expensive.

Also, when receiving images from a television camera, interlaced scanning can be performed and a stable screen can be obtained. In the case of such a television system, the television camera generally has complex circuits such as a power supply circuit, a deflection circuit, a high voltage circuit, a synchronization signal mixing circuit, and a video blanking circuit, and outputs a 1Vpp synchronization signal. If a standard television camera, which can be obtained as a composite video signal, could be used, the switching circuit would be simpler, but the television camera would be large, heavy, and expensive.

Furthermore, the monitor television is more complicated and expensive than the monitor television of a simple camera system. In the present invention, an adapter section is added to a conventional simple television camera system, thereby making it possible to receive images of the television system with a relatively simple and inexpensive configuration.

[Brief explanation of the drawing]

Figures 1A and 1b are block diagrams of conventional television systems;
Figure 2 is a block diagram of the same system, and Figure 3 is an example of the present invention! FIG. 4 is a block diagram of the television system using the IC. 1... Monitor TV, 3, 28... TV camera, 6... Oscillator circuit, 17...
・High voltage circuit, 24... Image tube, 27...
・Adapter part, 30...Digital charge display signal generator, 31...Monitor TV, 36, 37...
...Switching circuit.

Claims (1)

[Scope of Claims] 1. A monitor television that is equipped with a plurality of television cameras and a monitor television capable of displaying images from other image generation means different from the television cameras and images from the television cameras; a switching means for switching each output of the video generating means and supplying one of them to the monitor television; a synchronization separation circuit for separating a synchronization signal from a composite video signal sent from the video generating means; A synchronizing signal generating circuit is provided on the monitor television side, and the necessary power supply voltage and synchronizing signal are supplied from the monitor television side to the plurality of television cameras, and the monitor television is provided with a necessary power supply voltage and a synchronizing signal from the video generating means. When displaying a video, the synchronization separation circuit separates a synchronization signal from the composite video signal from the video generation means and applies it to the monitor television, and only high voltage is applied from the monitor television to the plurality of television cameras. The television system is characterized in that when an image of the television camera is displayed on the monitor television, a synchronization signal obtained from the synchronization signal generation circuit is simultaneously applied to the television camera and the monitor television. 2. Claim 1, characterized in that the video generating means includes a second monitor television that displays only the video of this means, and the second monitor television is directly connected to the video generating means. Television system as described.