JPH05291778A - Video signal processing device - Google Patents

Abstract

PURPOSE:To reduce jump-in of noise with a simple configuration by connecting a shield plate to a digital video signal processing board and then separating the grounding of an analog video signal processing board from that of the digital video signal processing board and then connecting them at a power supply part. CONSTITUTION:Groundings 60 and 62 analog video signal processing boards 42 and 44 and digital video signal processing boards 46 and 48 are guided individually to a power supply part 28 and then are connected each other and at the same time are connected to a case 52. Then, a shield plate 50 is connected to the analog video signal processing boards 42 and 44, the power supply part 28, and the case 52 through the connection wire 62 from the digital video signal processing boards 46 and 48 to the power supply part 28. thus reducing noise which jumps in through the grounding lines 60 and 62 and further absorbing radiant noise of the digital video signal processing boards 46 and 48 for reducing noise as a whole.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention is described in detail in the following order. Field of Industrial Application Conventional Technology Problem to be Solved by the Invention Means for Solving the Problem (FIGS. 3 to 5) Action (FIGS. 3 to 5) Example (1) Overall System Configuration (FIG. 1) (2) Camera control unit (FIGS. 2 to 5) (3) Effects of the embodiment (4) Other embodiments Effects of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing device, and can be applied to, for example, a camera control unit.

[0003]

2. Description of the Related Art Conventionally, among video equipment for broadcasting stations, a switcher and a video tape recorder are capable of processing a video signal converted into a digital signal (hereinafter referred to as a digital video signal). is there.

That is, in this type of video equipment,
By inputting a digital video signal from a separate analog digital conversion device or the like and processing this digital video signal, it is possible to prevent deterioration of image quality and repeat various processes any number of times.

[0005]

By the way, if digital video signals can be input / output between all video devices in a studio, various advantages such as simplification of connection between devices can be considered.

However, most of the video cameras currently in use output video signals in the form of analog signals, and even when various video devices are connected by digital video signals, such video cameras can be used. Need to connect.

In this case, a method in which an analog digital conversion circuit is housed in the camera control unit and a digital video signal is directly output by this can be considered.
That is, by incorporating an analog digital conversion circuit in the camera control unit, the configuration of the entire system can be simplified.

However, when the analog signal processing circuit and the analog digital conversion circuit are mixed in the camera control unit in this way, there is a problem that noise is mixed in the analog signal processing circuit. Especially in this type of digital video signal, by serial transmission,
Since the clock frequency is high, there is a problem in the analog signal processing circuit that the influence of noise becomes larger than that in the case where a normal digital circuit is mixed.

As one method for solving this problem, the entire analog signal processing circuit board is completely covered with a metal plate,
A method of shielding the analog signal processing circuit can be considered. However, this method has the drawback that the work becomes complicated during maintenance, and the heat dissipation of the analog signal processing circuit is also reduced, and the temperature rise cannot be avoided.

The present invention has been made in consideration of the above points, and in a video device in which an analog signal processing circuit and a digital signal processing circuit are mixed, noise jump can be reduced with a simple structure. It is intended to propose a video signal processing device.

[0011]

In order to solve the above problems, according to the present invention, analog video signal processing boards 42 and 44 for processing a video signal in the form of an analog signal,
Digital video signal processing boards 46 and 48 for converting a video signal into a digital video signal or a digital video signal into a video signal, and a predetermined shield plate 50.
The analog video signal processing boards 42 and 44 are sandwiched between
And a board housing section 26 for housing the digital video signal processing boards 46 and 48, and the analog video signal processing board 4.
2, 44 and digital video signal processing board 46, 48
The substrate storage unit 2 includes a power supply unit 28 for supplying power to the
Reference numeral 6 denotes a predetermined guide rail 36 on which analog video signal processing boards 42 and 44 and a digital video signal processing board 4 are provided.
By sliding 6 and 48 and inserting them into a predetermined connector 40, analog video signal processing boards 42 and 44
And the digital video signal processing boards 46 and 48 are held at predetermined positions, and the analog video signal processing boards 42 and 44, the digital video signal processing boards 46 and 48, and the power supply section 28 are connected to each other through the connector 40 to provide an analog video signal. The grounds 60 and 62 of the signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48 are individually led to the power supply section 28, and the power supply section 28 causes the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 4 to operate.
8 grounds 60 and 62 are connected to each other and the case 52
, The shield plate 50 is connected to the ground 62 of the digital video signal processing boards 46 and 48, and the analog video signal processing board 42 is connected through the connection line 62 from the digital video signal processing boards 46 and 48 to the power supply section 28. Four
4, the shield plate 50 is connected to the power supply unit 28 and the case 52.

[0012]

The earth 60 of the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48,
62 are individually led to the power supply unit 28, connected to each other and connected to the case 52, and the digital video signal processing board 4 is connected.
If the shield plate 50 is connected to the analog video signal processing boards 42, 44, the power supply unit 28, and the case 52 via the connection line 62 from the power supply unit 28 to the power supply unit 6, the noise that jumps in via the ground lines 60 and 62. The radiation noise of the digital video signal processing boards 46, 48 can be absorbed by the shield plate 50, and the noise can be reduced as a whole.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

(1) Overall Configuration of System In FIG. 1, reference numeral 1 denotes a video system as a whole,
The video signals of the video cameras 2 and 4 are recorded on the video tape recorder 6.

The video cameras 2 and 4 are controlled by camera control units 8 and 10, respectively, and are supplied with power via triax cables 12 and 14. This allows the video camera 2
And 4 output the video signal of the subject to the camera control units 8 and 10 in the form of analog signals via the triax cables 12 and 14.

The triax cables 12 and 14 are dedicated cables for transmitting video signals, respectively. Two signal lines for transmitting video signals are arranged at the center, and the outsides thereof are shielded by a mesh line. It is done like this.

Camera control units 8 and 10
Is connected to the set-up units 16 and 18 so that the video cameras 2 and 4 can be set to various states. Further, the camera control units 8 and 10 perform signal processing on the video signal input in the form of an analog signal and then convert the video signal into a digital video signal for output.

The switcher 20 inputs the digital video signals output from the camera control units 8 and 10, edits them, and outputs them to the video tape recorder 6. As a result, the video system 1 can operate the switcher 20 as necessary to perform editing processing.
The resulting video signal is recorded on the video tape recorder 6 in the form of a digital signal.

(2) Camera control unit Here, as shown in FIGS. 2 and 3, the camera control units 8 and 10 are designed so that the entire camera control unit 8 and 10 can be stored in a predetermined rack, and a rear part for connecting a triax cable. A terminal 22 and a terminal 24 for connecting the set-up unit are arranged. Further, the camera control units 8 and 10 are designed so that the front panel can be easily removed. By pulling out the panel from the rack and removing this panel, the signal processing board can be easily replaced.
It is designed to be maintainable.

That is, each of the camera control units 8 and 10 stores a signal processing board in a predetermined board housing 26, and a power supply block 28 is arranged adjacent to the board housing 26. Power supply block 2 here
8, a line filter 30 and a power transformer 32 are sequentially arranged from the rear side, and a secondary output of the power transformer 32 is stabilized by a power circuit unit 34 and output to each signal processing board, and a video is output via a terminal 22. It is adapted to output to the cameras 2 and 4.

On the other hand, the board housing section 26 inserts the wiring board into the connector 40 provided on the mother board 38 by pushing the wiring board into the board guide rail 36, and houses a total of four wiring boards. It is designed to be able to do.

As shown in FIG. 4, the camera control units 8 and 10 house the analog video signal processing boards 42 and 44 in the upper two wiring board housing positions, and the analog video signal processing boards 42 and 44 are input here in the form of analog signals. Process the video signal. Further, the camera control units 8 and 10 arrange the digital video signal processing boards 46 and 48 at the lower two storage positions and convert the video signals processed by the analog video signal processing boards 42 and 44 into digital video signals.

Further, the board housing section 26 includes an analog video signal processing board 42 and a digital video signal processing board 4.
A shield plate 50 is arranged between the six terminals, and the shield plate 50 is connected to the ground of the digital video signal processing boards 46 and 48 by the mother board 38.

At this time, the board housing portion 26 guides the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48 by the resin board guide rail 36, and holds the shield plate 50. The signal processing boards 42, 44, 46, 48 are held so that the ground and shield plates 50 do not directly contact the metal parts of the board housing section 26. As a result, in the camera control units 8 and 10, the board housing portion 26
And the ground and shield plate 50 of the signal processing boards 42 to 48
Is held so as not to be directly connected to the case 52.

As shown in FIG. 5, the motherboard 38 is
By soldering the connector 40 and connecting the connectors 40 via a predetermined wiring pattern, necessary signals are input / output between the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48. Further, the mother board 38 connects the terminals 22 and 24 on the rear surface to the connector 40, whereby the video signals can be input to the analog video signal processing boards 42 and 44 and the digital video signals can be output.

At this time, the mother board 38 insulates the ground lines 60 and 62 from the case 52, and further insulates the grounds 60 and 62 between the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48 from each other. Then, a wiring pattern is formed. Further, the mother board 38 guides the grounds 60 and 62 between the analog video signal processing boards 42 and 44 and the digital video signal processing boards 46 and 48 to the power supply block 28 independently of each other, and connects them to each other, and grounds the case 52. It is designed to do.

That is, when the signal level of the analog signal fluctuates in this kind of analog signal processing circuit, in many cases, the pulsation of the consumption current of the digital signal processing circuit is mixed into the ground line of the analog signal processing system. To do. Further, in the wiring in which the pulsation is mixed in the ground line as described above, the impedance of the ground line is high, and in this case, noise jumps in frequently.

However, as in this embodiment, when the output terminal of the power supply block 28 is connected to the ground, the analog signal processing circuit and the digital signal processing circuit are separated from each other, and finally the ground line is connected, Noise jumping from the digital signal processing circuit through the ground line can be reduced, and the noise can be reduced as a whole.

Further, the digital video signal processing board 4
Radiation noises from the antennas 6 and 48 can also be absorbed by the shield plate 50. By connecting the shield plate 50 to the ground of the digital video signal processing boards 46 and 48, it is possible to reduce the radiant noise jump.

Thus, the analog video signal processing board 4
2, 44 and digital video signal processing board 46, 48
In the above, since it is not necessary to cover the whole with a metal plate etc., it is possible to perform maintenance by simple work of removing the front panel and pulling it out, and the maintenance work can be simplified correspondingly Can also be simplified.

(3) Effects of the Embodiments According to the above construction, the shield plate is inserted to hold the analog video signal processing board and the digital video signal processing board, and the shield board is grounded to the digital video signal processing board. By connecting and grounding the analog video signal processing board and the digital video signal processing board independently to the power supply block, and connecting them to each other,
With a simple configuration, it is possible to reduce noise jumps without impairing maintainability.

(4) Other Embodiments In the above-mentioned embodiments, the case where the present invention is applied to the camera control unit which outputs a digital video signal has been described. However, the present invention is not limited to this, and the video signal is A video signal processing device for converting and processing digital video signals, and a video signal processing device for processing analog video signals and converting them to digital video signals. Conversely, a video signal processing device for converting digital video signals to analog signals. It can be widely applied to a video signal processing device that processes a signal in an analog signal format or a digital video signal format.

[0033]

As described above, according to the present invention, the analog video signal processing board and the digital video signal processing board are arranged with the shield plate sandwiched between them, and the shield board is connected to the digital video signal processing board for analog connection. By separating the ground of the video signal processing board and the ground of the digital video signal processing board and connecting them with the power supply section, with a simple configuration,
It is possible to obtain a video signal processing device that can reduce noise jumping.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a video system according to an embodiment of the present invention.

FIG. 2 is a plan view showing a camera control unit.

FIG. 3 is a front view of a camera control unit.

FIG. 4 is a perspective view of a camera control unit.

FIG. 5 is a plan view showing a mother board.

[Explanation of Codes] 8, 10 ... Camera control unit, 26 ... Board storage section, 28 ... Power supply block, 38 ... Motherboard, 40 ... Connector, 42, 44 ... Analog video signal processing board, 46, 48: Digital video signal processing board.

Claims (1)

[Claims] 1. An analog video signal processing board for processing a video signal in the form of an analog signal, and a digital video signal processing board for converting the video signal into a digital video signal or converting the digital video signal into the video signal. , A board housing unit for housing the analog video signal processing board and the digital video signal processing board with a predetermined shield plate interposed therebetween, and supplying power to the analog video signal processing board and the digital video signal processing board The board housing section includes a power supply section, a board housing section, and a case for housing the power supply section, and the board housing section slides the analog video signal processing board and the digital video signal processing board on a predetermined guide rail. By plugging in the connector, the above analog video signal processing board And the digital video signal processing board at a predetermined position, and the analog video signal processing board, the digital video signal processing board and the power supply unit are connected to each other through the connector, and the analog video signal processing board and the analog video signal processing board are connected. Lead the ground of the digital video signal processing board individually to the power supply unit,
In the power supply unit, the grounds of the analog video signal processing board and the digital video signal processing board are connected to each other and to the case, and the shield plate is connected to the ground of the digital video signal processing board to perform the digital video signal processing. A video signal processing device, characterized in that the shield plate is connected to the analog video signal processing board, the power supply section, and the case via a connection line from the board to the power supply section.