JPH05103329A - Receiver - Google Patents

Abstract

PURPOSE:To obtain such a receiver that the receiver does not cause such a state where no signal-processed output is obtained due to an erroneous operation by surely performing signal processing on either electric or optical signals even when the operator of the receiver does not recognize either signal being received. CONSTITUTION:This receiver is provided with a terminal 2 for receiving and inputting electric signals, terminal 4 for receiving and inputting optical signals, converter 6 which converts optical signals from the terminal 4 into electric signals, and a carrier detector 12 which detects the presence/absence of a carrier in the electric signals outputted from the converter 6. Then the receiver is constituted in such a way that the electric signals from the terminal 2 and electric signals from the converter 6 are selectively inputted to a signal processing circuit 14 in accordance with the output of the detector 12 so that an output can always be obtained from the circuit 14 when the signal is inputted to at least either one of the terminals 2 and 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver, and more particularly to a receiver capable of receiving both optical signals and electric signals.

[0002]

2. Description of the Related Art In a device (for example, TV-transceiver or CD player) for converting image signals and audio signals into digital signals and transmitting them between devices or to a remote place, a digital signal is transmitted as an electric signal. There is a method of converting into an optical signal and transmitting.

In general, this type of transceiver is provided with a terminal for inputting each signal and a selection switch on the receiving side so that the signal transmitted by either of these transmission methods can be used. User selected.

FIG. 5 is a block diagram showing an outline of a circuit on the receiving side of a transmitter / receiver constructed by using a conventional technique. The signal from the transmission side is input to the electric signal input terminal 2 as an electric signal through a coaxial cable or the like, and the optical signal input terminal 4
Is input as an optical signal through an optical fiber cable or the like.

This optical signal is converted to an optical-electrical converter (hereinafter referred to as O / E).
It is converted into an electric signal by the converter 6. The electric signal from the electric signal input terminal 2 and the electric signal from the O / E converter 6 are input to the signal selection switch 8 and either one is selected by the operation of the user, and the electric signal output terminal 16 continues to the next stage. It is output to the signal processing circuit.

[0006]

In such an apparatus in which there are a plurality of input signal forms and a plurality of input terminals and one of the input signals is selected, the user always determines to which input terminal the signal is input. It is necessary to grasp and operate the switch.

If the operation of this switch is forgotten or an erroneous operation is performed, the received signal is not output from the signal processing circuit in the subsequent stage. For example, when the signal to be transmitted is an image signal, such an operation error causes a situation in which the received image is not output during this period. Therefore, when the output of this type of receiving device is to be recorded by a VTR or the like, a definite failure such as a non-recorded portion is caused.

Under such a background, according to the present invention, even if the operator of the receiving device does not recognize what signal is being received, the signal processing can be surely performed on any one of the signals, and the signal processing output by the operation error. It is an object of the present invention to provide a receiving device that does not bring about such a situation that the above cannot be obtained.

[0009]

For such a purpose, in the receiving apparatus of the present invention, the first receiving means for receiving an electrical signal, the second receiving means for receiving an optical signal, and the optical signal are provided. Converting means for converting the signal into an electric signal; detecting means for detecting the presence or absence of the electric signal received by the first receiving means or the electric signal output from the converting means; and depending on the output of the detecting means Switching means for selectively outputting the electric signal received by the first receiving means and the electric signal output from the converting means, and signal processing means for processing the output of the switching means. It is configured.

[0010]

According to the receiving apparatus having the above-mentioned structure, the operator can process an appropriate signal without operating the apparatus, and the output from the signal processing means cannot be obtained. ..

[0011]

1 is a block diagram of a receiver according to a first embodiment of the present invention.

In the figure, constituent elements similar to those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted. The output of the O / E converter is input to the carrier detector 12 in this example. The carrier detector 12 outputs a Hi level by detecting the carrier when a signal is input,
When it is not input, it outputs Low level.

The signal from the electric signal input terminal 2 and the signal from the O / E converter 6 are input to the signal selection switch 8, which is controlled by the output of the carrier detector 12. When the signal is Hi level, O
Operates to output the signal from the / E converter 6,
When the level is set, the signal from the electric signal input terminal 2 is output. Further, when a signal is input to both the electric signal input terminal 2 and the optical signal input terminal 4, the carrier detector 12 outputs the Hi level, so that the signal from the O / E converter 6 is output. The signal from the signal selection switch 8 is input to the signal processing circuit 14, subjected to processing such as decoding and error correction, and then output from the output terminal 16 as an information signal such as an image signal.

In the receiving device having the above-mentioned configuration, the signal selection switch 8 is automatically controlled, so that the user does not have to care where the signal is input to a plurality of input terminals. .. In addition, when a signal is input to both the electrical signal input and the optical signal input, the side with the carrier detector, that is, the optical signal input is selected with priority,
In any case, an image output can be obtained from the output terminal 16.

In FIG. 2, in addition to the operation described in the first embodiment, a display device 18 and operation keys 22 are added so that the user can recognize the state of the carrier detector 12 (signal selection state). It is a figure which shows the 2nd Example of this invention.

As shown in FIG. 3, the display device 18 is attached to a position such as a front panel of the device which is easy to see. That is, when a signal is input to the optical signal input 4, the carrier detector 12 operates, and if the output of the operation key 22 is at the Hi level, the output of the AND gate 20 becomes at the Hi level and the display device 18 lights up. .. By attaching the display device 18, it is possible to confirm which of the electrical signal input and the optical signal input is selected. The operation key 22 is operated even when there is an input of an optical signal when it is desired to use the electric signal input, and by setting the output to the Lo level,
This is for setting the output of the AND gate to the Lo level.

In FIG. 4, in addition to the operation described in the first embodiment, a carrier detector 24 and a switch 26 are added to preferentially select either the electric signal input or the optical signal input. It is a figure which shows the 3rd Example which a user can set it.

The output of the carrier detector 24 is inverted in polarity as compared with the carrier detector 12, and outputs a Hi level when an electric signal is not input and outputs a Lo level when an electric signal is input. It is supposed to do.

First, the switch 26 is set to the carrier detector 12.
When the signal from is selected, the operation is the same as in the first embodiment, and the optical signal is selected with priority.

Next, when the switch 26 is selecting the signal from the carrier detector 24 and only the optical signal input is input, the output of the carrier detector 24 becomes Hi level, and the switch 8 switches the optical signal input. If the electric signal is input at this time, the output of the carrier detector 24 is Lo.
At the w level, the switch 8 preferentially selects the electric signal input. In this way, the priority of automatic selection is switched by operating the switch 26.

[0021]

As is apparent from the above description, the receiving apparatus of the present invention is configured to selectively process either signal by automatically detecting the input of an optical signal or the input of an electrical signal. Therefore, the signal processing can be surely performed on any of the signals without the operator performing any operation, and the state in which the output from the signal processing means cannot be obtained does not occur.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a receiving apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a receiving device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an external appearance of the receiving apparatus of FIG.

FIG. 4 is a block diagram showing a schematic configuration of a receiving apparatus according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a general configuration of a conventional receiving device.

[Explanation of symbols]

 2 electrical signal input terminal 4 optical signal input terminal 6 optical / electrical converter 8, 26 switch 12, 24 carrier detector 14 signal processing circuit 16 output terminal 18 display device 20 AND gate 22 operation key

─────────────────────────────────────────────────── ───Continued from the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H04N 5/44 Z 7037-5C

Claims (4)

[Claims] 1. A first receiving means for receiving an electrical signal, a second receiving means for receiving an optical signal, a converting means for converting the optical signal into an electrical signal, and the first receiving means. Detecting means for detecting the presence or absence of the received electric signal or the electric signal output from the converting means; and the electric signal received by the first receiving means according to the output of the detecting means and the converting means. A receiving device comprising: switching means for selectively outputting an electric signal to be output; and signal processing means for processing an output of the switching means. 2. Which of the electric signal received by the first receiving means and the electric signal output from the converting means is processed by the signal processing means in accordance with the output of the detecting means? The receiving apparatus according to claim 1, further comprising a display device for displaying. 3. The first irrespective of the output of the detecting means.
2. A manual operation member for forcibly supplying either the electric signal received by the receiving means or the electric signal output from the converting means to the signal processing means. Receiver. 4. The first detecting circuit for detecting the presence or absence of the electric signal received by the first receiving means, and the second detecting means for detecting the presence or absence of the electric signal output from the converting means. 2. The receiving device according to claim 1, further comprising a detection circuit for controlling the switching means by selectively using outputs of the first and second detection circuits.