JPS62268284A - Catv receiver - Google Patents

Abstract

PURPOSE:To simultaneously receive signals in good condition with plural receivers even if the transmission signal is the digital signal on the like of high density by executing the proper characteristic correction of the signal by the cable compensation circuit of respective reccording to the length of the cables. CONSTITUTION:A transmission signal from a CATV center A is inputted to the input terminal 101 of a main receiver 10 from a terminal 14 through a transmission cable l1. A signal input part 102 is constituted of an impedance matching circuit and an impedance transformer, changes the impedance of the transmission signal to be suitable for the reception, and supplies it to the cable compensation circuit 103. The cable compensation circuit 103 can be so set as optimally corresponding to the length of the transmission cablel1. The output signal from the circuit 103 whose signal characteristic is thus compensated is supplied to the a terminal 105 and a signal output part 106. As a result, a reception in good condition can be executed by plural receivers 10, 11, and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a CATV receiving device that transmits television broadcast signals and the like by wire.

[Summary of the invention]

The present invention relates to a CATV receiving device that transmits television broadcast signals and the like by wire, and is provided between a signal input section and a signal output section consisting of an impedance matching device and an impedance converter, and between the signal input section and the signal output section. A cable compensation circuit is installed in the cable compensation circuit to compensate for changes in characteristics caused by the cable, and the compensation characteristics of the cable compensation circuit can be switched according to the length of the cable to the receiving device. Even if there are multiple receiving devices, good reception is possible.

[Conventional technology]

Conventionally, CAT transmits television broadcasts by cable.
V system was put into practical use. Television broadcasts are received by this CATV system by supplying a transmission signal supplied from the CATV center to the receiving household to a receiver installed in the receiving household.

In addition, when reception is performed by multiple receivers in a receiving household, for example, as shown in FIG. 22), and this distributor (
22) a receiver that distributes the transmission signal and requires it;
For example, the first receiver (23).

This split signal was supplied to the second receiver (24), third receiver (25), etc. In addition, as another configuration, for example, as shown in FIG.
A transmission signal is supplied to the receiver (23'), and this transmission signal is supplied to the demodulation circuit of the first receiver (23'), and is transmitted as it is (outputs No. 8 and transmits it to the second receiver (24).
'). Similarly, the second receiver (24') also supplies the transmitted signal to a demodulation circuit, etc., and outputs it as it is to the third receiver (25'). In this way, they were connected in series.

[Problem that the invention seeks to solve]

However, when the distribution is performed by the distributor (22) as shown in FIG. 3, there is a distribution loss, so each receiver (23) is divided.

The distribution signals supplied to (24), (25), . . . become attenuated signals, making it impossible to receive them well. In addition, as shown in Fig. 4 (when connected in series, the signal deteriorates in the order of the second receiver (24') and the third receiver (25').In particular, in recent years CATV A system has been proposed that uses high-density transmission lines to transmit digital signals other than television broadcasting at high density, but when transmitting such high-density digital signals, signal attenuation and deterioration occur. There was a risk that reception would not be possible at all.

In view of the above, an object of the present invention is to provide a CATV receiving apparatus that can simultaneously perform good reception with a plurality of receivers.

[Means for solving problems]

The CATV receiving device of the present invention includes, for example, as shown in FIG. , this signal human power section (102), (112) and the signal output section (10
6).

(116) between the cable e1. Cable compensation circuit (103), (1
13), and a cable compensation circuit l8 (103),
The correction characteristic of (113) is transmitted to the receiving device (10), (
11) can be switched according to the length of the cables Ill and N2.

[Effect]

According to the CATV receiving device of the present invention, each receiving device (1
0), (I]) cable compensation circuit (103).

(113) to perform appropriate signal characteristic correction IF according to the length of the cable 11.7!2, even if it is a high-density transmission signal such as a digital signal, multiple receiving devices (10)
, (11) ... allows good reception.

〔Example〕

Hereinafter, one embodiment of the CATV receiving device of the present invention will be described in the first embodiment.
This will be explained with reference to FIG.

An example in which the CATV receiving apparatus of this example is used in CATV using a digital multimedia service system (hereinafter referred to as a DMS system) as shown in FIG. 2 will be described.

(D D M S system is a transmission bag ffi fl
1 is installed on the CAT system center A side, and after multiplexing the various combination data signals, digital audio signals, etc. obtained in the transmission device W (11) using the method described later, this digital multiplexed signal is sent to the transmission signal mixing device. (5) is modulated into a signal with a band corresponding to one channel of the television broadcasting signal and is supplied to the transmission signal mixing device (5).
Then, the digital multiplex signal is mixed with the television broadcast signals of multiple channels by changing carrier waves, and this mixed signal is sent to multiple tuners (6a) installed in CATV center A.
, (6b), (6c)...

This tuner (6a), (6b), (6c
) are installed, for example, as many as the number of receivers who have contracted to use this CATV system, and each tuner (6a) is installed.

(6b), (6c), . . . are instructed to select a channel by a selection signal supplied from the receiving household B side, which will be described later.

Then, the signal of this designated channel is demodulated into a baseband demodulated signal, and each tuner (6a)
, (6b), (6c)... Photoelectric converter (7a), (7b), (7c)
This photoelectric converter (7a
), (7b), (7c)... convert the demodulated signal into an optical signal, and convert this optical signal into a photoelectric converter (7a).
, (7b), (7c) . . . a photoelectric converter (9a) installed on the receiver side of each home or the like.

(9b), (9c)... Optical fiber cable capable of bidirectional communication (8a), (8h),
(8c) Supplied via... For example, if this photoelectric converter (9C) is installed in the home of receiving household B, this photoelectric converter (9c) is connected to the main receiver (10) on the receiving household B side, and electrical demodulation is performed. The optical signal obtained by the photoelectric converter (9c) converted into a signal is sent to the main receiver (
10). This main receiver (10) sends the supplied demodulated signal to the TV adapter (10a) as a signal as it is, or to output terminals (10b) to (]Of) connected to various playback devices, etc., which will be described later. It is supplied as a signal that has undergone signal processing and is also sent to the first sub-receiver (11
), the second sub-receiver (12)... and the sub-receivers (1'l), (12)... connected in series in sequence. Also, this main receiver (1O) or this main receiver (
10) A remote controller that sends control signals to
R) allows you to select the reception channel, and the main receiver (
The received channel selection signal from 10) is sent to CAT via a path opposite to that of the demodulation signal described above, that is, a photoelectric converter (9c), an optical fiber cable (8C), and a photoelectric converter (7C).
Supplied to 1,1-s (6c) on the side of Sycenter A. This selection signal causes the tuner (6c) to control the transmission signal mixer (5).
), only the signal of a desired channel is demodulated from among the signals of a plurality of channels supplied from the receiver, and is supplied to the main receiver (10) on the receiving household B side. And this main receiver (10
), when the supplied demodulated signal is a television broadcasting channel signal, the demodulated signal is directly supplied to the 1゛■ adapter (1, Oa), and this TV adapter (loa) converts the television broadcasting signal. A certain demodulated signal is adjusted and supplied to a television receiver (13), and the television broadcast is viewed on this television receiver (13). Further, when the supplied demodulated signal is a channel signal of a digital multiplexed signal, predetermined signal processing is performed and a digital audio signal or data signal is supplied to any of the terminals (iob) to (10f).

This digital multiplexed signal is sent to the sending side, that is, CATV center A.
On the side, the system controller (3) in the transmission device (1)
), the transmission is controlled by the data converter (2), that is, the digitized still image signal obtained at the terminal (2a), the computer data signal obtained at the terminal (2b), and the obtained data at the terminal (2C). Telegraphic data signals obtained at the terminal (2d), facsimile data signals obtained at the terminal (2d), etc. are converted into signals suitable for formatting, which will be described later, under control from the system controller (3). Then, the converted data signal is supplied to the data transmitter (4), and the CD played by the CD ROM player (4b) is
I? OM playback data, a 2-channel stereo digital audio signal (16-bit signal according to standards such as CD) obtained at the terminal (4c), and a monaural digital audio signal (non-linear modulation) obtained at the terminal (4d). 8-bit signal) to the data transmitter (4). Necessary signals among the supplied signals are multiplexed in a predetermined format by the data transmitter (4) according to instructions from the system controller (3), and are converted into digital multiplexed signals. The signal is modulated into a signal with a band corresponding to one channel of the broadcast signal. In addition, when performing this multiplexing, the mode and special information of the multiplexed data are multiplexed using a predetermined format h. and,
This modulated digital multiplexed signal is converted into a transmission signal mixture value w(5
).

For example, when the tuner (6C) selects the channel corresponding to the digital multiplexed signal transmitted as described above based on the selection signal from the receiver 13 side, if the channel corresponding to the digital multiplexed signal transmitted as described above is rK is supplied to the main receiver (10) on the side of party B. When this digital multiplex signal is supplied to the main receiver (10), 'C'
1. For example, the mode and type information of the supplied signal are supplied to the output terminal (10e) so as to display the mode and type information of the signal supplied on the monitor receiver connected to the output terminal (FOE). do. Then, the recipient views the display on the monitor receiver and operates the front panel or remote controller (IOR) of the main receiver (10).
Select necessary data etc. from the multiplexed digital signals, and output the selected signals to corresponding output terminals (10b).
-(10f). That is, for example, when a digital audio signal or digital audio signal is selected, this digital audio signal or digital audio signal is supplied to the terminal (1, Ob) connected to the stereo playback device, and when a CD ROM playback data signal is selected, the CD Terminal connected to ROM data decoder (10c
), and when a facsimile data signal is selected, this facsimile data signal is supplied to the terminal (LOD) connected to the facsimile device, and when a still image signal is selected, the facsimile data signal is supplied to the terminal (LOD) connected to the monitor receiver. This still image signal is supplied to a terminal (10e) connected to the personal computer, and when a computer data signal is selected, this computer data signal is supplied to a terminal (lof) connected to a personal computer.

In this way, the reception 1q band B is sent to the CATV center 8 side.
An OMS system is constructed in which a digital data signal is supplied together with a television broadcast signal to each device using a CATV line.

Next, the main receiver t) 31 of this example used in this receiving household B
(10) and sub-receiver (11), (12) ・
The configuration of ... will be explained. Figure 1 shows the main receiver (10
) and the configuration of the signal person output section of the first sub-receiver (1j) and its vicinity are shown in the Neo diagram, and the second sub-receiver (12) has a similar configuration.

First, a transmission signal from CATV center A is obtained at the supply terminal (14) of this receiving household B, and from this terminal (14) via the transmission cable β1, the input terminal (1,01> This input terminal (1
The transmission signal obtained at 01, ) is supplied to the signal human power section (102). This signal input section (102) is composed of an impedance matching device and an impedance converter, and supplies the impedance of the transmission signal to a cable compensation circuit (103) as being suitable for reception. This cable compensation circuit (103) is connected to the transmission cable 1 in the receiving household B.
This circuit compensates for the signal characteristics attenuated by 1. The compensation characteristics are controlled by the compensation characteristic setting circuit (104), and can be set in several stages by this setting circuit (104), depending on the length of the transmission cable 11. Optimal settings can be made. Cable compensation circuit (
103) to the terminal (105) and the signal output section (1
06). The transmission signal obtained at this terminal (105) is transmitted to the receiving circuit (not shown) of the receiver (10).
and receives television broadcasts or various digital data. Further, the signal output section (106) is composed of an impedance matching device and an impedance converter, and supplies the impedance of the transmission signal to an output terminal (107) as one suitable for transmission. Then, a transmission signal is supplied from the output terminal (107) to the input terminal (111) of the first sub-receiver (11) via the transmission cable 12.

The configuration of the signal output section and its vicinity of the first sub-receiver (11) is the same as that of the main receiver (10). That is, the transmission signal is supplied from the input terminal (iFl) to the cable compensation circuit (113) via the signal input unit (1, 12) that performs impedance matching and conversion, and the cable compensation circuit (113)
Then, the characteristics set by the compensation characteristic setting circuit (114) are compensated, and the output signal of each cable compensation circuit (113) is supplied to the terminal (115) and the signal output section (116). It is assumed that the compensation characteristics of this cable compensation circuit (113) correspond to the length of the transmission cable la2 connecting the main receiver (10) and the first sub-receiver (11). Then, the transmission signal obtained at the terminal (115) is transmitted to the receiver (11).
The signal output section (116) performs impedance matching and adjustment, and the output signal of the signal output section (116) is supplied to the output terminal (117).
). When further connecting a receiver, the output terminal (117) is connected to another receiver such as the second sub-receiver (12) via the transmission cable 13.

By having the receiver of this example configured as described above, the first sub-receiver (11) is connected in series to the main receiver (10).

Even if connected to the second sub-receiver (12)..., the respective receivers (10), (11), (12)...
・In order to compensate for the signal characteristics corresponding to the length of the transmission cable zi, le2+ #3..., the respective receivers (10).

(11) , (12) . . . receive good signals with signal compensation. For this reason, multiple receivers (10), (11), (12)
It is possible to receive good reception by multiple receivers even when transmitting signals with high area density such as digital signals, and it is possible to receive good reception by multiple receivers. We can provide you with the best service. In addition, the signal compensation characteristics of the transmission cable '1+7!2. #3 ... can be set freely according to the length, so each receiver (10)
, (11), (12)... can perform optimal signal compensation.

It should be noted that the present invention is not limited to the two-part embodiment, and it goes without saying that various other configurations can be taken without forming a film based on the gist of the present invention.

〔Effect of the invention〕

According to the CATV receiving device of the present invention, each receiving device (1
0), (11)...(7) Cable compensation circuit (103).

(113) In order to perform appropriate signal characteristic correction according to the length of the cables 11, 12..., multiple receiving devices (10 ), (11) . . . has the advantage of good reception.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the CATV receiving device of the present invention, FIG. 2 is a system diagram of a DMS system, and FIGS. 3 and 4 show examples of connection states of conventional receiving devices, respectively. FIG. (10) is the main receiver, (11) is the first sub receiver, (10
2), (112) a signal input section, (103); (113) is a cable compensation circuit, (104), (
1, 14> is a compensation characteristic setting circuit, (106), (
116) is a signal output section, and β□+7!2+13 is a transmission cable.

Claims (1)

[Claims] A signal input section and a signal output section comprising an impedance matching box and an impedance converter, and a cable compensation circuit for correcting characteristic changes due to the cable are provided between the signal input section and the signal output section, and the cable compensation circuit A CATV receiving device characterized in that the correction characteristic of the signal can be switched according to the cable length to the receiving device.