JP2011015113A - Signal transmitter - Google Patents

Abstract

Even if a cable to be used is changed, attenuation compensation of an analog signal is appropriately performed.
An analog signal R, G, B is transmitted from a transmitter 3 to a receiver 4 via a cable 2. When the user inputs information about the type of cable 2 being used using the cable information input unit 8, the amplification factor selection unit 9 selects the amplification factor for the cable (first amplification factor for low frequency compensation). Then, the second amplification factor for high frequency compensation) is selected from the amplification factor storage unit 7. Then, when the user operates the variable specifying unit 11, adjustment according to the length of the cable 2 (adjustment of the amplification factor selected by the amplification factor selection unit 9) is performed. Then, the first attenuation compensator 5 and the second attenuation compensator 6 perform attenuation compensation for low and high frequencies using the adjusted amplification factor. According to the present invention, even if the cable to be used is changed, attenuation compensation of the analog signal is properly performed.
[Selection] Figure 1

Description

    The present invention relates to a signal transmission apparatus that transmits an analog signal from a transmitter to a receiver, and more particularly to a mechanism that compensates for attenuation of an analog signal caused by the transmission.

    Devices that transmit analog signals as they are without converting them into digital signals (referred to as “signal transmission devices” in this specification) are used in various places. For example, in a facility where many people come and go, such as department stores, shopping malls, stations, etc., a large monitor is placed, and a video signal (analog signal) is transmitted by the signal transmission device to display an image. (For example, see Patent Document 1).

    FIG. 3 is a schematic diagram illustrating an example of a conventional configuration of such a signal transmission apparatus, in which reference numeral 101 indicates a transmitter that transmits an analog signal (for example, a video signal such as an RGB signal), and reference numeral 102 indicates , A cable for transmitting the analog signal (for example, a category 5 twisted pair cable), and a reference numeral 103 indicates a receiver for receiving a signal transmitted through the cable 102. Reference numeral 104 denotes a device (for example, a personal computer) for inputting an analog signal to the transmitter 101, and reference numeral 105 denotes a monitor connected to the receiver 103 to display an image.

    By the way, when the analog signal is transmitted over a long distance by the signal transmission apparatus 100 as described above, the low frequency component and the high frequency component are particularly significantly attenuated. Since it varies depending on the length, two adjustment knobs (not shown) for low frequency and high frequency are provided on the receiver 103 side, and both analog controls on the receiver side are operated simultaneously. The signal was set to an appropriate waveform.

JP 2004-328661 A

    However, in order to operate the two adjustment knobs simultaneously as described above, a certain degree of familiarity is required.

    In addition, the degree of attenuation of the analog signal varies greatly depending not only on the length of the cable but also on the standard of the cable (for example, the standard of category 5 or category 6) and the manufacturer. For this reason, in a commercially available signal transmission apparatus, the standards and manufacturers of cables that can be used are limited in advance so that other cables are not used.

    An object of the present invention is to provide a signal transmission apparatus that can solve the above-described problems.

The invention according to claim 1 is illustrated in FIG. 1, and is connected to one end of the cable (2) and transmits an analog signal (R, G, B), and the cable. A signal transmission device (1) comprising: a receiver (4) connected to the other end of (2) and receiving an analog signal transmitted from the transmitter (3);
A first attenuation compensator (5) for performing attenuation compensation of one frequency component included in the analog signal transmitted to the receiver (4);
A second attenuation compensator (6) for performing attenuation compensation of other frequency components included in the analog signal transmitted to the receiver (4);
An amplification factor storage unit (7) that stores a first amplification factor for the first attenuation compensation unit (5) and a second amplification factor for the second attenuation compensation unit (6) according to the type of the cable (2). )When,
A cable information input unit (8) for inputting the type of the cable (2) actually used;
Based on the information input to the cable information input unit (8) and the data stored in the amplification factor storage unit (7), the first amplification factor and the second amplification factor relating to the cable (2) actually used. An amplification factor selection unit (9) for selecting
An amplification factor adjustment unit (10) that adjusts the first amplification factor and the second amplification factor selected by the amplification factor selection unit (9) according to a cable length.

The invention according to claim 2 is the invention according to claim 1, wherein each of the first amplification factor and each second amplification factor is stored in the amplification factor storage unit (7) in the form of a dependent variable of the independent variable x. And
The amplification factor adjusting unit (10) can be manually operated and can arbitrarily specify an independent variable x. A variable specifying unit (11), and a first corresponding to the independent variable x specified by the variable specifying unit (11). And an amplification factor reading unit (12) for reading out the amplification factor and the second amplification factor.

    Note that the numbers in parentheses are for the sake of convenience indicating the corresponding elements in the drawings, and therefore the present description is not limited to the descriptions on the drawings.

    According to the first aspect of the present invention, since the amplification factor storage unit stores the amplification factor for each type of cable, any cable can be used as long as data is stored in the amplification factor storage unit. Can be selected.

    According to the invention according to claim 2, since the two amplification factors of the first amplification factor and the second amplification factor are set only by designating one independent variable x by the variable designation unit, as in the conventional device. There is no need to adjust the two adjustment knobs at the same time, and the operation is simple.

FIG. 1 is a block diagram showing an example of the configuration of a signal transmission apparatus according to the present invention. FIG. 2 is a schematic diagram for explaining an example of data (first amplification factor and second amplification factor) stored in the amplification factor storage unit. FIG. 3 is a schematic diagram illustrating an example of a conventional configuration of a signal transmission device.

    Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The signal transmission apparatus according to the present invention is illustrated by reference numeral 1 in FIG.
A transmitter 3 connected to one end of the cable 2 for transmitting analog signals R, G, B;
A receiver 4 connected to the other end of the cable 2 for receiving an analog signal (an analog signal transmitted from the transmitter 3);
It has. Examples of the cable 2 include a category 5 twisted pair cable.

Further, the signal transmission device 1 according to the present invention is configured to compensate for attenuation accompanying the transmission of an analog signal. Specifically, the signal transmission device 1 according to the present invention includes:
A first attenuation compensator 5 that performs attenuation compensation of one frequency component (for example, a low-frequency component) that easily deteriorates among frequencies included in the analog signal transmitted to the receiver 4;
A second attenuation compensator 6 that performs attenuation compensation of other frequency components (for example, high frequency components) that are likely to deteriorate among frequency components included in the analog signal transmitted to the receiver 4; ,
It has.

The attenuation compensators 5 and 6 amplify each frequency component with an appropriate amplification factor. The signal transmission device 1 is provided with an amplification factor storage unit 7, and the storage unit 7
An amplification factor for the first attenuation compensator 5 (hereinafter referred to as “first amplification factor”);
An amplification factor for the second attenuation compensator 6 (hereinafter referred to as “second amplification factor”);
Is saved. Since the degree of attenuation of the analog signal varies depending on the type of cable used (manufacturer, standard, etc.) as described above, the first and second amplification factors stored in the amplification factor storage unit 7 are According to the type of cable. In other words, when data for six types of cables A, B, C, D, E, and F is stored,
The first and second gains for cable A The first and second gains for cable B The first and second gains for cable C The cable D The first gain and the second gain of the first and second gains for the cable E and the first and second gains for the cable F are stored separately. It becomes.

    The signal transmission device 1 according to the present invention is a cable for inputting the type of cable actually used (for example, information on which manufacturer's cable and information on which standard cable). An information input unit 8 is provided, and amplification is performed based on information input to the cable information input unit 8 and data stored in the amplification factor storage unit 7 (first amplification factor and second amplification factor). The rate selection unit 9 is configured to select a first gain and a second gain for a cable that is actually used. The cable information input unit 8 can be a known switch such as a dip switch. For example, when the cable information input unit (dip switch) 8 is operated so as to use the cable D, the amplification factor selection unit 9 reads “the first amplification factor and the second amplification factor for the cable D” from the amplification factor storage unit 7. Will be selected.

    By the way, even if the cables are of the same type, the degree of attenuation of the analog signal is different if the length is different. Therefore, it is necessary to perform attenuation compensation in consideration of not only the type of cable but also the length of the cable. For this purpose, an amplification factor adjustment unit 10 that adjusts the first amplification factor and the second amplification factor selected by the amplification factor selection unit 9 according to the cable length may be provided. It is better to configure as follows.

The first amplification factor and the second amplification factor (that is, the first amplification factor for a certain cable and the second amplification factor for a certain cable) stored in the amplification factor storage unit 7 are fixed values. Instead, it is in the form of a dependent variable of an independent variable x. That is, the amplification factor storage unit 7 stores data for each cable in the state of a function of the independent variable x and the amplification factor (dependent variable). FIG. 2 is a schematic diagram for explaining an example of data (first amplification factor and second amplification factor) stored in the amplification factor storage unit. FIG. 2 (a) shows data for one cable. Figure (b) shows data for other cables. In each figure, the vertical axis represents the amplification factor g, the horizontal axis represents the independent variable x, g1 represents the first amplification factor (dependent variable), and g2 represents the second amplification factor (dependent variable). The signal transmission device 1 includes
A variable specification unit 11 that can be manually operated and can arbitrarily specify an independent variable x;
An amplification factor readout unit 12 that reads out the first amplification factor and the second amplification factor corresponding to the independent variable x designated by the variable designation unit 11;
Is provided. Now, it is assumed that the data of FIG. 2B (first amplification factor and second amplification factor for a certain cable) is selected by the amplification factor selection unit 9 and x = a is specified by the variable specification unit 11 described above. Then, the first amplification factor ga1 and the second amplification factor ga2 are read by the amplification factor reading unit 12. In this case, the variable specifying unit 11 and the amplification factor reading unit 12 constitute the amplification factor adjusting unit 10 described above. Here, examples of the variable specifying unit 11 include known operation means such as a rotary volume (knob) and a touch panel. For example, when the analog signal to be transmitted is a video signal (for example, RGB signal) and the video is actually displayed on the monitor on the receiver side, is the length of the cable 2 100 m? There is no need to recognize whether the distance is 150 m, and it is only necessary to operate the variable designating unit 11 so that the video displayed on the monitor is appropriate. On the other hand, when the result of attenuation compensation cannot be immediately known, it is necessary to configure so that the length of the cable 2 being used can be input using the rotary volume or touch panel described above. is there. For example, in the case of a rotary volume, a scale (a scale indicating the cable length) may be provided around it, and in the case of a touch panel, the length of the cable may be directly input.

    The operation of the present invention is as follows. That is, when an analog signal is transmitted from the transmitter 3 to the receiver 4, when a user inputs cable information through the cable information input unit 8, data related to the cable (that is, the first function data). The amplification factor and the second amplification factor are selected by the amplification factor selector 9. Next, when the user operates the variable designating unit 11, the first amplification factor and the second amplification factor corresponding to the cable length are read, and the first attenuation compensation unit 5 performs attenuation compensation based on the first amplification factor. The second attenuation compensator 6 performs attenuation compensation using the second amplification factor.

    According to the present invention, since the amplification factor storage unit 7 stores the amplification factor for each type of cable, any cable can be selected as long as the data is stored in the amplification factor storage unit 7. can do. In addition, since only two independent amplification factors x are designated by the variable designation unit 11 described above, two amplification factors, the first amplification factor and the second amplification factor, are set. There is no need for adjustment and the operation is simple.

    The present invention can be applied to a device that transmits a video signal, but may be applied to a device that transmits an analog signal other than a video signal.

DESCRIPTION OF SYMBOLS 1 Signal transmission apparatus 2 Cable 3 Transmitter 4 Receiver 5 1st attenuation compensation part 6 2nd attenuation compensation part 7 Amplification rate preservation | save part 8 Cable information input part 9 Amplification rate selection part 10 Amplification rate adjustment part 11 Variable designation part 12 Amplification Rate readout unit

Claims (2)

A signal transmission apparatus comprising: a transmitter connected to one end of a cable for transmitting an analog signal; and a receiver connected to the other end of the cable for receiving an analog signal transmitted from the transmitter. In
A first attenuation compensation unit that performs attenuation compensation of one frequency component included in the analog signal transmitted to the receiver;
A second attenuation compensator for performing attenuation compensation of other frequency components included in the analog signal transmitted to the receiver;
An amplification factor storage unit that stores a first amplification factor for the first attenuation compensation unit and a second amplification factor for the second attenuation compensation unit for each type of cable;
A cable information input section for entering the type of cable actually used;
An amplification factor selection unit that selects a first amplification factor and a second amplification factor for a cable that is actually used based on information input to the cable information input unit and data stored in the amplification factor storage unit;
An amplification factor adjustment unit for adjusting the first amplification factor and the second amplification factor selected by the amplification factor selection unit according to the cable length;
A signal transmission device comprising: Each first amplification factor and each second amplification factor are stored in the amplification factor storage unit in the form of a dependent variable of the independent variable x,
The amplification factor adjusting unit reads a first amplification factor and a second amplification factor corresponding to the independent variable x designated by the variable designation unit that can be manually operated and can arbitrarily designate the independent variable x. An amplification factor reading unit;
The signal transmission device according to claim 1.

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