JP3779796B2 - LVDS signal distributor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an LVDS signal distributor suitable for use in distributing an LVDS signal (low voltage differential signaling signal) to a plurality of systems.
[0002]
[Prior art]
In general, in a manufacturing inspection process of a flat panel display such as a liquid crystal display or a plasma display, a display test is performed by assigning a test pattern using a digital video signal to many manufactured displays.
[0003]
By the way, the distance at which a high-speed digital video signal can be transmitted by a general cable line is limited to about 50 cm, and electrical stability and reliability cannot be ensured at a distance longer than this because of the high speed of the signal. Therefore, normally, when transmitting a distance longer than this, the digital video signal is once converted into an LVDS signal with little signal deterioration even at a long distance transmission, and this LVDS signal is transmitted by a cable line. . In this case, on the receiving side, the LVDS signal is distributed to a plurality of systems by an LVDS signal distributor connected to the end of the cable line, and the distributed LVDS signal is converted into a digital video signal and then applied to each display. It was.
[0004]
Conventionally, an LVDS signal distributor used for this kind of application usually includes an input unit for receiving an LVDS signal, an LVDS signal receiving circuit for converting the LVDS signal input to the input unit into a digital signal, and the digital signal. A distribution circuit that distributes signals to a plurality of systems, a plurality of LVDS signal transmission circuits that convert and output the distributed digital signals to LVDS signals, and a plurality of output units that output LVDS signals from each LVDS signal transmission circuit These parts are configured integrally or by a combination of a mother board and a daughter board. Since distribution of the LVDS signal is electrically difficult, it is once converted into a digital signal and distributed.
[0005]
[Problems to be solved by the invention]
However, the conventional LVDS signal distributor has the following problems.
[0006]
First, since it is necessary to secure a certain number of distributions per unit, the size and cost of the distributor are increased.
[0007]
Secondly, since the wiring inside the distributor is complicated and long, there is a possibility that the digital signal will deteriorate inside the distributor, resulting in poor electrical stability and reliability.
[0008]
Third, since the number of distributions per unit is fixed, an output unit that cannot be used is generated depending on the use situation, and there are difficulties in use efficiency, usability, and convenience.
[0009]
The present invention solves such problems existing in the prior art, and can greatly reduce the size and cost per unit, as well as ensure electrical stability and reliability, and can be used. An object of the present invention is to provide an LVDS signal distributor capable of dramatically improving efficiency, usability, and convenience.
[0010]
[Means for Solving the Problems and Embodiments]
The LVDS signal distributor 1 according to the present invention includes an input unit 2 to which an LVDS signal Sx is input, an LVDS signal reception circuit 3 that converts the LVDS signal Sx input to the input unit 2 into a digital signal Sy, and outputs the digital signal Sy. A distribution circuit 4 that distributes the digital signal Sy to one or more systems, and one or more LVDS signal transmission circuits 5a, 5b that convert the distributed digital signal Sy to an LVDS signal Sx and output it. , One or two or more output units 6a, 6b,... For outputting the LVDS signals Sx from the LVDS signal transmission circuits 5a, 5b, and the distribution circuit 4 to input digital signals Sy from other signal distributors. A first connector unit 7 that outputs a digital signal Sy from the distribution circuit 4 to another signal distributor, and a digital signal Sy that is output from the distribution circuit 4 to another signal distributor. Characterized in that it comprises a second connector portion 8.
[0011]
In this case, according to a preferred embodiment, the first connector portion 7 and the second connector portion 8 are configured to be connectable to each other. The second connector section 8 is connected to the distribution circuit 4 via the latch circuit 9, and the LVDS signal transmission circuits 5a, 5b... Are connected to the distribution circuit 4 via the latch circuits 10a, 10b.
[0012]
Therefore, a plurality of LVDS signal distributors 1a, 1b, 1c... Are prepared, and an arbitrary LVDS signal distributor, for example, an input connector part 7 of the LVDS signal distributor 1b is connected to an output connector part of another LVDS signal distributor 1a. 8 and connecting the input connector part 7 of another LVDS signal distributor 1c to the output connector part 8 of the arbitrary LVDS signal distributor 1b, a plurality of LVDS signal distributors 1a, 1b, 1c can be connected. Can be connected sequentially. If the LVDS signal Sx is input to the input unit 2 of one LVDS signal distributor 1a, the LVDS signal Sx is converted into the digital signal Sy by the LVDS signal receiving circuit 3, and then applied to the distribution circuit 4. The distributed digital signal Sy... Is converted to the LVDS signal Sx... By the LVDS signal transmission circuits 5a, 5b. Output from the units 6a, 6b. At the same time, the digital signal Sy given to the distribution circuit 4 of the LVDS signal distributor 1a is output from the second connector unit 8, and the LVDS signal distributor from the first connector unit 7 of the other LVDS signal distributor 1b. 1b is directly applied to the distribution circuit 4 and output from the second connector portion 8 of the LVDS signal distributor 1b, and distributed from the first connector portion 7 of the other LVDS signal distributor 1c to the LVDS signal distributor 1c. Applied directly to the circuit 4. As a result, similarly distributed LVDS signals Sx ... are output from the output units 6a ... in the LVDS signal distributors 1b and 1c.
[0013]
As described above, a plurality of LVDS signal distributors 1 (1a, 1b, 1c...) Can be connected and used as necessary, so that the number of distributions per unit can be reduced, and miniaturization and cost reduction can be achieved. In addition, utilization efficiency, usability and convenience are improved. In particular, if the digital signals Sy... Are output via the latch circuits 9, 10a, 10b..., Even if a large number of LVDS signal distributors 1 (1a...) Are connected, deterioration of the digital signals Sy. .
[0014]
【Example】
Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.
[0015]
First, the configuration of the LVDS signal distributor 1 according to the present embodiment will be described with reference to FIG.
[0016]
Reference numeral 21 denotes a rectangular substrate, which is accommodated in a casing if necessary. Reference numeral 2 denotes a connector-type input unit provided on one side of the substrate 21, and the input unit 2 is connected to the input side of the LVDS signal receiving circuit 3. The LVDS signal receiving circuit 3 has a function of converting the input LVDS signal Sx into a digital signal Sy and outputting the digital signal Sy. The output side of the LVDS signal receiving circuit 3 is connected to the distribution circuit 4. The distribution circuit 4 includes a bus line 22 that distributes the digital signal Sy into two systems, and the output ends of the branched bus lines 22a and 22b are connected to the input sides of the latch circuits 10a and 10b, respectively, and the latch circuits 10a and 10b. Is connected to the input side of the LVDS signal transmission circuits 5a and 5b. Each of the LVDS signal transmission circuits 5a and 5b has a function of converting the input digital signal Sy... Into an LVDS signal Sx..., And a connector-type output unit 6a on the output side of each LVDS signal transmission circuit 5a and 5b. , 6b. In this case, the output units 6a and 6b are provided on the side of the substrate 21 opposite to the side on which the input unit 2 is provided. Reference numeral 23 denotes a switch for turning on / off the signal output of the LVDS signal receiving circuit 3.
[0017]
On the other hand, according to the present invention, the first connector portion 7 and the second connector portion 8 are provided on each side orthogonal to the side where the input portion 2 and the output portion 6a. The first connector portion 7 is connected to the bus line 22 in the distribution circuit 4. As a result, the digital signal Sy from the other LVDS signal distributor input to the first connector section 7 is directly applied to the distribution circuit 4. The second connector portion 8 is connected to the bus line 22 in the distribution circuit 4 via the latch circuit 9. Thereby, the digital signal Sy of the distribution circuit 4 is directly applied to the distribution circuit 4 in another LVDS signal distributor via the latch circuit 9 and the second connector unit 8. In this case, the 1st connector part 7 and the 2nd connector part 8 have a structure which can be connected mutually.
[0018]
Next, the operation and usage of the LVDS signal distributor 1 (1a ...) according to this embodiment will be described with reference to FIGS.
[0019]
First, as shown in FIG. 2, a plurality of LVDS signal distributors 1a, 1b, 1c, 1d, and 1e are prepared. An output connector 8 of another LVDS signal distributor 1a is connected to an input connector 7 of an LVDS signal distributor, for example, an LVDS signal distributor 1b, and an output connector of the arbitrary LVDS signal distributor 1b. If the input connector portion 7 of another LVDS signal distributor 1c is connected to the portion 8, a plurality of LVDS signal distributors 1a, 1b, 1c can be sequentially connected.
[0020]
A connector 25 on the signal generator 28 side is connected to the input unit 2 of the LVDS signal distributor 1a. A signal generator 28 is connected to the connector 25 via a relatively long cable line 26 and an LVDS signal transmitter 27. On the other hand, a connector 29 on the liquid crystal display 31... Side is connected to each output section 6 a, 6 b... Of each LVDS signal distributor 1 a, 1 b, 1 c, 1 d. A liquid crystal display 31 to be tested is connected to each connector 29 through an LVDS signal receiver 30. Therefore, the display test of the liquid crystal displays 31 can be performed by such a system.
[0021]
First, the digital video signal (test pattern) output from the signal generator 28 is converted into the LVDS signal Sx by the LVDS signal transmitter 27, and this LVDS signal Sx is input to the LVDS signal distributor 1a via the cable line 26. To 2. The LVDS signal Sx input to the input unit 2 is converted into a digital signal Sy by the LVDS signal receiving circuit 3 and then given to the distribution circuit 4 and distributed to two systems. The distributed digital signals Sy are latched by the latch circuits 10a and 10b, respectively, and the latched digital signals Sy are applied to the LVDS signal transmission circuits 5a and 5b, respectively. The digital signals Sy... Are converted into LVDS signals Sx... By the LVDS signal transmission circuits 5a and 5b, and then given to the LVDS signal receivers 30 through the output units 6a, 6b. The LVDS signals Sx... Are converted into digital signals (digital video signals) Sy... By the respective LVDS signal receivers 30.
[0022]
In addition, the digital signal Sy given to the distribution circuit 4 of the LVDS signal distributor 1a is output from the second connector unit 8, and is transmitted from the first connector unit 7 of the other LVDS signal distributor 1b to the LVDS signal distributor 1b. It is given directly to the distribution circuit 4 and is output from the second connector part 8 of the LVDS signal distributor 1b, and from the first connector part 7 of the other LVDS signal distributor 1c, the distribution circuit 4 in the LVDS signal distributor 1c. Granted directly to. As a result, similarly distributed LVDS signals Sx... Are output from the output units 6 a in the LVDS signal distributors 1 b and 1 c and are given to the liquid crystal displays 31.
[0023]
Thus, since the LVDS signal distributor 1 (1a ...) according to the present embodiment can be used by connecting a plurality of them as necessary, the number of distributions per unit can be reduced, and a significant reduction in size and In addition to cost reduction, it is possible to dramatically improve usage efficiency, usability and convenience. Further, since the digital signal Sy... Is output via the latch circuits 9, 10a, 10b..., Even if a large number of LVDS signal distributors 1 (1a...) Are connected, the deterioration of the digital signal Sy. Stability and reliability can be secured.
[0024]
Although the embodiments have been described in detail above, the present invention is not limited to such embodiments, and the detailed configuration, method, etc., can be arbitrarily changed, added, or deleted without departing from the spirit of the present invention. can do.
[0025]
For example, as shown in FIG. 2, a connection cable 32 is prepared, and an arbitrary connected LVDS signal distributor, for example, the output section 6b of the LVDS signal distributor 1c and the input section 2 of another LVDS signal distributor 1e are connected. You may connect and use with the cable 32. FIG. Moreover, although the Example showed the case where the two output parts 6a and 6b were provided, three or more may be sufficient and one may be sufficient. One case is a special form of distribution. The LVDS signal distributor can also be used as an LVDS signal repeater for the purpose of further extending the transmission distance.
[0026]
Further, the first connector section 7 shown in FIG. 1 has a function for inputting the digital signal Sy from another signal distributor to the distribution circuit 4, but the digital signal from the distribution circuit 4 to the other signal distributor is provided. A function of outputting Sy may be provided. In this case, a latch circuit is connected between the first connector portion 7 and the distribution circuit 4 in the same manner as the second connector portion 8. As described above, when an LVDS signal distributor having an output function in both the first connector section 7 and the second connector section 8 is used, the signal generator 28 is connected to the LVDS signal distributor and the LVDS signal is connected. Other LVDS signal distributors can be connected in both directions around the distributor.
[0027]
On the other hand, the positions shown in FIGS. 3 and 4 may be selected for the first connector portion 7 and the second connector portion 8. In FIG. 3, the first connector portion 7 is surface-mounted at the center of the upper surface of the substrate 21, and the second connector portion 8 is surface-mounted at the center of the lower surface of the substrate 21. As a result, the LVDS signal distributors 1a, 1b,. 4 shows the first connector portion 7 provided on one side of the upper surface of the substrate 21 and the second connector portion 8 provided on the other side of the lower surface of the substrate 21. In this case, the LVDS signal distributors 1a, 1b,... Can be connected vertically so that they overlap, but one side and the other side of the LVDS signal distributors 1a, 1b,. 3 and 4, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the configuration is clarified.
[0028]
Furthermore, although the embodiment exemplifies a case where a display test of a liquid crystal display is performed as an application of the LVDS signal distributor, it can be used for various other applications for distributing the LVDS signal to a plurality of systems.
[0029]
【The invention's effect】
As described above, the present invention relates to an LVDS signal distributor that distributes an LVDS signal to a plurality of systems. In particular, a digital signal from another signal distributor is input to a distribution circuit or a digital signal is distributed from the distribution circuit to another signal distributor. Since the first connector portion for outputting a signal and the second connector portion for outputting a digital signal from the distribution circuit to another signal distributor are provided, the following remarkable effects can be obtained.
[0030]
(1) The number of distributions per unit can be reduced, the size and cost can be greatly reduced, and the utilization efficiency, convenience and convenience can be dramatically improved.
[0031]
(2) According to a preferred embodiment, if a digital signal is output via a latch circuit, even if a large number of LVDS signal distributors are connected, deterioration of the digital signal can be prevented, and electrical stability and reliability can be prevented. Can be secured.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram of an LVDS signal distributor according to an embodiment of the present invention;
FIG. 2 is a system diagram for explaining how to use the LVDS signal distributor;
FIG. 3 is a side view showing a connection state of an LVDS signal distributor according to a modified embodiment of the present invention;
FIG. 4 is a side view showing a connection state of an LVDS signal distributor according to a modified embodiment of the present invention;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 LVDS signal distributor 2 Input part 3 LVDS signal receiving circuit 4 Distribution circuit 5a ... LVDS signal transmission circuit 6a ... Output part 7 First connector part 8 Second connector part 9 Latch circuit 10a ... Latch circuit Sx LVDS signal Sy Digital signal

Claims (4)

An input unit for receiving an LVDS signal (low voltage differential signaling signal), an LVDS signal receiving circuit for converting the LVDS signal input to the input unit into a digital signal and outputting it, and one or more systems of the digital signal A distribution circuit that distributes the LVDS signal, one or more LVDS signal transmission circuits that convert and output the distributed digital signal to an LVDS signal, and one or more outputs that output the LVDS signal from each LVDS signal transmission circuit And a first connector for causing the distribution circuit to input a digital signal from another signal distributor or to output a digital signal from the distribution circuit to another signal distributor, and from the distribution circuit to another signal distributor. And an LVDS signal distributor, comprising: a second connector portion for outputting a digital signal to the LVDS signal distributor. 2. The LVDS signal distributor according to claim 1, wherein the first connector part and the second connector part are configured to be connected to each other. 2. The LVDS signal distributor according to claim 1, wherein the second connector portion is connected to the distribution circuit via a latch circuit. 2. The LVDS signal distributor according to claim 1, wherein the LVDS signal transmission circuit is connected to the distribution circuit via a latch circuit.

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