JP2742760B2 - Information display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a display unit in which a large number of display elements such as light-emitting diodes (particularly, display elements of different colors) are arranged in a matrix and turns on any display element to display characters, figures, etc. The present invention relates to an information display device for displaying the information.

[0002]

2. Description of the Related Art In the above-mentioned information display apparatus, a total of 256 display elements, such as 16 light-emitting diodes, are arranged in a matrix in a matrix form in consideration of manufacturability, maintainability and the like, as one display unit. None, the display units have a structure in which a large number of display units are arranged in a matrix. If one display unit fails for some reason, the failed display unit is separated and displayed.

The circuit of a conventional display unit is shown in FIG. 4 and the entire circuit of an information display device is shown in FIG. 5, and this circuit will be described. As shown in FIG. 5, a large number of display units 2 are arranged in a matrix in the information display device 1, and the control unit 3 sends the display data to each display unit 2 as a serial signal in response to a command from a central device (not shown). The feed display is performed.

Each of the display units 2 is, as shown in FIG.
A display element array 21 in which light emitting diodes 21a are arranged in a matrix to perform display, a latch drive circuit 22 for storing display data and driving the display element,
A required number of shift register circuits 23 corresponding to the number of display elements for inputting serial format display data and outputting serial data and parallel data, a switch circuit 24 for switching the display data transmission direction, and a faulty display unit. And a switch circuit 25 for separating the display unit from other display units.

A signal line SL for transmitting a signal for switching the transmission direction of the display data is provided to the switch circuit 24.
However, a signal line DT for transmitting a signal for disconnecting the failed display unit 2 is connected to the switch 25.

In the above description, the latch / drive circuit 22 and the shift register circuit 23 are represented as one block, but these are usually composed of a plurality of circuits. In FIGS. 4 and 5, a clock signal for shifting serial data, a latch signal for storing data in the latch drive circuit 22, and the like are well known, and thus those signal lines are omitted.

Next, the operation will be described based on the above configuration. When the same display data is transmitted twice in the direction of arrow A (positive direction) from the terminal Df of the control unit 3, all the display units 2 are normally operated. In this case, the last display unit 2n
The same data as the display data transmitted from is returned to the control unit 3.

As a result, the data coincidence is confirmed by the control unit 3, and it is determined that there is no failure. Then, after confirming the data coincidence, the control unit 3 transmits a latch signal to the latch drive circuit 22, stores the display data in each latch drive circuit 22, and turns on the light emitting diode 21a corresponding to the display data. Displays characters, figures, etc.

On the other hand, the shift register 2 of the display unit 2
3 has failed, the last display unit 2n
Is a continuous signal of "0" or "1", the control unit 3 does not confirm that the display data matches, and determines that there is a failure.

In this case, the control unit 3 sends a select signal for switching the transmission direction from the terminal SELECT via the signal line SL to the switch circuit 24 to switch the line connection from AY to BY. The display data currently held in the shift register circuit 23 is returned from the terminal Db of the control unit 3 in the direction of arrow B (the reverse direction).

Thus, the display data transferred in the reverse direction by the control unit 3 is compared with the original display data obtained by converting the data array and matching the order of the data to find the position where the data mismatch starts. Detects a fault display unit. Then, a signal line wired one-to-one to the display unit from the terminal DETOUR of the control unit 3 for the detected failure display unit is disconnected from the display unit via DT.
A DETOUR signal is sent to the switch circuit 25 to switch the line connection from AY to BY.

After performing the above processing and confirming that the display data is not included in the failure display unit,
The display is performed by transmitting compressed (omitted) data of the display data at the position corresponding to the failed display unit from the control unit 3.

Further, in the above-described conventional example, the description has been given of the case where the transmission direction of the display data is switched by the switch circuit 24. However, by using a shift register circuit having an input terminal for switching the shift direction, the switching circuit 2 is switched.
4 may be omitted. In this case, the signal line SL is directly connected to the shift direction switching terminal of the shift register circuit 23, and the signal line Db is directly connected to the serial signal input terminal of the shift register circuit 23, and the control unit 3 switches to the signals Df and Db. .

[0014]

By the way, in the conventional information display device described above, the circuit configuration is simple, and the disconnection operation of the disconnection operation is performed by connecting the disconnection signal line of the display unit on a one-to-one basis. Although there is an advantage that certainty is ensured, there is a problem that the wiring becomes very complicated since several signal lines are required for the display unit.

There is also a method in which address data of a failed display unit is sent as a serial signal from the control unit to disconnect the display unit. However, in this method, malfunction is likely to occur due to noise or the like. There was a problem.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide an information display device capable of separating a highly reliable fault display unit even with a simple circuit configuration. To offer.

[0017]

SUMMARY OF THE INVENTION An information display device according to the present invention is intended to solve the above-mentioned problems.
Each display unit is provided with a disconnection signal determination circuit for disconnecting the failed display unit via the switch by the display data and the clock signal, and the control unit controls the clock of the number of addresses corresponding to at least two display elements in the failed display unit. The fault display unit is separated by transmitting a signal and two display data whose state has changed.

[0018]

According to the information display apparatus of the present invention having the above-described structure, the control unit controls at least two of the failed display units.
By transmitting display data of two display elements and a clock signal corresponding to the address of the corresponding display element, and latching the switching of the display data by the clock signal as a disconnection signal of the faulty display unit,
A highly reliable display unit is separated.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the information display device according to the present invention will be described below with reference to FIGS. In FIG.
Reference numeral 25 is the same as the above-described conventional circuit block, and a description thereof will be omitted. However, in the present invention, the display data transmission direction is changed in order to use the individual display data for the red and green light emitting elements constituting the two-color light emitting diode as the disconnection signal condition of the failure display unit 2. The switch circuit 24 for switching is connected to a red signal line RD and a green signal line GD as display data signal lines. The switch 25 for disconnecting the display unit 2 is also connected to the signal lines RD and GD similarly to the switch 24.

Reference numeral 26 denotes a signal decision circuit, which comprises four D-type flip-flop circuits 26a, one AND circuit 26b, and a JK type flip-flop circuit 26c. (Not shown) from the signal lines RDf, GDf in the positive direction and the clock signal line
CLOCK and display data explained in the previous example are latched.
The shared signal line LATCH for storing in the drive circuit 22 is connected.

Next, the operation of the present invention will be described with reference to the timing chart of FIG.
The operation until the failure display unit is specified is the same as that in the above-described conventional example except that the number of signal lines for display data is two, and thus the description is omitted.

First, for the failed display unit 2, the control unit determines addresses of specific red / green display elements in the failure display unit, for example, 255th and 256th display elements, and corresponds to the terminal c. The clock signal up to the element to be input is input. In addition, a signal for switching the display data of the corresponding display element from low to high for the red display element and high to low for the green display element is input from terminals a and b, respectively.

Since the display data signal is monitored only for the 255th and 256th elements, any other data may be used.
Then, by inputting the 255th and 256th display data and the clock signal, the pulse signals shown in FIG. 2 are output to the terminals d to g.

The signals from the D-type flip-flop circuit 26a at the preceding stage are delayed due to signal propagation, so that the terminals d and f become high level with the 256th clock signal, and the 257th signal is not input. A high-level signal is input to the AND circuit 26b, and J-
A high-level signal is input to the h terminal of the K-type flip-flop circuit 26c.

In this state, after a lapse of a predetermined time, the latch signal i is input from the signal line LATCH to the i terminal of the JK flip-flop circuit 26c to latch the disconnection signal of the display unit 2.

Then, the line connection of the switch 25 for disconnecting the display unit 2 is set to 1A, 2A =
By switching from 1Y, 2Y to 1B, 2B = 1Y, 2Y, it is possible to form a bypass line avoiding the shift register circuit 23 and to perform a display avoiding the failure display unit described in the above-described conventional example. .

In the above-described embodiment, the case where the separation signal of the display unit is generated based on the condition of the two signals of red / green and the clock signal has been described. However, the separation signal from either one of the signals and the clock signal is generated. Even if you generate
It is possible to perform control without malfunction.

Next, another embodiment of FIG. 3 will be described. The signal judging circuit 26 in the first embodiment has four D-type flip-flop circuits 26a, one AND circuit 26b, and JK. In contrast to the configuration including the flip-flop circuit 26c, the signal determination circuit 26 according to the present embodiment is configured such that the red / green display data signal is input separately.
A comparison circuit 26f that compares the levels of the output signals from the shift registers 26d and 26e with the output signals from the shift registers 26d and 26e, and sends a high-level signal when they have the same level. JK flip-flop circuit 26 to which a signal is input to terminal h
c.

In the case of this embodiment, the same display data of red and green is determined by the signal determination circuit 26,
The reliability can be further improved.
In addition, reliability can be improved by providing a plurality of JK flip-flop circuits 26c on the condition that latch signals are repeatedly output.

That is, the features of the present invention are as follows:
A signal for disconnecting a faulty display unit is determined based on a combination of a display data signal and a clock signal. In addition to the above two embodiments, the determination of the characteristic is not limited to the technical scope of the present invention. It is included in.

[0031]

As described above, according to the present invention, the display unit transmits display data of at least two display elements in a failed display unit and a clock signal corresponding to the address of the corresponding display element by the control unit. Is switched to the disconnection signal of the failure display unit by latching with the clock signal, malfunctions due to noise or the like can be prevented, reliability can be improved, wiring can be simplified, cost can be reduced, and the like. It has the effect of.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of an information display device according to the present invention.

FIG. 2 is a timing chart of the above circuit.

FIG. 3 is a circuit diagram of another embodiment.

FIG. 4 is a circuit diagram of a display unit in a conventional example.

FIG. 5 is a circuit diagram of the entire information display device including the above.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 information display device 2 display unit 21 display element array 22 latch / drive circuit 23 shift register circuit 24 switch circuit for switching display data transmission direction 25 switch circuit for disconnecting fault display unit 26 signal determination circuit

 ──────────────────────────────────────────────────続 き Continuing from the front page (73) Patentee 000243881 Nagoya Electric Industrial Co., Ltd. 1-36, Yokobori-cho, Nakagawa-ku, Nagoya-shi, Aichi (72) Inventor Takehisa Seki 1-6-2, Hatchobori, Chuo-ku, Tokyo (72) Inventor Mitsuru Sakai 100, Maeda-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Koito Industry Co., Ltd. (72) Inventor Kazuhisa Murata 492, Mino-cho, Minato-cho, Yamatokoriyama, Nara Pref. 72) Inventor Shotaro Nakajima 36, Terada Shinike, Joyo-shi, Kyoto Seiwa Electric Co., Ltd. (72) Inventor Sakae Ito 29-1 Shinoda-ku, Iwoku, Miwa-cho, Kaifu-gun, Aichi Prefecture Nagoya Electric Industrial Co., Ltd.

Claims (1)

(57) [Claims] 1. A display element array in which a large number of display elements are arranged in a matrix, a shift register circuit for taking in display data for controlling lighting of each display element of the display element array, and a switch for separating a failed display unit. And a control unit that sends display data to the plurality of display units and monitors a failed display unit, wherein each of the display units includes display data and A disconnection signal determination circuit for disconnecting the failed display unit via the switch by the clock signal, wherein the control unit changes the state of the clock signal having the number of addresses corresponding to at least two display elements in the failed display unit; Disconnect the fault display unit by sending two display data Information display apparatus characterized by the.