JP2931387B2 - Display device - Google Patents

Description

The present invention relates to a display device for displaying a three-color dot matrix display by arranging a plurality of light-emitting diode lamps having, for example, two-color light-emitting diode chips vertically and horizontally.

(B) Conventional technology Conventionally, a display device that uses a dot matrix display as disclosed in Japanese Patent Application Laid-Open No. Sho 60-1007084 and that displays display contents prepared in advance at stores, streets, buses, and the like has been commercialized. ing.

By the way, in recent years, a display using a light emitting diode lamp having a light emitting diode chip of two colors has been developed as a display element for color display. In the display, three-color display is possible by single light emission and simultaneous light emission of each light emitting diode chip.

(C) Problems to be Solved by the Invention In the above-described color type display, due to the problem of allowable current, the product of the current flowing through each diode chip and time in the case of simultaneous light emission is solely used for light emission. In the case of simultaneous light emission, the luminous intensity decreases in comparison with the other cases. Therefore, only half of the luminous intensity of the diode lamp can be used for energizing the light of the third color in accordance with the monochromatic luminous intensity.

(D) Means for Solving the Problems According to the display device of the present invention, a plurality of light emitting diode lamps having light emitting diode chips of a plurality of colors are arranged vertically and horizontally, and the number of colors is larger than the number of light emitting diode chips included in the light emitting diode lamps. A display for performing dot matrix display, and a plurality of drive circuits that perform dynamic drive for the light emitting diode chips of each color of the display,
Each of the driving circuits scans in a different order so as not to scan the same line at the same time.

(E) Function The present invention is configured as described above, and dynamic driving is performed on the light emitting diode chips of each color without simultaneously driving the light emitting diode chips of each color of the light emitting diode lamp. Done. If the respective light emitting diode chips of the light emitting diode lamps are turned on during one screen scan by the respective driving circuits, the third color is recognized by an illusion of a human.

(F) Example An example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a display device according to the present invention, wherein (1) is a light-emitting diode chip of two colors of red and green (R), (G) (hereinafter referred to as LE).
A light-emitting diode lamp (2) (hereinafter, referred to as an LED lamp) having a D chip (hereinafter referred to as a D-chip) arranged vertically and horizontally to display a dot matrix of three colors (red, green, orange); It is a drive circuit for driving the display (1). (4) storage means for storing dot data of the content to be displayed on the display (1), which is a so-called IC card (a semiconductor memory is fixed to a substrate so as to be detachably attached to the device). Backed up as necessary and used, for example, in JP-B-53-6491 and Electronic Technology Magazine, 1986, p. 79).
In this storage means (4), dot data for red and green dot data are stored for one screen, and in the case of orange, dot data for red and green are stored corresponding to the same display location. Will be stored. (5) is a data memory for a work area, and (6) is a control circuit for controlling each section according to a program written in a program memory (7).

FIG. 2 shows a detailed view of the display (1) and the drive circuit (3). Here, for the sake of simplicity, 4 × 4
16-dot display is used as an example. Drive circuit (2)
Are the column sink driver (201) and the source driver (2
02), a sink driver (203) for rows in columns A and B,
It has a source driver (204), a sink driver (205) for the rows of the C and D columns, and a source driver (206), and a sink driver (201) and a source driver (2
02), a decoder (207) is connected, and each of the row sink drivers (203) and (205) and the source driver (20)
4) and (206) are 4-bit latch circuits (208), respectively.
(209), (210), (211) and the shift register (21
2), (213), (214), and (215) are connected.

In the above configuration, the source driver (204) (206)
, And the red LED chips (R), (R) ... in combination with the sink driver (201)
Green LED with combination of (205) and source driver (202)
The chips (G), (G)... Are driven.

Thus, in the shift register (215) corresponding to the source driver (206), the serial data for red as shown in FIG. 3 is controlled in the order of the A, B, C, and D columns. Provided by circuit (6). The data during the period (T ₁ ) is read in 8 bits at the clock timing shown in FIG. 4 in detail, as shown in FIG. Here, 8 bits are used because the LED lamp groups are arranged in columns A and B in order to drive the red LED chip (R) and the green LED chip (G) of one LED lamp (2) at different timings. This is because it is divided into two groups, namely, column C and column D, and it is necessary to supply data to each group. Therefore, the control circuit (6) gives the display data to the first four bits of the lamp groups on the A-th column and the B-th column (this 4-bit data is transferred from the shift register (215) to the shift register (213). )), Imaginary data is given to the latter 4 bits. For the lamp grape in the C and D columns, imaginary data is given to the first four bits and display data is given to the last four bits.

Next, in the shift resist (214) corresponding to the sync driver (205), green serial data is sequentially stored in the control circuit (C, D, A, and B columns) in the order shown in FIG. 6). The data format is the same as that of the red data described above, and the first four bits of data are transferred to the shift register (212).

Next, each latch circuit (208), (209).
A latch pulse as shown in the figure is applied, and data is latched in synchronization with the fall of the pulse. Decoder (207)
A and B signals indicating binary codes as shown in FIG. 3 are applied to input terminals I _A and I _{B of} this decoder, and this decoder (207) decodes them to obtain 0 ₀ , 0 ₁ , 0 ₂ , 0 _3. Are sequentially set to the "1" level. By the way, a B signal is applied to the enable terminals (▲ ▼) of the latch circuits (209) and (210), and the enable terminals (▲ ▼) of the latch circuits (208) and (211) via the inverter (216). B
A signal is provided.

In addition, each output terminal of the decoder (207) and the sing driver (2
01) Input order of input terminal and source driver (20
The connection order of the input terminals in 2) corresponds to the transfer order of red and green data as shown in FIG.

The operation in the above configuration will be described. First, the control circuit (6) stores red data for display from the storage means (4),
The data for green is read, processed in the data transfer order, and stored in the data memory (5). And
Transfer the red data in column A to the shift register (215),
The green data in column C is transferred to the shift register (214). As described above, in the data in column A, display data is given to the first four bits of the eight bits,
In the column data, display data is given to the latter 4 bits of the 8 bits. When the 8-bit data is transferred, a latch pulse is applied to each of the latch circuits (208), (209),..., And each of the shift registers (212), (21)
3) The output signal of ... is latched, but the B signal is in the period (T ₁ )
Therefore, the outputs of the latch circuits (208) and (211) are held at the "0" level. Thus, the period (T ₁ )
Since the A and B signals become “0” and “0” levels,
The display control of the red LED chips (R), (R)... In the A-th column and the green LED chips (G), (G) in the C-th column is performed based on the display data. This period (T ₁ )
In the meantime, red data in column B and green data in column D are transferred,
In the period (T ₂ ), since the A and B signals become “1” and “0” levels, the red LED chip (R) in the B-th column,
(R), the green LED chips (G), (G),. Next, in the period (T ₂ ), red data in the C column and green data in the A column are transferred. Then, in the period (T ₃ ), A,
Since the B signal goes to the “1” or “0” level, the outputs of the latch circuits (209) and (210) are held at the “0” level, and the red LED chip ( R),
(R), the green LED chips (G), (G),... In row A are subjected to display control based on the display data. Next, in the period (T ₃ ), the red data in the D column and the green data in the B column are transferred, and in the period (T ₄ ), the A and B signals become “1” and “1” levels. The red LED in the D column
The chips (R), (R),..., And the green LED chips (G), (G),.

The display form is as shown in FIG. 5, for example, in the period T _{1 to} T ₄ , the red LED chip and the green LED chip of the same LED lamp are used.
If the LED chip lights up, the LED is illusioned by the human eye
The lamp will appear to be lit orange.

FIG. 6 shows a detailed view of a display (1) and a drive circuit (3) of another embodiment. The embodiment in FIG. 2 uses an LED lamp in which the direction is reversed and each LED chip is connected in parallel, and the brightness of one pixel can be increased by connecting the LED lamps in series. However, the sink driver, the source driver, and the latch circuit for the row are each 4
And it is necessary to transfer 8-bit data to display one line.

Therefore, in the embodiment of FIG. 6, although the LED lamps cannot be connected in series, two row sink drivers, two source drivers, and two latch circuits are required, and the display of one row is four times.
This is made possible by bit data.

Hereinafter, this embodiment will be described. The source driver (302) (303), the sink driver (301) (304), the decoder (305), the latch circuits (306) (307), and the shift registers (308) (309) The basic operation is the same as that of the embodiment of FIG. 2, but as shown in FIGS. 7 and 8, serial data for red and green is latched every 4 bits, and data for red is A, The control circuit (6) supplies the data in the order of B, C, and D columns, and the green data is supplied from the control circuit (6) in the order of B, C, D, and A. The connection order of each output terminal of the decoder (305) and the input terminal of the sink driver (301) and the connection order of the input terminal of the source driver (302) are as shown in FIG. Are made in accordance with the transfer order.

The operation in the above configuration will be described. First, the control circuit (6) stores the red data for display from the storage means (4),
The data for green is read, processed in the data transfer order, and stored in the data memory (5). Then, the control circuit (6) transfers the red data in column A to the shift register (308) and the green data in column B to the shift register (309). 4-bit data has been transferred, a latch pulse is applied to each of the latch circuits (306) (307), a latch circuit (306) (307) period T ₁ the shift register (308) output signal (309) Latch. In the period T _1,
The A and B signals are at “0” and “0” levels, and the red LED chips (R), (R),..., The green LED chips (G), (G),. It will be controlled based on the display data.

Thereafter, the T ₂ through T ₄ period given data as of Figure 7, so that the LED chips are displayed controlled at the timing shown in FIG. 9.

(G) Effect of the Invention The present invention is configured as described above, and the light-emitting diode chips of the respective colors of the light-emitting diode lamp are not simultaneously driven, and the dynamic light-emitting diode chips of the respective colors are dynamically driven. When the driving is performed, and the respective light emitting diode chips of the light emitting diode lamps are turned on during one screen scan by the respective driving circuits, the third color is recognized by the illusion of the human eye. Therefore, in the case of a single color, the performance of the light emitting diode lamp can be sufficiently utilized, and the luminous intensity of the single color and the luminous intensity of the third color can be made substantially the same.

[Brief description of the drawings]

FIG. 1 is a block diagram of a display device of the present invention, and FIG.
Similarly, FIG. 3 is a timing chart of each signal, FIG. 4 is a timing chart of red data, FIG. 5 is an operation explanatory diagram, and FIG.
FIG. 7 is a detailed view of a display and a drive circuit of another embodiment. FIG. 7 is a timing chart of each signal, FIG. 8 is a timing chart of red data, and FIG. 9 is an operation explanatory diagram. It is. (1) ... display, (2) ... light-emitting diode lamp,
(3) ... Drive circuit.

Continued on the front page (56) References JP-A-53-148298 (JP, A) JP-A-63-26889 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G09G 3 / 00-3/38

Claims (1)

(57) [Claims] 1. A display for arranging a plurality of light-emitting diode lamps having light-emitting diode chips of a plurality of colors vertically and horizontally to display a dot matrix of a color larger than the number of light-emitting diode chips included in the light-emitting diode lamp, and the display. A plurality of driving circuits for dynamically driving the light emitting diode chips of the respective colors of the device, wherein each of the driving circuits scans in a different order so as not to scan the same line simultaneously. apparatus.