JPH0122624B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a display device consisting of a light emitting diode, a fluorescent display tube, or a liquid crystal display that displays characters, symbols, etc. by combining a plurality of display elements. The present invention relates to a display control device that enables blinking at a constant cycle.

Conventionally, this type of display control device has had a configuration as shown in FIG. Store “1” in the storage area of the storage device 11 corresponding to the element to be displayed,
"0" is stored in other areas, and the stored contents of the storage device 11 are supplied to a drive circuit 12 that drives a display element to display characters and the like. If you want to make part of the display blink, you must set the contents of the storage area in the storage device 11 corresponding to the element you want to blink to "0" or "1" in accordance with the cycle of the blinking. Ta.

When performing this blinking operation, the side sending display data to the display device, such as a microcomputer, must rewrite the data in the storage device 11 in accordance with the blinking cycle. This means that when the side sending display data, such as a microcomputer, does not have enough time to perform other operations such as controlling a printer, or when it is in a hold state due to direct memory access, data cannot be sent to the display device. There was a drawback that the flashing operation could not be sent and the flashing operation would stop.

An object of the present invention is to provide a display control device that reduces the burden on the side that sends display data and easily enables blinking operations.

The display control device according to the present invention includes a drive circuit 12 that drives a display element, a first storage device 13 that stores a large amount of display information, and a second storage device 13 that stores a large amount of blinking information that respectively corresponds to the large amount of display information. storage means 15, and a control signal generator 16, the plurality of display information simultaneously outputted from the first storage means 13 and the plurality of corresponding blinking information simultaneously outputted from the second storage means 15. and logic circuits 1 ₁ to 1 ₄ , 2 ₁ to 2 ₄ that supply the same number of drive information as the plurality of display information to the drive circuit 12, and the logic circuit supplies the plurality of drive information to the drive circuit 12. The unit logic circuit includes an AND gate _{2 1} to which only one of the output lines from the second storage means and the output line of the control signal generator are connected to inputs. 2 ₄ and exclusive OR gates 1 1 _{to 1 4} whose inputs are connected to only one output line from the first storage means and the output line of the AND gate, and whose outputs output the drive information. It is characterized by having the following.

Furthermore, in the present invention, each unit logic circuit has two gates, an AND gate and an E-OR gate, and these two gates.
This can be realized using a total of four wires, including only one output line each from the first and second storage means input to one gate, a control output line, and an inter-gate wire. Therefore, each unit logic circuit can be formed in a small space using extremely few elements and wiring, so it is possible to realize a display control device suitable for driving high-density, high-resolution display elements.

One embodiment of the present invention will be described with reference to FIG. The display information is stored in the first storage device 13,
The output enters the logic circuit 14 and the logic circuit 14
E-OR gate 1 which takes the internal exclusive OR of ₁ ~
1 Input to ₄ . On the other hand, the blinking information is stored in the second storage device 15, and its output is stored in the logic circuit 14.
It is input to AND gates 2 ₁ to 2 ₄ . Furthermore, a control signal generator 16 is provided, the output of which is e.g.
Generates a control signal with the waveform shown in the figure. The period when the control signal is “1” is T ₁ and the period when it is “0” is T 1 .
Let it be T ₀ . The control signal is within the logic circuit 14.
It is commonly input to AND gates 2 ₁ to 2 ₄ . Here, the blinking information stored in the second storage device 15 corresponds to the display information stored in the first storage device 13. Therefore, when one display information of the storage device 13 is "1", the corresponding flashing information of the storage device 15 is "1" or "0", and when the information of the storage device 13 is "0", the storage device 15 The corresponding blinking information is set to "0".

Therefore, AND gates 2 ₁ to 2 ₄ are closed during the control signal period T ₀ and their outputs are zero.
On the other hand, in period T ₁ , AND gates 2 ₁ to 2 ₄ are opened,
The blinking information of the second storage device 15 appears in its output. The outputs of AND gates ₂₁ to ₂₄ are input to E-OR gates ₁₁ to ₁₄ , respectively. The feature of the E-OR gate is that when one input is "0", the output is the same as the other input, and when one input is "1", the output is the inverse of the other input. It is something.

Therefore, in period T ₀ , E-OR gate 1 ₁ ~
Since the inputs of one of the 1 ₄ are all "0", its output is the same as the output of the first storage device 13, that is, the display information. On the other hand, in period T ₁ ,
One input of the E-OR gates 1 ₁ to 1 ₄ is the output of the second storage device 15, that is, blinking information. Therefore, if there is an output of "1" in the blinking information, the corresponding display information in the first storage device 13 is inverted and output from the E-OR gate.
The outputs of the E-OR gates 1 ₁ to 1 ₄ are supplied to the display element drive circuit 12 .

As an example of a display, a display of a digital measuring instrument will be explained with reference to FIG. 4. This is the case when a measurement error occurs and all digits on the display blink. Figure 4A
4B shows the display information of the first storage means 13, and FIG. 4B shows the blinking information of the second storage device 14, respectively. The storage area of the first storage device 13 that contains the display data of each digit is made up of 7 segments arranged in a square shape, 7 bits corresponding to each segment to represent a number, and 1 bit representing a decimal point. . The first digit storage area of the first storage device 13 contains 11111111 as storage data for displaying the number 8 and a decimal point. 11111110 is stored in the storage area corresponding to the first digit of the second storage device 14 that stores the data for blinking the display.

Therefore, the first digit in the output of the logic circuit 13 during period T ₀ is the number 8 as shown in FIG. 4C.
and the decimal point, and in period _T1 , only the decimal point is output as shown in FIG. 4D. As a result, in the period _T0 , 8 is displayed as shown in FIG. 4E, and in the period _T1 , only the decimal point is lit as shown in FIG. 4F. Since these two displays are repeated, the number 8 blinks. In this example, only numbers are displayed from the second digit to the eighth digit. In FIG. 4, the data column from the 3rd digit to the 8th digit is shown in hexadecimal. Therefore, the contents of the first storage device 13 and the contents of the second storage device 15 corresponding to the second to eighth digits are the same. Then,
A number is output from the logic circuit 14 during the period T ₀ ,
Nothing is output during period _T1 .

If this display example were performed using the prior art, it would be necessary to alternately write a set of numbers and a decimal point and a set of a blank and a decimal point as display data in the display information storage device 11 of FIG. 1 at a blinking cycle. This has the disadvantage that the blinking operation cannot be performed if there is not enough time for the rewriting operation due to other operations, printer control, etc. However, according to the display control device of the present invention, the blinking operation can be performed by simply writing data to the first storage device 13 and the second storage device 15 once. In the example shown in Fig. 4, all digits of the number blink, but it is also possible to blink only certain specific digits, for example, the first and second digits, or to blink only a certain segment. is clear.

As explained above, by repeating the periods T ₀ and T ₁ at a desired blinking cycle, it is possible to blink the display. If it is desired to stop the blinking operation, the output of the control signal generator 16 may remain in the T ₀ state for a period of time, or the contents of the second storage device 15 may be set to all "0".

As explained above, in this invention, based on the control signal of the control signal generator 16, the output of the first storage device 13 that stores display information is changed to the output of the second storage device 15 that stores blinking information. By controlling the display according to the present invention, it is possible to omit rewriting data at the blinking cycle, which was a drawback of the prior art, reducing the burden on the side sending display data, and eliminating the possibility that the blinking operation will be interrupted.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional display control device, FIG. 2 is a block diagram showing an embodiment of the display control device according to the present invention, FIG. 3 is a waveform diagram showing an example of a control signal, and FIG. It is a figure showing an example of operation of this display control device. 12: Drive circuit, 13: First storage device, 1
4: logic circuit, 15: second storage device, 16: control signal generator.

Claims (1)

[Claims] 1. A drive circuit that drives a display element, a first storage means that stores a large number of display information, a second storage means that stores a large number of blinking information corresponding to each of the plurality of display information, and a control signal generator. the plurality of display information to the drive circuit using the plurality of display information simultaneously output from the first storage means and the plurality of corresponding flashing information simultaneously output from the second storage means. and a logic circuit that supplies the same number of drive information as the number of drive information, the logic circuit is composed of a unit logic circuit that outputs each of the plurality of drive information, and the unit logic circuit is configured to output the output from the second storage means. an AND gate having inputs connected to only one of the lines and the output line of the control signal generator; and only one of the output lines from the first storage means and the output line of the control signal generator;
1. A display control device comprising: an exclusive OR gate to which an output line of the AND gate is connected to an input and the drive information is output from the output.