JPS63281194A - Display scan system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] When scanning a plurality of light emitting elements arranged in a grid on a plane one by one and lighting up a selected light emitting element, the light emission to be turned on is determined based on a predetermined value. When the number of elements is small or equal, the average current value supplied to the light emitting elements to be lit is increased to increase brightness, compared to when all light emitting elements are scanned.

[Industrial application field]

The present invention is a dot matrix system that scans and lights up a plurality of light emitting elements in accordance with a display pattern to display characters, etc.
The present invention relates to displays, and particularly to a display scanning method that increases the brightness of a display by increasing the supply time of current to the light emitting diodes that light up.

2. Description of the Related Art Some information processing apparatuses display a plurality of characters or the like on an operator panel or the like to give instructions to an operator regarding the operation of the apparatus or to display the status of the apparatus. In order to perform such a simple display, a dot matrix display (hereinafter abbreviated as a display) is constructed by arranging a plurality of light emitting elements such as light emitting diodes in a grid pattern vertically and horizontally on a plane. However, by sequentially scanning the light emitting elements of this display one by one, current is repeatedly supplied to the light emitting elements corresponding to the display pattern in each scanning cycle to light them up and display characters, etc.

In such a display, all light emitting elements are normally scanned equally, regardless of whether each light emitting element is lit or not. However, the average current supplied to the light-emitting elements that light up decreases as the number of light-emitting elements that make up the display increases, and the brightness also decreases. Except for certain cases, it is desirable to be able to increase the brightness when the number of light emitting elements lit is less than a predetermined number.

[Conventional technology]

FIG. 3 is a block diagram illustrating an example of a conventional technique, and FIG. 4 is a diagram illustrating an example of display data.

1 is a processor, 2.3 is a decoder that decodes display data sent by the processor 1, 4 to 15 (some not shown) are transistors forming a driver, and 16 to 15 are transistors that constitute a driver.
Reference numeral 50 (some of which are omitted from the drawings) represents a light emitting diode constituting a display 51 that displays 35 dots as shown in FIG.

If the light-emitting diodes 16 to 22 form a vertical line of display pixels shown by ■ in the display 51 of FIG. 4, the light-emitting diodes 23 to 29 form a vertical line of display pixels shown by A vertical row of display pixels shown in (2) is formed.

The operation of FIG. 3 will be explained using FIG. 4. For example, a display pattern is input from a device such as a magnetic tape device through terminal A. This display pattern is, for example, as shown in FIG. 4, in which the letter B is displayed on a display 51 in which seven light emitting diodes are arranged vertically and five horizontally in a grid pattern.

In this case, the display 51 displays the light emitting elements selected in ■a in order of ■a, ■a, ■a, ■a, ■b, ■b■b,
Assuming that the display pattern B is sequentially scanned like ■b, ■b, ■C5-1■g, the processor l stores this display pattern B in its internal memory, reads it out, synchronizes with the clock, and first sends it to the decoder 2. Data for driving transistor 4 is sent to decoder 3, and data for driving transistor 11 is sent to decoder 3.

Therefore, decoder 2 decodes this data and drives the base of transistor 4, and decoder 3 decodes this data and drives the base of transistor 11. Therefore, the power source E passes through the transistor 4, the current limiting resistor, the light emitting diode 16, and the transistor 1.
1 flows through the display 5 shown in FIG.
The light-emitting diode 1 (■a) lights up.

Processor l sends data for driving transistor 4 to decoder 2 and data for driving transistor 12 to decoder 3 in synchronization with the next clock.

Therefore, decoder 2 decodes this data and drives the base of transistor 4, and decoder 3 decodes this data and drives the base of transistor 12. Therefore, a current flows from the power source E to the light emitting diode 23 in the same manner as described above, and the display 5 shown in FIG.
The light-emitting diode 1 (■a) lights up.

Processor 1 synchronizes with the next clock and sends data to drive transistor 4 to decoder 2 and data to drive transistor 13 to decoder 3. Therefore, decoder 2 drives the base of transistor 4,
drives the base of transistor 13. Therefore, current flows from the power source E to the light emitting diode 30, and the light emitting diode 2a of the display 51 shown in FIG. 4 lights up.

Similarly, at the clock after lighting the light emitting diode (a) of the display 51, the transistors 4 and 15
The display 51
■a does not light up. In this way, when processor 1 finishes scanning row a, it moves on to scanning rows c, d, and e.
, i, and g rows, and when scanning is completed up to the 0g light emitting diode 50, the next scanning cycle begins, and
Scanning of row a is started from the light emitting diode.

[Problem that the invention seeks to solve]

As described above, conventionally, all the light emitting diodes 16 to 50 of the display 51 are sequentially scanned one by one every one scanning cycle, and by supplying current to the light emitting diodes corresponding to the display pattern, the corresponding light emitting diodes are The average current value supplied to one light emitting diode becomes smaller as the total number of light emitting diodes increases.

That is, if the scan cycle time is held constant, the time for supplying current to one light emitting diode will be shortened, and if the scan cycle time is increased by the total number of light emitting diodes, the number of scan repetitions will be reduced. It's for a reason.

Therefore, there is a problem that the brightness of the light emitting diode is reduced.

[Means for solving problems]

As shown in FIG. 4, when displaying characters etc. on the display 51, not all the light emitting diodes are lit, but when displaying, for example, B as shown in the figure, 19 out of 35 light emitting diodes are lit. Only the diode is lit.

Therefore, the present invention does not constantly scan all the light emitting diodes, for example 35, but analyzes the display pattern and determines the number of light emitting diodes to be lit up to a predetermined number, for example 20.
If the number is less than 20, limit the scanning range to 20, make the time for supplying current to one light emitting diode longer than before, or increase the number of repetitions of scanning,
This increases the average current value supplied to the light-emitting diodes that light up, thereby increasing their brightness.

That is, when a display pattern is received, the number of light emitting diodes to be lit is checked and the number is set to a predetermined number, for example 20.
In the following cases, the scanning range is set to 20, and only light emitting diodes that are lit are scanned, and scanning for light emitting diodes that are not lit is skipped.

If the number of light-emitting diodes that light up is less than 20, scanning for the remaining number is paused.

That is, for example, if the number of light-emitting diodes that are lit is 19, scanning for the remaining one light-emitting diode is paused.

When the number of light emitting diodes to be lit exceeds a predetermined number, for example 21 or more, the scanning range limited to 20 is expanded and all light emitting diodes to be lit are sequentially scanned. It is something to do.

FIG. 1 is a block diagram of the principle of the present invention.

FIG. 1 is the same as in FIG. 3 with a scanning instruction means 52 added.
Based on the instruction from the scan instruction means 52, the processor 1 analyzes the display pattern input from the terminal A and stored in the internal memory, and checks the number of light emitting diodes lit on the display 51.

If it is less than or equal to a pre-given value, the scanning range is limited to the given value, and in synchronization with the clock, the light-emitting diodes that light up in accordance with the display pattern are sequentially scanned, and the light-emitting diodes that do not light up are scanned in sequence. The scanning of the diodes is skipped, and the scanning remaining after subtracting the number of lit light emitting diodes from the given value is paused.

In particular, if the number of light emitting diodes lit on the display 51 obtained from the display pattern is greater than the given value, the processor 1 expands the scanning range limited to the given number and requires lighting. Scan all light emitting diodes.

[Effect]

With the configuration as described above, the processor 1, based on the instructions from the scan instruction means 52,
When the number of light-emitting diodes to be lit corresponding to the display pattern is small or equal, it is possible to increase the average current value supplied to the light-emitting diodes to be lit compared to conventional methods, so the brightness can be increased. I can do it.

〔Example〕

FIG. 2 is a block diagram of a circuit showing one embodiment of the present invention.

The same reference numerals as in FIG. 3 indicate the same functions. When the processor 1 stores the display pattern input from the terminal A in its built-in memory, it analyzes this display pattern based on instructions from the scan instruction program 53.

For example, if you want to display the letter B as shown in Figure 4,
The number of light emitting diodes in the display 51 that are lit is nineteen.

If alphanumeric characters are to be displayed on such a display 51, the number of light emitting diodes that are normally turned on is 20 or less. Therefore, the processor 1 has a numerical value to be compared with the number of light emitting diodes that light up corresponding to the display pattern in advance.
For example, if 20 is set, the processor 1 starts scanning by limiting the scanning range to 20 light emitting diodes because the number of B lights up is 19.

That is, in order to first send data for driving the transistor 4 to the decoder 2 and data for driving the transistor 11 to the decoder 3 in synchronization with the clock, the light emitting diode (a) of the display 51 is sent in the same manner as in FIG. 16 lights up.

In synchronization with the next clock, the processor 1 sends the data for driving the transistor 4 to the decoder 2 and the data for driving the transistor 12 to the decoder 3, so that the display 51 flashes ■a! The diode lights up. The processor 1 sends data for driving the transistor 4 to the decoder 2 and data for driving the transistor 13 to the decoder 3 in synchronization with the next clock, so that the light emitting diode 1a on the display 51 lights up.

Similarly, at the clock after lighting the light emitting diode 37 (a) of the display 51, the processor l sends data for driving the transistor 5 to the decoder 2 and data for driving the transistor 12 to the decoder 3. . That is, the scanning of the light emitting diodes 44 and 17 of the display 51 (a) and (b) is skipped. Therefore,
The light-emitting diode 24 (b) on the display 51 lights up.

Next, the processor 1 displays ■b and ■b on the display 51.
The scanning for the light emitting diodes 31 and 38 is skipped, and the light emitting diode 45 of b on the display 51 is turned on. Similarly, the scanning of the light-emitting diode 18 in the bottom part of the display 51 is skipped, and the light-emitting diode 25 in the bottom part of the display 51 is turned on, and then the light-emitting diode 46 in the bottom part of the screen is turned on.

In this way, when scanning rows d, e, f, and g sequentially and lighting up the 0g light emitting diode 43 of the display 51, the processor 1 lights up the 0g light emitting diode 43 of the display 51. There will be some margin, but after the scanning for this one item is paused, the next scanning cycle will be started.
A scan is started to light up the light emitting diode 16 of ①a on the display 51.

If a display pattern in which 21 or more light emitting diodes are turned on is input, the processor 1 expands the scanning range, which was limited to 20, in accordance with the number of light emitting diodes to be turned on. Therefore, as the number of light-emitting diodes increases, the average current value supplied to each light-emitting diode gradually decreases compared to the case where 20 light-emitting diodes are used as the scanning range, and the brightness decreases, but this happens less frequently. It is more effective than always reducing the brightness.

〔Effect of the invention〕

As explained above, the present invention provides a dot matrix display in which a plurality of light emitting elements are arranged in a grid pattern in the vertical and horizontal directions on a plane, and the display elements are scanned one by one to display a display pattern. can increase the brightness of

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention, FIG. 3 is a block diagram explaining an example of a conventional technique, and FIG.
The figure is a diagram illustrating an example of display data. In the figure, 1 is a processor, 2.3 is a decoder, 4 to 15 are transistors, 16 to 50 are light emitting diodes, 51 is a dot matrix display, 52 is a scanning instruction means,

Claims (1)

[Claims] A plurality of light emitting elements (16 to 50) are arranged in a grid pattern in the vertical and horizontal directions on a plane, and light emitting elements present at the intersections of the grids are selected from the vertical and horizontal directions and lit. decoders (2) (3) that supply current to
1), the light emitting elements present at the intersections of the grid are sequentially scanned one by one, and a current is repeatedly supplied to the light emitting element at the selected position for each scanning cycle to light up the character. In a dot matrix display that displays such things as If the value is less than the numerical value, scan instruction means (52) is provided which limits the scanning range to the predetermined numerical value, scans only each light emitting element to be lit, and instructs to suspend scanning remaining in the limited scanning range. provided, each time a display pattern is input to the processor (1),
The number of light emitting elements to be lit is extracted, and if the extracted number is less than or equal to the predetermined value, the light emitting elements to be lit are sequentially scanned in each scanning cycle, and the scanning of the light emitting elements not to be lit is skipped, and the limitation is met. A display scanning method characterized by pausing the remaining scanning for the scanned range.