JPH05150740A - Display device - Google Patents

Abstract

PURPOSE:To make a display with ternary brightness s the dynamic display device whose display is driven on a time-division basis by adjusting a display drive time of each dot. CONSTITUTION:The display device has a driving circuit 11 which scans a display unit 1, having dots at intersections of a matrix, in lateral line units, a display driver circuit 13 which performs longitudinal display driving in synchronism with the scanning, and a display memory 22 for storing display data and is equipped with a function for controlling and adjusting the driving time of the display data from the display driver circuit 13 by a display control circuit 15 and a function for adjusting the brightness of the display dots by storing flag information on a display driving time corresponding to the display dots in the display memory 22. Consequently, the display with the ternary brightness is provided and smooth figures and characters can be displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic display device for driving a display in synchronization with a time-division scanning line,
In particular, the present invention relates to a display device that adjusts the display drive time to adjust the lighting brightness of a dot display element.

[0002]

2. Description of the Related Art Conventionally, a display device for displaying characters or figures by displaying a set of one light emitting element as one dot will be described with reference to FIG. 4 showing the present invention.
The current is dynamically supplied while sequentially scanning the lines in the horizontal direction (line) dot display element unit as in the holding circuit 12 of the line current driver circuit 11, and the vertical direction corresponding to this corresponds to the horizontal dots. The display data is driven by the circuit holding unit 14 of the display driver circuit 13 to drive the dot display element.

The dot display element 2 of the display 1 in which the line current driver output and the display driver output match is instantly turned on.

The scanning period of the line current driver circuit is
Dot display element which is lit supplies a sufficient current for display during the time of several tens ms to several tens ms and the current supply time of each line is several hundred μs to several ms.

The fluorescent substance applied to each dot display element is stimulated by the current supply to the dot display element for several hundred μs to several ms, and the dot display element seems to be constantly lit by the afterglow of this substance. become.

As described above, the dynamic display device which performs the time-divisional scanning display displays characters and figures with a minimum of a minimum display drive circuit and current.

[0007]

In this conventional display drive type display device, each dot display element is formed by a common line current driver circuit and display driver circuit, and a dot is generated by an instantaneous current of several hundreds μs to several ms. To turn on the display element, the current supplied to the dot display element is rated at 2
Since the current is up to 3 times, and the current-generation characteristic is used in the saturation region, the brightness of each dot display element is uniform brightness, and the dot roughness is conspicuous.

However, when characters and figures are displayed with a mixture of brightness displays of intermediate brightness, a very smooth and easy-to-see display is possible, which was not possible with the prior art method. ..

Further, when the display position of a character or the like is moved in the horizontal direction depending on time, in the conventional method, the afterglow of the dot display element influences the small characters of the extinguished part, and the part is surrounded by the surrounding dots. There is a drawback that the display element appears crushed due to the afterglow of lighting of the display element.

An object of the present invention is to provide a display device which enables an extremely smooth and easy-to-see display.

[0011]

In order to achieve the above-mentioned object, in the display device according to the present invention, a display comprising a plurality of dot display elements each having one dot at a matrix-shaped intersection is used as a line in one direction of a matrix. A line current driver circuit that periodically scans in units and supplies current in a time-division manner, and correspondingly, drives a line in the other direction that intersects, and A display driver circuit for lighting the dot display element,
And a regulation circuit that adjusts the drive time of the dot display element in the display driver circuit that drives the line current driver circuit in units of scanning lines.

Further, the display memory has a display memory for supplying display data to a display driver circuit in synchronization with scanning on a scanning line. It has a function of storing the information of.

[0013]

[Function] By adjusting the display drive time of each dot, display is performed with three-value brightness.

[0014]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a time chart showing a display operation. FIG. 4 is a partially enlarged view of the display drive circuit.

In the figure, display data for driving and displaying the dot display elements of the display 1 is received via the I / O bus and the I / O receiver 25 and written in the display memory 22.

In the display data, the characters or figures to be displayed are converted into display dots in advance, and the line current driver 11 scans the lines in a time-divisional manner with a scanning cycle of several tens of ms, and the lines L _{1 to} L ₂₅ are driven by current. It is stored in the display memory 22 as display data R ₂ to R _K which is driven from the vertical direction of the display driver 13 corresponding.

Further, in the display memory 22, the information data of the display drive time for adjusting the brightness of the display is converted into the display data corresponding to the presence / absence information of each dot of the display data R _{2 to} R _K. It is stored using a 1-dot flag in correspondence with 1: 1. 21 is a bus driver.

This display drive time information data is driven and turned on all the time during the display data drive time T ₁ of FIG. 3 when the corresponding flag is “0 or blank”, and when the flag is “1”. , T ₁ is set in advance by the control circuit 24 so as to be lit for T ₂ which is about 2/3 of T ₁ ,
_The display control signal 30 is sent from the control circuit 24 in each line scanning drive time unit of _{1 to} L ₂₅ , and the display control circuit 15 displays the display drive time information data corresponding to the display data held in the holding circuit 16. The display driver circuit 13 holds this and regulates the presence / absence information of lighting during display driving.

By this operation, when the flag is "0", the dot display element 2 of FIG. 4 is turned on during the entire display data driving time T ₁ , and when the flag is "1",
The corresponding display drive data R _X of the display driver circuit 13 is T ₂
After turning on the corresponding dot display element for a period of time, the corresponding holding circuit 14 shown in FIG.
Is reset and goes out.

For this reason, when the flag is "1", the dot display element is turned on. When the flag is "0", the driving time is 2/3, so that the brightness is lowered and the flag is set to "0". It will start to shine at an intermediate brightness compared to the brightness in the case of.

The adjustment of the display brightness is performed by converting character or graphic symbols into display dot information for display, and generating the display drive time regulation information in advance before storing it in the display memory 22. At the same time, it is stored in the display memory 22.

As shown in the display example of the character "A" in FIG. 2A, in the present embodiment, the basic left-side illuminated dots and the upper illuminated dots that are illuminated as characters are the total display data drive time T ₁ All the lighting dots during T _{1 and} the lighting dots on the right side and the lower lighting dot of all the lighting dots during T ₁ are preset as the dot display which is lit for T ₂ hours by the restriction of the display restriction circuit 15, and the display memory 22 is set. Accumulate in.

The display data thus generated and stored in the display memory 22 is displayed on the display 1 at the timing shown in the time chart of FIG.
An example of the display shown in (a) is displayed.

In this way, when displayed with the three-value brightness of light, intermediate brightness, and darkness, each display dot is compared with the display of only two levels of light and dark due to blurring due to the intermediate brightness.
The two bumps are displayed smoothly and can be displayed more smoothly.

When the characters to be displayed on the display 1 are scrolled horizontally from right to left, the data for the characters to be displayed on the display 1 + 1 character is stored in the display memory 22 once every few seconds and stored for 100 ms. Line select 23 every 1 dot in cycle
Is used to scroll the selection of the display memory 22, and the display displayed on the display unit 1 is scrolled in dot units.

At this time, the horizontal line is scanned at a cycle of 25 ms, and the dot display to be displayed is scrolled.
Although it is affected by the afterglow of the dot display element before the dot, it is less affected by the afterglow at intermediate brightness.

[0027]

As described above, according to the present invention, the driving time of the display driver circuit for driving the display data in the horizontal dot display unit in synchronization with the driving of the line current driver circuit which periodically scans in time division is set. By adjusting to a predetermined time, the display of the intermediate brightness is added to the display of the reference brightness, and a display that is extremely smooth and easy to see is possible as compared with the display of the uniform brightness.

Further, when the display is scrolled in the horizontal direction, the phenomenon that the figure is crushed due to the effect of the afterglow phenomenon of the display element becomes weak due to the display of intermediate brightness, and the slippage of the figure is prevented. be able to.

Further, by storing the display drive time together with the display data in the display memory and adjusting the drive time of the display data in accordance with the display drive time at the time of outputting the display, it is possible to display the brightness in a fine hierarchy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a display time chart in one embodiment of the present invention.

FIG. 3 is a partially enlarged view of the time chart of FIG.

4 is a partially enlarged view of the display drive circuit of FIG.

[Explanation of symbols]

 1 display device 2 dot display element 11 line current driver circuit 12, 14 holding circuit 13 display driver circuit 15 display regulation circuit 16 regulation holding circuit 21 bus driver 22 display memory 23 line select 24 control circuit 25 I / O lesser 30 display regulation signal

Claims (2)

[Claims] 1. A line current driver circuit for supplying a current in a time-division manner by periodically scanning a display comprising a plurality of dot display elements each having a matrix of intersections as one dot in line units in one direction of the matrix. Corresponding to this, driving the line in the other direction intersecting,
A display driver circuit that lights the dot display element at the intersection of the line in the other direction that intersects with the scanning line, and the drive time of the dot display element in the display driver circuit that drives the scan line unit of the line current driver circuit are adjusted. A display device having a regulation circuit. 2. A display memory for supplying display data to a display driver circuit in synchronization with scanning in a scan line,
2. The display device according to claim 1, wherein the display memory has a function of storing display driving time information of each of the dots, in addition to the presence / absence information of each dot.