JPH05273925A - Led dot matrix type full-color display device - Google Patents

Abstract

PURPOSE:To provide an LED dot matrix type full-color display device capable of making respective red, green and blue color LEDs emit with the same degree of brightness by a low cost with high reliability. CONSTITUTION:The dot matrix type LED display unit 1 is composed so that a set of respective red, green and blue color LEDs constituting the respective dots are arranged in the shape of a dot matrix and capable of a full-color display. The respective driving parts of red and green LEDs 2, 3 are composed of a dynamic type drive with a few components and only a blue LED driving part 7 is composed of a comparatively complicated static type drive. Consequently, the structure is inexpensive not complicated as a whole and holds high reliability as well owing to the simplified constitution. The brightness of the blue LED emitted by the static drive is on the same order as that of the red and green LEDs emitted by the dynamic drive and high quality of the display is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention According to the present invention, each dot is composed of three colors of blue in addition to red and green to form a dot matrix array, so that an image of a television receiver or the like is displayed with high image quality. The present invention also relates to an LED dot matrix type full-color display device that can also be used.

[0002]

2. Description of the Related Art A general L having a conventional multicolor display function.
The ED dot matrix type display device configures each dot by using one set of red LEDs and one set of green LEDs, captures each pixel data for one row, and arranges each dot on a horizontal scanning line designated by an address signal. The LEDs of the respective colors are driven to emit light, and are driven to emit light by a dynamic drive system in which this operation is repeated.

[0003]

By the way, the above-mentioned dot matrix type LED display device has only three colors, red, green and orange, emitted by one set of red and green LEDs, and the colors are insufficient. Therefore, it is impossible to display the image of the television receiver. Therefore, if a blue LED is added, full color display can be performed. However, the blue LED has red and green L
Since the luminance is relatively low with respect to the ED, it is not possible to obtain the luminance reaching a practical level when the red and green LEDs are made to emit light under the same conditions. Further, while the above-mentioned dynamic driving method has an advantage that it can be configured with a small number of parts, it is necessary to increase the current at the time of LED light emission due to the duty cycle driving. Therefore, the blue LED is replaced with the red and green LEDs. In order to emit light with the same brightness, it is necessary to pass a larger forward current to the blue LED, and this too large forward current significantly deteriorates the reliability of the LED chip, and further, such a large driving capability is required. As for the electronic components, the package becomes large and hinders miniaturization. That is, a device for full-color display by driving a dot matrix LED display unit having blue LEDs in addition to red and green to emit light by a dynamic drive system has never been put to practical use.

Therefore, if the LEDs of all the dots are controlled to emit light individually based on the pixel data and are driven to emit light by a static drive method at the same time, it is possible to obtain a practical level of brightness for the blue LEDs. However, if each of the three types of LDDs of red, green and blue is driven to emit light by the static drive method, the number of terminals and the number of drive elements connected for each color will be very large and the cost will be high. In addition, the reliability is significantly reduced as the configuration becomes complicated.

In view of the above, the present invention provides an LE that allows a red, green and blue LED to emit light at the same level of brightness and to obtain a high display quality with an inexpensive and highly reliable structure.
It is a technical object to provide a D dot matrix type full-color display device.

[0006]

The present invention has an LED dot matrix type full-color display device constructed as follows as a technical means for achieving the above-mentioned problems.
That is, a dot matrix type LED display unit in which a set of red, green and blue LEDs forming each dot are arranged in a dot matrix, and the red LEDs of all dots are divided into a plurality of sets and are then divided into groups. A dynamic drive type red LED drive unit that drives light emission with red pixel data in a divided manner, and each green LED of all dots is divided into a plurality of sets, and these are synchronized with the red LED drive unit to repeat green in a time division manner. A dynamic drive type green LED drive section which drives light emission by pixel data, and a static drive type blue LED which controls light emission of each blue LED of all dots individually based on blue pixel data and drives the light emission intermittently at the same time. And a drive unit.

[0007]

The red LED and the green LED respectively hold, for example, one row of red pixel data and green pixel data by a latch signal by the dynamic driving type red LED driving section and the green LED driving section, and drive the light emission by this data. The light emission is driven by a line-sequential scanning method which sometimes transfers the data of the next row. On the other hand, each blue LED is individually controlled to emit light by a static drive type blue LED driver based on blue pixel data, and is driven so as to emit light intermittently at the same time.

Therefore, the red LED driver and the green LE
The D drive unit is a dynamic drive type configuration that can be configured with a small number of components, respectively, and only the blue LED drive unit is a static drive type configuration having a relatively complicated configuration, and thus the configuration can be complicated as a whole. In addition, it can be manufactured at low cost and maintains high reliability with the simplification of the configuration. Further, the blue LED can easily emit light with the same brightness as the red and green LEDs that are driven to emit light by the dynamic drive method by driving the light emission by the static drive method, and high display quality can be obtained. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a block configuration of an embodiment of the present invention, which is a dot matrix type LED.
The display unit (1) is configured in a dot matrix of, for example, 16 × 16 dots in which each dot is combined with one LED for red, one for green, and one for blue, and has a full-color display function. A dynamic drive type red LED drive unit is constituted by the red shift register (2), the decoders (4) and (5), and the line driver (6), and the green shift register (3) and the decoder (4). , (5) and the line driver (6) constitute a dynamic drive type green LED drive section. The blue LED is driven by the static driver for blue (7) to emit light in a static drive system.

The red pixel data (R) and the green pixel data (G) of the input video signal are, for example, 16-bit red shift register and green shift register (3) depending on the timing of the clock signal (C). 2A, and when the red pixel data and the green pixel data for one row in the horizontal scanning direction are respectively captured as shown in FIG. 2A, the latch signal (L) shown in FIG. The serial pixel data is latched and converted into parallel pixel data. After that,
The red pixel data (R) and the green pixel data (G) for one row, which are respectively output from the red shift register (2) and the green shift register (3) by the enable signal (E), are decoded by the decoder (4). , (5) and the line driver (6) through the address signals (A1) to
The red LED and the green LED of each dot of the horizontal scanning line designated by (A4) are driven to emit light, and the data of the next row is transferred at the time of this light emission drive. This operation is repeated at the timing of the enable signal (E) as shown in FIGS. 2A and 2B to display the screen by the line-sequential scanning method.

On the other hand, the blue pixel data (B) is captured by the blue static driver (7) in one screen portion and latched by the latch signal shown in FIG.
It is held until changing to the next screen, and based on the held data, as shown in FIG. 2 (c), each blue LED of all dots
Are individually controlled to emit light and are simultaneously driven intermittently. The data transfer at this time is set arbitrarily.

[0012]

As described above, according to the LED dot matrix type full-color display device of the present invention, the red LED and the green LED are driven to emit light by the line-sequential scanning method by the dynamic driving type driving section, respectively, and the blue L
Since the ED is configured to emit light by the static drive type drive unit, the red LED drive unit and the green LED drive unit are dynamic drive type configurations each of which can be configured with a small number of parts, and only the blue LED drive unit is compared. Since it is a static drive type configuration with a complicated structure,
As a whole, the structure does not become complicated, it can be manufactured at low cost, and high reliability is maintained due to the simplification of the structure. In addition, the blue LED can easily emit light with the same brightness as the red and green LEDs driven by the dynamic driving method by driving the static driving method, which is inexpensive, highly reliable, and has high brightness. It is possible to provide an LED dot matrix type full-color display device having a high display quality capable of displaying the screen of a television receiver without variation.

[Brief description of drawings]

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

FIG. 2 is a timing chart of the same.

[Explanation of symbols]

 1 dot matrix type LED display unit 2 red shift register (red LED drive section) 3 green shift register (green LED drive section) 7 blue static driver (blue LED drive section) R red pixel data G green pixel data B blue Pixel data

Claims (1)

[Claims] 1. A dot matrix type LED display unit in which a set of red, green and blue LEDs forming each dot are arranged in a dot matrix, and the red LEDs of all dots are divided into a plurality of sets. A dynamic drive type red LED drive section which repeatedly drives them in a time-division manner with red pixel data, and the green L of all dots.
A dynamic drive type green LED drive unit that divides the ED into a plurality of sets and synchronizes them with the red LED drive unit to repeatedly emit light with green pixel data in a time-division manner; An LED dot matrix type full-color display device comprising: a static drive type blue LED driving unit which controls light emission individually based on the above, and drives so that the light emission is performed intermittently at the same time.