JP3467045B2 - LED dot matrix type full color display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a television system in which each dot is composed of three colors of blue in addition to red and green to form a dot matrix arrangement. The present invention relates to an LED dot matrix type full-color display device that can be used to project an image or the like of a receiver with high image quality. 2. Description of the Related Art A conventional L having a conventional multi-color display function is used.
The ED dot matrix type display device is configured such that each dot is constituted by one set of one LED for each of red and green, each pixel data is fetched for one row, and each dot on a horizontal scanning line designated by an address signal. The LEDs of each color are driven to emit light, and are driven to emit light by a dynamic driving method in which this operation is repeated. In the above-described dot matrix type LED display device, only three colors of red, green and orange are emitted by a pair of red and green LEDs. Is insufficient to display an image of a television receiver or the like. Therefore, full-color display can be performed by adding a blue LED. However, the blue LED is a red LED and a green LED.
Since the luminance is relatively low with respect to the ED, if the light is emitted under the same conditions as the red and green LEDs, the luminance reaching the practical level cannot be obtained. In addition, the above-described dynamic drive method has an advantage that it can be configured with a small number of parts, but because it is a duty cycle drive, it is necessary to increase the current at the time of LED emission, so that the blue LED is replaced with the red and green LEDs. In order to emit light with the same level of brightness, it is necessary to supply a larger forward current to the blue LED, and this excessively large forward current significantly reduces the reliability of the LED chip, and furthermore, such a large driving capability is required. The electronic component has a large package, which hinders miniaturization. In other words, a device that performs 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 driving method is hardly practical. [0004] Therefore, if the LEDs of all dots are driven to emit light by a static driving method in which the light emission is individually controlled based on the pixel data and simultaneously performed intermittently, it is possible to obtain a practical level of luminance even for the blue LED. However, if each of the three types of LDDs of red, green, and blue is driven to emit light by a static driving method, the number of terminals and driving elements connected for each color becomes very large, resulting in high cost. In addition, the reliability is remarkably reduced as the configuration becomes more complicated. [0005] Therefore, the present invention provides an LE capable of obtaining high display quality by emitting red, green, and blue LEDs at the same level of luminance by using a low-cost and highly reliable configuration.
An object of the present invention is to provide a D dot matrix type full color display device. According to the present invention, as a technical means for achieving the above object, an LED dot matrix type full-color display device is constituted as follows.
That is, a dot matrix type LED display unit in which a set of red, green, and blue LEDs constituting each dot are arranged in a dot matrix form, and the red LEDs of all the dots are divided into a plurality of sets and these are set A dynamic driving type red LED driving unit that emits light with red pixel data repeatedly in a divided manner, and divides each of the green LEDs of all dots into a plurality of sets and synchronizes them with the red LED driving unit and repeats the green color in a time division manner. A dynamic drive type green LED driving unit for driving light emission by pixel data, and a static drive type blue LED for individually controlling light emission of each of the blue LEDs of all dots based on blue pixel data and driving the light emission simultaneously and intermittently And a drive unit. A red LED and a green LED respectively hold, for example, one row of red pixel data and green pixel data by a latch signal by a dynamic driving type red LED driving unit and a green LED driving unit. Is driven by a line-sequential scanning method in which data of the next row is transferred at the time of light-emission driving. On the other hand, each blue LED is individually controlled to emit light based on blue pixel data by a blue LED driver of a static drive type, and is driven so as to emit light intermittently at the same time. Accordingly, the red LED driving section and the green LE
The D drive unit is a dynamic drive type configuration that can be configured with a small number of components, and only the blue LED drive unit is a static drive type configuration having a relatively complicated configuration. Therefore, the overall configuration may be complicated. In addition, it can be manufactured at low cost and keeps high reliability with simplification of the configuration. In addition, the blue LED is easily driven to emit light by the static drive method, and can easily emit light with the same luminance as each of the red and green LEDs driven to emit light by the dynamic drive method, so that high display quality can be obtained. . Preferred embodiments of the present invention will be described below in detail with reference to the accompanying 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 as a dot matrix of, for example, 16 × 16 dots in which each dot is configured by combining one red, green, and blue LED as one set, and has a full-color display function. A red LED driving section of a dynamic drive type 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 unit. The blue LED is driven to emit light by a static driving method by a blue static driver (7). The red pixel data (R) and green pixel data (G) of the input video signal are converted into, for example, a 16-bit red shift register and a green shift register (3) according to the timing of the clock signal (C). 2A, and at the time 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. Then,
One row of red pixel data (R) and green pixel data (G) output from the red shift register (2) and the green shift register (3) by the enable signal (E), respectively, are output to the decoder (4). , (5) and the line signal (A1) through the line driver (6).
The red LED and the green LED of each dot of the horizontal scanning line specified 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, and the screen is displayed by the line sequential scanning method. On the other hand, with respect to the blue pixel data (B), one screen portion is taken into the blue static driver (7) and latched by a latch signal shown in FIG.
It is held until the next screen is changed, and based on the held data, as shown in FIG.
Are individually controlled to emit light and are simultaneously driven intermittently. The data transfer at this time is arbitrarily set. As described above, according to the LED dot matrix type full-color display device of the present invention, each of the red LED and the green LED is driven to emit light in a line-sequential scanning manner by a dynamic drive type driving unit, and the blue LED is driven in blue. L
Since the ED is driven to emit light by a static drive type drive unit, the red LED drive unit and the green LED drive unit are each a dynamic drive type configuration that can be configured with a small number of components, and only the blue LED drive unit is compared. Because it is a statically driven configuration with a complicated configuration,
As a whole, the configuration is not complicated, the device can be manufactured at low cost, and high reliability is maintained with the simplification of the configuration. Moreover, the blue LED is easily driven to emit light at the same luminance as the red and green LEDs driven to emit light by the dynamic driving method by being driven to emit light by the static driving method. It is possible to provide an LED dot matrix type full-color display device having a high display quality and capable of projecting a screen of a television receiver without variation.

[Brief description of the drawings] FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is a timing chart of the above. [Explanation of symbols] 1 Dot matrix type LED display unit 2 Red shift register (Red LED driver) 3 Green shift register (green LED driver) 7 Blue static driver (blue LED driver) R red pixel data G green pixel data B Blue pixel data

Continuation of the front page (56) References JP-A-6-124069 (JP, A) JP-A-5-29657 (JP, A) JP-A-5-257432 (JP, A) JP-A-4-241384 (JP) JP-A-60-131597 (JP, A) JP-A-60-73577 (JP, A) JP-A-58-91497 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB G09G 3/00-3/38 H04N 5/65-5/74 H01L 33/00

Claims (1)

(57) [Claim 1] A dot matrix type LED display unit in which a set of red, green and blue LEDs constituting each dot are arranged in a dot matrix form; A red LED driving unit that divides the red LED into a plurality of sets, repeats them in a time-division manner, and drives the light emission with red pixel data;
A dynamic drive type green LED drive unit that divides the ED into a plurality of sets, synchronizes them with the red LED drive unit and emits light in a time-divisional manner and repeatedly emits green pixel data, and An LED dot matrix type full-color display device, comprising: a static drive type blue LED drive unit that individually controls light emission based on the above and drives the light emission simultaneously and intermittently.