KR890007193A - LED Array Driver Using Time Division Sequential Circuit - Google Patents

Abstract

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Description

LED Array Driver Using Time Division Sequential Circuit

As this is a public information case, the full text was not included.

3 is a block diagram of the present invention;

4 is a detailed circuit diagram of the present invention;

5 is an operation timing diagram of FIG.

Claims (3)

In the LED array driving apparatus of an LED printer head using a time-division sequential circuit having an LED array 17 consisting of N LED arrays and a timing controller 20 for generating a clock and a timing signal, the LED array driving apparatus of the LED printer head has a block unit from the head controller. The shift register 37 for serially inputting print data by the first clock CLKI of the timing controller 20 and the output of the print data in units of blocks when the shift register 30 is completed, the timing controller ( The first latch 40 which latches in parallel by the first control signal ENI of 20), and the correction data according to the predetermined number of bits by the address signal and the second clock CLK2 other than the timing controller 20 are consecutive. A light quantity correcting unit 50 which generates light quantity correction data by logically combining the correction data having a predetermined number of bits and the output of the first latch 47, and the LED array unit 17 by the light quantity correcting unit 50. ) The first driving unit 60 for applying the first driving signal for correcting the amount of light and the third clock CLK3 of the timing controller 27 when the input of the shift register 37 is completed are used to determine the current LED block unit value. A decoder 80 for counting the counter value of the counter 70 by the counting counter 77 and the first control signal ENI of the timing controller 27, and generating the LED block selection data; A second latch 90 which latches the output of the decoder 80 by the second control signal EN2 of the timing controller 20 until the output of the light quantity correction data of the block is finished; And a second driver (100) for generating a second drive signal for driving the corresponding LED block of the LED array (57) by the second latch (90). The first driving unit (77) generated by the first driving signal applies light quantity correction data corresponding to the number of block units of the light quantity correction unit (50) to the base of the transistor having the same number. The collector terminals of each transistor are connected to the first power supply terminal (VCC), and the emitter terminal of each transistor is connected to a corresponding LED among the LED blocks in the LED array 17 through a resistor in common. Device. The transistor of claim 1, wherein the second driver 100 generating the second driving signal is the same as the LED block of the LED array 70 as the LED block selection signal of the second latch 90. Applying to a base, connecting the collector stages of each transistor to the cathode stages of all LEDs of the corresponding LED block and the emitter stages of each transistor to ground. ※ Note: The disclosure is based on the initial application.