TW201840244A - Multiplexed driving dimming light-emitting module and method having LED driving chip to control individually the plural LED groups to emit light sequentially at different times in the way of frequency scanning according to the driving setting value of the microcontroller - Google Patents

Abstract

The present invention provides a multiplexed driving dimming light-emitting module and method, wherein the light-emitting diode driving chip is electrically connected to the plurality of light-emitting diode groups, and comprises a pulse width modulation generator and a micro-controller electrically connected to the LED driving chip, respectively. A selector is electrically connected to the microcontroller and the plurality of LED groups, so that the LED driving chip can individually control the brightness of the plural light-emitting diode groups according to the pulse width modulation setting value of the pulse width modulation generator. The LED driving chip controls individually the plural LED groups to emit light sequentially at different times in a frequency scanning manner according to the driving setting value of the microcontroller. The selector controls the plurality of LED groups according to the control switching setting value of the microcontroller to form the light-emitting frequency at which human eye does not feel blinking, thereby achieving the purpose of multiplex driving and dimming of a single LED driving chip.

Description

 Multiplexed driving dimming lighting module and method  

The invention provides a multiplexed driving dimming lighting module and a method, in particular, a micro-controller capable of controlling a light-emitting diode driving chip to output a pulse width modulation setting value at different times in a frequency scanning manner, and a selector Each of the plurality of light-emitting diode groups is individually controlled to form a human eye that does not find a blinking light-emitting frequency.

According to the rapid development of today's electronic technology and information industry, various electronic products are moving toward light, thin, short, small and powerful trends, such as computers, notebook computers, mobile Internet devices (MIDs), smart phones, Tablet PCs, etc., have become indispensable electronic products for modern people in daily life or work, and most of the users and electronic products use mouse, keyboard and other input devices to communicate, and the keyboard is most convenient. Input operations for text, numbers, or commands, and enhance useful functions.

Moreover, in order to enable the human eye to clearly see the symbols on each button in a low-light environment, a manufacturer introduces a light guide plate and a light source technology into the keyboard, and develops an illuminated keyboard with a backlight module to make the backlight The light generated by the module can be projected onto the back of each keycap to form a backlight effect, so that the user can see the character symbols on the keycap for convenient operation. Currently, the illuminated keyboard on the market includes a backlight module. And a button module, wherein the backlight module has a light guide plate, and a light source is disposed at one side of the light guide plate, and the light-emitting diode of the light source projects light to the light guide plate to make the light guide plate uniformly emit light, and The lower surface of the light guide plate is provided with a reflective sheet that can reflect the light emitted from the lower surface of the light guide plate back to the light guide plate, and the light guide plate corresponding to the button module is disposed on the surface of the light guide plate, so that the light guide plate can be guided and projected. After passing through the light transmitting portion of the light shielding film, the light is incident on the corresponding key cap of the button module to form a backlight.

Since the design of the keyboard will become thinner and thinner in a limited space, the internal space of the keyboard is also narrowed. The total thickness of the backlight module is the thickness of the light guide plate plus the stacking unit of the light-emitting unit and the light-reflecting sheet. The overall thickness will be limited by its own structure and cannot be effectively reduced. Therefore, some manufacturers have developed a method in which a plurality of LED dies are formed on the surface of a conductive layer by a printing process, and are cured to be electrically connected thereto. A light-emitting main layer is formed on the conductive layer, and the light-emitting layer is disposed between the bottom plate of the button module and the keycap. The layered structure design can not only omit the thickness of the light guide plate and the reflective sheet stack, and The thickness is relatively reduced to simplify the overall structure and reduce the cost of manufacturing.

With the increasing performance requirements of the keyboard backlight, the driving circuit for LED is continuously developed, and it is gradually integrated into the integrated circuit and applied to the light-emitting module of the keyboard backlight display. The group controls the brightness of the keyboard backlight. The light module comprises a plurality of LEDs and a control circuit, and the control circuit comprises a power source, a driving chip and a pulse width modulation generator. The driving chip is connected between the power source and the plurality of LEDs. The pulse width modulation generator is connected between the power source and the driving chip to generate a pulse width modulation signal, which can be used to control the driving chip to adjust the brightness of the LED, but the plurality of LEDs of the lighting module correspond to each other. The position of the key cap, and in the practical application of the keyboard, in order to provide the uniformity and stability of the LED current, and to respond quickly to changes in the input voltage, it is generally required to provide four driving chips according to the pulse width modulation signal. The current of the channel drives the complex LEDs to adjust the brightness of the LEDs to maintain stability, thereby improving the efficiency of the keyboard backlight. This control circuit utilizes four Driving the chip not only affects the layout and complexity of the circuit on the circuit board, but also takes up a certain volume to limit the overall space utilization, and also causes an increase in the cost of manufacturing and setting a plurality of driver chips, and the plurality of driver chips The brightness control of the complex LED becomes complicated, and it consumes a large power of the control circuit itself, and it is yet to be redesigned by the industry to effectively improve it.

Therefore, in view of the above-mentioned problems and shortcomings of the above-mentioned practices, the inventors have collected and evaluated relevant materials through various parties, and have used the trial and modification of many years of R&D experience in this industry to start such multiplex drive dimming. The invention patent for the light-emitting module and method was born.

The main purpose of the present invention is to control the brightness of the plurality of light emitting diode groups according to the pulse width modulation setting value generated by the pulse width modulation generator by using the LED driving chip, and according to the micro The driving set value generated by the controller separately controls the plurality of LED groups to be sequentially illuminated at different times in a frequency scanning manner, and then the selector controls the switching value according to the control generated by the microcontroller. A plurality of light-emitting diode groups form a human eye without detecting a blinking light-emitting frequency and providing a uniform brightness output. The multiplexed drive control circuit of the light-emitting module only needs to drive a single wafer with a single light-emitting diode. The purpose of driving dimming can simplify the overall circuit layout and complexity, and save the volume occupied by multiple LED driving chips to improve the flexibility of space application and reduce the cost of manufacturing and installation, and also reduce the cost of itself. The power consumed.

1‧‧‧Lighting diode group

11‧‧‧Lighting diode

2‧‧‧Lighting diode driver chip

3‧‧‧ Pulse width modulation generator

4‧‧‧Microcontroller

5‧‧‧Selector

51‧‧‧Transistor Switch

The first figure is a block diagram of the multiplex drive control circuit of the light-emitting module of the present invention.

The second figure is a flow chart of the steps of the method for multiplexed driving dimming of the light-emitting module of the present invention.

In order to achieve the above objects and effects, the technical means and constructions of the present invention will be described in detail with reference to the preferred embodiments of the present invention.

Please refer to the first figure, which is a block diagram of the multiplex drive control circuit of the light-emitting module of the present invention. It can be clearly seen from the figure that the multiplexed drive dimming light-emitting module of the present invention comprises a plurality of light-emitting diodes. a polar body group 1, a light emitting diode driving chip 2, a pulse width modulation generator 3, a microcontroller 4 and a selector 5, wherein: the light emitting diode group 1 comprises six groups each Four illuminating diodes 11 in parallel and having a number of twenty-four, and the multiplex drive control circuit of the illuminating module of the present invention has four illuminating diode groups 1 in the embodiment, and the four illuminating groups The diode group 1 includes twenty-four groups of four light-emitting diodes 11 connected in parallel and having a number of ninety-six. However, in practical applications, it is not limited thereto, and may also be based on the two light-emitting diodes. The pole body 11 individually changes the number of settings corresponding to the keycap position of the adjustable keyboard.

The plurality of pins of the LED driving chip 2 are electrically connected to the plurality of LED groups 1 .

The plurality of pins of the Pluse Width Modulation (PWM) generator 3 are electrically connected to the LED driving chip 2 for generating a pulse width modulation setting value to enable the illuminating The diode driving chip 2 can control the percentage of the pulse width modulation signal outputted to each of the plurality of LED groups 1 according to the pulse width modulation setting value, and the timing modulation signal is sequentially turned on or The repeated repetitive pulse sequences individually control the brightness produced by the plurality of light emitting diode groups 1 .

The plurality of pins of the microcontroller 4 are electrically connected to the LED driving chip 2, and the power supply or preset power supply provided by the adjustable keyboard to generate a driving set value and a control The set value is switched such that the LED driving chip 2 can control the plurality of LED groups 1 to emit light at different times according to the driving setting value.

The selector 5 includes at least four transistor switches 51, which are Field Effect Transistors (FETs) or Bipolar Junction Transistors (BJTs). The field effect transistor can be divided into an insulated metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor FET, referred to as MOSFET; can be divided into enhanced and depleted type), and junction type junction field effect transistor (Junction FET, abbreviated as JFET), and the bipolar junction transistor can be divided into an NPN transistor and a PNP transistor. In this embodiment, the transistor switch 51 is an NPN transistor and is input by the NPN transistor. The base (B) of the terminal and the collector (C) of the common terminal are electrically connected to the plurality of frequency scanning signal pins and a power pin of the microcontroller 4, respectively, and the emitter of the output terminal (E) Electrically connected to the anodes of the plurality of LED groups 1 respectively, so that the selector 5 supplies an input voltage including Vcc through the microcontroller 4, and controls a plurality of transistor switches 51 according to the control switching setting value. Turn-on and cut-off.

The electronic device to which the multiplexed drive dimming lighting module of the present invention can be applied includes, but is not limited to, a notebook computer, a detachable keyboard or a keyboard used by a desktop computer, etc., when the user presses down on the keycap of the keyboard When the key cap is pressed down, the elastic component is pressed to trigger the electrical connection of the corresponding switch on the circuit board, and the multiplexed driving control circuit of the lighting module controls each of the plurality of LED groups 1 facing the keycap. The light is projected to form a backlight, so that the function of the keyboard illumination can be realized.

In the actual operation process, the multiplexer driving chip 2 can generate a pulse width modulation setting value according to the pulse width modulation generator 3, and control each channel to output the plurality of channels. The percentage of the pulse width modulation signal of the group 1 of the LEDs, and the pulse width modulation signal respectively controls the brightness generated by the plurality of LED groups 1 by repeating pulse sequences that are turned on or off in sequence. The brightness of the light-emitting diodes 11 of each of the light-emitting diode groups 1 can be controlled to provide a consistent brightness output, and the microcontroller 4 generates a drive set value and a control. Switching the set value, so that the LED driving chip 2 sequentially controls the illumination of the plurality of LED groups 1 at different times according to the driving setting value in a frequency scanning manner, and then the selector 5 is further controlled by the selector 5 The switching and setting of the plurality of transistor switches 51 can be controlled according to the control switching setting value, so that the input voltage provided by the microcontroller 4 including Vcc can be separately switched and outputted to the plurality of LEDs through the plurality of transistor switches 51. In the polar group 1, the frequency of the illumination of the plurality of LED groups 1 is controlled to form a flicker that is not found by the persistence phenomenon of the human eye, thereby achieving the multiplex drive dimming of the single LED driving chip 2 The purpose and provide consistent brightness output.

In this embodiment, the multiplex drive control circuit of the light-emitting module only needs to drive the chip 2 by using a single LED, and the pulse width modulation setting value of the pulse width modulation generator 3 can be adjusted according to the pulse width modulation generator 3, and One of the microcontrollers 4 drives the set value to output a pulse width modulation signal at different times in a frequency scanning manner to control the brightness of the plurality of light emitting diode groups 1 and is controlled by the selector 5 according to the microcontroller 4 A control switching setting value respectively controls the plurality of light emitting diode groups 1 to form a human eye without detecting a blinking light emitting frequency, so the single light emitting diode driving chip 2 can simplify the overall circuit layout and complexity. And saving the occupied volume to improve the flexibility of space application, and can reduce the cost of manufacturing and setting multiple LED driving chips 2, thereby making the brightness control of the LED group 1 easier and more The power consumed by the drive control circuit itself is more practical.

Please refer to the second figure, which is a flow chart of the steps of the multiplexer driving dimming method of the illuminating module of the present invention, as can be clearly seen from the figure, wherein a illuminating module applying the method comprises a plurality of illuminating two The polar body group 1, a light emitting diode driving chip 2, a pulse width modulation generator 3, a microcontroller 4 and a selector 5, the method comprises the following steps:

(601) The pulse width modulation generator 3 has a pulse width modulation setting value, and writes the pulse width modulation setting value to the light emitting diode driving wafer 2.

(602) The LED driving chip 2 controls the brightness of the plurality of LED groups 1 according to the pulse width modulation setting value.

(603) The microcontroller 4 has a driving set value and a control switching setting value, and the LED driving chip 2 controls the plurality of illuminating lights at different times in a frequency scanning manner according to the driving setting value. The diode group 1 emits light sequentially.

(604) The selector 5 controls the frequency at which the plurality of light-emitting diode groups 1 emit light according to the control switching setting value.

In this embodiment, the LED driving chip 2 is electrically connected to the plurality of LED groups 1 , and is electrically connected to the LED driver by the pulse width modulation generator 3 . The chip 2 is configured to generate a pulse width modulation setting value, and the microcontroller 4 is electrically connected to the LED driving chip 2 to provide a current value of a preset power source, so that the LED driving chip 2 can be The pulse width modulation setting value respectively controls the brightness generated by the plurality of LED groups 1 , and the microcontroller 4 can generate a driving set value and a control switching setting value, and the LED is generated by the LED The body driving chip 2 controls the plurality of light emitting diode groups 1 to sequentially emit light according to the driving set value at different times, and then the selector 5 switches the set value according to the control to control and control the plurality of transistor switches 51. Turning on and off, and driving the plurality of light-emitting diode groups 1 to form a light-emitting frequency that the human eye does not find flicker.

Therefore, the present invention is mainly directed to the LED driving chip 2, and the brightness of the plurality of LED groups 1 can be individually controlled according to the pulse width modulation setting value generated by the pulse width modulation generator 3, and according to The driving set value generated by the microcontroller 4 controls the plurality of LED groups 1 to be sequentially illuminated at different times in a frequency scanning manner, and then switched by the selector 5 according to the control generated by the microcontroller 4. The set value separately controls the plurality of light-emitting diode groups 1 to form a human eye that does not detect the blinking light-emitting frequency, and only needs to drive the wafer 2 with a single light-emitting diode to achieve the purpose of multiplex driving dimming, Simplify overall circuit layout and complexity, and save the cost of manufacturing and setting up multiple LEDs.

The detailed description of the present invention is intended to be a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and other equivalents and modifications may be made without departing from the spirit of the invention. Changes are intended to be included in the scope of the patents covered by the present invention.

In summary, the multiplexer-driven dimming light-emitting module and method of the present invention can achieve its efficacy and purpose when used, so the invention is an invention with excellent practicability, and is in compliance with the application requirements of the invention patent. , 提出 file an application in accordance with the law, I hope that the trial committee will grant this case as soon as possible to protect the inventor's hard work. If there is any doubt in the bureau, please do not hesitate to give instructions, the inventor will try his best to cooperate, and feel really good.

Claims (8)

 A multiplexed driving dimming light emitting module comprises: a plurality of light emitting diode groups; a light emitting diode driving chip electrically connected to the plurality of light emitting diode groups; a pulse width modulation generator Electrically connected to the LED driving chip for generating a pulse width modulation setting value, wherein the LED driving chip controls the plurality of LED groups according to the pulse width modulation setting value a brightness of the group; a microcontroller is electrically connected to the LED driving chip for generating a driving set value and a control switching setting value, and the LED driving chip is scanned at a frequency according to the driving setting value The method respectively controls the plurality of light emitting diode groups to sequentially emit light at different times; a selector is electrically connected to the microcontroller and the plurality of light emitting diode groups, and the selector is controlled according to the control Switching the set values individually controls the frequency at which the plurality of light emitting diode groups emit light.    The multiplexer-driven dimming light-emitting module according to claim 1, wherein the light-emitting diode group comprises six groups of four light-emitting diodes each having a parallel connection.    The multiplexer-driven dimming light-emitting module of claim 1, wherein the selector comprises at least four transistor switches electrically connected to the microcontroller and the plurality of transistors Light-emitting diode group.    The multiplexer-driven dimming lighting module of claim 3, wherein the transistor is in a field-effect transistor.    The multiplexer-driven dimming lighting module of claim 3, wherein the electro-optic body is in contact with a bipolar junction transistor.    A multiplexed driving dimming method, wherein a lighting module using the method comprises a plurality of light emitting diode groups, a light emitting diode driving chip, a pulse width modulation generator, a microcontroller and a a selector, the method comprising the steps of: (a) the pulse width modulation generator having a pulse width modulation setting value, and writing the pulse width modulation setting value to the LED driving chip; (b) The LED driving chip controls the brightness of the plurality of LED groups according to the pulse width modulation setting value; (c) the microcontroller has a driving set value and a control switching setting value, and The LED driving chip sequentially controls the plurality of LED groups to sequentially emit light at different times according to the driving setting value in the frequency scanning manner; (d) the selector switches the set value according to the control. The frequency at which the plurality of light emitting diode groups emit light.    The multiplexer-driven dimming method of claim 6, wherein the micro-controller is electrically connected to the LED driving chip and provides a current value, and the step (b) of the light-emitting diode The polar body driving chip controls the brightness generated by the plurality of light emitting diode groups according to the pulse width modulation setting value.    The method of multiplex drive dimming according to claim 6, wherein the selector of the step (d) comprises at least four transistor switches, and the selector controls the complex number according to the control switching setting value. The transistor switches are turned on and off to control the plurality of light-emitting diode groups to form a light-emitting frequency that is not found by the human eye.