Abstract:
A package structure of full-color LED (Light Emitting Diode) with driving mechanism includes an IC (Integrated Circuit) chip, a red LED dice, a green LED dice, a blue LED dice, and corresponding current limiting resistors. The IC chip has a driving mechanism to control the red LED dice, the green LED dice, and the blue LED dice. By the specific arrangement of these internal elements, the package structure generates full-color light with high resolution, compact structure and high mixing uniformity, and also achieves low cost and decreases usage of space.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a package structure of full-color LED (Light Emitting Diode) adapted to various LED displays with special light-shadow effects, and more particularly, to a package structure of full-color LED equipped with internal driving mechanism. 
     2. Related Art 
     Light plays a significant role for a very long time in human life. Accompanying with the constant progresses of science and technology, LED (Light Emitting Diode) has been invented in 1970s. With the advantages of compact size, long lifetime, low breakage, low power consumption, no heat radiation and no toxic pollution (such as mercury and etc.), comparing with conventional light sources, LED is now broadly utilized in our daily life. 
     Through the environment/economization policies driven by the governments around the world, LED is well-developed and applied to two major applications including display and illumination functions. Due to plenty of nonstop technology advancements, the conventional single-color LED is gradually unable to satisfy human&#39;s visual needs. Consequently, advanced LED products such as bicolor LED and full-color LED are developed afterwards.  FIG. 1  illustrates a schematic view for a package structure of a conventional full-color LED. 
     To display every color perfectly, the package structure  10  of the conventional full-color LED at least includes a red LED dice  11 , a green LED dice  12  and a blue LED dice  13  configured therein, so that the tree primary color lights, red, green and blue lights may be used to mix and generate various colors of light. However, every color light needs different mixing ratio of the tree primary color lights so the full-color LED  10  needs to collocate with externally connected current limiting resistor(s) and driving element(s) and control the mixing ratio of the tree red, green and blue primary color lights. 
     In the prior art, the full-color LED  10 , current limiting resistors  20   a ˜ 20   c  and a driving element  30  is disposed on a printed circuit board (PCB)  40 , as shown in  FIG. 2 , a schematic view for a practical structure of a conventional full-color LED. While multiple PCBs  40  are electrically connected with each other, plus using an operation power and control signals provided by a host to drive the full-color LED, a complete LED display screen is thus integrated by multiple well-arranged full-color LEDs. 
     SUMMARY OF THE INVENTION 
     To solve the aforesaid problems of the prior art, the present invention provides an electronic device equipped with an interactive display screen, and a processing method for interactive displaying. The present invention automatically controls and switches between a digitizer board and a touch panel, thereby saves the cost of an external hardware switch button and prevents the digitizer board and the touch panel from generating different input signals corresponding to the same touch behavior. 
     The technologies for the LED display screen integrated by full-color LEDs are almost fully developed. However, the LED display screen is unable to display fine images due to the overlarge interval between the adjacent full-color LEDs, where the overlarge interval results from configuring the current limiting resistors and the driving element on the PCB, together with the full-color LEDs. Meanwhile, circuit malfunction/failure also results from bad contacts generated between soldering pads of a bended flexible circuit board and the components disposed thereon. The exposed driving element is also easily to be affected by radio frequency interference (RFI) and electromagnetic interference (EMI), thereby affects the operations of the whole LED display screen. 
     Accordingly, the present invention discloses a package structure of a full-color LED that is equipped with driving mechanism. One aspect is to effectively improve the overlarge intervals between the adjacent full-color LEDs in the conventional LED display screen. The package structure of the full-color LED in the present invention includes an IC (Integrated Circuit) chip, a red LED dice, a green LED dice and a blue LED dice configured together with current limiting resistors. In the IC chip, driving mechanism is equipped therein to control the red, green and blue LED dices. Through optimized arrangements and allocations for the internal components, a full-color LED is provided with a compact structure, high mixing uniformity and high resolution, and also achieves low cost and decreases usage of space. 
     On the other hand, packaging the IC chip into the full-color LED may further reduce radio frequency interference (RFI) and electromagnetic interference (EMI). Furthermore, the flexible circuit board may be omitted since the components are simplified; the present invention completely improves the problems of bad contacts between soldering pads of a bended flexible circuit board and the components disposed thereon. Besides, when the intervals between adjacent full-color LEDs are lessened, the overall power consumption of the LED display screen is reduced, thereby facilitate the effects of easy control and power economization. 
     These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. It is to be understood that both the foregoing general description and the following detailed description are examples, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus is not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic view for a package structure of a conventional full-color LED; 
         FIG. 2  is a schematic view for a practical structure of a conventional full-color LED; 
         FIG. 3A  is a schematic view of a first embodiment according to the present invention, illustrating a package structure of a full-color LED equipped with driving mechanism; 
         FIG. 3B  is a lateral cross-sectional view of the first embodiment according to the present invention; 
         FIG. 4  shows a equivalent electrical circuit for the full-color LED equipped with driving mechanism according to the present invention; 
         FIG. 5A  is a schematic view of a second embodiment according to the present invention, illustrating another package structure of the full-color LED equipped with driving mechanism; 
         FIG. 5B  is a lateral cross-sectional view of the second embodiment according to the present invention; 
         FIG. 6A  is a schematic view of a third embodiment according to the present invention, illustrating another package structure of the full-color LED equipped with driving mechanism; 
         FIG. 6B  is a lateral cross-sectional view of the third embodiment according to the present invention; and 
         FIG. 7  shows a schematic view for a display screen of the full-color LED equipped with driving mechanism according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description refers to the same or the like parts. 
     Please refer to  FIG. 3A , which is a schematic view of a first embodiment according to the present invention, illustrating a package structure of a full-color LED equipped with driving mechanism. 
     The package structure of the full-color LED equipped with driving mechanism has six pins, including a power input Vcc, a power output Gnd, a clock input CLKI, a clock output CLKO, a serial data input SDI and a serial data output SDO. The package structure allocated inside a frame  100  includes an IC (Integrated Circuit) chip  30 , three current limiting resistors  20   a ,  20   b ,  20   c , a red LED dice  11 , a green LED dice  12  and a blue LED dice  13 . Each of the three red, green and blue LED dices  11 - 13  has a first electrode and a second electrode respectively configured thereon; all the three red, green and blue LED dices  11 - 13  are fixed on a carrier  101 . 
     The power input Vcc extends into the package structure of the full-color LED  10  to form a rectangular extension section  102 . On the extension section  102 , there are three current limiting resistors  20   a ˜ 20   c  pasted thereon. The current limiting resistors  20   a ˜ 20   c  are the chip resistors with two electro-conductive surfaces. Therefore, when the bottoms of the current limiting resistors  20   a ˜ 20   c  are pasted on the extension section  102 , the current limiting resistors  20   a ˜ 20   c  form electrical connections with the power input Vcc directly. On the tops of the current limiting resistors  20   a ˜ 20   c , metal wirings are used for wire bonding to the first electrodes of the blue, red and green LED dices  13 ,  11 , and  12 . 
     The second electrodes of the red, green and blue LED dice  11 - 13  connect to control points of the IC chip  30  through wire bonding. The IC chip  30  is pasted on the carrier  101 , and is connected by wire bonding with the six pins including the power input Vcc, the power output Gnd, the clock input CLKI, the clock output CLKO, the serial data input SDI and the serial data output SDO. Eventually, feed in light-mixing glue  103  of light-pervious material to complete the package. For the corresponding positions of said components, please refer to  FIG. 3B , which is a lateral cross-sectional view of the first embodiment according to the present invention. 
     Please refer to  FIG. 4 , which shows a equivalent electrical circuit for the full-color LED equipped with driving mechanism according to the present invention. First of all, the operation power is input from the power input Vcc and sent to the IC chip  30 . Then the operation power is provided to the red, green and blue LED dices  11 - 13  through the three current limiting resistors  20   a ˜ 20   c  in parallel. The current limiting resistors  20   a ˜ 20   c  are used to precisely distribute the operation power in to the three LED dices, thereby ensure the light colors generated by mixing lights of the LED dices and also to form protections for the LED dices. Through the clock input CLKI and the serial data input SDI, control signals are sent to the IC chip  30 ; afterwards, the driving mechanism of the IC chip  30  generates various voltage controls on the red, green and blue LED dices  11 - 13  to mix for different light colors. The operation power is sent through the power output GND; the control signals are sent to a next full-color LED through the clock output CLKO and serial data output SDO. 
     Without against the uniform inventive concepts, the present invention further has another practical embodiment. Please refer to  FIG. 5A , which is a schematic view of a second embodiment according to the present invention, illustrating another package structure of the full-color LED equipped with driving mechanism. 
     In this embodiment of the package structure of the full-color LED equipped with driving mechanism, the package structure of the full-color LED has similarly six pins, including a power input VCC, a power output GND, a clock input CLKI, a clock output CLKO, a serial data input SDI and a serial data output SDO. The feature is that the power input Vcc extends into the frame  100  to form a rectangular planar extension section  102  on carrier  101 . The IC chip  30  is directly pasted on the extension section  102  and connects through wire bonding with the six pins, the power input Vcc, the power output Gnd, the clock input CLKI, the clock output CLKO, the serial data input SDI and the serial data output SDO. 
     Each of the red, green and blue LED dices  11 - 13  is configured respectively with a first electrode and a second electrode. In the present embodiment, the red, green and blue LED dices  11 - 13  are fixed on the control points of the IC chip  30  and form electrical connections with the control points by means of joint-chip or direct paste. 
     The three current limiting resistors  20   a ˜ 20   c  are pasted on optimal positions of the extension section  102 . Such current limiting resistors are all chip resistors with two electro-conductive surfaces. Therefore, when the bottoms of the current limiting resistors  20   a ˜ 20   c  are pasted on the extension section  102 , the current limiting resistors  20   a ˜ 20   c  form electrical connections with the power input Vcc directly. On the tops of the current limiting resistors  20   a ˜ 20   c , metal wirings are used for wire bonding to the first electrodes of the blue, red and green LED dices  13 ,  11 , and  12 . After all the electrical connections are completed, feed in light-mixing glue  103  of light-pervious material to complete the package. Refer to  FIG. 5B  to review the stacked status;  FIG. 5B  is a lateral cross-sectional view of the second embodiment according to the present invention. From the drawing, it is obvious that in the second embodiment, the amount of ‘wire bonding’ is reduced. Meanwhile, the three primary color dices are configured together on the IC chip, thereby facilitate shorten light-mixing distances and more complete light colors. 
     Aside from the aforesaid embodiment, the present invention further discloses another practical embodiment. Please refer to  FIG. 6A , which is a schematic view of a third embodiment according to the present invention, illustrating another package structure of the full-color LED equipped with driving mechanism. 
     In the package structure of this embodiment, the full-color LED has similar six pins, including a power input Vcc, a power output Gnd, a clock input CLKI, a clock output CLKO, a serial data input SDI and a serial data output SDO. The power input Vcc may still extend into the frame  100  and form a rectangular planar extension section  102  on the carrier  101 . The IC chip  30  is still directly pasted on the extension section  102 , and is connected through wire bonding with the power input Vcc, the power output Gnd, the clock input CLKI, the clock output CLKO, the serial data input SDI and the serial data output SDO. 
     Each of the red, green and blue LED dices  11 - 13  is respectively configured with a first electrode and a second electrode. To avoid the normal operation of the IC chip  30  due to the heat produced by the LED dices  11 - 13  during illuminating, a heat isolating layer  13  is pasted on the IC chip  30 . The heat isolating layer  32  is made of glass or ceramic material to isolate the heat produced by the LED dices  11 - 13 . Moreover, a heat conducting layer  31  is pasted on the heat isolating layer  32  and connected to the carrier  101  or the inner frame. The heat produced by the LED dices  11 - 13  is transmitted out of the package structure through the heat conducting layer  31 . The heat conducting layer  31  is made of materials with high heat transfer coefficient, such as metal or alloy. The red, green and blue LED dices  11 - 13  is respectively pasted on optimal positions of the heat conducting layer  31 . The first electrode and the extension section  102  forms electrical connections through wire bonding. 
     The three current limiting resistors  20   a ˜ 20   c  are pasted on the control points of the IC chip  30 . Such current limiting resistors are all chip resistors with two electro-conductive surfaces. Therefore when the bottoms of the current limiting resistors  20   a ˜ 20   c  are pasted on the control points of the IC chip  30 , the current limiting resistors  20   a ˜ 20   c  directly form electrical connections. On the tops of the current limiting resistors  20   a ˜ 20   c , metal wirings are used for wire bonding to the second electrodes of the blue, red and green LED dice  13 , 11 , 12  on the IC chip  30 . Afterwards, feed in light-mixing glue  103  of light-pervious material to complete the package. Refer to  FIG. 6B  to review the stacked status;  FIG. 6B  is a lateral cross-sectional view of the third embodiment according to the present invention. From the drawings, the third embodiment is obviously similar to the second embodiment. Although the current limiting resistors  20   a ˜ 20   c  and the blue, red and green LED dices  13 , 11 , 12  exchange connection relationships with each other, the functions are not affected. Therefore this embodiment has the same advantages of the second embodiment. Meanwhile the third embodiment will dispose current limiting resistors  20   a ˜ 20   c  on the IC chip  30 , so as to shorten the intervals between full-color LEDs, at the same time the blue, red and green LED dice  13 ,  11 , 12  have closer positions to achieve a better light-mixing effects. 
     In the end, please refer to  FIG. 7 , which shows a schematic view for a display screen of the full-color LED equipped with driving mechanism according to the present invention. 
     Through connecting the full-color LED  10  disclosed the present invention, a large LED display screen may be integrated and formed; wherein each of the full-color LED  10  connects with another through cascade control. The control signals may be output through a large control end. In the control signals, there are clock (CLK) data for all the full-color LEDs  10  to operate in synchronization, serial data (SD) for controlling the red, green and blue LED dices. After the full-color LED  10  receives control signals from the clock input CLKI and the serial data input SDI, PWM (Pulse Width Modulation) may be used to control the light-color mixing of the red, green and blue LED dices. The control signals may be sent to another full-color LED  10  through the clock input CLKO and the serial data input SDO. By means of said method, a designer many connect a large amount of full-color LEDs to form a large-scale LED display screen. Since the full-color LED has an IC chip and current limiting resistors, the intervals between the adjacent full-color LEDs so that the distance in-between is effectively shortened and a large-scale display screen may display finer images. 
     Additional advantages and modifications will readily occur to those proficient in the relevant fields. The invention in its broader aspects is therefore not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.