Abstract:
A converting module for connecting a memory card to a projector is provided. The converting module is modulized and coupled to the projector so that the projector can directly read and play the image data stored in the memory card on the basis of not altering the system configuration of the projector itself. Furthermore, I2C communication protocol is used as the standard of signal transmission between the memory card and the projector so as to save cost of designing pertinent hardware and software.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention generally relates to a converting module, and in particular relates to a converting module for connecting a memory card to a projector.  
         [0003]     2. Related Art  
         [0004]     As digital cameras being widely used, people are gradually accustomed to use digital cameras for recording images. Digital cameras take pictures; transfer them into digital signals and store into flash memory cards mounted on the cameras. The memory card stores a lot of images, more than a conventional film can do. When users want to view the images, they only need to transfer the image data from the memory card to a display device, without the need of the developing and printing processes for a conventional film.  
         [0005]     However, the transmission interface between the memory card and the display device requires specific software and hardware that increase the complicacy and inconvenience of the application. Especially, when a user want to show the images in the memory card through a projector, the user has to connect the memory card to a computer having a memory card transmission interface for reading the image data into the computer and transferring the image data to the projector for display. The process is rather complicated and inconvenient.  
         [0006]     Therefore, it is desired to a module applicable to a projector for reading image data from the memory card directly so as to simplify the process without changing the original configuration of the projector.  
       SUMMARY OF THE INVENTION  
       [0007]     The object of the invention is to provide a converting module for connecting a memory card to a projector so that the projector can display the image data stored in the memory card.  
         [0008]     A converting module according to the invention includes an interface processing unit, a register, a microprocessor and a memory unit. Through the interface processing unit, a universal serial bus (USB) connects to the memory card for transferring the image data stored in the memory card in a serial format to the interface processing unit. The interface processing unit further transfers the serial data to the register and stores there.  
         [0009]     Then, the microprocessor receives commands from the projector that define resolution, updating rate, etc. of the image data so as to read the related program stored in the memory unit according to the commands. After processing the image data stored in the register, the image signals are transferred to the projector for display.  
         [0010]     The signal transmission between the projector and the microprocessor is via I2C bus. The I2C bus is composed of a serial clock (SCL) bus and a serial data (SDA) bus that the SCL bus transfers time signals for controlling the data transmission, and the SDA bus transfers the data and commands. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention will become more fully understood from the detailed description given hereinbelow. However, this description is for purposes of illustration only, and thus is not limitative of the invention, wherein:  
         [0012]     The sole  FIG. 1  is a circuit block diagram of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]     As shown in  FIG. 1 , a circuit block diagram of the invention, the converting module  100  is mounted on, or placed individually from, a projector  101  through connections of an interface. The converting module  100  connects with a memory card  102  so that the projector  101  can read the image data stored in the memory card  102  and display.  
         [0014]     The memory card  102  can be plugged to a digital camera (not shown) for storing the image data it takes, The memory card  102  can be a CompactFlash card, MicroDrive card, SmartMedia card, memory stick, Secure Digital (SD) card or MultiMedia card (MMC) and so on.  
         [0015]     The converting module  100  includes an interface processing unit  103 , a register  104 , a microprocessor  105  and a memory unit  106 . The interface processing unit  103  connects to the memory card  102  for reading and transferring the image data to the register  104 . The interface processing unit  103  utilizes a universal serial bus (USB)  107  to transfer image data in a serial data format from the memory card  102  to the interface processing unit  103 . After converting the serial data into parallel data, the interface processing unit  103  stores the data in the register  104 .  
         [0016]     The register  104  connects to the interface processing unit  103  for storing the image data read from the memory card  102  and processed by the microprocessor  103 .  
         [0017]     The microprocessor  105  connects to the register  104  for processing and converting image data. The microprocessor  15  can be a 8051 or 8086 single chip CPU. The microprocessor  105  reads data from the register  104  and processes for output.  
         [0018]     The memory unit  106  connects to the microprocessor  105  for storing software of the microprocessor  105  that handles the image conversion and processing.  
         [0019]     The projector  101  connects to the microprocessor  105  of the converting module  100  for data transmission through an I2C bus. The projector  101  also outputs commands to the microprocessor  105  for informing the microprocessor  105  to read relative software from the memory unit  106 , to process accordingly and to output the image data to the projector  101  for display.  
         [0020]     The commands of the projector  101  define the image resolution, data updating rate and methods of playing, such as playing forwards, backwards, repeatedly, etc..  
         [0021]     The I2C bus includes a serial clock bus  108  and a serial data bus  109 . The serial clock bus  108  transfers time signals for controlling the data transmission. The serial data bus  109  transfers data and commands.  5  After the converting module  100  of the invention being connected to a projector  101 , the microprocessor  105  of the converting module  100  connects to the projector; the memory card  102  connects to the interface processing unit  103 ; then, the projector  101  commands the microprocessor  105  to read image data from the memory card  102 , and defines the resolution, the updating rate and the playing method of the image.  
         [0022]     The microprocessor  105  receives the commands of the projector  101 , then starts to read the image data from the memory card  102  via the interface processing unit  103 . The interface processing unit  103  receives the serial data, transforms them into parallel data to be stored in the register  104 . Then, the microprocessor  105  reads relative software from the memory unit  106  and reads the image data stored in the register  104 . The microprocessor  105  processes the data with the relative software and outputs to the projector  101  for display.  
         [0023]     The data and command transmission procedure between the projector  101  and the microprocessor  105  is that when the projector  101  and the microprocessor  105  are idle, the serial clock bus  108  and the serial data bus  109  are in high potential. Before the projector  101  sending commands to the microprocessor  105 , the serial data bus  109  first changes to low potential. After a short time, the serial clock bus  108  changes to low potential. Then, the projector  101  sends a start signal to the microprocessor  105 , and further sends its address signal to the microprocessor  105  to trigger the conversation.  
         [0024]     When the microprocessor  105  correctly receives the start and address signals from the projector  101 , it returns an acknowledge signal to the projector  101 . The projector  101  keeps the serial data bus  109  at high potential. The microprocessor  105  changes the serial data bus  109  to low potential for confirmation. If the microprocessor  105  cannot correctly receive the signal of the projector  101 , it holds and keeps the serial data bus  109  at high potential.  
         [0025]     The projector  101  starts sending commands after the microprocessor  105  confirms. The commands define the information of image playing, including the resolution, the updating rate and so on.  
         [0026]     When the data transmission from the projector  101  to the microprocessor  105  is finished, the serial clock bus  108  is first released to high potential. After a short time, the serial data bus  109  is also released to high potential so as to end the data transmission.  
         [0027]     The converting module  100  of the invention is not only applicable to a projector  101  but also applicable to other kinds of display, such as LCD, plasma display and CRT.  
         [0028]     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.