Abstract:
A digital light projector (DLP) enabling to support at least two digital micromirror devices (DMD) with different resolution is provided. Appending with a predetermined resolution, the DLP comprises a scalar transform unit and an image control unit. The scalar transform unit has a plurality of scalar firmware respect to various resolutions including the predetermined resolution stored therein. The image control unit electrically connects to the scalar transform unit and has a DMD firmware and a register number respect to the predetermined resolution. While the DLP is operating, the scalar transform unit reads the register number and chooses a proper scalar firmware accordingly.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (1) Field of the Invention  
         [0002]     The invention relates to a digital light projector (DLP), and more particularly to a DLP with alterable resolution by replacing elements contained therein.  
         [0003]     (2) Description of the Prior Art  
         [0004]     The devices for displaying pictures, in addition to the conventional CRT TV, now include PDP, LCD TV, projection TV and the like. The PDP and LCD TV are still very expensive. Moreover, LCD TV has view angle problem, and the display dimension is constrained by the limitation of glass substrate fabrication. The projection TV is quite bulky. On the other hand, projector overcomes most of the problems mentioned above. It is compact, easy to carry, reasonably priced, and has few geographic restrictions. With a flat wall, it can display pictures at a size not achievable by other facilities.  
         [0005]     The present image projection techniques are divided into two main types: transmissive LCD panel and digital light processing. The transmissive LCD projector uses a LCD panel as the picture display device. Light of the projector passes through the LCD panel to generate images. The digital light processing projector (DLP) employs a Digital Micromirror Device (DMD) developed by Texas Instrument (TI) Co. to display images.  
         [0006]     In the DMD technique, a light source is split into four colors (red, green, blue and white) by a high speed rotating color wheel (7200 RPM). The split light projects on a micromirror device. The micromirror device has numerous micromirrors. Digital signals that represent  0  and  1  drive those micromirrors to rotate to selected angles to reflect unnecessary light, and direct the required light to an incident lens. Through the principle of persistence of visual, lights of different colors are synthesized to become a colored image and present to human eyes.  
         [0007]     Compared with the conventional transmissive LCD projector, DLP has a simpler structure, and can better meet the prevailing trend of thin and light requirements. Moreover, DLP adopts holographic image process. It not only conforms to the digitized home appliances direction, the image signals input into the DLP do not require digital/analog signal conversion, thus can provide a stable and undistorted image display. In addition, displaying the pictures through the micromirrors overcomes the limitation of image display caused by the transmissive rate of the LCD panel of the transmissive LCD projector. It also does not have the grid pixel pattern occurred to the transmissive LCD projector. Moreover, the micromirror has life span up to 100,000 hours. The chip can last eleven years even if it is being used 24 hours a day continuously. The aging problem also is less severe.  
         [0008]     Refer to  FIG. 1  for a typical DLP  100 . It includes a frequency generation unit  110 , a scalar transform unit  120 , an image control unit  140  and a DMD  160 . The scalar transform unit  120  has a scalar firmware F resided therein. The image control unit  140  has a DMD firmware D resided therein. The frequency generation unit  110  generates a frequency signal f. The specifications of the frequency signal f, scalar firmware F and DMD firmware D have to match the resolution of the DMD  160 .  
         [0009]     The scalar transform unit  120  is connected to the frequency generation unit  110 , and executes the scalar firmware F according to the frequency signal f to transform input image data A to a digital image signal B corresponding to the resolution of the DMD  160 . The image control unit  140  is connected to the scalar transform unit  120  and executes the DMD firmware D to transform the digital image signal B to a level signal C to control operation of the micromirrors in the DMD  160 .  
         [0010]     The present resolutions of DLPs mainly adopt SVGA and XGA specifications. Hence fabrication of the DLP has to support these two resolutions. To reduce fabrication cost, the elements used in the DLP should support these two resolutions as much as possible. However, in the typical DLP  100  as shown in  FIG. 1 , the DMD 160 , frequency generation unit  110 , scalar firmware F and DMD firmware D have to be replaced when the resolution changes. Namely, to alter the resolution of the DLP, at least four elements have to be switched. This is a great burden to the production line and results in a higher cost.  
         [0011]     Therefore, how to reduce the number of switching elements when the resolution of the DLP is changed without affecting the normal DLP operation is an important issue in production, and seriously affects the performance of production line.  
       SUMMARY OF THE INVENTION  
       [0012]     Accordingly, it is an object of the present invention to provide a DLP structure to reduce the required switching elements when the resolution is altered to lower the production cost.  
         [0013]     In one aspect, the DLP according to the present invention can support two or more DMDs of different resolutions, including a predetermined resolution. The DLP includes a scalar transform unit and an image control unit. The scalar transform unit has a plurality of scalar firmware resided therein corresponding to a plurality of resolutions that include the predetermined resolution and output a digital image signal. The image control unit is connected to the scalar transform unit and has a DMD firmware and a register number resided therein to transform the digital image signal to a level signal to control the DMD. When the DLP is in operation, the scalar transform unit selects and executes a corresponding scalar firmware according to the register number. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which  
         [0015]      FIG. 1  is a schematic view of a typical DLP structure;  
         [0016]      FIG. 2  is a schematic view of an embodiment of the DLP of the present invention;  
         [0017]      FIG. 3  is a schematic view of another embodiment of the DLP of the present invention;  
         [0018]      FIG. 4  is a schematic view of yet another embodiment of the DLP of the present invention;  
         [0019]      FIGS. 5A, 5B  and  5 C are schematic views of an embodiment of the DLP fabrication process of the invention;  
         [0020]      FIG. 5D  is a schematic view of the DLP of the invention in an operating condition; and  
         [0021]      FIGS. 6A, 6B  and  6 C are schematic views of an embodiment of the DLP fabrication process of the invention when the resolution is altered. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     Refer to  FIG. 2  for a first embodiment of a DLP  200  of the present invention. It aims to support two or more DMDs  260  of different resolutions. In the condition of matching a predetermined resolution, the DLP  200  includes a frequency generation unit  210 , a scalar transform unit  220 , an image control unit  240  and the DMD  260  equipped with the predetermined resolution.  
         [0023]     The frequency generation unit  210  aims to generate a frequency signal f corresponding to the predetermined resolution. The scalar transform unit  220  has stored a plurality of scalar firmware F 1  and F 2  corresponding respectively to a plurality of different resolutions including the predetermined resolution. The image control unit  240  is connected to the scalar transform unit  220  and stores a DMD firmware D  1  and a register number S 1  corresponding to the predetermined resolution.  
         [0024]     While the DLP is operating, the scalar transform unit  220  reads the register number S 1  through a communication circuit  270  connecting to the image control unit  240 , and selects and executes a corresponding scalar firmware F 1  based on the register number S 1 . Meanwhile, the scalar transform unit  220  also is connected to the frequency generation unit  210  to receive the frequency signal f 1  to transform input image data A to a digital image signal B corresponding to the predetermine resolution. The image control unit  240  is connected to the scalar transform unit  220  and executes the DMD firmware D 1  to transform the digital image signal B to a level signal C to control the DMD  260 .  
         [0025]     Due to the scalar transform unit  220  has to execute the scalar firmware F 1 , and the image control unit  240  has to execute the DMD firmware D 1 , hence, as shown in  FIG. 3 , the scalar transform unit  220  has a processing center  222  to execute the scalar firmware F 1 , and the image control unit  240  has a control center  242  to execute the DMD firmware D 1  and a buffer  244  to store the register number S 1 . In addition, referring to  FIG. 4 , if the control center  242  has sufficient space to store the register number S 1 , the register number S 1  may also be directly written into the control center  242  without the need to add the buffer  244 . The processing center  222  requests the control center  242  for the register number S 1 .  
         [0026]     Basically, the register number S 1  merely serves as the selection basis for switching the scalar firmware F 1  and F 2 . In the condition of switching the scalar firmware for two different resolution specifications, the register number S 1  may be one byte, namely using 1 and 0 to indicate two different resolution specifications. For instance, if the scalar firmware adopts XGA and SVGA specifications, register number S 1  may be set  0  for the predetermined resolution of XGA specification, and S 1  may be set  1  for the predetermined resolution of SVGA specification.  
         [0027]     Next, the communication circuit  270  may be an Inter-Integrated Circuit (I2C) to serve as the communication path between the scalar transform unit  220  and the image control unit  240 . If the scalar transform unit  220  and the image control unit  240  have I/O ports, a conductive wire may be directly connected to the desired I/O ports to function as the communication circuit  270 .  
         [0028]     Refer to  FIGS. 5A, 5B  and  5 C for an embodiment of the fabricating method of the DLP  200  of the invention. First, as shown in  FIG. 5A , install a scalar transform unit  220 , an image control unit  240  and a DMD  260  with a predetermined resolution in the DLP  200 . Next, referring to  FIG. 5B , install a selected frequency generation unit  210  to generate a frequency signal corresponding to the predetermined resolution; meanwhile, write a plurality of scalar firmware F 1  and F 2  into the scalar transform unit  220  corresponding to a plurality of resolutions including the predetermined resolution. Then, referring to  FIG. 5C , write a DMD firmware D 1  and a register number S 1  into the image control unit  240  corresponding to the predetermined resolution.  
         [0029]     Refer to  FIG. 5D , while the DLP  200  is operating, the scalar transform unit  220  is connected to the image control unit  240  to request the register number S 1  to confirm the resolution, and, based on the register number S 1 , executes a desired scalar firmware F 1  to generate a digital image signal B corresponding to the predetermined resolution.  
         [0030]     By means of the fabricating method of the DLP  200  previously discussed, if there is a desire to change the resolution of the DLP, referring to  FIG. 6A , first, replace the DMD  260  with a second DMD  360  of a different resolution; next, referring to  FIG. 6B , install a second frequency generation unit  310  corresponding to the resolution of the second DMD  360  to replace the frequency generation unit  210  shown in  FIG. 5B ; similar to  FIG. 5B , write a plurality of scalar firmware F 1  and F 2  into the scalar transform unit  220  corresponding to the resolutions of the second DMD  360 ; next, referring to  FIG. 6C , write a second DMD firmware D 2  and a second register number S 2  into the image control unit  240  corresponding to the resolutions of the second DMD  360 .  
         [0031]     Compared with the conventional DLP  100  shown in  FIG. 1  that has to switch four elements including the DMD  160 , frequency generation unit  110 , scalar firmware F and DMD firmware D to change the resolution of the DLP,  FIGS. 6A, 6B  and  6 C indicate that the DLP  200  of the invention does not has to change the scalar firmware. And the second register number S 2  and the second DMD firmware D 2  may be written into the image control unit  240  simultaneously at the same step. Hence the same result can be achieved by merely switching three elements, including the second DMD  360 , the second frequency generation unit  310  and the second DMD firmware D 2  (indicated by broken lines in the drawings). Thus the DLP of the invention can reduce production burden and cost. It also may be adapted to higher DMD resolutions that might be available in the future. Hence the DLP of the invention has an improved expandability to meet future requirements.  
         [0032]     While the embodiments of the present invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the present invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the present invention.