Patent Publication Number: US-2011069240-A1

Title: Projector and Control Method Thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a projector control method; more particularly, it relates to a projector control method capable of driving a projector by connecting a video signal cable and checking quickly the signal input port connected to a video source for projecting images. 
     2. Description of the Related Art 
     Generally, when a user wants to project images with a projector, he or she may use a video signal cable to connect the projector with a video source, such as a computer or a media player, and the video source may send video signals to the projector via the video signal cable. The user may press a power switch of the projector first, and the projector may be driven from a standby mode to an active mode. When the lamp of the projector is warmed up, the projector may emit light to project images. With developments in remote technology in recently years, the user may drive the projector conveniently with a remote control. 
     The projectors may comprise at least one kind of signal input ports, such as a VGA port, a DVI port, or an HDMI port. Furthermore, the projector may also comprise two or more of the same signal input ports. When the projector is driven every time, it may search all of the signal input ports in sequence to detect whether the video signal input is inputted. If the video signal is detected, the projector may project the image according to the video signal. 
     However, in the case of a notebook computer, unlike a desktop computer, which may be often disposed near the projector, when the user wants to project the images of the notebook computer with the projector, he or she must connect the projector to the notebook computer via a video signal cable and press the power button of the projector to search for the video source every time. It is not convenient for the user to use the projector. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a projector control method capable of driving a projector by connecting a video signal cable and finding a correct signal input port. 
     To achieve the abovementioned object, a projector control method of the present invention is used for a projector in a standby mode, and the projector is connected to an active video source for image projecting. The method comprises the follow steps of: connecting electronically the projector and the video source via a video signal cable; detecting whether a defining signal is produced from the input port of the projector, wherein the defining signal is selected from one of the following: a current variation, a voltage variation, an encoded signal, a clock signal, and a synchronous signal; and supplying power to the projector and igniting a lamp when the defining signal is detected, such that the projector enters an active mode. Accordingly, when the video signal cable connected the video source connects to the projector, the projector will work to execute its projection functions without the necessity of the projector being turned on in a manual manner and the user searching for the signal. 
     The projector of the present invention applies to the aforementioned projector control method. The projector connects electronically to the active video source via a video signal cable. The projector comprises a lamp, an igniting module, a power module, at least one input port, and a microprocessor. The igniting module is used for igniting the lamp. The power module is used for supplying power to the projector. The at least one input port is used for connecting to the video signal cable. The microprocessor connects electronically to the igniting module, the power module, and each input port. The projector may check whether a certain input port is connected to the video source by the microprocessor detecting each input port to determine whether a defining signal is produced, wherein the defining signal is selected from one of the following: a current variation, a voltage variation, an encoded signal, a clock signal, and a synchronous signal. Then the microprocessor may notify the power module to supply power to the projector and notify the igniting module to ignite the lamp, such that the projector  10  may enter an active mode from a standby mode. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and advantages of the present invention will become apparent from the following description of the accompanying drawings, which disclose several embodiments of the present invention. It is to be understood that the drawings are to be used for purposes of illustration only, and not as a definition of the invention. 
       In the drawings, wherein similar reference numerals denote similar elements throughout the several views: 
         FIG. 1  illustrates a schematic drawing of using an embodiment of a projector of the present invention. 
         FIG. 2  illustrates a main flowchart of a projector control method of the present invention. 
         FIG. 3  illustrates a schematic drawing of using another embodiment of a projector of the present invention. 
         FIG. 4  illustrates a main flowchart of the projector control method of the present invention applied to another embodiment of the projector. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Please refer to  FIG. 1  for a schematic drawing of using an embodiment of a projector  10  of the present invention. As shown in  FIG. 1 , a projector  10  of the present invention is connected electronically to an active video source  30  via a video signal cable  20 . The video source  30  may transmit video signals to the projector  10  through the video signal cable  20 . In this embodiment, the video source  30  may be a computer device, and the video signal cable  20  may be a VGA cable, a DVI cable, an HDMI cable, or other cables with similar functions. The video signal cable  20  may be selected according to a different output port  31  of the video source  30 . 
     The projector  10  of the present invention comprises a lamp  11 , an igniting module  12 , a power module  13 , an input port  14 , a microprocessor  15 , and a switch  16 . The igniting module  12  is used for igniting the lamp  11  and transferring the power from the power module  13  into suitable current and voltage for the lamp  11 . In one embodiment of the present invention, the igniting module  12  is a ballast, a starter, or other elements with similar functions, but please note that the scope of the present invention is not limited to the above description. The power module  13  is used for supplying power to each element of the projector  10 . The input port  14  is used for connecting to the video signal cable  20  for receiving video signals from the video source  30 . 
     The microprocessor  15  connects electronically to the igniting module  12 , the power module  13 , and the input port  14 . When the projector  10  is in a standby mode, the power module  13  may still supply power to the microprocessor  15 , and the microprocessor  15  may detect the input port  14  in real-time to determine whether a defining signal is produced. When the defining signal is detected from the input port  14 , the microprocessor  15  may notify the power module  13  to supply power to the projector  10  and notify the igniting module  12  to ignite the lamp  11 . Then the projector  10  may enter an active mode from the standby mode. The switch  16  is used for turning on/off the power of the projector  10  and switching into different modes in a manual manner. 
     Pins of the input port  14  of the projector  10  and pins of the output port  31  of the video source  30  may be pre-defined. The pins of the input port  14  and the output port  31  correspond to each other. Some of the pins are used for transmitting video signals, and pins which are grounded or unused may be selected for defining. The defined pin corresponding to different input ports may be changed according to different types of the video signals; for example, pin  5  is usable in a VGA port, pin  15  is usable in a DVI port, and pin  19  is usable in an HDMI port. 
     When the video signal cable  20  connects the active video source  30  and the projector  10  in the standby mode, electrical signals may be transmitted from the defined pin of the output port  31  of the video source  30  to the defined pin of the input port  14  of the projector  10  via the video signal cable  20 . Therefore, the projector  10  may have connected to the active video source  30 , according to the defining signal detected from the defined pin of the input port  14  by the microprocessor  15 . The defining signal is selected from one of the following: a current variation, a voltage variation, an encoded signal, a clock signal, and a synchronous signal. But please note that the scope of the present invention is not limited to the above description. 
     For the voltage variation, assume that the microprocessor  15  may obtain an initial potential by detecting the defined pin of the input port  14  before the projector  10  connects electronically to the video source  30  via the video signal cable  20 . The initial potential may be high or low. When the input port  14  connects to the active video source  30  via the video signal cable  20 , the voltage variation of the defined pin may be detected by the microprocessor  15 ; for example, the potential is changed from high potential to low potential or from low potential to high potential. Accordingly, the microprocessor  15  may determine that the projector  10  has connected to the active video source  30 , and notify elements of the projector  10  to enter the active mode. 
     Please refer to  FIG. 2  for a main flowchart of a projector control method of the present invention. It is noted that although the following description uses the projector  1  in  FIG. 1  to illustrate the projector control method, the present invention is not limited to using the projector  1 . As shown in  FIG. 2 , the projector control method comprises step S1 to step S5. The following will explain the various steps in detail. 
     Step S1: Connecting electronically the projector  10  in a standby mode and the video source  30  via the video signal cable  20 . As shown in  FIG. 1 , the projector control method of the present invention is used for a projector  1  in a standby mode. When the projector  1  connects to the power source via a power cable (not shown), the projector  1  may enter the standby mode from a power failure status. The user may connect the output port  31  of the video source  30  to one end of the video signal cable  20 , and connect the input port  14  of the projector  10  to another end of the video signal cable  20 . Therefore, an electrical circuit between the video source  30  and the projector  10  may be formed for transmitting video signals or other electrical signals. 
     Step S2: Detecting the input port  14  via the microprocessor  15  of the projector  10 . When the projector  10  enters the standby mode, the power module  13  may supply some power to the microprocessor  15  for detecting signals through the defined pin of the input port  14 . 
     Step S3: Detecting whether the defining signal is produced from the input port  14  of the projector  10 . As shown in  FIG. 1 , when the video signal cable  20  connects to the output port  31  of the active video source  30 , the video source  30  may continuously transmit video signals via the video signal cable  20 . When the projector  10  is in the standby mode, the microprocessor  15  may detect the status of the defined pin of the input port  14  in real-time. Therefore, when the video signal cable  20  connects to the input port  14  of the projector  10 , the defining signal may be produced from the defined pin of the input port  14  according to the aforementioned design of the defined pin and electrical signals transmitted from the video source  30 . The defining signal may be, but is not limited to, a current variation, a voltage variation, or a specific encoded signal. At this moment, the microprocessor  15  may detect the occurrence of the defining signal and execute the following process. 
     Step S4: Notifying the power module  13  to supply power to the projector  10  and notifying the igniting module  12  to ignite the lamp  11  of the projector  10  when the defining signal is detected, such that the projector  10  enters an active mode. As shown in  FIG. 1 , when the defining signal is detected in Step S3, the microprocessor  15  may send commands to notify the power module  13  and the igniting module  12 . The power module  13  may supply power to the projector  10 , and the igniting module  12  may ignite the lamp  11  according to the commands. Then the projector  10  may enter the active mode from the standby mode for projecting images. 
     Step S5: locking on to the input port  14  that produced the defining signal and processing the inputted video signals to project images. As shown in  FIG. 1 , when the projector  10  enters the active mode, the input port  14  may be locked on to. The video signals may be transmitted from the video source  30  via the video signal cable  20  and be inputted into the projector  10  via the input port  14 . The corresponding image processing for the video signals may be executed and images of the video signals may be projected by the lamp  11 . 
     Accordingly, when the video signal cable  20  connects the active video source and the projector  10 , the projector  10  may enter the active mode from the standby mode. The users need not operate any remote control device or turn on the power switch  16  of the projector  10 . It is more convenient for users to operate the projector  10 . 
     Please refer to  FIG. 3  for a schematic drawing of using another embodiment of a projector  10   a  of the present invention. This embodiment is a modification of the aforementioned embodiment. As shown in  FIG. 3 , the projector  10   a  of the present invention comprises a plurality of input ports  14   a  for receiving different types of video signals or connecting to different video sources  30   a . In this embodiment, the plurality of input ports  14   a  comprises a first input port  142 , a second input port  144 , and a third input port  146 . The first input port  142  corresponds to a VGA cable, the second input port  144  corresponds to a DVI cable, and the third input port  146  corresponds to an HDMI cable. The user may select the suitable video signal cable  20   a  (e.g. the video signal cables  22 ,  24 ,  26  corresponding respectively to transmitting VGA signals, DVI signals, and HDMI signals) to connect to the corresponding input port  14   a  according to the different types of the output port  31   a  of the video source  30   a  or different results. But please note that the number and types of the input ports  14   a  of the present invention are not limited to the above description. 
     Please refer to  FIG. 4  for a main flowchart of the projector control method of the present invention applied to another embodiment of the projector  10   a . It is noted that although the following description uses the projector  10   a  in  FIG. 3  to illustrate the projector control method, the present invention is not limited to using the projector  10   a . As shown in  FIG. 3 , the projector control method comprises step S1′ to step S5. The steps S1′, S2′, and S3′ in  FIG. 4  are different from the corresponding steps in  FIG. 2 . The following will explain the various steps with differences between  FIG. 2  and  FIG. 4  in detail. 
     Step S1′: Connecting electronically the projector  10   a  in the standby mode and the video source  30   a  via any video signal cable  20   a . As shown in  FIG. 3 , the projector  10   a  comprises a plurality of input ports  14   a  supporting to different signal interfaces (e.g. the first input port  142  supports a VGA interface, the second input port  144  supports a DVI interface, and the third input port  146  supports an HDMI interface). The user may select one of the video signal cables  22 ,  24 , or  26  to connect correspondingly to the output port  31   a  of the video source  30   a  and the input port  14   a  of the projector  10   a . Therefore, an electrical circuit between the video source  30   a  and the projector  10   a  may be formed. For example, when the video signal cable  26  supporting HDMI signals is selected, the video signal cable  26  may connect to the third input port  146  with the HDMI interface. 
     Step S2′: Detecting one of the input ports  14   a  via the microprocessor  15  of the projector  10   a . The projector  10   a  comprises the plurality of input ports  14   a . When the projector  10   a  enters the standby mode, the microprocessor  15  may select one of the input ports  14   a  first to detect the signals through the defined pin of the selected input port  14   a.    
     Step S3′: Detecting whether the defining signal is produced from one of input port  14   a  of the projector  10   a . Furthermore, step S3 comprises: 
     Step S31′: Determining whether the defining signal is produced from the input port  14   a  after the video signal cable  20   a  is connected. 
     Step S32′: Switching to another input port  14   a.    
     As shown in  FIG. 3 , for the plurality of the input ports  14   a , the microprocessor  15  may detect each input port  142 ,  144 ,  146  in sequence. Assuming the first input port  142  of the projector  10   a  is connected to the output port  31   a  of the video source  30   a  via the video signal cable  22 , the defining signal produced from the defined pin of the first input port  142  may be detected by the microprocessor  15 . Then the following step S4 of the method may be executed. 
     Assume that the second input port  144  of the projector  10   a  is connected to the output port  31   a  of the video source  30   a  via the video signal cable  24 . When the microprocessor  15  detects the first input port  142  first and determines that the defining signal is not produced, step S32′ may be executed to switch another input port  14   a , e.g. the second input port  144  or the third input port  146 , and then return to step S2′ again to detect the selected input port. When the defining signal produced from the defined pin of the first input port  144  may be detected by the microprocessor  15 , the microprocessor  15  may stop to detect other input ports  14   a . Accordingly, in this embodiment, the microprocessor  15  may detect each input port  14   a  continuously until the defining signal produced from any input port  14   a  is detected. Furthermore, steps S4 and S5 in  FIG. 4  are the same as the corresponding steps in  FIG. 2 . 
     Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.