Abstract:
An energy-saving control device for remote image receiver is disclosed. The control device is electrically connected to an image receiver, and includes a detection module, a control module, and a power control module. The detection module detects a differential signal transmission state at the remote image receiver, and generates a detection signal to the control module accordingly. The control module generates a control signal according to the detection signal, so as to control the power control module to control on/off of power supply to the image receiver. With these arrangements, it is able to control the image receiver to automatically turn off when the differential signal transmission stops, so as to achieve the effects of energy saving and extended service life of the image receiver.

Description:
[0001]    This application claims the priority benefit of Taiwan patent application number 100202535 filed on Feb. 10, 2011. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a control device for a remote image receiver, and more particularly to an energy-saving control device electrically connected to a remote image receiver for controlling the on/off of power supply to the image receiver according to a differential signal input state of the image receiver. 
       BACKGROUND OF THE INVENTION 
       [0003]    A remote image transmission system is frequently used in a public place, such as an airport, a rapid transit railway station, a shopping mall, etc. The remote image transmission system includes a remote receiving device, such as an electronic signboard, a television, a display and so on. The remote receiving device, no matter what type, is connected via a signal transmission line to a front end transmission device, such as a DVD (digital versatile disk) image player, a computer or a notebook computer, so that an image signal output from the front end transmission device is transmitted via the signal transmission line to the remote receiving device for displaying at a remote location. 
         [0004]    According to some remote image transmission techniques, image signal is transmitted via signal conversion. However, in the course of signal conversion, it is possible the image signal could not be perfectly transmitted under some situations. Particularly, in the remote image transmission, signal phase delay might occur and the remote receiving device could not recover the clock of the signal and accordingly, the exact signal. 
         [0005]    Therefore, signal transmission between a front end transmission device and a remote receiving device by way of analog signal differentiation is developed. According to this way, a differential receiver module and a delay correction module are used at the remote receiving device to avoid the occurrence of phase delay in the differential signal and to avoid the problem of poor definition or smearing of the image shown on a screen. The differential signal is transmitted from a signal transmission interface to the differential receiver module and the delay correction module, and the delay correction module generates an image synchronizing signal to a display device. However, during the differentiate signal transmission, power must be continuously supplied to the remote receiving device for receiving the differentiate signal. Since the remote receiving device is not provided with any mechanism for automatically shutting down or cutting off the remote receiving device when there is not differentiate signal transmission, electric power will be continuously supplied to the remote receiving device even when the front end transmission device stops sending the differential signal or does not send any differential signal. Under this condition, electric power is unnecessarily wasted and the remote receiving device being continuously turned on for a long period of time tends to become overheated and have shortened service life accordingly. 
         [0006]    Therefore, the conventional remote image receiving device has the following disadvantages: (1) consuming a high amount of electric energy; (2) tending to become overheated due to being continuously turned on for a long period of time; and (3) having shortened service life caused by overheat. 
         [0007]    It is therefore tried by the inventor to develop an energy-saving control device for a remote image receiver; so as to solve the above-mentioned problems existed in the conventional remote image receiving device. 
       SUMMARY OF THE INVENTION 
       [0008]    A primary object of the present invention is to provide an energy-saving control device for a remote image receiver. 
         [0009]    Another object of the present invention is to provide an energy-saving control device capable of automatically turning off a remote image receiver when the latter does not have image signal input thereto. 
         [0010]    A further object of the present invention is to provide an energy-saving control device capable of automatically turning on a remote image receiver when the latter has image signal input thereto again. 
         [0011]    To achieve the above and other objects, the energy-saving control device for remote image receiver according to the present invention is electrically connected to an image receiver that includes a differential demodulation module, a delay correction module, and a signal transmission interface for transmitting a differential signal converted from an image signal; and the differential signal is sequentially processed by the differential demodulation module and the delay correction before being output. 
         [0012]    The energy-saving control device for remote image receiver according to the present invention includes a detection module, a control module, and a power control module. The detection module is electrically connected to the signal transmission interface for detecting a differential signal transmission state at the signal transmission interface, and generating a detection signal to the control module accordingly. The control module is electrically connected to the detection module and generates a control signal according to the detection signal. The power control module is electrically connected to the control module, the differential demodulation module and the delay correction module for controlling a power supply state of the image receiver according to the control signal. 
         [0013]    In the present invention, the control device performs the following energy-saving procedures: the detection module detects the differential signal transmission state at the signal transmission interface, and generates the detection signal to the control module when the state at the signal transmission interface changes from having differential signal transmission into no differential signal transmission; and the control module generates the control signal to the power control module for the latter to automatically cut off the power supply to the image receiver. 
         [0014]    On the other hand, the detection module generates the detection signal to the control module when the state at the signal transmission interface changes from no differential signal transmission into having differential signal transmission, and the control module generates the control signal to the power control module for the latter to automatically turn on the power supply to the image receiver. 
         [0015]    Therefore, when the image receiver works, power can be continuously supplied to the image receiver; and when the differential signal transmission stops, the control device automatically cuts off the power supply to the image receiver to avoid unnecessary power consumption. On the other hand, when the detection module detects the differential signal transmission at the signal transmission interface starts again, the control device would immediately turn on the power supply to the image receiver for the same to work. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
           [0017]      FIG. 1  is a block diagram of an energy-saving control device for remote image receiver according to a first embodiment of the present invention; 
           [0018]      FIG. 2  is an operation flowchart showing the energy-saving procedures of the energy-saving control device for remote image receiver according to the first embodiment of the present invention; 
           [0019]      FIG. 3  is a block diagram of an energy-saving control device for remote image receiver according to a second embodiment of the present invention; and 
           [0020]      FIG. 4  is a block diagram of an energy-saving control device for remote image receiver according to a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The present invention will now be described with some preferred embodiments thereof and with reference to the accompanying drawings. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals. 
         [0022]    Please refer to  FIGS. 1 and 2  that are block diagram and operation flowchart, respectively, for an energy-saving control device for remote image receiver according to a first embodiment of the present invention. As shown, the energy-saving control device for remote image receiver in the first embodiment is generally denoted by reference numeral  20 , and is externally connected to an image receiver  10 . 
         [0023]    The image receiver  10  includes a signal transmission interface  11 , a differential demodulation module  12 , and a delay correction module  13 . The signal transmission interface  11  receives and transmits a differential signal converted from an image signal. The differential signal includes a red, a green and a blue signal. The red signal, green signal and blue signal respectively include a horizontal synchronizing signal and a vertical synchronizing signal. 
         [0024]    The signal transmission interface  11  is electrically connected to the differential demodulation module  12 , and transmits the differential signal to the differential demodulation module  12 . The differential demodulation module  12  receives the differential signal and demodulates the same to obtain RGB signals and synchronizing signals. The RGB signals include the above-mentioned red, green and blue signals; and the synchronizing signals include the above-mentioned horizontal synchronizing signals and vertical synchronizing signals. The delay correction module  13  is electrically connected to the differential demodulation module  12  and receives the RGB signals. The delay correction module  13  adjusts time delay for the red, green and blue signals, so as to output a synchronized image signal. 
         [0025]    The control device  20  is electrically connected to the image receiver  10 , and includes a detection module  21 , a control module  22  and a power control module  23 . 
         [0026]    The detection module  21  includes a signal demodulation unit  211  and a differential amplifier unit  212 . The detection module  21  is electrically connected to the signal transmission interface  11  for detecting a differential signal transmission state at the signal transmission interface  11  and generating a detection signal. After the detection module  21  receives the differential signal, the signal demodulation unit  211  demodulates the differential signal to obtain the horizontal synchronizing signals and the vertical synchronizing signals; and the differential amplifier unit  212  avoids noise in the differential signal and acquires small signals thereof, and then differentially amplifies the small signals to a detection signal of high-level or low-level long instruction. Therefore, when the signal demodulation unit  211  obtains the horizontal synchronizing signals and the vertical synchronizing signals, and detects a differential signal transmission at the signal transmission interface  11 , the differential amplifier unit  212  generates a detection signal having high-level or low-level long instruction for turning power on or off. It is understood the above description of the detection manner of the detection module  21  is only illustrative and not intended to limit the actual detection manner of the detection module  21  in any way. Any technique or circuit structure that is able to detect any differential signal input shall fall within the protection scope of the present invention. 
         [0027]    The control module  22  is electrically connected to the detection module  21  for receiving the detection signal generated by the detection module  21 . Further, according to the detection signal, the control module  22  determines the on/off of power supply to the image receiver  10 . In the illustrated first embodiment, the control module  22  is a microcontroller unit (MCU). 
         [0028]    The power control module  23  is electrically connected to the control module  22 , the differential demodulation module  12  and the delay correction module  13 . When the control module  22  receives the detection signal and generates a control signal, the power control module  23  controls the power supply to the image receiver  10  according to the control signal, so as to turn on or cut off the power input to the differential demodulation module  12  and the delay correction module  13  while controls a power supply state of the image receiver  10 . The control module  22  is further electrically connected to a back-up power unit  24 . When the power control module  23  shuts down the power supply, the back-up power unit  24  keeps supplying power to the control module  22  and the detection  21  for them to continuously detect the state of differential signal input. It is noted the power control module  23  can be connected to the image receiver  10  in at least two different manners. In the first manner, the power control module  23  is connected to an internal power supply or a power input terminal of the image receiver  10 . In the second manner, the power control module  23  is connected to a power supply device at a power output terminal thereof that is connected to the image receiver  10 . The power supply device can be a central control circuit, a panel board or an uninterruptible power system. It is understood the above description of the implementing manners of the power control module  23  is only illustrative and not intended to limit the actual structure or circuit of the power control module  23  in any way, and any skills techniques that can be used to turn on/off power input to the differential demodulation module  12  and the delay correction module  13  as well as to control the power supply state of the image receiver  10  also fall within the protection scope of the present invention. 
         [0029]    It is noted the control device  20  may be implemented in different forms, such as an integrated IC (integrated circuit) integrating the detection module  21 , the control module  22 , and the power control module  23  into one single IC circuit; or an integrated circuit with the detection module  21 , the control module  22  and the power control module  23  respectively being an individually packaged IC and connected to one another via a printed circuit board (PCB); or an electronic circuit with the three modules  21 ,  22 ,  23  respectively being an electronic component and connected to one another via a PCB; or any combination of the above forms. Further, the control device  20  can be electrically connected to the image receiver  10  by mounting it in the image receiver  10 , integrating it into an internal circuit of the image receiver  10 , or externally electrically connecting it to the image receiver  10 . 
         [0030]      FIG. 2  shows the operation procedures  100 ˜ 105  of the energy-saving control device  20  according to the first embodiment of the present invention 
         [0031]    In the operation procedure  100 , the detection module  21  detects a differential signal transmission state at the signal transmission interface  11 . 
         [0032]    More specifically, in the operation procedure  100 , the detection module  21  is electrically connected to the signal transmission interface  11  and starts detecting whether there is any differential signal transmission at the signal transmission interface  11 . 
         [0033]    In the operation procedure  101 , the detection module  21  generates a detection signal to the control module  22 . 
         [0034]    More specifically, in the operation procedure  101 , when a state at the signal transmission interface  11  is changed from having differential signal transmission into no differential signal transmission, or changed from no differential signal transmission into having differential signal transmission, the detection module  21  generates a detection signal to the control module  22 . 
         [0035]    In the operation procedure  102 , the control module  22  generates a control signal to the power control module  23 . 
         [0036]    More specifically, in the operation procedure  102 , the control module  22  generates a control signal according to a state represented by the detection signal, and the control signal is transmitted to the power control module  23  to determine the latter&#39;s movement. In the case the detection signal indicates the state at the signal transmission interface  11  is changed from having differential signal transmission into no differential signal transmission, the control signal controls the power control module  23  to cut off the power supply to the image receiver  10 . On the other hand, when the detection signal indicates the state at the signal transmission interface  11  is changed from no differential signal transmission into having differential signal transmission, the control signal controls the power control module  23  to turn on the power supply to the image receiver  10 . 
         [0037]    In the operation procedure  103 , the power control module  23  controls the power input to the differential demodulation module  12  and the delay correction module  13 . 
         [0038]    More specifically, in the operation procedure  103 , the power control module  23  determines the power supply condition of the differential demodulation module  12  and the delay correction module  13  according to the control signal from the control module  22 . In the case the state at the signal transmission interface  11  is changed from having differential signal transmission into no differential signal transmission, the operation procedure  104  is performed. On the other hand, when the state at the signal transmission interface  11  is changed from no differential signal transmission into having differential signal transmission, the operation procedure  105  is performed. 
         [0039]    In the operation procedure  104 , the power control module  23  cuts off the power input to the differential demodulation module  12  and the delay correction module  13 . 
         [0040]    And, in the operation procedure  105 , the power control module  23  turns on the power input to the differential demodulation module  12  and the delay correction module  13 . 
         [0041]    With the energy-saving control device  20  of the present invention, when the image receiver  10  works, the detection module  21  of the control device  20  keeps detecting the differential signal transmission state at the signal transmission interface  11 . When the signal transmission interface  11  does not transmit any differential signal, the control device  20  will cut off the power supply to the image receiver  10  so as to avoid unnecessary power consumption and protect the image receiver  10  against overheat and shortened service life due to being turned on over an excessively long period of time. On the other hand, when the signal transmission interface  11  transmits differential signal again, the control device  20  will resume the power supply to the image receiver  10  for the same to work immediately. 
         [0042]      FIG. 3  is a block diagram of a second embodiment of the present invention. The second embodiment is generally structurally similar to the first embodiment, except that, in the second embodiment, the image receiver  10  is further electrically connected to an image transmission device  30  and a display  40 , and further includes an image output interface  25 . The image transmission device  30  is remotely connected to the signal transmission interface  11  via a cable  50  of several hundred meters in length, so that a differential signal converted from an image signal is sent from the image transmission device  30  to the signal transmission interface  11  via the cable  50 . The cable  50  can be a category  5  cable (CAT  5 ), a category  5   e  cable (CAT  5   e ) or a category  6  cable (CAT  6 ) for connecting and transmitting the differential signal to the signal transmission interface  11 . The differential demodulation module  12  demodulates the differential signal to obtain the RGB signals and the synchronizing signals. The delay correction module  13  receives the RGB signals and adjusts time delay for the red, green and blue signals thereof, so as to produce a synchronized image signal and outputs the same to the image output interface  25 . The image output interface  25  receives the synchronized image signal and the synchronizing signals, and generates a VGA (Video Graphics Array) signal to the display  40  for displaying. 
         [0043]      FIG. 4  is a block diagram of a third embodiment of the present invention. As shown, the third embodiment is generally structurally similar to the first embodiment, except that, in the third embodiment, the control module  22  of the control device  20  further includes an operation interface  221  and a display interface  222 . 
         [0044]    The operation interface  221  is electrically connected to the control module  22  for a user to set the movement for the control device  20 . For example, the detection module  21  can detect and determine whether there is any differential signal transmission at the signal transmission interface  11  according to the duration or intervals of changes of the differential signal. That is, a sudden interruption lasted for a few seconds while the differential signal is being continuously input might occur due to signal delay or replacement of an image disc by a user. To avoid repeatedly turning on or off the image receiver  10  many times within a very short time period, the user may make settings via the operation interface  221 , so that the control module  22  does not cut off the power supply to the image receiver  10  when the differential signal transmission is interrupted for only a short time not longer than a preset time. On the other hand, it is also possible a sudden differential signal transmission occurs at the signal transmission interface  11  and lasts a short time, such as a few seconds or a few fractions of a second, while the image receiver  10  is cut off. The user may make settings via the operation interface  221 , so that the control module  22  does not turn on the power supply to the image receiver  10  when the differential signal transmission lasts only for a very short time period. It is noted the user can use the operation interface  221  to set the duration or intervals of changes of the above-mentioned short time periods for determining the on/off of power supply to the image receiver  10 . Alternatively, the settings of the durations or intervals, during or at which the differential signal transmission changes, can be preset in the control module  22  of the energy-saving control device  20  shown in  FIG. 1 . With the third embodiment shown in  FIG. 4 , the user may operate at the operation interface  221  to change the preset settings. According to the present invention, the operation interface  221  may be a mechanical switch, such as a DIP (dual-in-line) switch, a toggle switch, a push-button switch, a rocker switch, a contact switch, a band switch, a micro switch or a proximity switch; or an electronic switch, such as a membrane switch or a touch switch; or a touch panel, such as a resistive touch panel, a capacitive touch panel, an optical touch panel, or a SAW (surface acoustic wave) touch panel. 
         [0045]    The display interface  222  is electrically connected to the control module  22  for displaying the current state of the control device  20  or the image receiver  10 . For instance, the display interface  222  may display the current on/off state of the image receiver  10 . When the detection module  21  keeps detecting whether there is any differential signal input or any change in the differential signal transmission, the display interface  222  also displays the current state detected by the detection module  21 , such as the number of times of noise input, the number of times of signal interruption, etc., so that the user can have an idea about the current working state of the image receiver  10  and the control device  20 . Moreover, the display interface  222  may be a seven-segment display, an LED (light-emitting-diode) array display, or an LCD (liquid crystal display) panel. 
         [0046]    It is understood that, in practical implementation of the present invention, the operation interface  221  and the display interface  222  are not necessarily provided at the same time. That is, the present invention can be designed according to actual need in application to include both or one of the operation interface  221  and the display interface  222 . 
         [0047]    The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.