Patent Publication Number: US-2007109450-A1

Title: Signal processing apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority from Korean Patent Application No. 2005-0109643, filed on Nov. 16, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a signal processing apparatus and a control method thereof, and more particularly, to a signal processing apparatus for improving the convenience of a user and a control method thereof.  
      2. Description of the Related Art  
      A signal processing apparatus, such as a liquid crystal display (LCD) television (TV), receives a video signal and/or an audio signal from a broadcasting station or an external device such as a video cassette recorder (VCR), a digital versatile disk (DVD) player, a personal computer (PC) and so on, processes the received video signal and/or the received audio signal, and then outputs the processed video signal and/or audio signal.  
       FIG. 1  is a schematic block diagram of a related art signal processing apparatus  1 . The signal processing apparatus  1  includes a signal receiver  11 , a decoder  12 , a scaler  13 , a display  14 , an analog-to-digital (AD) converter  15 , a digital video receiver  16 , an audio processor  17 , a signal amplifier  18 , an audio output unit  19 , and a controller  20 . The signal receiver  11  receives a radio frequency (RF) signal. The decoder  12  receives an analog video signal from the signal receiver  11  and outputs a digital video signal. The AD converter  15  converts the received analog video signal, such as “Component” or “HVRGB”, to a digital video signal. The digital video receiver  16  receives a digital video signal such as “DVI/HDMI” and demultiplexes the received digital video signal. The scaler  13  receives the video signal from at least one of the decoder  12 , the AD converter  15  and the digital video receiver  16 , adjusts resolution of the video according to a characteristic of the display  14  and a user&#39;s setting, and outputs the video signal having the adjusted resolution to the display  14 . The audio processor  17  receives the audio signal from the signal receiver  11  and decodes the received audio signal, or outputs a received “Audio L/R” signal. The signal amplifier  18  amplifies the audio signal output from the audio processor  17 . The audio output unit  19  outputs the audio based on the audio signal received from the signal amplifier  18 . The controller  20  controls the overall operation of the components.  
      As constructed above, the components of the signal processing apparatus  1  can be implemented using integrated circuits (ICs). When the signal processing apparatus  1  is powered on, the components need to be initialized. For example, the components need to be reset by hardware and/or software. Particularly, the signal receiver  11  requires initialization of “phase locked loop (PLL)”, “charge pump” and so on. The decoder  12  requires initialization of “input port switching”, “clamping”, “analog-to-digital converter (ADC) setup” and so on. In many cases, it takes much time for the components to initialize. Especially, when the display  14  is implemented using a LCD panel, after power is supplied to the panel, initialization of backlight (not shown) turn-on, pulse width modulation (PWM) dimming, analog dimming and so on takes a great deal of time in comparison to other components.  
      However, in the related art signal processing apparatus  1 , since the sole controller  20  takes charge of controlling of the other components, there is a disadvantage in that only one command is executed at a time. Thus, upon confirming the powered-on of the signal processing apparatus  1 , the controller  20  initializes the components one by one according to a predetermined order. As a result, it takes a considerable time to display the video on a screen after completing the initialization of all the components.  
     SUMMARY OF THE INVENTION  
      The present invention provides a signal processing apparatus for improving the convenience of a user by shortening an initialization time, and a control method of the signal processing apparatus.  
      According to an aspect of the present invention, there is provided a signal processing apparatus including a signal receiver which receives a video signal; a video processor which processes the video signal received by the signal receiver; a display which displays a video based on the video signal processed by the video processor; a main controller which determines whether the signal processing apparatus is powered on and initializes the signal receiver and the video processor; and a sub controller which initializes the display while the main controller initializes at least one of the signal receiver and the video processor.  
      The main controller first initializes one of the signal receiver and the video processor having a longest initialization time. The video processor includes a decoder which decodes the video signal received by the signal receiver. The video processor includes a scaler which scales the video signal received by the signal receiver.  
      The signal receiver further receives an audio signal, and the apparatus further includes an audio processor which processes the audio signal received by the signal receiver. The signal processing apparatus further includes a signal amplifier which amplifies the audio signal processed by the audio processor. The signal processing apparatus further includes an audio output unit which outputs the audio signal amplified by the signal amplifier. The sub controller initializes at least one of the audio processor and the signal amplifier while the main controller initializes at least one of the signal receiver and the video processor.  
      The sub controller initializes the display, the audio processor, and the signal amplifier in an order based on initialization times of the display, the audio processor, and the signal amplifier. The sub controller controls the audio processor to process the audio signal which is received by and output from the signal receiver.  
      According to another aspect of the present invention, there is provided a control method of a signal processing apparatus comprising a signal receiver which receives a video signal, a video processor which processes the video signal received by the signal receiver, and a display which displays the video signal processed by the video processor, the method including determining whether the signal processing apparatus is powered on; initializing the signal receiver and the video processor if it is determined that the signal processing apparatus is powered on; and initializing the display while initializing at least one of the signal receiver and the video processor.  
      The initializing the signal receiver and the video processor includes first initializing one of the signal receiver and the video processor having a longest initialization time.  
      The signal receiver further receives an audio signal, the signal processing apparatus further includes an audio processor which processes the audio signal received by the signal receiver, and a signal amplifier which amplifies the audio signal processed by the audio processor, and the control method of the signal processing apparatus further includes initializing at least one of the audio processor and the signal amplifier while initializing at least one of the signal receiver and the video processor.  
      The initializing the display, the audio processor, and the signal amplifier includes first initializing one of the display, the audio processor, and the signal amplifier having a longest initialization time.  
      The control method further includes controlling the audio processor to process the audio signal received by and output from the signal receiver. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and/or other aspects of the prevent invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompany drawings, in which:  
       FIG. 1  is a block diagram of a related art signal processing apparatus;  
       FIG. 2  is a schematic block diagram of a signal processing apparatus according to an exemplary embodiment of the present invention; and  
       FIG. 3  is a flow chart illustrating a control method of the signal processing apparatus according to an exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE, NON-LIMITING EMBODIMENTS OF THE INVENTION  
      Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below so as to explain the present invention by referring to the figures.  
       FIG. 2  is a schematic block diagram of a signal processing apparatus  10  according to an exemplary embodiment of the present invention. The signal processing apparatus  10  may be a digital TV such as an LCD TV, a plasma display panel (PDP) TV, a digital light processing (DLP) TV and the like. The signal processing apparatus  10  receives a video signal and/or an audio signal from a broadcasting station or an external device such as a VCR, a DVD apparatus, a PC and so on, processes the received video signal and/or the received audio signal, and then outputs the processed video signal and/or audio signal. The signal processing apparatus  10  has two controllers to initialize two or more components in parallel. Therefore, the convenience of a user can be enhanced by shortening an initialization time.  
      As shown in  FIG. 2 , the signal processing apparatus  10  includes a signal receiver  110 , a video processor  120 , a display  130 , a main controller  191 , and a sub controller  192 . The signal receiver  110  receives a radio frequency (RF) video signal. The signal receiver  110  tunes the video signal to a frequency corresponding to a channel selected by a user under control of the main controller  191 . The video signal output from the signal receiver  110  may carry a video in an intermediate frequency such as a picture intermediate frequency (PIF).  
      The video processor  120  receives the video signal from the signal receiver  110  and processes the video signal. The video processor  120  includes a decoder  121  and a scaler  122 . The decoder  121  receives an analog video signal from the signal receiver  110  and outputs a digital video signal by performing analog-to-digital (AD) conversion and decoding for the analog video signal.  
      The scaler  122  receives the video signal from the decoder  121 , adjusts resolution of the video according to a characteristic of the display  130  and a user&#39;s setting, and outputs the video signal having the adjusted resolution to the display  130 .  
      The display  130  receives the video signal from the scaler  122  and displays the video based on the received video signal. The display  130  may include an LCD panel, a PDP panel, or the like according to the form of display.  
      The main controller  191  controls the signal receiver  110  and the video processor  120 . The main controller  191  initializes the signal receiver  110  and the video processor  120  by checking whether the signal processing apparatus  10  is powered on by the user. The signal processing apparatus  10  may further include a user input unit  101  through which the main controller  191  may receive input information from the user. The user input unit  101  may be implemented by a remote controller.  
      The main controller  191  initializes “PLL”, “charge pump”, “SAW filter”, “AGC” of the signal receiver  110 , initializes “input port switching”, “clamping”, “ADC setup”, “output format setup” of the decoder  121 , and initializes “input port switching”, “contrast/brightness/color/tint setup” of the scaler  122 .  
      It may be preferable but not necessary that the main controller  191  first initializes a component having a longer initialization time. For instance, provided that the scaler  122  has the longest initialization time among the signal receiver  110 , the decoder  122 , and the scaler  122 , the main controller  191  may first initialize the scaler  122 .  
      Additionally, the controller  191  can initialize the components based on user setup information. By way of example, the main controller  191  can initialize the components corresponding to information relating to the channel number, the volume, and the screen adjustment state at the time when the user is watching just before the signal processing apparatus is powered down. In this situation, the signal processing apparatus  10  may further include an information storage  102  in which the user setup information is preferably stored.  
      The sub controller  192  initializes the display  130  in parallel with the main controller  191  initializing the other components, while communicating with the main controller  191 . In case that the signal processing apparatus  10  is an LCD TV, the sub controller  192  initializes “panel power supply”, “backlight (not shown) turn-on”, “PWM dimming”, “analog dimming” of the display  130 .  
      The signal processing apparatus  10  may further include an audio processor  160 , a signal amplifier  170 , and an audio output unit  180 . The audio processor  160  receives the audio signal containing the audio from the signal receiver  110  and performs the audio decoding with respect to the audio signal, or receives and outputs the “audio L/R” signal. The signal amplifier  170  amplifies the audio signal output from the audio processor  160 . The audio output unit  180 , such as a speaker or the like, outputs the audio based on the audio signal received from the signal amplifier  170 .  
      The sub controller  192  can initialize the audio processor  160  and the signal amplifier  170 , as well as the display  130 . Particularly, the sub controller  192  initializes “sound port switching”, “prescale”, “deemphasis”, “equalizer”, “balance”, etc. of the audio processor  160 , and “volume”, “mute on/off”, etc. of the signal amplifier  170 .  
      It is preferable but not necessary that the sub controller  192  initializes the components in order of a longest initialization time to a shortest initialization time, similar to the main controller  191 .  
      The signal processing apparatus  10  further includes an AD converter  140  and a digital video receiver  150  and receives and processes a video signal in various formats. The AD converter  140  converts the received analog video signal, such as “component” and “HVRGB”, to the digital video signal. The digital video receiver  150  demultiplexes the received digital video signal such as “DVI/HDMI.” The scaler  122  scales the video signals output from the AD converter  140  and the digital video receiver  150 .  
      After the completion of the initialization, the main controller  191  and the sub controller  192  control the components to receive the video signal and/or the audio signal, and output the video and/or audio with respect to the received signal(s). In more detail, the main controller  191  and the sub controller  192  set up the respective corresponding components. In this case, the main controller  191  and the sub controller  192  perform the component setup based on their respective input signals.  
      For example, the main controller  191  sets up “PLL”, “charge pump”, “SAW filter”, and “AGC” of the signal receiver  110 , “input signal standard recognition”, “filter setup”, and “mixer setup” of the decoder  121 , and “capture/display setup” and “scaling coefficient setup” of the scaler  122 , and the sub controller  192  sets up “input signal standard recognition” and “filter setup” of the audio processor  160 .  
      At this time, the sub controller  192  checks whether the setup of the signal receiver  110  is completed using the information received from the main controller  191 , and then sets up the audio processor  160  based on the audio signal output from the signal receiver  110 . The audio signal output from the signal receiver  110  may contain the audio in an intermediate frequency such as a sound intermediate frequency (SIF).  
      It is noted that the main controller  191  and the sub controller  192  can be implemented by computer programs executed by a microprocessor such as a central processing unit (CPU).  
       FIG. 3  is a flow chart illustrating a control method of the signal processing apparatus  10  according to an exemplary embodiment of the present invention. First, it is determined whether the signal processing apparatus  10  is powered on by the user at operation S 100 . If it is determined that the signal processing apparatus  10  is powered on, as a unit of the main control, the signal receiver  110 , the decoder  121 , the AD converter  140 , and the digital video receiver  150  of the signal processing apparatus  150  are initialized at operation S 101 . As a unit of the sub-control in temporal-parallel with the main control, the audio processor  160 , the display  130 , and the signal amplifier  170  of the signal processing apparatus  10  are initialized at operation S 111 .  
      Upon completing the initialization of the signal receiver  110 , the decoder  121 , the AD converter  140 , and the digital video receiver  150 , as a unit of the main control, the signal receiver  110  is set up based on the input video signal at operation S 102 . Upon completing the setup of the signal receiver  110 , the decoder  121  is set up based on the video signal output from the signal receiver  110  at operation S 103 . After the setup of the decoder  121 , the scaler  122  is set up based on the video signal output from the decoder  141  at operation S 104 .  
      Finally, as a unit of the sub-control, it is determined whether the setup of the signal receiver  110  is completed at operation S 112 . If it is determined that the set up of the signal receiver  110  is completed, the audio processor  160  is set up based on the audio signal output from the signal receiver  110  at operation S 113 .  
      Accordingly, the present invention provides a signal processing apparatus for improving the convenience of a user by shortening an initialization time, and a control method thereof.  
      Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.