KR101509242B1 - Display apparatus for having function of noise reducing feature and method of controlling the same - Google Patents

Abstract

The present invention relates to an image display device, and more particularly, to an image display device having a noise removing function for selectively removing a noise introduced into a specific channel by changing a clock frequency of a memory and a control method thereof.

According to an embodiment of the present invention, there is provided an image display apparatus having a noise removing function, the apparatus comprising: a tuner for searching for a specific channel selected from the outside; A memory capable of reading / writing data; And a control unit for comparing the frequency of the channel searched through the tuner with the clock frequency of the memory and changing the clock frequency of the memory according to the comparison.

Memory clock frequency, channel frequency, change

Description

[0001] The present invention relates to an image display apparatus having a noise canceling function and a control method thereof,

The present invention relates to an image display device, and more particularly, to an image display device having a noise removing function for selectively removing a noise introduced into a specific channel by changing a clock frequency of a memory and a control method thereof.

Hereinafter, a method of controlling a memory of a video display device according to the related art will be described with reference to the accompanying drawings.

FIG. 1 is a flowchart illustrating a method of controlling a memory of a video display device according to an embodiment of the present invention. Referring to FIG.

First, control is performed so that all the SDRAMs operate at a frequency (S10).

Then, it is determined whether or not access to all the SDRAMs is not generated for a predetermined time (S20). Here, access is an operation of writing or reading data to or from a storage device of a memory such as an SDRAM in a computer.

As a result of the determination (S20), if it is determined that access to all the SDRAMs has not occurred for a predetermined time, control is performed such that all the SDRAMs operate at a low frequency (S30).

Next, after controlling all the SDRAMs to operate at a low frequency, it is determined whether or not access occurs to at least one SDRAM (S40).

If it is determined that access is made to at least one SDRAM (S40), the process returns to step S10 to control all the SDRAMs to operate at a high frequency.

If it is determined in step S40 that access to all SDRAMs does not occur, it is determined whether there is an interruption command in operation S50.

Then, if it is determined that there is no interruption command (S50), the process returns to step S30 to control all the SDRAMs to operate at a low frequency.

As described above, the memory control method of the video display device according to the related art drives the memory based on any one of the high frequency and the low frequency according to whether or not access to the entire memory occurs.

That is, if an access to the memory occurs, any one frequency is fixedly used to drive the memory.

However, in the memory control method of the image display device according to the related art, there is a problem that noise is introduced from the clock frequency of the memory when a specific channel is viewed, resulting in a picture bar phenomenon.

In other words, by searching the channel without considering the frequency of the memory clock during the current channel search, a noise introduced from the memory clock occurs in the display screen when a specific channel which is a multiplication frequency of the memory clock is viewed, A vertical bar phenomenon occurs.

In the embodiment of the present invention, a clock frequency of a memory is selectively changed according to a broadcast frequency of a current search channel to provide a function of removing noise introduced into a specific channel.

According to an embodiment of the present invention, there is provided an image display apparatus having a noise removing function, the apparatus comprising: a tuner for searching for a specific channel selected from the outside; A memory capable of reading / writing data; And a control unit for comparing the frequency of the channel searched through the tuner with the clock frequency of the memory and changing the clock frequency of the memory according to the comparison.

According to another aspect of the present invention, there is provided a method of controlling an image display apparatus having a noise canceling function, the method comprising: receiving an externally input channel switching command; Searching for a broadcast signal of a corresponding channel according to the received channel switching command; Comparing a frequency of the searched channel with a preset memory clock frequency; And selectively changing the predetermined memory clock frequency according to the comparison result.

According to another aspect of the present invention, there is provided an image display apparatus having a noise removing function, including: a key input unit for receiving a request command from a user; A tuner for searching for a broadcast channel according to a command input through the key input unit; A memory capable of reading / writing data; And a controller for comparing a frequency of each broadcast channel searched through the tuner with a reference clock frequency of the memory and setting a clock frequency of the memory to be applied for each broadcast channel.

According to another aspect of the present invention, there is provided a method of controlling an image display device having a noise removing function, the method comprising: receiving an automatic channel search command input from the outside; Searching for a broadcast channel according to the received channel automatic channel search command; Comparing the searched broadcast channel frequency with a predetermined reference memory clock frequency; And setting a memory clock frequency to be applied to each broadcast channel according to the comparison result.

The video display device and the control method thereof having the noise canceling function according to the embodiment of the present invention prevent the vertical bar noise generated when viewing a specific channel according to the clock frequency of the memory in advance, There is an effect that can be provided.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It should be understood, however, that there is no intention to limit the scope of the present invention to the embodiment shown, and that other embodiments falling within the scope of the present invention may be easily devised by adding, Can be proposed.

≪ Embodiment 1 >

As shown in FIG. 3, the video display device having the noise canceling function according to the first embodiment of the present invention includes a tuner 100 for searching for a specific channel selected from the outside, A display unit 120 for displaying a video signal signal processed through the image processing unit 110, and a display unit 120 for displaying various menu screens in an on-screen display form A memory 140 capable of reading / writing data, a key input unit 150 for inputting a request command from a user, a frequency detector 140 for detecting a frequency of a channel searched through the tuner 100, And a controller 160 for comparing the clock frequency of the memory 140 and the clock frequency of the memory 140 according to the comparison result.

The operation of the image display apparatus having the noise removing function according to the first embodiment of the present invention will now be described.

The tuner 100 tunes to a broadcast signal of a specific channel selected through the key input unit 150 from an external broadcast signal.

The image processing unit 110 processes the image signal among the broadcasting signals selected through the tuner 100 to be displayed through the display unit 120. [

The image processing unit 110 includes an MPEG-2 decoder and a scaler for converting the video data to a vertical frequency, a resolution, an aspect ratio, and the like, according to an output standard of the display unit 120.

The display unit 120 may be applied to various types of display modules such as a digital light processing (DLP), a liquid crystal display (LCD), and a plasma display panel (PDP).

The OSD processing unit 130 generates various menu screens according to a command input through the key input unit 150 according to a control signal of a control unit 160 to be described later and processes the generated menu screens in an on-screen display form.

The memory 140 is a storage device capable of reading and writing. That is, the memory 140 is a storage device capable of writing or reading data such as an SDRAM. In addition, the memory 140 has a reference clock frequency to be applied at the time of access.

The control unit 160 changes the reference clock frequency of the preset memory 140 according to the frequency of the channel currently searched for when the channel is changed.

That is, when the channel switching command is inputted from the key input unit 150, the control unit 160 controls the tuner 100 to tune to the corresponding channel according to the input channel switching command.

When the channel is tuned through the tuner 100, the controller 160 compares the frequency of the selected channel with the reference clock frequency of the preset memory. Here, the reference clock frequency of the memory 140 is the clock frequency of the currently set memory 140.

If the frequency of the selected channel is a multiple of the reference clock frequency of the memory, the control unit 160 changes the clock frequency of the currently set memory 140.

For example, if the currently set memory 140 clock frequency is 182 MHz and the frequency of the channel selected through the tuner 100 is 543.25 MHz, the frequency of the currently tuned channel is three times the predetermined memory clock frequency do.

Accordingly, the controller 160 changes the clock frequency of the currently preset memory to a specific frequency at which the frequency of the selected channel is not multiplied.

At this time, the controller 160 may store clock frequency information that can be set in the memory 140, and may select one of the stored clock frequency information, which is not different from the frequency of the channel, Set to the memory clock frequency to be applied to the channel.

The control unit 160 controls the display unit 120 to display the corresponding change information according to whether the memory clock frequency is changed or not.

Accordingly, the OSD processing unit 130 generates the OSD type change information of the memory clock frequency under the control of the controller 160, and transmits the change information to the image processing unit 110.

However, when the memory clock frequency is changed according to the frequency of the currently searched broadcast channel, the OSD is broken.

Accordingly, the controller 160 disables the OSD processing unit 130 before changing the memory clock frequency. When the change of the memory clock frequency is completed, the control unit 160 returns to the OSD processing unit 130 Thereby preventing the OSD from being broken in accordance with the change of the memory clock frequency.

As shown in FIG. 4, the method of controlling the image display device having the noise removing function according to the first embodiment of the present invention operates the memory 140 based on a specific memory clock frequency S100). Here, the specific memory clock frequency may be the reference memory clock frequency as described above.

Then, it is determined whether a channel switching command is inputted from the outside (S110).

If the channel switching command is inputted from outside, the broadcast signal of the selected channel is searched for by the user (S120).

Next, the frequency of the searched channel is compared with the clock frequency of the predetermined memory (S130).

Then, it is determined whether the frequency of the searched channel is a multiple of the memory clock frequency according to the comparison result (S140).

If it is determined in operation S140 that the frequency of the searched channel is a multiple of the memory clock frequency, the OSD processing unit 130 is disabled in operation S150.

Then, the preset memory clock frequency is changed according to the frequency of the searched channel (S160).

Then, the OSD processing unit 130 is enabled (S170).

Then, corresponding information corresponding to the change of the memory clock frequency is displayed (S180).

As described above, according to the image display device and the control method thereof having a noise removing function according to the embodiment of the present invention, the vertical bar noise generated when viewing a specific channel is prevented in advance according to the clock frequency of the memory, Image quality can be provided.

≪ Embodiment 2 >

Hereinafter, a video display device having a noise canceling function and a control method thereof according to a second embodiment of the present invention will be described.

Here, the detailed description of the configuration and operation of the video display device having the noise canceling function according to the second embodiment and the control method thereof, which are substantially the same as those of the first embodiment, will be omitted .

The video display device having the noise canceling function and the control method thereof according to the second embodiment of the present invention includes a key input unit 150 for receiving a request command from a user, A tuner 100 for searching for a broadcast channel, a memory 140 for reading / writing data, and a tuner 140 for comparing the frequency of each broadcast channel searched through the tuner 140 and the reference clock frequency of the memory 140 And a controller 160 for setting a clock frequency of the memory 140 to be applied to each of the broadcast channels.

That is, in the first embodiment of the present invention, it is determined whether or not the clock frequency of the memory 140 is changed at the time when the channel switching command is input later, and the preset memory clock frequency is changed. However, in the second embodiment of the present invention Set the memory clock frequency to be applied to each channel in automatic channel search.

In other words, the tuner 100 sequentially searches for a channel in which a valid signal exists by searching for a channel-by-channel broadcast signal, and the controller 160 controls the frequency of each channel, which is searched through the tuner 100, Compares the reference memory clock frequency, and sets the memory clock frequency to be applied per broadcast channel accordingly.

That is, the reference memory clock frequency to be applied to all initial channels is set to the default.

The control unit 160 changes the reference clock frequency of the set memory only for a specific channel having a multiplication frequency of the memory reference clock frequency among the frequencies of the sequentially searched broadcast channels and generates a new memory clock Set the frequency.

The control unit 160 stores the memory clock frequency set for each broadcast channel. When a channel switching command is input from the user, the control unit 160 extracts a corresponding memory clock frequency of the channel to be switched, .

In other words, the video display device having the noise canceling function according to the second embodiment of the present invention compares the frequency of each channel detected during automatic channel search with the reference memory clock frequency, Set the frequency.

Accordingly, the second embodiment of the present invention can perform a faster channel switching operation by not performing the frequency comparison operation every channel switching as in the first embodiment of the present invention.

As shown in FIG. 5, the control method of the video display device having the noise removing function according to the second embodiment of the present invention determines whether an automatic channel search command is inputted from the outside (S200) .

When the automatic channel search command is input, the first channel search is performed (S210).

Then, it is determined whether a valid signal exists in the searched channel (S220).

If it is determined in operation S220 that a valid signal exists in the channel, the frequency of the channel is compared with a reference frequency of a predetermined memory clock in operation S230.

If the frequency of the searched channel is a multiple of the reference frequency of the memory clock, the memory clock frequency for the channel is changed from the memory clock reference frequency to the new frequency at step S250.

Then, it is determined whether the channel search has been completed (S260).

If the channel search is completed (S260), the clock frequency of the memory set for each channel is stored (S270).

If it is determined in step S260 that the channel search has not been completed, the flow returns to step S220 to search for the next channel in step S280.

As described above, the video display device and the control method thereof having the noise canceling function according to the second embodiment of the present invention set a memory clock frequency to be applied to each broadcast channel based on each channel frequency searched for in automatic channel search .

In other words, a memory clock frequency to be applied to all channels is set as a reference clock frequency, a reference clock frequency of a preset memory is changed only for a specific channel having a multiplication frequency of the memory reference clock frequency, Set the clock frequency.

As described above, according to the image display device and the control method thereof having the noise canceling function according to the embodiment of the present invention, the vertical bar noise generated when viewing a specific channel is prevented in advance according to the clock frequency of the memory, Image quality can be provided.

The image display apparatus having the noise removing function and the control method thereof according to the embodiment of the present invention have been described with reference to the embodiments shown in the drawings for the sake of understanding, Those skilled in the art will appreciate that various modifications and equivalent embodiments may be possible.

Accordingly, the true scope of the present invention should be determined by the appended claims.

FIG. 1 is a flowchart illustrating a method of controlling a memory of a video display device according to the related art.

BACKGROUND OF THE INVENTION Field of the Invention [0001]

3 is a view illustrating a configuration of an image display device having a noise removing function according to an embodiment of the present invention.

4 is a flowchart illustrating a method of controlling an image display device having a noise removing function according to an exemplary embodiment of the present invention.

FIG. 5 is a flowchart illustrating a method of controlling an image display device having a noise removing function according to another embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

100: tuner 110: image processor

120: display unit 130: OSD processing unit

140: memory 150: key input unit

160:

Claims (15)

A key input unit for receiving a key input; A tuner for searching for a broadcast channel according to an automatic channel search command received through the key input unit; A memory capable of reading / writing data; And Sequentially determining whether a reference frequency of a preset memory clock is a multiple of the searched channel frequencies, and if the reference frequency of the preset memory clock is a multiple of the searched channel frequency, And a control unit for changing the reference frequency for each channel A video display device having a noise canceling function. The method according to claim 1, Wherein the control unit determines whether or not the automatic channel search is terminated and stores the changed memory clock frequency for each changed channel when the determination result is completed. 3. The method of claim 2, And an OSD processing unit for generating clock frequency change information of the memory in an on-screen display form according to a control signal of the control unit. The method of claim 3, Wherein the control unit disables the OSD processing unit before changing the memory clock frequency. Receiving an automatic channel search command; Searching for a broadcast channel according to the automatic channel search command; Sequentially determining for each channel whether a reference frequency of a preset memory clock is a multiple of the searched channel frequencies; And changing the reference frequency of the memory clock for each channel when the reference frequency of the preset memory clock is a multiple of the searched channel frequency as a result of the determination A method of controlling a video display device having a noise canceling function. 6. The method of claim 5, Determining whether the automatic channel search is terminated; And And storing the changed memory clock frequency for each channel when the determination result is completed A method of controlling a video display device having a noise canceling function. 6. The method of claim 5, The step of changing the memory clock frequency And maintaining a predetermined memory clock frequency when the reference frequency of the preset memory clock is not a sine of the searchable channel frequency. 8. The method of claim 7, And displaying change information of the memory clock frequency on the basis of the change information of the memory clock frequency. 9. The method of claim 8, Further comprising disabling a processing block that generates change information of the memory clock frequency before changing the memory clock frequency. delete delete The method according to claim 1, Wherein the control unit changes a preset memory clock frequency based on a memory clock frequency of the channel to be switched when a channel switching command is input through the key input unit. delete delete 6. The method of claim 5, And changing a preset memory clock frequency based on the memory clock frequency of the channel to be switched when the channel switching command is input from the outside.

Images