KR100299591B1 - Flat panel display device that can automatically adjust image size and its adjustment method - Google Patents

Abstract

When the analog video signal provided from the host is converted into a digital video signal, the disclosed flat panel display apparatus detects the number of pixels of the effective display data area for one horizontal line from the digital video signal, and supports the flat panel display device. In order to adjust the number of pixel cells in the effective display data area to suit the resolution, a division value for determining a frequency of a sampling clock is calculated, and a division value of a sampling clock generator is set to the calculated division value to display the horizontality of the displayed image. The size is automatically adjusted to match the screen size.

Description

Flat panel display device that can automatically adjust image size and its adjustment method

The present invention relates to a flat panel display device and a control method thereof, and more particularly, to a flat panel display device having a function of automatically adjusting a horizontal size of an image displayed on a screen. And a method of adjusting the same.

Liquid crystal display (LCD) devices, plasma display devices, and the like are generally referred to as flat panel display devices. Unlike a CRT (Cathode Ray Tube) display device, a flat panel display device converts analog video signals input from a host such as a system unit of a personal computer system to a digital video signal. Display the image by converting it into (Digital Video Signals). The analog video signal is converted into a digital video signal by an analog-to-digital converter provided in the flat panel display device. The converted digital video signal is provided to a display panel to drive respective unit pixels Pixels (pixels are also referred to as dots) on the screen, thereby displaying an image. Such a flat panel display device may display within a resolution supported by the flat panel display device.

On the other hand, flat panel display makers do not adhere to a certain standard, but by their own specifications (eg, in the case of VGA mode, various specifications such as 640x350, 640x480, 640x400, 640x350 are used). The size of the displayed image even if an image signal of the same display mode (eg, VGA, SVGA, XGA, or SXGA) is input to the display device because of And the screen sizes supported by the display device do not completely match.

Currently, in order to overcome the problems described above, the flat panel display apparatus is generally provided with a function of adjusting an image size. This feature is commonly referred to as Image Lock or Coarse Control. Coarse adjustment adjusts the frequency of the sampling clock provided by the analog-to-digital converter to convert the analog video signal from the host into a digital video signal. To adjust the horizontal size of the image. 1 is a block diagram showing a circuit configuration of a part related to coarse adjustment function in a circuit configuration of a conventional LCD monitor device, and FIG. 2 is an internal circuit of the phase locked loop circuit shown in FIG. A block diagram is shown in detail.

Referring to FIG. 1, an analog video signal provided from a host (not shown) is converted into a digital video signal through the analog-to-digital converter 10. The analog-to-digital converter 10 receives a sampling clock CLK from a phase locked loop circuit (PLL) 20. The phase locked loop circuit 20 includes a phase detector 21, a low pass filter 22, a voltage control oscillator 23, as shown in FIG. It consists of a divider 24. The phase locked loop circuit 20 determines the frequency of the sampling clock CLK according to the division value set in the divider 24. The phase of the output sampling clock CLK is fixed to the phase of a horizontal synchronous signal Hsync provided from the host. The division value is set by the microcomputer 40. The microcomputer 40 inputs the horizontal synchronization signal Hsync to set a division value suitable for the frequency divider 24 according to the resolution of the analog video signal currently input. However, if the size of the image does not match the screen size due to the above-described causes, the user adjusts the horizontal size of the image by using a manual control key for coarse adjustment.

However, the image adjustment function must be performed manually by the user while viewing the screen, and manual coarse adjustment each time is very cumbersome for the user. And it is not easy for a user who does not have professional knowledge about a flat panel display device to manually adjust an image accurately.

Accordingly, an object of the present invention is to provide a flat panel display apparatus and a method for adjusting the horizontal size of an image to be displayed as proposed to solve the above problems.

1 is a block diagram showing a circuit configuration of a part related to an image size adjusting function in a circuit configuration of a conventional LCD monitor device;

FIG. 2 is a block diagram showing details of the internal circuit of the phase locked loop circuit shown in FIG. 1; FIG.

3 is a block diagram showing a circuit configuration of a part related to an automatic image resizing function in a circuit configuration of an LCD monitor device according to a preferred embodiment of the present invention;

4 is a waveform diagram showing valid display data within one horizontal sync interval;

5 is a flowchart of a control operation performed by the microcomputer shown in FIG. 3; And

FIG. 6 is a flowchart of the control operation performed by the self-course tuning processor shown in FIG.

* Explanation of symbols for main parts of the drawings

10: analog-to-digital converter 20: phase locked loop circuit

21: phase detector 22: low pass filter

23: voltage controlled oscillator 24: divider

30: Manual adjustment key 40, 60: microcomputer

50: self-course tuning processor 70: automatic adjustment key

According to one aspect of the present invention for achieving the object of the present invention as described above, a flat panel display device comprising: an analog-to-digital converter for converting an analog video signal provided from a host into a digital video signal; Sampling clock generation means for providing a sampling clock having a frequency corresponding to a set division value to the analog-to-digital converter; Input the display information for the horizontal pixel number and the division value of the display device and the digital video signal, and the number of pixels of the effective display data area for the horizontal line is adapted to the resolution supported by the flat panel display device. Coarse tuning means for outputting data for adjusting frequency; And a control means for providing the display information to the coarse tuning means when a horizontal size automatic adjustment operation is started, and receiving the adjustment data to set a division value of the sampling clock generating means. Adjust automatically.

In this embodiment, the display apparatus further includes an automatic adjustment key for inputting a signal for starting the horizontal size automatic adjustment operation to the control means.

According to another aspect of the present invention, a method for automatically adjusting a horizontal size of a flat panel display device includes: when an analog video signal provided from a host is converted into a digital video signal, the number of pixels of an effective display data area for one horizontal line from the digital video signal. Detecting; Calculating a frequency division value for determining a frequency of a sampling clock to adjust the number of pixel cells of the effective display data area to be compatible with a resolution supported by a flat panel display device; And setting a division value of a sampling clock generation unit using the calculated division value.

In this embodiment, the detecting step includes: detecting a starting point and an ending point of a valid display data area of the digital video signal; Calculating the number of pixels of the effective display data area using the starting point and the ending point.

In this embodiment, the calculation of the division value calculates the division value to be adjusted using the current division value, the number of pixels of the detected effective display data area, and the resolution supported by the flat panel display apparatus.

According to the present invention as described above, the horizontal size of the image displayed on the screen is automatically adjusted to the size of the resolution suitable for the display panel.

EXAMPLE

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The flat panel display device having the automatic image resizing function and the control method thereof according to the present invention automatically adjust the size of the image so that the horizontal size of the displayed image matches the screen size of the display panel when the user inputs the automatic adjustment key. do. In the present embodiment, an LCD monitor in which an automatic image adjustment function is implemented will be described as an example.

3 is a block diagram showing a circuit configuration of a part related to the automatic image adjustment function in the circuit configuration of the LCD monitor device according to the preferred embodiment of the present invention. Referring to FIG. 4, the LCD monitor device may include an analog-to-digital converter 10, a phase locked loop circuit (PLL) 20, a self-coarse tuning processor 50, and a microcontroller. It comprises a computer (Micro Computer) 60, Auto Control Key (70).

The analog-to-digital converter 10 and the phase locked loop circuit 20 are the same as those provided in the conventional LCD monitor device, and the operation thereof is also the same. The microcomputer 60 inputs a horizontal sync signal Hsync to determine the resolution of the currently input analog video signal, and sets the divided value to the phase locked loop circuit 20 with a corresponding divided value. This operation is the same as in the conventional case, but when the user inputs the automatic adjustment key 70 to automatically coarse control, the microcontroller 60 recognizes this and starts the automatic adjustment operation.

Each control step performed by the microcontroller 60 in the automatic adjustment operation is shown in a flow chart in FIG. Referring to FIG. 5, the microcomputer 60 senses an input of the automatic adjustment key 70 in step S100, and drives the self-course tuning processor 50 in step S110. In operation S120, the current division value a and the number of horizontal pixels (or horizontal resolution) m are output to the self-course tuning processor 50. The division value a is a division value currently set in the phase locked loop circuit 20, and the horizontal pixel number m represents the number of pixels in the horizontal line of the panel (not shown) of the LCD monitor. The operation of the self coarse tuning processor 50 is shown in FIG. 6, which will be described later. The microcomputer 60 is provided with data for adjusting the division value from the self-course tuning processor 50 in step S130, and sets the adjusted division value in the phase locked loop circuit 20 in step S140. In operation S150, the operation of the self-course tuning processor 50 is stopped.

On the other hand, when the self-course tuning processor 50 starts the operation, in step S200, the division value a and the horizontal pixel number (or horizontal resolution) m of the display device are determined from the microcomputer 60 as described above. Receive input. In operation S210, the digital video signal converted from the analog-to-digital converter 10 is input to detect a starting point of valid display data. In operation S220, an end point of the valid display data is detected. That is, as shown in FIG. 4, the starting point and the ending point of the valid display data are detected within one horizontal synchronization section. Subsequently, in step S230, the number of pixels (or horizontal resolution) n in the section is obtained using the start point and the end point of the valid display data detected in the previous step. Subsequently, in step S240, the division value to be adjusted is calculated as in Equation 1 below.

[Equation 1]

Equation

In step S250, the obtained divided value b is output to the microcomputer 60. The microcomputer 60 sets the frequency division value b adjusted as described above in the phase locked loop circuit 20.

In the present embodiment, the automatic adjustment of the image size as described above is performed by inputting the automatic adjustment key 70, but may be automatically performed when the resolution of the input signal changes. In addition, the LCD monitor may be automatically performed even when power is input to the LCD monitor device.

According to the present invention as described above, the user does not have to adjust the horizontal size of the image displayed manually manually as in the prior art. In addition, if the user manually adjusts the size, it is not easy to precisely adjust the size of the image automatically.

Claims (3)

A flat panel display device comprising: an analog to digital converter for converting an analog video signal provided from a host into a digital video signal; Sampling clock generation means for providing a sampling clock having a frequency corresponding to a set division value to the analog-to-digital converter; Input the display information for the horizontal pixel number and the division value of the display device and the digital video signal, and the sampling clock so that the number of pixels of the effective display data area for the horizontal line is suitable for the maximum resolution supported by the flat panel display device. Coarse tuning means for outputting divided data for adjusting the frequency of the signal; And a control means for providing the display information to the coarse tuning means when a horizontal scale automatic adjustment operation is started, and receiving the divided data from the coarse tuning means and setting the divided value of the sampling clock generating means. A flat panel display device characterized by automatically adjusting the horizontal size of an image. The flat panel display apparatus according to claim 1, wherein the display device further comprises an automatic adjustment key for inputting a signal for starting the horizontal size automatic adjustment operation to the control means. Image signal horizontal size in a flat panel display device having a sampling clock generation circuit for generating a sampling clock having a frequency corresponding to a current division value, and an analog-to-digital converter for converting an analog video signal into a digital video signal in synchronization with the sampling clock. CLAIMS 1. A method of adjusting a pixel, the method comprising: detecting the number of pixels of an effective display data area of a horizontal line of said digital video signal; Calculating a new division value for generation of the sampling clock to adjust the number of pixel cells of the effective display data area to suit the resolution supported by the flat panel display device; Setting the calculated division value as the division value of the sampling clock generator; And calculating the new division value by using the current division value, the number of pixels of the detected effective display data area, and the resolution supported by the flat panel display device.