KR100387349B1 - On Screen Display Apparatus - Google Patents

Abstract

The present invention relates to an on-screen display device capable of displaying an on-screen signal regardless of the presence or absence of an input signal only by on / off control of a transistor without using a separate semiconductor device and a circuit.

An on-screen display device according to the present invention comprises: a video signal mixer for extracting red, green, and blue data and a synchronization signal from a composite video signal; A liquid crystal display device having an internal oscillator for supplying red, green, and blue data and a synchronization signal and generating an oscillation signal; A switch element connected between the image signal mixing unit and a liquid crystal display element to switch the synchronization signal to a base voltage source; Generates screen data synchronized with any one of a synchronization signal from the video signal mixer and an oscillation signal generated from an internal oscillator of the liquid crystal display, and supplies the screen data to the video signal mixer and the presence or absence of the composite video signal. It characterized in that it comprises a control element for controlling the switch element by detecting the.

By such a configuration, the on-screen display device according to the present invention has an advantage of displaying a stable on-screen signal regardless of the presence or absence of an input signal only by the on / off control of the transistor.

Description

On Screen Display Apparatus}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen display, and in particular, an on-screen display capable of displaying an on-screen signal regardless of the presence or absence of an input signal only by controlling on / off of a transistor without using a separate semiconductor device and a circuit. Relates to a device.

Recently, a user desired mode (for example, volume, brightness, color, etc.) is displayed on a screen by pressing a switch provided in a liquid crystal television ("TV") set. Specific parts of the image are visually displayed in graphical form. This is implemented by an On Screen Display (hereinafter referred to as "OSD") mounted inside a TV set, and displays information of a mode desired by a user on a specific portion of the screen. In this case, as shown in FIG. 1, the liquid crystal display displays images by receiving a mixed video signal in which a video signal and an OSD signal are mixed.

Referring to FIG. 1, a liquid crystal display device 20 for displaying an image, a composite video signal 14 externally supplied, a vertical synchronizing signal 4, and a horizontal synchronizing signal In order to supply (6), a multivibrator (2) provided separately and a vertical / horizontal synchronization signal are supplied from the multivibrator (2, OSD, R, G, B) signals and fast blanking (FB) ( 10) is installed between the microprocessor (8) for outputting a signal, the liquid crystal display device 20 and the microcomputer (8) to generate a mixed video signal by mixing the video signal 14 and the OSD signal (10) And a panel driver 15 installed in the video signal mixer 12 and the liquid crystal display device 20 to supply the horizontal synchronization signal 18 to the video signal mixer 12.

The multivibration 2 forcibly generates the horizontal synchronizing signal 4 and the vertical synchronizing signal 6 necessary for implementing the OSD signal 10.

The microcomputer 8 converts an analog signal of the horizontal synchronous signal 4 and the vertical synchronous signal 6 supplied from the separately provided multivibrator 2 into a digital signal (Analog Digital Converter; And a graphic font memory (not shown) for storing characters and graphic fonts. According to the user's intention, the input analog signal is converted into a digital signal by the ADC. In response to the digital signal, the microcomputer 8 reads a font corresponding to a character or graphic to be displayed on the screen from a graphic font memory (not shown) to generate an OSD signal. On the other hand, the microcomputer 8 generates a fast blanking (FB) signal that processes a portion of the video signal corresponding to the character or graphic to be displayed on the screen as a blank.

The image signal mixer 12 receives the input image composite signal 14, the OSD image signals R, G, and B, and the FB signal to extract the synthesized signal 17 to extract the composite signal 17. Supply to the panel driver (15) installed in the interior. The image signal mixer 12 receives the horizontal synchronization signal 18 from the panel driver 15 and supplies the mixed image signals 16a, 16b, and 16c to the liquid crystal display device 20. The panel driver 15 receives the synthesized signal 17 extracted from the image signal mixer 12 and supplies the synchronized horizontal synchronization signal 18 to the image signal mixer 12.

The liquid crystal display device 20 supplies a synthesized signal 17, which is a synchronization signal extracted from the image signal mixing unit 12, to the panel drive 15 therein to display the horizontal synchronization signal 18 switched to the internal oscillation output. In addition to being supplied to the signal mixing section 12, an image of the synthesized mixed video signals 16a, 16b, and 16c supplied from the video signal mixing section 12 is displayed on the liquid crystal panel.

The separately provided multivibrator 2 forcibly generates and supplies the vertical and horizontal synchronization signals 4 and 6 to the microcomputer 8. The microcomputer 8, which receives the vertical and horizontal synchronization signals 4 and 6 from the multivibrator 2, outputs an image signal of the red (R), green (G), and blue (B) and FB signals (10) for the OSD. The video signal mixer 12 supplies the composite video signal 14 from the outside, and red (R), green (G), and blue (B) for the OSD from the microcomputer (8). The composite image signal 14 and the OSD signal 10 are supplied with the video signal, the FB signal 10, and the horizontal synchronization signal 18 from the panel driver 15 installed inside the liquid crystal display device 20. The synthesized video signals 16a, 16b, and 16c are supplied to the liquid crystal display device 20 to display an image on the liquid crystal panel.

By the FB signal applied from the microcomputer 8, a specific portion (e.g., a portion corresponding to a character or graphic to be displayed on the image) of the video signal is blanked. Subsequently, the OSD signal is synthesized in the blanked portion of the video signal. The mixed video signal generated by this process is supplied to the liquid crystal display device 20 to display an image. For example, when a user inputs an up signal with an up / down switch to increase / decrease the volume level, an up signal may be applied to the screen by the above-described process. In response, the volume level is increased.

Since the vertical synchronous signal 4 and the horizontal synchronous signal 6 for realizing the OSD signal are configured and supplied as separate circuits, a problem arises that the configuration becomes complicated.

In addition, the conventional OSD device has a disadvantage in that the manufacturing cost is excessive as the circuit configuration is complicated.

Accordingly, it is an object of the present invention to provide an on-screen display device capable of displaying an on-screen signal regardless of the presence or absence of an input signal only by on / off control of a transistor without using a separate semiconductor device and circuit. .

1 is a block diagram showing a conventional on-screen display device.

2 is a block diagram showing an on-screen display device according to the present invention.

3 is a flowchart illustrating an operation of a microcomputer shown in FIG. 2.

<Explanation of symbols for main parts of drawing>

2: multivibrator 4, 38: horizontal synchronization signal

6, 39: vertical synchronization signal 8, 28: microcomputer

12, 22: video signal mixing unit 15, 25: panel driver

20, 40: liquid crystal display element TR1: transistor

In order to achieve the above object, the on-screen display device according to the present invention comprises a video signal mixing unit for extracting the red, green, and blue data and the synchronization signal from the composite video signal; A liquid crystal display device having an internal oscillator for supplying red, green, and blue data and a synchronization signal and generating an oscillation signal; A switch element connected between the image signal mixing unit and a liquid crystal display element to switch the synchronization signal to a base voltage source; Generates screen data synchronized with any one of a synchronization signal from the video signal mixer and an oscillation signal generated from an internal oscillator of the liquid crystal display, and supplies the screen data to the video signal mixer and the presence or absence of the composite video signal. It characterized in that it comprises a control element for controlling the switch element by detecting the.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 and 3.

2, the vertical / horizontal synchronization signals 39 and 38 are supplied from the liquid crystal display device 40 for displaying an image, the composite video signal supplied from the outside, the composite video signal, and the liquid crystal display device 40. FIG. Microprocessor 28 for outputting video signals (R, G, B) and FB (Fast Blanking) 30 signals for On Screen Display (hereinafter referred to as "OSD"), and liquid crystal An image signal mixing unit 22 disposed between the display element 40 and the microcomputer 28 to generate a mixed image signal by mixing the image signal 24 and the OSD signal 30, and the liquid crystal display element 40. Installed inside the panel driver 25 for outputting the vertical / horizontal synchronization signals 38 and 39, and between the image signal mixer 22 and the ground voltage source GND. And a transistor TR1 for controlling the supply of the synthesized signal extracted from the liquid crystal display device.

The microcomputer 28 receives the horizontal synchronizing signal 38 and the vertical synchronizing signal 39 and the image composite signal 24 input from the liquid crystal display device 40 and converts the analog signal into a digital signal. A digital converter (hereinafter referred to as "ADC") and a graphic font memory (not shown) for storing characters and graphic fonts are built in. According to the user's intention, the input analog signal is converted into a digital signal by the ADC. In response to the digital signal, the microcomputer 28 reads a font corresponding to a character or graphic to be displayed on the screen from a graphic font memory (not shown) to generate an OSD signal. On the other hand, the microcomputer 28 generates a fast blanking (FB) signal that processes a portion of the video signal corresponding to the character or graphic to be displayed on the screen as a blank, and controls the presence / absence of the OSD signal. In order to prevent the inflow force, the output of the low state is supplied, and when the OSD signal is not input, the detection signal 35 of the high state is supplied to the base electrode of the transistor TR1.

The image signal mixer 22 receives the input image composite signal 24, the OSD image signals R, G, and B, and the FB signal 30 to extract the synthesized signal 37, thereby extracting the liquid crystal display device. It supplies to 40. The image signal mixer 22 receives the horizontal synchronizing signal 38 from the liquid crystal display device 40 and supplies the mixed image signals 26a, 26b, and 26c to the liquid crystal display device 40.

The liquid crystal display device 40 displays the mixed image signals 26a, 26b, and 26c of the red (26a), green (26b), and blue (26c) OSDs supplied from the video signal mixer 22 on the corresponding liquid crystal panel. The internal panel drive drive 25 is supplied with a composite signal 37, which is a synchronization signal extracted from the image signal mixer 22, to mix the horizontal synchronous signal 38 switched to the internal oscillation output. In addition to the unit 12, the vertical / horizontal synchronization signals 38 and 39 are supplied to the microcomputer 28.

The panel driver 25 receives the composite signal 37 extracted from the image signal mixer 22 and outputs the vertical / horizontal synchronization signals 38.39, and extracts the image signal from the video signal mixer 22. If there is no input of the synthesized signal 37, it is internally switched to the internal oscillation output to output the vertical / horizontal synchronization signals 38 and 39 on the same line.

The transistor TR1 is provided between the video signal mixing section 22 and the ground voltage source GND, and is turned off when the output of the detection signal 35 from the microcomputer 28 is in a low state. The synthesized signal 37 extracted from the unit 22 is supplied to the liquid crystal display device 40, and when the output of the detection signal 35 from the microcomputer 28 is in a high state, the signal is turned on. The synthesized signal 37 extracted from the signal mixer 22 flows to the ground voltage source GND.

3 is a flowchart illustrating an operation of the OSD. Referring to FIG. 3, the microcomputer 28 determines whether the composite video signal supplied from the outside is a signal or a non-signal. The detection signal 35 of the state is outputted so that the transistor TR1 is turned off and does not operate, and the synthesized signal 37 extracted from the image signal mixing unit 22 is the liquid crystal display device 40. It is supplied to the panel driver 25, which is set in the interior thereof, and supplies the horizontal synchronizing signal 38 to the image signal mixing unit 22 by the oscillation output of the panel driver 25 and also the vertical synchronizing signal 39. And a horizontal synchronizing signal 38 to the microcomputer 28.

The microcomputer 28 receives the vertical synchronizing signal 39 and the horizontal synchronizing signal 38 from the panel driver 25, generates an OSD signal, and supplies the OSD signal to the image signal mixing unit 22. The image signal mixer 22 synthesizes the image composite signal 24 supplied from the outside and the OSD signal 30 and displays them on the liquid crystal panel of the liquid crystal display device 40.

If the composite video signal supplied from the microcomputer 28 is no signal, the microcomputer 28 outputs a high detection signal 35 so that the transistor TR1 is turned on. do. As a result, the synthesized signal 37 extracted from the image signal mixing unit 22 flows to the base voltage source GND through the transistor TR1, and the panel driver 25 installed inside the liquid crystal display element 40. By supplying the horizontal synchronizing signal 38 to the video signal mixing unit 22 by the oscillation output, the vertical synchronizing signal 39 and the horizontal synchronizing signal 38 are supplied to the microcomputer 28.

The microcomputer 28 receives the vertical synchronizing signal 39 and the horizontal synchronizing signal 38 from the panel driver 25, generates an OSD signal, and supplies the OSD signal to the image signal mixing unit 22. The image signal mixer 22 synthesizes the image composite signal 24 supplied from the outside and the OSD signal and displays them on the liquid crystal panel of the liquid crystal display device 40.

Accordingly, in the operation of the OSD, a specific portion (for example, a portion corresponding to a character or graphic to be displayed on the image) of the image signal is blanked by the FB signal applied from the microcomputer 28. Subsequently, the OSD signal is synthesized in the blanked portion of the video signal. The mixed video signal generated by this process is supplied to the liquid crystal panel to display an image.

For example, when a user inputs an up signal with an up / down switch to increase / decrease the volume level, an up signal may be applied to the screen by the above-described process. In response, the volume level is increased.

As described above, the on-screen display device according to the present invention is configured by forming a transistor without configuring a separate semiconductor device and a circuit to display an on-screen signal, regardless of the presence or absence of an input signal by only controlling the transistor on / off There is an advantage that can display a stable on-screen signal without. In addition, the configuration of the on-screen display device can be simplified. Furthermore, the cost of manufacturing the on-screen display can be reduced.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (4)

A video signal mixer for extracting red, green, and blue data and a synchronization signal from the composite video signal; A liquid crystal display device having an internal oscillator for supplying red, green, and blue data and a synchronization signal and generating an oscillation signal; A switch element connected between the image signal mixing unit and a liquid crystal display element to switch the synchronization signal to a base voltage source; Generates screen data synchronized with any one of a synchronization signal from the video signal mixer and an oscillation signal generated from an internal oscillator of the liquid crystal display, and supplies the screen data to the video signal mixer and the presence or absence of the composite video signal. And a control element for controlling the switch element by detecting a switch. The method of claim 1, And said switch element connects said synchronous signal output line to a ground voltage source under control of said control element when said composite video signal is not supplied. The method of claim 1, And the switch element transfers a current path between the synchronization signal output line and a ground voltage source under control of the control element when the composite image signal is supplied. The method of claim 1, And the control device receives an oscillation signal of a horizontal / vertical synchronization signal output from an internal oscillator of the liquid crystal display device.