Apparatus for generating on-screen display in digital TV

An apparatus for generating an OSD in a digital TV is provided, which comprises an OSD generator for generating an OSD associated with a digital broadcast received through a digital tuner and an OSD associated with an analog broadcast received through an analog tuner, and a controller for controlling the OSD generator according to a user command requesting that the OSD be displayed. The OSD associated with the analog broadcast and the OSD associated with the digital broadcast are processed in an image processor in an integrated manner under the control of the controller for controlling the OSD generator, thereby preventing degradation of the image quality of the OSD associated with the digital broadcast.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a digital television (TV), and more particularly to a digital TV that processes an On-Screen Display (OSD) for analog broadcasts and an OSD for digital broadcasts in an integrated manner.

2. Description of the Related Art

Currently provided broadcasts include both analog and digital broadcasts. Thus, current digital TVs have been manufactured so as to be able to receive not only digital broadcast signals but also analog broadcast signals.

FIG. 1is a block diagram of a conventional digital TV. The configuration of the conventional digital TV is described below with reference toFIG. 1.

The conventional digital TV includes a digital tuner110, an analog tuner112, a demultiplexer120, an MPEG decoder122, an audio digital-to-analog converter (DAC)124, a first controller (MICOM 1)130, a first OSD generator140, an image processor150, a video analog-to-digital converter (ADC)160, an analog amplifier162, a speaker164, a second controller (MICOM 2)170, a display180, and a key input unit (not shown). The digital tuner110receives digital broadcast signals, and the analog tuner112receives analog broadcast signals. The demultiplexer120divides a digital broadcast signal received through the digital tuner110into audio and video signals. The MPEG decoder122processes the audio and video signals divided by the demultiplexer120. The ADC160converts an analog video signal of the analog broadcast signal received through the analog tuner112into a digital video signal. The analog amplifier162amplifies both an analog audio signal of the analog broadcast signal received through the analog tuner112, and an analog audio signal, which is produced by the DAC124through conversion of a digital audio signal output from the MPEG decoder124. The speaker164outputs audio signals amplified by the analog amplifier162. The key input unit (not shown) receives user commands for selecting and setting various functions of the digital TV. The first OSD generator140generates an OSD signal for the digital broadcast signal according to user commands input through the key input unit (not shown), and outputs the generated OSD signal to the image processor150. The first controller130controls the first OSD generator140to display an OSD screen on the display180and controls the overall operation of the digital TV to perform various functions according to user commands input through the key input unit.

The term “OSD” refers to any type of information such as text, a figure, and a menu, other than broadcast images, displayed on the display180to indicate states of the digital TV and allow the user to input commands for setting and changing parameters of various functions of the digital TV. For example, the OSD includes a channel number input field, time information, and menu information, which are overlaid on broadcast images on the display180.

Since current broadcasting systems provide both analog and digital broadcast signals, the first OSD generator140for digital broadcast signals and the second OSD generator152for analog broadcast signals are individually provided in the conventional digital TV as shown inFIG. 1.

The second OSD generator152is embedded in the image processor150, and the second controller170is separately provided to control the second OSD generator152.

The image processor150includes the scaler154that functions to appropriately adjust the resolution of video images or graphics input to the image processor150. The second controller170also controls the scaler154.

The second controller170further controls image quality-related aspects of the picture displayed on the display180, such as brightness, contrast, sharpness, color temperature, and RGB color.

The digital TV configured as described above operates in the following manner. If the user selects a channel through the key input unit (not shown), the digital tuner110or the analog tuner112tunes in to the selected channel and receives its broadcast signals.

A digital broadcast signal (ATSC) received through the digital tuner110is divided into audio and video signals through the demultiplexer120and the MPEG decoder122. An analog broadcast signal (NTSC) received through the analog tuner112is converted into a digital video signal through the video ADC160, which is then output to the image processor150.

That is, digital and analog broadcast signals are received through the digital and analog tuners110and112, respectively, and the received digital and analog broadcast signals are separately processed as shown inFIG. 1.

If the user selects an OSD key on the key input unit, for example, on a remote controller or on a key panel provided on the main body of the digital TV, the first or second controller130or170detects this selection and controls the first or second OSD generator140or152to display various digital and analog function menus in the form of an OSD on the display180.

In the conventional digital TV described above, an OSD associated with a digital broadcast and a video image layer are combined into a single digital video signal, which is then transferred to the image processor150. Even if a digital signal having a very high image quality is transferred to the image processor150, the image quality of the OSD associated with the digital broadcast is lowered since the scaler154and the second OSD generator152in the image processor150are controlled by the second controller170responsible for controlling analog signals.

In order to receive digital and analog broadcast signals, the conventional digital TV includes the digital tuner110and the analog tuner112and a plurality of controllers (MICOM 1,2)130and170for controlling the tuners110and112. The controllers130and170have different responsibilities.

The first controller130is responsible for controlling the digital tuner110, managing digital channels, and controlling other operations of the digital TV, which are associated with the digital tuner110. The second controller170is responsible for controlling the analog tuner112, managing analog channels, and controlling display image quality or the like.

In the conventional digital TV, in order to draw and display an OSD associated with a digital broadcast, which includes an Electronic Program Guide (EPG), a digital channel related menu, and a digital channel list, on the display180, the first controller130responsible for controlling the digital tuner110controls the separate OSD generator140to generate an OSD, and combines the generated OSD and a digital broadcast image into a single video signal, and then transfers the single video signal to the image processor150.

Since an OSD image associated with a digital broadcast is not generated by the OSD generator152in the image processor150but is instead combined into a single video signal and then transferred to the image processor150, the image quality of the OSD is lowered.

In addition to the lowered OSD image quality, since OSDs associated with digital and analog broadcasts are generated respectively by the first and second controllers130and170having different performance and characteristics, it is difficult to manage analog and digital channels in an integrated manner, and also the generated digital and analog broadcast OSDs have different formats. Even if OSDs associated with digital and analog broadcasts are designed to have the same format, they are different in terms of format in actual implementation since the controllers130and170and the OSD generators140and152for generating OSDs associated with digital and analog broadcasts have different performance.

Further, the first controller130for controlling the digital tuner110and the second controller170for controlling the analog tuner112do not perform data management in an integrated manner, thereby lowering their processing performance.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a device for generating OSDs in a digital TV that receives both analog and digital broadcasts, which prevents degradation of the image quality of an OSD associated with digital broadcasts.

In accordance with the present invention, the above and other objects can be accomplished by the provision of an apparatus for generating an On-Screen Display (OSD) in a digital TV, the apparatus comprising an OSD generator for generating an OSD associated with a digital broadcast received through a digital tuner and an OSD associated with an analog broadcast received through an analog tuner; and a controller for controlling the OSD generator according to a user command requesting that the OSD be displayed.

Preferably, the apparatus further comprises an image processor for performing image processing so that the generated OSD is overlaid on an image of the received broadcast, wherein the OSD generator is provided in the image processor. Preferably, the image processor further includes a scaler for adjusting the resolution of images of the broadcast or graphics, which is controlled by the controller. Preferably, the controller controls the digital and analog tuners.

Preferably, the apparatus further comprises a second controller responsible for controlling image quality-related aspects of a picture to be displayed on the digital TV, and data communication is preferably performed between the controller for controlling the OSD generator and the second controller. Preferably, the controller for controlling the OSD generator controls the image quality-related aspects. Preferably, the image quality-related aspects include brightness, contrast, sharpness, color temperature, RGB color, or the like.

Preferably, the OSD provides a user interface for indicating states of the digital TV and setting functions thereof. Preferably, the OSD associated with the digital broadcast includes an electronic program guide, a digital channel list, a digital channel search menu, a digital broadcast setup menu, or the like. Preferably, the OSD associated with the analog broadcast includes an analog channel search menu, an analog channel list, a channel number input field, and the like.

According to the present invention, the controller of the digital tuner directly controls the OSD generator provided in the image processor to generate OSDs associated with digital and analog broadcasts, thereby preventing degradation of the image quality of the OSD associated with the digital broadcast, which is caused in the conventional digital TV. Since all of the OSDs associated with digital and analog broadcasts are generated by the single OSD generator, it is easy to manage analog and digital broadcasts in an integrated manner, and it is also possible to implement a consistent user interface format.

In the conventional digital TV, the first OSD generator, which is responsible for generating a user interface OSD for controlling the digital tuner and displaying data associated with the digital broadcast, and the second OSD generator, which is responsible for generating a user interface OSD for displaying data associated with the analog broadcast and a user interface OSD for controlling image quality-related aspects of the picture to be displayed, are separately provided, and the first and second OSD generators are controlled respectively by two separate controllers. However, the digital TV according to the present invention includes an integrated OSD generator, instead of both the first and second OSD generators, which is controlled by the controller (i.e., the first controller) responsible for controlling the digital tuner. The second controller is implemented so as to perform only control functions associated with image processing of the digital TV, and the first and second controllers are configured to be able to communicate data with each other so that all elements of the digital TV are integrated into one system.

DETAILED DESCRIPTION OF PREFFERRED EMBODIMENTS

FIG. 2is a schematic block diagram of a digital TV according to one embodiment of the present invention.

As shown inFIG. 2, the digital TV according to this embodiment receives digital and analog broadcast signals through digital and analog tuners210and212. The digital TV includes both the digital and analog tuners210and212since all of the currently provided broadcasts are not digital broadcasts.

First, a description is given of components of the digital TV, which are responsible for processing digital broadcast signals. The digital TV includes a demultiplexer220for dividing a digital broadcast signal received through the digital tuner210into audio and video signals, and an MPEG decoder222for processing the divided audio and video signals.

A digital audio signal, into which the MPEG decoder222decodes the audio signal output from the demultiplexer220, is output to a speaker264via an audio digital-to-analog converter (DAC)224and an analog amplifier262.

A digital video signal, into which the MPEG decoder222decodes the video signal output from the demultiplexer220, is input to an image processor250, and is then output to a display280after being subjected to predetermined processing in the image processor250.

The image processor250includes a scaler254for appropriately adjusting the resolution of video images or graphics input to the image processor250. The image processor250may be configured so as to be included in a display controller (not shown) for controlling the display280.

If the user activates an OSD using a key input unit (not shown) such as a remote controller in order to select or set various functions, an integrated OSD generator252provided in the image processor250generates an OSD signal for the digital broadcast according to user commands input through the key input unit.

The present invention is characterized in that the OSD generator252for digital broadcasts is embedded in the image processor250, and that the OSD generator252is also responsible for generating a user interface OSD for displaying data associated with an analog broadcast and a user interface OSD for controlling image quality-related aspects of the picture displayed on the display280, which will be described later.

The term “OSD” refers to any type of information such as text, a figure, and a menu, other than broadcast images, displayed on the display280to indicate states of the digital TV and allow the user to input commands for setting and changing parameters of various functions of the digital TV. For example, the OSD includes a channel number input field, time information, and menu information, which are overlaid on broadcast images on the display280.

The OSD associated with a digital broadcast includes an Electronic Program Guide (EPG), a digital channel list, a digital channel search menu, a digital TV setup menu, and the like. The OSD associated with an analog broadcast includes an analog channel search menu, an analog channel list, a channel number input field, and the like.

The digital TV further includes, as a component for processing digital broadcast signals, a first controller (MICOM 1)230for controlling the overall operation of the digital TV to perform various functions according to user commands input through the key input unit (not shown) and for controlling the integrated OSD generator252to display an OSD screen on the display280.

The first controller230controls not only the digital tuner210but also the analog tuner212, which will be described later.

Next, a description is given of components of the digital TV, which are responsible for processing analog broadcast signals. An analog video signal of the analog broadcast signal received through the analog tuner212is converted to a digital video signal through the video ADC260, which is then input to the image processor250. An analog audio signal of the analog broadcast signal received through the analog tuner212is output through the speaker264after being amplified through the analog amplifier262.

The integrated OSD generator252provided in the image processor250also generates an OSD associated with the digitalized video signal, which is converted from the analog video signal received through the analog tuner212and is then input to the image processor250. The integrated OSD generator252is also controlled by the first controller230.

The scaler254provided in the image processor250is also controlled by the first controller230.

According to the present invention, an OSD associated with an analog broadcast and an OSD associated with a digital broadcast are processed in an integrated manner under the control of the first controller230as described above, thereby preventing degradation of the image quality of the OSD associated with the digital broadcast.

Accordingly, the second controller240is responsible only for controlling image quality-related aspects of the picture displayed on the display280, such as brightness, contrast, sharpness, color temperature, and RGB color.

The present invention is also characterized in that the first and second controllers230and240can perform data communication with each other. That is, data communication can be performed between the first controller230responsible for performing data management of all elements of the digital TV and controlling the OSD generator252and the scaler254, and the second controller240responsible for performing control functions associated with image processing of the digital TV, thereby preventing degradation of processing performance of the controllers230and240.

The digital TV according to this embodiment of the present invention operates in the following manner. If the user selects a channel through the remote controller, the digital tuner210or the analog tuner212tunes in to the selected channel and receives its broadcast signals.

A digital broadcast signal received through the digital tuner210is divided into audio and video signals through the demultiplexer220and the MPEG decoder222. An analog broadcast signal received through the analog tuner212is converted into a digital video signal through the video ADC260, which is then output to the image processor250.

That is, digital and analog broadcast signals are received through the digital and analog tuners210and212, respectively, and the received digital and analog broadcast signals are separately processed as shown inFIG. 2.

If the user selects an OSD key on the key input unit (not shown), for example, on the remote controller or on the key panel provided on the main body of the digital TV, the first controller230detects this selection and controls the integrated OSD generator252to display various digital and analog function menus in the form of an OSD on the display280, thereby preventing degradation of the image quality of the OSD associated with the digital broadcast.

As described below, the second controller240may be integrated into the first controller230, instead of being separately provided, so that the first controller230performs all functions of the second controller240.

FIG. 3is a schematic block diagram of a digital TV according to another embodiment of the present invention. As shown inFIG. 3, in this embodiment, the second controller240is not provided but instead a first controller232is configured so as to perform operations of the second controller.

The other elements of the digital TV in this embodiment have the same configuration and operation as those in the previous embodiment, which are described above with reference toFIG. 2, and thus they are denoted by the same reference numerals and a description thereof is omitted herein.

As is apparent from the above description, the present invention provides an apparatus for generating an OSD in a digital TV, which prevents degradation of the image quality of an OSD associated with digital broadcasts, and also prevents degradation of processing performance of controllers, which is caused by redundancy of the controllers.