KR100468696B1 - On screen display apparatus and method having fanction of detecting 2dimensional fringe and color displaying by line - Google Patents

Abstract

PURPOSE: An OSD(On Screen Display) device with a 2D fringe detection function and a line-classified color display function and a method therefor are provided to detect a 2D fringe without using a line buffer by outputting successive line information in the first and second character generating units and display an OSD character with inter-different colors according to each line using a lookup table. CONSTITUTION: The first character generating unit(810) stores font data of two lines in response to an address, and outputs the font data of the two lines in response to a designated address. The second character generating unit(815) stores font data of two lines successively connected with the font data of the two lines stored in the first character generating unit, and outputs the font data of the two lines in response to a designated address. The first address multiplexer(800) selectively outputs an address of the first character generating unit or another higher-priority address, in response to the first address selection signal. The second address multiplexer(805) selectively outputs an address of the second character generating unit or another lower-priority address, in response to the second address selection signal. A data multiplexer(820) receives the data of the four lines outputted from the first and second character generating units, and outputs the font data of three lines among the four lines in response to the three address selection signals. A parallel/serial converting unit(830) converts the font data of the three lines outputted from the data multiplexer into serial data. A fringe detecting unit(840) receives the serial data, and generates an OSD font setup signal and an OSD interval setup signal. A signal mixer(880) selectively outputs an OSD character and an image signal in response to the OSD font setup signal and the OSD interval setup signal.

Description

On screen display apparatus and method having fanction of detecting 2dimensional fringe and color displaying by line}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen display, and in particular, a two-dimensional fringe detection function of the OSD that clearly displays the boundaries of characters when displaying OSD characters, and each line of the OSD characters in different colors. The present invention relates to an OSD device and method having two-dimensional fringe detection and line-by-line color display.

On-Screen Display (OSD) is one of the essential functions in video processing such as television, video, Moving Ficture Experts Group (MPEG) and digital camera. That is, the OSD function allows a bitmap of a character or symbol defined by a user to be displayed on the area where the image is displayed regardless of the position and size. In addition, the OSD function includes a caption processing, a display function for user selection. In particular, in the case of a digital still camera or a general digital camera, an image captured by the camera is displayed to the user through a view finder, and the user may select the current device status or the current operation mode on the screen. The OSD function is used to display a message that the user should know.

1 (a) to (d) are diagrams for explaining the function of the OSD, 1 (a) represents the image displayed on the monitor, 1 (b) represents the OSD character to display, 1 (c) Denotes an OSD character displayed with an image on a monitor, and 1 (d) denotes an OSD character string displayed as a plurality of lines on the image.

That is, the OSD function is a function to be displayed on the screen as shown in (c) when the message shown in (b) is to be displayed on the background image shown in FIG. 1 (a). It is put on display and can use conveniently. However, when the displayed text is the same color as the background color of the screen, the identification of the OSD text becomes difficult. In order to solve this problem, as shown in FIG. 2 (b), black is displayed at the boundary of a character so that it is easily identified, which is called a fringe function in the OSD.

2 (a) to 2 (b) are diagrams for explaining a fringe function of an OSD, and 2 (a) shows a character generator for displaying a letter 'A', that is, font data of a character generator ROM. 2 (b) is a diagram for explaining the one-dimensional fringe function, and 2 (c) is a diagram for explaining the two-dimensional fringe function.

That is, in order to display the letter 'A', the font data of the character generator ROM is shown as shown in Fig. 2A. 2 (b) and 2 (c), reference numeral 21 denotes a background screen, 22 denotes a fringe, and 24 denotes an OSD font. When detecting the one-dimensional fringe illustrated in FIG. 2 (b) and displaying 'A', since the fringe is generated only on the left and right sides of the OSD font, the two-dimensional illustrated in FIG. It can be seen that the discernment is lower than.

3 is a schematic block diagram illustrating a general OSD device, including an X-counter 312, a Y-counter 314, an address generator 320, a frame buffer 330, a character generator 340, The parallel / serial converter 350, the fringe detector 360, and the signal mixer 370 are configured.

The X-counter 312 and the Y-counter 314 shown in FIG. 3 count X and Y coordinates in synchronization with a scan signal of an image to designate a position where an OSD character is displayed on the screen. The outputs of the X-counter 312 and the Y-counter 314 are decoded by the address generator 320 to generate an address of the frame buffer 330, and the character information output from the frame buffer 330 is a character generator. Is applied as an input of 340. The character generator 340 outputs a bit map of the corresponding address based on the character information and the line information. Here, the bitmap is output in word units and converted into a serial signal by the parallel / serial converter 350. The fringe detector 360 sharpens the boundary of the OSD character, and the output signal is mixed with the image from the signal mixer 370 and output to the monitor through the output terminal OUTPUT.

4 is a block diagram illustrating a conventional OSD device having a one-dimensional fringe detection function, and includes a character generator 410, a parallel / serial converter 420, a fringe detector 430, and a signal mixer 440. Is done.

The fringe detector 430 of FIG. 4 inputs a bitmap output from the parallel / serial converter 420 to logically combine each pixel value, and generates an OSD font setting signal OSDC and an OSD section setting signal OSDP. do. That is, in order to implement the one-dimensional fringe function, pixel values of both sides of the pixel to be displayed must be given. That is, if the preceding pixel is the foreground of the OSD character or the latter pixel is the foreground of the OSD character, the currently displayed pixel becomes the fringe pixel.

FIG. 5 is a block diagram illustrating a conventional OSD device having a two-dimensional fringe detection function, and includes a parallel / serial conversion unit 520, a first line buffer 530, a second line buffer 535, and a fringe detection unit ( 540, the signal mixer 550.

That is, the OSD device having the one-dimensional fringe detection function shown in FIG. 4 can be easily implemented since the fringe needs to be determined only by referring to the left and right pixels of the OSD character, but the OSD device having the two-dimensional fringe detection function shown in FIG. In this case, since the fringe must be determined by referring to the pixels of the front and rear lines as well as the left and right, it is difficult to implement the device. That is, the conventional OSD device having a one-dimensional fringe detection function has a problem in that the identification power is lowered because the boundary is formed only at the left and right of the pixel. Although it is excellent, there is a problem that the size of the circuit is increased because a line buffer of two or more lines must be provided inside.

On the other hand, as shown in Figure 1 (d), when you want to display a plurality of lines of OSD text on the screen or monitor, it is convenient to distinguish the OSD text lines selected for the user interface to be expressed in different colors.

6 is a schematic block diagram illustrating a conventional OSD device having a line / character color display function, and includes a frame buffer 600, a delay buffer 610, a character generator 620, and a parallel / serial converter. 630, and a multiplexer 650.

7 (a) and 7 (b) are diagrams for explaining an AT (Attribute) code and a CC (Character) code output from the frame buffer 600 shown in FIG. That is, Fig. 7 (a) shows the AT code in which 8 to 11 bits represent a background (Bg), that is, a fringe color, and 12 to 15 bits represent a foreground (Fg), that is, an OSD font color. In addition, 7 (b) is a figure which shows CC code, 0-7 bits represent a character code, and 7th bit represents a blink code.

That is, the data output from the frame buffer 600 of the OSD device having the line / character color display function shown in FIG. 6 includes an AT code for designating the foreground (FOREGROUND) and the background (BACKGROUND) colors, and the OSD character. It consists of a character code to display. The AT code and CC code of the designated position are simultaneously read from the frame buffer 600, and the CC code is decoded into a bitmap of characters via the character generator 620 and the parallel / serial converter 630, and at the same time, the AT code Is delayed a predetermined time in the delay buffer 610 to synchronize with the character code. The multiplexer 650 inputs the foreground color and the background color output from the delay buffer 610 and selectively outputs the output color through the output terminal OUT1 in response to the bitmap output from the parallel / serial converter 630.

In general, however, the OSD uses BLINKING instead of displaying the line-by-line colors differently. In addition, in this case, there is a problem that the size of the frame buffer must be large, and in particular, the size of the built-in OSD must be smaller. In addition, the above-described conventional OSD device is a device for changing the color by character rather than changing the color by line, and has a problem that it is not used in most cases including a digital still camera.

SUMMARY OF THE INVENTION The first technical problem to be solved by the present invention is to have a two-dimensional fringe detection function capable of detecting two-dimensional fringes without using a line buffer by outputting sequential line information from a character generator divided into two blocks. It is to provide a screen display device.

The second technical problem to be achieved by the present invention is to provide an on-screen display method performed in the on-screen display device having the two-dimensional fringe detection function.

A third technical problem to be achieved by the present invention is to provide an on-screen display device having a line-by-line color display function that can display on-screen display characters in different colors for each line using a lookup table.

A fourth technical object of the present invention is to provide an on-screen display method performed in the on-screen display device having the color display function for each line.

In order to achieve the first object, the OSD device having a two-dimensional fringe detection function according to the present invention stores two lines of font data corresponding to a predetermined address, and outputs two lines of font data corresponding to a specified address. A second character generating means for storing two lines of font data sequentially connected to two lines of font data stored in the first character generating means and the first character generating means, and outputting two lines of font data corresponding to a specified address; A first address multiplexer for selectively outputting a predetermined address or an address higher than the address in response to the first address selection signal, a predetermined address of the second character generation means in response to the second address selection signal, or A second address multiplexer for selectively outputting an address lower than the address; A data multiplexer for inputting four lines of data output from the second character generating means and outputting font data of three of four lines in response to the third address selection signal, and three lines of font data output from the data multiplexer Parallel / serial conversion means for converting to serial data, and fringe detection means for inputting serial data to generate an OSD font setting signal and an OSD interval setting signal, and OSD characters in response to the OSD font setting signal and the OSD interval setting signal. It is preferable that the signal mixing means selectively outputs the video signal.

In order to achieve the second object, the OSD method having a two-dimensional fringe detection function according to the present invention comprises the steps of: (a) configuring the data to output two lines of font data from each of the separated character generating means. Determining whether an OSD font line is selected, if an OSD font line is selected, outputting font data of an OSD font line and a line before and after a line, and setting on-screen display fonts by combining font data of each line Generating a signal and an on-screen display section setting signal, (b) determining whether to output an OSD character, (c) selectively outputting an OSD font and a fringe font, if desired to output the OSD character, and (d) In order not to output the OSD character, it is preferable that the video signal is output.

In order to achieve the third object, the OSD device having a line-by-line color display function according to the present invention includes a frame buffer for storing a character code of an OSD character corresponding to a predetermined address, and a character code output from the frame buffer. Character generating means for generating parallel data, parallel / serial conversion means for converting parallel data to serial data, and logic combination by inputting serial data, and generating the logical combined result as an on-screen display font setting signal or OSD section setting signal. Fringe detection means, line-by-line color selection means for selecting each OSD character of one or more lines in different colors for each line, and OSD character or video signal having a selected color in response to an OSD font setting signal or an OSD section setting signal It is preferable that it is comprised by the signal mixing means which selectively output | transformed.

In order to achieve the fourth task, the OSD method having a color display function for each line according to the present invention includes the steps of counting an OSD string of one line, determining whether one line has elapsed, and if one line has elapsed, a lookup Selecting a foreground and background color of a predetermined OSD character from a table; (e) determining whether to output the OSD character and outputting the OSD character, an OSD font having a foreground color or a fringe font having a background color. It is preferable that the step of selecting, and (e) do not output the OSD character, and outputting a video signal.

Hereinafter, an OSD device and method having a two-dimensional fringe detection function according to the present invention will be described with reference to the accompanying drawings.

FIG. 8 is a block diagram of a preferred embodiment for explaining an OSD device having a two-dimensional fringe detection function according to the present invention. The first address multiplexer 800, the second address multiplexer 805, and the first character generator ( 810, a second character generator 815, a data multiplexer 820, a parallel / serial converter 830, a fringe detector 840, and a signal mixer 880. Here, the data multiplexer 820 is composed of three multiplexers 822, 824, and 826, and the parallel / serial converter 830 is composed of three parallel / serial converters 831, 832, and 834. The fringe detector 840 is comprised of flip-flops 842, 844, 846, flip-flops 852, 854, 856, flip-flops 862, 864, 866, and OR gate 870. It consists of a multiplexer 882 and a multiplexer 884.

That is, the first address multiplexer 800 shown in FIG. 8 receives an arbitrary address ADD generated from an address generator (not shown) and an address increased by one, ADD + 1, respectively, and the first address is input. In response to the selection signal AS1, an arbitrary address ADD or an incremented address ADD + 1 is selectively output to the first character generator 810. In addition, the second address multiplexer 815 receives an arbitrary address ADD and one reduced address ADD-1, respectively, and receives an arbitrary address ADD or a reduced value in response to the address selection signal AS2. The address ADD-1 is selectively output to the second character generator 815. Here, the arbitrary address ADD is an address for designating two lines of data of the first character generator 810 and the second character generator 815, respectively. In addition, the first character generator 810 and the second character generator 815 shown in FIG. 8 are embodied as a ROM or a RAM as described above. Unlike the conventional ROM, the first character generator 810 and the second character generator 815 are separated into two blocks, respectively. Save it. Each of the multiplexers 822, 824, and 826 of the data multiplexer 820 includes two lines of data D0 and D1 output from the first character generator 810 and two outputs from the second character generator 815. Four lines of font data, each of which combines the data of lines D2 and D3, are input, and information of one line of the input four lines of data is selectively output in response to the selection signal AS3. In other words, the data multiplexer 820 is a 4: 3 multiplexer, and outputs font lines of lines before and after the OSD font among the input four lines of data. Each parallel / serial converter 830 is composed of three parallel / serial converters 831, 832, and 834, and each of the multiplexers 831, 832 834, respectively, has three lines of output from the data multiplexer 820. Convert parallel font data to serial data. The fringe detector 840 inputs serial data output from the parallel / serial converter 830 to generate an OSD font setting signal OSDC and an OSD section setting signal OSDP. That is, the flip-flops 842, 844, and 846 connected to the first parallel / serial converter 831 determine the size of the fringe, and each output of the OR gate 870 generates the OSD section setting signal 870. Is applied as input. The output of the flip-flop 852 that takes the output of the second parallel / serial converter 832 and the flip-flops 854, 856 that take the output thereof is similarly applied to the input of the OR gate 870. Generates an OSD section setup signal (OSDP). Similarly, a flip-flop 862 that takes an output of the third parallel / serial converter 834 and a flip-flop that takes an output of the flip-flop 864 and a flip-flop 864 as an input. The output of 866 is also applied to the input of the OR gate 870. Here, if the output of the flip-flop 852 is defined as the OSD font setting signal (OSDC), it is defined that the front and rear fonts are fonts to display fringes, and the OR gates 870 are fonts on the top, bottom, left, and right sides of the OSD font, respectively. By ORing them, an OSD section setting signal (OSDP) is generated. The OSD font setting signal OSDC and the OSD section setting signal OSDP generated by the fringe detector 880 are input to the signal mixer 880 of the OSD device to selectively output a fringe font, an OSD font, or an image signal IMAGE. do. That is, the multiplexer 882 selectively outputs a fringe font or an OSD font in response to the OSD font setting signal OSDC, and the multiplexer 884 is configured to output an output of the multiplexer 882 in response to the OSD section setting signal OSDP. The video signal is selectively output to the monitor through the output terminal OUT.

9A to 9C are diagrams for explaining font data of the separated character generators 810 and 815 shown in FIG. 8, and FIG. 9A shows a conventional character 'A'. Font data is shown, and 9 (b) and 9 (c) indicate font data for the letter 'A' stored in the separated first and second character generators 810 and 815, respectively.

That is, font data of the first and second lines of the conventional character generator of FIG. 9A is stored in the first and second lines of the first character generator 810 and 9 (a The font data of the third and fourth lines of the conventional character generator shown in FIG. 6 are stored in the first and second lines of the second character generator 815. In addition, the font data of the fifth and sixth lines of 9a may be stored in the third and fourth lines of the first character generator 810. The data is stored in each of the character generators separated in this manner, and the font data of two lines of the first character generator 810 or the second character generator 815 is set to one address.

10 (a) to 10 (d) are diagrams for explaining signals output from the signal mixer 880 of the OSD device shown in FIG. 8, wherein 10 (a) shows an output image signal and 10 (b). ) Indicates an OSD font setting signal OSDC, 10 (c) indicates an OSD section setting signal OSDP, and 10 (d) indicates an output signal for each section.

That is, referring to FIG. 10, it can be seen that the video signal shown in FIG. 10 (a) is output in all sections. In addition, when the value of the ODS section selection signal OSDC shown in FIG. 10 (b) is 1, the OSD font is output. In addition, if the value of the OSD section setting signal (OSDP) shown in 10 (c) is 1, the OSD font and the fringe font are output. Therefore, the section in which the OSD font setting signal OSDC is 0 and the OSD section setting signal OSDP is 1 becomes a fringe section. In addition, the section in which both the OSD font setting signal OSDC and the OSD section setting signal OSDP are 0 is an output section of the video signal. In FIG. 10 (d), it is well illustrated that an image, a fringe, and an OSD font are output for each section according to the state of each OSDP and OSDC.

FIG. 11 is a flowchart for describing a fringe detection method performed in the two-dimensional fringe detection apparatus of the OSD shown in FIG. 8, in which data is configured to output two lines of font data in a separate character generator (FIG. Step 81), it is determined whether a line for outputting the OSD font is selected, and if it is selected, outputting font data of two lines before and after the OSD font is output (steps 82 to 84), and outputting 3 Generating an OSD font setting signal (OSDC) and an OSD section setting signal (OSDP) from the font data on the line (step 84), determining whether to output the OSD text, and outputting the OSD font and fringe. Optionally outputting fonts and outputting video signals (steps 85 to 87) in order not to output OSD characters.

Hereinafter, the operation and OSD method of the OSD device having a two-dimensional fringe detection function according to the present invention will be described.

As described above, the OSD device having the two-dimensional fringe detection function according to the present invention stores data as shown in FIGS. 9 (b) and 9 (c) by separating the character generator, that is, the character generator ROM into two. . That is, the data is configured so that the separated character generator 810 or 815 outputs font data of two lines, respectively (step 81). If the data is configured, it is determined whether the line of the OSD font to be output is selected (step 82), and if selected, the font font of the OSD font line to be output and the font data of two lines before and after the OSD font line are output together (step 83). step).

In more detail, first, two lines of data output from the first character generator 810 are called D0 and D1, respectively, and two lines of data output from the second character generator 815 are respectively D2, Set to D3. In this case, the OSD font is output in response to the selection signal AS3 input to the data multiplexer 820 and the selection signals AS1 and AS2 applied to the first address multiplexer 800 and the second address multiplexer 805. And font data on the front and back lines, that is, font data on three lines. From here. The selection signals AS3, AS1, and AS2 are signals obtained by combining addresses input to the character generators 810 and 815. If the 8 * 8 font is assumed, the most significant bit of the three-bit addresses A2, A1, and A0 is used. Combined with A0 and A1 except A2. The selection signal AS3 may be 11, 10, 01, 00 represented by two address bits A1 and A0, the selection signal AS1 indicates 11, and the selection signal AS2 indicates that the address bit 00 indicates the case. Here, 11 represents the highest address among font data lines for displaying one character, and 00 represents the lowest address.

That is, the case where the address of the data stored in the character generator 810 or 815 has 01 or 10, that is, the case where the address is not the highest or lowest position when referring to FIG. In the first address multiplexer 800, since the address selection signal AS1 is not 11, the original address ADD is selected so that the addresses of the first character generator 810 and the second character generator 820 are respectively. Outputs a font data line corresponding to (ADD). That is, the information of two lines D0 and D1 corresponding to the address ADD of the first character generator 810 and the two lines D2 and D3 corresponding to the address ADD of the second character generator 815. ) Information is input to the data multiplexer 820. Therefore, in each of the multiplexers 822, 824, and 826 of the data multiplexer 820, data D0, D1, and D2 are sequentially output, or data such as D1, D2, and D3 are sequentially output, and the parallel / serial conversion unit 830, respectively. At this time, the OSD font line to be output becomes D1 or D2 and is output to the parallel / serial converting unit 830 together with the font data of the previous and subsequent lines.

Meanwhile, operations of the address multiplexers 800 and 805 and the data multiplexer 820 when the selection signal AS3 is 00 or 11 will be described. For example, when the selection signal AS3 is 11, since the selection signal AS1 input to the address multiplexer 800 is 11, an address ADD + 1 higher than the original address is selected to generate the first character. The line information of D0 and D1 corresponding to the address ADD + 1 of the unit 810 is output. In addition, since the selection signal AS1 input to the second address multiplexer 805 is not 00, the second character generator 815 receives line information D2 and D3 corresponding to the original address ADD. Output Accordingly, in response to the selection signal AS3, the data multiplexer 820 receives the font data of the line D0 corresponding to the address ADD + 1 of the first character generator 810 and the second character generator 815. The font data of the lines D2 and D3 corresponding to the address ADD may be output, and as shown in FIG. 9, the font data may be continuous line information. In addition, even when the selection signal AS3 is 00, continuous line information, that is, lines for displaying OSD fonts and information before and after the lines are output in the same manner as described above. That is, since the selection signal AS2 input to the second address multiplexer 805 is 00, the address ADD-1 one level lower than the original address ADD input to the second address multiplexer AS2 is selected. The second character generator 815 outputs line information corresponding to the input address ADD-1. Subsequent operations are the same as those described above, and font data of each line output from the data multiplexer 820 is applied to each block 831, 832, and 834 of the parallel / serial conversion unit 830 and serialized. Converted to data.

The serially converted data is input to the fringe detector 840 to generate an OSD font setting signal OSDC and an OSD section setting signal OSDP (step 84). Since the output of the flip-flop 854 of the fringe detector 840 is defined by the font of the OSD, it is input to the signal mixer 880 as the OSD font setting signal OSDC. The OSD section setting signal OSDP is generated by ORing the outputs of all flip-flops at the OR gate. The signal mixer 880 inputs an input OSD font setting signal OSDC and an OSD section setting signal OSDP to determine whether to output an OSD character or an image signal. That is, it is determined whether to output the OSD text on the monitor (step 85), and selectively outputs the OSD font and fringe font to output the OSD text (step 86). If no OSD text is to be output, only the video signal is output to the monitor (step 87).

That is, the fourth multiplexer 882 inputs a fringe font and an OSD font, and selectively outputs a fringe font or an OSD font in response to the OSD font setting signal OSDC. The fourth multiplexer 884 inputs the output of the second multiplexer 882 and an image signal, and selectively outputs the input signal in response to the OSD section setting signal OSDP. If the OSD font setting signal OSDC is 1, the OSD font is output through the output terminal OUT. Also, when the OSD section setting signal (OSDP) and the OSD font setting signal (OSDC) are 1, the OSD font is output. When the OSD section setting signal (OSDP) is 1, the OSD font setting signal (OSDC) is 0, the fringe font is displayed. Is output. In addition, if both the OSD font setting signal OSDC and the OSD section setting signal OSDP are 0, an image signal is output.

As described above, the OSD device and method having the two-dimensional fringe detection function according to the present invention has an advantage that the size of the circuit can be considerably reduced because no line buffer is used.

Hereinafter, an OSD device and method having a color display function for each line according to the present invention will be described with reference to the accompanying drawings.

12 is a schematic block diagram illustrating an OSD device having a color display function for each line according to the present invention, wherein an address generator 900, a frame buffer 910, a character generator 920, and parallel / serial conversion are shown. The unit 930 includes a line color selection unit 940, a fringe detector 950, and a signal mixer 960. Here, the line-by-line color selector 940 includes a foreground (Fg) lookup table register 942, a background (Bg) lookup table register 944, a row counter 948, and a first multiplexer 946. The signal mixer 960 includes a second multiplexer 962 and a third multiplexer 964.

The address generator 900 shown in FIG. 12 inputs the counting value of the X coordinate for displaying the OSD character through the input terminal IN1 and the counting value of the Y coordinate for displaying the OSD character through the input terminal IN2. do. Accordingly, the address generator 900 generates an address of the frame buffer 910 corresponding to the counting value of the input X coordinate and the Y coordinate. The frame buffer 910 is generally implemented as a RAM and is a memory for storing image signals in units of frames. The frame buffer 910 generates a CC code and an AT code at a location corresponding to an address designated by the address generator 900. In addition, the CC code output from the frame buffer 910 is output to the character generator 920 and the blink controller (not shown).

Herein, the character generator 920 outputs N-bit font data output from the frame buffer 910, that is, a parallel CC code representing a character to be displayed, to the parallel / serial converter 930. The parallel / serial converter 930 converts the input parallel data into serial to generate a bitmap. The serially converted bitmap is input to the fringe detector 950 to generate an OSD font setting signal OSDC and an OSD section setting signal OSDP, respectively.

In addition, the line color selection unit 940 shown in FIG. 12 is a block for selecting the line color of the OSD text, and the row counter 948 corresponds to one OSD text line using the horizontal synchronization signal HS. The counted strings are counted and the counted result is input as the selection signal of the third multiplexer 946. The foreground and background lookup table registers 942 and 944 preset and store the color Bg of the fringe font to be displayed for each OSD character line and the color Fg of the OSD font. That is, the lookup table registers 942 and 944 are registers set by tabulating the background color and the foreground color of each OSD character, and the output is applied to the input of the third multiplexer 946. Further, the background lookup table register 944 is a register set by tabulating the color of the fringe font of each OSD character, and its output is applied to another input of the first multiplexer 946. The first multiplexer 946 selectively outputs a preset line-by-line foreground color or background color in response to the low counting value output from the row counter 948. The second multiplexer 962 of the signal mixer 960 outputs the selected background color or foreground color to the third multiplexer 964 in response to the OSD font setting signal OSDC output from the fringe detector 950. In addition, the third multiplexer 964 selectively outputs the output of the video signal or the second multiplexer 962 through the output terminal OUT in response to the OSD section setting signal OSDP.

Hereinafter, the operation and method of the OSD device having the line-by-line color display function according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 13 is a flowchart illustrating a color display method performed in the line-by-line color display device of the OSD shown in FIG. 12, in which an OSD string of one line is counted (step 91); If it has elapsed, select the preset foreground and background colors from the lookup table (steps 92-93), determine whether to output the OSD text, and display the OSD text with the selected Fg and Bg colors to output the OSD text. And outputting a video signal (steps 94 to 96) in order not to output the OSD text.

First, when OSD character information corresponding to a predetermined address generated by the address generator 900 is output from the frame buffer 910 by X and Y counting values of the screen, the character generator 920 inputs the input CC code. An OSD character corresponding to the first and second OSD characters is generated to be serially converted by the parallel / serial converter 930 to form a bitmap. At this time, the row counter 948 counts an OSD string of one line using the horizontal synchronization signal HS (step 91), and the counted result is applied as a selection signal of the first multiplexer 948. The first multiplexer 946 selects a preset Fg and Bg color for each line in response to the applied selection signal. As illustrated in FIG. 12, a plurality of preset colors are stored in the Fg lookup table register 942 and the Bg lookup table register 944 for each line.

That is, the background color and the foreground color of each OSD character line stored in the background lookup table register 942 and the foreground lookup table register 944 are output to the multiplexer 946. Here, the background color represents the fringe color when the OSD text is displayed, and the foreground color represents the color of the OSD font. Accordingly, the row counter 948 determines whether one line has elapsed according to the counted value (step 92). Here, if one line has passed, the low counter 948 applies the counted value as the select signal of the first multiplexer 946. Accordingly, the preset Bg color and the Fg color corresponding to one line of the OSD character to be output from the Fg and Bg lookup table registers 942 and 944 are selected and output to the signal mixer 960 (step 93). That is, when the bitmap converted from the parallel / serial converter 930 to the serial is 1 as the OSD font setting signal (OSDC) generated by the fringe detector 950, the bitmap of the OSD character, that is, the OSD font, is output. If the OSD font setting signal OSDC is 0, a fringe or video signal is output.

The bitmap of the OSD characters output from the second multiplexer 962 of the signal mixer 960 is input to the third multiplexer 964 which is the final output block. Therefore, an image signal or an OSD character is selectively output in response to the OSD section setting signal OSDP. That is, it is determined whether to display the OSD text on the monitor (step 94), and if the OSD text is to be output, the OSD font having the selected Fg color or the fringe font having the Bg color is selected through the output terminal OUT ( Step 95). On the other hand, if the OSD character is not to be output, the video signal is output through the output terminal OUT (step 96). As described above, when the OSD region setting signal OSDP is 1, a fringe font or a selected OSD character is output, and when the OSD region setting signal OSDP is 0, an image signal is output.

That is, if the OSD character lines are designated with different colors by using the look-up table described above, the size of the frame buffer 910 may be reduced in half since there is no need to store AT codes in the frame buffer as in the prior art.

According to the present invention, by adding a multiplexer and a parallel / serial conversion unit, it is possible to implement an OSD device that executes a two-dimensional fringe function with excellent discrimination without increasing the size of the circuit. In addition, since the size of the frame buffer can be reduced by half and the color of each line can be displayed, the size of the entire OSD circuit can be reduced, which is particularly suitable for the embedded OSD design.

1A to 1D are diagrams for describing various functions of an on-screen display (OSD).

2 (a) to 2 (c) are diagrams for explaining the fringe function of the OSD.

3 is a schematic block diagram illustrating a general OSD device.

4 is a schematic block diagram illustrating a conventional OSD device having a one-dimensional fringe detection function.

5 is a schematic block diagram illustrating a conventional OSD device having a two-dimensional fringe detection function.

6 is a schematic block diagram illustrating a conventional OSD device having a line / character color display function.

FIG. 7 is a view for explaining an AT (Attribute) code and a CC (Character) code output from the frame buffer of the conventional OSD device shown in FIG.

8 is a block diagram of a preferred embodiment for explaining an OSD device having a two-dimensional fringe detection function according to the present invention.

9A to 9C are diagrams for describing font data of a character generator of an OSD device having a two-dimensional fringe detection function shown in FIG. 8 shown in FIG.

10 (a) to 10 (d) are diagrams for explaining the output signal for each section of the OSD device having the two-dimensional fringe detection function shown in FIG.

FIG. 11 is a flowchart for explaining an OSD method performed in an OSD device having a two-dimensional fringe detection function shown in FIG. 8.

12 is a block diagram of a preferred embodiment for explaining an OSD device having a line-by-line color display function according to the present invention.

FIG. 13 is a flowchart for describing an OSD method performed in an OSD device having a line-by-line color display function illustrated in FIG. 11.

Claims (9)

First character generating means for storing two lines of font data corresponding to a predetermined address and outputting two lines of font data corresponding to a specified address; Second character generating means for storing two lines of font data sequentially connected to said two lines of font data stored in said first character generating means, and outputting two lines of font data corresponding to a specified address; A first address multiplexer for selectively outputting a predetermined address of said first character generating means or an address higher than said address in response to a first address selection signal; A second address multiplexer for selectively outputting a predetermined address of said second character generating means or an address lower than said address in response to a second address selection signal; A data multiplexer for inputting four lines of data output from the first and second character generating means and outputting font data of three of the four lines in response to a third address selection signal; Parallel / serial conversion means for converting font data of three lines output from said data multiplexer into serial data, respectively; And Fringe detection means for inputting the serial data to generate an on-screen display font setting signal and an on-screen display interval setting signal; And And a signal mixing means for selectively outputting an on-screen display character and an image signal in response to the on-screen display font setting signal and the on-screen display interval setting signal. . The method of claim 1, wherein the data multiplexer consists of three multiplexers, The multiplexers respectively input four lines of data combining the two lines of font data outputted from the first character generating means and the second character generating means, and each one line in response to the third address selection signal. An on-screen display device having a two-dimensional fringe detection function characterized by outputting font data. The method of claim 2, wherein the fringe detection means, Flip-flops for inputting three lines of serial data output from the parallel / serial conversion means, respectively, connected in series with each other and outputting the input data according to a predetermined clock signal; And And OR for outputting the output of the flip-flop and outputting the OR result as an on-screen display section setting signal. 2. The method of claim 3, wherein the signal mixing means, A first multiplexer for selectively outputting a fringe font or an on-screen display font in response to the on-screen display font setting signal; And a second multiplexer for selectively outputting an output of the first multiplexer and an image signal in response to the on-screen display interval setting signal. 2. (A) constructing data to output two lines of font data from each of the separated character generating means; (B) determining whether an on-screen display font line to be output has been selected; If the on-screen display font line is selected, (c) outputting font data of the on-screen display font line and a line before and after the line; (D) generating an on-screen display font setting signal and an on-screen display interval setting signal by combining the font data of each line; Determining whether to output the on-screen display character, selectively outputting the on-screen display font and fringe font when outputting the on-screen display character, and outputting an image signal if not to output the on-screen display character An on-screen display method having a two-dimensional fringe detection function comprising the step (e). The method of claim 5, wherein step (e) (E-1) determining whether the on-screen display interval setting signal has a first level and the on-screen display font setting signal has a second level; (E-2) outputting the fringe font when the on-screen display interval setting signal has a first level and the on-screen display font setting signal has a second level; (E-3) outputting an on-screen display font when the on-screen display interval setting signal and the on-screen display font setting signal have the first level; And And (e-3) outputting an image signal when the on-screen display section setting signal and the on-screen font setting signal have a second level. 2. A frame buffer for storing a character code of an on screen display character corresponding to a predetermined address; Character generation means for generating parallel data corresponding to a character code output from the frame buffer; Parallel / serial conversion means for converting the parallel data into serial data; Fringe detection means for inputting and serially combining the serial data and generating an on-screen display font setting signal or an on-screen display interval setting signal based on the logical combined result; Line-by-line color selection means for selecting one or more lines of the on-screen display characters in different colors for each line; And And a signal mixing means for selectively outputting an on-screen display character or an image signal having the selected color in response to the on-screen display font setting signal or the on-screen display interval setting signal. On-screen display device having a. The method of claim 7, wherein the color selection means for each line, A low counter that counts the on-screen display string to be displayed on one line and outputs the counted result as a first selection signal; A foreground lookup table register that stores a foreground color of the on-screen display character line; A background lookup table register that stores a background color of the on-screen display character line; And And a multiplexer for selectively outputting foreground and background colors of the on-screen display character in response to a counted value of the low counter. Counting a line of on-screen display string (a); (B) determining whether the one line has passed; (C) selecting a foreground and background color of a predetermined on-screen display character from the lookup table if the one line has passed; Determining (d) whether to output the on-screen display text; Selecting the on-screen display font having the foreground color or the fringe font having the background color to output the on-screen display character in the step (d); And And (e) outputting an image signal in order not to output the on-screen display character in the step (d).

Images