US 2004/0165114 A1 · On-screen display device

Abstract

This invention provides an on-screen display device that can display an increased number of types of characters without enlarging the video RAM area. This on-screen display device includes a character generator ROM that has n (n is an integer that is equal to or larger than 3) areas, a flag holding unit that outputs an area designation flag for designating a desired number of desired areas among the n areas in the character generator ROM, a display character setting unit that writes a desired character code at a predetermined position in a video RAM, and a display control unit that reads the character code from the video RAM, reads font data corresponding to the read character code from an area in the character generator ROM, which is indicated by the area designation flag outputted from the flag holding unit, and outputs an on-screen output signal using the font data.

Claims6

Dependent claims

An on-screen display device that provides an on-screen display of a display character, including;

a character generator ROM having n pieces of areas from 1st to n-th areas (n is an integer that is equal to or larger than 3), and storing predetermined font data in the respective areas;
a flag holding unit for outputting an area designation flag that designates a desired number of areas among the n pieces of areas in the character generator ROM;
a display character setting unit for writing a desired character code at a predetermined position in a video RAM;
and
a display control unit for reading the character code from the video RAM, reading font data corresponding to the character code from an area designated by the area designation flag in the character generator ROM, and outputting an on-screen output signal using the font data at a predetermined timing with respect to an input video signal.

2 more elements

An on-screen display device that provides an on-screen display of a display character, including:

a character;
generator ROM having n pieces of areas from 1st to n-th areas (n is an integer that is equal to or larger than 3), and storing predetermined font data in the respective areas;
a flag holding unit for outputting an area designation flag that designates any of the 2nd to n-th areas among the n pieces of areas in the character generator ROM;
a display character setting unit for writing a desired character code at a predetermined position in a video RAM;
and
a display control unit for reading the character code from the video RAM, and when the area designation flag outputted from the flag holding unit designates the second area, reading respective font data corresponding to the character code that has been read from the video RAM, from the first and second areas in the character generator ROM, while when the area designation flag outputted from the flag holding unit designates the third area, reading respective font data corresponding to the character code that has been read from the video RAM, from the first and third areas in the character generator ROM, and outputting an on-screen output signal using the read font data at a desired timing with respect to an input video signal.

3 more elements

Dependencies are inferred from the claim text.

On-screen display device

Life of this patent

On-screen display device

Life of this patent

Abstract

Claims6