Display apparatus

Claim 2

A display apparatus for displaying character information in various modes, comprising: a display device having a two-dimensional screen for displaying the character information; character data generating means for generating character data corresponding to the character informa­tion to be displayed; display mode judging means for judging a display mode to display the character information on the screen; operating means for operating a display start address for each display mode on the basis of a reference position on the screen; control means for controlling said character data generating means to operate a character font of a size necessary to each display mode; and display service drive means for causing the character information to be displayed in a selected mode on the screen in response to the character data generated by said character data generating means and the display start address operated by the operating means.

Claim 3

A display apparatus as claimed in Claim 1, wherein said reference position on the screen is a cursor position.

Claim 4

A display apparatus as claimed in Claim 1, wherein the various display modes involve changes in number of lines and character size without changing a relative cursor position.

Claim 5

A display apparatus as claimed in Claim 1, wherein said character data generating means stores different size character fonts and gnerates a character font designated by a font select command from said control means.

Claim 6

A display apparatus as claimed in Claim 1, wherein said character data generating means has an external memory, said control means being operable to cause a high speed transfer of font bit data from said external memory to an internal memory, whereby the character data stored in said internal memory are rewritten for a selected character size.

Claim 7

A display apparatus for displaying character information in various modes, comprising: a display device having a two-dimensional screen for displaying the character information; character data generating means for generating character data corresponding to the character informa­tion to be displayed; display mode judging means for judging a display mode for displaying the character information on the screen; operating means for operating a display start address for each display mode on the basis of a relative position of a cursor on the screen; control means for controlling said character data generating means to generate a a character font of a size necessary to each display mode; and display device drive means for causing the chara­cter information to be displayed in a selected mode on the screen in response to the character data generated by said character data generating means and the display start address operated by the operating means.

Claim 8

A display apparatus for displaying character information in various modes, comprising: a display device having a two-dimensional screen for displaying the character information; character data generating means for generating character data corresponding to the character informa­tion to be displayed; display mode judging means for judging a display mode for displaying the character information on the screen; operating means for operating a display start address for each display mode on the basis of a relative position of a cursor on the screen; control means for controlling said character data generating means to generate a a character font of a size necessary to each display mode; and display device drive means for causing the chara­cter information to be displayed in a selected mode on the screen in response to the character data generated by said character data generating means and the display start address operated by the operating means.

Claim 9

A display apparatus as claimed in Claim 6, wherein said character data generating means stores different size character fonts and generates a character font designated by a font select command from said control means.

Claim 10

A display apparatus as claimed in claim 6, wherein said character data generating means has an external memory, said control means being operable to cause a high speed transfer of font bit data from said external memory to an internal memory, whereby the character data stored in said internal memory are rewritten for a selected character size.

Claim 11

A display apparatus for displaying character information in various modes, comprising: a display device having a two-dimensional expanse for displaying the character information; a video memory for generating character code data; character data generating means for generating selected character data in response to the character code data; parallel to serial conversion means for convert­ing the character data into serial data for input to said display device; a display sequencer for providing controls to determine a character to be displayed on the display device and to determine a position on the display device at which the character is displayed; a CPU for calculating a display start address for each display mode on the basis of a cursor position, rewriting a display start address in said display sequencer, and transmitting a character font size designating signal to said character data generating means; and a display device drive means for causing the character information to be displayed in response to a synchronizing signal received from said display sequencer and a serial signal received from said parallel to serial conversion means.

Claim 12

A display apparatus for displaying character information in various modes, comprising: a display device having a two-dimensional expanse for displaying the character information; a video memory for generating character code data; character data generating means for generating selected character data in response to the character code data; parallel to serial conversion means for convert­ing the character data into serial data for input to said display device; a display sequencer for providing controls to determine a character to be displayed on the display device and to determine a position on the display device at which the character is displayed; a CPU for calculating a display start address for each display mode on the basis of a cursor position, rewriting a display start address in said display sequencer, and transmitting a character font size designating signal to said character data generating means; and a display device drive means for causing the character information to be displayed in response to a synchronizing signal received from said display sequencer and a serial signal received from said parallel to serial conversion means.

Claim 13

A display apparatus as claimed in Claim 9, wherein the various display modes involve changes in number of lines and character size without changing a relative cursor position.

Claim 14

A display apparatus as claimed in Claim 9, wherein said character data generating means stores different size character fonts and generates a charac­ter font designated by a font select command from said CPU.

Claim 15

A display apparatus as claimed in Claim 9, wherein said character data generating means has an external memory, said CPU being operable to cause a high speed transfer of font bit data from said external memory to an internal memory, whereby the character data stored in said internal memory are rewritten for a selected character size.

Claim 16

A display apparatus as claimed in Claim 9, wherein said display sequencer includes a register for receiving the display start address from said CPU, said register outputting an address signal to said video memory.

Claim 17

A display apparatus as claimed in Claim 9, wherein said display sequencer includes a one charac­ter register storing a number of scan lines necessary for displaying one character, and a number of lines register storing a number of lines to be displayed.