System and method for storing and displaying font data representing fixed-width and compressed characters

• US 5,519,824 A
• Filed: 03/18/1994
• Issued: 05/21/1996
• Est. Priority Date: 03/18/1994
• Status: Expired due to Fees

• Current Assignee: Timex Corporation (Tanager Group BV)
• Original Assignee: Timex Corporation (Tanager Group BV)
• Inventors: Lizzi, Ronald S.
• Primary Examiner(s): Herndon, Heather R.
• Assistant Examiner(s): Feild, Joseph H.
• Application Number:
  US08/214,504
• Time in Patent Office: 795 Days
• Field of Search: 395/110, 395/150, 395/151, 345/26-28, 345/33-39, 345/55, 345/127-130, 345/141, 345/143, 345/189-195, 345/202, 345/200, 368/29-30, 368/69-73, 368/82-84, 368/223, 368/241-242
• US Class Current: 345/170
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 2215/0028 characterised by the format per se
• CPC Class Codes: G09G 5/20 Function-generator circuits, e.g. circle generators line or curve smoothing circuits

Abstract

A system and method for storing and retrieving fixed-width and compressed characters of at least one font, which includes memory having a plurality of memory addresses for storing instructions and encoded character font data representing fixed-width and compressed characters, wherein the encoded character font data for a fixed-width character of any given font is identical to the encoded character font data for a compressed character for the same font. The system addresses the plurality of memory addresses so as to read out the encoded character font data and then, depending upon the value of a control signal generated by the system'"'"'s control unit, decodes the encoded character font data through a decoder as either a fixed-width or compressed character. The fixed-width or compressed character is then displayed on a dot-matrix display. Each memory address commonly contains a plurality of bits which represents a column of said character. A first subset of the bits may then be set or not set in accordance with the particular shape and form of that particular columnar portion of the character. A second subset of bits are then set or not set to indicate which column(s) may be ignored for generation of the compressed characters. The instant invention thus achieves both storage simplicity and display efficiency, by providing a system which can store character font data for both the fixed-width and compressed characters of any given font using the same memory addresses, but which can display those characters of that font using only the minimum amount of columns necessary to accurately represent same.

Claims

1. A system for storing, retrieving and displaying a character, where the character is to be displayed in either a compressed character display format or a fixed-width character display format, which comprises:

memory means for storing the character as an encoded font data, the encoded font data comprising a plurality of bytes;

each byte of the encoded font data comprising a first set and a second set where each set comprises at least one bit, the collective first sets for the plurality of bytes representing both a fixed-width character and a compressed character, and the second set indicating whether the corresponding first set of the byte should be displayed when the system is in the compressed character display format; and

means responsive to a control signal for causing the character to be displayed on a display, a first value for the control signal causing the character to be displayed in the fixed-width character display format and a second value for the control signal causing the character to be displayed in the compressed character display format.

2. The system according to claim 1, wherein the display is a dot matrix display.

3. The system according to claim 1, wherein the means responsive to the control signal includes decoding means for decoding the encoded font data.

4. The system according to claim 1, which further comprises actuating means coupled to the means responsive to the control signal, the actuating means generating the control signal.

5. A system for storing, retrieving and displaying a character, where the character is to be displayed in either a compressed character display format or a fixed-width character display format, which comprises:

memory means for storing the character as an encoded font data, the encoded font data comprising a plurality of bytes;

each byte of the encoded font data comprising a first and a second set of bits, the collective first sets for the plurality of bytes representing both a fixed-width character and a compressed character, and the second set serving as a flag to indicate whether the corresponding first set of the byte should be displayed when the system is in the compressed character display format;

a display;

an actuator generating a control signal having a first and a second value; and

means responsive to the control signal for causing the character to be displayed on the display, the first value for the control signal causing all the first sets for the plurality of bytes to be displayed, and the second value for the control signal causing each first set of the byte having the second set indicating that the first set should be displayed when the system is in the compressed character display format to be displayed.

6. The system according to claim 5, wherein the display is a dot matrix display.

7. The system according to claim 5, wherein the means responsive to the control signal includes decoding means for decoding the encoded font data.

8. The system according to claim 5, wherein the system is contained within a digital timepiece.

9. The system according to claim 8, wherein the actuator is a push button.

10. A method for storing, retrieving and displaying a character in a system, where the character is to be displayed in either a compressed character display format or a fixed-width character display format, comprising the steps of:

storing the character in memory as an encoded font data, the encoded font data comprising a plurality of bytes;

formatting each byte of the encoded font data to comprise a first set and a second set where each set comprises at least one bit, the collective first sets for the plurality of bytes representing both a fixed-width character and a compressed character, and the second set indicating whether the corresponding first set of the byte should be displayed when the system is in the compressed character display format; and

providing to the system a control signal having a first and a second value, the first value causing all the first sets for the plurality of bytes to be displayed on a display and the second value causing each first set of the byte having the second set indicating that the first set should be displayed when the system is in the compressed character display format to be displayed on the display.