US5774110A — Filter RAMDAC with hardware 11/2-D zoom function

Claim 1

Independent Claim 160 words

A RAMDAC for converting graphics data into analog display signals, comprising: a color look-up table for converting incoming image data into corresponding color image data; a line buffer for storing original image data and for generating a zoomed line of image data; means for switching between color data from the color look-up table corresponding to image data that is not within a zoom area and zoomed line data from the line buffer corresponding to image data within a zoom area; a plurality of digital to analog converters for converting the color data or zoomed line data to analog video signals; and zoom control means for enlarging a portion of image data by generating a write and read address and signals for controlling the line buffer and switching means wherein, the zoom control means selectively enables the line buffer to store original image data and to read out original image data from said line buffer to create an enlarged display image.

Claim 2

Dependent Claim 160 words

A RAMDAC for converting graphics data into analog display signals, comprising: a color look-up table for converting incoming image data into corresponding color image data; a line buffer for storing original image data and for generating a zoomed line of image data; means for switching between color data from the color look-up table corresponding to image data that is not within a zoom area and zoomed line data from the line buffer corresponding to image data within a zoom area; a plurality of digital to analog converters for converting the color data or zoomed line data to analog video signals; and zoom control means for enlarging a portion of image data by generating a write and read address and signals for controlling the line buffer and switching means wherein, the zoom control means selectively enables the line buffer to store original image data and to read out original image data from said line buffer to create an enlarged display image.

Claim 3

Dependent Claim 91 words

A RAMDAC according to claim 1 wherein the zoom control means further comprises: zoom detector means for monitoring horizontal and vertical blank signals to determine if a current position of a raster scan is within a zoom area or a zoom exclusion area and generating a zoom now signal; means for interrupting a zoom now signal when the raster scan is within a zoom exclusion area; and means for enabling the selection means to read and output the zoomed data in the line buffer in response to the zoom now signal.

Claim 4

Dependent Claim 54 words

A RAMDAC according to claim 2 wherein the zoom detector means further comprises a set of counters and comparator to determine when a raster is above, to the left of, and within a zoom area and wherein the zoom detector has stored constants which indicate the start and end coordinates of the zoom area.

Claim 5

Dependent Claim 20 words

A RAMDAC according to claim 2 wherein said zoom exclusion areas are temporary screen items including cursors and pull-down menus.

Claim 6

Dependent Claim 38 words

A RAMDAC according to claim 3 wherein the zoom detector means generates a left-of-zoom-area signal in response to a horizontal blank signal and an above-zoom-area signal in response to a vertical blank signal to provide zoom control initialization.

Claim 7

Dependent Claim 80 words

A RAMDAC according to claim 2 wherein the zoom control means further comprises: a vertical unit for determining when a line of original image data is input into the RAMDAC, and for enabling the line buffer to store the line of original image data; and a horizontal unit for identifying original image data in the image data stored in the line buffer, and for horizontally enlarging the original image data and outputting the enlarged image data to the line buffer.

Claim 8

Dependent Claim 37 words

A RAMDAC according to claim 6 wherein the vertical unit includes a Y-step register, a current Y-position fraction register and an adder; and the horizontal unit includes an X-step register, a current X-position fraction register and adder.

Claim 9

Dependent Claim 41 words

A RAMDAC according to claim 1 further comprising: a bypass means for bypassing the color look-up table when the images are stored in a color format; and a second selection means for alternatively enabling the color look-up table or by-pass means.

Claim 10

Dependent Claim 120 words

A graphics controller for converting data into analog display signals comprising: a line buffer for storing image refresh data and for generating a zoomed line of image data; means for switching between image refresh data that is not within a zoom area and zoomed line data from the line buffer corresponding to original image refresh data within a zoom area; and zoom control means for enlarging a portion of the image refresh data by generating a write and read address and signals for controlling the line buffer and switching means wherein, the zoom control means selectively enables the line buffer to store original refresh image data and to read out the line buffer contents to create an enlarged display image.

Claim 11

Dependent Claim 120 words

A graphics controller for converting data into analog display signals comprising: a line buffer for storing image refresh data and for generating a zoomed line of image data; means for switching between image refresh data that is not within a zoom area and zoomed line data from the line buffer corresponding to original image refresh data within a zoom area; and zoom control means for enlarging a portion of the image refresh data by generating a write and read address and signals for controlling the line buffer and switching means wherein, the zoom control means selectively enables the line buffer to store original refresh image data and to read out the line buffer contents to create an enlarged display image.

Claim 12

Dependent Claim 92 words

A graphics controller according to claim 9 wherein the zoom control means further comprises: zoom detector means for monitoring horizontal and vertical blank signals to determine if a current position of a raster scan is within a zoom area or a zoom exclusion area and generating a zoom now signal; means for interrupting a zoom now signal when the raster scan is within a zoom exclusion area; and means for enabling the selection means to read and output the zoomed data in the line buffer in response to the zoom now signal.

Claim 13

Dependent Claim 55 words

A graphics controller according to claim 10 wherein the zoom detector means further comprises a set of counters and comparator to determine when a raster is above, to the left of, and within a zoom area and wherein the zoom detector has stored constants which indicate the start and end coordinates of the zoom area.

Claim 14

Dependent Claim 21 words

A graphics controller according to claim 10 wherein said zoom exclusion areas are temporary screen items including cursors and pull-down menus.

Claim 15

Dependent Claim 39 words

A graphics controller according to claim 11 wherein the zoom detector means generates a left-of-zoom-area signal in response to a horizontal blank signal and an above-zoom-area signal in response to a vertical blank signal to provide zoom control initialization.

Claim 16

Dependent Claim 83 words

A graphics controller according to claim 10 wherein the zoom control means further comprises: a vertical unit for determining when a line of original image refresh data is input into the controller, and for enabling the line buffer to store the line of original image data; and a horizontal unit for identifying original image refresh data in the image data stored in the line buffer, and for horizontally enlarging the original image data and outputting the enlarged image data to the line buffer.

Claim 17

Dependent Claim 38 words

A graphics controller according to claim 14 wherein the vertical unit includes a Y-step register, a current Y-position fraction register and an adder; and the horizontal unit includes an X-step register, a current X-position fraction register and adder.

Claim 18

Independent Claim 155 words

A method of enlarging still pictures and full motion video in a display comprising the steps of: A. selecting a zoom area within an image area wherein the zoom area includes original pixels to be enlarged; B. storing the original pixels in locations spaced apart by zooming constants as scan lines in an intermediate frame buffer, the remainder of the scan lines containing insignificant pixels that will be overwritten in a zoomed image; C. determining if a scan line in the intermediate frame buffer contains the original pixels to be enlarged; D. reading the scan line into a single line buffer only if the scan line contains original pixels creating a zoomed line to be displayed; E. writing from the line buffer the zoomed line and displaying it; F. reading the next scan line from the intermediate frame buffer; and G. repeating steps C, D, E, F, for all scan lines in the intermediate buffer.

Claim 19

Independent Claim 155 words

A method of enlarging still pictures and full motion video in a display comprising the steps of: A. selecting a zoom area within an image area wherein the zoom area includes original pixels to be enlarged; B. storing the original pixels in locations spaced apart by zooming constants as scan lines in an intermediate frame buffer, the remainder of the scan lines containing insignificant pixels that will be overwritten in a zoomed image; C. determining if a scan line in the intermediate frame buffer contains the original pixels to be enlarged; D. reading the scan line into a single line buffer only if the scan line contains original pixels creating a zoomed line to be displayed; E. writing from the line buffer the zoomed line and displaying it; F. reading the next scan line from the intermediate frame buffer; and G. repeating steps C, D, E, F, for all scan lines in the intermediate buffer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-06-29	2001-12-29	2002-06-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-06-29	2005-12-29	2006-06-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-06-29	2009-12-29	2010-06-30	$7700.00	Window Closed / Lapsed

Filter RAMDAC with hardware 11/2-D zoom function

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