US4593372A
Expired / Lapsed
US
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Line generating method
Assignee: Toshiba Corp
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Filing: 1983-11-23
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Granted: 1986-06-03
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Expires: 2003-11-23
Abstract
Abstract A start point (x' 0 ,y' 0 ) and an end point (x' m ,y' m ) of a sub-line are obtained from a start point (x 0 ,y 0 ) and an end point (x m ,y m ) of a main line, and coordinate data of the start point (x' 0 ,y' 0 ) and the end point (x' m ,y' m ) are supplied to a DDA, so that a point array of the sub-line can be generated from the DDA. The main line is shifted along the x- or y-axis by one dot to obtain the sub-line. Intensity information from an intensity modulation circuit is noninverted/inverted in accordance with the main line/sub-line mode so as to provide a complementary relationship between the main line and the sub-line. A vector direction from the start point (x 0 ,y 0 ) to the end point (x m ,y m ) is detected to belong to one of the four areas obtained by dividing the x-y coordinate plane by lines y=x and y=-x when the start point (x 0 ,y 0 ) is defined as the origin of the coordinate system. In accordance with this detection, the start point (x 0 ,y 0 ) and the end point (x m ,y m ) are shifted by one (+1 or -1) along the x- or y-axis. These shifted points are used as the start point and the end point for interpolation and are supplied to the DDA. The DDA generates the sub-line obtained by shifting the main line by one dot in the upper direction (positive direction along the y-axis), the lower direction (negative direction along the y-axis), the left direction (negative direction along the x-axis), or the right direction (positive direction along the x-axis).
Inventors
- 👤 Yoshiaki Bandai
- 👤 Khoki Hasebe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:48
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
248 words
A line generator comprising: (a) a digital differential analyzer (DDA) generating coordinate data of an interpolated point in accordance with given start and end points and absolute difference data between an actual value and the coordinate data of an interpolated point; (b) an intensity modulation circuit for generating digital intensity information corresponding to the absolute difference data; (c) an inversion control circuit for noninverting/inverting a level of an output from said intensity modulation circuit in accordance with a main line/sub-line designating signal; and (d) a microprocessor for supplying coordinate data of the start point (x O ,y O ) and the end point (x m ,y m ) to said digital differential analyzer, to supply to said inversion control circuit a main line/sub-line designating signal indicating said main line, for determining that a vector direction from the start point (x O ,y O ) to the end point (x m ,y m ) belongs to one of four areas divided by lines y=x and y=-x when the start point (x O ,y O ) is defined as an origin of an x-y coordinate system, and for supplying to said digital differential analyzer coordinate data of a start point (x O ',y O ') and an end point (x m ',y m ') which are obtained by moving x or y coordinates of the start point (x O ,y O ) and the end point (x m ,y m ), respectively, by one in accordance with the vector determination.
Claim 2
Dependent Claim
248 words
A line generator comprising: (a) a digital differential analyzer (DDA) generating coordinate data of an interpolated point in accordance with given start and end points and absolute difference data between an actual value and the coordinate data of an interpolated point; (b) an intensity modulation circuit for generating digital intensity information corresponding to the absolute difference data; (c) an inversion control circuit for noninverting/inverting a level of an output from said intensity modulation circuit in accordance with a main line/sub-line designating signal; and (d) a microprocessor for supplying coordinate data of the start point (x O ,y O ) and the end point (x m ,y m ) to said digital differential analyzer, to supply to said inversion control circuit a main line/sub-line designating signal indicating said main line, for determining that a vector direction from the start point (x O ,y O ) to the end point (x m ,y m ) belongs to one of four areas divided by lines y=x and y=-x when the start point (x O ,y O ) is defined as an origin of an x-y coordinate system, and for supplying to said digital differential analyzer coordinate data of a start point (x O ',y O ') and an end point (x m ',y m ') which are obtained by moving x or y coordinates of the start point (x O ,y O ) and the end point (x m ,y m ), respectively, by one in accordance with the vector determination.
Claim 3
Dependent Claim
221 words
A generator according to claim 1, wherein the sub-line can be obtained by increasing the y coordinates of the main line points by one each when the vector direction from the start point to the end point of the main line belongs to area A or H, the sub-line can be obtained by decreasing the y coordinates of the main line points by one each when the vector direction corresponds to the area D or E, the sub-line can be obtained by decreasing the x coordinates of the main line points by one each when the vector direction corresponds to the area B or C and the sub-line can be obtained by increasing the x coordinates of the main line points by one each when the vector direction corresponds the area F or G, wherein the areas A and H are defined as divided by the axis x and one of the lines y=x and y=-x, the areas B and C are defined as divided by the axis y and one of the lines y=x and y=-x, the areas D and E are defined as divided by the axis x and the one of the lines y=x and y=-x, and the areas F and G are defined as divided as the axis y and one of the lines y=x and y=-x.
Claim 4
Independent Claim
323 words
A method for generating a line from a line generator having a digital differential analyzer generating coordinate data of an interpolated point in accordance with given start and end points, an intensity modulation circuit for generating digital intensity information indicating an intensity level corresponding to a difference between an actual value and the coordinates of the interpolated point, and an inversion control circuit for noninverting/inverting a level of an output from said intensity modulation circuit in accordance with a main line/sub-line designating signal, comprising the steps of: (a) supplying coordinate data of the start point (x O ,y O ) and the end point (x m ,y m ) to said digital differential analyzer; (b) supplying to said inversion control circuit a main line/sub-line designating signal indicating a main line; (c) causing said inversion control circuit to generate digital intensity information corresponding to a point array of the main line; (d) determining that a vector direction from the start point (x O ,y O ) to the end point (x m ,y m ) belongs to one of four areas divided by lines y=x and y=-x when the start point (x O ,y O ) is defined as an origin of an x-y coordinate system; (e) supplying to said digital differential analyzer coordinate data of a start point (x O ',y O ') and an end point (x m ',y m ') which are obtained by incrementing or decrementing x or y coordinates of the start point (x O ,y O ) and the end point (x m ,y m ), respectively, by one in accordance with the vector determination, (f) supplying a main line/sub-line designating signal indicating a sub-line to said digital differential analyzer; (g) generating digital intensity information indicating a point array of the sub-line; and (h) generating the sub-line which is shifted by one to be parallel to the main line in one of upper, lower, right and left directions.
Claim 5
Independent Claim
323 words
A method for generating a line from a line generator having a digital differential analyzer generating coordinate data of an interpolated point in accordance with given start and end points, an intensity modulation circuit for generating digital intensity information indicating an intensity level corresponding to a difference between an actual value and the coordinates of the interpolated point, and an inversion control circuit for noninverting/inverting a level of an output from said intensity modulation circuit in accordance with a main line/sub-line designating signal, comprising the steps of: (a) supplying coordinate data of the start point (x O ,y O ) and the end point (x m ,y m ) to said digital differential analyzer; (b) supplying to said inversion control circuit a main line/sub-line designating signal indicating a main line; (c) causing said inversion control circuit to generate digital intensity information corresponding to a point array of the main line; (d) determining that a vector direction from the start point (x O ,y O ) to the end point (x m ,y m ) belongs to one of four areas divided by lines y=x and y=-x when the start point (x O ,y O ) is defined as an origin of an x-y coordinate system; (e) supplying to said digital differential analyzer coordinate data of a start point (x O ',y O ') and an end point (x m ',y m ') which are obtained by incrementing or decrementing x or y coordinates of the start point (x O ,y O ) and the end point (x m ,y m ), respectively, by one in accordance with the vector determination, (f) supplying a main line/sub-line designating signal indicating a sub-line to said digital differential analyzer; (g) generating digital intensity information indicating a point array of the sub-line; and (h) generating the sub-line which is shifted by one to be parallel to the main line in one of upper, lower, right and left directions.
References Cited (Backward Citations)
US4479192A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-02 | 1989-12-02 | 1990-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-02 | 1993-12-02 | 1994-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-02 | 1997-12-02 | 1998-06-03 | $7700.00 | Window Closed / Lapsed |