JPS63223690A - Oval acr lithography apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a graphic display device, and more particularly to an elliptical arc drawing device that can quickly and accurately determine the starting and ending positions of an elliptical arc and display the elliptical arc.

2. Description of the Related Art In recent years, among display devices having a graphic display function, display devices having a graphic drawing function have become popular. One of the basic functions of this device is the ability to draw circular arcs or elliptical arcs.

When drawing a circular arc or an elliptical arc using the above device, the radius (in the case of an ellipse, the radius in the major axis direction and the radius in the minor axis direction)
There are two possible methods: specifying the starting point position and ending point position and drawing, and drawing by finding the starting point position and ending point position from the radius, starting angle, and ending angle.

A first example of the conventional arc or elliptical arc drawing device described above will be described below with reference to the drawings.

FIG. 3 is a block diagram of a conventional elliptical arc drawing device, where l is a central processing unit (hereinafter abbreviated as CPU), and 2 is a drawing control unit which generates the coordinates of an elliptical arc and a write permission signal. 3 is a refresh memory that converts the coordinates of the elliptical arc generated by the drawing control unit 2 into a memory address and updates the contents of the corresponding memory under the control of a write permission signal. A video circuit 4 periodically reads out the refresh memory 3 and outputs a video signal, which is displayed on a display 5.

FIG. 4 is a first detailed diagram of the drawing control section 2 of the elliptic arc drawing device shown in FIG. 10 is an elliptical arc coordinate generation part;
IIX is an output line to which the X coordinate value generated by the elliptical coordinate generator 10 is output, and lly is an output line to which the Y coordinate value generated by the elliptic coordinate generator 10 is output. 12 is a register that holds the X coordinate value of the starting point of the elliptical arc, 13 is a register that holds the X coordinate value of the ending point of the elliptical arc, 14 is a register that holds the Y coordinate value of the starting point of the elliptical arc, and 15 is the ending point of the elliptical arc. This is a register that holds the Y coordinate value of the position.

A selector 16 selects the outputs of the registers 12 and 13, and a selector 17 selects the outputs of the registers 14 and 15. 18 is a coincidence detector that compares the coordinate values output by the elliptic coordinate generator 10 and the value output by the selector 16 and outputs a coincidence signal; 19 is an elliptic coordinate generator I;
This is a coincidence detector which compares the coordinate value outputted by O and the value outputted by selector 7 and outputs a coincidence signal.

20 is a start point/end point determination unit, 21 is a write permission signal, 22
is the start point/end point selection signal. In addition, output lines 11x, ll
y and the write permission signal 21 are connected to the refresh memory 3.

The operation of the elliptical arc drawing device configured as follows will be described below.

First, when the register 12.14 holds the X and Y coordinate values of the starting point of the elliptical arc and the register 13.15 holds the X and Y coordinate values of the ending point of the elliptical arc, the starting point and ending point determination unit The selectors 16 and 17 output the outputs of the registers 12 and 14 to the coincidence detectors 18 and 19, respectively, by setting the start and end point selection signals 22 outputted by the selectors 16 and 17 as the "start points".

The elliptic coordinate generating section 10 generates elliptic coordinates and outputs the elliptic coordinates to the coincidence detectors 18 and 19 and the refresh memory 3. However, the start/end point determination unit 20 sets the write permission signal 21 to "not writeable" until both the match detectors 18 and 19 output a match signal, making it impossible to update the memory contents in the refresh memory 3. Elliptical coordinate generator 1
0 sequentially generates elliptical coordinates, and when the coincidence detectors 18 and 19 both output coincidence signals, the start point and end point determination unit 20 determines that the start point is the start point, sets the write permission signal 21 to "writable", and stores the data in the refresh memory 3. On the other hand, the start/end point selection signal 2 allows the memory contents to be updated using the values of the output lines 11X and lly, and sets the start/end point selection signal 22 to the "end point".
2, selectors 16 and 17 respectively register 1
3.15 to the coincidence detector 18.19. Again, the write permission signal 21 holds "Writable" until both the coincidence detectors 18 and 19 output one-defeat signals, and during that time the ellipse coordinate generator 10 outputs the output lines 11X and 11y for the ellipse coordinates generated. An elliptical arc can be drawn by updating the memory contents of the refresh memory 3 using the values.

Next, a second example of a conventional circular arc or elliptical arc drawing device will be described with reference to the drawings. The configuration diagram of the conventional elliptical arc drawing device is the same as that shown in FIG. 3, but FIG. 5 is a second detailed diagram of the drawing control section 2 of the elliptic arc drawing device shown in FIG. Elliptical coordinate generator lO1 output line 11 in FIG.
x, 11y-defeat detector 18.19, start point end point judgment unit 20
, write permission signal 21, and start/end point selection signal 22 perform the same operations as those shown in FIG. 23 is a register that holds the radius, 24 is a register that holds the starting angle, 25 is a register that holds the ending angle, and 26 is a selector that selects the output of registers 24 and 25. 27 is a conversion table, in which the radius, which is the value of register 23, and register 24.
Using the value of 25 as the starting angle or ending angle passed through the selector 26, the X coordinate value and Y coordinate value of the starting angle or ending angle are output.

Regarding the elliptical arc drawing device configured as follows, the first
The operation will be explained by comparing the example and the second example.

In the first example, the starting point coordinates and ending point coordinates are directly set and output to the coincidence detectors 18 and 19, whereas in the second example, the radius, starting angle, ending angle is set, the start point coordinates and end point coordinates are derived using the conversion table 27, and output to the coincidence detectors 18 and 19. The same operation as in the example can also be realized in the second example. (For example, Japanese Unexamined Patent Publication No. 58-107588) Problems to be Solved by the Invention However, in the above configuration, in the first example, the coordinate values generated by the elliptical coordinate generation unit 10 and the set starting point or If the X and Y coordinate values of the end point coordinates do not match, the elliptical arc cannot be drawn correctly. The same can be said for the second example. Furthermore, the second example has a problem in that the larger the aspect ratio of the ellipse (the flatter it becomes), the larger the error becomes.

In view of the above problems, the present invention is an elliptical arc that draws an elliptical arc with less error even when the aspect ratio of the ellipse is large or when the generated ellipse coordinate values and the X and Y coordinate values of the starting point or end point do not coincide at the same time. The present invention provides a drawing device.

Means for Solving the Problems In order to solve the above-mentioned problems, the elliptical arc drawing device of the present invention includes an ellipse coordinate generation section that generates the coordinates of an ellipse using an ellipse approximation formula, and detects the starting point and end point of the ellipse arc. It has a start point/end point detection control section that performs drawing control, and a judgment area detection section that is connected to the ellipse coordinate generation section and specifies a judgment area to the start/end point detection control section. The difference between the directional radius and the vertical radius is compared with the difference between the absolute value of the horizontal coordinate and the absolute value of the vertical coordinate of the ellipse coordinates generated by the ellipse coordinate generator, and the start point/end point detection controller The start and end point detection control unit is configured to indicate a determination area, and includes a register that stores start point coordinates and end point coordinates of an elliptical arc, a selector that selects the start point coordinates and end point position coordinates, and an ellipse coordinate generator. A comparator that compares the ellipse coordinates generated by the section with the output of the selector, and a detection control section that is connected to the comparator and the determination area detection section and outputs a drawing control signal and a selection signal of the selector.

Effect of the Invention With the above-described configuration, when drawing an elliptical arc, especially when the aspect ratio of the ellipse becomes large, the present invention eliminates errors even if the coordinates of the start point and end point and the ellipse coordinates where the ellipse coordinate generation part does not completely match. By determining the start and end points with fewer errors, it is possible to draw elliptical arcs.

EXAMPLE Hereinafter, an elliptical arc drawing apparatus according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an elliptical arc drawing device according to an embodiment of the present invention. In FIG. 1, ■ is a CPU, 3 is a refresh memory, 4 is a video circuit, and 5 is a display device, which has the same functions as those in FIG. 4 used to explain the conventional example.
Reference numeral 6 denotes a determination area detection section, 7 a start point/end point detection control section, and 10 an elliptical coordinate generation section that sequentially generates elliptical coordinates clockwise, for example. FIG. 2 is a detailed explanatory diagram showing the relationship among the determination area detection section 6, start point/end point detection control section 7, and ellipse coordinate generation section 10 in FIG. 1. In FIG. 2, 11x is an output line to which the X coordinate value generated by the elliptic coordinate generator 10 is output, lly is an output line to which the Y coordinate value generated by the elliptic coordinate generator 10 is output, and 12 is an elliptical arc. 13 is a register that holds the X coordinate value of the end point of the elliptical arc. 14 is a register that holds the Y coordinate value of the starting point of the elliptical arc.
15 is a register that holds the Y coordinate value of the end point position of the elliptical arc; 16 is a selector that selects the outputs of registers 12 and 13; 17 is a selector that selects the outputs of registers 14 and 15; Reference numeral 22 denotes a start point/end point selection signal, which has the same function as the one shown in FIG. This is a register that holds the radius. 30 is an absolute value circuit that calculates the absolute value of the value of the output line 11x, and 31 is an absolute value circuit that calculates the absolute value of the value of the output line 11y.

32 is a subtracter that calculates the difference between the values of register 28 and register 29; 33 is a subtracter that calculates the difference between the values output by absolute value circuit 30 and absolute value circuit 31; and 34 is a subtracter that calculates the difference between the values of register 28 and register 29; This is a comparator that compares the magnitude of output values.

35 is a comparator that compares the value of output line 11x and the value of selector 16; 36 is a comparison between the value of output line 11y and selector 1;
This is a comparator that compares the magnitude of the value of 7. 37 is a detection control unit, 38 is a write permission signal, and the detection control unit 37
determines the drawing area from the magnitude comparison signals output by the comparators 34, 35, and 36, and outputs the start point/end point selection signal 22 and the write permission signal 38.

The operation of the ellipse drawing apparatus configured as described above will be described below with reference to FIGS. 1 and 2.

In FIG. 2, the X and Y coordinate values of the starting point of the elliptical arc are stored in register 12.14, the X and Y coordinate values of the ending point of the elliptical arc are stored in register 13.15, and register 28.2
When the value in the X-axis direction (referred to as RX) and the value in the Y-axis direction (referred to as RY) of the elliptical arc is held in 9, the start point/end point selection signal 22 output by the detection control unit 37 is set as the "start point". As a result, selectors 16 and 17 are connected to registers 12 and 14, respectively.
The outputs of are outputted to comparators 35 and 36. (Here, the value output by the selector 16 is PX, and the value output by the selector 17 is PY.) The elliptic coordinate generator 10 generates elliptic coordinates (
Let the X coordinate value be x and the X coordinate value be Y. ) and outputs the ellipse coordinates to the comparators 35 and 36, the absolute value circuits 30 and 31, and the refresh memory 3. Considering the signal input to the comparator 34, the signal from the subtracter 32 is R
X-RY17) value is IXI-IYI from the subtracter 33
The value is entered. Comparator 34 connects RX-RY and IXI
-IYI is compared in magnitude, and the result is output to the detection control unit 37 as a signal instructing the determination area.

The detection control unit 37 detects the comparator 3 when the points indicated by PX and PY are in the first quadrant.
The value output by 4 is RX-RY> l X l -IYI
When the following relationship is satisfied, the value output by the comparator 35 is PX≦
The value output by the comparator 34 is RX until it shows a relationship of
-RY≦lX1-IYI, comparator 3
Until the value output by 6 shows the relationship PY≦Y, ■ P
When the point indicated by until the value output by the comparator 34 is RX-RY
When the relationship ≧lX1-IYI is satisfied, ■ PX, P until the value output by the comparator 35 indicates the relationship PX≦X.
When the point indicated by Y is in the third quadrant, when the value output from the comparator 34 satisfies the relationship RX-RY>IXl-IYI, the value output from the comparator 35 indicates the relationship px≧X. Until the value output by the comparator 34 is RX-RY≦lX
When the relationship 1-IYI is satisfied, the value output from the comparator 34 is R until the value output from the comparator 36 shows the relationship PY≧Y.
When the relationship X-RY<lXl-IYI is satisfied, the value output from the comparator 34 is RX-RY
When the relationship YI is satisfied, the value output by the comparator 35 is p
Until the relationship xa; The i-circular coordinate generating section 10 sequentially generates elliptical coordinate generating sections (for example, clockwise), and the detection control section 3
7 determines that the X and Y generated by the elliptical coordinate generating unit IO at that time are the starting points when any of the above-mentioned conditions ■ to ■ are satisfied, sets the write permission signal 38 to "Writable", and writes the data to the refresh memory 3. On the other hand, the output line 11x.

The value of 11y is used to permit updating of the memory contents, and the start/end point selection signal 22 is set as the 'end point'.

Depending on the start point/end point selection signal 22, selectors 16 and 17 select the outputs of registers 13 and 15 from comparators 35 and 36, respectively.
Output to. Again, the write permission signal 21 maintains "writable" until the detection control unit 37 satisfies any of the above-mentioned conditions (■) to (■), and during that time, the output lines 11X, lly for the ellipse coordinates generated by the ellipse coordinate generation unit 10 By updating the memory contents of the refresh memory 3 using the value of , an elliptical arc can be drawn.

Effects of the Invention As described above, the present invention includes: an ellipse coordinate generation unit that generates the coordinates of an ellipse using an ellipse approximation formula; a start/end point detection control unit that detects the start point and end point of an elliptical arc and performs drawing control; a determination area detection unit connected to the coordinate generation unit and specifying a determination area to the start point/end point detection control unit, and the determination area detection unit detects the difference between the horizontal radius and the vertical radius of the ellipse, Compare the difference between the absolute value of the horizontal coordinate and the absolute value of the vertical coordinate of the elliptical coordinate generated by the coordinate generation part,
The start point/end point detection control section is configured to indicate a determination area I, and the start/end point detection control section includes a register storing the start point coordinates and end point coordinates of the elliptical arc, and a register storing the start point coordinates and end point position coordinates of the elliptical arc. a selector that selects the ellipse, a comparator that compares the ellipse coordinates generated by the ellipse coordinate generator with the output of the selector, and a detection control that is connected to the comparator and the judgment area detector and outputs a drawing control signal and a selector selection signal. When drawing an elliptical arc, especially when the aspect ratio of the elliptical arc becomes large, errors may occur even if the coordinates of the start point or end point and the ellipse coordinates generated by the ellipse coordinate generation part do not completely match. An object of the present invention is to provide an excellent elliptical arc drawing device that can draw an elliptical arc by making fewer start and end point determinations.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an elliptical coordinate generation section in an embodiment of the present invention, and FIG. 2 is a detailed explanation showing the relationship among the determination area detection section, start point/end point detection control section, and ellipse coordinate generation section in FIG. 1. figure,
Figure 3 is a configuration diagram of a conventional elliptical arc drawing device, and Figure 4 is a diagram of a conventional elliptical arc drawing device.
A first detailed view of the drawing control section in the figure, and FIG. 5 is a second detailed view of the drawing control section in FIG. 1...CPU, 3...Refresh memory, 4...Video circuit, 5...Display device, 6...Judgment area detection section , 7...Start point/end point detection control unit, 10...Ellipse coordinate generation unit,
12, 13, 14, 15.28゜29...Register, 16.17...Selector, 30.31.
...Absolute value circuit, 32.33...Subtractor, 34.35.36...Comparator, 37...
...Detection control section.

Claims (2)

[Claims] (1) In a raster scan type display device having a graphic display function, an ellipse coordinate generation unit generates the coordinates of an ellipse using an ellipse approximation formula, and a start point and end point detection control unit that detects the start point and end point of an elliptical arc and performs drawing control. and a determination area detection unit that is connected to the ellipse coordinate generation unit and instructs the start point and end point detection control unit to determine the determination area,
The determination area detection unit detects the difference between the horizontal radius and the vertical radius of the ellipse, and the difference between the absolute value of the horizontal coordinate and the absolute value of the vertical coordinate of the ellipse coordinates generated by the ellipse coordinate generation unit. An elliptical arc drawing device, characterized in that the elliptical arc drawing device is configured to compare the start point and end point and instruct the start point and end point detection control unit to determine a determination area. (2) The start point and end point detection control section includes a register that stores the start point coordinates and end point coordinates of the elliptical arc, a selector that selects the start point coordinates and the end point coordinates, and the ellipse coordinates generated by the ellipse coordinate generation section and the selector. a comparator that compares the output of
The elliptical arc drawing device according to claim 1, comprising a comparator and a detection control section connected to the judgment area detection section and outputting a drawing control signal and a selection signal of the selector. .