JPS6097442A - Write control system of image memory - Google Patents

Abstract

PURPOSE:To speed up vector writing operation by calculating previously the number of dots in a row (column) direction, and repeating bit access function in a column (row) direction and varying the number of bits by a specific value corresponding to each access operation in the row (column) direction at a time or continuously. CONSTITUTION:When a vector between a point r, e.g. (3, 3) and a point S, e.g. (6, 8) is re-stored in a memory, the X-directional difference DX between the coordinates and Y-directional difference DX are 3 and 5, and the number of times of loop operation in a flow chart is five. The number of a set of dots arrayed in the Y-direction is determined by DY-2DXi+2SYj shown by an equation A. A downward coordinate (i) and the value of A are varied and i+1 and A-2DX are substituted in (i) and A to move a pen by one dot slantingly to right unless the value is smaller or zero. A leftward coordinate j+1 is substituted in (j) and A+2DY is substituted to move the pen by a unit number in the Y-direction when the loop frequency is zero or plus.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a write control system for an image memory in which a steeply sloped P1 line is quickly written as a set of dots 1.

The present invention is an invention previously filed by the present applicant (Japanese Patent Application No.
The use of a 10149E (JJ-) image memory is particularly effective.

(2) Prior art and problems When a laser printer prints a single sheet of paper or a graph, it first stores bar graph data in memory, then obtains a line graph using a computer and stores the data in memory. It is convenient to have the following. As shown in FIG. 1, when each bar graph data from January to April is shown in analog form, let us consider the vector VT shown by the solid line. For example, point P (a, b) indicating the highest level of bar graph data in January and point Q (c) indicating the highest binary value in February.
, d) are connected with a large number of dots to obtain a vector similar to a straight line. Figure 2 shows the dot arrangement.One dot in both the column and row directions is processed and stored in memory, and then one dot is processed in the direction of the fire, so the adjacent F no.1 Even if the processing time to obtain - is short, for example about 0.degree. 5 milliseconds, it is necessary to continue the /JfW processing 20 to 30 times, resulting in a long time.

(3) Object of the Invention An object of the present invention is to improve the above-mentioned drawbacks and to provide a write control system for an image memory in which steeply sloped diagonal lines can be quickly written as a set of dots 1-.

(4) Structure of the Invention The structure of the present invention to achieve the above-mentioned object is a memory writing method having a bit access function when accessing an image memory, in which the number of dots in the row (or column) direction is predefined. Note that in the column (or row) direction, the bit access machine OF= is repeatedly used for writing,
It means to change in the row (or column) direction by a predetermined number corresponding to each access simultaneously or continuously.

(5) Embodiment of the Invention FIG. 3 is a diagram showing the operation of an embodiment of the invention, and FIG. 4 is an operation flowchart when the computer operates according to FIG. FIG. 3 shows a state in which data is stored in the image memory, and a vector between R-5 points is obtained and stored in the memory again. In Figure 3, the coordinates of point R are (3, 3), the coordinates of point 8 are (6, 8), the origin is at the upper left corner, the right direction is the positive direction of j (x), and the downward direction is i.
(y) positive direction. When ΔX=positive and Δy−positive, it can be seen that the line segment is diagonally downward to the right. The difference in coordinates in the X direction DX is 3, Y
The difference DY in the coordinates in the direction is 5, and the number of loop operations in the flowchart is equal to DY, which is 5 times. Also, calculate the formula DY-20X-i+2DY-j (defined as formula A). The obtained value is the number of clusters of dots aligned in the Y direction.

First, as shown in the flowchart in Figure 4, set the value of DY to 5, diagonally to the lower right, 2DX/2DYI;! Got 6/10,
Start the operation of the electronic computer, change the value of i,
Assign +l to i, assign A-2DX to A, and determine whether the value is small or zero. If the result is negative, move the pen diagonally to the right (one dot), substitute j+l for j, substitute A+2DY for 8, and if the loop count is not zero, return to before changing i to 8. If it is zero or positive, move the pen (one dot) in the Y direction. In this case (1
Dot) refers to a single operation when multiple dots are lined up in the vertical direction.

When the number of loops and the value of formula A are calculated for FIG. 3, the results are as shown in the table below.

Loop count A (]) 5-6 -1 -1+IO9 (2) 9-6 3 (3) 3-6 -3 -3-1107 (4) 7-6 1 (5) 1-6 -5 Scheduled loop When the process proceeds the same number of times, a broken line connecting the dots up to the end point is created, and straight line vectors A and higher are jq.

Since the above description has been made regarding the case where the bits are lined up in the row direction, this is particularly effective when the slope is steeper than 45 degrees. On the other hand, if the slope is gentler than 45 degrees, it is possible to perform processing by reversing the row and column directions, and by doing this, a line with a gentle slope close to the axis in the column direction can be processed. It is also possible to perform effective processing for (a line with a steep slope on the axis in the column direction).

(6) Effects of the Invention As described above, according to the present invention, multiple simultaneous writes are possible and vector writing to the memory can be achieved in a short time, so that printing can be done quickly from the beginning.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the vector writing method, Figure 2 is a diagram explaining the operation of the conventional vector writing method, Figure 3 is a diagram explaining the operation according to an embodiment of the present invention, and Figure 4 is the operation of Figure 3. A flowchart is shown. vT-Vector Patent Applicant Fujitsu Co., Ltd. Representative Patent Attorney Eisuke Suzuki January February March 48 Figure 1 Figure 3

Claims (1)

[Claims] A memory writing method that has a bit access function when accessing image memory, and uses row (or column)
The number of dots in the direction is set in advance, and in the column (or row) direction, the focus access function described in ii. An image memory write control force type that is characterized by a change in the write control force of an image memory.