JPS6314996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing pattern forming device for a sewing machine, and particularly to an improvement in a monitor display section during pattern formation.

In industrial automatic sewing machines, etc., sewing is performed repeatedly along a desired sewing pattern many times, and the sewing pattern is stored in a pattern memory such as P-ROM in order to arbitrarily change this sewing pattern to a desired shape. When sewing, the sewing pattern in this memory is read out and the desired shape is efficiently sewn multiple times, and when the sewing pattern is changed, the contents of this R-ROM are changed according to the desired shape. There is. Such a sewing pattern generator is operated by drawing a desired sewing pattern on an input board and electronically writing it into a memory.

When inputting the sewing pattern, the input data is displayed on a monitor in order to form an accurate pattern, and for this purpose the display CRT displays stitches along the input pattern.

However, conventional display units of this type have the disadvantage that the resolution of the display image is low and cannot accurately indicate stitches, and the input data
- Since a common CPU was used to control storage in ROM etc. and monitor display on a CRT, it took time to transfer the display data, resulting in coarse image density and flickering. The drawback was that the quality deteriorated significantly.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a monitor display section that forms an extremely stable monitor image without flickering, has high resolution, and can accurately display even fine seams. An object of the present invention is to provide an improved sewing pattern forming device for a sewing machine.

In order to achieve the above object, the present invention provides a sewing pattern generator for a sewing machine that stores a desired sewing pattern drawn on an input board in a pattern memory and uses it as input information for an automatic sewing machine. Processing to store the sewing pattern in the pattern memory and this sewing pattern
a CPU that performs processing for displaying on a CRT; a random scan CRT that sequentially displays images of sewing patterns drawn on an input board; a display memory that stores sewing pattern data displayed on this CRT as absolute value data; A DMA controller that controls the transfer of absolute value data in the display memory to the CRT; and a DMA controller provided on a bus connecting the CPU and the DMA controller, and a DMA controller that controls the transfer of the absolute value data by the DMA controller.
It is characterized by including a gate that is independent from the CPU.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a pattern former according to the present invention, and FIG. 2 shows its internal circuit.
A tablet digitizer 10 forming an input board is provided at the front of the device, and a stylus pen 12 is provided.
By drawing the desired sewing pattern on the tablet, this is converted into an XY image signal.
Under the control of the CPU 14, the P-ROM writing circuit 16
P- to form a predetermined pattern memory through
It is written to the ROM as a sewing pattern signal. The P-ROM is installed in a P-ROM socket 18 provided on the rear surface of the digitizer 10. Various modes and other information at the time of this input are displayed on the LED display board 20. The CPU 14 converts the input data from the digitizer 10 into P-
The program for writing to the ROM is written in the system program ROM 22, and the CPU 14 performs processing according to this program.The input data from the digitizer 10 is temporarily stored in the data memory 24 consisting of RAM, and the CPU 14 performs processing according to this program. In the embodiment, the values are stored as relative value data indicating the XY coordinate data of the digitizer 10 by the amount of XY change of each stitch.

The input data of the digitizer 10 is stored in P-ROM.
A monitor display CRT26 is provided to monitor data when writing to the
Desired sewing patterns can be sequentially input from the digitizer 10 while viewing the monitor image on the CRT 26. In the present invention, a random scan type CRT is used as the CRT26,
Compared to normal raster scan type CRTs, it displays images with higher resolution and accurately displays even fine seams, and can simplify peripheral circuits such as video RAM, reducing the price of monitor equipment. can. A CRT controller 28 is provided to drive the CRT 26.
8 is supplied with control signals corresponding to the X and Y coordinates of the monitor image from an X data D/A converter 30 and a Y data D/A converter 32, respectively, and a brightness control signal from a brightness control circuit 34. There is.

In the present invention, the monitor display of the sewing pattern by the monitor display CRT 26 is operated by display data from a display memory 36 provided separately from the data memory 24 for the P-ROM, and this display memory 36 is transmitted from the digitizer 10. RAM that stores input data as absolute value data of XY coordinates
Consists of. The output of this display memory 36 is connected to two latches 38 and 4 for each X data and Y data.
Converter 30, 32 via 0 and 42, 44
The brightness information is also supplied to the brightness control circuit 34, thereby controlling the CRT controller 28.
can make the CRT 26 draw a monitor image that is faithful to the input data.

In the present invention, the random scan
In order to display images on CRT26 at high speed,
It is characterized in that data transfer from the display memory 36 to the CRT 26 is performed by a direct memory access method using a DMA controller separately from the CPU 14 that controls writing to the P-ROM, thereby improving image quality and preventing flickering and other problems. It is possible to do so. In the embodiment, display memory 36 is controlled by CPU 14 when writing input data from digitizer 10 and when transferring this written data to CRT 26.
The display memory 36 is controlled by the DMA controller 46, and for this purpose, the display memory 36 is commonly connected to the CPU 14 and the DMA controller 46. However, in order to make the control by both controllers independent, a separation gate 48 is connected to the common bus. It is provided.

The sewing pattern forming device according to the present invention has the above-mentioned configuration, and the operation of writing input data from the digitizer 10 into the P-ROM will be briefly explained below.

When the operator draws a desired sewing pattern on the surface of the digitizer 10 with the stylus pen 12, the digitizer 10 captures this sewing pattern as an electrical signal on the XY coordinates, which is sent to the CPU 14.
is written into the data memory 24 as relative value data for each stitch. The CPU 14 reads the relative value data written in the data memory 24 based on the program in the program ROM 22.
The sewing pattern is supplied to the ROM writing circuit 16, whereby a desired sewing pattern can be written into the P-ROM.

At the same time as writing the P-ROM, in the present invention, input data from the digitizer 10 is sequentially written.
Image can be monitored by CRT26,
This image monitor uses the data memory 2 for monitoring.
4, a display memory 36 and a random scan type CRT 26 are used, and a DMA
By transferring data from the display memory 36 by the controller 46 independently from the CPU 14 for P-ROM writing, it becomes possible to form a display image at high speed and display extremely accurate seams. .

An example of DMA in the present invention will be explained below with reference to FIG.

According to the method of the present invention, the CPU 14 and the DMA controller 46 can function simultaneously and independently, thereby making it possible to use a simplified online display method for monitor display, as shown in FIG. After the DMA controller 46 transfers one pattern of the display memory 36, the CPU 14 is interrupted, thereby controlling the restart from the CPU 14 to the DMA controller 46.

In FIG. 3, for the first transfer, the device operates from an initial state in which the CPU 14 writes input data from the digitizer 10 as an absolute value to the display memory 36.
In this initial state, CPU14 is the master and DMA
The controller 46 is in a slave relationship.

As is clear from the initial flowchart shown in FIG. 3, when one coordinate data is input from the digitizer 10, the CPU 14 calculates this data and writes a relative value to the data memory 2 for P-ROM writing.
4, the absolute value for monitor display is written into the display memory 36.

Then, the CPU 14 uses the DMA controller 4
6 is started, and the absolute value data of the display memory 36 is transferred to the CRT 26 for one pattern. When the data transfer for one pattern is completed, the completion signal interrupts the CPU 14, and the CPU 14 restarts the DMA controller 46 every time one pattern is transferred, and the transfer for one pattern is repeated again. In the present invention, when the DMA controller 46 is transferring data, the CPU 1
4 and the controller 46 are both independent masters and function separately from each other, making it possible to transfer data in an extremely short time compared to when transferring data to a CRT while performing calculations when transferring data using the CPU. As a result, the number of transferred screens increases significantly, and conventional drawbacks such as flickering can be reliably prevented. For example, with conventional devices, when the number of stitches exceeds 200, quality deteriorates significantly due to occurrence of flickering, etc., but with the present invention,
It becomes possible to provide an extremely high quality monitor image without flickering even for a large number of stitches of 4,000 to 10,000 stitches.

When the DMA controller is restarted by a CPU interrupt for each pattern transfer, the CPU 14 becomes the master and the DMA controller 46 becomes the slave.

As is clear from FIG. 3, the second and subsequent transfers after the above initial transfer is completed are almost the same as the first transfer, but data is input from the digitizer 10, and this In order to write absolute value data from the CPU 14 to the display memory 36 after it has been written to the data memory 24 for
It is understood that the DMA controller 46 is controlled to stop, and that during this writing, the CPU 14 becomes the master and the DMA controller 46 becomes the slave, as in the initial state. After this absolute value data writing is completed, DMA transfer is performed pattern by pattern in the same manner as the initial transfer.

As described above, by using the DMA transfer method, the present invention can accurately display a large amount of data on a monitor image with a large number of screens per second without flickering, and also by using the random scan method as the CRT26. This has the advantage of providing an extremely high image resolution, suitable for displaying fine stitches, and providing a low-cost device with a simplified peripheral circuit.

FIG. 4 shows a timing chart of DMA due to the CPU interrupt, and the CPU 14 and DMA
It will be understood that when controller 46 performs the master function independently of each other, isolation gate 48 provides separation between the two.

In addition, the normal random scan method CRT2
6 uses electromagnetic deflection to drive the cathode ray tube, so
The frequency that the deflection yoke can follow needs to be larger than the DMA transfer cycle, and the DMA transfer cycle needs to be set larger than the number of screens per second, thereby obtaining a good image with less flickering. becomes possible. However, these conditions are not always constant; for example, when there is a lot of data to be transferred and you want to transfer all the data even if some flickering is allowed, or when there is little data to be transferred and the required number of screens can be secured even if the frequency is low. There are various cases such as these, and it is necessary to perform optimal control according to these different conditions. Especially when the amount of data to be transferred is small, in a random scan type CRT, the beam concentrates on a specific part of the CRT surface when there is zero data. It is necessary to prevent such accidents because the CRT surface may be burnt out by the irradiation. In the present invention, if necessary,
It is preferable to make the DMA frequency variable in order to adapt to the various conditions mentioned above, and by setting the DMA drive frequency to an optimal value according to the transferred data and the number of screens, it is possible to eliminate flickering and achieve random scan type CRT. It becomes possible to display images without causing burnout.

As described above, according to the present invention, it is possible to obtain an extremely high quality monitor image, and it is also possible to simplify the apparatus and obtain a low-cost sewing pattern forming device.

[Brief explanation of the drawing]

FIG. 1 is an external view of a sewing pattern forming device to which the present invention is applied, FIG. 2 is a circuit diagram of the main part of the present invention, and FIG.
The figure is a flow diagram of FIG. 2, and FIG. 4 is a timing chart of FIG. , 26 is a monitor display CRT, 36 is a display memory, 46 is a
DMA controller 48 is an isolation gate.

Claims (1)

[Claims] 1. In a sewing pattern generator for a sewing machine in which a desired sewing pattern drawn on an input board is stored in a pattern memory as input information for an automatic sewing machine, a sewing pattern generator drawn on an input board is stored in the pattern memory. CPU that performs processing and displays this sewing pattern on the CRT
, a random scan CRT that sequentially displays images of the sewing patterns drawn on the input board, and this CRT.
a display memory that stores sewing pattern data displayed as absolute value data; a DMA controller that controls transfer of the absolute value data in the display memory to a CRT; and a DMA controller that is provided on a bus that connects the CPU and the DMA controller. a gate for making a DMA controller independent from a CPU during transfer of the absolute value data by the sewing machine.