JPS59224962A - Processing method of input data in electrophotography recorder - Google Patents

Abstract

PURPOSE:To reduce the amount of memory to be used and to improve the memory efficiency by compressing raster data after raster conversion to store the data in a page memory. CONSTITUTION:The transfer of data from a host computer 10 to a plotter 20 is conducted in any stage from an unsorted vector to a raster. In the indirect electrostatic system PPC, the sorted data transmitted from the computer 10 is converted into a raster data by a raster memory 43. Parallel/series conversion is attained for the data by a raster decoder 44 and the result is applied to a sequence control section 45 as a raster signal. The control section 45 conducts the control that the converted raster is compressed, the data is stored in a page memory and then restored.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic recording apparatus, and more particularly to a method for processing input data in an indirect electrophotographic recording apparatus using a photoreceptor.

In an electrophotographic recording device, if data is sent from the host computer as an unsorted vector, uncompressed page memory is required to perform rask conversion, but it is not possible to send the data as a sorted vector. When the data is processed, sequential rask transformation becomes possible, so if data compression is performed immediately after rask transformation, the amount of data can be considerably reduced. Therefore, if we assume that the information is sent as sorted vectors, the large capacity memory needed to store uncompressed pages in the conventional method becomes unnecessary, resulting in poor memory usage and cost. There are no drawbacks such as high prices.

Stop--1 The present invention was made in view of the above-mentioned circumstances, and
In particular, by compressing raster data after rask conversion and storing it in page memory, the amount of memory used can be reduced and
This is intended to improve memory usage efficiency.

''-11 The configuration of the present invention will be described below based on one embodiment.

Generally, graphical information (data files) in a host computer is composed of an index file and a group of small files referenced by the index file. To extract shapes from these files, select a plan view, three-view view, or
To create an image file according to the conditions such as a bird map, etc., and to plot it, enter the elements you want to plot, magnification, etc. from the image file mentioned above, and create coordinate information for plotter control (unsorted vector ). At this stage, the content of the data consists of lines, broken lines, filled lines, and their coordinates, and curves are treated as a series of short lines. Therefore, the pen plotter can already plot at this stage. However, since the electrostatic plotter writes data sequentially from the edge of the paper, it is necessary to rearrange the data in the order in which it will be written. A sorted vector performs this work. This work can also be done inside the plotter. The sorted vector becomes a signal that can be plotted only after it is finally converted into a bit pattern (raster), and the plotter directly applies this signal to the head or modulator to draw a plot.

FIG. 1 is an internal wiring diagram of the host computer and plotter that operate as described above. In the figure, 10 is the host computer, 20 is the plotter, and as shown, the host computer 10 has a data file 11, an unsorted vector 12, sorted vector 13, task 1
The plotter 20 also consists of an unsorted vector 21, a sorted vector 22, a task 23, etc. Data is transferred from the host computer 10 to the plotter 20 at any stage between unsorted vector rasters. In general, the host computer 10 is faster at processing data, so if the host computer 20 is relatively busy, it will be processed on the host side, and if it is busy, it will be transferred to the plotter at an appropriate stage and processed within the plotter. conduct. Inside the plotter 20, as mentioned above, the vector signal is converted into a raster signal, and the raster signal is temporarily stored as is in the internal raster memory, and when the data transfer and processing is completed, the data in the raster memory is sequentially sent out. and record it.

Recording methods include the direct electrostatic method (a method in which a charge is directly applied with a stylus etc. and then developed...same as facsimile) and the indirect electrostatic transfer method (a method in which a toner image is created on a photoreceptor and transferred to paper...・Same as a copy machine). Other simple recording methods include the sabre method and the optical method (CR).
There are methods such as copying the image of T on silver halide paper) and the discharge destruction method.

In methods other than indirect electrostatic transfer (PPC), the process speed for recording can be varied, so it is possible to record while transferring and processing data, and therefore one page of raster memory can be recorded. You don't need to last a minute. However, in the PPC method, once recording has started, it cannot be interrupted midway, so it requires a raster memory for one page. Instead, even if the input is an unsorted vector, there is no need to sort it.

Figure 2 is an electrical block diagram of the inside of the plotter (data processing section) when using the above PPC method.
1 is an external interface, 32 is an internal interface, 33 is a CPU, 34 is a program memory, 35 is a work memory, 36 is a raster data signal separation circuit, 37 is a vector character buffer, 38 is a character generator, 39 is a vector/raster converter, 40 is a raster buffer, 41 is a raster encoder (pressure W), 42 is an address controller, 43 is a raster memory, 44 is a raster decode and serial conversion circuit (expansion), and 45 is a sequence control section. An overview of the operation will be explained.

External interface (31) From an external device, in particular a host computer, the R5232
It converts the input signal sent in a format such as C Centronics IEEE or the output signal sent from the plotter to the internal bus format.

Interface unit Mainly performs input/output of signals with the sequence control unit for machine control. The contents include commands such as plot start and stop, and in-flight status signals such as no paper and busy.

It resolves and executes commands sent from the external interface 31. It also manages each part within the data processing unit.

=7 data signal separation circuit (36 Raster data is a command that indicates the meaning of raster data →
The amount of data to be transferred is sent in the order of data blocks. Therefore, here, when transferring a data block portion, an operation is performed in which signals are continuously fetched into the raster memory, apart from CPU processing. , FIG. 3 is a diagram showing an example of a signal of raster data. When the code is 00 or FF, the number of repeats (03.Of in the illustrated example) is entered next.

Character generator (38) If the sent signal means a character, this part generates a character raster and sends it to the raster memory 43.

Vector/Raster Converter 39 If the sent signal means a vector, it converts the vector data into a bit pattern such as a line or fill-in and sends it to the raster memory. Taking a straight line as an example as a specific operation, the data format is as shown in FIG. That is, in FIG. 4, ■ is a data type area such as raster, vector, control, etc., II is a data length area, ■ is an image data (raster or vector) area, and ■ is data end and check data (sum check, etc.) The image data area (2) is structured as shown in FIG. That is, in FIG. 5, Xi and Yl are the start coordinates, and X2
．． Y2 is the end coordinate, Z, , Z2 are control bits, and the control bits indicate the type of line (solid line, broken line, etc.), thickness, etc. As mentioned above, taking the case of a straight line as a specific example, the coordinates between two points are Xs, Y1,
X2, Y2 (7) Based on the data, the slope (Y2-Y
+)/(X2-Xt) to find the increase or decrease speed of memory addresses in the X and Y directions, access the memory between x1 and X2 at that speed, and write the corresponding data between 71 and 72. I'm leaving. As mentioned above, the standard vector data is the coordinates between two points, but it is also possible to specify the start point, direction, and length, or the start point and access width. In general, they are often used differently depending on the type or nature of the figure.

Address controller (42) This part generates raster memory addresses and basically consists of a preset type counter and a multiplexer. The initial setting value is operated by an internal bus, and increment, decrement, and small range changes from there are operated by a relative address signal. Also, when writing data (when plotting), it is no longer under the control of the data processing section and is under the control of the sequence control section, and is operated by the DMA control signal.

Raster memory 43) This is where data for writing is stored.If it is sent as a compressed raster from the host computer, it will be stored as is, or if it is created by Beft Raster conversion, it will be stored as a page worth of raster (uncompressed). becomes.

Raster decoder and serial l (44) Converts the data stored in the raster memory from parallel to serial and sends out a serial raster signal (video signal) to be applied to the stylus or modulator. Furthermore, if the raster data signal is compressed, a decoding operation is also performed in which the data is shifted by the amount of compression and the data in the raster is repeated.

Sequence control unit 45 A part that controls mechanical operations for recording raster signals. Start, stop, status conversion, etc. are performed by the data processing unit through an internal interface, but DMA
Control signals and raster signals are directly connected because software processing is slow. The DMA control signal is
This control signal consists of clocks, synchronization signals, gate signals, etc. for main scanning inside the machine, and is used to transfer raster signals in synchronization with machine operations. In addition, in the stylus method, the rise, fall, and correction of the paper feed step motor are necessary, and in the optical method (laser plotter, etc.), it is necessary to correct the accuracy of the polygon mirror, so the control at the time of writing is controlled. Normally, electricity corresponds to the mechanical side. If the data sent from the host computer is a sorted vector, the raster conversion order is in the recording sub-scanning direction, so the raster converter can handle multiple pieces of data to be recorded from generation to destruction at the same time. (The raster converter in this case is the same as the one for the stylus). In the case of a stylus, the converted signal is directly applied to the head and recorded, but in the case of a PPC, it is necessary to temporarily store one page worth of data due to the process. However, recording this data as it is requires a large capacity memory, so in the present invention, it is converted into a compressed disk at this stage. The conversion method may be as shown in Figure 3, or if the compression ratio is to be further increased, the MH method or MR method may be used.
In the present invention, by performing this operation, the amount of data becomes 115th in the normal case. Additionally, compared to conventional methods, this method requires a buffer for vector data (the vector being converted must be stored in order to perform raster conversion processing), but the vector data itself is numeric data. Therefore, a small memory capacity is sufficient. For writing, compressed raster data is sent directly from the host computer, and the compressed data is restored (decompressed) and sent to the sequence control unit in the same way as in the case of writing.
Perform MA transfer.

9-11 As is clear from the above description, according to the present invention, if only sorted vector and compressed raster signals are received, the memory capacity can be reduced and costs and costs can be reduced. Furthermore, if the data is received from an unsorted vector, the sorted vector can have a recording size that is larger than the raster conversion of the unsorted vector. For example, an uncompressed A4 size memory can store sorted vectors and compressed rasters up to A3 to A2 size (in compressed form, of course).

[Brief explanation of drawings]

Fig. 1 is an electrical block diagram for explaining an example of a graphic data processing method, Fig. 2 is a detailed electrical circuit diagram inside the plotter (data processing section), and Fig. 3 is a raster data signal. FIG. 4 is a diagram showing an example of the data format, and FIG. 5 is a detailed diagram of the image data area (2) shown in FIG. 4. DESCRIPTION OF SYMBOLS 10... Host computer, 11... Data file, 12... Unsorted vector, 13... Sorted vector, 14... Raster, 20... Plotter 21... Unsorted vector , 22... sorted vector, 23... raster, 31... external interface, 32... internal interface, 33
...CPU, 34...Program memory, 35...
- Work memory, 36... Raster data signal separation circuit, 37... Vector character buffer, 38... Character generator, 39... Vector/raster converter, 40... Raster buffer, 41... Rask encode, 42...address controller, 43.
... Raster memo 3, 44... Raster decoding and serial conversion circuit,
45...Sequence control unit. 4

Claims (1)

[Claims] A means for converting sorted vectors sent from a host computer into raster data, a means for compressing the converted raster data, a means for temporarily storing the compressed data, and a means for storing the compressed data at the time of recording. 1. A method for processing input data in an electrophotographic recording apparatus, comprising: a means for returning data.