JP3380393B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Forming device, especially image form for enlarging / reducing image data
Related to forming equipment. [0002] 2. Description of the Related Art Conventionally, a laser printer has a main scanning.
Main scan direction expansion to scan the beam in the direction
・ Reduction is performed by modulating the pulse width as shown in FIG.
Therefore, by changing the size of the dot, it is relatively easy
Can be realized. However, in the sub-scanning direction, the beam
Since the position cannot be changed, it is shown in FIG.
By duplicating image data in units of one line,
As shown in FIG. 7 (c), the enlargement is realized, and one line unit is used.
Reduces image data by thinning
You. In the case of reduction, to prevent image deterioration,
Logic of the line to be thinned and the lines before and after it
In some cases, a sum operation is performed. Conventionally, LED printers have been
To enlarge or reduce the scanning direction, the pulse width of the LED
By changing, it can be realized relatively easily. However, the dot position in the main scanning direction is fixed.
Processing in the sub-scanning direction of the laser printer
Take a similar approach. That is, as shown in FIG.
At regular intervals or pattern matching.
The overlap is realized by performing the duplication of the
Or logical AND operation of two dots.
Or dot thinning calculation using pattern matching, etc.
To achieve reduction. [0006] However, the conventional laser
Sub-scanning direction of user printer, main scanning method of LED printer
Direction enlargement / reduction is done in units of 1 dot or 1 line
Or, because it is a thinning process, it causes image degradation and
Or the enlargement / reduction processing in the other scanning direction is different
The problem is that the image becomes unbalanced
there were. [0007] This problem is caused by a graphic system such as shading.
The problem of becoming noticeable at the turn and causing unevenness
there were. [0008] The present invention has been made in view of the above-mentioned problems.
Image data input from outside.
Data by overlapping or thinning out lines or dots
In an image forming apparatus that performs reduction,Store image data
Line buffer and, in the case of enlargement, the line buffer
The same line of image data twice from the
In this case, one line was skipped from the line buffer
Send out image dataData distribution circuit and data distribution
A shift register that writes data from the circuit
Image data from the shift register after duplication.
Data, in the case of reduction, based on the image data before thinning
A smoothing circuit for outputting smoothing information;
Correction sub that generates correction subdots based on the aging information
An image forming apparatus provided with a dot generation circuit.
You. [0009] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be described. FIG. 1 is a block diagram showing the configuration of an image forming apparatus according to the present invention.
The block diagram is shown. The serial-parallel conversion circuit 1
Synchronize with the clock A to acquire serial image data B
This is a circuit for converting the data into parallel data. In addition,
Since the print data B can be stored directly in the line buffer 2,
If so, the serial-parallel conversion circuit 1 is unnecessary. The line buffer 2 is a serial-parallel
A multifunction device for storing the image data converted by the conversion circuit 1.
It is composed of numbers. As line buffer 2
May use a FIFO or an SRAM. The line buffer control circuit 3 has a line buffer
This is the circuit that controls the camera 2
Then, the information C of the enlargement ratio / reduction ratio is fetched. The data distribution circuit 4 is connected to the line buffer 2
Or enlargement or reduction from the data distribution circuit control circuit 5
Read from the line buffer 2 based on the rate information C
Lines or dots for duplicating or thinning image data
To determine the image data after the enlargement or reduction process.
This is a circuit for determining whether to write to the shift register 6. The data distribution circuit control circuit 5 includes a data distribution circuit
This is a circuit that controls the circuit 4, and in the case of an LED printer
Then, the information C of the enlargement ratio / reduction ratio is fetched. The shift register 6 performs enlargement or reduction processing.
Writes the subsequent image data and sequentially prints one dot per clock
Next, it is sent to the smoothing circuit 8. The shift clock generation circuit 7 has a shift register.
This is a circuit for sending the shift clock D to the star 6. In the case of enlargement, the smoothing circuit 8
Image data after enlargement (duplication) processing from shift register 6
In the case of reduction based on data, before reduction (thinning) processing
A circuit that sends out smoothing information based on image data
Yes, with reference to the line or dot before and after
This is a circuit that matches the data to the surroundings. The correction sub-dot generation circuit 9 is a
Correction sub-address based on the smoothing information from the
And a circuit for generating an image data transfer clock E
Image data after final enlargement or reduction processing synchronized with
It is a circuit that sends out F. In the case of a laser printer, live buffer system
The control circuit 3 is based on the information C of the enlargement ratio or the reduction ratio,
It controls which line of image data to read. An example
For example, as shown in FIG.
Image data of the same line (n'th line) twice
Line buffer 2 to data distribution circuit 4Shift through
Register 6To send out. Also, for example, as shown in FIG.
In the case of reduction, skip one line according to the reduction ratio
(N−(Skipping the first line)
Start. In the case of an LED printer, a data distribution circuit system
The control circuit 5 is based on the information C of the enlargement ratio or the reduction ratio,
The image data read from the line buffer 2
Control to send to the register. In addition, enlargement rate
Is also transmitted to the shift clock generation circuit 7.
Shift clock according to the enlargement or reduction ratio
By stopping or generating extra D, the shift register
Image data sent from the star 6 to the smoothing circuit 8
Control the flow of data. More specifically, as shown in FIG.
In this case, the surrounding data of the data supplied to the smoothing circuit 8 is
Shifts each time the shift clock D is input.
You. In the case of enlargement, as shown in FIG.
D stops and D_TwoTwice (D_TwoAnd D_Two') Smoothing times
D, which is supplied to road 8 but is not exactly the same data_TwoAnd D
_Two'Retrieve the smoothing information from the data and_TwoIs D_Two
Correction suitable for D_Two'Is D_Two'
Compared to simply duplicating the same data twice.
A clear image can be obtained. In the case of reduction,
As shown, shift clock D generates extra clock
By doing D_FourIs no longer supplied to the smoothing circuit 8.
But D_FourInstead of completely losing your data
D_Three, D_FiveD at the output of_FourA which is the data of_Four, B_Four,
C_FourData is revived in the form of correction dots, smoothing
Information is determined by referring to the dots around the dot of interest
Is better than simple thinning or disjunction.
A beautiful image can be obtained. According to the present invention, during the enlargement process,
Image data is degraded at the line or dot
However, these image data are processed by a smoothing circuit 8 and a correction circuit.
To be corrected by the sub-dot generation circuit 9, a simple
Deterioration of an image is suppressed as compared with duplication of data. Also, during the reduction processing, the thinned lines
Or the image data may be degraded at the dots,
The image data itself before the drawing process will not be lost.
To output lines or dots before and after
Sent to the smoothing circuit 8 as ricks data
Therefore, data remains as correction sub-dots. Yo
And some% of the thinned data is the image after the thinning process
Simply thin out the image data to be reflected in the data
The deterioration of the image is suppressed as compared with the case of (1). Before thinning processing
% Of the image data of the image is revived as corrected subdots
Depends on the smoothing circuit 8. [0023] As described above, the image forming method of the present invention
According to the device, in the case of enlargement, from the shift register
Image data after duplication, in the case of reduction, before thinning
Smooth output of smoothing information based on image data
Sub dot corrected by smoothing circuit and smoothing information
And a correction sub-dot generation circuit for generating
Of the image data when enlarging / reducing the image data.
And to prevent images with poor balance
Can be.

FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to the present invention. FIG. 2 is a diagram showing an enlargement process according to the present invention. FIG. 3 is a diagram showing a reduction process according to the present invention. FIG. 4 is a diagram showing a normal process of the LED printer according to the present invention. FIG. 5 is a diagram showing an enlargement process of the LED printer according to the present invention. FIG. 6 is a diagram showing a reduction process of the LED printer according to the present invention. FIG. 7 is a diagram illustrating enlargement and reduction processing of a conventional laser printer. FIG. 8 is a diagram showing enlargement and reduction processing of a conventional LED printer. [Description of Signs] 1: Serial-parallel conversion circuit 2: line buffer 3: line buffer control circuit 4: data distribution circuit 5: data distribution circuit control circuit 6: shift register 7: shift clock generation circuit 8: smoothing circuit 9: Correction sub-dot generation circuit A: Video clock B: Image data C: Information on enlargement or reduction ratio D: Shift clock E: Image data transfer clock F: Image data after enlargement or reduction processing

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/393

Claims (1)

(57) [Claim 1] A line buffer for storing image data in an image forming apparatus for enlarging / reducing by overlapping or thinning out lines or dots of image data input from the outside.
And in the case of enlargement, the same line from the line buffer
Image data twice, and in the case of reduction,
Image data skipped by one line from the line buffer
A data distribution circuit to send out, a shift register for writing data from the data distribution circuit, and smoothing information based on the image data after duplication from the shift register in the case of enlargement and the image data before thinning out in the case of reduction. And a correction sub-dot generation circuit for generating a correction sub-dot based on the smoothing information.