JPH01167863A - Image recorder - Google Patents

Abstract

PURPOSE:To freely change the width of a vertical line by providing a data width changing means which changes the length of input image data in a main scanning direction according to instructions from the operational part of an image recorder and which outputs it to a driver. CONSTITUTION:Based on processing information input from the operational part 7, a CPU 2 initially controls an image processing circuit 3, and applies a variety of image processings to image element data input from a host computer, etc. Image element data image-processed by the image processing circuit 3 is input as black and white digital data to a dot width control circuit 4, which modifies the width of the image element data. Namely, the CPU 2 outputs data width data WD specifying the dot width of the image element data according to line width setting instructions input from the operational part 7, and simultaneously outputs a chip enable signal, controls the dot width control circuit 4 and changes the dot width of the image element data.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus in which the width of recording lines drawn in the sub-scanning direction in the main scanning direction is variable.

(Prior Art) Recently, image recording devices that utilize laser light have become popular because of their faster printing speed and higher resolution than other methods.

In this image recording device using laser light, a driver drives a laser based on image data, and the laser beam emitted from the laser is swung in the main scanning direction by a polygon mirror and irradiated onto the surface of a photoreceptor. The surface of the photoreceptor is uniformly charged in advance, and when the photoreceptor is irradiated with a laser beam, the charge on the irradiated area disappears and an electrostatic latent image is formed. Toner is applied to the surface of the photoreceptor on which the electrostatic latent image is formed and developed, and the toner is transferred to recording paper to record the image.

(Problems to be Solved by the Invention) However, in such conventional image recording devices, the line width in the sub-scanning direction, that is, the main-scanning width of the line (vertical line) recorded in the sub-scanning direction The width in the direction is determined by the one-dot width of the laser beam set in advance for the image recording device, and is fixed as the line width specific to the product of the image recording device. Therefore, the operator cannot freely set the line width of the vertical line, and there is room for improvement.

(Object of the Invention) Therefore, the present invention provides a data width changing means that changes the data length of input image data in the main scanning direction and inputs it to the driver, thereby freely changing the dot width of the laser beam. It is an object of the present invention to provide an image recording device that can freely change the line width of vertical lines.

(Structure of the Invention) In order to achieve the above object, the present invention causes a driver to drive a laser based on input image data, and forms an electrostatic latent image by irradiating a laser beam from the laser onto the surface of a photoreceptor in the main scanning direction. In an image recording device that attaches toner to a photoreceptor surface and develops it, then transfers the toner to recording paper for recording, the main scanning direction of the input image data is determined based on an instruction from the operation unit of the image recording device. The present invention is characterized in that it is provided with data width changing means for changing the length of the data and outputting it to the driver.

Hereinafter, the present invention will be specifically explained based on examples.

1 to 4 are diagrams showing an embodiment of the present invention, which is applied to a laser printer.

FIG. 1 shows a laser printer 1, which serves as a terminal such as a host computer and records an image on recording paper based on pixel data sent from the host computer or the like. Laser printer 1 is a CPU
(Central Processing Unit)
2, image processing circuit 3, dot width control circuit (data width changing means) 4, driver 5, laser 6, and operation unit 7
The image processing circuit 3 receives pixel data from a host computer or the like. The image processing circuit 3 performs various image processing on the input pixel data, such as inversion processing, enlargement/
The data is subjected to reduction processing and the like and outputted to the dot width control circuit 4 as white/black digital data.

As shown in FIG. 2, the dot width control circuit 4 includes a decoder 11, buffers 12.13, and resistors R1, R2, R3, and
4, R5, R6, R7, R8, capacitor C1 switch SWI, SW2, SW3, SW4, SW 5, SW6
, SW7, SW8 and an OR circuit 16.
The dot width of pixel data is controlled based on dot width data (WD) input from PU2. That is, the CPU
Dot width data (WD) specifying the dot width is input from CPU 2 to the decoder 11, and the decoder 11 decodes the dot width data WD from the chip select signal and dot width data WD from the CPU 2 to generate a switch selection signal (SS). Output. The switches SWI to SW8 are switched to the switches SWI to SW according to the switch selection signal SS from the decoder 11.
One of the 8 is turned on.

Resistors R1 to R8 and capacitor C are switches SW that are turned on.
1 to SWa constitute an integration circuit 15 whose resistance value changes, and the pixel data inputted from the image processing circuit 3 via the buffer 12 is converted to its integration constant (delay constant) (RC).
It is output to the buffer 13 with a delay according to the following. Therefore, the pixel data is stored in two stages of buffers 12 and 13.
The switch SWI is delayed and turned on by
It is delayed by the integrating circuit 15 with a delay constant (RC) selected by SW8, and is input to the OR circuit 14. This pixel data is at a high level "H" when it is a black pixel, and the OR circuit 14 performs an OR operation on the pixel data from the image processing circuit 3 and the delayed pixel data and outputs the result to the driver 5.

The driver 5 supplies a driving current to the laser 6 when the pixel data input from the dot width control circuit 4 is at a low level "L". For example, a semiconductor laser is used as the laser 6, and when a drive current is supplied from the driver 5, the laser 6 oscillates and emits a laser beam.

The laser beam emitted from the laser 6 is deflected in the main scanning direction by a polygon mirror, converted into uniform linear motion by an fθ lens, and irradiated onto the surface of the photoreceptor. The surface of the photoreceptor is uniformly charged in advance, and when the photoreceptor is irradiated with a laser beam, the charge disappears in the area irradiated with the laser beam, forming an electrostatic latent image. Toner is attached to the surface of the photoreceptor on which the electrostatic latent image is formed. In this case, toner is attached only to the portions of the photoreceptor where the laser beam is not irradiated and the charge remains.

Recording is performed by transferring and fixing this toner onto recording paper.

Further, in the operation section 7, the operator gives instructions on various image processing contents, the number of prints, etc., and also gives instructions on setting the line width of the present invention. Various instructions input through the operation unit 7 are input to the CPU 2, and the CPU 2 controls the image processing circuit 3, dot width control circuit 4, etc. based on these various instructions to perform image processing and control the dot width. Width data (WD) and a chip enable signal are output to the dot width control circuit.

Next, the effect will be explained.

The operator operates the operation unit 7 to set processing information such as image processing content, number of prints, and dot width (line width). Based on processing information input from the operation unit 7, the CPU 2 first controls the image processing circuit 3 and performs various image processing on pixel data input from a host computer or the like. The pixel data subjected to image processing by the image processing circuit 3 is input as white/black digital data to the dot width control circuit 4, and the dot width control circuit 4 changes the pixel data width. That is, the CPU 2 outputs dot width data (WD) specifying the dot width of pixel data according to the line width setting instruction input from the operation unit 7, and also outputs a chip enable signal to control the dot width control circuit 4. to change the dot width of pixel data. When the dot width control circuit 4 receives dot width data (WD) and a chip enable signal from the CPU 2, the decoder 11 decodes the dot width data (WD) and outputs a switch selection signal (
SS) is output. This switch selection signal (SS) turns on one of the switches SW1 to SW8, and the delay constant (CR) of the integrating circuit 15 is determined. The pixel data (original pixel data) input from the image processing circuit 3 is directly input to the OR circuit 14 and also input to the buffer 12, and the original pixel data input to the buffer 12 is first buffered. It is delayed by 12 delay times t1. Delay time t in buffer 12
The pixel data delayed by 1 is input to the buffer 13 after being delayed by the delay time t2 by the integration circuit 15 of the delay constant (CR), and is input to the OR circuit 14 after being delayed by the buffer 13 by the delay time t3.

Therefore, as shown in FIG.
Figure (a)) shows the buffers 12, 13 and the integrating circuit 15.
The delayed pixel data is delayed by delay times tl, tz, and j3, respectively, and delayed by a total delay time 1 (1=1.+12+1.1), which is the sum of these delay times t1, t2, and t3 (see FIG. b)) OR circuit 1 as)
4 is input. As a result, the synthesized pixel data output from the OR circuit 14 is a pixel whose data length is longer than the original pixel data (input pixel data) by the total delay time t, since the black pixel data is a high level signal. It becomes data. Therefore, the time during which the laser 6 is off becomes longer, and in the image recorded on the recording paper, the white dot (width of one dot of the laser beam) shown by the dashed line in FIG. (L)) is expanded to the width shown by the solid line and recorded.

In this embodiment, the width of this vertical line (line recorded in the sub-scanning direction) can be changed to eight types selected by switches SWI to SW8, and the line width can be set freely by the operator using the operation unit 7. It can be carried out. As a result, the width of the vertical line can be freely selected, and a wide variety of clear images can be obtained. In the above embodiment, eight switches SWI to SW8 are provided to switch the line width in eight steps, but the number of line widths to be switched is not limited to this, and the number of line widths can be changed depending on the purpose of the image recording device. All you have to do is set .

(Effects) According to the present invention, the dot width of the laser beam can be freely changed, and the line width of the vertical line can be freely changed.

[Brief explanation of the drawing]

1 to 4 are diagrams showing one embodiment of the image recording device of the present invention. FIG. 1 is a block diagram of the main parts of a laser printer to which the image recording device is applied, and FIG. FIG. 3 is a circuit diagram of the width control circuit, FIG. 3 is a waveform diagram of pixel data showing the dot width control action of the dot width control circuit, and FIG. 4 is a diagram showing the recording lines thereof. 1...Laser printer, 2...CPU. 3... Image processing circuit, 4... Dot width control circuit (data width changing means)
, 5...Driver, 6...Laser, 7...Operation unit, 11...Decoder, 12.13...Buffer, 14 ...OR circuit, R1-R8...Resistor, C...Capacitor, SWI~SW8...Switch.

Claims (1)

[Claims] A driver drives a laser based on input image data, irradiates the photoreceptor surface with a laser beam in the main scanning direction to form an electrostatic latent image, and after the toner is attached to the photoreceptor surface and developed, the toner is removed. In an image recording apparatus that transfers and records an image data onto a recording paper, data width changing means changes the length of input image data in a main scanning direction based on an instruction from an operation unit of the image recording apparatus and outputs the same to a driver. An image recording device characterized in that: