KR20010000109U - Apparatus for embodying reduction printing of laser printer - Google Patents

Abstract

The present invention provides an apparatus for implementing reduced printing of a laser printer.

An object of the present invention is to reduce the size of a laser printer, which prevents data loss and lowers the printing speed by adjusting the rotational speed of the reflecting mirror scanning the laser beam emitted from the laser diode of the laser scanning unit according to the reduction ratio received from the computer. The present invention provides a printing implement.

To this end, the present invention, by scanning the laser beam emitted from the laser diode (LD) in the polygon mirror according to the video signal of the data received from the host computer to form an image on the photosensitive drum, by transferring the latent image formed on the photosensitive drum on paper A laser printer for reproducing an image image, comprising: an optical power control unit for adjusting the power of a laser beam emitted from a laser diode according to a predetermined reduction ratio selected by a user in a printer driver of a host computer, and a rotation according to a predetermined reduction ratio The motor drive unit drives the polygon mirror and the photosensitive drum at a speed, and stores the control information about the power of the laser beam, the rotational speed of the polygon mirror and the rotational speed of the photosensitive drum in the form of a look-up table corresponding to each reduction ratio. A predetermined reduction ratio among the memory and control information stored in the memory. Detecting the response control information for the rotational speed of the rotational speed and the photosensitive drum and the polygon mirror of the power of the laser beam, and a control unit for transmitting the detected control information to the optical power adjusting section and the motor drive.

According to the present invention, since the power of the laser beam, the rotational speed of the reflective mirror and the rotational speed of the photosensitive drum are adjusted according to the reduction ratio received from the computer, there is an advantage of preventing data loss and lowering of the printing speed.

Description

Apparatus for embodying reduction printing of laser printer

The present invention relates to an apparatus for implementing reduced printing of a laser printer, and more particularly, to determine a rotation speed of a reflecting mirror for scanning a laser beam emitted from a laser diode of a laser scanning unit according to a reduction ratio of an image created by a computer application program. The present invention relates to an apparatus for reducing printing of a laser printer.

In general, a facsimile machine, a printer, a copier, or a multifunction device that can realize a combination of these functions through a single device are all products manufactured based on a printing function, and thus, an image forming apparatus is provided. The image forming apparatus picks up and transports the paper from the paper cassette on which the green chain paper is loaded, and forms an image by using an image forming material such as ink or toner on the paper conveyed through the image forming unit. do.

Among such image forming apparatuses, a laser printer is a representative example of a toner type printer that records an image on paper using toner.

1 is a block diagram illustrating a printer engine of a laser printer, and FIG. 2 is a perspective view of the laser scanning unit illustrated in FIG. 1.

As shown in FIG. 1, the surface of the photosensitive drum 200 is uniformly charged by contact rotation with the photosensitive drum 200 while applying a high voltage to the charging roller 100, and the laser scanning unit (LSU) 300 is charged. After scanning the surface of the photosensitive drum 200 to generate an electrostatic latent image (Electro-static Latent Image) through the developer 400 to the toner (toner) is supplied to the electrostatic latent image formed on the photosensitive drum 300 as a visible image Develop. Then, a transfer voltage is applied between the transfer roller 500 and the photosensitive drum 200 to rotate, thereby transferring an image formed of toner to the paper passing therebetween, and between the heating roller 600 and the pressing roller 700. After passing through the paper, the image is fixed and discharged by heat and pressure to perform an image forming process of one cycle.

These laser printers have recently been developed with various types of laser scanning units with increasing penetration rate. A laser scanning unit is an optical device that scans a laser beam on an image plane to form a desired image on the image plane as a point, or an optical device that scans an original with a laser beam to read an image of a prepared original or the like. And means for deflecting the laser beam for moving scanning in the main scanning direction with respect to the imaging surface, and means for imaging the laser beam in the form of points on the imaging surface.

Looking at the configuration of the LSU 300 with reference to Figure 2, the laser diode 301 for emitting a laser beam used as a light source; A collimator lens 302 for making the laser beam emitted from the laser diode 301 into parallel light with respect to the optical axis; A cylinder lens 303 for making parallel light through the collimator lens 302 into linear light in a horizontal direction with respect to the sub-scan direction; A polygon mirror 304 having a plurality of reflective surfaces for scanning by moving the linear light in the horizontal direction through the cylinder lens 303 at an isotropic speed; A polygon mirror driving motor 305 for rotating the polygon mirror 304 at an isotropic speed; An f · θ lens 306 having a constant negative refractive index with respect to the optical axis and polarizing light at an equilinear velocity through the polygon mirror 304 in the main scanning direction and correcting spherical aberration to focus on the scanning surface; an imaging reflection mirror 307 for vertically reflecting the laser beam through the f? lens 306 to form an image on the surface of the photosensitive drum 308, which is an imaging plane; a horizontal synchronous mirror 309 for reflecting the laser beam through the f? lens 306 in a horizontal direction; The optical sensor 310 is configured to receive the laser beam reflected from the horizontal synchronous mirror 309 and to synchronize the laser beam.

When a user wants to print an image created by an application program of a computer through a laser printer including the laser scanning unit, a print command is executed by selecting a predetermined reduction ratio in the printer driver of the computer. A method of implementing a reduction mode for printing an image received from an image according to a predetermined reduction ratio will be described below.

Here, it will be described on the assumption that the image received from the computer is composed of 16 dots as shown in Table 1 below, and the reduction ratio is 50% horizontally and 50% vertically.

1 row 2 rows 3 row 4 rows 1 row One 2 3 4 2 row 5 6 7 8 3 rows 9 10 11 12 4 rows 13 14 15 16

Since the reduction ratio of width and length designated by the user is 50%, respectively, the data of 4 rows and 4 columns should be changed to the data of 2 rows and 2 columns. To do this, we take the first and third columns of data in the horizontal case and give up the data in the second and fourth columns, and the first and third rows of the data in the vertical direction and give out the two and four rows of data. . Of course, it is also possible to take data in rows 2, 4 and 2, 4, which is up to you.

When the video data of the reduced image is received, the laser scanning unit forms a point image according to the received video data on the surface of the photosensitive drum 308, and the electrostatic latent image formed on the photosensitive drum 308 is used to fix each roller of the laser printer. Is recorded on the printing paper.

However, in the case where the 2, 6, 10, 14 dots form a single vertical line, when the 50% reduction copy is performed, the 2, 6, 10, 14 data are discarded, so the printed paper is printed. No data will be recorded. Therefore, a significant error may occur between the data before and after the reduction, and this problem may cause a very serious problem depending on the matter.

In addition, in order to solve such a problem, a method of determining the presence or absence of printing of one dot data with reference to surrounding dots may be used.

In other words, before giving up data 2, data 1 and 3 to be written are checked. If the 1st and 3rd data exist as a result of the check, the 2nd data is abandoned, and if the 1st and 3rd data do not exist as a result of the check, the 2nd data is recorded at the 1st or 3rd position to prevent the loss of data. However, this method has a problem in that the printing speed becomes slow because it is necessary to check the presence or absence of data of dots before and after the data abandoned before printing.

Accordingly, the present invention is to solve such problems, the object of the present invention is to adjust the rotational speed of the reflection mirror for scanning the laser beam emitted from the laser diode of the laser scanning unit according to the reduction ratio received from the computer data It is to provide an apparatus for implementing reduced printing of a laser printer that prevents the loss of the printer and a decrease in printing speed.

1 is a configuration diagram showing a printer engine of a laser printer;

2 is a perspective view of the laser scanning unit shown in FIG.

3 is a schematic block diagram for performing reduced printing according to the present invention;

4 is an operation flowchart for performing reduced printing.

<Description of the code used in the main part of the drawing>

10: video controller 20: engine controller

21: control unit 22: memory

23: laser diode driver 24: optical power control unit

25: motor drive unit 30: printer engine

301: laser diode 305: polygon mirror driving motor

308: photosensitive drum 308a: photosensitive drum drive motor

A feature of the present invention for achieving the above object is, in accordance with the video signal of the data received from the host computer, the laser beam emitted from the laser diode (LD) is scanned in a polygon mirror to form an image on the photosensitive drum, formed on the photosensitive drum A laser printer for reproducing an image image by transferring a latent image to a paper, the laser printer comprising: an optical power control unit for adjusting the power of a laser beam emitted from a laser diode according to a predetermined reduction ratio selected by a user in a printer driver of a host computer; The motor drive unit drives the polygon mirror and the photosensitive drum at a rotational speed according to a predetermined reduction ratio, and controls information about the power of the laser beam, the rotational speed of the polygon mirror and the rotational speed of the photosensitive drum corresponding to each reduction ratio. Memory stored in the form of up-table and control tablet stored in memory The control unit detects the control information on the power of the laser beam corresponding to the predetermined reduction ratio, the rotation speed of the polygon mirror and the rotation speed of the photosensitive drum, and transmits the detected control information to the optical power control unit and the motor driving unit. Include.

Preferably, the laser beam power, the rotational speed of the polygon mirror and the rotational speed of the photosensitive drum are reduced in proportion to the reduction ratio.

Preferably, if the predetermined reduction ratio is horizontal reduction, the rotation speed of the polygon mirror is controlled. If the predetermined reduction ratio is vertical reduction, the rotation speed of the photosensitive drum is controlled. If the predetermined reduction ratio is horizontal / vertical reduction, the polygon mirror is controlled. It controls the rotation speed and the rotation speed of the photosensitive drum at the same time.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, in the following description, many specific details such as components of a specific circuit are shown, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a schematic block diagram for performing reduced printing according to the present invention, and FIG. 4 is a flowchart illustrating an operation for performing reduced printing.

Referring to FIG. 3, when a laser printer receives print data and print information converted into data that can be interpreted by a printer from a host computer, the laser printer converts the received print data into bitmap data, which is data actually printed by the printer ( 10), the engine controller 20 for driving the printer engine 30 according to the data received from the video controller 10, and the printer engine 30 for performing the actual print job under the control of the engine controller 20. It consists of.

Here, the engine controller 20 controls the driving of the printer engine 30 as a whole, and in particular, controls the optical power of the laser beam and the rotation speed of the reflection mirror scanning the laser beam according to a predetermined reduction ratio selected by the user. The control unit 21, the control program required to drive the printer engine 30, the optical power of the laser beam and the rotational speed of the reflection mirror according to a predetermined reduction ratio selected by the user according to a preferred embodiment of the present invention And a printer engine driver for driving each component of the printer engine 30 under the control of the stored memory 22 and the control unit 21.

The printer engine driver includes a laser diode driver 23 for controlling the time when the laser diode 301 emitting the laser beam is turned on, and an optical power controller 24 for adjusting the power of the laser beam emitted from the laser diode 23. And a motor driver 35 for driving each motor of the printer engine 30 including the polygon mirror driving motor 305 and the photosensitive drum driving motor 308a.

The configuration of the printer engine 30 is shown in FIG. 1, at a controlled speed and with a laser diode 301 that emits a laser beam at a controlled optical power when performing reduced printing according to a preferred embodiment of the present invention. A polygon mirror driving motor 305 for driving the polygon mirror 304 and a photosensitive drum driving motor 308a for driving the photosensitive drum 308 at a controlled speed.

The operation of the present invention configured as described above will be described in detail with reference to FIGS. 1 to 4.

First, the video controller 10 checks whether print data is received from the host computer (S401), and when the print data is received, controls the engine controller 20 to operate each component of the printer engine 30 to preheat (S402). ).

The engine controller 20 checks whether video data is received from the video controller 10 (S403), and if the video data is received, checks whether the print mode is a reduced mode (S404).

If the print mode is the reduced mode, that is, the user selects a predetermined reduction ratio in the zoom mode in the printer driver of the host computer, the control unit 21 of the engine controller stores the look-up table previously stored in the memory 22. In operation S405, the speed of the motor driving the photosensitive drum 308 and the polygon mirror 304 and the power of the laser beam emitted from the laser diode 301 are detected according to the reduction ratio selected by the user.

The motor driving unit 25 drives the polygon mirror driving motor 305 at the speed detected under the control of the control unit 21 of the engine controller, and is driven by the polygon mirror driving motor driven under the control of the motor driving unit 25 ( 305 rotates the polygon mirror 304 (S406), and the laser diode driver 23 radiates the laser beam by turning on the laser diode 301 with the optical power detected according to the video data (S407).

The laser beam radiated from the laser diode 301 at a predetermined optical power is incident on the polygon mirror 304 through the collimator lens 302 and the cylinder lens 303, and the polygon mirror 304 rotating at a predetermined speed is The incident laser beam is scanned to form an electrostatic latent image on the photosensitive drum 308.

Here, the relationship between the laser beam radiated from the laser diode 301 and the rotation speed of the polygon mirror 304 will be briefly described.

For example, assuming that the rotation speed of the polygon mirror 304 that is rotated by the driving of the polygon mirror driving motor 305 is once / second, the radiation speed of the laser beam emitted from the laser diode 301 is The laser beam scanned on one of the plurality of reflective surfaces of the polygon mirror 304 is 1/6 second to form an electrostatic latent image for a line of data in the photosensitive drum 308.

Therefore, if the predetermined reduction ratio selected by the user in the reduction mode is 50% in width, in step 406 (S406), the motor driving unit 25 causes the polygon mirror driving motor (to rotate the polygon mirror 304 by 0.5 times / 1 second). 305 is driven.

That is, if the laser beam radiated from the laser diode 301 in the normal radiation mode scans from the scan start position to the scan end position of the photosensitive drum 308, the laser beam emitted from the laser diode 301 in the 50% reduction mode The laser beam scans only from the scan start position of the photosensitive drum 308 to the scan intermediate position to perform 50% reduction in width. Then, the laser diode 301 does not emit the laser beam until the polygon mirror 304 is rotated at a rotational speed of 0.5 times / second so that the next reflective surface of the polygon mirror 304 reaches the radiation position of the laser beam. . At this time, since the image becomes darker as the interval of each dot becomes narrower, the power of the laser beam emitted from the laser diode 301 is preferably weakened in proportion to the reduction ratio.

Thereafter, the controller 21 of the engine controller checks whether scanning of one line of video data is completed (S408), and if scanning of one line is completed, checks whether video data of the next line exists (S409).

As a result, if the video data of the next line does not exist, the printing operation is terminated. If the video data of the next line exists, the photosensitive drum driving motor 308a is controlled to rotate the photosensitive drum 308 by a predetermined interval (S410). ).

If the predetermined interval at which the photosensitive drum 308 is rotated is 50% vertically, the motor for driving the photosensitive drum driving motor 308a detected in step 405 (S405). Speed is 1/2 of the motor speed in normal printing mode. That is, if it is assumed that the predetermined interval at which the photosensitive drum 108 is rotated in the normal printing mode is 1 mm, the motor driving unit 25 in the step 410 (S410) so that the photosensitive drum 108 is rotated at intervals of 0.5mm Drive 308a.

After the photosensitive drum 308 is rotated at predetermined intervals, the controller 21 of the engine controller returns to step 407 (S407) of emitting the laser beam from the laser diode 301 according to the video data and repeatedly performs it.

Here, to check whether the horizontal synchronization signal is received through the horizontal synchronization mirror 309 and the optical sensor 310 to check whether the next reflective surface of the polygon mirror 304 has reached the position where the laser beam is imaged at the start position of scanning. Is the same as the conventional method.

Therefore, in the horizontal reduction mode, the vertical reduction mode, or the horizontal / vertical reduction mode, dot data is lost because the printing operation is performed by adjusting the optical power of the laser beam, the rotation speed of the polygon mirror, and the rotation speed of the photosensitive drum, respectively. Can be prevented.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the embodiments described, but should be defined by the utility model registration claims as described below and equivalents to the utility model registration claims.

As described above, according to the apparatus for implementing reduced printing of a laser printer according to the present invention, data is lost because the power of the laser beam, the rotational speed of the reflection mirror, and the rotational speed of the photosensitive drum are adjusted according to the reduction ratio received from the computer. And there is an advantage that can prevent the degradation of the printing speed.

Claims (3)

According to the video signal of the data received from the host computer to scan the laser beam emitted from the laser diode (LD) in the polygon mirror to form an image on the photosensitive drum, and to reproduce the image image by transferring the latent image formed on the photosensitive drum on paper In laser printers: An optical power control unit for adjusting the power of the laser beam emitted from the laser diode according to a predetermined reduction ratio selected by the user in the printer driver of the host computer; A motor driver for driving the polygon mirror and the photosensitive drum at a rotational speed according to the predetermined reduction ratio; A memory for storing control information on the power of the laser beam, the rotational speed of the polygon mirror, and the rotational speed of the photosensitive drum in the form of a look-up table corresponding to each reduction ratio; The control information stored in the memory detects corresponding control information about the power of the laser beam corresponding to the predetermined reduction ratio, the rotation speed of the polygon mirror and the rotation speed of the photosensitive drum, and detects the detected control information. And a control unit transmitting the optical power control unit and the motor driving unit. The apparatus of claim 1, wherein the laser beam power, the rotational speed of the polygon mirror, and the rotational speed of the photosensitive drum are reduced in proportion to the reduction ratio. The method of claim 1, If the predetermined reduction ratio is horizontal reduction, the rotational speed of the polygon mirror is slowed down, and if the predetermined reduction ratio is vertical reduction, the rotational speed of the photosensitive drum is reduced, and if the predetermined reduction ratio is horizontal / vertical reduction, An apparatus for reducing printing of a laser printer, characterized in that the rotation speed of the polygon mirror and the rotation speed of the photosensitive drum are reduced.