JPH0752458A - Printing speed control method for electronic printing device - Google Patents

Abstract

PURPOSE:To facilitate the change of a printing speed by a method wherein the reflection surface of a polygon mirror which reflects a laser beam is used at least by an interval of every other surface, and a printing speed is changed in response to the using interval. CONSTITUTION:When a horizontal synchronizing signal counter HSYNCCNT becomes 0 (YES at S28), at this point, a video signal, i.e., a modulation signal for a semiconductor lazer is output as a first time (S34). Thus, each time when the number of times which is specified by a speed control factor N arrives, the video signal is output, and a printing motion is executed. However, when a plotting load is high, and it is set such as N=2, a scanning of the laser beam is executed each time when the horizontal synchronizing signal HSYNC is output twice, i.e., under a condition in which every other reflection surface of the polygon mirror is used orderly. As the result, the printing speed in this case is reduced to one half printing speed, compared with a normal printing speed of N=1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing speed control method for an electronic printing apparatus which forms an image on a recording paper by using an electrophotographic method.

[0002]

2. Description of the Related Art Conventionally, for example, a page printer which prints an image on a recording sheet by using an electrophotographic method using a laser beam as an electronic printing apparatus has a high printing speed. In order to reduce the total print time, the page memory has multiple surfaces (for example, 2 pages).
Surface), and the drawing operation to the page memory at the position and the printing operation to the printer (that is, the operation of transferring the page memory data to the printer engine) are performed in parallel.

In such a conventional page printer having a two-sided page memory, as shown in FIG. 12, basically, when the printing operation for the nth page is completed, one page memory is previously stored in advance. The printing operation for the (n + 1) th page that has been drawn and (n +
2) The drawing operation of the page is set to start at the same time. Then, at the time when the print operation of the (n + 1) th page is completed, the print operation of the (n + 2) th page previously drawn in the other page memory and the drawing operation of the (n + 3) th page in the one page memory Will be started at the same time.

By utilizing such a two-sided page memory, the drawing time T _b for one page memory is compared with the printing time T _p for the other page memory which is executed at the same time. As long as the drawing time T _b <print time T _p , when printing images of a plurality of pages continuously, the print operation of each page is continuously executed. For example, the print speed is 16PPM in terms of function. (Pa
ge per minute), this number will be definitely achieved.

[0005]

However, the drawing load of the image to be drawn is high, and the drawing time T _b is compared with the printing time T _p of the other page memory which is executed at the same time to draw the image. It occurs when it is time T _b> print time T _p. For example, as shown in FIG. 13, the drawing time T _b for the second page in the other page memory may be longer than the time T _p for printing the first page using one page memory. When it occurs, (T _b −T
Only _p ), the print operation ends early and the drawing operation finishes waiting.

Once such a printing operation is completed and the printer enters the standby state, the printer engine also enters the standby state.
When the printer engine is in the standby state in this way, the recording paper conveyance system is stopped, the rotation of the photosensitive drum is also stopped, and the heating temperature in the fixing device is lowered from the fixing temperature to the standby temperature, for example. In addition, when the recording paper is continuous paper, the heat roller and the backup roller (press roller) that sandwich the continuous paper.
Will be separated from each other. As a result, even if the drawing time T _b of the second page to the other page memory is finished,
Even if an attempt is made to start the printing operation for the second page using this other page memory, the warm-up time of the printer engine is required. In some cases, this warm-up time is converted from the print speed of 16 PPM, for example. Compared with the print time per page,
It may take about 3 times. This means that the faster the print speed of the printer engine, the greater the influence of the warm-up time.

In this way, in the continuous printing operation, when the drawing time T _b simultaneously executed in the one and the other page memories is longer than the printing time T _p , the printing operation is in the standby state, 1
There was a situation where the printing speed of 6PPM could not be achieved, and improvement was demanded.

In particular, when the recording paper is continuous paper, as described above, the heat roller and the backup roller are separated from each other due to the standby state of the printing operation, and both are in rolling contact with each other when the printing operation is restarted. It will be a matter. In this way, when the contact / separation operation between the heat roller and the backup roller is performed at the position where the unfixed toner is formed, the heat roller and the backup roller that are once separated are exactly the same as the rolling contact position before the separation. It is not re-contacted again at the position, and for example, unfixed toner is discharged unfixed, or a toner image that has already been fixed is again fixed and discharged as overfixed. It became a matter, and improvement was requested.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to easily achieve a change in print speed without changing the rotational speed of a polygon mirror. An object of the present invention is to provide a print speed control method for an electronic printing device. Another object of the present invention is to change the rotation speed of the polygon mirror without changing
An object of the present invention is to provide a print speed control method for an electronic printing device, which can easily reduce the print speed.

[0010]

In order to solve the above-mentioned problems and to achieve the object, a printing speed control method for an electronic printing apparatus according to the present invention is described in claim 1.
In an electronic printing apparatus configured to reflect a laser beam modulated according to an image on a polygon mirror and scan the surface of a photoconductor, a first method for maintaining a constant rotation speed of a polygon mirror having a plurality of reflecting surfaces. And a second step in which the reflecting surfaces of the polygon mirror that reflects the laser beam are used at intervals of at least every other surface, and the printing speed is changed according to this usage interval. It is characterized by things. According to a fourth aspect of the present invention, there is provided a printing speed control method for an electronic printing apparatus, wherein the laser beam is reflected by a polygon mirror to scan the photosensitive member. A first step of keeping the rotation speed of a polygon mirror having a plurality of reflecting surfaces constant, a second step of outputting a horizontal synchronizing signal using the laser beam reflected by each reflecting surface; And a fourth step of modulating the laser beam in accordance with an image every time the horizontal synchronizing signal is counted by a predetermined number, the predetermined number is changed. It is characterized by changing the print speed depending on the situation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an electronic printing apparatus to which an embodiment of a speed control method for an electronic printing apparatus according to the present invention is applied will be described in detail below with reference to FIGS. 1 and 2 of the accompanying drawings.

FIG. 1 shows a laser beam printer 10 as an electronic printing apparatus of this embodiment, which uses, for example, fan-hold paper which is continuous paper as recording paper. The laser beam printer 10 is configured to print print information such as character information input from an external device such as a computer (not shown) on a fan hold paper P by electrophotography and output the print information.

In the laser beam printer 10, a photosensitive drum 12 is arranged so as to be driven to rotate clockwise by a main motor (not shown). Around the photosensitive drum 12, there are a cleaning unit 14, a charge eliminating unit 16, a charging unit 18, a laser scanning unit 20 for guiding the laser beam onto the photosensitive drum 12, a developing unit 22, and a transfer charger 24, respectively, in the rotation direction of the drum 12. Are arranged one after another. Further, a fixing device 26 for fixing the unfixed toner image transferred from the photosensitive drum 12 by the transfer charger 24 is disposed on the left side in the drawing, which is the front side in the conveying direction of the fan hold paper P. Then, while the photosensitive drum 12 is rotationally driven (sub-scanning), the surface thereof is main-scanned (exposed) in the rotational axis direction by the laser beam from the laser scanning unit 20 to form an electrostatic latent image, and the latent image is developed. Toner is attached at the portion 22 to form a toner image (development), and the toner image is transferred onto the fan hold paper P by the transfer charger 24, and the toner image is fixed onto the fan hold paper P by the fixing device 26 and output. To do.

The drive unit of each mechanical portion of the printing mechanism utilizing the electrophotographic method is the photosensitive drum 12 described above.
Is configured to be driven by a main motor (not shown) for rotationally driving.

The fixing device 26 is a so-called heat roll fixing device including a heat roller 28 to be heated and a press roller 30 pressed against the heat roller 28. The fixing device 26 performs a fixing action and a fan hold paper P. It also carries the transport drive of. The fixing device 26 is configured such that the heat roller 28 and the press roller 30 are separated from each other in the fixing standby state.

Further, the fan hold paper P is introduced from the right side in the drawing, and the fixing device 26 is provided via the transfer charger 24.
The sheet is ejected to the left side in the figure after the fixing operation is performed here.

Next, the structure of the above laser scanning unit 20 will be described with reference to FIG. That is, the laser scanning unit 20 includes the housing 32 having a hollow inside. An opening 34 extending along one direction (that is, along the vertical direction in the drawing) is formed on one side (right side in the drawing) of the lower surface of the housing 32 in a state of penetrating in the thickness direction. On the right side of the opening 34 in the drawing,
An optical path bending mirror 36 is attached. The optical path bending mirror 36 is set at an attachment angle such that a laser beam emitted from a scanning lens system 48 described later can be reflected toward a print position on the outer peripheral surface of the photosensitive drum 12.

A laser writing optical system L is arranged in the housing 32 in a state of being mounted on the inner surface of the housing 32. The laser writing optical system L includes a semiconductor laser 38 that outputs laser light modulated according to a print signal, and the semiconductor laser 38.
Collimator lens 40 for converting the laser beam output from the collimator into a parallel beam, a slit plate 42 for shaping the laser beam output from the collimator lens 40 into a predetermined beam diameter, and a slit of the slit plate 42. Four
An anamorphic lens (cylinder lens) 44 for correcting the elliptical light flux of the laser beam transmitted through 2a into a circular light flux on the scanning surface and correcting astigmatism, and output from this anamorphic lens 44. And a polygon mirror (rotating polygonal mirror) 46 as a deflecting means for deflecting the laser beam at a constant angular velocity.
The laser beam deflected by 6 is made to scan the outer peripheral surface of the photosensitive drum 12 as an image surface at a constant linear velocity, and the principal ray of the laser beam becomes parallel to the optical axis of the laser writing optical system L. It basically includes a scanning lens system 48 as an imaging lens for conversion.

The semiconductor laser 38 described above is, in this embodiment, configured to emit a laser beam having a laser wavelength of 780 nm, for example. The polygon mirror 46 described above is set to be rotated at a constant rotation speed of about 6,500 rpm by a drive motor (not shown).

Although not shown in detail, the above-mentioned scanning lens system 48 is composed of three lenses, that is, first to third lenses. The first and second lenses are polygon mirrors 46. The fθ lens group is formed so as to scan the deflected laser beam at a constant linear velocity, and the third lens telecentrically, that is, the scanning lens, the laser beam output from the second fθ lens. It is formed of a telecentric lens so that an image is formed on the outer peripheral surface of the photosensitive drum 12 with the optical axis of the system 48 parallel to the principal ray of the laser beam.

Further, as shown in FIG. 2, a scanning lens system 48
On the right side of the drawing, a reflection mirror 50 for reflecting the laser beam that is outside the scanning range on the outer peripheral surface of the photosensitive drum 12 within the deflection range of the polygon mirror 46 is provided in the housing 32. It is fixed on the inner surface.
On the other hand, a light receiving element 52 for receiving the laser beam reflected by the reflection mirror 50 is fixed on the inner side surface of the housing 32 while being positioned on the other side outside the scanning range. In this embodiment, the light receiving element 52 outputs a horizontal synchronizing signal in one main scan of the laser beam on the outer peripheral surface of the photosensitive drum 12 in response to the incidence of the laser beam thereon. It is set to function as a beam detector for the. In other words, this light receiving element 5
With the incidence of the laser beam on the beam No. 2, the respective scanning start positions for each main scanning of the outer peripheral surface of the photosensitive drum 12 are defined. Therefore, the output of the horizontal synchronizing signal (HSYNC) from the light receiving element 52 is determined. As a reference, the irradiation position of the laser beam in each scan is accurately detected.

The laser beam printer 10 configured as described above is a fan as a recording sheet based on print data input from an external device such as the host computer 56 under the control of the built-in controller 54. It is configured to print on the hold paper P. Here, the controller 54, as shown in the schematic configuration of FIG.
And a ROM 60 and a RAM 62 connected to. The CPU 58 is connected to a printer engine 64 that executes a printing operation based on the print data output from the CPU 58. The printer engine 64 executes a drive operation of a drive system such as a main motor for driving the photosensitive drum 12 and the like, a modulation operation of the semiconductor laser 38, etc. based on the contents (data) drawn in a page memory described later. It is configured to do.

Here, when the print data is character-based (for example, when this laser beam printer is used as a line printer connected to a computer), the internal configuration of the CPU 58 is configured as shown in FIG. There is. In this embodiment, this CP
U58 is the page memories 66 and 6 of the first and second sides.
Eight.

More specifically, the CPU 58 has an input buffer section 70 connected to the host computer 56 by communication or the like.
And a decoding unit 72 for decoding the print data stored in the input buffer unit 70 into an intermediate code in the FIFO format, and a count unit for taking out the print data stored in the input buffer unit 70 and counting the number of bytes of the print data. 74, a speed control factor determining unit 76 that determines the speed control factor N in the FIFO format from the count value of the counting unit 74, and a first speed control factor N that is stored in the speed control factor determining unit 76. FIFO memory unit 7
8, a second FIFO memory unit 80 that stores the intermediate code decoded by the decoding unit 72 described above, and first and second page memories based on the intermediate code stored in the second FIFO memory unit 80. A drawing unit 82 that draws an image on one of 66 and 68, the speed control factor N from the first FIFO memory unit 78 described above, and a drawing output from the other of the first and second page memories 66 and 68. It is provided between the print control unit 84 for controlling the drive of the printer engine 64, the drawing unit 82, the print control unit 84, and the first and second page memories 66, 68 based on the data, and (n + 1). The intermediate code of the print data of the page is sent to one of the first and second page memories 66 and 68 to allow the drawing here, and at the same time, the first and second pages.
Of the page memories 66 and 68 to send the drawing data of the nth page to the print control unit 84, and the memory management unit 86 which allows the printing operation here is roughly provided.

Specifically, n is defined as an integer of 0 or more, and when n = 0, that is, when the print data of the first page is input to the input buffer unit 70,
Since this print data is not stored in the second FIFO memory unit 80, the first and second page memories 6
No storage operation is executed at 6 and 68. On the other hand, when the input of the print data of the first page to the input buffer unit 70 is completed, the decoding operation for the intermediate code is executed in the decoding unit 72, and the second FIFO memory unit 80 is executed.
It will be stored in the drawing unit 8 as shown in FIG.
The drawing data of the first page is output from 2
The memory management unit 86 sets the drawing data of the first page to the first drawing data.
Of the page memory 66.

At this point, the second page memory 6
Since no drawing data is stored in 8, the print operation is not executed. Further, when the input of the print data of the first page is completed, the print data of the next page is continuously input to the input buffer unit 70.
Since the input time is shorter than the drawing time in the drawing unit 82, it is not necessary to consider the end timing of the print data input to the input buffer unit 70 thereafter.

Next, the switching operation for each page of the memory management unit 86 will be described. When n = 1, that is, when the drawing data of the second page is output from the drawing unit 82, the memory management unit 86 sends the drawing data from the second page memory 68 to the print control unit 86. Since it is not output,
The drawing data of the first page stored in the first page memory 66 is sent to the print controller 84 due to the end of the storage operation of the drawing data of the first page in the first page memory 66. The drawing data for each line is output, and the drawing data for the second page is stored in the second page memory 68.

When n = 2, that is, the drawing unit 82
When the drawing data for the third page is output from the memory management unit 86, the memory management unit 86 prints the drawing data for one page of the first page stored in the first page memory 66.
The drawing data content of the third page is stored in the first page memory 66 and the drawing data of the second page stored in the second page memory 68 is printed due to the end of the output to the second page memory 68. The control unit 84 is made to output every line.

When n = 3, that is, when the drawing data of the fourth page is output from the drawing unit 82, the memory management unit 86 stores the first page data stored in the second page memory 68. The drawing data of the fourth page is stored in the second page memory 68 due to the completion of the output of the drawing data of the second page to the print control unit 84.
The drawing data of the third page stored in the first page memory 66 is output to the print control unit 84 line by line.

Further, when n = 4, that is, when the drawing data of the fifth page is output from the drawing unit 82, the memory management unit 86 stores the first page memory 66 in the first page memory 66. The drawing data of the fifth page is stored in the first page memory 66 due to the end of the output of the drawing data of the third page to the print control unit 84.
The drawing control unit 84 is caused to output the drawing data of the fourth page stored in the second page memory 68 for each line.

Thereafter, the memory management unit 86 performs the same processing as in the case of n = 1 or more, and the first and second page memories 6
The usage states of 6, 68 are sequentially switched between the drawing operation and the data output operation.

Next, the control procedure in the controller 54 described above will be described with reference to FIGS.
This will be described in detail with reference to the flowchart and map shown in FIG. First, when the host computer 56 outputs a command indicating continuous printing (print operation of at least two pages), the controller 56 sets the continuous print mode, and the control procedure described below is started.

First, the general procedure of the controller 56 will be described with reference to FIG. That is, the host computer 56
From the input buffer unit 70 until the print data for one page is received (S10). When the print data for one page is received, the print data is discriminated and the drawing load corresponding to this print data is determined. The speed control factor N is determined according to (S12). After that, the contents of the print data are interpreted and drawn in the page memory designated by the memory management unit 86 (S14). After this (specifically, if the drawing operation is the first page, the drawing operation is completed, and if the drawing operation is the second page or later, the printing operation of the previous page is performed. At the time of completion), the speed control factor N is output to the printer engine 66, and the drawing data is output from the corresponding page memory (S16).

In this way, the series of printing operations for one page are completed, and the printing operation for the next page is started.

Next, the control procedure for determining the speed control factor N in S12 described above will be described as a subroutine with reference to the flowchart shown in FIG.

First, when the speed control factor determination routine of S12 is called, the count value (COUNT) in the counting section 74 is reset to 0 (S12A).
Then, it is determined whether the print data for one page has been processed (S12B), and it is determined that the print data for one page (that is, all the lines on the page) has not been processed. In the case (NO in S12B), the input buffer unit 7
The print data (that is, the received data) of the page from 0 is taken out line by line (S12C), the number of bytes for one line taken this time is added to the previous count value, and updated as a new count value (S12D). ). After that, the print data taken out from the input buffer unit 70 is decoded into an intermediate code by the decoding unit 72, and the decoded intermediate code is stored in the second FIFO memory unit 80 (S12E).

The above processing is executed for all the lines on the page, and when the processing for all the lines is completed, that is, when the processing of the print data for the page is completed (S12B: Y
ES), and the end code of the page is stored in the second FIFO memory unit 80 (S12F). Then, the above S12
The speed control factor N is determined from the count value obtained in D (S12G).

Here, as described above, in this embodiment, the laser beam printer 10 is used as a line printer of a computer, so the print data is character-based. Therefore, the drawing time (drawing load) for drawing to the corresponding page memory is substantially proportional to the print data amount. In this way, in this embodiment, the speed control factor N is based on the count value (COUNT), and from the map as shown in FIG. Will be decided to be longer. After the speed control factor N is thus determined according to the drawing load, the speed control factor N thus determined is determined by the first F
The data is stored in the IFO memory unit 78 (S12H).

In this way, the control procedure for determining a series of speed control factors is completed, and the process returns to the original main routine.

Next, the procedure for controlling the drawing in the page memory in S14 described above will be described as a subroutine with reference to the flowchart shown in FIG.

First, in S14, when the drawing operation routine for the corresponding page memory is called, the second
The print data decoded into the intermediate code is fetched from the FIFO memory unit 80 (S14A), and then it is determined whether the drawing process for one page is completed (S14B), and the drawing process for one page is completed. If it is determined that the print image is not present (NO in S14B), the print image is drawn on the bitmap of the page memory designated by the memory management unit 86 according to the intermediate code.

When such a drawing process is executed for all the lines on the page and the process for all the lines is completed, that is,
When the drawing process for the page ends (YES in S14B),
The control procedure of the series of drawing processes is ended, and the process returns to the original main routine.

Next, the control procedure of the printer engine 64 in S16 described above will be described as a subroutine with reference to the flowchart shown in FIG.

First, at S16, when the control operation routine of the printer engine 64 is called, the speed control factor N stored in the first FIFO memory unit 78 is called.
Is taken out (S16A), and then the taken out speed control factor N is sent to the printer engine 64 via the print controller 84 (S16B). Next, it is determined whether the print control processing for one page is completed (S16C), and if it is determined that the print processing for one page is not completed yet (NO in S16C), the memory management unit 86. The page memory data for one line from the page memory specified by
It is sent to the printer engine 64 via the print control unit 84.

Such a print process is executed for all the lines on the page, and when the print process for all the lines is completed, that is, when the print process for the page is completed (S1
If YES in 6C), the control procedure of the series of print processes is ended, and the process returns to the original main routine.

Next, the control procedure for changing the print speed when the above-described printer engine 64 receives the speed control factor N will be described with reference to the flowchart shown in FIG.

First, waiting for reception of the speed control factor N (S2
0) When the speed control factor N is received, the rotational speed of the main motor (not shown) is controlled to be changed to (1 / N) in the steady state in a state of being synchronized with the vertical synchronizing signal of the page ( S22). Then, the horizontal synchronization signal counter HSYN
C Substitute N for CNT (S24). Thereafter, the input signal of the output signal from the light receiving element 52 functioning as the beam detector, that is, the horizontal synchronizing signal HSYNC is waited for (NO in S26).

When the horizontal sync signal HSYNC is input (YES in S26), the horizontal sync signal counter HSYNC described above is input. Update by subtracting 1 from CNT (S2
8), this updated horizontal sync signal counter HSYNC
It is determined whether CNT has become 0 (S30). Here, the horizontal synchronization signal counter HSYNC If CNT is not 0 (NO in S28), it is determined whether or not the printing operation for the one page has been completed (S32), and if the printing operation is not yet completed (NO in S32). Returns to S24 described above and re-executes the following control procedure.

On the other hand, the horizontal synchronizing signal counter HSYNC
When CNT becomes 0 (YES in S28), the video signal, that is, the semiconductor laser 38, is first recorded at this point.
The modulated signal of is output (S34). In this way, every time the number of times defined by the speed control factor N arrives, the video signal is output and the printing operation is executed.
In other words, in this embodiment, when N = 1, the laser beam of the laser beam is output every time the horizontal synchronizing signal HSYNC is output, that is, in the state where the reflecting surfaces of the polygon mirror 46 are sequentially used. The scan will be performed and normal print speed will be achieved.

However, when the drawing load is high and N = 2 is set, every time the horizontal synchronizing signal HSYNC is output twice, that is, every other reflecting surface of the polygon mirror 46 is sequentially arranged. The scanning of the laser beam will be executed in the used state. As a result, the print speed in this case is reduced to half of the normal print speed in the case of N = 1. When N is 1 to 4, the speed control factor N and the printing speed, the usage surface of the polygon mirror 46, the rotation speed of the polygon mirror 46, the rotation speed of the photosensitive drum 12, and the rotation speed of the developing roller (not shown) of the developing unit 22. The relationship between the feed speed of the fan hold paper P, the rotation speed of the heat roller 28 in the fixing device 26, etc. is shown in FIG.

When the printing operation for one page is completed by outputting the video signal every N times of the speed control factor (YES in S32), the printing operation for one page is completed.

By executing the control procedure as described above, a concrete description will be given in the state shown in FIG. 4, for example. Here, the print data amount of each of the first page, the second page, and the fourth page is 4000 bytes or less, the print data amount of the third page is about 7,000 bytes, and the print data amount of the fifth page. Is about 10,000 bytes. By discriminating the data content of each page, it is found that the print data of the third and fifth pages has a cause of speed reduction (that is, a large print data amount accompanied by a large drawing load). . As a result, from the table shown in FIG. 7, the speed control factor N sent to the printer engine 64 when drawing the first page, the second page, and the fourth page is set to 1, respectively. The speed control factor N sent to the printer engine 64 when drawing page 3 is set to 2, and the speed control factor N sent to the printer engine 64 when drawing page 5 is set to 3. .

By thus defining the speed control factor of the printing operation simultaneously executed for each drawing operation of each page, the printing time of each page is always longer than the drawing time executed simultaneously. In other words, the drawing time of each page is always shorter than the printing time executed simultaneously, and it is surely prevented that the printing operation is finished before the drawing operation is completed and the printer engine 64 is in the standby state. It will be a matter.

Thus, according to this embodiment,
In the state where the continuous print mode is set, it is possible to reliably prevent the printer engine 64 from being in the standby state during the continuous print because the print operation ends before the drawing operation ends and the print operation is interrupted. Even if the print operation time of the page is set to be long, the print time of all pages is set short as a result by preventing the warm-up time from occurring due to the standby state.

Needless to say, the present invention is not limited to the configuration of the above-described embodiment, but can be variously modified without departing from the scope of the present invention.

For example, in the above-described embodiment, the fan-hold paper as the continuous paper is used as the recording paper, but the present invention is not limited to such a structure, and for example, the recording paper may be used. Needless to say, it can be applied to the case where cut paper is used.

Further, in the above-described one embodiment, the laser beam printer has been described as being mainly used as a character-based line printer, but the present invention is not limited to such a configuration, and, for example,
It goes without saying that the present invention can be applied to those that print arbitrary images such as figures.

[0058]

As described above in detail, by configuring the printing speed control method for the electronic printing apparatus according to the present invention, the rotational speed of the polygon mirror is not changed.
Changing the print speed can be easily achieved. Further, according to the present invention, the printing speed can be easily reduced without changing the rotation speed of the polygon mirror.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a laser beam printer to which an embodiment of a printing speed control method for an electronic printing apparatus according to the present invention is applied.

FIG. 2 is a top view schematically showing the configuration of a laser scanning unit of the laser beam printer shown in FIG.

FIG. 3 is a block diagram showing a configuration of a controller of the laser beam printer shown in FIG. 1 as a functional block.

4 is a timing chart specifically showing a control mode of speed change in the controller shown in FIG.

FIG. 5 is a flowchart showing a main routine of a control procedure in the controller.

FIG. 6 is a flowchart showing a control procedure for determining a speed control factor N in the main routine shown in FIG. 5, as a subroutine.

FIG. 7 is a map showing a relationship between a speed control factor N and a count value COUNT.

8 is a flowchart showing a control procedure for a drawing operation in the main routine shown in FIG. 5 as a subroutine.

9 is a flowchart showing a control procedure for controlling the printer engine in the main routine shown in FIG. 5 as a subroutine.

FIG. 10 is a flowchart showing a control procedure for changing the print speed in the printer engine.

FIG. 11 is a map showing the relationship between speed control factors and various factors in the printer engine.

FIG. 12 is a timing chart showing a normal execution state of drawing and printing operations when two page memories are used.

FIG. 13 is a timing chart for explaining problems when two page memories are used.

[Explanation of symbols]

 10 Laser Beam Printer (Electronic Printing Device) 12 Photosensitive Drum 14 Cleaning Section 16 Electrification Section 18 Charging Section 20 Laser Scanning Unit 22 Developing Section 24 Transfer Charger 26 Fixing Device 28 Heat Roller 30 Press Roller 32 Housing 34 Opening 36 Optical Path Bending Mirror 38 Semiconductor Laser 40 Collimator lens 42 Slit plate 42a Slit 44 Anamorphic lens 46 Polygon mirror 48 Scanning lens system 50 Reflecting mirror 52 Light receiving element (beam detector) 54 Controller 56 Host computer 58 CPU 60 ROM 62 RAM 64 Printer engine 66 First page memory 68 Second page memory 70 Input buffer unit 72 Decoding unit 74 Count unit 76 Speed control factor judgment unit 78 First FIFO memory Part 80 The second FIFO memory 82 drawing unit 84 the print controller 86 memory manager

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 15/08 8530-2H 21/00 350 9122-2H 21/14

Claims (6)

[Claims] 1. An electronic printing apparatus configured to reflect a laser beam modulated according to an image by a polygon mirror to scan on a photoconductor, wherein a polygon mirror having a plurality of reflecting surfaces has a constant rotation speed. And a second step in which the reflecting surfaces of the polygon mirror that reflects the laser beam are used at intervals of at least every other surface.
And a printing speed control method for an electronic printing apparatus, wherein the printing speed is changed according to the use interval. 2. A third step of reducing at least the moving speed of the photosensitive member, the driving speed of the developing means, and the conveying speed of the paper according to the use interval of the reflecting surface. 2. A printing speed control method for an electronic printing device according to 1. 3. When the use interval N of the reflecting surfaces is 1, and a plurality of reflecting surfaces are used successively in succession, at least the moving speed of the photoconductor, the driving speed of the developing means, and the conveying speed of the sheet. Is 1 / N, where N = 1 and 1
The printing speed control method for an electronic printing device according to claim 2, wherein 4. An electronic printing apparatus configured to scan a photosensitive member by reflecting a laser beam on a polygon mirror, the first step of maintaining a constant rotation speed of a polygon mirror having a plurality of reflecting surfaces. A second step of outputting a horizontal synchronizing signal using the laser beam reflected by each reflecting surface, a third step of counting the number of outputs of the horizontal synchronizing signal, and a predetermined number of counting of the horizontal synchronizing signal. And a fourth step of modulating the laser beam in accordance with an image each time the print speed is changed, and the print speed is changed by changing the predetermined count number. Method. 5. The method according to claim 4, further comprising a fifth step of reducing at least the moving speed of the photoconductor, the driving speed of the developing means, and the conveying speed of the paper in accordance with the predetermined count number. A printing speed control method for an electronic printing device as described. 6. When the predetermined count number N is 1, and a plurality of reflecting surfaces are successively used, at least the moving speed of the photoconductor, the driving speed of the developing means, and the conveying speed of the paper are: The printing speed control method for an electronic printing apparatus according to claim 5, wherein each of the cases where N = 1 is set to 1 / N.