TW211612B - Laser beam printer - Google Patents

Abstract

A laser beam printer capable of changing the printing speed and quality. The laser beam printer includes a speed decoding unit for decoding a specification of the printing speed, and a speed setting unit for setting a transport speed for a sheet of paper taken as an object of recording in accordance with decoded contents of the printing speed.

Description

211612 Printed 3i printed by the EX Industry and Consumer Products Cooperative of the Central Bureau of Economic Affairs of the Ministry of Economic Affairs V. Description of the invention (1) [Background of the invention] The present invention relates to laser printers, in particular to lasers capable of changing the printing speed and quality Shot printer. With the development of workstations and word processors, various types of printers have been developed. Among these different types of printers, laser printers are the most popular because they can print on plain paper at high speed. Fig. 1 shows a schematic structure of a laser printer currently in use. The main unit 12 of the laser printer 11 is provided with a laser scanning unit 13 installed in the upper region thereof. The laser scanning unit 13 is configured to irradiate the laser beam modulated according to the image signal to the photoreceptor On the drum 15. Like the charge corotron 16, the image unit 17, the transfer corotron 18 and the cleaning device 19 are arranged around the photoreceptor drum 15. In such a configuration, the charge tube 16 performs the function of uniformly charging the photoreceptor drum 15. The charged photoreceptor drum 15 selectively loses its charge according to the scanning action of the laser beam to form an electrostatic latent image. This electrostatic latent image is developed by the developing unit 17, and a toner development is produced on the surface of the drum. This sulfonate powder development is transferred onto the printing paper 23 fed from the cartridge tray 21 by the half-moon cylinder 22. The printing paper transferred with the powder development is melted by the melting unit 24 and then discharged out of the printer. The dotted line in FIG. 1 indicates the transport path 26 of the printing paper 23 fed from the cassette tray 21. The laser printer has a fixed printing speed and a fixed scanning line density (that is, the scanning line density per unit time), and its method is the same as that of an ordinary electrostatic copier (please read back and forth and pay attention to the matter before writing this page) Binding · Thread · This paper is used in the middle 8 B's "CH (Specification (2) 0) < 297 public goods) 3 81. 6. 10,000¾ (H) 211612 Λ 6 η 6 Ministry of Economic Affairs Printed by the Bureau of Standards, Industry, Work and Cooperation Fifth, the invention description (2) is the same, and the photoreceptor drum 15 needs to be controlled at a fixed speed. For the scanning line density, in most laser printers, the density of 240 dots per inch (dpi) to 300dpi was used in the initial period, but laser printers capable of obtaining 400dpi to 600dpi have become the current Mainstream. This development trend is combined with the so-called desktop typesetting expansion and the recent increase in the input / output device's reception. This input / output device can process graphic image data in important steps that are different from the previous printed text data. . For text data, printers or others need to meet the requirements of font anti-aliasing, so a trend has emerged to provide better font outlines. As described above, in the current state in which the quality of the printed image is improved in tandem, the image processing of the laser printer becomes more complicated, and the number of scanning lines also increases. In this case, the current actual state is that although the printing speed of the laser printer has been developed in various technologies, it has not yet reached any important improvement. Therefore, due to the increased workload of offices with laser printers, we need to install an additional laser printer, but there is a problem of economic burden that causes a heavy operation cost. Another problem is that, as the quality of printed images improves, a larger-capacity paging memory is needed to store one page of images, and this demand will have a considerable impact on the cost of laser printers. . In addition, there is a problem that laser printers also process image data in addition to text data. Compared with the processing time of text data, image data processing requires a relatively long time, so from the beginning of data processing to the completion of printing, The amount of time required by the printer will vary considerably, depending on the content of the data to be printed. (Please read it back and pay attention to the following items to write this page) This paper is used in the standard a B standard (CNS) f 4 specifications (210X297; ¢) ^ 4 81. 6. 10,000¾ (H) Λ 6 Π 6

Λ Ming's invention; S This is printed on the machine table and printed on the mine 1. The supply is 100 of 1 / — '. Ming 3] θι Ming £ The normal speed of the line is completed and printed from time to time. In addition, the increase of the machine can be printed by the appearance, and a few shots of thunder in the situation are provided for it to be mentioned, and the emphasis is on the point of sight and the image of the quality of the quality. The photocopying of the published image book needs to be taken nowhere. The machine table prints the first line of the laser device, which can be used to raise the number of -3-33. It is a complex borrowing item. Return the page to explain how to use the printed version of the printed version, including the printing of the machine type, including the type of the mine 1 for the description of the published version, and the behavior; to set the code and set the line to enter the grid , Within the tolerance, the speed of the code is printed and the speed is printed according to the speed, and the speed is set according to the installation. The speed of the code is unfixed and set: the speed has a speed of .m / · The Biography record clearly states that the general picture is attached with the clear explanation on the giant statement: the complete picture of the whole picture is available, and the specific point is the special picture of the details and the detailed description. Thunder; an example of a machine with a machine that prints the thunder of the machine from the table. According to the practice, the chart is used to use the chart. The sketch is roughly 1 2 (please read the back first. Please fill in this page for more details.) Printed by the Ministry of Economic Affairs of the Central Bureau of the Ministry of Economic Affairs of the Employee Consumer Cooperative ^. Map of the printed map _ copy ® process · “block ^ process flow_ 方 | ^ 流 Jr 流 为 为^ For the table 3, the main 4 control, the 5 structure of the road, the machine is printed with the lightning indicator 2 and the icon table is used to execute Time-varying changes ΙΊ / 1 Progress dense line scanning of the indicator table to use the control meter to print the information image in the content according to the indicator table to use the paper 5t scale side to use the β 8 standard (CNS) A 4 specifications ( 210X297 male dragon) 5 81. 6. 10,000 sheets (H) 211612 Λ 6 Β 6 The Ministry of Economic Affairs approved by the central government and the W Gongxiao Cooperative Society printed by Honghong V. Description of the invention (4) The control that is executed when the system is changed Process; Figures 6 (a) and 6 (b) are waveform diagrams used to compare the occurrence status of video time for two printing speeds. Figure 7 is a block diagram illustrating a second specific example according to the present invention The main part of the laser printer; Figures 8 (a) to 8 (d) are timing diagrams used to represent the relationship between the horizontal synchronization signal and the image data; Figure 9 is a flowchart to illustrate the existence of Regarding the setting of scanning density and printing speed, and the processing steps for determining the cycle period of the horizontal synchronization signal; FIG. 10 is a block diagram used to show the details of the horizontal synchronization signal control circuit shown in FIG. 7; FIG. 11 is a chart, Used to represent the contents of the reference table stored in the memory shown in Figure 10; Figure 12 is a flowchart It is used to explain the details of the period control of the horizontal synchronization signal; FIG. 13 (A) and FIG. 13 (B) are graphs, which are used to show the printing status of the laser printer with the second skeleton of the present invention. An example; Fig. 14 (A), Fig. 14 (B) and Fig. 14 (C) are graphs used to show the second example of the status of printing with the same laser printer; Fig. 15 (A), diagram 15 (B) and FIG. 15 (C) are graphs used to show the third example of the printing status using the same laser printer; FIG. 16 (A), FIG. 16 (B) and FIG. 16 (C) It is a graph used to show the fourth example of printing using the same laser printer; and FIG. 17 is a block diagram showing the third specific example of the mine according to the present invention (please pay attention to it first卞 项 # 碣 write this page) This paper standard is used in the aa family standard (CNS) A 4 specifications (2 丨 0x297 g) g 81. 6. 10,000 sheets (Η) 211612 Λ 6 η 6 Ministry of Economy + Central The quasi-monthly work permit of the Ministry of Industry and Commerce allows the cooperative to make a slave. V. Description of the invention (5) The main part of the printer. [Detailed description of preferred skeletal examples] The structure of the preferred specific examples of the present invention will be described in detail below with reference to the drawings. In all drawings, the same reference symbols are used to indicate the same or corresponding parts. In the following description, several specific examples of the present invention are used as examples. However, it should be understood that the present invention is not limited to the examples shown in the specific examples, and can be effectively applied to other forms of the specific examples without departing from the technical scope defined by the present invention. Fig. 2 shows an outline of the structure of a laser printer according to a first specific example of the present invention. It should be noted in this respect that FIG. 2 shows a laser printer viewed from one side, and the front of the laser printer is displayed in the left area of the figure. The laser printer 100 is provided with a laser scanning unit 101. The semiconductor laser generating the modulated laser beam according to the image signal is disposed on the laser scanning unit 101 through the laser not shown in FIG. 2. The laser beam emitted from the semiconductor laser illuminates the polygon mirror 102 and is deflected according to the rotation of the mirror. The deflected laser beam passes through the f0 lens 103, and its moving direction is changed by the mirror 104 and 105 after being fed from the laser scanning unit. The photoreceptor drum 106 rotates at a predetermined constant speed in the direction indicated by the arrow, and is arranged on a line extending from the laser beam output from the laser scanning unit 101. The laser beam output from the laser scanning unit 101 performs a repeated scanning operation at a predetermined exposure position 107 of the photoreceptor drum 106 in the axial direction, that is, in the main scanning direction. A charging tube 108 is arranged slightly before the exposure position 107 with respect to the photoreceptor drum 106. This charge (please read first-note that Bian Xianger fills in this page). (CNS) A 4 specifications (210x297 cm; ¢) 7 81. 6. 10,000 sheets (11) 211612 Λ 6 Ιϊ 6 The Ministry of Economic Affairs is accurate and the 3 industrial and consumer cooperatives print the five-electron light single-structured image The device rotation and the end-type domain are equipped in the outer cylinder. The roller is charged and the uniform is used to produce the surface wheel watch drum device [06 光 ί 感 的 电 电 在 射 照 0 为 ί10 像 i> Ln 管 潜 明 朦 电 »# 电 静The light perception of the drum drum is above the constellation of mines. 6 0 Image shadow 0 Image latent electrostatics ο Formed and the material image shadow above the table drum should respond to the set light exposure under the side swim of the beam drum. The image display is within 9 0 IX yuan. It includes 9 Θ 1-element single image display. This 0 image development sneaks in. It should be 0 powder and sulfide combined magnetic 0 1 * 1X barrel roll The image display is as regular as the RM piece to be sent to the display to be determined, first 11 pre-construction one 0O send 11 feeder powder rolls the master image 00 to display 11, to the barrel image powder rolls the development of the sulfonate image. The sub-cartridge is carried out in the powder plus Jingshuo. Fan Yingshuo ’s position is in this shape, Cheng Zhi ’s position is like a movement 9 cr 0 shift ^ turn ^ spin single image 6 < display 10 is faced by the wheel through the drum printed electric tube 112, and then Electrostatic transfer to recording paper (normal printing paper). In this regard, the charging corona tube 108 transfer corona tube 112 used in this specific example is configured such that a single electric tube is suspended in a space covered by a shielding material by means of a voltage applicator provided at one end of a wire. The transport path of the recording paper will be briefly described below. The recording paper not shown in the drawing is stacked on the cassette tray 114, and the tray 114 is inserted into the paper feed unit 113 from the front area, and the unit 113 is detachably placed under the laser printer 100. The half-moon roller 115 is used to feed the recording paper placed on the uppermost layer of the cassette tray 114 from the cassette tray 114. In addition, another device such as a deceleration roller can be used instead of the half-moon roller 115. The recording paper sent in this way is transported forward by the transport cylinder 128 via the path indicated by the dotted line, before the paper reaches the front end of the registration roller 129 In an instant, the 6 paper scale uses the Chinese standard (CNS) A4 specifications (210X297 mm). 810.1. 10,000 sheets (Η) (please read the notes beforehand and write this page by Sun Xun) 211612 Λ β η 6 followed by ○ before the stop) 7 stop V said that it was issued UlK temporarily, the pattern diagram of Gongwu paper's dissociation magnetoelectricity is shown in the picture 2 i. Hold, keep the rotation of the rotation rotation 29 rotation 11 barrel 6 roll 10 the quasi-wheel to the drum of the device, the light and movement of the device and the rotation of the rotor to send 0 f 1 The wheel is recorded in the order of the drum paper light recording Sometimes it ’s just a matter of looking at the paper that is recorded in this way, and it ’s sent in this style. It ’s 2 IX 1X tube halo printing and 2 1X tube halo printing. It ’s worth 10, and the electric drum player will Guangcai Guanguan's electroprint turns to Guan Fangyu's electricity I12 & The shadow powder is above the sulphur and the square shadow powder has 11 printed tubes and a halo-type electric square seal. This rotation is dependent. Set on the paper, the recording image will be predicted before the printing is displayed and the paper is taken, and the suction mark is directed to the image. The overcharge is transferred to the paper by electric transmission, and the trip to the record office is separated from the needle and the needle is removed or removed according to the needle. up Interpretation is based on the fact that the heat transmission of the roller diameter roller path is one degree. It must have a roller pressure and 6 11 packs of 8 to 11 yuan. The single delivery will melt and it will melt 17 and 6? Shadow 11 powder There is a hot stamp on the drum roller, which is converted into shape paper and passed through the recording paper, which should be recorded when recording. , Gap 18, seam fusion 11, drum C, drum roll heat, roll 11 is set on the cylinder, the heated surface is added to the pressure side paper, a record of the type II will be 7 square 11 roll rate, high pressure enough to be able to side it Make it 16-by the level of 1 to maintain a high temperature and hold M to control it (please read the notes first and then write this page) The Central Bureau of Economic Affairs of the Ministry of Economic Affairs only cooperates with Du Yin 3i The paper record is recorded on the fixed-type heat as the shadow fan. The 11 paper tube records the roll heat. The 〇-state quantity of heat species is transferred to the above table to the transmission and the 8 1X 1 yuan singulation melts out of the side mouth. When the 9 1X 1X barrel roll-out surface is used to book a book recorder, it will be printed on the machine when the book is booked for 10, and then the page row will be printed by the outgoing page. The imprint on the paper description is quoted by the scrolling-out record on the paper. To this area is the original paper on the part of the district. 5) The standard-size medium-sized standard (CNS) A 4 specifications (210x297 cm; ¢) 9 81. 6. 10,000 sheets (H) 211612 Λ 6 Π 6 Ministry of Economic Affairs According to the standard and printed by the β-work permit cooperative, the description of the invention (8) discharges the stacked sheets in order. On the other hand, the remaining sulfonate image that has not been transferred to the recording paper is removed from the surface by the cleaning device 120 disposed on the downstream side of the transfer tube 112. The cleaning device 120 is provided with a blade 120b for scraping sulfonic powder off the surface of the drum, and a film 120a for preventing leakage of sulfonic powder. In this regard, the photoreceptor drum 106, the cleaning device 120, the charging tube 108, and the developing unit 109 in this specific example are constituted as an EP master cartridge 121 in the laser printer 100 in an overall structure. In addition, the laser printer 100 described in this specific example has a front cover 123 which can be opened and closed by moving around the hinge 122 through the center. By opening the front cover 123, the user can easily remove paper jams and replace the EP cartridge and transfer tube 112. The laser printer 100 of this specific example is constructed in such a manner that the user can easily install or remove the melting unit 118. A power block 124 including a low-voltage power supply and a high-voltage power supply is installed at a position behind the laser scanning unit 101, and supplies power required by each component part. A control unit 125 is arranged behind the power supply block 124 to perform electrical control of the laser printer 100. An image data processing unit 126 is installed above the power block 124 and the control unit 125. This unit 126 is configured to translate image data received from a computer or the like into a language for the laser printer 100, and then The translated data is sent to the control unit 125. As described above, the laser printer 100 in this specific example has a so-called mechanical component portion arranged in the front area and a so-called electrical component portion arranged in the rear area. Figure 3 shows the main part of the circuit structure of the laser printer. This laser print (please read first-please note that Ping Xianger fills in this page) This paper size is not in the Chinese SB standard (CNS) T4 specification (210X297 public A) 10 81. 6. 10,000 sheets (II) 2ίί6ί2 Λ 6 Β 6 Printed by the β-Consumer Cooperative Society of the Central Standards Bureau of the Ministry of Economic Affairs. 5. Description of the invention (9) The meter 100 is equipped with a first central processing unit (CPIO201 to perform general operations of the printer. This The first CPU 201 is connected to some circuits or components via an internal bus 202, such as a ROM 203, —RAM 204, —operation panel 205, —internal interface (I / F) circuit 206, —scanner motor drive circuit 207, —main motor drive Circuit 209, and a laser drive circuit 209. ROM (read only memory) 203 is used to store the program used to control the general control operation of the laser printer. RAM (random access memory) 2 0 4 is designed to store temporary data needed to control the laser printer. The operation panel 2 0 5 is connected via an I / O port that is not shown in the diagram, and it is designed to input all Required information and not displayed on the graphic LCD panel to inform the operation The internal interface circuit 206 is connected to the CPU 211 via another bus 212, which is set to exclude the use of image processing. The scanner motor drive circuit 207 is a circuit for driving the scanner motor 215, and the scanning motor is set to Drive the polygon mirror shown in Fig. 2. In this specific example, the polygon mirror 102 is configured to be controlled to perform its rotation at a constant speed regardless of the conveyance speed of the recording paper. The main motor drive circuit 208 is constituted To perform the control of driving the main motor 216. The main motor 216 is used not only to rotate the photoreceptor drum 106 shown in FIG 2, but also to transfer recording paper. The laser drive circuit 209 is connected to a laser oscillation The device 217 irradiates the laser beam on the polygon mirror 102. The laser oscillation device 217 is designed to control the oscillation output from the laser in two stages to change the diameter of the laser beam. At the same time, it is used to process the image The CPU211 is connected via the internal bus 212 (please read back to the page and fill in this page). This paper is used in the national standard (CNS) A 4 specification (2 丨 0X297 male dragon) ^ 81. 6. 10,000 sheets (11) CX Gongxin & Co., Ltd. of the Ministry of Economic Affairs, CXGCC “Cooperative Society 211612 Λ6 _Π_6_ V. Description of the invention (10) To the internal interface circuit 206, R0M221, RAM222, line memory group 223, And the external interface circuit 224. The ROM 221 stores the control program for processing images. The RAM 222 is used to temporarily store the data needed to control the image processing. The line memory group 223 contains 12 line memory devices. The external interface circuit 224 is connected to the host computer 231, and can provide instructions related to image signal feeding and image printing. With the instructions given by the operation of the main computer 231 or the operation panel 205, the laser printer can occasionally be set to (a) change the scanning line density to two types during printing, namely, high density and low density. One, (b) automatically changes the transmission speed of the recording paper according to the content of the image data. In this regard, the laser printer of this specific example performs printing at 600 dpi when the scanning line density is set to "High Density" and when the scanning line density is set to "Low Density" At the time of printing, the printing operation is performed at 300 dpi. Figure 4 shows the outline of the execution control of the laser printer when receiving the instruction from the host computer to change the scanning line density. In this case, when the laser printing When the CPU 211 of the watch machine receives the print command from the main computer 231 via the external interface circuit 224 (in step S101; Y), the CPU 211 receives a resolution instruction command in addition to the print command (in step S102; Y), And it is determined whether the received resolution instruction command indicates 300dpi (step S103). If the CPU 211 of the laser printer finds the resolution, that is, the scanning line density instruction is 300dpi (Y), it causes the scanning unit to scan Each side of the polygon mirror 102 (step S104), that is, when scanning the surface of the polygon mirror 102, one of every two surfaces of the polygon mirror 102 is omitted, this point will be described in more detail later. (Please read back first And pay attention Item # Gong Yun page) This paper is used in the "National Standard (CNS) T4 Specification (210X297 male dragon) 81. 6. 10,000 sheets (H) Printed by the Cooperative Society of the Ministry of Economic Affairs, the Central Bureau of Labor and Economics Beta". System V. Description of Invention (U) With respect to this mode of operation, the CPU 211 of the laser printer performs general control, when the indicated resolution is not 300dpi, but 600dpi (in step S103; N), It causes the scanning unit to scan all the surfaces of the polygon mirror 102 (step S105). In the control shown in FIG. 4, one of the premises is that the recording paper is conveyed at a constant speed, and the other premise is that after the print command is issued, the scanning line The density will not be changed until the printing operation is completed. In contrast, the transport speed of the recording paper can be fixed at a certain speed. When the printing command about the resolution is issued, the unit is line or block. In the case where one block contains a given complex number line), only the number of scan lines per unit time can be changed. In this case, the control flow can be organized to identify the change of the command according to the resolution instruction, Scan every other side An offset is controlled between step S104) and scanning all surfaces (step S 1 0 5). Figure 5 shows the automatic control of the printing operation performed by the laser printer according to the type of image data sent by the autonomous computer An example of the control operation performed in the case. In this example, when a print command from the main computer 231 is received (at step S201; Y), the laser printer recognizes that the image data sent is text data Or image data (step S202). Then, if the image data is text data composed of coded data such as characters, it can perform operations in the laser printer at a relatively fast speed, and the recording paper is transmitted The control is started at a printing speed of 2V (where V represents a designated speed) (step S203). In this case, the entire surface of the polygon mirror 102 is scanned by the laser beam (step S204). (Please read the back-to-back precautions first and write this page) This paper is 51-size edge-use medium SB home sample standard (CNS) T4 specification (210X297 male dragon) 13 81. 6.〗 0,000 sheets (H) Λ β π 6 V. Description of the invention (12) On the other hand, if the image data received from the autonomous computer 231 is image data (step S202; Ν), the processing time is quite long because the data is executed in units of bits deal with. Therefore, in this case, the control of the recording paper transport is performed at the printing speed V (step S205), which is half the speed of the text data. At this time, the rotation speed of the polygon mirror 102 does not change. Therefore, when scanning every other side of the polygon mirror (step S206), the scanning line density is the same as that of the text data. Now, assume that the number of mirrors on the polygon mirror 102 of the laser printer in this specific example is 2N. In addition, the transfer speed of the recording paper, that is, the printing speed in the sub-scanning direction can be selected as described above Vmm / sec or 2Vm / sec. In the laser printer of this specific example, the scanner motor 215 The number of revolutions is set to a printing speed of 2V with appropriate adjustment. Therefore, the number of revolutions of the scanner motor 215 can be expressed by the following formula (1), where f represents the scanning line density per lm of the recording paper:

2V f X 60 [rpm] ..... (1 (please read the back-to-back precautions, please fill out this page) install < order · thread ·

2N The Ministry of Economic Affairs, Central Liangzhun Bureau Beta Engineering Consumer Cooperative Printing Co., Ltd. Therefore, when the video frequency of the laser printer used to process the signal in pixels is expressed as F [Η z], the following formula can be used (2) to represent: F = 2V X f2 X w ... (2) where W is the total scan width (m). Assume that in this state, from the main computer 231, the typical one is a personal computer Give the laser printer 10 0-the command to select the printing speed V. The private paper scale shown in Figure 3 uses the Chinese B Jiayu Bi (CHS) T4 specification (210x297 g; ¢) ^ 81. 6. 10,000 sheets (H) 211612 Λ 6η 6 The Ministry of Economic Affairs standardizes and the β work eliminates Cooperative Independence V. The CPU 201 of the invention description (13) receives the command via the internal interface circuit 206 and selects the data stored in the ROM 203 to obtain the printing speed V. This data indicates that (1) the polygon mirror 101 should be scanned every other side, (2) at a printing speed of 2V, the rotation speed of the main motor 216 should be set to one-half of its rotation speed, and (3 ) The control timing of other f items including recording paper transmission should be adjusted to simply double the equivalent value when printing at 2V. However, when the laser beam performs the main scanning operation and detects the presence of the laser beam, the sensor sets the starting position of the image signal, and the period from the set time to the time when the image signal is started is set The result is just the same when the printing speed is 2V. This is because the number of rotations of the polygon mirror itself has not changed, and if this time is set to be doubled when the printing speed is 2 V, a problem will occur that the starting position of the image signal on each line will The printing operation at a printing speed of 2V is different. When the CPU 201 reads the data suitable for the printing speed V from the ROM 203, the CPU 201 controls each part according to the read data. In addition, when the image data sent from the main computer 231 arrives, the CPU 211 divides the line memory group 223 into two subgroups, and then writes the image data line by line to the multiple lines in the subgroup. At the same time, the line-by-line image data of the multiple line recorders in the other sub-groups. The execution of the control of the CPU 211 on the line recorder group 2 2 3 is based on the sub-group, and when the writing of image information to another sub-group is completed, the action of outputting the image data from one sub-group It is started, and at the same time, the writing of the image data to another subgroup is also started. Then follow the same method in Myanmar (please pay attention to the item first and then write this page). The standard of this paper is easy to use. A Beta (CNS) A 4 specifications (210 > < 297 male dragon) 15 81. 6. 10,000 sheets (H) 211612 A 6 Π 6 approved by the Ministry of Economics and A Gong Xiaoxian cooperated with Du Du. 5. Description of the invention (15) This control situation, at the time t as the starting time ; L, t 2, t 3, ... for each single line scan time. A video clock 251 is generated, where these times correspond to the individual scanned mirror surfaces. Relative to FIG. 6 (a), FIG. 6 (b) shows the case where the printing operation is performed at a printing speed of 2V. In this case, at the time 11, t 2, t3 as the starting time, the first face, the third face, the fifth face, etc. of the polygon mirror 102 (FIG. 3) are intermittently The scan time of the line generates the video clock 252. That is, the example shown in Fig. 6 (b) does not have any video clock on line starting at time t2 because a gate circuit not shown in the figure suppresses the occurrence of the video clock. Therefore, no image is formed on this fixed line. Therefore, as shown in FIG. 6 (a) at the printing speed V, if the scanning operation is performed on the first line at time t i, the scanning operation is performed on the second line at time t2. In addition, as shown in FIG. 6 (b), when the printing operation is performed at a printing speed of 2V, if the first line scan is performed at time 11, the second line scan is performed at time t3. The following will supplement the description of the control for changing between different scanning line densities. When the main computer 231 issues the scan line density f command, the number of revolutions π of the scanner motor 215 is obtained from the above equation (1). In this example, the scan line density f is "300". In this case, the laser printer performs a scanning operation on every other side of the polygon mirror 102. Therefore, the scanning line density f can be obtained by the following formula (5). NX η f =-[sheets / minute] ...... (5) 2V X 60 (please read the precautions to write this page first) Er · line. This paper size is used in a country. Standard (CNS) T4 specification (210X297 g; Ϊ) 17 8J. 6. 10,000¾ ⑻ 211612 Λ 6 η 6 Co-production by the Ministry of Economic Affairs, Central Standards Bureau, Mgongzhong, V. Printing 5. Description of the invention (U) Operation. When the control is performed at the printing speed V, the polygon mirror 102 rotates at the same rotation speed under the rotation of the printing speed 2 V, and the video frequency is set to be the same as the case of operating at the printing speed V. Therefore, in order to set the scanning line density when operating at the printing speed V to be the same as the scanning line density when operating at the printing speed 2 V, the scanning operation of every other side as described above is performed. Suppose that A1 represents the number of sheets printed by the laser printer at a printing speed V per minute. In addition, L (ram) represents the length of the recording paper, and Δ L represents the interval between two recording papers that are continuously transported on the transport path. Then the number of paper sheets printed per minute Αι can be obtained by the following formula (3): 60V Αι = —- [sheets / minute] …… (3) L + aL On the other hand, in the issued The command is used to make the printer perform printing at a printing speed of 2V. This laser printer will perform the specified control on the printing operation performed at a printing speed of 2V. That is, the laser printer is modulated for each side of the polygon mirror 102, and the number of printable sheets per minute of the laser printer can be expressed by the following formula (4): 60 X 2V Αι = -[Zhang / min] …… (4) L + aL Figure 6 (a) and Figure 6 (b) show the video clock used to control the scanning surface of the polygon mirror, which is related to the printing speed. Figure 6 (a) shows when the printing speed is V (please pay attention to the section and fill in this page). Binding · Threading · This paper is used for the standard side. Β 家 斀 准 (CNS) 言 4 Specifications (2 丨 0X297 male dragon) 16 81. 6. 丨 0,000 sheets (Η) 2x1612 Λ 6 η 6

Printed by the KX Industrial Consumer Cooperation Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. V. Description of the invention (16) On the other hand, if the command issued by the host computer 231 requires a scan line density of 2f, then this laser printer The scanning operation is performed on all surfaces of the polygon mirror. In this case, when the scanning line density is 2f, the following formula (6) can be used to obtain -2N X η 2f =-[sheets / minute] ...... (6) 2V X 60 The direction will occur twice the scanning line density. In this specific example, the change between the scanning line densities is based on the premise that the transfer speed of the recording paper does not change before and after the change, as described above. Therefore, when the printing operation is performed at the scanning line density f, the line interval becomes too wide in some cases depending on the printer. In this case, one solution is to make the spot diameter of the laser beam projected on the photoreceptor drum 106 substantially larger, in such a way that when the printing operation is performed at the scanning line density f The power is increased to a higher level than when the printing operation is performed with the scanning line density 2f. As mentioned above, the laser printer in this specific example can obtain the advantage of greatly reducing the capacity of the buffer memory (used to store image data during printing), because the high processing speed of text data makes the printer The printing speed is increased, and the processing speed of the image data is low, and the printing speed can be accelerated under consideration of the data processing speed of the printer, as long as the change between the printing speeds is achieved by the method shown in FIG. 5. In some undetermined conditions, this system is equipped with a page register as in the traditional way without performing image processing in units of pages, so that it can use a plurality of line records as described in the specific example above Yiqi (please read it back and pay attention to Xiang Xiang'er to fill out this page). Install-_ line. This paper is used in the standard a B Jiayu standard (CNS) A 4 specifications (210X297 male dragon) 18 81. 6. 10,000 sheets (H) 2116x2 Λ 6 Π 6 The Ministry of Economic Affairs, Central Bureau of Economic and Social Development printed by the Industrial and Commercial Cooperative Fifth, Invention Instructions (V7) to print images. In addition, the control data is written to R Ο Μ 2 0 3 to perform the change control of the printing speed and the scanning line density, so it can easily perform the control, in addition, you can also rewrite the contents of the ROM or Replace the ROM to change the content of the control in an easy and simple way. In addition, the above-mentioned laser printer is configured such that the scanning unit performs a scanning operation with a scanning line density f in the case of text data, and performs a scanning line density 2f finer than the scanning line density f in the case of image data Scan operation. If such a scanning system is adopted, the laser printer can improve the rapid efficiency of printed matter in view of the substantial quality improvement of the regenerated image data. The second specific example of the present invention will be described below. The outline of the configuration of the laser printer of this specific example is the same as that of the laser printer of the first specific example (as shown in FIG. 2), so its description is omitted here. First, the details of the scanning operation of the laser scanning unit 101 on the photoreceptor drum 106 will be described in detail. 7 is a diagram showing a part of a member for performing a scanning operation with the laser beam emitted from the structure of the laser printer shown in FIG. However, these parts are not important for the explanation here, so they are omitted in FIG. 7. The polygon mirror 102 in the laser scanning unit 101 is driven by a drive motor not shown in FIG. 7, which rotates at a constant speed in the direction shown by the arrow R. The polygon mirror 102 sequentially deflects the laser beam 313, and the laser beam is projected from the laser vibrator 311 through the modulator 312, and reflects the projected beam on the polygon mirror 102, six surfaces 102a to 102f Beam, and then the laser scanning unit with the built-in polygon mirror 102 is installed through the above lens 103 (Figure 2) according to (please read first-the precautions before filling this page) ..? Τ- 线- The size of this paper is printed in China National Standards (CNS) Grade 4 (210X297 mm) ^ 81. 6. 10,000¾ (H) Λ 6 II 6 Standards issued by the Ministry of Economic Affairs and printed by the A Cooperative Cooperative Society DESCRIPTION OF THE INVENTION (18) The main scanning direction M of the photoreceptor drum 106 performs a scanning operation at a certain speed. Therefore, one rotation of the polygon mirror 102 can perform up to 6 main scanning operations. The laser beam reflected by the polygon mirror 102 is changed in angle at a position 316 by a mirror 3 2 1 and then irradiated on the beam detector 3 2 2. The beam detector 322 is constructed so that it can detect the projection of the laser beam and generate a pulse beam detection signal 324 for the horizontal synchronizing signal control circuit 3 2 3 provided in the control unit 125. The horizontal synchronization signal control circuit 323 performs shaping processing on the pulse waveform of the light beam detection signal 324, and then feeds the shaped signal as the horizontal synchronization signal 331 to the image data processing unit 126. In this case, the horizontal synchronization signal The control circuit 323 executes the control of the desalination horizontal synchronization signal 331, and in this way, at specified intervals, according to the printing speed data 3 2 7 and the scanning density control circuit 3 2 8 completed by the printing speed control circuit 326 Data 3 2 9 to perform control. The printing speed control circuit 32 6 supplies the printing speed data 3 2 7 according to the printing speed control signal 3 3 3 completed by the image data processing unit 12 6. In addition, it also supplies the driving speed control signal 335 to the motor 334 to Drive the photoreceptor drum 106. The scanning density control circuit 328 outputs the scanning density data 329 according to the scanning density control signal 337 supplied from the image data processing unit 126. The laser control circuit 315 is configured such that it controls the laser oscillator 311 and the modulator 3 12 in accordance with the image data 338 fed from the image data processing unit 126. In addition, the main scanning operation is equivalent to six minutes of the rotation period of the polygon mirror 102 (please read-back to the precautions #filling this page) Binding · Order · Line-This paper is used in the standard 8 Η 家 槔 准 (CNS ) TM specifications (210x297 g *) 2〇81. 6. 10,000 sheets (Η) printed by the Ministry of Economic Affairs and printed by the β Gongxiao Cooperative Society 21ί6ί2 Λ 6 _Π_6_ V. Description of invention U9), corresponding to polygon mirror 102 Each side is set to execute a cycle at a position facing the photoreceptor drum 106. However, the laser beam modulation according to the image signal during this main scanning period is only performed during the period between the beam position 317 and the beam position 3 18, and the beam is located at any position before or after these beam positions Was intercepted. In addition, in this specific example, it is designed to produce a laser output when each side of the polygon mirror 102 reaches an angular position that deflects the laser beam 313 to the beam position 316 at a certain amplitude every time. Therefore, regardless of whether the image signal is supplied or not, each main scanning operation often generates a beam detection signal 3 2 4. The image data processing unit 126 is configured to receive unprocessed image data supplied from a computer or the like not shown in the figure, and receive print parameters of the print speed and scan density fed into it. According to the completed printing parameters, the unprocessed image data supplied in this way is converted into image data 338 suitable for the required printing conditions, and the image data obtained by this conversion is stored in the undisplayed Picture memory in the picture. Then, the stored image data is fed out one line at a time synchronized with the horizontal synchronization signal 331, wherein the horizontal synchronization signal 331 is from the horizontal synchronization signal control circuit 3 2 3 in the control unit 125. The reason for data conversion based on printing parameters will be explained below. Specifically, unprocessed image data supplied by computers and the like sometimes contains a total number of pixels per page that is not suitable for the specified scan density. Therefore, to adjust the number of pixels, the method is to fade the pixels of each line or add a new line of pixels. Figures 8 (a) to 8 (d) show the feed from the horizontal synchronization signal control circuit 323 (please take care to create this page in advance). This paper standard is used in the SB family standard (CNS) T 4 Specifications (210X297 male dragon) 21 8J. 6. 10,000¾ (H) A 6 η 6 Printed by the Beibei Consumers Cooperative Society of the Central Bureau of Central Development Fifth, the invention description (20) of the horizontal synchronization multiple 331 and from The relationship between the image data 338 of the image data processing unit 126. As shown in FIG. 8 (a), the original horizontal synchronization signal 331 has a period T equal to one-sixth of the rotation period of the polygon mirror 102, and a line of image data 338 (i.e. 8 (b) the area indicated by the diagonal line) is supplied to the laser control unit 315 of the control unit 125 (FIG. 7). The operation of the control unit 125 and its peripheral devices having the above-mentioned configuration will be explained below. First, referring to FIG. 9 to explain that before performing the printing operation, it is necessary to set the scanning density, set the printing speed, and determine the period of the horizontal synchronization signal. When a computer not shown in the figure applies a command to the image data processing unit 126 to define the printing parameters (step S301), the image data processing unit 126 decodes the command and then sends the printing speed control signal 3 3 3 (FIG. 7) and the scanning density control signal 3 3 7 are given to the printing speed control circuit 326 and the scanning density control circuit 328 (step S302). When receiving these signals, the printing speed control circuit 326 and the scanning density control circuit 328 respectively supply the printing speed data 327 and the scanning density data 329 to the horizontal synchronization signal control circuit 323 (step S303). At this time, the print speed control circuit 326 determines whether it needs to set any value different from the print speed at this time (step S304), and when it needs to set a different print speed (Y), it outputs a drive control signal 335 to The motor 334 drives the photoreceptor drum 106, thereby causing the motor 334 to change its rotation speed (step S305). The horizontal synchronizing signal control circuit 323 is based on the type of data supplied (please read the precautions before filling in this page) _ _ order _ line 'This paper is used in the standard a B home standard (CNS) T4 specifications (210X297 male dragon) 22 81. 6. 丨 0,000 sheets (H) 21161 ^ EX Industrial Consumers ’Cooperation of the Ministry of Economic Affairs, Bureau of Standards, Du Duh ¾ V. Description of the invention (2U determines the period of the horizontal synchronization signal 331. The following will be more detailed The description of is used to determine the operation of this cycle. Figure 10 is a detailed description of the horizontal synchronization signal control circuit 323. This circuit is provided with a CPU (central processing unit) 342 of the register 341, and is connected to the memory 344 via the bus 343 , Counter 345, and input / output signal interface circuit 3 4 6. The beam detection signal 3 2 4 supplied from the light detector 3 2 2, and the printing speed data from the printing speed control circuit 326, and the scanning density The scanning density data 329 of the control circuit 328 is transferred to the CPU 342 through the input / output signal interface circuit 346, and at the same time, the horizontal synchronization signal 3 3 1 is output through the signal interface circuit 346. Then the counter 3 4 5 is used to count in this way The pulse number of the beam detection signal 3 2 4 is given. The memory 344 stores a value reference table 348 for determining the period of the horizontal synchronization signal 331. Figure 11 shows the reference table 348. This table contains the horizontal synchronization signal established therein Various combinations of scanning density and printing speed corresponding to the period. For example, when the scanning density D is 600dpi (dots / inch) and the printing speed S is 10PP (number of printed sheets / minute), the table shows horizontal synchronization The signal 331 is set to the basic period T seconds (sec). The table also shows that when the scanning density D is 400 dpi and the 'print speed S is 5ρρπ, the period of the horizontal synchronization signal 331 is set at 3T seconds. In addition, this laser printer can choose one of 4 scanning densities, that is, one of 600, 400, 300, and 200dpi, and two printing speeds, that is, one of 10 and 5ρρπι. After the printer, scan at 600dpi (please read the notes before you fill in this page) to install. Order-This paper is used in the standard (CNS) > f 4 specifications (210x29 / cm; jt) 23 81. 6. 10,000 sheets ⑻ 211612 Λ 6 15 6 Printed by the Ministry of Economic Affairs, Central Bureau of Standards and Staff Cooperative Cooperative V. Invention description (22) The scanning density and the printing speed of 10 ppm are set as default values. It can be clearly seen from the table that the scanning density D, the printing speed S, and the period HT of the horizontal scanning signal 331 always have a relationship that can satisfy the following equation (7), where N is expressed as a positive integer. DXSX NT = 6000T ... (7) In step S303 shown in FIG. 9, when the print speed data 327 and the scanning density data 329 are fed into the horizontal synchronization signal control circuit 323, the CPU 342 of the circuit refers to The reference value 348 stored in the megameter 344 extracts the NT value of the period to be used as the horizontal synchronization signal 331 (step S306). For example. When the scanning density D is 300 dpi and the printing speed S is 10PPΠ1, the period of the horizontal synchronization signal 331 is set at 2T, that is, N = 2. The CPU 342 sets this N value in the register 341 (step S307). The scanning density and printing are in the register 341 (step S307). The setting of the scanning density and the printing speed and the determination of the period of the horizontal synchronization signal 331 are completed in the above manner. The output control of the horizontal synchronization signal 331 by the horizontal synchronization signal control circuit 3 2 3 will be described below with reference to FIG. The laser control circuit 315 (FIG. 7) controls the laser oscillator 311 operating in synchronization with the rotation of the polygon mirror 102, and each time each side of the polygon mirror 102 arrives at an angular position corresponding to the beam position 316, a Short pulse width output laser beam. When receiving the laser beam, the beam detector 322 applies a beam detection signal 3 2 4 having a predetermined pulse width to the horizontal synchronization signal control circuit 3 2 3.

Tk first min in the back of the matter Sun Yanmu bound the paper size to use a National Standard (CNS) Y 4 specifications (210x297 male dragon) 24 81. 6. 10,000 sheets ⑻ 211613 Ministry of Economic Affairs Central Bureau of Examination and Cooperation Du Yin 51 V. Description of the invention (23) The CPU 342 (圔 10) of the horizontal synchronization signal control circuit 323 sets the C value of the counter 345 to 0, which is used to count one of the beam detection signals 3 2 4 when its operation is started The number of pulse waves (step S401). Whenever the light beam detection signal 324 is fed into the counter (step S 4 0 2), the counter 3 4 5 is incremented by the count value C (step S403). The CPU 342 is used to monitor the count value C (step S404). When the value becomes equal to the value N (Y) stored in the register 341, the CPU 342 imposes a requirement on the input / output signal interface circuit 346 that the circuit generates a level Synchronization signal 331 instructions. When receiving the command, the input / output signal interface circuit 346 performs shaping on the pulse waveform of any beam detection signal 324 received as the input at that time, and then uses the shaped signal as the horizontal synchronization signal 331 Output (step S405). Then, one of the column processing operations of steps S401 to S405 is repeatedly executed until the input signal indicates that the print table operation is completed (step S406). In the case of the above example, when the scanning density D is 300 dpi and the printing speed S is 10 pp π m, the value of "2" is set in the register 3 4 1 and then the operation shown in FIG. 12 is performed Therefore, the horizontal synchronization signal 331 will be output at a pulse wave interval of 2T, as shown in FIG. 8 (c). That is, the horizontal synchronization signal 331 is output once whenever the beam detection signal 324 is input twice. The image data processing unit 126 outputs a line of image data to the laser control unit 3 1 5 each time it receives a horizontal synchronization signal 331 with a pulse interval NT. For example, when N is 2, the line of image data 3 3 8 is output at 2T intervals, as shown in Figure 8 (d). This image data 338 is of course not provided by the computer (please read first, please pay attention to the Bian item and fill out this page). Η Standards (CNS) A 4 specifications (2 丨 0x297 g; «:) 25 8]. 6. 10,000 sheets (Η) 211612 Λ 6 η 6 Ministry of Economic Affairs, Bureau of Standards, A Industrial Consumer Cooperation Cooperative, Yin Yu V. Invention Note (24) The unprocessed image data is given, but has been converted to a scanning density suitable for 300dpi The data format of the 10PPB1 print table speed requirement is then stored in the megameter, as described above. The laser control unit 315 controls the laser oscillator 311 and the modulator 312 according to the image data 338, and then converts the laser beam 313 is output to the polygon mirror 102. When the value of N is 2, the laser beam 313 is reflected on the first surface 102a, the third surface 102c, and the fifth surface 102e of the six surfaces of the polygon mirror 102, and then is projected on The photoreceptor drum 106. In other words, when the second surface 102b, the fourth surface 102d, and the sixth surface 102f of the polygon mirror 102 are located at any position facing the photoreceptor drum 106, the laser beam 313 is not output. In this case, using the processing operations in steps S304 and S305 shown in FIG. 9 to maintain the photoreceptor drum 106 at the original rotation speed, the result is that the print table speed is maintained at 10 PPm, and only the scanning density is changed to 300 dpi. It corresponds to half of the original scanning density. In addition, if the specified scanning density D is 600 dpi and the printing speed S is 5ρρπ, the pulse wave interval is 2T by referring to FIG. 11. In this case, the processing operations of steps S304 and 305 will Rotation speed of photoreceptor drum 106 The degree becomes one-half of its original rotation speed, so that the scanning density is finally maintained at 600dpi, and only the printing speed is changed to 5 ppn, which is one-half of the original printing speed. At the specified scanning density D of 300dpi and printing speed S of 5ρριη In this case, it can be found by referring to FIG. 11 that the pulse wave interval is 4 T, and the rotation speed of the photoreceptor drum 106 is half of the original rotation speed. As a result, the printing speed is changed to 5PP, which is half of the original value, and the scanning density is changed to 300dpi, which is also half of the original scanning density value. In addition, in this situation '(please read the back and forth precautions # 塡 write this page) This paper standard is used in the SS family home rate (CNS) A 4 specifications (210x297 g *) 26 81. 6. 10, 〇〇〇 Zhang (H) 2li〇i2 The Ministry of Economic Affairs, Bureau of Standards, Beta Engineering Consumer Cooperative, printed 5i. V. Description of the invention (25) The surface for the polygon mirror 102 to reflect is the fourth surface, such as the first surface 102a, fifth surface 102e, third surface 102c, first surface 102a, ... In the case where the specified scanning density D is 400 dpi and the printing speed S is 5 ρρπι, it can be known by referring to FIG. 11 that the pulse wave interval is 3T, and the rotation speed of the photoreceptor drum 106 is half of the original rotation speed. As a result, the scanning density was changed to 400 dpi, which is two-thirds of the original density value, and the printing speed was also changed to 5 p p m, which is half of the original speed. In addition, in this case, only two polygonal mirror surfaces are used for reflection, that is, the first surface 102a and the fourth surface 102 2 d. FIG. 13 (A) shows the printing status of the laser printer with a scanning density of 600 dpi and a preset value of a printing speed of 10 ppm. In this case, the period of the horizontal synchronization signal 331 is T, and all six faces of the polygon mirror 102 are used. Fig. 13 (B) shows the printing condition at a scanning density of 600dpi and a printing speed of 5ppid. In this case, the period of the horizontal synchronization signal 331 is 2T, and every other side of the polygon mirror 102 is used. In addition, the solid line in the figure represents the line actually irradiated by the laser beam, and the dotted line represents the line irradiated by the dilution. This method is also applicable to the drawings described later. Fig. 14 (A) shows a state where printing is performed at a scanning density of 300dpi and a printing speed of 100PP1D. In this case, the period of the horizontal synchronization signal 331 is 2T, and every other side of the polygon mirror 102 is used. Fig. 14 (B) shows a state where printing is performed at a scanning density of 300 dpi and a printing speed of 5 ρπι. In this case, the period of the horizontal synchronization signal 331 is 4T, and every fourth plane of the polygon mirror 102 is used. Figure 14 (C) shows the scanning density of 400dpi and the printing speed of 5ppij. (Please pay attention to the back of the page before you go to this page) Binding · Binding-This paper standard is used in a renter standard (CNS) T4 specification (210x297 male dragons) 81. 6. 10,000¾ (H) 2l: L6i2 Λ 6 B 6 Duiny in cooperation with the A Department of the Central Bureau of Preparatory Administration of Part β Du Yin ^ V. Description of the invention (26) Line printing Situation. In this case, the period of the horizontal synchronization signal 331 is 3T, and every third plane of the polygon mirror 102 is used. In addition, this specific example of the present invention has described the system. The product of the scanning density D, the printing speed S, and the period NT of the horizontal synchronization signal 331 is 6000 T, but the present invention is not limited to this form of the specific example. For example, in a system with printing conditions as shown in FIGS. 15 (A) to 15 (C), the effect of obtaining a low level can be obtained because the product of these factors is 3000T. The situation shown in FIG. 15 (A) is that the scanning density is 300dpi, the printing speed is 10PPΠ1 and the period of the horizontal synchronization signal 331 is T, and the situation shown in circle 15 (B) is that the scanning density is 300dP 丨, the printing speed It is 5ρρπ and the period of the horizontal synchronization signal 331 is 2T. In addition, the case shown in FIG. 15 (C) is that the scanning density is 600 dpi, the printing speed is 5 ppm, and the period of the horizontal synchronization signal 331 is that. On the other hand, the system with the printing conditions as shown in pictures 16 (A) to 16 (C) can obtain the high level of efficiency because the product of these factors is 12000T. The situation shown in Fig. 16 (A) is that the scanning density is 600dpi, the printing speed is 10PP1D and the period of the horizontal synchronization signal 331 is 2T. The situation shown in FIG. 16 (B) is that the scanning density is 400 dpi, the printing speed is 10 PPΠ1, and the period of the horizontal synchronization signal 331 is 3T. In addition, the situation shown in Figure 16 (C) is that the scanning density is 300 dpi, the printing speed is 10 PPm, and the period of the horizontal synchronization signal 331 is 4T. As described above, in this specific example, the horizontal synchronization signal control circuit 323 dilutes the beam detection signal 3 2 4 at appropriate intervals, and the horizontal synchronization signal 331 can be obtained within a predetermined period. In contrast to this, in the third specific example shown below, by diluting the laser beam itself irradiated on the beam detector 322, it can be obtained within a predetermined period {Please first-back-to-back note * Item # 塡 写 木Page) Binding-Order _ Line, the paper size is used in the middle of a family home pregnancy (CNS) T4 specification (210x297 male dragon) 28 81. 6. 10,000 sheets (H) by the Central Bureau of the Ministry of Economics and Agriculture to: 工 消 杨Cooperation Duin 5i ~ Λ 6 91 1 _ [16_ V. Invention description (27) Horizontal synchronization signal 331. Fig. 17 shows the main part of a laser printer of a third specific example of the present invention. In the drawing, the same parts as those in the second specific example are denoted by the same reference numbers, and descriptions of these parts are appropriately omitted here. In this example, the printing speed data 327 output from the printing speed control circuit 326 and the scanning density data 3 2 9 output from the scanning density control circuit 328 are supplied to the laser control circuit 315. The internal structure of the laser control circuit 315 is substantially the same as the circuit structure shown in FIG. 11. This control circuit 315 is provided with a reference table to establish the correlation between scan density, printing speed, and the period of the horizontal synchronization signal 3 31. The operation performed by this laser control circuit 315 is the same as that described in the second specific example. In other words, by referring to the reference table, the CPU not shown in the figure extracts an NT value from it as the period of the horizontal synchronization signal 331. The counter (not shown in the figure) of the laser control circuit 315 is used to count the number of pulses in the rotation synchronization signal fed from an encoder (not shown in the figure). This encoder is used to monitor and Each side of the polygon mirror 102 rotates synchronously with the rotation of the polygon mirror 102. The CPU monitors the count value. When the value becomes equal to the value N stored in the register, the CPU controls the laser oscillator 3 1 1 and the modulator 312, and outputs a synchronous beam to irradiate the detector 322 . In this way, the beam detector 3 2 2 outputs the beam detection signal 3 2 4 to the horizontal synchronization signal control circuit 3 2 3. Each time the horizontal synchronization signal control circuit 323 receives a signal input, it shapes the pulse waveform of the beam detection signal 3 2 4 or other, and uses the shaped pulse waveform as the output of the horizontal synchronization signal 331 . Water (Please first, 1, back to the note * 肀 项 #Fill in this page) Binding · Stranding. The size of this paper is easy to use China National Standard (CNS) T4 specifications (210x297 male dragon) 29 81. 6. 10,000 sheets (H) A6 ___ V. Description of the invention (28) The period of the horizontal synchronization signal 311 is therefore set to HT. The subsequent operations of this third specific example are the same as the corresponding operations of the second specific example. Therefore, in this third specific example, the beam detection signal 3 2 4 fed into the horizontal synchronization signal control circuit 3 2 3 will not be diluted, but the synchronization beam output to the beam detector 322 itself is borrowed from the laser oscillator The control of 311 was downplayed. (Please read the back and the precautions # fill in this page) Packing. Threading. Ministry of Economic Affairs, Bureau of Standards, Ai Consumers, Co-operation, Duin 3i, this paper is used in the standard a S Family Support (CNS) 4 specifications (210X29 / male; it) 30 81. 6. 1〇, 〇〇〇 Zhang (Η)

Claims (3)

211612 A7 B7 C7 D7 82. 3. 17 amended Long Sixth, apply for a patent Fan Yuan Central Standards Bureau of the Ministry of Economy ®: Industrial and Consumer Cooperatives print Guangcheng to print the rules to explain Guangcheng to print the line code Guangcheng to use the form to transfer The shape of the pre-transformer into the solution of the shape of the thunder. The image on the thunder is the image on the thunder. The image on the thunder is the device on the image of the thunder on the grid. The code is spent on the powder, and the light modulation is on the shape, the demodulation is on the device, the image is on the device, the image is on the device, the device number is on, and the light is in the dive speed. The number and the light have a medium stroke and the letter of the optical sighting machine is believed to be scanned by the machine. As shown in the scan data. Imprinted on the image beam, such as the light beam, the light beam is printed on the surface light beam. • According to the light in the _ shot, speed: according to the light. There is an outgoing imaging thunderbolt, and a description of the outgoing thunder-shaped display is shown. The upper part of the equipment is described,, the upper pseudo-structure is set to print, the pseudo-structure is set to the mirror, the stolen machine is borrowed, and the machine is listed! $, ， The image of the selected angle machine is set here. The table-mounted system is set here. The quick-state table-mounted system is set here. The multi-surface table-mounted system is printed out. The device is installed and printed. The device is installed and displayed. , Loaded with a mirror image, loaded with a fixed-shot image, loaded with a mirror image of the laser beam angle display to the code, set the beam angle to the code, and scan the beam angle to display the light beam and more Paper solution to plant more light and paper solution and seed selection to light more than one shot and ..; India travels with one shot 5 ;; India;, one shot and; 1. Thunder; image column: speed advance 2 Thunder; Image column: Password capacity 3. Thunder., Beam lurking appears with lattice code beam lurking appears with solution beam lurking ----------- 1 < * 1 ---- ------------- Order ----- 4 (Please read the precautions on the back before filling this page) This paper size is applicable to China National Standards (CNS) A 4 specifications (210 X 297? '^ 1 81.9.10,000 A7 Β7 C7 D7 VI. Scope of patent application The Ministry of Economic Affairs t Central Standards Bureau β Industrial and Consumer Cooperatives prints and prints a copy of the image of the device to guide the scan of the letter to the internal latent mine. With less image, the speed of the image and the beam direction are changed to It is necessary to dive into the light beam on the body's manifestation, and it should be submerged. The dimming shot should be returned for its mastery, and the mine sweep should be provided by the main part. ·, Lei Yan delineated the secondary mirror to obtain the low motion of the middle system to shoot at the mid-angle anti-speed sweep. The light control beam of the machine was used for the transfer. In ,, the beam is set up to print a rapid fire control: Fang credit device shoots to the polarizing device and there is an image of thunder. The time side should change the given image to the thunder. Lei Zhiyi's decision on the material loading package is based on the scan. In the past, the formation of the capital will be based on the root speed. The user will use the time to construct the image of the object. Use the drawing, surface, and damaged drawing machine to set it in the direction of the one, and scan it. Set this, or set the mirror in the direction of installation in the direction of installation, and install it as a step. The appearance of the re-scanning side is equipped with the same print, the information is loaded, the shot, the angle is re-scanned, and the supply side is turned to literacy as a lightening device beam. The shifting of the beam vice shifts to the tracing of the summation and the identification of the paper. If the speed of light and light is turned into the light, the letter is scanned; the letter is scanned and the signal is sent by Rong Gaoyi. The angle of rotation is the same as that of the mirror. Seeking the image between the master and the image: 4 within the knowledge, a beam of light and a corner of the light, densely shadowed, will be displayed in the discerning light making it so many fingers --------- ------------ 装 ------. 玎 ----- ^ (Please read the precautions on the back before filling this page) This paper ruler is suitable for Chinese national standards ( CNS) A 4 gauge (210 X 297 public) 2 81.9.10,000 82. 3.! 7 Proposed Claim Amendment 1. A laser beam printer coiuprising laser beam output means for outputting a laser beam modulated based on an image signal , a polygon mirror for forming a latent Image on a. phot ore captor by scanning with the laser beam; developing means for developing the latent, image formed on the photoreceptor / and transferring means for transferring a toner image obtained by said developing means to a sheet of paperf wherein said laser beaia printer is provided wit: h speed decod ing means for decoding a specification of forming speed of the latent image for the laser beam ,, and speed setting means for setting a transport 'speed for the sheet of paper in accordance with contents decoded by s ^ id speed decoding means. 2. Λ lasex: beam printer · comprising laser beam output meono for ourpurriug a laser beam modulated based on an Image signal ·, a polygon mirror for forming a latent image on a photoreceptor by scanning with the laser bea ^ r developing means for developing the latent image formed on the photoreceptor, and transferring means for transferring a toner image obrained by said developing means to a sheet of paper, wherein said laser bemn printer ie provided with density decoding means for decoding a specification of a scanning line density for the laser beam, and scanning surface selecting τη 色 ans for making a selection 〇 £ scanning surfaces of said polygon mirror in accordance with contents decoded by said density decoding means. reflection of t he laser beam in response to at least one of a demand for a change in a scanning density and a demand, for a change in a printing speed in the subsidiary scanning direction; and image signal supply means for supplying an image signal for one main scanning portion in synchronization with facets at a prescribed interval as, determined for use thereof · by said facet interval determining means. 211612 3. A laser Deam printer comprising laser beam output, means -for outputting a laser baam modulated based on an image signal, a polygon rnirror for forming a latent image on a photoreceptor · by scanning with the laser beamr developing means for developing ther latent image formed on uhe piiotureceptor, and troutsCerrlng means for transferring a toner image obtained by said developing means to a sheet of paper, wherein said laser ..beam printer is provided with inforraation discerning means for discerning whether Information of the latent image to formed on the photoreceptor is text information or picture information ^ and speed control means for controlling a latent image forming spaed for the laser beam to a high speed side in case the information of the latent image is rext information and to a low speed side in case said information is picture information.- 4. A laser beam printer comprising: a photoreceptor moving in a predetermined direction; laser beam output means for generating a laser beam modulated on the basis of an image signal; a rotating polygon for reflecting the laser beam while rotating at a constant speed and for irradiating the laser beam repeatedly onto said photoreceptor ^ directing the laser beam in a main scanning direction different from a subsidiary scanning direction which coincides with a moving direction of said polygon;. facet interval determining means for determining Intervals among facets of said rotating polygon as used for