KR100343173B1 - Optical scanning system of printer - Google Patents

Abstract

An optical scanning system of a printing press is disclosed. The optical scanning system is circularly circulated, and a slit portion formed by alternating light-transmitting portions and light-shielding portions in the non-imaging mouth region along the progress direction thereof, a photosensitive medium having a light-transmitting window, and spaced apart from each other by a predetermined interval. A first light-receiving unit which is arranged to receive light passing through the light-transmitting part from the light-receiving unit from a plurality of light-receiving unit for scanning light, and at least one light-receiving unit selected mainly on the photosensitive medium; A second light receiving unit installed to receive light passing through the light-transmitting window from each of the light emitting yarn units at opposite sides of the photoreceptor units centering on a photosensitive medium; and a first light receiving unit and a second light receiving unit. Using the output signal, the page area set for the photosensitive medium is displayed on the same page when it arrives at the dice of each of the photosensitive units. To write the image information on the photosensitive medium and a Gwangju Co. fisherman for controlling the image scanning start timing of each other ju reason knit. According to the optical scanning system, the page synchronization occurrence time interval data can be calculated internally, so that after the replacement of the optical scanning unit, there is no need to perform a separate operation for matching the color registration, thereby improving convenience and improving the belt slip. Image writing error can be determined, thereby reducing the image writing error.

Description

Optical scanning system of printer

The present invention relates to a light scanning system of a printing press. In detail, a page simultaneous generation time interval data required for writing color information of a page in a page area set on a photosensitive medium that is circulated with a plurality of light scanning units is not shifted. The optical scanning system of the printing press that can be calculated internally.

1 is a view showing a general wet color printing machine.

Referring to the drawings, the reset device 15, the optical scanning unit 30, 40 (adjacent to the circulation path of the photosensitive belt 14 circulating by the plurality of rollers 11, 12, 13) ( 50, 60, photodetectors 38, 48, 58, 68, developer 36, 46, 56, 66, drying device 18, transfer device 20 It is placed at a certain distance. Reference numeral 15a denotes an exposure apparatus for erasing the electrostatic latent image, and reference numerals 15b, 37, 47, and 57 denote chargers for charging the photosensitive belt to a predetermined potential to enable the electrostatic latent image writing.

Looking at the printing process, first, when the tip of the image writing page area set on the photosensitive belt 14 reaches the dice of the first light scanning unit 30 through the reset device 15, the first light scanning unit 30 ) Scans light with yellow color image information. The electrostatic latent image formed on the photosensitive belt 14 by the first light scanning unit 30 is developed by the first developing unit 36 for supplying a developer Y of yellow color. When the page area on the photosensitive belt 14 is charged by the charger 37 to write a new electrostatic latent image, and then reaches the dice of the second light scanning unit 40, the second light scanning unit ( 40) scans light for image information of magenta color. The electrostatic latent image formed on the photosensitive belt 14 by the second light scanning unit 40 is developed by the second developing unit 46 which supplies the developer M of magenta color.

This process includes the third and fourth light scanning units 50 and 60 for scanning the cyan and black image information and supplying the corresponding cyan and black developer (C) and BK. And the fourth developer 56, 66. As a result, a color image is formed on the photosensitive belt 14 which has passed through the fourth developer 66. The color image formed of the developing material on the photosensitive belt 14 is firstly transferred to the transfer roller 21 through which the photosensitive belt 14 and a part thereof are rotated through the drying device 18 for removing the liquid carrier element. Is transferred. Subsequently, the color image transferred to the transfer roller 21 is secondarily transferred to the paper 23 entering between the transfer roller 21 and the fixing roller 22.

On the other hand, the optical fiber unit 30, 40, 50, 60 are each configured to emit light while gradually changing the angle within a predetermined angle range. In general, the optical scanning unit 30, 40, 50, 60, which are commonly used, includes a light source, a rotating polygon mirror and a lens unit, and a hologram disk instead of the rotating mirror mirror.

The optical unit 30, 40, 50 and 60 can scan the optical signal corresponding to the image information in turn whenever the page area set on the photosensitive belt 14 reaches the dice. In order to ensure that the front end of the page area of the photosensitive belt 14 has to be able to accurately determine whether or not to reach the dice of each of the photo-wang unit (30, 40, 50, 60).

In particular, a color printing machine provided with a plurality of optical scanning units 30, 40, 50, and 60 so as to scan different color information with respect to the photosensitive belt 14, which is a circulating photosensitive medium, while maintaining a predetermined distance. In this case, if the optical signal emitted from each of the photoreceptor units 30, 40, 50 and 60 is not controlled to reach a desired pixel position in the page area set on the photosensitive belt 14, The patterns are shifted from each other and a desired image cannot be obtained.

In this way, the color restoring error means that the images for each color are written shifted from the pixel image writing position in the page area set on the photosensitive belt 14.

In order to correct such a color registration error, conventionally, after instructing to print an image of a set test pattern, the inspector directly measures the distance difference between the test patterns for each color output on the paper 23, and therefrom a registration error. The amount was calculated. However, this method has the disadvantage that the operator has to calculate the registration error amount directly, and that the artificial error is likely to be included in the error amount calculation.

The present invention has been devised to solve the above problems, and each Gwangju unit is a page for each Gwangju unit which is required to emit light to the pixel position desired for the image information by color in the page area set on the photosensitive medium. It is an object of the present invention to provide a optical scanning system of a printing press that can increase the printing quality while improving the convenience of use by allowing internal calculation of the synchronization occurrence time interval data.

1 is a cross-sectional view showing a typical wet color printing press,

Figure 2 is a perspective view showing a light scanning system of the printing machine according to the present invention,

3 is a flowchart illustrating a process of acquiring page synchronization time interval data.

<Explanation of symbols for the main parts of the drawings>

11, 12, 13, 71, 72, 73: Roller 14, 74: Photosensitive belt

15: reset device 15a: exposure device

15b, 37, 47, 57: charger 18: drying device

20: transfer device 21: transfer roller

22: fixing roller 23: paper

30, 40, 50, 60, 80, 90, 100, 110: Gwangju company unit

36, 46, 56, 66: developer

38, 48, 58, 68: photodetectors

81, 91, 101, and 111: first light receiving unit

85, 95, 105, and 115: second light receiving unit

75: slit portion 75a: light transmitting portion

75b: Shading part 76: Floodlight

82, 92, 102, 112: light source 83, 93, 103, 113: rotating face mirror

84, 94, 104, 114: lens unit 120: optical scanning controller

121: memory 122: counter

In order to achieve the above object, the optical scanning system of the printing machine according to the present invention is circulated by a plurality of rollers, and a light-transmitting portion and a light-shielding portion are arranged in a non-image writing area outside the image writing area set in the center portion along the direction of travel. A photosensitive medium having a slit portion continuously formed in alternating rows, and a light transmission window formed in a predetermined size to transmit light to the non-image writing region; A plurality of optical scanning units which scan light side by side along a main scanning direction intersecting at a predetermined angle with respect to a traveling direction of the photosensitive medium spaced apart from each other by a predetermined interval; A first output unit configured to receive light passing through the light-transmitting part from the optical fiber unit at opposite sides of the at least one optical fiber unit selected from the photosensitive medium, and outputting electrical signals corresponding to light reception; A light receiving unit; A second light receiving unit arranged to receive light passing through the light-transmitting window from the light-receiving unit through the light-receiving unit at opposite sides of the light-receiving unit around the photosensitive medium, and outputting electrical signals corresponding to the light-receiving unit; Wow; When the page area set for the photosensitive medium arrives at the dice of each of the photoreceptor units using the output signal of the first light receiving unit and the second light receiving unit, the image information of the same page is displayed. And a light scanning control unit for controlling each image scanning start time between the optical scanning units so as to be written in, so as to drive each optical scanning unit.

Preferably, the optical scanning control unit is based on the time when the light receiving signal is output from the second light receiving unit when the light-transmitting window arrives with the dice of the reference optical scanning unit selected from the optical scanning unit when the photosensitive medium moves at a set speed As a result, each of the floodlights arrives at the dice of the remaining photoreceptor unit, and a value of counting the received light signals output in correspondence with the passage of the transmissive portion of the light scanned by the first light receiver until the light receiver signal is generated from the second light receiver is The count value of the received light signal output from the first light receiving unit reaches a count value stored in the memory, which is stored in the memory, and at the time of printing, based on the start time of optical scanning corresponding to the image information of the reference light scanning unit. Gwangju Corp. corresponding to the image information of other Gwangju Incident Units The lock controls the Gwangju reason knit. The optical scanning controller may count values of the light receiving signals output from the first light receiving unit until the floodlight arrives at the dice of other optical fiber units based on the time point at which the light emitting window arrives at the dice of the reference optical fiber unit. If the count value differs from the corresponding count value recorded in the memory, the operation of the optical scanning unit is stopped.

Hereinafter, the optical scanning system of the printing press according to a preferred embodiment of the present invention with reference to the accompanying drawings in more detail.

Figure 2 is a perspective view showing a light scanning system of a printing press according to the present invention.

Referring to the drawings, the optical scanning system is circulated by a plurality of rollers (71) (72) (73) and a photosensitive belt having a slit portion (75) and a light-transmitting window (76) formed along an advancing direction in an edge region thereof. 74 and a plurality of optical scanning unit 80, 90, 100, 110 for scanning light onto the photosensitive belt 74, and the light passing through the slit 75 can be received. The first light receivers 81, 91, 101, and 111 installed in the light-receiving unit 80, 90, 100, and 110 may receive light passing through the light-transmitting window 76. The second light receiving unit 85, 95, 105, 115 and the optical scanning control unit 120 is installed in a fixed position so as to be.

The photosensitive belt 74 forms an electrostatic latent image in response to incident light, and the slit portion 75 and the light-transmitting window 76 are spaced apart from each other by a predetermined distance in a non-image writing region outside the image writing region D in the center portion. It is prepared.

The light transmission window 76 is formed of a through hole or a transparent material.

In the slit portion 75, a plurality of light-transmitting portions 75a and light-shielding portions 75b are alternately formed successively along the sub-scanning direction (the direction orthogonal to the main scanning direction) that is the traveling direction of the photosensitive belt 74. The light-transmitting portion 75a of the slit portion 75 may be formed in the form of a through hole. Preferably, the light-transmitting portion 75a is formed of a transparent material in consideration of an increase in the ability to withstand tension. The light blocking portion 75b may be formed of a light blocking material. The light transmitting portion 75a is formed to be as fine as possible at equal intervals, for example, preferably to maintain the distance between the image writing line interval (pixel interval in the sub-scanning direction) or several times thereof.

The optical fiber units 80, 90, 100, and 110 are light sources 82, 92, 102, 112, rotating mirrors 83, 93, 103, 113, and lenses, respectively. Units 84, 94, 104 and 114 are provided. The optical fiber unit (80, 90, 100, 110) is provided with a scan disk (not shown) having a hologram pattern so as to deflect the incident light, and a light source for emitting light to the rotating scan disk It may be configured.

The first light-receiving portion is a light-transmitting portion of the slit portion 75 formed on the photosensitive belt 74 behind the photosensitive belt 74 with respect to the selected one or a plurality of optical scanning units 80, 90, 100, 110 ( And photodetectors 81, 91, 101, and 111 installed to receive light passing through 75a and output electrical signals corresponding thereto. One light scanning unit 80 is selected to detect the passage of the light-receiving portion 75a of the first light receiving unit, for example, the first light scanning unit 80 is selected, and one photodetector at a corresponding position of the selected light scanning unit 80. In the case where 81 is installed and configured, there is an advantage that the structure becomes simple, but the selected one optical fiber unit 80 is scanned by other optical fiber units 90, 100, 110 corresponding to the image information. Keep running until it's complete. On the other hand, in order to detect the passage of the light-receiving portion 75a of the first light-receiving unit, the photodetectors 81, 91, 101 are respectively located at positions corresponding to the optical scanning units 80, 90, 100, 110, respectively. In the case in which the 111s are installed, the structure becomes more complicated, but there is an advantage in that the optical scanning unit in which image information scanning is completed is not driven. Considering these points, it is necessary to select the number of photodetectors appropriately.

The second light-receiving unit is a light-transmitting window 76 when the light-emitting window 76 reaches the dice L1, L2, L3, and L4 of each of the optical fiber units 80, 90, 100, and 110. Four photodetectors 85, 95, 105, and 115 are provided at positions capable of receiving light passing through. The second light receiver outputs an electrical signal corresponding to the light reception to the optical scanning controller 120.

The optical scanning controller 120 sets light on the photosensitive belt 74 corresponding to the color image data of each optical scanning unit 80, 90, 100, 110 for one page of image information. The light exit timing of the optical scanning units 80, 90, 100, and 110 is controlled to reach a desired pixel position of the page area 74a. The optical scanning unit 120 is configured for each optical scanning unit 80 required to write image information for each color in the same page area 74a of each optical scanning unit 80, 90, 100, 110. The page synchronization signal generation interval data between (90), (100) and (110) can be internally calculated. The page synchronization signal generation interval data calculation between each optical unit may be programmed to be performed internally by the optical scanning controller 120 at a set period or a warm-up period performed after the power is turned on, or the page synchronization signal generation interval from the outside. The data calculation may be instructed. When the page synchronization signal generation interval data calculation instruction can be received from the outside, the page synchronization signal generation interval data calculation request signal is output on the operation panel (not shown), which is an input device provided outside the main body of the printer. ), Or in the case of a printer connected to a computer, with the help of a printer driver program installed in the computer, the user can transmit a page sync signal generation interval data calculation request signal from the computer to the printer. do.

When there is a request for calculating the page synchronization signal generation interval data, the optical scanning controller 120 controls each device to internally calculate the page synchronization signal generation interval data using the provided counter 122, and the calculated data is The memory 121 stores the memory.

A process of calculating the page synchronization signal generation interval data will be described with reference to FIG. 3.

First, if there is a request for calculating the page synchronizing signal generation interval data, the rollers 71, 72 and 73 are driven to circulate the photosensitive belt 74 at the same speed as in the printing operation (step 200). When the photosensitive belt 74 proceeds at the set feed rate, the photowangwang unit 80, 90, 100, 110 so that light is continuously emitted from the photowangwang unit 80, 90, 100, 110. ).

Then, when a light receiving signal output from the photodetector of the second light receiving unit is input when the light transmitting window 76 reaches the scanning position of the reference light scanning unit, the light receiving signal corresponding to the passage of the light transmitting portion 75a in the first light receiving unit is input. Start counting the number of inputs. In the following description, for the sake of simplicity, the reference optical scanning unit is the first light scanning unit 80, and the first light receiving unit is made of only the photodetector 111 provided to correspond to the fourth light scanning unit 110. Explain.

The light transmission window 76 reaches the dice L2 of the second light scanning unit 90 by the continuous movement of the photosensitive belt 74, and the signal corresponding to light reception from the photodetector 95 of the second light receiving unit 90 is received. When is input, the number of received signal counts corresponding to the number of passages of the transmissive portion 75a from the photodetector 111 of the first light receiver until then is stored in the memory 121 (step 210). At this time, counting may be reset and counting may restart, or counting may be continued.

In the same manner as in step 210, thereafter, in steps 220 and 230, the light transmission window 76 causes the third light scanning unit 100 and the fourth light scanning unit 110 to be moved by the continuous movement of the photosensitive belt 74. Each time it reaches each of the dice L3 and L4 of, the photodetector of the first light receiver of the first light receiver is up to that point, based on the time point at which a signal corresponding to the light reception is input from the photodetectors 105 and 115 of the second light receiver. The number of received signal counts corresponding to the number of passages of the transmissive portion 75a from 111 is stored in the memory 121.

Through this process, the light-emitting window 76 reaches the dice (L2) L3 (L4) of the other Gwangju unit (90) (100) 110 from the dice (L1) of the reference Gwangju company unit (80). Set the count value corresponding to the number of light-transmitting portions 75a to be passed as the page synchronization occurrence interval data of the other optical scanning unit 90, 100, 110 for the reference optical scanning unit 80 ( Step 240).

After the page synchronization generation interval data is obtained, the scanning start interval for each optical scanning unit 80, 90, 100, 110 for the image information of the same page is stored by the stored page synchronization occurrence interval data. This is controlled.

That is, when the light transmission window 76 reaches the dice L1 of the reference optical unit 80, the portion of the photosensitive belt 74 corresponding to the dice L1 is set as the page area tip 74b. When the light transmission window 76 reaches the dice L1 of the reference light scanning unit 80 during the printing operation and a light reception signal is input from the photodetector 85 of the second light receiving unit, the photosensitive belt is received from the light transmission window 76. The light output is stopped for a time required for light to scan the separation distance d to the tip of the image writing area D on the 74, and the tip of the image writing area D on the photosensitive belt 74 is stopped. When it is time for light to be emitted, light corresponding to the image information of the reference optical fiber unit 80 is started. This process is performed until all the image information of one page is written.

On the other hand, the optical scanning control unit 120 is based on the light receiving signal input time of the photodetector 85 generated when the light transmission window 76 reaches the dice L1 of the reference optical scanning unit 80, the first The light receiving signal output every time the light transmitting portion 75a passes from the light detector 111 of the light receiving portion is counted. In this case, the fourth light scanning unit 110 is driven so that light can be scanned only into the non-image writing area.

When the counted number of received signals reaches the count number stored as the page synchronization interval data of the second light scanning unit 90, the page area tip 74b has the dice L2 of the second light scanning unit 90. ), And the optical scanning of the second optical scanning unit 90 is started in the same manner as described above. The third light scanning unit 100 and the fourth light scanning unit 110 also reach a count value corresponding to the page synchronization occurrence interval set in the memory 121 when the value of counting the received signal output from the first light receiving unit is reached. Image scanning is started in the granulation region D.

On the other hand, according to the method of adjusting the image writing timing for the same page between each of the optical scanning unit 80, 90, 100, 110 by this method, one or two lines of photosensitive in the middle of a print job Even if a belt slip occurs with respect to the progression distance of the belt 74, the image writing start positions of the optical scanning units 80, 90, 100, and 110 can be matched, thereby reducing image writing errors.

In parallel with this scanning control, the light-transmitting window 76 is output every time the light-transmitting portion 75a passes from the photodetector 111 of the first light-receiving unit on the basis of the point of time when the light-emitting window 76 reaches the dice value of the reference optical unit 80. The count value obtained until the light reception signal is counted and the light transmission window 76 reaches the dice L2 of the second light scanning unit 90 until the light reception signal is input from the photodetector 95 of the second light reception unit is stored in memory. Compared with the value stored in 121, if it is equal, it is determined that no belt slip has occurred, and the optical scanning corresponding to the image information of the second light scanning unit 90 is started. If the light-transmitting window 76 reaches the dice L1 of the reference light scanning unit 80 to the dice L2 of the second light scanning unit 90, the photodetector 111 of the first light receiving unit may be used. When the light reception signal count value corresponding to the number of passages of the light transmitting portion 75a is different from the count value set in the memory 121, it is determined that the belt slip has occurred and the printing operation is stopped. The error message is then displayed on the display device. According to this method, an image writing error due to a belt slip can be avoided.

The same applies to the third and fourth light scanning units.

As described so far, according to the optical scanning system of the printing press according to the present invention, the page synchronization occurrence time interval data which can determine when the page area set on the photosensitive belt reaches the dice value of each optical scanning unit. Can be calculated internally, and even after replacement of the photoreceptor unit, the user does not need to perform a separate operation to match the color registration, thereby improving convenience and determining an image writing error due to belt slip. Can be reduced.

Claims (6)

A slit portion which is circulated by a plurality of rollers, which is set at the center portion along the advancing direction and continuously formed by alternating rows of light-transmitting portions and light-shielding portions in a non-image writing area outside the image writing area, and the non-image A photosensitive medium having a light transmission window formed to a predetermined size to transmit light to the writing area; A plurality of optical scanning units which scan light side by side along a main scanning direction intersecting at a predetermined angle with respect to a traveling direction of the photosensitive medium spaced apart from each other by a predetermined interval; A first output unit configured to receive light passing through the light-transmitting part from the optical fiber unit at opposite sides of the at least one optical fiber unit selected from the photosensitive medium, and outputting electrical signals corresponding to light reception; A light receiving unit; A second light receiving unit arranged to receive light passing through the light-transmitting window from the light-receiving unit through the light-receiving unit at opposite sides of the light-receiving unit around the photosensitive medium, and outputting electrical signals corresponding to the light-receiving unit; Wow; When the photosensitive medium moves at a set speed, when the floodlight arrives at the dice of the reference photonic yarn unit selected from the photoreceptor units, the light guide window is the remaining photoreceptor unit based on the time when the light reception signal is output from the second light receiver. The memory device stores a counted number of received signals outputted in correspondence to the passage of the light-transmitting portion of the light scanned by the first light receiver until the light arrives at each of the second light receivers and generates a light signal. When the count value of the light receiving signal output from the first light receiving unit reaches the count value stored in the memory on the basis of the start time of optical scanning corresponding to the image information of the reference light scanning unit, Controlling the optical fiber unit so that the optical fiber corresponding to the image information of the knits is started Optical scanning system of the printing machine comprising a; optical scanning control unit. The method of claim 1, The optical scanning controller controls the count value of the light receiving signal output from the first light receiving unit until the floodlight arrives at the dice of the other optical fiber unit based on the time when the floodlight arrives at the dice of the reference optical fiber unit. The optical scanning system of the printing machine, characterized in that the operation of the optical scanning unit is stopped if it is different from the corresponding count value recorded in the memory. The optical scanning system of claim 1, wherein the light transmitting portion is formed of a transparent material. The optical scanning system of claim 1, wherein the light transmitting portion is formed of a through hole. The optical scanning system of claim 1, wherein the light transmission window is formed of a transparent material. The optical scanning system of claim 1, wherein the light transmission window is formed of a through hole.