JP2007279125A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To configure a printer which has a scanning exposure system that reflects three primary color laser beams by a polygon mirror to scan/expose, and does not cause deviation in exposure-timing even when environmental temperature changes. <P>SOLUTION: A main scanning chart and a sub scanning chart are printed by a chart printing means 56, the chart having the visually smallest line deviation in terms of C(cyan), M(magenta) and Y(yellow) lines is selected, and index information on the chart is inputted, and thus a table updating means 55 stores the measurement temperature by a temperature sensor S obtained at the timing of exposing the chart, and a correction value, in a correction table 54, wherein they are associated with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a scanning exposure system that performs scanning exposure by reflecting laser beams of different wavelengths generated by a plurality of laser light sources by a polygon mirror that rotates around an axis, and is synchronized with the rotation of the polygon mirror. The present invention relates to a printing apparatus including an exposure control unit that reads density values of image data in a main scanning direction and adjusts the light amounts of a plurality of laser beams, and more particularly to a technique for correcting an exposure position by a laser beam.

  As a printing apparatus configured as described above, there is one described in Patent Document 1. In this patent document 1, a main scanning direction correction unit, a sub-scanning direction correction unit, and a temperature sensor are provided, and R (red), G (green), and B (blue) 3 based on the temperature measured by the temperature sensor. The main scanning direction correction unit and the sub-scanning direction correction unit correct the timing for reading out the image data corresponding to the primary color from the memory unit, thereby shifting the exposure timing deviation of the image data of the two primary colors in the main scanning direction and the sub-scanning direction. It is configured to be eliminated.

Japanese Patent Laid-Open No. 2003-5107

  As an example of a printing apparatus that exposes photographic paper in a form in which laser beams of three primary colors of R (red), G (green), and B (blue) are scanned, in this printing apparatus, when assembling the printing apparatus Is adjusted so that the error of the irradiation position on the photographic paper by the three laser beams corresponding to one pixel of the image data is as small as possible. If the position cannot be set, a correction table for correcting the exposure timing in the main scanning direction and the exposure execution line in the sub-scanning direction is set to eliminate the deviation of the exposure positions of the three primary color laser beams. It was.

  In addition to the thermal expansion of the laser beam support system members, the cause of the deviation in the exposure position is considered to be the deformation of the fθ lens that guides the laser beam to the photosensitive material, particularly for cost reduction. When the fθ lens is made of a resin material, the influence of heat is large.

  As described above, in a printing apparatus using a laser beam, a slight deviation occurs in a path through which the laser beams of the three primary colors are sent depending on the temperature to be used. To correct this deviation, it is described in Patent Document 1. As described above, it is effective to perform correction based on the temperature measured by the temperature sensor.

  However, because there are individual differences in hardware scanning exposure systems, when correction is performed based on the temperature measured by the temperature sensor, a fixed correction table or the like cannot be used. It is not only necessary to acquire and store correction values in the main scanning direction and the sub-scanning direction in advance for the three types of laser beams corresponding to the above, but it takes time to acquire the correction values. In order to save the correction data, a memory area is required in the memory, and there is room for improvement.

  An object of the present invention is to perform scanning exposure by reflecting laser beams of different wavelengths generated by a plurality of laser light sources with a polygon mirror, and a print that does not cause a deviation in the exposure position even if the environmental temperature changes. The point is to construct the device rationally.

A feature of the present invention is that it includes a scanning exposure system that performs scanning exposure by reflecting laser beams of different wavelengths generated by a plurality of laser light sources by a polygon mirror that rotates around an axis, and is synchronized with the rotation of the polygon mirror. In the printing apparatus including an exposure control unit that reads out the density value of the image data in the main scanning direction and adjusts the light amounts of the plurality of laser beams.
The exposure control unit includes a correction table for setting an exposure timing in the main scanning direction of the image data corresponding to the laser beams of different wavelengths and an exposure execution line in the sub-scanning direction,
A chart printing means for printing a calibration chart using laser beams of different wavelengths, and a temperature sensor for measuring the temperature of the scanning exposure system,
An optimum exposure state is selected from the calibration chart printed on the print medium by the chart printing means, and a correction value corresponding to the exposure state is associated with the measured temperature of the temperature sensor, and the exposure timing of the correction table is newly set. A table update means for setting is provided.

  With this configuration, the table updating unit corresponds to the optimum exposure state by printing the calibration chart on the print medium by the chart printing unit in the environment where the printing apparatus is used, and selecting the optimum exposure state from the calibration chart. A correction table is newly set by associating the correction value with the measured temperature of the temperature sensor. After the correction table is newly set in this way, main scanning of image data corresponding to laser beams of different wavelengths based on the correction table newly set by the exposure control unit based on the measurement value of the temperature sensor. The exposure timing in the direction and the exposure execution line in the sub-scanning direction are set. As a result, scanning exposure is performed in which laser beams of different wavelengths generated by a plurality of laser light sources are reflected by a polygon mirror to perform scanning exposure. Even if the environmental temperature changes, the exposure position by each laser beam is shifted. Thus, a printing apparatus capable of printing a high-quality image without causing the problem has been constructed.

According to the present invention, the chart printing means changes the exposure timing in the main scanning direction for each laser beam having a different wavelength in a preset step, and prints index information indicating each exposure timing on the print medium. The main scanning chart as the calibration chart, and the exposure execution line in the sub-scanning direction are changed in a preset step for each of the laser beams of different wavelengths, and the index information indicating the exposure execution line is printed on the print Configured to print a sub-scan chart as the calibration chart printed on a medium;
The table updating means inputs the index information of the main scanning chart and the index information of the sub-scanning chart by an operator, so that the index information and the main scanning chart and the sub-scanning chart are printed when the index information is printed. A correction value may be set from the measured temperature of the temperature sensor.

  With this configuration, the main scanning chart and the sub scanning chart are printed on the print medium by the chart printing means, and the table is updated by inputting the index information indicating the optimum exposure state from the main scanning chart and the sub scanning chart. The means sets the exposure timing and the exposure execution line based on the index information and the temperature measured by the temperature sensor, so that it is possible to reduce the trouble of inputting correction data.

  According to the present invention, the table updating unit performs printing of the main scanning chart and the sub-scanning chart a plurality of times by the chart printing unit, and then indexes information of the plurality of main-scanning charts and the index of the sub-scanning chart. The correction value may be set from the average value of the correction values indicated by the plurality of index information by the operator inputting the information.

  In this configuration, when the operator inputs index information indicating the optimum exposure timing from the main scanning chart and the sub-scanning chart a plurality of times, the average value of the exposure timing specified by the plurality of inputs is set as the correction value. As a result, it is possible to reduce the error and print higher quality image data.

  In the present invention, the scanning exposure system is configured to generate three laser beams corresponding to three primary colors of R (red), G (green), and B (blue) as the laser light source, and the exposure control unit includes: , R (red), G (green), and R (red), G (green), based on the correction value associated with the measured temperature of the temperature sensor in the correction table with reference to the timing at which the laser beam reflected by the polygon mirror is received by the synchronous sensor Image data read start timings corresponding to the three primary colors B (blue) may be set.

  With this configuration, even if the scanning exposure system includes a light source that generates three laser beams corresponding to the three primary colors, it corresponds to the three primary colors based on the correction values associated with the measurement values of the temperature sensor in the correction table. By performing the process of setting the readout start timing of the image data, it is possible to maintain the exposure timing appropriately.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
〔overall structure〕
As shown in FIG. 1, the exposure block Ex, the development block De, and the drying block Dr are housed in a housing 10 to constitute a printing apparatus. Outside the casing 10 is provided with a belt conveying mechanism 11 that conveys photographic paper P as a print medium fed out from the upper part of the casing 10 in a horizontal direction after the printing process, and the print sent from the belt conveying mechanism 11. A sorter (not shown) for sorting and collecting the paper P in order units is provided.

  The development block De includes a plurality of development processing tanks 14 including a color development tank, a bleach-fixing tank, and a stabilization tank, and a transport mechanism that supplies the photographic paper P to each of the development processing tanks 14. The drying block Dr includes a transport mechanism that transports the photographic paper P sent out from the developing block De, and a blower 15 that supplies dry air heated by a heater to the photographic paper P transported by the transport mechanism. Yes.

  The exposure block Ex supplies the photographic paper P from the photographic paper magazine M to the exposure conveyance unit Ue by the front conveyance unit Uf, and the exposure conveyance unit Ue conveys the photographic paper P in the sub-scanning direction (upward in the drawing). The basic processing mode is such that the image data is exposed with the laser beam from the exposure unit E, and the photographic paper P exposed at the time of transport by the exposure transport unit Ue is sent to the development processing tank 14 by the rear transport unit Ur. Is set.

  More specifically, the front transport unit Uf draws one roll-shaped photographic paper P of the two photographic paper magazines M, M by the transport roller 16, cuts it into a print size by the cutter 17, and prints on the back side. After necessary information is printed by the head 18, it is fed upward by the feeder 19 and supplied to the exposure transport unit Ue.

  The exposure transport unit Ue receives the photographic paper P from the feeder 19 by a receiving roller 20, and the photographic paper P from the receiving roller 20 is moved upward by two sets of exposure transport rollers including a driving roller 21 and a driven roller 22. While being conveyed in the (sub-scanning direction), exposure is performed in the main scanning direction by the laser beam from the exposure unit E at the exposure position X. The pair of driving rollers 21 are driven at a constant speed by a driving force from a transport motor 21M (see FIG. 2).

  In this exposure transport unit Ue, when the photographic paper P sent from the receiving roller 20 is received by the lower exposure transport roller, the driven roller 22 is set to the open position, and the photographic paper P can be crimped. Similarly, when the driven roller 22 is switched to the pressure-bonding position at the time when it is conveyed to the position, and the photographic paper P is received by the upper exposure conveying roller, the driven roller 22 is set to the open position, and the photographic paper P Smooth transfer is realized by switching the driven roller 22 to the pressure-bonding position at the time when the roller is conveyed to the position where pressure-bonding is possible.

  The rear transport unit Ur converts the transport direction of the photographic paper P from the exposure transport unit Ue from a vertical direction to a horizontal direction by a curved transport unit U1 having a plurality of pressure-bonding-type transport rollers 23, and a pair of chuckers The distribution transport unit U2 having 24 distributes to the distribution path in two rows, and the photographic printing paper P thus distributed is developed from the introduction transport unit U3 having a plurality of pressure-bonding-type transport rollers 25 to the development block De. Introduce into the tank 14.

  As shown in FIGS. 2 and 3, the exposure unit E includes a housing 32 of a light metal alloy such as an aluminum alloy having a sealed structure provided with a dust-proof glass 31 at an opening for sending a laser beam, and an interior of the housing 32. It is comprised with the accommodated laser light source unit. The laser light source unit includes R (red), G (green), and B (blue) three primary colors of laser light sources 33r, 33g, and 33b, and G (green) and B (blue) laser light sources 33g and 33b. Light quantity adjusting mechanisms 44g and 44b composed of acousto-optic conversion elements for adjusting (modulating) the intensity (light quantity) of the laser beam from the laser beam, beam mirrors 35r, 35g and 35b for reflecting the laser beam, and beam mirrors 35r and 35g, A polygon mirror 36 to which the laser beam from 35b is guided; an electric motor 37 for driving and rotating the polygon mirror 36; and an fθ lens group 38 for guiding the laser beam reflected by the polygon mirror 36 to the photographic paper P at the exposure position X; Synchronous detection of the timing at which the laser beam from the polygon mirror 36 reaches the scanning end from the laser beam reflected by the timing mirror 39 And a capacitors 40.

  The R (red) laser light source 33r is configured as a semiconductor laser type, and the G (green) and B (blue) laser light sources 33g and 33b are configured as a solid-state laser type. The R (red) laser light source 33r controls the amount of laser beam emitted by controlling the supply power.

  The polygon mirror 36 is supported by the driving force from the electric motor 37 so as to be rotatable around the axial center Y in the vertical orientation. The electric motor 37 has a structure that rotates at a rotational speed corresponding to the frequency of the drive signal by supplying a drive signal from the outside, and the polygon mirror 36 is viewed in a direction along the axis Y. A plurality of reflecting surfaces 36m are formed by finishing the outer peripheral surface, which is a regular polygon, into a flat mirror surface. The fθ lens group 38 is formed by combining a plurality of resin-made cylindrical lenses, and applies a laser beam equiangularly scanned (scanned at a constant angular velocity) in the main scanning direction by the rotation of the polygon mirror 36 to the photosensitive surface of the photographic paper P. It functions to convert it into a laser beam that scans at a constant speed (scanning at a constant linear velocity).

  An exposure control unit 45 that exposes image data by irradiating the photographic paper P with laser beams of the three primary colors R (red), G (green), and B (blue) from the exposure unit E is provided below the exposure unit E. Prepared on the side.

(Control configuration)
As shown in FIG. 4, the exposure controller 45 outputs light amount control information to the laser light source 33r, the light amount adjusting mechanism 44g, and the light amount adjusting mechanism 44b, and R (red) and G (green). , B (blue) corresponding to the three primary colors, a light amount control unit 50 comprising light amount control means 50r, 50g, 50b is provided. The light quantity control unit 50 includes an input system for acquiring image data from the image data storage unit 51, and also includes a detection signal from the synchronization sensor 40, a clock signal generated by the clock generation unit 52, and a timing setting unit 53. Timing signals corresponding to (red), G (green), and B (blue) are input.

  The exposure control unit 45 includes a correction table 54 that gives correction values of R (red), G (green), and B (blue) to the timing setting unit 53. Table update means 55 for storing correction values or updating correction values, and chart printing means 56 for realizing printing of a calibration chart. Further, a signal system for inputting the measured temperature of the temperature sensor S to the timing setting means 53 and the table updating means 55 is formed, and index information (described later) is input to the table updating means 55 from a keyboard or a mouse (not shown). The print execution information is input to the chart print unit 56.

[Exposure processing]
An outline of the exposure process in the exposure control unit 45 can be shown as a flowchart of FIG. That is, the image data storage unit 51 acquires and stores image data to be printed (step # 101). The image data to be stored in this way is acquired from a medium used in a digital camera, or acquired as image data by photoelectrically converting a frame image of a photographic film with a film scanner.

  Next, a correction value corresponding to the measured temperature of the temperature sensor S is extracted from the correction table 54, and the three primary colors R (red), G (green), and B (blue) based on the extracted correction value are in the main scanning direction. The exposure start timing at 1 and the exposure execution line in the sub-scanning direction are set (steps # 102 and # 103).

  More specifically, the correction table 54 stores correction values for the three primary colors R (red), G (green), and B (blue) in association with the temperature, and associates them with the measured temperature of the temperature sensor S. If there is no corrected value, an approximate measured temperature correction value is extracted. This correction value indicates the exposure start timing in the main scanning direction based on the detection timing of the synchronization sensor 40, and indicates the exposure execution line in the sub-scanning direction corresponding to the number of detections of the synchronization sensor 40. The exposure start timing and the exposure execution line are set in the light quantity control means 50r, 50g, 50b of the light quantity control unit 50.

  Next, when executing the exposure process, the exposure control unit 45 integrates the number of detections of the synchronous sensor 40 and gives the integrated value to the light amount control unit 50. In this light quantity control unit 50, every time the synchronous sensor 40 detects a laser beam based on correction values already set for the three primary colors of R (red), G (green), and B (blue), this detection timing On the exposure execution line and at the exposure start timing, the exposure process is started. That is, the process in which the light quantity control unit 50 transmits one line of data (density value) along the main scanning direction from the image data storage means 51 to the corresponding one of the laser light source 33r and the light quantity adjustment mechanisms 44g and 44b. Is started, and this process is repeated for each line until the exposure of image data for one frame is completed (steps # 104 and # 105).

  In other words, when the exposure unit E scans the laser beam, the light quantity control means 50r, 50g, 50b are counted when the number of clocks set in advance is counted based on the timing at which the synchronization sensor 40 detects the laser beam. A basic exposure processing mode is set so that exposure processing is realized by starting reading out image data of three primary colors of R (red), G (green), and B (blue).

  However, when one of the laser beams of the three primary colors R (red), G (green), and B (blue) to be exposed at the same position on the photographic paper P deviates in the main scanning direction (when misalignment occurs). In this case, the deviation is eliminated by changing the exposure start timing, that is, by changing the number of clocks to be counted on the basis of the detection timing of the synchronization sensor 40, and R to be exposed at the same position on the photographic paper P. If even one of the three primary color laser beams (red), G (green), and B (blue) deviates in the sub-scanning direction (when misalignment occurs), the exposure line is changed (reflection of the polygon mirror 36). By changing the surface 36m, correction is performed so as to eliminate the deviation in the sub-scanning direction.

[Print calibration chart]
In this printing device, if the temperature of the installed environment is not what was assumed or if the scanning exposure system changes due to aging even if the environment temperature is assumed, appropriate correction will be performed. 6 is configured so that the chart printing means 56 prints a calibration chart, and an operator can set a correction value for realizing optimum exposure from this chart. The processing form is shown in the flowchart of FIG. It is possible.

  That is, the correction value of the correction table 54 is acquired, and the measured temperature of the temperature sensor S is acquired (Steps # 201 and # 202). Next, image data of the main scanning chart and image data of the sub-scanning chart are generated based on the correction value and the measured temperature (Steps # 203 and # 204).

  After the image data is generated in this way, print processing is executed and the measured temperature is stored (steps # 205 and # 206).

  More specifically, the calibration chart includes a main scanning chart 61 shown in FIG. 8 and a sub-scanning chart 62 shown in FIG. 9. In the main scanning chart 61, R (red), G (green), Lines of the three primary colors C (cyan), M (magenta), and Y (yellow) corresponding to the three primary colors B (blue) are formed by changing the exposure timing in a predetermined step in the main scanning direction. In addition, a code is formed as index information in the index area 61B. Note that when generating the image data of the main scanning chart 61, the step of changing the exposure timing is preferably smaller than the diameter of one dot formed on the photographic paper P by the laser beam.

  In the sub-scan chart 62, C (cyan) and M (magenta) lines corresponding to R (red) and G (green), and G (green) and B (blue) in two types of exposure areas 62A. Corresponding M (magenta) and Y (yellow) lines are formed by changing the exposure timing in a predetermined step in the sub-scanning direction, and a code is formed as index information in the index area 62B. Note that, when generating the image data of the sub-scan chart 62, the step of changing the exposure execution line is determined by the reflection surface 36m of the polygon mirror 36. Therefore, for example, the laser beam is continuously emitted from the adjacent reflection surface 36m. In the case of performing scanning exposure with reflection, the step of changing the exposure execution line is in units of one line.

[Update processing]
After the two types of calibration charts are printed as described above, the correction values are stored in the correction table 54 by the process shown in the flowchart of FIG.

  With the operator selecting the process for updating the correction table 54, the operator matches the three primary color lines of C (cyan), M (magenta), and Y (yellow) in the exposure area 61A of the main scanning chart 61. Visually selected, the code of the index area 61B of the selected one is discriminated, and similarly, in the two types of exposure areas 62A of the sub-scan chart 62, the operator visually selects and selects the matching one The code of the index area 61B of the object is discriminated, and an operation of inputting via the keyboard, mouse or the like is performed (step # 301).

  After the index information is input in this way, the table updating unit 55 generates a correction value indicating the exposure execution line and the exposure start timing corresponding to the three types of laser beams based on the input code. (Step # 302). Further, in this update process, the calibration chart is printed a plurality of times in a state where the temperature sensor S measures the same temperature, and based on the plurality of calibration charts thus printed (the main scanning chart 61 and the sub scanning chart 62). When a plurality of correction values are obtained, the average value of the correction values is set as a correction value to be stored.

  After the correction value is set in this way, the measured temperature of the temperature sensor S when the calibration chart is exposed and the correction value are associated with each other and stored in the correction table (step # 302). When the correction value is stored in this way, if a correction value associated with the same measured temperature already exists, the correction value in the correction table 54 is updated, and the correction value associated with the same measured temperature is updated. If no exists, a correction value is newly stored in the correction table 54.

  As described above, according to the present invention, the calibration charts of the main scanning chart 61 and the sub-scanning chart 62 are printed by the chart printing means 56, and C (cyan), M (magenta), and Y (yellow) are visually displayed on the chart. By simply selecting the one with the smallest deviation of the line and inputting the index information, the measured temperature of the temperature sensor S and the correction value at the timing when the table updating means 55 performs the chart exposure are obtained. The data are stored in the correction table 54 in association with each other. In other words, high-quality printing is realized by setting correction values most suitable for the environment in which the printing apparatus is used without performing processing for storing correction values corresponding to various temperatures in advance.

Longitudinal front view of printing device The perspective view which shows the structure of an exposure unit Plan view of exposure unit Block diagram of control system Print processing flowchart Chart print processing flowchart Update process flowchart Diagram showing main scanning chart outline Diagram showing the outline of the sub-scan chart

Explanation of symbols

36 polygon mirror 40 synchronization sensor 45 exposure control unit 54 correction table 55 table updating means 56 chart printing means 61 main scanning chart 62 sub scanning chart P print medium (printing paper)
S Temperature sensor

Claims (4)

A scanning exposure system that performs scanning exposure by reflecting laser beams of different wavelengths generated by a plurality of laser light sources by a polygon mirror that rotates around an axis of the image, and synchronizes with the rotation of the polygon mirror. A printing apparatus including an exposure control unit that reads density values in a scanning direction and adjusts the light amounts of a plurality of laser beams,
The exposure control unit includes a correction table for setting an exposure timing in the main scanning direction of the image data corresponding to the laser beams of different wavelengths and an exposure execution line in the sub-scanning direction,
A chart printing means for printing a calibration chart using laser beams of different wavelengths, and a temperature sensor for measuring the temperature of the scanning exposure system,
An optimum exposure state is selected from the calibration chart printed on the print medium by the chart printing means, and a correction value corresponding to the exposure state is associated with the measured temperature of the temperature sensor, and the exposure timing of the correction table is newly set. A printing apparatus comprising table update means for setting. The chart printing means changes the exposure timing in the main scanning direction for each laser beam having a different wavelength in a preset step, and prints index information indicating each exposure timing on the print medium. For each laser beam having a different wavelength, the exposure execution line in the sub-scanning direction is changed in a preset step, and index information indicating the exposure execution line is printed on the print medium. Configured to print a sub-scan chart as the calibration chart;
The table updating means inputs the index information of the main scanning chart and the index information of the sub-scanning chart by an operator, so that the index information and the main scanning chart and the sub-scanning chart are printed when the index information is printed. The printing apparatus according to claim 1, wherein the correction value is set based on the temperature measured by the temperature sensor.   The table updating means performs printing of the main scanning chart and the sub-scan chart by the chart printing means a plurality of times, and then an operator obtains index information for the plurality of main scanning charts and index information for the sub-scan charts. The printing apparatus according to claim 2, wherein a correction value is set from an average value of correction values indicated by the plurality of index information by inputting. The scanning exposure system is configured to generate three laser beams corresponding to three primary colors of R (red), G (green), and B (blue) as the laser light source, and the exposure control unit includes the polygon mirror R (red), G (green), B (blue) based on the correction value associated with the measured temperature of the temperature sensor in the correction table with reference to the timing at which the laser beam reflected by the synchronous sensor is received. The printing apparatus according to claim 1, wherein the reading start timing of image data corresponding to the three primary colors is set.

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