KR101005420B1 - Image recording apparatus and image recording method - Google Patents

Abstract

In the image recording apparatus, a shift amount for shifting the transition position of the output light amount from the light modulation element is obtained for each change point at which the pixel value of the pixel column corresponding to each light modulation element changes. When the shift amount exceeds the width of the scanning direction of the area on the substrate corresponding to one pixel 71, the target image is moved so that the change point moves in the column direction by the number of pixels of the integer portion of the value obtained by dividing the shift amount by the width. The pixel value of the pixel 71a is changed, and the shift amount corresponding to the change point is corrected to a value corresponding to the fractional part. Then, the spatial light modulator is controlled based on the target image after the change and the shift amount after the correction, so that when the image is recorded, the image is shifted by shifting the transition position of the output light amount from the light modulation element over a distance equivalent to one pixel. Recording with high precision is realized.

Description

Image recording apparatus and image recording method {IMAGE RECORDING APPARATUS AND IMAGE RECORDING METHOD}

The present invention relates to a technique for recording an image on a recording medium by irradiation of light.

A diffraction grating type optical modulation device has been developed that can change the depth of a diffraction grating by alternately forming a fixed ribbon and a flexible ribbon on a substrate using a semiconductor device manufacturing technique, and bending the flexible ribbon with respect to the fixed ribbon. . In such a diffraction grating, the intensity of the specularly reflected light or the diffracted light changes by changing the depth of the groove, and therefore, use as an image recording apparatus for recording an image on various recording media as an optical modulation element is proposed.

For example, a plurality of diffraction grating type optical modulation elements are provided in the image recording apparatus to irradiate light, and the reflected light from the optical modulation elements with the fixed ribbon and the flexible ribbon located at the same height from the reference plane (zero-light). Is guided to the recording medium and the non-zeroth order diffracted light (mainly primary diffracted light) from the optical modulation element with the flexible ribbon bent is shielded, thereby recording the image onto the recording medium.

In Japanese Laid-Open Patent Publication No. 2004-4525 (Document 1), in such an image recording apparatus, by correcting the timing at which the optical modulation element transitions between ON-OFF, the optical modulation element can transition from the OFF state to the ON state. Asymmetry in transition from ON state to OFF state, difference in characteristics of each photosensitive material, and misalignment of the drawing region caused by misalignment of the length or position in the scanning direction of the irradiation region for each light modulation element. A technique for correcting is disclosed.

However, in the image recording apparatus of Document 1, within a time corresponding to one pixel, one clock is sequentially selected from a clock group shifted by a small amount of time, so that the driving voltage corresponding to the pixel value of the pixel corresponding to the clock is increased. Since it is input to the optical modulation element, it is not possible to shift the transition timing beyond the time equivalent to one pixel (or shift the transition position beyond the distance corresponding to one pixel).

This invention is suitable for the image recording apparatus which records an image on a recording medium by irradiation of light, and aims at shifting a transition position beyond the distance equivalent to one pixel when recording an image on a recording medium.

An image recording apparatus according to the present invention includes an optical modulator having an optical modulation element, a holding portion for holding a recording medium on which an image is recorded by the signal light from the optical modulator, and the holding portion relative to the optical modulator. And a moving mechanism that continuously moves the irradiation position on the recording medium to which the light from the optical modulation element is irradiated in the scanning direction, and a plurality of target images in the column direction corresponding to the scanning direction in the target image to be recorded on the recording medium. Each pixel column in which the pixels are arranged is a set of a plurality of pixel groups each having the same pixel value in succession in the column direction, and each change point is a position between two adjacent pixel groups in the pixel columns. Shift amount for shifting the transition position of the output light amount from the light modulation element in order to correct the writing shift of the pixel group In the case where the shift amount exceeds the width of the scanning direction of the area on the recording medium corresponding to one pixel, the respective change point is equal to the number of pixels of the integer portion of the value obtained by dividing the shift amount by the width. An arithmetic unit that changes the pixel value of the pixel of the target image so as to move in the direction, and corrects the shift amount corresponding to each change point to a value corresponding to a fractional part of the value, while being synchronized with the movement mechanism And a control unit for controlling the light modulator based on the target image after and the shift amount after correction.

According to the present invention, when recording an image on a recording medium, the transition position can be shifted beyond a distance equivalent to one pixel.

In a preferred embodiment of the present invention, in the calculation unit, the shift amount before correction is determined based on a combination of pixel values of the two adjacent pixel groups with respect to each of the change points, and the calculation unit includes a plurality of types of two. The pixel processing table is constructed by using a combination of a first table storage unit that stores a pixel processing table indicating a shift amount of a change point with respect to each of the combination of two pixel values, and a combination of two pixel values at each change point of each pixel column. By reference, a correction shift amount indicating a shift amount after correction for each of a combination of an image change unit which acquires the shift amount of each change point and moves the shift point in the column direction, and the plurality of types of two pixel values A combination of a second table storage unit for storing a table and two pixel values at the respective change points of the pixel columns; By using reference to the modified shift amount table, and comprising a shift amount obtained for obtaining a shift amount after the modification for each of the change point. Thus, by using the pixel processing table and the correction shift amount table, the shift of the transition position over a distance equivalent to one pixel can be easily realized.

In another preferred aspect of the present invention, in the controller, a base clock is provided each time the irradiation position on the recording medium moves in the scanning direction by a constant distance corresponding to a predetermined number of pixels in each pixel column of the target image. This occurs, and the transition of the amount of output light from the light modulation element is possible only once in the base clock period between two adjacent base clocks, and in the target image after the change, each is continuous in the column direction. In the case where the number of pixels of the smallest pixel group having the smallest number of pixels among the plurality of pixel groups having the same pixel value is smaller than the number of pixels of the predetermined number of pixels, the calculation unit causes the constant distance to be the number of pixels of the minimum pixel group. Shorten to the equivalent distance. As a result, in the image recording apparatus in which the transition of the output light amount of the optical modulation element is possible only once in the base clock period, the image recording can be performed with high accuracy.

In one aspect of the present invention, since the shift amount before correction is a value obtained by increasing or decreasing the distance based on the writing shift of the pixel group from half of the width in the scanning direction of the region on the recording medium corresponding to one pixel, the optical modulation is performed. The transition position of the output light amount of the element can be easily moved to both sides in the scanning direction.

In another aspect of the present invention, the target image is input to the calculation unit as run length data, and the length of the run length of the run length data is changed when the respective change points are moved in the calculation unit. Thereby, the change point can be easily moved.

The present invention is also suitable for an image recording method of recording an image on the recording medium by irradiation of the light while continuously moving the irradiation position on the recording medium onto which the light from the light modulation element of the optical modulator is irradiated in the scanning direction.

The above objects and other objects, features, aspects, and advantages will become apparent from the following detailed description of the invention made with reference to the accompanying drawings.

1 is a side view of an image recording apparatus 1 according to a first embodiment of the present invention, and FIG. 2 is a plan view of the image recording apparatus 1. The image recording apparatus 1 is an apparatus (also called a pattern drawing apparatus) which irradiates light to the photosensitive material on the glass substrate (henceforth simply called a "substrate") for liquid crystal display devices, and records an image. As shown in FIG. 1 and FIG. 2, the image recording apparatus 1 includes a substrate having a layer of photosensitive material formed on a main surface 91 (hereinafter referred to as an "upper surface 91") on the (+ Z) side ( The holding part moving mechanism 2 which is provided on the board | substrate holding part 3 and the base 11 which hold | maintains 9, and moves the board | substrate holding part 3 to the X direction and the Y direction perpendicular | vertical to a Z direction. ), A frame 12 fixed to the base 11 so as to span the substrate holding portion 3 and the holding portion moving mechanism 2, and light attached to the frame 12 and modulated to the photosensitive material on the substrate 9. The light irradiation part 4 which irradiates is provided. Moreover, the image recording apparatus 1 is equipped with the control part 6 which controls each structure of the holding part moving mechanism 2, the light irradiation part 4, etc., as shown in FIG.

The substrate holding part 3 is provided on the stage 31 on which the substrate 9 is placed, the supporting plate 33 and the supporting plate 33 rotatably supporting the stage 31. The stage rotating mechanism 32 which rotates the stage 31 centering on the rotating shaft 321 perpendicular | vertical to the upper surface 91 is provided.

The holding | maintenance part movement mechanism 2 is the sub scanning mechanism 23 and the sub scanning mechanism 23 which move the board | substrate holding part 3 to X direction (henceforth "sub scanning direction") in FIG. 1 and FIG. The base plate 24 and the substrate holding part 3 which support the support plate 33 through () are continuous with the base plate 24 in the Y direction perpendicular to the X direction (hereinafter referred to as the "scanning direction"). And a main scanning mechanism 25 which moves to. In the image recording apparatus 1, the holding part moving mechanism 2 moves the substrate holding part 3 in the main scanning direction and the sub scanning direction parallel to the upper surface 91 of the substrate 9.

As shown in FIG. 1 and FIG. 2, the sub scanning mechanism 23 is parallel to the main surface of the stage 31 at the lower side (ie, (-Z) side) of the supporting plate 33 and in the main scanning direction. A linear motor 231 extending in the sub-scan direction perpendicular to the direction and a pair of linear guides 232 extending in the sub-scan direction on the (+ Y) side and the (-Y) side of the linear motor 231. do. The main scanning mechanism 25 is a linear motor 251 which extends in the main scanning direction parallel to the main surface of the stage 31 at the lower side of the base plate 24, (+ X) side of the linear motor 251, and ( A pair of air sliders 252 extending in the main scanning direction on the -X) side and a linear scale (not shown) are provided.

As shown in FIG. 2, the light irradiation part 4 is equipped with the optical head 41 of plurality (8 in this embodiment) arranged in equal pitch along the sub-scanning direction, and attached to the frame 12. As shown in FIG. Moreover, the light irradiation part 4 is equipped with the light source optical system 42 connected to each optical head 41, the UV light source 43 which emits ultraviolet light, and the light source drive part 44 as shown in FIG. . The UV light source 43 is a solid laser, and the light source driver 44 is driven to emit ultraviolet light having a wavelength of 355 nm, for example, from the UV light source 43, and to the optical head 41 through the light source optical system 42. Is delivered.

Each optical head 41 has an optical system for reflecting the light from the UV light source 43 downwardly and the light exiting portion 45 and the light emitted from the emitting portion 45 to the spatial light modulator 46 ( 451, the modulated light from the spatial light modulator 46 and the spatial light modulator 46, which modulates and reflects the light from the emission unit 45 irradiated through the optical system 451. The optical system 47 is guided onto the photosensitive material provided in the 91.

3 is an enlarged view of the spatial light modulator 46. As shown in FIG. 3, the spatial light modulator 46 includes a plurality of diffraction gratings that guide light from the UV light source 43 irradiated through the emission unit 45 to the upper surface 91 of the substrate 9. An optical modulation element 461 is provided. The light modulation element 461 is manufactured using a semiconductor device manufacturing technique, and is a diffraction grating which can change the depth of a grating. In the optical modulation element 461, a plurality of flexible ribbons 461a and a fixed ribbon 461b are alternately arranged in parallel, and the plurality of flexible ribbons 461a can be individually lifted and moved relative to the rear reference plane. The plurality of fixing ribbons 461b are fixed with respect to the reference plane. As the diffraction grating type light modulation element, for example, GLV (Grating Light Valve: Grating Light Valve) (registered trademark of Silicon Light Machines (Sunny Vale, California)) is known.

4A and 4B are cross-sectional views of the light modulation element 461 in a plane perpendicular to the flexible ribbon 461a and the fixed ribbon 461b. As shown in FIG. 4A, when the flexible ribbon 461a and the fixed ribbon 461b are positioned at the same height with respect to the reference plane 461c (that is, the flexible ribbon 461a is not bent), the light modulation element 461 The surface of) becomes one surface, and the reflected light of incident light L1 is derived as 0th order light (normally reflected light) L2. On the other hand, when the flexible ribbon 461a is bent to the reference plane 461c side than the fixed ribbon 461b, as shown in FIG. 4B, when the difference between the height of the flexible ribbon 461a and the fixed ribbon 461b becomes a predetermined value, The ribbon 461a becomes the bottom surface of the groove of the diffraction grating, and the first-order diffraction light L3 (also a higher-order diffraction light) is derived from the light modulation element 461, and the zero-order light L2 is extinguished. In the actual light modulation element 461, the intensity of the zero-order light L2 is changed to a plurality of types by changing the difference between the heights of the flexible ribbon 461a and the fixed ribbon 461b to a plurality of types, and a diffraction grating is used. Gradation light modulation is performed.

In the light irradiation part 4 shown in FIG. 1, the light from the UV light source 43 becomes linear light (light whose beam cross section is linear) by the light source optical system 42, and the spatial light through the emission part 45. Irradiated onto a plurality of flexible ribbons 461a and a fixed ribbon 461b (see FIGS. 4A and 4B) arranged in a line shape of the modulator 46. In the optical modulation element 461, when each adjacent flexible ribbon 461a and the fixed ribbon 461b are made into one ribbon pair, three or more ribbon pairs correspond to one pixel of the pattern to be drawn. Of course, the light modulation element 461 may be one basic pair, and one ribbon pair may correspond to one pixel.

In the optical modulation element 461, the flexible ribbon 461a of the ribbon pair corresponding to each pixel of the pattern is controlled based on a signal from the modulator control unit 60 connected to each spatial light modulator 46, respectively. It is possible to transition between a plurality of states in which ribbon pairs corresponding to pixels emit zero-order light of a plurality of types of output light intensity (intensity). The zeroth order light emitted from the light modulation element 461 is directed to the optical system 47, and the nonzeroth order diffracted light (mainly the first order diffracted light ((+1) th order diffracted light and (-1) th order diffracted light)) It is guided in a direction different from the optical system 47. In addition, in order to prevent stray light, primary diffraction light is shielded by a light shielding portion (not shown).

Zero-order light from the optical modulation element 461 is guided to the upper surface 91 of the substrate 9 through the optical system 47, whereby the X direction (that is, on the upper surface 91 of the substrate 9). Modulated light is irradiated to each of the plurality of irradiation positions arranged in the sub-scanning direction). As described above, the ribbon pair corresponding to each pixel of the light modulation element 461 applies light on the substrate 9 in multiple gradations (including gradations in which light for drawing is not irradiated on the substrate 9). It becomes possible to investigate.

In the image recording apparatus 1 shown in FIG. 1 and FIG. 2, the light modulation of the light irradiation section 4 with respect to the substrate 9 which is moved in the main scanning direction by the main scanning mechanism 25 of the holding unit moving mechanism 2. Modulated light is irradiated from the element 461. In other words, the main scanning mechanism 25 transfers the position (that is, the irradiation position) of the irradiation area on the substrate 9 of the light guided from the light modulation element 461 to the substrate 9 to the substrate 9. The irradiation position moving mechanism moves relatively and continuously in the main scanning direction. In the image recording apparatus 1, the irradiation position on the substrate 9 may be moved in the main scanning direction by moving the optical head 41 in the main scanning direction without moving the substrate 9. In the image recording apparatus 1, the modulation of the light from the optical modulation element 461 is controlled by the modulator control unit 60 of the control unit 6, so that an image that is a recording target on the substrate 9 (hereinafter referred to as a "target image"). Is recorded on the substrate 9.

FIG. 5 is a diagram showing a configuration of a part of the modulator controller 60, and is an element related to driving of each of the optical modulation elements 461 in the modulator controller 60 (hereinafter referred to as "element drive element 61"). Part). The element driving element 61 outputs the outputs from the registers 610 and 611, the shift unit 616 and the D / A converter 612, and the D / A converter 612 to the actual output of the optical modulation element 461. It has a circuit which converts into a drive voltage (henceforth "real drive voltage"), and the shift part 616 has the register 613, the counter 614, and the comparator 615. As shown in FIG.

The modulator controller 60 further includes a clock generator (not shown), and a signal from the linear scale of the main scanning mechanism 25 is input to the clock generator. 6, the irradiation position of the light from each light modulation element 461 on the board | substrate 9 is a fixed distance (the distance set at the time of image recording of the following description, and it sets it below). The base clock 303 is generated by the clock generator every time the motor moves in the main scanning direction (Y direction) by the distance of the " distance ", and the register 613 shown in FIG. It is input to the counter 614. In Fig. 5, the base clocks sequentially input to the registers 610 and 613 and the counter 614 are indicated by arrows indicated by 303 (the delay clock 304, the driving voltage data 301, and the number of shift delays described later). The same for data 302 and shifted clock 305).

In addition, when the clock generation unit moves the irradiation position on the substrate 9 by a distance (for example, 10 nanometers (nm)) obtained by dividing the set distance into predetermined numbers as shown in the interruption of FIG. Each time, a delay clock 304 is generated and input to the counter 614. In addition, since the movement speed of the board | substrate 9 to the main scanning direction by the main scanning mechanism 25 is substantially constant, it is also possible to regard a horizontal axis as time in each of the upper end and the interruption of FIG. The same in FIGS. 14 to 16, 18, 19, 22 and 23).

In the register 610 of FIG. 5, driving voltage data 301 indicating a target voltage (hereinafter, referred to as a "target driving voltage") at which the actual driving voltage gradually changes with time and finally reaches the base clock 303 is provided. In addition, the driving voltage data 301 is output from the register 610 to the register 611 in synchronization with the base clock 303. In the register 613 of the shift unit 616, shift delay data 302 used to adjust the operation position (operation timing) of the optical modulation element 461 is sequentially performed in response to the base clock 303. FIG. Is entered.

The shift delay number data 302 is input to the comparator 615 from the register 613 in synchronization with the base clock 303. Each time the delay clock 304 is input to the counter 614, the count number of the delay clock 304 in the counter 614 is output to the comparator 615, and the shift delay number data 302 indicates. When the value and the count from the counter 614 match, the clock 305 delayed with respect to the base clock 303 (hereinafter referred to as "shifted clock") 305 is output from the comparator 615 to the register 611. As a result, the analog signal of the driving voltage data 301 is output from the register 611 via the D / A converter 612. The count number of the delay clock 304 in the counter 614 is reset every time the base clock 303 is input.

The drive voltage data 301 for each shifted clock 305 corresponds to the target drive voltage when the optical modulation element 461 is driven once, and the output from the D / A converter 612 is the current source 51. ) Is also converted into current. One end of the current source 51 is connected to the high potential Vcc side through the resistor 52, and the other end is grounded.

Both ends of the current source 51 are connected to the flexible ribbon 461a and the reference plane 461c of the optical modulation element 461 via the connection pads 53. Therefore, when the driving voltage data 301 is converted into current through the D / A converter 612 and the current source 51, the driving voltage data 301 is converted into the actual driving voltage between the two connection pads 53 by the voltage drop by the resistor 52. Is converted. As described above, the element driving element 61 sets the operation position of the optical modulation element 461 based on the shift delay number data 302 while setting the distance corresponding to the delay clock 304 to the minimum resolution. It is possible to shift (adjust) from the position corresponding to 303).

In addition, since the connection pads 53 have a stray capacitance, the actual drive voltage (actual drive voltage) between the connection pads 53 changes in accordance with the time constant between the connection pads 53, and with time To the target drive voltage.

7 is a block diagram showing the configuration of the modulator controller 60. In addition to the element driving element 61 described above, the modulator control unit 60 includes a main operation unit 62 having a CPU for performing various operations and a memory for storing various kinds of information, and a field programmable gate array (FPGA) which is a programmable electronic circuit. ) Control element 63 (indicated by a broken line block in FIG. 7). In practice, the modulator control unit 60 is provided with one element driving element 61 and one FPGA control element 63 for each optical modulation element 461, but in FIG. 7, one optical modulation element 461. Only the element driving element 61 and the FPGA control element 63 corresponding to FIG.

The main operation unit 62 includes a table generation unit 622 for generating various tables used in image recording, and a shift amount excess detection unit 621 for detecting a condition related to generation of a table at the time of generation of a table described later. . In the FPGA control element 63, the pixel values of the pixels of the target image are stored by using the memory 631 and the pixel processing table 6311 which store the pixel processing table 6311 used to change the target image (processing of pixels). The functions of the pixel column processing unit 632 to be changed and the output data generation unit 633 to convert the changed image into a data format for the element driving element 61 are realized.

Each element driving element 61 includes a corrected shift amount acquisition unit 618 for acquiring the shift delay number data 302, a drive voltage acquisition unit 619 for acquiring the drive voltage data 301, and a memory 617. And a correction shift amount table 6171 described later prepared for each of the light modulation elements 461, the reference position address table 6172 common to all the light modulation elements 461, and the amount of output light of multiple gradations at the time of drawing. The drive voltage table 6173 indicating the corresponding target drive voltage is input to and stored in the memory 617 from the main calculation unit 62.

Here, in the target image which is the recording target in the image recording apparatus 1, a plurality of pixels are arranged in the column direction corresponding to the main scanning direction and the row direction corresponding to the sub scanning direction, and image recording (pattern drawing) described later. In FIG. 2, each light modulation element 461 is used to draw one pixel column using a plurality of pixels arranged in the column direction as pixel columns. Further, each pixel column is a set of a plurality of pixel groups each having the same pixel value in succession in the column direction (that is, each pixel column is composed of a plurality of pixel groups each of which is a set of two or more pixels), The position between two adjacent pixel groups in the pixel column is a change point indicating the transition of the amount of output light irradiated from the light modulation element 461 to the irradiation area. In the present embodiment, the target image is an image having four values of 1 to 4, but of course, an image having a gradation level of 5 or more, or an image having a gradation level of 2 or 3 may be used.

In the pixel column processing unit 632 connected to the element driving element 61 of each light modulation element 461, data of pixel columns corresponding to the light modulation element 461 (hereinafter referred to as "pixel column data") 691 is input as run length data, and pixel column data 691 is processed using the pixel processing table 6311 as described later. In the output data generation unit 633, the processed pixel column data 691 is converted into a data format for the element driving element 61, and as the converted pixel data 692 every time the base clock 303 occurs. The element driving elements 61 are sequentially output.

Here, in the image recording apparatus 1, in the image recording apparatus 1, the period between two adjacent base clocks 303 (as shown in the upper part of FIG. 6 showing the base clock 303 and the lower part of FIG. 6 showing the pixels of one pixel column) Hereinafter, in the "base clock period", two or more pixels 71 (four pixels 71 in the example at the lower end of FIG. 6) in each pixel column of the target image are subject to drawing control. In other words, the number of pixels subject to drawing control in the base clock period is the number of pixels between the base clocks, and the set distance at which the irradiation position of the light from the light modulation element 461 moves in the main scanning direction in the base clock period is The distance corresponding to the pixel 71 of the number of pixels between the base clocks (the distance indicated by an arrow denoted by the symbol W at the upper end of FIG. 6). In the following description, the positions in the main scanning direction corresponding to the head of each pixel 71 of the target image (the position indicated by the arrowhead indicated by the symbol A1) at the upper and lower ends of FIG. 6 are referred to as "reference positions" of the pixel. The distance between two adjacent reference positions (that is, the distance divided by the number of pixels between base clocks and can be regarded as a logical minimum resolution in drawing) is referred to as a "reference distance". In the lower part of FIG. 6, the reference distance is shown by the arrow which attached the code | symbol T. As shown in FIG.

In the image recording apparatus 1, since the clock 305 shifted in the configuration of the element driving element 61 shown in Fig. 5 is output only once in the base clock period, the amount of output light from the light modulation element 461 Transition is possible only once in the base clock period, and the converted pixel data 692 outputted in accordance with the base clock 303 is a pixel having the number of pixels between the base clocks in the base clock period as shown in FIG. 8. In this case, the number of the pixel whose pixel value changes from the immediately preceding pixel and the pixel value of the pixel (hereinafter referred to as "change pixel number" and "post-change pixel value", respectively) are indicated.

For example, the number of pixels between base clocks is 4, and as shown in the lowermost part of FIG. 9, the four pixels 71 in a certain base clock period (pixels 71 surrounded by a rectangle with a thick line in the lowermost part of FIG. 9). In the case where the pixel value changes from 1 to 2 between the third pixel 71 and the fourth pixel 71 (the pixel 71 having the pixel value of 1 at the bottom of FIG. 9 is white). And a parallel oblique line is drawn to the pixel 71 whose pixel value is 2. The second to fifth columns from the bottom of Fig. 9 and the same in Figs. 14 to 16, 18, and 19), the change pixel number and the change The pixel values become 4 and 2, respectively, and when the pixel values change from 1 to 2 between the second pixel 71 and the third pixel 71 as shown in the second row from the bottom of FIG. The change pixel number and the change pixel value become 3 and 2, respectively, and are shown below in FIG. Since in the case of, variation 2 in the pixel value 1 between the first pixel 71 and second pixel 71 of the as shown in the third stage, and both the second pixel value after the change pixel number, and change.

As shown in the fourth column from the bottom of Fig. 9, when the pixel value changes from 1 to 2 between the first pixel 71 and the fourth pixel 71 in the immediately preceding base clock period. The change pixel number and the changed pixel value become 1 and 2, respectively, and when there is no pixel 71 whose pixel value changes as shown in the fifth stage from the bottom (the second stage from the top) in FIG. The pixel number is 1, and the pixel value after the change is equal to the pixel value of the last pixel in the immediately preceding base clock period. In addition, the change pixel number can be regarded as a logical coordinate value based on the reference distance T.

10 is a diagram showing a reference position address table 6172. The reference position address table 6172 shown in FIG. 10 shows a distance in the main scanning direction from a position where the base clock 303 immediately before occurrence occurs to a reference position for each of the first to fourth pixels (hereinafter referred to as "reference position address"). Is a table showing the number of counts of the delay clock 304 (see the top of FIG. 9). In FIG. 10, reference position addresses of the first to fourth pixels are described as "first reference position address", "second reference position address", "third reference position address", and "fourth reference position address", respectively. have.

11 is a diagram showing a correction shift amount table 6171. The correction shift amount table 6171 is generated by modifying the correction table described later, and is obtained by correcting (changing) the shift amount (the value delivered from the correction table described later) for each of a combination of two types of two pixel values. Value, hereinafter referred to as " correction shift amount ", and in practice, the correction shift amount is represented by the count number of the delay clock 304. As shown in FIG. In FIG. 11, the correction shift amount with respect to the combination of pixel value M and pixel value N is described as "the correction shift amount at the time of pixel value M-> N change, provided M and N are 1-4. The correction shift amount is smaller than the count number corresponding to the distance between two adjacent reference positions (that is, the reference distance T).

In the correction shift amount acquisition unit 618 of FIG. 7, the reference position address table of FIG. 10 is used by using the change pixel number of the conversion pixel data 692 inputted from the output data generation unit 633 for each base clock 303. By referring to 6172, one reference position address is specified. In addition, in the correction shift amount acquisition unit 618, the pixel value after the change of the converted pixel data 692 input from the immediately preceding base clock 303 is stored, and the pixel value after the previous change and the pixel value after the current change By using this, referring to the correction shift amount table 6171 of FIG. 11, one correction shift amount is specified. Then, a value obtained by adding the specified reference position address and the correction shift amount (as described above, both are indicated as the number of counts of the delay clock 304) is obtained as the number of shift delays, and the shift portion of FIG. The register 613 of 616 is input as the shift delay number data 302.

12 is a diagram showing a drive voltage table 6171. The driving voltage table 6173 is a table indicating target driving voltages corresponding to a plurality of types of pixel values, and the driving voltage obtaining unit 619 of FIG. 7 uses the pixel values after the change of the converted pixel data 692. By referring to the drive voltage table 6173, the drive voltage corresponding to the pixel value after the change is specified. In FIG. 12, the driving voltages corresponding to the pixel values 1 to 4 after the change are referred to as "first gradation driving voltage", "second gradation driving voltage", "third gradation driving voltage", and "fourth gradation driving voltage", respectively. It is described. The specified drive voltage is input to the register 610 of FIG. 5 as drive voltage data 301.

As described above, the drive voltage data 301 and the shift delay number data 302 are generated from the converted pixel data 692 in the element driving element 61 of FIG. 7, thereby outputting from the light modulation element 461. It is possible to shift the amount of light to a gray level corresponding to the pixel value after the change, and to shift (adjust) the transition position. In addition, the detail of the pixel processing table 6311 and the correction shift amount table 6171 is mentioned later.

Next, the operation of the image recording apparatus 1 to record an image on the substrate 9 will be described with reference to FIG. 13. In the image recording apparatus 1, first, a correction table is prepared for each light modulation element 461 by an operator, and is input to the main operation unit 62 of FIG. 7 (step S11). 7, the correction table is shown by the arrow shown with the code | symbol 681. In addition, in FIG.

Here, the correction table means two regions (1) on the substrate 9 corresponding to two pixel groups with the change points interposed with respect to each change point in the pixel column corresponding to each light modulation element 461. The shift position of the output light quantity from the light modulation element 461 is shifted in order to correct the positional shift in the main scanning direction of the boundary between the two regions where the pattern corresponding to the two pixel groups is formed (i.e., the drawing shift). The shift amount is shown. As the cause of the writing shift, the time until the state of the flexible ribbon 461a stabilizes when the amount of warpage changes is different depending on the combination of the pixel values of the two pixel groups sandwiching the change point, or the The length and position (irradiation position) of the main scanning direction of the irradiation area of the light modulation element 461 differ from the other light modulation elements 461, etc. are mentioned. In addition, the correction table actually draws a pattern extending in the sub-scanning direction on the dummy substrate, or provides a light detector on the stage 31 to irradiate light from all the light modulation elements 461. It is acquired by measuring the length and the position of the main scanning direction of the area.

In the correction table shown in Table 1, the pixel value of the pixel immediately preceding (adjacent to) the pixel of interest and the pixel value of the pixel of interest (in Table 1, "the previous pixel value" and "the current pixel", respectively). "Standard shift amount", "line width correction shift amount" and "position correction shift amount" are set for each of all combinations). In addition, although Table 1 shows only the case where "the previous pixel value" and "the present pixel value" are a combination of 1 and 1, a combination of 1 and 2, a combination of 2 and 1, and a combination of 2 and 2, The "standard shift amount", the "line width correction shift amount", and the "position correction shift amount" are set also for the combination of "previous pixel value" and "current pixel value" of 3 and 4, respectively.

(Table 1)

14 is a diagram for explaining a standard shift amount in a correction table. The upper part of FIG. 14 shows the base clock 303, the interruption shows the target driving voltage, and the lower part shows the pixel column. Here, as shown in the upper and lower parts of FIG. 14, the number of pixels between the base clocks is 4, and at the upper part of FIG. 14, the set distance W is divided by the number of pixels between the base clocks as in the upper part of FIG. The reference distance is indicated by an arrow with the symbol T.

Even if it is not necessary to correct the drawing shift mentioned above, the standard shift amount is the front of the relative movement direction with respect to the substrate 9 at the irradiation position from the position corresponding to the change point (in the main scanning direction) from the position corresponding to the change point. Is the front side at the time of movement, and to the right side of FIG. For example, in the example shown in the middle and the bottom of FIG. 14, the target driving voltage for the light modulation element 461 is the second gray level corresponding to the pixel value 2 from the first gray level driving voltage V1 corresponding to the pixel value 1. The position of the change point from the white pixel 71 of the pixel value 1 to the pixel 71 of the pixel value 2 in which parallel transitions are drawn from the white pixel 71 of the pixel value 1 (that is, the pixel group of the pixel group of the pixel value 2). The reference position A1a of the first pixel 71 is shifted by 1/2 times the reference distance T which is the standard shift amount. As described above, the correction table is prepared separately for each of all the light modulation elements 461, but the standard shift amount is the same for all the combinations of the pixel values of all the correction tables.

15 is a diagram for explaining a line width correction shift amount in a correction table. The line width correction shift amount is for correcting a writing shift that depends on the combination of pixel values of two adjacent pixel groups. For example, when the pixel value changes from 1 to 2 at the change point, the table 1 is referred to. The transition position of the output light quantity from the light modulation element 461 (for example, the position depending on the rise time of the output light quantity) is moved forward of the relative movement direction of the irradiation position by 1/3 times the reference distance T. (+ (1/3) T) indicating that the pattern is to be specified, whereby the boundary position of the region corresponding to the pixel group of pixel value 1 and the region corresponding to the pixel group of pixel value 2 on the substrate 9 Misalignment is corrected (that is, the imaging misalignment of the pixel group is corrected). When the pixel value changes from 2 to 1 at the change point, the transition position of the amount of output light from the light modulation element 461 (for example, the position depending on the fall time of the amount of output light) is determined by referring to Table 1. (-(1/3) T), which indicates moving to the rear of the relative movement direction of the irradiation position by 1/3 times the reference distance T, is specified, whereby pixel value 2 on the substrate 9 is specified. The deviation of the boundary position between the area corresponding to the pixel group of and the area corresponding to the pixel group of the pixel value 1 is corrected.

In the second stage from the top of Fig. 15, the change in the target drive voltage at the interruption in Fig. 14 (the same is shown in the third stage from the top of Fig. 15 by dashed lines. It shows that the shift by the linewidth correction shift amount of Table 1 was added further, Here, as shown in the lowermost part of FIG. 15, the pixel values of the adjacent three pixel groups change in the order of 1, 2, 1, and the number of pixels of the pixel group of the pixel value 2 in the center is 5, so from the top of FIG. From the second stage, the distance at which the target driving voltage of the light modulation element 461 is the second gray scale driving voltage V2 is equal to the reference distance T than the distance corresponding to five pixels (five times the reference distance T). By 2/3 times shorter, the width | variety of the main scanning direction of the area | region on the board | substrate 9 corresponding to the pixel group of pixel value 2 is correct | amended. As described above, the line width correction shift amount in the correction table is for substantially correcting the width (line width) in the main scanning direction of the region on the substrate 9 corresponding to the pixel group of each pixel value.

It is a figure for demonstrating the position correction shift amount in the correction table. The position correction shift amount is for correcting the deviation (deviation in the main scanning direction) of the irradiation position of the optical modulation element 461 from the other optical modulation elements 461. The position correction shift amount is set individually for each light modulation element 461, and the same value is set for all combinations of pixel values of two pixels. For example, in the example shown to the 2nd step | paragraph from the top of FIG. 15 (the same thing is shown by the dashed-dotted line also the 3rd step | paragraph from the top of FIG. 16), and the position correction shift amount of Table 1 (+ (1/3 When the shift by (T) is added, the second stage from the top in Fig. 16 is used in the case where the pixel value changes from 1 to 2 at the change point and the pixel value changes from 2 to 1 at the change point. As shown, the transition position of the output light quantity from the light modulation element 461 further moves forward ((+ Y) side) of the relative movement direction of the irradiation position by 1/3 times the reference distance T.

In this case, the position (that is, the transition position of the output light quantity) of the target driving voltage of the optical modulation element 461 from the first grayscale driving voltage V1 to the second grayscale driving voltage V2 is the lowest level in FIG. 16. It is larger than the reference distance T with respect to the position of the change point (the reference position A1a of the pixel 71a) from the pixel 71 of the pixel value 1 to the pixel 71 of the pixel value 2 in the pixel column shown in FIG. In addition, it moves by a distance not more than twice the reference distance T, and the shift amount of the transition position of the amount of output light from the light modulation element 461 exceeds the distance corresponding to one pixel. As a result, the transition timing of the amount of output light with respect to the point of change (the reference position A1a) from the pixel 71 of the pixel value 1 to the pixel 71 of the pixel value 2 is the next base of the base clock period to which the change point belongs. It is included in the clock period. As described above, since the count number of the delay clock 304 in the counter 614 of FIG. 5 is reset every time the base clock 303 is input, in the image recording apparatus 1 of FIG. It is not possible to change the target drive voltage as shown in the second stage from the top of FIG. 16 based on the pixel column shown in the lowest stage of the sixteenth stage.

Therefore, as described in detail below, in the image recording apparatus 1, the pixel value of the pixel 71a enclosed by the thick rectangle at the bottom of FIG. 16 is changed to 0, thereby converting the pixel value 1 to the pixel value 2. A process of moving (delaying) the change point by one pixel is performed, and a process of obtaining a corrected shift amount with respect to the change point after the movement is performed.

When the correction table is prepared in the image recording apparatus 1, the number of pixels (or set distances) between base clocks employed in the image recording operation is determined by the main operation unit 62 of FIG. 7 (step S12). The number of pixels between base clocks is input to the output data generator 633, and a reference position address table 6172 corresponding to the number of pixels between base clocks is input to the element driving element 61. In reality, the process of step S12 is checked whether or not the number of pixels between base clocks (hereinafter referred to as "initial base clock interpixels") set in advance for the image recording apparatus 1 is changed and changed. When it is confirmed that this is done, it is a process of determining the number of pixels between base clocks actually used. Here, it is assumed that the number of pixels between initial base clocks is set as 5, and is changed to 4 by a predetermined process. The detail of the process of step S12 is mentioned later.

Subsequently, in the main operation unit 62, a process corresponding to the generation of the pixel processing table 6311 and the correction shift amount table 6171 is performed. First, in the shift amount excess detection unit 621 of FIG. 7, as shown in Table 2 by adding the standard shift amount, the line width correction shift amount, and the position correction shift amount in each combination of the two pixel values in Table 1. The total shift amount is obtained (step S13).

(Table 2)

Subsequently, in all combinations of two different pixel values (in Table 2, the combination of pixel value 1 and pixel value 2 and the combination of pixel value 2 and pixel value 1), the reference distance T corresponding to one pixel is obtained. It is checked whether there is an excess. Here, in only the combination in which the previous pixel value and the current pixel value are 1 and 2, respectively, the total shift amount is (+7/6) times the reference distance T, which is larger than one times the reference distance T, and It is confirmed that it becomes 2 times or less. In the table generating unit 622, "pixel processing number" is set to (+1) in a combination in which the previous pixel value and the current pixel value are 1 and 2, respectively, and "pixel processing number" is set in another combination. By setting it to 0, the pixel processing table 6311 shown in Table 3 is produced.

(Table 3)

The pixel processing number indicates the amount of shift of the change point between two adjacent pixel groups, and in the pixel processing table 6311 of Table 3, the pixel processing number is used for the change point that changes from the pixel value 1 to the pixel value 2. By (+1), processing of the pixel string for delaying the change point by one pixel is instructed, and for the combination of other pixel values, the pixel processing number becomes zero, indicating that the pixel is not processed. The pixel processing table 6311 is input to and stored in the memory 631 of the FPGA control element 63 of FIG. 7 (step S14). In addition, when the total shift amount is larger than α times the reference distance T (where α is an integer of 1 or more) and becomes (α + 1) times or less, the number of pixel processes becomes α.

In the table generating unit 622, in the combination of pixel values in which the total shift amount is larger than the reference distance T and the number of pixel processing numbers is other than 0, the value obtained by multiplying the corresponding pixel processing number by the reference distance T is calculated and summed. The value obtained by subtracting the value from the shift amount (that is, the value obtained by multiplying the reference distance T by the fractional part of β in the total shift amount expressed as β times the reference distance T) is obtained as the corrected shift amount. In addition, for the combination of pixel values in which the total shift amount is smaller than the reference distance T, the total shift amount is a corrected shift amount. Therefore, in the example of Table 2, in the combination where the previous pixel value and the current pixel value are 1 and 2, respectively, the correction shift amount is (+1/6) times the reference distance T, and the sum is about the combination of other pixel values. The shift amount becomes a correction shift amount as it is, and the correction shift amount table 6171 shown in Table 4 is generated. The correction shift amount table 6171 is input to and stored in the memory 617 of the element driving element 61 of FIG. 7 (step S15). If the total shift amount exceeds the reference distance T in the combination of two identical pixel values, the reference distance (in the fractional part of β in the total shift amount expressed as β times the reference distance T). The value multiplied by T) is the correction shift amount. In practice, the corrected shift amount is changed to a value close to an integer multiple of the shift amount corresponding to the resolution of the delay clock 304, and as described above, the shift delay number, which is the count number of the delay clock 304, is changed. The element driving element 61 can be applied.

(Table 4)

As described above, when the pixel processing table 6311 and the correction shift amount table 6171 are prepared, the movement of the substrate 9 at a constant speed in the main scanning direction is started (step S16), and the control unit 6 The data of the target image stored in the picture memory (not shown) of the data is input to the modulator controller 60. As described above, in the modulator controller 60 of FIG. 7, pixel string data 691 corresponding to each pixel string processor 632 is input.

In the pixel column processing unit 632, as shown in the lowermost part of FIG. 16, when the pixel values of three adjacent pixel groups are 1, 2, and 1, respectively, the white of the first pixel value 1 (left of FIG. 16) is white. The number of pixel processes for the point of change between the pixel group and the pixel group in which the pixel values 2 are drawn with parallel oblique lines is obtained as (+1) by referring to the pixel processing table 6311 of Table 3, and the pixel group of pixel value 2 The pixel value of the first pixel 71a of is changed to 1 so that the change point is shifted (delayed). In addition, the pixel processing number with respect to the change point between the pixel group of the pixel value 2 and the pixel group of the next pixel value 1 (on the right side in FIG. 16) is obtained as 0, and the change point is not moved. In addition, as shown in Table 3, the pixel processing number becomes 0 between the pixels 71 having the same pixel value, and since the pixel processing is not performed, the pixel processing number affects only the change point.

In practice, the pixel column processing unit 632 moves the change point by changing the length of the run length in the data of the pixel column input as the run length data as shown in FIG. 17. In FIG. 17, one run length is shown by the rectangle (labeled with 690a, 690b, and 690c).

The change point which is a position between the run length 690b described as "DATA (n)" in FIG. 17 and the run length 690c immediately described as "DATA (n + 1)" (hereinafter, the "notice change point"). First, by referring to the pixel processing table 6311 using the pixel value of the run length 690b and the pixel value of the run length 690c immediately afterwards, the pixel processing number for the point of interest change is obtained. Become. In the pixel column processing unit 632, correction conditions for the pixel column data 691 shown in Table 5 are stored in advance, and described as, for example, "DATA (n-1)" immediately before the run length 690b. The pixel processing number (described as "pixel processing number for DATA (n-1)" in Table 5) obtained for the change point between the run length 690a and the run length 690b is 0. When the number of pixel processes (referred to as "pixel process number for DATA (n)" in Table 5) obtained for the point is also 0, the amount of change in the length of the run length 690b ("DATA ( n) is 0.

(Table 5)

As shown in Table 5, when the pixel processing number obtained for the change point between the run length 690a and the run length 690b is 0, and the pixel processing number obtained for the change point of interest is (+1), The amount of change in the length of the run length 690b becomes (+1) (that is, the run length 690b is lengthened by one pixel). If the pixel processing number obtained for the change point between the run length 690a and the run length 690b is (+1), and the pixel processing number obtained for the change point of interest is 0, the run length 690a is used. Since the change point of interest is delayed by one pixel by increasing by (+1), the amount of change in the length of the run length 690b becomes (-1) (that is, the run length 690b is shortened by one pixel). . Further, when the pixel processing number obtained for the change point between the run length 690a and the run length 690b is (+1) and the pixel processing number obtained for the change point of interest is (+1), the run length is achieved. By extending 690a by (+1), since the point of interest change is already delayed by one pixel, the amount of change in the length of the run length 690b becomes zero.

In the example shown in the lowermost part of FIG. 16, when the number of pixels (the length of run length) of the center pixel group among three adjacent pixel groups is 5, the white of the first pixel value 1 (left side of FIG. 16) is white. The pixel processing number of the point of change between the pixel group and the pixel group in which the pixel value 2 is drawn in parallel diagonal lines is (+1), and the pixel value 1 of the pixel group of the pixel value 2 and the next pixel value 1 (on the right side in FIG. When the number of pixel processes for the change point between the pixel groups is 0, the amount of change in the number of pixels (length of run length) of the pixel group of pixel value 2 becomes (-1), and the pixel of the pixel group of pixel value 2 The number changes to four.

As described above, in the image recording apparatus 1, the target image data is input to the pixel string processing unit 632 as run length data, and by changing the length of the run length of the run length data when each change point is moved, The change point is easily moved, and the pixel column data 691 is processed (step S17). Depending on the design of the pixel column processing unit 632, the data of the target image may be displayed in a format other than the run length data.

In parallel with the processing of the pixel string data in the pixel string processing section 632, the processed pixel column data (part of) is decoded by the output data generating section 633 and divided by the number of pixels between base clocks. As described above, in the pixel of the pixel number between base clocks, the converted pixel data 692 indicating the number of the pixel whose pixel value changes from the immediately preceding pixel and the pixel value of the pixel (that is, the changing pixel number and the changed pixel value). ) Is generated.

For example, at the bottom of FIG. 16, the pixel value of the pixel 71a is changed to 1 (to be a white pixel) by the processing of the pixel column processing unit 632, and the base clock 303a is used. The change pixel number and post-change pixel value of the converted pixel data 692 referenced at the time of corresponding drawing are all 1 due to the absence of the change point in the four pixels 71 between the base clocks 303a and 303b. (As described above, even when there is no change point, the change pixel number is 1, and the pixel value after the change is equal to the pixel value of the last pixel in the immediately preceding base clock period). The changed pixel number of the converted pixel data 692 referred to at the time of drawing corresponding to the base clock 303b, and the changed pixel value are the first pixels among the four pixels 71 between the base clocks 303b and 303c. 1 and 2, respectively, due to the presence of the change point from the pixel value 1 to the pixel value 2 at the first reference position), and the converted pixel data 692 referred to at the time of drawing corresponding to the base clock 303c. The change pixel number and the changed pixel value are caused by the presence of a change point from pixel value 2 to pixel value 1 in the first pixel (first reference position) among the four pixels 71 between the base clocks 303c and 303d. , All 1s.

Then, the converted pixel data 692 is output to the element driving element 61 in accordance with the base clock 303 generated whenever the substrate 9 moves by a set distance corresponding to the number of pixels between the base clocks (step S18). ). In the element driving element 61, the drive voltage data 301 and the shift delay number data 302 are generated from the converted pixel data 692 (step S18a), thereby controlling the light modulation element 461, thereby making the light modulation element The pattern is drawn on the board | substrate 9, shifting the transition position of the output light quantity from 461 (step S19).

At this time, at the time of drawing corresponding to the base clock 303b at the top of Fig. 16, the first pixel is based on the converted pixel data 692 where the changed pixel number and the changed pixel value are 1 and 2, respectively. The corresponding reference position address (here, 0 is specified) is specified, and the correction shift amount is specified as (+ (1/6) T) using the pixel value after the immediately preceding change and the pixel value after the current change. As a result, the shift delay number data 302 is obtained as the count number corresponding to the distance (+ (1/6) T), and the change of the target drive voltage as shown in the second stage from the top of FIG. 16 is realized. . The target driving voltage after the change is the second gray scale driving voltage V2 based on the pixel value after the change of the converted pixel data 692.

In practice, the generation of the conversion pixel data 692 in step S18 and input to the element driving element 61 and the drawing of the pattern based on the conversion pixel data 692 in steps S18a and S19 are performed by the substrate 9. ) Is repeated until the entirety of the image representing the target image is recorded (step S20). When the entirety of the target image is recorded, the movement in the main scanning direction of the substrate 9 is stopped, and the operation of recording the image on the substrate 9 is completed (step S21).

Next, a process of determining the number of pixels between base clocks in step S12 will be described. 18 is a diagram illustrating a base clock 303 and a pixel column. The upper part of FIG. 18 shows the base clock 303, the interruption shows the pixel column before the change point moves, and the lower part shows the pixel column after the change point moves (same in FIG. 19 described later). In addition, in the middle part and the lower part of FIG. 18, the position of a change point is shown by the arrow shown with the code | symbol A2.

18, when the number of pixels between the initial base clocks is set as 5, the data of the target image has 5 pixels in each pixel group having the same pixel value continuously in each pixel column. An image generated as described above (which can be regarded as a logical minimum line width corresponding to 5 pixels), whereby a transition of the amount of output light from the light modulation element 461 is enabled only once in the base clock period. In the recording apparatus 1, it is possible to appropriately record an image. In this case, for example, in the processing of the pixel string data of step S17 of FIG. 13, if a process of delaying the change point by one pixel is performed, as shown in the lower part of FIG. 18, the pixel group having four pixels ( A set of pixels 71 drawn in parallel diagonal lines is generated so that two change points exist in the base clock period.

Therefore, in the main operation unit 62, first, in the correction table of Table 1, the pixel value is the current pixel from the maximum value of the line width correction shift amount in the combination of the plurality of two pixel values in which each pixel value is the immediately preceding pixel value. The value obtained by subtracting the minimum value of the line width correction shift amount in a plurality of combinations of values is obtained as the maximum reduction amount. Then, a value corresponding to the number of pixels between the initial base clocks (that is, a set distance corresponding to the number of pixels between the initial base clocks) minus the maximum value of the maximum reduction amount for all the pixel values can be regarded as the physical minimum line width. The integer portion of the value obtained by dividing by the reference distance T is obtained as the pixel group minimum width.

In the example of Table 1, when the pixel value 1 is the previous pixel value, the maximum value of the line width correction shift amount is (+1/3) times the reference distance T, and the pixel value 1 is the current pixel value. The minimum value of the line width correction shift amount becomes (-1/3) times the reference distance T, and (-1/3) of the reference distance T at (+1/3) times the reference distance T. The value obtained by subtracting the double ((2/3) times the reference distance T) becomes the maximum value for all pixel values of the maximum reduction amount. Then, the value obtained by subtracting the maximum value of the maximum reduction amount from (5 times the reference distance T corresponding to the number of pixels between the initial base clocks ((13/3) times the reference distance T)) the reference distance T The integer part 4 of the value divided by is obtained as the pixel group minimum width. As shown in the upper part of FIG. 19, the number of pixels between base clocks is determined as 4 which is smaller than the number of pixels between initial base clocks. Thereby, in processing the pixel column data, a process of delaying the change point by one pixel is performed, and as shown in the lower part of FIG. 19, a group of pixels having a pixel count of four (parallel diagonal lined pixel 71) Even if) is generated, the presence of two change points in the base clock period is prevented.

As described above, in the main operation unit 62, the number of pixels of the smallest pixel group having the smallest number of pixels among the plurality of pixel groups each having the same pixel value in the column direction after processing is smaller than the number of pixels between initial base clocks. In a few cases, a process of shortening the set distance to a distance corresponding to the number of pixels of the minimum pixel group is performed. As described above, in the output data generation unit 633, the conversion element data 692 is generated with the number of pixels between the base clocks being 4, so that two modulation points are not present in the base clock period. Pattern writing by modulation of the element 461 is performed.

As described above, in the image recording apparatus 1 of FIG. 1, by calculating the total shift amount for each combination of two pixel values in the correction table, the pixels substantially corresponding to the respective optical modulation elements 461 are obtained. With respect to each change point of the column, a shift amount (shift amount before correction) for shifting the transition position of the output light amount from the light modulation element 461 is determined in order to correct the writing shift of the pixel group. Subsequently, with respect to the combination in which the total shift amount is larger than 1 times the reference distance T, the integer part of the β in the total shift amount expressed as β times the reference distance T is referred to as the pixel processing number, and the reference distance is the reference distance. The pixel processing table 6311 and the correction shift amount table 6171 are created using the value multiplied by (T) as the correction shift amount. Thereby, in the case of actual image recording, when the shift amount with respect to each change point exceeds the width | variety of the main scanning direction of the area | region on the board | substrate 9 corresponding to one pixel, the value of this shift amount divided by the said width | variety The pixel value of the pixel of the target image is changed so that the change point moves in the column direction by the number of pixels of the integer portion, and the shift amount corresponding to the change point is corrected to a value corresponding to the fractional part. By controlling the spatial light modulator 46 based on the target image after the change and the shift amount after the correction while synchronizing with the main scanning mechanism 25, a distance equivalent to one pixel is recorded when the image is recorded on the substrate 9. In addition, it is realized that the image is recorded with high accuracy while shifting the transition position of the output light amount from the light modulation element 461.

In addition, in the image recording apparatus 1, a plurality of correction tables indicating shift amounts of the change points before movement for each of the combination of two types of two pixel values are prepared in advance in correspondence with all the light modulation elements 461, The shift amount (correction shift) which corrected the value of the correction table with respect to each pixel combination table 6311 which shows the shift amount of the change point with respect to each combination of two pixel values by the main calculation part 62, and each combination of two pixel values. A plurality of correction shift amount tables 6171 are generated from the plurality of correction tables. In the pixel column processing unit 632, by referring to the corresponding pixel processing table 6311 using a combination of two pixel values at each change point of the pixel column, the shift amount of the change point is obtained and the change point is obtained. The process of moving in the column direction is performed, and the correction shift amount obtaining unit 618 refers to the corresponding correction shift amount table 6171 by using a combination of two pixel values at each change point of the pixel column, thereby changing the change. The process of acquiring the correction shift amount of a point is performed. Thereby, in the image recording apparatus 1, when recording an image on the board | substrate 9, the shift of the transition position more than the distance corresponded to one pixel can be implement | achieved easily.

Here, when generating the data of the target image in the RIP (Raster Image Processor), it is also conceivable to create the image data in which the change point is moved in advance based on the correction table. In this case, the contents of the correction table are changed. If necessary, the need to regenerate the image data occurs again, and the time required for processing related to image recording becomes long.

On the other hand, even in the case where the contents of the correction table are changed in the image recording apparatus 1, since the pixel processing table 6311 and the correction shift amount table 6171 need only be updated (modified) as described above, the image recording is performed. It is possible to shorten the time required for the processing related to the above.

As described above, in the image recording apparatus 1, one element driving element 61 and one FPGA control element 63 are provided for each of the plurality (all) of the optical modulation elements 461, In the present embodiment, a first table storage in which a set of memories 631 in the plurality of FPGA control elements 63 stores a plurality of pixel processing tables 6311 corresponding to the plurality of light modulation elements 461 respectively. Second table storage in which the set of memories 617 in the plurality of element driving elements 61 stores a plurality of correction shift amount tables 6171 corresponding to the plurality of light modulation elements 461 respectively, which are regarded as negative. It is considered wealth. In addition, the set of pixel column processing units 632 in the plurality of FPGA control elements 63 is regarded as an image changing unit which acquires the movement amount of each change point and moves the change point in the column direction. The set of the correction shift amount acquisition unit 618 in the drive element 61 is regarded as a shift amount acquisition unit that acquires the shift amount after correction for each change point.

20 is a diagram showing the configuration of an image recording apparatus 1a according to a second embodiment of the present invention. The image recording apparatus 1a has one optical head 41a for emitting light for image recording and a holding drum 70 which is a holding portion for holding the recording medium 9a on which an image is recorded on the outer side. An image is recorded on the recording medium 9a by drawing by irradiation (exposure) of light by the optical head 41a. As the recording medium 9a, for example, a chain plate, a film for chain plate formation, or the like is used. As the holding drum 70, a photosensitive drum for plateless printing may be used. In this case, the recording medium 9a corresponds to the surface of the photosensitive drum, and the holding drum 70 integrally holds the recording medium 9a. It can be regarded as being held.

The holding drum 70 is rotated by the motor 81 about the central axis of the cylindrical surface, whereby the optical head 41a is in the main scanning direction with respect to the recording medium 9a (from a plurality of light modulation elements described later). In a direction perpendicular to the direction of the arrangement of the position at which light is irradiated). Moreover, the optical head 41a is movable by the motor 82 and the ball screw 83 in the sub scanning direction parallel to (perpendicular to the main scanning direction) the rotation axis of the holding drum 70, and the optical head 41a. The position of is detected by an encoder (not shown). In this manner, by the moving mechanism including the motors 81 and 82 and the ball screw 83, the outer surface of the holding drum 70 and the recording medium 9a have an optical head 41a having a spatial light modulator. In addition to moving relative to the main scanning direction at a constant speed with respect to the sub-scan direction intersecting the main scanning direction. The motors 81 and 82 and the encoder are connected to the control section 6a, and the control section 6a controls the emission of the signal light from the spatial light modulator in the motors 81 and 82 and the optical head 41a, thereby maintaining the holding drum ( Image recording by light is performed on the recording medium 9a on 70.

21 is a diagram showing an outline of an internal configuration of the optical head 41a. In the optical head 41a, a light source 43a which is a bar-type semiconductor laser having a plurality of light emitting points in a row, and a spatial light modulator 46 having a plurality of diffraction grating-shaped light modulation elements arranged in a row are arranged. The light from the light source 43a is guided to the spatial light modulator 46 through the lens 471 (actually composed of a condenser lens, a cylindrical lens, etc.) and a prism 472. At this time, the light from the light source 43a is linear light (light whose beam cross section is linear) and is irradiated onto a plurality of light modulation elements arranged in a line shape.

Each optical modulation element of the spatial light modulator 46 is controlled by the modulator controller 60 (see FIG. 20) of the controller 6a having the same configuration as that of the first embodiment. In addition, in FIG. 21, the element drive element 61 of the modulator control part 60 is shown by the block. The zero-order light emitted from the light modulation element is returned to the prism 472, and the first-order diffracted light is directed in a direction different from that of the prism 472. Further, in order to prevent stray light, the first diffracted light is shielded by a light shielding portion (not shown).

Zero-order light from each light modulation element is reflected by the prism 472, and is directed to the recording medium 9a other than the optical head 41a through the zoom lens 473, and the images of the plurality of light modulation elements are directed in the sub-scanning direction. It is formed on the recording medium 9a to be arranged. The zoom lens 473 has a magnification variable at the zoom lens drive motor 474, whereby the resolution of the image to be recorded is changed.

Also in the image recording apparatus 1a of FIG. 20, the image is recorded on the recording medium 9a by the same operation | movement as the image recording apparatus 1 of FIG. At this time, with respect to each change point of the pixel column corresponding to each light modulation element, a shift amount for shifting the transition position of the output light amount from the light modulation element in order to correct the writing shift of the pixel group is obtained, and the shift amount is one. When the width of the region on the recording medium 9a corresponding to the pixel exceeds the width in the main scanning direction, the pixel value of the pixel of the target image is shifted so that the change point is moved by the number of pixels of the integer portion of the value obtained by dividing the shift amount by the width. In addition to the change, the shift amount corresponding to the change point is corrected to a value corresponding to the fractional part. When the image is recorded on the recording medium 9a by controlling the spatial light modulator 46 based on the target image after the change and the shift amount after the correction while moving the irradiation position on the recording medium 9a, one pixel is used. Shifting the transition position of the amount of output light from the light modulation element over a distance corresponding to is realized, so that an image can be recorded with high accuracy.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible.

In the example of FIG. 15, for the example in which the distance of the target driving voltage of the second gray scale driving voltage V2 corresponding to the pixel value 2 is shortened in the optical modulation element 461 (see the fourth stage from the top in FIG. 22). As described above, as shown in the third stage from the top of FIG. 22, the line width correction shift amount in the correction table may be determined so that the distance at which the target driving voltage is the second gray scale driving voltage V2 becomes long. Moreover, in the image recording apparatuses 1 and 1a, besides shifting the transition position of the optical modulation element 461 to the front of the advancing direction of an irradiation position (refer the 5th stage from the top of FIG. 22), it is located in the lowest stage of FIG. As shown, you may shift to the back of the advancing direction of an irradiation position.

Even in such a case, the standard shift amount, which is the shift amount when the drawing shift is not corrected, is set to 1/2 times the reference distance T, and on the substrate 9 or the recording medium 9a corresponding to one pixel. Correct the value (depending on the processing of the pixel) by increasing or decreasing the distance (in the above embodiment, the line width correction shift amount and the position correction shift amount) based on the misalignment of the pixel group from half of the width in the main scanning direction of the region. By setting it as the shift amount before, the transition position of the output light quantity of the optical modulation element 461 can be easily moved to both sides of a main scanning direction, As a result, an image can be recorded with high precision.

In the image recording apparatuses 1 and 1a, for example, if the number of pixels between the initial base clocks is 1, the number of pixels between base clocks cannot be determined to be less than the number of pixels between initial base clocks in the processing of step S12 of FIG. It is not possible to prevent the existence of a plurality of change points in. Therefore, in the image recording apparatuses 1 and 1a, it is necessary that the number of pixels between the initial base clocks is 4 or 2, that is, 2 or more, as shown in the middle of FIG.

In the first and second embodiments, it is possible to easily shift the transition position over a distance equivalent to one pixel by using the pixel processing table 6311 and the correction shift amount table 6171, but each change is realized. When the shift amount of the point exceeds the distance corresponding to one pixel, the pixel value of the pixel of the target image is changed so that the change point moves by the number of pixels of the integer portion of the value obtained by dividing the shift amount by the distance, and the change is performed. If the shift amount corresponding to the point is corrected to a value corresponding to the fractional part, image recording may be performed without using the pixel processing table 6311 and the correction shift amount table 6171.

In the image recording apparatuses 1 and 1a of FIGS. 1 and 20, a spatial light modulator 46 having a plurality of light modulation elements 461 is provided and included in a target image by the plurality of light modulation elements 461. By writing a plurality of different pixel columns, the image is recorded at a high speed. However, depending on the design of the image recording apparatus, an optical modulator having one light modulation element may be used. In this case, one pixel column processing unit 632 and one correction shift amount acquisition unit 618 respectively acquire the movement amount of each change point and move the image change unit and each change point to move the change point in the column direction. It is regarded as a shift amount acquisition unit for acquiring the shift amount after the correction, and the drawing corresponding to the plurality of pixel columns is performed using the same pixel processing table 6311 and the correction shift amount table 6171.

In the image recording apparatuses 1 and 1a, the signal light in drawing does not necessarily need to be 0th order light, and the primary diffraction light may be signal light. Moreover, unlike the said embodiment, the relative positional relationship of the flexible ribbon 461a and the fixed ribbon 461b of the unbent state differs from the said embodiment, The optical modulation element 461 which the 0th order light is radiate | emitted with the flexible ribbon 461a bent. May be used. Also in these cases, appropriate image recording is realized by shifting the operation timing of the light modulation element 461.

If the flexible ribbon 461a and the fixed ribbon 461b can be regarded as a strip-shaped reflection surface, it is not necessary to be a ribbon shape in a strict sense. For example, the block-shaped upper surface may serve as a reflective surface of the fixing ribbon.

The light modulation element 461 is not limited to the diffraction grating type, but may be, for example, a liquid crystal shutter. In addition, the light modulation element 461 is not limited to reflecting light, for example, the laser array may serve as the light modulation element 461. Also in these cases, appropriate image recording is realized by correcting the writing shift in each element.

In addition, a two-dimensional spatial light modulator may be employed, and in this case, correction to the plurality of light modulation elements 461 in the above-described embodiment is applied to each one-dimensional array of the light modulation elements 461. do.

In the image recording apparatuses 1 and 1a of FIG. 1 and FIG. 20, the calculation part which detects the change point over which the total shift amount exceeds a distance equivalent to 1 pixel, and corrects a shift amount, moving the said change point is a main operation part ( 62) is realized by the plurality of FPGA control elements 63 and the plurality of element drive elements 61, but when it is not necessary to record an image at high speed, the function of the calculation unit is calculated by the main operation unit 62. It may be realized by software alone.

Moreover, in the image recording apparatuses 1 and 1a, the moving speed of the board | substrate 9 and the recording medium 9a to the main scanning direction becomes substantially constant, and the concept of the distance (or position) in the above description is based on time ( Or time). In this case, in the processing in the calculation unit, a shift time for shifting the transition timing of the output light amount from the light modulation element in order to correct the writing shift of the pixel group with respect to each change point of the pixel column corresponding to each light modulation element When the shift time exceeds the time for which the irradiation position moves by the width in the column direction of one pixel, the integer part and the fractional part of the value obtained by dividing the shift time by the time corresponding to the width in the column direction of the pixel are obtained. The pixel value of the pixel of the target image is changed so that the change point moves by the number of pixels of the integer portion, and the shift time corresponding to the change point is corrected to a time corresponding to the fractional part. Then, by controlling the spatial light modulator based on the target image after the change and the shift time after the correction, it is possible to shift the transition timing of the amount of output light from the light modulation element over a time equivalent to one pixel when recording an image. Thus, the image can be recorded with high accuracy.

The substrate 9 and the recording medium 9a may be moved by other methods as long as they can be moved relative to the optical heads 41 and 41a. The recording medium holding the image information may be a photosensitive material such as a printed wiring board or a semiconductor substrate, or another material having photosensitivity, or may be a material that reacts to heat by irradiation of light.

Although the invention has been described and described in detail, the foregoing description is by way of example and not restrictive. Accordingly, many modifications and aspects are possible without departing from the scope of the present invention.

1 is a side view of the image recording apparatus according to the first embodiment.

2 is a plan view of the image recording apparatus.

3 shows a spatial light modulator.

4A is a diagram illustrating a cross section of the light modulation element.

4B is a view showing a cross section of the light modulation element.

5 is a diagram illustrating a configuration of a part of the element drive element.

6 shows a base clock and a delay clock.

7 is a block diagram showing the configuration of a modulator controller.

8 is a diagram illustrating a structure of converted pixel data.

9 is a diagram for explaining converted pixel data.

10 is a diagram showing a reference position address table.

11 is a diagram illustrating a correction shift amount table.

12 is a diagram illustrating a driving voltage table.

13 is a diagram illustrating a flow of an operation of recording an image on a substrate.

14 is a diagram for explaining a standard shift amount.

15 is a diagram for explaining a line width correction shift amount.

16 is a diagram for explaining the position correction shift amount.

17 is a diagram showing a data structure of a pixel column.

18 is a diagram illustrating a base clock and a pixel column.

19 is a diagram illustrating a base clock and a pixel column.

20 is a diagram illustrating a configuration of an image recording apparatus according to the second embodiment.

21 is a diagram illustrating an internal configuration of an optical head.

22 is a diagram illustrating another example of the line width correction shift amount and the position correction shift amount.

23 is a diagram illustrating another example of the number of pixels between base clocks.

Claims (18)

An image recording apparatus for recording an image on a recording medium by irradiation of light, An optical modulator having an optical modulation element, A holding unit for holding a recording medium on which an image is recorded by the signal light from the optical modulator; A moving mechanism for moving the holding portion relatively to the light modulator to continuously move the irradiation position on the recording medium to which light from the light modulation element is irradiated in the scanning direction; In the target image to be recorded on the recording medium, each pixel column in which a plurality of pixels are arranged in a column direction corresponding to the scanning direction is a set of a plurality of pixel groups each having the same pixel value in succession in the column direction. For each change point which is a position between two adjacent pixel groups in the pixel columns, a shift amount for shifting the transition position of the output light quantity from the light modulation element to correct the writing shift of the pixel group is obtained. When the shift amount exceeds the width of the scanning direction of an area on a recording medium corresponding to one pixel, the respective change points move in the column direction by the number of pixels of an integer portion of the value obtained by dividing the shift amount by the width. The pixel value of the pixel of the target image is changed so that the shift amount corresponding to each change point is changed to a decimal number of the value. And a computing unit for modifying a value corresponding to, And a control unit which controls the optical modulator based on the target image after change and the shift amount after correction while synchronizing with the moving mechanism. The method according to claim 1, The light modulator has a plurality of light modulation elements, An image recording apparatus, wherein the plurality of light modulation elements draw a plurality of different pixel strings included in the target image. The method according to claim 1, In the calculating section, the shift amount before correction is determined for each of the change points based on a combination of pixel values of the two adjacent pixel groups, The calculation unit, A first table storage unit which stores a pixel processing table indicating a movement amount of a change point with respect to each of a combination of two types of two pixel values; An image changer for acquiring a shift amount of each change point and moving the change points in the column direction by referring to the pixel processing table using a combination of two pixel values at each change point of each pixel column; , A second table storage unit which stores a corrected shift amount table indicating a shift amount after correction for each of the combination of the plurality of two pixel values; An image recording having a shift amount acquiring unit for acquiring the shift amount after the correction for each change point by referring to the correction shift amount table using a combination of two pixel values at the respective change points of the respective pixel columns; Device. The method according to claim 3, The light modulator has a plurality of light modulation elements, The plurality of light modulation elements draw a plurality of different pixel columns included in the target image, And a plurality of pixel processing tables and a plurality of correction shift amount tables respectively corresponding to the plurality of light modulation elements are stored in the first table storage section and the second table storage section. The method according to claim 4, A plurality of correction tables indicating shift amounts of the change points before movement for each of the combination of the two types of two pixel values are prepared in advance corresponding to the plurality of light modulation elements, And the computing unit generates the plurality of pixel processing tables and the plurality of correction shift amounts tables from the plurality of correction tables. The method according to claim 2, Each of the plurality of light modulation elements is a diffraction grating type light modulation element in which a band-shaped fixed reflection surface and a flexible reflection surface are alternately arranged. The method according to claim 1, In the control unit, a base clock is generated whenever the irradiation position on the recording medium moves in the scanning direction by a constant distance corresponding to a predetermined number of pixels in the pixel columns of the target image, and the optical modulation element The transition of the amount of output light from the signal is possible only once in the base clock period between two adjacent base clocks, In the target image after the change, when the number of pixels of the smallest pixel group having the smallest number of pixels among the plurality of pixel groups each having the same pixel value in succession in the column direction is smaller than the number of pixels of the predetermined number of pixels, And an operation unit shortens the constant distance to a distance corresponding to the number of pixels of the minimum pixel group. The method according to claim 1, The image recording apparatus according to claim 1, wherein the shift amount before correction is a value obtained by increasing or decreasing the distance based on the writing shift of the pixel group from half of the width in the scanning direction of the region on the recording medium corresponding to one pixel. The method according to any one of claims 1 to 8, The target image is input to the calculation unit as run length data, And the run length of the run length data is changed when the change points are moved in the calculation unit. An image recording method of recording an image on the recording medium by irradiation of the light while continuously moving the irradiation position on the recording medium to which light from the optical modulation element of the optical modulator is irradiated in the scanning direction, a) A plurality of pixel groups in the target image to be recorded onto the recording medium, in which each pixel column in which a plurality of pixels are arranged in a column direction corresponding to the scanning direction has a pixel value each of which is successively the same pixel value in the column direction; A shift for shifting the transition position of the output light amount from the light modulation element to correct the writing shift of the pixel group with respect to each change point that is a set and is a position between two adjacent pixel groups in each pixel column Process of finding the quantity, b) in the case where the shift amount exceeds the width in the scanning direction of the area on the recording medium corresponding to one pixel, the respective change point is equal to the number of pixels of the integer part of the value obtained by dividing the shift amount by the width; Changing a pixel value of a pixel of the target image so as to move in a direction, and correcting the shift amount corresponding to each change point to a value corresponding to a fractional part of the value; c) controlling the light modulator based on the target image after change and the shift amount after correction while synchronizing with the movement of the irradiation position. The method according to claim 10, The light modulator has a plurality of light modulation elements, An image recording method, wherein the plurality of light modulation elements draw a plurality of different pixel strings included in the target image. The method according to claim 10, In the step a), the shift amount before correction is determined for each of the change points based on a combination of pixel values of the two adjacent pixel groups, In the step b), by referring to a pixel processing table indicating a shift amount of a change point with respect to each of a combination of two or more kinds of two pixel values, by using a combination of two pixel values at each change point of each pixel column. And a correction shift amount table for obtaining shift amounts of the respective change points, shifting each change point in the column direction, and indicating a shift amount after correction for each of the combinations of the plurality of two pixel values. And the shift amount after the correction with respect to each change point is obtained by referring using a combination of two pixel values at each change point. The method according to claim 12, The light modulator has a plurality of light modulation elements, The plurality of light modulation elements draw a plurality of different pixel columns included in the target image, An image recording method in which a plurality of pixel processing tables and a plurality of correction shift amount tables respectively corresponding to the plurality of light modulation elements are used during image recording. 14. The method of claim 13, A plurality of correction tables indicating shift amounts of the change points before movement for each of the combination of the two types of two pixel values are prepared in advance corresponding to the plurality of light modulation elements, And the plurality of pixel processing tables and the plurality of correction shift amount tables are generated from the plurality of correction tables. The method of claim 11, And each of the plurality of light modulation elements is a diffraction grating type light modulation element in which a band-shaped fixed reflection surface and a flexible reflection surface are alternately arranged. The method according to claim 10, In the step c), a base clock is generated whenever the irradiation position on the recording medium moves in the scanning direction by a constant distance corresponding to a predetermined number of pixels in each pixel column of the target image, The transition of the amount of output light from the light modulation element is made possible only once in the base clock period between two adjacent base clocks, In the target image after the change, when the number of pixels of the smallest pixel group having the smallest number of pixels among the plurality of pixel groups each having the same pixel value in succession in the column direction is smaller than the number of pixels of the predetermined number of pixels, An image recording method wherein a constant distance is shortened to a distance corresponding to the number of pixels in the minimum pixel group. The method according to claim 10, And the shift amount before correction is a value obtained by increasing / decreasing a distance based on a writing shift of a pixel group from half of the width in the scanning direction of an area on the recording medium corresponding to one pixel. The method according to any one of claims 10 to 17, The target image is run length data, In the step b), the length of the run length of the run length data is changed when the respective change points are moved.

Images