JP6287112B2 - Light beam scanning device, scanning method for light beam scanning device, scanning program for light beam scanning device, recording medium storing scanning program for light beam scanning device, and image forming apparatus - Google Patents

Description

  The present invention relates to a light beam scanning device having a laser light source or an LED array as a light source, a scanning method of the light beam scanning device, a scanning program of the light beam scanning device, a recording medium storing the scanning program of the light beam scanning device, and image formation Relates to the device.

  In general, a light beam scanning device includes a light source that emits an exposure scanning beam (light beam) that is modulated based on exposure scanning data generated from an image signal, a deflection unit that deflects the exposure scanning beam from the light source, and It has. In the light beam scanning device, the exposure scanning beam is exposed and scanned to the exposure target through the optical system, thereby writing on the exposure target.

  In such a light beam scanning apparatus, in recent years, an arrayed laser light source, an LED light source, or the like is used as a light source. In this case, a plurality of exposure scanning beams are used. It is necessary to expose the object simultaneously. In this case, when there are a plurality of exposure scanning beams, positional deviation occurs in exposure data in a portion where the edges of adjacent exposure scanning beams may overlap each other (referred to as a beam overlap possible section).

  On the other hand, in the conventional light beam scanning device, correction data for pitch deviation, light quantity difference, and reciprocity failure of a plurality of beams forming a pixel is stored in advance in a memory. Then, when outputting to the light source unit, the correction data is read from the memory and superimposed, thereby correcting the positional deviation of the exposure data (see Patent Document 1).

  Further, it has been proposed that a plurality of beams correct exposure data misalignment by selecting a light source based on a difference in scanning start time and a difference in sub-scanning position (see Patent Document 2).

  Further, in the beam overlap possible section, the beam spot of the adjacent scanning beam is alternately arranged, and the position deviation of the exposure data is corrected by setting each beam intensity to be different in the region where the adjacent beam overlaps. This has also been proposed (see Patent Document 3).

  However, in the conventional technique described above, the connection position (separation) of the exposure scanning beams is fixed in the beam overlap possible section where the edges of the adjacent exposure scanning beams may overlap each other. If there are multiple pixels in the beam overlap possible section, but the connection position in the beam overlap possible section is fixed, the scan data changes at the connection position. Deviation occurs. If the exposure data is misaligned, there is a possibility that the exposure data that is not in contact with the exposure data will be short-circuited.

  In order to deal with such a problem, it may be possible to move the connection position in the beam overlap possible section. However, in the case where the connection position is a pixel having an intermediate gray level, the exposure position of the exposure scanning beam may be reduced. In addition, due to the exposure characteristics, there has been a problem that the exposure amount at the connection position becomes larger or smaller than the gradation data to be actually written and changes from the original gradation value.

  The present invention aims to solve such problems.

  That is, an object of the present invention is to provide a light beam scanning apparatus capable of performing exposure based on correct gradation values.

In order to solve the above-described problem, the invention described in claim 1 includes a light emitting unit that emits a light beam modulated based on exposure scanning data having a plurality of gradation values, and a light emitting unit that emits the light beam. A light beam scanning device that performs writing on the exposure object by exposing and scanning the light beam deflected by the deflection unit. A plurality of light emitting units are provided along the scanning direction, and the connection positions of the light beams emitted from the adjacent light emitting units are in a beam overlap possible section where the adjacent light beams can overlap each other. A connection position determining unit for determining based on the exposure scanning data;
A correction unit that corrects gradation values of the exposure scanning data around the connection position determined by the connection position determination unit, and the plurality of gradation values are levels on which the exposure target is not exposed. The connection position determination unit performs exposure without determining a connection position at a position where the exposure scanning data in the beam overlap possible section is a gradation value that is not exposed in the beam overlap possible section. A connection position is determined at a position that is a gradation value, and the correction unit is configured to detect the exposure scan data positioned at the end of the connection position in the preceding stage and the end of the connection position in the subsequent stage in the scanning direction of the adjacent light beams. A light beam that corrects the gradation value of the exposure scanning data located at an end of at least one of the preceding stage and the succeeding stage based on the exposure scanning data located in a section. It is a scanning device.

  According to the first aspect of the present invention, since the gradation value of the exposure scanning data around the connection position is corrected, exposure based on the correct gradation value can be performed.

It is a schematic block diagram of the light beam scanning apparatus concerning one Embodiment of this invention. It is explanatory drawing of the connection relation between the adjacent exposure scanning beams in the duplication possible area | region of the light beam scanning apparatus shown by FIG. It is explanatory drawing of the connection position which moved from the connection position shown by FIG. It is explanatory drawing of the state which correct | amended the gradation value from FIG. It is explanatory drawing of the other correction | amendment state of FIG. 3 is a flowchart of a light beam scanning method according to an embodiment of the present invention. It is a schematic block diagram of the printed circuit board exposure apparatus concerning one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a light beam scanning apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of the connection relationship between adjacent exposure scanning beams in the overlapping section of the light beam scanning apparatus shown in FIG. FIG. 3 is an explanatory diagram of a connection position moved from the connection position shown in FIG. FIG. 4 is an explanatory diagram of a state in which the gradation value is corrected from FIG. FIG. 5 is an explanatory diagram of another correction state of FIG. FIG. 6 is a flowchart of a light beam scanning method according to an embodiment of the present invention. FIG. 7 is a schematic block diagram of a printed circuit board exposure apparatus according to an embodiment of the present invention.

FIG. 1 shows a schematic configuration of a light beam scanning apparatus according to this embodiment. The light beam scanning device 10 is provided, for example, in a printed board exposure apparatus that forms wiring of a printed board. The light beam scanning device 10 includes a plurality of light sources (light emitting units) 11 _{1 to} 11 _N, and the same number of fθ lenses (deflecting units) 12 _{1 to} 12 _N provided corresponding to the light sources 11 _{1 to} 11 _N , respectively. And a control unit 15 that controls the light sources 11 _{1 to} 11 _N.

The light sources 11 _{1 to} 11 _N emit an exposure scanning beam (light beam) modulated to a predetermined gradation value by the control unit 15 based on an image signal of a wiring or the like to be formed, and fθ lenses 12 _{1 to} 12 _N. Deflects exposure scanning beams from the light sources 11 _{1 to} 11 _N , respectively. The plurality of exposure scanning beams deflected by the fθ lenses 12 _{1 to} 12 _N become constant speed scanning light via an optical system (not shown), and the exposure object 13 (for example, a print on which a photosensitive member such as a resist is formed). Substrate). Thereby, an image such as a wiring pattern is written on the exposure target 13. For example, a laser light source or an LED array can be used as the plurality of light sources 11 _{1 to} 11 _N provided.

The fθ lenses 12 _{1 to} 12 _N are arranged so that the edges of the adjacent exposure scanning beams among the exposure scanning beams 1 to N can overlap (overlap) each other. For example, the right side edge of the exposure scanning beam 1 overlaps the left side edge of the exposure scanning beam 2, and the right side edge of the exposure scanning beam 2 overlaps the left side edge of the exposure scanning beam 3. Although not shown in the drawing, the right edge of the exposure scanning beam (N-1) overlaps the left edge of the exposure scanning beam N.

Among the exposure scanning beams 1 to N, a section where adjacent exposure scanning beams may overlap is referred to as a beam overlapping section. This indicates a section in which either one of them may be scanned or overlapping scanning may be performed. That is, as long as it is within the beam overlapable section, any adjacent exposure scanning beam may be separated (connected position). For example, in FIG. 1, the beam can overlap zone B ₁₂ is a section where the left edge of the right edge and the exposure scanning beam 2 of the exposure scanning beam 1 may be duplicated, beam overlap can section B ₂₃ is This is a section where the right edge of the exposure scanning beam 2 and the left edge of the exposure scanning beam 3 may overlap. The length of each overlapping section (length along the scanning direction) is set to be constant. For example, the length of the beam overlapping section B _{12 and} the length of the beam overlapping section B ₂₃ are the same. .

  Hereinafter, processing performed by the control unit 15 based on the connection relationship between adjacent exposure scanning beams in each beam overlapable section will be described with reference to FIGS. That is, the control unit 15 functions as a connection position determination unit and a correction unit. In the following description, it is assumed that the exposure scanning data has pixel values of four gradations of 0, 1, 2, and 3 for each pixel, with 0 being the lowest gradation value and no exposure, and 3 being the highest. The gradation values 1 and 2 are intermediate gradation values. The exposure target 13 is a printed circuit board 131 as an example, and the wiring interval of the printed circuit board 131 requires at least 5 pixels or more.

  FIG. 2 shows an example of the gradation values of the exposure scanning beam at the preceding stage (N) and the succeeding stage (N + 1) along the scanning direction in the beam overlap possible section. FIG. 2 shows a case where the vicinity of the center of the beam overlap possible section is a gradation value 0, that is, there is no wiring (not exposed), and there are wirings on both sides so as to sandwich it. Further, the wiring interval is 5 pixels of the prescribed minimum value, that is, the number of 0s near the center is 5.

  In the case of the printed circuit board 131, the gradation value of the wiring data sandwiching the wiring space becomes halftone (intermediate gradation) when the wiring is obliquely rotated or rotated, enlarged, or reduced by data alignment processing. There is a case.

  In the case of FIG. 2, if the exposure scanning beams N and N + 1 and the gradation value 0 is the connection position of the two exposure scanning beams in the beam overlapable interval, the exposure end position (the gradation value 1) of the exposure scanning beam N is assumed. Due to the scanning position shift of the exposure scanning beam at the edge of the pixel and the exposure characteristics, the exposure amount is slightly increased, or exposure that protrudes to the non-exposed portion (gradation value 0) is performed, and the wiring space The width may be reduced and the minimum space width may not be met.

  Therefore, as described below, the gradation value is corrected after determining the connection position of the two exposure scanning beams in the beam overlap possible section. First, as shown in FIG. 3, the connection position is determined in a range in which pixels having gradation values of 1 or more continue. In FIG. 3, “-” indicates that exposure scanning is not performed.

  In the case of FIG. 3, the position where the gradation value is the maximum gradation value is set as the connection position based on the gradation value of the exposure scanning data in the beam overlap possible section. However, the exposure amount may be slightly increased or slightly protruded to the right depending on the exposure position shift of the pixel at the right edge of the exposure scanning beam N and the exposure characteristics at the scanning end position. May be done. Therefore, double exposure is performed with the gradation value 1 of one pixel at the left edge of the exposure scanning beam N + 1. As a result, the gradation value becomes larger than 1 and correct halftone exposure may not be performed. . Therefore, as shown in FIG. 4, the gradation value 3 of the pixel at the right end of the exposure scanning beam N is reduced to 2 so that correct halftone exposure is performed.

  In other words, by reducing the gradation value 3 of the pixel value at the right edge of the exposure scanning beam N to 2, the amount of protrusion of exposure is reduced, and the left edge of the exposure scanning beam N + 1 is exposed at the original gradation value 1. can do. That is, based on the exposure scanning data of the exposure scanning beam located at the end of the preceding stage (N) and the exposure scanning data of the exposure scanning beam located at the end of the succeeding stage (N + 1), of the preceding stage and the succeeding stage at the connection position. The gradation value of the exposure scanning data located at at least one of the ends is corrected.

  Further, depending on the exposure characteristics at the scanning start position and scanning end position of the exposure scanning beam, the gradation value on the exposure scanning beam N + 1 side may be changed as shown in FIG. In the case of FIG. 5, since the exposure at the scanning end position (right edge) on the exposure scanning beam N side protrudes slightly to the right, exposure of the gradation value 1 at the left edge of the exposure scanning beam N + 1 is not performed. This is an example. That is, as long as the gradation value is around the connection position, the gradation value of the exposure scanning beam on the large gradation value side may be corrected by comparing the edges of adjacent exposure scanning beams, or the gradation level may be reduced. The exposure scanning beam on the tone value side may be corrected. However, the correction to reduce the smaller gradation value as shown in FIG. 5 is limited to the case where the gradation value is not the minimum (0).

  4 and 5 show an example in which the gradation value is corrected to be small. However, the present invention is not limited to this. For example, the gradation value of one exposure scanning beam at the connection position is increased and the other gradation value is corrected. You may correct | amend so that the gradation value of an exposure scanning beam may be made small.

  The operation of the control unit 15 described above is summarized in the flowchart of FIG. In step S1 in FIG. 6, a beam overlapping possible section of adjacent exposure scanning beams is extracted. Next, in step S2, the connection position is determined to be, for example, an edge in a range where one or more gradation values are continuous (connection position determination step). In step S3, correction is performed so that the gradation value of the exposure scanning beam having the larger gradation value among the connection positions is reduced (correction step).

  In the present embodiment, the connection position of the exposure scanning beam is determined as the highest gradation value, but the present invention is not limited to this. It may be in a range where adjacent exposure scanning beams are exposed in an overlapping manner (tone value of 1 or more). Setting the highest gradation value as the connection position means that the pixel of the highest gradation value is the end of the preceding exposure scanning data or the leading edge of the subsequent exposure scanning data, as shown in FIGS. Means.

  Further, the pixel to be corrected is not limited to one pixel, and may be two or more pixels that are continuous in accordance with the characteristics of exposure. That is, the edge of the exposure scanning beam or the periphery of the connection position is not limited to one pixel. Furthermore, the connection position may be set in advance in the center of the beam overlap-possible section and then moved based on the gradation value of the beam overlap-possible section.

  Next, the configuration of the printed circuit board exposure apparatus 1 as an image forming apparatus having the light beam scanning apparatus 10 having the above-described configuration will be described with reference to FIG. As shown in FIG. 7, the printed circuit board exposure apparatus 1 includes a base 2 and an exposed portion 3.

  A printed circuit board 131 is placed on the base 2, and the printed circuit board 131 is conveyed in the direction of arrow A. The base 2 has a conveying means (moving means) (not shown) for conveying the printed circuit board 131 as described above. For example, the conveying means includes a pair of rollers, an endless belt spanned between the rollers, and a driving means such as a motor that drives one of the pair of rollers, and is conveyed by the movement of the endless belt. do it.

  The exposure unit 3 includes a main body unit 3a, a support column unit 3b, a support unit 3c, and a light beam scanning device 10. The main body 3a is formed in a substantially rectangular parallelepiped shape and is disposed on the side surface in the longitudinal direction of the base 2, and image information (exposure scanning data) of wiring formed on the control unit 15 and the printed board 131 shown in FIG. ) Etc. are stored in a storage device (not shown), a power source and the like.

The column portion 3 b is formed in a substantially rectangular parallelepiped column shape, and is disposed on the side surface of the base 2 facing the main body portion 3 a in the longitudinal direction. The support 3c is provided so as to connect the upper end of the main body 3a and the column 3b, and the light beam scanning device 10 (light sources 11 _{1 to} 11 _N , fθ lenses 12 _{1 to} 12 _N, etc.) faces the base 2. It is attached to do. That is, the support portion 3 c is provided in parallel with the printed circuit board 131 placed on the base 2 with a predetermined interval.

  In the printed circuit board exposure apparatus 1 shown in FIG. 7, the control unit 15 reads the image information of the wiring from the storage device (that is, the control unit 15 functions as a data input unit). Next, the printed circuit board 131 placed on the base 2 is conveyed in the direction of arrow A. When the transported printed circuit board 131 reaches under the support unit 3c (under the light beam scanning device 10), the control unit 15 sends an exposure scanning beam modulated based on the image information from the light beam scanning device 10 to the arrow. The light is emitted so as to be scanned in the direction B, and the wiring portion formed on the printed board 131 is exposed.

  According to the present embodiment, when there are a plurality of exposure scanning beams along the scanning direction, the control unit 15 overlaps the connection positions of the adjacent exposure scanning beams with the edges of the adjacent exposure scanning beams. It is determined based on the exposure scanning data in the beam overlap possible section, and the gradation value of either the preceding exposure scanning beam or the subsequent exposure scanning beam at the determined connection position is corrected. By doing so, it is possible to satisfy the prescribed inter-wiring space and to perform correct halftone exposure. Further, it is possible to reduce exposure data short-circuit due to misalignment or the like without fixing the connection position.

  In addition, since the connection position is determined as the position of the maximum gradation value and the gradation value is corrected, the influence of double exposure due to the protrusion of exposure or the like can be reduced, and correct halftone exposure can be performed.

  Since the light beam scanning device 10 is provided in the printed circuit board exposure apparatus 1, when exposing a wiring pattern formed on the printed circuit board 131, the prescribed wiring interval is observed and correct halftone exposure is performed. It can be performed.

  Further, the operation of the flowchart shown in FIG. 6 may be configured as a computer program (scanning program) that is executed by a computer. In this way, the function can be realized by a computer having a CPU and a memory, so that the porting and expansion of the function is facilitated. Further, by storing this computer program in a computer-readable recording medium, it is possible to distribute the program alone as well as to incorporate it into a device, and it is possible to easily upgrade the version.

  In the above-described embodiments, the printed board exposure apparatus has been described as the image forming apparatus. However, the present invention is not limited thereto, and may be a printer, a copier, or the like. In this case, an exposure object written by exposure scanning corresponds to, for example, a photosensitive drum whose position moves relative to the light beam scanning device 10.

  The present invention is not limited to the above embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are included in the scope of the present invention as long as the configuration of the light beam scanning apparatus and the image forming apparatus of the present invention is provided.

1 Printed circuit board exposure device (image forming device)
2 Base (moving means)
10 Light Beam Scanning Device 11 _{1 to} 11 _N Light Source (Light Emitting Unit)
12 _{1 to} 12 _N fθ lens (deflection unit)
131 Printed circuit board (exposure target)
15 Control unit (connection position determination unit, correction unit, image acquisition unit)

JP 2011-143565 A Japanese Patent No. 4118013 Japanese Patent No. 4955267

Claims (6)

A light emitting unit that emits a light beam modulated based on exposure scanning data having a plurality of gradation values; and a deflecting unit that deflects the light beam from the light emitting unit, and is deflected by the deflecting unit. In the light beam scanning apparatus for performing writing on the exposure object by exposing and scanning the light beam to the exposure object,
A plurality of the light emitting units are provided along the direction in which the scanning is performed,
A connection position determining unit that determines a connection position of the light beams emitted from the adjacent light emitting units based on the exposure scanning data in a beam overlap possible section in which the adjacent light beams can be overlapped;
A correction unit that corrects a gradation value of the exposure scanning data around the connection position determined by the connection position determination unit;
Equipped with a,
The plurality of gradation values are values of three or more gradations including a gradation value that does not expose the exposure object,
The connection position determination unit determines a connection position at a position that is a gradation value to be exposed without determining a connection position at a position that is a gradation value at which the exposure scanning data in the beam overlap possible section is not exposed,
The correction unit is based on the exposure scanning data positioned at the end of the connection position in the preceding stage and the exposure scanning data positioned at the end of the connection position in the subsequent stage in the scanning direction of the adjacent light beams. Correcting the gradation value of the exposure scan data located at the end of at least one of the preceding stage and the following stage,
A light beam scanning device characterized by the above. The light beam scanning apparatus according to claim 1, wherein the connection position determination unit determines a position where a gradation value in the beam overlapable section is a maximum gradation value as the connection position. A data input unit to which exposure scanning data is input, a light beam scanning device for writing to an exposure object based on the exposure scanning data input from the data input unit, and the exposure object to the light beam scanning device An image forming apparatus having moving means for moving
An image forming apparatus wherein a light beam scanning apparatus according to claim 1 or 2, as the light beam scanning apparatus. A light emitting unit that emits a light beam modulated based on exposure scanning data having a plurality of gradation values; and a deflecting unit that deflects the light beam from the light emitting unit, and is deflected by the deflecting unit. In the scanning method of the light beam scanning apparatus for performing writing on the exposure object by exposing and scanning the light beam to the exposure object,
When a plurality of the light emitting units are provided along the scanning direction and a plurality of the light beams exist along the scanning direction, the connection positions of the adjacent light beams are determined as the adjacent light beams. A connection position determining step for determining based on exposure scanning data in a beam overlapping possible section capable of overlapping
A correction step of correcting a gradation value of the exposure scanning data around the connection position determined in the connection position determination step;
Only including,
The plurality of gradation values are values of three or more gradations including a gradation value that does not expose the exposure object,
The connection position determining step determines a connection position at a position that is a gradation value to be exposed without determining a connection position at a position that is a gradation value at which the exposure scanning data in the beam overlap possible section is not exposed,
The correction step is based on the exposure scanning data positioned at the end of the connection position in the preceding stage and the exposure scanning data positioned at the end of the connection position in the subsequent stage in the scanning direction of the adjacent light beams. Correcting the gradation value of the exposure scan data located at the end of at least one of the preceding stage and the following stage,
A scanning method for a light beam scanning device. 5. A scanning program for a light beam scanning apparatus, wherein the scanning method for the light beam scanning apparatus according to claim 4 is executed by a computer. A computer-readable recording medium storing a scanning program of the light beam scanning apparatus according to claim 5 .

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