WO2007040165A1

WO2007040165A1 - Image exposure apparatus

Info

Publication number: WO2007040165A1
Application number: PCT/JP2006/319420
Authority: WO
Inventors: Shuichi Ishii; Takao Ozaki; Norihisa Takada
Original assignee: Fujifilm Corporation
Priority date: 2005-09-30
Filing date: 2006-09-29
Publication date: 2007-04-12
Also published as: TW200745768A; TWI352879B; JP2007101730A

Abstract

An image exposure apparatus is provided with a spatial light modulating element wherein irradiated light is modulated at each of two-dimensionally arranged pixel sections; a light source for irradiating the spatial light modulating element with light; a first optical system which collects the light passed through the spatial light modulating element and forms images of the pixel sections; a microlens array for forming images on a photosensitive material by the luminous flux passed through the first optical system from the pixel sections by means of a plurality of two-dimensionally arranged microlenses; a positional shift detecting means for detecting a relative positional shift of the photosensitive material and the light from the microlens array; and a microlens array moving means for moving the microlens array based on the positional shift detected by the positional shift detecting means.

Description

Specification

Image exposure device

Technical field

TECHNICAL FIELD [0001] The present invention relates to an image exposure apparatus, and more particularly to an image exposure apparatus that exposes a photosensitive material by forming an image of light modulated by a spatial light modulator on a photosensitive material.

Background art

Conventionally, an image exposure apparatus is known in which light modulated by a spatial light modulation element is passed through an imaging optical system, an image formed by this light is formed on a predetermined photosensitive material, and the photosensitive material is exposed. It has become. This type of image exposure apparatus basically irradiates light to a spatial light modulation element in which a plurality of pixel units that modulate irradiated light according to control signals are arranged in parallel, and the spatial light modulation element. And an imaging optical system that forms an image of light modulated by the spatial light modulator on the photosensitive material.

In this type of image exposure apparatus, for example, a DMD (digital 'micromirror' device) or the like can be suitably used as the spatial light modulation element. The DMD is a mirror device that is two-dimensionally arranged on a semiconductor substrate such as a number of rectangular micromirror forces silicon that changes the angle of the reflecting surface in accordance with a control signal. The mirror acts as a reflective pixel portion.

[0004] In the image exposure apparatus as described above, there is often a demand for enlarging the image projected onto the photosensitive material. A system is used. In doing so, if the light passing through the spatial light modulator is simply passed through the magnification imaging optical system, the luminous flux from each pixel portion of the spatial light modulator is expanded, and the projected image is reduced. The pixel size increases and the sharpness of the image decreases.

[0005] Therefore, the first imaging optical system is arranged on the optical path of the light modulated by the spatial light modulation element, and each of the light beams of each pixel portion of the spatial light modulation element passes through this imaging optical system. A microlens array in which microphone-lenses are arranged in an array is arranged, and a modulated light image is formed on the photosensitive material screen in the optical path of the light that has passed through the microlens array. 2 imaging optical systems are arranged, and these first and second imaging optical systems are arranged. Therefore, it is considered to enlarge and project an image. In this configuration, the size of the image projected on the photosensitive material screen is enlarged, while the light from each pixel portion of the spatial light modulator is condensed by each microlens of the microlens array. Since the pixel size (spot size) in the projected image is reduced and kept small, the sharpness of the image can be kept high.

[0006] Note that Patent Document 1 shows an example of an image exposure apparatus that uses a DMD as a spatial light modulation element and combines it with a microlens array.

In Patent Document 2, an aperture array (aperture plate) having an aperture (opening) corresponding to each microlens of the microlens array is arranged behind the microlens array in the same type of image exposure apparatus. Thus, a configuration is shown in which only the light that has passed through the corresponding microlens passes through the aperture. In this configuration, the light from the adjacent microlens is prevented from entering each aperture of the aperture plate, so that the stray light can be prevented from entering the adjacent pixel. In addition, even when the DMD pixel (micromirror) is turned off so that light is not irradiated onto the exposure surface, a slight light may be incident on the exposure surface. As a result, the amount of light on the exposure surface when the DMD pixel is in the off state can be reduced.

Patent Document 1: Japanese Patent Laid-Open No. 2001-305663

Patent Document 2: JP 2004-122470 A

Disclosure of the invention

Problems to be solved by the invention

[0008] In a conventional image exposure apparatus in which a spatial light modulation element having a reflective pixel portion, a microlens array, and an imaging optical system, such as the DMD described above, are combined with the microscopic lens by an imaging optical system. An image of a pixel portion such as a mirror is formed, and each microlens of the microlens array is positioned near the image formation position.

The image exposure apparatus having such a configuration exposes a photosensitive material with a beam of about 3 μm. However, when disturbance vibration is applied, there is a problem that the relative position between the exposure head and the stage holding the photosensitive material is shifted by about 1 to 2 / zm, and a correct image cannot be formed on the photosensitive material. In order to cope with such a problem, it is conceivable to correct image data obtained by exposure with software. However, the correction process using software is complicated, and the processing time cannot be reduced for the high tact.

Means for solving the problem

The present invention has been proposed to solve the above-described problems.

[0012] The image exposure apparatus of the present invention includes a spatial light modulation element that modulates irradiated light at each pixel section arranged in a two-dimensional manner, a light source that irradiates light to the spatial light modulation element, A first optical system that collects light passing through the spatial light modulator and forms each image of the pixel portion, and a plurality of light beams that pass through the first optical system are arranged in a two-dimensional manner. A microlens array that forms an image on a photosensitive material with each microlens, a positional deviation detection unit that detects a relative positional deviation between the photosensitive material and light from the microlens array caused by disturbance vibration, and And a microlens array moving means for moving the microlens array based on the positional deviation detected by the positional deviation detection means.

When disturbance vibration occurs, the relative position between the exposure side having the light source and the optical system and the photosensitive material shifts, and the positional shift of the light on the photosensitive material occurs. Therefore, the image exposure apparatus includes a positional deviation detection unit that detects a relative positional deviation between the photosensitive material caused by disturbance vibration and the light from the microlens array, and a positional deviation detected by the positional deviation detection unit. Accordingly, by providing the microlens array moving means for moving the microlens array, it is possible to obtain a high quality image by exposing the photosensitive material without being affected by disturbance vibration.

The invention's effect

The image exposure apparatus according to the present invention can obtain a high-quality image by exposing a photosensitive material without being affected by disturbance vibration.

Brief Description of Drawings

FIG. 1 is a perspective view showing an appearance of an image exposure apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a scanner of the image exposure apparatus.

FIG. 3A is a plan view showing an exposed area formed on a photosensitive material. FIG. 3B is a diagram showing an arrangement of exposure areas by each exposure head.

FIG. 4 is a perspective view showing a schematic configuration of an exposure head of the image exposure apparatus.

FIG. 5 is a schematic sectional view of an exposure head.

FIG. 6 is a partially enlarged view showing the configuration of a digital micromirror device (DMD).

FIG. 7A is an explanatory diagram for explaining the operation of DMD.

FIG. 7B is an explanatory diagram for explaining the operation of the DMD.

FIG. 8A is a plan view showing exposure beam arrangement and scanning lines when DMD is not inclined.

FIG. 8B is a plan view showing the arrangement of exposure beams and scanning lines when the DMD is inclined.

FIG. 9A is a perspective view showing a configuration of a fiber array light source.

FIG. 9B is a front view showing the arrangement of light emitting points in the laser emitting section of the fiber array light source.

FIG. 10 is a diagram showing a configuration of a multimode optical fiber.

FIG. 11 is a plan view showing a configuration of a multiplexed laser light source.

FIG. 12 is a plan view showing a configuration of a laser module.

FIG. 13 is a side view showing a configuration of a laser module.

FIG. 14 is a partial front view showing a configuration of a laser module.

FIG. 15 is a block diagram showing an electrical configuration of the image exposure apparatus.

FIG. 16 is a plan view of the image exposure apparatus.

FIG. 17A is a diagram for explaining the movement operation of the microlens array and the light transmission flat plate.

FIG. 17B is a diagram for explaining the movement operation of the microlens array and the light transmission flat plate.

FIG. 18A is a diagram showing an example of a DMD usage area.

FIG. 18B is a diagram showing an example of a DMD usage area.

FIG. 19 is a schematic sectional view of an exposure head.

FIG. 20 is a schematic sectional view of an exposure head. FIG. 21 is a schematic sectional view of an exposure head.

FIG. 22 is a diagram for explaining a microlens array and an aperture array.

FIG. 23A is a view for explaining the movement operation of the microlens array and the aperture array.

FIG. 23B is a diagram for explaining the movement operation of the microlens array and the aperture array.

FIG. 24 is a diagram for explaining a microlens array and an aperture array.

FIG. 25 is a diagram for explaining a microlens array.

FIG. 26 is a schematic sectional view of an exposure head.

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an image exposure apparatus according to a first embodiment of the present invention will be described.

(Configuration of image exposure device)

As shown in FIG. 1, this image exposure apparatus includes a flat plate-like moving stage 152 that holds a sheet-like photosensitive material 150 by adsorbing to the surface. Two guides 158 extending along the stage moving direction are installed on the upper surface of the thick plate-shaped installation base 156 supported by the four legs 154. The stage 152 is disposed so that the longitudinal direction thereof faces the stage moving direction, and is supported by the guide 158 so as to be reciprocally movable. Note that this image exposure apparatus is provided with a stage drive unit 304 (see FIG. 15), which will be described later, that drives a stage 152 as a sub-scanning means along a guide 158.

A U-shaped gate 160 is provided at the center of the installation table 156 so as to straddle the moving path of the stage 152. Each end of the U-shaped gate 160 is fixed to both side surfaces of the installation table 156. A scanner 162 is provided on one side of the gate 160, and a plurality of (for example, two) sensors 164 for detecting the front and rear ends of the photosensitive material 150 are provided on the other side. The scanner 162 and the sensor 164 are respectively attached to the gate 160 and fixedly arranged above the moving path of the stage 152. The scanner 162 and the sensor 164 are connected to a controller (not shown) that controls them. [0018] As shown in FIGS. 2 and 3B, the scanner 162 includes a plurality of (for example, 14) exposure heads 166 arranged in a matrix of m rows and n columns (eg, 3 rows and 5 columns). Yes. In this example, four exposure heads 166 are arranged in the third row in relation to the width of the photosensitive material 150. It should be noted that the individual exposure heads arranged in the m-th row and the n-th column are denoted as exposure head 16 6.

mn

An exposure area 168 by the exposure head 166 has a rectangular shape with the short side in the sub-scanning direction.

Accordingly, as the stage 152 moves, a strip-shaped exposed region 170 is formed in the photosensitive material 150 for each exposure head 166. In addition, when the exposure area by each exposure head arranged in the m-th row and the n-th column is indicated, it is expressed as an exposure area 168.

mn

In addition, as shown in FIGS. 3A and 3B, each of the exposure heads in each row arranged in a line is arranged so that the strip-shaped exposed regions 170 are arranged without gaps in the direction orthogonal to the sub-scanning direction. They are arranged with a predetermined interval in the direction (a natural number multiple of the long side of the exposure area, twice in this example). For this reason, exposure cannot be performed between the exposure area 168 and the exposure area 168 in the first row.

11 12

The exposure area is exposed using the exposure area 168 in the second row and the exposure area 168 in the third row.

21 31

Can do.

Each of the exposure heads 166 to 166 converts the incident light beam into an image as shown in FIG.

11 mn

As a spatial light modulation element that modulates each pixel according to data, it is equipped with a digital micro mirror 1 device (DMD) 50 made in Texas USA. The DM D50 is connected to a controller 302 (see FIG. 15), which will be described later, provided with a data processing unit and a mirror drive control unit. The data processing unit of the controller 302 generates a control signal for driving and controlling each micromirror in the region to be controlled by the DMD 50 for each exposure head 166 based on the input image data. Further, the mirror drive control unit controls the angle of the reflection surface of each micromirror of the DMD 50 for each exposure head 166 based on the control signal generated by the image data processing unit.

[0022] On the light incident side of the DMD 50, a fiber array light source including a laser emitting portion in which the emitting end portion (light emitting point) of the optical fiber is arranged in a line along the direction corresponding to the long side direction of the exposure area 168 66, a lens system 67 that corrects the laser light emitted from the fiber array light source 66 and collects it on the DMD, and reflects the laser light transmitted through the lens system 67 toward the DMD 50. The mirrors 69 to be operated are arranged in this order. In FIG. 4, the lens system 67 is schematically shown.

As shown in detail in FIG. 5, the lens system 67 includes a condensing lens 71 that condenses the laser light B as the illuminating light emitted from the fiber array light source 66, and the light that has passed through the condensing lens 71. It is composed of a rod-shaped optical integrator (hereinafter referred to as a rod integrator) 72 inserted in the optical path, and an imaging lens 74 disposed in front of the rod integrator 72, that is, on the mirror 69 side. The condensing lens 71, the rod integrator 72, and the imaging lens 74 cause the laser light emitted from the fiber array light source 66 to enter the DMD 50 as a light beam that is close to parallel light and has a uniform beam cross-sectional intensity.

The laser beam B emitted from the lens system 67 is reflected by the mirror 69 and irradiated to the DMD 50 via a TIR (total reflection) prism 70. In FIG. 4, the TIR prism 70 is omitted.

In addition, an optical system 51 that forms an image on the photosensitive material 150 with the laser beam B reflected by the DMD 50 is disposed on the light reflecting side of the DMD 50. As shown in FIG. 5, the optical system 51 includes a first optical system including lens systems 52 and 54, a microlens array 55, and a light transmission flat plate provided between the lens system 54 and the microlens array 55. 80.

A photosensitive material 150 is arranged at a condensing position by each microlens 55a of the microlens array 55, and an image condensed by the microlens array 55 is directly exposed to the photosensitive material 150.

In the present embodiment, each microlens 55 a of the microlens array 55 is defocused by the micromirror 62 and the lens systems 52, 54, which is out of the imaging position of the micromirror 62 by the lens systems 52, 54. Since they are arranged at positions, even if the DMD 50 and the microlens array 55 are slightly misaligned, the light use efficiency and the extinction ratio are kept high.

[0028] The light transmitting flat plate 80 is a flat plate made of, for example, BK7 and having a predetermined thickness. The light transmitting flat plate 80 has a force arranged parallel to the exposure surface and the surface of the microlens array 55, and an angle formed with the exposure surface can be adjusted by a light transmitting flat plate driving device described later.

[0029] As shown in Fig. 6, the DMD 50 has a large number of micromirrors 62 (for example, 1024 x 768) that constitute each pixel (pixel) on an SRAM cell (memory cell) 60. This is a mirror device arranged in a child shape. In each pixel, a rectangular micromirror 62 supported by a support column is provided at the top, and a material having high reflectivity such as aluminum is deposited on the surface of the micromirror 62. The reflectivity of the micromirror 62 is 90% or more, and its size is 13 m as an example in both the vertical and horizontal directions, and the array pitch is 13.7 m as an example in both the vertical and horizontal directions. Each micromirror 62 is formed in a concave mirror shape having a light collecting function by a method described later. In addition, a silicon gate CMOS SRAM cell 60 manufactured in a normal semiconductor memory manufacturing line is arranged directly below the microphone mirror 62 via a support including a hinge and a yoke. It is configured.

[0030] When a digital signal is written in the SRAM cell 60 of the DMD50, the microphone mirror 62 supported by the support is ±± degrees (eg ± 12 °) with respect to the substrate side on which the DMD50 is arranged with the diagonal line as the center. ) Tilted within the range. FIG. 7A shows a state tilted to + α degrees when the micromirror 62 is on, and FIG. 7B shows a state tilted to α degrees when the micromirror 62 is off. Therefore, by controlling the tilt of the micromirror 62 in each pixel of the DMD 50 according to the image signal as shown in FIG. 6, the laser light incident on the DMD 50 is reflected in the tilt direction of each micromirror 62. The

FIG. 6 shows an example of a state in which a part of the DMD 50 is enlarged and the micromirror 62 is controlled to + α degrees or α degrees. On / off control of each micromirror 62 is performed by the controller 302 connected to the DMD 50. Further, a light absorber (not shown) is arranged in the direction in which the laser beam reflected by the micro mirror 62 in the off state travels.

The microlens array 55 shown in FIG. 5 is formed by two-dimensionally arranging a large number of microlenses 55a corresponding to each pixel of the DMD 50, that is, each micromirror 62. Each microlens 55a is located at the position where the laser beam B from the corresponding micromirror 62 is incident, and is out of the imaging position of the micromirror 62 by the lens system 52, 54. It is arranged at the condensing position by 54. In this example, as will be described later, only 1024 x 256 columns of the DMD50's 1024 x 768 micromirrors are driven, so the microlens 55a is correspondingly arranged with 1024 x 256 columns. Is placed. The size of the microlens 55a is 41 μm in both the vertical and horizontal directions. As an example, the micro lens 55a has a focal length of 0.23 mm, NA (numerical aperture) of 0.06, and is formed of a quartz glass cover. In the figure, the photosensitive material 150 is sub-scanned in the direction of arrow F.

Here, it is preferable that the DMD 50 is arranged with a slight inclination so that the short side forms a predetermined angle 0 (eg, 0.1 ° to 5 °) with the sub-scanning direction. FIG. 8A shows the scanning trajectory of the reflected light image (exposure beam) 53 by each micromirror when the DMD 50 is not tilted, and FIG. 8B shows the scanning trajectory of the exposure beam 53 when the DMD 50 is tilted.

[0034] The DMD50 has a multi-row mirror array force in which a large number of micromirrors are arranged in the longitudinal direction (for example, 1024). A force in which a large number of ^ 1_ (for example, 756 threads) is arranged in the short direction. As shown in the figure, by tilting the DMD50, the pitch P1 of the trajectory (scanning line) of the exposure beam 53 by each micromirror becomes narrower than the pitch P2 of the scanning line when the DMD50 is not tilted, greatly increasing the resolution. Can be improved. On the other hand, since the inclination angle of the DMD 50 is very small, the scanning width W2 when the DMD 50 is inclined and the scanning width W1 when the DMD 50 is not inclined are substantially the same.

[0035] In addition, the same scanning line is overlaid and exposed (multiple exposure) by different micromirror arrays. In this way, by performing multiple exposure, it is possible to control a minute amount of the exposure position and realize high-definition exposure. Further, the joints between a plurality of exposure heads arranged in the main scanning direction can be connected without a step by controlling a very small amount of exposure position.

[0036] It should be noted that the same effect can be obtained by arranging the micromirror rows in a staggered manner by shifting the micromirror rows by a predetermined interval in a direction orthogonal to the sub-scanning direction instead of inclining the DMD 50.

[0037] As shown in FIG. 9A, the fiber array light source 66 includes a plurality of (for example, 14) laser modules 64, and one end of the multimode optical fiber 30 is coupled to each laser module 64. ing. The other end of the multimode optical fiber 30 is coupled with an optical fiber 31 having the same core diameter as the multimode optical fiber 30 and a cladding diameter smaller than the multimode optical fiber 30. As shown in detail in FIG. 9B, seven ends of the multimode optical fiber 31 opposite to the optical fiber 30 are arranged along the main scanning direction orthogonal to the sub-scanning direction. These are arranged in two rows to constitute the laser emitting portion 68.

[0038] As shown in FIG. 9B, the laser emitting portion 68 formed by the end portion of the multimode optical fiber 31 is sandwiched and fixed between two support plates 65 having a flat surface. Moreover, it is desirable that a transparent protective plate such as glass is disposed on the light emitting end face of the multimode optical fiber 31 for protection. The light exit end face of the multimode optical fiber 31 has a high light density and is likely to collect dust and easily deteriorate.However, the protective plate as described above prevents the dust from adhering to the end face and deteriorates. Can be delayed.

[0039] In this example, as shown in FIG. 10, an optical fiber 31 having a cladding diameter of about 1 to 30 cm and a small cladding diameter of S is coaxially provided at the tip of the laser light emission side of the multimode optical fiber 30 having a large cladding diameter. Combined. The optical fibers 30 and 31 are coupled by fusing the incident end face of the optical fiber 31 to the outgoing end face of the optical fiber 30 in a state where the respective core axes coincide. As described above, the diameter of the core 31a of the optical fiber 31 is the same as the diameter of the core 30a of the multimode optical fiber 30.

[0040] As the multimode optical fiber 30 and the optical fiber 31, any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber can be applied. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used. In this example, the multimode optical fiber 30 and the optical fiber 31 are step index type optical fibers, and the multimode optical fiber 30 has a cladding diameter = 125, a core diameter = 50 / ζ πι, NA = 0.2, an incident end face Coat transmittance = 99.5% or more, and optical fiber 31 has a cladding diameter = 60 m, a core diameter = 50 m, and NA = 0.2.

[0041] However, the cladding diameter of the optical fiber 31 is not limited to 60 m. The clad diameter of many optical fibers used in conventional fiber light sources is 125 m. The smaller the clad diameter, the deeper the focal depth. Therefore, the clad diameter of multimode optical fibers should be 80 μm or less. 60 μm or less is preferable. On the other hand, in the case of a single mode optical fiber, the core diameter needs to be at least 3-4 / ζ πι, and therefore the cladding diameter of the optical fiber 31 is preferably 10 m or more. In addition, it is preferable from the viewpoint of force coupling efficiency that the core diameter of the optical fiber 30 matches the core diameter of the optical fiber 31. In the present invention, as described above, it is not always necessary to use two optical fibers 30 and 31 having different clad diameters by fusing (so-called different diameter fusion). A fiber array light source may be configured by bundling a plurality of fibers (for example, optical fiber 30 in the case of FIG. 9A) as they are.

[0043] The laser module 64 is configured by a combined laser light source (fiber light source) shown in FIG. This combined laser light source is composed of a plurality of (for example, 7) chip-shaped lateral multimode or single mode GaN-based semiconductor lasers LD 1, LD2, LD3, LD4, LD5, LD6 arranged and fixed on the heat block 10. , And LD7, collimator lenses 11, 12, 13, 14, 15, 16 and 17 provided corresponding to each of the GaN-based semiconductor lasers LD1 to LD7, one condenser lens 20, and one And a multimode optical fiber 30. Note that the number of semiconductor lasers is not limited to seven, and other numbers may be adopted. Further, instead of the seven collimator lenses 11 to 17 as described above, a collimator lens array in which these lenses are assembled can be used.

[0044] The GaN-based semiconductor lasers LD1 to LD7 have substantially the same oscillation wavelength (for example, 405 nm), and all the maximum outputs are also almost the same (for example, about 100 mW for the multimode laser and about 50 mW for the single mode laser). The outputs of the GaN-based semiconductor lasers LD1 to LD7 may be different from each other below the maximum output. As the GaN-based semiconductor lasers LD1 to LD7, lasers that oscillate at wavelengths other than 405 nm in the wavelength range of 350 nm to 450 nm may be used.

[0045] As shown in Figs. 12 and 13, the combined laser light source is housed in a box-shaped package 40 having an upper opening together with other optical elements. The package 40 is provided with a package lid 41 that is designed to close the opening thereof, and a sealing gas is introduced after the deaeration process, and the opening of the knock 40 is closed by the package lid 41, thereby forming the package lid 41. The combined laser light source is hermetically sealed in a closed space (sealing space) formed.

[0046] A base plate 42 is fixed to the bottom surface of the package 40. On the top surface of the base plate 42, the heat block 10, the condensing lens holder 45 for holding the condensing lens 20, and the multimode light. A fiber holder 46 that holds the incident end of the fiber 30 is attached. The exit end of the multimode optical fiber 30 is formed on the wall surface of the knock 40. It is pulled out of the package from the opened opening.

Further, a collimator lens holder 44 is attached to the side surface of the heat block 10, and collimator lenses 11 to 17 are held there. An opening is formed in the lateral wall surface of the package 40, and a wiring 47 for supplying a driving current to the GaN semiconductor lasers LD1 to LD7 is bowed out of the package through the opening! /.

In FIG. 13, in order to avoid complication of the drawing, only the GaN semiconductor laser LD 7 among the plurality of GaN semiconductor lasers is numbered, and the collimator lens 17 among the plurality of collimator lenses is assigned. Only numbered.

FIG. 14 shows the front shape of the mounting portion of the collimator lenses 11 to 17. Each of the collimator lenses 11 to 17 is formed in a shape obtained by cutting an area including the optical axis of a circular lens having an aspherical surface into an elongated shape with a parallel plane. This elongated collimator lens can be formed, for example, by molding a resin or optical glass. The collimator lenses 11 to 17 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD 7 (left and right direction in FIG. 14). Yes.

[0050] On the other hand, the GaN-based semiconductor lasers LD1 to LD7 have an active layer with an emission width of 2 μm, and the divergence angles in a direction parallel to and perpendicular to the active layer are, for example, 10 ° and 30 °, respectively. Lasers that emit laser beams B1 to B7 are used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer.

[0051] Therefore, the laser beams B1 to B7 emitted from the respective light emitting points are spread with the direction in which the divergence angle is large coincides with the length direction with respect to the elongated collimator lenses 11 to 17 as described above. The incident light enters in a state where the direction with a small angle coincides with the width direction (direction perpendicular to the length direction). In other words, the width of each collimator lens 11 to 17 is 1. lmm and the length is 4.6 mm, and the beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 2 respectively. 6mm. Each of the collimator lenses 11 to 17 has a focal length f 1 = 3 mm, NA = 0.6, and a lens arrangement pitch = 1.25 mm.

[0052] The condensing lens 20 is formed by cutting a region including the optical axis of a circular lens having an aspherical surface into a long plane in a parallel plane, and extending it in the arrangement direction of the collimator lenses 11 to 17, that is, in the horizontal direction. It is formed in a short shape in a perpendicular direction. This condenser lens 20 has a focal length f 2 = 23 mm and NA = 0.2. This condensing lens 20 is also formed, for example, by molding a resin or optical glass.

Next, the electrical configuration of the image exposure apparatus of this example will be described with reference to FIG. As shown here, a modulation circuit 301 is connected to the overall control unit 300, and a controller 302 that controls the DMD 50 is connected to the modulation circuit 301. The overall control unit 300 is connected to an LD drive circuit 303 that drives the laser module 64 and a stage drive device 304 that drives the stage 152. The overall control unit 300 further includes a microlens array driving device 305 that moves the microphone aperture lens array 55 in a direction parallel to the exposure surface, and a light transmission flat plate 80 that changes an angle formed by the microlens array 55. The light transmitting flat plate driving device 306 to be inclined is connected to displacement sensors 192, 194, and 196 for detecting vibrations such as disturbance vibrations.

As shown in FIG. 16, the displacement sensor 192 measures the relative position in the x direction between the photosensitive material 150 and the exposure head. The displacement sensors 194 and 196 measure the relative position in the y direction between the photosensitive material 150 and the exposure head. In this embodiment, the displacement sensors 192, 194, and 196 are laser measuring instruments, and are fixed to the scanner 162 by an unillustrated indicating member so as to be able to move rigidly.

The displacement sensor 192 is disposed at a position corresponding to the bar-shaped mirror 193 provided on the side surface parallel to the y direction of the stage 152, and performs position measurement using reflection by the mirror 193. The displacement sensors 194 and 196 perform position measurement using reflections by two mirrors 195 and 197 provided near both ends of a side parallel to the X direction of the stage 152, respectively.

The displacement sensors 192, 194, 196 measure the relative position of the exposure head with respect to the photosensitive material 150, and output the measurement information to the overall control unit 300 shown in FIG. The measurement information includes the X position and two y positions.

The overall control unit 300 calculates the position of the stage 152 in the X direction and the y direction and the attitude of the stage 152 (the rotation angle around the z axis) from the measurement information, and the X direction of the exposure head with respect to the photosensitive material 150 Calculate the relative displacement in the y and y directions, and calculate the shift amounts in the x and y directions to correct the relative displacement. The overall control unit 300 then determines the shift amount. Based on the above, the microlens array driving device 305 and / or the light transmission flat plate driving device 306 are controlled.

(Operation of image exposure device)

Next, the operation of the image exposure apparatus will be described. Lasers emitted in a divergent light state from each of the GaN-based semiconductor lasers LD 1 to LD 7 (see FIG. 11) constituting the combined laser light source of the fiber array light source 66 in each exposure head 1 66 of the scanner 162 Each of the lights B1, B2, B3, B4, B5, B6, and B7 is made parallel by the corresponding collimator lenses 11-17. The collimated laser beams B1 to B7 are collected by the condensing lens 20 and converge on the incident end face of the core 30a of the multimode optical fiber 30.

In this example, the collimator lenses 11 to 17 and the condenser lens 20 constitute a condensing optical system, and the condensing optical system and the multimode optical fiber 30 constitute a multiplexing optical system. That is, the laser beam Bl to B7 force condensed as described above by the condensing lens 20 is incident on the core 30a of the multimode optical fiber 30, propagates in the optical fiber, and is combined into one laser beam B. Then, the light is emitted from the optical fiber 31 coupled to the emission end of the multimode optical fiber 30.

[0059] In each laser module, when the coupling efficiency of laser light B1 ~: B7 to the multimode optical fiber 30 is 0.9 and each output of the GaN-based semiconductor laser LD1 ~: LD7 is 50mW, it is an array For each of the optical fibers 31 arranged in the optical fiber 31, a combined laser beam B having an output of 315 mW (= 50 m WX 0.9 × 7) can be obtained. Therefore, with the entire 14 multi-mode optical fibers 31, a laser beam B with an output of 4.4 W (= 0.315 WX 14) can be obtained.

In image exposure, image data corresponding to the exposure pattern is input from the modulation circuit 301 shown in FIG. 15 to the controller 302 of the DMD 50 and stored in the frame memory thereof. This image data is data in which the density of each pixel constituting the image is expressed by binary values (whether or not dots are recorded).

The stage 152 having the photosensitive material 150 adsorbed on the surface is moved at a constant speed from the upstream side to the downstream side of the gate 160 along the guide 158 by a stage driving device 304 shown in FIG. Sensor attached to gate 160 as stage 152 passes under gate 160 When the leading edge of the photosensitive material 150 is detected by 164, the image data stored in the frame memory is sequentially read out for each of a plurality of lines, and each exposure head 166 is based on the image data read out by the data processing unit. A control signal is generated every time. Then, each of the micromirrors of the DMD 50 is controlled on and off for each exposure head 166 by the mirror drive control unit based on the generated control signal.

[0062] When the DMD 50 is irradiated with laser light B from the fiber array light source 66, the laser light reflected when the microphone mirror of the DMD 50 is on is imaged on the photosensitive material 150 by the lens system 51. . In this manner, the laser light emitted from the fiber array light source 66 is turned on / off for each pixel, and the photosensitive material 150 is exposed in approximately the same number of pixels (exposure area 168) as the number of pixels used in the DMD 50. In addition, the photosensitive material 150 is moved at a constant speed together with the stage 152, so that the photosensitive material 150 is sub-scanned in the direction opposite to the stage moving direction by the scanner 162, and a strip-shaped exposed area for each exposure head 166. 170 is formed.

At this time, as shown in FIG. 17A, the light transmission flat plate 80 is disposed in parallel to the exposure surface. Therefore, the light from the lens system 54 shown in FIG. 5 passes through the light transmitting flat plate 80 as it is, and is imaged on the photosensitive material 150 by each microlens 55a of the microphone aperture lens array 55. However, when external force disturbance vibration is applied, the stage 55 and the optical system are displaced, and the exposure position is displaced.

Accordingly, when at least one of the displacement sensors 192, 194, 196 detects displacement due to disturbance vibration, the microlens array driving device 305 shown in FIG. 15 detects the exposure position due to the disturbance vibration as shown in FIG. 17B. The microlens array 55 is moved in parallel in the direction to cancel the displacement. As a result, the deviation of the exposure position can be corrected, and a high-quality image can be formed without being affected by disturbance vibration.

[0065] At this time, as shown in FIG. 17B, the light transmission flat plate driving device 306 further changes the angle formed between the light transmission flat plate 80 and the exposure surface in a direction to cancel the deviation of the exposure position due to disturbance vibration. The light transmission flat plate 80 is inclined. Thereby, the light incident on the light transmission flat plate 80 is refracted in the light transmission flat plate 80 and is emitted from the light transmission flat plate 80 in a state shifted in the horizontal direction. For this reason, the light transmission flat plate driving device 306 cancels the exposure position due to disturbance vibration. The displacement of the exposure position can be corrected by tilting the light transmitting flat plate 80 in the direction.

[0066] In this example, as shown in FIGS. 18A and 18B, DMD 50 has a power map in which 768 pairs of micro mirror arrays in which 1024 microphone aperture mirrors are arranged in the main scanning direction are arranged in the sub scanning direction. In the example, the controller 302 controls only a part of the micromirror rows (for example, 1024 × 256 rows).

[0067] In this case, as shown in FIG. 18A, a micromirror array arranged at the end of DMD50 may be used as shown in FIG. 18B. May be. In addition, when a defect occurs in some of the micromirrors, the micromirror array to be used may be appropriately changed depending on the situation, such as using a micromirror array in which no defect has occurred.

[0068] There is a limit to the data processing speed of the DMD50, and the modulation speed per line is determined in proportion to the number of pixels to be used. The modulation speed per hit is increased. On the other hand, in the case of an exposure method in which the exposure head is continuously moved relative to the exposure surface, it is not necessary to use all the pixels in the sub-scanning direction.

[0069] When the sub-scan of the photosensitive material 150 by the scanner 162 is completed and the rear end of the photosensitive material 150 is detected by the sensor 164, the stage 152 is moved along the guide 158 by the stage driving device 304. The origin returns to the upstream side, and is moved again along the guide 158 from the upstream side of the gate 160 to the downstream side at a constant speed.

[0070] Next, the laser light B as illumination light is provided to the DMD 50, which includes the fiber array light source 66, the condensing lens 71, the rod integrator 72, the imaging lens 74, the mirror 69, and the TIR prism 70 shown in FIG. An illumination optical system that irradiates the light will be described. The rod integrator 72 is, for example, a translucent rod formed in a square columnar shape, and the intensity distribution in the beam cross section of the laser beam B is made uniform while the laser beam B travels while totally reflecting inside the rod integrator 72. Note that the entrance end face and the exit end face of the rod integrator 72 are coated with an antireflection film to increase the transmittance. As described above, if the intensity distribution in the beam cross section of the laser beam B that is illumination light can be made highly uniform, non-uniform illumination light intensity can be eliminated and a high-definition image can be exposed on the photosensitive material 150.

In this apparatus, each microlens 55 of the microlens array 55 shown in FIG. a is disposed at the converging position of the micromirror 62 and the lens systems 52 and 54, which are out of the imaging position of the micromirror 62 by the lens systems 52 and 54, so that the DMD 50 and the microphone lens array 55 Even if there is a slight misalignment, the light utilization efficiency and the extinction ratio are kept high.

[0072] As described above, the image exposure apparatus according to the first embodiment is a case where a relative deviation occurs between the exposure position of the laser beam and the position on the stage 152 due to disturbance vibration. The microlens array 55 is moved in parallel to the exposure surface based on disturbance vibrations, and the aperture array 59 is also moved in parallel, thereby correcting the deviation of the exposure position and exposing the photosensitive material to obtain a high-quality image. Can be obtained.

Note that the image exposure apparatus of the present embodiment may include an optical system 51 as shown in FIG. 19 instead of the optical system 51 shown in FIG. As shown in detail in FIG. 19, the optical system 51 includes a first optical system including lens systems 52 and 54, a microlens array 55, and an aperture array 59. That is, the optical system 51 further includes an aperture array 59 provided between the microlens array 55 and the photosensitive material 150 in addition to the configuration shown in FIG.

The aperture array 59 is formed by forming a large number of apertures (openings) 59a corresponding to the microlenses 55a of the microlens array 55 on the light shielding member 59b. In other words, the aperture array 59 has a plurality of circular apertures (openings) 59 a arranged in a two-dimensional manner.

The image exposure apparatus provided with such an aperture array 59 can further shape the beam shape and expose the photosensitive material to obtain a high-quality image.

Further, instead of the optical system 51 shown in FIG. 19, an optical system 51 as shown in FIG. 20 may be provided. As shown in detail in FIG. 20, the optical system 51 includes a first optical system including lens systems 52 and 54, a microlens array 55, and a second microlens array. In other words, the optical system 51 includes a second microlens array 81 instead of the aperture array 59 of the optical system 51 shown in FIG.

[0077] Thereby, even when the aperture array 59 cannot be provided between the microlens array 55 and the exposure surface where the distance is small, the microlens array 55 and the exposure surface are exposed. The photosensitive material 150 can be exposed by providing the second microlens array with the surface.

[Second Embodiment]

Next, a second embodiment of the present invention will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the image exposure apparatus according to the second embodiment, the arrangement positions of the microlens array 55 and the aperture array 59 shown in FIG.

Specifically, as shown in FIG. 21, the aperture array 59 has a plurality of circular apertures (openings) 59a arranged in a two-dimensional manner on the light shielding member 59b. Each aperture 59a is formed in the aperture array 59 so that the image of each micromirror 62 of the DMD 50 corresponds to each aperture 59a. The aperture array 59 can shape the beam shape by the aperture 59a.

Note that the aperture array 59 is not limited to the above-described configuration, and may be configured as follows. For example, as shown in FIG. 22, the aperture array 59 is a mask that shields the outer peripheral area of each microphone aperture lens 55a (the part excluding the area of a predetermined distance from the center of the microlens 55a) on the light transmitting substrate 59c. 59b may be formed. Accordingly, the aperture array 59 has a plurality of circular apertures 59a arranged in a two-dimensional shape.

On the other hand, in the microlens array 55, a large number of microlenses 55a corresponding to each aperture 59a of the aperture array 59 (that is, corresponding to each micromirror 62 of the DMD 50) are arranged in a two-dimensional shape. These microlenses 55a form images of the corresponding portions of the apertures 59a on the photosensitive material 150, respectively.

At this time, as shown in FIG. 23A, the light that has passed through each aperture 59a of the aperture array 59 enters the microlens 55a of the microlens array 55 as it is, and the photosensitive material 150 passes through each microlens 55a. Imaged on top.

[0083] When at least one of the displacement sensors 192, 194, 196 detects displacement due to disturbance vibration, the microlens array driving device 305 cancels the deviation of the exposure position due to the disturbance vibration, as shown in FIG. 23B. The microlens array 55 and the aperture array 59 are both translated in the direction. As a result, the amount of light displaced by disturbance vibrations The light is always shielded by the array 59, and only the light is incident on each microlens 55a of the microlens array 55 without being shifted in the exposure position. As a result, since the deviation of the exposure position is shielded, the photosensitive material 150 can be exposed without being affected by disturbance vibration, and a high-quality image can be obtained.

Note that the microlens array 55 and the aperture array 59 may have the following configuration instead of the configuration shown in FIG. For example, as shown in FIG. 24, a first mask 55b that shields the outer peripheral area of each microlens 55a may be formed in the microlens array 55.

Further, the aperture array 59 is not limited to the aspect of the present embodiment, and may be formed integrally with the microlens array 55 on the light incident side or the light emitting side of the microphone port lens array 55. Good.

For example, as shown in FIG. 25, a first mask 55b for shielding the outer peripheral area of each microlens 55a is formed on the light exit side of the microlens array 55, and the light incident side of the microlens array 55 is formed. Further, a second mask 55c that shields the outer peripheral area of each microlens 55a may be formed. Note that only one of the first mask 55b and the second mask 55c may be formed. With such a microlens array 55, the beam shape can be shaped by the aperture 59a.

[0087] [Third Embodiment]

Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the site | part same as embodiment mentioned above, and the detailed description is abbreviate | omitted. As shown in FIG. 26, the image exposure apparatus according to the third embodiment includes an imaging optical system 51 having a configuration different from the configuration shown in FIG. 5 or FIG. 19, an imaging optical system 51, and a photosensitive material 150. And an optical path length changing member 73 disposed between them.

On the light reflection side of the DMD 50, as shown in FIG. 26, an imaging optical system 51 that forms an image on the photosensitive material 150 of the laser light B reflected by the DMD 50 is disposed. This imaging optical system 51 is inserted between the first imaging optical system consisting of lens systems 52 and 54, the second imaging optical system consisting of lens systems 57 and 58, and these imaging optical systems. A microlens array 55 and an aperture array 59. Microlens array 55 and aperture array 5 As in the second embodiment, 9 can be moved in a direction parallel to the exposure surface by the microlens array driving device 305 shown in FIG.

The light beam emitted from the fiber array light source 66 is modulated by the DMD 50, and then directed and emitted to the photosensitive material 150 through the imaging optical system 51. In the figure, the photosensitive material 150 is sub-scanned in the direction of arrow F.

[0090] The optical path length changing member 73 also has a wedge-shaped prism 73OA and a wedge-shaped prism 730B force arranged adjacent to each other in an inverted direction. The wedge-shaped prism 730A and the wedge-shaped prism 730B are obtained by, for example, cutting a parallel plate made of a transparent material such as glass or acrylic on a plane inclined obliquely with respect to the parallel plane of the parallel plate. A wedge prism can be used. Here, it is assumed that the wedge prism 730A and the wedge prism 730B are made of glass having a refractive index of 1.51.

[0091] By combining the wedge-shaped prism 730A and the wedge-shaped prism 730B, an air layer is formed between them. The wedge-shaped prism 730A and the wedge-shaped prism 730B are mounted on a ヽ holder (not shown) so that a parallel plate is formed through this air layer!

[0092] The optical path length changing member 73 configured as described above has a substantial thickness of a parallel plate formed by a combination of a pair of wedge prisms 730A and 730B (the thickness of the parallel plate formed as described above). Thus, the optical path length between the photosensitive material 150 and the imaging optical system 51 is corrected by changing the thickness excluding the thickness t of the air layer). The optical path length is a value obtained by multiplying the substantial thickness of the parallel plate by the refractive index of the parallel plate.

[0093] It should be noted that the present invention is not limited to the above-described embodiments, but can be applied to those modified in design within the scope described in the claims. is there.

For example, a mask that shields the outer peripheral region of the microlens 55a may be formed on the microlens array 55 shown in the first and third embodiments. In addition, the aperture array 59 shown in FIG. 26 may be one in which an aperture 59a is formed on a light-shielding member as shown in FIG. 19, or an aperture 59a is formed by forming a mask on a light transmitting member. A little. In the above-described embodiment, the displacement sensor detects the vibration of the stage with a laser measuring device arranged around the stage, and calculates the positional deviation of the light on the exposure surface of the exposure beam. However, the present invention is not limited to this. That is, as long as it can detect a change in the relative positional relationship between the exposure head and the stage, vibrations of both the exposure head and the stage may be detected. Further, it is possible to adopt a configuration for detecting the positional deviation of the direct exposure beam on the exposure surface.

Explanation of symbols

[0096] LD1 to LD7 GaN semiconductor laser

30, 31 Multimode optical fiber

50, 250 digital micromirror device (DMD)

51 Optical system

52, 54 Lens system

55 Micro lens array

55a micro lens

57, 58 lens system

59 Aperture array

59a aperture

62 Micromirror

66 Laser module

66 Fino Array Light Source

68 Laser emission part

72 Rod integrator

150 photosensitive material

Claims

The scope of the claims

[1] A spatial light modulation element that modulates the irradiated light in each pixel section arranged in a two-dimensional manner, a light source that irradiates light to the spatial light modulation element,

A first optical system for condensing the light that has passed through the spatial light modulator and forming an image of the pixel unit, and

A microlens array that forms an image on a photosensitive material with a plurality of microlenses arranged in a two-dimensional manner by a plurality of light beams from the pixel unit that have passed through the first optical system;

A displacement detection means for detecting a relative displacement between the photosensitive material and the light of the microlens array force;

A microlens array moving means for moving the microlens array based on the positional deviation detected by the positional deviation detection means;

An image exposure apparatus comprising:

[2] The apparatus further includes a second optical system that projects and projects an image formed by the microlens array onto the photosensitive material.

The image exposure apparatus according to claim 1.

[3] a light-transmitting flat plate that transmits light from the first optical system and enters the microlens array;

A light transmission flat plate tilting unit that tilts the light transmission flat plate so that an angle formed by the light transmission flat plate and the microlens array is changed based on the positional shift detected by the positional shift detection unit; The

The image exposure apparatus according to claim 1.

[4] It further comprises an aperture array in which a mask for shielding the outer peripheral area of each microlens of the microlens array is formed,

The microlens array moving means moves the aperture array together with the microlens array based on the positional deviation detected by the positional deviation detection means.

The image exposure apparatus according to claim 1.

[5] The aperture array is integrally formed with the microlens array on the light incident side or the light emitting side of the microlens array.

The image exposure apparatus according to claim 4.

[6] In the microlens array, a mask for shielding the outer peripheral area of each microlens is formed on at least one of the light incident side and the light output side.

The image exposure apparatus according to claim 1.