CN101120285A - Image exposing apparatus - Google Patents

Abstract

An image exposing apparatus, in which a photosensitive material is exposed by light modulated by a spatial optical modulation device, which is capable of securing high light utility efficiency and extinction ratio. In an image exposing apparatus including a spatial optical modulation device 50, such as a DMD having multitudes of reflective pixel sections disposed two-dimensionally, each for modulating light irradiated thereon; a light source 66 for irradiating light B on the spatial optical modulation device 50; and an imaging optical system 51 for focusing an image represented by the light B transmitted via the spatial optical modulation device 50 on a photosensitive material 150, each of the pixel sections (e.g., micromirrors of DMD) is shaped like a concave or convex mirror that converges the light B used for image exposure.

Description

Image exposing apparatus

Technical field

The present invention relates to a kind of image exposing apparatus.More specifically, the present invention relates to a kind of image exposing apparatus, in described device, photosensitive material is exposed thereon by being focused on by the optical imagery of the light representations of spatial light modulator modulation.

Background technology

Known a kind of image exposure system, in this exposure system, in order to use the image exposure photosensitive material, by the light of spatial light modulator modulation by imaging optical system and with the image focusing of light representations on predetermined photosensitive material.Basically, this image exposure system comprises: by the spatial light modulator that a plurality of pixel portions are by rows formed, each pixel portions is used for according to control signal modulation irradiates light; Be used for the light source of rayed on spatial light modulator; And be used for to be imaged on by the optical imagery of the light representations of spatial light modulator modulation imaging optical system on the photosensitive material.

In this image exposure system, for example DMD (Digital Micromirror Device) or other similar devices are preferably used as spatial light modulator.Above-mentioned DMD is a kind of micromirror devices, and in this device, the rectangle micro mirror of a plurality of angles that change reflecting surface according to control signal is arranged in the mode of bidimensional at the semiconductor-based end of being made by for example silicon or other analogs.Here, above-mentioned micro mirror is as reflective pixel portion.

In above-mentioned image exposure system, image often occurs and before being projected on the photosensitive material, need condition of enlarged.If this is the case, image amplification and Focused Optical system are used as imaging optical system.Via spatial light modulator, amplify and the simple path of the light that Focused Optical system is propagated can cause wideer light beam from each pixel portions of spatial light modulator by image.So it is big that the Pixel Dimensions on the projected image becomes, and the acutance of image descends.

As a result, for adopting first and second kinds of imaging optical systems to amplify and projected image, some considerations have been provided.In this structure, first kind of imaging optical system is set on the light path of the light of being modulated by the spatial light modulator with microlens array, wherein microlens array is provided with lenticule with array way, each lenticule is corresponding with each pixel portions of spatial light modulator, is set on the imaging plane of first imaging optical system.Be used for to be set at by second imaging optical system of image focusing on photosensitive material or screen that light modulated is represented the light path of the light that transmits by microlens array.In above-mentioned structure, the size of images that is projected on photosensitive material or the screen can be amplified, and the acutance of image still can remain on high level, because the light from each pixel portions of spatial light modulator is assembled by each lenticule of microlens array, therefore the Pixel Dimensions (spot definition) on projected image narrows down and keeps little size.

Having described this class in the patent No. is the Japanese uncensored patent of 2001-305663 adopts DMD as spatial light modulator and a kind of in conjunction with the image exposure system of microlens array.

A kind of image exposure system of same-type in being the Japanese uncensored patent of 2004-122470, the patent No. has been described.In this system, hole array (orifice plate) has the hole, and each hole is corresponding to each lenticule of microlens array, and the hole array is in the rear side of microlens array, only allows to pass through the hole via the light that corresponding lenticule is propagated.This structure prevents to enter contiguous pixel from entering the hole with the hole of the orifice plate lenticular light of not corresponding vicinity so that can prevent parasitic light.Further, even close to cover the light time, still have a spot of optical energy irradiation sometimes to exposed when the pixel (micro mirror) of DMD.Also be in this case, above-mentioned structure can reduce the amount that is present in the light of exposed when the pixel of DMD is closed.

In the existing image exposure system that constitutes by spatial light modulator with reflective pixel portion (as DMD etc.), microlens array and imaging optical system, the image of each pixel portions (such as micro mirror or similar device) expression is focused on by imaging optical system, and microlens array is configured to: each lenticule is positioned over the imaging plane that is formed by imaging optical system.

The image exposing apparatus that makes up in mode as mentioned above has the problem that reduces optics utilization ratio and extinction ratio, unless the relative position relation between spatial modulator and the microlens array strictly keeps the form of being scheduled to, just this problem can not occur.Detailed description to this point will be carried out below.

By the square of the drawing reference numeral among Figure 18 A 100 expression is the image of being represented by the pixel portions of spatial light modulator (such as the micro mirror of the DMD that is focused on by imaging optical system etc.).Rectangle by 101 expressions of the drawing reference numeral among Figure 18 B is the microlens array with the lenticule 102 that is arranged side by side.In the time of on the part of each lenticule 102 that these micro mirror images 100 is arranged on microlens array 101, when if micro mirror image 100 forms with the size greater than lenticule 102, in the image and the pass between the lenticule that form is the situation shown in similar Figure 19 A, if and spatial modulator and microlens array be when skew takes place on passing the direction of optical axis, this pass is the situation shown in similar Figure 19 B.In both of these case, big blocking (eclipse) occur, and the light that reflects on the marginal portion of micro mirror is not used further to image exposure, cause low light utilization ratio.

Usually, stop that the mask of undesirable light is arranged on the outside of the marginal portion of lenticule 102 integratedly or respectively.If these masks are set, the light that is blocked in the above described manner is masked to be stopped.Even these masks are not set, the light that is blocked in the above described manner also departs from the hole of lenticule 102 and can not assembled by lenticule 102.So,, described only disabled for desirable application.

Further, when the spatial modulator shown in Figure 19 B and the skew between the microlens array became bigger, the part that should focus on the micro mirror image 100 on the part of the lenticule 102 that is called A focused on the part of the contiguous lenticule that is called B 102.If this is the case, for example, when the light of transmission by B lenticule 102 need be stopped fully, the light that should be input to A lenticule 102 entered B lenticule 102, has reduced the extinction ratio of B lenticule 102 thus.

Consider above-mentioned situation, target of the present invention provides a kind of the have high light utilization ratio and the image exposing apparatus of High Extinction Ratio.

Summary of the invention

A kind of image exposing apparatus of the present invention comprises:

Spatial light modulator, described spatial light modulator have a plurality of reflective pixel portions that are arranged side by side, and each pixel portions is used for according to control signal modulation irradiation light thereon;

Light source is used to light shine spatial light modulator; And

Imaging optical system is used for the image focusing that the light of being modulated by spatial light modulator is represented to photosensitive material; Wherein

Each pixel portions of spatial light modulator is made into the shape of similar concave mirror or convex mirror.

In the image exposing apparatus that makes up in the above described manner, if imaging optical system comprises: be used to receive via the light of each pixel portions transmission of spatial light modulator and focus on the optical system of the image of each pixel portions; And have a plurality of lenticular microlens arrays that are arranged side by side, each lenticule is used to receive by the light of optical system transmission and assembles light via each pixel portions transmission of spatial light modulator respectively, microlens array preferably will be set on the optical convergence plane that pixel portions and optical system by concave surface or convex shape form, and break away from the imaging plane of the pixel portions that lens combination forms.

Further, if microlens array is set, then imaging optical system preferably includes the light that is used to receive the light by the microlens array transmission and will receives from each lenticule of microlens array and focuses on optical system on the photosensitive material.

Further, substitute microlens array, the array of the hole with a plurality of holes that are arranged side by side is provided, each hole difference transmission is via the light of each pixel portions transmission of spatial light modulator.In this case, the hole array preferably is arranged on the optical convergence plane that is formed by the pixel portions of concave surface or convex shape and optical system, and breaks away from the imaging plane of the pixel portions of lens combination formation.

If the hole array is set, then imaging optical system preferably include the light that is used to receive by the hole array transmission, and the light that will receive from each hole of hole array focus on optical system on the photosensitive material.

Further, in image exposing apparatus of the present invention, aforesaid DMD is preferably used as spatial light modulator.

According to another embodiment of the invention, image exposing apparatus comprises:

Spatial light modulator, described spatial light modulator have a plurality of reflective pixel portions that are arranged side by side, and each pixel portions is modulated the light that shines on it according to control signal;

Light source is used to light shine spatial light modulator; And

Optical system is used for the image focusing that the light of being modulated by spatial light modulator is represented to photosensitive material, wherein:

Each pixel portions of spatial light modulator is all made the shape of similar curved; And

When the main beam that sends from spatial light modulator had the angle of divergence, the convergent angle of the main beam that is provided by pixel portions and optical system was greater than the angle of divergence of main beam.

Here, each pixel portions of spatial light modulator can have arbitrary shape, as long as it has curved surface.It can become the shape of similar recessed or convex lens.

Microlens array can be arranged on the optical convergence plane that is formed by pixel portions and optical system, and breaks away from the imaging plane that is formed by pixel portions and optical system.In this case, this microlens array can be installed in the mode that can move along the optical axis direction of light, to allow to focus on adjustment.

This device can further comprise the hole array with a plurality of holes that are arranged side by side, and its each hole is respectively applied for the light that receives by the optical system transmission and the transmission light via each pixel portions transmission of spatial light modulator.Preferably, the hole array is set on the optical convergence plane that is formed by pixel portions and optical system, and breaks away from the imaging plane of the pixel portions that is formed by optical system.

Preferably, in order to make the convergent angle of main beam greater than its angle of divergence, the angle of diffraction that forms less than the convergent angle of main beam with by spatial light modulator as the illumination angle of the angle of divergence of main beam poor.

Here the plane, place that used " optical convergence plane " refer to is assembled respectively by the light of pixel portions reflection, and break away from the imaging plane that forms by pixel portions and optical system.

When by being mapped to via the illumination of each pixel portions transmission of spatial light modulator when realizing image exposure on the photosensitive material, at first need to assemble and focus on light via each pixel portions transmission.In image exposing apparatus of the present invention, each pixel portions of spatial light modulator becomes the shape of similar recessed or convex lens, to allow the converging light respectively of each pixel portions.Further, suffer the structure of a pixel based on a pixel, the optical convergence ability also provides by the convergent angle that forms main beam, and it is by the shape and the optical system decision of each pixel portions, greater than the angle of divergence of main beam.Correspondingly, if each light beam of being assembled respectively by pixel portions has the beam diameter of expection, then microlens array can be left in the basket.Thus, can prevent that light utilization ratio and extinction ratio from reducing, if microlens array as mentioned above mode provide then the light utilization ratio can occur and extinction ratio descends.

Further, at the light and the optical system that is used to focus on by the image of pixel portions representative that are provided for receiving via each pixel portions transmission of spatial light modulator, and be provided for receiving under the situation of above-mentioned microlens array of the light by the optical system transmission, on the optical convergence plane that the decline of light utilization ratio and extinction ratio can form by the pixel portions that microlens array is arranged on by concave surface or convex, and the imaging plane that breaks away from the pixel portions that forms by above-mentioned optical system realize.This will describe in detail with reference to Figure 20 and 21 below.

Circle by 110 expressions of the drawing reference numeral among Figure 20 A is by the pixel portions of concave shape and the convergence image of optical system generation.Rectangle by 101 expressions of the drawing reference numeral among Figure 20 B is the microlens array with the lenticule 102 that is arranged side by side.Above-mentioned convergence image is undersized (convergence size) luminous point and unlike the image of pixel portions.As a result, the relation object between the lenticule 102 of these convergence images and microlens array 101 is like the situation shown in Figure 21 A and 21B.Here it is, even a little skew shown in Figure 21 B takes place between spatial modulator and the microlens array, and their concentric relation is also shown in Figure 21 A, also can prevent from perhaps to prevent to input to specific lenticular convergence image and enter adjacent lenticule to assembling the appearance of blocking of image.By this way, the decline of light utilization ratio and extinction ratio can be prevented from.

Further, only a small amount of distortion light beam transmission of being assembled by the pixel portions of concave shape is by lenticule, and the hole array or the analog that make the parasitic light of not assembled and reflecting distortion can be set at the microlens array outside easily stop.

Description of drawings

Fig. 1 is the skeleton view of the image exposing apparatus of first embodiment according to the invention, illustrates that it is overall;

Fig. 2 is the skeleton view of the scanner of image exposing apparatus as shown in Figure 1, and its structure is shown.

Fig. 3 A is the planimetric map of photosensitive material, and its exposure area is shown;

Fig. 3 B is the figure of the situation that is provided with that the exposure section of each photohead is shown;

Fig. 4 is the skeleton view of the photohead of image exposing apparatus as shown in Figure 1, and its schematic configuration is shown;

Fig. 5 is the schematic sectional view of above-mentioned photohead;

Fig. 6 is the partial enlarged drawing of Digital Micromirror Device (DMD), and its structure is shown;

Fig. 7 A is the figure that explains the operation of DMD;

Fig. 7 B is the figure that explains the operation of DMD;

Fig. 8 A is the planimetric map of DMD, and the riding position of exposing light beam and sweep trace when DMD does not tilt with respect to sub-direction of scanning is shown;

Fig. 8 B is the planimetric map of DMD, and the riding position of exposing light beam and sweep trace when DMD tilts with respect to sub-direction of scanning is shown;

Fig. 9 A is the skeleton view of fiber array light source, and its structure is shown;

Fig. 9 B is the front view of fiber array light source, and the installation situation of the luminous point at laser efferent place is shown;

Figure 10 is the figure that the structure of multimode optical fiber is shown;

Figure 11 is the planimetric map of beam combination LASER Light Source, and its structure is shown;

Figure 12 is the planimetric map of laser module, and its structure is shown;

Figure 13 is the side view of laser module as shown in figure 12, and its structure is shown;

Figure 14 is the partial front elevation view of laser module as shown in figure 12, and its structure is shown;

Figure 15 is the block diagram that the electricity structure of above-mentioned image exposing apparatus is shown;

Figure 16 A is the figure that is illustrated in an example area that adopts among the DMD;

Figure 16 B is the figure that is illustrated in an example area that adopts among the DMD;

Figure 17 is the schematic cut-open view according to the photohead that is used for image exposing apparatus of second embodiment;

Figure 18 A and 18B are the explanatory diagram that is used for explaining the problem of existing image exposing apparatus;

Figure 19 A and 19B are the explanatory diagram that is used for explaining the problem of existing image exposing apparatus;

Figure 20 A and 20B are the explanatory diagram that is used to explain the beneficial effect of device of the present invention;

Figure 21 A and 21B are the explanatory diagram that is used to explain the beneficial effect of device of the present invention;

Figure 22 is the schematic plan view that is used for the DMD of image exposing apparatus of the present invention, and its relevant part is shown;

Figure 23 is the side view of DMD as shown in figure 22, and its relevant portion is shown;

Figure 24 A is the explanatory diagram that is used to explain the manufacturing process of DMD as shown in figure 22 to 24F;

Figure 25 is the schematic side elevation that is used for the drive circuit board of DMD as shown in figure 22;

Figure 26 is the schematic plan view that is used for the optional DMD of image exposing apparatus of the present invention, and its relevant portion is shown;

Figure 27 is the schematic side elevation of DMD as shown in figure 26, and its relevant portion is shown;

Figure 28 A is the explanatory diagram that is used to explain the manufacturing process of DMD as shown in figure 26 to 28F;

Figure 29 is the schematic side elevation that is used for the drive circuit board of DMD as shown in figure 26;

Figure 30 illustrates the mode chart (pattern diagram) how light assembled by DMD in the device of the present invention and optical system;

Figure 31 illustrates the mode chart how light assembled by DMD in the conventional device and optical system;

Figure 32 is the mode chart that another example how light assembled by DMD in the device of the present invention and optical system is shown;

Figure 33 A and 33B are the mode charts that the relevant portion of image exposing apparatus according to another embodiment of the invention is shown;

Figure 34 A and 34B are the mode charts that the relevant portion of image exposing apparatus according to another embodiment of the invention is shown.

Embodiment

After this, the preferred embodiments of the present invention are described with reference to the accompanying drawings meticulously.Image exposing apparatus according to first embodiment will at first be described.

[structure of image exposing apparatus]

As shown in Figure 1, the image exposing apparatus of the embodiment of the invention comprises and is used for by suction the photosensitive material 150 of sheet being kept thereon tabular transfer table 152.Two guide rails 158 that extend along the moving direction of platform are arranged on the upper surface of the thick tabular mounting platform 156 that is supported by four legs 154.Platform 152 is configured such that it vertically along the moving direction of platform, is supported in a movable manner by guide rail 158, seesaws allowing.Image exposing apparatus in the present embodiment further comprises the platform driver element 304 (Figure 15) that is described further below, be used to drive platform 152, and wherein platform 152 uses as the sub-scanner along guide rail 158.

The inverted U-shaped door 160 that strides across the mobile route of platform 152 is set at the core of mounting platform 156.Each end of this inverted U-shaped door 160 is fixedly attached to each side of mounting platform 156.Scanner 162 is arranged on door 160 the side, and a plurality of sensors 164 (for example two) that are used to detect the edge, front and back of photosensitive material 150 are arranged on opposite side.Scanner 162 and sensor 164 are fixedly attached on the door 160 of the mobile route that strides across platform 152.Scanner 162 and sensor 164 are connected on their the controller (not shown) of control.

Shown in Fig. 2 and 3B, scanner 162 comprises a plurality of photoheads (for example 14) by the cells arranged in matrix of " m " row and " n " row.In this example, four photoheads 166 are arranged on the third line with respect to the width of photosensitive material 150.Below, the photohead that is installed in the capable n of m row will be expressed as photohead 166 _Mn

The exposure section 168 of each photohead 166 has the rectangular in form of short side along sub-direction of scanning.Correspondingly, along with moving of platform 152, banded exposure area 170 is formed on photosensitive material 150 by each photohead 166.Below, the exposure section that is arranged on the photohead of the capable n of m row will be expressed as exposure section 168mn.

Shown in Fig. 3 A and 3B, each follows the linearly aligned photohead 166 of direction position in orientation and (for example differs predetermined distance, the natural several times on the long limit of exposure section, be the twice on long limit in this case) so that each banded exposure area 170 be arranged on the direction vertical with sub-direction of scanning with adjacent exposure area 170 without any the gap.As a result, with first the row in exposure area 168 ₁₁With 168 ₁₂Between the corresponding photosensitive material in space unexposed area can by second the row in exposure area 168 ₂₁With the exposure area 168 in the third line ₃₁Exposure.

Shown in Figure 4 and 5, each photohead 166 ₁₁To 166 _MnHaving can be from the digital micro mirror device (DMD) 50 of TIX (U.S.Texas Instrument Inc.) acquisition, as the spatial light modulator that suffers a pixel ground modulated incident light beam according to view data, a pixel.DMD50 is connected to the controller 302 (Figure 15) that will be described later.Controller 302 comprises data processing division and mirror drive control part.The data processing division of controller 302 produces control signal, be used for based on the view data drive controlling DMD50 of input, will be at each photohead 166 and each micro mirror of controlled section.The implication in " with controlled field " will provide in the back.The mirror drive control component is at each photohead 166, based on the control signal that generates by the view data processing element, and the angle of the reflecting surface of each micro mirror of control DMD50.Controlling the method for angle of the reflecting surface of each micro mirror will describe below.

Fiber array light source 66, lens combination 67 and mirror 69 with laser efferent in turn are arranged on the light approaching side of DMD50.In the efferent of laser, the output face of optical fiber (luminous point) along with the corresponding direction linear array of direction on the long limit of exposure area 168.Described lens combination 67 is used to proofread and correct and focus on the laser beam of fiber array light source 66 outputs from the DMD.Described mirror 69 is used for the laser beam of scioptics system 67 transmissions is reflected to the DMD50 mirror.In Fig. 4, lens combination 67 is schematically illustrated.

As being shown specifically among Fig. 5, lens combination 67 comprise be used for aggregation laser bundle B as the collector lens 71 of the irradiates light that sends from fiber array light source 66, place the shaft-like optical integrator (being called " rod integrator " hereinafter) on the light path of the light by collector lens 71 transmissions and be arranged on before the rod integrator 72, that is, in the side of mirror 69.The laser beam of sending from fiber array light source 66 is radiated on the DMD50 by collector lens 71, rod integrator 72 and imaging len 74, restraints as the collimated light that has even light intensity on xsect (collimated light).The shape of rod integrator 72 and function will be described in detail below.

The laser beam B of sending from lens combination 67 is reflected by mirror 69, is radiated on the DMD50 by total internal reflection (TIR) prism 70.In Fig. 4, total internal reflection prism 70 has been left in the basket.

Be used for and focused on the light reflection side that imaging optical system 51 on the photosensitive material 150 is set at DMD50 by DMD50 laser light reflected bundle B.Imaging optical system 51 is schematically shown in Figure 4.Shown in detailed among Fig. 5, imaging optical system 51 comprises first imaging optical system of being made up of lens combination 52,54 and second imaging optical system of being made up of lens combination 57,58, and microlens array 55 and hole array 59 are arranged between two optical systems.

As shown in Figure 6, DMD50 be by a plurality of (for example, 1024 * 768) mirror assembly of small mirror (micro mirror) 62 compositions, each mirror forms a pixel, and described a plurality of mirrors are arranged in static RAM (SRAM) unit (storage unit) 60 with the form of grid pattern.In each pixel, the rectangle micro mirror all is arranged on the top, by they sup-port.High reflecting material, for example aluminium or analog are deposited on the surface of micro mirror.The reflectivity of micro mirror is not less than 90%.For example, the size of mirror in vertical direction with all be 13 μ m on the horizontal direction, and the arrangement pitches on vertical and horizontal direction for example is 13.7 μ m.Each micro mirror 62 forms the similar concave mirror that light is assembled (focusing) ability that has by the back with the method that is described.Silicon gate complementary MOS (CMOS) sram cell 60 can be produced making on the common production line of semiconductor memory, it by the support bar with pivotal position and yoke be arranged on each micro mirror 62 below.Whole DMD is made of monolithic.

When digital signal is written into the sram cell of DMD50, the substrate of DMD50 being installed relatively thereon by the micro mirror of they sup-port, with the diagonal line be the center ± tilt in α degree (for example, ± 12 degree) scope.Fig. 7 A represented to tilt+micro mirror 62 at α degree angle, represent that it is in out state, and Fig. 7 B represented to tilt-micro mirror 62 at α degree angle, and represent that it is in off status.Correspondingly, by the inclination of the micro mirror 62 in each pixel that is controlled at DMD50 according to as shown in Figure 6 picture signal, the laser beam B that shines on the DMD50 is reflected on the vergence direction of each micro mirror 62.

Fig. 6 is the partial enlarged drawing of DMD50, and the state of an example is shown, wherein some micro mirrors in the part of DMD50 be controlled so as to+or-the α degree tilts.The switch control of each micro mirror 62 is realized by the controller 302 that is connected to DMD50.The light absorbing material (not shown) is arranged on the direction of propagation by the micro mirror laser light reflected bundle B that is in off status.

Microlens array 55 as shown in Figure 5 comprises a plurality of lenticule 55a that arrange with two-dimensional way, and each is corresponding with each pixel or the micro mirror 62 of DMD50.Each lenticule 55a is placed on the position that is entered by corresponding micro mirror 62 laser light reflected bundle B, and this position is the optical convergence plane that is formed by micro mirror 62 and lens combination 52,54, and breaks away from the imaging plane of the micro mirror 62 that is formed by lens combination 52,54.Though DMD50 has 1024 * 768 row micro mirrors altogether, hereinafter with in the present embodiment of describing, only 1024 * 256 row are driven.So the lenticule 55a of the respective number of 1024 * 256 row is set up.The size of lenticule 55a all is 41 μ m in vertical and horizontal direction.For example, lenticule 55a is made by silica glass, and has the focal length of 0.23mm and 0.06 numerical aperture (NA).

Simultaneously, hole array 59 is made by the non-transparent parts that has a plurality of holes (opening) 59a, and wherein hole shape becomes the perforation non-transparent parts, and each hole is corresponding to each lenticule of microlens array 55.In the present embodiment, the diameter of each hole 59a is 12 μ m.

The image of DMD50 is focused on the microlens array by lens combination 52,54 first optical systems that form, as shown in Figure 5, be exaggerated three times, and the image that forms after microlens array is focused on and is projected on the photosensitive material 150 by second optical system of being made up of lens combination 57,58, is exaggerated 1.6 times.

In the present embodiment, prism is arranged between second optical system and the photosensitive material 150 73, and in Fig. 5, and the focusing of image on photosensitive material 150 can be adjusted 73 by mobile prism up and down.In Fig. 5, photosensitive material 150 moves on the sub-direction of scanning that arrow F represents.

Preferably, DMD50 installs in the mode that tilts a little, so that its minor face and sub-direction of scanning form predetermined angle θ (for example, 0.1 to 5 degree).Fig. 8 A illustrates when DMD50 does not tilt, and the track while scan of the reflected light image 53 (exposing beam) that is produced by each micro mirror, and Fig. 8 B shows when DMD50 tilts is from the track while scan of the exposing beam 53 of each micro mirror.

DMD50 comprises a plurality of micro lens arrays (for example, 756) that are arranged on transversely, and each row has a plurality of micro mirrors (for example, 1024) that longitudinally are provided with.Shown in Fig. 8 B, the spacing P between the track while scan (sweep trace) of the exposing beam 53 that when DMD50 tilts, produces by micro mirror ₂Than the spacing P when DMD50 does not tilt ₁Narrow, and image resolution ratio improves significantly.Simultaneously, DMD50 is very little with respect to the inclination angle of sub-direction of scanning, so that the sweep length W when DMD tilts ₂With the sweep length W when it does not tilt ₁Approximate identical.

Further, identical sweep trace passes through different micro lens arrays exposures repeatedly (multiple-exposure).Multiple-exposure allows the precision control of exposure position, and the high resolving power exposure can be implemented.Further, the seam between a plurality of photoheads that are arranged on the main scanning direction can be eliminated by the exposure position control of precision.

Similar effect can be by being offset each micro lens array predetermined distance, making micro lens array be arranged in serrate and being obtained the mode of alternative inclination DMD50 along the direction perpendicular to sub-direction of scanning.

Shown in Fig. 9 A, fiber array light source 66 comprises a plurality of laser modules 64 (for example, 14), and an end of the length of multimode optical fiber 30 is connected to each laser module 64.The length of comparing the optical fiber 31 with identical core diameter and littler clad diameter with multimode optical fiber 30 is engaged to the other end of each root multimode fiber 30.As the detailed expression of Fig. 9 B, along aiming at the vertical main scanning direction in sub-direction of scanning, and two arrays on the end face are configured to form laser efferent 68 at each end faces of seven optical fiber 31 of a side opposite with multimode optical fiber 30.

The laser efferent of being made up of the end face of optical fiber 31 68 is by two back up pad 65 clampings regularly, and each back up pad has plane surface.Preferably, the transparent protection plate of being made by glass or analog is arranged on each light output surface of optical fiber 31, shields.Because the light gasing surface of each the root optical fiber in the optical fiber 31 has high optical density (OD), so its is assembled dust easily and aggravates.The setting of above-mentioned fender can prevent from the absorption of dust and delay to worsen.

In the present embodiment, have littler outer covering layer diameter, length is about optical fiber of 1 to 30cm 31 is joined to the laser beam outgoing side of the multimode optical fiber 30 with higher outer covering layer diameter in coaxial mode end. Optical fiber 30,31 is joined together by the output face that the input face with optical fiber 31 is fused to optical fiber 30, and wherein their wire mandrel is alignd.As mentioned above, optical fiber 31 has the core diameter identical with multimode optical fiber 30.

For multimode optical fiber 30 and optical fiber 31, can adopt step-refraction index type optical fiber (step indextype optical fiber), graded index type optical fiber (graded index type optical fiber) or mixed type optical fiber.For example, can be from Mitsubishi Cable Industries, the step-refraction index type optical fiber that Ltd. obtains can be used.In the present embodiment, multimode optical fiber 30 and optical fiber 31 are step-refraction index types.Multimode optical fiber 30 has the outer covering layer diameter of 125 μ m, the core diameter of 50 μ m, 0.2 NA, and the transmissivity that is not less than 99.5% input face coating.Optical fiber 31 has the outer covering layer diameter of 60 μ m, the core diameter of 50 μ m and 0.2 NA.

Yet the outer covering layer diameter of optical fiber 31 is not limited to 60 μ m.Many outer covering layer diameters that are used for the optical fiber of existing optical fiber source are 125 μ m.Because more little outer covering layer diameter causes dark more depth of focus, therefore, preferably, the outer covering layer diameter of multimode optical fiber is not more than 80 μ m, and more preferably, is not more than 60 μ m.Because single-mode fiber needs the core diameter of at least 3 to 4 μ m, therefore, preferably, the outer covering layer diameter of optical fiber 31 is not less than 10 μ m.Preferably, optical fiber 30,31 point of fixity at coupling efficiency (stand point) locate to have identical internal diameter.

In the present invention, not to adopt two kinds of dissimilar optical fiber 30,31 that the outer covering layer diameter differs from one another, that be welded together (so-called conical engagement (taper splicing)).Fiber array light source can have identical outer covering layer diameter (for example, the optical fiber 30 among Fig. 9 A) and is formed by tying up many, but each optical fiber does not have dissimilar optical fiber to engage.

Laser module 64 is made up of beam combination LASER Light Source (optical fiber source).This beam combination LASER Light Source comprises: be fixedly mounted in a plurality of horizontal multimode or single mode GaN system semiconductor laser chip LD1, LD2, LD3, LD4, LD5, LD6 and LD7 on the hot piece (heat block) 10; Collimation lens 11,12,13,14,15,16 and 17, each lens are that each GaN system semiconductor laser LD1 is provided with to LD7; Convergent lens 20; And multimode optical fiber 30.Semiconductor laser quantity is not limited to seven, can adopt the semiconductor laser of varying number.Further, can adopt the collimator lens array of integrated these collimation lenses to substitute seven independently collimation lenses 11 to 17.

GaN system semiconductor laser LD1 each in the LD7 all has roughly the same oscillation wavelength (for example, 405nm) and maximum output (for example, being about 100mW to the multimembrane laser instrument, is 50mW to single-mode laser).The output of GaN system semiconductor laser LD1 each in the LD7 can differ from one another in the scope below peak power output.For GaN system semiconductor laser LD1 to LD7, the laser instrument that also can adopt the wavelength in the wavelength coverage except 405nm to vibrate from 350nm to 450nm.

The beam combination laser light source is installed in other optical elements to have in the open-topped box type packaging part 40.Packaging part 40 comprises cap 41, and the opening that is formed packaging part 40 seals.Sealing gas enters in the packaging part 40 after the degassing, and the opening of packaging part 40 by cap 41 sealing so that the beam combination laser light source is sealed in enclosure space (seal cavity) lining that forms thus with air tight manner.

Substrate 42 is fixedly mounted on the basal surface of packaging part 40, and hot piece 10, is used to keep the collimation lens keeper keeper 45 of collimation lens 20 and is used to keep the optical fiber keeper keeper 46 of the input end of multimode optical fiber 30 to be installed in the upper surface of substrate 42.The output terminal of multimode optical fiber 30 is pulled to the outside by the hole that is arranged on packaging part 40 walls.

Collimation lens keeper 44 is installed in the horizontal side surface of hot piece 10, and collimation lens 11 to 17 is maintained at this place.The hole is arranged on the sidewall, wherein by this hole, for GaN system semiconductor laser LD1 provides the lead of drive current to be pulled to the outside to LD7.

In Figure 13, for clarity sake, the GaN system semiconductor laser LD1 of seven semiconductor laser LD1 in the LD7 only is shown, and the collimation lens 17 in seven collimation lenses 11 to 17.

Figure 14 is the front view in the installation cross section of collimation lens 11 to 17, and the geometric configuration of its front is shown.In the collimation lens 11 to 17 each forms by this way: promptly, the feasible zone of the optical axis of the circle lens with non-spherical surface that comprises is cut by parallel plane in the mode of extending.The collimation lens of elongation can for example be made into by casting resin or optical glass.Collimation lens 11 to 17 closely is arranged on GaN system semiconductor laser LD1 (left and right directions among Figure 14) to the orientation of the luminous point of LD7 each other so that the length direction of collimation lens 11 to 17 towards with GaN system semiconductor laser LD1 to the perpendicular direction of the orientation of the luminous point of LD7.

Simultaneously, for GaN system semiconductor laser LD1 to LD7, can adopt the active coating that comprises illumination width with 2 μ m with as become the angles of divergence of 10 degree and 30 degree to send the laser instrument that each laser beam B 1 arrives B7 with the parallel direction of active coating respectively with vertical direction.GaN system semiconductor laser LD1 is set to LD7, so that its luminous point is being parallel to linear alignment on the direction of active coating.

Correspondingly, the laser beam B of sending from corresponding luminous point 1 to B7 enters the collimation lens 11 to 17 of corresponding elongation, wherein have correspondingly with the length direction of collimation lens, and have corresponding with the Width of collimation lens (perpendicular to the direction of length direction) than the direction of small divergence angle than the direction at Vernonia parishii Hook angle.That is, the width of each in the collimation lens 11 to 17 all is 1.1mm, and its length all is 4.6mm, and the beam diameter that enters the laser beam B 1 to B7 of collimation lens 11 to 17 is respectively 0.9mm and 2.6mm in the horizontal direction with on the vertical direction.In the collimation lens 11 to 17 each all has the focal distance f of 3mm ₁With 0.6 NA, it is with the spacing arrangement of 1.25mm.

Convergent lens 20 forms: the feasible zone of the optical axis of the circle lens with non-spherical surface that comprises is cut by parallel plane in the elongation mode.Be arranged to: the orientation of its long limit and collimation lens 11 to 17, that is, horizontal direction is corresponding, and its minor face is corresponding with the direction perpendicular to horizontal direction.Convergent lens 20 has the focal distance f of 23mm ₂With 0.2 NA.Convergent lens 20 is also made by casting resin or optical glass.

Electrical configuration according to image exposing apparatus of the present invention is described with reference to Figure 15.As shown in figure 15, whole control part 300 is connected to modulation circuit 301, and this modulation circuit is connected to controller 302 successively with control DMD50.Whole control part 300 also is connected to LD driving circuit 303, with driving laser module 64.Further, it is connected to platform driver element 304 to drive platform 152.

[operation of image exposing apparatus]

The operation of aforementioned image exposing apparatus will be described below.In each photohead of scanner 162, each laser beam B 1, B2, B3, B4, B5, B6 and the B7 that sends from GaN system semiconductor laser LD1 to LD7 (Figure 11) in the mode of dispersing formed the beam combination light source of fiber array light source 66, and it is collimated by in the corresponding collimation lens 11 to 17 each.Collimated laser beam B1 can coalescences be focused on by convergent lens 20 to B7 on the input end face of core 30a of multimode optical fiber 30.

In the present embodiment, collimation lens 11 to 17 and convergent lens 20 formed convergence optical systems, and this convergence optics multimode optical fiber 30 of unifying is formed the beam combination optical systems.That is, the laser beam B of being assembled by convergent lens 20 1 to B7 enters the core 30a of multimode optical fiber 30 in the above described manner, and passes through its propagation, and sends from optical fiber 31 as single combined laser beam B, and wherein optical fiber 31 is bonded on the output terminal of multimode optical fiber 30.

In each laser module 64, when the coupling efficiency that is coupled to multimode optical fiber 30 when laser beam B 1 to B7 is 0.9, and each GaN system semiconductor laser LD1 is when the output power of LD7 is 50mW, and combined laser beam B has from the output power of the 315mW of each optical fiber 31 of lining up array (50mW * 0.9 * 7).Correspondingly, can access from laser beam B 14 optical fiber, that have the output power of 4.4mW (0.315 * 14) altogether.

When carrying out image exposure, be input to the controller 302 of DMD50 from the modulation circuit shown in Figure 15 301 according to the view data of the image that will expose, and be stored in its frame memory (frame memory) temporarily.The data that this view data is represented by binary value (comprising/do not comprise a little) for the GTG of each pixel of formation image.

Platform 152 of absorption photosensitive material 150 moves to downstream with constant speed from the upstream of door 160 along guide rail 158 on it.When platform 152 passes through for 160 times at door, and the forward position of photosensitive material 150 is installed in sensor 164 on the door 160 when detecting, and the view data of storage is read out for many lines at every turn continuously in the frame memory (frame memory).Then, the control signal that is used for each photohead 166 by data processing division, suffer head ground based on the view data head of reading and generate, and each micro mirror of the DMD50 on each photohead 166 by the mirror drive control part, suffer head ground based on the control signal head that generates and be carried out switch and control.

When laser beam B shines DMD50 when going up from fiber array light source 66, focus on the photosensitive material 150 by the micro mirror laser light reflected bundle scioptics system 51 of the DMD50 that is driven into out state.By this way, the laser beam pixel of sending from fiber array light source 66 is carried out switch control with suffering pixel, and photosensitive material 150 is exposed with the pixel quantity pixel quantity (exposure area 168) about equally with the DMD that uses.Photosensitive material 150 is along with platform 152 moves with constant speed, so that photosensitive material 150 carries out son scanning by scanner 162 along the direction opposite with the moving direction of platform, and banded exposure area 170 is formed by each photohead 166.

Though DMD50 comprises 768 micro mirror arrays that are arranged on the sub-direction of scanning, and each has 1024 micro mirrors that are arranged on the main scanning direction, but in the present embodiment shown in Figure 16 A and 16B, only a part of micro mirror array (for example, 1024 * 256 arrays) is by controller 302 controlling and driving.

In this case, can use in the central section (Figure 16 A) that is arranged on DMD50 or be arranged on the micro mirror array of top (or end) end section (Figure 16 B) of DMD50.In addition, if defective appears in some micro mirrors, the single or multiple micro mirror arrays with the micro mirror that does not have defective can substitute the single or multiple micro mirror arrays of the micro mirror that has defective.By this way, micro mirror array can according to circumstances correspondingly change.

DMD50 has the data processing speed that is subject to certain restrictions.The modulating speed of every line is inversely proportional to the pixel quantity of employing.So the modulating speed of every line can increase by a part that only adopts whole micro mirror array.Simultaneously, with respect to the continuous exposure method that moves of exposed, be not that all pixels that are positioned on the sub-direction of scanning all need to be used for photohead.

When the scanning of the son of photosensitive material 150 is finished by scanner 162, and the back edge of photosensitive material 150 is when being detected by sensor 164, and platform 152 is driven by platform driver element 304, gets back to the original position of the upstream of door 160 along guide rail 158.After this, its 160 upstream moves to the downstream along guide rail 158 from door with constant speed once more.

Lamp optical system is made up of fiber array light source 66, convergent lens 71, rod integrator 72, imaging len 74, mirror 69 and total internal reflection prism 70, as shown in Figure 5.This lamp optical system be used to send light beam B to DMD50 as irradiates light, will be described hereinafter.Rod integrator 72 is the transparent bars that for example form square rod.When laser beam B was propagated in rod integrator 72 in the total reflection mode, the intensity distributions in the xsect of laser beam B was homogenized.The input and output face of rod integrator 72 is equipped with antireflecting coating to improve transmissivity.The laser beam B that is provided at the intensity distributions that has the height homogenising in the xsect in the above described manner can produce the irradiates light with even light intensity as irradiates light, allows to have high-resolution image and exposes on photosensitive material 150.

In the device according to present embodiment, each lenticule 55a of microlens array 55 as shown in Figure 5 is placed on the optical convergence plane that is formed by micro mirror and lens combination 52,54, and breaks away from the imaging plane of the micro mirror that is formed by lens combination 52,54.Even when the skew of a little occurring between DMD50 and the microlens array 55, this configuration also can keep high light utilization ratio and extinction ratio.Reason is as above with reference to Figure 20 and 21 described.

Next second embodiment of the present invention will be described.Figure 17 is the schematic cross sectional views according to the photohead of the image exposing apparatus of second embodiment.Because it is the photohead among second embodiment does not comprise second optical system of being made up of lens combination 57,58, therefore different substantially with photohead shown in Figure 5.That is, in the image exposing apparatus according to second embodiment, photosensitive material 150 is positioned over the optical convergence plane that the lenticule 55a by microlens array 55 forms, and the image of being assembled by microlens array 55 directly exposes on photosensitive material.

In the present embodiment, each lenticule 55a of microlens array 55 also is positioned on the optical convergence plane that is formed by micro mirror 62 and lens combination 52,54, and break away from the imaging plane of the micro mirror 62 that forms by lens combination 52,54, even so that when the skew of a little occurring between DMD50 and the microlens array 55, this configuration also can keep high light utilization ratio and extinction ratio, with identical among first embodiment.

Simultaneously, if the laser beam B of being assembled by micro mirror and lens combination 52,54 has the beam diameter of expection, then microlens array 55 can be left in the basket.

Further, also can use hole array, and substitute the microlens array 55 that in above-mentioned two embodiment, adopts with a plurality of holes that are arranged side by side.In this case, the hole array is arranged on the optical convergence plane that is formed by micro mirror array and lens combination 52,54.Except high light utilization ratio, this hole array can also provide via the beneficial effect of hole at shaped beam.

After this, will the method for the example of making DMD50 be described.Figure 22 is the detailed planimetric map of the element 400 of above-mentioned DMD50, and Figure 23 is the side sectional view along the element 400 of Figure 22 center line A-A acquisition.At first, with the element of describing as the pixel portions of DMD50 400.

Element 400 is included in the first and second bottom electrode 463a, the 463b that each interval forms in the driving circuit substrate 451, the first and second top electrode 467a, the 467b that forms at interval with the first and second bottom electrode 463a, 463b respectively, and be arranged on mobile member 461 (it comprises pivotal position 455 and mirror portion 457) between bottom electrode 463a, 463b and top electrode 467a, the 467b.The first top electrode 467a be arranged on the corresponding position of the first bottom electrode 463a on, and the second top electrode 467b be arranged on the corresponding position of the second bottom electrode 463b on.Part by drawing reference numeral 479 and 483 expressions in Figure 22 is respectively the support portion of pivotal position 455 and the support portion of top electrode 467a, 467b.

The micro mirror 62 that schematically shows in Fig. 7 and other accompanying drawings is corresponding with the central area (not blocked by top electrode 467a, 467b) of mirror portion 457.In Figure 22, for clarity sake, the central area of expression appearance portion 457 is quite little with respect to the whole dimension of element 400.Yet in fact, the central area of mirror portion 457 has occupied the major part of element 400.

As shown in figure 23, the first bottom electrode 463a and the second top electrode 467b are connected to each other, and are connected to first drive electrode 485 then, and simultaneously, the second bottom electrode 463b and the first top electrode 467a are connected to each other, and are connected to second drive electrode 487 then.The pivotal position of being made by conductor material 455 is connected to mobile member electrode 489.Current potential V1, V2 and the Vm of first drive electrode 485, second drive electrode 487 and mobile member electrode 489 are controlled by SIC (semiconductor integrated circuit), for example, are arranged on the suprabasil cmos circuit of driving circuit.

Here, V1 is expressed as V (1) with respect to the potential difference (PD) of Vm, and V2 is expressed as V (2) with respect to the potential difference (PD) of Vm.When setting member 400, when making V (1)=V (2), then keep mobile member, promptly mirror portion 457 is parallel to driving circuit substrate 451.This is to be equal to each other because of the electrostatic force that acts on the electrostatic force between mobile member 461 1 ends and the first bottom electrode 463a and act between mobile member 461 these ends and the first top electrode 467a.Further, act on the electrostatic force between mobile member 461 other ends and the second bottom electrode 463b and act on mobile member 461 other ends and the second top electrode 467b between electrostatic force be equal to each other.Parastate is kept by the elastic stability ground of pivotal position 455.

When setting member 400 makes V (1)＞V (2), mirror portion 457 as shown in figure 23 along with pivotal position 455 by stranded and tilt.This be because act on the electrostatic force F between mobile member 461 1 ends and the first bottom electrode 463a and act on mobile member 461 other ends and the second top electrode 467b between electrostatic force F greater than act on the electrostatic force f between mobile member 461 1 ends and the first top electrode 467a and act on mobile member 461 other ends and the second top electrode 463b between electrostatic force.On the other hand, when setting member 400 made V (1)＜V (2), minute surface parts 457 were towards tilting in the opposite direction with side as shown in figure 23.By this way, minute surface parts 457 can be set on any one position in two obliquities.

After this, be described with reference to Figure 24 and 25 pairs of methods of producing element 400.In Figure 24, the schematic side sectional view of the element 400 that the line A-A in Figure 22 obtains is illustrated in the left side, and those are illustrated in the right and the line B-B in Figure 22 obtains.

Shown in Figure 24 A, provide driving circuit substrate 451.As the detailed expression among Figure 25, driving circuit substrate 451 comprises cmos circuit 471 and wire circuit 473, and described wire circuit 473 configuration examples are as being formed on the driving circuit in the Si substrate 469.In addition, insulation course 475 is formed at the top of substrate, and the contact hole (contact hole) that is used for wire circuit 473 is connected to corresponding electrode is formed after the surface planarization that makes insulation course with cmp method or similar approach.

Then, the first aluminium film (preferably, comprise aluminium alloy with high-melting point metal) form (not shown) by sputtering in the driving circuit substrate 451, its by common photoengraving be formed pattern, to be provided for forming the expection electrode shape of the first and second bottom electrode 463a, 463b.The first and second bottom electrode 463a, 463b are connected to the outgoing side of cmos circuit by the lead that passes contact hole and wire circuit 473, and set the current potential of expection respectively.

Then, shown in Figure 24 B, first positive photoetching rubber 491 is coated in the substrate, and after the regional 491a of the support portion 479 that is used to provide pivotal position 455 formed pattern, first positive photoetching rubber 491 was cured (hard bake) subsequently firmly.The layer that comprises first photoresist 491 is used as sacrifice layer (sacrificelayer), and is removed in the process of describing hereinafter.Correspondingly, the distance between bottom electrode 463a, 463b and the pivotal position 455 that will form afterwards is by the thickness decision of the photoresist film that cures firmly.Here, the also alternative positive photoetching rubber 491 of the polyimide of sensitization or analog is used.

Then, shown in Figure 24 C, the second aluminium film (preferably, comprising the aluminium alloy with high-melting point metal) 493 is formed by sputter, and pivotal position 455 and its support portion 479 will be formed by this aluminium film 493.After this, silicon dioxide (SiO ₂) the film (not shown) forms by plasma enhanced chemical vapor deposition (PE-CVD).Silicon dioxide (SiO ₂) film is as the etching mask of the second aluminium film 493.Then, silicon dioxide film is formed pattern by photoetch, so that the anticipated shape of corresponding pivotal position 455 and its support portion to be provided.

Then, the 3rd aluminium film (preferably, comprising the aluminium alloy with high-melting point metal) 495 is formed by sputter, and mirror portion 457 will be formed by this aluminium film 493.After this, silicon dioxide (SiO ₂) the film (not shown) forms by plasma enhanced chemical vapor deposition (PE-CVD).Silicon dioxide (SiO ₂) film is as the etching mask of the 3rd aluminium film 493.Then, silicon dioxide film by photoengraving be formed pattern, so that the anticipated shape of corresponding mirror portion to be provided.

Then, the 3rd and second aluminium film 495,493 quilts are etching continuously, and silicon dioxide film is as etching mask, and silicon dioxide film is removed by plasma etching at last.The etching of aluminium film realizes that by the wet etching that adopts the aluminium etching agent, the plasma etching that adopts chlorine or other similar approach wherein said aluminium etching agent is the mixed aqueous solution of phosphoric acid, nitric acid and acetic acid.Contact hole forms by silicon dioxide film, and pivotal position 455 is connected to the outgoing side of cmos circuit by the lead that passes contact hole and wire circuit 473, and sets the current potential of expection respectively.

Then, shown in Figure 24 D, second positive photoetching rubber 497 is coated, and it is formed the support portion 483 of pattern so that top electrode 467a, 467b to be provided, and after this, substrate is cured firmly.The surface of positive photoetching rubber 497 is flattened by backflow effeet when curing firmly, and no matter whether the film under it uneven.The layer that comprises second photoresist 497 is used as sacrifice layer, and is removed in the process of describing hereinafter.Correspondingly, the distance between pivotal position 455 and minute surface parts 457 and the top electrode 467a, the 467b that form in the step in the back is by the thickness decision of the photoresist film that cures firmly.Here, the polyimide of sensitization or analog also can preferably substitute positive photoetching rubber 497 and be used.

Then, shown in Figure 24 E, the 4th aluminium film (preferably, comprising the aluminium alloy with high-melting point metal) 499 is formed by sputter, and top electrode 467a, 467b and its support portion will be formed by this aluminium film 499.After this, the 4th aluminium film by photoengraving be formed pattern, so that the shape of top electrode 467a, 467b and its support portion to be provided.The etching of aluminium film realizes that by the wet etching that adopts the aluminium etching agent, the plasma etching that adopts chlorine or similar approach wherein said aluminium etching agent is the mixed aqueous solution of phosphoric acid, nitric acid and acetic acid.At this moment, the first and second top electrode 467a, 467b are connected respectively to the second and first bottom electrode 463b, 463a.

Then, shown in Figure 24 F, get rid of by the plasma etching that uses oxygen, form air gap 453,465 as second and first photoresist layer 497,491 of sacrifice layer.Produce element 400 like this, this element 400 comprises substrate 451, described substrate 451 has the first and second bottom electrode 463a, the 463b that forms in substrate 451, mobile member 461 (pivotal position 455 and minute surface parts 457) is placed on the top of the first and second bottom electrode 463a, 463b by intermediate air gap 453, and the first and second top electrode 467a, 467b are placed on the top of mobile member 461 by intermediate air gap 465.A plurality of such elements 400 are formed simultaneously, to produce DMD50.

In producing DMD 50 in the above described manner, the shape of above-mentioned similar concave mirror can be made with the stress distribution of giving membrane by the temperature that controlling diaphragm when the 3rd aluminium film 495 that will form minute surface parts 457 is shaped is shaped by mirror portion 457, and after this removes the layer as first photoresist 491 of sacrifice layer.

Alternatively, by using the material different with the 3rd aluminium film 495 of making mirror portion 457, and use pivotal position 455 as its backing substrate (backing substrate) and utilize the material coefficient of thermal expansion coefficient difference to come crooked mirror portion 457, mirror portion 457 can be made for the shape of similar concave mirror.

Further, can be by before the coating photoresist, on first photoresist, 491 coating surfaces thereon, the shape that the concave surface pattern is made similar concave mirror be set as the surface of first photoresist 491 of the backing substrate of mirror portion 457 and pivotal position 455, wherein said concave surface pattern will come along with first photoresist 491 in the step of back and remove.Like this, the lip-deep mirror portion 457 that is formed on first photoresist 491 can be formed similar concave mirror.Here, can the surface of first photoresist 491 be flattened according to its viscosity, and need not consider the surface profile of backing substrate.Therefore, need provide first photoresist 491 with suitable viscosity.

Next, the manufacture method that description is had heteroid DMD.Figure 26 is the careful planimetric map of the element 500 of optional DMD, and the lateral sectional view of the element 500 that Figure 27 is the line A-A in Figure 26 to be obtained.At first, with the element of describing as the pixel portions of DMD 500.

Element 500 is included in the first and second bottom electrode 543a, the 543b that is spaced apart from each other in the driving circuit substrate 521 and forms, distinguish the first and second top electrode 545a, the 545b of spaced apart formation with the first and second bottom electrode 543a, 543b, and be arranged on the mobile member 531 (it comprises pivotal position 525 and mirror portion 527) between the first upper and lower electrode pair 543a, 545a and the second upper and lower electrode pair 543b, the 545b.The first top electrode 545a is arranged at and corresponding position, the position of the first bottom electrode 543a, and intermediate insulating layer 549 is arranged between them.The second top electrode 545b is arranged at and corresponding position, the position of the second bottom electrode 543b, and intermediate insulating layer 549 is arranged between them.Part by drawing reference numeral among Figure 26 551 and 553 expressions is respectively the support portion of pivotal position 525 and the support portion of top electrode 545a, 545b.

In this example, the micro mirror 62 that schematically shows in mirror portion 527 and Fig. 7 and other accompanying drawings is corresponding.In Figure 26, for clarity sake, the mirror portion 527 that expresses is quite little with respect to the whole dimension of element 500.In fact, mirror portion 527 has occupied the major part of element 500.

As shown in figure 27, the first bottom electrode 543a is connected to each other with the second top electrode 545b and is in the same place, and is connected to first drive electrode 555 then, simultaneously, the second bottom electrode 543b is connected to each other with the first top electrode 545a and is in the same place, and is connected to second drive electrode 557 then.Pivotal position 455 and the mirror portion 527 integrally formed with conductive material are connected to mobile member electrode 559.Current potential V1, V2 and the Vm of first drive electrode 555, second drive electrode 557 and mobile member electrode 559 are controlled by SIC (semiconductor integrated circuit), as are arranged on the suprabasil cmos circuit of driving circuit.

Here, V1 represents to do V (1) with respect to the potential difference (PD) of Vm, and V2 represents to do V (2) with respect to the potential difference (PD) of Vm.When setting element 500 makes V (1)=V (2), keep mobile member, promptly mirror portion 527 is parallel to driving circuit substrate 521.This is to be equal to each other because of the electrostatic force that acts on the electrostatic force between mobile member 531 1 ends and the first bottom electrode 543a and act between mobile member 531 these ends and the first top electrode 545a.Further, act on the electrostatic force between mobile member 531 other ends and the second bottom electrode 543b and act on mobile member 531 other ends and the second top electrode 545b between electrostatic force be equal to each other.Parastate is kept by the elastic stability ground of pivotal position 525.

When setting member 500 made V (1)＞V (2), mirror portion 527 tilted as shown in figure 27, and pivotal position 525 is by stranded.This be because act on the electrostatic force F between mobile member 531 1 ends and the first bottom electrode 543a and act on mobile member 531 other ends and the second top electrode 545b between electrostatic force F greater than act on the electrostatic force f between mobile member 531 1 ends and the first top electrode 545a and act on mobile member 531 other ends and the second bottom electrode 543b between electrostatic force.On the other hand, when setting member 500 made V (1)＜V (2), mirror portion 527 was towards tilting in the opposite direction with side as shown in figure 27.By this way, mirror portion 527 can be set on any one position in two obliquities.

After this, be described with reference to Figure 28 and 29 pairs of methods of producing element 500.In Figure 28, the schematic side sectional view of the element 500 that the line A-A in Figure 26 obtains is illustrated in the left side, and those are illustrated in the right and the line B-B in Figure 26 obtains.

Shown in Figure 28 A, provide driving circuit substrate 521.As the detailed expression among Figure 29, driving circuit substrate 521 comprises cmos circuit 537, and the wire circuit 539 of composition driving circuit for example is formed on the silicon base 535.In addition, insulation course 541 is formed at the top of substrate, and the contact hole (contact hole) that is used for wire circuit 539 is connected to respective electrode is being formed after the surface planarization to insulation course with cmp method or similar approach.

Then, the first aluminium film (preferably, comprise aluminium alloy with high-melting point metal) form (not shown) by sputtering in the driving circuit substrate 521, it carries out patterning, is used to form the first and second bottom electrode 543a, 543b with the electrode shape that expection is provided, as shown in Figure 28 B by common photoengraving.The first and second bottom electrode 543a, 543b are connected to wire circuit 539 (Figure 29) by contact hole, make the current potential that they can be configured to be scheduled to.Here, bottom electrode 543a, 543b need be arranged on closely adjacent pivotal position 525 and mirror portion 527 places with high precision, will be described later.So preferably, the photoetching of bottom electrode 543a, 543b is realized by the stepping exposure, and realizes etching by dry etching for this reason.

Then, shown in Figure 28 C, the insulation course made by silicon dioxide or silicon nitride 549 is formed by plasma enhanced chemical vapor deposition.Insulation course 549 is as interlayer dielectric between bottom electrode 543a, 543b and top electrode 545a, the 545b, that will be described below, and the position of top electrode 545a, 545b is by the bed thickness decision of insulation course 549.After this, this insulation course is by common photoengraving, with predetermined shape formation pattern.Here, the end face of insulation course 549 need be arranged on closely adjacent pivotal position 525 and mirror portion 527 places with high precision.So preferably, the etching of insulation course is realized by the stepping exposure, and realizes etching by dry etching for this reason.

Then, shown in Figure 28 D, positive photoetching rubber 561 is coated on substrate 521, and is cured firmly after the zone of the support portion 551 that pivotal position 525 is provided forms pattern.The layer that comprises photoresist 561 is used as sacrifice layer, and will get rid of in the described process in the back, to form air gap 523.Correspondingly, with the thickness decision of the position of the mobile member 531 (pivotal position 525 and mirror portion 527) that forms in the step in the back by the photoresist 561 that cures firmly., replace photoresist 561 here, can preferably use the polyimide or the analog of sensitization.

Then, shown in Figure 28 E, the second aluminium film (preferably, comprising the aluminium alloy with high-melting point metal) is formed, this is by the normal optical etching processing, so that the support portion 551 and the mirror portion 527 of the first and second top electrode 545a, 545b, pivotal position 525 (beam body), pivotal position to be provided.Further, the first and second top electrode 545a, 545b are connected to wire circuit 539 (Figure 29) in the substrate 521 by contact hole.In this example, the first top electrode 545a and the second bottom electrode 543b are connected to each other by wire circuit 539, and the second top electrode 545b and the first bottom electrode 543a are connected to each other by wire circuit 539.Pivotal position 525 is connected to the cmos circuit 537 shown in Figure 29 by not shown member.

Here, top electrode 545a, 545b need be arranged on closely adjacent mobile member 531 places with high precision.So the photoetching of preferred top electrode 545a, 545b is realized by the stepping exposure, and etching is realized by dry etching for this reason.

At last, shown in Figure 28 F, get rid of by the plasma etching that adopts oxygen, to form air gap 523 as the photoresist 561 of sacrifice layer.This makes pivotal position 525 and mirror portion 527 to move along the axis that passes pivotal position 525 in the mode of seesaw.

Produce element 500 like this, this element 500 comprises the pivotal position 523 that is arranged on substrate 521 tops by intermediate air gap 523, and is configured to the mirror portion 527 that moves in the mode of seesaw by the motion of pivotal position 525.A plurality of such elements 500 are formed simultaneously, to produce DMD 50.

When producing DMD 50 in the above described manner, above-mentioned three kinds of methods mirror portion 457 being made the shape of similar concave mirror can be employed in a similar manner, mirror portion 527 is made the shape of similar concave mirror.

Above-mentioned two elements 400 and 500 are configured to adopt two pairs of electrodes to move in the mode of seesaw, and do not comprise the beam that is positioned at mirror subordinate side, is used to contact address electrode.Image exposing apparatus of the present invention also can adopt DMD structure, and wherein pair of electrodes is used for making the motion of mirror portion in the mode of seesaw, and comprises the downside that is positioned at mirror portion, the beam that is used to contact address electrode, as at the available typical DMD of current reality.

Further, the image exposing apparatus according to the foregoing description adopts DMD as spatial light modulator.But in the image exposing apparatus of the reflective spatial light modulator beyond adopting DMD, the decline of light utilization ratio and extinction ratio can prevent by using the present invention.

To carry out hereinafter for the detailed description of how assembling independently by the light of DMD 50 reflections.Figure 30 illustrates the mode chart how light assembled by the DMD shown in Fig. 5 or 17 50 (spatial light modulator).Each pixel portions 62 of DMD 50 is as shown in figure 30 all made the shape of above-mentioned similar convex mirror (concave mirror that for example, forms) on curved surface.The light that shines on the pixel portions 62 of similar concave mirror is assembled by the pixel portions 62 and the optical system 52,54 of similar concave mirror, and focuses on the imaging plane f1.Overlap mutually the position of the convergence image 110 of each pixel portions 62 in from optical system 52,54 to the scope of imaging plane f1.

On the other hand, the convergence image 110 of each pixel portions 62 is along away from the direction of optical system 52,54 (arrow X1 direction) and break away from the position of imaging plane f1 independently of one another.If each assembles the beam diameter that image 110 has expection, then image can directly be exposed on photosensitive material from optical system 52,54.Therefore, above-mentioned microlens array no longer needs, and can prevent the light utilization ratio that caused by microlens array and the reduction of extinction ratio thus.

Promptly, if each pixel portions of DMD 50 is made with flat surfaces, then each is assembled image 110a and is set on the imaging plane f0, and between image without any the gap, and leave on any optical convergence plane of imaging plane and overlap each other, as shown in figure 31.Therefore, the skew that departs from imaging plane f0 of lenticule 102 and mask causes the problem with reference to Figure 18 and 19 described reduction light utilization ratios.On the other hand, in Figure 30, each width of cloth is assembled image 110 and is focused at the optical convergence plane respectively and breaks away from imaging plane f1.If assemble the beam diameter that image has expection, so, can ignore microlens array.

Further, in Figure 30, if microlens array 55 is arranged on the optical convergence plane that the pixel portions 62 by similar concave mirror forms, and break away from the imaging plane of the pixel portions that forms by optical system 52,54, can prevent reduction so as reference Figure 20 and 21 described smooth utilization ratios and extinction ratio.

Figure 32 is the synoptic diagram according to the image exposing apparatus of the 3rd embodiment of the present invention.Next, with reference to Figure 32 image exposing apparatus is described.In image exposing apparatus shown in figure 32, have the part identical and be presented identical drawing reference numeral, and will not be described in detail at this with section construction in as shown in figure 30 the image exposing apparatus.

Because image exposing apparatus shown in figure 32 comprises the spatial light modulator that contains pixel portions, each pixel portions is made the shape of similar convex mirror, so it is different with image exposing apparatus as shown in figure 30.More specifically, each pixel portions 262 of DMD (spatial light modulator) 250 is made the shape of similar convex mirror (convex mirror that for example, forms) on convex surface.The light that shines on the pixel portions 262 of similar convex mirror focuses on the imaging plane f10 by imaging optical system 52,54.

Here, the position of the convergence image 210 of each pixel portions 262 in from optical system 52,54 to the scope of imaging plane f10 is separated from each other.On the other hand, the convergence image 210 of each pixel portions 262 is along the direction of being represented by arrow X1 and leave on the position of imaging plane f10 and overlap each other.If each width of cloth is assembled image 210 and is separated from each other, and in the scope between imaging plane f10 and optical system 52,54 and leave the beam diameter that has expection on the optical convergence plane of imaging plane f10, this image can directly be exposed on photosensitive material from optical system 52,54.Therefore, microlens array 55 can be removed, and if the light utilization ratio that may occur when as mentioned above microlens array 55 being set and the decline of extinction ratio can be prevented from thus.

Further, even under the situation that the microlens array 55 that receives the light that transmits by optical system 52,54 is provided, also on the optical convergence plane that can form by the pixel portions 262 that microlens array 55 is placed on by similar convex mirror, and break away from the imaging plane that forms by optical system 52,54 (Figure 20 and 21), prevent the decline of light utilization ratio and extinction ratio.

DMD 250 with pixel portions of similar convex mirror can be to make with the similar mode of the DMD 50 of reference Figure 22 to 28 pixel portions that describe, that have similar concave mirror.

Simultaneously, the light that enters DMD 50 or DMD 250 is roughly formed the collimated light beam that has even light intensity on xsect by convergent lens 71, rod integrator 72 and imaging len 74 (Fig. 4 and Fig. 5).Yet in fact, the light that enters DMD 50 or DMD 250 has the angle of divergence.As a result, the light that sends from DMD 50 or DMD 250 also has certain angle of divergence.By each pixel portions 62 or 262 and the beam sizes assembled of imaging optical system 52,54 depend on the angle of divergence.Therefore, a problem may occur: the light from each pixel portions 62 or 262 is not that the size that depends on scattering angle is assembled separately.

The result, when the main beam that enters DMD 50 or DMD 250 has predetermined divergence angle beta, form by each pixel portions 62 or 262 and the convergent angle γ of the main beam of optical system 52,54 decisions (γ＞β) is shown in Figure 30 and 32 greater than the divergence angle beta of main beam.

Figure 33 A and 33B are convergent angle γ and the divergence angle beta that illustrates when each pixel portions 62 is made similar concave mirror surface shape.Shown in Figure 33 A, (γ＞β), then the light by each pixel portions 62 reflection can be focused on the optical convergence plane independently, and breaks away from imaging plane f1 (Figure 30) if the convergent angle γ of main beam is greater than its divergence angle beta.On the other hand, if the convergent angle γ of main beam is not more than divergence angle beta shown in Figure 33 B (γ≤β), then can not be assembled independently by the light of each pixel portions 62 reflection, and before imaging plane f1 and overlap each other afterwards.

Similarly, shown in Figure 34 A, make the shape of similar convex mirror when each pixel portions 262, if and the convergent angle γ of main beam is greater than its divergence angle beta (during γ＞β), light by each pixel portions 262 reflection can be assembled on the optical convergence plane independently, and breaks away from imaging plane f10 (Figure 32).On the other hand, if shown in Figure 34 B, the convergent angle γ of main beam is not more than its divergence angle beta (γ≤β), then can not assemble independently by the light of each pixel portions 262 reflections, and by the converging light of each pixel portions before imaging plane f10 and overlap each other afterwards.Therefore, shown in Figure 33 A and 34A,, can assemble independently by the light of each pixel portions 62 or 262 reflections by forming convergent angle γ greater than divergence angle beta.

Here, the convergent angle γ of main beam is by each pixel portions 62 or 262 and the decision of the light collection power (light collecting power) of optical system 52,54.Simultaneously, divergence angle beta can be expressed as illumination angle β 1 and angle of diffraction β 2 sums (β=β 1+ β 2).Illumination angle β 1 expression outputs to the angle of divergence of the main beam of DMD 50 by convergent lens 71, rod integrator 72 and imaging len 74.The light that angle of diffraction β 2 is arranged on above-mentioned DMD 50 withdraws from the angle of diffraction of the diffraction optical device on the face side, for example, and in (not shown in Figure 30 and 32) described in uncensored Jap.P. publication No.2004-133279 and the 2000-338475.

As a result, in order to satisfy the relation of convergent angle γ＞divergence angle beta (Figure 4 and 5), the light that satisfies the relation of illumination angle β 1＜convergent angle γ-angle of diffraction β 2 outputs to DMD 50 by convergent lens 71, rod integrator 72 and imaging len 74.

By forming convergent angle γ, can assemble independently as mentioned above by the light of each pixel portions 62 or 262 reflections greater than the main beam of its divergence angle beta.Especially, if each light beam 210 of being assembled independently by each pixel portions 62 or 262 has the beam diameter of expection, then described light beam can directly be exposed on photosensitive material from optical system 52,54.Therefore, microlens array can be left in the basket, and if the light utilization ratio that may occur when providing microlens array 55 as mentioned above and the decline of extinction ratio can be prevented from thus.

Further, microlens array 55 can be provided in by the light of pixel portions 62 or 262 reflections and assemble independently on the plane at place, and it breaks away from the pixel portions 62 that formed by optical system 52,54 or 262 imaging plane f1 or f10.This can prevent above decline with reference to Figure 20 and 21 described smooth utilization ratios and extinction ratio.

Further, if microlens array 55 is installed in (arrow directions X) on the optical axis direction in a movable manner, the focal position of light can easily be adjusted so.Especially, microlens array 55 is placed on the optical convergence plane and substitutes imaging plane f1 and f10, can focus on the minimize variations of adjusting the time utilization ratio.That is, in Figure 30 or 32, in the variation of the light utilization ratio between the plane of optical convergence plane and its front or back variation less than the light utilization ratio between the plane of imaging plane f1 or f10 and its front or back.Therefore, can prevent to work as microlens array 55 moves the time utilization ratio along the arrow directions X rapid change.

Bend shown in Figure 34 A, 34 (b) if be positioned at the imaging plane f1 or the imaging surface on the f10 that are formed by optical system 52,54, then microlens array can be placed based on the mean place at the place, summit of the imaging plane of pixel portions or imaging plane.

Further, the hole array can be arranged on by the light of pixel portions 62 or 262 reflections and assemble independently on the plane at place, and it breaks away from the pixel portions 62 that formed by optical system 52,54 or 262 imaging plane f1 or f10.Such setting can stop above-mentioned parasitic light.Further, hole array and microlens array can both be placed on (Figure 20 and 21) on the optical convergence plane.

Claims (12)

1. image exposing apparatus comprises:

Spatial light modulator, it has a plurality of reflective pixel portions that are arranged side by side, and each pixel portions is used for according to control signal modulation irradiation light thereon;

Light source is used to light shine spatial light modulator; And

Imaging optical system is used for the image focusing that the light of being modulated by spatial light modulator is represented to photosensitive material; Wherein

Each pixel portions of spatial light modulator is made into the shape of similar concave mirror or convex mirror.

2. image exposing apparatus according to claim 1, wherein, described imaging optical system comprises:

Optical system is used to receive via the light of each pixel portions transmission of spatial light modulator and focuses on the image of each pixel portions; And

Microlens array, it has a plurality of lenticules that are arranged side by side, each lenticule receives the light of transmission by optical system, and assembles light via each pixel portions transmission of spatial light modulator respectively, microlens array is arranged on the optical convergence plane that is formed by the pixel portions of concave surface or convex shape and optical system, and breaks away from the pixel portions imaging plane that optical system forms.

3. image exposing apparatus according to claim 2, wherein, described imaging optical system comprise receive the light of transmission by microlens array, and the light that will receive from each lenticule of microlens array focus on optical system on the photosensitive material.

4. image exposing apparatus according to claim 1, wherein, described imaging optical system comprises:

Optical system is used to receive via the light of each pixel portions transmission of spatial light modulator and focuses on the image of each pixel portions; And

Array of apertures, it has a plurality of apertures that are arranged side by side, each aperture receives the light of transmission by optical system, and makes respectively via the transmittance of each pixel portions transmission of spatial light modulator and pass through, the hole array is arranged on the optical convergence plane that is formed by the pixel portions of concave surface or convex shape and optical system, and breaks away from the imaging plane of the pixel portions that is formed by optical system.

5. image exposing apparatus according to claim 4, wherein, described imaging optical system comprise be used to receive the light of transmission by the hole array, and the light that will receive from each hole of hole array focus on optical system on the photosensitive material.

6. according to each described image exposure system in the claim 1 to 5, wherein, described spatial light modulator comprises the Digital Micromirror Device with micro mirror that the bidimensional as pixel portions is provided with.

7. image exposing apparatus comprises:

Spatial light modulator, it has a plurality of reflective pixel portions that are arranged side by side, and each pixel portions is modulated the light that shines on it according to control signal;

Light source is used to light shine spatial light modulator; And

Optical system is used for the image focusing that the light of being modulated by spatial light modulator is represented to photosensitive material, wherein:

Each pixel portions of spatial light modulator is all made the similar curved shape; And

When the main beam that sends from spatial light modulator had scattering angle, the convergent angle of the main beam that is provided by pixel portions and optical system was greater than the angle of divergence of main beam.

8. image exposing apparatus according to claim 7, wherein, each pixel portions of spatial light modulator is made the shape of similar concave mirror or convex mirror.

9. according to claim 7 or 8 described image exposing apparatus, wherein, microlens array is arranged on the optical convergence plane that is formed by pixel portions and optical system, and breaks away from the imaging plane that is formed by pixel portions and optical system.

10. image exposing apparatus according to claim 9, wherein, microlens array is installed in the optical axis direction of light in a movable manner.

11. image exposing apparatus according to claim 7, further comprise hole array with a plurality of holes that are arranged side by side, each hole be used to receive the light of transmission by optical system, and respectively transmission via the light of each pixel portions transmission of spatial light modulator, the hole array is arranged on the optical convergence plane that is formed by pixel portions and optical system, and breaks away from the imaging plane of the pixel portions that is formed by optical system.

12. according to each described image exposing apparatus in the claim 7 to 11, wherein, formed illumination angle promptly shines the angle of divergence of the main beam on the spatial light modulator, be less than the convergent angle of main beam and the angle of diffraction that forms by spatial light modulator between poor.

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