DK175895B1 - Light sensitive medium illumination apparatus - Has micro-lenses to focus emitted light onto light valves optical axes and face - Google Patents

Abstract

Apparatus comprises light emitters (3) in the form of light guides illuminating a face via light valves. Now at least two of the emitters each illuminate multiple light valves. The device also has a lens with at least one micro-lens arranged w.r.t. each light valve to focus the emitted light on or near the optical axis of the individual light valves.

Description

DK 175895 B1 i

BACKGROUND OF THE INVENTION The invention relates to a lighting unit as set forth in the preamble of claim 5 l.

In the graphic industry, offset printing plates are traditionally produced by copying a film containing the image to be printed onto the printing plate.

10

This is done in a print-down frame under vacuum to ensure close contact between film and printing plate. The plate, whose photoemulsion is sensitive in a given range, for example 350-450nm, is illuminated through the film with a powerful lamp such as a mercury lamp, whereby the image from the film is transferred to the printing plate.

The image of the film used is typically made by a laser beam drawing the image of the film in a 20 imagesetter. The laser beam is turned on and off using a modulator controlled by digital information.

Thus two major process steps are taken: film making and record copying.

25

It is obvious that there is both time and money to be saved by skipping the film making and directly illuminating the image on the plate from the digital information. This solution would be particularly advantageous if one could expose conventional commercially attractive printed circuit boards.

However, it is problematic to obtain digitally controlled lighting sources or, more specifically, laser sources that - ---- --—--

DK 175895 B1 I

2 I

can illuminate the conventional pressure plates at the correct I

wavelength and sufficient optical power. This problem I

is particularly pronounced in the UV region and the blue region in 350 I

The 450 nm range. IN

H

For example, one way to address these conditions is to

develop especially highly susceptible, exposed plates

I of lasers at larger wavelengths. This technique is used

Today in so-called CtP machines (Computer-to-Plate Image- I

10 setters). However, these printing plates are costly in use

In procurement, just like these high-sensitivity printing plates, you must

You are handled taking into account that these are exposed by I

In daylight. Thus, in several respects it will be an advantage

In part, if sufficient lighting could be obtained

In 15 of more commercially attractive printing plates with lower foil

luminescence, which can be achieved by increasing the light intensity I

on the printing plate itself.

However, this solution will present new problems as the only 20 commercially available light sources such as those mentioned above do not provide sufficient optical power at the required wavelengths.

However, this problem can be addressed by using, for example, short arc lamps which can give a greater optical effect.

However, this technical solution offers further H complications, since a lamp cannot be modulated in the same way as the known lasers, which can, however, be solved by purely mechanical modulation of the light source. j

From European Applicants' European patents EP 0 642 423 and EP 0 643 645, applications of the above-mentioned type 3 DK 175895 B1 are known in which a film or printing plate is illuminated directly through so-called microshutters by a so-called direct exposure.

However, these applications with increased requirements for § illumination resolution will be relatively complicated and expensive in their construction, as each microshutter is illuminated by an associated light source in the form of an optical fiber via focusing optics. Thus, at large illumination solutions, these entail a very high complexity and the necessity of a very large number of optical fibers, each of which must be calibrated for the current application. Thus, for lighting systems of the aforementioned type, the optical fibers will in practice limit the possible resolution, and the optical losses will have a limiting factor for the overall system, as utilization of this proximity exposure requires the individual pinholes to be illuminated evenly over the entire hollow surface of the entrance side. If the light is simply sent down to the individual pinholes from e.g. a collimation lens, there will be a very large loss of light hitting outside the pinhole. If the light is focused down into the hole, for example by means of a micro lens, the intensity profile of the light at the entrance to the hole will not be smooth, but "Gauss curve" -like, so that only a small part of the beam can be used to get even illumination. .

A system of the above type is also known from EP 709 706 A1, in which a microshutter arrangement of microshutters is individually illuminated by light sources attached to each shutter. This system also suffers from the above disadvantages.

30

US Patent No. 5,049,901 discloses a light modulator which uses so-called DMD mirrors to illuminate larger areas.

I DK 175895 B1 I

i 4 I

For a modulator based on mirrors, however, I

In the positioning of the mirrors is very critical and you do

In high demand for precision. For example, it is difficult

to control the tolerance at the angle at which the mirrors are tilted I 5 with 100% accuracy. If the mirrors are not positioned fully correctly, not all the light will be reflected, and

You lose light energy / intensity, and maybe hit the spot you

In which to elucidate, not exactly or not at all. Before I

For the graphic industry, it is essential to be able to pla I

In 10 high precision cere dots (often within a few μπι), I

And this can be difficult or directly impossible with those

In existing types of DMD. In addition, the achievable I

In many transmitted optical energies you do not

sufficient if scanning over I

In 15 larger areas with higher speeds with high illumination I

In intensity. IN

In addition, in the case of DMD the technique refers to I

In a reflective method, why the efficiency is less I

In 20 than, for example, a transmissive modulation. IN

US Patent No. 4,836,652 discloses an illumination system

voice to illuminate a medium in which an LCD monitor uses

can be tested as a light module or pixel level. A disadvantage of it

In the system described 25, the used LCD shutters are required

ted with large transmissive losses, like that of the shutter- I

The on / off ratio is too small. The low transmis- I

The degree of education has further its cause in that the lighting source I

light must be distributed among several microshutters. IN

I 30 I

U.S. Patent No. 5,579,149 also discloses a specification

lighting system in which a single light fiber illuminates an I

plurality of microshutters. A disadvantage of the re- I used

volatile shutter types according to D4 are that there are risks

5 DK 175895 B1 a variation of allignment of incident light against a illuminating surface over time, as the ON position is not static. This reduces the efficiency of the system. Thus, the lighting system used has the disadvantage that precision as well as both the static and not least the dynamic efficiency are too low, which is why this has not found commercial use.

Thus, the object of the invention is to obtain a modulator type which can be used in a lighting system for efficient and economical lighting of standard plate requiring a relatively high lighting intensity.

Background of the Invention

As stated in claim 1, by allowing at least one of said electrically actuated aperture devices to mechanically block the light transmitted to the light channel in at least one of the microshutter's closed states, an apparatus particularly suitable for illuminating photosensitive light is obtained. media with lower optical sensitivity.

Thus, light from one of the light source (s) is focused on the individual microshutter, which can thus modulate the continuous light supplied at a lighting site.

Thus, it has been found that using commercially available plates can provide sufficient "optical energy" or intensity from one light emitter 30 to multiple microshutters at one time. Thus, according to the invention, it will be sufficient to subdivide the microshutters used into smaller groups.

I DK 175895 B1 I

I I

It has also been found that a total (collimated) I

In light beam can be focused in several different microshutters I

In under minimal losses. IN

According to the invention, it is thus possible to illuminate several shutters with a light emitter in the form of, for example, an optical

fiber end. IN

It has thus been found that it is possible to obtain and educate

I 10 maintain a high illumination intensity at each individual I

In bright spots at a very high illumination rate, since I

The illumination of a medium thus takes place in parallel under I

Using one or relatively few light emitters. IN

Thus, the possibility of reproducible illumination I is obtained

I of a medium based on stored digital data at high speed

In heat exposure, having a high illumination intensity gives you

The opportunity to reduce the opening hours of the individual I

In microshutters, or more specifically, rise / fall hours. Up in

Thus, in the 20 finding, it is possible to use micromeca- I

In niche shutters that have a very low rise / fall time. IN

With a sensible structure of the micromechanical shutters

You can achieve a rise / fall hour that is so small that you

In the shutter arrangement of the invention can be used, and- I

Then, when in the overall system, a relative I occurs

movement between the lighting area and the lighting arrangement- I

This may be the case, for example, in the connection I

In the process of scanning a lighting area. A little I

Thus, during the rise / fall hour, the lighting spot I

30 will approach its ideal form. This advantage becomes particularly important

H marked when it is taken into account that the micromechanical I

H shutters can transmit a relatively large light

energy for the lighting area over a short period of time, I

why, in connection with the relay described above

l --- -: DK 175895 B1 7 tive movement between shutter arrangement and illumination area must be taken less into account the fact that a given point on the illumination area must be supplied to a certain amount of aircraft before the desired illumination result is obtained.

Thus, the invention allows for a quick and powerful illumination of individual illumination points, although the illumination is done by, for example, scanning, and it is possible to increase the speed of scanning movement.

Examples of photosensitive media may be, for example, printing plates, films, printed circuit boards (PCBs), etc.

It is thus noted that the invention effectively allows for simultaneous parallel modulation over a larger area at a very high illumination intensity.

According to the present invention, it is also possible to achieve a very high on / off ratio, i.e. the ratio of how much light passes a microshutter in 20 open and closed states respectively.

By a microshutter is meant a hole constituting a light channel through which light can be transmitted without the use of mirrors and the opening can be mechanically blocked and released for transmission by an electrically actuated mechanical aperture.

The design of the light channel can be adapted to the individual applications by suitable variation of, for example, cross sections.

Further, according to the invention, it is possible to make a digital proof method, i.e. executing proofs, on the same machine that exposes pressure plates, which in ---

I DK 175895 B1 I

i 8 I

You are not possible with the existing proof methods without

First you have to expose a movie like you are

In the case of the recognized proof methods such as Cromalin I

In and Matchprint.

Thus, according to the invention, it is possible to form one

In identical picture on both proof and printing paper, why it you

You will be able to obtain a proof that is extremely large

In accordance with the finished print. IN

I 10 I

In This, for example, the invention provides

"an opportunity to anticipate Moiré problems in print, I

In which it has its reason that according to the invention it is mu-

You are able to directly modulate UV light, thereby generating I

15 the same break points on the proof as in the finished print. IN

I A source of illumination that can be used to perform op

For example, in the finding may be a UV short arc lamp. There you

Thus, a very high illumination intensity can be obtained (ra- I

I 20 diant intensity) in the 350-450nm range using an I

In short arc mercury lamp (mercury short arc gap lamp). Here

You can achieve a beam intensity greater than 10 W / sr, which I

The ket with one lamp is enough to achieve a reasonable illumination

speed of a conventional offset plate. IN

I 25 I

Thus, according to the invention, the overall possibility of I is obtained

In modulating at a very high illumination intensity and at I

In very small wavelengths, why conventional cheap I

In printing plates can be used. IN

I 30 I

Another and very significant advantage of the invention and others

In the reversal of the said pressure plates is that also before-

In the mentioned lower light sensitivity is a major advantage in connection

In terms of both storage and handling, since these, in I

9 DK 175895 B1 unlike highly sensitive pressure plates, can withstand daylight without being exposed for a certain period of time.

It is to be understood that the invention can not only be used to expose films or printing plates, but advantageously P can be used to illuminate other types of photosensitive materials in completely different fields of application.

A further advantage of the invention is achieved by the use of 10 micro-lenses on the light input of the shutter arrangement for distribution of light in the individual micro-shutter, since it has been found that precisely the use of microlenses on the input side results in sufficiently low losses in the light splitting of the macro lenses arriving at the micro lenses. beam.

In particular, according to the invention, an improved dynamic efficiency is obtained since the invention reduces both static and dynamic allignment-related losses.

As stated in claim 2, to allow the illumination unit to comprise yet another microlens arrangement arranged between the microshutter and the illumination surface so that light transmitted through the illumination channel of the individual microshutter is appropriately focused on the illumination surface, 2S provides an advantageous illumination on the illumination surface, Modulated light through the shutter can focus on the illuminating surface of the light spot, the shape and extent of which is provided by the design and design of the optical system. Since the intensity profile 30 of the individual beams in the shutter aperture is non-uniform, the utilization of the optical energy is increased by the use of the second microlens arrangement. This is especially true in the case of light channels that have a small diameter (pinholes). By applying focusing optics to the microshutter output side __________-____ __ ----------

I DK 175895 B1 I

in 10 I

Thus, a significant increase in efficiency is obtained

In the radius of the beam profile, which otherwise does not

In sufficient optical energy for lighting purposes, likewise H

You are focused on the lighting point.

As stated in claim 3, to allow at least one of the light emitters-

The ne is constituted by an optical fiber which is optically connected

With at least one light source, an advantageous embodiment H is obtained

In the form of the invention, light in an easy manner selectively H

I 10 can be directed to the relevant micro-shutter arrangements I

In under reduced optical loss. H

I Optical guides are optical fibers, selfoc guides, I

I etc. I

I 15 I

I By using optical conductors as light emitters, and by H

thus connecting these optically to a light source is thus obtained

Likewise, to optimally direct a large amount of light

In the lighting spot. This is especially the case if you

In 20, for example, arc light bulbs are used as a light source, since I

In these, emits substantially less well-defined light than it

In the case of lasers, for example. IN

Furthermore, it will be possible to graduate the amount of light, H

25 injected into each optical fiber, for example by

You use different gray filters depending on the injection I

In the tick's spatial location relative to the arc of the light source.

I 30 Using optical fibers, such as optical fibers, can

The light source or lamps are centrally located at distance I

from the modulation unit, which facilitates servicing and I

In cooling. IN

DK 175895 B1 i 11

An additional degree of freedom is also obtained in the placement of the light sources, which makes design and construction easier. This is especially to be seen as an advantage when it is recalled that the physical extent of the light sources upon placement immediately above the shutter demands the sizing of a lighting system where a relatively high exposure solution is desired.

in

Thus, space considerations limit the illumination system to a lesser extent, since it may be easier to arrange light conductor ends than light sources directly over the microshutter arrangements, since fiber ends usually have a smaller extent than light sources.

By using optical or optical fibers as light emitters that can be optically connected to a light source, it is also possible to produce some very compact illumination units which can be assembled in relatively simple ways into larger illumination units, and it becomes possible to assemble these illumination units primarily taking into account the physical illumination conditions that may be required, since the optical transmission between the illumination source and the individual illumination points or the overall illumination site is not critical in relation to the physical location of the individual illumination units or the necessary location of the light sources in the overall lighting system.

It will also be possible to place the light sources at a distance from sensitive components that may be in the construction, so the operation of the overall arrangement can be greatly reduced, which should be seen as a special advantage when a large number of laser sources are used.

I DK 175895 B1 12

Finally, it should be noted that an optical fiber over a certain length, typically a few meters, is "beam-cleansing", which is why the light emitted by the light source undergoes an automatic correction before it is directed towards the illumination site or the illuminating surface and the modulation optics.

As stated in claim 4, to allow the optical fiber (s) to be optical fibers, a particularly advantageous embodiment of the invention is obtained, since optical fibers 10 are relatively easy to handle compared to conventional optical systems. This relationship is pronounced in relation to relatively complicated optical systems, where conventional transmission optics without light conductors will not be able to handle a greater number of sub-illumination systems 15, each with their own light emitter.

As stated in claim 5, allowing at least one of the light sources to be constituted by a short-arc lamp, it is possible to achieve a very high illumination intensity over a very large number of microshutters and thus over a large illumination area, since it is possible to obtain a relatively greater power at given desired wavelengths than can be obtained by, for example, commercially available laser sources.

25

The benefit obtained is particularly pronounced when the number of light sources is desired to be limited, with state of the art short arc lamps having an edge over laser sources so that a single lamp can illuminate larger illuminating surfaces via modulating microshutter.

For example, the desired radiant intensity in the 350-450nm range can be obtained by using a mercury short arc gap lamp. Here, a radiation intensity of over 10 W / sr can be achieved, which with one lamp is enough to achieve a reasonable illumination rate for a conventional offset plate.

Thus, by using optical fibers as light emitters and by optically connecting them to a light source, it is possible to optimally direct a large amount of light to the illumination site. This is especially the case if, for example, arc light bulbs are used as a light source, since these emit substantially less well-defined light than is the case for, for example, lasers.

Furthermore, it will be possible to graduate the amount of light injected into each fiber, for example, by using different gray filters depending on the spatial location of the injection optics relative to the arc of the light source.

The invention thus provides a relatively simple way to achieve a previously unattainable homogeneous illumination intensity over a larger area.

Also, by using optical fibers to absorb the optical power of an arc lamp, a simple and optimal way to avoid wastage is achieved due to the physical shape and structure of the light source, since optical fibers can be placed relatively freely and as needed in the arc fields of the light bulb.

Optical fibers also allow to add the illumination intensity over the illumination area.

As stated in claim 6, including the light source a short-arc lamp which, within an angle of +/- 75 °, to the equator axis E of a ball surface around it

DK 175895 B1 I

14 I

the lamp has arranged light-receiving optical light-conductors I

or fibers which are optically connected to and direct light to I

the light emitters, an advantageous embodiment according to I is obtained

the invention, in which light from a short arc lamp is optically absorbed

5 painted in the individual fibers which can thus be arranged around I

on a ball surface which, at a distance from the bulb, has the same shape ^ I

as this. IN

According to an example of a concrete application, fi- I

10 the compound about. 150 optical fibers arranged between I

the card arc lamp and microshutter array. IN

Accordingly, it is apparent that, according to the invention, it is said to be

it is attractive to use a lamp, for example a UV-I

15 lamp, since the otherwise slightly different light orientation of the lamp I

and intensity can be absorbed and utilized by corresponding I

oriented optical conductors that subsequently lead to I

and illuminates the surface lighting system used. IN

The lamp may, for example, be a mercury card arc lamp. IN

By distributing a number of light-receiving ends over the lamp I

ball surface, it will also be possible to adjust the light fixture

taking into account the light-receiving ends of the light-conductors by:

25 adjust their position relative to the lamp and its output

radiation profile. IN

By as stated in claim 1, allowing at least one of the light separators

there being a laser source, an additional advantage is obtained

30 part according to the invention, with the necessary lighting effect

weight over a larger illumination area can be summarized by I

using multiple laser sources. IN

15 DK 175895 B1

Also, according to the invention, less energy loss and thus an increased efficiency are achieved, partly due to the possibility of less injection loss, and partly due to a significantly higher utilization of the light source. Where, from 5 a 2000W arc lamp, an effect can typically be set in the desired wavelength range of 20W in the form of modulated light spots on the photosensitive medium, ie. ca. 1%, for example, from a diode laser of well-defined wavelength can typically be deposited in the order of 5% 10 of the power.

The light from, for example, a laser source is elliptical and astigmatic, which must be corrected for in the optical system. Using fiber, light is distributed within the fiber and the fiber emits a substantially more uniform, "blended" beam, requiring less optical correction.

Thus, by flattening the illumination source as multiple laser sources, it is possible to increase illumination homogeneity across the illumination surface, since the laser sources can be individually adjusted for the purpose of achieving a homogeneous illumination of the individual microshutter arrangements while simultaneously increasing the overall system efficiency.

25

The laser sources may be, for example, diode lasers, solid state lasers, gas lasers, liquid lasers, semiconductor lasers or the like.

By as stated in claim 8, allowing the activatable aperture devices to be made up of hinges hinged to the microshutter arrangement, an advantageous embodiment of the invention is obtained.

DK 175895 B1 I

By as stated in claim 9, letting the lighting unit switch on- H

mount a light emitter in the form of a light source optical

connected optical fiber or optical fiber arranged for be- I

illuminating a plurality of microshutters arranged in an I

5 given that at least one collimation lens is ar

ranked between the light sensor and the surface shape so that I

collimated light is directed toward the plurality of microshutter by it

first microlens microlens arrangement, I

advantageous subdivision of microshutter arrays is obtained

10 ments and associated optics that can be part of an overall subdivided lighting system.

It should be noted that the lighting unit can be designed as I

a compact device with microshutter, optics and integrated I

15 optical fibers or optical fibers so that the device as such

dan can be marketed with as a compact and adjusted one- I

only to be adjusted to an applied light I

source in a given application. IN

By as stated in claim 10, letting the flats of the microshutters

deform to form a hexagon, a flat shape of micro-I is obtained

the shutter arrangement, which can be easily assembled I

and interact with similar micro-shutter arrangements. IN

25 In addition to the above-mentioned geometric conditions in connection with I

assembly with similar microshutter arrangements, I

Hexagonal surface shape has the advantage of being possible

to achieve a relatively high degree of filling when used I

a light emitter illuminating the microshutter arrangement with an I

30 circular cross section. IN

Thus, the fill rate for a hexagon face shape is 83%, I

which should be seen in relation to a degree of filling of 63% I

for a square surface shape relative to a circumscribed circle. IN

DK 175895 B1 17

In addition, a hexagon surface shape has the advantage that it is possible to distribute the individual microshutters over the surface shape in a simple manner so that the desired illumination distribution is achieved.

However, many other surface shapes may also be implemented within the scope of the invention.

By, as stated in claim 11, allowing the illumination unit to comprise at least eight hexagons, each illuminated with an optical fiber optically connected to an illumination source, obtains a "macro" illumination system which can be easily assembled to a desired illumination characteristic. , where 15 each hexagon is fed by an illumination source via an optical fiber.

As stated in claim 12, leaving the individual microshutter with associated microlensing optics in rows 20 in the transverse direction T of the surface shape with the microshutters at a given spacing, and since the rows are set apart in the longitudinal direction of the rows, it is possible to achieve Increased illumination solution 25 As arranged in claim 13, arranging the rows such that all projection of each individual microshutter on the transverse direction T in the surface form results in a number of illumination points with a spacing AL in the transverse direction T, an advantageous embodiment according to the invention is obtained, 30 The surface shape can advantageously be used, for example, for scanning or similar motion lighting, where an illumination solution is less than the minimum distance between the microshutter.

i -.- -----

DK 175895 B1 I

18 I

As stated in claim 14, the first and / or the first

other lens arrangement consists of hexagonal focus line I

see, a particularly advantageous geometric shape of the line I is obtained

sear arrangement, as hexagonal lenses can be packed closer

5 than circular lenses, which further results in a mu

similarity to increase system efficiency and resolution

equipment. IN

By as stated in claim 15, letting the flats of the microshutters

10 or shape forms may be arranged on one or more surfaces.

re lighting heads, with the lighting head and lighting I

the operating surface is arranged to make a relative motion

lighting over an area of illumination, the device being similar

it is equipped with a control unit for controlling micros

15, depending on the relative motion between I

the bar and the illuminating surface, an advantageous alteration is obtained

native for glare exposure, as the lighting unit soles I

it can be used for illumination of larger illumination areas

clay, just as the lighting solution can be increased. IN

20 I

It is understood that the relative motion between I

each lighting head and lighting area can also be provided

is taken by fixing each illumination head and moving it

light area. IN

25 I

The movement over the illuminating surface can, among other things, be arranged

depending on the structure of the moving unit and

form. For example, a discrete illumination unit with I

the number of shutters is moved around the illuminating surface at I

30 step motion, whereby a given exposure can be obtained as I

a summary of discrete illuminating surfaces for an overall I

area. IN

By providing, as stated in claim 16, that the movable unit is constituted by a rod whose relative movement between the illuminating surface and the rod is a simple forward motion in the transverse direction of the rod, a particularly advantageous advantage is obtained. According to the invention, such scanning can provide a total illumination over the entire illumination cross-sectional direction, thereby avoiding boundary lines between discrete illumination zones, thus substantially reducing the location uncertainty in the exposure of points across the direction of movement over the total exposure. for the mutual location uncertainty between the lighting unit's individual microshutters and the uncertainty in the guide.

As stated in claim 17, each micros-hut is made up of a pivoting aperture element which can move back and forth between two positions, the pivotal aperture member being suspended so that elastic forces act against an equilibrium position between the two positions, and wherein the illumination unit further comprises a control unit for controlling the oscillating aperture element by electrostatic forces, and the aperture element in one of the two positions blocks the microshutter's light channel allowing rapid modulation; since the intrinsic frequency of the oscillating element, as a function of the oscillation parameters of the element, such as mass, elasticity and geometry as well as internal and external forces, determines the switching time of the microshutter.

Thus, the reaction time of each microshutter to a given control signal from the control unit is amplified by the oscillating system's own frequency, which can thus be dimensioned to the desired switching time.

DK 175895 B1 I

By as stated in claim 18, charging the lighting unit I

between the microshutter arrangement and the illuminating surface I

further comprising optical means for scattering those of I

light rays emitted by the illuminating surface, I

5, the opportunity to make a glare exposure over I is obtained

a greater illumination area since the optical means for I

scattering of the light rays emitted by the light channels ensures,

that the microshutter arrangement may illuminate an area which I

corresponds to the extent of the associated microshutter I

10 arrangement. IN

By allowing at least one of the cross-section of the light channels to have the largest diameter at the lower end of the light channel towards the

the illuminating surface, it is possible in the best possible way that you

15 direct light through the microshutter if the individual shut- downs

plates are located at or above the upper channel of the light channel.

end, recalling that light from the first I

microlens arrangement will typically be focused on I

the shutter plate itself. IN

20 I

By leaving at least one of the light channels conical, with I

the largest diameter at the lower end of the light channel towards I

the illuminating surface, an advantageous embodiment I is obtained

according to the invention. IN

25 I

Figures I

The invention will now be described below

view of figures in which I

FIG. 1 shows the invention in its basic principle

form, I

FIG. 2 shows an example of how light emitters can be

You are connected to a light source, I

r ----- .-- DK 175895 B1 21! FIG. Figure 3 shows a further embodiment of the invention in which the light sources are laser diodes; Fig. 4 shows a further embodiment of the invention in which the light emitters are constituted by light conductors; Fig. 5 shows the construction of a further illumination unit according to the invention; 6 shows a scanning unit according to the invention; Figs. 7-10 illustrate the operation of a lighting unit with a large number of microshutter according to the invention; 11 and 12 show lighting modules for scanning according to the invention.

FIG. 13 shows a structure of lighting modules according to the invention for glare exposure; FIG. 14 is a cross-sectional view of the lighting modules shown in FIG. 13, and in which FIG. 15 shows examples of the design of light channels according to the invention.

30

Embodiment Example An embodiment of the invention is shown in Fig. 1.

DK 175895 B1 I

An apparatus for spotlighting a medium 9 comprises I

a light emitter 1 arranged at a distance from a lens array

ment consisting of lenses 2 as well as a microshutter arrangement

ment consisting of a plate element having a plurality of openings 6 I

5 and associated aperture elements 4. The aperture elements 4 I

are individually electrically activatable by displacement or I

smiles turning. IN

By microshutters or light valves is understood in broad terms

10 capable transmissive light apertures, for example, they can

is made up of micromechanical shutters. The individual shutter- I

elements may, for example, be of the type that is involved

written in French Patent Application No. 9412928 or the I

corresponding to EP-A 709 706 described in accordance with I

The invention is essential that the light to be modulated

transmitted directly through the individual microshutter to I

achieving a minimum transmission loss. IN

In this connection, it should be noted that the microshutters

20 described in the above-mentioned patent application is particularly advantageous

similar to this invention, since microshut I

the terns must (and can) have a very small rise / fall time, I

if a reasonably well-defined spot on one is to be obtained

photosensitive medium under mutual motion between be- I

25 and the medium. It must further in the I

In this connection, it is noted that according to the invention it is mu-

It is easy to settle for a relatively small illumination time on the I

some illumination points due to the high transmit- I

tethered light effect. IN

30 I

Each light valve has at least one individually addressable open I

and closed state in which states respectively

one is shown in relation to the light's review of the associated I

running light channel minimal and maximum attenuation. IN

23 DK 175895 B1

In this connection, micromechanical shutters have the advantage that the attenuation in the above two states is actually optimal, the attenuation of the light being purely physically provided by a micromechanical plate or the like which in the maximum attenuation state simply blocks light transmission and at the minimum state dimming in principle does not give rise to dimming of the light beam.

10

The function of the illustrated embodiment is that a total collimated light beam A is focused in the openings 6 of the micro-shutter arrangement, so that the aperture elements 4 in the embodiment shown in FIG. 1 blocks light transmittance while in their open state they allow light transmittance in the openings 6, thereby illuminating a lighting point associated with the individual opening 6 on the medium 9.

It should be noted that the present embodiment is particularly simple in its construction since focusing optics are not used between the openings 6 and the medium 9.

This technique is described in its basic form in EP 0 642 423 B1, with the medium 9 or the illumination plane 25 arranged precisely in the transition between the Fre-speed region of the light rays and the Frauenhofer region.

It should also be noted that the shutter plates, by an appropriate design of the microshutter arrangement, may also be located on the underside of the wafer plate oriented towards the illuminating surface or medium 9.

FIG. 2 shows a cross section of a further embodiment according to the invention.

I DK 175895 B1 I

I 24 I

In A lighting system, a number of micro-

In shutter arrangements (not shown), each optically for I

You are bound by a number of optical fibers 13 which are further up

5 connected to an arcuate receptacle 11, 12 which I

Together, 360 ° extends around the axis of a short-arc lamp 10

You see. IN

In the optical fibers 13 are fixed to the recording sheath 11, 12, I

10 so that they absorb light 360 ° around the lamp in an I

In the region of the recording sheath 11, 12 between an upper angle Ua and I

lower angle La. IN

In the angles Ua and La are adapted to the concrete used I

In 15 short arc lamp 10. For an Hg short arc lamp, Ua and La I

For example, I is selected to + 60 ° and - 30 ° to lamb I

In the equator plane of the pen E. I

In The location and fixation of the individual fibers 13 I

I 20 on the recording caps 11, 12 relative to the angle between

In these and the equator plane can also be chosen in relation to I

the intensity profile of the current lamp. IN

Thus, each optical fiber 13 can illuminate a subsystem, I

25 which may, for example, correspond to that of FIG. 1 where you

the light-emitting end 13 of the optical fiber corresponds to light g1

In springs 1. I

According to one embodiment, the number of optical fibers 13L

At 30 around the recording sheath 11, 12 be approx. 150 which thus I

each may illuminate a microshutter optically connected thereto

system. IN

DK 175895 B1 r ----- - '25

According to the present embodiment, each optical fiber can illuminate 5-600 light channels, thereby dividing the light from the fiber into a corresponding number of smaller light rays.

Thus, according to the invention, it is possible to obtain a homogeneous illumination of the microshutters and thus the illumination surface while maintaining a good efficiency.

According to the illustrated embodiment of the invention, the number of required optical light guides between the light source and the illuminating surface is reduced by a factor of 5-600, while maintaining a homogeneous illumination over the entire illuminating surface.

The fibers 13 can advantageously be distributed to the micro-hut systems so that the intensity difference between two neighboring fibers does not exceed a given maximum limit or so that if the maximum limit is exceeded, two neighboring microshutter arrangements are not allowed.

FIG. 3 shows a further embodiment of the invention, a laser diode being used as a light source.

25

Laser diodes 21 are thus positioned in a fixture 20 for illuminating a collimation lens 22, a first microlensing arrangement 23, a microshutter arrangement arranged in a wafer plate 25 with light channels 26 and associated aperture elements 24, a second microlensing arrangement 27, and finally an illumination plane 28 .

It should be emphasized that for the sake of clarity, the figure shown does not reflect a typical application to

I DK 175895 B1 I

I 26 I

In, for example, image exposure, since the collimating lens 22 in I

In such applications, typically a much larger I will be illuminated

In number of microlenses and associated shutters. IN

I The individual aperture elements 24 are opened and closed, ie. modu- I

You learn, depending on digitally stored data as well as one

In any given relative motion in relation to illumination I

In the plan of action 28. I

Thus, in the laser diodes 21, a light beam emits a collision

You are added in the collimation lens 22 to a light beam A '. Light I

In the beam A 'is subsequently led to the microlens I

In the arrangement 23 focusing the light beam A 'to another

number of light rays B 'in the microshutter arrangement of light channels I

I 26, from which the light rays C are passed on to the second I

In microlens arrangement 27, where the individual rays D 'fo- I

You are interrupted on illumination plane 28 as illumination spots with I

spot diameter Sd. IN

20 In a current application, each light emitter can illuminate 5-600 I

In light channels. A solution according to the invention may be exemplified

For example, 2540 DPI is selected, ie 10pm between the points. IN

The diameter of the collimation lens 22 is 5-10mm and they are only one

25 cell microlenses in the microlens arrangements 23 and 27 I

has a diameter of 2-300pm. The center distance between mi- I

The H lenses are also on the order of 2-300pm, I

which thus also corresponds to the distance between the holes I

I in the wafer plate 25. The individual light channels 26 in the wafer plate I

Typically, the 25 25 has a diameter of 20-40pm and the shutter I itself

the plate 24 is slightly larger so that it can completely cover the hole

easy. The spot diameter Sd of the illumination plane 28 can according to I

the present embodiment will be 12-20µπι. IN

I ~ ----------------- DK 175895 B1 27

The on-off ratio (ratio of how much light passes through an open and closed shutter, respectively) is in the order of 1000: 1 or better, which is about 10 times better than for the best LCD chips.

5

It is to be understood that a collimation lens according to the invention can, and in some cases, be designed as a system of collimation lenses to obtain a higher efficiency.

10

FIG. 4 shows an embodiment which in its basic form is similar to that of FIG. 3.

Thus, light guide 29 is located in a fixture 20 for illumination of a collimation lens 22, a first microlenser arrangement 23, a microshutter arrangement arranged in a plate 25 with light channels 26 and associated aperture elements 24, a second microlenser arrangement 27, and finally an illumination plane 28 .

20

It should be emphasized that for the sake of clarity, the figure shown does not reflect a typical application for image exposure, for example, since in such applications the collimating lens 22 will typically illuminate a much larger number of microlenses and associated shutters.

The individual aperture elements 24 are opened and closed, i.e. is modulated, depending on digitally stored data as well as any relative movement, with the illumination plane 28.

30

Optical fibers 29, or light conductors with adapted optical properties, emit a light beam which is collimated in the collimating lens 22 to a light beam A '. The light beam A 'is subsequently directed to the microlensing arrangement 23 which

I DK 175895 B1 I

I 28 I

In light beam A ', a number of light beams B' in microshut H are connected

In the terrain arrangement openings 26, from which the light rays C

In addition, to the second micro-lens arrangement 27, where H

In the individual rays D 'is focused on the illumination plane 28 I

In 5 as lighting spots. IN

I The crucial thing in this application is that they en- I

In the cell the individual microshutter group is supplied light from an H

In light source via the optical fibers shown. H

I 10 I

I As shown, it is thus possible to place the individual mi-

In croshutters with primary consideration for their needs

In or desired position in relation to the illumination itself

In the illuminating surface, after which light can be admitted microshut- I

In the 15 groups without major technical difficulties via the I

Optical fibers or optical fibers shown with similar properties

You create. IN

I In FIG. 5 shows an example of a microshutter architecture I

In the top view of the invention. IN

In a scanning rod 30 for movement in the direction X comprises an H

In number of hexagons 32, each comprising a large number of mi-H

In croshutters according to the invention. H

I 25 I

In each hexagon, a microshutter arrangement comprises the answer I

In those of FIG. 4, showing the microshutter arrangement I

You include 400-600 light channels with associated microlensers

In ranking and aperture elements 26. I

I 30 I

Each hexagon 32 is illuminated by an optical I arranged above

In fiber 33 via a collimating lens 31 similar to that of I

In FIG. 4. 'DK 175895 B1 29

The subareas 34 and 38, in the longitudinal direction of the scanning rod 30, constitute so-called overlap zones, arranged so that the individual microshooters of the scanning rod 30, when moving the scan rod 30 in the direction X, can illuminate 5 illumination points with equal spacing on an underlying photosensitive medium.

Thus, a projection of all illumination points of the microshutter in the hexagons on the longitudinal direction of the scan bar 30 will provide illumination points at equal distance over the entire longitudinal direction of the scan bar 30.

The location of the individual microshutters in the hexagon of the invention shown above is shown in detail in FIG. 7-9.

In FIG. 6 shows a cross section of a scanning arrangement 40.

The overall purpose of using a scanning rod for the practice of the invention is partly to achieve a larger resolution than the dimensions of the selected microshutters allow, and partly to achieve an economically advantageous structure of the system.

The scanning arrangement 40 can perform relative movement in the direction X with respect to the support 41 by means of movement not shown. The scanning arrangement 40 comprises a scanning bar 30 which corresponds to that of FIG. 5.

30 The scanning arrangement shown can perform a relatively fast scan movement while maintaining an effective illumination with a high illumination intensity, high on / off ratio, high illumination resolution and low rise / fall time.

DK 175895 B1 I

30 I

In FIG. 7-9 shows a section of a microshutter arrangement I

according to the invention, wherein the individual microshutters are ar

ranked in a flat form of rows 61, 62, 63, 64, 65 and I

66. I

For the sake of clarity, only the individual micros I

hutters belonging to microlens 50, as well as those in microshutter I

pure designed light channel 51. I

10 I

Each microshutter with associated optics has a maximum I

extent corresponding to the center distance between the I

belonging to microlenses 50, which according to the illustration I

running example is approx. 100 pm and that of the individual I

15 microshutters associated with light spots on the underlying foil

two-sensitive medium (not shown) is approx. 12-20 µπι at an op- I

solution of approx. ΙΟμιη and 10 rows of shutters. IN

Rows 61, 62; 63, 64; 65 and 66 are offset from one another

20 with half the effective spacing, while I

rows 62, 63; 64, 65 are interposed with half I

of the effective spacing plus the desired up

solution. IN

In practice, each microshutter will typically have an extension I

about 250µπι, which is why at a resolution of approx. 10 I

μπι requires a larger number of rows in the microshutter array. IN

Figure 7 shows how row 61 under the motion of I

The scanning arrangement passes through a scan line SL, which I

entails a possible addressing and modulation of scanning I

nine in the points on line BL 1. IN

DK 175895 B1 31 In FIG. 8 shows how row 62 passes the scanning line SL during movement of the scanning arrangement, which causes a possible addressing and modulation on the scan line at the points shown on the line BL 2, where the points 5 61 'are derived from microshutter row 61 and the points 62' are from microshutter row 62.

In FIG. 9, it is seen how row 63 passes the scanning line SL during movement of the scanning arrangement, which causes a possible addressing and modulation on the scan line at the points shown on line BL 3, where the points 61 'are derived from microshutter row 61 and the points 62' are from microshutter row 62, and wherein the points 63 'are derived from microshutter rows 63.

15 In FIG. 10 is shown how a summarized image can be formed when all ten rows (of which only rows 61-66 are shown) have passed the scan line, the light spots 61'-66 'corresponding to rows 61-66.

20 In connection with FIG. 7-9, it should be noted that the individual microlenses belonging to each shutter can, for example, be designed as hexagonal lenses, thereby minimizing light loss by avoiding light falling outside the microlens.

25 In FIG. 11 is a further example of a lighting module according to the invention.

The lighting module 80 comprises eight hexagon surfaces 81, each comprising 400-600 microshutters according to the invention (not shown) and associated optics. Each hexagon is illuminated by collimated light 82 from an optical fiber (not shown). The basic structure of the individual hexagon surfaces is

DK 175895 B1 I

as shown in FIG. 4. The optical fibers are connected to an H

UV light source, in the form of a Hg mercury-short arc lamp. Η

The individual lighting modules can be placed with one another

5 an accuracy of approx. ± Ιμπι. IN

Each hexagon surface 81 interacts so that H

the overlap zones together form a lighting array that H

corresponds to the illumination array which is outside the upper H

10 lap zones. H

The hexagon surfaces 81 microshutters are electrically connected

to a control unit which, for example, from a RIP (Raster H

Image Processor) provides the necessary control data H

15 for the microshutters. H

The geometric shape of the lighting modules 80 ensures that H

the modules 80 can be easily assembled for example I

display a scan bar the length you want. H

Each of the lighting modules shown is illuminated according to the H

present example of eight optical fibers (not shown). IN

The lighting modules 80 can be manufactured as compact modular units.

25 clays with integrated collimation optics and optical fibers, I

so that the modules are pre-calibrated and "ready to I

go ", by simply connecting and adjusting the optical I

fibers with a light source, such as one or more electrical

ports (not shown) can be connected to an overall control H

30 processor unit (not shown). IN

The lighting modules can, for example, be used in a scanning H

unit similar to that of FIG. 6, 24 illuminating H

80 (LSA, Light Switch Array) modules, each of which I

DK 175895 B1 33 optically connected to 8 light guides is arranged on a scanning bar. A total of 192 fibers are connected to the same light source, for example a 15 kW Hg Short arc mercury lamp.

5 By using one long scan bar, rather than illuminating discrete areas, continuous illumination is achieved over the total cross-section of an illuminating surface, thus avoiding discontinuities or so-called shock zones at boundary areas.

10 is a sketch of an example of an illumination module 85 according to the invention, which corresponds in general to that of FIG. 11 illustrating module 80.

The individual lighting modules 85 can be positioned among themselves 15 with an accuracy of approx. ± 1 μπι.

For example, the lighting module 85 can be used in an image setter of the FLATBED type by one. resolution of 2540 DPI.

The lighting module 85 comprises eight hexagon surfaces 87, each comprising 400-600 microshutters according to the invention (not shown) and associated optics. Each hexagon surface is illuminated by collimated light 87 from an optical fiber (not shown). The optical fibers are connected to a UV light source, in the form of, for example, a Hg mercury-short arc lamp.

Each hexagon surface 87 interacts so that the overlap zones together form an illumination array corresponding to the illumination array outside the overlap zones.

30

The hexagon surfaces 87 microshutters are electrically connected to a control unit which provides, for example, a RIP (Raster Image Processor) the necessary control data for the microshutters.

DK 175895 B1 I

The geometric shape of the lighting modules 85 ensures that H

the modules can be easily assembled for example I

a scan bar of the desired length. IN

Further, the surface shape shown may advantageously be used

for double exposure whenever desired, with I

each point can be easily illuminated twice. IN

10 Each of the lighting modules shown is illuminated by eight opti- I

spoon fibers (not shown). IN

The lighting modules 85 can also be manufactured as combo

packed modules with integrated collimation optics and optical I

15 fibers so that the modules are fully calibrated and "real."

dy to go "by simply connecting the optical fibers

with a light source, like one or more electrical gates I

(not shown) can be connected to an overall control process

purity unit (not shown). IN

20 I

FIG. 13 shows a sketch of an example of a lighting module

95 according to the invention. The lighting module responds in its I

basic form to that of FIG. 12, though there are

added scattering optics between the lower terminals of the light channels

25 and the illumination area I

The lighting module 95 comprises eight hexagon surfaces 87, which I

each comprising 400-600 microshutters according to the invention I

(not shown) and associated optics. Each hexagon surface is i

30 is illuminated by collimated light 97 from an optical fiber (not I

shown). The optical fibers are connected to a UV light source, I

in the form of, for example, laser diodes (not shown). IN

DK 175895 B1 35

Each hexagon surface 97 interacts so that they together form an illumination array that can illuminate the entire underlying illumination area at once without performing a scan. This type of glare exposure can, for example, be carried out at a resolution of approx. 50 µm and illumination spots of 50-100pm. For A4, such an illumination matrix would thus comprise 4200 X 5940 number of microshutters.

10 The individual lighting modules 95 should ideally be placed here with an accuracy of approx. in 1 μπι on the projected image.

Hexagon surfaces 97 microshutters are electrically connected 15 to a control unit which provides, for example, a RIP (Raster Image Processor) the necessary control data for the microshutters.

The geometric shape of the lighting modules 95 ensures that the 20 modules can be easily assembled into a single lighting unit of the desired area.

It should be noted that the light source in the example shown must be monochromatic, so that each surface shape can be illuminated, for example, as shown in FIG. 3 of laser diodes.

At the same time, it should be noted that the layout of the individual shutter pads or surface shapes can be, for example, 30 square instead of hexagonal and of different sizes.

I DK 175895 B1 I

I I

In FIG. 14 is a cross-sectional view of those of FIG. 13

I modules 95. H

In the Lighting modules, its basic features are similar to those of I

In FIG. 4, the second microlensing arrangement being I

by the diffusion optics 98 which diffuses the light rays C ,. M

I 99 for light rays D ', 99' and focus these on illumination I

In the plate 94. I

In FIG. 15 is a further example of the invention I

See how the light channels can be designed.

I For the sake of clarity, the light channels shown are shown in

In the same wafer plate. IN

I 15 I

Thus, a light channel 101 may be designed as two sub-chambers

In re, etched into a glass wafer plate 100. IN

Another light channel 102 may also be configured as an I

20 cone in the same or in another wafer plate 100. I

In the embodiments shown it will belong to the light channel

In the shutter plate be oriented at the side of the wafer plate- M

In the one where the cross-section of the light channel is the least, light M

I 25 from the light sources or the light source (not shown) typically H

You focus on the shutter plate itself to achieve such a M

In discrete and rapid modulation over the entire associated I

As brightly as possible. M

I 30 It is understood that the examples shown in some respects

Senses are simplified for illustrative purposes. This should

However, you do not in any way limit the invention to that above

You describe, but serve solely for the purpose of illu- I

In the overall and principled features of the invention. IN

DK 175895 B1 37

It is thus to be understood that the invention can not only be used for exposing films or printing plates as in the examples shown, but can advantageously be used to illuminate other types of photosensitive materials entirely. three applications.

Claims (18)

A spotlight illumination unit for a medium I 5 comprising at least one light emitter arranged via a microshutter array for illumination of at least one illumination surface, the microshutter arrangement comprising a plurality of micromechanical microshutters, each microshutter comprises a light channel as well as an associated electrically actuated aperture device (4), wherein at least one of the light sources (1) is arranged to illuminate at least two micro-cutters via a first lens arrangement (2; 23), the lens arrangement comprises at least one microlens arrangement arranged with respect to each microshutter, such that at least a portion of the light emitted by the light source (s) is focused on or in the vicinity of the optical axis of the light channel of the individual microshutter (s). (6; 26) when the microshutter I's aperture device (4) defines a fully or partially open state, characterized in that at least one of said electrically actuable aperture devices (4) You make a mechanical blocking of the light supplied to the light channel I in at least one of the closed states of the microshutter. H Lighting unit according to claim 1, characterized in that it further comprises a second micro-H lens arrangement (21) arranged between the micro-shutter I and the illuminating surface, so that light transmitted through the light channel (6; 26) of the individual microshutter - I 30 is suitably viewed on the illuminating surface (9; 28). IN Lighting unit according to claim 1, characterized in that at least one of the light sources is constituted by an optical light guide (13; 29) which is optically connected to at least one light source. . Lighting unit according to claim 3, characterized in that the optical light guide (s) are optical. fibers. Lighting unit according to claims 1-4, characterized in that at least one of the light sources (10) is constituted by a 10 short arc lamp. Lighting unit according to claims 1-5, characterized in that the light source comprises a short-arc lamp (10) which, within an angle of +/- 75 ° to the equator axis (E) of the lamp 15 on a ball surface (11, 12) around the lamp has arranged light-receiving optical fibers or fibers (13) which are optically connected to and direct light to the light emitters. Lighting unit according to claims 1-6, characterized in that at least one of the light sources is a laser source (21). Lighting unit according to claims 1-7, characterized in that the activatable aperture devices are constituted by plates hingedly hinged to the microshutterar arrangement. Lighting unit according to claims 1-8, characterized in that it comprises a light emitter in the form of an optical fiber or optical fiber (29) arranged with a light source for illuminating a plurality of microshutters arranged in a given face shape, with at least one collimation lens (22) arranged between the light sensor 40 I DK 175895 B1 I and the surface shape, so that collimated light is directed towards the plurality of the first microlens arrangement (2; 23) of the microshutter. IN Illumination unit according to claim 9, characterized in that the surface shape of the microshutters is a hexagon I (32; 81; 87). IN Illumination unit according to claim 9 or 10, characterized in that the illumination unit comprises at least eight hexagons (81; 87), each illuminated by an optical fiber optically connected to an illumination source. Illumination unit according to claims 9-11, characterized in that the individual microshutters with associated I microlens optics are placed in rows in the transverse direction (T) of the surface shape with the microshutters in a given distance between them, and the rows are intersected in the transverse direction. IN 20 I Lighting unit according to claims 9-12, characterized in that the rows are arranged such that all of the projections of the individual microshutter on the transverse direction (T) I in the flat form result in a number of illumination points with a distance AL in the transverse direction. (T). IN Illumination unit according to claims 1-13, characterized in that the first and / or the second lens arrangement (23, 27) are hexagonal focus lenses. IN 30 I Lighting unit according to claims 1-14, characterized in that the surface shape or surface shapes of the microshutters are arranged on one or more lighting heads I (40), each lighting head (40) and the lighting surface I DK 175895 B1 being arranged for making a relative motion over an illumination area, the device also provided with a control unit for controlling the microshutters in dependence on the relative motion between the illumination head 5 and the illumination surface (41). e Illumination unit according to claims 1-15, characterized in that the illumination head is constituted by a rod (30) whose relative movement between the illuminating surface 10 (41) is a simple forward movement in the transverse direction of the rod (30). Lighting unit according to claims 1-16, characterized in that each microshutter is constituted by a pivoting aperture element which can move back and forth between two positions, the pivoting aperture element being suspended so that elastic forces act against an equilibrium position between the two positions, and wherein the illumination unit further comprises a control unit for controlling the oscillating aperture element by electrostatic forces, the aperture element in one of the two positions blocking the microshutter light channel. Illumination unit according to claims 1-17, characterized in that the illumination unit between the microshutter arrangement and the illumination surface further comprises optical means (98) for spreading the light rays emitted by the light channels over the illumination surface. 30