FR3073839B1 - SYSTEM FOR ALIGNING A THERMAL TREATMENT DEVICE AND ITS OPERATION - Google Patents

Abstract

The present invention relates to a device for heat treatment (1) of a glass substrate (S), extending in a first direction and a second direction orthogonal to the first direction, comprising conveying means (2) of said glass substrate and heating means (10) for carrying out the heat treatment, characterized in that said heating means (10) comprise at least two laser generators (L) each generating a laser beam (F), said laser generators being arranged so that the beams together form a continuous laser line, said device further comprising an alignment system (100) arranged to detect at least a portion (f) of two contiguous laser beams and comprising a computing unit (130).

Description

SYSTEM FOR ALIGNING A THERMAL TREATMENT DEVICE AND ITS OPERATION

The present invention relates to the field of thin-film heat treatment on glass substrates.

PRIOR ART

It is known to carry out local and rapid laser annealing (laser flash heating) of coatings deposited on flat substrates. For this purpose, the substrate is scanned with the coating to be annealed under a laser line, or a laser line above the substrate carrying the coating.

Laser annealing is used to heat thin coatings at high temperatures, on the order of several hundred degrees, while preserving the underlying substrate. The scroll speeds are of course preferably the highest possible, preferably at least several meters per minute.

However, currently, there are laser lines of small sizes, less than 30 cm or monolithic lines up to 150 cm. There is also the possibility of creating a laser line by adding a multitude of laser lines of a few tens of centimeters each, to create a large laser line. However, the width of such a laser line is a few hundred microns.

It is therefore understood that the alignment of the different laser lines forming the line is important. This alignment is done during the installation of the line. Nevertheless, when the width of the laser line is less than 100 μm, the environmental disturbances are not negligible and disturb the alignment. It therefore becomes necessary to perform alignment adjustment operations. This adjustment of the alignment is done during the heating time of lasers or in the long term in case of disruption during production.

A disadvantage of these frequent adjustments is that they generate production inefficiency while mobilizing staff. Similarly, this generates losses because, since the conveying of the glass substrate is continuous, the misalignment is not detected immediately resulting in loss of substrate.

SUMMARY OF THE INVENTION

The present invention therefore proposes to solve these drawbacks by providing a heat treatment device which is provided with an alignment system which allows an automatic adjustment of the alignment of the lasers. To this end, the invention relates to a device for heat treatment of a glass substrate, extending in a first direction and a second direction orthogonal to the first direction, comprising means for conveying said glass substrate and heating means for performing the heat treatment, characterized in that said heating means comprise at least two laser generators each generating a laser beam, said laser generators being arranged so that the beams together form a continuous laser line, said device further comprising a laser system. alignment comprising means for detecting at least a portion of two contiguous laser beams and comprising a calculating unit for determining the alignment of the position of said two adjacent laser beams with respect to a reference position and sending a control command, and setting means receiving said adjustment command for modify said alignment.

According to one example, the alignment system comprises a reflector device arranged at the junction of two contiguous laser beams to reflect a portion of these two adjacent laser beams to an optical receiver, the reflector device and the optical receiver being arranged to be movable in translation.

In one example, the alignment system comprises a plurality of pairs each comprising a reflector device and an optical receiver, said reflector device being arranged at the junction of two contiguous laser beams to reflect a portion of these two contiguous laser beams towards said receiver optical.

In one example, the alignment system comprises a plurality of reflector devices arranged at the junction of two contiguous laser beams to reflect a portion of these two adjacent laser beams, a mobile optical receiver being arranged to translate to receive successively said portions contiguous laser beam.

According to one example, the alignment system comprises a multiplexer reflector device comprising a plurality of movable reflectors arranged at the junction of two contiguous laser beams to reflect a part of these two contiguous laser beams, each movable reflector being capable of taking at least one first position in which the beams are not reflected and a second position in which the beams are reflected, and an optical receiver arranged opposite one of the movable reflectors, the alignment system further comprising prisms or cube or blade or semi-reflecting mirror each arranged facing a movable reflector, a semi-reflective prism being interposed between a movable reflector and the optical receiver.

According to one example, each semi-reflecting prism comprises a first input face through which an incoming beam is transmitted to an output face which is the parallel face facing said first input face and a second input perpendicular face. at the first face through which an incoming beam is reflected towards said exit face, and in that the prism interposed between a movable reflector and the optical receiver is oriented so that the portion of the contiguous laser beams reflected by said movable reflector enters on the first input face, the prisms facing each of the other movable reflectors are oriented so that the portion of contiguous laser beams reflected by said movable reflector enters the second input face and that the exit face of these prisms is facing the second input face of the prism interposed between a movable reflector and the optical receiver.

In one example, the reference position is an absolute position.

In one example, the reference position is a relative position.

In one example, the relative position is the position of one of the beams.

In one example, the reflector devices are arranged under the glass substrate to be treated to reflect the portion of the beam F not used during the heat treatment to the optical receiver.

In one example, the reflector devices are arranged to be placed relative to the laser generators so as to direct the beams forming the laser line to the coating to be treated and to partially transmit a portion of the beams forming the laser line to the optical receiver. The invention further relates to a method of aligning a heat treatment device according to the invention, said method comprising the following steps: - detecting for each junction of two contiguous laser beams a portion of these two beams; determining, for each beam portion, the position of said beam on a reference mark; - Compare the position of each beam with respect to a reference position, - send a control signal for each of the laser generators, the latter being provided with adjustment means for changing the position of the laser beam. The invention also relates to a method for aligning a heat treatment device according to the invention, said method comprising, for each junction of two contiguous laser beams, the following steps: detecting a part of these two beams; determining, for each beam portion, the position of said beam on a reference mark; comparing the position of each beam with respect to a reference position, sending a control signal to the laser generators supplying the beams of the junction, the latter being provided with adjustment means making it possible to modify the position of the laser beam; and in that the different junctions are processed successively.

In one example, two successively processed junctions comprise a beam portion in common.

DESCRIPTION OF THE FIGURES Other particularities and advantages will become clear from the description which is given below, by way of indication and in no way limitative, with reference to the appended drawings, in which: FIG. 1 is a schematic representation of the heat treatment device according to the invention; -the figs. 2 and 3 are schematic representations of the alignment system according to the invention; FIG. 4 is a schematic representation of the pattern of an optical receiver of the heat treatment device according to the invention; FIG. 5 is a schematic representation of the pattern of an optical receiver of the heat treatment device according to a first embodiment of the alignment; -the figs. 6 and 7 are a schematic representation of the pattern of an optical receiver of the heat treatment device according to a second embodiment of the alignment; -the figs. 8 and 9 are variants of the alignment system of the invention;

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows the heat treatment device 1 of a glass substrate S according to the invention. The treated glass substrate S is, for example, a substrate of great width, such as a flat glass sheet of "jumbo" size (6 m × 3.21 m) emerging from flat or float glass processes.

This heat treatment device 1 comprises conveying means 2 for transporting the glass substrates S. Such conveying means 2 may be in the form of two parallel rails on which a frame provided with supports for the substrate are arranged. It can also be provided that the conveying means 2 are in the form of two parallel rails on which wheels are mounted allowing the substrate to be movable. Some wheels are then connected to a motor to allow the scrolling of the substrate. Similarly, the conveying can be done on a roller conveyor.

For a flat glass sheet jumbo size (6 m x 3.21 m), it will be expected that the conveying is done in a first direction extending in the greater of the two dimensions of the sheets. In the case of a "jumbo" size sheet (6 mx 3.21 m), it will be defined that the sheet has a length of 6 m and a width of 3.21 m and that the conveying means allow said glass sheet to move along its length.

The heat treatment device 1 further comprises heating means 10. These heating means 10 comprise a plurality of laser generators L. Each laser generator L can use solid-state laser or diode laser technology or a disk laser. presenting as the perfect combination of a solid-state laser with a diode laser allowing beam quality and superior performance.

The laser generators L each provide a beam F passing through an optical element to obtain a beam in the form of a line having a length ranging from 10 to 50 cm and a width less than or equal to 100 μm. These laser generators L are then arranged next to each other so that the beams add up to form a single line of great length.

In order to be able to adjust the alignment of these different beams and thus obtain a laser line as accurate as possible, the present invention advantageously comprises an alignment system 100.

The alignment system 100 according to a first embodiment of the invention comprises a plurality of optical devices 110 associated with at least one optical receiver 120.

Cleverly according to the invention, the reflector devices 110 also called attenuator devices are arranged to use a portion of two light beams F to allow their comparison. These reflector devices 110 are here partially reflecting mirrors M. For this, each mirror M partially reflecting is arranged at the junction between two beams F forming the line. In this way, it is possible to use a portion or fraction of the beam F of each of the two beams through an optical receiver 120 as visible in Figure 2. This optical receiver 120 is here a camera C comprising for example a sensor with charge-coupled device (CCD) whose principle is based on a field of photosites, small cells which accumulate the light individually, the color being then determined by an analog filter according to the received intensity. The arrangement of the mirrors M and the optical receiver 120 can be made according to several alternative embodiments.

In an alternative embodiment, the partially reflecting mirrors M are used to reflect a portion of two contiguous beams. Typically, this embodiment is such that the partially reflecting mirrors M are arranged under the glass substrate to be treated. The partially reflecting mirrors M are then used to reflect the part or the fraction of the beam F not used during the heat treatment of each of the two beams. This part of the beam F not used during the heat treatment, of lower power, is reflected to be directed towards the optical receiver 120.

In another alternative embodiment, the mirrors M are used to directly reflect the beams of the laser line, along its length, towards the target, that is to say the coating on glass substrate. These M partially reflecting mirrors M are then arranged to be placed relative to the laser generators so as to direct the beams forming the laser line to the coating to be treated. However, since these mirrors M are partially reflective, part of the beams forming the laser line is transmitted to the optical receiver 120.

In the two alternative embodiments, it is conceivable that the beam used for the determination of the alignment must be refocused on the receiver 120 by an EF lens or a curved mirror. Indeed, the use of a reflector may lengthen the optical path and thus shift the focal plane. Since two fractions / parts of beams are received by a single optical receiver 120, it is possible, with an appropriate algorithm, to determine, calculate whether the two beam fractions f are shifted relative to one another. .

In a first embodiment, the alignment system 100 will comprise a number of reflector devices 110 for having a reflector device 110 at each junction between two beams F and a receiver device 120 associated with each reflector device 110 as visible at Figure 3. The alignment system 100 further comprises a computing unit 130 to which the receiving devices 120 are connected. This computing unit 130 is responsible for collecting the data and then processing them and sending control signals.

Indeed, after a step of retrieving the information, a processing step occurs. This step consists of determining whether the alignment between the different beams F is present / realized. For this, each optical receiver 120 is provided with a pattern 121. This pattern 121 consists of a multitude of electrodes, each capable of detecting a light beam and its intensity. The center of the beam is characterized by its maximum intensity. Consequently, the computing unit 130 is able to detect the maximum intensity of the two beams reflected on the same optical receiver 120 and to determine the position of this maximum intensity on the target 121. In FIG. a pattern 121 and two beams f1, f2 are shown.

Once this processing step is performed, it is necessary to proceed to a determination step. This determination step is used to determine whether the detected beam is aligned or not.

According to a first solution, the alignment is determined with respect to a value or reference position ready. This ready reference position is previously defined. This ready reference position is transcribed on the photonic sensor grid forming the target 121 as shown in FIG.

Thus, the computing unit 130 is able to determine the offset between the position of the detected reflected beam and the ready reference position.

Following this determination, the computing unit 130 sends a signal to each laser generator L. Indeed, each laser generator L is provided with a setting device for adjusting the position of the beam in the form of a line. In this case, the adjustment of the laser generator is done so that the line can be "lowered" or "up" on the pattern 121 of the gate of the optical detector 120.

This adjustment operation is performed for each of the laser generators L. This operation can be performed in parallel since the alignment of the beams F of the laser generators L is relative to a single reference pref for all the beams.

According to a second solution, the alignment is relative. It is understood by relative alignment that the alignment is not operated according to an absolute position, fixed but relative to a point which may itself vary position. In this case, the alignment of the laser beams is made with respect to one of them.

For this, it is necessary to choose one of the beams f and to detect its position relative to the target 121 of the optical receiver 120. Once this positioning is determined, it is used as a reference for realigning the laser generators L The alignment process is then similar to that described previously, that is to say that the other beams f are detected and that their positioning is determined. Once the different positions have been detected, they are compared by the calculation unit 130. This calculation unit 130 therefore generates adjustment signals to modify the position of the laser generators L and to allow the alignment. These laser generators L are equipped with adjustment means (not shown).

According to a nonlimiting example, the reference beam will be one of the two beams located at the ends of the laser line. This preferential use of one of the two beams located at the ends of the laser line makes it possible to use the fact that the beams are detected two by two for the detection of the alignment. Indeed, this two-to-two detection makes it possible to use the setting of the preceding laser generator L for setting the next generator.

Taking the example of FIGS. 6 and 7, with a laser line formed using three beams, heating means 10 are obtained comprising three laser generators L1, L2, L3, the setting being made via two optical receivers 120 and two reflector devices 110. The laser generators L are arranged so that the laser generator L2 is central and surrounded by the laser generators L1 and L3. The reflector devices 110 are arranged to be placed between the laser generators L1 and L2 and between the laser generators L2 and L3.

In order to adjust the alignment of the laser line by taking the laser beam of the generator L1 as a reference, the procedure is as follows.

One starts, during a sequence A, by detecting the position of the beams F1, F2 of the laser generators L1 and L2. Then, the positional difference between the reflected beams f of the laser generators L1 and L2 is determined. The computing unit 130 then sends a control signal to the laser generator L2 so that its beam is aligned with the beam of the laser generator L1 as visible on the sequence B. Then, in this sequence B, the position of the beams of the beams is detected. L2 and L3 laser generators. The positional difference between the beams of the L2 and L3 laser generators is then determined. Since the beam of the laser generator L2 has already been set to be aligned with the beam of the laser generator L1, the computing unit 130 then sends a control signal to the laser generator L3 so that its beam is aligned with the laser beam. L2 laser generator as visible on the C sequence.

For previously presented solutions, it will be possible to have an additional and optional step of verification. This verification step is performed once the adjustment is made. This verification step consists of detecting the position of the beams F of the laser generators L and determining whether the alignment is correct.

Of course, both solutions can be combined. It will be understood that it is possible to adjust one of the beams of the laser line with respect to a predefined position pref and that the other beams of the line are adjusted with respect to this beam of the previously adjusted laser line.

In order to adjust the laser generators, the alignment system 100 comprises adjustment means 200 used for modifying the position of said laser generators and in particular for modifying the position of the laser lines.

In an exemplary embodiment, these adjustment means 200 comprise a rail system on which each laser generator is mounted. This rail system makes it possible to modify the position of the laser generator in order to modify the position of the beam that it emits.

In another example, the adjustment means consist of an optical system integrated in the laser generator. This optical system is partially mobile so that it is possible to orient the laser beam.

In another exemplary embodiment, the adjustment means comprise an articulated support. Such articulated support comprises a base or base plate fixed on a frame. The articulated support further comprises a fixing plate on which the laser generator L is fixed, for example, by bolting. The fixing plate is connected to the base plate by means of connection means for adjusting the position of the fixing plate. These connection means use micrometrically adjustable rails or jacks to modify the longitudinal, lateral or angular position of said fixing plate.

In a variant of the invention, the alignment system 100 comprises a single optical receiver 120. For this, the optical receiver 120 is associated with a multiplexer reflector device 110 'as can be seen in FIG. 8. Such a multiplexer reflector device 110 consists of an optical device for selecting a portion of two contiguous light beams among others to allow their comparison.

Such a multiplexer reflector device 110 'comprises, for example, movable mirrors M' each arranged to reflect a portion of two adjacent beams. These movable mirrors M 'are capable of taking at least two different positions, a first position being a rest position in which the beams are not reflected and a second position being a working position in which the beams are reflected. These movable mirrors M 'are advantageously placed under the glass substrate to reflect the part of the laser beam not used for the treatment.

Advantageously, the optical receiver 120 is placed opposite one of the moving mirrors M 'so that these moving mirrors M' reflect the beams directly on said optical receiver 120. To enable the detection of the other beams by said optical receiver 120, the device multiplexer reflector 110 'further comprises three semi-reflective prisms P. These semi-reflective prisms P are cubic and are in the form of two associated triangular prisms.

Each triangular prism comprises an entrance face and an oblique face, the two triangular prisms being glued by their oblique face. The two triangular prisms are glued so that the input faces are parallel to each other. A first semi-reflecting prism P is arranged between the optical receiver 120 and the moving mirror M 'facing said optical receiver 120. The two other prisms P are each arranged opposite one of the moving mirrors M'.

The various semi-reflecting prisms P are arranged to enable the beams reflected by the moving mirrors M 'to be directed towards the optical receiver 120. For this, the prisms P are placed to have the same orientation, that is to say that the junction line between the two triangular prisms forming the semi-reflective prism is oriented in the same way for all prisms.

These prisms P are arranged to allow, when a light beam enters through a first input face E1, the transmission of this light beam by an output face S which is the parallel face opposite and to allow, when a beam light enters a second input face E2 perpendicular to the first face, the reflection of the light beam by the parallel face facing the first face.

As a result, the light beam reflected by the moving mirror M 'arranged opposite the optical receiver 120 is transmitted by the prism P which it passes through, the light beams from the other moving mirrors M' are reflected by the prisms P, in look at the movable mirrors M 'from which they are coming, towards the prisms opposite the optical rector which reflects them towards said optical receiver.

Of course, it is conceivable that the beam used should be refocused by a lens during its extraction from the laser line.

In another variant comprising a single optical receiver visible in Figure 9, said optical receiver 120 and the single reflector device 110 are movable. The mobility of the optical receiver and the reflector device is in translation for example via rails 300. This makes it possible to detect different beams while limiting the number of elements constituting the device. To prevent deviations due to the translation movement, it will be provided that the computing unit 130 is used. Indeed, since the beams are compared in pairs, it becomes possible to detect a deviation from the translation by comparing the position of the same beam in two separate measurements.

Of course, the present invention is not limited to the illustrated example but is susceptible of various variations and modifications that will occur to those skilled in the art.

Claims (10)

1. Device for heat treatment (1) of a glass substrate (S) extending in a first direction and a second direction orthogonal to the first direction, said heat treatment device comprising means for conveying (2) said glass substrate and heating means (10) for carrying out the heat treatment, characterized in that said heating means (10) comprise at least two laser generators (L) each generating a laser beam (F), said laser generators being arranged so that the beams together form a continuous laser line, said apparatus further comprising an alignment system (100) including means for detecting at least a portion of two contiguous laser beams and a computing unit (130) for determining the alignment of the position of said two contiguous laser beams with respect to a reference position (ready) and sending an adjustment command, and setting means receiving (200) said adjustment command for modifying said alignment. The heat treatment device according to claim 1, wherein the alignment system (100) comprises a reflector device (110) arranged at the junction of two adjacent laser beams (F) for reflecting a portion of these two adjacent laser beams. to an optical receiver (120), the reflector device and the optical receiver being arranged to be movable in translation. The heat treatment device of claim 1, wherein the alignment system (100) comprises a plurality of pairs each comprising a reflector device (110) and an optical receiver (120), said reflector device being arranged at the junction a pair of adjacent laser beams (F) for reflecting a portion of these two contiguous laser beams to said optical receiver. The heat treatment device according to claim 1, wherein the alignment system (100) comprises a plurality of reflector devices (110) arranged at the junction of two contiguous laser beams to reflect a portion of these two adjacent laser beams, a mobile optical receiver (120) being arranged to translate to successively receive said contiguous laser beam portion. The heat treatment device according to claim 1, wherein the alignment system (100) comprises a multiplexer reflector device (110 ') comprising a plurality of movable reflectors (M') arranged at the junction of two contiguous laser beams for reflecting a portion of these two contiguous laser beams, each movable reflector (M ') being capable of taking at least a first position in which the beams are not reflected and a second position in which the beams are reflected, and an arranged optical receiver (120) facing one of the movable reflectors, the alignment system further comprising semi-reflective prisms (P) each arranged facing a movable reflector (M '), one of the semi-reflective prism being interposed between a movable reflector and the optical receiver. The heat treatment device according to claim 5, wherein each semi-reflective prism (P) comprises a first input face (E1) through which an incoming beam is transmitted to an output face (S) which is the parallel face. opposite said first input face and a second input face (E2) perpendicular to the first face through which an incoming beam is reflected towards said output face, and in that the prism (P) interposed between a reflector mobile (M ') and the optical receiver (120) is oriented so that the portion of the contiguous laser beams reflected by said movable reflector enters on the first input face, the prisms (P) facing each of the other movable reflectors ( M ') are oriented so that the portion of the contiguous laser beams reflected by said movable reflector enters the second input face and that the exit face of these prisms is opposite the second prism input face interposed between a movable reflector and the optical receiver. 7 heat treatment device according to one of the preceding claims, wherein the reference position (ready) is an absolute position. 8 heat treatment device according to one of claims 1 to 6, wherein the reference position (ready) is a relative position. The heat treatment device of claim 8, wherein the relative position is the position of one of the beams. 10 heat treatment device according to one of the preceding claims, wherein the reflector devices (110, 110 ') are arranged under the glass substrate to be treated to reflect the portion of the beam F not used during the heat treatment to the optical receiver (120). 11 heat treatment device according to one of claims 1 to 4, wherein the reflector devices (110) are arranged to be placed relative to the laser generators so as to direct the beams forming the laser line to the coating to be treated and transmit partially part of the beams forming the laser line to the optical receiver (120). 12. A method of aligning a heat treatment device according to one of the preceding claims, said method comprising the steps of: - detecting, for each junction of two contiguous laser beams (F), a portion of these two beams by through an alignment system; - determining, for each beam portion, the position of said beam on a marker by means of a calculation unit (130); - Compare the position of each beam with respect to a reference position, - Generate and send a control signal to the adjustment means (200) of each laser generator (L), to change the position of the laser beam. 13. A method of aligning a heat treatment device according to one of claims 1 to 11, said method comprising, for each junction of two contiguous laser beams, the following steps: - detect a portion of these two beams; determining, for each beam portion, the position of said beam on a reference mark; comparing the position of each beam with respect to a reference position, sending a control signal to the laser generators supplying the beams of the junction, the latter being provided with adjustment means making it possible to modify the position of the laser beam; and in that the different junctions are processed successively. The method of aligning a heat treatment device according to claim 13, wherein two successively processed junctions comprise a common beam portion. 15. The method of aligning a heat treatment device according to claim 13, wherein the reference position is a predefined position. The method of aligning a heat treatment device according to claim 13, wherein the reference position is selected from one of the beam portions of the laser line.