Holding device for optical elements

Abstract

The invention relates to a device (100, 101, 102, 103, 104, 105, 106, 107) for holding a plurality of optical elements (10) to be measured in a measurement system using a measurement beam, the device comprising: - a first support element (2) having a plurality of openings (3) arranged in a measurement plane and configured to receive the plurality of optical elements (10), the first support element (2) being configured to hold the plurality of optical elements (10) during their movement; - a second support element (4) configured to receive the plurality of optical elements (10) during the measurement step, the second support element (4) being used as a measurement reference plane.

Description

[0001] Holding device for optical elements

[0002] Technical field

[0003] The present invention relates to a holding device for optical elements to be measured in a measuring device.

[0004] The field of the invention is, in a non-limiting manner, that of optical control and measurement systems.

[0005] State of the art

[0006] Mass production of optical elements, such as lenses or objectives, for example to manufacture camera modules, may require handling these elements or supports containing them, in order to carry out manufacturing steps (for example the deposition of an anti-reflection layer), or to carry out control steps (for example dimensional geometry, or quality of optical transmission).

[0007] It is then necessary to ensure very precise positioning of these optical elements, for example during an optical geometry measurement phase, in particular in terms of the inclination of the optical element and also centering in a plane to be able to pass an optical beam through the optical axis of these elements, for example. The elements to be measured are generally moved in baskets produced by low-cost techniques, for example stamping a plastic sheet, but which do not ensure very precise positioning of said elements, in particular in terms of attitude. The movement of the optical elements from said basket to a collective support ensuring a reference positioning comprises, for its part, two loading and unloading steps before and after the measurement which generate additional cost and time in the context of mass production. Presentation of the invention

[0008] An aim of the present invention is to overcome these drawbacks.

[0009] It is in particular an object of the invention to propose a holding device for positioning and holding in place optical elements to be measured in a measuring device.

[0010] Another aim of the present invention is to propose a holding device allowing the collective movement of the optical elements to be measured.

[0011] It is also an object of the present invention to propose a holding device for holding the optical elements in a position known a priori for each optical element, in a measurement plane.

[0012] At least one of these aims is achieved with a device for holding a plurality of optical elements to be measured in a measuring apparatus implementing a measuring beam, the device comprising: a first support element having a plurality of openings arranged in a measuring plane and configured to receive the plurality of optical elements, the first support element being configured to hold the plurality of optical elements during their movement, a second support element configured to receive the plurality of optical elements during the measurement, the second support element representing a measurement reference plane.

[0013] In the context of the present invention, an “optical element” may designate any type of optical object, intended for example to be inserted into an optical beam, to shape an optical beam, and / or to produce an image. It may designate for example:

[0014] - a single optical component such as an individual lens; - an assembly of lenses and / or other optical components, such as an imaging lens, camera lens, or optical beam shaping device.

[0015] An optical element may in particular consist of, or include, refractive elements such as lenses.

[0016] The device according to the present invention makes it possible, firstly, to collectively transport or move a plurality of optical elements to or into a measuring apparatus and, secondly, to collectively hold or support them in a desired position in the measuring apparatus so that they can be measured. The device according to the invention is therefore a device for holding, or supporting, a plurality of optical elements during their movement and measurement in a measuring apparatus.

[0017] The device according to the invention thus makes it possible to collectively measure several optical elements, avoiding errors in the positioning of these optical elements in a measuring device. The optical elements can thus be correctly positioned in terms of attitude inclination and centering in a plane called X,Y perpendicular to an axis called Z. Thus, it is possible to orient in a known manner an optical measurement beam relative to the plane X,Y, for example along an axis equal to or close to the axis Z, and therefore perpendicular to X,Y, or even significantly differently. Once the plurality of optical elements are placed in the desired position, the measurements on all the elements can be carried out without it being necessary to reposition them between measurements.Alternatively, the optical elements may be moved with the device between or during measurements, these mechanical movements not degrading knowledge of the positioning of the optical elements relative to the first support element or relative to a reference frame of the measuring device.

[0018] In addition, the device according to the invention allows said optical elements, lenses or objectives, to be loaded and unloaded very quickly into the measuring equipment or apparatus. It avoids having to transfer the elements to be tested out of it. The device according to the invention can be manufactured using standard technology, with low manufacturing precision, because the precision of the measurements carried out on the optical elements is decoupled. The optical elements are held in a position known a priori for each optical element, in a horizontal plane, with a reduced positioning tolerance. Thus, the cost of implementing the device is very low, independently of the quality of the measurements generated.

[0019] The device also makes it possible to block possible micro-displacements of the optical elements to be measured during possible movements of the entire measuring device, or vibrations of the latter.

[0020] When implementing the device according to the invention, during the measurement or metrological phase, the optical elements rest on the second support element which constitutes a reference plane for the measurements.

[0021] The second support element is not necessarily integral with the first support element and may be separated from it, for example during the loading or unloading phases of the optical elements.

[0022] The device according to the invention can in particular be implemented in a metrology machine for geometry and / or final quality measurements (measurements of the MTF, of the point spread function (PSF for point spread function according to Anglo-Saxon terminology), etc.).

[0023] Advantageously, the device may further comprise a third support element, configured to hold the plurality of optical elements against the second support element during measurement.

[0024] The third support element may correspond to an additional reference plane.

[0025] The second and / or third support element may be made of a material transparent to the measurement beam. According to an advantageous embodiment, the third support element may comprise a stabilizing plate configured to press the plurality of optical elements against the reference plane.

[0026] The stabilizing plate helps stabilize the position of the optical elements during measurement. The stabilizing plate can also serve as a reference plane for measurements.

[0027] According to one embodiment, the second support element and / or the third support element may comprise a flexible sheet configured to bear between the second support element respectively the third support element and the optical elements during the measurement.

[0028] The flexible sheet may have openings at the openings of the first support element, allowing measurement beams to pass through.

[0029] According to one embodiment, the third support element may comprise non-deformable zones and deformable zones, the deformable zones being configured to bear against the optical elements.

[0030] The second support element and / or the third support element may have openings at the openings of the first support element, allowing measurement beams to pass through.

[0031] According to embodiments, the first and / or the second support element can be produced by 3D printing or by plastic injection.

[0032] The device according to the present invention can in particular be implemented in the context of the production of optical elements, for example to produce camera modules for smartphones, for digital tablets, computers, webcams, etc.

[0033] The device according to the invention can also be used in the context of mass production of camera modules usable in automobiles, for example as driver assistance or to power autonomous piloting systems, or for taking images or piloting flying systems such as airplanes, drones, helicopters, etc.

[0034] The device according to the invention can also be used to control optical elements used in medicine, such as those used in endoscopes, or even camera modules for video surveillance.

[0035] Of course, these application examples are in no way limiting.

[0036] Description of figures and embodiments

[0037] Other advantages and characteristics will appear on examining the detailed description of non-limiting examples, and the appended drawings in which: Figures 1 to 8 are schematic representations of a holding device according to embodiments of the invention.

[0038] It is understood that the embodiments which will be described below are in no way limiting. In particular, it is possible to imagine variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection includes at least one preferably functional characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0039] In the figures, elements common to several figures retain the same reference.

[0040] Subsequently, embodiments of a holding device according to the invention will be described with reference to the Figures. The device according to the invention may be in particular in a first configuration called transport or movement, when optical elements to be measured are transported or moved with the device, as well as in a second configuration called measurement, when the optical elements are placed in or on a measuring device to be measured.

[0041] In Figures 1 to 5 and 7, the first part of Figure (a) represents the transport configuration, and the second part of Figure (b) represents the measurement configuration of the device according to the invention.

[0042] Figure 1 is a schematic representation of a sectional view of a holding device according to one embodiment of the invention.

[0043] The device 100, shown in Figures 1a and 1b, comprises a first support element 2. The first support element 2 comprises a plurality of openings 3. This first support element 2 may in particular be in the form of a plate or a basket with holes.

[0044] When the device 100 is implemented in a measuring apparatus and the optical elements are measured, the first support element 2 is positioned such that the openings 3 are arranged in a measuring plane of the apparatus.

[0045] The device 100 according to the invention also comprises a second support element 4. This is a flat element on which the optical elements can be placed, in particular during the measurement. The second support element 4 thus constitutes a reference plane for the measurement.

[0046] The optical elements to be measured can be placed in the openings 3. In the embodiment shown in Figures 1a and 1b, the optical elements 10 to be measured are objectives with a shoulder 11.

[0047] In Figure 1a, the device 100 according to the embodiment and optical elements 10 are shown during transport or movement of the optical elements. The lenses 10 are respectively held in the first support element 2 by the support of the shoulder 11 on the edge of the openings 3. The lenses 10 are not placed on the second support element 4.

[0048] In Figure 1b, the device 100 according to the embodiment and the optical elements 10 are shown when the optical elements 10 are placed on the second support element 4. In this case, the lenses 10 are not held in the openings 3. By being positioned on the second support element 4 which constitutes a reference plane, the optical elements 10 can be measured by the measuring device.

[0049] Figure 2 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0050] In addition to the components of the device 100 shown in relation to Figure 1, the device 101 according to the embodiment shown in Figures 2a and 2b comprises a stabilizing element 5. The stabilizing element 5, or support element, has the form of a plate or a blade. It is arranged on the opposite side of the second support element 4. It is intended to come to bear against the optical elements 10 to be measured during the measurement, the optical elements 10 then being placed on the second support element 4.

[0051] The stabilizing element 5 may constitute an additional optical reference plane for the measurements. The stabilizing element 5 is preferably made of transparent material, in particular when a measuring beam must pass through it to measure the optical elements 10.

[0052] Of course, the stabilizing element 5 can also be made of opaque material.

[0053] As shown in Figures 2a and 2b, the stabilizing element may be equipped with an elastic plate, or flexible sheet, 6 arranged on the side of the optical elements 10 to be measured. The elastic plate 6 is slightly compressed when the stabilizing element 5 is in abutment against the optical elements 10. Preferably and as shown in Figures 2a and 2b, the elastic plate 6 has openings 7 at the level of the openings 3 of the first support element 2.

[0054] Figure 3 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0055] The device 102 according to the embodiment shown in Figures 3a and 3b comprises all the components of the device 101 according to Figure 2. However, the stabilizing element, or plate, 5' comprises openings 8 at the level of the openings 3 of the first support element 2. The openings 8 of the stabilizing element 5' coincide with the openings 7 of the elastic plate.

[0056] The optical elements 10 can thus be measured by a measuring beam coming from the top of the Figure.

[0057] Figure 4 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0058] In addition to the components of the device 100 shown in relation to Figure 1, the device 103 according to the embodiment shown in Figures 4a and 4b comprises a semi-flexible stabilizing element, or plate 12. The semi-flexible element 12 comprises hard zones and soft or deformable zones 13, the latter being located at the locations or openings 3 for the optical elements 10 of the first support element 2.

[0059] The flexible or deformable zones 13 allow, in the measurement configuration, to lightly press the optical elements 10 against the second support element 4. The pressure on the optical elements 10 is regulated by the deformation of the flexible zones 13 when they are pressed on the edges of the optical elements, respectively.

[0060] The semi-flexible stabilizing element 12 can advantageously replace the support plates 5, 5' described in other embodiments of the device.

[0061] Figure 5 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0062] The device 104 according to the embodiment shown in Figures 5a and 5b comprises all the components of the device 102 according to Figure 3. However, the second support element 4 also comprises openings 11 at the level of the openings 3 of the first support element.

[0063] The optical elements 10 can thus be measured by a measuring beam coming from the top or bottom of the Figure.

[0064] Subsequently, holding devices will be presented according to different embodiments particularly adapted for holding and moving optical elements of which a wider part is oriented downwards and a narrower part is oriented upwards.

[0065] Figure 6 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0066] The device 105 according to the embodiment shown in Figure 4 includes all the components of the device 104 according to Figure 5.

[0067] The device 105 is shown in the measurement configuration. The device 105 further comprises a semi-flexible sheet or plate 9. The semi-flexible plate 9 is arranged on the second support element 4, on the side of the first support element 2. The plate 9 essentially serves to hold the optical elements 10 in place during transport.

[0068] The plate 9 is secured to the support element 2. The securing can be achieved, for example, by glue dots at locations between the locations for the optical elements. The glue dots must be far from the optical elements 10 to avoid any traces of glue in the location areas for the optical elements 10.

[0069] During the measurement of the optical elements 10, the latter are placed on the second support element 4. The flexibility of the plate 9 allows the second support element 4 to represent the position reference. For this, the pressure of the stabilizing plate 5' applies pressure to the elements to be measured 10, keeping the plate 9 strictly in contact with the support element 4.

[0070] During the transport of the optical elements 10, the latter are held by the plate 9. The plate 9 - first support element 2 assembly supports the optical elements 10 during movement.

[0071] Figure 7 is a schematic representation of a sectional view of a holding device according to another embodiment of the invention.

[0072] The device 106, as shown in Figures 7a and 7b, further comprises a holding member 14 configured to hold the optical elements 10 in place in the openings 3 during transport or movement thereof. The holding member 14 preferably consists of a single piece. As illustrated in Figure 7, the holding member 14 is a shiftable plate with openings 15. The holding plate 14 is attached to the first support member 2 by means of a fastening mechanism. This fixing mechanism may be a screw 19 screwed into the element 2, the screw head of which allows the holding plate 14 to be secured to the support element 2 in the vertical direction of Figure 7. The screw is however not blocked to allow the holding plate 14 to slide horizontally along slides 20 secured to the holding plate 14. The screw 19 is wedged by friction in the first support element 2 to remain in place.This degree of freedom of the holding plate 14 relative to the first support element 2 makes it possible to shift the holding plate 14 in a horizontal direction by a distance corresponding to a lateral dimension of an optical element 10.

[0073] Preferably, the openings 15 in the plate 14 have chamfers, making it easier to slide the plate 14 under the optical elements 10 placed on the second support element 4.

[0074] When the device 106 is in the transport configuration (Figure 7a), the holding plate 14 is in a closed position, in which the openings 3 of the first support element 2 are closed by the plate 14. The optical elements 10 are held in place in the openings 3 of the support element 2.

[0075] When implementing the measurement configuration of the device 106, the optical elements 10 are no longer held by the holding plate 14 and are thus freely supported on the reference plate 4.

[0076] Figure 8 is a schematic representation of a sectional view of a holding device according to yet another embodiment of the invention.

[0077] The device 107, as shown in Figure 8, comprises a perforated plate 16 for accommodating the optical elements 10 during transport and during measurement of the optical elements.

[0078] Device 107 is shown in the measurement configuration.

[0079] The drilled plate 16 does not need to be offset to take the measurements.

[0080] For the displacement configuration of the device 107, a removable connection (not shown) must be provided between the pierced plate 16 and the first support element 2. The connection may be a removable fixing mechanism.

[0081] In the embodiment of the device 107 according to Figure 8, the first support element 2 can be configured to exert by its weight a pressure on the optical elements to be measured 10, in addition to the weight of the optical elements 10 themselves. Thus, a support plate as shown in Figures 2 to 7 (element 5 or 5') is not necessary. In addition, the first support element 2 ensures that the optical elements 10 are held on the pierced plate 16 during movement, thanks to the complementary shape of the openings 3 at the shoulders of the optical elements 10.

[0082] Of course, other additional holding elements can be provided in the device, such as a removable or retractable plate to hold the optical elements when transporting the device.

[0083] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

Claims

CLAIMS 1. Device for holding (100, 101, 102, 103, 104, 105, 106, 107) a plurality of optical elements (10) to be measured in a measuring apparatus implementing a measuring beam, the device comprising: a first support element (2) having a plurality of openings (3) arranged in a measuring plane and configured to receive the plurality of optical elements (10), the first support element (2) being configured to hold the plurality of optical elements (10) during their movement, a second support element (4) configured to receive the plurality of optical elements (10) during the measurement, the second support element (4) representing a measurement reference plane.

2. Device (100, 101, 102, 103, 104, 105, 106, 107) according to claim 1, characterized in that it further comprises a third support element (5, 12), configured to hold the plurality of optical elements (10) against the second support element (4) during the measurement.

3. Device (100, 101, 102, 103, 104, 105, 106, 107) according to claim 1 or 2, characterized in that the second support element (4) and / or the third support element (5, 12) comprise a flexible sheet (6, 9) configured to bear between the second support element respectively the third support element and the optical elements (10) during the measurement.

4. Device (100, 101, 102, 103, 104, 105, 106, 107) according to claim 3, characterized in that the flexible sheet (6, 9) has openings (7) at the level of the openings (3) of the first support element (2).

5. Device (100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, characterized in that the second and / or the third support element are made of a material transparent to the measuring beam.

6. Device (100, 101, 102, 103, 104, 105, 106, 107) according to any one of claims 2 to 5, characterized in that the third support element (5, 12) comprises non-deformable zones and deformable zones (13), the deformable zones (13) being configured to bear against the optical elements (10).

7. Device (100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, characterized in that the second support element and / or the third support element has openings (8, 17) at the level of the openings (3) of the first support element (2).

8. Device (100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, characterized in that the first and / or the second support element are produced by 3D printing or by plastic injection.

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