Rear light device, assembly forming a modular zoom, and method for changing the zoom of a camera lens - Patents.com

Abstract

A rear light device (14A, 14B) intended to form an image in response to a light flux captured by a front light device (12) is disclosed, the rear light device (14A, 14B) comprising: a housing (22A, 22B) comprising a sensor (26A, 26B) defining an image format; - coupling units (24A, 24B) formed from nuts (30A, 30B) intended to detachably couple the housings (22A, 22B) to the front optical device (12) to form the zooms (18A, 18B); Equipped with.

Description

[Technical Field]

[0001] The present invention relates to a rear light device intended to form an image based on the light flux captured by a front light device, an assembly forming a modular zoom, and a method for changing the zoom of a camera lens. [Background technology]

[0002] Generally, the zoom of a motion picture camera lens is adapted to be used with a particular sensor size to provide an image in a given format.

[0003] Accessories such as converters can be configured to accommodate zooming to produce images in other formats.

[0004] However, using such a converter results in a significant loss of quality and also in an increase in capacity.

[0005] To overcome these drawbacks, it is known, in particular from document FR3060771A1, to use a modular optical system comprising a front optical device designed to capture a light beam and a number of rear optical devices, each intended to form an image in a given format based on the light beam captured by the front optical device. The combination of a common front optical device and a rear optical device forms a zoom adapted to a specific image format.

[0006] Each rear optical device is made up of a number of sub-elements, including a housing with an image format specific sensor, an iris diaphragm, an indexing ring, a focus engraving ring, and a focus ring.

[0007] However, changing a zoom lens adapted to one specific format to another is relatively complicated. For example, it is necessary to disassemble the sub-elements that form the first rear optical device and reassemble the sub-elements that form the second rear optical device. These disassembly and assembly operations must be performed in a precise order and generally require many specialized tools.

[0008] These operations are therefore generally redundant and must be performed in dedicated service centers. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] FR3060771A1 Summary of the Invention [Problem to be solved by the invention]

[0010] One of the aims of the present invention is to improve this solution and provide an optical assembly that allows changing the image format easily, quickly and without the use of specific tools, while maintaining good image quality. [Means for solving the problem]

[0011] For this purpose, the invention proposes a rear light device intended to form an image on the basis of the light flux captured by the front light device, the rear light device comprising: a housing comprising a sensor defining an image format; a coupling unit formed from a nut intended to detachably couple the housing to a front optical device to form a zoom; Equipped with.

[0012] According to a particular mode of implementation, the nut is a notched nut.

[0013] The invention also relates to an assembly forming a modular zoom, the assembly comprising: a front light device designed to capture a luminous flux; - a first rear optical device as previously mentioned, the first rear optical device forming a first zoom by coupling the first rear optical device and the front optical device by a nut; - a second rear optical device as previously mentioned, wherein coupling of the second rear optical device and the front optical device by a nut forms a second zoom; Equipped with.

[0014] According to a particular mode of implementation, the assembly comprises one or more of the following optional features, taken individually or in any technically possible combination: - the image format of the sensor of the first rear optical device is different from that of the second rear optical device; - the front optical device comprises an iris diaphragm and an alignment ring designed to adjust the opening of the diaphragm, the iris diaphragm and the alignment ring being common to the first zoom and the second zoom; - in a first zoom, the aperture of the front optical device is at a first distance from the sensor of the first rear optical device, and in a second zoom, the aperture of the front optical device is at a second distance from the sensor of the second rear optical device, the first distance and the second distance being substantially equal; - the alignment ring is movable between a first configuration adapted to adjust the aperture opening of a first zoom and a second configuration adapted to adjust the aperture opening of a second zoom; - the front optical device comprises a focus ring, the focus ring being common to the first zoom and the second zoom, the focus ring being movable between a first configuration suitable for adjusting the focal length of the first zoom and a second configuration suitable for adjusting the focal length of the second zoom.

[0015] The present invention also relates to a method for changing the zoom of a camera lens, the method comprising the steps of: - providing the above assembly, wherein the front optical device is coupled to a first rear optical device to form a first zoom; - rotating a nut of the first rear optical device to release the first rear optical device from the front optical device; - placing a second rear optical device on the front optical device and rotating a nut of the second rear optical device to couple the front optical device to the second rear optical device to form a second zoom; Includes.

[0016] According to a particular implementation mode, the front optical device comprises an iris diaphragm and an alignment ring, and the method comprises the further step of rotating the alignment ring of the front optical device from a first configuration adapted to adjust the aperture opening of the first zoom to a second configuration adapted to adjust the aperture opening of the second zoom, and / or the front optical device comprises a focus etched ring, and the method comprises the further step of moving the focus etched ring of the front optical device from a first configuration adapted to adjust the focal length of the first zoom to a second configuration adapted to adjust the focal length of the second zoom.

[0017] The invention and its advantages will be better understood on reading the following description, given purely by way of non-limiting example and made with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of an assembly forming a modular zoom according to the present invention; [Figure 2] FIG. 2 is a schematic diagram of a first zoom formed by the assembly of FIG. 1; [Figure 3] FIG. 2 is a schematic diagram of a second zoom formed by the assembly of FIG. 1; DETAILED DESCRIPTION OF THE INVENTION

[0019] FIG. 1 shows an assembly 10 for forming a modular zoom, particularly a cinema camera lens zoom.

[0020] The assembly 10 comprises a front light device 12 designed to capture a light beam, a first rear light device 14A, and a second rear light device 14B.

[0021] The assembly 10 combines the front optical device 12 and the first rear optical device 14A to form the first zoom 18A shown in FIG.

[0022] In the first zoom 18A, the first rear optical device 14A is arranged contiguously with the front optical device 12, for example along the longitudinal axis XX' (corresponding to the optical axis).

[0023] The first zoom 18A is adapted to provide an image in a first image format, for example, the FF format (which is the English abbreviation for "Full Frame").

[0024] The assembly 10 also forms a second zoom 18B shown in FIG. 3 by combining the front optical device 12 and a second rear optical device 14B.

[0025] In the second zoom 18B, the second rear optical device 14B is arranged contiguously with the front optical device 12, for example along the longitudinal axis XX'.

[0026] The second zoom 18B is, for example, adapted to provide images in a second image format.

[0027] The second image format is preferably different from the first image format, for example the S35 image format.

[0028] Alternatively, the first image format and the second image format may be, for example, 24.89 x 18.6 mm. 2 S35 image format, 24 x 36 mm, corresponding to the sensor size of 2 FF image format corresponding to the sensor size of 22 x 316 mm 2 The format is selected from academic 35mm formats corresponding to the sensor size.

[0029] First, the first rear optical device 14A and the second rear optical device 14B will be described in more detail.

[0030] Each of the first rear light device 14 A and the second rear light device 14 B is intended to form an image resulting from the light beam captured by the front light device 12 .

[0031] More specifically, the first rear light device 14A is intended to form an image in a first image format, such as, for example, the FF format, and the second rear light device 14B is intended to form an image in a second image format, such as, for example, the S35 image format.

[0032] Each of the first rear light device 14A and the second rear light device 14B includes a housing 22A, 22B and a coupling unit 24A, 24B.

[0033] The housings 22A, 22B of the first rear light device 14A and the second rear light device 14B, respectively, preferably comprise, for example, outer walls 21A, 21B, advantageously defining housings 23A, 23B of a shape of revolution around a longitudinal axis X-X'.

[0034] The housings 22A, 22B of the first and second rear light devices 14A, 14B, respectively, include sensors 26A, 26B that define an image format.

[0035] Each sensor 26A, 26B is preferably housed in a corresponding housing 23A, 23B, for example at a longitudinal end of the housing 22A, 22B.

[0036] More specifically, each sensor 26A, 26B is a digital sensor having a substantially rectangular shape, the size of which, for example, defines the corresponding image format.

[0037] For example, the image format of the sensor 26A of the first rear light device 14A is different from that of the second rear light device 14B.

[0038] In particular, the sensor 26A of the first rear light device 14A defines a first image format.

[0039] If the first image format is the FF format, the sensor 26A of the first rear light device 14A has, for example, a rectangular shape with a length equal to 36 mm and a width equal to 24 mm.

[0040] In particular, the sensor 26B of the second rear light device 14B defines a second image format.

[0041] If the second image format is the S35 format, the sensor 26B of the second rear light device 14B has, for example, a rectangular shape with a length equal to 24.89 mm and a width equal to 18.6 mm.

[0042] The respective housings 22A, 22B of the first rear light device 14A and the second rear light device 14B also advantageously comprise optical elements 28A, 28B, in particular fixed lenses housed in the corresponding housings 23A, 23B.

[0043] The coupling units 24A, 24B of the first rear optical device 14A and the second rear optical device 14B, respectively, are intended to removably couple said housings 22A, 22B to the front optical device 12 to form zooms 18A, 18B.

[0044] More specifically, the coupling unit 24A of the first rear optical device 14A is intended to detachably couple the housing 22A of the first rear optical device 14A to the front optical device 12 to form the first zoom 18A shown in FIG. 2.

[0045] Similarly, the coupling unit 24B of the second rear optical device 14B is intended to removably couple the housing 22B of the second rear optical device 14B to the front optical device 12 to form the second zoom 18B shown in FIG. 3.

[0046] The coupling units 24A, 24B of the first rear optical device 14A and the second rear optical device 14B, respectively, are formed from nuts 30A, 30B.

[0047] Advantageously, the coupling units 24A, 24B of the first rear optical device 14A and the second rear optical device 14B, respectively, comprise only said nuts 30A, 30B.

[0048] More specifically, the coupling units 24A, 24B of the first rear light device 14A and the second rear light device 14B, respectively, do not include screws, and therefore coupling is achieved without the use of screws.

[0049] As shown, each nut 30A, 30B extends, for example, around a portion of the outer wall 21A, 21B of the corresponding housing 22A, 22B.

[0050] Preferably, each nut 30A, 30B is rotatable around said outer wall 21A, 21B of the housing 22A, 22B, for example between a locked position and a free position.

[0051] Advantageously, each nut 30A, 30B is a knurled nut.

[0052] In other words, each nut 30A, 30B includes an outer surface that exhibits an alternating arrangement of knurls and grooves to facilitate gripping and turning of the nut 30A, 30B.

[0053] The front optical device 12 and its interaction with each of the first and second rear optical devices 14A, 14B will now be described more specifically.

[0054] The front light device 12 comprises, for example, a housing 34 comprising an outer wall 36 that defines a housing 38, in particular a shape of revolution of the housing 38 around a longitudinal axis XX'.

[0055] The front optical device 12 preferably comprises at least one coupling element 40 designed to cooperate with the nuts 30A, 30B of the first rear optical device 14A and the second rear optical device 14B, respectively.

[0056] The coupling element 40 is configured, for example, on the outer wall 36 of the housing 34 .

[0057] In particular, the coupling of the first rear optical device 14A and the front optical device 12 by the nut 30A forms the first zoom 18A.

[0058] More precisely, the coupling element 40 of the front optical device 12 cooperates with the nut 30A of the first rear optical device 14A in its locked position, for example by geometric cooperation, to fix the housing 22A of the first rear optical device 14A on the front optical device 12, forming the first zoom 18A shown in Figure 2.

[0059] Similarly, coupling of the second rear optical device 14B and the front optical device 12 by a nut 30B forms a second zoom 18B.

[0060] More precisely, the coupling element 40 of the front optical device 12 cooperates with the nut 30B of the second rear optical device 14B in its locked position, for example by geometric cooperation, to fix the housing 22B of the second rear optical device 14AB on the front optical device 12, forming the second zoom 18B shown in Figure 3.

[0061] The front light device 12 preferably comprises optical elements (not shown) designed to capture a light beam, such as at least one group of movable lenses housed in a housing 38 .

[0062] Advantageously, the front optical device 12 comprises an iris diaphragm 42 and an alignment ring 44 designed to adjust the opening of the diaphragm 42 .

[0063] Preferably, as can be seen in the figure, the iris diaphragm 42 and alignment ring 44 are common to the first zoom 18A and the second zoom 18B.

[0064] In particular, in the first zoom 18A shown in FIG. 2, the aperture 42 of the front optical device 12 is a first distance D from the sensor 26A of the first rear optical device 14A. A The first distance D A is preferably measured along the longitudinal axis X-X'.

[0065] Similarly, in the second zoom 18B shown in FIG. 3, the aperture 42 of the front optical device 12 is a second distance D from the sensor 26B of the second rear optical device 14B. B The second distance D B is preferably measured along the longitudinal axis X-X'.

[0066] Advantageously, the first distance D A and the second distance D B are substantially equal, and therefore the capacities of the first zoom 18A and the second zoom 18B are substantially identical.

[0067] In other words, the first distance DA and the second distance D B Preferably, the difference between is less than 0.05 mm.

[0068] To this end, the optical elements 28A, 28B of the first rear optical device 14A and the second rear optical device 14B, respectively, are advantageously spaced apart from each other by a first distance D A and the second distance D B The device is configured to allow this uniformity between

[0069] Preferably, alignment ring 44 is movable between a first configuration shown in FIG. 2 and a second configuration shown in FIGS.

[0070] For example, alignment ring 44 is rotatable about longitudinal axis XX' relative to housing 34, eg, by a 180° rotation, between a first configuration and a second configuration.

[0071] In its first configuration, shown in FIG. 2, the alignment ring 44 is adapted to adjust the opening of the aperture 42 of the first zoom 18A.

[0072] In particular, in its first configuration, alignment ring 44 exposes first alignment inscriptions 46 that are specific to a first image format.

[0073] Each first alignment marking 46 defines a specific opening of the aperture 42 that is adapted, for example, to the first image format defined by the first zoom 18A and in particular to the size of the sensor 26A of the first rear optical device 14A.

[0074] For example, alignment ring 44 includes a first window 48 that allows first alignment inscription 46 to be visible only in the first configuration of alignment ring 44 .

[0075] In its second configuration, shown in FIG. 3, the alignment ring 44 is adapted to adjust the opening of the aperture 42 of the second zoom 18B.

[0076] In particular, in its second configuration, the alignment ring 44 makes visible second alignment inscriptions 50 specific to the second image format. Each second alignment inscription 50 defines a specific opening of the iris 42 adapted to the second image format defined, for example, by the second zoom 18B, and particularly adapted to the size of the sensor 26B of the second rear light device 14B.

[0077] For example, alignment ring 44 includes a second window 52 that allows second alignment inscription 50 to be visible only in the second configuration of alignment ring 44 .

[0078] Advantageously, the front optical device 12 also comprises a focus ring 54 .

[0079] Preferably, as can be seen, the focus ring 54 is common to the first zoom 18A and the second zoom 18B.

[0080] Preferably, the focus ring 54 is movable between a first configuration shown in FIG. 2 and a second configuration shown in FIG.

[0081] For example, the focal line engraved ring 54 is movable parallel to the longitudinal axis XX' relative to the housing 34 between its first configuration and its second configuration.

[0082] In its first configuration shown in FIG. 2, the focus ring 54 is adapted to adjust the focal length of the first zoom 18A.

[0083] In its second configuration shown in FIG. 3, the focus ring 54 is adapted to adjust the focal length of the second zoom 18B.

[0084] Advantageously, the front light device 12 also comprises a focus ring 56 .

[0085] Preferably, the focus ring 56 is common to the first zoom 18A and the second zoom 18B.

[0086] In one particular example, the focus ring 56 has a single configuration. The focus ring 56 adjusts the first distance D when changing between the first zoom 18A and the second zoom 18B. A and the second distance D B is equal, this is particularly advantageous as no adaptation is required.

[0087] Next, we will describe how to change the zoom of the camera lens.

[0088] The method includes a first step of providing an assembly 10 that forms a modular zoom.

[0089] In particular, a method for changing from a first zoom 18A shown in FIG. 2 to a second zoom 18B shown in FIG. 3 is described.

[0090] Thus, during this first step, the front optical device 12 is coupled to a first rear optical device 14A to form a first zoom 18A.

[0091] The method then includes rotating the nut 30A of the first rear light device 14A to release the first rear light device 14A from the front light device 12.

[0092] In particular, the nut 30A of the first rear light device 14A is rotated from its locked position to its free position.

[0093] Advantageously, this step of rotating the nut 30A is the only step required to release the first rear light device 14A from the front light device 12.

[0094] In particular, no unscrewing is required to release the first rear light device 14A from the front light device 12.

[0095] The first rear light device 14A is then preferably disconnected from the front light device 12.

[0096] The method then proceeds with the step of placing a second rear optical device 14B over the front optical device 12.

[0097] The method then includes rotating the nut 30B of the second rear optical device 14B to couple the front optical device 12 to the second rear optical device 14B to form a second zoom 18B.

[0098] In particular, the nut 30B of the second rear light device 14B is rotated from its free position to its locked position.

[0099] Advantageously, this step of turning the nut 30B is the only step required to couple the second rear optical device 14B and the front optical device 12 together.

[0100] In particular, no screws are required to couple the second rear optical device 14B and the front optical device 12 together.

[0101] Preferably, the method includes the further step of rotating the alignment ring 44 of the front optical device 12 from its first configuration adapted to adjust the opening of the aperture 42 of the first zoom 18A to its second configuration adapted to adjust the opening of the aperture 42 of the second zoom 18B.

[0102] In particular, alignment ring 44 is rotated relative to housing 34, for example, by an angle of 180° about longitudinal axis XX', so that second window 52 thereof exposes second alignment inscription 50.

[0103] Preferably, the method also includes the further step of moving the focus line engraved ring 54 of the front optical device 12 from its first configuration adapted to adjust the focal length of the first zoom 18A to its second configuration adapted to adjust the focal length of the second zoom 18B.

[0104] In particular, the focal line engraved ring 54 is moved relative to the housing 34 along the longitudinal axis XX', such as forward.

[0105] Advantageously, the above method steps are the only steps required to change from the first zoom 18A to the second zoom 18B.

[0106] The modular zoom assembly 10 according to the present invention is particularly advantageous thanks to the nuts 30A, 30B of the rear optical devices 14A, 14B, respectively.

[0107] In fact, the nuts 30A, 30B allow coupling or disengagement of the rear optical devices 14A, 14B, respectively, with the front optical device 12 in a single rotation step.

[0108] Furthermore, changing between the first zoom 18A and the second zoom 18B, and thus modifying the image format, requires only a few steps. Modifying the image format is therefore quick and uncomplicated. In particular, it can be performed without the need for specific tools, for example, outside a service center.

[0109] Those skilled in the art will understand that the above-mentioned embodiments and variants can be combined with each other if they are technically compatible. [Explanation of symbols]

[0110] 10 assembly 12 Front Optical Device 14A First Rear Optical Device 14B Second Rear Optical Device 18A First Zoom 18B Second Zoom 21A Exterior wall 21B Exterior wall 22A Housing 22B Housing 23A Housing 23B Housing 24A Combined Unit 24B Combined Unit 26A Sensor 26B Sensor 28A Optical Elements 28B Optical Elements 30A Nut 30B Nut 34 Housing 36 Exterior Wall 38 Housing 40 Bonding Elements 42 Iris Diaphragm 44 Alignment ring 46 First alignment marking 48 First Window 50 Second alignment marking 52 Second Window 54 Focal line engraved ring 56 Focusing ring D A First distance D B Second distance X-X' axis

Claims

1. A rear light device (14A, 14B) intended to form an image based on the light flux captured by the front light device (12), a housing (22A, 22B) comprising a sensor (26A, 26B) defining an image format; - coupling units (24A, 24B) formed from nuts (30A, 30B) intended to removably couple said housings (22A, 22B) to said front optical device (12) to form zooms (18A, 18B); A rear light device (14A, 14B) comprising:

2. 2. The rear light device (14A, 14B) of claim 1, wherein the nuts (30A, 30B) are knurled nuts.

3. A modular zoom assembly (10) comprising: a front light device (12) suitable for capturing the light beam; a first rear optical device (14A) according to claim 1, wherein the coupling of said first rear optical device (14A) and said front optical device (12) by said nut (30A) forms a first zoom (18A); a second rear optical device (14B) according to claim 1 or 2, wherein the coupling of said second rear optical device (14B) and said front optical device (12) by said nut (30B) forms a second zoom (18B); A modular zoom assembly (10) comprising:

4. 4. The assembly (10) of claim 3, wherein the image format of the sensor (26A) of the first rear light device (14A) is different from that of the second rear light device (14B).

5. 4. The assembly (10) of claim 3, wherein the front optical device (12) comprises an iris diaphragm (42) and an alignment ring (44) suitable for adjusting the opening of the diaphragm (42), the iris diaphragm (42) and the alignment ring (44) being common to the first zoom (18A) and the second zoom (18B).

6. In the first zoom (18A), the aperture (42) of the front optical device (12) is at a first distance (D) from the sensor (26A) of the first rear optical device (14A). Ａ ) and In the second zoom (18B), the aperture (42) of the front optical device (12) is at a second distance (D) from the sensor (26B) of the second rear optical device (14B). Ｂ ) and The first distance (D Ａ ) and the second distance (D Ｂ 6. The assembly (10) of claim 5, wherein:

7. 6. The assembly (10) of claim 5, wherein the alignment ring (44) is movable between a first configuration suitable for adjusting the aperture of the diaphragm (42) for the first zoom (18A) and a second configuration suitable for adjusting the aperture of the diaphragm (42) for the second zoom (18B).

8. 6. The assembly (10) of claim 5, wherein the front optical device (12) comprises a focus ring (54), the focus ring (54) being common to the first zoom (18A) and the second zoom (18B), and the focus ring (54) being movable between a first configuration suitable for adjusting the focal length of the first zoom (18A) and a second configuration suitable for adjusting the focal length of the second zoom (18B).

9. 1. A method for changing the zoom of a camera lens, comprising: - providing an assembly (10) according to claim 4, wherein said front optical device (12) is coupled to said first rear optical device (14A) to form said first zoom (18A); - rotating the nut (30A) of the first rear light device (14A) to release the first rear light device (14A) from the front light device (12); - placing the second rear optical device (14B) on the front optical device (12) and rotating the nut (30B) of the second rear optical device (14B) to couple the front optical device (12) to the second rear optical device (14B) to form the second zoom (18B); A method comprising:

10. the front optical device (12) comprises an iris diaphragm (42) and an alignment ring (44), the method comprising the additional step of rotating the alignment ring (44) of the front optical device (12) from a first configuration suitable for adjusting the aperture of the diaphragm (42) for the first zoom (18A) to a second configuration suitable for adjusting the aperture of the diaphragm (42) for the second zoom (18B); and / or 10. The method of claim 9, wherein the front optical device (12) comprises a focus line engraved ring (54), and the method includes the additional step of moving the focus line engraved ring (54) of the front optical device (12) from a first configuration suitable for adjusting the focal length of the first zoom (18A) to a second configuration suitable for adjusting the focal length of the second zoom (18B).

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