Magnifying optical device

Abstract

Magnifying optical device intended to cooperate with a portable terminal 202 equipped with smartphone or tablet type image capture functions, said device consisting of a housing 106 equipped with an optical objective 101 comprising at least one lens, an eyepiece 107 comprising at least one lens and an optical path connecting the objective 101 and the eyepiece 107, as well as attachment means 303, 304 for said terminal 202.More specifically: - the optical path includes at least two optical reflections 102, 103, 104; - the device housing 106 includes a flat surface 110 containing the eyepiece 107 and designed to receive the terminal 202; - the attachment means 303, 304 of the terminal 202 to the device are positioned in an adjustable manner relative to the flat surface 110, by displacement at least in the plane of said surface 110, and are capable of making the optical axes of the eyepiece 107 of the device and the camera of the terminal 202 collinear; - the optical axis of the objective lens 101 is perpendicular to the optical axis of the eyepiece 107. The abstract figure is Figure 2.

Description

Title of the invention: Magnifying optical device

[0001] The present invention relates to a magnifying optical device or instrument intended to be used with a portable terminal equipped with image capture functions, such as a smartphone, tablet or equivalent. In practice, it is a device intended to be used as a complement, from an optical point of view, with the optics of a camera of a conventional personal terminal whose optical power proves insufficient for certain uses. One of the advantages of this association lies in the possibility of using the software processing power of the portable terminal to process the images captured by the complex optical system combining the resident optics of the terminal with that of the complementary device of the invention.

[0002] Of course, the simple optical association of two separate elements is not enough: it must be adapted to users accustomed to handling compact and coherent objects the size of a smartphone or a tablet, and who value a certain comfort of handling but are dissatisfied with the current optical possibilities of the bare device. The device of the invention is therefore made up of a housing whose dimensions are compatible with these requirements of ease of handling, without compromising the optical characteristics aimed at reasonable magnification. An additional feature of the device according to the invention, in addition to a certain compactness, is to allow a method of docking to the mobile terminal which preserves - at least to a certain extent - the maneuverability of the assembly, which is important to users.

[0003] In practice, the additional magnifying optical instrument of the invention consists of a housing having, quite conventionally, the following optical elements: an optical objective (at least one lens) through which the light rays forming the input image enter, an eyepiece (at least one lens) which constitutes the output component of the image optically processed by the device, and an optical path connecting the objective and the eyepiece, comprising components carrying out, on the one hand, the magnifying treatment and, on the other hand, directing the light rays between the input and the output.

[0004] The housing of the optical device must also include means for attachment to the terminal, in order to connect the two optical paths respectively of the complementary device and the portable terminal so that they have the same optical axis at their interface, so that the image arriving at the eyepiece - that is to say at the output of the device of the invention - can be optically processed by the terminal. These attachment means must of course be adjustable, to adapt the housing of the device of the invention to the sometimes very different dimensions of smartphone or tablet cases. The attachment of one to the other must also obey certain consi practical arrangements allowing for everyday use designed to avoid taking images requiring the user to make unnecessary contortions.

[0005] Indeed, among the applications for which the new image-taking apparatus resulting from the association of the device of the invention with the portable terminal is intended, one can cite the observation of the moon, the sun and more generally the sky, preferably at night. The optical system of the device, which complements that of the portable terminal, is designed to allow a detailed view of the observed stars, with a reduced field of the order of a few degrees. Such observation of the sky obviously imposes some constraints on the user, insofar as the observed areas are above him, making taking images with a simple personal terminal not really comfortable. To maintain immobility which is essential for certain shots, it is also necessary to be able to use a fixed support, and therefore to ensure that the assembly of the terminal with the optical complement of the invention lends itself to this.

[0006] The aim of the present invention is therefore firstly to improve the optical properties of a conventional portable terminal of the tablet or smartphone type by adding a casing, which is then designed such that the assembly can be easily handled, furthermore allows images of the sky to be captured in good conditions of comfort for the user, and finally allows the use of a fixed support of the tripod type.

[0007] For these purposes, the magnifying optical device of the invention, which is, as mentioned, intended to cooperate with a portable terminal equipped with image capture functions of the smartphone or tablet type, is conventionally constituted by a housing provided with an optical objective comprising at least one lens, an eyepiece comprising at least one lens and an optical path connecting the objective and the eyepiece, as well as means for attachment to said terminal. It is in particular such that:

[0008] - the optical path comprises at least two optical returns;

[0009] - the housing of the device comprises a flat surface comprising the eyepiece and provided to receive the terminal;

[0010] - the means for attaching the terminal to the device are positioned in such a way adjustable relative to the flat surface, by displacement at least in the plane of said surface, and capable of making the optical axes of the eyepiece of the device and the camera of the terminal collinear;

[0011] - the optical axis of the objective is perpendicular to the optical axis of the eyepiece.

[0012] The system for attaching the portable terminal to the complementary optical instrument of the invention is designed so that the two, when combined, form a single compact object for reasons relating to the handling of the assembly, therefore preferably without protrusion. The shape of the housing is therefore itself designed to have minimal relative bulk, and capable of “melting” as much as possible against the volume of the terminal, hence the existence of a flat face coming into contact with the face - also flat - of the terminal containing the camera lens, the volume constituted by the two elements then being tightened.

[0013] The number of optical returns also allows folding of the optical path, for the purpose of the mentioned compactness, but also to be able to ensure perpendicularity between the optical axes respectively of the objective and the eyepiece of the device of the invention.

[0014] In order to be an adequate optical complement, in particular for the purpose of photographing or filming the celestial vault, the device of the invention preferably has a magnification ratio of at least 20. This magnification, added to the optical capacities of current portable imaging terminals, makes them correctly adapted to the intended use, namely to be an optical accessory sufficiently efficient to improve the performance of mobile terminals available on the market while remaining economically accessible to consumers.

[0015] In practice, in most cases, the device casing is designed substantially parallelepiped with two walls connected by four sides forming the edge of the casing, the receiving flat surface being on the external face of one of said walls. It is on the latter that the portable terminal is placed, all known designs of which, regardless of the brands, are also parallelepiped in shape with large flat faces. The two elements are then simply placed in contact with each other, with flat surfaces capable of sliding over each other before fixing. The mobile terminals can be seen as plates of reduced thickness, and the casing of the device according to the present invention is designed so that two external flat surfaces of these two elements are joined together in order to ensure that the joint volume is strictly equal to the sum of the volumes, no more.

[0016] Preferably, the attachment means may consist of at least two brackets movable on the flat receiving surface. The portable terminal is positioned so that the lens of its camera is placed on the eyepiece, in order to obtain coaxiality of their optical axes. The brackets may for example be secured to the housing by magnetic means. The flat receiving surface may be magnetized, as well as the brackets, making the movements of one on the other easy to carry out by hand, with good quality of attachment. The attachment of the terminal to the device is then very easy and reliable.

[0017] Furthermore, the complementary optical device of the invention may comprise means for fixing a tripod-type support, and it may therefore be made dependent on a fixed base avoiding the inevitable parasitic movements when the assembly is carried by hand, movements which are very detrimental to the quality of the images, particularly at night. In this case, the means for fixing the tripod may be placed on the housing opposite the wall presenting the flat receiving surface. The photographic foot can for example be screwed to the magnifying optical instrument of the invention in order to allow long observations in a stable manner, and the corresponding wall is then provided with a thread, a threaded ring or more generally a threaded system.

[0018] The housing may further comprise a solar pointing system consisting of an orifice and a transparent or translucent target, placed colinearly on two opposite sides of the housing. The sun is in fact a target provided for the optical device complementary to a portable terminal according to the invention, obviously in conjunction with the use of an attenuating solar filter equipping the lens of said device. The orifice, when pointed towards the sun, then lets sunlight enter the housing. The light rays are then collimated towards the translucent target which reveals a small luminous circle corresponding to the incident sunlight, which it is sufficient to center in the target to know that the assembly is correctly oriented towards the sun.

[0019] The housing may also include, on one of the sides connecting the walls, a slide for attaching accessories, provided parallel to the optical axis of the lens. There are indeed possibilities for mounting additional accessories which can further enhance the use of the kit, and which can therefore be mounted while respecting good alignment with the field pointed by the optical device of the invention to which the accessory is mounted. The accessories in question may for example be a finder scope, a light pointer, etc.

[0020] More precisely, according to one possibility, the parallelepiped housing therefore comprises two walls and four sides, two large sides and two small sides, one of the small sides comprising the objective of the device and the sighting orifice, the other small side presenting the sight, the slide then being arranged on one of the large sides.

[0021] Other aims and advantages of the present invention will appear during the description which follows, relating to embodiments which are given only as indicative and non-limiting examples.

[0022] Thus, in particular, the understanding of this description will be facilitated by referring to the drawings attached in the appendix and in which:

[0023] [Fig.l] illustrates in schematic perspective view the magnifying optical device of the invention;

[0024] [Fig.2] represents a perspective view of the same device secured to a smartphone;

[0025] [Fig.3] shows an explanatory elevation view of the operation of the brackets for attaching a smartphone to a complementary optical device;

[0026] [Fig.4]] represents a schematic perspective view of the device alone, illustrating the operation of the solar pointing system; and

[0027] [Fig.5]] shows, still in schematic perspective view, the device equipped with a side slide for attaching accessories.

[0028] With reference to [Fig.l], the optical instrument or device of the invention is in the form of a generally parallelepipedal housing 106. It has an objective 101 of the device, comprising a lens or a group of lenses, said objective 101 being the visible optical part of the instrument through which the light enters. This first lens or group of lenses of the objective 101 defines the optical axis of the objective 101 which is also the axis of sight of the optical system specific to the device of the invention. The optical path 105 of the light, in the extension of the axis of sight, has a first sector which is merged with the optical axis of the objective 101, inside the optical instrument. The optical path 105 continues with a second sector oriented at 90 degrees, after reflection by a first mirror 102 whose reflecting surface is oriented at 45° to the optical axis of the objective 101.A third sector of the optical path 105 starts after reflection on a second mirror 103, symmetrical to the previous mirror with respect to a longitudinal median plane of the housing 106. All these reorientations take place in the same plane, and result in a U-shaped path of the light, which constitutes an efficient fold, taking into account the available volume, of said path. Then, the optical path is again reoriented by 90 degrees by a third mirror 104, in a fourth sector directed perpendicular to the plane of the first three sectors. Following this third mirror 104, the optical path passes through what can be seen as an eyepiece 107 of the optical device of the invention, composed of a lens or a group of lenses. The name comes from its positioning, in the manner of the eyepieces to which the eye is glued for an astronomical telescope or for a telescope.

[0029] The optical path of [Fig.l] is U-shaped with 3 mirrors. The number of mirrors can be 2 with an L-shape also guaranteeing the folding of the optical path and an eyepiece whose optical axis is perpendicular to the optical axis of the objective. The number of mirrors can be greater than 3 in order to allow greater folding of the complete optical path.

[0030] In the parallelepiped geometry of the housing 106, the eyepiece 107 is visible on the upper face of the optical instrument as shown in [Fig.l]. The virtual image formed by the lens or the group of lenses of the eyepiece 107 is intended to be aligned / centered on the objective of the camera of the smartphone or tablet. The parallelepiped housing 106 comprises in this case two opposite walls 100, 111 connected by four sides 112, 113, 114, 115 forming the edge of said housing 106. The eyepiece 107 is therefore, in the representation of [Fig.l], arranged in the upper wall 100 of the parallelepiped, while the objective 101 for inputting the light signal located on one of the lateral sides 112 of the housing. The optical axes of the objective 101 and the eyepiece 107 are perpendicular.

[0031] The first lens (or group of lenses) of the objective 101 can be equipped with a screw thread in order to screw filters for specific observations. For example, it is possible to mount a solar filter, absorbing a very large fraction of the solar flux, in order to avoid damaging the camera of the mobile phone when observing the solar star. Other filters can be used for night observations, such as filters masking light pollution from cities, or filters allowing the typical wavelengths of ionized hydrogen to pass through, for the more contrasted observation of nebulae. Many other filters can also be screwed onto this outer lens of the objective 101.

[0032] The use of the first two mirrors 102, 103 therefore makes it possible to set up a longer, folded optical path, while remaining within the reasonable dimensions of the magnifying optical device of the invention. This option allows the design of a relatively compact optical instrument, the great length of which is much less than the complete optical path. This optical solution of folding the optical path is not essential to obtain a magnifying effect, but it makes it possible to achieve an optical system with a greater magnification. Indeed, in this case the lens or the group of lenses of the objective 101 may have a long focal length, normally too long to fit into an optical instrument whose size must be comparable to and compatible with that of a mobile phone. The design of the optical system shown diagrammatically in [Fig.l] is however not the only possible one.Thus, mirrors 102, 103 and 104 can be replaced by prisms producing the same effect of changing direction at 90° to the optical axis.

[0033] [Fig.2] schematically illustrates the positioning of a mobile phone or smartphone 202 placed on the flat surface 110 of the wall 100 of the housing 106 of the complementary optical instrument of the invention. The latter can also be held by a photographic tripod 203. The fixing of the photographic tripod on the optical instrument can for example be done by means of a screw thread system 204 incorporated in the housing 106. The head of the photographic tripod is then equipped with a screw compatible with the screw thread 204. Other systems for attaching the photographic tripod to the optical instrument are however conceivable. The system described has the advantage of being common and compatible with existing photographic stands. The tripod allows long and stable observations, which is important - particularly for the purposes of the present invention - because the typical magnification of 25 times makes the optical instrument of the invention difficult to use when it is simply held in the hand.

[0034] [Fig. 3] illustrates a diagram, seen from above, showing the holding of the telephone portable 202 on the housing 106 of the optical instrument of the invention. At least 2 brackets 303 and 304 are used to position the telephone relative to the flat surface 110 of the optical device so that the optical axis of the photographic lens of the portable telephone 202 aligns with that of the eyepiece 107 of the optical instrument. These brackets 303, 304 are for example held on the housing 106 of the device or optical instrument by means of magnets or more generally magnetic means. Thanks to these magnetized brackets 303, 304, it is possible to easily adjust the position of the telephone on the flat upper face 110 of the wall 100 of the optical instrument, in order to guarantee good alignment of the optical axes.

[0035] The user can activate the camera of his mobile phone 202 in video mode to carry out a position validation and correction procedure, with a view firstly to guaranteeing and / or then optimizing the alignment of the axes by visual control. This step must be carried out at least once. The brackets 303, 304 can then keep their positions, and it is possible to remove the mobile phone 202 and then replace it with the guarantee that it is correctly aligned, without repeating the alignment procedure. This design makes it possible to make the optical device of the invention compatible with a wide variety of mobile phones or smartphones 202, because each model has its own size and camera position.

[0036] One or two other brackets can be used to hold the other corners of the mobile phone 202. The 3 or 4 brackets used cover all or almost all of the corners of the phone in order to secure it sufficiently to the optical instrument of the invention. The use of magnetic brackets 303, 304 makes the system both simple and adjustable. Other holding and adjustment systems can obviously also be envisaged.

[0037] Solar pointing means may also be provided, according to the invention. Thus, the sun is a potential target provided, as already mentioned, by using a solar filter placed at the lens 101, a filter which is essential to avoid damaging the mobile phone. Pointing the sun is then possible, although it remains difficult due to the glare of the user, who must obviously take precautions to protect his eyes. [Fig.4] illustrates a modification of the optical instrument allowing solar pointing.

[0038] The optical device or instrument of the invention again comprises, in this configuration, a housing 106 of parallelepipedal appearance. The optical objective 101 constituted by a lens (or a group of lenses) of the instrument is shown in dotted lines in the front side 112. This first lens or group of lenses of the objective 101 points along an optical axis 406 which is perpendicular to it. A small through hole 404 is drilled in the same front side 112 of the optical instrument. This hole 404 lets in the sunlight, which it collimates. When the device is oriented towards the sun, the light rays which enter are parallel to the axis 405 and point towards a target 403 located on the opposite side 114. This target 403 is for example a transparent or slightly transparent screen, allowing a luminous circle to be seen corresponding to the luminous signal in the direction of pointing of the sun. The transparency of this target 403 is controlled for example by a variable thickness of plastic, having concentric circles as indicated in [Fig.4]. The center of the concentric circles 403 on the rear face 114 and the hole 404 on the front face 112 of the housing 106 define an axis 405 which must be parallel to the optical axis 406 of the lens or group of input lenses forming the objective 101. The user aligns the optical instrument of the invention so that the luminous point due to the sun is at the center of the concentric circles of the target 403. This operation is of course also valid for carrying out lunar pointing.

[0039] [Fig. 5] illustrates another possible characteristic of the optical device of the invention allowing accessories to be mounted thereon along a parallel axis. The housing 106 of the instrument is - as in the preceding figures - represented schematically by a parallelepiped envelope. The objective 101 consisting of a lens or a group of lenses is represented by the dotted circle, and the hole 404 and the target 403 for solar pointing have also been shown. According to this new characteristic, a slide 505 is mounted on a lateral face of the optical instrument. This slide 505 makes it possible to mount, in an aligned manner, accessories whose axis is then oriented in the same direction as the pointing direction of the optical instrument of the invention, due to the orientation of the side 113 on which the slide 505 is mounted.This slide 505 is in fact parallel to the optical axis of the objective 101, in order to allow and guarantee good alignment between the accessories and the field pointed by the optical device or instrument according to the present invention.

[0040] Among the possible accessories, a small finder scope has already been mentioned for observing the field pointed by the device. The usefulness of such a scope may lie in the fact that its field may be wider and its magnification lower than the device of the invention, and can therefore "roughen up" the positioning of the device / portable terminal assembly. It is also possible to add a light pointer for viewing a light ray, for example during night observation, indicating to the user the orientation of the field observed by the overall optical instrument of the invention.

[0041] The examples illustrated in these figures are obviously not exhaustive of the invention, which encompasses the differences in structure / geometry, dimensions, etc., in particular of the housing 106, the fixing means 204 of the tripod 203, the means for attaching the portable terminal 202, etc.

Claims

Claims

1. Magnifying optical device intended to cooperate with a portable terminal 202 equipped with image capture functions of the smartphone or tablet type, said device consisting of a housing 106 provided with an optical objective 101 comprising at least one lens, an eyepiece 107 comprising at least one lens and an optical path connecting the objective 101 and the eyepiece 107, as well as attachment means 303, 304 of said terminal 202, characterized in that: - the optical path comprises at least two optical deflections 102, 103, 104; - the housing 106 of the device comprises a flat surface 110 comprising the eyepiece 107 and intended to receive the terminal 202;- the attachment means 303, 304 of the terminal 202 to the device are positioned in an adjustable manner relative to the flat surface 110, by displacement at least in the plane of said surface 110, and capable of making the optical axes of the eyepiece 107 of the device and of the camera of the terminal 202 collinear; - the optical axis of the objective 101 is perpendicular to the optical axis of the eyepiece 107.;

2. Magnifying optical device intended to cooperate with a portable terminal 202 according to the preceding claim, characterized in that it has a magnification ratio of at least 20.

3. Magnifying optical device intended to cooperate with a portable terminal 202 according to one of the preceding claims, characterized in that the housing 106 of the device is substantially parallelepipedal with two walls 100, 111 connected by four sides 112, 113, 114, 115 forming the edge of the housing 106, the flat receiving surface 110 being on the external face of one of said walls 100.

4. Magnifying optical device intended to cooperate with a portable terminal 202 according to one of the preceding claims, characterized in that the attachment means consist of at least two brackets 303, 304 movable on the flat receiving surface 110.

5. Magnifying optical device intended to cooperate with a portable terminal 202 according to the preceding claim, characterized in that the brackets 303, 304 are secured to the housing 106 by magnetic means.

6. Magnifying optical device intended to cooperate with a terminal portable 202 according to one of the preceding claims, characterized in that it comprises means 204 for fixing a tripod-type support 203.

7. Magnifying optical device intended to cooperate with a portable terminal 202 according to the preceding claim, characterized in that the fixing means 204 of the tripod 203 are placed on the housing 106 opposite the wall 100 having the flat receiving surface 110.

8. Magnifying optical device intended to cooperate with a portable terminal 202 according to one of claims 3 to 7, characterized in that the housing 106 comprises a solar pointing system consisting of a sighting orifice 404 and a transparent or translucent target 403 placed collinearly on two opposite sides 112, 114 of the housing 106.

9. Magnifying optical device intended to cooperate with a portable terminal 202 according to one of claims 3 to 8, characterized in that the housing 106 comprises, on one of the sides 113 connecting the walls 100, 111, a slide 505 for fixing accessories provided parallel to the optical axis of the lens 101.

10. Magnifying optical device intended to cooperate with a portable terminal 202 according to the preceding claim, characterized in that the parallelepiped housing 106 comprises two walls 100, 111 and four sides, two large sides 113, 115 and two small sides 112, 114, one of the small sides 112 comprising the objective 101 of the device and the sighting orifice 404, the other small side 114 having the sight 403, the slide 505 being arranged on one of the large sides 113.

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