Optical instrument for sky observation with a portable image capture device

Abstract

Optical instrument for observing the sky with a portable image capture device.

Description

Title of the invention: Optical instrument for observing the sky with a portable image capturing device Introduction Subject of the invention

[0001] The invention relates to a magnifying optical instrument intended to be used as an optical complement with a portable image capture device (mobile phone, tablet). The portable device is then used to capture images observed through this optical complement and also possibly to execute computer programs in order to improve image capture.

[0002] This magnifying instrument is primarily dedicated to the observation of the moon, the sun and the night sky. The magnification of the optics allows a detailed view of the observed stars with a small field of the order of a few degrees.

[0003] The particularity of the optical instrument is to fit in a case on which the back face of the mobile phone rests. The assembly of the optical instrument and the mobile phone forms a compact object without protrusion. The advantage is then to have a robust device easy to handle manually, and easy to place on a photographic tripod. In contrast, an optical supplement with a clamp adds a protrusion to the mobile phone, this protrusion is all the longer as the optical supplement allows a magnification of the image, the assembly is then fragile and less manageable.

[0004] Another feature of the instrument is that the optical axis of the mobile phone and optical instrument assembly is parallel to the sides of the phone. Thus, for a field observed high in the sky, the mobile phone has a position close to vertical. The advantage of this instrument is that it allows the sky to be observed with a vertical phone position that is easy for a user to look at. In contrast, an optical complement mounted on a mobile phone pointing at a point high in the sky requires the user to look at the phone screen, which is oriented towards the ground, making observation tiring or even impossible. Means for implementing the invention Means essential to the invention#:

[0005] 1. An optical instrument allowing a magnification of at least 10 times (we speak of magnification in optical terms) sufficiently important to observe details with objects such as the moon, the sun or the starry sky. 2. A system for attaching the mobile phone to the optical instrument which allows it to form a single compact object without any protrusion. 3. An optical system that allows the phone to be pointed upwards in order to observe a point high in the sky with the phone's screen in an inclined or vertical position (This could be a mirror that reflects the image from the optical instrument directly into the cell phone's camera) 4. A support for screwing a photographic foot to the optical instrument in order to allow long observations in a stable manner, (this means may be complementary depending on the coverage of the first claims). Additional resources:

[0006] 1. The optical instrument can be “folded” using mirrors or prisms so that its optical path is contained in a small volume compatible with the size of a mobile phone. 2. A system for attaching the mobile phone to the optical instrument with adjustable brackets. These brackets are held on the optical instrument by magnets. 3. A hole and a sight to easily point the sun 4. A slide to support accessories: finder, viewfinder, etc. List of figures

[0007] • [Fig.l]: Diagram of the optical instrument alone • [Fig.2]: Diagram of the optical instrument mounted with a mobile phone • [Fig.3]: Attaching the mobile phone to the optical instrument • [Fig.4]: Solar aiming target integrated into the optical instrument • [Fig.5]: Accessory holder integrated into the optical instrument Detailed description The optical instrument

[0008] The optical instrument 106 is illustrated schematically [Fig.l]. It consists of a first lens 101 or group of lenses. This is the visible optical part of the instrument where the light enters. This first lens or group of lenses defines the line of sight of the optical system. The optical axis 105 extends the line of sight in the optical instrument. The optical axis is rotated 90 degrees by a first mirror 102. The optical axis is again rotated 90 degrees by a second mirror 103. The optical axis is again rotated 90 degrees by a third mirror. Following this third mirror the optical axis becomes perpendicular to the upper face of the optical instrument. Finally the optical axis passes through a second lens 104 or group of lenses. This last lens is visible on the upper face of the optical instrument. The virtual image formed by this last lens or group of lenses is intended for the mobile phone camera.This last lens 104 or . lens group is also called eyepiece like eyepieces or looks at our eye with an astronomical telescope or telescope.

[0009] The first lens or group of lenses 101 can be equipped with a screw thread in order to screw filters for specific observations. For example, a solar filter absorbing a very large fraction of the solar flux in order to avoid damaging the camera of the mobile phone. Other filters can be used for night observations such as filters masking light pollution from cities, or a filter allowing the typical wavelengths of ionized hydrogen to pass for the more contrasted observation of nebulae. Any other filters can also be screwed onto this external lens 101.

[0010] The use of the first two mirrors makes it possible to have an optical axis which travels a longer optical path while remaining in the optical instrument. This option makes it possible to have a more compact optical instrument whose long length is less than the complete optical path. This optical solution is not essential but makes it possible to have an optical system with a greater magnification. Indeed, in this case the first lens or group of lenses has a long focal length which would then be too long to fit into the optical instrument whose size must be comparable to that of a mobile phone.

[0011] It is important to note that the optical design shown schematically in [Fig.l] is not the only possible one. Other optical designs known to those skilled in the art may be used for this invention. For example, the mirrors 102, 103 and 104 may be replaced by prisms producing the same effect of rotation of the optical axis.

[0012] The assembly of the optical instrument and the mobile phone

[0013] [Fig.2] schematically illustrates the mobile phone 202 placed on the optical instrument 201. The optical instrument can be held by a photographic tripod 203. The photographic tripod is held with the optical instrument by means of a screw thread 204 incorporated in the shell of the optical instrument 201. The photographic tripod head is equipped with a screw compatible with the screw thread 204. Other systems for attaching the photographic tripod with the optical instrument are conceivable. The system described has the advantage of being common and is compatible with existing photographic stands. The tripod allows long and stable observations, which is important, because the typical magnification of 25 times makes the optical instrument difficult to use when held in the hand.

[0014] [Fig. 3] illustrates a top view diagram describing the holding of the mobile phone 302 on the optical instrument 301. At least 2 brackets 303 and 304 are used to align the phone on the optical instrument such that the photographic lens of the mobile phone aligns with the eyepiece 104 of the optical instrument. These brackets are held to the optical instrument by magnets. Thanks to these magnetic brackets, it is possible to adjust the position of the telephone on the upper face of the optical instrument in order to guarantee good alignment.

[0015] The user can activate the camera of his mobile phone in video mode in order to guarantee the alignment by visual control. This step must be carried out at least once. The brackets keep their positions, it is then possible to remove the mobile phone and then replace it with the guarantee that the phone is correctly aligned without repeating the alignment procedure. This design makes the optical instrument compatible with a wide variety of mobile phones, because each model has its own size and camera position.

[0016] One or two other brackets can be used to hold the upper corners of the mobile phone. Also these brackets can cover the corners of the phone in order to secure the mobile phone to the optical instrument.

[0017] The use of magnetic brackets makes the system both simple and adjustable. Other holding and adjustment systems can also be considered. Solar pointing aid

[0018] The sun is a target intended by the optical instrument. In this case, the use of a solar filter screwed to the lens 101 is essential to avoid damaging the mobile phone. Pointing the sun is made difficult because of the glare of the user.

[0019] [Fig.4] illustrates a modification of the optical instrument in order to facilitate solar pointing. The optical instrument 401 is represented by a box. The first lens or group of lenses of the instrument is indicated by the dotted circle 402. This first lens or group of lenses points along the axis 406 which is perpendicular to it. A small hole 404 is drilled in the front face of the optical instrument. This small hole lets sunlight enter. When the device is oriented towards the sun, the light rays are parallel to the axis 405 which points towards a target 403. This target is a transparent or slightly transparent screen allowing a small luminous circle corresponding to the sun to be seen. The transparency of this target is controlled for example by a variable thickness of plastic taking the form of circles as indicated in [Fig.4].The center of the concentric circles 403 and the small hole 404 on the front face define the axis 405 which must be parallel to the optical axis 406 of the input lens or lens group 402.

[0020] The user aligns his optical instrument so that the small luminous point of the sun is at the center of the concentric circles 403. This operation is also valid with lunar pointing. Accessory support

[0021] [Fig.5] illustrates a modification of the optical instrument in order to mount accessories in parallel. The optical instrument 501 is represented by a box. The first lens or group of lenses of the instrument is indicated by the dotted circle 502, as well as the small hole 503 and the target 504 for solar pointing. A slide 505 is mounted on a side face of the optical instrument. This slide makes it possible to align accessories in the same direction as the pointing of the optical instrument. This slide is parallel to the optical axis of the first lens or group of lenses 502 in order to guarantee good alignment between the accessories and the field pointed by the main optical instrument 501.

[0022] Among the accessories we note: 1 / a small finder scope allowing observation of the field pointed by the optical instrument 501. The field of the finder scope is wider with a lower magnification than the optical instrument 501; 2 / a light pointer in order to visualize a light ray during a night observation indicating to the user the orientation of the field observed by the optical instrument 501.

Claims

[Claim 1] Claims : Claim

Images