DE102014007704A1 - Optical extension for a smartphone camera - Google Patents

Abstract

Optical extension for a smartphone camera, characterized in that the optical beam path of the extension is folded, this extension includes a mechanical device with which the extension can be connected to the smartphone containing the camera, so that the optical axis of the smartphone camera at the output of the Smartphone camera coincides with the optical axis of the extension at the entrance of this extension.

Description

The invention relates to an optical extension for a smartphone camera or a camera on a mobile or other compact device (tablet PC or laptop), in particular a telephoto lens, a telescope or a microscope, according to independent claim 1.

motivation

The smartphone cameras are nowadays often ideal for group and extensive landscape shots, but they are due to the large FOV and lack of optical zoom, not suitable for detail, personal and portrait shots. Also video recordings and the photographing of astronomical objects and events are closed to them. Likewise, the image composition inherent in any compact camera is eliminated by selective selection and enlargement of the image section, by means of which the image components can be suitably weighted. There is a real need here.

State of the art

The great need for these missing features was already recognized years ago and some smartphone manufacturers tried to equip their devices with optical zoom, but with little convincing results. The quality of the Zooms was very bad, at the same time, the smartphones equipped with it were large, thick and clunky against the general trend and customer demand. After just two years (2007 and 2008), these devices by Nokia and Samsung have disappeared from the European and North American markets. Successors are still to be found in Asia, where the size of the devices does not play such a major role as in Europe or America.

• 1. Hohes Gewicht
• 2. Großes Volumen, wobei
• 3. Gewicht und Volumenverteilung nicht kompakt sondern gestreckt und dazu senkrecht zu dem Smartphone verläuft (s. 1(b)) und dies führt zu
• 4. Großen Hebel, die schon bei kleinen Gewichten hohe Momente bewirken. Daher sind die Geräte, insbesondere wenn zusammengesetzt
• 5. Schlecht transportierbar und
• 6. Schlecht verwackelungsfrei auszurichten und zu halten
• 7. Erfordern daher verhältnismäßig große und stabile Stative, insbesondere bei höheren Vergrößerungen, was das Gesamtgewicht und die Transportprobleme noch weiter erhöht.
• 8. Will man das Gewicht reduzieren, in dem Korrekturoptiken eingespart werden, leidet die ohnehin nicht berühmte Qualität.
• 9. Die Verbindung zwischen der Erweiterung und dem Smartphone ist nicht besonders stabil, die resultierende Empfindlichkeit erfordert erhöhte Aufmerksamkeit und besondere Sorgfalt im Umgang mit dem Gerät, was sowohl die Ergonomie als auch jeden Spaß verdirbt.
• 10. Nicht sofort betriebsbereit, muss erst mit einigem Aufwand an Mühe und Zeit zusammengesetzt werden.

Instead of the built-in optical zoom then increasingly external optical extensions were offered for placement on the smartphone, such as those with telephoto property (Case 1). At the moment, solutions with 6x, 8x, 10x and 12x magnification are on the market. Their principal optical structure with Kepler telescope shows 1 (a) , approximate appearance is in 1 (b) outlined 1 (c) shows another possible optical arrangement (Galilei telescope), but probably not offered. Because of the beam path running only perpendicular to the smartphone, the extension spreads from the smartphone and makes the arrangement bulky, unwieldy and therefore not ergonomic. The list of disadvantages of these extensions is long:

• 1. High weight
• 2. Large volume, where
• 3. Weight and volume distribution not compact but stretched and perpendicular to the smartphone runs (s. 1 (b) ) and this leads to
• 4. Big levers that cause high moments even with small weights. Therefore, the devices, especially when assembled
• 5. Poorly transportable and
• 6. Align and hold poorly shake-free
• 7. Therefore require relatively large and stable tripods, especially at higher magnifications, which further increases the overall weight and transportation problems.
• 8. If you want to reduce the weight in which correction optics are saved, suffers the already not famous quality.
• 9. The connection between the extension and the smartphone is not particularly stable, the resulting sensitivity requires increased attention and extra care in handling the device, spoiling both ergonomics and fun.
• 10. Not ready for immediate use, it must be put together with some effort and time.

As a further solution (Case 2) is also offered a connection between the smartphone and a pair of binoculars, wherein an optical beam path of the binoculars serves as a telephoto lens. For a hefty price of about $ 70 US (pre-order) or $ 95 US (normal price) you get an even clunkier solution, where you can use an existing binoculars additionally as such, but depending on the binoculars only marginally better result delivers as the existing in the smartphone anyway, but lossy digital zoom. Usually, only the resolution of the magnified image improves slightly, the light distribution and optical errors are often even worse. The disadvantages are up to the point 8 the same as above for the telephoto extension. In addition, only one optical channel of the binoculars is used, and here too the heavy and complex image erection is actually superfluous, it could be software-moderately completely free of weight realize. Furthermore, the connection mechanism is quite heavy and very unwieldy.

Most and the biggest problems in both cases are caused by the fact that the entire optical beam path of the extension and thus its optical axis runs in full length perpendicular to the smartphone.

task

It is therefore the object of the present invention to remedy the shortcomings described above of existing solutions, at least in part, and to find an optical extension that provides the desired function (telephoto, microscope, etc.), without the smart phone with the extension clunky , becomes unwieldy and not ergonomic. The object is achieved with an optical extension according to independent claim 1. Advantageous developments can be found in the subclaims.

Description of the invention

The solution to the problem consists essentially in the folding of the optical beam path. The weight and the volume are thereby reduced significantly only in case 2 (connector to the binoculars), in case 1 (telephoto extension) by additional or additional mirrors even slightly increased. Therefore, the folded arrangement is not obvious, because it is more expensive and expensive in design and manufacturing due to more optical elements and correspondingly high adjustment requirements. The advantages of the acquired ergonomics become clear only at second glance. What is significantly changed by the folding is the weight and volume distribution, which is very compact close to the smartphone. This causes the particularly disturbing moments to decrease by up to an order of magnitude, which results in better portability and alignability. You can use smaller tripods. Additional correction optics are not so negative in weight, so can be used rather. The connection with the smartphone almost inevitably falls over a large area and thus robust. This allows a fast and compact snap connection can be realized, which allows an almost immediate use, or the extension can remain mounted on the smartphone, because the composite arrangement is not so bulky.

The folding preferably ensures that the optical beam path and thus the optical axis of the extension runs at least partially along the smartphone surface. This means that the optical axis of the extension has in sections an angle different from 90 ° to the smartphone surface, preferably this angle is less than or equal to 45 °, more preferably this angle is less than 30 °. By way of example, it should be preferred here: over half of the path within the extension.

The folding can be at fixed angles. However, it can be realized in some applications with variable angles.

The folding can be realized with the help of mirrors but also by prisms. These can also be made rotatable and / or movable.

It makes sense, but not essential, that the mounted extension provides a way to operate the smartphone camera by bypassing or disabling the extension. This function can be useful for finding the object that you actually want to magnify with the camera with ease, positioning it in the center of the frame, and then only turning on the magnification. This is especially useful for astronomy applications and nature observation on Earth. This function can be realized by removing the input lens and / or the first (input) mirror from the beam path, for. B. in which the entrance lens and / or the mirror are moved.

The attachment part of the extension to the smartphone can make sense, but not necessarily, take over a protective function for the smartphone. This attachment part may, but not necessarily, be separable from the actual optical extension and serve as a protective cover or protective frame.

The extension may contain information for some applications and / or deliver it to the smartphone, e.g. B. position and / or orientation in space, relative and / or absolute, concerning the entire extension and / or their parts, in particular optical axes.

The extension may include manual or motorized actuation. This can be supported and / or controlled by software on the smartphone (eg to find celestial bodies or to follow them over time).

If some (more than 1) optical elements are movable, they can be coupled together to make the control particularly easy.

In order to keep the correction of optical errors of the extension particularly simple, the unit Smartphone and extension can have the possibility to measure the Point Spread Function (PSF), in order to remedy the optical errors software-wise retrospectively. This can save a lot of weight, which is always important for mobile devices. The measurement of the PSF is preferably location-dependent, but preferably with a resolution that is significantly smaller than the camera resolution.

By eliminating the second optical channel and preferably also the image erection, the solution according to the invention is significantly lighter and more space-saving. more economical than the Link-to-Binocular Solution (Case 2).

In the description, the term smartphone is often representative of both smartphone and other mobile or compact devices such as a laptop PC or tablet PC.

Lenses and lens-mirror combinations can be replaced with non-plane mirrors.

1 (a) State of the art: Function sketch Smartphone with extension containing simple Kepler arrangement as a telephoto lens seen from the side.

1 (b) State of the art: View sketch smartphone with extension containing simple Kepler arrangement

1 (c) Function sketch smartphone with extension containing simple Galileo arrangement

2 State of the art: Function sketch smartphone with binoculars

• (a) erste Lösung
• (b) zweite Lösung
• (c) dritte Lösung
• (d) vierte Lösung
• (e) erste Lösung für eher kleine Vergrößerungen
• (f) erste Lösung für eher höhere Vergrößerungen
• (g) vereinfachte Lösung ohne Auskoppelspiegel

3 Function sketches Smartphone with inventive extension containing folded stationary Kepler arrangement

• (a) first solution
• (b) second solution
• (c) third solution
• (d) fourth solution
• (e) first solution for rather small magnifications
• (f) first solution for rather higher magnifications
• (g) simplified solution without output mirror

• (a) Lösung mit Auskoppelspiegel
• (b) vereinfachte Lösung ohne Auskoppelspiegel

4 Function sketches Smartphone with inventive extension containing folded variable Kepler arrangement

• (a) Solution with output mirror
• (b) simplified solution without output mirror

5 Functional sketch of laptop with inventive extension containing folded Kepler arrangement

6 Function sketch Tablet PC with inventive extension containing folded Kepler arrangement for the front camera

7 Function sketch Tablet PC with inventive extension containing folded Kepler arrangement for the rear camera

8 (a) A solution as under 3 (a) with additional field lens
(b) A solution as under 3 (a) with non-planar mirror

9 Function sketch smartphone with inventive extension, containing three times folded stationary Kepler arrangement

10 Screen sharing of the smartphone for the supporting software

11 Suggestion for the control panel of the software

12 (a) simple slider
(b) cascaded slider

13 Inventive extension with specially adapted geometry for use as a hit display on a shooting range.

1 (a) schematically represents the function of the optics of telephoto extension 22 for smartphone camera 2 a smartphone 1 The optical path at the exit of the camera and within the entire extension point in the same direction and run along the optical axis 7 the camera and the optical axis 77 the extension, where the two optical axes coincide. The optics of the extension here forms a telescope in Kepler arrangement with an intermediate image (not shown) between the eyepiece 3 and the lens 4 and a picture reversal. Optionally, the arrangement may be an optical device, usually again between the eyepiece 3 and the lens 4 , included for image erection (the optional image reversal optics is not shown). The image erection can also be implemented in the smartphone software, without the heavy and expensive Bildumkehroptik. The image reversal optics is usually realized with prisms. The Kepler arrangement is preferably used at higher magnifications. The arrow on the optical axis 7 also indicates the viewing direction of the camera in the following illustrations.

1 (b) schematically represents the appearance of the overall arrangement of the smartphone 1 and the telephoto extension 22 within the associated housing 34 The fastening device for the extension has not been shown for the sake of simplicity.

1 (c) schematically represents the function of telephoto extension 23 for smartphone camera 2 a smartphone 1 similar to the 1 (a) Here was, however, instead of the Kepler arrangement 22 the Galileo arrangement 23 with eyepiece 3 and lens 4 and optical axis 7 / 77 shown. Although the Galilei arrangement has the advantage that it can be designed significantly shorter because it has no intermediate image. The decisive disadvantage of the Galilei arrangement, however, is the fact that it allows enlargements by more than a factor of 3 only with great effort, whereas the Kepler arrangement significantly higher magnification factors allowed. It is not known if the Galileo order is even offered in the market. It differs from the Kepler arrangement by an eyepiece 3 with negative refractive power. There is no image reversal and there is no intermediate image.

2 schematically represents the arrangement with binoculars 24 (Case 2). In front of the camera 2 of the smartphone 1 is an optical channel 33 from the two optical channels 33 and 33 ' with the optical axes 7 and 7 ' of the binoculars 24 arranged. The optical channels are as Kepler telescopes each with eyepiece 3 and 3 ' and lens 4 and 4 ' educated. The image inversion of the arrangement is in each case with the corresponding image inversion device 11 and 11 ' reversed, which is useful for the usual purpose. When used with the smartphone camera, the image reversal hardware-free software can be done in the smartphone, so the heavy image reversal device is unnecessary, as well as a second optical channel.

3 (a) schematically illustrates an inventive optical extension for smartphone camera 2 a smartphone 1 dar. The optical beam path 7 with the sections 8th . 9 and 10 was using the mirrors (it could also be prisms) 5 and 6 folded, so that the optical beam path initially in the section 8th runs substantially perpendicular to the smartphone surface, but then in the section 9 essentially along the smartphone surface, though not necessarily parallel to it. Since the optical axes of the beam paths of the camera and the extension are essentially congruent, a distinction was made here. The arrangement of the optical elements is here in the following order: the camera is followed by the eyepiece of the extension, then the first deflecting mirror 5 , the second deflecting mirror 6 and then the lens 4 ,

3 (b) schematically illustrates a further possibility of the inventive optical extension for smartphone camera 2 a smartphone 1 dar. The only difference to the variant in 3 (a) is that the lens 4 in front and not behind the mirror 6 is arranged.

3 (c) schematically illustrates a further possibility of the inventive optical extension for smartphone camera 2 a smartphone 1 dar. The only difference to the variant in 3 (a) is that the eyepiece 3 behind and not in front of the mirror 5 is arranged.

3 (d) schematically illustrates a further possibility of the inventive optical extension for smartphone camera 2 a smartphone 1 Here is the eyepiece 3 behind the mirror 5 and the lens 4 in front of the mirror 6 arranged. This arrangement is particularly suitable, the lenses 3 and 4 rotatable to store and thus to realize a Kepler magnification changer. The movable magnification changer can also be extended by further stationary optics, preferably outside the actual changer.

3 (e) essentially corresponds to the 3 (a) , it is only more clearly stated that the beam path section 9 not necessarily run parallel to the smartphone interface, but can the smartphone between the mirrors 5 and 6 approach. This case will preferably occur at smaller magnifications. It is clear that the mirrors are no longer at an angle of 45 ° to the smartphone.

3 (f) essentially corresponds to the 3 (a) , it is only more clearly stated that the beam path section 9 does not necessarily have to run parallel to the smartphone interface, but can from the smartphone between the mirrors 5 and 6 remove. This case will preferably occur at larger magnifications. It is clear that the mirrors are no longer at an angle of 45 ° to the smartphone.

3 (g) essentially corresponds to the 3 (b) It only became the deflecting mirror 6 omitted, so that the optical beam path is not redirected towards the direction substantially perpendicular to the smartphone, but continues to run substantially along the smartphone. This solution offers z. For example, if you want to photograph upstairs (eg skyscrapers, airplanes, trees) without having to hold the smartphone over your head.

The inventive optical extension for smartphone camera 2 a smartphone 1 were in 3 represented by a Kepler telescope. It could just as well have been a Galilean telescope. Likewise it could have been a microscope arrangement, it would possibly use a different number of optics. All folded extensions are within the scope of the invention.

4 (a) shows one of the in 3 (a) similar arrangement. In 4 (a) However, the optical elements are at least partially movable, which in addition to translation expressly also the rotation may be meant. For example, the mirror 5 rotate and the mirror 6 both rotated and moved. Also lens 4 can be moved. The movement of the optical elements can be coupled together, at any time the optimal alignment of the optical elements without further To ensure adjustment. The possibility of movement was indicated by arrows.

A possible application of this solution would be a device for observation of celestial bodies. You could by an optional tripod, a software on the smartphone to z. As mechanics to control or position and / or orientation determination be supplemented and would form a very compact mobile astronomical unit. Due to the very small exit pupil of the smartphone camera, the other optics would also be very compact.

In the solution 4 (b) became the second deflecting mirror 6 omitted. Astronomical applications are also possible, but it is not quite as flexible with adjusting the angle of the display and the direction of observation, but so a mirror and a lot of mechanics is saved.

5 shows a further variant of the optical extension according to the invention, here for a laptop PC 1 , consisting of part 1' , usually with keyboard, and part 1'' usually with a screen. It is achieved that the webcam 2 not looking to the operator but away from him, in which the optical axis 7 with the sections 8th . 9 and 10 over the deflection mirror 5 and 6 is redirected behind the laptop PC. Be the lenses 3 and 4 omitted, the enlargement of the camera is maintained, with the lenses, there is preferably a higher magnification. This solution is useful if you want to control pictures on the screen with the laptop camera without being in the picture yourself. Some optical elements, preferably mirrors 5 and 6 and the lens 4 , are preferably designed to be movable because of the angle between the laptop parts 1' and 1'' rarely is a right angle. This angle is usually set variable, so the extension should be adjustable with respect to the beam guidance. This can but z. B. accounts for the cases where the angle between the laptop parts 1' and 1'' is known (for example, particularly ergonomic or preferred angle) and the beam guide in the extension is fixed to it, so that the optical elements must not be moved.

6 shows a further variant of the optical expansion according to the invention, here for a tablet PC 1 with the front camera 2 ' (on the display page). The beam path is similar to in 5 , the angle between the sections 8th and 10 the optical axis 7 but is not equal to zero from the beginning, unlike 5 where both cuts 8th and 10 parallel to each other. Again, the lenses can 3 and 4 be omitted to leave the magnification at 1. A flexible solution contains at least one movable optical element.

7 shows a further variant of the optical expansion according to the invention, here for a tablet PC 1 with the rear camera 2 '' (on the side facing away from the display). Here, too, the sections can be preferred with the optical elements 9 and 10 the optical axis 7 move as indicated by the dashed arrows. This solution is preferably used at higher magnifications. For lower magnifications and magnification 1, the extension may be around the section 8th the optical axis 7 rotated by 180 °, since in this case the section 9 the optical axis is relatively short.

Will the solution be in 4 (a) executed without moving parts, it can be used for specific tasks, such. B. Taking pictures with a tablet PC. Because of the size and weight, a tablet PC may not necessarily be held up for taking pictures. In order to still be able to use the display, the tablet is held at an angle and the camera axis is deflected by the extension, s. 7 , It is conceivable to use the extension without lenses and only with mirrors to achieve an ergonomic position when taking pictures alone.

The optical axis 7 the extension with the sections 8th . 9 and 10 preferably runs in a plane. However, applications are conceivable where the sections do not run in one plane. The effects are parallel offset of the image axis and / or image rotation of the camera image. Both effects can be software-corrected if necessary.

The extension or the connector to the smartphone preferably includes a mechanical interface to a tripod or other mounting option formed preferably as standard as internal thread. Regardless, parts of the extension or the connector to the smartphone may be designed to change the location of the overall arrangement of the extension and the smartphone in the room controlled to change or hold.

The eyepiece of the extension may consist of more than one lens, eg. To increase field of view or FOV (field of view) or to correct optical errors or both. Also, the lens may consist of more than one lens, here rather to correct optical errors. Frequently used eyepieces contain two lenses: the actual eyepiece lens and a field lens. These lenses are usually spatially separated. For even larger FOV and better optical quality, additional lenses can be added. So that our arrangement is as compact as possible, For example, the lenses may be spaced so that the first mirror 5 (in 8 (a) ) between the eyepiece lenses, here 3 ' and 3 '' , lies and our arrangement z. B. as in 8 (a) looks. If it is not possible to position the mirror between the eyepiece lenses, the height of the arrangement grows unnecessarily because the mirror can only be positioned after the eyepiece lenses and the compactness is partially lost. 8 (a) corresponds to the arrangement 3 (a) except for the newly added field lens 3 '' , This is how the camera looks 2 of the smartphone 1 through the eyepiece lens 3 ' in the direction 8th on the deflection mirror 5 where the beam direction is deflected. Then it goes through the lens 3 '' in the direction 9 on the deflection mirror 6 where the beam direction is deflected and then through the lens 4 in the direction 10 into which the extension will leave.

The mirrors do not necessarily have to be flat, but can also have "optical power". This could be z. B. at least part of the task of the field lens or the actual eyepiece are taken over by a mirror, s. 8 (b) where the mirror 5 is designed as a concave mirror. Of course, the mirror can also be a free-form mirror or convex mirror. Again, the camera looks 2 of the smartphone 1 through the eyepiece lens 3 ' in the direction 8th on the non-planning deflection mirror 5 where the beam direction is deflected. Then it goes through the lens 3 '' in the direction 9 on the deflection mirror 6 where the beam direction is deflected and then through the lens 4 in the direction 10 into which the extension will leave. The lenses 3 ' and 3 '' are optional in this case. They can also be designed as negative lenses, despite their presentation as positive lenses.

For the correction of the optical errors, the virtually volume-less diffractive lenses (lenses, which are realized by diffractive optical elements, DOEs) can also be used. They are suitable for such space-critical applications. You could find particular use in a version of the expansion according to the invention, which serves as a hit indicator for sports shooters. Because of the low field of view (FOV), the resulting "ghost spots" may possibly be placed outside the area of interest. They can also be corrected relatively easily by suitable software, because the recorded image (the target) is very well known except for a few places (hits).

It is conceivable to fold the beam path more than once or twice, for. B. three times or four times to produce suitable long optical paths, especially for higher magnifications. In this case, one or more mirrors or prisms can be substantially perpendicular to the smartphone level. Thus, not only one but several parts of the beam path can be guided substantially parallel (<30 °, preferably <10 °) to the smartphone level, s. 9 (a) , (b) and (c), where three parts of the optical beam path run along the smartphone plane by folding three times.

9 (a) shows a side view of the arrangement, wherein only the next parts of the viewer have been shown, which are in 9 (c) below the imaginary dividing line 100 are located. This part initially resembles (coming from the camera 2 of the smartphone 1 in the direction 8th through the eyepiece lens 3 on the deflection mirror 5 and then in the direction 7 ) from the orders 3 (a) and 3 (g) , The mirror 6 but does not direct the beam path from the smartphone here 1 away, but again along the smartphone, but at an angle of 90 °. Although this angle of 90 ° is obvious, it is not absolutely necessary.

The mirror 6 (and 6 ' ) itself is now essentially perpendicular to the smartphone level. The further course of the beam path can be best described by the 9 (c) Track: The one in the direction 7 ' through the deflection mirror 6 deflected beam path hits the deflection mirror 6 ' and will be back in the direction 7 '' redirected, the lens happens 4 and leaves the arrangement.

9 (b) shows a side view of the arrangement, wherein only the remote parts of the viewer have been shown, which in 9 (c) above the imaginary dividing line 100 and it will be in the direction 7 ' looked. The deflection mirror 6 ' directs the beam path in the direction 7 '' around, this happens to the lens 4 and leaves the arrangement.

It is already apparent from the drawings that the beam path of the extension preferably runs essentially over the smartphone plane. This results from the requirement for compactness of the overall arrangement. Also, the first deflected part of the observation beam path (extending away from the camera in the direction of the camera) preferably points to the farthest edge of the smartphone (s. 9 (c) ) or to the second-most edge, rarely to the next edge. This way you can realize long optical paths right from the beginning, before you have to fold again. Long optical paths along the smartphone are not so annoying and do not affect the compactness as negatively as paths or parts that point away from the smartphone. These should be kept well below 50%, preferably below 30%, more preferably below 20%.

In some cases it could be useful in our extension a hardware-moderate image erection (based on 11 or 11 ' out 2 ) too to use. You might then be able to do without software image correction.

Of course, all variants presented here can be combined or replaced with each other. Such solutions also fall within the scope of the application.

M_tele:

Vergrößerungsfaktor des Teleobjektivs

M_digi:

Faktor des Digitalzooms

FOV:

Field of View/Sichtfeld der Smartphone-Kamera

Except for telephoto function, astronomy and nature observation in particular the arrangements are suitable 3 (g) and 9 also for shooters as a hit. Because of the long distance and the relatively small target, it is advisable to use the digital zoom in addition to the telephoto lens in order to optimally perceive the hits. In this case, the digital zoom is preferably from the range factor 2 to 20, more preferably from the range 4 to 10. The magnification factor of the telephoto lens is preferably selected such that M _tele × M _digi / FOV for the 10m shooting range in about 1.33 (from 0.66 to 2.66), for the 25m level by 1.1 (from 0.55 to 2.2) and for the 50m level 2.2 (from 1.1 to 4.4). It is

M _tele :

Magnification factor of the telephoto lens

M _digi :

Factor of the digital zoom

FOV:

Field of view / field of view of the smartphone camera

Taking the shooting range and target geometry into account, the same applies to the less common 15 m, 100 m and 300 m stands. The default is that the target should preferably occupy at least half the screen width of the smartphone on one side, on the other hand, at least half of the target height and width should be seen in each case.

When choosing the telephoto lens, the price also plays a role, with a higher magnification costs more at the same quality. The above formula indicates the latitudes in the choice of the magnification factor of the telephoto lens. Thus one realizes an inexpensive variant with a smaller telephoto _{magnification} M _tele and a larger digital zoom M _digi .

Since in the shooter version only a small field of view is needed, one has some freedom in eyepiece design, so could the field lens u. May be omitted or moved significantly so that it is not in the way of placing the first mirror in the way. The aberrations of the optics could be treated by achromats or apochromats both in the eyepiece and in the lens or by alternative special design.

Since the firing point geometry (height of the target center, distance to the target, height of the table before the shooter) is known, in 13 the floor 83 of the housing 84 the expansion of the invention 85 , which is parallel to the plate 81 of the tray table is, with a small angle ∡ ( 82 . 83 ) against the outgoing optical axis 82 be executed. This angle is in the case of the 10 m level, taking into account the tolerances allowed 2.0 ° -4.3 °, in the case of the 25 m level 1.6 ° -2.1 °, which is best an angle of 3 ° chooses. Will the arrangement 80 from the smartphone 1 with the camera 2 and the extension according to the invention 85 on the plate 81 placed in front of the shooter, it shows immediately about the height of the target center and can be immediately aligned by turning sideways on the target. The possible rest alignment can be made on the touch screen of the smartphone by swiping gestures. Then the entire device practically no longer needs to be changed in height or inclination, which in the absence of the adjusting screws u. Ä. Can result and with what the extension even more compact.

Of course you can also realize the hit display with a spotting scope or binoculars, which you have put the smartphone suitable to view the observation beam path with the smartphone camera. Or one can realize the hit display with a stand-alone compact or system camera that communicates wirelessly or by wire with the smartphone to output the image information on the smartphone screen. In these cases you do not need to program any image inversion. These solutions are, however, voluminous, hardly ergonomic, to cumbersome and complex and miss any compactness. In addition, plenty of money has to be paid for sufficient quality, so that this solution is significantly more expensive overall, because cheap devices are simply not able to provide an acceptable picture.

A special feature compared to spotting scopes and telephoto and zoom cameras is our focus device. The extension according to the invention itself preferably has only a relatively rough possibility to set the focus or possibly none at all. For focusing or fine focusing preferably a software-especially upgraded focusing device of the smartphone itself is used. This upgraded focusing device has a particularly fine adjustment of the focus (this is about the accuracy of the specification for focus removal) despite touchscreen operation. This particularly fine adjustment of the focus is complemented by a particularly fine controllability of the focus, whereby any hysteresis effects are considered in the control, s. further down. In the controllability of Focus is on the ability to follow the defocusing presetting and to set exactly that focus distance. A comparably fine mechanical focus device on a spotting scope or on our extension would be very expensive, expensive and space consuming and could not be operated so easily by far. The better operation is also related to the good decoupling of the focusing mechanism of the control element, which is an image on the touch screen and can be operated almost free of force together. A spotting scope can not offer that because here the optical beam path is coupled with the adjustment mechanism. In addition to the more convenient and accurate focus setting and thus more detailed images, the solution of the invention allows tremendous cost savings in space and weight over a mechanical focusing mechanism outside the smartphone and has to offer a lot of ergonomics.

Furthermore, the viewer or the sports shooter, by the non-ergonomic posture and Augenzukneifen when using the spotting scope and consequent tension, often not relax the eye muscles sufficiently and can not find the right focus, because his eye constantly refocuses. A relaxed view with focus at infinity is desired, on the one hand because of the ergonomics, on the other hand because of the reproducibility of the setting, otherwise work two focusing devices, the spotting scope and the eye, against each other. This artifact, which is very common, although individually very different, is not possible in the expansion according to the invention, because the geometric beam path to the eye is interrupted by the electronics. Between the object and the image sensor (smartphone camera chip), there is only a Feinfokussiervorrichtung and this works undisturbed and unambiguous. The focusing device of the eye can no longer intervene there. The eye clearly focuses only on the screen, but this has nothing to do with the actual focusing of the object.

The extension or connector to the smartphone may be a target device, e.g. B. have sight and grain to align the arrangement easier. For smaller magnifications <8 × only conditionally necessary, it is from about 10 × z. T. desirable. Such a target device is also suitable for spotting scopes, because they usually have high magnifications.

Another advantage of the expansion according to the invention as a hit display for the shooter is the extensive software that supports the shooter in training and competition. A spotting scope or telephoto lens on the camera alone can not provide such support. An example of such software is presented below on the basis of a specification of the software. This is a preferred embodiment, many other variants are conceivable. The underlying smartphone has a screen of 960 × 540 pixels and 10.85 cm (4.27 inches) screen size and a camera with 8 MPixel.

Specifications sketch for the associated software:

Basic module:

The screen (resolution 960 × 540 pixels) 101 of the smartphone 1 in 10 will be in information area 102 (above), display area 103 (Center / 540 × 540 pixels, preferably in principle substantially square) and operating area 104 (below) divided into three parts. The smartphone lies with the upper screen area facing the viewer. So the screen output must be done "upside down".

Display / display range 103 :

The image information from the camera is mirrored on the vertical axis, so the left and right are reversed. Here the target is shown with physical hits.

operating area 104 :

The operating area is a little closer in 11 shown. Here are the digital zoom controls on the left and the focus controls on the right.

Digital Zoom:

A digital zoom up to 10 × is required, continuously adjustable with a slider ("Slider"), which, however, appears only for the time of the setting in the display area for reasons of space. One possible implementation is in 12 (a) shown. The slider 110 consists of the slider channel 111 and the slider 112 , which can be moved in the direction of the arrow (see dashed arrow). Two zoom settings, their values by the lengths of the indicator bars 141 and 145 are intended to be stored and via switches ("buttons") 142 and 146 be available. The indicator bars 141 and 145 are respectively in the counters 142 and 146 , The display and operating functions are thus combined to save space in one element. In addition, a switch 144 with 1x zoom required to find only with a small zoom the target and the device roughly aligned. The switches 142 and 146 should be oblong and contain a bar indicating the zoom factor, or the zoom factor should appear as a number on the switch surface of a not necessarily oblong switch. The slider 110 ( 12 (a) ) appears when the zoom switch is pressed 143 left in the display area, with the last used zoom factor being preset. It disappears when you press the zoom button again 143 , whereby the set zoom value is maintained. Or by pressing one of the two switches 142 and 146 , wherein the set zoom value is maintained, the switch is assigned and stored. In total there are 4 switches for the zoom functions.

Focus:

The quality of the hit display stands and falls with a good focus on the target, since the hits are very small. For manual continuous focus adjustment is the switch 147 provided, as the pressure on the switch 147 on the right in the display area appearing sliders (s. 12 (a) ). Optionally included is a focus distance indicator bar 148 on the focus display panel 149 , This display can also be used as a focus quality indicator in which z. B. the contrast value is displayed. This would make finding the focus easier by looking for the maximum contrast value. By pressing the switch again 147 the slider disappears and the found setting is accepted and saved.

Normally, the resolution of the slider is not sufficient to set the optimum focus. Here cascaded fine adjustment helps, which is explained by the following example: with the slider 112 the focus is roughly adjusted with a vertical movement on the screen. Without putting your finger down z. B. a swipe gesture to the right and it appears as in 12 (b) another slider 120 with the slider channel 121 and the slider 122 , He is z. B. associated with the same length only a tenth of the focus area, which ten times resolution is available. The middle of the new fine adjustment area is where the coarse adjustment was left, which is perceived as intuitive. Ie. after the swipe gesture is the slide 122 in the middle of the slider channel 121 , The coarse slider 110 out 12 (a) is now shown paler or with a lower contrast and is in the new arrangement as 110 ' in 12 (b) to see. The slider 112 ' remains in its last position within the slider channel at the last coarse focus value. The assignment of the fine slider 120 to a small range of focus values is indicated by the assignment arrow 130 and the miniature 120 ' of the fine slider 120 on the slider 112 ' displayed, with the assignment arrow 130 the slider 120 and his miniature 120 ' combines. Of course, the fine adjustment can be cascaded again if necessary. This will usually not be the case with the expansion according to the invention.

However, the just presented possibility of fine adjustment only makes sense if the focus itself can actually follow the fine adjustment. Due to z. T. different hysteresis effects is not always the case. Therefore, it makes sense to measure these hysteresis effects and to consider them accordingly during the activation, be it by means of a suitable hysteresis curve or by values stored in a table, with which the focus device of the smartphone camera can be appropriately controlled. Example: after a focus shift by the value x with the aid of the drive signal y, one returns to -x in the starting position with the aid of a drive signal -z, with z> y. Without hysteresis, z = y would hold.

Of course, the sliders can be replaced with knobs or other setting instruments. Also conceivable is a voice control, wherein at most the values of the changed parameters and variables are displayed.

Information area:

Here are details of the software made.

The base module can run in HDR (High Dynamic Range) mode to better detect the black hits on the black background. Since the target contains only two colors: black and beige, a special, faster HDR mode is proposed. Here, instead of three and more shots, only two are made. Preferably, this HDR mode is not implemented adjustable. The exposure measurement takes place z. B. in black for the first shot, the distance to the beige is known from preliminary tests and thus the second shot can be made without further exposure measurement or you once performs the exposure measurement in black and once in the beige. If the smartphone hardware does not manage these tasks fast enough, you may be able to forego HDR and expose only in black, because here are the different color values (the black of the target and the black of the hits) closest to each other. Or you can give the smartphone more time, in which the hit display appears with a small delay.

Module 1:

It is important to determine where the hit is (in screen coordinates) and whether a shot has fallen at all. The best results on the screen are obtained by subtracting the image content before and after the shot. The artifacts of other shooter's shooting activities (without hitting their own target) are most easily resolved by making the result of subtracting the image content above a certain threshold, and this value was gained away from the other hits. If this value was obtained adjacent to another hit, it may be set to z. B. 1/10 are reduced (double hit). The extraction of the first image content takes place immediately after the training / competition start. The next image content is won after each next shot. The shot is registered by the acoustic signal on the microphone input of the smartphone and serves as a trigger. For trigger evaluation, a lower than maximum resolution of the image information can be used to get the fastest possible results.

Display area:

Here is the last hit very noticeable, z. B. red / poison green or signal yellow or quickly pulsating. The penultimate hit is conspicuous, z. B. bicolor or slowly pulsating. All hits before that are displayed unchanged or black or with a thin outer ring. Possibly. Each hit can be provided with its shot number.

Information area:

Here are details of the software made.

Operating area:

• s. basic version

Module 2:

It is important to find out where the hit is located, in target coordinates (with origin / origin at the center of the target) and what is the hit value. The hit value is equal to the smallest ring number of a ring within which the innermost (next to the target center) point of the hit is or a ring of the hit (also from the outside!) Is touched. Here it is necessary that the target by z. B. Object recognition algorithms is detected that the target center and the rings are displayed in target coordinates. For this purpose, a picture with maximum contrast can be created in which all colors below a certain value (here really only black) are converted to deep black, all colors above a certain value (here actually only beige) are converted to white. The difference of the image thus created and the image represented by functions (obtained from object recognition) should be minimal, ideally equal to zero.

Information area:

The information area is pretty packed here. In addition to information on the software and possibly company name and logo, up to ten last scores (numbers) are displayed consecutively, starting from the left, in groups a five values (at the border to the scoreboard). Far from right, the average score is displayed (also at the border to the display area), above the right the shot number is displayed (here preferably in inverse font). After the last shot, the total number of rings is displayed here. Above the hit values left the remaining time is displayed. After every 5 shots there is a warning that the target has to be changed and a new series is to be started.

After 40 shots training or competition stop and evaluation takes place, storing the results (hit values, numbers, times, hit position) and at least 1 image per 5-series.

Display area:

• s. Module 1

Operating area:

s. Basic version. There is also a switch for training or competition start, which changes into stop switch mode after pressing. If this switch is pressed, the evaluation is forced (eg during a workout abort).

Module 3:

Here you can connect to social networks (FaceBook, Twitter, also YouTube: here a short standard movie or a short slide show or a standard protocol (with possibility of comment input) is created and uploaded) (eg with name / pseudonym , Club, competition) and possibly a connection to the cloud with data storage.

Module 4:

A list of clubs with GPS co-ordinates will be added here, so the place or club can also be taken over into the processing abroad.

Module 5:

The shooting book function is realized: Date, time, location, training / competition, discipline, possibly opponents, number of firing shots are saved. Entries that have been created once can not be changed. Authenticity is confirmed by location (from GPS) or daily evaluation.

Module 6:

In the display area the target image is made movable with swipe gestures. You can thus save the mechanical alignment and thus the alignment mechanism. (possibly with a lock switch ("lock button") to "freeze" the found position)

Module 7:

Training module 1: Here is a long-term presentation of the results (average values, Einzellwerte, average values with scattering, ...) for different periods, possibly with additional representation of parameters (eg: temperature, day of the week, time of day, self-determined and self to be entered parameters, ...)

Module 8:

Training module 2: Here is an evaluation of the shot image. It allows conclusions about settings of the weapon or performance of the shooter (calm / restless hand, trigger optimally or too far forward / backward, trigger finger optimally or too far left / right, sight optimally or too far left / right / up / down, Sighting optimally or not in cover, ...). Here is also a long-term presentation with different characteristics / parameters or targeted comparison with a specific day or period. On the basis of the evaluations, suggestions for improvement are made and specific instructions given.

Module 9:

Here, the individual or team competition season is evaluated automatically or manually.

Module 10:

Here the target is automatically detected, positioned in the middle and displayed filling the screen.

In the evaluation, preferably only the display area of the image is processed (possibly with a relatively narrow edge), because high processing speed must be achieved.

When creating the software, it is preferable to use the correlation of the digital zoom factor with the registered size of the target (helps with image recognition, parameter: smartphone camera FOV and magnification of the telephoto lens), the correlation of the discipline with the target and correlation of the hit size with the discipline. These correlations are stored in the memory with meaningful tolerances.

Claims (11)

Optical extension for a smartphone camera, characterized in that the optical beam path of the extension is folded, this extension includes a mechanical device with which the extension can be connected to the smartphone containing the camera, so that the optical axis of the smartphone camera on Output of the smartphone camera coincides with the optical axis of the extension at the entrance of this extension. Optical extension according to claim 1, characterized in that the part of the optical beam path coming from the smartphone camera after the first deflecting mirror points substantially in the direction of the camera farthest or second most distant smartphone edge. Optical extension according to claim 1, characterized in that the beam path is folded at least twice. Optical extension according to claim 1, characterized in that the extension contains a Kepler or a Galilean telescope or a microscope. Optical extension according to claim 1, characterized in that the extension contains at least one diffractive optical element serving as a lens. Optical extension according to Claim 5, characterized in that the "ghost patches" caused by the diffractive optical element lie outside the target display. Optical extension according to claim 1, characterized in that the extension contains only non-moving optical parts. Optical extension according to claim 1, characterized in that the first deflecting mirror is arranged between the eyepiece and the field lens. Optical extension according to claim 1, characterized in that the extension contains at least one non-planar mirror. Optical extension according to claim 1, characterized in that the bottom of the Extension is at an angle between 1.6 ° and 4.3 ° to the optical output axis of the extension. Optical extension according to claim 1, characterized in that the associated software includes at least one control element which is cascadable in at least two accuracy levels.

Images