DE9302485U1 - Viewing device for transparent objects - Google Patents

Description

Patent attorney's office Tergau & Pohl, Nuremberg . * ! ;.: : .·.·..; ·. Page 1

Description

Viewing device for transparent objects

&bgr; The invention relates to a viewing device for transparent objects, such as

9 Example gemstones, optical lenses, contact lenses, with at least one magnifying glass

10 and with a holder for the object to be viewed, with an electrical

11 Lighting unit for illuminating the object under observation and with a

12 dark object background.

14 For the assessment and testing of transparent objects using opti-

15 scientific aids, e.g. magnifying glass or microscope, it is known that the object to be examined

ie object using light passing through from the side, in order to

17 to be able to recognize fine structures or contours that are not visible in normal

is transmitted light cannot be perceived due to insufficient contrast.

zo This well-known examination technique, also commonly known as dark

21 field illumination is well known from microscopy.

22. Here, illumination rays are passed through a special condenser

23 or through a special condenser aperture through the transparent examination

24 object is guided past the lens. Only the structural details

25 Light deflected or diffracted in the object enters the lens, where it

26 for the dark field characteristic image with bright structural details in front

27 dark background. To obtain this high-contrast image,

28 is often used, especially in stereomicroscopes, the dark field illumination

29 unit is designed so that the object background is formed by a dark plate which weakly reflects incident light.

32 The dark field investigation principle is based on the fact that the

33 The object to be searched is placed against a dark background and can only be identified by

34 Scattered light is imaged, as the remaining light is diffused by the dark background.

35 feet and thus hardly dazzles the viewer's eye and thus only slightly impairs his vision. However, it must be taken into account that when using an opaque dark plate, e.g. black, the illumination light as well as the ambient light is reflected on the plate.

18 February 1993

Patent Attorney's Office Tergau & Pohl, Nuremberg _m * Z !.: ; .·.·..; ·. Page 2

· 4

&igr; and in an image the object background is no longer black

2 but appears grey.

4 However, in some cases, due to the effects described,

5 In addition, the desired resolution, i.e. clarity of the image,

β is not achieved because there is a residual brightness next to the object being examined.

7. This can lead to any traces of the object being examined being

8 characteristics remain unrecognized or undiscovered because they are inadequately

9 depicted accordingly or made recognizable.

11 In addition, the technical effort required is relatively high, in particular

12 especially when only small magnifications are required and the user

13 use of a microscope is unnecessary or inappropriate.

is Based on this state of the art, it is therefore the object of the invention,

ie to create a viewing device of the type mentioned above, which has a

&eegr; has the simplest possible structure, is inexpensive to manufacture and at which

18 The glare effect described above is largely avoided.

20 This object is achieved according to the invention by the characterizing

21 Features of claim 1. According to the teaching given therein,

22 that the object background is a material with particularly low light transmission

23 liquid is provided which absorbs incident light instead of reflecting it.

24 and thus provides a uniformly dark background, which ensures a

25 possible observation of the object under observation or investigation is permitted.

27 It is advantageous to use a grey filter as the object background.

28 Place of a grey filter, which absorbs light of all wavelengths, can also

29 an arrangement of two polarization filters should be provided, which are in blocking

30 position, i.e. in a crossed position, in which, due to the light-extinguishing effect, the viewer's eye is presented with a glare-free

32 surface.

34 According to a preferred embodiment of the invention, the enlargement

35 lens arrangement provided for adjustment in an adjustable holder or in a tube, each of which is connected to a magnifying glass pot.

37 are bindable, i.e. removably attached to the said magnifying glass pot.

18 February 1093

Patent Attorney's Office Tergau & Pohl, Nuremberg ·' I 1*1 I ·*„*·.! *. Page 3

&igr; Another useful development is that the lighting

2 unit is arranged perpendicular to the optical axis of the lens arrangement,

3 wherein the light emitted by the lighting unit is between the

4 Object and the object background, the optical axis of the lens

s sen arrangement so that the object under examination or observation

&bgr; is not directly illuminated.

8 A favorable embodiment of the invention consists in that the lighting

9 power unit is battery powered, making it independent of local power sources.

10 len, so that not least due to its compact design

11 can be transported without any particular problems.

is For handling reasons but also with regard to cost-effective production

14 position, it can also be provided that the lighting unit as

is a lighting handle with a lamp. The lighting

16 handle, which corresponds to the lighting handle of a commercially available

17 flashlight can be designed, batteries housed.

19 Advantageously, the magnifying glass pot is connected to the lighting handle with lamp

μm formed lighting unit is detachably attached, whereby the connection

21 between the magnifying glass pot and the lighting handle as a plug connection

22 is trained.

24 In a further development of this design, it may be provided that the

25 lighting unit is part of a flashlight in which the commercially available reflector attachment is replaced by the magnifying glass pot.

28 In order to ensure the simplest possible handling of the device according to the invention,

29 viewing device, the support for holding the viewing device is

30 object between the magnifying glass pot on the one hand and the tube or holder that holds the lens arrangement on the other hand.

32 according to a preferred embodiment of the invention, the support of we-

33 at least two spaced apart webs must be formed, which

34 are arranged crosswise or parallel to each other and on which the

35 Object of observation can be fixed.

37 An advantageous development of the invention provides that the webs are made of

made of thin wire. The bars can also be made of transparent

13. Photo 1SB3

Patent Attorney Office Tergau & Pohl, Nuremberg .* J :.: : .*.·.. J ·. Page 4

&igr; material, e.g. glass or plastic.

3 Instead of a web arrangement to accommodate the respective loading

4 object of observation, in a further development of the invention, a support plate

5 made of transparent material, preferably with an etched or engraved

6 fourth division scale are used.

8 The filter provided as object background is a further development of the invention

s below the light radiation emitted by the lighting unit at the

10 bottom of the magnifying glass pot, where it collects the light from the inner wall of the

11 pentopfes reflected light radiation is absorbed. To connect the support with

12 The filter serving as the object background can be a cylindrical ring made of

13 crystal-clear plastic, e.g. polymethacrylate.

16 With regard to the desired cost-effective production of the

The viewing device can be mounted on the magnifying glass head with

&eegr; lighting unit formed device the housing of a commercially available

18 Illuminated magnifier, with only a holding device for the viewing object

19 project and a possibility to attach the lens arrangement to it. The lens arrangement is designed as a focusing magnifier, with

21 which, by turning a focusing ring provided for this purpose, the axial

22 Distance between the lenses can be changed and in this way the desired focus

23 is adjustable.

25 The viewing device described above is in accordance with the invention

26 as a dark field device. This and the other features of the

27 Invention are the subject of the dependent claims.

29 Based on an embodiment of the invention shown in the drawing,

30 The invention, advantageous embodiments and special advantages

31 of the invention will be explained and described in more detail.

34 Show:

36 Fig. 1 a viewing device according to the invention in so-called exploded

37 representation of all main parts

18. Febnjflf10S3

Patent Attorneys Tergau & Pohl, Nuremberg . * * * * · * ·· ·* Page 5

&igr; Fig. 2 shows a different holder for the lens arrangement than shown in Fig. 1

2 Fig. 3 a support ring for the object to be viewed and

3 Fig. 4 a cuvette as a support for the examination of soft contact lenses in

4 hydrated state.

6 A viewing device 10 according to the invention is composed of a

7 attachable magnifying glass 27 or lens arrangement 12, which in a tube-like

&bgr; holder 14 is optionally adjustable, from a magnifying glass pot 16

9 designated pot-like hollow cylinder with a provided at the upper edge

10 hen support 17 and a laterally formed on the magnifying glass pot 16

11 nozzle-like connection 18 for a lighting unit 20, which is essentially

12 consists of a hollow cylindrical lighting handle 22.

14 The lighting unit 20 largely corresponds to a housing of a rod

15 flashlight, in which the necessary for operating the flashlight

the batteries are housed, and in which the reflector is replaced by the magnifying glass

17 pot 16 is replaced. Accordingly, the lighting handle 22 is provided with a

is provided with lamp holder 23 at the end which is for connection to the

ig magnifying glass pot 16 is provided. In the lamp socket

20 23 a light bulb 26 is inserted.

22 The lens arrangement 12 can also be a conventional attachable magnifying glass 27. It

23 may, where appropriate, be applied to the different levels of consideration of a

24 viewing object 30, i.e. to the desired

25 object distance. For this purpose, the lens arrangement 12 is in the holder

26 14 adjustable. The distance between magnifying glass 27 and object 30 is then

27 variable.

2a The object of observation 30 mentioned above is a contact

30 lens; it can also be any other object, but preferably

31 only translucent objects, which can be identified with the aid of the method described below,

32 dark field device trained viewing device 10 and

33 should be visually inspected.

35 For observation, the respective object 30 to be observed is placed on the support 17 located on the magnifying glass pot after the holder 14 with the magnifying glass 37 27 or lens arrangement 12 has been removed. The support 17 for the object 30 to be observed is protruding from the magnifying glass pot 16 in the example shown.

18 February 1993

Patent Attorney's Office Tergau & Pohl, Nuremberg ,*; &idigr;.&iacgr; I .*.*.»! * Page 6

&igr; taken to clearly show that the support 17 with the object background

2 base 32 forms a structural unit. The support 17 itself is connected to each other

3 parallel arranged webs 28 are formed, which at the edge at the support 17

4 are attached.

e Fig. 3 shows a modified support in which the webs 28 with their

7 both ends are held in a plastic injection-molded support ring,

β which can be placed on the ring cylinder 34. The cuvette 36 (Fig. 4) is a

&bgr; special form of a support 17 for the examination of soft contact lenses.

10 The cuvette 36 is made of transparent material. It contains the

11 Examination: Insert soft contact lenses in a hydrated state.

13 With regard to the fine structures of the respective object under observation 30,

&eegr; which are to be examined in the viewing device 10, e.g. hairline cracks in

15 of a contact lens or similar, the bars are very narrow to avoid

16 causing misrepresentations.

is After the object 30 has been placed in the viewing device

io 10, the holder 14 with the lens arrangement 12 is placed back on the magnifying glass pot

20 16 set up.

22 The magnifying glass pot 16 has a not visible here on its underside

23 circular, the inner diameter of the circular cylindrical magnifying glass pot 16

24 adapted optical filter 32, which can be used as a neutral, extremely strong

25 absorbing grey filter or as a polarizing filter in blocking position, that is

26 with mutually crossed polarization planes, and

27 serves to create a dark field by absorbing the incident light.

28 produce an object background that is as evenly dark as possible.

30 The magnifying glass pot 16 is also commercially available as an illuminated magnifying glass, where

31 However, the changes described above with regard to the previous

32 seen use as darkfield viewing device 10 made

33 were.

35 As already mentioned, the magnifying glass pot 16 is designed according to the

This illuminated magnifying glass has a removable cover attached radially to its side.

37 lighting unit 20, with which the object being viewed is illuminated

se should become.

18 February 1893

Patent Attorney's Office Tergau & Pohl, Nuremberg ·"! &iacgr; · &Sgr; I ·*.*·.! *. Page 7

2 Since the detection of the smallest details on the object 30 requires a

3 observation in bright field by direct incident light on the object under observation 30

4 is unsuitable because the viewer’s eye is distracted by the

6 object 30 can be dazzled, the illumination is carried out β by scattered light diffusely reflected on the inner wall of the magnifying glass pot 16. This

7 is achieved in that the irradiation plane of the lighting unit 20 β in the magnifying glass pot 16 is provided between the support 17 of the object 30 to be observed and β the object background formed by the optical filter 33.

10 This means that the object 30 under observation is illuminated only by

11 from its back, which is turned away from the viewer’s eye. This

12 light hitting the object from behind is reflected from the viewing

13 object 30 is diffracted or refracted, while the remaining light from the

&eegr; object background forming filter 33. This creates a very

A high-contrast image is achieved. It is essential that

no light is directed directly into the viewer's eye.

is To adjust the distance between the support 17 and the object background

19 Background with the light-extinguishing optical filter 33 is a ring cylinder 34

20 made of transparent material, e.g., polymethacrylate with the trade name

21 Plexiglas, provided.

23 In Fig. 2, a second lens arrangement 13 is shown as a variant of the lens arrangement

24 12 according to Fig.1, which instead of the lens arrangement shown in Fig. 1

25 12 is held in a differently designed holder 15. While the holder shown in Fig. 1 2β is designed as a tube 14, the one shown in Fig. 2 consists of

27 provided a holder made of a plastic housing 15 in which the

28 lens arrangement 13 is mounted, whereby for adjustable setting of the lens

29 arrangement 13, an adjusting pin is connected to the housing 15 for the purpose of adaptation to the desired object distance, which pin engages in a recess provided for this purpose in the magnifying glass pot 16, not shown in Fig. 1.

18, February 1993

Patent attorney's office Tergau & Pohl, Nuremberg , *
List of reference symbols Viewing device · · · * * 10 Lens arrangement 12 Lens arrangement 13 Tube 14 Housing 15 Magnifying glass pot 16 Edition 17 Connection 18 Lighting unit 20 Lighting handle 22 Lamp holder 23 Cover cap 24 light bulb 26 Magnifying glass 27 web 28 Object of observation 30 Object background 32 filter 33 Ring cylinder 34 Support ring 35 Cuvette 36

February 18, 1893

Claims (1)

Patent Attorney's Office Tergau & Pohl, Nuremberg *&iacgr;&iacgr;&iacgr; JI* I Il .»Page &igr; 90155-1/24 3 18 February 1993 Expectations 9 1. Viewing device (10) for transparent objects, such as precious 10 stones, optical lenses, contact lenses, with a magnifying glass (27) or lens 11 arrangement (12,13), with a support (17) for the object to be viewed (30), iz with an electrical lighting unit (20) for illuminating the is object of observation (30) and with a dark object background (32), µm characterized by 15 that a plate (33) of low light transmission is provided as the object background. 16 is seen, soft absorbs incident light. ie 2. Viewing device according to claim 1, ig characterized by 20 that a grey filter (33) is provided as the object background (32), which 21 is preferably extremely light-absorbing. 23 3. Viewing device according to claim 1, 24 characterized by 25 that a polarization filter (33) is provided as the object background (32), the 2β is in the blocking position. 28 4. Viewing device according to one of the preceding claims, 29 characterized by so that the lens arrangement (12,13) is adjustable in a magnifying glass si (16) connectable tube (14) or a housing (15) as a holder 32 is. 34 5. Viewing device according to one of the preceding claims, 35 characterized by that the illumination unit (20) is perpendicular to the optical axis of the lens 37 arrangement (12,13) and that the light emitted by the lighting 38 unit (20) outgoing light between the object (30) and the 18 February 1SB3 (U:\AN\gO 155.TXT) Patent Attorney's Office Tergau & Pohl, Nuremberg · :; ; ; ! *"*i ·**· """"Page &igr; Object background (32) the optical axis of the lens arrangement (12,13) 2 cuts. 4 6. Viewing device according to one of the preceding claims, 5 characterized by 6 that the lighting unit (20) is battery powered. 8 7. Viewing device according to one of the preceding claims, g characterized by 10 that the lighting unit (20) as a lighting handle (22) with lamp (26) 11 is formed, in which lighting handle (22) batteries are housed 12 are. 14 8. Viewing device according to one of the preceding claims, is characterized by ie that the area formed by the lighting handle (22) with lamp (26) The lighting unit (20) can be attached radially to the magnifying glass pot (16). 19 9. Viewing device according to one of the preceding claims, 20 characterized by 21 that the lighting unit (20) is powered by a mains transformer, in particular 22 which is supplied with adjustable brightness. 24 10. Viewing device according to one of the preceding claims, 2s characterized by 26 that the connection between the magnifying glass pot (16) and the lighting handle 27 (22) is designed as a plug connection. 2β 11. Viewing device according to one of the preceding claims, so characterized by 31 that the lighting unit (20) is part of a flashlight, in which 32 the reflector attachment is replaced by the magnifying glass pot (16). 34 12. Viewing device according to one of the preceding claims, 35 characterized by se that the support (17) for holding the object to be viewed (30) between 37 the tube (14) accommodating the magnifying glass (27) or the lens arrangement (12) se or housing (15) and the magnifying glass pot (16). 18 February 1993 (Ui\AN\S0155.T)CT) Patent Attorney's Office Tergau & Pohl, Nuremberg "&idigr;&iacgr;&iacgr;.&idigr;&idigr;'&idigr; ti . 'Page a 13. Viewing device according to claim 12, 3 characterized by 4 that the support (17) is supported by at least two spaced-apart 5 net webs (28) on which the viewing object (30) can be fixed. 8 14. Viewing device according to claim 13, &thgr; characterized by io that the webs (28) are arranged parallel. 12 15. Viewing device according to claim 13 or 14, 13 characterized by 14 that the webs (28) are made of thin wire. ie 16. Viewing device according to one of claims 13-15, &eegr; characterized by is that the webs (28) with their ends in a pointed plastic 19 bearing ring (35). 21 17. Viewing device according to claim 12, 22 characterized by 23 that the support (17) is made of transparent material by a 24 cuvette (36) is formed. 26 18. Viewing device according to claim 12, 27 characterized by 28 that a transparent pane is provided as a support (17). 30 19. Viewing device according to one of the preceding claims, 31 characterized by 32 that the filter (33) provided as object background (32) is below the 33 the light radiation emitted by the lighting unit (20) at the bottom of the 34 magnifying glass pot (16). 36 20. Viewing device according to one of the preceding claims, 37 characterized by that the viewing device (10) is designed as a dark field device. (S. February 1B93 (UWfS01S5.TXT)