DE587079C - Reflexless ophthalmoscope - Google Patents
Reflexless ophthalmoscopeInfo
- Publication number
- DE587079C DE587079C DEB153636D DEB0153636D DE587079C DE 587079 C DE587079 C DE 587079C DE B153636 D DEB153636 D DE B153636D DE B0153636 D DEB0153636 D DE B0153636D DE 587079 C DE587079 C DE 587079C
- Authority
- DE
- Germany
- Prior art keywords
- ophthalmoscope
- reflexless
- reflective surfaces
- eye
- mirror
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/14—Arrangements specially adapted for eye photography
- A61B3/15—Arrangements specially adapted for eye photography with means for aligning, spacing or blocking spurious reflection ; with means for relaxing
- A61B3/156—Arrangements specially adapted for eye photography with means for aligning, spacing or blocking spurious reflection ; with means for relaxing for blocking
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Ophthalmology & Optometry (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Eye Examination Apparatus (AREA)
Description
Reflexloser Augenspiegel In der deutschen Patentschrift 218 227 ist ein reflexloser Augenspiegel beschrieben, bei dem die wirksamen Spiegelflächen, wie in Abb. r der Zeichnung dargestellt ist, aus je einer achsensymmetrischen, sphärischen und ebenen Fläche bestehen.Non-reflex ophthalmoscope In the German patent specification 218 227 a reflex-free ophthalmoscope is described in which the effective mirror surfaces, as shown in Fig. R of the drawing, each consist of an axially symmetrical, spherical and flat surface.
Infolge der erforderlichen Spiegelneigung erscheint das beobachtete Bild ein wenig verzerrt; so wird beispielsweise ein Quadrat (Abb. 2a) in eine trapezförmige Figur (Abb.2b) verwandelt.The observed appears as a result of the required mirror inclination Image a little distorted; for example, a square (Fig. 2a) turns into a trapezoidal one Figure (Fig.2b) transformed.
Dieser Mangel wird nun gemäß der Erfindung dadurch beseitigt, daß mindestens eine der spiegelnden Flächen nicht sphärisch oder plan, sondern in einer Richtung stärker gekrümmt ist als in der darauf senkrechten. Auf diese Weise gelingt es, ein Quadrat auch annähernd wieder als Quadrat abzubilden, und die etwa verbleibende trapezförmige Verzerrung kann man weiter dadurch beseitigen, daß man nicht einen Ausschnitt aus der torischen Fläche verwendet, bei dem der Äquator durch die Mitte des Spiegels geht (I in Abb. 3), sondern einen seitlichen Ausschnitt aus dieser Fläche (1I in Abb. 3).This deficiency is now eliminated according to the invention in that at least one of the reflective surfaces is not spherical or flat, but in one Direction is more curved than in the one perpendicular to it. In this way it succeeds it is to approximate a square again as a square, and the remaining one trapezoidal distortion can be further eliminated by not using a Section of the toric surface used with the equator through the middle of the mirror (I in Fig. 3), but a side section from this Area (1I in Fig. 3).
Die Entstehung solcher Flächenstücke ist in Abb. 3 dargestellt. In dieser Abbildung lasse man die Kurve a, die im allgemeinen ein Kreisbogen ist, aber nicht notwendig ein solcher zu sein braucht, um die Achse b rotieren; dabei erzeugt sie eine torische Fläche. Der Punkt c, in dem diese Kurve d zur Rotationsachse b parallel ist, beschreibt dabei einen Kreis, den man den Äquator des Torus nennt. Das obengenannte Flächenstück I liegt also symmetrisch zum Äquator, während er durch das genannte Kurvenstück II nicht in der Mitte, sondern seitlich hindurch oder daran vorbeigeht. Ist die Kurve a eine gerade Linie, so ist die erzeugte Fläche eine Kegel- oder Zylinderfläche, und auch diese sind erfindungsgemäß zur Behebung der erwähnten Verzerrung geeignet.The creation of such patches is shown in Fig. 3. In but leave the curve a, which is generally an arc of a circle, to this figure does not need to be such, to rotate about the axis b; generated in the process they have a toric surface. The point c at which this curve d to the axis of rotation b is parallel, describes a circle called the equator of the torus. The above-mentioned patch I is therefore symmetrical to the equator, while it is through said curve piece II not in the middle, but laterally through or on it passes by. If the curve a is a straight line, the surface generated is a conical or cylinder surface, and these are also according to the invention to remedy the mentioned Suitable for distortion.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEB153636D DE587079C (en) | Reflexless ophthalmoscope |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEB153636D DE587079C (en) | Reflexless ophthalmoscope |
Publications (1)
Publication Number | Publication Date |
---|---|
DE587079C true DE587079C (en) | 1933-10-30 |
Family
ID=7002907
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DEB153636D Expired DE587079C (en) | Reflexless ophthalmoscope |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE587079C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990000026A1 (en) * | 1988-06-29 | 1990-01-11 | G. Rodenstock Instrumente Gmbh | Device for producing an image of an object |
-
0
- DE DEB153636D patent/DE587079C/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990000026A1 (en) * | 1988-06-29 | 1990-01-11 | G. Rodenstock Instrumente Gmbh | Device for producing an image of an object |
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