# US 4,396,260 A · Slit lamp having replaceable objective lens unit for observation of cornea

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- Number: US 4,396,260 A
- Document ID: US4396260A
- Status: Granted
- Kind: A
- Application number: 06/122,673
- Filed: 1980-02-19
- Granted: 1983-08-02
- Earliest claimed: 1979-02-20
- Assignees: Tokyo Kogaku Kikai Kabushiki Kaisha
- Inventors: Shiro Takizawa; Shinichi Nishimura
- Web page: https://patentgrep.com/patent/US4396260A

## CPC

- A61B 3/135: Slit-lamp microscopes
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

Slit lamp having a slit illumination system, a binocular microscopic system and a photographing system. The binocular microscopic system has an objective lens assembly which is mounted replaceably on the body. A replaceable lens unit is provided for observation of the endothelial cell of the cornea. The lens unit include an objective lens, a relay lens and mirrors for directing the light bundle through the objective lens to one of the optical paths in the binocular microscopic system.

## Claims

### Claim 1

Slit lamp including a slit illumination system for projecting a slit luminous flux to a patient's eye, a body provided with a mount, objective lens means adapted to be mounted through said mount on said body so that it can be easily replaced, a binocular microscopic system including a pair of optical paths for observing an illuminated portion of the patient's eye through said objective lens means, a pair of variable power lenses for varying the magnification of the image observed, said pair of variable power lenses being placed between said objective lens and said observing optical paths, a photographing optical system for taking photographs of said illuminated portion of the patient's eye, said photographing system having at least one optical path which is at least partially in common with said binocular optical system, and an alternative lens means for observing the ocular anterior of the patient's eye in high magnification, said alternative lens means being replaceably mountable through said mount on said body in lieu of said objective lens means, said alternative lens means including alternative objective lens means for focusing a beam of light at an image point, relay lens means for relaying said beam of light from said image point and optical means for directing the beam of light to one of the variable power lenses in the binocular microscopic system.

### Claim 2 (depends on 1)

Slit lamp in accordance with claim 1 in which said photographing optical system includes a pair of optical paths which respectively correspond to the observing optical paths.

### Claim 3 (depends on 1)

Slit lamp in accordance with claim 1 in which said optical means includes reflective mirror means.

### Claim 4 (depends on 1)

Slit lamp in accordance with claim 1 having mirror means for directing light into said photographing system comprising a pair of parallel mirrors having reflective surfaces opposed to each other and inclined with respect to an optical axis of the objective lens.