Ophthalmologic apparatus

Abstract

For improving the operability of the apparatus, the ophthalmologic apparatus of the invention comprises a measuring optical system which optically measures an eye to be examined, a detection system which detects alignment information of the eye for the measurement, a driving mechanism which moves the measuring optical system relative to the eye, an operating device which allows an operator to manually control the driving mechanism in order to move the measuring optical system, and a controller which controls the driving mechanism to perform alignment of the measuring optical system with respect to the eye, with a plurality of modes including a first mode executing automatic alignment within a predetermined range based on the alignment information of the detection system and a second mode executing manual alignment within a range broader than the predetermined range based on the operation of the operation device, wherein the controller automatically changes between the first mode and the second mode based on a predetermined event.

What is claimed is:  
     
         1 . An ophthalmologic apparatus, comprising: 
 a measuring optical system which optically measures an eye to be examined;    a detection system which detects alignment information of the eye for the measurement;    a driving mechanism which moves said measuring optical system relative to the eye;    an operating device which allows an operator to manually control the driving mechanism in order to move said measuring optical system; and    a controller which controls the driving mechanism to perform alignment of said measuring optical system with respect to the eye, with a plurality of modes including a first mode executing automatic alignment within a predetermined range based on the alignment information of said detection system and a second mode executing manual alignment within a range broader than said predetermined range based on the operation of said operation device, wherein said controller automatically changes between the first mode and the second mode based on a predetermined event.    
     
     
         2 . An apparatus according to  claim 1 , wherein the controller controls, during the second mode, to change automatically from the second mode to the first mode when the detection system detects the positional information which lies within said predetermined range.  
     
     
         3 . An apparatus according to  claim 1 , wherein the controller controls, during the first mode, to change automatically from the first mode to the second mode when the operating device is operated.  
     
     
         4 . An apparatus according to  claim 1 , further comprising an indicator which gives a distinguishable indication between the first mode and the second mode for the operator.  
     
     
         5 . An apparatus according to  claim 1 , further comprising an optical element with at least one prism disposed in an optical path of the detection system at least during the alignment and an area sensor, wherein the prism serves to separate a partial light beam and the area sensor serves to detect the position of the separated partial light beam in order to detect alignment information.  
     
     
         6 . An apparatus according to  claim 5 , wherein said optical element has a plurality of said prism, and further comprises an actuator for putting said optical element into the optical path during the alignment with said detection system and for putting said optical element out of the optical path during the measurement with said measuring optical system.  
     
     
         7 . An apparatus according to  claim 6 , further comprising an aperture selectively disposed, while the measurement, within the optical path of the measurement optical system independently of said optical element.  
     
     
         8 . An apparatus according to  claim 5 , wherein said optical element has an aperture for the measurement with said measuring optical system, and a plurality of said prism disposed around the aperture for the alignment with said detection system.  
     
     
         9 . An apparatus according to  claim 1 , wherein said controller serves to automatically start the measurement with said measurement optical system after the alignment with said detection system.  
     
     
         10 . An apparatus according to  claim 1 , wherein said measuring optical system includes a system to measure at least one of a refractive power and the cornea of said eye to be examined.  
     
     
         11 . An apparatus according to  claim 1 , said measuring optical system and said detection system have a lens and an area sensor, being used both for a cornea measurement by said measuring optical system and for a three-dimensional alignment detection by said detection system.  
     
     
         12 . An ophthalmologic apparatus, comprising: 
 a measuring optical system which optically measures a cornea of an eye to be examined; and    a detection system which detects three-dimensional alignment information of the eye,    wherein the measuring optical system and the detection system have a lens and an area sensor, being used both for a cornea measurement by said measuring optical system and for a three-dimensional alignment detection by said detection system.