Apparatus for measuring refractive power

A refracting power measuring apparatus comprising:

• a measuring optical system for projecting a measuring light toward a soft contact lens wet with liquid to measure optical characteristic values of the soft contact lens in air;
• a light receiving optical system having a light receiving sensor which receives the measuring light passed through the soft contact lens and outputs a received signal;
• an arithmetic circuit in which the received signal is input and computes the optical characteristic values based on the received signal;
• a residual quantity arithmetic circuit in which optical characteristic values data corresponding to the optical characteristic values of the arithmetic circuit are input every sample time and computes a residual quantity by means of a statistical processing based on the optical characteristic values data to output the residual quantity signal;
• a memory storing means to memorize the residual quantity computed by the residual quantity arithmetic circuit;
• a judging means to judge whether a difference is a predetermined values with computing the difference in sequence of time based on the residual quantity stored in the memory storing means;
• and
• a display means to represent with extracting optical characteristic values corresponding to a difference which is less than a predetermined values.

A refracting power measuring apparatus comprising:

• a measuring optical system for projecting a measured bean toward a soft contact lens to measure optical characteristic values of the soft contact lens in air;
• a light receiving optical system having a light receiving sensor which receives a measuring light passed through the soft contact lens and outputs a light receiving signal;
• and
• an arithmetic optical system in which the light receiving signal is input and computes the optical characteristic values based on the light receiving signal,
• said measuring optical system being a pattern beam projecting optical system which projects a pattern beam for measuring a refracting power of the soft contact lens on a reflected surface through the soft contact lens,
• said light receiving optical system guiding the pattern beam which is reflected on the reflected surface and returned through the soft contact lens to the light receiving element,
• a portion of an optical system of the pattern beam projecting and light receiving optical systems being shared,
• a deflecting member which deflects and projects the ring shaped pattern beam with respect to an optical axis of the pattern beam projecting optical systems being provided in the shared portion of the pattern beam projecting and light receiving optical systems,
• said deflecting member being a deflecting prism which is rotated about an optical axis.