Device and Method for Optically Sensing a Specimen with a Large Depth of Field

Abstract

A device for optically sensing a specimen with a large depth of field has a lighting module which illuminates a zone of the specimen during a predetermined measurement period with a pattern whose phase is modified in time during the measurement period, generating a specimen light to which a corresponding time-variable phase is imparted. The device also includes a detection module having a space-resolving detection zone which records the specimen zone and has multiple recording pixels, two analysis channels which can be connected to the recording pixels, and an analysis unit is connected to both analysis channels. A control unit is provided which, during the measurement period, connects each recording pixel in synchrony with the phase of the detected specimen light to the two analysis channels, alternatively, in such a way that the detected specimen light is divided into two portions phased in relation to one another, and the analysis unit calculates an optical split-image of the specimen zone on the basis of the two phased portions supplied to the analysis channels.

1 . A device for optical sensing a specimen with a large depth of field,
 an illumination module that illuminates an area of the specimen during a predetermined measurement period with a pattern, the phase of which varies over time during the measurement period, generating a specimen light, to which a corresponding time-varying phase is imparted, is generated,   a detection module having a space-resolving detection area with multiple recording pixels, two analysis channels connectable to recording pixels, and an analysis unit connected to the two analysis channels, and   a control unit that alternately connects each recording pixel in temporal synchronism with the phase of the detected specimen light to the two analysis channels during the measurement period, so that the detected specimen light is subdivided into two components having a phase shift with respect to one another, and is supplied to the analysis channels, wherein the analysis unit calculates an optical sectional image of the specimen area based on the components supplied to the analysis channels.   
   
   
       2 . The device according to  claim 1 , in which the control unit connects each recording pixel alternately to the two analysis channels such that the phase shift amounts to 180°. 
   
   
       3 . The device according to  claim 1 , in which each recording pixel has two subpixels, wherein one of subpixels can be connected only to the first of the two analysis channels and the other subpixel can be connected only to the second analysis channel. 
   
   
       4 . The device according to  claim 1 , in which the recording pixels are arranged side by side along an extension direction. 
   
   
       5 . The device according to  claim 1 , in which each of the analysis channels is constructed as a separate analysis electronic unit. 
   
   
       6 . The device according to  claim 1 , in which each analysis channel for each recording pixel has an integrator that sums the supplied components during the measurement period. 
   
   
       7 . The device according to  claim 1 , in which the analysis unit subtracts the two components from one another to calculate the optical sectional image. 
   
   
       8 . The device according to  claim 1 , in which said illumination module illuminates the specimen linearly and varies the phase in the direction of the linear illumination. 
   
   
       9 . A method for optical sensing of a specimen with large depth of field, in which an area of the specimen is illuminated during a predetermined measurement period with a pattern, the phase of which is temporally varied during the measurement period, generating a specimen light, to which a corresponding time-varying phase is imparted, and in which the specimen area is detected during the measurement period in a space-resolving manner and the detected specimen light is subdivided into two components having a phase shift with respect to one another, wherein an optical sectional image of the specimen area is calculated based on the components supplied to the analysis channels. 
   
   
       10 . The method according to  claim 9 , in which the detected specimen light is subdivided with a phase shift of 180°. 
   
   
       11 . The method according to  claim 9 , in which several recording pixels are provided for space-resolving detection wherein each recording pixel ( 12 ) has two subpixels ( 15 ,  16 ) and one of the subpixels ( 15 ,  16 ) supplies only the first of the two components, and the other subpixel supplies only the second component. 
   
   
       12 . The method according to  claim 9 , in which a linear, space-resolving detection is performed. 
   
   
       13 . The method according to  claim 9 , in which a separate analysis electronic unit is provided for each component. 
   
   
       14 . The method according to  claim 9 , in which an integrator that sums up the supplied components over the measurement period in a space-resolving manner is provided for each component. 
   
   
       15 . The method according to  claim 9 , in which the two components are subtracted from one another to calculate the optical sectional image. 
   
   
       16 . The method according to  claim 9 , in which the specimen is illuminated linearly and the phase is varied in the direction of the linear illumination.