Scanning microscope, scanning width detecting device, and magnification indicating apparatus

Claim 1

A scanning microscope provided with: i) a sample supporting member on which a sample is supported, ii) an optical means which irradiates a light beam to said sample, iii) a movement mechanism which reciprocally moves said optical means with respect to said sample supporting member such that said light beam may scan said sample in main scanning directions and in sub-scanning directions, and iv) a photodetector for detecting light radiated out of the portion of said sample, which is exposed to said light beam, an image of said sample being thereby formed, wherein the improvement comprises the provision of: a) a signal processing means for sampling a serial output of said photodetector and thereby generating image signal components of a digital image signal, which correspond to each main scanning line, b) a means for feeding pixel clock pulses into said signal processing means, the period of said pixel clock pulses being modulated so as to compensate for fluctuations in a speed, at which said optical means is moved reciprocally with respect to said sample supporting member, c) a means for generating a timing signal that determines the timing, with which the sampling process is begun, d) a grid pattern, which is secured to either one of said sample supporting member and said optical means and which is constituted of a plurality of light reflecting members or light blocking members standing side by side with one another in the direction, along which said optical means is moved reciprocally with respect to said sample supporting member, e) a light projector, which is associated with the other of said sample supporting member and said optical means and which irradiates a light beam to said grid pattern, f) a light receiver for detecting the light beam, which has been reflected by said grid pattern, or the light beam, which has passed through said grid pattern, g) a means for sampling a light beam detection signal, which has been generated by said light receiver, in accordance with said pixel clock pulses and thereby generating a digital displacement signal, and h) a means for approximating the relationship between the order x, where x=1, 2, 3, . . . , in which signal components of said digital displacement signal representing specific points appearing at equal pitches on said grid pattern occur, and the order y, in which said signal components of said digital displacement signal are sampled, with a quadratic equation y=ax 2 +bx+c, determining the direction, in which a phase of a drive signal fed into said movement mechanism is shifted with respect to a phase of said timing signal, in accordance with whether the coefficient a in said quadratic equation is positive or negative, and thereafter shifting the phase of said drive signal with respect to the phase of said timing signal.