Problem P. 3822. (September 2005)
P. 3822. The DLP chip (Digital Light Processor), developed by Texas Instruments, is a new display solution used in modern projectors. Peter heard that the chip contains millions of hinge-mounted microscopic mirrors, and all of them can be tilted (separately) into two positions (even 5000 times in a second) reflecting or not reflecting light onto the screen. He lighted the rectangular chip of sides 17 mm and 9.5 mm nearly perpendicularly by a laser beam of wavelength 633 nm. He observed that the reflected laser light formed a diffraction pattern of a grid of squares with 2.4 cm long sides on a screen 50 cm from the chip. Using these data find the length of the sides and the number of the micromirrors in the chip.
Deadline expired on October 11, 2005.
29 students sent a solution. 4 points: Engedy Balázs, Molnár 811 Kristóf, Pásztor Attila, Széchenyi Gábor, Székely Csaba, Török Péter. 3 points: Demeter Dániel, Dudás János, Gombási Gábor, Kocsis Vilmos, Kónya 495 Gábor, Matulik Gábor, Nagy 317 Péter, Nagy 555 Zoltán, Nyíri Dávid Ákos, Pálovics Róbert, Pap Éva Fruzsina, Pósa László, Steierhoffer Gergő, Szarvas Tamás, Szolnoki Lénárd, Szük Dániel, Takátsy Balázs, Tóth 123 László. 2 points: 4 students. 1 point: 1 student.