The CP-770 serves refraction rooms in optometry practices and ophthalmology clinics that test distance vision at 2.9 to 6.1 m, with the optical zoom setting the installation distance. Its main argument is flexibility. The projector therefore adapts to rooms of different lengths. The charts are programmable, so the examiner can present up to 33 charts in any order with the infrared remote, which works from almost anywhere in the room.
The set includes Snellen, illiterate E, number and paediatric charts, and two ETDRS LogMAR charts. Masking isolates single horizontal or vertical lines, letters, numbers and characters. Ten individual 20/20 lines, plus 20/15 and 20/10 lines, help prevent memorisation; polarised tests, a red and green chart, and separate red and green filters extend the examination.
A high-intensity white LED lights the chart, and the illumination system needs no maintenance and no halogen bulbs. An internal brightness rheostat adjusts the projected intensity, and the circuitry compensates for supply-voltage fluctuations and changes in viewing distance. A special projector screen maintains the polarisation effect, and the control box on a refractor can operate the projector.
A chart change takes 0.03 seconds, and the projector enters standby after 5 or 15 minutes. It operates on 100 to 240 V, 50/60 Hz, and consumes 70 VA. The unit measures 177 × 278 × 192 mm and weighs 3.5 kg, which keeps it compact in a busy refraction room. The compact body leaves the bench or wall free for the rest of the examination equipment.