Abstract: Presented herein is an optical filter system for visible light, which has a first average transmittance T1 between a limit wavelength ?G and a wavelength of 700 nm and a second average transmittance T2 between a wavelength of 380 nm and the limit wavelength ?G. In this case: 410 nm<?G<520 nm and 0.05 < T 1 T 2 < 0.60 .

Abstract: Presented herein is an optical filter system for visible light, which has a first average transmittance T1 between a limit wavelength ?G and a wavelength of 700 nm and a second average transmittance T2 between a wavelength of 380 nm and the limit wavelength ?G. In this case: 410 nm<?G<520 nm and 0.05 < T 1 T 2 < 0.60 .

Abstract: A digital phase to digital sine and cosine amplitude translator generates sine and cosine outputs from an input angle word, which is decomposed into the most significant bits (MSBs) and the least significant bits (LSBs), and the octant number of the angle is identified by the octant identifier bits. Radix-4 multiplier/adder circuits improve the efficiency of multiplication/addition computations. An incrementor and a decrementor are used for sine and cosine MSB computations, respectively, to further save the computer memory and logic. In a preferred embodiment, the MSBs of the sine and cosine outputs for all octants are generated based upon the octant number of the input angle, and the LSBs of the outputs are generated by trigonometric approximations and octant selection, thereby resulting in a savings in computer memory and logic.