A solid-state imaging element comprising a plurality of light-receiving sensors that convert optical signals into electrical signals and a memory storing the electrical signals. A housing includes an aperture in its top side into which a pet, typically feline, would deposit waste. For pure floating-point data, it is preferred to use the MMX unit to adjust the data address and map data and to use the SSE unit to perform the backprojection. The first light source is disposed on the surface of the light holder and projects colorful light outward through the light-transmitting material, and the projection of the patterns created by a color light source projecting light through the light-transmitting light post can create desired atmosphere. The difference between the base-emitter junction voltages of the first and second bipolar transistors, in part, defines the voltage at which the n-type region is clamped.