Patent ID: 8463003

Claim:
A biometric information acquisition apparatus comprising: a light guide that guides a light beam through a plurality of light reflective surfaces; and an image pickup unit that receives the light beam output from the light guide and captures a subject image, wherein the light guide has a flat-plate shape as a whole, the light guide comprises an upper surface including an input area that receives the subject image, when a direction perpendicular to the upper surface is defined as an x-axis direction and two axes orthogonal to each other within a plane perpendicular to the x-axis are defined as a y-axis and a z-axis, the light guide further comprises: a first light reflective surface that reflects light incident from the input area along the x-axis so as to include at least a y-axis direction component; and a second light reflective surface that reflects the light reflected by the first light reflective surface and having the y-axis direction component so as to include at least a z-axis direction component, and the first light reflective surface and the second light reflective surface form a part of an external surface of the light guide.