Patent ID: 8823944
Filing Date: 2014-09-02
Classification: A61B,G01N

Abstract:
1. A biological information detector comprising: a light-emitting part; a light-receiving part subjected to receive light having biological information, the light being emitted by the light-emitting part and reflected at a detection site of a test subject; a reflecting part subjected to reflect the light having biological information; a protecting part subjected to protect the light-emitting part, the protecting part having a contact member provided with a contact surface in contact with the detection site, and the contact member being formed from a material that is transparent with respect to a wavelength of the light emitted by the light-emitting part; and a substrate arranged between the reflecting part and the protecting part, the light-emitting part being arranged on a first surface towards the protecting part, the light-receiving part being arranged on a second surface, opposite the first surface and towards the reflecting part, and the substrate being formed from a material that is transparent with respect to the wavelength of the light emitted by the light-emitting part; a once-reflected light, which is the light emitted from the light-emitting part being reflected once on a contact-surface side of the contact member, being inhibited from being incident on the light-receiving part, a twice-reflected light, which is the light emitted from the light-emitting part reflected twice on the contact-surface side of the contact member, being inhibited from being incident on the light-receiving part, the reflecting part having a reflecting surface including a part of a spherical surface; the diameter of an outer circumferential circle of the reflecting part with respect to a plan view being set at a predetermined value; and in an instance in which there exist, as ranges of a focal distance of the reflecting part, a first focal distance range, in which a ratio of a once-reflected incident light, which is the once-reflected light reflecting on the reflecting surface and being incident on the light-receiving part, with respect to a total amount of received light being higher than a first threshold value; a second focal distance range; and a third focal distance range, in which a ratio of a twice-reflected incident light, which is the twice-reflected light reflecting on the reflecting surface and being incident on the light-receiving part, with respect to the total amount of received light being higher than a second threshold value; the focal distance of the reflecting surface being set within the second focal distance range, which is between the first focal distance range and the third focal distance range.