Optical sensor and electronic apparatus

摘要

An optical sensor includes: a driving circuit that turns off a light-emitting element during a first period, a second period, and a fourth period and that turns on the light-emitting element during a third period; an integrating circuit that outputs a first integrated-value difference (FID) and a second integrated-value difference (SID), the FID being a difference between an integrated value of a photocurrent generated by a light-receiving element in accordance with respective states of the light-emitting element during the first period and the second period, the SID being a difference between an integrated value of a photocurrent generated in accordance with respective state of the light-emitting element during the third period and the fourth period; and an output control circuit that outputs the SID when the FID is zero and that outputs a difference between the SID and the FID when the FID is not zero.

主权项

1. An optical sensor comprising:
a light-emitting element; a light-receiving element that generates a photocurrent upon receiving reflected light from an object to be sensed reflecting light emitted by the light-emitting element; a driving circuit that causes the light-emitting element to be on or off during a first period, a second period, and a fourth period among four periods provided consecutively and that causes the light-emitting element to be off or on during a third period among the four periods, the first period and the second period constituting a disturbance light sensing period during which disturbance light is sensed, and the third period and the fourth period constituting a disturbance light/object-to-be-sensed sensing period during which the disturbance light and the object to be sensed are sensed; an integrating circuit that outputs a first integrated-value difference and a second integrated-value difference, the first integrated-value difference being a difference between an integrated value of the photocurrent generated in accordance with a state of the light-emitting element during the first period and an integrated value of the photocurrent generated in accordance with a state of the light-emitting element during the second period, the second integrated-value difference being a difference between an integrated value of the photocurrcnt generated in accordance with a state of the light-emitting element during the third period and an integrated value of the photocurrent generated in accordance with a state of the light-emitting element during the fourth period; and an output control circuit that outputs the second integrated-value difference when the first integrated-value difference is zero and that outputs a difference between the second integrated-value difference and the first integrated-value difference when the first integrated-value difference is not zero.