The present invention relates to an insulin injector (100) capable of measuring an injection amount by using an optical sensor, the insulin injector comprising: a drug cartridge (10) which stores insulin and has a piston (11) capable of moving therein an injection operation unit (20) which is operated to inject the insulin stored in the drug cartridge (10) and comprises a screw (22) which is rotated and operated in cooperation with a driving motor (21) and a plunger (23) which is linearly operated by rotation operation of the screw (22) and compresses and operates the piston (11) as one end portion on one side comes in contact with the piston (11) and a main control unit (40) which controls operation of the injection operation unit (20). The insulin injector additionally comprises: a light reflection plate (110) installed on an end portion on the other side of the plunger (23) and an injection amount measurement unit (120) which comprises a light transmission unit (121) which transmits an optical signal toward the light reflection plate (110), a light reception unit (122) which receives the optical signal reflected by the light reflection plate (110), and an injection amount calculation module (123) which measures the linear movement distance of the plunger (23) by comparing the optical signal, transmitted by the light transmission unit (121), to the optical signal, received by the light reception unit, and transmits the linear movement distance of the plunger (23), calculated by the injection amount calculation module (123), to the main control unit (40).COPYRIGHT KIPO 2018본 발명은 광센서를 이용한 주입량 측정이 가능한 인슐린 주입기에 관한 것으로, 인슐린을 저장하며 내부에는 이동이 가능한 피스톤(11)을 구비하는 약물 카트리지(10)와, 상기 약물 카트리지(10)에 저장된 인슐린을 주입하도록 구동하며, 구동 모터(21)에 연동하여 회전 구동하는 스크류(22)와, 상기 스크류(22)의 회전 구동에 의하여 선형 구동되도록 작동하며 일 측 말단이 상기 피스톤(11)에 접촉되어 상기 피스톤(11)을 압축 구동하는 플런저(23)를 포함하여 구성되는 주입 구동부(20)와, 상기 주입 구동부(20)의 구동을 제어하는 주제어부(40) 를 포함하여 구성되는 인슐린 주입기에 있어서, 상기 플런져(23)의 타 측 말단에 설치되는 광 반사판(110)과, 상기 광 반사판(110)을 향하여 광신호
