The invention discloses an
alternating current pointing
light pen, a multi-light-pen
identification device and a method of multi-light-pen identification. The shell of the
alternating current pointing
light pen is internally provided with an alternating
light control circuit which is respectively electrically connected with a power
supply management circuit and a
light source, and a
touch switch is close to the switch of the alternating
light control circuit. A transmitting device and a receiving device of the multi-light-pen
identification device are arranged at the same side of a writing screen or are respectively arranged at the two sides of the writing screen, wherein the transmitting device comprises a first pointing
light pen and a second pointing light pen, and the first pointing light pen is an alternating
point light pen; the receiving device comprises a camera and a
signal processing circuit which are mutually and electrically connected, the lens of the camera aims at the normal of the screen, the
signal processing circuit comprises an amplifying circuit, a high-speed comparing circuit and an identification
control circuit which are sequentially connected in series, and the identification
control circuit comprises a multi-light-pen identification module. The invention has the advantages that firstly, the alternating pointing light pen can be obtained only by increasing the alternating
control circuit on the basis of the traditional
direct current pointing light pen, thereby the alternating pointing light pen has simple structure; and secondly, the multi-light-pen
identification device can quickly identify a plurality of light pens.