AUTO-FOCUSING PROJECTION SYSTEM

摘要

An auto-focusing projection system includes a projection module, an infrared monitoring module (300), an infrared source (400) provided on the projection module, and a focusing device for driving the first lens group (201) moving forward and backward. An IR light spot emitted from the infrared source falls within the monitoring scope of the infrared monitoring module, preferably inside the projected picture of the projection module or on the edge thereof, and after reflected back, it also can travel through the first lens group, and the splitting element in turn, and then be transmitted to the infrared monitoring module. Analyzing the IR light spot picture emitted from the infrared source which is collected by the infrared monitoring module, a control signal can be sent to a focusing motor to adjust the first lens group to an appropriate position, so as to realize auto-focusing.

主权项

1. An auto-focusing projection system comprising:
a projection module comprising a projection light source (100) and a projection objective (200), light emitted from the projection light source (100) traveling through a light splitting element (500) in the projection objective (200) and a first lens group (201) in turn, and then emitting out; an infrared monitoring module (300) comprising a monitoring objective and an induction chip (301), an infrared source (400) provided on the projection module, an IR light spot (700) emitted from the infrared source (400) falling within the monitoring scope of the infrared monitoring module (300), an IR light of the IR light spot (700) reflected back travelling through the first lens group (201), the light splitting element (500) in turn, and then into the infrared monitoring module (300); a focusing device for driving the first lens group (201) moving forward and backward, the focusing device comprising a focusing control module and a focusing motor, the focusing control module receiving a real-time IR monitoring signal from the infrared monitoring module (300), and emitting a control signal to the focusing motor, the focusing motor being connected to the first lens group (201) driving the first lens group (201) to move forward and backward; the optical axis of the infrared monitoring module (300) being coaxial with that of the projection objective (200) after passing through the light splitting element (500), the optical characteristics of the projection objective (200) and the monitoring objective ensuing that the projection objective focus clearly when the first lens group (201) is driven to move forward and backward by the focusing device to make the IR monitoring picture received by the induction chip (301) to be focused clearly.