CN2425370Y

CN2425370Y - USB camera with automatic focusing function

Info

Publication number: CN2425370Y
Application number: CN 00235483
Authority: CN
Inventors: 陆祖康; 王立强; 林斌; 倪旭翔
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2000-06-09
Filing date: 2000-06-09
Publication date: 2001-03-28
Anticipated expiration: 2010-06-09

Abstract

The utility model relates to an autofocus USB video camera, which comprises a lens, an imaging sensor, a USB interface for connecting with a computer, a motor drive circuit, a stepping motor and a transmission mechanism. The camera is used as a peripheral of the computer. When in use, the computer performs spectrum analysis on the video image to generate a corresponding control signal and sends it to the motor drive circuit. Low cost, fast and accurate focusing, and easy to use.

Description

A kind of USB video camera that automatic focus function is arranged

The utility model relates to the USB video camera of automatic focusing.

Along with people to the video communication growth of requirement, also obtain more and more widely application as a kind of video camera of computer peripheral equipment with USB interface.To utilize computing machine only be that video image is shown on display device to the USB video camera of selling on the market now, and it does not have automatic focus function, adopt manual focus, and focusing speed is slow, uses inconvenient.

The purpose of this utility model provides a kind of USB video camera that automatic focus function is arranged, and its cost is low, can realize accurate, fast automatic focusing, and is easy to use.

Of the present utility modelly there is the USB video camera of automatic focus function to comprise camera lens, imaging sensor spare, is used for the USB interface that links to each other with computing machine, motor-drive circuit, stepper motor and gear train, automatic focusing control signal from computing machine is imported motor-drive circuit by USB interface, output control step motor movement by motor-drive circuit, the output terminal of motor-drive circuit links to each other with the stepper motor winding, and stepping motor rotor is by gear train and camera lens mechanical connection.This video camera is as the peripheral hardware of computing machine, during use, USB interface by video camera links to each other with computing machine, the optical imagery that obtains of camera lens converts vedio data to by imaging sensor spare like this, again through USB interface input computing machine, in the frame buffer of computing machine, carry out buffer memory, computing machine shows the vedio data in the frame buffer on the one hand on display device, simultaneously also the vedio data in the frame buffer is carried out rapid fourier change, obtain the spectrum information of this frame video image, the out of focus degree of this spectrum information and current USB camera lens is closely related, when defocusing amount hour, the high fdrequency component value of frequency spectrum is just big, otherwise, when the out of focus degree was big, the high fdrequency component value of frequency spectrum was just little.Computing machine produces control signal corresponding according to the spectrum information of vedio data, this control signal still is sent to the motor-drive circuit of USB video camera by USB interface, output drive stepping motor by motor-drive circuit, stepper motor drives the camera motion of video camera, realizes automatic focus function.

Below in conjunction with accompanying drawing the utility model is further described:

Fig. 1 is the utility model structure and principle of work block diagram;

Fig. 2 is a kind of embodiment of the present utility model.

With reference to Fig. 1, the USB video camera that automatic focus function is arranged of the present utility model, comprise camera lens 1, imaging sensor spare 2, be used for the USB interface 3, motor-drive circuit 4, stepper motor 5 and the gearing 6 that link to each other with computing machine, the input end of motor-drive circuit 4 links to each other with USB interface 3, output terminal links to each other with the winding of stepper motor 5, and stepping motor rotor is by gear train 6 and camera lens 1 mechanical connection.This video camera links to each other with computing machine 7 by USB interface during use, the optical imagery that camera lens 1 obtains converts vedio data to by imaging sensor spare 2, convert the vedio data input computing machine of USB transformat again to by USB interface 3, in the frame buffer 8 of computing machine, carry out buffer memory, vedio data in the frame buffer is sent on the one hand and carries out the video demonstration on the display device 9, read by CPU on the other hand and carry out rapid fourier change, obtain the spectrum information of current frame image, CPU produces control signal corresponding through USB interface 3 input motor-drive circuits 4 according to the spectrum information that obtains, motor-drive circuit turns to and rotating speed by control signal control step motor 5, this stepper motor moves by the camera lens 1 that gear train 6 drives video camera, finishes automatic focusing.

The USB video camera that automatic focus function is arranged shown in Figure 2, its imaging sensor spare adopts the OV7620 chip, and USB interface 3 adopts the OV511PLUS chip, and motor-drive circuit 4 is made up of PIC16C73A chip and two SN75452 chips.The SCL of OV511PLUS links to each other with the SDA pin with the SCL of PIC16C73A respectively with the SDA pin, the RB7 of PIC16C73A and RB6 pin link to each other with 1B pin, 2A and 2B pin with the 1A of one of them SN75452 respectively, the RB5 pin links to each other with the 1B pin with the 1A of another SN75452, each links to each other three output terminals of SN75452 with A, B, C three phase windings of stepper motor 5, and the camera lens 1 of stepper motor and video camera is by gear train 6 mechanical connections.

Of the present utility modelly have the USB camera structure of automatic focus function simple, cost is low, it can fast, accurately realize focusing automatically as the peripheral hardware of computing machine, and is more complete than prior USB camera function, uses more convenient.

Claims

1. A USB video camera with autofocus function, comprising a lens [1], an imaging sensor [2] and a USB interface [3] for being connected to a computer, is characterized in that it also includes a motor drive circuit [4], a step Into the motor [5] and the transmission mechanism [6], the autofocus control signal from the computer is input to the motor drive circuit through the USB interface, the output of the motor drive circuit controls the movement of the stepper motor, and the output end of the motor drive circuit is connected to the winding of the stepper motor Connected, the stepper motor rotor is mechanically connected with the camera lens through the transmission mechanism.

2. The USB camera with autofocus function according to claim 1 is characterized in that said imaging sensing device [2] is an OV7620 chip, USB interface [3] is an OV511PLUS chip, and the motor drive circuit [4] is composed of PIC16C73A chip and two SN75452 chips.