A kind of projector automatic focusing control system
[technical field]
The present invention relates to a kind of projector automatic focusing control system, belong to Digital Image Processing and the optical lens field of focusing automatically.
[background technology]
For a long time, the focusing of projector all is the form appearance with manual focusing, and after the distance that changes between projector and the screen, ambiguous phenomenon often appears in the picture that casts out.And to watch clearly picture to focus again, this brings certain inconvenience to people.
Therefore, be necessary to address the above problem.
[summary of the invention]
The present invention has overcome the deficiency of above-mentioned technology, and projector's automatic focusing control system a kind of simple in structure, easy to use is provided.
For achieving the above object, the present invention has adopted following technical proposal:
A kind of projector automatic focusing control system, include for the digital signal image with want projection and convert the projection head 2 of light image output to and be used for the light image enlarging projection of the projection head 2 outputs projection camera lens 3 to the screen, described projection head 2 and projection are provided with between the camera lens 3 be used to the optical filtering catoptron 4 of choosing the projected picture information of reflected back projection camera lens 3 from the screen, described optical filtering catoptron 4 reflection output terminals are connected with image collection chip 5, described image collection chip 5 signal output parts are connected with the controller 1 of the projected picture contrast that reflects for calculating, described projection head 2 control signal input ends are connected with controller 1, are provided with between described controller 1 and the projection camera lens 3 for adjusting projection camera lens 3 makes the screen prjection clear picture with the raising contrast to correct position drive motor 6.
Also be connected with the input button 7 that arranges for manually on the described controller 1.
Compared with prior art, the invention has the beneficial effects as follows:
1, realizes the closed-loop control of projector's focusing, the picture that projects on the screen converts data image signal to again through projection camera lens, optical filtering catoptron, image collection chip, controller calculates contrast, throw camera lens to correct position by the drive motor adjustment then, make the screen prjection clear picture to improve contrast, finish the automatic focusing process.
2, controller is provided with the input button, realizes the combination of manual focusing and automatic focusing, is convenient to actual use.
3, one-piece construction is simple, and control is simple, and is easy to use, easy to utilize.
[description of drawings]
Fig. 1 is structure principle chart of the present invention.
[embodiment]
Be described in further detail by the feature of the present invention of embodiment and other correlated characteristic below in conjunction with accompanying drawing, so that technician's of the same trade understanding:
As shown in Figure 1, a kind of projector automatic focusing control system, include for the digital signal image with want projection and convert the projection head 2 of light image output to and be used for the light image enlarging projection of the projection head 2 outputs projection camera lens 3 to the screen, described projection head 2 and projection are provided with between the camera lens 3 be used to the optical filtering catoptron 4 of choosing the projected picture information of reflected back projection camera lens 3 from the screen, described optical filtering catoptron 4 reflection output terminals are connected with image collection chip 5, described image collection chip 5 signal output parts are connected with the controller 1 of the projected picture contrast that reflects for calculating, described projection head 2 control signal input ends are connected with controller 1, are provided with between described controller 1 and the projection camera lens 3 for adjusting projection camera lens 3 makes the screen prjection clear picture with the raising contrast to correct position drive motor 6.
Also be connected with the input button 7 that arranges for manually on the aforesaid controller 1.
The course of work and the principle of work of this case are as follows:
Projection head 2 by projection camera lens 3 with image projection to screen, reflection ray is through 3 incidents of projection camera lens, after the reflection of optical filtering catoptron 4, enter image collection chip 5, obtain the current feedback digital image that is incident upon picture on the screen, this feedback digital image is sent into controller 1 degree of comparing calculate, adjust projection camera lens 3 positions by drive motor 6, after projected picture is clear, just finish the automatic focusing process, wherein, automatic focusing process and principle are as follows in detail:
After opening initialization is finished, the running of controller 1 control drive motor 6, projection camera lens 3 is walked one time at whole focusing stroke, controller 1 selects the most tangible zone of projected picture contrast as sample area, the calculating contrast is also noted, and after finishing the data that obtain is compared, and finds a highest position of contrast and gives drive motor 6 corresponding signals, make it run to the highest position of contrast, finish first automatic focusing process.In use gather the contrast of current picture in real time, when contrast starts the automatic focusing process again when great changes have taken place, remember that current contrast value is G0, at first give drive motor 6 signals to certain direction running, the calculating contrast is designated as G1 after gathering projected picture information at this moment, compares G0 and G1 size then; If G0〉G1, then illustrate and current drive motor 6 traffic directions focus with projector direction is opposite clearly, so give drive motor 6 signals toward the reverse direction operation, find a contrast for the highest position in that this side up, the automatic focusing process was finished after control drive motor 6 ran to this position; If G0<G1, illustrate that then current direction is projector's direction clearly of focusing, continue control drive motor 6 in this side up operation, find a contrast to be the highest position, drive motor 6 is run to this position after the automatic focusing process finish.
As mentioned above, what this case was protected is a kind of New Projection Display automatic focusing control device, and all technical schemes identical or close with this case structure all should be shown in the protection domain that falls into this case.