A kind of optical devices that are used for the interactive projection demonstration
Technical field
The present invention relates to a kind of optical devices that interactive projection shows that are used for.
Background technology
Along with the fast development of correlation techniques such as computing machine, multimedia presentation field product emerges in an endless stream: from projector, video presenter, to interactive electric whiteboard etc.; From traditional recordable type, multimedia mode, develop into interactivelyly, these products have also progressively been come into every field such as each big enterprises and institutions, tutoring system, medical institutions, daily life, have brought brand-new science and technology to enjoy to the user.
The photodetector head assembly that present its projection lens of photoelectricity interactive projection display screen and being used to receives the electronic writing pen signal is not coaxial installation.As shown in Figure 1, the structure of promptly existing photo-electric interactive projection display screen, lettering pen 1 is positioned at the front of projection display screen 2, is respectively arranged with projector body 6 and photodetector head assembly 7 at the back side of projection display screen 2.They are placed apart, and separating appears in optical axis.Not coaxial being provided with can make the image that detects produce bigger distortion, and the distortion of this distortion and camera lens itself merges, and is difficult to proofread and correct, and the cost of correction is also very high.The existence of distortion and distortion directly has influence on the bearing accuracy of lettering pen.Though adopted corresponding correcting algorithm aspect electronics, distortion and distortion have directly influenced the resolution of detection image on the one hand, and the precision of electronic calibration is not high yet, adopts electronic calibration to improve cost again on the other hand.And since projection lens and photodetector head assembly not common optical axis can't realize the synchronous adjustment that distorts, signal Processing is relative complex also.
Summary of the invention
The objective of the invention is to improve the precision and the resolution of lettering pen photodetection, provide that a kind of employing is coaxial to be provided with optical device and to reach hi-Fix, low cost, need not the optical devices that interactive projection shows that are used for of additional corrections.
In order to achieve the above object, the present invention has adopted following technical scheme, be a kind of optical devices that interactive projection shows that are used for, be positioned at a side of projection display screen, the projection optical axis of these optical devices is provided with spectroscope, makes photodetector and projection lens common optical axis in these optical devices; Photodetector can all or part of use projection lens optical element converge luminous energy.
According to a kind of optical devices that interactive projection shows that are used for of the present invention, described spectroscope is arranged in the light path between each optical element of projection lens.
Another kind according to the present invention is used for the optical devices of interactive projection display screen, and its adopts L type projection lens, spectroscope is set in projection lens optical axis turning point replaces reflective mirror in the former L type projection lens.
Between spectroscope and photodetector, be provided with supplementary lens, this supplementary lens is finished converging of luminous energy with shared projection lens optical element, this auxiliary lens can be identical with the optical element after projection lens is positioned at spectroscope, also can be to aim at the infrared eye design in addition.
According to a kind of optical devices that are used for the interactive projection display screen of the present invention, spectroscope is arranged in the light path between image composer and the projection lens.
According to a kind of optical devices that interactive projection shows that are used for of the present invention, described spectroscope can be the optical element that applies spectro-film.
The present invention also provides a kind of optical devices that are used for the interactive projection display screen, and spectroscope is arranged on before the projection lens, and photodetector is arranged on spectroscope one side, and its optical axis is vertical with projection optical axis.
Spectroscope of the present invention is to be used for projected light and the carrier wave light that has a lettering pen positional information separately, and promptly it can be back projection's light wave and the spectroscope of printing opacity electrical resistivity survey photometry ripple or the spectroscope of the saturating projection light wave of reflective electrical resistivity survey photometry ripple.Common situation can be selected anti-visible saturating infrared light spectroscope or anti-infrared visible light light-splitting mirror.
Projected light of the present invention and the carrier wave light that has a lettering pen positional information can be but be not limited only to visible light and infrared light, can be the light of any tool different wave length that can be separated by spectroscope; Described spectroscope can be anti-visible saturating infrared or anti-infrared visible, but also is not limited only to this, and it can select different kinds according to projected light and the carrier wave light that has the lettering pen positional information different.
Beneficial effect of the present invention is:
1, adopts spectroscopical beam split to realize the coaxial fully of photodetector and projection lens, eliminate photodetector, improved the bearing accuracy of lettering pen from the detection image distortion that axle produces;
2, since photodetector used projection lens partly or completely, and projection lens run-of-the-mill height, the distortion little, improved bearing accuracy and resolution.Even there is a spot of distortion,, do not write consistance with Projection Display and do not influence this device because the distortion of projection and photodetection is consistent yet.
3, because the image fault of photodetection is little, and consistent with the image fault of Projection Display, need not carry out treatment for correcting again, make subsequent process circuit simplify greatly, reduced cost.
Description of drawings
Fig. 1 is the structural representation of existing interactive electric whiteboard projection arrangement;
Fig. 2 is the structural representation of embodiment one;
Fig. 3 is the structural representation of embodiment two;
Fig. 4 is the structural representation of embodiment three;
Fig. 5 is the structural representation of embodiment four;
Fig. 6 is the structural representation of embodiment five;
Fig. 7 is the enlarged diagram of prism structure among the embodiment three.
Embodiment
Embodiment one:
A kind of as shown in Figure 2 optical devices that are used for the interactive projection display screen, the carrier wave light that has positional information that lettering pen 1 sends is infrared light, wherein image composer 5, prism 4 linearly are provided with projector lens 3, and anti-infrared visible spectroscope 8 is set between the optical element of projector lens 3.Photodetector 9 is an infrared eye, is arranged on spectroscope 8 one sides, and its optical axis is vertical with projector lens 3 optical axises.Between spectroscope 8 and photodetector 9, be provided with supplementary lens 10.
Embodiment two:
A kind of as shown in Figure 3 optical devices that are used for the interactive projection display screen, the carrier wave light that has positional information that lettering pen 1 sends is infrared light, it adopts L type projection lens, what projector lens 3 light paths were turned back anti-visible saturating infrared beamsplitter 8 ' is set, replace original reflective mirror, it with projected light and the carrier wave light that has lettering pen 1 positional information separately, photodetector 9 is arranged on the optical axis at spectroscope 8 ' rear the infrared light that has the lettering pen positional information is surveyed.Between spectroscope 8 ' and photodetector 9, be provided with supplementary lens 10 '.
Embodiment three:
A kind of as shown in Figure 4 optical devices that are used for the interactive projection display screen, the carrier wave light that has positional information that lettering pen 1 sends is infrared light, wherein image composer 5, prism 4 linearly are provided with projector lens 3, the enlarged diagram of prism structure as shown in Figure 7, scribble anti-infrared visible spectro-film on the inclined-plane in prism 4, it separates projected light and the carrier wave light that has the lettering pen positional information, and photodetector 9 is arranged on a side of prism, and its optical axis is vertical with projection optical axis.
Embodiment four:
A kind of as shown in Figure 5 optical devices that are used for the interactive projection display screen, the carrier wave light that has positional information that lettering pen 1 sends is infrared light, wherein image composer 5, linearly be provided with projector lens 3, anti-infrared visible spectroscope 8 is set between image composer 5 and projector lens 3, it separates projected light and the carrier wave light that has the lettering pen positional information, photodetector 9 is arranged on a side of anti-infrared visible spectroscope 8, and its optical axis is vertical with projection optical axis.
Embodiment five:
A kind of as shown in Figure 6 optical devices that are used for the interactive projection display screen, the carrier wave light that has positional information that lettering pen 1 sends is infrared light, wherein image composer 5, prism 4 linearly are provided with projector lens 3, anti-infrared visible spectroscope 8 is arranged on the preceding projection optical axis of projection lens, photodetector head assembly 7 is arranged on a side of spectroscope 8, converge the infrared light that has the lettering pen positional information by other camera lens of configuration, its optical axis is vertical with projection optical axis.This structure can only be eliminated the image fault that causes from axle, and the distortion of camera lens is proofreaied and correct by infrared acquisition camera lens oneself.
Lettering pen described in the present invention can be the active pen of emission light wave, also can be the form of a stroke or a combination of strokes thing that reflection or alternate manner change the detection light wave.This device can be used in the interaction display screen of back projection, also can be applied in the interaction display screen of front projection.