Electronic whiteboard device and display method thereof
Technical Field
The present invention relates to electronic whiteboards, and particularly to an electronic whiteboard device and a display method thereof.
Background
The electronic whiteboard is an interactive display device widely used in recent years, and the display principle is that an operating device held by a user is positioned through a positioning system, so that corresponding display operation is performed at a positioning position, and the effect of writing on a common whiteboard or clicking operation of a computer mouse is simulated. The existing electronic whiteboard device usually uses an optical positioning element, and positioning is performed by blocking light rays by using an operating device, so that the positioning mode is not high in precision, the problem of misoperation often occurs in the operation process of a user, and the user experience is poor.
Disclosure of Invention
The technical problem to be solved by the invention is to provide an electronic whiteboard device and a display method thereof, which can solve the defects of the prior art and improve the positioning display precision of the electronic whiteboard.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows.
An electronic whiteboard device comprises a whiteboard device,
the frame is used for mounting electronic whiteboard components;
the pressure-sensitive display screen is arranged in the frame and is used for displaying images;
the pressure sensor group is arranged on the back of the pressure-sensitive display screen and used for detecting the pressure state of the surface of the pressure-sensitive display screen;
a first emission light source installed at an edge of the frame for emitting a first light;
the first light source receiver is arranged at the edge of the frame and used for receiving the first light;
the second emission light source is arranged at the edge of the frame and is used for emitting second light rays, and the wavelengths of the first light rays and the second light rays are different;
the second light source receiver is arranged at the edge of the frame and used for receiving the second light;
the second transmitting light source and the second light source receiver are positioned outside the first light source receiver and the first light source receiver;
and the controller is arranged on the back of the frame and used for positioning the image display position of the electronic whiteboard.
The display method of the electronic whiteboard device comprises the following steps:
A. the first transmitting light source and the second transmitting light source emit detection light simultaneously, and the first light source receiver and the second light source receiver receive corresponding light;
B. the method comprises the steps that clicking operation is carried out on the surface of a pressure-sensitive display screen through an operating pen, the operating pen shields first light and second light at corresponding positions, and the shielding positions of the operating pen are determined according to received light changes through a first light source receiver and a second light source receiver;
C. the controller establishes a three-dimensional coordinate system on the surface of the pressure-sensitive display screen, and marks the shielding positions of the operating pen on the first light and the second light in the three-dimensional coordinate system;
D. correcting two shielding positions marked in the three-dimensional coordinate system, and determining the position posture of the operating pen in the three-dimensional coordinate system according to the two shielding positions;
E. and D, comparing and analyzing the position posture of the operating pen obtained in the step D with the pressure state of the surface of the pressure sensing display screen obtained by the pressure sensor group, correcting the position posture of the operating pen in a three-dimensional coordinate system, finally determining the contact position of the operating pen on the pressure sensing display screen, and performing corresponding display operation on the contact position of the pressure sensing display screen.
Preferably, step D comprises the steps of,
d1, determining the outer contours of the two shielding positions;
d2, deforming the shielding position into a spherical or ellipsoidal shape according to the outer contour of the shielding position;
d3, selecting the centers of the deformed shielding positions to be connected, taking a plane which passes through the connection line and is perpendicular to the surface of the pressure-sensitive display screen 2 as a reference plane, correcting the connection line according to the size of the shielding position volumes on the two sides of the reference plane to realize the equal shielding position volumes on the two sides of the reference plane, wherein the direction of the corrected connection line is the position posture of the operating pen in the three-dimensional coordinate system.
Preferably, the step D2 of deforming the shielding position according to the outer contour of the shielding position includes the steps of,
d21, selecting a plurality of characteristic points on the outer contour of the shielding position, and connecting the adjacent characteristic points by using line segments;
d22, smoothing the line segments to form a smooth closed curved surface;
d23, making a straight line perpendicular to the positions of the feature points on the closed curved surface on each feature point;
d24, marking the intersection points of the straight lines in the closed curved surface, and performing weighted fusion on the intersection points by taking the number of the straight lines passing through the intersection points as weight values to obtain a final fusion intersection point;
d25, taking the fusion intersection point as the center of the deformed sphere, respectively performing spherical deformation and ellipsoidal deformation tests of different spherical diameters, and selecting a deformation mode and a shape with higher coincidence degree with the closed curved surface to perform final deformation operation.
Preferably, in the step D21, the selecting the feature points includes the following steps:
d211, establishing a feature point pre-selection area on the outer contour of the shielding position;
d212, traversing the coordinate points in the feature point pre-selection area, selecting the coordinate points as feature points when the coordinate points simultaneously meet the following conditions,
a. taking the coordinate point as a sphere center to form a spherical detection area, wherein the outer contour in the spherical detection area is a smooth surface; the radius of the spherical detection area is 1% of the distance between the maximum two points of the shielding position outline distance;
b. the area of the spherical detection area positioned in the shielding position and inside the outer contour accounts for 50-80% of the whole spherical detection area;
c. there are no other feature points within this spherical detection zone.
Preferably, step E comprises the following steps,
e1, taking the intersection point of the extension line of the connecting line in the step D3 and the surface of the pressure-sensitive display screen as a calculation contact point of the operating pen and the surface of the pressure-sensitive display screen;
e2, establishing a pressure state three-dimensional stereo map of the surface of the pressure-sensitive display screen, and fitting a pressure source point according to the pressure state three-dimensional stereo map;
e3, placing the calculated contact points obtained in the step E1 into the pressure state three-dimensional stereo image established in the step E2, and performing weighted fitting on the calculated contact points and the pressure source points;
e4, reversely deducing the fitted pressure state three-dimensional stereo map by using the fitted points, if the fitted pressure state three-dimensional stereo map is linearly related to the pressure state three-dimensional stereo map in the step E2, determining the fitted points as the contact positions of the operating pen on the pressure-sensitive display screen, and if not, returning to the step E, changing the fitting weight and carrying out weighted fitting again.
Preferably, in step E3, the initial weight value of the contact point is calculated in proportion to the distance between the contact point and the pressure source point, and the initial weight value of the pressure source point is calculated in inverse proportion to the distance between the contact point and the pressure source point.
Adopt the beneficial effect that above-mentioned technical scheme brought to lie in: according to the invention, the two groups of light source positioning systems are arranged, and the three-dimensional positioning structure is utilized to position the operating pen, so that the influence of external interference on positioning can be effectively reduced. In the three-dimensional positioning process, the positioning precision of the light source system is effectively improved by optimizing the light detection processing flow, and then the accurate positioning of the operating pen is finally realized by matching with the correction of the pressure detection system.
Drawings
FIG. 1 is a block diagram of one embodiment of the present invention.
Fig. 2 is a block diagram of a light source emitting end in one embodiment of the present invention.
Fig. 3 is a block diagram of a light source receiving end in an embodiment of the present invention.
In the figure: 1. a frame; 2. a pressure-sensitive display screen; 3. a pressure sensor group; 4. a first emission light source; 5. a first light source receiver; 6. a second emission light source; 7. a second light source receiver; 8. and a controller.
Detailed Description
The standard parts used in the invention can be purchased from the market, the special-shaped parts can be customized according to the description and the description of the attached drawings, and the specific connection mode of each part adopts the conventional means of mature bolts, rivets, welding, sticking and the like in the prior art, and the detailed description is not repeated.
Referring to fig. 1-3, one embodiment of the present invention includes,
the electronic whiteboard device comprises a frame 1 for mounting electronic whiteboard components;
a pressure sensitive display screen 2 installed in the frame 1 for displaying an image;
the pressure sensor group 3 is arranged on the back of the pressure-sensitive display screen 2 and is used for detecting the pressure state of the surface of the pressure-sensitive display screen 2;
a first light emitting source 4 installed at an edge of the frame 1 for emitting a first light;
a first light source receiver 5 installed at an edge of the frame 1 for receiving a first light;
a second emission light source 6 installed at an edge of the frame 1 for emitting a second light, the first light having a different wavelength from the second light;
a second light source receiver 7 installed at an edge of the frame 1 for receiving a second light;
the second transmitting light source 6 and the second light source receiver 7 are located outside the first light source receiver 5 and the first light source receiver 5;
and a controller 8 mounted on the back of the frame 1 for positioning the image display position of the electronic whiteboard.
The display method of the electronic whiteboard device comprises the following steps:
A. the first emitting light source 4 and the second emitting light source 6 emit detection light simultaneously, and the first light source receiver 5 and the second light source receiver 7 receive corresponding light;
B. performing click operation on the surface of the pressure-sensitive display screen 2 by using an operating pen, shielding the first light and the second light at corresponding positions by using the operating pen, and determining the shielding position of the operating pen by using the first light source receiver 5 and the second light source receiver 7 according to the received light change;
C. the controller 8 establishes a three-dimensional coordinate system on the surface of the pressure-sensitive display screen 2, and marks the shielding positions of the operating pen on the first light and the second light in the three-dimensional coordinate system;
D. correcting two shielding positions marked in the three-dimensional coordinate system, and determining the position posture of the operating pen in the three-dimensional coordinate system according to the two shielding positions;
E. and D, comparing and analyzing the position posture of the operating pen obtained in the step D with the pressure state of the surface of the pressure-sensitive display screen 2 obtained by the pressure sensor group 3, correcting the position posture of the operating pen in a three-dimensional coordinate system, finally determining the contact position of the operating pen on the pressure-sensitive display screen 2, and performing corresponding display operation on the contact position of the pressure-sensitive display screen 2.
In the step D, the method comprises the following steps,
d1, determining the outer contours of the two shielding positions;
d2, deforming the shielding position into a spherical or ellipsoidal shape according to the outer contour of the shielding position;
d3, selecting the centers of the deformed shielding positions to be connected, taking a plane which passes through the connection line and is perpendicular to the surface of the pressure-sensitive display screen 2 as a reference plane, correcting the connection line according to the size of the shielding position volumes on the two sides of the reference plane to realize the equal shielding position volumes on the two sides of the reference plane, wherein the direction of the corrected connection line is the position posture of the operating pen in the three-dimensional coordinate system.
The step D2 of deforming the shielding position according to the outer contour of the shielding position includes the steps of,
d21, selecting a plurality of characteristic points on the outer contour of the shielding position, and connecting the adjacent characteristic points by using line segments;
d22, smoothing the line segments to form a smooth closed curved surface;
d23, making a straight line perpendicular to the positions of the feature points on the closed curved surface on each feature point;
d24, marking the intersection points of the straight lines in the closed curved surface, and performing weighted fusion on the intersection points by taking the number of the straight lines passing through the intersection points as weight values to obtain a final fusion intersection point;
d25, taking the fusion intersection point as the center of the deformed sphere, respectively performing spherical deformation and ellipsoidal deformation tests of different spherical diameters, and selecting a deformation mode and a shape with higher coincidence degree with the closed curved surface to perform final deformation operation.
In step D21, the selecting feature points includes the following steps:
d211, establishing a feature point pre-selection area on the outer contour of the shielding position;
d212, traversing the coordinate points in the feature point pre-selection area, selecting the coordinate points as feature points when the coordinate points simultaneously meet the following conditions,
a. taking the coordinate point as a sphere center to form a spherical detection area, wherein the outer contour in the spherical detection area is a smooth surface; the radius of the spherical detection area is 1% of the distance between the maximum two points of the shielding position outline distance;
b. the area of the spherical detection area positioned in the shielding position and inside the outer contour accounts for 50-80% of the whole spherical detection area;
c. there are no other feature points within this spherical detection zone.
In the step E, the method comprises the following steps,
e1, taking the intersection point of the extension line of the connecting line in the step D3 and the surface of the pressure-sensitive display screen 2 as the calculation contact point of the operating pen and the surface of the pressure-sensitive display screen 2;
e2, establishing a pressure state three-dimensional stereo map of the surface of the pressure-sensitive display screen 2, and fitting a pressure source point according to the pressure state three-dimensional stereo map;
e3, placing the calculated contact points obtained in the step E1 into the pressure state three-dimensional stereo image established in the step E2, and performing weighted fitting on the calculated contact points and the pressure source points;
e4, reversely deducing the fitted pressure state three-dimensional stereo map by using the fitted points, if the fitted pressure state three-dimensional stereo map is linearly related to the pressure state three-dimensional stereo map in the step E2, determining the fitted points as the contact positions of the operating pen on the pressure-sensitive display screen 2, and if not, returning to the step E, changing the fitting weight and carrying out weighted fitting again.
In step E3, the initial weight of the contact point is calculated in proportion to the distance between the contact point and the pressure source point, and the initial weight of the pressure source point is calculated in inverse proportion to the distance between the contact point and the pressure source point.
After the touch position of the operating pen on the pressure-sensitive display screen 2 is determined, feedback correction is performed on the weight values of the intersections in the step D24 according to the correction data for calculating the touch point, so as to improve the accuracy of obtaining the fusion intersections in the step D24.
In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience of description of the present invention, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.