CN1281209A - 'Photoelectric virtual blackboard' system based on large-screen display - Google Patents

Abstract

A photoelectric virtual blackboard system based on layge-screen display is disclosed. The position information pointed by an optical pen whose head has controllable infrared dot light source is obtained by optical imaging of video signal processor with CCD camera device. The functional operating instruction information of the optical pen is obtained by modulating the light source of pointer rod. After the position information and instruction information are encoded, they are then fed to a computer via port pin, and finally transmitted via VGA video line to a projector to project them on large-sreen flat display. Its advantages include directly pointing on large screen and convenient operation.

Description

" photoelectricity virtual blackboard " system based on large screen display

The present invention relates to a kind of " photoelectricity virtual blackboard " system based on large screen display.

The history that human information exchanges is the same remote with mankind itself's history.At literal as yet before the invention, people rely on to draw and make a gesture always and help other people and understand important information.For thousands of years, the polymath hand is taught whip, and the literal that in kind, figure or amplification are write carries out the explanation of " indication " property, becomes mediate knowledge and teaches leading form with the one-to-many information interchange.Giving lessons near, contemporary, traditional blackboard formula is exactly typical case's performance of this leading form.Teacher's hand is held chalk and write on blackboard on the dais, and student group is personally instructed, and the weakness of this mode of giving lessons is apparent, and is big as dust, the information amount of teaching is little, causes the inefficiency of giving lessons because the student is busy with taking down notes, or the like.Have or not the new mode of giving lessons to remedy these weakness so

Along with popularizing of computer utility, the birth and the development of multimedia technology make may becoming a reality of reform traditional form of teaching especially in the recent period.The advantage of computer technology has been given full play in computer-aided instruction (CAI), has become a key areas of computer utility.Because the man-machine interface-display sizes of computing machine is less, group scale of being taught students is restricted, thereby has restricted the scale of utilizing area of computer aided to personally instruct to a certain extent.This just becomes one of reason of the modern display technique of development.

Display device is the requisite man-machine interface of real-time session between people and the computing machine as the soft copy device.The progress of LSI makes liquid crystal display (LCD), fluorescent display tube show that (VFD), Plasma Display (PDP), diode displaying (LED), electroluminescence demonstration (ELD) etc. have all had tremendous development.Along with the progress of modern display technique, the giant-screen plane shows the main flow that has become contemporary display technique.From present domestic technique level and application prospect, liquid crystal light valve Projection Display (LCLV) military project and civilian on all have big application market, be particularly useful for utilizing computer assisted one-to-many information interchange occasion.External now relevant producer, as PROXIMA, SHARP, JVC etc., domestic as Zhejiang University's Opto-electrical Section etc., all development and production go out that volume is little, light intensity is big, multiple functional or even portable LCLV projector, be widely used in reply, lecture, projection, the explanation of extension dish, product introduction and the teaching.This class projector is connected on the VGA interface of computing machine, can synchronized projection go out the graphoscope interface on giant-screen, thereby realizes the substituting of blackboard remedied all weakness that the blackboard formula is given lessons fully.

Self also there is drawback in the demonstration of giant-screen plane, is mainly reflected on the convenience of man-machine interaction.The man-machine interaction means that present giant-screen plane shows mainly are to use keyboard and mouse to the computing machine direct control, are with the wireless mouse of tracking ball the most easily when number, but still need keyboard to assist input.This has 2 deficiencies at least, and the one, the operator must lack vividness and necessary emotion communication thereby make to demonstrate in the face of input equipment rather than towards the audience; The 2nd, the operator can not resemble arbitrarily performance on display interface freely writing on the blackboard, or sign emphasis, or displaying contents carried out additions and deletions, realize that this point must make amendment to text or image file, thereby require the operator must be familiar with very much operating system, while is input characters or figure very fast, and this obviously requires too high to the user.Can find a kind of new method to overcome above-mentioned deficiency

The purpose of this invention is to provide a kind of " photoelectricity virtual blackboard " system based on large screen display of operating facility, visual pattern.

In order to achieve the above object, the present invention takes following measures:

" photoelectricity virtual blackboard " system based on large screen display, the indication positional information that it is characterized in that the light pen hit rod of the controlled infrared point-like light emitting source of head band is obtained by optical imagery by the apparatus for processing of video signals of being with the CCD picture pick-up device, the light-pen function operation instruction information is by obtaining giving directions excellent light emitting source to modulate, the through port line feed-in of the synthetic back of positional information and instruction information coding has the computing machine of keyboard, deliver directly by VGA video line control projector or rear-projection obtains giant-screen plane display interface, the interface of this interface and graphoscope shows synchronously again.

Advantage of the present invention:

1, has the function of on the large screen display interface, directly giving directions the operational computations machine

Adopt the light pen hit rod to substitute mouse, can realize directly to the large screen display interface give directions, locate, follow the tracks of, functions such as orientation, selection, and can realize full compatibility with computer entry devices such as mouse, keyboards;

2, has the function that on the large screen display interface, realizes the drawing board operation

Can be on the large screen display interface directly mapping, can change settings such as live width, color, prospect, background, can realize block copy, wipe, function such as consolidation;

3, have on the large screen display interface and to realize by directly writing function with character, numeral, Chinese character input computing machine;

4, operation is convenient, the user is required low;

5, visual pattern can be realized facing the person's of receiving instruction lively demonstration in the information interchange occasion;

6, be widely used, both be suitable for improving the intuitive of multimedia teaching, can be applied to occasions such as all kinds of replies, projection, product performance, military investigation, stock analysis, the explanation of chessboard extension dish, Entertainment again.

Elaborate below in conjunction with accompanying drawing:

Fig. 1 is based on large screen display " photoelectricity virtual blackboard " system's perspective view;

Fig. 2 is based on large screen display " photoelectricity virtual blackboard " systematic square frame synoptic diagram;

Fig. 3 is the apparatus for processing of video signals frame principle figure;

Fig. 4 is pre-service and feature screening circuit and the circuit theory diagrams that stop counting circuit.

The indication positional information of the light pen hit rod [2] of the controlled infrared point-like light emitting source of head band is obtained by optical imagery by the apparatus for processing of video signals [8] of band CCD picture pick-up device as shown in Figure 1, the light-pen function operation instruction information is by obtaining giving directions excellent light emitting source to modulate, synthetic back through port line [9] feed-in of positional information and instruction information coding has the computing machine [4] of keyboard [6], deliver directly by VGA video line [7] control projector [3] or rear-projection obtains giant-screen plane display interface [1], the interface of this interface and graphoscope [5] shows synchronously again.

By the large screen projector of main frame control band VGA interface, on the large screen projection display interface, produce and the synchronous content displayed of display interfaces as shown in Figure 2.The large screen projection display interface can be regarded a virtual blackboard interface as, with the trace operation thereon of light pen hit stick simulating chalk.The track that this moment, light pen was described is surveyed by the CCD picture pick-up device through optical system imaging, the output signal of CCD picture pick-up device reaches apparatus for processing of video signals and handles, obtain light pen and describe the coordinate of track sequence of points, synthetic and the serial communication driving through the coordinate sequence, with sequence of points coordinate feed-in computing machine, be implemented in location, trace on the virtual blackboard interface at real-time trace drive software under driving, confirm, write, function such as drawing.

The CCD picture pick-up device is under the driving of driving circuit as shown in Figure 3, survey the indication position of the light pen hit rod in the controlled infraluminescence of head band source, through pre-service and the screening of unique point screening circuit, deliver to the termination counting circuit, controlling vertical coordinate counting circuit counts the bidimensional coordinate of giving directions the position with horizontal coordinate counting circuit, from driving circuit, isolate the field frequency trigger circuit and the line frequency trigger circuit of vision signal, the bidimensional coordinate counting of giving directions the position is realized segmentation through electronic sub-circuit, and synthesize by the coordinate sequential value of coordinate combiner circuit to unique point.

The vision signal [11] of CCD picture pick-up device output is via U1 as shown in Figure 4, two voltage comparators of U2 are handled, filter out luminous point characteristic signal [12] and line frequency signal [13], U1 wherein, the reference voltage of U2 is respectively by potentiometer W1, W2 provides, line frequency signal [13] is through resistance R, capacitor C constitutes integrating circuit, for providing datum, voltage comparator U3 extracts field frequency signal [14] in the vision signal by potentiometer W3, line frequency signal [13] is imported d type flip flop U5 jointly with luminous point characteristic signal [12] after the paraphase of U4 phase inverter, obtain X numeration termination signal [15], field frequency signal [14] is imported d type flip flop U6 jointly with luminous point characteristic signal [12], obtains Y numeration termination signal [16].Interior each symbol of d type flip flop square frame shown in U6, the U5 is represented each lead end function respectively among the figure, and wherein D represents input, and Q represents output, $\stackrel{\‾}{Q}$ Represent anti-phase output, CLK represents input clock, and CD represents zero clearing, and SD represents to preset.

Claims (3)

1. " photoelectricity virtual blackboard " system based on large screen display, the indication positional information that it is characterized in that the light pen hit rod [2] of the controlled infrared point-like light emitting source of head band is obtained by optical imagery by the apparatus for processing of video signals [8] of being with the CCD picture pick-up device, the light-pen function operation instruction information is by obtaining giving directions excellent light emitting source to modulate, synthetic back through port line [9] feed-in of positional information and instruction information coding has the computing machine [4] of keyboard [6], deliver directly by VGA video line [7] control projector [3] or rear-projection obtains giant-screen plane display interface [1], the interface of this interface and graphoscope [5] shows synchronously again.

2. a kind of " photoelectricity virtual blackboard " system according to claim 1 based on large screen display, the principle that it is characterized in that the apparatus for processing of video signals of said band CCD picture pick-up device is: the CCD picture pick-up device is under the driving of driving circuit, survey the indication position of the light pen hit rod in the controlled infraluminescence of head band source, through pre-service and the screening of unique point screening circuit, deliver to the termination counting circuit, controlling vertical coordinate counting circuit counts the bidimensional coordinate of giving directions the position with horizontal coordinate counting circuit, from driving circuit, isolate the field frequency trigger circuit and the line frequency trigger circuit of vision signal, the bidimensional coordinate counting of giving directions the position is realized segmentation through electronic sub-circuit, and synthesize by the coordinate sequential value of coordinate combiner circuit to unique point.

3. a kind of " photoelectricity virtual blackboard " system according to claim 1 and 2 based on large screen display, the circuit theory that it is characterized in that said pre-service and unique point screening circuit and termination counting circuit is: the vision signal [11] of CCD picture pick-up device output is via U1, two voltage comparators of U2 are handled, filter out luminous point characteristic signal [12] and line frequency signal [13], U1 wherein, the reference voltage of U2 is respectively by potentiometer W1, W2 provides, line frequency signal [13] is through resistance R, capacitor C constitutes integrating circuit, for providing datum, voltage comparator U3 extracts field frequency signal [14] in the vision signal by potentiometer W3, line frequency signal [13] is imported d type flip flop U5 jointly with luminous point characteristic signal [12] after the paraphase of U4 phase inverter, obtain X numeration termination signal [15], field frequency signal [14] is imported d type flip flop U6 jointly with luminous point characteristic signal [12], obtains Y numeration termination signal [16].

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