JP2009169653A - Position detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly detect the indication position of an indication body even when an obstacle exists on a display screen, and to prevent consumption of a battery inside the indication body. <P>SOLUTION: A position detecting device includes: synchronizing signal projecting means 5, 6 for detecting the non-valid period of an image to be projected from a projector 12 to the rear surface 11b side of a display screen 11, and projecting non-visible light to the rear surface 11b side of the display screen 11 in the non-valid period; the indication body 2 for performing indication by projecting the light to the front surface 11a side of the display screen 11 during recognizing the non-valid period by receiving the non-visible light from the front surface 11a side of the display screen 11; an imaging means 3 for taking the image of the light projected from the indication body 2 from the rear surface 11b of the display screen 11, and converting the light into an electric signal; and an image processing means 4 for analyzing the electric signal converted by the imaging means 3, and calculating the indication position of the indication body 2 on the display screen 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a position detection device that detects the position of an indicator indicated on a display screen.

  In a device that optically detects the indicated position on the screen, a light source and a retroreflective material are provided on the outer edge of the front side of the display screen, and scanning light parallel to the display screen is irradiated to indicate the position on the screen. There is a position detection device that detects an indication position of an indicator by taking an image of a body retroreflected light (see, for example, Patent Document 1).

  In addition, there is a position detection device that outputs an identification signal from the pointer only while the tip of the pointer is in contact with the display screen, and determines that the received positional information is valid while receiving the identification signal ( For example, see Patent Document 2).

JP 2004-5171 A (page 4, FIG. 1) JP 2003-263274 A (pages 5 and 6 and FIG. 4)

  However, in Patent Document 1, if there is an obstacle on the display screen, there is a problem that the obstacle cannot be distinguished from the indicator and the position of the indicator cannot be accurately detected.

  Further, in Patent Document 2, since the identification signal is continuously output while the tip of the indicator provided with the battery inside the housing is in contact with the display screen, the battery inside the indicator is consumed in a short time. There's a problem.

  The present invention has been made to solve these problems, and accurately detects the pointing position of the indicator even when an obstacle is present on the display screen, and prevents the battery inside the pointer from being consumed. With the goal.

  In order to solve the above-described problem, a position detection device according to the present invention detects an ineffective period of an image projected from the projection device to the back side of the display screen, and transmits invisible light to the back surface of the display screen during the ineffective period. By projecting synchronization signal projection means to project to the side and invisible light projected by the synchronization signal projection means from the front side of the display screen, light is projected to the front side of the display screen while the ineffective period is recognized An indicator that can be instructed, an imaging unit that captures light projected from the indicator from the back side of the display screen and converts it into an electrical signal, and analyzes the electrical signal converted by the imaging unit And image processing means for calculating the indicated position of the indicator on the display screen.

  According to the present invention, the synchronization signal projecting means detects the ineffective period of the image projected from the projection device to the back side of the display screen, projects invisible light to the back side of the display screen during the ineffective period, and By receiving non-visible light projected by the synchronization signal projection means from the front side of the display screen, it is possible to instruct by projecting light on the front side of the display screen while recognizing the ineffective period. The imaging means captures the light projected from the indicator from the back side of the display screen and converts it into an electrical signal, and the image processing means analyzes the electrical signal converted by the imaging means, and displays the indicator on the display screen. Therefore, even if there is an obstacle on the display screen, it is possible to accurately detect the pointing position of the pointer and prevent the battery inside the pointer from being consumed.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a position detection apparatus according to an embodiment of the present invention. As shown in FIG. 1, the position detection device detects a synchronization signal of a video signal output from a projection device 12 that is a rear projector, and generates a synchronization signal indicating a video blanking period (invalid period). Generation means 6 (synchronization signal projection means), non-visible light projection means 5 (synchronization signal projection means) for projecting invisible light onto the display screen 11 based on the synchronization signal generated by the synchronization signal generation means 6, An indicator 2A that receives the invisible light output from the invisible light projection means 5 and analyzes the synchronization signal, and projects light of a predetermined wavelength onto the display screen 11 from the display surface 11a only during the blanking period of the video signal. And 2B (hereinafter, the indicators are collectively referred to as an indicator 2) and the indicators 2A and 2B during the blanking period of the video signal based on the synchronization signal generated by the synchronization signal generating means 6. From the imaging means 3 that images the emitted light from the back surface 11b side of the display screen 11, and the image processing means 4 that calculates the two-dimensional coordinates of the indicators 2A and 2B on the display screen 11 captured by the imaging means 3. Become. The invisible light projected from the invisible light projection unit 5 may be infrared rays, for example.

  The indicator 2 projects a light having a predetermined wavelength onto the display screen 11 by placing the tip on the display surface 11 a of the display screen 11. FIG. 2 is a configuration diagram of the indicator 2 according to the embodiment of the present invention. As shown in FIG. 2, the indicator 2 includes a light receiving unit 26 that receives light projected from the invisible light projection unit 5, and synchronous conversion that electrically converts light received by the light receiving unit 26 into a synchronization signal. Select one of the light emitting unit 21 having a plurality of diodes (21a, 21b, 21c) having different wavelengths and the wavelength of light projected from the indicator 2, that is, the light emitting diodes 21a, 21b, 21c. A switch 22 for driving, a driver 23 for driving the light emitting unit 21 selected according to the synchronization signal output from the synchronization converting unit 27, and the indicator 2 for efficiently projecting the light output from the light emitting unit 21. It consists of a lens 24 provided at the tip and a battery 25 that is a power source for driving the indicator 2, and these are housed in a housing 28.

  The light emitting unit 21 includes three types of light emitting diodes 21a, 21b, and 21c having different wavelengths. The light emitting diode 21a is red (660 nm), the light emitting diode 21b is blue-green (550 nm), and the light emitting diode 21c is blue (440 nm). Each light is emitted. By switching the light emitting diodes (21a, 21b, 21c) by operating the switch 22, the wavelength of the light projected from the indicator 2 can be changed.

  In the embodiment of the present invention, the indicator 2A and the indicator 2B are used, and the indicator 2A selects the light emitting diode 21a by operating the switch 22 and sets it to project red light, and the indicator 2B The light emitting diode 21b is selected by the operation 22 and set to project blue-green light. At this time, the wavelengths of light projected by the indicator 2A and the indicator 2B are made not to overlap. In the embodiment of the present invention, two indicators 2A and 2B are used, but one or three or more indicators 2 may be used.

  As shown in FIG. 1, the imaging unit 3 is housed and installed in a housing (not shown) so as to be close to the projection device 12. In other words, the front surface of the projection device 12 and the front surface of the imaging unit 3 are installed so as to be aligned in a plane substantially parallel to the display screen 11. By doing so, the imaging range of the imaging means 3 includes a range in which the projection device 12 projects an image on the display screen 11. In addition, the imaging unit 3 does not block the optical path through which the projection device 12 projects an image on the display screen 11. The imaging means 3 is provided with an optical filter (not shown) for distinguishing light according to the wavelength. After the light projected from the indicator 2 is distinguished for each wavelength and converted into an electrical signal, image processing is performed. Output to means 4.

  In the image processing means 4, an electrical signal distinguished for each wavelength is input from the imaging means 3, the positions of the indicator 2 </ b> A and the indicator 2 </ b> B are determined based on the input electrical signal, and two-dimensional on the display screen 11. It is calculated by processing as coordinates. The calculated two-dimensional position information of the indicator 2A and the indicator 2B is input to the computer 31 via an external interface 30 such as a LAN (Local Area Network) or a USB (Universal Serial Bus).

  The synchronization signal generation means 6 detects a period (blanking period) in which the vertical synchronization signal of the image projected from the projection device 12 and the effective image are not output (blanking period), and uses the invisible light projection means 5 and the image processing means 4 as the synchronization signal. Output to. The non-visible light projection unit 5 projects a pulse of non-visible light such as infrared rays on the display screen 11 only during the effective period of the synchronization signal input from the synchronization signal generation unit 6. On the other hand, the image processing unit 4 generates an imaging timing signal based on the synchronization signal input from the synchronization signal generation unit 6 and outputs it to the imaging unit 3. The imaging unit 3 images the light projected from the indicator 2 according to the imaging timing signal input from the image processing unit 4.

  The computer 31 has video information inside, and outputs the video information to the projection device 12 as a video signal. At this time, when the position information of the indicator 2A and the indicator 2B is input from the image processing unit 4 via the external interface 30, it is based on the input position information by the application software installed in the computer 31. The video information is controlled, and the controlled video information is output to the projection device 12 as a video signal.

  The projection device 12 to which the video signal is input from the computer 31 projects the video on the back surface 11 b side of the display screen 11, and the projected video is imaged on the display surface 11 a of the display screen 11. An image can be viewed from the display surface 11a side.

  Next, the operation of the position detection device will be described.

  FIG. 3 is a diagram showing an electrical signal of the synchronization signal generating means 6 according to the embodiment of the present invention. For example, when a vertical synchronizing signal and an image signal of a video are input to the projection device 12 at timings as shown in FIGS. 3A and 3B, the projection device 12 receives the display screen 11 from FIG. A vertical synchronizing signal and an image signal are output at timings as shown in c) and (d). When projecting an image on the display screen 11 from the projection device 12, there are a period during which an effective image is output and a blanking period during which no effective image is output. At this time, the synchronization signal generation means 6 detects a blanking period from the vertical synchronization signal output from the projection device 12 as shown in FIG. 3E until an effective image is generated, and uses the invisible light projection means as the synchronization signal. 5 is output.

  The invisible light projection unit 5 projects a pulse of invisible light on the display screen 11 as an effective period of the synchronization signal input from the synchronization signal generation unit 6 only during the “L” period of FIG.

  In the indicator 2, the light-receiving unit 26 receives a pulse of invisible light projected from the invisible light projection unit 5. The invisible light pulse received by the light receiving unit 26 is electrically converted by the synchronization conversion unit 27 to restore the synchronization signal shown in FIG. The driver 23 performs control so that the light emitting unit 21 is driven only during the effective period of the synchronization signal input from the synchronization conversion unit 27. That is, control is performed so that one of the light emitting diodes 21a to 21c of the indicator 2 is driven only during a blanking period in which an effective image is not output among images projected from the projection device 12 onto the display screen 11.

  FIG. 4 is a diagram showing the positions of the indicator 2A and the indicator 2B detected by the imaging means 3 according to the embodiment of the present invention. As shown in FIG. 4, when the light emitted from the indicator 2A and the indicator 2B is simultaneously projected onto the display surface 11a of the display screen 11, the light 20A of the indicator 2A (wavelength 660 nm) and the indicator 2B (wavelength 550 nm) The light 20B is projected on the back surface 11b side of the display screen 11. In the imaging means 3, the light of the indicator 2A and the indicator 2B is distinguished by an optical filter provided therein, and only the light 20A and the light 20B are detected as an image as shown in FIG. Then, the imaging unit 3 images the light 20A and the light 20B according to the imaging timing signal input from the image processing unit 4 illustrated in FIG. That is, the imaging means 3 is light projected from the indicator 2 once for each frame of the output video in synchronization with the blanking period of the video signal projected from the projection device 12 onto the display screen 11. Is controlled by the image processing means 4 so that

  When detecting the light projected from the indicator 2 by the imaging means 3, if the effective image is output from the projection device 12, the light projected from the indicator 2 and the projection device on the back surface 11b side of the display screen 11 The image projected from 12 may interfere with each other, and the imaging unit 3 may not be able to accurately detect the position of the indicator 2. However, as in the present embodiment, since the imaging by the imaging unit 3 is performed in synchronization with a period during which no effective image is projected from the projection device 12 (blanking period), the imaging unit 3 determines the position of the indicator 2. There is no false detection. Further, since the imaging unit 3 distinguishes and captures the light 20A projected from the indicator 2A and the light 20B projected from the indicator 2B and outputs the image to the image processing unit 4, there is an obstacle on the display screen 11. Even if there is an object, the image pickup means 3 picks up only the light projected from the indicator 2, so that an obstacle is not erroneously detected.

In the image processing means 4, the electrical signal SR of the light 20 </ b> A and the electrical signal SB of the light 20 </ b> B are separated from the signal input from the imaging means 3, and the indication positions of the indicator 2 </ b> A and the indicator 2 </ b> B indicated on the display screen 11. Are obtained by calculating each independently. FIG. 5 is a diagram showing an example of coordinate calculation in the image processing means 4 according to the embodiment of the present invention. 5A to 5C detect the positions of the indicator 2A and the indicator 2B in the x-coordinate direction shown in FIG. As shown in FIG. 5, (a) is a horizontal synchronization signal, (b) is a signal for detecting red light 20A projected from the indicator 2A, and (c) is blue-green light projected from the indicator 2B. A signal for detecting the position of 20B is shown. In (a), the starting point SH _O of the horizontal synchronizing signal corresponds to the horizontal left end (x = 0) on the display screen 11, and the end point SH _e is the horizontal right end (x = X) on the display screen 11. ). The horizontal position (Rx) of the light 20A on the display screen 11 can be calculated from the time tR _H from SH 2 _O to SR _H for detecting the light 20A of the indicator 2A shown in (b). Similarly, the horizontal position (Bx) of the light 20B on the display screen 11 can be calculated from the time tBH from SH 2 _O to SB _H for detecting the light 20B of the indicator 2B shown in (c).

5D to 5F detect the positions of the indicator 2A and the indicator 2B in the y-coordinate direction shown in FIG. (D) is a vertical synchronization signal, (e) is a signal for detecting the red light 20A projected from the indicator 2A, and (f) is a signal for detecting the position of the blue-green light 20B projected from the indicator 2B. Is shown. In (d), the starting point SV _O of the vertical synchronization signal corresponds to the lower end (y = 0) on the display screen 11, and the end point SV _e corresponds to the upper end (y = Y) on the display screen 11. The vertical position (Ry) of the light 20A on the display screen 11 can be calculated from the time tR _H from SV _O to SR _V for detecting the light 20A of the indicator 2A shown in (e). Similarly, it is possible by the time tB _V to SB _V for detecting the light 20B of the pointer 2B showing the SV _O (f), the calculated vertical position of the light 20B on the display screen 11 (By A) .

  The two-dimensional position information of the indicator 2A and the indicator 2B calculated by the image processing means 4 is input to the computer 31 via the external interface 30. The computer 31 controls the video information held based on the input position information. The video controlled by the computer 31 is displayed by projecting it on the display screen 11 in real time.

  In this embodiment, the indication positions of the indicator 2A and the indicator 2B are detected as the two-dimensional coordinate positions on the display screen 11, but the positions are detected as the one-dimensional coordinates of only the X axis or the Y axis. You may make it do.

  From the above, the light projected on the display surface 11a side of the display screen 11 from the indicator 2 is imaged by the imaging means 3 from the back surface 11b side of the display screen 11 and the indicated position of the indicator 2 is detected. Even when there is an obstacle on the screen 11, it is possible to accurately detect the indicated position of one or more indicators 2 indicated on the display screen 11. In addition, light is projected from the indicator 2 and is imaged in synchronization with the timing at which light is projected from the indicator 2 only during a period when the image is not projected from the projection device 12 on the display screen 11, that is, the ineffective period. Since the control is performed so that the image is taken by the means 3, the indication position of the indicator 2 displayed on the display screen 11 is not erroneously detected.

  In addition, since the front surface of the camera provided in the image pickup means 3 and the front surface of the projection device 12 are arranged so as to be aligned in the same plane substantially parallel to the display screen 11, the projection device 12 projects onto the display screen 11. The imaging means 3 does not block the optical path of the emitted light, and the quality of the image displayed on the display screen 11 is not deteriorated.

  Since the imaging means 3 is configured to distinguish and convert the light of a predetermined wavelength projected from the indicator 2 into an electric signal, the light projected from the single or plural indicators 2 on the display screen 11 respectively. It is possible to distinguish and accurately detect the indication position of the indicator 2 without erroneously recognizing outside light other than the indicator 2. When a plurality of indicators 2 are used, the wavelength of light projected from each indicator 2 can be changed as appropriate. Therefore, even when a plurality of indicators 2 are used at the same time, each of the indicators 2 shown on the display screen 11 is used. Can be detected independently. In the present embodiment, since three types of light having different wavelengths can be selected and projected onto the indicator 2, even if the three indicators 2A to 2C are used simultaneously, the indicators 2A to 2C are used. If the adjustment is made by the switch 22 so that the wavelengths of the light projected from each other do not overlap, the indication positions of the indicators 2A to 2C can be calculated simultaneously and independently. The wavelength of the light projected from the indicator 2 at this time is a wavelength different from the line spectrum of the light source of the projection device 12. If the types of wavelengths that can be distinguished by the imaging unit 3 and the types of wavelengths of light projected from the corresponding indicators 2 are increased, the number of indicators 2 that can be used simultaneously can be increased. is there.

  The indicator 2 drives the light emitting diodes 21a to 21c of the light emitting unit 21 by the battery 25. However, since the indicator 2 drives the light emitting diodes 21a to 21c only during the blanking period of the image projected from the projection device 12, Electric power can be reduced, and the life of the battery 25 can be extended. Further, if the indicator 2 is mounted with a light source having light condensing properties such as laser light so that the display screen 11 can be irradiated with light from a distant position, the indicator 2 is applied to the display screen 11. It is possible to indicate the position without pressing.

  Further, the period during which the indicator 2 projects light does not have to be immediately after the vertical synchronization signal of the output video as shown in FIG. 3E, but in the blanking period of the video signal output from the projection device 12. Control may be performed in synchronization. Further, the indicator 2 may be controlled to project light for a certain period after detecting the falling edge of the synchronization signal shown in FIG. When there are a plurality of blanking periods of the video signal output from the projection device 12, the emission control and imaging of light projected from the indicator 2 in synchronization with any one blanking period in one frame. Control may be performed.

  FIG. 6 is a diagram showing an electrical signal of the synchronization signal generating means 6 according to the embodiment of the present invention. For example, when light output from a single light source provided in the projection device 12 is processed in a time-sharing manner using a three-plate color wheel of R, G, and B, the effective area of the image output from the projection device 12 is a color. The data is output in units of wheels R, G, and B. Here, when the color wheel is rotated at the triple speed of the video signal, the effective area of the video output from the projection device 12 is output by dividing one frame into nine as shown in FIG. There are also 9 blanking periods. In this case, the indicator 2 may be controlled in synchronization with an arbitrary blanking period from nine blanking periods. For example, when controlling the indicator 2 and the imaging means 3 in synchronization with the second blanking period of the video signal output from the projection device 12, the synchronization signal generating means 6 is as shown in FIG. 6 (e). A simple synchronization signal is output to the invisible light projection means 5 and the image processing means 4, and the imaging means 3 is controlled at the imaging timing as shown in FIG.

  In this embodiment, invisible light such as infrared rays is projected from the invisible light projection means 5, but the blanking period of the image projected from the projection device 12 is transmitted to the indicator 2 using radio waves or the like. However, the same effect is obtained.

It is a block diagram of the position detection apparatus by embodiment of this invention. It is a block diagram of the indicator by embodiment of this invention. It is a figure which shows the electric signal of the synchronous signal generation means by embodiment of this invention. It is a figure which shows the position of the indicator detected by the imaging means by embodiment of this invention. It is a figure which shows an example of the coordinate calculation in the image processing means by embodiment of this invention. It is a figure which shows the electric signal of the synchronous signal generation means by embodiment of this invention.

Explanation of symbols

  2 indicator, 3 imaging means, 4 image processing means, 5 invisible light projection means, 6 synchronization signal generating means, 11 display screen, 11a display surface, 11b back surface, 12 projection device, 30 external interface, 31 computer, 21 light emission Part, 22 switch, 23 driver, 24 lens, 25 battery, 26 light receiving part, 27 synchronization conversion part, 28 housing.

Claims (6)

Synchronization signal projection means for detecting an ineffective period of an image projected from the projection device to the back side of the display screen, and projecting invisible light to the back side of the display screen during the ineffective period;
Receiving the invisible light projected by the synchronization signal projecting means from the front side of the display screen to project and instruct light on the front side of the display screen while recognizing the ineffective period. An indicator capable of
Imaging means for photographing the light projected from the indicator from the back side of the display screen and converting it into an electrical signal;
Image processing means for analyzing the electrical signal converted by the imaging means and calculating an indication position of the indicator on the display screen;
A position detecting device.   The position detection device according to claim 1, wherein the front surface of the imaging unit and the front surface of the projection device are installed so as to be aligned in the same plane substantially parallel to the display screen.   The position detection apparatus according to claim 1, wherein the invisible light projected from the synchronization signal projecting unit is an infrared ray.   The position detection device according to any one of claims 1 to 3, wherein the imaging unit distinguishes and converts light having a predetermined wavelength projected from the indicator into an electric signal.   4. The position detection according to claim 1, wherein the imaging unit distinguishes and converts each of light having different predetermined wavelengths projected from the plurality of indicators into an electrical signal. 5. apparatus.   The position detection device according to claim 4, wherein the predetermined wavelength is a wavelength different from a line spectrum of a light source of the projection device.

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