JP3772127B2 - Presentation system using laser pointer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a presentation system for giving a lecture or the like while indicating an image projected on a screen with a projection spot of a laser pointer.
[0002]
[Prior art]
In a presentation in which an image is projected on a screen by a projection device such as a liquid crystal projector and various presentations and explanations are given to the audience while referring to the image, a laser pointer for indicating a specific portion of the image is provided. Well used. When the laser pointer is turned on, a laser beam is projected and a spot is projected onto the screen. However, if the presenter who is the user accidentally turns the laser pointer toward the audience, the audience will feel uncomfortable. Strong power is dangerous for eyes. Therefore, for example, Japanese Patent Laid-Open No. 2000-321531 discloses a safety measure for avoiding such danger. In this publication, while infrared light is projected from the laser pointer in the same direction as the laser light, whether the infrared light is projected on the screen is imaged by an imaging means such as a CCD, and the infrared light is imaged. The laser pointer is emitted only when the laser pointer is emitted, and the laser pointer is not projected when the laser pointer is not directed to the screen.
[0003]
[Problems to be solved by the invention]
In the safety measures described in the above publication, the laser pointer is separated from the imaging means such as a CCD that images the infrared light projected from the laser pointer onto the screen, so the construction of the system is complicated, There has been a drawback that it is expensive to use the imaging means.
[0004]
Accordingly, an object of the present invention is to provide a presentation system using a laser pointer that can prevent erroneous projection of the laser pointer with a simple and inexpensive configuration and can further improve safety.
[0005]
[Means for Solving the Problems]
The present invention includes an image projection device that projects an image on a screen while selecting light of each color that is sequentially switched to a plurality of colors at regular timing by a color switching unit, and a laser pointer that projects laser light on the screen. The laser pointer includes a laser light projecting unit, a light receiving unit that detects light directed in a direction opposite to the projection direction of the laser beam projected from the laser light projecting unit, and the light receiving unit. The color separation means for separating the received light into light of each color switched by the color switching means, the color signal detection means for detecting the color signal separated by the color separation means, and the color signal detection means Color signal switching timing detecting means for detecting the switching timing of the color signal, and the color signal detected by the color signal switching timing detecting means It is determined whether or not the switching timing coincides with the color switching timing by the color switching means, and the control means for driving the laser light projection means and projecting the laser light only when they coincide with each other. It is characterized by that.
[0006]
According to the present invention, when the laser pointer is directed to the image projected on the screen from the image projection device, the laser pointer recognizes the image, and when the laser light projection means is turned on in this state, the laser light is projected onto the screen. Is done. When the pointing direction of the laser pointer is removed from the screen, the laser pointer does not recognize the image, and in that case, the laser beam is not projected. That is, the laser beam is projected only when the laser pointer is directed to the screen on which the image is projected from the image projection device, and the laser beam is projected onto the screen.
[0007]
The action of the laser pointer recognizing the screen image is as follows.
In the image projected from the image projection device to the screen, a plurality of colors are sequentially switched at regular timing by the color switching means of the image projection device, and the reflected light of the image reflected on the screen is the same. Here, when the laser pointer is directed to the screen, the light receiving means included in the laser pointer detects light that is directed in the direction opposite to the projection direction of the laser light projected from the laser pointer among the reflected light from the screen. Next, the light detected by the light receiving means is separated into light of each color (light of each color sequentially switched by the color switching means). Next, the color detection means detects the color signal separated by the color separation means, and the color signal switching timing detection means detects the switching timing of the color signal. Then, the control means determines whether or not the detected color signal switching timing coincides with the color switching timing by the color switching means, and if so, the image projecting device projects the result onto the screen. It is recognized that the image is. In this way, when the laser pointer recognizes the image, the laser beam projection means is driven to project the laser beam.
[0008]
On the other hand, when the pointing direction of the laser pointer is removed from the screen on which the image is projected, the light detected by the light receiving means is “light that is sequentially switched to a plurality of colors at regular timing by the color switching means of the image projection apparatus”. Is completely different. Therefore, the image is not recognized and the laser beam is not projected from the laser pointer.
[0009]
As described above, in the present invention, it is accurately determined whether or not the projection direction of the laser beam from the laser pointer is within the screen range (strictly within the image range), and the laser pointer is directed to the screen. Only the laser beam is projected. As a result, erroneous projection of laser light is reliably prevented, and safety is further improved. Since the present invention does not require an image pickup means such as a CCD for picking up the infrared light projected on the screen as in the prior art, it can be configured simply and inexpensively.
[0010]
As the image projection apparatus of the present invention, for example, a DLP (Digital Light Processing) type reflection type projector using a DMD (Digital Micromirror Device) element disclosed in Japanese Patent Application Laid-Open No. 2000-231066 is suitably used. Some projectors include a color filter that rotates at high speed as color switching means, and a specific example of the configuration will be described later.
[0011]
A laser diode is preferably used as the laser light projection means provided in the laser pointer of the present invention. Further, a lens is preferably used as the light receiving means, a filter is used as the color separating means, and a photodiode is preferably used as the color signal detecting means. Further, the color signal switching timing detection means and the control means can be configured by an appropriate microcomputer or the like.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows an overall system according to an embodiment of the present invention. In the figure, reference numeral 10 denotes a screen, 20 denotes a DLP projector (image projection apparatus) that projects an image on the screen 10, 30 denotes a personal computer, and 40 denotes a laser pointer that is held by a presenter (not shown). The personal computer 30 processes various commands and generates image data, and an image based on the image data is projected from the projector 20 onto the screen 10.
[0013]
In this case, the projector 20 uses a single-plate DMD element. As shown in FIG. 2, the projector 20 includes a white light source 21 such as a metal halide lamp, and a first condenser lens that condenses the white light emitted from the white light source 21. 22a, a disk-shaped color filter (color switching means) 24 that is rotated at high speed in the direction of arrow F by the motor 23, a second condensing lens 22b that condenses the light transmitted through the color filter 24, and a second The DMD element 25 reflects the light transmitted through the condenser lens 22b, and the projection lens 26 projects the light reflected from the DMD element 25 onto the screen 10.
[0014]
The color filter 24 is divided into three equal parts of R (red), G (green), and B (blue), and the white color emitted from the white light source 21 and condensed by the first condenser lens 22a. Light passes through the rotating color filter 24 and is switched to R, G, and B colors in this order at equal intervals. The light is collected by the second condenser lens 22 b and enters the DMD element 25.
[0015]
The DMD element 25 includes a large number of micromirrors (hundreds of thousands) corresponding to one pixel integrated on one chip. Each mirror is supported so as to be tiltable, and reflects light according to the tilt angle. Digital control is performed based on the image data input from the personal computer 30 so as to be turned ON / OFF. Light that has entered the DMD element 25 (light that has been sequentially switched to three colors by passing through the color filter 24) is reflected by the mirror that is turned on in the DMD element 25 and projected onto the screen 10 as an image. The image is generated by sequentially projecting three colors of R, G, and B. Since the color switching by the color filter 24 is performed at a high speed, the colors are perceived as a mixture, and the image is formed.
[0016]
Next, the configuration of the laser pointer 40 will be described. As shown in FIG. 3, the laser pointer 40 includes a control unit (control unit) 41, a laser diode (laser light projection unit) 42, and a switch 43. When the switch 43 is turned on, an ON signal is transmitted to the control unit 41. The control unit 41 drives the laser diode 42 and the laser light is projected from the laser diode 42.
[0017]
The laser pointer 40 has a lens (light receiving means) 44 for detecting light directed in the direction opposite to the projection direction of the laser light projected from the laser diode 42, and the light received by the lens 44 is R, G, B. A filter (color separation means) 45 for separating the light into a light, a photodiode (color signal detection means) 46 for detecting a color signal separated by the filter 45, and a switching timing of the color signal detected by the photodiode 46. And a timing detection unit (color signal switching timing detection means) 47 for detecting the above. The color signal switching timing detected by the timing detection unit 47 is input to the control unit 41. Then, the control unit 41 determines whether or not the switching timing of the input color signal coincides with the switching timing of R, G and B by the color filter 24 of the projector 20, and only when they match, the laser The diode 42 is driven.
[0018]
The above is the configuration of the system according to the present embodiment. Next, the operation of this system will be described.
In the image projected from the projector 20 onto the screen 10, the three colors R, G, and B are sequentially switched at equal intervals by the color filter 24, and the reflected light of the image reflected on the screen 10 is the same. Here, when the presenter points the laser pointer 40 toward the screen 10, among the reflected light from the screen 10, the light directed in the direction opposite to the projection direction of the laser light projected from the laser pointer 40 is converted into the lens of the laser pointer 40. 44 detects.
[0019]
Next, the light detected by the lens 44 is separated into light of R, G, and B colors by the filter 45. Next, the photodiode 46 detects the color signal separated by the filter 45, and the timing detection unit 47 detects the switching timing of the color signal. Then, the switching timing is input to the control unit 41, and the control unit 41 determines whether or not the switching timing of the color signal coincides with the switching timing of the color by the color filter 24 of the projector 20. In this case, since the switching timing is naturally coincident, when the switch 43 is turned on, the laser diode 42 is driven and laser light is projected, and the laser light is projected onto the screen 10. The determination of the color switching timing of the control unit 41 is performed by collating with a previously stored switching timing of one color or by collating with whether or not it matches with the stored switching pattern.
[0020]
On the other hand, when the pointing direction of the laser pointer 40 is removed from the screen 10 on which the image is projected, the light detected by the lens 44 is light that is sequentially switched by R, G, and B at equal intervals by the color filter 24 of the projector. Are completely different. Therefore, the control unit 41 does not drive the laser diode 42 and no laser beam is projected from the laser pointer 40.
[0021]
As described above, according to the present system, when the laser pointer 40 is directed from the projector 20 to the image projected on the screen 10, the laser pointer 40 recognizes the image, and when the switch 43 is turned on in this state, the laser beam is emitted. Is projected onto the screen 10. When the pointing direction of the laser pointer 40 is removed from the screen 10, the laser pointer 40 does not recognize the image, and in this case, the laser beam is not projected. That is, the laser beam is projected only when the laser pointer 40 is directed from the projector 20 to the screen 10 on which the image is projected, and the laser beam is projected onto the screen 10.
[0022]
As described above, in the present system, it is accurately determined whether or not the projection direction of the laser light from the laser pointer 40 is within the range of the screen 10 (strictly, within the range of the image). The laser beam is projected only when the is directed. As a result, erroneous projection of laser light is reliably prevented, and safety is further improved. Further, since the system mainly includes the projector 20 and the laser pointer 40, there is an advantage that it can be configured simply and inexpensively.
[0023]
In the above embodiment, the DLP projector is a type that uses a single-plate DMD element, but it can also be applied to, for example, a DLP projector that uses a two-plate DMD element. The color filter in this type is divided into M (magenta) that changes white light into R and B, and Y (yellow) that changes white light into R and G, and light that always contains R is generated. The The light is split by a prism into an R-dedicated DMD element and another DMD element that handles B and G alternately, and is further reintegrated by the prism and projected onto the screen. Therefore, the color switching determination system provided in the laser pointer in this case is for G and B.
[0024]
【The invention's effect】
As described above, according to the present invention, the laser pointer is controlled to project the laser beam only when the light reflected on the screen is recognized as the light of the specific image projected from the image projection device. With a simple and inexpensive configuration, it is possible to accurately determine whether the pointing direction of the laser pointer is within the screen range. As a result, erroneous projection of the laser pointer is reliably prevented, and safety is further improved. There is an effect such as.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a system according to an embodiment of the present invention.
FIG. 2 is a perspective view schematically showing a configuration of a projector according to an embodiment of the invention.
FIG. 3 is a block diagram showing a configuration of a laser pointer according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Screen 20 ... Projector (image projection apparatus)
24. Color filter (color switching means)
25 ... DMD element 40 ... Laser pointer 41 ... Control unit (control means)
42 ... Laser diode (laser beam projection means)
44 ... Lens (light receiving means)
45. Filter (color separation means)
46. Photodiode (color signal detection means)
47. Timing detector (color signal switching timing detector)

Claims (1)

Presentation system comprising: an image projection device that projects an image onto a screen while selecting light of each color that is sequentially switched to a plurality of colors at regular timing by a color switching means; and a laser pointer that projects a laser beam onto the screen Because
The laser pointer includes a laser beam projecting unit, a light receiving unit that detects light directed in a direction opposite to the projection direction of the laser beam projected from the laser beam projecting unit, and the color switching of the light received by the light receiving unit. Color separation means for separating the light of each color switched by the means, color signal detection means for detecting the color signal separated by the color separation means, and detection timing of the color signal detected by the color signal detection means Determining whether the color signal switching timing detecting means and the color signal switching timing detected by the color signal switching timing detecting means coincide with the color switching timing by the color switching means. And a control means for driving the laser light projection means to project the laser light only when there is a presentation using a laser pointer. Deployment system.

Images