JP4142814B2 - Image projection system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image projection system that projects an image from a projector onto a screen.
[0002]
[Prior art]
In recent years, there have been increasing opportunities for lecturers, lectures, explanations and the like to a plurality of listeners using a projector. This is mainly due to the fact that the quality of the projected image of the projector has increased and the hardware and software functions of information input devices such as personal computers have been enhanced.
[0003]
However, in the conventional image projection system, in order to edit the image projected on the screen, the projector user (referred to as the presenter), or an agent on the information input device such as a personal computer, operates the mouse and inputs the key. I had to do some operations.
[0004]
Therefore, even if the presenter tries to underline or surround the character string to be emphasized in the explanatory text in order to increase the effect of the explanation, the operation of the personal computer during the explanation is troublesome and it cannot be left to the thought.
[0005]
In order to solve this problem, it is necessary to have a technique capable of marking a certain image pattern in the original image on the screen as if writing a line with a pen on the blackboard while explaining.
[0006]
In Japanese Patent Laid-Open No. 5-46129, a screen having a magnetic sensor and an indicator bar (magnet pointer) provided with a magnet at the tip are combined, and the presenter indicates the position on the screen with the magnetic pointer and is detected by the magnet sensor. The supplied signal is supplied to the coordinate detection device, and the coordinate data from this is input to the image signal processing device, and the image signal supplied from the image source is synthesized as a symbol M, and this display signal is sent from the projector to the screen. An image display apparatus for projecting is provided. Japanese Patent Application Laid-Open No. 8-160539 discloses a non-contact type input method in addition to a contact type input method.
[0007]
[Problems to be solved by the invention]
The apparatus disclosed in Japanese Patent Application Laid-Open No. 5-46129 can improve the annoyance because the position can be specified with an indicator bar and an image can be formed on the screen. However, when giving a lecture at a large venue, the presenter often explains from the place with some distance from the screen with an optical pointer, rather than explaining while holding the pointing rod near the screen. It cannot be applied to the venue.
[0008]
Further, there is no means for matching the coordinate data on the screen with the image signal data in the image signal processing apparatus, and when the projector is moved with respect to the screen, the positional relationship between the position of the original image on the screen and the symbol M is not matched. .
[0009]
Further, the technique disclosed in Japanese Patent Laid-Open No. 8-160539 is effective only for a transmissive projector and is not suitable for a reflective projector (usually, the image projection of a projector is performed by projecting from the back surface of a translucent screen. There is a “transmission type” that forms an image on top and a “reflection type” that projects from the surface side of the white screen and forms an image on the screen surface).
[0010]
In a reflection type projector, since the projector main body and the screen can be separated and transported, the projector is excellent in portability, is inexpensive compared with the transmission type, and has better image quality than the transmission type. Therefore, it is a fatal defect that it is not suitable for a reflection type projector having such advantages.
[0011]
The present invention has been made in view of the above-described problems, and provides an image projection system that allows a presenter to perform marking or the like with a simple operation by superimposing an image on a screen at the time of explanation in a reflective projector. It is intended.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is directed to a reflective screen, a projector for projecting an image on the screen, an image input device for supplying an image signal to the projector, and an image on the screen. In the image forming system provided with the optical pointer, the screen has a matrix of optical sensors that detect light emitted from the optical pointer, and the projector outputs a plurality of optical signals of the same type as the optical pointer. The image input device projects an image on the screen in a state including the location, and the image input device calculates the coordinates on the screen, which is the position of the light beam on the screen, based on the electrical signal emitted from the light sensor that senses the light beam. Based on the coordinates on the screen calculated by the position detection function, a certain image pattern is superimposed on the original image. Alignment features for aligning, and the original image and the image signal of the image pattern have a image editing function of combining, the alignment feature is a screen on the coordinates and the projection image in a detected position the optical signal on the screen The relative position relationship between the on-screen coordinates and the projected image coordinates is calculated from the projected image coordinates which are the light signal irradiation positions of the two, and the two are aligned .
[0013]
In order to achieve the above object, according to a second aspect of the present invention, there is provided the image projection system according to the first aspect , wherein the image input device performs correction projection from the coordinates on the screen of the projection image obtained by the light beam position detection function. It has a correction function of calculating an area and correcting the original image so that the projected image is not distorted on the screen .
[0015]
According to the first aspect of the present invention, the image input device calculates the coordinates on the screen, which is the position of the light beam on the screen, based on the electrical signal emitted from the light sensor that senses the light beam, and uses the calculated screen coordinate as a reference. In addition, a predetermined image pattern is superimposed on the original image, and further, the original image and the image signal of the image pattern are synthesized.
[0017]
According to the first aspect of the present invention, in the technique for superimposing the original image formed (projected) on the screen and drawing (projecting) an image of a certain pattern by the operation of the presenter, the necessary alignment is performed. Alignment is performed automatically without the presenter being aware of it.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of an image projection system showing an embodiment of the present invention.
The image projection system includes a reflective screen 1, a projector 2 for projecting an image onto the screen 1, an image input device 3 for supplying an image signal to the projector 2, and an optical pointer for indicating an image on the screen 1. 4 is provided.
[0019]
The image input device 3 receives an electrical signal emitted from the optical sensor on the screen 1 when receiving the optical signal, and based on this signal, a light beam position detecting means for calculating the light irradiation position 5 on the screen 1, a light beam position detection It can also serve as image editing means for synthesizing an image signal obtained by superimposing a predetermined image on the original image on the basis of the light beam position calculated by the means. The presenter P can irradiate the screen 1 with visible light by the optical pointer 4 to indicate a desired position of the projected image on the screen 1.
[0020]
FIG. 2 is a schematic configuration diagram of the screen.
On the surface of the screen 1, there are a plurality of transparent or similar color optical sensors 11 arranged in a matrix, and when each optical sensor 11 receives a specific light beam (optical signal), the optical sensor 11 The position of the photosensor 11 that has been displaced from the off level to the on level and that has been displaced (that is, irradiated with light) is recognized by the light beam position detecting means 12 as on-screen coordinates.
[0021]
The light beam position detection unit 12 may be installed as a single device and transmit a light beam position signal to the image editing unit, but may be incorporated in the image input device 3. The arrangement interval of the photosensors 11 should be close in order to increase the position resolution, but the manufacturing cost increases as the density increases, so it should be determined from the viewpoint of cost performance. Usually, the optical sensors 11 are arranged at intervals of several mm to several cm.
[0022]
Thus, by arranging the optical sensors 11 on the screen 1 in a matrix, the image is superimposed on the original image formed (projected) on the screen 1 and a certain image pattern is drawn (projected) by the operation of the presenter P. It becomes possible.
[0023]
In addition, by using the optical signal and the optical sensor 11, it is not necessary to bring the indicator bar into contact with the screen 1 as in the prior art. Therefore, even when the presenter P is away from the screen 1, it is easy to explain. On the other hand, it is possible to mark a certain image pattern in the original image on the screen 1 as if writing a line with a pen on the blackboard. Moreover, since it is a reflection type screen, there is no malfunction which exists in the above-mentioned projection type screen.
[0024]
When the optical signal is sensed by the optical sensor 11, the projection image itself emits various colors depending on the image. Therefore, the optical sensor 11 must be able to sense the optical signal and the light of the projection image separately. For this reason, it is desirable to use infrared light as the optical signal or visible light obtained by applying a modulation to the light irradiation intensity so that the optical sensor 11 can be separated and sensed from the image light. .
[0025]
When infrared light is used as the optical signal, the optical sensor 11 that has been conventionally used can be used as the optical sensor 11. For example, a pyroelectric sensor, a quantum sensor (reference: Tanno et al. Basic and its application (Morita Kita Publishing) etc. can be used. Since these sensors are relatively inexpensive, they are advantageous in terms of the production cost of the screen 1. In addition, since the projection image and the wavelength range of light are different, stable signal detection is possible by performing filtering or the like.
[0026]
Further, when visible light is used as an optical signal, it is not necessary to provide the optical pointer 4 with a mechanism for transmitting both infrared light and visible light, and the configuration of the optical pointer 4 can be simplified. Further, since the optical signal can be transmitted by the visible light handled by the projector 2 as the alignment means, a mechanism for transmitting the infrared light to the projector 2 is not necessary and no burden is applied. However, the optical sensor 11 and the conductor that transmits the signal of the optical sensor 11 should be transparent or have the same color as the background color of the screen so that the quality of the projected image does not deteriorate.
[0027]
Here, in the present invention , the image input device 3 in FIG. 1 calculates the position (coordinate on the screen) of the light beam on the screen 1 based on the electric signal emitted from the optical sensor 11 that senses the light beam (light signal). Functions as a position detecting means, a positioning means for superimposing a predetermined image pattern on the original image, and an image editing means for synthesizing image signals based on the coordinates on the screen calculated by the light position detecting means. I have it.
[0028]
Here, the concept of alignment between the coordinates on the screen and the projected image coordinates will be described below.
4A, 4 </ b> B, and 4 </ b> C show a projection range 10 (region displayed by a one-dot chain line) when an image is projected on the screen 1. The projection image from the projector 2 is generally radial light and has a rectangular outline.
[0029]
If the optical axis is parallel to the normal line of the screen 1, the image is kept rectangular without distortion as shown in FIG. When the light ray has an angle in the vertical direction with respect to the normal line, the rectangle is distorted into a shape as shown in (b), and the image is also distorted at the same time. When the optical axis has an angle in the left-right direction with respect to the normal, the rectangle is distorted into a shape as shown in (c), and the image is also distorted at the same time.
[0030]
FIG. 5 shows a screen 1 and optical sensors 11 arranged on the surface thereof, and each optical sensor 11 corresponds to a coordinate on the screen. In the figure, 336 sensors from (1,1) to (24,14) are shown for convenience. Further, in the drawing, the contour is shown so that the arrangement of the optical sensor 11 can be recognized, but in reality, it is desirable to be transparent or a color similar to the color of the screen so as not to disturb the visibility of the projected image.
[0031]
On the other hand, as described above, the projected image is often projected onto the screen 1 with a certain distortion (projection range 10). If the projected image coordinates are set from (1,1) to (640,480), the (1,1) on-screen coordinates ((3,3) in the figure), (640,1) on-screen coordinates. The coordinates on the screen [(23, 3) in the figure] and (18, 13) in the figure ((18, 13) in the figure) are recognized in advance by the light beam position detecting means. On-screen coordinates corresponding to arbitrary projected image coordinates are obtained by proportional calculation.
[0032]
In other words, when an operation such as underlining a character string at an arbitrary position or enclosing the character string with a line is performed, by aligning in advance, the corresponding part on the screen 1 is irradiated with light. It becomes possible to calculate to which part of the projected image coordinates these image patterns should be synthesized.
[0033]
In the example shown here, a point at the upper left corner of the projected image (point (1, 1) in the projected image coordinates), a point at the upper right corner (point (640, 1) in the projected image coordinates), and the right The lower corner point (point of (640, 480) in the projected image coordinates) is pointed by the optical pointer 4 to perform alignment, but the projected image coordinates are (1, 1), (640, 1) and ( 640, 480), and a plurality of arbitrary points (preferably three or more points) may be set.
[0034]
Here, for example, positioning by the hand of the presenter P may be performed (hereinafter referred to as a reference example in the present invention), but in the present invention , an optical signal for positioning is added to the projection image in advance. In either case, by performing this operation immediately after starting up the projector 2, the positional relationship between the projected image coordinates and the coordinates on the screen is stored in the image input device 3. As long as does not change, there is no need to operate.
[0035]
In the reference example , since the presenter P itself emits the optical signal for alignment, it is not necessary to provide the projector 2 or the image input device 3 with a mechanism for generating the optical signal, which is advantageous in terms of cost. On the other hand, the present invention is convenient because the alignment is performed automatically without the user being aware of it.
[0036]
Next, with reference to FIG. 7, the operation up to the calculation of the positional relationship between the coordinates on the screen and the projected image coordinates will be described. Here, alignment by the optical pointer 4 will be described.
When each power source of the projector 2, the image input device 3, the optical pointer 4, and the screen 1 is turned on, the projector 2, the image input device 3, and the optical pointer 4 perform initialization such as an internal test (S1-1 to S1-3). ). The screen 1 turns on the power of the optical sensor 11 (S1-4).
[0037]
After the initialization is completed, a light beam position detection image pattern is displayed from the projector 2 (S2). In this image, the user is prompted on the screen to irradiate with light for alignment, and the irradiated portion is shown (see FIG. 8). The presenter P emits the light beam of the optical pointer 4 toward the irradiation unit (S3).
[0038]
When the light beam is irradiated, the light beam is detected by the optical sensor 11 (S4), the signal is recognized as a coordinate on the screen by the light beam position detecting means in the image input device 3, and the positional relationship with the projected image coordinate is further determined. Calculated by the alignment means (S5).
[0039]
An example of an image pattern forming method using the optical pointer 4 will be described with reference to FIGS. In FIG. 9, a description will be given from a scene where the on-screen coordinates and the projected image coordinates in FIG.
[0040]
First, the presenter P sends an original image to be projected from the image input device 3 to the projector 2 (S11), and the projector 2 projects this image on the screen 1 (S12). When a personal computer is used as the image input device 3, the application software for presentation is started, and a desired file to be projected on the application software is read and output to the personal computer screen instead of being output to the personal computer screen. At the same time, it is generally output to the projector 2. The presenter P explains to the listener using the optical pointer 4 based on the projected image, and adds an image pattern to the original image as necessary.
[0041]
In FIG. 3, a light beam (light signal) is irradiated by continuing to press the button 42a, an image on the screen 1 can be indicated by a visible light beam, and the position of the optical sensor 11 is detected by an infrared light beam. When the button 42a is released, the last detected position information of the optical sensor 11 (referred to as an image pattern start point) is sent to the light beam position detecting means (S13).
[0042]
Subsequently, another point is similarly designated by the button 42a, and another point of the image pattern (image pattern end point) is designated (S14). As the image pattern, a straight line, a wavy line, a rectangle, an ellipse, etc. are assigned to each of the buttons 43. After designating the image pattern start point and end point, pressing the desired button 43 (S15), the image pattern is restored to the original pattern. Can be synthesized and formed into an image.
[0043]
If the previous instruction is canceled, the button 42b may be pressed. Further, the formed image pattern can be erased by double-clicking the button 42b. The buttons corresponding to these operations are not limited to the examples shown here, and can be freely combined without departing from the intention of the present invention.
[0044]
As described above, in the present invention, when the projector 2 is started up, the contour of the original image projected from the projector 2 onto the screen 1 is detected and calculated by the position detection means, but this is distorted and lacks visibility. Can also correct the image and project an image with excellent visibility.
[0045]
When the image of the projector 2 is displayed on the screen 1, as described above, the projection area is often distorted as shown in FIGS. 4 (b) and 4 (c). If this distortion is too large, the visibility deteriorates, which is a problem. Therefore, if this area is significantly distorted from the rectangle and needs to be corrected, calculate the corrected image with a rectangle similar to the original image that has the largest shape in the current projection area, and project the corrected image. Visibility is restored. Of course, the above-mentioned image pattern marking can also be performed during the correction image projection.
[0046]
FIG. 10 shows an example of image editing in which the image projection range of the original image calculated by the alignment means is converted into a predetermined area.
Since the calculation of the positional relationship between the coordinates on the screen and the projected image coordinates (S1-1 to S1-4, S2 to S5) is the same as that in FIG. In the flow shown in FIG. 10, the projection area is corrected (S 6) and the original image coordinates are converted (S 7), and the corrected image is projected onto the screen 1.
[0047]
Specifically, as an example of alignment, four vertices of the projection range 10 of the original image in FIG. 6 ((2, 1), (24, 1), (4, 13) ( 22 and 13)] is measured by the optical sensor 11, and a correction area 13 which is the largest rectangle similar to the rectangle of the projected image is calculated within this area, and the original image is manually and automatically positioned as described above. What is necessary is just to obtain and project a corrected image that is calculated by the matching means and fits in the correction area 13.
[0048]
【The invention's effect】
According to the first aspect of the present invention, the image input device calculates the coordinates on the screen, which is the position of the light beam on the screen, based on the electrical signal emitted from the optical sensor that senses the light beam, and the calculated on-screen coordinates. Based on the above, a predetermined image pattern is superimposed on the original image, and further, the image signal of the original image and the image pattern is synthesized, so the optical pointer is used to draw a line on the blackboard on the screen. It is possible to easily mark certain image patterns in the original image.
[0050]
Further , according to the present invention , in the technique for superimposing the original image formed (projected) on the screen and drawing (projecting) an image of a pattern by the operation of the presenter, the presenter Without being conscious, it is possible to automatically align the position and improve usability.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an image projection system showing an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a screen.
FIG. 3 is a schematic configuration diagram of an optical pointer.
FIG. 4 is a diagram illustrating a projection range when an image is projected on a screen.
FIG. 5 is a diagram showing an optical sensor on a screen and a projection range.
FIG. 6 is a diagram illustrating a projection range and a correction area of an original image.
FIG. 7 is a flowchart at the time of alignment of on-screen coordinates and projected image coordinates with an optical pointer.
FIG. 8 is a diagram showing a light position detection image pattern;
FIG. 9 is a flowchart of an image pattern forming method.
FIG. 10 is a flowchart at the time of image editing for converting the image projection range of the original image calculated by the alignment unit into a predetermined area.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screen 2 Projector 3 Image input device 4 Optical pointer 5 Pointer irradiation position 11 Optical sensor 12 Ray position detection means

Claims (2)

In an image forming system comprising a reflective screen, a projector for projecting an image on a screen, an image input device for supplying an image signal to the projector, and an optical pointer for indicating an image on the screen,
The screen is arranged in a matrix of optical sensors that detect the light emitted from the optical pointer.
The projector projects an image onto the screen with multiple optical signals of the same type as the optical pointer,
The image input device calculates the coordinates on the screen, which is the position of the light beam on the screen, based on the electrical signal emitted from the light sensor that senses the light beam, and the coordinates on the screen calculated by the light beam position detection function. the reference, possess certain defined position adjustment function for superimposing on the original image the image pattern, and the image editing function of combining the image signals of the original image and the image pattern,
The alignment function calculates the relative positional relationship between the on-screen coordinates and the projected image coordinates from the on-screen coordinates where the light signal is detected on the screen and the projected image coordinates as the light signal irradiation position in the projected image. Then , the image projection system is characterized in that both are aligned .   The image projection system according to claim 1.
  The image input device has a correction function for calculating a corrected projection area from the coordinates on the screen of the projection image obtained by the light beam position detection function and correcting the original image so that the projection image is not distorted on the screen. An image projection system characterized by that.

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