JP5664725B2 - Projector, image projection system, and image projection method - Google Patents

Description

  The present invention relates to a projector, an image projection system, and an image projection method.

  As described in JP 2003-276399 A, an electronic blackboard system using a PC, an electronic pen, an infrared camera, and a projector has been proposed. Further, as described in Japanese Patent Application Laid-Open No. 2005-286575, a projector that corrects image distortion using an imaging unit and a projection unit has been proposed.

JP 2003-276399 A JP 2005-286575 A

  For example, when these projectors are combined, it is necessary to provide an infrared camera and a normal camera in the projector, and the user cannot effectively use the imaging function.

  Some aspects of the present invention provide a projector, an image projection system, and an image projection method capable of effectively utilizing an imaging function by solving the above-described problems.

  A projector that is one aspect of the present invention images a projection target region in a visible light band to generate a first captured image, and the projection target region including instruction light having a wavelength of invisible light is converted into invisible light. An imaging unit that captures images in a band to generate a second captured image, an image generation unit that performs trapezoidal distortion correction based on the first captured image, and a position of the instruction light based on the second captured image And a projection unit that projects an image based on the position information in a state where the trapezoidal distortion correction is performed.

  An image projection system according to an aspect of the present invention is an image projection system including the projector and the image supply device, and the image supply device transmits the image information to the projector. And a supply-side interface unit that receives the position information from the projector, and an image information generation unit that generates the image information based on the position information.

  In the image projection method according to one aspect of the present invention, the imaging unit captures the projection target area in the visible light band to generate a first captured image, and the image generation unit performs the first imaging. Based on the image, trapezoidal distortion correction is performed, and the imaging unit captures the projection target area including the instruction light having the wavelength of invisible light in the invisible light band to generate a second captured image, and generates position information. A unit generates position information indicating the position of the indication light based on the second captured image, and the projection unit projects an image based on the position information in a state where the trapezoidal distortion correction is performed. Features.

  According to the present invention, the projector or the like can perform trapezoidal distortion correction using a single imaging unit, and can project an image based on the position information of the indication light in a state where the keystone distortion correction has been performed. Can be used more effectively.

  In addition, the imaging unit includes a first filter whose invisible light transmittance is higher than the visible light transmittance, an image sensor that generates the first captured image and the second captured image, and the first filter. A drive unit that moves the first filter to the outside of the imaging region when generating the captured image, and moves the first filter to the imaging region when generating the second captured image. Good.

  The imaging unit includes a second filter having a visible light transmittance higher than an invisible light transmittance. When the first captured image is generated, the invisible light transmittance is a visible light transmittance. The projection target area is imaged through a higher first filter to generate the first captured image, and the projection target is not transmitted through the first filter when generating the second captured image. The region may be imaged to generate the second captured image.

  According to this, the projector or the like can use the imaging function more effectively by changing the light transmission function by moving the first filter.

  Further, the projection unit projects a position adjustment image for adjusting the position of the indication light and a trapezoidal distortion correction image for performing the trapezoidal distortion correction, or adjusts the position of the indication light and the trapezoid. A calibration image for performing distortion correction may be projected.

  According to this, a projector or the like can perform position adjustment and keystone distortion correction more accurately by projecting an image for position adjustment and keystone distortion correction.

  The image generation unit may generate state information indicating a correction state of the trapezoidal distortion correction, and the position information generation unit may generate the position information corresponding to the correction state based on the state information. Good.

  According to this, the projector or the like can project an image corresponding to the position of the instruction light more accurately by generating the position information corresponding to the correction state of the trapezoidal distortion correction.

  The projector may include a projection-side interface unit that transmits the position information to an image supply apparatus and receives image information indicating an image corresponding to the position information from the image supply apparatus.

  According to this, the projector or the like can project an image corresponding to the position of the instruction light by projecting an image based on image information indicating an image corresponding to the position information from the image supply device, for example.

FIG. 1A is a diagram illustrating an image projection state in the first embodiment. FIG. 1B is a perspective view of the projector in the first embodiment. It is a functional block diagram of the projector and PC in a 1st Example. FIG. 3A is a diagram illustrating an example of the configuration of the imaging unit in the first embodiment. FIG. 3B is a diagram illustrating another example of the configuration of the imaging unit in the first embodiment. It is a flowchart which shows the image projection procedure in a 1st Example. It is a figure which shows an example of the trapezoid distortion correction image in a 1st Example. It is a figure which shows an example of the position adjustment image in a 1st Example. It is a figure which shows another example of the position adjustment image in a 1st Example. It is a functional block diagram of the projector and PC in a 2nd Example. It is a flowchart which shows the image projection procedure in a 2nd Example. It is a figure which shows an example of the calibration image in a 2nd Example.

  Embodiments in which the present invention is applied to a projector will be described below with reference to the drawings. In addition, the Example shown below does not limit the content of the invention described in the claim at all. In addition, all of the configurations shown in the following embodiments are not necessarily essential as means for solving the problems described in the claims.

(First embodiment)
FIG. 1A is a diagram illustrating an image projection state in the first embodiment. FIG. 1B is a perspective view of the projector 100 in the first embodiment. The projector 100 has a function of projecting an image 20 onto the screen 10 having a projection target area and capturing an imaging range 30 including the image 20 projected onto the screen 10 using the imaging unit 130.

  The projector 100 is connected to a PC 200 that is a type of image supply device via a USB cable or the like. The projector 100 receives image information from the PC 200 and transmits position information indicating the position of instruction light (infrared light in this embodiment) from the electronic pen 40 to the PC 200. The PC 200 generates image information corresponding to the position information and transmits the image information to the projector 100, and the projector 100 projects an image based on the image information. That is, the projector 100 and the PC 200 function as an interactive projection system that projects an image according to an instruction from the electronic pen 40.

  Next, functional blocks of the projector 100 and the PC 200 having such functions will be described. FIG. 2 is a functional block diagram of the projector 100 and the PC 200 in the first embodiment.

  The projector 100 includes an imaging unit 130 that generates a captured image, a position information generation unit 140 that generates position information based on the captured image, a projection-side interface unit 110 that transmits position information and receives image information, and an image. The image generation unit 120 includes an image generation unit 120 that generates an image based on information and the like, an operation unit 150, and a projection unit 190 that projects an image.

  The PC 200 includes a supply-side interface unit 210 that receives position information and transmits image information, an image information generation unit 220 that generates image information, and a display unit 290 that displays an image based on the image information. It is configured.

  Here, the configuration of the imaging unit 130 will be described in more detail. FIG. 3A is a diagram illustrating an example of the configuration of the imaging unit in the first embodiment. FIG. 3B is a diagram illustrating another example of the configuration of the imaging unit in the first embodiment.

  The imaging unit 130 includes an imaging lens 131, a first filter 132 whose invisible light transmittance such as infrared light is higher than the visible light transmittance, and a visible light transmittance higher than the invisible light transmittance. The second filter 134, the imaging sensor 135, and the first filter 132 are arranged in an imaging region (for example, an imaging lens 131 centered on the optical axis indicated by a one-dot chain line in FIGS. 3A and 3B). A driving unit 133 that moves in and out of the transmitted light range and the like, and a control unit 136 that controls the driving unit 133 are included. In general, the function of the second filter 134 is built in the imaging sensor 135 as shown in FIG.

  In addition, the projector 100 and the PC 200 may function as these units using the following hardware. For example, in the projector 100 and the PC 200, the projection-side interface unit 110, the supply-side interface unit 210 is a USB interface, the position information generation unit 140, the image information generation unit 220 is a CPU, the image generation unit 120 is an image processing circuit, and the like. The unit 130 is an imaging lens, a filter, a motor for driving the filter, a CCD sensor, a CPU, the operation unit 150 is an operation button, the projection unit 190 is a lamp, a liquid crystal panel, a liquid crystal drive circuit, a projection lens, etc., and the display unit 290 is a liquid crystal A display or the like may be used.

  Next, an image projection procedure using these units will be described. FIG. 4 is a flowchart showing an image projection procedure in the first embodiment.

  The projector 100 performs calibration by correcting keystone distortion and adjusting the position of the instruction light, and executes interactive processing for projecting an image according to the position of the instruction light after calibration.

  The user operates an operation panel included in the operation unit 150 or a remote controller (not shown) to start setup of the projector 100 for performing trapezoidal distortion correction and position adjustment of instruction light.

  When performing the trapezoidal distortion correction, the control unit 136 controls the driving unit 133 to move the first filter 132 outside the imaging region in order to facilitate detection of visible light (step S1). Thereby, the imaging unit 130 can capture the screen 10 in the visible light band. The image generation unit 120 generates a trapezoidal distortion corrected image based on an internal program or image data. The projection unit 190 projects the trapezoidal distortion corrected image (step S2). The imaging unit 130 captures the imaging range 30 including the trapezoidal distortion correction image projected on the screen 10 and generates a first captured image (step S3). The image generation unit 120 performs trapezoidal distortion correction based on the first captured image (step S4).

  FIG. 5 is a diagram illustrating an example of the trapezoidal distortion correction image 300 in the first embodiment. The trapezoidal distortion correction image 300 includes a pattern image in which rectangles are connected in 2 rows and 2 columns. As shown in FIG. 5, the trapezoidal distortion corrected image 300 has a total of nine reference points as the end points or intersections of the lines in the pattern image. When the screen 10 and the projector 100 do not face each other, the trapezoidal distortion corrected image 300 is projected in a trapezoidally distorted state as the image 20 in FIG.

  The position information generation unit 140 generates position information indicating the position (for example, XY coordinate value) of each reference point in the imaging region of the image sensor 135 based on the first captured image. The image generation unit 120 grasps the state of image distortion based on the position information, and determines the coordinates of each vertex of the correction target area where the image should be generated after the trapezoidal distortion correction in the image forming area of the liquid crystal panel. Perform keystone distortion correction. When the image generation unit 120 generates an image in the correction target area, an image without distortion is projected on the screen 10. If there is no image distortion or there is almost no image distortion, the projector 100 may not perform the trapezoidal distortion correction.

  The projector 100 adjusts the position after correcting the keystone distortion in order to accurately detect the position indicated by the electronic pen 40. When performing position adjustment, in order to make it easy to acquire infrared light from the electronic pen 40, the control unit 136 controls the drive unit 133 to move the first filter 132 into the imaging region (step S5). Thereby, the imaging unit 130 can capture the screen 10 in the invisible light band. Note that in the case where the first filter 132 and the second filter 134 overlap, the transmittance of invisible light is higher than the transmittance of visible light.

  The image generation unit 120 generates a position adjustment image based on image information from the PC 200. The projection unit 190 projects the position adjustment image (step S6).

  FIG. 6 is a diagram illustrating an example of the position adjustment image 310 in the first embodiment. FIG. 7 is a diagram illustrating another example of the position adjustment image 311 in the first embodiment. The position-adjusted images 310 and 311 have a total of nine measurement points, three in the horizontal direction and three in the vertical direction.

  Actually, in order to make it easy for the user to specify the measurement points, the image generation unit 120 generates a position adjustment image indicating the measurement points one by one from the upper left measurement point to the lower right measurement point. For example, only the upper left measurement point is displayed in the position adjustment image 310, and only the upper measurement point is displayed in the position adjustment image 311.

  The user instructs the measurement points of the position adjustment images 310 and 311 projected on the screen 10 using the electronic pen 40. For example, infrared light is emitted from the tip of the electronic pen 40 when the user presses the electronic pen 40 against the screen 10. The imaging unit 130 captures the imaging range 30 including the position adjustment images 310 and 311 in which the position is instructed, and generates a second captured image (step S7).

  The PC 200 adjusts the indicated position with the electronic pen 40 based on the second captured image (step S8). More specifically, for example, the position information generation unit 140 generates position information indicating the position of infrared light in the imaging region of the image sensor 135 based on the second captured image. The projection-side interface unit 110 transmits the position information to the PC 200.

  The supply-side interface unit 210 receives the position information, and the image information generation unit 221 compares the position of the measurement point indicated by the position information with the position of the measurement point measured in the standard environment. The position adjustment data is generated according to the difference.

  The projector 100 determines whether or not the position adjustment of the nine measurement points described above has been completed (step S9). When the position adjustment of the nine measurement points described above is completed, the position adjustment is completed. The PC 200 can grasp the difference between the standard environment and the actual projection environment based on the position adjustment data.

  When the trapezoidal distortion correction and the position adjustment described above are completed, the calibration is completed. After the calibration is completed, the image information generation unit 220 generates image information for presentation. The supply side interface unit 210 transmits the image information to the projector 100.

  The projection side interface unit 110 receives the image information. The image generation unit 120 generates an image based on the image information. The projection unit 190 projects an image on the screen 10 (step S10).

  The user indicates a desired position using the electronic pen 40 in a state where the image is projected on the screen 10. For example, when the image is an image showing a question and answer options for the question, the user emits infrared light by pressing the answer part with the electronic pen 40.

  The imaging unit 130 captures an image in a state in which the position is instructed to generate a third captured image (step S11). The position information generation unit 140 generates position information indicating the designated position in the imaging region based on the third captured image. The projection-side interface unit 110 transmits the position information to the PC 200 (step S12).

  The supply-side interface unit 210 receives the position information. The image information generation unit 220 determines an actual designated position based on the position information and the position adjustment data, and generates image information indicating an image corresponding to the designated position. For example, the image information generation unit 220 generates image information of an image indicating that the answer is correct and the correct answer when the answer specified by the user is correct. The supply side interface unit 210 transmits the image information to the projector 100.

  The projection side interface unit 110 receives the image information. The image generation unit 120 generates an image indicating an answer and a correct answer based on the image information. The projection unit 190 projects the image (step S10).

  As described above, in the interactive process, the projector 100 repeatedly executes the processes of steps S10 to S12.

  As described above, according to the present embodiment, the projector 100 performs the trapezoidal distortion correction using the single imaging unit 130 and projects an image based on the position information of the instruction light in a state where the keystone distortion correction is performed. Therefore, the imaging function can be utilized more effectively.

  In addition, according to the present embodiment, the projector 100 can realize an automatic trapezoidal distortion correction function and an interactive processing function using the electronic pen 40 by using one imaging unit 130.

  Further, according to the present embodiment, the projector 100 can perform position adjustment and keystone distortion correction more accurately by projecting the keystone distortion correction image 300 and the position adjustment images 310 and 311.

  Further, according to the present embodiment, the projector 100 can project an image according to the position of the instruction light by projecting an image based on image information indicating an image corresponding to the position information from the PC 200, for example. it can.

(Second embodiment)
In the first embodiment, the projector 100 projects the trapezoidal distortion correction image 300 and the position adjustment images 310 and 311. However, the projector 100 may project a calibration image capable of performing both the keystone distortion correction and the position adjustment. In the first embodiment, the PC 200 grasps the difference between the designated positions in the actual environment and the standard environment and determines the actual designated position. However, the projector differs in the designated position in the actual environment and the standard environment. It is also possible to determine the actual designated position by grasping.

  FIG. 8 is a functional block diagram of the projector 101 and the PC 201 in the second embodiment. The projector 101 includes an imaging unit 130, a position information generation unit 141, a projection-side interface unit 110, an image generation unit 121, an operation unit 150, and a projection unit 190 that projects an image. The projector 101 is such that the image generation unit 121 transmits state information indicating the correction state of the trapezoidal distortion correction to the position information generation unit 141, and the position information generation unit 141 generates the position information according to the state information. Is different.

  The PC 201 includes a supply-side interface unit 210, an image information generation unit 221, and a display unit 290 that displays an image based on the image information. The PC 201 is different from the PC 200 in that the image information generation unit 221 does not have a function of determining the actual designated position by grasping the difference between the designated position in the actual environment and the standard environment.

  Next, an image projection procedure using these units will be described. FIG. 9 is a flowchart showing an image projection procedure in the second embodiment.

  As in the first embodiment, the projector 101 performs calibration by performing trapezoidal distortion correction and position adjustment of the instruction light in accordance with a setup start instruction from the user using the operation unit 150 or the like, and instructs after the calibration. Interactive processing for projecting an image according to the position of light is executed.

  The control unit 136 controls the drive unit 133 to move the first filter 132 out of the imaging region (step S21). The image generation unit 121 generates a calibration image based on an internal program or image data. The projection unit 190 projects the calibration image (step S22).

  FIG. 10 is a diagram illustrating an example of the calibration image 320 in the second embodiment. The calibration image 320 includes a pattern image in which rectangles are arranged in 3 rows and 4 columns. As shown in FIG. 10, the calibration image 320 has a total of 20 reference points as the end points or intersections of each line in the pattern image.

  The imaging unit 130 captures the imaging range 30 including the calibration image 320 projected on the screen 10 to generate a fourth captured image (step S23). The position information generation unit 141 generates position information (intersection position information) indicating the position of each reference point in the imaging region based on the fourth captured image (step S24).

  The image generation unit 121 grasps the state of image distortion based on the intersection position information, and determines the coordinates of each vertex of the correction target area where the image should be generated after the trapezoidal distortion correction in the image forming area of the liquid crystal panel. To correct trapezoidal distortion. Further, the image generation unit 121 generates state information indicating the state of distortion of the image (step S25).

  Further, the position information generation unit 141 determines the correction amount of each reference point in the state where the trapezoidal distortion correction is performed based on the intersection position information and the state information, thereby adjusting the position for adjusting the indicated position. Data is generated (step S26).

  When the trapezoidal distortion correction and the position adjustment described above are completed, the calibration is completed. After the calibration, the projector 101 controls the drive unit 133 to move the first filter 132 into the imaging region in order to make it easier for the projector 101 to acquire infrared light from the electronic pen 40 (Step 1). S27).

  The image information generation unit 221 generates image information for presentation. The supply side interface unit 210 transmits the image information to the projector 101. The projection side interface unit 110 receives the image information. The image generation unit 121 generates an image based on the image information. The projection unit 190 projects an image on the screen 10 (step S28).

  The user indicates a desired position using the electronic pen 40 in a state where the image is projected on the screen 10. The imaging unit 130 captures an image in a position-instructed state and generates a fifth captured image (step S29). The position information generation unit 141 generates position information indicating the indicated position in a state where the trapezoidal distortion correction is performed based on the third captured image and the state information, and based on the position information and the position adjustment data, Position information indicating the indicated position in the imaging region of the imaging unit 130 in a state where distortion correction has been performed is generated. The projection-side interface unit 110 transmits the position information to the PC 201 (step S30).

  The supply-side interface unit 210 receives the position information. Based on the position information, the image information generation unit 221 determines an actual designated position in the image and generates image information indicating an image corresponding to the designated position. The supply side interface unit 210 transmits the image information to the projector 101.

  The projection side interface unit 110 receives the image information. The image generation unit 121 generates an image based on the image information. The projection unit 190 projects the image (step S28).

  As described above, in the interactive process, the projector 101 repeatedly executes the processes of steps S28 to S30.

  As described above, according to the present embodiment, the projector 101 has the same operational effects as the first embodiment. Further, according to the present embodiment, the projector 101 can project the image according to the position of the instruction light more accurately by generating the position information according to the correction state of the trapezoidal distortion correction.

  According to the present embodiment, the projector 101 can shorten the calibration time by using the calibration image 320 for performing both the trapezoidal distortion correction and the pointing position adjustment, and the electronic pen 40 can be used. The designated position can be adjusted without using it.

(Other examples)
In addition, application of this invention is not limited to the Example mentioned above, A various deformation | transformation is possible. For example, the position information generation units 140 and 141 may transmit not only the position information but also the light emission state information indicating the light emission pattern of the electronic pen 40 to the PCs 200 and 201.

  According to this, since the projectors 100 and 101 can transmit a light emission pattern corresponding to an operation such as click and drag to the PCs 200 and 201, the PCs 200 and 201 can receive image information corresponding to more complicated operations. Can be generated.

  Further, the indicator light is not limited to infrared light, and may be, for example, ultraviolet light. In addition, as a moving method of the first filter 132, various methods such as parallel movement and rotational movement can be employed, for example.

  Further, the drive unit may move the second filter 134 instead of the first filter 132, or may move both the first filter 132 and the second filter 134. For example, in a state where the first filter 132 is provided in the imaging region, the driving unit moves the second filter 134 to the imaging region when generating the first captured image, and the second filter 134 is generated when generating the second captured image. The second filter 134 may be moved outside the imaging region. In this case, it is assumed that the visible light transmittance is higher than the invisible light transmittance when the first filter 132 and the second filter 134 overlap.

  The images used in the interactive processing are not limited to the problem image and the answer image. For example, an image that draws the movement locus of the electronic pen 40 and an effect such as underlining according to the operation of the electronic pen 40 are performed. Various images used in interactive processing such as images can be employed.

  Further, the position information generated by the position information generation unit 140 is not limited to information indicating the coordinates in the imaging region of the imaging unit 130, and may be information indicating the coordinates in the image forming region of the liquid crystal panel, for example. .

  Further, the projector 100 is not limited to a liquid crystal projector (transmission type, reflection type such as LCOS), and may be a projector using DMD (Digital Micromirror Device), for example. DMD is a trademark of Texas Instruments Incorporated. Further, the function of the projector 100 may be distributed to a plurality of devices (for example, a PC and a projector, a camera and a projector, etc.).

  Further, the image supply device is not limited to the PC 200, and may be, for example, a mobile phone, a game device, an HDD recorder, a DVD player, or the like.

  10 screen, 20 images, 30 imaging range, 40 electronic pen, 100, 101 projector, 110 projection-side interface unit, 120, 121 image generation unit, 130 imaging unit, 131 imaging lens, 132 first filter, 133 drive unit, 134 Second filter, 135 Image sensor, 136 Control unit, 140, 141 Position information generation unit, 150 Operation unit, 190 Projection unit, 200, 201 PC (image supply device), 210 Supply side interface unit, 220, 221 Image Information generation unit, 290 display unit, 300 trapezoidal distortion correction image, 310, 311 position adjustment image, 320 calibration image.

Claims (6)

The projection target area is imaged in the visible light band to generate a first captured image, and the projection target area including the instruction light having the wavelength of invisible light is imaged in the invisible light band through the first filter. An imaging unit that generates two captured images;
Based on the first captured image, position adjustment data for adjusting position information indicating the position of the indication light is generated, and the position information is generated based on the position adjustment data and the second captured image. A position information generation unit;
A projection unit that projects an image based on the position information;
A drive unit for moving the first filter;
Including
The driving unit moves the first filter outside the imaging region of the imaging unit when the imaging unit captures the first captured image, and captures the second captured image by the imaging unit. Sometimes moving the first filter to the imaging region,
projector. The projector according to claim 1.
The projection unit projects a calibration image for generating the position adjustment data;
projector. The projector according to claim 2 ,
The imaging unit generates the first captured image by capturing the calibration image projected by the projection unit without passing through the first filter.
projector. The projector according to any one of claims 1 to 3,
A projector including a projection-side interface unit that transmits the position information to an image supply apparatus and receives image information indicating an image corresponding to the position information from the image supply apparatus. A projector according to claim 4;
The image supply device;
An image projection system comprising:
The image supply device includes:
A supply-side interface unit that transmits the image information to the projector and receives the position information from the projector;
An image information generation unit that generates the image information based on the position information;
including,
Image projection system. An image projection method using a projector having an imaging unit,
The imaging unit captures a projection target region in a visible light band to generate a first captured image,
The imaging unit captures the projection target area including the instruction light having the wavelength of invisible light in the invisible light band through the first filter to generate a second captured image,
Based on the first captured image, generating position adjustment data for adjusting position information indicating the position of the instruction light,
Based on the position adjustment data and the second captured image, the position information is generated,
Projecting an image based on the position information;
Including
When capturing the first captured image, the first filter is moved outside the imaging region of the imaging unit, and when capturing the second captured image, the first filter is moved to the imaging region. Characterized by
Image projection method.

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