JP2009186528A - Projector and its position calculation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of informing a user of a position for projecting images on a screen normally and to provide its position detecting method. <P>SOLUTION: The projector includes an image correcting means 23 for correcting image, a projecting means for projecting the image corrected by the image correcting means 23 on the screen SC, an imaging means 27 for imaging the image projected on the screen SC, a storing means 26 for storing a reference image obtained as a result of imaging the image projected from a predetermined position and a reference corrected value being an image corrected value of image, a relative position calculation means for calculating relative positions of the predetermined position and an optional position based on difference between an optional image obtained as a result of imaging the image projected from the optional position by correcting the image based on the reference corrected value and the reference image stored in the storing means 26, and an informing means 19 for informing the user of the information about the calculated relative positions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector that projects an image on a screen and a position calculation method thereof.

Conventionally, a projector that projects an image on a screen installed in a conference room or the like is known. The projector includes a lens shift unit that translates the projection lens to move the optical axis, an electric focus unit that adjusts the focus of the projection lens, an electric zoom unit that performs zoom adjustment of the projection lens, and the tilt and projection of the projector. Projection direction / tilt setting means for setting the light projection direction, and relative position detection means for detecting relative position information of the screen and the projector. The relative position detecting means detects these relative positions / distances using a communication device arranged on the projector side and the screen side. Based on the detection result, the lens shift unit, the electric focus unit, the electric zoom unit, and the projection direction / tilt setting unit are controlled to bring the effective area of the projected image closer to the effective area of the screen. Further, if trapezoidal distortion remains in the projected image even after the above control is performed, the keystone correction of the projected image is performed. Thereby, a high quality image is projected on a screen (for example, refer patent document 1).
Japanese Patent Laid-Open No. 2004-341029

  By the way, in the above-described projector, when the installation position changes, based on the installation position (based on the installation position), correction of an image to be projected (focus adjustment, keystone distortion correction, etc.) is automatically performed. However, it is difficult to completely correct the image only by this automatic correction, and finally, the operator of the projector must finely adjust these corrections. For this reason, every time the installation position changes, the operator has to correct (finely adjust) the image, which is troublesome.

  In view of the above problems, an object of the present invention is to provide a projector capable of notifying a user of a position where an image can be normally projected on a screen, and a position detection method thereof.

  The projector according to the present invention includes an image correction unit that performs image correction, a projection unit that projects an image corrected by the image correction unit on a screen, an imaging unit that captures an image projected on the screen, and an image projected from a predetermined position. A storage unit that stores a reference image that is an imaging result and a reference correction value that is an image correction value of the image, and an imaging result of an image that is projected from an arbitrary position after image correction based on the reference correction value Relative position calculation means for calculating the relative position between the predetermined position and the arbitrary position based on the difference between the arbitrary image and the reference image stored in the storage means, and notification means for notifying information on the calculated relative position And.

  Further, the projector position calculation method of the present invention includes an image correction process for performing image correction, a projection process for projecting an image corrected by the image correction process on a screen, an imaging process for capturing an image projected on the screen, a predetermined process A storage step for storing a reference image that is an imaging result of an image projected from a position and a reference correction value that is an image correction value of the image, and image correction based on the reference correction value and projection from an arbitrary position A relative position calculating step of calculating a relative position between a predetermined position and an arbitrary position based on a difference between an arbitrary image that is an image pickup result and a reference image stored in a storage unit; And a notifying step for notifying information.

  According to these projectors and their position calculation methods, an imaging result obtained by imaging an image projected from a predetermined position (corrected image) is used as a reference image. Then, the reference image and a reference correction value that is an image correction value when the image is projected are stored. On the other hand, an imaging result of an image projected from an arbitrary position based on the reference correction value is an arbitrary image. Then, the reference image and the arbitrary image are compared, a relative position between the predetermined position and the arbitrary position is calculated based on the difference, and information on the calculated relative position is notified. That is, the user can know how far and in what direction an arbitrary position (current installation position of the projector) is from the predetermined position where the projection image that is the basis of the reference image is first projected. Thus, as long as the user only corrects the image at the predetermined position, even if the installation position of the projector subsequently changes, the user can simply move the position of the projector to the predetermined position based on the information on the relative position. A normal image can be projected on the screen. For this reason, the trouble of the image correction (fine adjustment) resulting from the change of the installation location of the projector can be saved. In addition, as the information on the relative position to be notified, the current position on the basis of the predetermined position may be notified, or the moving direction and amount from the current position to the predetermined position, or the moving method may be notified. good.

  The projector of the present invention further includes position change detection means for detecting a position change of the apparatus main body, and the relative position calculation means can calculate the relative position when detecting a position change exceeding a predetermined amount. preferable.

  According to this configuration, a change in the position of the projector is detected, and when the amount of the change in position exceeds a predetermined amount, a relative position between the reference position and the current position (arbitrary position) is calculated. Thereby, for example, by setting the predetermined amount small, the relative position can be calculated every time the position of the projector changes, and information regarding the position where the projector should be installed can be notified.

  In the projector according to the aspect of the invention, it is preferable that the relative position calculation unit calculates the relative position using an instruction from the user as a trigger.

  According to this configuration, the relative position between the reference position and the current position is calculated using a user instruction (for example, pressing a button mounted on the apparatus body) as a trigger. Thus, for example, the processing load of the projector can be reduced as compared with the case where the relative position is calculated every moment in accordance with the change in the position of the projector, which is preferable when the performance of the projector is low.

  In the projector according to the aspect of the invention, it is preferable that the relative position calculation unit calculates the relative position in the three-dimensional direction and the rotation angle in the horizontal direction with respect to the mounting surface of the apparatus main body as the relative position.

  According to this configuration, the position of the projector is calculated as a relative position in the three-dimensional direction and in the horizontal direction with respect to the mounting surface of the apparatus main body. As a result, the user knows how far the current position of the projector is from the predetermined position in the front-rear direction, the left-right direction, and the up-down direction (where it is), and how much it rotates in the horizontal direction. I can do it.

  In the projector according to the aspect of the invention, it is preferable that the image correction unit includes at least a focus unit, a lens shift unit, and a trapezoidal distortion correction unit.

  According to this configuration, since the focus correction unit, the lens shift unit, and the trapezoidal distortion correction unit are included as the image correction unit, the image correction can be performed more accurately.

  In the projector according to the aspect of the invention, it is preferable that the notifying unit reports information on the relative position by projecting the information on the screen by the projecting unit.

  According to this configuration, information on the relative position between the reference position and the current position of the projector is projected onto the screen and notified. Thereby, since the relative position information can be visually provided to the user, the user can easily grasp the position where the projector should be installed (or the direction and distance to the position where the projector should be installed). .

  In the projector according to the aspect of the invention, it is preferable that the notification unit notifies the information on the relative position by voice.

  According to this configuration, information related to the relative position between the reference position and the current projector position is notified by voice. Thereby, for example, by notifying the user, “Please move X centimeters backward and Y centimeters to the left.”, The user can easily install the projector (or the distance to the installation location). Can be grasped.

  Hereinafter, a projector and a position calculation method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a configuration of a projector 1 according to an embodiment of the present invention. As shown in the figure, the projector 1 of the present embodiment includes an illumination optical system 17, a liquid crystal light valve 18, and an optical system (projection unit, notification unit) that projects an image (video light) onto the screen SC. A projection optical system 19. Further, the projector 1 includes a light source lamp driving unit 11, a liquid crystal light valve driving unit 12, a projection optical system adjusting unit 13, a shift position detecting unit 14, and a zoom position detecting unit as components related to these optical systems. 15 and a focus position detector 16.

  Further, the projector 1 includes, as other components, a CPU (Central Processing Unit) 21 that is a central processing unit, an image input unit 22, an image processing unit 23, an operation unit 24, and an acceleration sensor 25 (position change). A detection unit), a storage unit 26 (storage unit), and an imaging unit 27 (imaging unit). Among these, the constituent elements 11 to 16 and the constituent elements 22 to 27 are connected to the CPU 21 via the bus 28.

  The light source lamp driving unit 11 drives a light source lamp included in the illumination optical system 17. The light source lamp may be a discharge light emitting type or a self light emitting element (such as a light emitting diode). The liquid crystal light valve driving unit 12 drives the liquid crystal light valve 18 that is an image forming element based on the image data processed by the image processing unit 23.

  The projection optical system adjustment unit 13 has a motor and adjusts the position of the projection lens included in the projection optical system 19. The projection lens is configured as a combined lens in which a plurality of lenses such as a zoom lens and a focus lens are accommodated in a cylindrical lens barrel.

  Specifically, the projection optical system adjustment unit 13 adjusts the shift position of the projection optical system 19 by moving the projection lens in a direction orthogonal to the light source optical axis LA (lens shift means). In addition, the projection optical system adjustment unit 13 moves the zoom lens included in the projection lens in a direction parallel to the light source optical axis LA by rotating a zoom ring that supports the zoom lens. Adjust. Furthermore, the projection optical system adjustment unit 13 moves the focus lens included in the projection lens in a direction orthogonal to the light source optical axis LA by changing the focus ring that supports the focus lens (changes the relative positions of the plurality of lenses). ) To adjust the focus position of the projection optical system 19 (focus means). The light source optical axis LA refers to the central axis of light emitted from the illumination optical system 17 and passes through the center of the effective display area (image forming surface) of the liquid crystal light valve 18.

  The shift position detector 14 detects the shift position of the projection optical system 19. The zoom position detection unit 15 detects the zoom position of the projection optical system 19. The focus position detector 16 detects the focus position of the projection optical system 19. The detection results of each of these detection units (shift position detection unit 14, zoom position detection unit 15 and focus position detection unit 16, hereinafter collectively referred to as “projection detection unit 10”) are the images obtained by the projection optical system adjustment unit 13. Used for adjustment. Further, as the projection detection unit 10, known position detection means such as a rotary encoder or a variable resistor can be applied.

  The image input unit 22 acquires image data from an external storage medium such as the memory card 35. In this case, the image input unit 22 includes a memory card slot that reads image data. The image input unit 22 can also acquire image data from an external device such as a personal computer 36 or a video recorder 37. In this case, the image input unit 22 is configured by an interface that receives RGB signals output from the personal computer 36 and composite signals output from the video recorder 37.

  The image processing unit 23 (image correction unit) includes a trapezoidal distortion correction unit 31 (trapezoidal distortion correction unit), and executes predetermined image processing based on an image processing program. The trapezoidal distortion correction unit 31 corrects image distortion due to the rotation of the projector 1 in the horizontal direction and the elevation angle change. For example, when projection by the projector 1 is performed on the screen SC from an oblique direction, if an image without distortion is formed on the liquid crystal light valve 18, the projected image G on the screen SC is distorted into a substantially trapezoidal shape. Therefore, if an image distorted in a substantially trapezoidal shape (a reverse image of the projection image G projected on the screen SC) is formed on the liquid crystal light valve 18, an image without distortion (a rectangular image having a correct aspect ratio) is formed on the screen SC. ) Can be projected. That is, the trapezoidal distortion correction unit 31 performs a process of generating the corrected image data along with the image correction process.

  The imaging unit 27 is attached to the front surface of the housing of the projector 1 and is configured by a CCD camera 34. The imaging unit 27 captures an image that has been corrected (adjusted) by the projection optical system adjustment unit 13 and the image processing unit 23 (trapezoidal distortion correction unit 31) and projected onto the screen SC.

  The operation unit 24 is operated by a user, and includes a power button and a key group for performing various settings (contrast setting, color correction, environment setting, and the like). The key group includes a correction information setting key 32 and an image correction mode selection key 33.

  The correction information setting key 32 is for causing the storage unit 26 to record the imaging result of the projection image G projected on the screen SC and information relating to the image correction of the projection image G. Specifically, when the correction information setting key 32 is pressed, the imaging result of the projection image G is used as a reference image, and the image correction value by the trapezoidal distortion correction unit 31 when the projection image G is projected is a reference correction value. Is recorded in the storage unit 26. The reference image and the reference correction value may be any imaging result and image correction value of the projection image G normally projected by the projector 1, and the size / shape and the image correction value of the projection image G are It differs for each installation position of the projector 1 at the time of acquisition. Further, the installation position of the projector 1 at this time is defined as a reference position (predetermined position).

  The image correction mode selection key 33 has a first correction mode and a second correction mode, and selects which of these correction modes is used to execute the image correction processing. When the first correction mode is selected, similarly to general image correction processing, the projection optical system adjustment unit 13 and the trapezoidal distortion so that the projection image G from the current installation position of the projector 1 is suitably projected. Image correction is executed by the correction unit 31.

  On the other hand, when the second correction mode is selected, image correction is performed on the target image based on the reference correction value stored in the storage unit 26. Then, based on the difference between the imaging result of the image projected based on this reference correction value (hereinafter referred to as “arbitrary image”) and the reference image stored in the storage unit 26, the reference position (the original of the reference image). The installation position of the projector 1 when the projection image G is projected) and the installation position of the projector 1 when the projection image G that is the source of the arbitrary image is projected (hereinafter referred to as “arbitrary position”). Relative position is calculated (relative position calculation means), and information on the calculated relative position is notified. If the reference correction value is not stored, the selection of the second correction mode is invalid.

  The acceleration sensor 25 detects the amount of change in the position of the projector 1. As the acceleration sensor 25, any of a piezoelectric type, a semiconductor strain gauge type, and a servo type may be used. In the present embodiment, the acceleration sensors 25 are mounted at a plurality of locations of the projector 1, and the CPU 21 moves the projector 1 in the front-rear direction, the up-down direction, and the left-right direction based on the measurement values output from each acceleration sensor 25. The amount, the amount of rotation in the horizontal direction, and the amount of change in elevation angle are detected.

  Note that “front-rear direction”, “vertical direction”, “left-right direction”, “horizontal direction”, and “elevation angle” refer to changes in the position of the projector 1 with respect to the screen SC, and FIG. FIG. 3 is a plan view of the projector 1 and FIG. 3 is a plan view of the projector 1 as viewed from above. In both figures, reference numeral 41 indicates an installation base on which the projector 1 is installed.

  Here, the procedure for storing the reference image and the reference correction value will be described with reference to FIG. First, the projector 1 receives an image correction instruction when the user selects the first correction mode from the image correction mode selection key 33 (S01). Using this instruction as a trigger, the projector 1 performs image adjustment (lens shift adjustment, zoom adjustment, focus adjustment) by the projection optical system adjustment unit 13 based on the detection result of the projection detection unit 10 (S02), and trapezoidal distortion. The correction unit 31 corrects image distortion due to horizontal rotation and elevation angle change (S03). Thereby, a normal projection image G can be projected on the screen SC. The installation position of the projector 1 at this time becomes the reference position.

  In this state, when the correction information setting key 32 is pressed by the user (S04), the projector 1 captures the currently projected projection image G (S05), and stores it in the storage unit 26 as a reference image (S05). S06). At the same time, the image correction value for the projection image G by the trapezoidal distortion correction unit 31 is stored in the storage unit 26 as a reference correction value (S07). The reference image and the reference correction value are not erased even when the projector 1 is turned off. When the correction information setting key 32 is pressed again, it is overwritten and saved. Note that the recording of correction information by the correction information setting key 32 is valid only when the first correction mode is selected. Thereby, for example, when the second correction mode is selected, the key 32 is pressed before the projector 1 is moved to the reference position, so that the imaging result of the projection image G that is not normally projected and the image correction value (that is, the image correction value). , Information that is not suitable as a basic image or basic correction value) can be prevented from being stored.

  Next, with reference to FIGS. 5 to 9, a procedure for notifying information on the relative position between the reference position and the current position (arbitrary position) of the projector 1 will be described. 6 shows the reference position P0 and the current position P1 of the projector 1 here, L1 in the figure is the distance in the front-rear direction between the reference position P0 and the current position P1, and L2 is the distance in the left-right direction. , Θ represents the horizontal direction (rotation angle) of the projector 1 (optical axis) at the current position P1 with reference to the direction of the projector 1 at the reference position P0. FIG. 7 shows images (reference image H0 and arbitrary image H1) captured at each position (reference position P0 and current position P1) in FIG. Further, it is assumed that the reference image H0 and the reference correction value are stored in the storage unit 26.

  First, when the projector 1 is installed at an arbitrary position and the user selects the second correction mode from the image correction mode selection key 33 (S11), the projector 1 stores the reference correction value and the reference image H0 from the storage unit 26. Read (S12, S13). Next, image correction is performed on the image to be projected based on the reference correction value (S14). Then, this image is projected onto the screen SC, and the projected image G is captured as an arbitrary image H1 (S15).

  Next, the projector 1 calculates the relative position between the reference position P0 and the current position P1 of the projector 1 from the difference between the reference image H0 and the arbitrary image H1 (S16). In this case, as shown in FIG. 7, based on the position of the image in the imaging area AR of the CCD camera 34, the coordinates of the four corners of the reference image H0 (coordinates A, B, C, D) and the coordinates of the four corners of the arbitrary image H1. (Coordinates A ′, B ′, C ′, D ′) are detected, and the relative position between the reference position P0 and the current position P1 of the projector 1 is calculated from the positional relationship of the coordinates of these four corners (difference for each coordinate). . Then, the projector 1 projects information on the relative position on the screen SC to notify the user (S17).

  For example, from the relative position between the reference position P0 and the current position P1 calculated in the above processing, the front-rear distance L1 in FIG. 6 is 30 cm, the left-right distance L2 is 30 cm, and the horizontal rotation angle θ is 30 °. If the projector 1 is found to be, as shown in FIG. 8A, the projector 1 projects the moving direction, moving amount, etc. from its current position P1 to the reference position P0 on the screen SC to notify the user. 8B, the current position P1 of the projector 1 with the reference position P0 as a base point may be projected onto the projector 1.

  Further, the projector 1 detects its own position change by the acceleration sensor 25, and when the position change exceeds a predetermined amount, the process from S14 to S17 is performed, and the reference position P0 and the current position P1 of the projector 1 are set. The relative position is calculated. Then, the information regarding the relative position is projected on the screen SC and notified (see FIG. 9). Thus, for example, by setting the predetermined amount small, the relative position can be calculated every time the position of the projector 1 changes, and information on the position where the projector 1 should be installed can be notified.

  As described above, according to the present embodiment, the reference image that is the imaging result of the projection image G projected from the predetermined position and the reference correction value that is the image correction value when the projection image G is projected are stored. . Further, the predetermined position at this time is set as a reference position of the projector 1. On the other hand, the imaging result of the projection image G projected from an arbitrary position based on the reference correction value is set as an arbitrary image. Then, the reference image and the arbitrary image are compared, the relative position between the reference position and the arbitrary position is calculated based on the difference, and information on the calculated relative position is notified. That is, the user can know how far the current position (arbitrary position) of the projector 1 is in which direction from the reference position. As a result, as long as the user only corrects the image at the reference position, the position of the projector 1 is changed to the reference position based on the information on the relative position even if the installation position of the projector 1 is changed thereafter. A normal image can be projected onto the screen SC simply by moving it. For this reason, the trouble of the image correction (fine adjustment) resulting from the change of the installation location of the projector 1 can be saved.

  In the present embodiment, the position change of the projector 1 itself is detected by the acceleration sensor 25, and when the position change exceeds a predetermined amount, the relative position of the current installation position of the projector 1 with respect to the reference position is calculated. However, the present invention is not limited to this, and a positional change by the acceleration sensor 25 may be detected every predetermined time, and the relative position may be calculated each time. Alternatively, the relative position may be calculated using an instruction from the user (for example, pressing a button mounted on the projector 1) as a trigger. By using the instruction from the user as a trigger, the processing load of the projector 1 can be reduced compared to the case where the relative position is calculated every time the position of the projector 1 changes. Is preferred.

  Further, not only the image correction value by the trapezoidal distortion correction unit 31 but also the detection result of the projection detection unit 10 (detection result of the focus position, the lens shift position, etc.) is used as a reference correction value, thereby projecting from an arbitrary position. Image correction may be performed.

  Further, as the information related to the relative position, information related to the vertical movement amount of the projector 1 and the elevation angle change may be notified.

  The projected image G to be imaged is preferably a white rectangular image that is projected when white light with high luminance is projected.

  Further, when the information regarding the relative position between the current position of the projector 1 and the reference position is projected onto the screen SC, the information including the diagram showing the positional relationship between the two may be projected. For example, as shown in FIG. 10, the reference position of the projector 1, the current position of the projector 1, and the horizontal direction of the optical axis are indicated by an image schematically showing the projector 1 and its arrangement angle, and the projector 1 By indicating the moving direction from the current position to the reference position with an arrow or the like, the user can more easily grasp in which direction the projector 1 should be moved.

  Further, in the present embodiment, information regarding the relative position between the reference position of the projector 1 and the current position is projected on the screen SC so as to be visually notified to the user. You may make it alert | report this information with an audio | voice. By notifying by voice, the user can easily grasp the installation position of the projector 1 (or the distance to the installation position).

  In addition, the apparatus configuration of the projector 1, the processing steps in the position calculation method, and the like can be changed as appropriate without departing from the gist of the present invention, regardless of the above-described embodiment.

It is a block diagram of the projector which concerns on one Embodiment of this invention. It is the top view which looked at the projector from the side. It is the top view which looked at the projector from the upper surface. It is a flowchart which shows the procedure which memorize | stores a reference | standard image and a reference | standard correction value. It is a flowchart which shows the process sequence which calculates the relative position of the reference position of a projector, and a present position. It is a figure which shows the example of the positional relationship of the reference position of a projector, and the present position. It is a figure which shows the image imaged in the reference | standard position and present position of FIG. It is a figure which shows an example of the information regarding the relative position projected on a screen. It is a figure which shows a mode that the information regarding the relative position projected on a screen changes with the position changes of a projector. It is a figure which shows an example of the information regarding the relative position projected on a screen.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector 13 ... Projection optical system adjustment part 17 ... Illumination optical system 18 ... Liquid crystal light valve 19 ... Projection optical system 23 ... Image processing part 25 ... Acceleration sensor 26 ... Memory | storage part 27 ... Imaging part 31 ... Trapezoid distortion correction part 34 ... CCD camera G ... projected image P0 ... reference position P1 ... current position H0 ... reference image H1 ... arbitrary image SC ... screen

Claims (8)

Image correction means for performing image correction;
Projection means for projecting the image corrected by the image correction means onto a screen;
Imaging means for imaging the image projected on the screen;
A storage unit that stores a reference image that is an imaging result of the image projected from a predetermined position, and a reference correction value that is an image correction value of the image;
Based on a difference between an arbitrary image that is an imaging result of an image projected from an arbitrary position after image correction based on the reference correction value and the reference image stored in the storage unit, the predetermined position and the arbitrary position Relative position calculating means for calculating a relative position with respect to the position of
A projector comprising: notification means for reporting information on the calculated relative position. It further comprises a position change detecting means for detecting a position change of the apparatus body,
The relative position calculating means includes
The projector according to claim 1, wherein the relative position is calculated in accordance with detection of a position change exceeding a predetermined amount. The relative position calculating means includes
The projector according to claim 1, wherein the relative position is calculated using an instruction from a user as a trigger. The relative position calculating means includes
The projector according to any one of claims 1 to 3, wherein a relative position in a three-dimensional direction and a horizontal rotation angle with respect to a mounting surface of the apparatus main body are calculated as the relative position. The image correcting means includes
The projector according to claim 1, comprising at least a focus unit, a lens shift unit, and a trapezoidal distortion correction unit. The notification means includes
The projector according to claim 1, wherein information on the relative position is reported by being projected onto the screen by the projection unit. The notification means includes
The projector according to claim 1, wherein information related to the relative position is notified by voice. An image correction process for performing image correction;
A projection step of projecting the image corrected by the image correction step onto a screen;
An imaging step of imaging the image projected on the screen;
A storage step of storing a reference image that is an imaging result of the image projected from a predetermined position and a reference correction value that is an image correction value of the image;
Based on a difference between an arbitrary image that is an imaging result of an image projected from an arbitrary position after image correction based on the reference correction value and the reference image stored in the storage unit, the predetermined position and the arbitrary position A relative position calculating step of calculating a relative position with respect to the position of
And a notifying step of notifying information on the calculated relative position.

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