JP5461452B2 - Control device and projection display device - Google Patents

Description

  The present invention relates to a trapezoidal distortion correction technique in a projection display apparatus.

  2. Description of the Related Art In recent years, a projection video display device (hereinafter referred to as a projector as appropriate) equipped with a camera has been put into practical use. Some projectors equipped with a camera have a so-called easy setting function in which a projected test pattern is captured by the camera, and autofocus adjustment is performed based on the captured image.

  When projecting an image onto a projection surface using a projector, trapezoidal distortion may occur in the image projected and displayed on the screen depending on the relative angle between the projector and the screen. In such a case, it is preferable to correct the trapezoidal distortion. When the projection surface is a screen, four corners or four sides of the screen are detected, and the image is corrected so that the projected image fits the screen. On the other hand, when the projection surface is a simple wall surface, there is no target for fitting the projection image, so it is necessary to perform keystone correction.

  Patent Document 1 discloses an image projector that corrects a trapezoidal distortion or the like of a projected image. The projector takes a projected keystone image with an imaging device, and executes keystone correction based on the image.

JP 2005-244955 A

  Whether to perform image correction to fit the screen (hereinafter referred to as “fitting correction”) or keystone correction is determined based on whether a screen frame is detected in the image captured by the camera. Is called. However, when an image is projected onto the wall surface from the projection display apparatus, the outer periphery of the projected image may be erroneously detected as a screen frame, and fitting correction may be selected.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique for preventing erroneous detection of the outer periphery of a projected image as a screen frame when an image is projected onto a wall surface by a projection display apparatus. There is.

  An aspect of the present invention is a control device mounted on a projection display apparatus that includes a projection unit that projects an image on a projection surface via a lens and an imaging unit that images the projection surface. In this apparatus, when a predetermined pattern for detecting a screen frame is projected by the projection unit, a screen frame detection unit that detects the screen frame from an image captured by the imaging unit, and a projection area is estimated by the projection unit Whether or not the projection area estimation unit for calculating the outer shape of the projection area from the image captured by the imaging unit and the outer shape of the screen frame and the projection area substantially coincide with each other when a predetermined pattern is projected And a determination unit that determines that the screen frame is erroneously detected when substantially matching.

  Another aspect of the present invention is a projection display apparatus. This apparatus includes a projection unit that projects an image on a projection surface via a lens, an imaging unit for imaging the projection surface, and the control device described above.

  ADVANTAGE OF THE INVENTION According to this invention, when projecting an image on a wall surface with a projection type video display apparatus, it can prevent misdetecting the outer periphery of a projection image as a screen frame.

It is a figure which shows the positional relationship of the projection type video display apparatus concerning one Embodiment of this invention, and a screen. It is a figure which shows the structure of the projection type video display apparatus concerning one Embodiment. It is a flowchart of the trapezoid distortion correction which concerns on one Embodiment. It is a flowchart of the trapezoid distortion correction which concerns on another embodiment. It is a flowchart of the trapezoid distortion correction which concerns on another embodiment. It is a figure for demonstrating the determination method of the screen frame misdetection by the determination part.

  FIG. 1 is a diagram showing a positional relationship between a projection display apparatus 200 and a projection plane 300 according to an embodiment of the present invention. The projection display apparatus 200 according to the embodiment includes an imaging unit 30 for photographing the direction of the projection plane 300. The imaging unit 30 is installed such that the optical axis center thereof and the optical axis center of the projection light projected from the projection display apparatus 200 have a parallel relationship, for example. In FIG. 1, the projection plane 300 does not face the projection display apparatus 200 and the right side is inclined toward the eyelid.

  FIG. 2 is a diagram illustrating a configuration of the projection display apparatus 200. The projection display apparatus 200 includes a projection unit 10, a lens driving unit 20, an imaging unit 30, and a control unit 100. The control unit 100 includes a screen frame detection unit 40, a projection area estimation unit 50, a determination unit 60, a correction unit 70, an image memory 82, a video signal setting unit 84, a drive signal setting unit 86, and an autofocus adjustment unit 90.

  The configuration of the control unit 100 can be realized in terms of hardware by a CPU, memory, or other LSI of an arbitrary computer, and can be realized in terms of software by a program loaded in the memory. Depicts functional blocks realized by. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The projection unit 10 projects an image on the projection plane 300. The projection unit 10 includes a light source 11, a light modulation unit 12, and a focus lens 13. As the light source 11, a halogen lamp having a filament-type electrode structure, a metal halide lamp having an electrode structure for generating arc discharge, a xenon short arc lamp, a high-pressure mercury lamp, an LED lamp, or the like can be employed.

  The light modulation unit 12 modulates the light incident from the light source 11 in accordance with the video signal set by the video signal setting unit 84. For example, a DMD (Digital Micromirror Device) can be employed for the light modulator 12. The DMD includes a plurality of micromirrors corresponding to the number of pixels, and generates desired video light by controlling the direction of each micromirror according to each pixel signal.

  The focus lens 13 adjusts the focal position of the light incident from the light modulation unit 12. The lens position of the focus lens 13 is moved on the optical axis by the lens driving unit 20. The image light generated by the light modulation unit 12 is projected onto the projection plane 300 via the focus lens 13.

  The lens driving unit 20 moves the position of the focus lens 13 according to the driving signal set from the driving signal setting unit 86. For the lens driving unit 20, a stepping motor, a voice coil motor (VCM), a piezoelectric element, or the like can be employed.

  The imaging unit 30 captures the projection plane 300 and the projection image projected on the projection plane 300 as a main subject. The imaging unit 30 includes a solid-state imaging device 31 and a signal processing circuit 32. As the solid-state imaging device 31, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a CCD (Charge Coupled Devices) image sensor, or the like can be adopted. The signal processing circuit 32 performs various signal processing such as A / D conversion and conversion from the RGB format to the YUV format on the signal output from the solid-state imaging device 31, and outputs the signal to the control unit 100.

  The screen frame detection unit 40 detects a screen frame that appears in the image captured by the imaging unit 30. More specifically, the screen frame detection unit 40 detects the positions of the four sides (upper side, lower side, left side, and right side) of the screen shown in the captured image by extracting the edges in the captured image. The detected screen frame is specified by, for example, vertex coordinates of four corners. When the projection plane 300 is a screen, the screen frame detection unit 40 often detects the screen frame correctly. However, when the projection surface 300 is a simple wall surface, the screen frame detection unit 40 may erroneously detect the outer periphery of the image projected on the wall surface as a screen frame.

  The projection area estimation unit 50 estimates the shape of the projection area of the projector based on the specific pattern captured in the image captured by the imaging unit 30. The video signal setting unit 84 reads a specific pattern for projection area estimation from the image memory 82 and causes the projection unit 10 to project the specific pattern. The specific pattern is formed by a figure such as a rhombus. The projection area estimation unit 50 can detect a specific pattern from the captured image, and calculate the outer peripheral shape of the projection area by the projector from the size and shape of the specific pattern.

  The determination unit 60 acquires the outer peripheral shape of the projection area estimated from the projection area estimation unit 50 from the screen frame detected from the screen frame detection unit 40. Then, it is determined whether or not the shapes of both are substantially the same. For example, if both the screen frame and the projection area are general quadrilaterals, it is determined whether or not the distance between the coordinates of the four corners of the screen frame and the coordinates of the four corners of the projection area is a predetermined value (for example, 1 cm). judge. Alternatively, it is determined whether or not the distance between the line segments on the four sides of the screen frame and the projection area is a predetermined value (for example, 1 cm) or less. If the coordinates of the four corners or the distances between the line segments of the four sides are all equal to or less than the predetermined value, it is determined that the screen frame and the outer periphery of the projection area are substantially coincident. If any one of the coordinates of the four corners or the distance between the line segments of the four sides is larger than the predetermined value, it is determined that the screen frame and the outer periphery of the projection area do not substantially match.

  When the outer periphery of the screen frame and the projection area substantially match, the determination unit 60 determines that the outer periphery of the image projected by the projector is erroneously detected as the screen frame. When the screen frame and the projection area do not substantially match, the determination unit 60 determines that the screen frame is correctly detected.

  It should be noted that the determination of whether or not they substantially match each other includes a plurality of theoretical errors determined by the resolutions of the projection display apparatus and the imaging unit, specifications of the projection display apparatus, tolerances for human deviation, and the like. It is preferable to adjust the determination condition based on the parameter. As an example, when the resolution of the imaging unit is lower than the display resolution of the projection display apparatus, for example, when the display resolution is XGA but the imaging resolution is VGA, the screen frame and the projection area are Even if it is shifted by several pixels on the display, it appears that there is almost no shift in the captured image. On the contrary, when the resolution of the imaging unit is higher than the display resolution of the projection display apparatus, even if the deviation in the captured image is very small, the deviation on the projection plane may not be corrected for convenience of resolution. Considering this, it is preferable to set a substantially coincidence determination condition.

  The correction unit 70 performs trapezoidal distortion correction of either fitting correction or keystone correction according to the determination result by the determination unit 60.

  When the determination unit 60 determines that the screen frame is erroneously detected, the correction unit 70 performs keystone correction. That is, the video signal setting unit 84 reads out a trapezoidal distortion adjustment test pattern from the image memory 82 and causes the projection unit 10 to project it. The test pattern is formed, for example, as a quadrangle (square, rectangle, parallelogram, rhombus, etc.). The imaging unit 30 images the test pattern projected on the projection plane 300. The correction unit 70 detects trapezoidal distortion based on the shape of the test pattern shown in the captured image, and corrects the video signal to be set in the video signal setting unit 84 so that the trapezoidal distortion is canceled. The video signal setting unit 84 sets the video signal after the trapezoidal distortion correction supplied from the correction unit 70 in the light modulation unit 12.

  When the determination unit 60 determines that the screen frame is correctly detected, the correction unit 70 performs fitting correction. That is, image conversion that matches the coordinates of the four corners of the outer periphery of the projection area with the coordinates of the four corners of the screen frame is performed on the video signal to be set in the video signal setting unit 84. The video signal setting unit 84 sets the video signal after the trapezoidal distortion correction supplied from the correction unit 70 in the light modulation unit 12. The correction unit 70 does not perform image conversion so that the coordinates of the four corners of the outer periphery of the projection area coincide with the coordinates of the four corners of the screen frame, but the projected image has a predetermined aspect ratio such as 4: 3 or 16: 9. Image conversion may be executed so that

  Since both the fitting correction and the keystone correction are well known, further detailed description is omitted in this specification.

  The autofocus adjustment unit 90 adjusts the focus using a known method such as a contrast detection method. When the projection display apparatus 200 is activated or when autofocus adjustment is instructed by a user operation, the video signal setting unit 84 reads out a test pattern for autofocus adjustment from the image memory 82 and causes the projection unit 10 to project it. . The test pattern is formed by, for example, a stripe pattern or a checker flag pattern. The imaging unit 30 images the test pattern projected on the projection plane 300.

  The autofocus adjustment unit 90 is configured to determine the position of the lens based on the sharpness of the detection area set by the screen frame detection unit 40 in a plurality of images respectively captured by the imaging unit 30 at a plurality of lens positions. To decide. Hereinafter, the configuration of the autofocus adjustment unit 90 will be described more specifically.

  The autofocus adjustment unit 90 includes a high-pass filter, an integration unit, and a lens position determination unit (not shown). The high-pass filter extracts a high-frequency component exceeding a predetermined threshold value of the image signal in the detection region, and supplies the extracted high-frequency component to the integrating unit. The high pass filter may extract a high frequency component in the horizontal direction, or may extract a high frequency component in both the horizontal direction and the vertical direction.

  The integrating unit integrates the high frequency components extracted by the high pass filter at each lens position, and supplies the integrated high frequency component to the lens position determining unit. Note that when high-frequency components are extracted in both the horizontal direction and the vertical direction by the high-pass filter, the accumulating unit adds both high-frequency components. The lens position determination unit determines the position of the focus lens from which the maximum integration value is detected among the plurality of integration values supplied from the integration unit as the focus position.

  When the autofocus function is enabled, the autofocus adjustment unit 90 instructs the video signal setting unit 84 to project a test pattern, and moves the focus lens 13 from the near side to the far side or from the far side to the near side. A control signal for sequentially moving in a predetermined step width is set in the drive signal setting unit 86. The video signal setting unit 84 sets the video signal of the test pattern in the light modulation unit 12, and the drive signal setting unit 86 sets the drive signal corresponding to the control signal in the lens driving unit 20.

  The autofocus adjustment unit 90 calculates the sharpness (the integrated value can be used) included in the test pattern imaged at each lens position of the focus lens 13. This sharpness increases as the focus lens 13 approaches the in-focus position. When the rise peaks and falls, the autofocus adjustment unit 90 determines the previous lens position as the focus position.

  The image memory 82 holds image data to be projected on the projection plane 300. The image data is supplied from a PC or the like via an external interface (not shown). In the present embodiment, a test pattern projected during autofocus adjustment is also held. The video signal setting unit 84 sets a video signal based on the image data held in the image memory 82 in the light modulation unit 12. The drive signal setting unit 86 sets a drive signal for moving the focus lens 13 to the lens position designated by the autofocus adjustment unit 90 in the lens drive unit 20.

FIG. 3 is a flowchart of trapezoidal distortion correction according to an embodiment of the present invention.
First, the projection unit 10 displays an OSD (on-screen display) message that prompts the user to move the zoom lens of the projection display apparatus 200 to the wide side (S10). In response to this, the user moves the zoom lens to the wide side (S12). This is performed in order to make maximum use of the resolution of the projection display apparatus 200, but S10 and S12 may be omitted. Further, when the zoom lens is motor driven and can automatically move to the wide side, S10 and S12 are not necessary.

  Subsequently, the projection unit 10 projects and displays a specific pattern for detecting the screen frame, for example, an entire white image on the projection plane 300 (S14). The imaging unit 30 captures the projected image (S16). The screen frame detection unit 40 detects a screen frame from the captured image (S18).

  After the screen frame is detected, the projection unit 10 displays an OSD message prompting the user to adjust the focus (S20), and a specific pattern for focus adjustment is projected and displayed on the projection plane 300 (S22). The user adjusts the focus while looking at the projected focus adjustment specific pattern (S24). If the focus lens 13 can be automatically adjusted by the lens driving unit 20, S20 to S24 are not necessary.

  Subsequently, the projection unit 10 projects and displays a specific pattern for projection area estimation on the projection plane 300 (S26). The imaging unit 30 images the projection plane 300, and the projection area estimation unit 50 estimates the outer peripheral shape of the projection area based on the captured image (S28).

  The determination unit 60 determines whether or not the difference between the screen frame detected in S18 and the outer peripheral shape of the projection area estimated in S28 substantially match (S30). When the screen frame and the projection area do not match (N in S30), the determination unit 60 determines that the screen frame is properly detected, and selects fitting correction (S32). The correction unit 70 refers to the projection area estimation result in S28, and acquires information necessary for fitting correction, such as the coordinates of the four corners of the projection area (S34). When the screen frame and the projection area match (Y in S30), the determination unit 60 determines that the screen frame is erroneously detected, and selects keystone correction (S42). The correction unit 70 acquires information necessary for keystone correction from the specific pattern for projection area estimation captured in S28 (S44). For example, feature points in a specific pattern are detected, and horizontal and vertical inclinations are acquired.

  The correction unit 70 executes either fitting correction or keystone correction based on the acquired information (S36). Thereafter, information indicating which one of fitting correction and keystone correction is selected and executed is projected and displayed on the projection plane 300 by the projection unit 10 (S38). Furthermore, an adjustment indicator corresponding to each correction process may be displayed on the OSD so that the user can perform further fine adjustment (S40). For example, when fitting correction is performed, buttons for finely adjusting the positions of the four corners of the trapezoid may be displayed. When the keystone correction is executed, buttons for finely adjusting the horizontal and vertical lengths of the specific pattern for projection area estimation may be displayed. The user can make fine adjustments by clicking these buttons displayed on the OSD using a device such as a laser pointer or a mouse.

  Even if the flowchart of FIG. 3 is followed, there may be a case where the determination of erroneous detection of the screen frame is not successful. For example, even if the projection plane 300 is not a wall but a screen, if the screen frame coincides with the projection area by chance, it is determined that the screen frame is erroneously detected, and keystone correction is executed. there is a possibility.

FIG. 4 is a flowchart of trapezoidal distortion correction according to another embodiment of the present invention in consideration of the above possibility.
S50 and S52 are the same as S10-S12 in the embodiment of FIG. Subsequently, first, the projection unit 10 projects and displays a specific pattern for screen frame detection, for example, an entire white image on the projection plane 300 (S54). The imaging unit 30 captures the projected image (S56). The screen frame detection unit 40 detects a screen frame (hereinafter referred to as “first screen frame”) from the captured image (S58).

  Next, the projection unit 10 reduces and projects the screen frame detection specific pattern used in S54 on the projection plane 300 (S60). The imaging unit 30 captures the projected image (S62). The screen frame detection unit 40 detects the screen frame (hereinafter referred to as “second screen frame”) again from the captured image (S64).

  In S60, the specific pattern for detecting the screen frame may be enlarged and projected and displayed on the projection plane 300 instead of being reduced. In this case, the process of moving the zoom lens to the wide side in S50-S52 is not necessary. Such enlargement / reduction of the specific pattern may be specified in percentage display with respect to the original specific pattern (for example, minus 20%), or may be specified by the number of pixels (for example, to 640 pixels). Reduced to the corresponding size). Further, such enlargement / reduction of the specific pattern may be performed by software processing on the video signal, or may be performed by operating an optical zoom lens. The operation of the optical zoom lens may be performed in one or both of S54 and S60. A combination of the operation of the optical zoom lens and software processing may realize enlargement / reduction of a specific pattern.

  The determination unit 60 determines whether or not the first screen frame detected in S58 substantially matches the outer peripheral shape of the second screen frame detected in S64 (S66). When the first screen frame and the second screen frame substantially match (Y in S66), the determination unit 60 determines that the screen frame is properly detected, and selects fitting correction (S68). At this time, the projection area fitting target is the first screen frame. If the first screen frame and the second screen frame do not match (N in S66), the determination unit 60 determines that the screen frame is erroneously detected and selects keystone correction (S88).

  The determination in S66 is, for example, whether or not the coordinates of the four corners of the first screen frame and the coordinates of the four corners of the second screen frame are equal to or less than a predetermined value, or the first screen frame and the second screen frame. What is necessary is just to determine whether the distance between the line segments of the four sides of a screen frame is below a predetermined value (for example, 1 cm). If the coordinates of the four corners or the distances between the line segments of the four sides are all equal to or less than the predetermined value, it is determined that the first screen frame and the second screen frame are substantially coincident. If any one of the coordinates of the four corners or the distance between the line segments of the four sides is larger than the predetermined value, it is determined that the first screen frame and the second screen frame do not substantially match.

  When either fitting correction or keystone correction is selected, a message prompting the user to adjust the focus is displayed as OSD (S70, S90), as in S20-S24 of FIG. The specific pattern is projected and displayed on the projection plane 300 (S72, S92), and the user adjusts the focus while viewing the projected specific pattern for focus adjustment (S74, S94).

  Thereafter, the projection unit 10 projects and displays a specific pattern for projection area estimation on the projection plane 300 (S76, S96). The imaging unit 30 captures the projection plane 300, and the correction unit 70 acquires information necessary for fitting correction from the captured projection area estimation specific pattern (S78) or information necessary for keystone correction. Is acquired (S98). Subsequent S80 to S84 are the same as S36 to S40 in FIG.

  Even if the embodiment described with reference to the flowcharts of FIGS. 3 and 4 is executed, in some cases, the determination of erroneous detection of the screen frame may not be successful. For example, in the embodiment of FIG. 4, the specific pattern for screen frame detection is reduced and projected in S60. For this reason, in the first projection in S54, even if the projection area is outside the screen frame, the projection area may be inside the screen frame in the second projection in S60. In this case, since it is determined in S66 that the first screen frame and the second screen frame do not match, the keystone correction is selected. Further, since the keystone correction is performed based on the first screen frame, there is a problem that the corrected projection area protrudes from the screen frame.

FIG. 5 is a flowchart of trapezoidal distortion correction according to still another embodiment of the present invention in consideration of the above possibility.
S100 to S130 are the same as S10 to S40 in the embodiment of FIG. If it is determined in S120 that the screen frame matches the projection area (Y in S120), the projection unit 10 enlarges the screen frame detection specific pattern used in S104 and displays it on the projection plane 300 (see FIG. 12). S132). The imaging unit 30 captures the projected image (S134). The screen frame detection unit 40 detects the screen frame (second screen frame) again from the captured image (S136).

  The determination unit 60 determines whether or not the first screen frame detected in S108 and the outer peripheral shape of the second screen frame detected in S136 substantially match (S138). When the first screen frame and the second screen frame do not match (N in S138), the determination unit 60 determines that the screen frame is erroneously detected and selects keystone correction (S140). The correction unit 70 acquires information necessary for keystone correction from the specific pattern for projection area estimation captured in S116 (S142). When the first screen frame and the second screen frame substantially coincide with each other (Y in S138), the determination unit 60 determines that the screen frame and the projection area overlap, and reduces the projection area and restores the original ( S144), correction processing is not performed (S146). In this case, in S130, the same adjustment indicator as when fitting correction is selected is displayed.

  FIGS. 6A to 6C are diagrams for explaining a determination method of screen frame error detection by the determination unit.

  6A shows a screen frame (indicated by a dotted line in the figure) detected by the screen frame detection unit 40 and an outer periphery of the projection area estimated by the projection area estimation unit 50 in the flowchart of FIG. (Shown by a solid line in FIG. 4) is almost the same. At this time, the determination unit 60 determines that the screen frame is erroneously detected.

  FIGS. 6B and 6C show an example of the first screen frame (indicated by a dotted line in the drawing) and the second screen frame (indicated by a solid line in the drawing) in the flowchart of FIG. 4. As shown in FIG. 6B, when a specific pattern for screen frame detection is projected and displayed in a normal size (first screen frame), and when it is projected and displayed at a reduced size (second screen frame), When the size of the detected screen frame changes, it can be seen that the outer periphery of the projected image is erroneously detected as the screen frame. Therefore, keystone correction is executed at this time.

  On the other hand, as shown in FIG. 6C, a specific pattern for detecting a screen frame is projected and displayed in a normal size (first screen frame), and is reduced and projected (second screen frame). If the size of the detected screen frame does not change, it can be seen that the screen frame is correctly detected. Therefore, fitting correction is executed at this time.

  As described above, according to the above-described embodiment, when an image is projected and displayed on the wall surface using the projection display apparatus, it is possible to prevent the outer periphery of the projected image from being erroneously detected as a screen frame. Therefore, the fitting correction and the keystone correction can be properly used properly, and accurate trapezoidal distortion correction is realized.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In each of the above-described embodiments, both the horizontal trapezoidal distortion that occurs when the projection plane 300 tilts in the left-right direction and the vertical trapezoidal distortion that occurs when the projection plane 300 tilts in the vertical direction can be corrected.

  DESCRIPTION OF SYMBOLS 10 Projection part, 30 Imaging part, 40 Screen frame detection part, 50 Projection area estimation part, 60 Judgment part, 70 Correction part, 82 Image memory, 84 Image signal setting part, 90 Auto-focus adjustment part, 100 Control part, 200 Projection Type image display device, 300 projection plane.

Claims (8)

A control device mounted on a projection display apparatus comprising: a projection unit that projects an image on a projection surface via a lens; and an imaging unit for imaging the projection surface,
A screen frame detection unit for detecting a screen frame from an image captured by the imaging unit when a predetermined pattern for detecting the screen frame is projected by the projection unit;
A projection area estimation unit that calculates an outer peripheral shape of the projection area from an image captured by the imaging unit when a predetermined pattern for estimating the projection area is projected by the projection unit;
A determination unit that determines whether or not the screen frame and the outer peripheral shape of the projection region substantially match, and determines that the screen frame has been erroneously detected when substantially matching;
A control device comprising: A control device mounted on a projection display apparatus comprising: a projection unit that projects an image on a projection surface via a lens; and an imaging unit for imaging the projection surface,
When a predetermined pattern for detecting a screen frame is projected by the projection unit, the first screen frame is detected from an image captured by the imaging unit, and the predetermined pattern is reduced by the projection unit. A screen frame detection unit for detecting a second screen frame from the image captured by the imaging unit,
A determination unit that determines whether or not the first screen frame and the second screen frame substantially match, and determines that the screen frame is erroneously detected when both do not match;
A control device comprising:   In the determination unit, the distance between the coordinates of the four corners of the screen frame and the coordinates of the four corners of the outer peripheral shape of the projection region corresponding to the coordinates of the four corners of the screen frame is a predetermined value in all combinations of coordinates. 2. The control device according to claim 1, wherein the control device determines that the screen frame and the outer peripheral shape of the projection area substantially coincide with each other.   The determination unit is configured such that distances between line segments constituting the screen frame and line segments constituting the outer peripheral shape of the projection area corresponding to the line segments constituting the screen frame are all line segments. 2. The control device according to claim 1, wherein when the combination is equal to or less than a predetermined value, it is determined that the screen frame and the outer peripheral shape of the projection area substantially coincide with each other.   In the determination unit, the distance between the coordinates of the four corners of the first screen frame and the coordinates of the four corners of the second screen frame corresponding to the coordinates of the four corners of the first screen frame is a combination of all coordinates. 3. The control device according to claim 2, wherein when the value is equal to or less than a predetermined value, the first screen frame and the second screen frame are determined to substantially coincide with each other.   In the determination unit, all the distances between the line segments constituting the first screen frame and the line segments constituting the second screen frame corresponding to the line segments constituting the first screen frame are all 3. The control device according to claim 2, wherein when the combination of line segments is equal to or less than a predetermined value, it is determined that the first screen frame and the second screen frame substantially coincide with each other.   Correction that performs keystone correction as trapezoidal distortion correction when it is determined that the screen frame is erroneously detected, and performs fitting correction that aligns the projection area with the screen frame or the first screen frame otherwise. The control device according to claim 1, further comprising a unit. A projection unit that projects an image onto a projection surface via a lens;
An imaging unit for imaging the projection plane;
A control device according to any one of claims 1 to 7,
A projection-type image display device comprising:

Images