Projection device

Abstract

A projection device (10) according to one embodiment of the present application is a projection device used at a construction site. The projection device (10) includes a projection section (21) that projects an image to a projection surface (110), a distance measuring section (24) that measures a distance to the projection surface (110), a rotation driving section (23) that rotates the projection section (21) and the distance measuring section (24), an angle measuring section (22) that measures a rotation angle of the rotation driving section (23), and a data processing section (25a) that corrects an image to be projected from the projection section (21). The distance measuring section (24) and the projection section (21) are arranged so that at least one or both of them is / are offset from a center line of a rotation axis of the rotation driving section (23). The data processing section (25a) corrects the image using the distance measured by the distance measuring section (24) and the rotation angle measured by the angle measuring section (22).

Description

Technical Field

[0001] This invention relates to a projection device. Background Technology

[0002] Previously, a projection device capable of projecting images onto a screen or similar object was known. As a technology associated with the projection device, Patent Document 1 discloses a device for projecting images by changing the projection angle.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application No. 2013-26529 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in the technology described in Patent Document 1, when it is desired to project an image with high precision over a wide viewing angle toward a broad space, such as inside a room, it may be impossible to project the image with high precision.

[0008] Therefore, the object of the present invention is to provide a projection device that can perform image correction with high accuracy and reduce errors when projecting images onto the target location even when projecting images into a wide space with a wide viewing angle.

[0009] Solution for solving the problem

[0010] To achieve the above objectives, one aspect of the present invention relates to a projection device for use on a construction site, comprising: a projection unit that projects an image onto a projection surface; a distance measuring unit that measures the distance to the projection surface; a rotation drive unit for rotating the projection unit and the distance measuring unit; an angle measuring unit that measures the rotation angle of the rotation drive unit; and a data processing unit for correcting the image to be projected from the projection unit. The distance measuring unit and the projection unit are arranged such that at least one or both are offset from the centerline of the rotation axis of the rotation drive unit. The data processing unit uses the distance measured by the distance measuring unit and the rotation angle measured by the angle measuring unit to correct the image.

[0011] The effects of the invention

[0012] According to the present invention, even when projecting an image into a wide space with a wide viewing angle, it is possible to perform image correction with high precision to reduce errors and project the image onto the target location. Attached Figure Description

[0013] Figure 1This is a diagram showing an outline of the projection device involved in the embodiment.

[0014] Figure 2A This is a perspective view of the projection device involved in the implementation method.

[0015] Figure 2B This is a front view of the projection device involved in the implementation method.

[0016] Figure 2C This is a right-side view of the projection device involved in the embodiment.

[0017] Figure 2D This is a top view of the projection device involved in the embodiment.

[0018] Figure 3 This is a block diagram illustrating the functional structure of the projection device according to the embodiment.

[0019] Figure 4 This is a flowchart illustrating an example of the operation of the projection device according to the implementation method.

[0020] Figure 5 It is a graph showing the coordinate axes of orthogonal coordinates in space.

[0021] Figure 6A This is a diagram showing the state before the positional relationship between the projection device and the projected surface changes according to the embodiment.

[0022] Figure 6B This is a diagram showing the state after the positional relationship between the projection device and the projected surface changes according to the embodiment.

[0023] Figure 7A It is shown Figure 6B A diagram showing a specific example of the positional relationship.

[0024] Figure 7B View from the front Figure 7A The diagram shown is a plan view of the projected surface.

[0025] Figure 8 It is shown Figure 7B The graph shows the errors at each measurement point. Detailed Implementation

[0026] The embodiments will now be described in detail with reference to the accompanying drawings. However, the embodiments described below are only one embodiment of the various embodiments of the present invention. Various modifications can be made to the embodiments described below, depending on the design, etc., as long as the objectives of the present invention are achieved. Furthermore, the figures described in the following embodiments are schematic diagrams, omitting components not necessary for the description of the present invention. Additionally, in the figures, substantially identical structures are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified. Moreover, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present invention, and are not intended to limit the subject matter of the claims.

[0027] (1) Summary

[0028] First, an overview of the projection device 10 involved in the embodiment will be described. Figure 1 This is a diagram illustrating an outline of the operation of the projection device 10 according to the embodiment. The projection device 10 according to the embodiment is installed in a space 100, for example, within a building under construction. The projection device 10 projects light used to assist construction work during the construction of the building onto the projection surface 110, for example, the building constituting the space 100 (specifically, the floor, walls, or ceiling, etc.). The projected content is light indicating the location where bolts are to be driven into the floor, or light indicating the location where bolts are to be driven into the wall, etc. If these locations are pre-input into the projection device 10 as images, the projection device 10 projects light onto the locations where the worker should perform the work according to the building design. In other words, the projection device 10 projects light used to assist in construction layout as an image. Therefore, the worker does not need to determine the work location themselves, but only needs to perform the work according to the location of the projected light, thus making construction work easy to carry out.

[0029] On the other hand, the image projected from the projection device 10 produces a projection error where the actual projected position differs from the desired projection position. Here, when the projection device 10 projects an image with a wide viewing angle into a spacious area 100 inside a building under construction as described above, the error (projection error) between the target projection position and the actual position projected onto the projection surface 110 increases because the projected surface 110 is far relative to the projection device 10. Therefore, the structure and operation of the projection device 10 will be explained as follows: it can perform high-precision correction of the image to be projected, thereby enabling high-precision projection onto the target position over a wide range.

[0030] (2) Structure

[0031] The structure of the projection device 10 according to the embodiment will be described. Figure 1The image shows the situation where light emitted from the projection device 10 is projected onto the projection surface 110. Figures 2A-2D This is a diagram showing the appearance of the projection device 10. Figures 2A-2D These are, respectively, a three-dimensional view of the projection device 10, a front view, a right side view, and a top view. Figure 3 This is a block diagram showing the functional structure of the projection device 10.

[0032] like Figures 1 to 3 As shown, the projection device 10 is a device for projecting images onto the projection surface 110. The projection device 10 is, for example, mounted on a tripod and placed on the floor. Alternatively, it is not limited to a tripod; the projection device 10 may also be mounted on a wall or a table. When the projection device 10 is mounted on a wall or a table, it is mounted via a mounting part (not shown).

[0033] In particular, Figures 2A-2D as well as Figure 5 In this embodiment, the vertically upward direction is defined as the Z direction, and the X and Y directions, which are orthogonal to the Z direction, are defined respectively to describe the structure of the projection device 10. Additionally, the XZ plane is sometimes shown as the front view of the projection device 10.

[0034] The projection device 10 includes a projection unit 21, an angle measuring unit 22, a rotation drive unit 23, a distance measuring unit 24, a control unit 25, and a storage unit 26.

[0035] The projection unit 21 is a projection module for projecting images onto the projection surface 110. The projection unit 21 includes a light source 21a and a scanning unit 21b. In addition, although not shown, the projection unit 21 also includes optical components such as lenses and mirrors.

[0036] Light source 21a is, for example, a laser light source implemented by a semiconductor light-emitting element. In addition, light source 21a may also be a structure that includes multiple light-emitting elements with different emission colors (e.g., red light-emitting element, green light-emitting element, and blue light-emitting element) and is capable of switching emission colors.

[0037] The scanning unit 21b is a mechanism that scans the light emitted by the light source 21a and projects it onto the projection surface 110, for example, by using a MEMS (Micro Electro Mechanical Systems) mirror.

[0038] The projection unit 21 includes a light source 21a and a scanning unit 21b, which are integrated as a module and are located near the outer shell of the housing 27.

[0039] The ranging unit 24 measures the distance from the projection device 10 to the structure constituting the projection surface 110. The ranging unit 24 is, for example, a ranging sensor such as a TOF (Time of Flight) sensor. The ranging unit 24 can also be other ranging sensors, such as a ranging sensor using phase difference detection or a ranging sensor using triangulation. The ranging unit 24 is, for example, composed of a light-receiving element such as a photodiode and a ranging light source. The ranging light source is a light source that emits light toward the structure. The ranging light source can be implemented, for example, by a light-emitting element that emits infrared light, but it can also be implemented by a light-emitting element that emits visible light. Furthermore, as described later, the ranging unit 24 has a laser pointer function for presenting the current ranging target point to the user. This function can be implemented, for example, by a light source different from the ranging light source, but it can also be implemented by the ranging light source if it emits visible light.

[0040] The rotation drive unit 23 is a rotation mechanism for changing the orientation of the projection device 10 (in other words, the orientation and angle of the ranging unit 24). The rotation drive unit 23 has a first rotation drive unit 23a for changing the orientation of the projection device 10 in the tilt direction and a second rotation drive unit 23b for changing the orientation of the projection device 10 in the pan direction. Figures 2A-2D In the diagram, the dashed line in the X direction indicates the center line of the rotation axis of the first rotation drive unit 23a. The dashed line in the Z direction indicates the center line of the rotation axis of the second rotation drive unit 23b. The first rotation drive unit 23a and the second rotation drive unit 23b are implemented by stepper motors or the like. Furthermore, the rotation drive unit 23 may also have a third rotation drive unit for changing the orientation of the projection device 10 in the roll direction. In this embodiment, the front view of the rotation drive unit 23 has a generally U-shaped shape, with the first rotation drive unit 23a arranged at both ends of the generally U-shape and the second rotation drive unit 23b arranged at the bottom edge of the generally U-shape, but the rotation drive unit 23 is not limited to this shape. The rotation drive unit 23 can be of any shape as long as it can rotate in both the pitch and roll directions. Additionally, in this embodiment, the ranging unit 24 and the projection unit 21 are respectively arranged at positions offset from the center line of the rotation axis of the first rotation drive unit 23a and the center line of the rotation axis of the second rotation drive unit 23b.

[0041] The angle measuring unit 22 measures the orientation of the projection device 10 (in other words, the orientation and angle of the distance measuring unit 24). Specifically, the angle measuring unit 22 is an angle sensor that measures the driving amount of the rotation drive unit 23. The angle measuring unit 22 is composed of a first angle measuring unit 22a that measures the angle of the first rotation drive unit 23a that rotates in the pitch direction and a second angle measuring unit 22b that measures the angle of the second rotation drive unit 23b that rotates in the roll direction. Furthermore, if the rotation drive unit 23 has a third rotation drive unit for changing the orientation of the projection device 10 in the flip direction, the angle measuring unit 22 can measure the flip angle as the driving amount of the rotation drive unit 23.

[0042] The control unit 25 is a control device that controls each part of the projection device 10, including the projection unit 21 and the rotation drive unit 23, to project an image onto the projection surface 110. The control unit 25 includes a data processing unit 25a and a tilt calculation unit 25b as its functional units. The data processing unit 25a uses information such as the rotation angle of the rotation drive unit 23 measured by the angle measuring unit 22 and the distance measured by the distance measuring unit 24 to correct the image to be projected. Details of the correction will be described later. Furthermore, the tilt calculation unit 25b calculates the tilt of the projection surface 110 based on the distances from the projection device 10 to at least three arbitrary points on the projection surface 110. Details of the calculation will be described later.

[0043] The control unit 25 is implemented, for example, by a microcomputer or processor. Additionally, the control unit 25 may include a drive circuit for driving the projection unit 21, a drive circuit for driving the rotation drive unit 23, or a drive circuit for driving the distance measuring unit 24.

[0044] The storage unit 26 is, for example, a storage device implemented using a semiconductor memory. The storage unit 26 stores images projected onto the projection surface 110, programs for the data processing unit 25a used to implement the control unit 25, programs for controlling other parts of the projection device 10, information temporarily needed for control by the control unit 25, information measured by the angle measuring unit 22 and the distance measuring unit 24, and information generated by the data processing unit 25a. Additionally, the storage unit 26 stores information related to the positional relationship between the distance measuring unit 24 and the projection unit 21.

[0045] The housing 27 houses the projection unit 21, the angle measuring unit 22, the distance measuring unit 24, the control unit 25, and the storage unit 26. The housing 27 may be made of resin, but it can also be made of metal. In this embodiment, the housing 27 is rectangular and is positioned in the gap between the ends of the rotation drive unit 23, which is approximately U-shaped in its front view. The shape and arrangement of the housing 27 are not limited to this, as long as it is connected to the rotation drive unit 23 and can rotate in both the pitch and roll directions.

[0046] Furthermore, the description assumes that the ranging unit 24 is housed in the housing 27, but the ranging unit 24 does not necessarily need to be housed inside the housing 27. For example, the ranging unit 24 may also be fixed to the outside of the housing 27.

[0047] Furthermore, the projection device 10 may also include a display unit and an operation unit (not shown). This allows the user to check status information related to the projection device 10 displayed on the display unit. Additionally, the user can operate and drive various parts of the projection device 10 by manipulating the operation unit. In this case, the display unit is a liquid crystal display (LCD) or the like. The operation unit is an input device such as a touch panel or keyboard.

[0048] Alternatively, the projection device 10 may also include a communication unit (not shown). The projection device 10 can be driven by the operation of the external electronic device by transmitting wired or wireless instructions from an external electronic device to the control unit 25 via the communication unit. In this case, the wired or wireless communication standard based on the communication unit is not particularly limited and can be any method.

[0049] Based on the above structure, the projection device 10 is able to project light, used to assist in the construction of buildings, onto the projection surface 110 in the form of an image.

[0050] (3) Example of an action

[0051] Next, an example of the operation of the projection device 10 will be explained. Figure 4 This is a flowchart illustrating an example of the operation of the projection device 10. Furthermore, in the following description of the operation example, in space 100, as... Figure 5 Set the coordinate axes of the orthogonal coordinate system as shown. Figure 5 It is a graph showing the coordinate axes of orthogonal coordinates in space 100. Figure 5 The coordinate axes shown define the position of the projection device 10 (more specifically, the predetermined positions around the projection section 21 and the ranging section 24 within the projection device 10) as the origin O. In this operational example, the origin O is described as the position where the center line of the rotation axis of the first rotation drive section 23a intersects with the center line of the rotation axis of the second rotation drive section 23b. Furthermore, in the following operational example, the projection surface 110 is assumed to be a floor surface, and the user operates the projection device 10 via external electronic equipment.

[0052] First, the user places the projection device 10 in the space 100 and rotates the rotation drive unit 23 at any angle, so that the housing 27, including the projection unit 21 and the distance measuring unit 24, faces the direction of the desired projection onto the projection surface 110 (S11).

[0053] Next, the angle measuring unit 22 measures and acquires the rotation angle of the rotation drive unit 23 at the end time of the process in step S11 (S12). Specifically, the first angle measuring unit 22a measures the pitch angle θ of the first rotation drive unit 23a. The second angle measuring unit 22b measures the roll angle Φ of the second rotation drive unit 23b. The pitch angle θ and roll angle Φ obtained by these measurements are stored in the storage unit 26.

[0054] Next, the ranging unit 24 measures and acquires the distance from the projection device 10 to the projected surface 110 in the positional relationship at the end time of the processing in step S11 (S13). Specifically, as Figure 6A and Figure 6B In this way, the distance (L) between the measuring unit 24 and the straight line connecting the projection surface 110 is measured and obtained. 测量 ).like Figure 6A and Figure 6B As shown, in this embodiment, the ranging unit 24 and the projection unit 21 are arranged apart by a distance h. Therefore, as Figure 6A In this case, when the ranging unit 24 and the projection unit 21 are perpendicular to the projected surface 110 (when the relative pitch angle θ between the ranging unit 24 and the projection unit 21 and the projected surface 110 is zero), the distance (L) of the straight line connecting the ranging unit 24 and the projected surface 110 is calculated. 测量 ) and the distance (L) of the straight line connecting the projection part 21 and the projected surface 110. 投影 Consistent.

[0055] However, as Figure 6B As shown, when the ranging unit 24 and the projection unit 21 have a relative pitch angle θ with respect to the projected surface 110 (when the relative pitch angle θ between the ranging unit 24 and the projection unit 21 and the projected surface 110 is not zero), L 测量 Become L 投影 The value obtained by adding the distance h×tanθ. In the image correction described later, the L value is calculated based on the angle between the projection device 10 and the projected surface 110. 测量 With L 投影 The calculations take into account the differences. Furthermore, the calculations also take into account the positional relationship between the projection unit 21 and the ranging unit 24, which is offset from the center line of the rotation axis of the first rotation drive unit 23a and the center line of the rotation axis of the second rotation drive unit 23b.

[0056] Next, the control unit 25 confirms the rotation angle of the rotation drive unit 23 and the distance (L) from the ranging unit 24 to the projected surface 110. 测量 Is the measurement of ) complete (S14)? If the rotation angle and L 测量If the measurement is not completed (S14: "No"), return to step S11 and repeat the process described up to this point.

[0057] If the rotation angle and L 测量 When the measurement ends (S14: "Yes"), the distance measuring unit 24 measures the distance from the projection device 10 to any three measurement points on the projected surface 110 that are not arranged in a straight line, and the angle measuring unit 22 obtains the rotation angle of the rotation drive unit 23 for each of these three points (S15). Figure 5 Points A, B, and C shown are diagrams illustrating the acquisition of distance and rotation angle of the rotation drive unit 23 in step S15. Point A is the point where distance and rotation angle of the rotation drive unit 23 were acquired in the process up to step S14. Therefore, distance and rotation angle of the rotation drive unit 23 are also measured and acquired for any points B and C.

[0058] At this time, points B and C are selected such that points A, B, and C are not arranged in a straight line. For example, from the state where the rotation angle of the rotation drive unit 23 at the end time of the process in step S14 causes the ranging unit 24 to point towards point A on the projection surface 110, any point B is selected. The first rotation drive unit 23a and the second rotation drive unit 23b rotate in such a way that the ranging unit 24 points towards point B. If the ranging unit 24 is in the state of pointing towards point B, the ranging unit 24 measures the distance from the ranging unit 24 to point B and stores it in the storage unit 26. In addition, the angle measuring unit 22 measures the pitch angle θ and roll angle Φ of the rotation drive unit 23 in this state and stores them in the storage unit 26. If the distance and angle information related to point B is obtained, the same applies to point C. The rotation drive unit 23 is rotated in such a way that the ranging unit 24 points towards point C, the distance from the ranging unit 24 to point C and the rotation angle of the rotation drive unit 23 at this time are obtained and stored in the storage unit 26. Alternatively, the selection of points B and C can be performed by the user simultaneously confirming the light emitted from the laser pointer emitted by the ranging unit 24 and by the user operating the projection device 10 for indication. Alternatively, the selection of points B and C can be performed automatically using a program pre-stored in the storage unit 26.

[0059] Next, the tilt calculation unit 25b calculates the tilt of the projected surface 110 (S16). The tilt calculation unit 25b calculates the orthogonal coordinates (xyz coordinates) of the three measurement points based on the stored information (that is, the measurement results of distance and rotation angle, and the positional relationship between the distance measuring unit 24 and the projection unit 21). Figure 5 This is a graph showing the polar and orthogonal coordinates of three measurement points.

[0060] When calculating the orthogonal coordinates of the three measurement points, the tilt calculation unit 25b first calculates the polar coordinates of the three measurement points. To calculate the polar coordinates, the tilt calculation unit 25b calculates the distance *r* from each of the three measurement points to the origin O, based on the distance information measured by the distance measuring unit 24 and stored in the storage unit 26, as well as information stored in the storage unit 26 related to the positional relationship between the distance measuring unit 24 and the projection unit 21. The distance information measured by the distance measuring unit 24 represents the distance from the distance measuring unit 24 to the measurement point. By using information about the positional relationship between the distance measuring unit 24 and the projection unit 21 (which also includes the positional relationship between the distance measuring unit 24 and the projection unit 21 relative to the origin O) from the distance information measured by the distance measuring unit 24, the distance *r* from the origin O to the measurement point is calculated. That is, the distance r is calculated in the form of an error reflecting the positional relationship between the ranging unit 24 and the projection unit 21, which is set apart from the center line of the rotation axis of the first rotation drive unit 23a and the center line of the rotation axis of the second rotation drive unit 23b. The distance r calculated in this way is combined with the roll angle Φ and pitch angle θ measured for each measurement point to calculate the polar coordinates of the three measurement points.

[0061] When the polar coordinates are calculated, the tilt calculation unit 25b transforms the calculated polar coordinates of the three measurement points into orthogonal coordinates.

[0062] When the orthogonal coordinates of the three measurement points are calculated, the tilt calculation unit 25b uses these coordinates to calculate the distance from the projection device 10 to the projected surface 110 (i.e., the plane passing through measurement points A, B, and C) and the tilt of the projected surface 110 relative to the projection device 10. When the equation of the projected surface 110 is set as ax + by + cz = d, the coordinates of point A are set as (xa, ya, za), the coordinates of point B are set as (xb, yb, zb), and the coordinates of point C are set as (xc, yc, zc), the tilt calculation unit 25b calculates the normal vector n = (a, b, c) of the projected surface 110 based on this information. The normal vector n represents the tilt of the projected surface 110 in orthogonal coordinates, and the length of the normal vector n represents the distance from the projection device 10 to the projected surface 110. In other words, calculating the normal vector n is equivalent to calculating the distance from the projection device 10 to the projected surface 110 and the tilt of the projected surface 110 relative to the projection device 10.

[0063] Next, the data processing unit 25a corrects the image to be projected based on the distance from the projection device 10 to each point measured by the ranging unit 24, the rotation angle of the rotation drive unit 23 at this time, and the tilt angle of the projected surface 110 calculated by the tilt angle calculation unit 25b, and projects the corrected image from the projection unit 21 (S17). Specifically, the data processing unit 25a corrects the image distortion based on the calculated tilt angle of the projected surface 110 and the rotation angle of the rotation drive unit 23, and corrects the projection magnification of the image data based on the calculated distance to the projected surface 110. In addition, in this correction, as described above, when there is an angle between the ranging unit 24 and the projection unit 21 relative to the projected surface 110, the distance (L) reflecting the straight line connecting the ranging unit 24 and the projected surface 110 is calculated. 测量 ) and the distance (L) of the straight line connecting the projection part 21 and the projected surface 110. 投影 Inconsistent corrections.

[0064] Through the operation of the projection device 10 described above, image correction can be performed with high precision even in a spacious space 100 such as the interior of a building under construction, so as to project an image onto the target location with high precision. In the projection device 10 of this structure, the pitch angle θ and roll angle Φ of the projection device 10 obtained by the first angle measuring unit 22a and the second angle measuring unit 22b are used to perform image correction that also takes into account the tilt of the projection surface 110, so high-precision image correction can be performed.

[0065] Furthermore, in calculating the tilt of the projected surface 110, the tilt of the projected surface 110 is calculated by eliminating the error in the positional relationship between the ranging unit 24 and the origin O, where the ranging unit 24 and the projection unit 21 are set to deviate from the center line of the rotation axis of the first rotation drive unit 23a and the center line of the rotation axis of the second rotation drive unit 23b. Therefore, the tilt of the projected surface 110 can be calculated with high accuracy, and the projected image can also be corrected with high accuracy.

[0066] Furthermore, in the correction of the projected image, the distance (L) of the straight line connecting the ranging unit 24 and the projected surface 110 is considered. 测量 ) and the distance (L) of the straight line connecting the projection part 21 and the projected surface 110. 投影 When there is a relative pitch angle θ between the ranging unit 24 and the projection unit 21 and the projected surface 110, a correction is performed to correct the distance measurement error caused by the positional relationship between the ranging unit 24 and the projection unit 21. This error is L. 测量 Become L 投影This error is calculated by adding the distance h×tanθ. Therefore, it is possible to correct the projected image with high precision.

[0067] Here, specific examples are given to illustrate the effects obtained by the projection device 10 according to this embodiment. Figure 7A It is shown Figure 6B A diagram showing a specific example of the positional relationship. For example... Figure 7A As shown, with the distance h between the projection unit 21 and the distance measuring unit 24 being 50 mm, the pitch angle θ being 45°, and the distance L measured by the distance measuring unit 24 being... 测量 Let's take a case of 1000mm as an example. In this case, the distance L of the straight line connecting the projection part 21 and the projected surface 110 is... 投影 It is 950mm. This is because, as mentioned above, it is related to L. 测量 Compared to the shortening of h×tanθ=50mm×tan45°=50mm. Like this, in L... 测量 With L 投影 An error of 50mm occurred between them.

[0068] Figure 7B View from the front Figure 7A The diagram shows a plan view of the projected surface 110. It is assumed that the projection unit 21 does not perform image correction and is based on L... 测量 The case where a square with one side of 1000mm is projected onto the projected surface 110. In Figure 7B In the image, a square with eight circular markings and a dashed line represents the image to be projected from the projection unit 21. Furthermore, for... Figure 7B The nine circular symbols are labeled with identification numbers "1" to "9" to represent the four vertices of the square, the midpoints of the four sides, and the center of the square.

[0069] Without correcting for the aforementioned 50mm error, the projected surface 110 is actually located at L. 投影 =950mm, therefore the nine circular marks will be projected onto the positions represented by the nine triangular marks. Specifically, the uncorrected image is projected at a size of 950 / 1000 to a position offset 50mm / cos45°≈70.7mm to the negative Y-axis. The specific correspondence between the circular and triangular marks is as follows: Figure 8 As stated above.

[0070] In the case of projection devices used for entertainment or presentation purposes, this level of error is acceptable. However, as a projection device 10 used on a construction site to project guide lights to indicate the work position, the dimensions of the building may not match the design, thus projection errors are unacceptable. According to the projection device 10 of this embodiment, the image is corrected based on distance and rotation angle as described above, thus enabling high-precision correction of the projected image.

[0071] Furthermore, in this embodiment, the ranging unit 24 and the projection unit 21 are respectively positioned offset from the center line of the rotation axis of the first rotation drive unit 23a and the center line of the rotation axis of the second rotation drive unit 23b. Based on this positional relationship between the ranging unit 24 and the projection unit 21, a balance of weight within the housing 27, including the electronic substrate (not shown) used to drive the projection device 10, can be achieved. Therefore, the force required by the rotation drive unit 23 to rotate the housing 27 can be reduced, simplifying and miniaturizing the device structure of the projection device 10.

[0072] As described above, embodiments of the present invention have been explained with reference to the accompanying drawings. However, the scope of the present invention is not limited by the above description. Various modifications and variations can be made within the scope of the spirit of the invention as set forth in the claims. For example, in embodiments of the present invention, a laser scanning projection device has been described, but the present invention can also be implemented with other projection devices. Furthermore, the projection device can also be implemented as a client-server system, in which case a portion of the processing described in the above embodiments as being performed by the projection device can be performed in the server device via the transmission and reception of information through a communication unit.

[0073] Furthermore, the structure shown in the above example is merely one example and is not limited thereto. For instance, the order and processing content of each step indicated by the reference numerals marked with "S" can be modified and altered in various ways without departing from the effects of the present invention. In addition, the present invention also includes methods obtained by implementing various modifications to each embodiment that can be conceived by those skilled in the art, or methods implemented by arbitrarily combining the constituent elements and functions of each embodiment without departing from the spirit of the present invention.

[0074] Industrial availability

[0075] This invention can be appropriately used when projecting the location where the operator should perform a task in a relatively spacious space, such as inside a building under construction, in an image-like manner.

[0076] Explanation of reference numerals in the attached figures

[0077] 10: Projection device; 21: Projection unit; 22: Angle measuring unit; 22a: First angle measuring unit; 22b: Second angle measuring unit; 23: Rotation drive unit; 23a: First rotation drive unit; 23b: Second rotation drive unit; 24: Distance measuring unit; 25: Control unit; 25a: Data processing unit; 25b: Inclination calculation unit; 26: Storage unit; 27: Housing; 100: Space; 110: Projected surface.

Claims

1. A projection device for use on a construction site, the projection device comprising: A projection unit that projects an image onto a surface to be projected. A ranging unit that measures the distance to the projected surface; A rotation drive unit is used to rotate the projection unit and the ranging unit; Angle measuring unit, which measures the rotation angle of the rotation drive unit; and The data processing unit corrects the image to be projected from the projection unit. in, The ranging unit and the projection unit are arranged such that at least one or both are offset from the center line of the rotation axis of the rotation drive unit. The data processing unit uses the distance measured by the ranging unit and the rotation angle measured by the angle measuring unit to correct the image. It also includes a tilt calculation unit for calculating the tilt of the projected surface. The tilt calculation unit calculates the tilt of the projected surface based on the distances measured by the distance measuring unit and the rotation angles measured by the angle measuring unit from at least three points not arranged in a straight line on the projected surface, as well as the positional relationship between the distance measuring unit and the projection unit. The data processing unit also corrects the image based on the tilt of the projected surface.

2. The projection device according to claim 1, wherein, The rotation drive unit includes a first rotation drive unit that rotates in a first direction and a second rotation drive unit that rotates in a second direction. The angle measuring unit includes a first angle measuring unit for measuring the rotation angle of the first rotation drive unit and a second angle measuring unit for measuring the rotation angle of the second rotation drive unit.

Images