JP6670429B2 - Transparent substrate measuring device and transparent substrate measuring method - Google Patents

Description

  The present invention relates to a transparent substrate measuring device and a transparent substrate measuring method for measuring characteristics of a transparent substrate made of, for example, glass or resin.

  In recent years, laminated glass has been used for windshields of passenger cars in place of conventional tempered glass. A virtual image head-up display (HUD) using this windshield as a screen has begun to spread. In the virtual image viewing HUD, a projected image from the projector is reflected at two interfaces of the laminated glass, so that a double image is generally generated. Therefore, for example, Japanese Patent Application Laid-Open No. H11-163873 proposes to correct a double image by giving an appropriate wedge angle to an intermediate layer between two bonded glasses.

Patent No. 5315358

  A vehicle windshield has a complicated free-form surface shape. If there is a variation in the shape, that is, a variation in the surface position or the curvature of the free-form surface, the reflected light deviates from the ideal design condition. In this case, distortion or blur occurs in the virtual image created by the reflected light. Further, with regard to distortion and blur, the cause of the occurrence may be in the concave mirror or the HUD optical unit, so that measurement should be performed so that the cause of occurrence can be identified. However, at present, the measurement must be performed by combining the HUD optical unit, the concave mirror, and the windshield, and it is difficult to determine the cause of the blur or the distortion.

  In order to efficiently develop the HUD system, it is desirable to be able to evaluate whether the glass satisfies the optical specifications required by the HUD system with a single glass even at the time when the trial manufacture of the concave mirror or the HUD projection optical system has not been completed yet. In addition, it is desirable that the glass alone can be evaluated in order to determine whether the cause of blurring or distortion is caused by the glass or other factors. It is considered that such a demand exists not only in the field of windshields for vehicles, but also in the general technical field of using a transparent substrate made of glass, resin, or the like as a screen.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a transparent base material measuring apparatus and a transparent base material measuring method capable of isolating the cause of an optical defect.

A transparent substrate measuring device according to one embodiment of the present invention includes a projection device, an imaging device, and an information processing device. The projection device is configured to be able to irradiate one or more portions of the transparent substrate with pinhole-shaped or slit-shaped projection light. The imaging device captures a virtual image created by reflected light of one or more projection lights emitted from the projection device on the transparent substrate. The information processing device derives characteristics of the transparent substrate based on image data obtained by imaging by the imaging device. The projection device includes a light source unit that emits one or a plurality of projection lights, and a first mechanism that moves the entire light source unit. The light source unit includes a point light source having a pinhole or a line light source having a slit, a telecentric projection optical system arranged on the optical axis of the projection device, and a point light source or a line light source and a telecentric projection optical system. And a second mechanism for changing the incident angle of the projection light on the transparent substrate without changing the position where the projection light intersects the transparent substrate.

A method for measuring a transparent substrate according to an embodiment of the present invention includes the following (A), (B) , and (C) .
(A) While a point or linear projection light is radiated from a light source unit to a predetermined location on a transparent substrate, a virtual image created by reflected light of the projection light on the transparent substrate moves to a designated measurement point. Adjust the position and orientation of the light source unit by changing the angle of incidence of the projection light on the transparent substrate without changing the position where the projection light and the transparent substrate intersect.
(B) capturing a virtual image obtained after the completion of the adjustment ;
(C) deriving characteristics of the transparent substrate based on image data obtained by capturing a virtual image;

  In the transparent substrate measuring apparatus and the transparent substrate measuring method according to one embodiment of the present invention, while a predetermined point on the transparent substrate is irradiated with point-like or linear projection light, the transparent substrate A virtual image created by the reflected light at the is captured. Further, characteristics of the transparent substrate are derived based on image data obtained by imaging. Thus, for example, the characteristics of the transparent substrate can be obtained without using a concave mirror or an HUD optical unit.

  According to the transparent substrate measuring apparatus and the transparent substrate measuring method according to one embodiment of the present invention, the characteristics of the transparent substrate can be obtained without using a concave mirror or a HUD optical unit. The cause of the occurrence of an optical defect such as a superimposed image, blur, or distortion can be identified.

It is a figure showing the example of composition of the transparent substrate measuring device concerning one embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration example of a subject. FIG. 3 is a diagram illustrating functions of a subject. It is a figure showing the example of a structure of a mounting table. It is a figure showing the example of composition of a target part. FIG. 2 is a diagram illustrating a configuration example of a light source unit in FIG. 1. FIG. 3 is a diagram illustrating another configuration example of the light source unit in FIG. 1. 9 illustrates an example of the intensity distribution of two images that are close to each other. It is a figure showing an example of displacement of a light ray when moving a pinhole or a slit. FIG. 3 is a diagram for explaining sampling in the image sensor. FIG. 2 is a diagram illustrating a configuration example of an information processing device. It is a figure explaining an example of a teaching data acquisition procedure. It is a figure explaining an example of the method of acquiring teaching data from a plurality of viewpoints. FIG. 9 is a diagram illustrating an example of a method for acquiring teaching data at a plurality of measurement points. FIG. 3 is a diagram illustrating an example of a procedure for measuring the optical characteristics of a subject. It is a figure showing an example of the measuring method of a double image. It is a figure showing an example of the measuring method of distortion. It is a figure showing an example of the measuring method of a blur. FIG. 4 is a diagram illustrating an example of a method of correcting a subject with a correction jig. FIG. 4 is a diagram illustrating a modification of the configuration of the transparent base material measuring device in FIG. 1.

  Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The following description is a specific example of the present invention, and the present invention is not limited to the following embodiments. Further, the present invention is not limited to the arrangement, dimensions, dimensional ratios, and the like of the components shown in the drawings.

<1. Embodiment>
[Constitution]
The configuration of the transparent substrate measuring device 1 according to one embodiment of the present invention will be described. FIG. 1 illustrates a configuration example of a transparent base material measuring device 1. The transparent base material measuring apparatus 1 is for measuring characteristics (for example, optical characteristics such as a double image, distortion, and blur) of the subject 100.

(Subject 100)
The subject 100 can be used as a screen on which an image is projected, and is a transparent substrate formed of glass, resin, or the like. The transparent substrate is a plate-shaped member that transmits visible light, and is made of, for example, a flat glass plate, a flat resin plate, or a flat resin film. The transparent substrate may be constituted by a curved glass plate, a curved resin plate, or a curved resin film.

  FIG. 2 illustrates a configuration example of the subject 100. FIG. 2 shows an example in which the subject 100 is a vehicle windshield. In the subject 100 shown in FIG. 2, the pair of main surfaces 100A and 100B facing each other have a free-form surface. Therefore, the curvature differs between the vertical direction and the horizontal direction. In addition, the angle formed by the vertical circle and the horizontal circle describing the curvature changes at each position in the free-form surface as indicated by α1 and α2 in the drawing. This vertical and horizontal curvature differs depending on the type of windshield.

  Next, the function of the subject 100 will be described. FIG. 3 is a view for explaining an example of the function of the subject 100. The subject 100 is for causing the observer 200 to visually recognize the light (projection light L) of the virtual image Iv1 emitted from the projection device together with the scenery behind the subject 100. In the subject 100, the pair of main surfaces 100A and 100B facing each other functions as a reflecting surface for the projection light L, and also functions as a transmitting surface for external light incident from behind the subject 100. Further, in the subject 100, the pair of main surfaces 100A and 100B can form two virtual images Iv2 and Iv3 behind the subject 100 by light reflected on the pair of main surfaces 100A and 100B. The virtual image Iv2 is generated by the reflected light L2 of the projection light L incident on the main surface 100A at a predetermined angle and reflected by the main surface 100A. The virtual image Iv3 is generated by the reflected light L3 of the projection light L incident on the main surface 100A at a predetermined angle on the main surface 100B. The virtual images Iv2 and Iv3 can be generated at substantially the same position.

  The main surfaces 100A and 100B are reflected by the main surface 100A when one light beam emitted from the virtual image Iv1 is obliquely incident on the main surface 100A, and the one light beam is refracted and transmitted through the main surface 100A. And is reflected by the main surface 100B. The principal surfaces 100A and 100B further form an image by overlapping the reflected light L2 on the principal surface 100A and the reflected light L3 on the principal surface 100B at the position of the retina 220 of the observer 200 via the pupil 210 of the observer 200. It is configured as follows. The principal planes 100A and 100B further have a reflection ray L2 on the principal plane 100A and a reflection ray L3 on the principal plane 100B at the position of the retina 220 of the observer 200 through the pupil 210 of the observer 200, which is lower than the eye resolution. Preferably, it is configured to form an image.

(Transparent substrate measuring device 1)
The transparent substrate measuring device 1 includes a projection device 10, an imaging device 20, a table 30, a target unit 40, and an information processing device 50.

(Table 30)
The mounting table 30 is for mounting the subject 100 thereon. When the subject 100 is a vehicle-mounted windshield, for example, as shown in FIG. 4, the mounting table 30 is mounted in the same position as when the vehicle-mounted windshield is mounted on a car, and Is provided. When the in-vehicle windshield is held in the same posture as when mounted on a car, the in-vehicle windshield is bent as in actual use.

(Target unit 40)
The target section 40 is disposed at a design position (for example, a prescribed height in a few meters ahead of the subject 100) where the virtual image Iv created by the reflected light Lr of the projection light L on the subject 100 is projected. I have. For example, as shown in FIG. 5, the target unit 40 is a paper surface or a display on which a frame line having the same outer shape as the virtual image display area and points to be measured (measurement points A to E in the figure) are drawn. It is. Instead of providing the target unit 40 as shown in FIG. 5, a virtual target corresponding to the target unit 40 is overlaid on a finder image of the camera 21 described later, and a CG (Computer) is displayed on the display screen of the information processing device 50. Graphics).

(Projection device 10)
The projection device 10 is configured to be capable of irradiating one or more locations of the subject 100 with projection light L. In the present embodiment, projection device 10 sequentially irradiates projection light L to a plurality of locations on subject 100. The projection device 10 has a light source unit 11 and a mechanism unit 12. The mechanism section 12 corresponds to a specific example of the “first mechanism section” of the present invention.

  The mechanism section 12 is for moving the entire light source unit 11. The mechanism section 12 is configured to be capable of adjusting the position of the projection device 10 and adjusting the angle of the optical axis AX1 of the projection device 10. The mechanism unit 12 includes, for example, two axes XY moving in a direction perpendicular to the optical axis AX1 of the projection device 10 (or the light source unit 11), one axis Z moving in the direction of the optical axis AX1, and an XZ plane. And two axes rotating in the YZ plane. The mechanism unit 12 is configured by, for example, a servo mechanism that moves the entire light source unit 11 in five axes based on a control signal from the information processing device 50. When the mechanism unit 12 is configured by a servo mechanism, the user can set the position and the attitude of the light source unit 11 with high accuracy by teaching the position and the attitude of the light source unit 11 to the servo mechanism. . Further, in this case, it becomes easy to incorporate the transparent base material measuring device 1 into a production line. Note that the mechanism section 12 may be configured by, for example, a manual slider.

  FIG. 6 illustrates a configuration example of the light source unit 11. The light source unit 11 is configured to correct astigmatism, adjust the position of the virtual image Iv, and adjust the angle of the optical axis AX1 of the projection device 10. The light source unit 11 includes, for example, a light source 111, a pinhole mask 112, a mechanism unit 113, cylindrical lenses 114 and 115, plano-convex lenses 116 and 117, and a mechanism unit 118. The light source 111 and the pinhole mask 112 correspond to a specific example of the “point light source” of the present invention. The cylindrical lenses 114 and 115 correspond to a specific example of the “astigmatism correction optical system” of the present invention. The plano-convex lenses 116 and 117 correspond to specific examples of the “projection optical system” and the “telecentric optical system” of the present invention. The mechanism units 113 and 118 are configured to be able to adjust the angle (light ray angle) of the optical axis AX1 of the projection device 10 (or the light source unit 11), and are also configured to be able to adjust the position of the virtual image Iv. The mechanism units 113 and 118 correspond to a specific example of the “second mechanism unit” of the present invention.

  The light source 111 is, for example, a light-emitting diode that emits incoherent light, and emits light having a wavelength in the visible region. The light emitting diode is, for example, a white light emitting diode. The light source 111 uniformly illuminates the pinhole 112A of the pinhole mask 112, for example. The pinhole mask 112 is provided with a pinhole 112A at a predetermined position in a sheet-like light shielding member. The pinhole 112A adjusts the divergence angle of the light emitted from the light source 111. The light source 111 emits the point-like projection light L to the outside of the optical unit 11 via the pinhole mask 112.

  In the light source unit 11, for example, as shown in FIG. 7, a slit mask 121 may be provided instead of the pinhole mask 112. The light source 111 and the slit mask 121 correspond to a specific example of the “line light source” of the invention. In this case, the light source 111 uniformly illuminates the slit 121A of the slit mask 121, for example. The slit mask 121 is provided with a slit 121A at a predetermined position in a sheet-shaped light shielding member. The slit 121A adjusts the divergence angle of the light emitted from the light source 111. The light source 111 emits linear projection light L to the outside of the optical unit 11 via the slit mask 121.

FIG. 8 illustrates an example of the intensity distribution of two images that are close to each other. The opening width Dp of the pinhole 112A or the opening width Ds of the slit 121A preferably satisfies the following expressions (1) and (2). When the opening width Dp of the pinhole 112A or the opening width Ds of the slit 121A satisfies the following expression (1), the angular resolution of the camera 21 (described later) can be set to the target angular resolution δ. .
Dx ≦ 2fδ (1)
Dx: width of the image of the pinhole 112A or the slit 121A on the captured image (image data 52C) f: focal length of the camera 21 (described later): target angular resolution

  The cylindrical lenses 114 and 115 collect light emitted from the light source 111, respectively. Both the cylindrical lenses 114 and 115 are arranged so that the convex surface is on the light emission side. The cylindrical lenses 114 and 115 are arranged so that a direction having a lens effect in the cylindrical lens 114 and a direction having a lens effect in the cylindrical lens 115 intersect at an intersection angle α (0 ° <α <180 °). . At least one of the cylindrical lenses 114 and 115 is rotatably supported around an axis parallel to the optical axis BX1 as a rotation axis. The optical axis BX1 is the optical axis of the light from the light source 111 that has passed through the pinhole 112A or the slit 121A. The cylindrical lenses 114 and 115 change the beam shape of the light incident on the cylindrical lenses 114 and 115 according to the change of the intersection angle α. That is, the cylindrical lenses 114 and 115 change the astigmatism of the light incident on the cylindrical lenses 114 and 115 according to the change of the intersection angle α.

  The plano-convex lenses 116 and 117 project the light transmitted through the cylindrical lenses 114 and 115 onto the subject 100 as projection light L. The plano-convex lens 116 is arranged such that the convex surface is on the light emission side. The plano-convex lens 117 is arranged so that the convex surface is on the light incident side. The plano-convex lenses 116 and 117 are object-side telecentric optical systems having the light source 111 as an object.

  The mechanism section 113 is for moving the pinhole mask 112 or the slit mask 121 and the cylindrical lenses 114 and 115 together. The mechanism unit 113 has, for example, a total of three axes of two axes of XY moving in a direction perpendicular to the optical axis BX1 and one axis of Z moving in the direction of the optical axis BX1. The mechanism unit 113 is configured by, for example, a servo mechanism that moves the pinhole mask 112 or the slit mask 121 and the cylindrical lenses 114 and 115 together on three axes based on a control signal from the information processing device 50. . When the mechanism unit 113 is configured by a servo mechanism, the user can elevate the position of the pinhole mask 112 or the slit mask 121 and the position of the cylindrical lenses 114 and 115 by teaching the position information to the servo mechanism. Can be set to accuracy. Further, in this case, it becomes easy to incorporate the transparent base material measuring device 1 into a production line. Note that the mechanism section 113 may be configured with, for example, a manual slider.

  FIG. 9 illustrates an example of displacement of a light beam when the pinhole 112A or the slit 121A is moved by the mechanism unit 113 in a direction perpendicular to the optical axis BX1. It is assumed that the plano-convex lenses 116 and 117 are telecentric optical systems, and that the rear focal point (P in the figure) of the telecentric optical system is arranged on the subject 100. At this time, when the pinhole 112A or the slit 121A is moved in the direction perpendicular to the optical axis BX1 by the mechanism unit 113, the position where the light beam and the subject 100 intersect does not change, and the light beam is transmitted to the subject 100. Only the angle of incidence changes. Therefore, the mechanism unit 113 is useful for fine adjustment of the projection position of the virtual image Iv in relation to the mechanism unit 12.

The mechanism 113 is also for rotating the cylindrical lenses 114 and 115. The mechanism unit 113 further has, for example, one axis that rotates in the XY plane, in addition to the three axes described above. Thereby, the mechanism unit 113 can adjust the gap D1, the gap D2, the gap D3, and the intersection angle α. When the mechanism unit 113 is formed of a servo mechanism, the user sets the position and orientation of the cylindrical lenses 114 and 115 with high accuracy by teaching the position and orientation of the cylindrical lenses 114 and 115 to the servo mechanism. can do. Further, in this case, it becomes easy to incorporate the transparent base material measuring device 1 into a production line. Note that the mechanism section 113 may be configured with, for example, a manual slider.
D1: a gap between the pinhole mask 112 or the slit mask 121 and the cylindrical lens 114 D2: a gap between the cylindrical lens 114 and the cylindrical lens 115 D3: a gap between the cylindrical lens 115 and the plano-convex lens 116

  The mechanism section 118 is for moving the plano-convex lenses 116 and 117. The mechanism section 118 has, for example, one Z axis that moves in the optical axis BX1 direction. Thereby, the mechanism section 118 can adjust the gap D3. When the mechanism section 118 is configured by a servo mechanism, the user can set the positions of the plano-convex lenses 116 and 117 with high accuracy by teaching the positions of the plano-convex lenses 116 and 117 to the servo mechanism. . Further, in this case, it becomes easy to incorporate the transparent base material measuring device 1 into a production line. Note that the mechanism section 118 may be configured by, for example, a manual slider.

  The mechanism units 113 and 118 adjust the position of the virtual image Iv by adjusting the gap D1, the gap D2, and the gap D3. Thereby, the mechanical units 113 and 118 can correct the astigmatism of the virtual image Iv and form the virtual image Iv up to the diffraction limit.

(Imaging device 20)
The imaging device 20 captures a virtual image Iv created by the reflected light Lr of the one or more projection lights L emitted from the projection device 10 on the subject 100. The imaging device 20 includes a camera 21 and a mechanism unit 22.

  The camera 21 receives the projection light L emitted from the light source unit 11 and reflected by the subject 100, and generates image data 52C (described later). The camera 21 outputs the generated image data 52C to the information processing device 50. The camera 21 has, for example, an objective lens and an image sensor. The objective lens collects the projection light L emitted from the light source unit 11 and reflected by the subject 100. The image sensor receives the light condensed by the objective lens on a light receiving surface, and generates image data 52C. The image sensor is, for example, a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. Preferably, the objective lens and the image sensor have a higher angular resolution than the human eye's angular resolution (e.g., 1 ').

FIG. 10 is a diagram for explaining sampling in the image sensor of the camera 21. The numerical aperture NA of the camera 21 satisfies the following equation (2). In order to restore an image discretely acquired by the sampling theorem into a continuous image, the size of the diffraction-limited image (1.22λ / NA) on the image sensor of the camera 21 depends on the number of pixels in the image sensor of the camera 21. It is necessary that the pitch be twice or more the pitch Pp. The following equation (2) can be used to express the condition under which the image obtained discretely by the sampling theorem can be restored to a continuous image.
1.22λ / NA ≧ 2Pp (2)
λ: wavelength Pp of the projection device 10 (or light source 111): pixel pitch in the image sensor of the camera 21

  The information processing device 50 derives characteristics (for example, optical characteristics such as a double image, distortion, and blur) of the subject 100 based on the image data 52C obtained by imaging with the camera 21. The information processing device 50 includes, for example, a control unit 51, a storage unit 52, a communication unit 53, and an input unit 54, as illustrated in FIG.

  The communication unit 53 communicates with the projection device 10 and also communicates with the imaging device 20. The input unit 54 receives an input from a user. The input unit 54 accepts information input from the user, for example, according to an instruction from the control unit 51 loaded with the measurement program 52A. The input unit 54 includes, for example, a keyboard, a mouse, or a touch panel.

  The storage unit 52 can store various programs and various data files. The storage unit 52 stores a measurement program 52A. The storage unit 52 can further store various data generated by executing the measurement program 52A. Such data includes, for example, teaching data 52B and a plurality of image data 52C. The storage unit 52 is configured by, for example, a nonvolatile memory, and is configured by, for example, an electrically erasable programmable read-only memory (EEPROM), a flash memory, a resistance change type memory, or the like.

  The measurement program 52A is for causing the processor (control unit 51) to execute a series of procedures for deriving characteristics (for example, optical characteristics such as a double image, distortion, and blur) of the subject 100. The measurement program 52A includes a teaching data acquisition procedure and a measurement procedure. In the following, the teaching data acquisition procedure and the measurement procedure will be described separately. The teaching data 52B includes, for example, teaching data set for the mechanical units 22, 113, and 118. Each image data 52C is image data obtained by the camera 21. The image data 52C includes an image of the target unit 40 seen through the subject 100. Among the plurality of image data 52C, some of the image data 52C include an image of the target unit 40 seen through the subject 100 and an image of the projection light L emitted from the light source unit 11 and reflected by the subject 100. Are included in the image.

  The control unit 51 reads the measurement program 52A from the storage unit 52 based on, for example, an instruction from a user, and executes the read content. The control unit 51 executes a teaching data acquisition procedure and a measurement procedure included in the measurement program 52A.

(Acquisition of teaching data)
First, the acquisition of teaching data will be described. FIG. 12 illustrates an example of a teaching data acquisition procedure. The user installs the master 100M manufactured as designed on the table 30 as the subject 100 (step S101, FIG. 13). After that, the user instructs the control unit 51 via the input unit 54 to acquire teaching data. Then, the control unit 51 reads the measurement program 52A from the storage unit 52, and executes a teaching data acquisition procedure included in the measurement program 52A.

  Specifically, first, the user adjusts the optical axis of the camera 21 (Step S102). The user moves the camera 21 to one viewpoint (for example, viewpoint Ch1) among a plurality of viewpoints (for example, viewpoints Ch1 to Ch5). At this time, at the viewpoint (for example, the viewpoint Ch1), the user sets a predetermined region (specifically, the entire region where the virtual image Iv can be displayed) of the target unit 40 seen over the subject 100 in the imaging region of the camera 21. The position of the camera 21 is finely adjusted so as to enter. When the fine adjustment of the position of the camera 21 is completed, the user instructs the control unit 51 via the input unit 54 to acquire teaching data. Then, the control unit 51 acquires the position information of the mechanism unit 22 at that time from the mechanism unit 22 and stores it in the storage unit 52 as the teaching data 52B (step S103).

  When performing the operation of acquiring the teaching data 52B from another viewpoint, the user executes Step S102 again (Step S104; Y). In other words, the user sequentially moves the camera 21 to another viewpoint (for example, viewpoints Ch2 to Ch5) in the same manner as described above, and every time the fine adjustment of the position of the camera 21 is completed, via the input unit 54, The control unit 51 is instructed to acquire teaching data. Then, each time the control unit 51 receives the instruction, the control unit 51 acquires the position information of the mechanism unit 22 at that time from the mechanism unit 22 and stores the acquired position information in the storage unit 52 as the teaching data 52B.

  When the user has completed the operation of acquiring the teaching data 52B at all viewpoints, the user designates one viewpoint (for example, viewpoint Ch1) and one measurement point (for example, measurement point E), and then specifies the light source unit 11B. The optical axis is adjusted (step S105). First, the user instructs the control unit 51 via the input unit 54 to set one viewpoint (for example, viewpoint Ch1) and output the projection light L. Then, the control unit 51 causes the camera 21 to read the teaching data 52B corresponding to the set viewpoint (for example, the viewpoint Ch1) from the teaching data 52B stored in the storage unit 52, and to read the read teaching data 52B. It outputs to the mechanism section 22 as a control signal. The mechanism unit 22 sets the camera 21 at a position based on the control signal input from the control unit 51. Thereafter, the control unit 51 causes the light source 111 to output the projection light L (FIG. 14). At this time, the user finely adjusts the position and orientation of the light source unit 11 while the projection light L is being output from the light source 111, and places the virtual image Iv on the specified measurement point (for example, the measurement point E). Move. When the fine adjustment of the position and orientation of the light source unit 11 is completed, the user instructs the control unit 51 via the input unit 54 to acquire the teaching data 52B. Then, the control unit 51 acquires the position information and the posture information of the mechanism units 12, 113, 118 at that time from the mechanism units 12, 113, 118, and stores the acquired information as the teaching data 52B in the storage unit 52 (step S106).

  When performing the work of acquiring the teaching data 52B at another measurement point, the user executes Step S105 again (Step S107; Y). The user similarly fine-adjusts the position and orientation of the light source unit 11 to move the virtual image Iv sequentially to other measurement points (for example, the measurement points A to D) via the input unit 54. Then, the control unit 51 is instructed to acquire the teaching data 52B. Then, every time the control unit 51 receives the instruction, the control unit 51 acquires the position information and the posture information of the mechanism unit 12, 113, 118 at that time from the mechanism unit 12, 113, 118, and stores it in the storage unit 52 as the teaching data 52B. Remember.

  When the user acquires the teaching data 52B at all the measurement points (for example, the measurement points A to E) at the set viewpoint (for example, the viewpoint Ch1), the user sets another viewpoint (for example, the viewpoint Ch2 to Ch5). Then, step S105 is executed again (step S107; N, step S108; Y). Each time the user sets a viewpoint (for example, viewpoints Ch2 to Ch5), the position and orientation of the light source unit 11 are finely adjusted, and a virtual image Iv is sequentially placed on each measurement point (for example, measurement points A to E). Every time it is moved, the control unit 51 is instructed via the input unit 54 to acquire the teaching data 52B. Then, every time the control unit 51 receives the instruction, the control unit 51 acquires the position information and the posture information of the mechanism unit 12, 113, 118 at that time from the mechanism unit 12, 113, 118, and stores it in the storage unit 52 as the teaching data 52B. Remember. In this way, the control unit 51 stores the teaching data 52B acquired for each viewpoint and each measurement point in the storage unit 52.

  Note that the information processing device 50 automatically adjusts the positions and orientations of the mechanical units 20, 12, 113, and 118 based on image data 52C obtained from the camera 21 instead of manually as described above. You may do so. Further, each time the information processing device 50 acquires the teaching data 52B from one viewpoint, the information processing device 50 may acquire the teaching data 52B at each measurement point.

(measurement)
Next, measurement will be described. FIG. 15 illustrates an example of a procedure for measuring the optical characteristics of the subject 100T. The user installs, as the subject 100, the subject 100T whose optical characteristics are to be obtained on the table 30 (step S201, FIG. 16). Thereafter, the user instructs the control unit 51 via the input unit 54 to execute the measurement of the optical characteristics. Then, the control unit 51 reads the measurement program 52A and the teaching data 52B from the storage unit 52, and executes the measurement procedure included in the measurement program 52A based on the teaching data 52B.

  Specifically, first, the control unit 51 selects one viewpoint (for example, Ch1) and one measurement point (for example, measurement point E) (Steps S202 and S203). Next, the control unit 51 outputs the teaching data 52B of the selected viewpoint (for example, Ch1) to the mechanism unit 22 as a control signal. Then, the mechanism unit 22 moves the camera 21 to the selected viewpoint (for example, Ch1) (Step S204). The control unit 51 further outputs the teaching data 52B of the selected measurement point (for example, the measurement point E) to the mechanism units 12, 113, and 118 as a control signal. Then, the mechanical units 12, 113, and 118 move the light source unit 11 to the selected measurement point (for example, the measurement point E) (Step S205).

  Next, the control unit 51 instructs the light source unit 11 (light source 111) to output the projection light L. Then, the light source unit 11 (the light source 111) outputs the projection light L (Step S206, FIG. 16). The control unit 51 instructs the camera 21 to shoot while the light source unit 11 (the light source 111) is outputting the projection light L. Then, the camera 21 captures the virtual image Iv at the selected viewpoint (for example, the viewpoint Ch1) (Step S207). The camera 21 stores the photographed image (image data 52C) obtained by photographing in the storage unit 52 (Step S208). Thereafter, the control unit 51 derives optical characteristics from the image data 52C obtained by the camera 21 (Step S209), and stores the derived optical characteristics (Step S210).

  If the user desires to select another measurement point (step S211; Y), the user instructs the control unit 51 to execute step S102 again. If the user further desires to select another viewpoint (step S212; Y), the user instructs the control unit 51 to execute step S103 again. The control unit 51 acquires the image data 52C for each viewpoint and each measurement point, derives optical characteristics from the acquired image data 52C (Step S209), and stores the derived optical characteristics (Step S210). When the user instructs the control unit 51 to end the selection of another measurement point or another viewpoint, the control unit 51 ends the execution of the measurement.

  The information processing device 50 (control unit 51) can measure, for example, a double image, distortion, and blur as the optical characteristics of the subject 100T.

(Double image)
FIG. 16 illustrates an example of a double image measurement method. The information processing device 50 (control unit 51) derives a double image interval DId and a double image shift angle DIθ for each image data 52C obtained by measurement. It is assumed that the image data 52C obtained by the measurement includes, for example, a double image Id including a main image Im and a sub image Is, as illustrated in FIG. Here, the main image Im is a virtual image Iv created by the reflected light Lr of the projection light L on the main surface of the subject 100 (the surface on the light source unit 11 side). The sub-image Is is, for example, a virtual image Iv created by the reflected light Lr of the projection light L on the main surface of the subject 100 (the surface on the side of the target unit 40).

  At this time, based on the coordinates of the main image Im and the coordinates of the sub-image Is, the information processing device 50 (the control unit 51) determines the distance between the main image Im and the sub-image Is and the main image Im and the sub-image Is. Measure the slope of the connected line segment. More specifically, the information processing device 50 (the control unit 51) performs both based on the coordinates of the point where the light intensity of the main image Im peaks and the coordinates of the point where the light intensity of the sub image Is peaks. The distance between the points and the inclination of the line connecting both points are measured. After that, the information processing device 50 (the control unit 51) derives the double image interval DId based on the obtained distance, the optical magnification m of the camera 21, and the pixel pitch Pp. The information processing device 50 (the control unit 51) further derives a double image shift angle DIθ based on the obtained inclination of the line segment, the optical magnification m of the camera 21, and the pixel pitch Pp. The information processing device 50 (the control unit 51) digitizes the double image in this way.

  Note that the information processing device 50 (the control unit 51) may derive the composite image data 52D by overlapping a plurality of image data 52C obtained by measurement at each measurement point. Even in such a case, the information processing device 50 (the control unit 51) can calculate the double image interval DId and the double image shift angle DIθ from the derived composite image data 52D.

(distortion)
FIG. 17 illustrates an example of a distortion measurement method. The information processing device 50 (the control unit 51) derives composite image data 52D by superimposing a plurality of image data 52C obtained by measurement at each measurement point. In the obtained composite image data 52D, for example, as shown in FIG. 17, a plurality of virtual images Iv are displayed one by one for each of the measurement points A to E. The information processing device 50 (the control unit 51) performs measurement from the combined image data 52D for each virtual image Iv based on the coordinates of a measurement point (a reference point on which the virtual image Iv should be projected) and the coordinates of the virtual image Iv. The distance between the point and the virtual image Iv and the inclination of a line connecting the measurement point and the virtual image Iv are measured. More specifically, the information processing device 50 (the control unit 51) calculates the distance between the measurement point and the virtual image Iv based on the coordinates of the measurement point and the coordinates of a point where the light intensity of the virtual image Iv reaches a peak. The inclination of a line connecting the measurement point and the virtual image Iv is measured. After that, the information processing device 50 (the control unit 51) derives the distortion amount Sd based on the obtained distance, the optical magnification m of the camera 21, and the pixel pitch Pp. The information processing device 50 (the control unit 51) further calculates a deviation angle Sθ of the distortion based on the obtained inclination of the line segment, the optical magnification m of the camera 21, and the pixel pitch Pp. The information processing device 50 (the control unit 51) digitizes the distortion in this way.

  Note that the information processing device 50 (the control unit 51) also measures the distance between the measurement point and the virtual image Iv and the inclination of the line connecting the measurement point and the virtual image Iv for each of the obtained image data 52C. Good. Even in such a case, the information processing device 50 (the control unit 51) can calculate the distortion amount Sd and the distortion deviation angle Sθ from each image data 52C.

(Bokeh)
FIG. 18 illustrates an example of a method of measuring blur. The information processing device 50 (the control unit 51) derives the half width or 1 / e ² width in the light intensity distribution of the virtual image Iv (for example, the main image Im) as the blur amount for each image data 52C obtained by the measurement. . The information processing device 50 (the control unit 51) digitizes the blur in this way.

Note that the information processing device 50 (the control unit 51) may derive the composite image data 52D by overlapping a plurality of image data 52C obtained by measurement at each measurement point. Even in this case, the information processing device 50 (the control unit 51) calculates the half width or the 1 / e ² width in the light intensity distribution of the virtual image Iv (for example, the main image Im) from the derived composite image data 52D. be able to.

[effect]
Next, the effect of the transparent substrate measuring device 1 according to the present embodiment will be described.

  In order to efficiently develop a HUD system, it is possible to evaluate whether a transparent substrate satisfies the optical specifications required by the HUD system with a single transparent substrate even when prototypes of concave mirrors and HUD projection optical systems are not yet completed. desirable. It is also desirable that the transparent substrate can be evaluated alone in order to determine whether the cause of blurring or distortion is caused by the transparent substrate or not. However, at present, the measurement must be performed by combining the HUD optical unit, the concave mirror, and the transparent substrate, and it is difficult to determine the cause of the blur or the distortion.

  However, in the present embodiment, while a predetermined portion of the subject 100 is irradiated with the pinhole-shaped or slit-shaped projection light L, the virtual image created by the reflected light Lr of the projection light L on the subject 100 Iv is imaged. Further, the optical characteristics of the subject 100 are derived based on the image data 52C obtained by the imaging. Thus, for example, the optical characteristics of the subject 100 can be obtained without using a concave mirror or a HUD optical unit. As a result, for example, the cause of an optical defect such as a double image, blur, or distortion can be identified. In addition, it is possible to evaluate the variation in the shape of the subject 100 based on the obtained optical characteristics, and use it for improving the design of the subject 100.

  In the present embodiment, the light source unit 11 that emits the projection light L is moved by the mechanism unit 12. The mechanism section 12 is configured to be capable of adjusting the position of the projection device 10 and adjusting the angle of the optical axis of the projection device 10. Thus, when measuring the optical characteristics of the subject 100, the teaching data 52B obtained by positioning the light source unit 11 in advance can be provided to the mechanism unit 12. Therefore, when measuring the optical characteristics of the subject 100, the position and orientation of the light source unit 11 can be accurately controlled.

  In the present embodiment, the light source unit 11 can correct astigmatism, adjust the position of the virtual image Iv, and adjust the angle of the optical axis AX1 of the projection device 10. Specifically, the light source unit 11 is provided with a mechanism section 12 configured to be capable of adjusting the angle of the optical axis AX1 of the projection device 10 and the position of the virtual image Iv. Thereby, when the curvature of the subject 100 is in the range of, for example, 3 m to 10 m, the virtual image Iv can be formed up to the diffraction limit, so that when the position or the posture of the light source unit 11 is changed, It is possible to reduce the occurrence of optical defects such as double images, blur, distortion, and the like due to the position and posture of the eleventh embodiment. Therefore, when measuring the optical characteristics of the subject 100, for example, it is possible to isolate the cause of an optical defect such as a double image, blur, distortion, or the like.

  In the present embodiment, the light source unit 11 includes an optical system that emits pinhole light (the light source 111 and the pinhole mask 112) and a projection optical system (a pair of optical systems) disposed on the optical axis AX1 of the light source unit 11. , A plano-convex lens 117), an astigmatism correction optical system (2) disposed between an optical system (a light source 111 and a pinhole mask 112) for emitting pinhole light, and a projection optical system (a pair of plano-convex lenses 117). Two cylindrical lenses 114, 115) are provided. Thereby, it is possible to reduce the occurrence of optical defects such as double images, blurs, and distortions due to the light source unit 11. Therefore, when measuring the optical characteristics of the subject 100, for example, it is possible to isolate the cause of an optical defect such as a double image, blur, distortion, or the like.

  In the present embodiment, the projection optical system (the pair of plano-convex lenses 117) is a telecentric optical system. Accordingly, when the pinhole 112A or the slit 121A is moved in the direction perpendicular to the optical axis AX1 by the mechanism unit 113, the position where the light beam and the subject 100 intersect does not change, and the light beam is transmitted to the subject 100. Only the angle of incidence changes. As a result, fine adjustment of the position and orientation of the light source unit 11 can be easily performed. Therefore, when measuring the optical characteristics of the subject 100, for example, it is possible to isolate the cause of an optical defect such as a double image, blur, distortion, or the like.

  Further, in the present embodiment, the astigmatism correction optical system includes two cylindrical lenses 114 and 115 arranged so that directions having a lens effect intersect each other. Further, in the present embodiment, at least one of the two cylindrical lenses 114 and 115 is rotatably supported about an axis parallel to the optical axis AX1 of the projection device 10 as a rotation axis. As a result, astigmatism can be easily corrected, and when measuring the optical characteristics of the subject 100, for example, it is possible to isolate the cause of an optical defect such as a double image, blur, or distortion. it can.

  Further, in the present embodiment, the virtual image Iv can be formed up to the diffraction limit by correcting the astigmatism of the virtual image Iv. Thereby, the angular resolution of the camera 21 can be set to the target angular resolution δ. As a result, optical defects such as double images, blur, and distortion can be measured with high accuracy.

  In the present embodiment, the double image interval DId, the distortion amount Sd, and the blur amount of the virtual image Iv are derived as optical characteristics based on the image data 52C obtained by the camera 21. When measuring the double image interval DId, the distortion amount Sd, and the blur amount of the virtual image Iv, it is not necessary to use a separate device or separately measure them with a common device. As a result, optical defects such as double images, blur, and distortion can be measured at high speed.

<2. Modification>
Hereinafter, a modified example of the transparent substrate measuring device 1 of the above embodiment will be described. In the following, the same components as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment. In addition, components different from those in the above embodiment will be mainly described, and descriptions of components common to the above embodiment will be omitted as appropriate.

[Modification A]
In the above embodiment, the master 100M manufactured as designed may not be prepared as the subject 100 in some cases. In other words, when the prototype 100 is poorly formed and distortion cannot be suppressed, it is not suitable as the master 100M used for teaching measurement points. In this case, for example, as shown in FIG. 19, when the subject 100 different from the master 100M is set on the mounting table 30, the subject 100 is bent so that the subject 100 has a desired bending (curved surface). The supporting jig 31 to be supported may be provided on the table 30. The correction jig 31 only needs to be arranged so as to avoid the region through which the projection light L passes. Note that the subject 100 may be corrected by a method different from a correction method based on the weight of the subject 100 such as the correction jig 31.

[Modification B]
In the above embodiment, the projection device 10 sequentially irradiates the projection light L to a plurality of locations on the subject 100. However, for example, as illustrated in FIG. 20, when the projection device 10 includes a plurality of light source units 11, the projection device 10 simultaneously irradiates the projection light L to a plurality of locations on the subject 100. You may. In this case, the measurement time can be significantly reduced as compared with the above embodiment.

[Modification C]
In the above embodiment, the master 100M manufactured as designed may not be prepared as the subject 100 in some cases. In that case, using the subject 100T, the control unit 51 may acquire the teaching data 52B only at one of the plurality of measurement points to be measured. Then, with respect to the teaching data 52B at the remaining measurement points, a difference from the position of the first measurement point is calculated by CAD or simulator software calculation, and this difference is added to the teaching data 52B at the actually acquired measurement point. In addition, off-line teaching that sufficiently satisfies the measurement accuracy becomes possible.

  Of course, all points can be taught off-line. However, high accuracy cannot be expected especially in distortion measurement for measuring an absolute position shift. In CAD and simulation, the subject 100, the light source unit 11, and the camera 21 are merely arranged in a virtual space on software. In the virtual space on the software and the actual device, a positional deviation error occurs. For example, if the mounting angle of the subject 100 has a slight error, the optical axis reflected by the subject 100 is reflected at a reflection angle twice as large as the angle error of the subject 100. This causes a large irradiation position shift.

[Modification D]
The present invention not only measures the double image, blur, and distortion for the HUD system, but also a normal transmission image, that is, a double image generated on a traffic signal or a road sign seen through the subject 100 by a vehicle driver, It can also be used for measuring distortion.

DESCRIPTION OF SYMBOLS 1 ... Transparent base material measuring device, 10 ... Projection device, 11 ... Light source unit, 12 ... Mechanical part, 20 ... Imaging device, 21 ... Camera, 22 ... Mechanical part, 30 ... Placement table, 31 ... Correcting jig, 40 ... Target part , 50 ... Information processing device, 51 ... Control unit, 52 ... Storage unit, 52A ... Measurement program, 52B ... Teaching data, 52C ... Image data, 52D ... Synthetic image data, 53 ... Communication unit, 54 ... Input unit, AX1 ... Optical axis, AX2: Optical axis, 100, 100T: Subject, 100A, 100B: Main surface, 100M: Master, 111: Light source, 112: Pinhole mask, 112A: Pinhole, 113: Mechanical part, 114, 115 ... Cylindrical lens, 116, 117: plano-convex lens, 118: mechanical unit, 121: slit mask, 121A: slit, 200: observer, 210: pupil, 22 ... retina, AX1, AX2 ... optical axis, D1, D2, D3 ... gap, DId ... double image interval, DIθ ... double image shift angle, Id ... double image, Im ... main image, Is ... sub image, Iv1, Iv2, Iv3: virtual image, L: projection light, L2, L3: reflected light, α: crossing angle.

Claims (14)

A projection device configured to be capable of irradiating point-like or linear projection light to one or a plurality of portions of the transparent substrate,
An imaging device for imaging a virtual image created by reflected light of the one or more projection lights emitted from the projection device on the transparent substrate,
An information processing device that derives characteristics of the transparent substrate based on image data obtained by imaging by the imaging device,
The projection device,
A light source unit that emits one or more projection lights,
And a first mechanism for moving the entire light source unit,
The light source unit,
A point light source having a pinhole or a line light source having a slit,
A telecentric projection optical system arranged on the optical axis of the projection device,
An astigmatism correction optical system disposed between the point light source or the line light source and the telecentric projection optical system,
A second mechanism for changing the angle of incidence of the projection light on the transparent substrate without changing the position where the projection light intersects with the transparent substrate. The second mechanism changes the incident angle of the projection light on the transparent substrate without changing the position where the projection light intersects with the transparent substrate by moving the pinhole or the slit. The transparent substrate measuring device according to claim 1. The transparent base material measuring device according to claim 2, wherein the astigmatism correction optical system includes two cylindrical lenses arranged so that directions having a lens effect intersect each other. The transparent substrate measuring device according to claim 3, wherein at least one of the two cylindrical lenses is rotatably supported around an axis parallel to an optical axis of the projection device as a rotation axis. The transparent substrate measurement according to any one of claims 2 to 4, wherein the first mechanism unit is configured to be capable of adjusting a position of the projection device and an angle of an optical axis of the projection device. apparatus. The first mechanism section includes two axes XY moving in a direction perpendicular to the optical axis of the projection device, one axis Z moving in the optical axis direction of the projection device, an XZ plane and a YZ plane. The transparent base material measuring apparatus according to claim 5, further comprising a mechanism for moving the entire light source unit with a total of five axes, that is, two axes rotating in the direction. The transparent substrate measuring device according to any one of claims 1 to 6, wherein a numerical aperture of the imaging device satisfies the following expression.
1.22λ / NA ≧ 2Pp
λ: wavelength of the projection device NA: numerical aperture of the imaging device Pp: pixel pitch of the imaging device The information processing device according to any one of claims 1 to 7, wherein the information processing device derives, as the characteristic, an optical characteristic including a double image interval, a distortion amount, and a blur amount of the virtual image based on the image data. The transparent substrate measuring device according to the above. The information processing device derives a double image interval of the virtual image based on a distance between a main image and a sub image included in the image data, an optical magnification of the imaging device, and a pixel pitch of the imaging device. The transparent substrate measuring device according to claim 8. The information processing device derives a distortion of the virtual image based on a distance between a main image and a reference point included in the image data, an optical magnification of the imaging device, and a pixel pitch of the imaging device. 9. The transparent substrate measuring device according to 8. The transparent substrate measuring device according to claim 8, wherein the information processing device derives a half width or a 1 / e ² width in a light intensity distribution of the virtual image included in the image data as the blur amount. The transparent base material measuring device according to any one of claims 1 to 11, wherein the projection device irradiates the projection light to a plurality of portions of the transparent substrate simultaneously or sequentially. While irradiating point-like or linear projection light from a light source unit to a predetermined portion of the transparent substrate, a virtual image created by the reflected light of the transparent substrate on the transparent substrate moves to a designated measurement point. As described above, without changing the position where the projection light intersects with the transparent substrate, by changing the angle of incidence of the projection light on the transparent substrate, adjusting the position and orientation of the light source unit. ,
Imaging the virtual image obtained after the completion of the adjustment;
Look including a deriving properties of the transparent substrate on the basis of image data obtained by imaging the virtual image,
The light source unit,
A point light source having a pinhole or a line light source having a slit,
A telecentric projection optical system arranged on the optical axis of the projection device,
An astigmatism correction optical system disposed between the point light source or the line light source and the telecentric projection optical system;
Has,
The transparent substrate measuring method, by moving the pinhole or the slit, without changing the position where the projection light and the transparent substrate intersect, changing the incident angle of the projection light to the transparent substrate A method for measuring a transparent substrate , further comprising : Performing the adjustment on a plurality of locations on the transparent substrate;
On the transparent substrate, sequentially at each location where the adjustment was performed, while irradiating the projection light from the light source unit, a virtual image created by the reflected light at each location where the adjustment was performed, of the projection light. Imaging,
The transparent substrate measuring method according to claim 13 , further comprising: deriving characteristics of the transparent substrate based on a plurality of pieces of image data obtained by capturing a virtual image.

Images