JP2019190919A - Shape measuring device, shape measuring method, shape measuring program, computer readable recording medium, and recorded apparatus - Google Patents

Abstract

To provide a shape measuring device with which it is possible to extend the depth in a direction Z.SOLUTION: The shape measuring device comprises: an image generation unit for respectively generating first three-dimensional shape data generated in a first depth measurement range by a three-dimensional shape data generation unit and second three-dimensional shape data generated by the three-dimensional shape data generation unit in a second depth measurement range shifted, by an optical axis direction drive unit 146 so that it partly overlaps the first depth measurement range in the same measurement range as for the first three-dimensional shape data; and a synthesized three-dimensional shape data generation unit 216 for synthesizing the first and the second three-dimensional shape data, the synthesized three-dimensional shape data generation unit 216 determining whether or not to adopt the pixels of either or both of the first and the second three-dimensional shape data on the basis of a reliability index that indicates the reliability of whether or not the height information of pixels within a measurement range, where the first and the second depth measurement ranges overlap, in which the first and the second three-dimensional shape data correspond, is close to a true value,.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shape measuring device, a shape measuring method, a shape measuring program, a computer-readable recording medium, and a recorded device.

  A shape measuring device that measures the shape of the surface of a measurement object (work) by a pattern projection method using the principle of triangulation is known (for example, Patent Document 1). With such a shape measuring apparatus, it is possible to measure the three-dimensional shape of the workpiece in a short time.

  However, since the depth measurement range is in a trade-off relationship with the visual field and measurement resolution, there is a problem that the depth measurement range is limited when attempting to acquire solid shape data with a sufficient visual field and resolution.

  Patent Document 1 shows an example of a conventional shape measuring apparatus. This shape measuring apparatus discloses a technique for synthesizing a plurality of obtained measurement data by changing the depth measurement range. Thereby, the depth measurement range in the height direction can be expanded by combining a plurality of measurement data that cannot be measured at one time.

  However, in this method, there is a problem that it is not possible to intuitively know how many times a measurement should be performed at which position in order to obtain a measurement result within a depth measurement range required by the user. For this reason, the three-dimensional shape data of the workpiece acquired in advance is displayed, and the range that can be measured by one measurement is displayed on the displayed three-dimensional shape data. However, in the method of Patent Document 1, it is necessary to acquire the solid shape data of the workpiece in advance, and the processing time may be long. There is also a problem that the user takes time.

Japanese Unexamined Patent Publication No. 2014-092490

  The present invention has been made in view of such conventional problems. An object of the present invention is to provide a shape measuring device, a measuring and measuring method, a shape measuring program, and a computer-readable recording medium capable of extending the depth in the Z direction.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, according to the shape measuring apparatus according to the first aspect of the present invention, a stage for placing a measurement object, and a pattern for the measurement object placed on the stage A light projecting unit for projecting light, a light receiving unit having a predetermined depth of focus for receiving pattern light irradiated from the light projecting unit and reflected from the measurement object, and the stage with respect to the light receiving unit. An optical axis direction drive unit that shifts a depth measurement range that is a measurable height range determined by the depth of focus by relatively moving in the optical axis direction of the light receiving unit, and a plurality of patterns received by the light receiving unit An image generation unit that generates, based on light, a height image of a measurement object within the depth measurement range for each pixel existing in a stage plane orthogonal to the optical axis direction of the light receiving unit, In the depth measurement range, The first height image generated by the shape data generation unit and the first depth image are shifted so as to partially overlap the first depth measurement range in the optical axis direction driving unit within the same stage plane as the first height image. In the second depth measurement range, an image generation unit that generates a second height image generated by the three-dimensional shape data generation unit, and a synthesis that combines the first height image and the second height image A three-dimensional shape data generation unit having pixels in a stage plane corresponding to the first height image and the second height image in a range where the first depth measurement range and the second depth measurement range overlap. Based on a reliability index indicating whether or not the height information is close to a true value, a composition obtained by determining whether or not one or both of the first height image and the second height image are adopted And a three-dimensional shape data generation unit. With the above configuration, when connecting a plurality of height images in the depth direction, it is possible to obtain a composite height image in which the reliability of the height information in the overlapping region is improved.

  Moreover, according to the shape measuring apparatus which concerns on the 2nd side surface of this invention, in addition to said structure, the said synthetic height image generation part is the range where said 1st depth measurement range and 2nd depth measurement range overlap. The pixels of the first height image are valid and the pixels of the second height image are invalid for the pixels within the orthogonal measurement range corresponding to the first height image and the second height image. The height information of the pixel of the first height image is the pixel value of the pixel, the pixel of the first height image is invalid, and the pixel of the second height image is valid Furthermore, the height information of the pixel of the second height image can be used as the pixel value of the pixel. With the above-described configuration, when connecting a plurality of height images in the depth direction, a combined height image obtained by interpolating missing pixels can be obtained for height information in overlapping regions.

  Furthermore, according to the shape measuring apparatus according to the third aspect of the present invention, in addition to any one of the configurations described above, the composite height image generation unit is configured to perform predetermined processing using the first height image and the second height image. It can comprise so that the pixel with the above difference may be extracted.

  Furthermore, according to the shape measuring apparatus according to the fourth aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generation unit is configured to provide the reliability index for the pixel extracted as the difference. Can be configured to employ a high pixel value.

  Furthermore, according to the shape measuring apparatus according to the fifth aspect of the present invention, in addition to any of the above configurations, the composite height image generation unit performs weighting based on the reliability index, The first height image and the second height image can be combined.

  Furthermore, according to the shape measuring apparatus according to the sixth aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generation unit determines the reliability index from the focal position of the light receiving unit. Distance.

  Furthermore, according to the shape measurement apparatus according to the seventh aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generation unit includes the first depth measurement range and the second depth measurement range. In the overlapping range, for the pixels in the orthogonal measurement range corresponding to the first height image and the second height image, the one having the shorter distance from the focal position of the light receiving unit is adopted, or the weighting is increased. It can be configured as follows.

  Furthermore, according to the shape measuring apparatus according to the eighth aspect of the present invention, in addition to any of the above-described configurations, the composite height image generation unit uses the height image as the reliability index of a certain pixel. The contrast between the corresponding pixel and the pixels located around the pixel in the pattern image in which the pattern light is received by the light receiving unit, which is the source of generating

  Furthermore, according to the shape measuring apparatus according to the ninth aspect of the present invention, in addition to any one of the configurations described above, the composite height image generating unit is configured to perform the first height based on the reliability index. Either the image or the pixel value of the second height image can be adopted.

  Furthermore, according to the shape measuring apparatus according to the tenth aspect of the present invention, in addition to any of the above-described configurations, the composite height image generation unit is based on a weighted average using the reliability index. It can be configured to calculate height information.

  Furthermore, according to the shape measuring apparatus according to the eleventh aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generation unit is configured based on the first height image and the second height image. When the extracted difference is equal to or greater than a predetermined value, based on the reliability index, adopts either the height information of the first height image or the second height image, and if the difference is equal to or smaller than the predetermined value May be configured to calculate height information from pixel values of the first height image or the second height image based on a weighted average using the reliability index.

  Furthermore, according to the shape measuring apparatus according to the twelfth aspect of the present invention, in addition to any one of the above-described configurations, the light projecting unit is configured to apply a first measurement object to the measurement object placed on the stage. A first light projecting unit that irradiates the first pattern light from the direction, and a second light projecting unit that irradiates the second pattern light from the second direction to the measurement object placed on the stage, The light receiving unit receives the first pattern light irradiated from the first light projecting unit and reflected from the measurement object, outputs first light reception data, and is irradiated from the second light projecting unit to measure The second pattern light reflected from the object is received and second received light data is output, and the composite height image generating unit is configured to generate a first measurement object based on the first received light data received by the light receiving unit. A height image is generated, and based on the second received light data received by the light receiving unit, A second height image of the object is generated, and a height range in which pattern light can be irradiated from the first light projecting unit and the second light projecting unit within the orthogonal measurement range of the light receiving unit on the stage is measured. The first height image having the height data within the measured height range and the second height image are combined to generate a combined height image.

  Furthermore, according to the shape measuring apparatus according to the thirteenth aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generating unit is configured such that the first height image is the first light projection. The second image is also obtained by irradiating the pattern light from the first light projecting unit and the second light projecting unit. Can be configured to be a height image.

  Furthermore, according to the shape measuring apparatus of the fourteenth aspect of the present invention, in addition to any one of the above-described configurations, the composite height image generating unit is configured such that the first height image is the first light projection. In the case of the height image obtained by irradiating the pattern light from either the first light projecting unit or the second light projecting unit, the second image is also obtained from either the first light projecting unit or the second light projecting unit. It can be configured to be a height image obtained by irradiation with pattern light.

  Furthermore, according to the shape measuring apparatus according to the fifteenth aspect of the present invention, in addition to any one of the above-described configurations, a scale value indicating a relative distance between the stage and the optical axis direction of the light receiving unit. The combined height image generation unit stores the scale value of the scale unit when each height image is generated, and each height is combined when the height image is combined. The pixel values of the image can be combined by being offset based on the scale value.

  Furthermore, according to the shape measuring apparatus according to the sixteenth aspect of the present invention, in addition to any of the above-described configurations, an illumination light output unit that emits illumination light for capturing an optical image of the measurement object And a texture image storage unit for storing a texture image obtained by optically imaging the measurement object. With the above configuration, the optical image of the measurement object illuminated by the illumination light output unit provided separately from the light projecting unit can be stored as a texture image.

  Furthermore, according to the shape measuring method according to the seventeenth aspect of the present invention, there is provided a shape measuring method for measuring a shape by generating a height image including height information of an object to be measured. The measurement object to be measured is placed on a stage, the pattern light is irradiated from the light projecting unit to the measurement object, and the pattern light reflected by the measurement object can be measured by the light receiving unit. The depth measurement range that is a range is defined as a first depth measurement range, and is received within the orthogonal measurement range orthogonal to the optical axis direction of the light receiving unit based on a plurality of pattern lights received by the light receiving unit and received by the light receiving unit. Generating a first height image of a measurement object within the first depth measurement range for each pixel to be performed by a height image generation unit, and an optical axis of the light reception unit with respect to the light reception unit. By moving relative to the direction, from the depth measurement range A step of shifting to the second depth measurement range that partially overlaps the first depth measurement range, and irradiating the measurement object with pattern light from the light projecting unit, and pattern light reflected by the measurement object , For each pixel existing in an orthogonal measurement range orthogonal to the optical axis direction of the light receiving unit based on a plurality of pattern lights received by the light receiving unit in the second depth measurement range and received by the light receiving unit. In the step of generating the second height image of the measurement object within the two depth measurement range by the height image generation unit, and in the range where the first depth measurement range and the second depth measurement range overlap, the first height Based on a reliability index indicating whether or not the height information of the pixels in the orthogonal measurement range corresponding to the height image and the second height image is close to the true value, the first height image and Deciding whether to accept one or both pixels of the second height image, It may include a step of synthetic single height image and a second height image in Synthesis height image generating unit. Thereby, when connecting a plurality of height images in the depth direction, it is possible to obtain a composite height image in which the reliability of the height information in the overlapping region is improved.

  Furthermore, according to the shape measurement program according to the eighteenth aspect of the present invention, there is provided a shape measurement program for measuring a shape by generating a height image including height information of the measurement object, With the measurement target object placed on the stage, pattern light reflected from the measurement target object can be measured by the light receiving unit. An orthogonal measurement range orthogonal to the optical axis direction of the light receiving unit based on a plurality of pattern lights received by the light receiving unit and received by the light receiving unit as a first depth measurement range A function for generating a first height image of a measurement object within the first depth measurement range by a height image generation unit for each pixel existing in the first depth measurement range, and the stage with respect to the light reception unit. Relative movement in the optical axis direction A function of shifting from the depth measurement range to a second depth measurement range that partially overlaps the first depth measurement range, and irradiating the measurement object with pattern light from the light projecting unit; The pattern light reflected by the light receiving unit is received by the light receiving unit in the second depth measurement range, and is present in the orthogonal measurement range orthogonal to the optical axis direction of the light receiving unit based on the plurality of pattern lights received by the light receiving unit. A function of generating a second height image of the measurement object in the second depth measurement range by the height image generation unit for each pixel to be overlapped with the first depth measurement range and the second depth measurement range In the range, based on a reliability index indicating whether or not the height information of the pixels in the orthogonal measurement range corresponding to the first height image and the second height image is close to a true value, One or both of the first height image and the second height image Of determining the adoption, it is possible to realize the function of combining the first height image and a second height image in Synthesis height image generation unit to the computer. With the above configuration, when connecting a plurality of height images in the depth direction, it is possible to obtain a composite height image in which the reliability of the height information in the overlapping region is improved.

  A computer-readable recording medium or a recorded device according to the nineteenth aspect stores the program. CD-ROM, CD-R, CD-RW, flexible disk, magnetic tape, MO, DVD-ROM, DVD-RAM, DVD-R, DVD + R, DVD-RW, DVD + RW, Blu-ray (registered) Trademark), HD DVD (AOD), and other magnetic disks, optical disks, magneto-optical disks, semiconductor memories, and other media that can store programs. The program includes a program distributed in a download manner through a network line such as the Internet, in addition to a program stored and distributed in the recording medium. Further, the recording medium includes a device capable of recording the program, for example, a general purpose or dedicated device in which the program is implemented in a state where the program can be executed in the form of software, firmware, or the like. Furthermore, each process and function included in the program may be executed by computer-executable program software, or each part of the process or function may be executed by hardware such as a predetermined gate array (FPGA, ASIC, DSP), or a program. You may implement | achieve in the format with which the partial hardware module which implement | achieves some elements of software and hardware is mixed.

It is a block diagram which shows the measuring microscope apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the measuring microscope apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the measurement microscope apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the imaging means of FIG. It is an image figure which shows an example of GUI of a measurement microscope apparatus operation program. It is a schematic diagram which shows the optical system of a telecentric double side light projection. It is a schematic diagram which shows the relationship between right-and-left light projection and a measurement range. It is a side view which shows the state which connected the upper head and the lower head. It is the schematic which shows the internal structure of a lower head. It is a flowchart which shows the procedure of a shape measurement. It is a flowchart which shows the procedure which acquires a texture image. It is a flowchart which shows the procedure which performs a measurement setting. FIG. 13A is a schematic diagram showing a configuration in which the Z stage is arranged below the stage and the scale portion is separated, and FIG. 13B shows a configuration in which the scale unit is arranged below the stage and the Z stage is arranged on the back surface. It is a schematic diagram. 14A is a schematic diagram showing a measurement range at height A, FIG. 14B at height B, and FIG. 14C at height C. FIG. 15A to 15C are optical images obtained at the respective heights shown in FIGS. 14A, 14B, and 14C, and FIGS. 15D to 15F are fringes obtained at the respective heights shown in FIGS. 14A, 14B, and 14C. It is an image figure which shows an image, respectively. 16A is the height A of FIG. 14A, FIG. 16B is the height B of FIG. 14B, FIG. 16C is the measurement result obtained at the height C of FIG. 14C, and FIG. is there. FIG. 17A is an image diagram of a composite image in which data in the depth search range is not displayed, and FIG. 17B is an image diagram of a composite image in which data in the depth search range is displayed. FIG. 18A is an image diagram of a composite image in which data in the depth search range of another measurement object is not displayed, and FIG. 18B is an image diagram of a composite image in which data in the depth search range is displayed. It is an image figure which shows the state which can confirm a fringe image in the height position of the measuring object which exists in the depth search range out of the measurable height range. It is an image figure which shows the state which can confirm a fringe image in the height position which exists in the depth search range outside the measurable height range with respect to another measuring object. It is a graph which shows the relationship between the roughness of an image at the time of connection, and a pitch. It is a schematic diagram explaining the depth search range which determines a connection measurement range automatically. It is a schematic diagram which shows a mode that the acquired pixel is accumulated. It is a schematic diagram which shows the transition of a cumulative image. It is a flowchart which shows the procedure of automatic depth extension. FIG. 10 is a schematic diagram for explaining automatic depth extension according to the second embodiment. It is an image figure which shows the user interface screen of the full auto mode of a shape measurement program. It is an image figure which shows the example which performs measurement mode selection. It is an image figure which shows the example which performs depth extension mode selection. It is an image figure which shows the example which performs a measurement direction selection. It is an image figure which shows the example which performs measurement brightness setting. It is a flowchart which shows the procedure of manual depth expansion. 33A is an optical image A displaying a measurement object, FIG. 33B is an optical image B at a higher focal position than FIG. 33A, FIG. 33C is an optical image C at a higher focal position than FIG. 33B, and FIG. Height image D, FIG. 33E is the height image E in FIG. 33B, FIG. 33F is the height image F in FIG. 33C, and FIG. 33G is a composite height image G that is a combination of the height images in FIGS. 33D, 33E, and 33F. FIG. It is an image figure which shows the manual observation screen of 3D measurement screen. It is an image figure which shows the 3D preview screen which shows a height image. It is an image figure which shows a 3D measurement screen. It is an image figure which shows the 3D preview screen which shows the height image obtained in the height designation position of FIG. It is an image figure which shows the 3D preview screen which displays the synthetic | combination height image which synthesize | combined the height image of FIG. It is an image figure which shows the 3D preview screen which displays a height image and a composite height image as a list. It is an image figure which shows the 3D preview screen which displays the synthetic | combination height image which synthesize | combined the height image of FIG. It is an image figure which shows the 3D preview screen which looked at the height image of FIG. 40 from a different angle. It is an image figure which shows the example of a setting of a partial area | region. FIG. 43 is an image diagram showing an optical image of the measurement object in FIG. 42. 44A is a height image generated from the measurement object of FIG. 43 in the normal measurement mode, and FIG. 44B is an image diagram of the height image generated in the reflection / simmering light removal mode. 45A is an image diagram of a stripe image of a certain measurement object, FIG. 45B is a luminance profile of a metal part of the measurement object of FIG. 45A, FIG. 45C is a luminance profile of a hole part, and FIG. 45D is a luminance profile of a white resin part. is there. It is a flowchart which shows the procedure which produces | generates synthetic | combination solid shape data by adjusting a partial area | region measurement setting automatically. It is a side view which shows the state which set the some partial area | region to the measuring object. 48 is a table showing partial area measurement settings for each divided measurement area in FIG. 47.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following embodiments exemplify a shape measuring device, a shape measuring method, a shape measuring program, and a computer-readable recording medium for embodying the technical idea of the present invention. Does not specify a shape measuring apparatus, a shape measuring method, a shape measuring program, and a computer-readable recording medium as follows. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

  In this specification, the “texture image” is an observation image having texture information represented by an optical image. On the other hand, the “height image” is also called a distance image or the like, and is used to mean an image including height information. For example, an image in which height information is converted into luminance, chromaticity, and the like and displayed as a two-dimensional image, and an image in which height information is displayed in three dimensions as Z coordinate information can be given. A three-dimensional composite image in which a texture image is pasted as texture information on such a height image is also included in the height image. Further, in the present specification, the display form of the height image is not limited to the one displayed in a two-dimensional form, but includes the one displayed in a three-dimensional form. For example, it includes information displayed as a two-dimensional image by converting height information of the height image into luminance, and information displayed three-dimensionally as height information as Z coordinate information.

Further, in this specification, the “posture” where the measurement object is placed on the stage means the rotation angle of the measurement object. In addition, when the measurement object has a point-symmetric shape in a plan view like a cone, the same result can be obtained regardless of the rotation angle, and thus the posture need not be defined.
[Embodiment 1]

FIG. 1 is a block diagram showing the configuration of the shape measuring apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the shape measuring apparatus 500 includes an imaging unit 100, a control unit 200, a light source unit 300, a display unit 400, and an operation device 450. This configuration is an example, and each member and the functional blocks included in each member can be appropriately integrated or divided. For example, a light source unit may be included in the control means. The control means may be divided into a controller and a general-purpose computer.
(Imaging means 100)

The imaging unit 100 includes a light projecting unit 110, a light receiving unit 120, a measurement control unit 150, a stage 140, an optical axis direction driving unit 146, and a stage plane direction driving unit 148. The light projecting unit 110 is a member for irradiating the measurement target object WK placed on the stage 140 with pattern light. The light receiving unit 120 receives the pattern light irradiated from the light projecting unit 110 and reflected by the measurement target WK, and outputs light reception data. The measurement control unit 150 is a member for driving light projection of the light projecting unit 110 and light reception of the light receiving unit 120 and outputting light reception data of the light receiving unit 120. This imaging means measures the shape of the measuring object WK based on the pattern projection method.
[Embodiment 2]

  In the example of FIG. 1, an example in which a pattern projection system that projects measurement light for obtaining a height image and an illumination projection system that illuminates illumination light for capturing a texture image are provided separately. explained. However, the present invention is not limited to the configuration in which the light projecting system is provided individually, and the light projecting system may be shared. Such an example is shown in the block diagram of FIG. In the shape measuring apparatus 500B shown in this figure, the same members as those in FIG.

  The shape measuring apparatus 500B according to the second embodiment does not include an illumination light output unit and an observation illumination light source, as compared with the shape measuring apparatus 500 in FIG. In the shape measuring apparatus 500B, the light projecting unit 110 also serves as illumination light irradiation. For example, by irradiating all the patterns when the light projecting unit 110 projects a pattern as lighting, it is possible to irradiate the same light as the illumination light by using as a planar light source. If it is this structure, since an illumination light output part can be abbreviate | omitted, the advantage which can simplify the structure of a shape measuring apparatus is acquired.

  On the other hand, the stage 140 is a member for placing the measurement object WK. The optical axis direction drive unit 146 is a member for adjusting the focal position of the light receiving unit 120 by moving the stage 140 relative to the light receiving unit 120 in the optical axis direction. In this example, the optical axis direction drive unit 146 functions as a focus adjustment unit that drives the stage 140 side and adjusts the focal length. The optical axis direction drive unit 146 includes a stage drive unit that electrically drives the stage 140 and a stage operation unit that manually operates the stage 140. Details of these will be described later.

The stage plane direction driving unit 148 is a member for relatively moving the stage 140 in the stage plane direction orthogonal to the optical axis direction of the light receiving unit 120. The stage plane direction drive unit 148 is a drive unit that drives the stage 140 in the horizontal plane, and can adjust the visual field range. In the example of driving the stage 140 side, the stage plane direction driving unit 148 corresponds to the XY stage 141, while the optical axis direction driving unit 146 corresponds to the Z stage 142.
[Embodiment 3]

  However, in the present invention, the optical axis direction driving unit 146 is not limited to the movement on the stage 140 side, and the light projecting unit 110 and the light receiving unit 120 side may be moved. Such an example is shown in the block diagram of FIG. 3 as a shape measuring apparatus according to the third embodiment. Also in the shape measuring apparatus 500C shown in this figure, members similar to those in FIG. 1 and the like are denoted by the same reference numerals and detailed description thereof is omitted.

The shape measuring apparatus 500C according to the third embodiment fixes the height on the stage 140 side in the imaging unit 100C, while moving the light projecting unit 110 and the light receiving unit 120 side by the optical axis direction driving unit 146C. The optical axis direction driving unit 146C includes an imaging system operation unit 144C for manually operating an imaging system such as the light projecting unit 110 and the light receiving unit 120, and an imaging system driving unit 145C for electrically driving the imaging system. ing. Even with this configuration, the focal position can be adjusted similarly. Further, by making the height of the stage 140 constant, the height of placing the measurement object WK on the stage 140 can be maintained constant, so that an advantage that the work of placing the measurement object WK can be performed smoothly is obtained. . Note that both the stage side and the light projecting unit and the light receiving unit side may be movable. Thus, in the present specification, the focal position can be adjusted in the depth direction even when either or both of the stage side, the light projecting unit and the light receiving unit side are moved. Therefore, in this specification, when “the stage is moved relative to the light receiving part in the optical axis direction”, the stage side is moved, the light projecting part and the light receiving part side are moved, and both are moved. It is assumed that the mode to be performed is included.
(Control means 200)

The control means 200 includes a three-dimensional shape data generation unit 212, a three-dimensional image composition unit 213, a determination processing unit 214, a depth extension processing unit 215, a composition processing unit 216, a measurement setting automatic adjustment unit 217, and a three-dimensional shape. The data connection part 219, the memory | storage part 240, and the setting part 250 are provided.
(Measurement setting automatic adjustment unit 217)

The measurement setting automatic adjustment unit 217 automatically sets the measurement setting of the partial area based on at least one of the solid shape data of each partial area and the received light data acquired in each partial area when the solid shape data is generated. It is a member for adjusting automatically. The measurement setting automatic adjustment unit 217 automatically adjusts the partial region measurement setting in each partial region, and changes the measurement setting to each partial region as necessary. Thus, when the measurement setting of each partial area is changed, according to the measurement setting of this partial area, the solid shape data generation part generates 3D shape data again. That is, according to the measurement settings of each adjusted partial area, the light projecting unit projects pattern light, the light receiving unit receives the adjusted light reception data, and based on this, the three-dimensional shape data generating unit receives the adjusted three-dimensional shape data. Generate. Further, the three-dimensional shape data connection unit 219 connects the adjusted three-dimensional shape data to generate connection adjusted three-dimensional shape data. As a result, it is possible to generate the three-dimensional shape data with the measurement settings of the partial regions that have been changed to the optimum conditions based on the received light data and the three-dimensional shape data, and perform more accurate measurement.
(Three-dimensional shape data connection unit 219)

The solid shape data connecting unit 219 is a member for connecting the solid shape data of each partial region measured according to the partial region measurement setting adjusted by the measurement setting adjusting unit, and generating connected solid shape data corresponding to the connected region. It is.
(3D shape data generation unit 212)

  The three-dimensional shape data generation unit 212 determines the measurement target object based on the light reception data output from the light receiving unit according to the measurement setting set by the measurement setting unit 255 in each partial region set by the connection region setting unit 256. It is a member that generates solid shape data indicating a shape by a pattern projection method. In the example of FIG. 1 and the like, the three-dimensional shape data generation unit 212 sequentially projects the phase by the light projecting unit 110, and the light receiving unit 120 receives the light reflected from the surface of the measurement object WK a plurality of times. Based on the output plurality of received light data, phase data that varies depending on the surface shape of the measurement object WK is acquired, and on the basis of the phase data, the measurement object that exists in the stage plane orthogonal to the optical axis of the light receiving unit 120 The shape of the object WK is measured by the pattern projection method to obtain solid shape data. This stage plane is specified as a planar shape, for example, specified on the XY plane. Further, it is preferable to obtain the solid shape data for each pixel. Note that the three-dimensional shape data here means data that can measure height information. For example, the three-dimensional shape data includes a height image in which each pixel indicating the measurement object indicates the three-dimensional coordinates of the measurement object. That is, solid shape data does not necessarily have height information directly. For example, before measuring height information, a fringe image measured by a pattern projection method, phase data, or a fringe image is used for each pixel. Data obtained by measuring height information indicating the three-dimensional coordinates (for example, XYZ coordinates) of the measurement object is also included in the three-dimensional shape data.

The three-dimensional shape data generation unit 212 can also generate a height image. Therefore, the three-dimensional shape data generation unit 212 can include a height image generation unit 212b that generates a height image and a shape measurement processing unit 212c that performs measurement on the height image. In this way, the three-dimensional shape data generation unit 212 may be configured to generate a height image in which each pixel indicating the measurement object included in the three-dimensional shape data indicates the three-dimensional coordinates of the measurement object.
(Determination processing unit 214)

  Based on the solid shape data acquired by the solid shape data acquisition unit 212, the determination processing unit 214 determines whether or not there is an unmeasured region having no height information within the depth measurement range. It is a member for determining according to conditions. In the pattern projection method, even if the contrast of the fringe pattern is low, it is possible to acquire the three-dimensional shape data as long as the adjacent bright and dark portions can be distinguished. Therefore, the depth measurement range is a certain constant in the optical axis direction of the light receiving unit 120 that can acquire height information without moving the stage 140 relative to the light receiving unit 120, the light projecting unit 110, or both. A range having a width of. More specifically, the depth measurement range has a certain range up and down in the optical axis direction with respect to the position where the fringe pattern projected on the measurement object WK by the light projecting unit 110 is imaged with the highest contrast. Here, the fixed range is a range where at least the stripe pattern projected from the light projecting unit 110 by the light receiving unit 120 can be imaged, and there are a plurality of light projecting units 110 that project pattern light from different directions. In this case, it may be defined based on a range in which stripe patterns projected from all the light projecting units 110 are imaged. Further, the unmeasured area refers to data in which height information cannot be acquired from the solid shape data. For example, a pixel that does not show a fringe pattern of fringe projection or a region composed of a plurality of pixels can be used. Further, the predetermined determination condition includes, for example, the contrast of the fringe image included in the three-dimensional shape data and whether the luminance reaches a predetermined value.

  In other words, if there is a pixel that has a brightness value enough to determine that the pattern is projected among the pixels for which final three-dimensional shape data has not been obtained, the measurement object exists. Based on this, the depth measurement range is changed, and acquisition of the three-dimensional shape data is attempted.

  Based on such a determination condition, the determination processing unit 214 determines whether or not the fringe pattern is obtained to such an extent that the height can be measured, thereby not having height information in the depth measurement range. It can be determined whether or not a measurement area exists.

  Further, the determination processing unit 214 accumulates acquired pixels that can measure height information within the depth measurement range, and whether or not there is an unmeasured pixel based on the accumulated image obtained by accumulating the acquired pixels. Can be configured to determine.

Furthermore, the determination processing unit 214 may be configured to determine whether or not there is solid shape data in any part within the depth measurement range, and determine whether or not there is an unmeasured pixel. Thus, if there is a pixel whose height can be measured within the depth measurement range, the depth may be automatically expanded. That is, if even one point can be measured within the depth measurement range, it can be controlled to expand.
(Depth extension processing unit 215)

The depth extension processing unit 215 changes the focal position of the light receiving unit 120 by controlling the optical axis direction driving unit 146 when it is determined that an unmeasured region exists by the non-measurement determination process by the determination processing unit 214. It is a member for.
(Setting unit 250)

The setting unit 250 includes a position specifying unit 251, an end condition setting unit 252, a depth range setting unit 253, a depth extension mode selection unit 254, a measurement setting unit 255, a connected region setting unit 256, and a measurement mode selection unit. 257.
(Position designation part 251)

The position specifying unit 251 is a member for specifying the XY position on the image of the measurement target WK displayed on the display unit 400.
(End condition setting unit 252)

  The end condition setting unit 252 is a member for setting a predetermined end condition for ending the focal position changing process for changing the focal position of the light receiving unit 120 by controlling the optical axis direction driving unit 146.

  Here, the predetermined end condition by the determination processing unit 214 includes a physical limit of the moving range, for example, a state where the stage 140 has reached a position where it cannot move any more. In addition to the state where measurement is not possible in the first place, the predetermined end condition includes a state where measurement is not performed but a fringe image cannot be acquired.

  The depth extension processing unit 215 is preferably operated in a direction in which the distance between the light receiving unit 120 and the stage 140 is increased when the optical axis direction driving unit 146 is operated. Thereby, the situation where the measuring object WK placed on the stage 140 contacts the light receiving unit 120 can be avoided. In this case, since the light receiving unit 120 and the stage 140 operate only in one direction away from each other, the entire measurement target WK cannot be measured unless the initial stage position is set appropriately. The user can measure the lowest position of the measuring object WK to be measured (position where the light receiving part 120 is separated) while moving the stage 140 in the optical axis direction of the light receiving part 120, and the measuring object WK. Is set as the initial position of the stage 140 at a position where the highest position (position closest to the light receiving unit 120) does not collide with the light receiving unit 120. This operation can be performed by the user confirming the three-dimensional shape data displayed on the display unit 400 or visually confirming the distance between the stage 140 and the light receiving unit 120.

  On the other hand, when the depth extension processing unit 215 permits the operation of the optical axis direction driving unit 146 in the direction in which the distance between the light receiving unit 120 and the stage 140 is shortened, the measurement target WK on the stage 140 is a camera or the like. It is preferable to provide a mechanism for preventing a situation in contact with the device. For example, a depth extension processing unit is obtained so that a rough height of the highest part of the measurement object WK is acquired in advance and the light receiving unit 120 and the stage 140 are prohibited from approaching at a distance shorter than this height. The operation of the optical axis direction driving unit 146 is limited at 215. When the stage is allowed to move in both the direction in which the distance between the light receiving unit 120 and the stage 140 is shortened and the direction in which the distance is increased, the stage 140 is first moved in one direction from the initial position of the stage 140. If the end condition by the determination processing unit 214 is not satisfied, the stage 140 is moved in the other direction, and a reciprocating operation is performed until the end condition is satisfied.

  The depth range setting unit 253 is a member for setting the range in which the focal position of the light receiving unit 120 is changed by controlling the optical axis direction driving unit 146.

The depth extension mode selection unit 254 controls whether to perform the focus position change process for changing the focus position of the light receiving unit 120 by controlling the optical axis direction driving unit 146 within a predetermined range or automatically extending. It is a member.
(Measurement setting unit 255)

The measurement setting unit 255 is a member for setting a connection area. The connection area is divided into a plurality of partial areas. Each partial area corresponds to a field of view that can be measured by the shape measuring apparatus or a slightly narrower area. As described above, there is a limitation in hardware specifications by dividing a plurality of partial areas, moving the stage to each partial area with a plane direction driving unit, and connecting the generated solid shape data in the XY plane direction. A wide-area image with an enlarged field of view can be obtained.
(Linked region setting unit 256)

The connection area setting unit 256 is a member that sets a connection area composed of a plurality of partial areas as an area for moving the relative position of the stage in the plane direction by the plane direction driving unit.
(Measurement mode selection unit 257)

The measurement mode selection unit 257 has a normal mode, a fine mode for performing finer measurement than the normal mode, and received light data as measurement modes when generating the three-dimensional shape data of the measurement object in the three-dimensional shape data generation unit. This is a member for selecting any one of the halation removal modes for removing halation from.
(Composition processing unit 216)

  The synthesis processing unit 216 obtains the solid shape data by the solid shape data generation unit 212 until it is determined by the non-measurement determination processing by the determination processing unit 214 that there is no unmeasured area or a predetermined end condition is satisfied. A member for generating a composite height image obtained by combining a plurality of height images generated by automatically repeating the processing, the unmeasured determination processing by the determination processing unit 214, and the focus position change processing by the depth extension processing unit 215. is there.

With such a shape measuring device, it is possible to extend the measurement range in the depth direction in each field of view.
(How to get height information)

In the present embodiment, a pattern projection method based on the principle of triangulation is used as a method for acquiring height information. In this method, the measurement is repeated by physically or optically moving the position of the object to be measured or the shape measuring device while using the triangular distance measuring method having a wide depth measurement range as a base. Then, by combining the obtained measurement results, the total height can be expanded in the depth direction by the amount of movement of the depth measurement range that can be realized by one measurement. As a result, it is possible to measure at a high speed and a wider range than the triangular distance measuring method. Thereby, a shape measuring device and a shape measuring method capable of measuring a wider field of view with high resolution are realized.
(XY image connection function)

  Further, the composition processing unit 216 can also connect a plurality of height images with different XY coordinates captured by moving the stage 140 in the XY direction on the XY plane. In the case of such XY connection, the stage 140 is moved in the horizontal direction by the stage plane direction driving unit 148, and images captured in different visual field ranges are connected in the horizontal direction. For example, texture images showing different parts captured by the texture image acquisition unit 218 in multiple times are connected by an XY connecting unit, and the connected image is used as a large texture image as a reference target image or an inspection target image. You can also. Especially in shape measuring devices that can capture high-magnification optical images, etc., low-power texture images may not be able to fully demonstrate their capabilities. Highly accurate image inspection can be realized. Alternatively, since a high-magnification image has a narrow field of view, it is also possible to obtain a connected image with an enlarged field of view by connecting images captured in different fields of view. Further, the image connection function, here, the XY connection function, can be executed not only on the texture image but also on the height image, the combined height image, or the combined image obtained by combining the texture image and the height image. When connecting a plurality of three-dimensional shape data acquired by moving the stage 140 in the XY direction, the depth extension processing by the depth extension processing unit 215 is automatically performed at each XY position, and the generated plurality of three-dimensional shape data They are linked together. Thereby, even if the measuring object WK is large in the XY direction and has large undulations in the height direction, the entire measuring object WK can be easily measured. Further, when the undulation in the height direction is different from the measurement target WK at each XY position, the presence / absence of the depth extension processing by the depth extension processing unit 215 or the number of times is different at each XY position. For example, the object to be measured is relatively flat, and the three-dimensional shape data is generated without performing the depth extension process at the XY position where the entire measurement is within the measurement depth range in one measurement. At the XY position where the extension process is required, the depth extension process is performed a plurality of times to generate the three-dimensional shape data, and these three-dimensional shape data can be connected in the XY direction.

  The storage unit 240 is a member for storing various data and storing set values, and a semiconductor storage element or the like can be used. Here, the storage unit 240 stores the height image storage unit 241 that stores the height image, the texture image storage unit 242 that stores the texture image, and the measurement setting of each partial region adjusted by the measurement setting automatic adjustment unit 217. A measurement setting storage unit 243 for storing is provided.

  The display unit 400 is a member for displaying acquired images and the like. For example, LCD, organic EL, CRT, etc. can be used.

The operation device 450 is a member for receiving user input and the like, and input devices such as a mouse, a keyboard, and a console can be used. Further, by using a touch panel for the display unit 400, the display unit and the operation device can be used together.
(Block Diagram)

A configuration example of the imaging unit 100 of the shape measuring apparatus 500 of FIG. 1 is shown in a block diagram of FIG. The imaging unit 100 includes a light projecting unit 110, a light receiving unit 120, an illumination light output unit 130, a stage 140, and a measurement control unit 150. The light projecting unit 110 includes a measurement light source 111, a pattern generation unit 112, and a plurality of lenses 113, 114, and 115. The light receiving unit 120 includes a camera 121 and a plurality of lenses 122 and 123. On the stage 140, the measuring object WK is placed.
(Light Projecting Unit 110)

  The light projecting unit 110 is disposed obliquely above the stage 140. The imaging unit 100 may include a plurality of light projecting units 110. In the example of FIG. 4, the imaging unit 100 includes two light projecting units 110. Here, the first light projecting unit 110A (right side in FIG. 4) capable of irradiating the measurement target object WK with the pattern light from the first direction and the measurement target object from the second direction different from the first direction. Second light projecting units 110B (left side in FIG. 4) capable of irradiating pattern light to WK are respectively arranged. The first light projecting unit 110 </ b> A and the second light projecting unit 110 </ b> B are arranged symmetrically across the optical axis of the light receiving unit 120. It should be noted that there are three or more light projecting units, or conversely, only one light projecting unit is used, or while using a common light projecting unit, the light projecting unit and the stage are moved relative to each other so that the illumination direction is different. It is also possible to make it light. Furthermore, in the example of FIG. 4, the illumination angle of the illumination light with respect to the vertical direction in which the light projecting unit 110 projects is fixed, but this may be variable.

  The light receiving unit 120 in FIG. 4 receives the first pattern light irradiated from the first light projecting unit 110A and reflected from the measurement object WK, and outputs first light reception data. On the other hand, the light receiving unit 120 receives the second pattern light irradiated from the second light projecting unit 110B and reflected from the measurement object WK, and outputs second light reception data. The light reception data output from the light receiving unit 120 is, for example, a fringe image based on the fringe projection method.

In addition, the three-dimensional shape data acquisition unit 212 that receives the light reception data generates a first height image of the measurement object WK based on the first light reception data received by the light reception unit 120. On the other hand, the three-dimensional shape data acquisition unit 212 generates a second height image of the measurement object WK based on the second light reception data received by the light receiving unit 120.
(Depth measurement range)

Here, the first pattern light and the second pattern light can be irradiated from the first light projecting unit 110A and the second light projecting unit 110B, respectively, in the stage plane where the imaging field of view of the light receiving unit 120 on the stage 140 is located. The common height range is set as the depth measurement range. The composition processing unit 216 synthesizes the first height image and the second height image having the solid shape data within the depth measurement range to generate a composite height image.
(Depth search range)

On the other hand, in the stage plane of the light receiving unit 120 on the stage 140, an area in which the first pattern light or the second pattern light can be irradiated from only one of the first light projecting unit 110A and the second light projecting unit 110B. The height range including the depth search range. The determination processing unit 214 can determine whether or not the surface region of the measurement object WK exists within this depth search range.
(Measurement light source 111)

  The measurement light sources 111 of the first light projecting units 110A and the second light projecting units 110B are, for example, halogen lamps that emit white light. The measurement light source 111 may be another light source such as a white LED (light emitting diode) that emits white light. Light emitted from the measurement light source 111 (hereinafter referred to as “measurement light”) is appropriately condensed by the lens 113 and then enters the pattern generation unit 112.

  The pattern generation unit 112 is a DMD (digital micromirror device), for example. The pattern generation unit 112 may be an LCD (Liquid Crystal Display), LCOS (Liquid Crystal on Silicon), or a mask. The measurement light incident on the pattern generation unit 112 is converted into a preset pattern and a preset intensity (brightness) and emitted. The measurement light emitted by the pattern generation unit 112 is converted into light having a diameter larger than the visual field that can be observed and measured by the light receiving unit 120 by the plurality of lenses 114 and 115, and then the measurement target WK on the stage 140. Is irradiated.

The arrangement in FIG. 4 is an example, and the arrangement of the optical system members can be changed as appropriate. For example, the pattern generation unit 112 may be disposed on the exit surface side of the lens 115.
(Light receiving unit 120)

The light receiving unit 120 is disposed above the stage 140. Measurement light reflected above the stage 140 by the measurement object WK is condensed and imaged by the plurality of lenses 122 and 123 of the light receiving unit 120 and then received by the camera 121.
(Camera 121)

  The camera 121 is, for example, a CCD (charge coupled device) camera including an image sensor 121a and a lens. The image sensor 121a is, for example, a monochrome CCD (charge coupled device). The image sensor 121a may be another image sensor such as a CMOS (complementary metal oxide semiconductor) image sensor. The color image sensor requires each pixel to receive light for red, green, and blue, so the measurement resolution is lower than that of a monochrome image sensor, and a color filter must be provided for each pixel. Sensitivity decreases. For this reason, in the present embodiment, a monochrome CCD is used as the image sensor, and a color image is acquired by illuminating the illumination light output unit 130 described later with illumination corresponding to RGB in a time-sharing manner. . With such a configuration, it is possible to acquire a color image of the measurement object without reducing the measurement accuracy.

However, it goes without saying that a color image sensor may be used as the image sensor 121a. In this case, although measurement accuracy and sensitivity are lowered, it is not necessary to irradiate illumination corresponding to RGB from the illumination light output unit 130 in a time-sharing manner, and a color image can be acquired simply by irradiating white light. The optical system can be configured simply. From each pixel of the image sensor 121 a, an analog electrical signal (hereinafter referred to as “light reception signal”) corresponding to the amount of received light is output to the measurement control unit 150.
(Measurement control unit 150)

The measurement control unit 150 includes an A / D converter (analog / digital converter) and a FIFO (First In First Out) memory. The light reception signal output from the camera 121 is sampled at a constant sampling period and converted to a digital signal by the A / D converter of the measurement control unit 150 based on control by the light source unit 300. Digital signals output from the A / D converter are sequentially stored in the FIFO memory. The digital signal stored in the FIFO memory is sequentially transferred to the control means 200 as pixel data.
(Control means 200)

  As shown in FIG. 1, the control means 200 includes a CPU (Central Processing Unit) 210, a ROM 220 (Read Only Memory), a working memory 230, a storage unit 240 and a setting unit 250. The control means 200 can be a computer such as a PC (personal computer) or a workstation. A dedicated controller may be prepared. Alternatively, the control means 200 may be constructed by combining a general-purpose computer and a dedicated controller. In this example, the control means 200 is configured by a computer in which a shape measurement program is installed.

  The setting unit 250 is operated by the operation device 450. The operation device 450 includes a keyboard and a pointing device. As a pointing device, a mouse or a joystick is used. In addition, the operation device 450 can be integrated with the display unit 400. For example, by using a touch panel for the display unit 400, the display unit can have a function of an operation unit.

  The ROM 220 stores a system program. The working memory is composed of a RAM (Random Access Memory) and is used for processing various data. The storage unit 240 includes a hard disk or the like. The storage unit 240 stores an image processing program and a shape measurement program. The storage unit 240 is used to store various data such as pixel data provided from the measurement control unit 150.

The CPU 210 generates image data based on the pixel data given from the measurement control unit 150. The CPU 210 performs various processes on the generated image data using the work memory 230 and causes the display unit 400 to display an image based on the image data. Further, the CPU 210 gives a driving pulse to a stage driving unit 145 described later. Further, this CPU realizes functions of a three-dimensional shape data generation unit 212, a determination processing unit 214, a synthesis processing unit 216, a three-dimensional image synthesis unit 213, and a depth extension processing unit 215, which will be described later.
(Display unit 400)

The display unit 400 is a member for displaying a measurement image acquired by the imaging unit 100 and a captured observation image. The display unit 400 is configured by, for example, an LCD panel or an organic EL (electroluminescence) panel.
(Stage 140)

  The stage 140 is a member for placing the measurement object WK on the upper surface. As shown in FIG. 1, the stage 140 includes a stage operation unit 144 for allowing the user to manually move the stage 140 and a stage driving unit 145 for electrically moving the stage 140.

  In FIG. 4, two directions orthogonal to each other within a plane (hereinafter referred to as “mounting surface”) on the stage 140 on which the measurement object WK is placed are defined as an X direction and a Y direction. , Y. A direction orthogonal to the mounting surface of the stage 140 is defined as a Z direction and is indicated by an arrow Z. A direction rotating around an axis parallel to the Z direction is defined as a θ direction, and is indicated by an arrow θ. Note that the rotation axis of the θ stage does not have to be parallel to the optical axis parallel to the Z direction, and may be inclined by 45 ° with respect to the optical axis, for example.

  The stage 140 includes an XY stage 141, a Z stage 142, and a θ stage 143. The XY stage 141 includes an X direction moving mechanism and a Y direction moving mechanism as a stage plane direction driving unit. The Z stage 142 has a Z direction moving mechanism. The θ stage 143 has a θ direction rotation mechanism. The XY stage 141, the Z stage 142, and the θ stage 143 constitute a stage 140. Stage 140 further includes a fixing member (clamp) that fixes measurement object WK to the placement surface. The stage 140 may further include a tilt stage having a mechanism that can rotate around an axis parallel to the placement surface.

  Stepping motors are used for the X direction moving mechanism, Y direction moving mechanism, Z direction moving mechanism, and θ direction rotating mechanism of the stage 140, respectively. The X direction moving mechanism, Y direction moving mechanism, Z direction moving mechanism, and θ direction rotating mechanism of the stage 140 are driven by the stage operation unit 144 or the stage driving unit 145 of FIG.

  The user manually operates the stage operation unit 144 to move the mounting surface of the stage 140 in the X direction, the Y direction, the Z direction, or rotate in the θ direction relative to the light receiving unit 120. be able to. The stage driving unit 145 supplies the current to the stepping motor of the stage 140 based on the driving pulse supplied from the control unit 200, thereby moving the stage 140 relative to the light receiving unit 120 in the X direction, Y direction, or Z direction. It can be moved or rotated in the θ direction.

Here, as shown in FIG. 4, the light receiving unit 120 and the light projecting unit are arranged such that the central axis of the left and right light projecting units 110 and the center axis of the light receiving unit 120 intersect each other on the focus plane where the focus of the stage 140 is best. 110 and the relative position of the stage 140 are determined. Since the center of the rotation axis in the θ direction coincides with the center axis of the light receiving unit 120, when the stage 140 rotates in the θ direction, the measurement target WK does not deviate from the field of view and is centered on the rotation axis. It is designed to rotate within the field of view. Further, the XYθ and tilt moving mechanisms are supported with respect to the Z direction moving mechanism. In other words, even if the stage is rotated in the θ direction or tilted, the center axis of the light receiving unit 120 and the movement axis in the Z direction are not displaced. With such a stage mechanism, even when the position and orientation of the measurement target WK are changed, it is possible to move the stage 140 in the Z direction to capture and combine a plurality of images at different focal positions. Become. In the present embodiment, an electric stage that can be driven by a stepping motor has been described as an example. However, a manual stage that can be moved only manually may be used.
(Light source unit 300)

The light source unit 300 includes a control board 310 and an observation illumination light source 320. A CPU is mounted on the control board 310. The CPU of the control board 310 controls the light projecting unit 110, the light receiving unit 120, and the measurement control unit 150 based on a command from the CPU 210 of the control unit 200. This configuration is an example, and other configurations may be used. For example, the control board may be omitted by controlling the light projecting unit 110 and the light receiving unit 120 with the measurement control unit 150 or controlling the light projecting unit 110 and the light receiving unit 120 with the control means 200. Alternatively, the light source unit 300 can be provided with a power supply circuit for driving the imaging unit 100.
(Light source for observation 320)

  The observation illumination light source 320 includes, for example, three color LEDs that emit red light, green light, and blue light. By controlling the luminance of the light emitted from each LED, light of an arbitrary color can be generated from the observation illumination light source 320. Light generated from the observation illumination light source 320 (hereinafter referred to as “illumination light”) is output from the illumination light output unit 130 of the imaging unit 100 through a light guide member (light guide).

  The illumination light output from the illumination light output unit 130 irradiates the measurement object WK by switching red light, green light, and blue light in a time-sharing manner. Thereby, the observation images captured with these RGB lights can be synthesized to obtain a color observation image, which can be displayed on the display unit 400.

  When the color observation image is displayed in this manner, if the switching frequency for switching the color of the illumination light is made to coincide with the frame rate when the display contents are updated (rewrite the screen), the frame rate is low. In such a case (for example, about several Hz), the flicker becomes remarkable. In particular, when color switching by RGB primary colors is conspicuous, the user may be uncomfortable. Therefore, such a problem can be avoided by setting the switching frequency for switching the RGB illumination light to a high speed (for example, several hundred Hz) that the user cannot recognize. The color of the illumination light is switched by the illumination light output unit 130 or the like. The timing at which the imaging unit 100 actually images the measurement object WK while switching RGB of illumination light at high speed is the timing for updating the display content of the display unit 400. In other words, it is not necessary that the observation image capturing timing and the illumination light switching timing coincide completely. In other words, the RGB switching period of the illumination light is captured to the extent that an RGB observation image can be captured by the image sensor. This can be handled by linking so as to be a multiple of the period. With this method, the illumination light switching timing can be increased, and the discomfort given to the user can be reduced without improving the frame rate that can be processed by the image sensor 121a.

  In the example of FIG. 1, the observation illumination light source 320 is externally attached to the imaging unit 100, and the observation illumination light source 320 is disposed in the light source unit 300. By doing so, it is possible to avoid a situation in which the heat generated by the observation illumination light source 320 affects the optical system of the imaging unit 100. However, the observation illumination light source can be provided on the image pickup means side by using an observation illumination light source with a small calorific value, or by providing a corresponding heat radiation mechanism on the image pickup means side. In this case, the illumination light output unit and the observation illumination light source can be integrated, for example, by incorporating an observation illumination light source into the illumination light output unit, and a light guide for optically connecting the light source unit and the imaging means. A member can be made unnecessary and a structure can be simplified. Similarly, with respect to the light projecting section, a light source for projecting light can be built in the imaging means, or can be externally attached to the light source section side.

The illumination light output unit 130 in FIG. 4 has an annular shape and is disposed above the stage 140 so as to surround the light receiving unit 120. Thereby, illumination light is irradiated from the illumination light output unit 130 to the measurement object WK so that no shadow is generated. The illumination light output unit 130 may be a ring-shaped ring illumination, a coaxial epi-illumination, a side-spot illumination, a transmission illumination, or a combination thereof. Further, the illumination light output unit may be omitted by irradiating uniform light from the light projecting unit 110 to obtain illumination light. For example, by allowing the light projection unit 110 to project a white pattern image using a two-dimensional array, the light projection unit 110 can also be used as an illumination light output unit. As described above, when using the two-dimensional array white pattern image projection of the light projecting unit 110 as the illumination light source for observation, the light transmitted or reflected through the two-dimensional array is projected onto the measurement object WK through the diffusion plate. The pixel grid of the two-dimensional array may not be reflected on the measurement object WK.
(Example of GUI)

  In the shape measuring apparatus, an operation program for operating the shape measuring apparatus 500 is installed in a PC that is the control means 200. The display unit 400 displays a GUI (Graphical User Interface) for operating the shape measurement program. An example of such a GUI screen is shown in FIG. In this example, in the display unit 400, the first measurement image S1 of the measurement object WK irradiated with the first measurement light from the first light projection unit 110A and the second measurement light from the second light projection unit 110B are irradiated. It can be displayed so that the second measurement image S2 of the measured object WK is aligned. In this example, the first display area 416 is provided on the right side and the second display area 417 is provided on the left side of the image display area 410 provided on the left side of the display unit 400. By using such a two-screen display, it is possible to confirm while comparing the state of the measurement image obtained with each measurement light, particularly the shadowed area. In addition, the division example of the image display area is not limited to the configuration in which the image display areas are arranged side by side in this manner, and an arbitrary configuration such as an arrangement in the vertical direction or a separate screen can be used as appropriate.

  The operation program of the shape measuring apparatus is provided with an image switching means capable of switching the displayed image between the observation image and the measurement image. In this example, when an “observation image” button 427 is pressed as an image switching unit, an observation image captured using an observation illumination light source is displayed in the image display area 410, and when a “measurement image” button 428 is pressed, A measurement image acquired using the measurement light projecting unit is displayed in the image display area 410. The user operates the operation area 420 provided in the GUI with the operation device 450 of the control unit 200 in FIG. 1 to adjust the brightness, for example, thereby adjusting the first light projecting unit 110A and the second light projecting unit. The brightness of the measurement light emitted from 110B or the corresponding camera exposure time can be changed. Here, the parameter that changes the brightness of the measurement light is the exposure time of the camera. Moreover, the imaging condition of an observation image is set as needed. In the upper part of the image display area 410 in FIG. 5, observation image imaging condition setting means 490 for setting the imaging conditions for such an observation image is provided. The observation image imaging condition setting means 490 includes settings such as shutter speed switching for imaging an observation image, imaging magnification, and focus adjustment. In the example illustrated in FIG. 5, the brightness of the imaging unit is selected from “auto” or “manual”. When “Manual” is selected, the brightness of the image pickup means is adjusted by the camera brightness adjustment slider.

  As described above, in the image display area 410, images of the measurement object WK when the measurement light is irradiated by each of the first light projecting unit 110A and the second light projecting unit 110B can be displayed in a line. Therefore, the user moves the positions of the brightness adjustment sliders 444 and 446 while looking at the image of the measurement object WK displayed in the image display area 410, whereby the first light projecting unit 110A and the second light projecting unit 110A. The brightness of the measurement light emitted from each of the units 110B or the camera exposure time corresponding to each light projecting unit 110 can be appropriately adjusted.

  The appropriate brightness of the measurement light emitted from the first light projecting unit 110A and the second light projecting unit 110B and the appropriate brightness of the illumination light emitted from the illumination light output unit 130, or cameras corresponding to each illumination There may be a correlation between the exposure time. In this case, the brightness of the measurement light emitted from each of the first light projecting unit 110 </ b> A and the second light projecting unit 110 </ b> B or the camera exposure time corresponding to each light projecting unit 110 is emitted from the illumination light output unit 130. It may be automatically adjusted based on the brightness of the illumination light or the camera exposure time corresponding to the illumination light.

  Alternatively, the measurement light emitted from each of the first light projecting unit 110A and the second light projecting unit 110B based on the brightness of the illumination light emitted from the illumination light output unit 130 or the camera exposure time corresponding to the illumination light. An adjustment guide for making the brightness of the camera or the camera exposure time corresponding to each light projecting unit 110 appropriate may be displayed on the display unit 400. In this case, the user moves the positions of the brightness adjustment sliders 444 and 446 based on the adjustment guide, so that the brightness of the measurement light emitted from each of the first light projecting unit 110A and the second light projecting unit 110B. Or the camera exposure time corresponding to each light projection part 110 can be adjusted appropriately.

If the light irradiation direction is different, the light reflection direction is also different, so that the brightness of the resulting image varies depending on the light irradiation direction even in the same region. That is, the brightness of the measurement light suitable for measurement and the exposure time of the image sensor vary depending on the irradiation direction. In the present embodiment, the brightness of each image captured by irradiating light from the plurality of first light projecting units 110 </ b> A and 110 </ b> B can be individually adjusted, so that it is appropriate for each irradiation direction. It is possible to set the brightness or exposure time of the measurement light. In addition, since the image whose brightness is being adjusted is displayed in the image display area 410 while being updated, the brightness can be adjusted while checking the adjusted image. At this time, in the image displayed in the image display area 410, a portion that is too bright and overexposed, or a portion that is too dark and obscured by black is displayed in an identifiable manner, so that the brightness is improved for the user. It is also possible to display whether or not can be adjusted appropriately.
(Telecentric double-sided projection optical system)

  Here, a schematic diagram of a telecentric double-sided projection optical system is shown in FIG. As shown in this figure, the right projection unit 110A includes a right projection unit 110A as a projection optical system that configures the projection unit 120 that projects the measurement target WK placed on the stage 140. A left light projecting optical system including the light optical system and the second light projecting unit 110B is disposed. By providing the light projecting optical systems on the left and right in this way, there are advantages such as reduction of the area in which the pattern light becomes a shadow and cannot be measured.

  On the other hand, the light receiving optical system constituting the light receiving unit 120 includes a low-magnification imaging device 120A and a high-magnification imaging device 120B. Above the central prism 124, a bifurcated both-side telecentric light receiving lens 125 is provided. On the right side of the prism 124, a high-magnification imaging device 120B is disposed. As shown in FIG. 6, the light projecting optical system is irradiated wider than the field of view.

  The light receiving optical system includes a light receiving lens and a camera unit. The light receiving lens has a fixed magnification and is a telecentric optical system giving priority to accuracy. However, the zoom lens may cover a wide magnification. The shape measuring apparatus employs a bifurcated fixed-focus both-side telecentric optical system, and has two cameras, a low-magnification camera and a high-magnification camera. As a result, it is possible to change the magnification by electrical switching instead of mechanical switching as in the zoom lens, and it is possible to realize stable measurement performance that does not cause a measurement accuracy shift due to the mechanical positioning accuracy.

  The measurement range by left and right side light projection will be described based on the schematic diagram of FIG. In the shape measuring device, in order to minimize the shadow area (unmeasurable area), the pattern can be projected from the left and right symmetrical directions with the light receiving lens in between. ing.

  The light receiving lens employs a two-branch both-side telecentric light-receiving lens 125, which can acquire an image without distortion caused by a change in magnification due to the height of the object to be measured WK, as well as a double-sided telecentric projection lens. When combined with this configuration, the effect of simplifying the measurement setting that the light projection / reception angle is constant everywhere in the field of view is exhibited. As shown in FIG. 7, the two-branch both-side telecentric light-receiving lens 125 has a field of view with two magnifications coaxial, and there is a merit that the field of view adjustment is not required even if the magnification is switched.

  From the left and right light projection lens 116, the two-dimensional pattern light is irradiated as a parallel light beam from the right and left light projection angles to the measurement object WK. The advantage of irradiating the target with the two-dimensional pattern light from the left and right is not only the effect of minimizing the above-mentioned shadow, but also by combining the measurement results of the left and right (for example, averaging) It is possible to reduce errors that occur on the left and right.

In the relationship between the left and right projections and the measurement range, as shown in the schematic diagram of FIG. 7, the width of the measurement visual field (XY direction) is the width of the light beam of the light receiving lens (the thin line (low magnification) or the thick line (high) in FIG. The range of height measurement using a set of pattern projections is determined from the relationship between light projection and light reception. A depth measurement range is defined as a common area of the received light flux and the projected light flux from the left and right, as in the dotted frame area in FIG. That is, the common area of the left and right light projection irradiation indicated by the dotted frame indicates the range of the measurable height. By determining the depth measurement range in this way, the light hitting from the left and right is uniform regardless of where in the depth measurement range, and by averaging the left and right measurements. The effect of stable measurement can be realized over the entire depth measurement range.
(Lower head 102)

  The stage 140 is connected to the base casing 149. The base casing 149 and the stage 140 are unitized as the lower head 102. The lower head 102 is connected to the upper head 101. Here, FIG. 8 shows an external side view of the shape measuring apparatus 100 in which the upper head 101 and the lower head 102 are connected, and FIG. 9 shows a configuration of the lower head 102. The upper head 101 houses the light projecting unit 110 and the light receiving unit 120. The lower head 102 includes an XY stage 141, a Z stage 142, a scale unit 160, a stage driving unit 145, a base casing 149, and a base 151 installed on the floor surface. The stage 140 includes an XY stage 141 and a Z stage 142. The base casing 149 connects the base portion 151 and the upper head 101. This configuration is an example, and for example, the upper head and the lower head 102 can be integrally configured.

The lower head 102 is electrically connected to the measurement control unit 150 (upper head 101 side) of the imaging unit 100 through the stage driving unit 145. Further, it is mechanically fastened by mechanical positioning in the base casing 149 and positioning bolts. The XY stage 141 is held from the Z stage 142 built in the base casing 149 via the stage support 152. By detecting the height of the XY stage 141 with the scale unit 160 for height detection, the stage surface height at the time of measurement can be accurately recognized.
(Scale unit 160)

  The scale unit 160 includes a sensor moving unit 161 and a scale unit 162. As shown in FIG. 9, the sensor moving unit 161 is connected to the back side of the stage support unit 152 and moves together with the stage support unit 152. On the other hand, the scale unit 162 is fixed to the base casing 149 and detects the position of the sensor moving unit 161. In this manner, the sensor moving unit 161 is moved along the scale unit 162 to detect the relative distance between the stage 140 and the light receiving unit 120 in the optical axis direction of the light receiving unit 120. In this configuration, the sliding surface on which the sensor moving unit 161 slides along the scale unit 162 serves as a measurement axis for measuring the height of the stage 140, that is, the working distance. As shown in FIG. 9, by making the extension line of the optical axis coincide with the measurement axis, measurement with less error is realized.

  As shown in FIGS. 8 and 9, the stage driving unit 145 is disposed on the base housing 149 side with respect to the scale unit 160. As a result, a stage configuration is realized in which a long stroke operation is performed in the Z direction while maintaining the rigidity of the high-load XY stage 141. Normally, a cross roller guide or a linear guide is used in a stage that maintains high rigidity. From the viewpoint of maintaining moment rigidity, it is important to have a sufficient width at the base of the movable part. Since the sum of the width and the stroke length is a necessary guide length, the Z stage guide is usually longer than the movable portion of the lightweight scale portion. Therefore, in this embodiment, by arranging the distance measuring surface and the optical axis direction driving unit 146 independently, it is possible to design a low-floor casing with a long stroke, and as a result, it is more resistant to disturbances such as floor vibration. There is an advantage that a stable measuring instrument can be realized.

  In this embodiment, an example in which the scale unit 160 is disposed on the base housing 149 side is shown, but the optical axis of the light receiving unit is aligned with the upper head side where the light projecting unit and the light receiving unit are provided. It may be arranged. In particular, when driving not the stage side but the light receiving unit side, it is preferable to arrange so that the amount of movement on the light receiving unit side to be driven is measured by the scale unit.

On the other hand, as a drawback of disposing the sensor moving unit 161 and the optical axis direction driving unit 146 independently, it is conceivable that the one-way guide is configured in a double manner. By arranging independent linear motion guides at two locations that are separated from each other, there may be disadvantages such as crosstalk between the straightness of each other, and deterioration of kodil and straightness. Therefore, in view of these points, the shape measuring apparatus according to the present embodiment is configured to connect the scale unit 160 and the stage support unit 152 with a magnetic force as shown in FIG. The configuration is realized.
(Connecting part)

As shown in FIG. 9, a magnet is used to connect the scale unit 162 that slides. Further, for fastening of the magnet surface, one is a spherical body 163 and the other is a flat plate material 164, and the spherical surface of the spherical body 163 is attracted by point contact with the flat plate of the plate material 164. Here, the spherical body 163 is made of a magnetic material, and the plate material 164 is made of a permanent magnet. The spherical body 103 is held by a holding unit 167, and the holding unit 167 is fixed to the stage support unit 152. Further, a plate-like member 165 having a smooth surface is interposed.
(XY stage 141)

The XY stage 141 includes a tilt sensor and a stage drive unit 145 (microcomputer, FPGA, motor driver) inside. The XY stage 141 is electrically connected to a stage driving unit 145 inside the base casing 149 through a stage support unit 152. By configuring the electrical connection between the stage support unit 152 and the XY stage 141 with a connector, the XY stage 141 can also be attached and detached, and can be switched to a different visual field adjustment stage such as a tilt / rotation stage.
(Measurement flow by fringe projection method)

  Next, based on FIG. 4, the outline of the flow of the operation | movement which measures a shape is demonstrated. It should be noted that all the descriptions here are for “one-shot measurement” in which the Z stage 142 is fixed in the height direction.

  First, the user arranges the measurement object WK to be measured on the stage 140 and adjusts the focus, visual field position, brightness, and the like with the illumination condition adjustment unit while viewing the optical image displayed on the display unit 400. Here, ring illumination is used as the illumination light output unit 130. However, the illumination light output unit 130 is not limited to the ring illumination, and for example, the illumination light output unit 130 may irradiate uniform illumination from the light projecting unit 110 constituting the light projecting system illumination unit.

  Next, the illumination light is switched from the ring illumination to the light projecting unit 110 to adjust the brightness of the light projecting illumination light. Since the illumination light from the light projecting unit 110 strikes from an oblique direction, a shadow due to the shape of the measurement target WK is generated. Further, depending on the surface state of the measurement object WK, it may be better to see the illumination light slightly inclined. In order to tilt the illumination light, for example, a tilt stage capable of tilting the stage 140 is used, or a tilt mechanism is provided in the light projecting unit 110. Further, in order to suppress the influence of the shadow of the illumination light and the surface state, the position and orientation of the measurement object WK are readjusted as necessary.

  In such an adjustment process in the light projecting unit 110, when the measurement object WK is moved, the measurement object WK is switched again to the ring illumination to confirm the appearance of the measurement object WK with the ring illumination light, or the ring illumination light. Readjust the brightness of the. This operation can be omitted if unnecessary.

When the posture, position, focus, and measurement illumination condition of the measurement object WK are determined, a measurement start command is transmitted from the control unit 200 to the measurement control unit 150. The control means 200 is configured by a computer in which the shape measurement program is installed as described above. Upon receiving this command, the measurement unit synchronously controls the pattern generation unit in the light projecting unit 110 and the imaging unit 100, and acquires a plurality of images of the measurement target WK with the imaging unit 100 while projecting a plurality of patterns. Then, after appropriate processing is performed on the control board 310, it is transmitted to the control means 200.
(Generation of height image)

The image data received by the control means 200 is appropriately image-processed and analyzed by a measurement algorithm in the shape measurement program, and solid shape data is generated. Specifically, a height image having height information is generated by the height image generation unit 212b.
(Generation of texture images)

  On the other hand, the measurement object WK is irradiated with illumination light, and a texture image that is an image showing the surface state of the measurement object WK is acquired by the imaging unit 100. For example, by irradiating the measurement object WK with ring illumination or irradiating a light projection pattern (all white) with all pixels turned on from the light projecting unit 110, an optical image is obtained with uniform illumination light. Take an image and use it as a texture image.

Further, not only one texture image but also a plurality of texture images may be captured. At this time, an HDR image or a depth composite image can be generated by combining a plurality of texture images. An HDR (high dynamic range) image is an image generated by capturing a plurality of texture images while changing the exposure time of the camera, and then combining these images with a high dynamic range (HDR). In addition, when the height difference of the measurement target part of the measurement target WK exceeds the depth of field, the depth composite image extracts only the in-focus part from the observation images taken individually with different height directions. This is an image synthesized.
(Generate composite image)

The obtained texture image is also transferred to the control means 200. The control unit 200 generates a composite image by combining the texture image and the height image. For example, a texture image is mapped to a height image that is three-dimensional shape data by a shape measurement program, and composite image data is generated by a three-dimensional image composition unit. The composite image is displayed on the display unit 400. In this state, desired measurement and analysis can be performed on the composite image.
(Shape measurement method)

  The procedure for generating the synthesized image and measuring the shape will be described based on the flowchart of FIG. First, in step S1001, the measurement object WK is placed on the stage 140.

  Next, in step S1002, the position, posture, focus, and brightness of the measurement object WK are adjusted using ring illumination.

  Next, in step S1003, switching to the light projecting system is performed to adjust the brightness of the light projecting system illumination and the position and orientation of the measurement target WK.

  Next, in step S1004, switching to ring illumination is performed again, and further switching to a light projecting system is performed to confirm the appearance.

  Next, in step S1005, it is confirmed whether there is a problem in appearance. If there is a problem, the process returns to step S1002 to repeat the above processing. On the other hand, if there is no problem, the process proceeds to step S1006 and the measurement start button is pressed.

  Next, in step S1007, a fringe pattern is projected and scanned from the light projecting system, and a plurality of fringe images of the measurement object WK are acquired by the camera in synchronization therewith. Here, this step may be repeated a predetermined number of times in order to improve left and right light projection, HDR, and other performances. For example, the influence of halation can be reduced by projecting pattern light a plurality of times while changing the exposure time.

  Next, in step S1008, the ring illumination is turned on, and a texture plane image of the measurement object WK is acquired.

  Next, in step S1009, the fringe image set is processed by a measurement algorithm to generate solid shape data.

  Next, in step S1010, the texture image is mapped to the solid shape data.

  In step S1011, the result is displayed. In step S1012, it is determined whether or not the data of the target location has been acquired correctly. If not, the process returns to step S103 and the above processing is repeated. On the other hand, if it can be obtained, the process proceeds to step S1013, and various measurements and analyzes are executed using measurement software or the like.

As described above, a shape measurement can be performed by generating a composite image using the shape measurement apparatus. Note that the order of step S1001 and step S1002 in FIG. 10 may be interchanged. In that case, first, the posture, position, and focus of the measurement object WK are adjusted in the measurement settings (step S1002), and the posture, position, and focus of the measurement object WK are not changed in the texture image acquisition (step S1001). Only the brightness of the ring illumination and the texture type are selected.
(Procedure for obtaining a texture image)

  Next, a procedure for acquiring a texture image will be described based on the flowchart of FIG. This procedure corresponds to the detailed description of the step S1002 of FIG. First, in step S1101, switching to ring illumination is performed.

  Next, in step S1102, the brightness of the ring illumination is adjusted. In step S1103, it is determined whether or not the brightness is appropriate. If it is not appropriate, the process returns to step S1102 to repeat the process. On the other hand, if the brightness is appropriate, the process proceeds to step S1104, the Z stage 142 is moved, and the focus position of the measurement object WK is adjusted. In step S1105, it is determined whether or not the focus position is correct. If not, the process returns to step S1104 to repeat the process. On the other hand, if the focus position is correct, the process advances to step S1106 to move the XY / θ / tilt stage to match the position and orientation of the measurement target WK. Note that the order of these steps S1102 to S1106 may be changed as appropriate.

  Next, in step S1107, it is determined whether the part to be seen is within the field of view. If not, the process returns to step S1106 to repeat the process. On the other hand, if it is within the range, in step S1108, the magnification is changed and the size is adjusted.

  Next, in step S1109, it is determined whether or not the magnification is appropriate. If not, the process returns to step S1108 and the process is repeated. On the other hand, if the magnification is appropriate, the process advances to step S1110 to determine whether or not to select a texture image type. If not, the process proceeds to step S1111 to select a normal image, and this process ends.

  On the other hand, when selecting the type of texture image, the process proceeds to step S1112 to determine whether or not to perform depth synthesis. If so, the process proceeds to step S1113 to execute setting of depth synthesis. On the other hand, if not, the process jumps directly to step S1114.

  Next, in step S1114, it is determined whether or not HDR is to be performed. If so, the process proceeds to step S1115 to execute HDR setting. On the other hand, if not, the process jumps directly to step S1116.

  Next, in step S1116, it is determined whether or not the texture image is to be confirmed. If doubled, the process proceeds to step S1117, where a preview of the texture image is displayed. On the other hand, if not, this process ends.

Next, in step S1118, it is determined whether or not the result of the texture image displayed as a preview is satisfied. If not, the process returns to step S1112 to repeat the process. On the other hand, if satisfied, this process is terminated. As described above, a texture image can be acquired.
(Procedure for setting measurement settings)

  The measurement settings for generating the three-dimensional shape data include the pattern light projection conditions of the light projecting unit, the light receiving conditions and imaging conditions of the light receiving unit, the illumination conditions of the illumination unit, and the like. These measurement settings are set by the measurement setting unit 255 shown in FIG. Here, the procedure for setting the measurement settings will be described based on the flowchart of FIG. This procedure corresponds to the detailed description of the step S1003 of FIG.

  First, in step S1201, the measurement light projection system is switched to the left light projection system in FIG. Next, in step S1202, the brightness is temporarily adjusted.

  In step S1203, it is determined whether or not the measurement location is illuminated. If not, in step S1204, the θ / tilt stage is moved to adjust the position and orientation of the measurement target WK. On the other hand, if the measurement location is illuminated, the process jumps directly to step S1206.

  Next, in step S1205, it is determined whether or not illumination has been applied, and the process returns to step S1204 to repeat the process. On the other hand, if it is illuminated, it is determined in step S1206 whether the brightness of the measurement location is appropriate. If not, the brightness is adjusted in step S1207. On the other hand, if it is illuminated, the process jumps directly to step S1209.

  Next, in step S1208, it is determined whether the brightness is correct. If not, the process returns to step S1207 to repeat the process. On the other hand, if the brightness is correct, it is determined in step S1209 whether the measurement location is in focus. If not, in step S1210, the stage 140 is moved to focus on the measurement location. On the other hand, if the brightness is correct, the process jumps to step S1212.

  Next, in step S1211, it is determined whether or not the subject is in focus. If not, the process returns to step S1210 to repeat the process. On the other hand, if the image is in focus, the process proceeds to step S1212 to make a comprehensive determination. Here, it is determined whether or not the brightness, posture, and focus of the measurement location are appropriate. If they are not appropriate, parameters that are not appropriate are confirmed in step S1213, and the procedure returns to an appropriate procedure. The return destination is one of step S1204, step S1207, and step S1210 depending on an inappropriate parameter.

  On the other hand, if it is determined as appropriate in the comprehensive determination, the process advances to step S1214 to switch to the measurement light projecting system (right light projecting system in FIG. 4). Next, in step S1215, the brightness is adjusted, and in step S1216, it is determined whether the brightness is correct. If not, the process returns to step S1215 to repeat the process. On the other hand, if the brightness is correct, this process ends.

  In these procedures, the order of position adjustment, posture adjustment, focus adjustment, and brightness adjustment can be changed as appropriate.

In this way, measurement settings can be set. The measurement setting can be automatically performed by the user from the measurement setting unit 255 or automatically by the shape measuring apparatus.
(Measurement range expansion function in the depth direction)

  In this embodiment, a pattern projection method based on a triangulation method is employed as a non-contact measurement method. This method is based on the triangular distance measurement method with a wide depth measurement range, and the measurement object is repeatedly moved by physically or optically moving the position of the measurement object or shape measuring device, and the measurement results are synthesized. Thus, the depth measurement range that can be realized by one measurement can be expanded by the amount of movement. As a result, it is possible to measure a wider range than the triangulation method at high speed, and to realize a shape measuring device and a shape measuring method capable of measuring a wider field of view with high resolution. And it becomes possible to extend the measurement range of a depth direction in each visual field.

  As shown in FIGS. 8 and 9 and the like, the shape measuring apparatus according to the first embodiment can measure the surface shape of the measurement object in a non-contact manner, and can be performed once by a triangulation method using a fringe projection method. The height information at each pixel in the light receiving optical system field of view can be acquired by measurement. Further, the shape measuring apparatus has a stage 140 that can move relative to the measuring unit, and the stage height reading axis and the observation optical axis have a common axis.

This shape measuring apparatus has a two-branch light receiving optical system that can be observed at two magnifications inside one upper head 101. As a result, it is possible to perform measurement with the magnification switched in the coaxial visual field. Two magnifications, a low magnification and a high magnification, have the same optical axis. A pattern projecting optical axis is tilted in a bilaterally symmetrical direction around the intersection of this optical axis and the best focus plane (focusing plane) of the light receiving optical system. Pattern projection is performed from each direction of the pattern projecting optical axis, and a plurality of images are captured and analyzed by the light receiving optical system to calculate height information.
(Range of measurement)

  As shown in FIG. 7, the in-focus surface and the measurement range of the shape measuring apparatus have an imaging field in which the upper head 101 looks down from directly above. The measurement object on the XYZ stage disposed at the lower part of the upper head 101 is measured from directly above. The user can adjust the focus by moving the XY stage 141 and moving the Z stage 142 by placing the object to be measured on the top surface of the XYZ stage. Alternatively, the focus can be adjusted by changing the relative distance (working distance) between the measurement object and the light receiving optical system by moving the light receiving optical system side. Note that the focus here means focusing of the light receiving optical system. In this shape measuring apparatus, as shown in FIG. 7, the depth measurement range in the height direction has a certain width that is a target up and down around the in-focus plane. However, it is not essential to be symmetric.

The XYZ stage is arranged in a direction in which the Z stage 142 substantially coincides with the light receiving optical axis. As a result, the height of the measurement object in the optical axis direction (or the relative positional relationship between the upper head 101 and the measurement object in the optical axis direction) can be changed only by moving the Z stage 142. A scale unit 160 capable of detecting the moving distance of the Z stage 142 is disposed inside the Z stage 142. The scale unit 160 is disposed immediately below the field of view of the upper head 101 as shown in FIGS. Since the scale unit 160 is arranged directly under the visual field in this way, the positional relationship between the depth measurement range and the measurement object can be detected with a minimum error. In general, when the position of the sensor to be detected, that is, the measurement axis is offset from the measurement position of the measurement object with respect to the coordinate point to be detected, a measurement error may occur based on Abbe's principle. This state occurs when the measurement axis is arranged in parallel with the position to be measured as shown in FIG. 13A. On the other hand, according to Abbe's principle, when the measurement axis and the measurement position of the measurement object are on the same plane extension as shown in FIG.
(Depth extension function)

  In order to extend the depth measurement range in the height direction, the optical axis direction driving unit 146 moves the relative distance between the stage 140 and the light receiving unit 120 in the optical axis direction. The light receiving unit 120 has a predetermined depth of focus, and can capture a pattern image only at a certain height (depth measurement range) determined by the depth of focus. Therefore, the measurable depth measurement range can be expanded by shifting the depth measurement range with the optical axis direction drive unit 146. That is, the height image generated in the same visual field (in the stage plane orthogonal to the optical axis direction of the light receiving unit 120) is connected in the height direction for each pixel of the corresponding XY coordinate, thereby limiting the depth measurement range. It is possible to obtain a composite height image that exceeds the height.

  In such a depth extension function, it is necessary to connect height images generated in the same field of view, that is, in the range of the XY plane. Moreover, it is necessary to connect height images generated under the same conditions. Specifically, when projecting pattern light from the left and right light projecting units 110 as shown in FIG. 7, in the case of a height image generated by projecting from both sides, the height images of both side projecting Are combined to generate a composite height image. Moreover, in the case of the height image produced | generated by the one side light projection which uses any one light projection part 110, the height image of one side light projection is connected similarly. At this time, the right-side projection height images are connected to each other in the case of right-side projection, and the left-side projection height images are connected to each other in the case of left-side projection.

  In the example of FIG. 7 and the like, the depth measurement range can be expanded by executing a plurality of measurements while moving the Z stage and combining the measurement results based on the heights of the Z stages at which the measurements were performed. . Such a single measurement with the Z stage height fixed is called “one-shot measurement”, and a measurement obtained by combining the results of measurement at a plurality of Z stage heights is called “depth extension measurement”.

  Here, the concept of extending the depth measurement range in the height direction will be described with reference to FIGS. 14A to 14C. 14A to 14C show the depth measurement ranges defined by the left projection range and the right projection range in the height A, the height B, and the height C, respectively, in a broken-line frame shape.

  When measuring the measurement object WK2 having a structure higher than the depth measurement range HIA (the range indicated by the dotted frame in FIG. 14A) of the shape measuring apparatus, the Z stage 142 is moved in the height direction (height A → B → C), it becomes possible to fit each surface of the measurement object WK2 within the depth measurement range. (Thick lines in FIGS. 14A to 14C)

  The optical images observed at this time are shown in FIGS. 15A to 15C, and the fringe images obtained by the fringe projection method are shown in FIGS. 15D to 15F, respectively. In FIG. 15A to FIG. 15C, the focused area is schematically shown by hatching.

  In FIGS. 15A and 15D, the lowest surface of the measurement object is focused at the height A, and the shape of the lowermost part of the measurement object can be measured. Also, as shown in FIGS. 15B and 15E, at the height B where the Z stage 142 is slightly lowered, the height A is outside the depth measurement range (a portion where the blurring of the fringe image is large, a red dotted line region). It is possible to measure the shape of a region that is in focus and within a certain width around this surface. Further, at the height C where the Z stage 142 is lowered, as shown in FIGS. 15C and 15F, the shape (red dotted line) existing at the highest point of the object to be measured has a focus, and the width is within a certain width centered on this surface. It becomes possible to measure the shape of the area.

  At these three heights, the height of the Z stage 142 is detected by the scale unit 160, and the stage height coordinate for each shot can be acquired. The scale unit 160 outputs a scale value indicating a relative distance between the stage 140 and the optical axis direction of the light receiving unit 120.

  Here, the procedure for connecting the measurement results for each one shot obtained by three measurements will be described based on the schematic diagrams of FIGS. 16A to 16D. As shown in FIGS. 16A to 16D, measurement data in a certain height range (a dotted line frame in FIG. 16A, a broken line frame in FIG. 16B, and a one-dot chain line frame in FIG. 16C) can be obtained by measurement for each shot. At this time, the relative movement amount of the stage 140 or the absolute stage height is detected at the time of measurement. By offsetting the detected coordinates as the value of the measurement data origin, the relative relationship of each shot is defined. By adding these results, it is possible to obtain linked measurement data in which the normal one-shot depth measurement range is expanded.

  In this way, the scale value when each height image is acquired by the scale unit 160 is stored, and at the time of synthesis, the pixel value of each height image is offset and synthesized based on the scale value. Specifically, the composition processing unit 216 stores the scale value of the scale unit 160 when each height image is generated, and when composing the height image, the pixel value of each height image is stored. Are combined with an offset based on the scale value.

As described above, the one-shot measurement that can be measured by one imaging by the fringe projection is repeatedly performed, and the height direction is connected, so that the measurement expanded in the depth direction is possible. It should be noted that the connection of the one-shot depth measurement ranges is not necessarily continuous, and may be discrete one-shot measurements separated in the depth direction. For example, when the user manually extends the depth, it is sufficient to acquire the three-dimensional shape data only for the area necessary for the measurement, and there is a case where all the information in the height direction of the measurement object is not required.
(Mask area)

  Further, even in the case of automatically extending in the depth direction, the user can set a range in which depth extension is desired. For example, the depth extension processing unit 215 includes a depth range setting unit 253 for controlling the optical axis direction driving unit 146 to set a range in which the focal position of the light receiving unit 120 is changed. A mask area may be set as an unnecessary range for expansion. Thus, the depth extension measurement includes not only the continuous connection of the one-shot measurement but also the separated connection.

  As described above, by detecting the height of the Z stage 142 together with the measurement of the measurement object, it is not necessary to consider the error of the actual movement amount with respect to the Z stage movement amount. Considering the case where the height of the Z stage is not detected here, in this case, the origin of each one shot is designated based on the Z stage movement pulse (movement instruction amount). It becomes a link measurement error as it is. In addition to this, depending on the configuration of the shape measuring apparatus, as shown in FIG. 13A, an error based on the Abbe principle may also occur due to a shift between the moving drive shaft and the actual measurement object loading position. On the other hand, as shown in FIG. 13B, the height of the Z stage is detected, and the measurement axis for detecting the height of the stage 140 is brought close to the optical axis, thereby reducing the error and increasing the height with high accuracy. Detection is realized. In addition, this makes it possible to improve the accuracy when combining in the height direction.

  When the stage 140 is expanded and measured in the depth direction, it is required to accurately detect the movement amount obtained by physically or optically moving the position of the measurement object or the light receiving unit 120. In the accurate detection of the movement amount, it is desirable that the photographing field of view of the measuring instrument and the detection position of the linear movement coincide with each other based on Abbe's principle. On the other hand, when detecting the movement of a stage with a long stroke, the detection mechanism tends to be long. For this reason, when the sensor is arranged directly under the stage, a longer sensor unit is arranged in accordance with the moving stroke, and there is a situation in which the entire length of the entire casing must be increased.

  Furthermore, in general, the linear motion mechanism itself requires a longer structure than the sensor moving part. This is because the width of the base casing is added to the amount of movement in order to increase the rigidity of the moving stage. In addition, an increase in size due to an overhang of the guide is inevitable. As a result, the height of the entire stage will increase, the top of the stage will be higher than the bottom of the installation, reducing the convenience for the user, and the amplitude of the measurement object due to vibration tends to increase. Disadvantages increase. In view of such circumstances, in the present embodiment, a scale unit 160 that detects the height of the stage 140 is arranged directly under the field of view, thereby increasing the degree of freedom of arrangement of the stage drive shaft.

In the example illustrated in FIGS. 16A to 16D, the measurement object WK <b> 2 has a relatively simple step. Depending on the measurement object, the entire height direction of the measurement object can be accommodated in the measurement region at two stages of Z stage height (for example, height A in FIG. 15A and height B in FIG. 15B). The synthesis of common height information in such a plurality of one-shot data at each height will be described.
(Common height information synthesis logic)

  As a method for synthesizing common height information, there are a method of calculating a weighted average, or a method of adopting only one from the viewpoint of reliability of height information. When the height information indicates almost the same height, it is considered that the height information obtained at a position closer to the in-focus plane has less error. Therefore, the calculation is performed by the weighted average according to the distance from the in-focus plane.

On the other hand, when the height information differs greatly, there is a high possibility that any height information is noise due to the influence of multiple reflection of light inside the measurement object. Therefore, in this case, the reliability for determining which height to use is determined from the degree of blurring of the image or the contrast of the luminance with or without illumination, and the higher reliability is adopted.
(Unreliable data)

  Among the data included in the height image, pixels with high reliability are displayed on the display unit 400 or used for measurement. On the other hand, since there is a concern that data with low reliability includes an error, it is not displayed on the display unit 400 and is not used for measurement or the like.

  On the other hand, even low-reliability data can be used to determine whether or not three-dimensional shape data exists during depth extension. Whether or not the height image is acquired by extending in the depth direction is sufficient if it can be determined whether or not the measurement object is continuously present in the height direction, and high accuracy is not required. Therefore, in the present embodiment, even low-reliability data that is not used for normal measurement or height image construction can be used for determining whether or not depth extension is necessary.

As an example, FIGS. 17A to 17B show height images generated in a depth measurement range up to a certain height due to restrictions on the specifications of the shape measuring device for a certain measurement object. In FIG. 17A, pixels with low reliability within the depth measurement range are not displayed. As described above, when a height image is displayed on the display unit 400, it is general that pixels with high reliability are displayed and pixels with low reliability are not displayed. On the other hand, FIG. 17B shows an example in which pixels with low reliability are displayed in the height image of FIG. 17A. In this figure, the pixel on the upper end surface of the columnar shape indicated by the area surrounded by the broken line is inaccurate and is not suitable as data used for measuring the dimension of the measurement object. It can be inferred that it will exist continuously above the end face. Therefore, when performing the depth extension measurement, a depth image can be generated in a wider range by further setting the depth measurement range above. Similarly, height images of measurement objects having other shapes are shown in FIGS. 18A to 18B. In this figure, FIG. 18A shows a height image in which pixels with low reliability are not displayed, and FIG. 18B shows a height image that is displayed including pixels with low reliability. Similarly, by using the area surrounded by the broken line in FIG. 18B, it can be estimated that there is a measurement object continuously further upward than this, and the direction in which the depth is expanded in the depth extension measurement is indicated by this solid shape data. It becomes possible to judge from.
(Pixel at the end of 3D shape data)

In this way, it is possible to determine whether or not to perform depth extension measurement using the solid shape data located at the end of the height image. Note that the present invention is not limited to the method of performing the depth extension measurement based on the pixels at the end of the three-dimensional shape data, and may perform the determination based on data in the middle of the depth measurement range. For example, it is determined based on whether or not a pixel at a predetermined distance from the edge has solid shape data, or if any pixel in the depth measurement range has solid shape data, depth extension measurement is performed. Can also be configured to execute. For example, an unmeasured pixel when there is a pixel whose luminance value is such that it can be determined that a pattern is projected among pixels for which final three-dimensional shape data has not been obtained It may be determined that the determination processing unit determines that there is a depth extension measurement. In this case, in order to avoid noise and erroneous detection, it is preferable to set a threshold value, such as a case where the number, area, and volume of the pixels having the three-dimensional shape data are equal to or greater than a certain level.
(Display mode switching part)

As described above, in the shape measurement program according to the present embodiment, it is possible to display pixels with low reliability on the display unit 400. For example, the display mode switching unit can switch between a normal display mode in which pixel data with low reliability is not displayed and a visualization mode in which pixel data with low reliability is also displayed. In the example of FIGS. 17 and 18 described above, FIGS. 17A and 18A show the normal display mode, and FIGS. 17B and 18B show the visualization mode, respectively.
(Necessity determination of depth extension measurement based on 3D shape data)

  In the above example, the example in which the necessity of the depth extension measurement is determined based on the pixel data constituting the height image, that is, the data obtained by calculating the height information has been described. However, the present invention is configured not to limit the necessity of depth extension measurement to a height image, but to perform the necessity determination based on original data or raw data before calculating height information. May be. Such an example will be described with reference to FIGS. FIG. 19 shows an example of a fringe image obtained by projecting a fringe pattern onto the measurement object. In this figure, since the area surrounded by the broken line is outside the depth measurement range, the contrast of the stripe pattern is low. However, since the fringe pattern is projected even outside the depth measurement range, the accuracy is lower than that of other fringe patterns, but it can be used to determine whether or not the depth extension measurement is necessary. That is, in the example of FIG. 19, since it can be grasped that the measurement object has a shape at a position higher than the depth measurement range (in this case, protrudes in a cylindrical shape), the depth extension measurement is performed in this direction. Can be determined by the fringe pattern outside the depth measurement range.

Furthermore, when performing the depth extension measurement, it is possible to determine whether to extend upward or downward based on such solid shape data. For example, in the example of the measurement object shown in FIG. 20, there are portions outside the depth measurement range on the upper side and the lower side in the figure. Of these, the upper region surrounded by the thick broken line has higher luminance than the lower region surrounded by the thin broken line. In general, for data outside the depth measurement range, the side closer to the camera or the illumination is brighter and the side farther away is more prone. Therefore, based on the brightness and contrast of the projection pattern, it is possible to determine whether data outside the depth measurement range exists outside the higher side of the height range or outside the lower side. Therefore, it is possible to estimate in which direction the depth extension measurement is performed to obtain the height image of this portion.
(Moving pitch)

In the case of connecting the height images so as to be continuous, the position where the Z stage 142 is moved is different from each other in the depth measurement range so that a gap in the height direction does not occur when the height images are connected. It is necessary to make it below the height of. In order to smoothly connect the heights at the time of synthesis, as shown in FIG. 16D, it is desirable that the depth measurement ranges are slightly shorter than the depth measurement ranges so that the depth measurement ranges partially overlap. However, if the overlap area is too large, the total number of sheets required for connection increases, and a trade-off with measurement time occurs. For this reason, it is preferable to overlap about 1% to 33% of the depth measurement range, more preferably 5% to 25%, and still more preferably 10% to 20%.
(Movement pitch of texture image)

  When generating a composite image, the movement pitch for moving the Z stage in the depth direction in order to capture a plurality of height images and the movement pitch for capturing a texture image may be the same, but it is not always necessary to match them. They can also be set independently. In particular, for a height image, height information can be measured if a contrast difference or the like can be confirmed even if a pattern image such as a fringe image is not always in focus. On the other hand, the texture image has a great influence on the appearance unless it is in focus. For this reason, it is preferable to make the movement pitch of the texture image finer than the movement pitch of the height image, in other words, to increase the number of texture images. By synthesizing a plurality of texture images photographed at a fine movement pitch, a clear depth synthesized image that is almost in focus can be obtained. By mapping this depth synthesized image to a synthesized height image obtained by synthesizing the height image, it is possible to obtain solid shape data having clear texture information and deep depth information.

  On the other hand, each time the stage is moved in the depth direction in order to capture multiple height images, the texture images are also captured together, the captured texture images are combined in depth, and the combined texture images are converted into height images. You may make it map on the synthetic | combination height image obtained by the synthesis | combination. In this case, although the sharpness of the depth composite image is lowered, there is an advantage that the processing does not take time because the stage movement for obtaining the depth composite image is not required other than the stage movement for capturing the height image.

  Here, the relationship between the roughness (relative value) of the image at the time of connection and the movement pitch is shown in the graph of FIG. In FIG. 21, the horizontal axis indicates the movement pitch with respect to the depth measurement range height, and the vertical axis indicates the surface roughness when the planes are connected obliquely. As shown in this figure, it can be seen that the roughness increases as the moving pitch is increased.

In the above example, the movement pitch for moving the Z stage is a fixed amount, but the present invention is not limited to this configuration, and may be an arbitrary movement amount specified by the user, for example.
(Connection area of height image)

In this way, when connecting a plurality of height images, there is a problem in handling of regions overlapping in the height direction between the height images. In other words, it is necessary to determine which should be used in the combined height image as the height information of the overlapping portions in the two height images to be connected. For this reason, the composition processing unit 216 predetermines how to handle overlapping portions. For example, when the height image HIA obtained in FIG. 16A is connected to the height image HIB obtained in FIG. 16B, in the composite height image CHI in FIG. 16D, the height image HIA and the height image HIB The lower portion overlaps in the overlap region OL1. Similarly, when the height image HIB is connected to the image HIC, the upper portion of the height image HIB and the lower portion of the height image HIC overlap in the overlap region OL1. In such a case, the composition processing unit 216 processes the overlapping region based on the reliability index.
(Reliability index)

  Here, the reliability index indicates how close the height information of the pixels in the stage plane corresponding to each height image is to the true value, that is, the true height in the overlapping region where the depth measurement ranges overlap. It is an indicator to show. When the height information is used as the pixel value of the pixels constituting the height image, it can be said that the index indicates the reliability of the pixel value.

  In this way, when connecting multiple height images in the depth direction, a composite height that improves the reliability of height information in overlapping areas by using a reliability index without using a simple addition average etc. An image can be obtained.

  As a specific reliability index, the one having a shorter distance from the focal position of the light receiving unit 120 is employed. When creating a height image by the pattern projection method, a pattern image (for example, a fringe image) can be obtained even if it is not the focal position, and although the height information can be calculated, the pattern image becomes clearer as it is closer to the focal position. Therefore, the accuracy of the height information tends to be high. Therefore, using the focal length as a reliability index, it can be determined that the reliability of the obtained height information is higher as the distance between the focal position when the height image is generated and the target pixel is closer.

  Alternatively, contrast with surrounding pixels may be used as a reliability index. Specifically, as a reliability index of a pixel of a certain height image, a contrast between a corresponding pixel in the pattern image from which this height image is generated and a pixel located around this pixel is used. The higher the contrast with surrounding pixels, the clearer the boundary, the higher the height information can be calculated. Alternatively, the luminance value or the like of the original pattern image may be used as a reliability index.

  Based on the reliability index obtained in this way, the pixel with the higher reliability index can be adopted as the pixel of the composite height image.

  In the case of a pixel for which height information is not obtained, the pixel for which height information is obtained is used as invalid. When the height information is not obtained for both pixels, the height information is null even in the composite height image. For example, in the region where the depth measurement ranges overlap, if the pixel value of one height image is valid and the pixel of the other height image is invalid for the corresponding XY coordinate pixel value of the height image, the valid pixel Are used. Thereby, when connecting a plurality of height images in the depth direction, it is possible to obtain a composite height image obtained by interpolating missing pixels with respect to height information in overlapping regions.

  On the other hand, not only can the higher reliability index be adopted and the lower one discarded, but weighting can also be performed. For example, it is expected that more accurate height information can be obtained by performing weighting so that the specific gravity of the pixel value having a higher reliability index is high and the specific gravity of the lower pixel value is low.

Alternatively, the height information of the composite height image may be calculated based on the weighted average using the reliability index.
(Difference)

  It is also possible to extract pixels having a difference greater than or equal to a predetermined value from two height images that partially overlap. Specifically, in a region where the depth measurement ranges overlap, the composition processing unit 216 can extract pixels as differences, and among them, a pixel value having a high reliability index can be adopted. In this case, the synthesis processing unit 216 may be provided with a difference pixel extraction unit that extracts pixels having a difference of a predetermined value or more between height images.

Further, when a height image in which the depth measurement ranges partially overlap, the condition for selecting or calculating the height information can be changed according to the difference amount of the data. For example, when the data difference is greater than or equal to a predetermined value, the pixel with the higher reliability index is used, and when the difference is less than or equal to the predetermined value, the height of the composite height image is calculated based on the weighted average using the reliability index. The information may be calculated.
(Set the range of consolidated measurement)

  When performing the above-mentioned connection measurement, several methods for determining the depth measurement range are conceivable. For example, (1) A method in which the upper and lower limit coordinates of the Z stage are input by the user, and a range including the upper and lower limits is measured and connected at a constant movement pitch; (2) How many steps in the vertical direction from the current Z stage height There may be a method of allowing the user to determine whether to acquire and performing and linking a plurality of steps at a constant movement pitch.

However, in any of these depth measurement range determination methods, a procedure for determining the depth measurement range is required as preprocessing for measurement. This procedure is not only labor-intensive, but also requires a setting each time a different height range is specified in a plurality of fields of view, resulting in a very complicated operation. Therefore, in the present embodiment, the range of connection measurement can be automatically determined.
(Depth measurement range setting)

  In order to automatically determine the connected depth measurement range, the first embodiment defines a depth search range. First, in the shape measuring apparatus shown in FIG. 22, the projection light beam is irradiated toward the measuring object WK as a parallel light beam from a symmetrical angle of the light receiving optical system. Here, the range in which the shape measuring device can measure with a guaranteed accuracy is the depth measurement range. In the depth measurement range, the measurement results obtained by averaging or synthesizing the measurement results from the left and right light projections can be expected to stabilize the measurement and increase the accuracy. Is defined as

On the other hand, in each of the light beams irradiated independently from the left and right, the projected light beam is irradiated in a height range wider than the depth measurement range set with high accuracy. Therefore, the union area of the left and right projected light beams that fall within the field of view is defined as the depth search range. Thereby, even if it cannot be used for measurement, it is possible to obtain approximate height information in a shape outside the depth measurement range on the measurement object.
(Combination of triangulation method)

  In the shape measuring apparatus according to the present embodiment, measurement is performed by combining the space code method and the multi-slit method, or the space code method and the sine wave phase shift method in order to perform measurement with higher accuracy. However, in the region beyond the depth measurement range, the projected fringe pattern is blurred due to the depth of field of the optical system, making it impossible to measure the height with sufficient resolution and accuracy. On the other hand, as shown in FIG. 19, the fringe pattern responsible for the relatively low resolution measurement of the spatial coding method has a depth measurement range because the thickness of the fringe itself is sufficiently thick with respect to the depth of field of the optical system. In many cases, a rough striped shape is maintained even in a region beyond the range. In FIG. 19, the fringe pattern irradiated on the cylindrical top surface is located on the depth search range, so that the fringes are blurred, but the rough fringe shape is maintained. By utilizing this characteristic, it is possible to obtain rough height information within the depth search range and outside the depth measurement range.

In this example, the spatial code method and the multi-slit method, or the spatial code method and the sine wave phase shift method were combined, but two or more patterns having different periods were used without using the spatial code method. By projecting each phase shifted, it is possible to obtain the same effect as the combination measurement with the spatial code method. For example, a first pattern with a coarse period is projected and phase-shifted to measure the measurement target WK with a low resolution, and then a second pattern with a short period is projected and phase-shifted to measure the measurement target WK. By performing high-resolution measurement and combining these, it is possible to perform highly accurate measurement having an absolute value. In this case, the low-resolution measurement result can be handled in the same manner as the measurement result of the spatial code method.
(Depth extension mode selection unit 254)

As described above, in the shape measuring apparatus according to the present embodiment, the one-shot measurement function that performs a single measurement with the Z stage height fixed, and the depth extension measurement function that combines the results measured at a plurality of Z stage heights. It has. Here, as the depth extension measurement function, either an automatic depth extension function that automatically performs depth extension or a manual depth extension measurement function that performs depth extension manually can be performed. Alternatively, these can be switched. In order to switch between automatic and manual of the depth extension measurement function, the depth extension mode selection unit 254 is used.
(Example 1: Automatic depth extension based on cumulative image)

Here, automatic depth extension according to the first embodiment will be described. From the approximate height information within the depth search range and outside the depth measurement range, find the Z stage position for measuring those heights within the depth measurement range, and move to that position to perform the measurement automatically. Extend the range of consolidated measurements. Here, as shown in FIG. 23, the pixels (measurement pixels) from which the three-dimensional shape data is acquired are accumulated among the pixels constituting the visual field. In the example of FIG. 23, in the image IG1 imaged in the depth measurement range HT1, the height can be acquired in the rectangular peripheral area, but the height cannot be acquired in the central elliptical area, and the height is high. The image has pixels with missing information. Then, when the depth measurement range is changed from HT1 to HT2 and the image IG2 is captured, the height is obtained in a part of the pixels whose height has not been measured in the image IG1. Similarly, when an image IG3 is imaged in the depth measurement range HT3 and an image IG4 is imaged in the depth measurement range HT4, the height is acquired with the missing pixels. In this way, the pixels whose height is obtained for each depth measurement range are accumulated as shown in FIGS. 24A to 24D. For example, FIG. 24A shows an image IG1, and FIG. 24B shows an accumulated image obtained by accumulating pixels in which the height information is obtained in the image IG2. Accordingly, it can be seen that the unmeasured pixels lacking the height information are reduced as compared with the image IG1 in FIG. Further, FIG. 24C shows an accumulated image obtained by accumulating pixels whose height information is obtained in the image IG3, and the area of unmeasured pixels is further reduced as compared with FIG. 24B. In FIG. 24D, the pixels obtained in the image IG4 are accumulated, and the height information is obtained from the pixels in all regions. In this way, the presence or absence of an unmeasured pixel (unmeasured pixel) is determined based on the accumulated image obtained by accumulating the acquired pixels, and if there is an unmeasured pixel, the acquisition of the three-dimensional shape data is continued automatically. . Then, the pixels constituting the visual field are sequentially filled with the measurement pixels, and the process is terminated when there are no unmeasured pixels.
(3D shape data)

Here, the three-dimensional shape data is data for measuring the shape of the measurement object by the pattern projection method, and does not necessarily include height information. That is, even if the height information is unmeasured data, the data including the data that can calculate the height information is called solid shape data.
(Automatic depth extension procedure)

  Such an automatic connection procedure is shown in FIG. First, in step S2501, measurement is performed. In step S2502, it is determined whether or not there is a region having a corresponding height in the depth search range. If there is a region, the process proceeds to step S2503, and the Z stage 142 is set to a height corresponding to the depth search range. The Z-stage position is moved to the measurable area. At this time, the already measured Z stage position is excluded. If there are a plurality of candidate Z stage positions, they are moved to the closest position. Then, the process returns to step S2501, and processing such as measurement is repeated. On the other hand, if it is determined in step S2502 that there is no region within the depth search range, the process proceeds to step S2504, and the measurement ends.

  As described above, the height information outside the depth measurement range is stored in the depth search range in the measurement at each position of the Z stage 142. As a result, even if the Z stage position to be moved exists on both the upper and lower sides, the Z stage can be expanded in both the upper and lower directions. Moreover, the situation where the measurement becomes an infinite loop can be avoided by not moving to the Z stage position once measured.

  By such a procedure, it is possible to perform a linked measurement that covers all the heights of the measurement object. In addition, since the measurement ends when the movement of the Z stage 142 is no longer necessary, the total time of the linked measurement is always minimized.

In addition, the upper limit height of the Z stage 142 can be set for automatic depth expansion. The upper limit height of the Z stage 142 is set to a prescribed value on the shape measuring device side as the maximum value of the Z stage position at the time of automatic depth extension, and is slightly different depending on the height of the measurement object placed on the stage 140 It is also possible to allow automatic setting taking into account the margin, or to allow the user to adjust the specified value or the automatically set value, or to specify an arbitrary value. As a result, it is possible to avoid a situation in which the Z stage rises too much during automatic depth extension and the measurement object on the stage collides with the lens.
(Modifications related to optical system)

In the shape measuring apparatus according to the first embodiment described above, the light receiving unit 120 constituting the imaging unit is a monocular camera, and the two light projecting units 110 are provided above the measurement object, and light is projected from two directions. Although the configuration has been described, the present invention is not limited to the configuration of the optical system, and other optical systems may be employed. For example, a monocular camera can be used as the light receiving unit, and the light projecting unit can project light from only one direction. Or you may make it project from one direction using a compound eye camera instead of a monocular camera as a light-receiving part.
(Variation regarding measurement principle)

In the shape measuring apparatus according to the first embodiment described above, the triangulation method of gray code and multi-slit projection is adopted as the measurement principle for measuring the three-dimensional shape of the measurement object. The measurement principle for measuring the three-dimensional shape is not limited to this, and other methods can be used as appropriate. For example, a triangulation method using sinusoidal light projection, a triangulation method using random pattern projection, a triangulation method using line light projection and scanning, and the like can be used.
(Modifications related to the movement mechanism of the measurement object)

Furthermore, in the shape measuring apparatus according to the first embodiment described above, a configuration in which the Z stage 142 is directly moved is adopted as a mechanism for moving the Z stage 142, but the present invention limits the moving mechanism of the measurement object to this. However, other configurations can be used as appropriate. For example, a moving stage having six degrees of freedom of translation and rotation may be used for each of the X, Y, and Z axes, or manual automatic movement may be used.
(Modified example of the working distance adjustment mechanism of the measurement object)

Furthermore, in the shape measuring apparatus according to the first embodiment described above, a configuration is adopted in which the working distance between the measurement object and the light receiving unit 120 is adjusted by moving the Z stage 142, but the present invention adjusts the working distance. The mechanism is not limited to this, and other configurations can be used as appropriate. For example, the light receiving unit side may be moved.
(Example 2: Automatic depth extension based on edge of single height image)

In the above example, the automatic depth extension procedure for determining whether or not the depth extension is necessary based on the accumulated image obtained by accumulating the acquired pixels has been described. However, according to the present invention, it is not always necessary to accumulate past pixels for depth extension in the height direction of an image and automatic connection. For example, whether or not depth extension is necessary can be determined from a single height image. Such an example will be described below as a second embodiment. Here, as shown in FIG. 26, a height image is acquired within a certain depth measurement range. Then, in the obtained single height image, it is determined whether or not the end portion of the depth measurement range, that is, the upper or lower limit of the depth measurement range has the three-dimensional shape data. For example, if there is solid shape data at one end of the height image, it is estimated that there is a high possibility that the measurement object extends outside the depth measurement range, and height measurement is performed by changing the depth measurement range. Do. In the depth measurement range after the change, it is similarly determined whether or not the end portion has the solid shape data. If the solid shape data is similarly included, the depth measurement range is further changed and the process is continued. On the other hand, when the solid shape data does not exist at the end, the process in this direction is finished, it is determined whether or not the solid shape data exists at the other end, and the same processing is performed. If there is no 3D shape data at both ends, the process is terminated. The above is an example. For example, when three-dimensional shape data exists at both ends, the depth measurement range is extended to one end, and then the depth measurement range is extended to the other end. Also good. However, in this method, after the Z stage is expanded in the direction of one end, the Z stage is returned to the original position and expanded in the direction of the other end, which may increase the amount of movement of the Z stage. Therefore, as described above, it is preferable to continue the expansion in one of the upper and lower directions and then expand in the other direction.
(Example 3: Automatic depth expansion based on the range of a single height image)

Further, the present invention is not limited to the above-described method for determining whether or not the depth measurement range is extended depending on whether or not the solid shape data exists at the end of the single height image. If there is a pixel whose data can be measured, the depth measurement range may be extended. That is, in the height image acquired in a certain depth measurement range, if there is a pixel whose solid shape data can be measured in any one of the depth measurement ranges, it is estimated that the measurement object exists, Continue to extend the depth in the direction. If this method is used, the determination can be made simply by including the three-dimensional shape data in the height image, so that the determination process can be easily performed.
(Shape measurement program with automatic depth extension measurement function)

Here, FIGS. 27 to 31 show examples of user interface screens of the shape measurement program for the automatic depth extension measurement function. The shape measurement program shown in these drawings also includes an image display area 410 and an operation area 420. The image display area 410 is an area for displaying a texture image and a height image of the measurement object. The operation area 420 is an area for the user to mainly instruct various operations and to explain and guide the operation content to the user. In the screen of FIG. 27 and the like, the image display area 410 is arranged on the most part of the screen from the left side, and the operation area 420 is arranged on the right side. Further, on the image display area 410, as one form of an imaging setting unit for setting imaging conditions, an imaging setting area for performing magnification display, focus adjustment, and the like on an image displayed in the image display area 410 510 is arranged. In addition, these arrangement | positioning is an example and the arrangement | positioning, magnitude | size, etc. of each member can be changed suitably.
(Observation mode switching part)

From the shape measurement program, observation based on the height image and observation based on the texture image can be performed. The observation is switched from the observation mode switching unit. In the example of FIG. 27, as one mode of the observation mode switching unit, a “3D measurement” tab 531 and an “image observation” tab 532 are provided in the operation area 420, and the observation mode is selected by selecting one of the tabs. Switching is possible. When the “3D measurement” tab 531 is selected, generation of a height image and observation such as measurement based on the generated height image can be performed. On the other hand, when the “image observation” tab 532 is selected, observation such as measurement based on the texture image becomes possible.
(Full auto observation mode)

Here, to execute the automatic depth extension measurement function by the shape measurement program, the “full auto” button 533 is pressed from the screen of FIG. Thereby, the full auto observation mode, that is, the automatic depth extension measurement mode is selected. In the full auto observation mode, expansion in the depth direction is automatically performed, and a composite height image of the measurement object displayed in the image display area 410 is acquired.
(Manual observation mode)

On the other hand, in order to execute the manual depth extension measurement function by the shape measurement program, the “manual” button 535 is pressed from the screen of FIG. Thereby, the manual observation mode is selected, and extension in the depth direction can be manually performed. An example of the manual observation mode is shown in FIG. In the manual observation screen 540 shown in this example, the operation area 420 includes a “Z measurement range” designation field 541, a “measurement mode” selection field 542, a “measurement direction” designation field 543, a “measurement brightness” setting field 544, and a “texture”. A “shoot” selection field 545 is provided.
("Z measurement range" designation field 541)

  The “Z measurement range” designation field 541 forms one form of the depth extension mode selection unit 254 that selects the depth extension measurement mode. In this example, as shown in FIG. 28, in the “Z measurement range” designation field 541, the user can select any one of “automatic”, “measurement”, and “manual” from the drop box. When “automatic” is selected, an automatic depth extension mode for automatically executing depth extension measurement is set. When “manual” is selected, the user enters a manual depth extension mode in which the user manually performs depth extension measurement. On the other hand, when “measurement” is selected, measurement in a predetermined depth range is performed. In other words, a height image is generated within a predetermined height range that can be measured by the shape measuring device without expanding the depth range. This corresponds to the above-described one-shot measurement function that performs one measurement with the Z stage height fixed.

  The “measurement mode” selection column 542 is an aspect of the measurement mode selection unit 257 that selects the measurement mode. The measurement mode is to adjust the imaging conditions of the fringe image captured when generating the height image, so that measurement according to the purpose of observation can be performed, and a plurality of measurement modes are prepared in advance. The user selects a desired measurement mode according to the purpose of observation. In the “measurement mode” selection field 542, one of a plurality of measurement modes is designated. Here, as shown in FIG. 29, one of “Auto”, “Standard”, “Reflection / Studding light removal mode”, and “High definition (roughness)” can be selected from the drop box.

  When “Auto” is selected, an odd measurement mode in which an appropriate measurement mode is automatically selected from a plurality of measurement modes is selected.

  When “Standard” is selected, the standard measurement mode, which is a standard measurement mode, is selected.

  When “reflection / recessed light removal” is selected, a reflection / recessed light removal mode suitable for reflection of light projection and removal of light leakage is selected. This measurement mode is also called a fine measurement mode, which is a measurement mode in which the projection pattern of measurement light is made finer than the standard measurement mode, and indirect light components such as diverging light, multiple reflection, and irregular reflection are eliminated. This measurement mode is highly effective when the object to be measured is a translucent body such as a cloudy resin or an uneven metal body such as a screw. The time required for measurement is longer than that in the standard measurement mode.

  When “high definition (roughness)” is selected, a high definition mode for generating a higher definition height image such as measurement of the roughness of the surface of the measurement object is selected.

  Other measurement modes may be added. For example, the halation removal measurement mode is a measurement mode in which the projection pattern is the same as the standard, but the dynamic range is expanded and measured by changing the exposure time or the projection light quantity of the measurement light. As a result, it is possible to obtain an effect of suppressing black crushing and overexposure with an object having a sharp contrast. For example, it is effective for an object in which a black resin is buried in a metal body. The time required for measurement is longer than that in the standard measurement mode. Furthermore, the super fine measurement mode is a combination of the above-described reflection / intrusion light removal mode and the halation removal measurement mode, and can improve the accuracy most, but the time required for the measurement is the longest.

  In the “measurement direction” designation field 543, the light projecting unit 110 is designated. Here, either or both of the first light projecting unit 110A and the second light projecting unit 110B shown in FIG. 4 can be selected. In the example shown in FIG. 30, one of “left side only”, “right side only”, and “both” can be selected from a drop box provided in the “measurement direction” designation field 543.

  When “left side only” is selected, the first light projecting unit 110A in FIG. 4 is selected, and only light projection from the left side is obtained. When “right side only” is selected, the second light projecting unit 110B of FIG. 4 is selected and light is projected only from the right side. When “both” is selected, the first light projecting unit 110A and the second light projecting unit 110B in FIG. 4 are selected and light is projected from both sides.

In the “measured brightness” setting field 544, the brightness of the image displayed in the image display area 410 is adjusted. The brightness of the texture image can be achieved, for example, by adjusting the exposure time and shutter speed of the light receiving unit 120 that is an imaging unit. In the “measured brightness” setting field 544, automatic brightness adjustment for automatically adjusting the brightness of the texture image and manual brightness adjustment for manual adjustment can be switched with a radio button. For example, as shown in FIG. 31, when “Auto” is selected, the brightness is automatically adjusted to an appropriate brightness according to the image currently displayed in the image display area 410. If “Manual” is selected, the user can manually adjust the brightness of the image. Here, the brightness of the texture image is adjusted with a slider. Further, the brightness of the image displayed in the image display area 410 is reflected in real time on the brightness after the adjustment in the “measurement brightness” setting field 544.
(Texture image selection means 460)

In the “texture photographing” selection column 545 which is one form of the texture image selection means 460, a texture image to be photographed is selected. Here, “normal” and “HDR” can be selected by radio buttons. When “Normal” is selected, a setting is made to capture a normal texture image. On the other hand, when “HDR” is selected, an HDR image is selected. Also, other texture images may be selectable. For example, a depth composite image may be selectable.
(Example 3: Manual depth extension)

  In the above example, the example in which the depth extension and the connection measurement are automatically performed has been described. However, the present invention is not limited to a configuration in which depth extension is performed automatically, and this can also be performed manually. Based on the flowchart of FIG. 32 and FIGS. 33A to 33G, a procedure for generating a composite height image from a plurality of height images having different heights by manually performing depth extension using this manual depth extension function. explain. First, in step S3201, an optical image of a measurement object for which a composite height image is to be acquired is displayed. Here, the user places the measurement object on the Z stage 142, acquires an optical image, and displays it on the display unit 400. As an example, FIG. 33A shows an optical image A on which a measurement object is displayed. At this time, the focus position may be adjusted by the user or automatically. Alternatively, the focus position need not be adjusted. As a method of automatically adjusting the focal position, for example, when the mouse is clicked at a desired position on the optical image, autofocusing is performed so that the designated position is focused.

  In step S3202, the position where the height image is to be acquired is designated as the height designation position. Here, on the optical image displayed on the display unit 400, the user designates a height designation position where a height image is to be obtained by the operation unit. At this time, since the optical image is a two-dimensional image, the height designation position is designated on the XY plane. For example, when a desired position is clicked on the display unit 400, the Z coordinate position of the XY position is recorded as the height designation position. In addition, autofocus may be automatically executed based on the height designation position. Thereby, the optical image at the height designated position can be displayed more clearly.

  In step S3203, a height image is generated at the designated height designation position. For example, the user presses a height image generation button on the user interface screen of the shape measurement program. Thereby, the shape measuring apparatus acquires height information (Z coordinate) at the designated height designation position (XY coordinate), and generates a height image in a predetermined depth measurement range based on this height. As an example, FIG. 33D shows a height image D obtained at the height designation position designated on the optical image A in FIG. 33A. Note that the height image D is not necessarily displayed on the display unit, and may be hidden. The processing can be performed in the background without making the user aware of the intermediate height image generation operation. However, the height image D may be displayed for the user to confirm. Further, the generated height image D is temporarily stored for use in a composite height image generation process to be described later.

  Note that when the designation of the height designation position is accepted in step S3202, the generation of the height image in step S3203 may be automatically executed. Thereby, labor of the operation on the user side can be saved. For example, when an arbitrary position on the optical image is single-clicked, autofocus works, and when double-clicked, the height image acquisition process is executed. Thereby, the user can adjust the focus position, specify the height designation position, and generate the height image with a few operations.

  Next, in step S3204, it is determined whether or not another height designation position is designated. That is, it is determined whether or not a necessary number of height images have been obtained in order to synthesize height images generated at different heights. Here, the shape measuring apparatus side receives an instruction whether the user designates another height designation position or finishes the designation of the height designation position and proceeds to the generation of the composite height image.

  If the user wants to add a height image, that is, if he / she wants to further specify another height designation position, the process returns to step S3202, and another height designation position is designated. At this time, the height designation position is designated on the same image as the optical image for which the height designation position has already been designated. In other words, the field of view of the optical image is not changed. This is because, in order to generate a composite height image, it is necessary to acquire height images of different heights from the measurement object having the same posture. If it is desired to change the field of view of the optical image, the process returns to step S3201 and starts again from the display of the optical image.

  In addition, when another height designation position is designated, it is necessary to designate a height different from the height designation position already designated on the optical image. For this reason, it is preferable to change the focal position of the optical image. At this time, the user may manually adjust the focal position, or may automatically adjust the focal position. For example, as described above, when the user clicks a desired position on the optical image, a method in which autofocus is executed at a designated position can be used. As an example, FIG. 33B shows an example of an optical image B in which a position higher than the height designation position designated in FIG. 33A is designated as the height designation position for the same measurement object as in FIG. 33A. Further, FIG. 33C shows an optical image C adjusted to a higher focal position than that in FIG. 33B. Further, FIG. 33E shows the height image E generated at the height specified position specified in FIG. 33B, and FIG. 33F shows the height image F generated at the height specified position specified in FIG. 33C.

  Thus, the user needs to acquire a plurality of height images in different height ranges so as to include the entire height range of the measurement object. Preferably, it is preferable to sequentially designate height designation positions in order from a low position to a high position or from a high position to a low position among different heights of the measurement object. For example, height information of a designated height designation position is displayed in a designated height designation position display field on the display unit 400 so that a plurality of different height designation positions can be appropriately designated. The height information list may be updated each time a position is added.

  When an additional height designation position is designated in this way, the process similarly proceeds to step S3203 to generate a height image at the designated height designation position and temporarily store it. In step S3204, it is similarly determined whether or not an additional height designation position is necessary.

  If the user determines that all necessary height images have been obtained in this way, the process advances to step S3205 to instruct generation of a composite height image. Here, the shape measurement apparatus combines the obtained plurality of height images in the depth direction, and generates a combined height image having a wider depth range by the combining processing unit 216. As an example, FIG. 33G shows a combined height image G obtained by combining the height image D of FIG. 33D, the height image E of FIG. 33E, and the height image F of FIG. 33F. In this way, a plurality of height images are combined, and a height image in a height range wider than the height range physically measurable by the shape measuring apparatus can be obtained.

The above manual depth extension procedure may be provided with a guidance function so as to guide the procedure to be performed to the user by the shape measuring apparatus. For example, when the manual depth extension is executed by the shape measurement program, the operation to be performed can be displayed on the display unit to guide the procedure to be performed. With this method, even a user who is not familiar with the operation of the shape measuring apparatus can easily generate a composite height image by presenting and guiding the operation to be performed.
(Z linkage manual setting)

  The procedure for executing the above manual depth extension function will be described with reference to the user interface screens shown in FIGS. First, as shown in FIG. 34, the “3D measurement” tab 531 is selected, and the “manual” button 535 is pressed to display the manual observation screen 540 of the 3D measurement screen. “Manual” is selected to switch to the manual depth extension mode, and a texture image is displayed in the image display area 410 (step S3201 in FIG. 32).

  In this state, the focus position of the texture image is adjusted, and the height designation position where the height image is to be acquired is designated (step S3202 in FIG. 32). The height designation position is displayed numerically in the focus position display field 516b of the imaging setting area 510.

Then, a height image is generated with reference to the designated height designation position (step S3203 in FIG. 32). Here, the “measurement” button 546 provided in the lower right of FIG. 34 is pressed to generate a height image.
(3D preview screen 550)

The generated height image is displayed on the 3D preview screen 550 as shown in FIG. Here, a height image in a range that can be measured by the shape measuring apparatus from the designated height designation position is displayed. In other words, depending on the hardware specifications of the shape measuring device, a height image that covers the entire height direction cannot be generated depending on the shape of the measurement object. In the example of FIG. 35, a height image HI1 of a part of the measurement object is displayed. The user looks at the height image HI1 displayed in the image display area 410, and if the desired height image is acquired, the user presses the “Register” button 551 provided at the lower right of the screen to The image HI1 is saved. Here, the image is stored in the height image storage unit 241 of FIG.
(Acquisition of texture image)

  In the 3D preview screen 550 of FIG. 35, a composite image with a texture image pasted is displayed as the height image HI1 (in this specification, the height displayed on the 3D preview screen 550 for the sake of explanation). A composite image obtained by combining a texture image with an image may be simply called a height image). The texture image is acquired by pressing a “measurement” button 546, for example. That is, the texture image is captured and stored in addition to the height image simply by pressing the “Measure” button 546 by the user. When capturing a texture image, illumination light is emitted from the illumination light output unit 130 of FIG. When the “Register” button 551 is pressed, the texture image is saved together with the height image. The captured texture image is stored in the texture image storage unit 242.

  The purpose is to display the height image and the texture image before saving, or a composite image thereof on the 3D preview screen 550 and confirm it to the user. In other words, even if it is not a high-definition image, it is sufficient if it can be confirmed visually. Therefore, at the stage of displaying on the 3D preview screen 550, a simple height image, a simple texture image, and a simple composition generated under simple conditions rather than generating a normal height image, a texture image, or a composite image thereof. It can also be an image. Then, when storing after confirmation by the user, a height image, a texture image, and a composite image may be generated again under normal conditions, and these may be stored as appropriate. By doing in this way, simplification and efficiency improvement of a process are achieved.

  In the 3D preview screen 550, various setting units are arranged in the operation area 420 as described above, and an operation on an image displayed in the image display area 410 can be performed. For example, by switching the upper “3D” button 553, the “texture” button 554, and the “height” button 555, it is possible to switch the display of the composite image, the texture image, and the height image. Here, when a height image is selected by pressing a “height” button 555, a height image color-coded according to the height is displayed. For example, in a contour line, the low area is blue, the high area is red, and the middle area is colored so as to change continuously from blue → green → yellow → orange → red, etc. Can be easily recognized. A scale indicating the relationship between height and coloring can be displayed at the corner of the image display area 410.

  Further, in the operation area 420 of the 3D preview screen 550, a height magnification adjustment field 556, a texture adjustment field 557, a missing point display selection field 558, a scale display selection field 559, a 3D measurement selection button 560, and the like are arranged. . In the height magnification adjustment field 556, the magnification in the height direction can be adjusted with a slider. In the texture adjustment field 557, the transmittance of the texture image displayed to be superimposed on the composite image can be set. In the missing point display selection column 558, ON / OFF of the missing point display function for highlighting and displaying the missing point for which height information is not obtained among the pixels constituting the height image is selected. In the scale display selection field 559, ON / OFF of the scale display function for displaying the scale along the coordinate axis can be selected. With the 3D measurement selection button 560, ON / OFF of the 3D measurement function can be selected. Further, a shadow adjustment may be emphasized with pseudo illumination light, or a quality adjustment function for adjusting the fineness of the height image displayed in the image display area 410 may be added.

  As described above, the work necessary for generating the height image can be efficiently performed on the shape measuring apparatus side. Also, an environment that is easy to use is realized by automatically performing operations such as capturing and storing texture images at an appropriate timing without any instruction from the user.

Next, returning to the 3D measurement screen, another height designation position is designated (step S3204 in FIG. 32). Here, the focal position is set to a high position to obtain the state shown in FIG. 36 (step S3202 in FIG. 32). In FIG. 36, the value of the focal position in the focal position display field 516b is large. In this state, a height image is similarly generated (step S3203 in FIG. 32) and displayed on the 3D preview screen 570 as shown in FIG. In the example of the height image HI2 shown in FIG. 37, a height image in a height range different from the height image HI1 of FIG. 35 is obtained.
(Composite height image generation function)

  Here, on the 3D preview screen 570, it is possible to execute a combined height image generation function for combining the acquired height images with different stored height images. In the example of FIG. 37, a single height image can be displayed and a combined height can be displayed with a “single” button 572 and a “Z connection” button 573 that are height image switching units 571 provided at the upper left of the image display area 410. The image display can be switched. In FIG. 37, the “single” button 572 is selected, and the currently generated height image is displayed. When the “Z connection” button 573 is pressed in this state, the screen is switched to the 3D preview screen 580 shown in FIG. 38, and the combined height image CHI2 obtained by combining the height image HI1 shown in FIG. 35 and the height image HI2 shown in FIG. It is displayed in the display area 410. As a result, it is possible to obtain a height image in a wider height range that exceeds the limitation of the height range in the specifications of the shape measuring apparatus.

  When the composite height image CHI2 in FIG. 38 is compared with the height image HI1 in FIG. 35, the cylindrical upper surface at the lower left of the measurement object that was not obtained in the height image HI1 in FIG. It can be seen that this is complemented by adding the height image HI2. Thus, the user can visually confirm whether or not the height information of the desired region is obtained from the 3D preview screen 580 by accumulating the obtained height images. Then, if you want to obtain height information for an area that lacks height information, for example, the area lacking the circular shape in the upper right of FIG. 38, go back to the 3D measurement screen and specify the height designation position for this area. A height image can be obtained. As described above, on the 3D preview screen 580, the display content can be updated to a combined height image obtained by combining with the acquired height image.

  When considering the height for generating the next height image, as described above, the height image alone display (“single” display) that displays only the height image that is currently being generated, and the already generated height image are displayed. The combined height image display (“Z connection” display) obtained by combining the height images is switched by the “single” button 572 and the “Z connection” button 573 from the height image switching unit 571 and displayed on the 3D preview screen 550. be able to. In addition to this, the height image single display and the composite height image display may be displayed side by side on a single screen as necessary. For example, in the 3D preview screen 590 shown in FIG. 39, the image display area 410 is divided into two, the left side is a height image single display area 591, and the right side is a composite height image display area 592. In this way, the user visually confirms whether or not the desired composite height image can be obtained by displaying the height image currently being generated on one screen and the composite height image obtained by adding it side by side. This makes it easy to determine whether or not the height designation position for generating the height image is correctly designated.

  In this manner, it is possible to add a height image while visually confirming a necessary portion as a height image on the 3D preview screen.

  Also, with this method, the user can focus on the height for which height information is desired and specify this height as the height designation position, so that the height is based on the specified height. An image can be generated. As a result, a height image having highly accurate height information can be generated. In particular, for the three-dimensional shape data such as a striped image captured when generating a height image, the height information is calculated based on the height at which the three-dimensional shape data is imaged. The accuracy of information tends to be high. Therefore, the user can directly specify the desired height, generate a height image based on this height, and then synthesize multiple images to obtain the required height information with high accuracy. The advantage that it can be used effectively is obtained. In other words, an advantage is obtained in that the height information of the necessary part can be obtained more accurately as compared with the configuration in which the depth measurement range is simply changed in the depth direction and the height images are sequentially acquired and connected.

In this way, observation and measurement in which the restriction in the depth direction of the height image is removed by depth extension is realized.
(Warning when the composite height image generation function cannot be executed)

  Note that the composite height image generation function can be executed when height images at different height designation positions are already stored. For example, in the 3D preview screen 550 of FIG. 35 described above, since no height image has been saved yet, the composite height image generation function cannot be executed. Therefore, the height image switching unit 571 such as the “single” button 572 and the “Z connection” button 573 is not displayed on this screen. This prevents the user from executing the composite height image generation function by mistake. On the other hand, in the 3D preview screen 570 of FIG. 37, since the height image is already stored, the height image switching unit 571 is displayed. Accordingly, it is possible to avoid an erroneous operation in which the user erroneously tries to operate the height image switching unit in a state where the composite height image generation function cannot be executed, and the usability is enhanced. Further, the prohibition of the composite height image generation function is not limited to display / non-display switching of the height image switching unit described above, but other configurations, for example, the height image switching unit is grayed out and cannot be selected, etc. Various modes can be used as appropriate.

  In this way, when the different height images are confirmed and saved, the “registration” button 551 is similarly pressed to continue the processing, and the composite height image CHI3 of FIG. 40 is obtained. .

  Note that the composite height image does not necessarily have to be continuous in the height direction, and may be discrete. FIG. 41 shows an example of a 3D preview screen 550 when the composite height image CHI3 of FIG. 40 is viewed from different directions. In this example, an intermediate height image of the cylindrical portion of the measurement object is not obtained. If the part to be measured is included in the measurement object, the purpose of observation and measurement can be achieved. As described above, the composite height image does not necessarily need to be continuous in the depth direction, and includes a discrete image.

  The generation and storage of the composite height image may be performed individually with each height image or may be performed simultaneously. For example, when the “Register” button 551 is pressed while the composite height image of FIG. 40 is displayed, the composite height image CHI3 of FIG. 40 is saved and other height images may be saved together. Alternatively, while the height images are individually stored in FIGS. 35 and 37, only the relative relationship is provided so that the composite height image of FIG. 40 can be constructed from these height designation positions and other height information. , And when the composite height image of FIG. 40 is called, the composite height image may be displayed based on the relative image information of each of the height image data of FIGS. Good.

  In this way, it is possible to execute a manual depth extension function for manually performing depth extension.

  As described above, the shape measuring apparatus can generate a height image having height information. Measurement can be performed on the three-dimensional shape of the measurement object obtained in this way using a shape measuring device. For example, it is possible to measure a specified dimension and height, and calculate an average value, maximum value, minimum value, area, and volume of these.

  Further, the measurement object placed on the stage can be stored in the same posture as measurement settings and used for continuous measurement. For example, after measuring these values for the measurement object of the reference product and storing it as a measurement setting in the storage unit, the measurement object of the comparison product is sequentially placed on the stage and compared with the value of the reference product. It can also be done. In the case of such comparative measurement, in order to measure the value of the measurement object of the comparative product, it is necessary to perform measurement in the same posture as the reference product. That is, it is necessary to place it on the stage in the same posture as when the height image of the measurement object of the reference product is acquired. For this reason, it is preferable to use a method such as displaying a guide indicating the position where the measurement object is placed on the stage or physically guiding the user using a jig.

Further, when the stage 140 is driven not only by the Z stage 142 but also by the XY stage 141, the stage side is moved and rotated so that the posture of the measurement object on the stage is measured with the reference product. It can also be adjusted to the same state as the posture of the object. In this case, for example, a texture image, a contour image, a height image, etc. of the measurement object of the comparison product are obtained, pattern matching is performed with the measurement object of the reference product, and a corresponding position and orientation (such as a rotation angle) are obtained, The XY stage 141 is moved by the stage drive unit so as to place the comparative measurement object at the obtained position and orientation. With this method, it is possible to simplify the work of placing a comparative measurement object on the stage 140.
(Automatic image XY connection function)

  Further, according to the shape measuring apparatus according to the present embodiment, when connecting the three-dimensional shape data such as the height image in the X and Y directions, the measurement setting for generating each three-dimensional shape data is individually adjusted, and this Adjustment work can also be automated. For example, when connecting XY images in an XY plane that is a plane orthogonal to the optical axis direction of the light receiving unit, an image captured at a low magnification as shown in FIG. 42 or a connection map image for navigation as a wide-area image, Consider a case where this wide-area image is divided into a plurality of partial areas, and a height image, which is solid shape data generated in each partial area, is connected in the XY direction to generate a combined height image. In such an image linking process on the XY plane, it is necessary to set measurement settings for measurement when generating height images in order in each partial region. Here, if the measurement setting is made common to each partial area, an image with sufficient accuracy may not be obtained. For example, if the object to be measured is made of a partially different material, the projected pattern light may be multiple-reflected by a glossy surface such as metal, or the pattern light may sink into the translucent resin part. Therefore, a correct height image may not be obtained by normal measurement. In this case, it is necessary to measure the height image with measurement settings suitable for multiple reflections and light penetration, but such measurement requires multiple imaging to generate a height image. take time. For this reason, if the height image is generated with the same measurement setting in all the partial areas, the time required in total is increased. Similarly, in the case where a region having a large unevenness and a flat region are mixed in the measurement object, it is necessary to repeat the imaging at different heights by driving the Z stage in the depth direction in the region having the unevenness of the unevenness. In some cases, if imaging with different heights is repeated in a flat region, useless operations increase in time. In addition, although it is conceivable that the user manually sets appropriate measurement settings individually for such various partial areas, there is a problem that this work is very time-consuming.

  On the other hand, if the user wants to display the 3D shape data after measurement for each partial area and the user wants to redo the shape measurement of that partial area, change the measurement settings and perform the measurement again. When the measurement result is obtained, a method of replacing the newly obtained solid shape data may be considered. However, even in this case, the user has to check the measurement results one by one and determine the necessity of remeasurement, which is troublesome. Also, it may not be easy to determine how the measurement setting is changed to obtain a desired measurement result, which further complicates the work.

Therefore, in the present embodiment, the three-dimensional shape with a wide field of view can be easily obtained by automating the measurement setting adjustment operation when generating the three-dimensional shape data by XY-linking the three-dimensional shape data such as the height image. It is possible to obtain data. In other words, the setting conditions can be automatically adjusted individually for a plurality of partial areas, thereby reducing the burden on the user. In particular, the partial area measurement settings are adjusted to appropriate conditions based on the received light data and 3D shape data once acquired, and 3D shape data is generated again with the measurement settings of each adjusted partial area as necessary. Thus, higher-quality or higher-precision solid shape data can be obtained. Also, by saving the measurement settings of each partial area adjusted for each partial area, when performing the same measurement object inspection, this is read out and set as the measurement setting, thereby automatically measuring the measurement settings. It can be omitted to simplify the process.
(Measurement setting automatic adjustment unit 217)

Such automatic adjustment of the measurement setting is performed by the measurement setting automatic adjustment unit 217 shown in FIG. When connecting the images XY, the measurement setting automatic adjustment unit 217 performs adjustment of the partial region measurement settings fully automatically, and the measurement setting automatic adjustment unit 217 automatically adjusts the measurement settings set by the user using the measurement setting unit 255. Or, conversely, the measurement setting automatically adjusted by the measurement setting automatic adjustment unit 217 may be adjusted by the measurement setting unit 255 by the user. In the automatic setting, the measurement setting set as the initial value on the shape measuring apparatus side can be adjusted by the measurement setting automatic adjustment unit 217 to obtain the adjustment measurement setting. As described above, the measurement setting automatic adjustment unit 217 may adjust the measurement setting for generating the three-dimensional shape data such as the height image completely automatically, or may be semi-automatic that combines the setting by the user. The measurement setting unit 255 is a member for the user to manually set initial measurement settings. However, the measurement setting unit 255 may be a member that inputs an initial setting value of a measurement setting prepared in advance on the shape measuring apparatus side. The measurement setting of each partial area is a condition in which the partial setting measurement specified by the user or the initial setting value prepared on the device side is automatically adjusted by the measurement setting automatic adjustment unit 217.
(Reflected light, submerged light removal mode)

  Here, a description will be given of a measurement mode in which measurement is performed with measurement settings for removing reflected light and submerged light. For example, as shown in FIG. 43, when a measurement object having a translucent resin diffusion plate is measured with a general measurement setting, that is, generated from a fringe image by projecting pattern light. An example of the height image is shown in FIG. 44A. As shown in this figure, in the normal scan mode, the translucent diffuser plate portion cannot be measured well due to the influence of the diverging light, and the height image data is lost. On the other hand, FIG. 44B shows an example of a height image measured with the measurement mode set as the reflection / dive light removal mode. As described above, in the reflection / dive light removal mode, the indirect light component is reduced by making the projection pattern of the measurement light finer than usual. As a result of the measurement in the submerged light removal mode, it can be seen that the translucent diffuser plate portion can also be measured in a considerable portion as shown in the figure.

  However, such a special measurement mode requires a longer processing time than usual. For this reason, if measurement is performed in the sublimation light removal mode at all partial regions or at all XY positions, the measurement time becomes long. Therefore, the measurement time can be shortened by using this measurement mode only for an area where there is a lot of diverging light or multiple reflected light. In the above example, the height image is once generated in the standard measurement mode, and the partial region measurement setting is reset by the measurement setting automatic adjustment unit 217 in the partial region where the missing region is generated as shown in FIG. 44A. Then, by regenerating and replacing the height image, it is possible to obtain a height image with few missing portions as shown in FIG. 44B.

Similarly, for areas where the height difference of the measurement object is large, the measurement is performed with the depth range expanded, while in the area where the height difference is small, the measurement is performed by limiting the depth range to reduce the measurement time. Measurement process can be performed efficiently. For example, in the example of FIGS. 44A and 44B, it takes time to measure the height range of the measurement object (the range indicated by the arrow in the figure) at all XY positions, but only the outer shell region of the measurement object (FIG. 44). While the depth extension measurement mode is performed for the partial area located around the connected area in 42), the Z range is not extended in the other partial areas (partial areas located inside the connected area in FIG. 42). Measurement time can be shortened.
(Distinction between dive light and air gap)

  In addition, when the measurement mode automatic selection unit 217 automatically selects the measurement mode, if there is a missing portion in a part of the height image, the cause is due to the intruding light, or the shape itself is missing in the first place. Distinguish between things (voids, holes, etc.). In other words, if it is determined that it is caused by the diverging light, remeasurement is performed with the partial area measurement setting changed, but if it is determined that the gap is a gap, remeasurement is not performed. An example of such a determination method will be described with reference to FIGS. 45A to 45D. In these drawings, FIG. 45A is an image diagram of a fringe image of a certain measurement object, FIG. 45B is a luminance profile of a metal part of the measurement object of FIG. 45A, FIG. 45C is a luminance profile of a hole part, and FIG. Indicates the luminance profile of the white resin portion, respectively. For the metal portion shown in FIG. 45B, a clear peak appears in the luminance profile, indicating that the height information can be measured correctly. On the other hand, the hole portion in FIG. 45C and the white resin portion in FIG. 45D are both black on the stripe image, and pattern light is not obtained. However, it can be seen that the base portion of the luminance profile is almost zero in the hole portion in FIG. 45C, whereas a certain displacement (luminance) is obtained in the base portion in the resin portion in FIG. 45D. 45C and 45D, as shown in FIGS. 45C and 45D, although a peak is hardly obtained on the luminance profile, whether the luminance signal is obtained in the base portion or not, it is a non-existent shape, or the luminance is reduced due to light penetration. Can be distinguished by the measurement setting automatic adjustment unit 217.

  In the state where the XY connection region is set in this way, measurement settings for measuring the solid shape data are set. Here, as shown in FIG. 28, a depth extension measurement mode for determining the presence / absence and range of extension in the depth direction is selected by the depth extension mode selection unit 254, and the measurement mode is measured as shown in FIG. As shown in FIG. 30, the mode selection unit 257 selects the measurement direction by the light projecting unit 110, and the measurement direction designation unit selects the measurement direction. Further, as shown in FIG. 31, the image displayed in the image display area 410 is displayed. Is set in the measurement brightness setting section.

  In the state where the measurement settings are set in this way, the linked measurement is started. Here, the user presses the “Measure” button. Then, measurement is performed to generate solid shape data, and a texture image is taken.

  Next, it is determined whether or not there is an area within the depth search range. If there is, the Z stage is moved to a height position where the area within the depth search range can be measured. At this time, the already measured height position is excluded. If there are a plurality of height positions, the process is repeated by moving to the closest height position.

  On the other hand, if there is no depth search range area, it is determined whether or not all the combined image data in the connected area has been generated. If not yet, that is, if there is an unmeasured partial area, the process is repeated after moving the XY stage to the partial area.

  When the measurement of each partial region is finished and it is determined that all the combined height image data in the connected region has been generated, the generated combined height image is displayed.

In this way, it is possible to generate a wide area composite height image in which the composite height image is XY connected.
(Automatic adjustment of partial area measurement settings)

  On the other hand, when generating such a wide-area composite height image, it is also possible to automatically adjust the partial area measurement settings for each partial area. The procedure for generating such a wide-area combined height image will be described based on the flowchart of FIG. First, in step S4601, a measurement object is placed on the stage 140. Next, in step S4602, a map image is created. In step S4603, a continuous area is set.

  Next, in step S4604, the XY stage is moved to a predetermined partial area. Here, the XY stage is moved to the partial area where the three-dimensional shape data is first generated by the planar direction driving unit.

  In step S4605, measurement settings in this partial area are set. Here, the initial value of the measurement setting in the partial region where the solid shape data is first generated is set. This measurement setting can be performed even if the initial setting value is designated in advance on the shape measuring device, the measurement setting automatic adjustment unit 217 automatically analyzes from the optical image of the partial area, or the measurement setting is manually set by the user. Good.

  Next, in step S4606, measurement is performed. Here, the solid shape data is generated by the solid shape data generation unit, and the texture image is captured by the texture image acquisition unit 218.

  In step S4607, the partial region measurement setting is automatically adjusted. Here, the measurement setting automatic adjustment unit 217 sets the partial region measurement settings to the partial region measurement settings as necessary. In step S4608, it is determined whether or not it is necessary to perform measurement again with the measurement setting of the partial region. If it is determined that measurement is necessary, the process returns to step S4606 to generate solid shape data again. Note that re-imaging of the texture image is not necessary. Here, the determination of the necessity of remeasurement is made, for example, when the measurement setting automatic adjustment unit 217 determines that the partial region measurement setting is appropriate and does not change it, and does not require remeasurement.

  After the measurement is performed in this way, the process proceeds to step S4609 to determine whether or not there is an unmeasured partial area. If there is, the process returns to step S4604 to move to the unmeasured partial area. The measurement is performed in the same way.

  When the measurement of all the partial areas is completed, the process proceeds to step S4610, where the obtained solid shape data is synthesized to create synthesized solid shape data.

In this way, it is possible to automatically adjust the partial region measurement settings, perform remeasurement as necessary, and re-acquire solid shape data, and finally obtain wide-field synthetic solid shape data with high quality. .
(Edit XY link measurement settings)

  Further, after completion of the connection measurement, the user can confirm the measurement result. For example, it is possible to visually confirm whether a desired result is obtained by displaying the obtained wide-area combined height image on the display unit. If necessary, measurement can be performed again by changing the division measurement setting in each partial region. In this case, the partial area measurement setting can be re-edited.

  In addition, a wide area composite height image can be regenerated using a height image obtained by re-measurement only in a partial area.

Furthermore, by storing the measurement settings in each partial area in the measurement setting storage unit 243, the measurement settings can be reused when the inspection is performed. For example, when a non-defective product inspection is performed to check the difference between the reference product and the measurement object, each partial area is measured from the measurement product of the reference product so that accurate results can be obtained in a short time during the operation of the inspection. It takes a long time to set the measurement settings. This makes it possible to perform quick and accurate measurement during inspection operation.
(Continuous measurement mode)

  In this case, the solid shape data generation unit can switch between the normal measurement mode and the continuous measurement mode. As described above, the normal measurement mode is a measurement mode in which the measurement setting automatic adjustment unit 217 changes the partial region measurement setting for each partial region to generate solid shape data. On the other hand, the continuous measurement mode is a measurement mode in which the partial area measurement settings stored in advance in the measurement setting storage unit 243 are read out for each partial area to generate solid shape data. In other words, in the continuous measurement mode, the partial area measurement settings are not automatically adjusted, and the processing time can be shortened by reading and using the stored partial area measurement settings.

For example, consider a case where a measurement object having projections partially on the surface as shown in the side view of FIG. 47 is measured. The protrusions have different colors and are provided with a translucent resin part on a part of the surface of the measurement object. Consider an example in which partial areas A to D are set for such a measurement object. In this case, partial area measurement settings for each partial area are set and stored in advance as shown in FIG. For example, since the color of the material is different between the partial area A and the partial area B, the contrast of each stripe pattern is easily expressed by varying the exposure level (exposure time and intensity of measurement light). Further, since the submerged light is generated in the partial area B, the measurement mode is set to the reflection / submerged light removal mode (fine mode). Furthermore, since the height difference is large in the partial region D, the Z measurement range is expanded so as to be in the depth extension measurement mode. In this way, measurement settings that are suitable for each partial area are set in advance and saved, and in the continuous measurement mode in which many measurement objects are inspected, automatic adjustment of the measurement settings is omitted and saved measurement settings are saved. By reading out and using, it is possible to perform highly accurate measurement and inspection while shortening the processing time.
(Guidance part)

In the continuous measurement mode, it is necessary to adjust the position and orientation of the measurement object so as to be the same as the reference orientation that is the position and orientation when the saved partial area measurement settings are set, as viewed from the imaging means. is there. For this reason, you may provide the guidance part which prompts a user to arrange | position a measuring object in the same position and attitude | position as a reference | standard attitude | position. For example, when the measurement object is placed on the stage 140 with respect to the user on the display unit, the guidance unit outputs a guidance message so as to be arranged at the same position and posture as the reference posture.
(Measurement position and orientation detection unit)

In addition, a measurement target position / orientation detection unit that detects the position and orientation of the measurement object placed on the stage 140 may be provided, and the measurement setting of the partial area stored in the measurement setting storage unit 243 may be obtained. Based on the position and orientation of the measurement object, the position and orientation of the measurement object detected by the measurement object position and orientation detection unit may be adjusted by driving the plane direction driving unit.
(Positioning jig)

  Alternatively, the position and orientation of the measurement object may be physically restricted using a positioning jig. With the positioning jig, the position and orientation of the measurement object placed on the stage 140 coincide with the position and orientation of the measurement object at the time of obtaining the measurement setting of the partial area stored in the measurement setting storage unit 243. Let

  The shape measuring device, shape measuring method, shape measuring program, computer-readable recording medium, and recorded device of the present invention can be suitably used for a microscope, measuring instrument, inspection device, and digitizer using the principle of triangulation. .

DESCRIPTION OF SYMBOLS 100, 100C ... Imaging means 101 ... Upper head 102 ... Lower head 110 ... Light projection part; 110A ... First light projection part; 110B ... Second light projection part 111 ... Measurement light source 112 ... Pattern generation parts 113-115, 122, 123 ... Lens 116 ... Left-and-right projection lens 120 ... Light receiving unit 120A ... Low-magnification imaging device; 120B ... High-magnification imaging device 121 ... Camera 121a ... Image sensor 124 ... Prism 125 ... Branch bilateral telecentric light-receiving lens 130 ... Illumination Output unit 140 ... Stage 141 ... XY stage 142 ... Z stage 143 ... θ stage 144 ... Stage operation unit; 144C ... Imaging system operation unit 145 ... Stage drive unit; 145C ... Imaging system drive unit 146, 146C ... Optical axis direction drive unit 147 ... Scale cover 148 ... Stage plane direction drive unit 149 ... Base housing 150 Measurement control unit 151 ... base portion 152 ... stage support part 160,160X ... scale unit 161 ... sensor moving unit 162 ... scale section 163 ... spherical body 164 ... sheet 165 ... plate-like member 167 ... holding unit 200 ... control unit 210 ... CPU
212 ... 3D shape data generation unit 212b ... Height image generation unit 212c ... Shape measurement processing unit 213 ... 3D image synthesis unit 214 ... Determination processing unit 215 ... Depth extension processing unit 216 ... Synthesis processing unit 217 ... Automatic measurement setting adjustment unit 218 ... Texture image acquisition unit 219 ... Solid shape data connection unit 220 ... ROM
230 ... Working memory 240 ... Storage unit 241 ... Height image storage unit 242 ... Texture image storage unit 243 ... Measurement setting storage unit 250 ... Setting unit 251 ... Position specifying unit 252 ... End condition setting unit 253 ... Depth range setting unit 254 Depth extension mode selection unit 255 ... Measurement setting unit 256 ... Connection region setting unit 257 ... Measurement mode selection unit 300 ... Light source unit 310 ... Control board 320 ... Observation illumination light source 400 ... Display unit 410 ... Image display region 416 ... First Display area 417 ... second display area 420 ... operation area 427 ... "observation image" button 428 ... "measurement image" button 450 ... operation device 490 ... observation image imaging condition setting means 450 ... operation devices 500, 500B, 500C ... shape measurement Apparatus 510 ... Imaging setting area 511 ... Camera adjustment field 512 ... Camera selection field 513 ... Magnification setting field 514 ... "Camera setting" button 515 ... Focus setting field 516 ... Focus adjustment field; 516b ... Focus position display field 517 ... "Auto focus" button 519 ... Maintenance setting field; 519b ... "Measurement adjustment" button 531 ... "3D measurement" tab 532 "Image observation" tab 533 ... "Full auto" button 535 ... "Manual" button 540 ... Manual observation screen 541 ... "Z measurement range" designation field 542 ... "Measurement mode" selection field 543 ... "Measurement direction" designation field 544 ... “Measurement brightness” setting field 545 ... “Texture shooting” selection field 546 ... “Measurement” button 550 ... 3D preview screen 551 ... “Register” button 552 ... “Remeasure” button 553 ... “3D” button 554 ... “Texture” Button 555 ... "Height" button 556 ... Height magnification adjustment field 557 ... Texture adjustment 558 ... Missing point display selection field 559 ... Scale display selection field 560 ... 3D measurement selection button 570 ... 3D preview screen 571 ... Height image switching unit 572 ... "Single" button 573 ... "Z connection" button 580 ... 3D preview Screen 590 ... 3D preview screen 591 ... Height image single display area 592 ... Composite height image display area WK, WK2 ... Measurement object CHI, CHI2, CHI3 ... Composite height images HIA, HIB, HIC, HI1, HI2 ... High Image OL1, OL2 ... Overlapping region HT1, HT2, HT3, HT4 ... Depth measurement range IG1, IG2, IG3, IG4 ... Image S1 ... First measurement image; S2 ... Second measurement image

Claims (19)

A stage on which a measurement object is placed;
A light projecting unit that projects pattern light on the measurement object placed on the stage;
A light receiving unit having a predetermined depth of focus for receiving pattern light irradiated from the light projecting unit and reflected from the measurement object;
An optical axis direction drive unit that shifts a depth measurement range that is a measurable height range determined by the depth of focus by moving the stage relative to the light receiving unit in the optical axis direction of the light receiving unit; ,
Based on the plurality of pattern lights received by the light receiving unit, the height information of the measurement object in the depth measurement range is provided for each position in the measurement range on the stage plane orthogonal to the optical axis direction of the light receiving unit. A three-dimensional shape data generation unit for generating three-dimensional shape data,
In the first depth measurement range, first solid shape data is generated,
In the same measurement range as the first three-dimensional shape data, the second three-dimensional shape data is obtained in the second depth measurement range shifted so as to partially overlap the first depth measurement range by the optical axis direction driving unit. A three-dimensional shape data generation unit to generate;
A three-dimensional shape data combining unit that generates combined three-dimensional shape data by combining the first three-dimensional shape data and the second three-dimensional shape data,
If the first three-dimensional shape data and the second three-dimensional shape data have height information at the same position within the measurement range, whether the height information corresponding to the first three-dimensional shape data is close to a true value or not Based on a reliability index indicating reliability and a reliability index indicating whether or not the height information corresponding to the second solid shape data is close to a true value, the first solid shape data and the second solid shape data A combined three-dimensional shape data generation unit that determines whether or not the height information of one or both of the three-dimensional shape data is adopted;
A shape measuring apparatus comprising: The shape measuring device according to claim 1,
The first stereoscopic shape data is a first height image in which each pixel has height information, and the second stereoscopic shape data is a second height image in which each pixel has height information,
In the range where the first depth measurement range and the second depth measurement range overlap, the synthesized solid shape data generation unit, for pixels in the measurement range corresponding to the first height image and the second height image,
When the pixel of the first height image is valid and the pixel of the second height image is invalid, the height information of the pixel of the first height image is set as the pixel value of the pixel,
When the pixel of the first height image is invalid and the pixel of the second height image is valid, the height information of the pixel of the second height image is used as the pixel value of the pixel measuring device. The shape measuring device according to claim 2,
A shape measuring apparatus configured to extract the pixel having a difference greater than or equal to a predetermined value between the first height image and the second height image, wherein the combined solid shape data generation unit. The shape measuring apparatus according to claim 3,
A shape measuring apparatus configured to adopt a pixel value having a high reliability index for the pixel extracted as the difference by the synthetic solid shape data generation unit. It is a shape measuring device according to any one of claims 2 to 4,
A shape measuring device configured to synthesize the first height image and the second height image by weighting the synthesized solid shape data generation unit based on the reliability index. It is a shape measuring device according to any one of claims 2 to 5,
The shape measuring apparatus in which the synthetic solid shape data generation unit uses the reliability index as a distance from a focal position of the light receiving unit. The shape measuring apparatus according to claim 6,
In the range where the first depth measurement range and the second depth measurement range overlap, the synthesized solid shape data generation unit, for pixels in the measurement range corresponding to the first height image and the second height image, A shape measuring apparatus configured to adopt a method in which the distance from the focal position of the light receiving unit is shorter or to increase weighting. It is a shape measuring device according to any one of claims 2 to 5,
The composite solid shape data generation unit generates the reliability index of a certain pixel, the corresponding pixel in the pattern image received the pattern light by the light receiving unit, which is the source of generating the solid shape data, and the pixel A shape measuring device that is used as a contrast with pixels located in the periphery of the object. It is a shape measuring device according to any one of claims 2 to 5,
The synthetic 3D shape data generation unit is a shape measuring device configured to adopt either the pixel value of the first height image or the second height image based on the reliability index. It is a shape measuring device according to any one of claims 2 to 5,
The synthetic solid shape data generation unit is a shape measuring device configured to calculate height information based on a weighted average using the reliability index. The shape measuring apparatus according to claim 3,
The synthetic three-dimensional shape data generation unit, the difference extracted from the first height image and the second height image,
In the case of a predetermined value or more, based on the reliability index, adopt either the height information of the first height image or the second height image,
A shape configured to calculate height information from pixel values of the first height image or the second height image based on a weighted average using the reliability index when the predetermined value or less. measuring device. It is a shape measuring device according to any one of claims 1 to 11,
The light projecting unit is
A first light projecting unit that irradiates a first pattern light from a first direction on the measurement object placed on the stage;
A second light projecting unit that irradiates a second pattern light from a second direction on the measurement object placed on the stage;
The light receiving unit is
Receiving the first pattern light irradiated from the first light projecting part and reflected from the measurement object, and outputs first light reception data;
Receiving the second pattern light irradiated from the second light projecting unit and reflected from the measurement object, and outputs second received light data;
The synthetic three-dimensional shape data generation unit
Based on the first light reception data received by the light receiving unit, to generate the first direction three-dimensional shape data of the measurement object,
Based on the second light reception data received by the light receiving unit, to generate the second direction three-dimensional shape data of the measurement object,
A height range within which the pattern light can be irradiated from the first light projecting unit and the second light projecting unit within the measurement range of the light receiving unit on the stage is defined as a measurement height range, and a height within the measurement height range is set. A shape measuring device formed by combining the first three-dimensional shape data having the height data and the second three-dimensional shape data to generate combined three-dimensional shape data. The shape measuring apparatus according to claim 12,
The synthetic three-dimensional shape data generation unit
When the first shape data is solid shape data obtained by irradiating pattern light from the first light projecting unit and the second light projecting unit,
The shape measuring apparatus configured to form the second shape data as solid shape data obtained by irradiating pattern light from the first light projecting unit and the second light projecting unit. The shape measuring apparatus according to claim 12,
The synthetic three-dimensional shape data generation unit
When the first three-dimensional shape data is three-dimensional shape data obtained by irradiating pattern light from either the first light projecting unit or the second light projecting unit,
The shape measuring device configured to be configured such that the second three-dimensional shape data is also three-dimensional shape data obtained by irradiating pattern light from either the first light projecting unit or the second light projecting unit. The shape measuring device according to any one of claims 1 to 14, further comprising:
A scale unit for outputting a scale value indicating a relative distance between the stage and the optical axis direction of the light receiving unit;
The combined solid shape data generation unit stores the scale value of the scale unit when each solid shape data is generated, and based on the scale value, the pixel value of each solid shape data when the solid shape data is combined. A shape measuring device configured to be offset and combined. The shape measuring device according to any one of claims 1 to 15, further comprising:
An illumination light output unit that emits illumination light for capturing an optical image of the measurement object;
A shape measuring apparatus comprising: a texture image storage unit for storing a texture image obtained by optically imaging a measurement object. A shape measurement method for measuring a shape by generating solid shape data including height information of a measurement object,
Place the measurement object to be measured on the stage, irradiate the measurement object with pattern light from the light projecting part, and measure the pattern light reflected by the measurement object with the light receiving part A depth measurement range that is a high height range as a first depth measurement range, on a stage plane orthogonal to the optical axis direction of the light receiving unit based on a plurality of pattern lights received by the light receiving unit and received by the light receiving unit For each pixel present in the measurement range, a step of generating the first three-dimensional shape data of the measurement object in the first depth measurement range by the three-dimensional shape data generation unit;
By moving the stage relative to the light receiving portion in the optical axis direction of the light receiving portion, the depth measuring range is shifted to a second depth measuring range that partially overlaps the first depth measuring range. A process of
A plurality of pattern lights received by the light receiving unit are received by the light receiving unit in the second depth measurement range by irradiating the measurement target with pattern light from the light projecting unit, and receiving the pattern light reflected by the measurement target. The second shape data generation unit generates second shape data of the measurement object in the second depth measurement range for each pixel existing in the measurement range orthogonal to the optical axis direction of the light receiving unit. And a process of
In the range where the first depth measurement range and the second depth measurement range overlap, is the height information of the pixels in the measurement range corresponding to the first three-dimensional shape data and the second three-dimensional shape data close to the true value? On the basis of a reliability index indicating the reliability of whether or not the first three-dimensional shape data and the second three-dimensional shape data are used or not, the first three-dimensional shape data and the second three-dimensional data are determined. A step of synthesizing the shape data with the synthetic three-dimensional shape data generation unit;
A shape measuring method including: A shape measurement program for measuring a shape by generating solid shape data including height information of a measurement object,
With the measurement object to be measured placed on the stage, pattern light reflected from the measurement object is measured by the light receiving part by irradiating the measurement object with pattern light from the light projecting part. A stage plane orthogonal to the optical axis direction of the light receiving unit based on a plurality of pattern lights received by the light receiving unit and received by the light receiving unit, with the depth measurement range being a possible height range as the first depth measurement range A function of generating the first three-dimensional shape data of the measurement object in the first depth measurement range by the three-dimensional shape data generation unit for each pixel existing in the measurement range in
By moving the stage relative to the light receiving portion in the optical axis direction of the light receiving portion, the depth measuring range is shifted to a second depth measuring range that partially overlaps the first depth measuring range. Function
A plurality of pattern lights received by the light receiving unit are received by the light receiving unit in the second depth measurement range by irradiating the measurement target with pattern light from the light projecting unit, and receiving the pattern light reflected by the measurement target. The second shape data generation unit generates second shape data of the measurement object in the second depth measurement range for each pixel existing in the measurement range orthogonal to the optical axis direction of the light receiving unit. Function to
In the range where the first depth measurement range and the second depth measurement range overlap, is the height information of the pixels in the measurement range corresponding to the first three-dimensional shape data and the second three-dimensional shape data close to the true value? On the basis of a reliability index indicating the reliability of whether or not the first three-dimensional shape data and the second three-dimensional shape data are used or not, the first three-dimensional shape data and the second three-dimensional data are determined. A function of synthesizing shape data in a synthetic three-dimensional shape data generation unit;
A shape measurement program for realizing a computer.   A computer-readable recording medium or a recorded device on which the program according to claim 18 is recorded.