Three-dimensional measuring device including projection optical component and camera optical component

Abstract

The present invention provides a three-dimensional measurement device, including an optical component as a projection unit (12) and an optical component as a camera unit (13), which can ensure that the measurement range is large within a specified temperature range. The optical component (12) as the projection unit and the optical component (13) as the camera unit each include: an optical lens (220, 320) forming a pair of conjugate surfaces in an optical conjugate relationship; an optical device (241, 244, 341) arranged on one of the pair of conjugate surfaces; a temperature sensor (254, 354) for detecting the temperature of the optical lens (220, 320); a heater (251, 351) for heating the optical lens (220, 320); and a control unit for controlling the operation of the heater (251, 351) based on the detection result of the temperature sensor (254, 354) so ​​that the optical lens (220, 320) becomes a fixed temperature.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional measuring device and an optical component for the three-dimensional measuring device. The three-dimensional measuring device projects pattern illumination onto a subject as a measurement object, captures the projection pattern projected onto the subject, and uses the image obtained thereby to measure the three-dimensional shape of the subject. The optical component for the three-dimensional measuring device is provided in the three-dimensional measuring device as a projection unit or a capture unit. Background Art

[0002] In the past, there is a known technique for measuring the three-dimensional shape of an object using an optical method. For example, Japanese Patent Laid-Open No. 2012-79294 (Patent Document 1) discloses an image information processing device that uses a projection pattern obtained by assigning a different symbol corresponding to each type of code to each code of a projection code string in which multiple codes are arranged in two dimensions, projects the projection pattern onto the object, and uses an image obtained by photographing the object to perform three-dimensional measurement of the object.

[0003] Furthermore, as a document that discloses the specific structure of a camera as an imaging unit that can be used in such a three-dimensional measuring device, there is, for example, U.S. Patent Application Publication No. 2017 / 0090076 (Patent Document 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-79294

[0007] Patent Document 2: U.S. Patent Application Publication No. 2017 / 0090076 Summary of the invention

[0008] Problems to be solved by the invention

[0009] The light-projecting lens and the light-receiving lens used in the three-dimensional measuring device (here, each light-projecting lens and the light-receiving lens may be composed of a lens group including a plurality of lenses or may be composed of a single lens) generally have a property that the focal position changes according to the temperature (hereinafter, sometimes simply referred to as "temperature characteristics"). The temperature characteristics of the light-projecting lens and the light-receiving lens have a great influence on the width of the measurement range (i.e., the range of the distance between the measuring head and the object in which the measurement can be performed) in which the three-dimensional shape of the object can be measured.

[0010] Therefore, some means must be taken to ensure that the measurement range is large so that the measurement range does not become extremely narrow or the measurement range itself does not disappear within a predetermined temperature range.

[0011] Therefore, the present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a three-dimensional measuring device that can ensure a large measurement range within a predetermined temperature region, and an optical unit for a three-dimensional measuring device provided in the three-dimensional measuring device.

[0012] Technical means of solving problems

[0013] According to one aspect of the present disclosure, an optical assembly for a three-dimensional measurement device includes an optical lens, an optical device, a temperature sensor, a heater, and a control unit. The optical lens forms a pair of conjugate surfaces that are optically conjugate, and the optical device is disposed on one of the pair of conjugate surfaces. The temperature sensor is used to detect the temperature of the optical lens, and the heater is used to heat the optical lens. The control unit controls the operation of the heater based on the detection result of the temperature sensor so that the optical lens reaches a fixed temperature.

[0014] By configuring in this way, the temperature of the optical lens can be maintained at a fixed temperature, thereby substantially suppressing the change in the focal position of the optical lens during three-dimensional measurement. Therefore, by configuring in advance so that the optical device is arranged at the focal position of the optical lens in a heated state, the state in which the optical device is always arranged at the focal position of the optical lens can be maintained during three-dimensional measurement. Therefore, by adopting the optical component for a three-dimensional measurement device having the above structure, when a three-dimensional measurement device including the optical component is adopted, it can help to ensure that the measurement range is large within a specified temperature range.

[0015] According to the one aspect of the present disclosure, the optical component for a three-dimensional measuring device may also include a lens support portion, which supports the optical lens around the optical lens in a direction orthogonal to the optical axis of the optical lens. In this case, the temperature sensor and the heater may also be assembled to the lens support portion.

[0016] By configuring in this way, the optical lens can be maintained at a fixed temperature via the lens support portion, and the temperature of the lens support portion supporting the optical lens can also be maintained at a fixed temperature, so that the distance between the optical lens and the optical device in the optical axis direction, that is, the distance between the elements, can be substantially suppressed from changing during three-dimensional measurement. Therefore, the state in which the optical device is always arranged at the focal position of the optical lens can be more reliably maintained during three-dimensional measurement.

[0017] According to the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure, there may also be a cover member, which surrounds the lens support part and covers the temperature sensor and the heater. In this case, preferably, the thermal conductivity of the cover member is the same as or smaller than the thermal conductivity of the lens support part.

[0018] By configuring in this way, the cover member can provide a heat-insulating effect, so that the optical lens and the lens support portion can be heated efficiently, and the temperature of the optical lens and the lens support portion can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation can be shortened, and the optical device can be more reliably maintained in a state where it is always arranged at the focal position of the optical lens during three-dimensional measurement.

[0019] In the optical assembly for a three-dimensional measuring device according to the first aspect of the present disclosure, the lens support portion may also include a lens barrel supporting the optical lens and an assembly component fixing the lens barrel. In this case, the cover component may also have a substantially sealed structure covering the assembly component.

[0020] With this configuration, the heat insulating effect of the cover member is further enhanced, so that the optical lens and the lens support portion can be heated more efficiently, and the temperature of the optical lens and the lens support portion can be maintained at a fixed temperature more stably.

[0021] In the optical unit for a three-dimensional measuring device according to the first aspect of the present disclosure, an air layer may be provided in at least a portion between the cover member and the mounting member.

[0022] With this configuration, a heat insulating effect is exerted not only by the cover member but also by the air layer, so that the optical lens and the lens support portion can be heated more efficiently and the temperature of the optical lens and the lens support portion can be maintained at a fixed temperature more stably.

[0023] The optical component for a three-dimensional measuring device according to the aspect of the present disclosure may also include a base portion, which fixes the lens support portion. In this case, preferably, the thermal conductivity of the base portion is the same as or smaller than the thermal conductivity of the lens support portion.

[0024] By configuring in this way, the base portion of the fixed lens support portion can exert a heat insulation effect, so the optical lens and the lens support portion can be efficiently heated, and the temperature of the optical lens and the lens support portion can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation can be shortened, and the state in which the optical device is always arranged at the focal position of the optical lens can be more reliably maintained during three-dimensional measurement.

[0025] In the optical component for a three-dimensional measuring device according to the first aspect of the present disclosure, the heater may also include a flexible heater, which includes a flexible substrate provided with an electric heating wire. In this case, preferably, the temperature sensor is mounted on the flexible substrate, and the flexible heater is arranged on the outer peripheral surface of the lens support portion.

[0026] With such a configuration, the optical lens and the lens support portion can be heated with a simple structure, and the temperature of the optical lens can be measured with a simple structure, so that the assembly work is facilitated, and as a result, the manufacturing cost can be reduced.

[0027] In the optical assembly for a three-dimensional measuring device according to the first aspect of the present disclosure, the flexible heater may be attached to the lens support portion using an adhesive tape having high thermal conductivity.

[0028] With such a configuration, the thermal conductivity can be improved and the flexible heater can be easily assembled to the lens support part. Furthermore, more accurate temperature measurement can be achieved and the temperature sensor can be easily assembled to the lens support part, thereby further reducing the manufacturing cost.

[0029] According to the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure, the optical device may include a pattern lighting forming element for forming pattern lighting, and the optical lens may include a projection lens for projecting pattern lighting onto an object arranged on the other surface of the pair of conjugate surfaces, thereby imaging the projection pattern.

[0030] With such a configuration, the optical unit for a three-dimensional measuring device can be used as a projection unit of a three-dimensional measuring device. When a three-dimensional measuring device including the projection unit is used, it can contribute to ensuring a large measurement range within a predetermined temperature range.

[0031] In the case of the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure, it is preferred that the fixed temperature is a temperature which is above the maximum temperature that the projection lens can reach when the heater is not heating the projection lens within the range of ambient temperature allowing the use of the optical component for the three-dimensional measuring device, and is below the upper limit of the operation guarantee temperature of the pattern lighting forming element.

[0032] By configuring in this way, it is possible to configure an optical unit for a three-dimensional measuring device that can ensure a large measurement range within a predetermined temperature range and has a long life and high reliability.

[0033] In the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure, the optical device may include a shooting element having a shooting surface, and the optical lens may include a light receiving lens, and the light receiving lens is used to image a projection pattern of the object projected onto the other surface of the pair of conjugate surfaces on the shooting surface.

[0034] With such a configuration, the three-dimensional measuring device optical unit can be used as an imaging unit of the three-dimensional measuring device, and when a three-dimensional measuring device including the imaging unit is used, it can contribute to ensuring a large measurement range within a predetermined temperature range.

[0035] In the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure, it is preferred that the fixed temperature is a temperature that is higher than the maximum temperature that the light-receiving lens can reach when the heater does not heat the light-receiving lens within the range of ambient temperature allowing the use of the optical component for a three-dimensional measuring device, and is lower than the upper limit of the action guarantee temperature of the shooting element.

[0036] By configuring in this way, it is possible to configure an optical unit for a three-dimensional measuring device that can ensure a large measurement range within a predetermined temperature range and has a long life and high reliability.

[0037] A three-dimensional measuring device according to one aspect of the present disclosure includes the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure as a projection unit, and includes the optical component for a three-dimensional measuring device according to the one aspect of the present disclosure as a photographing unit.

[0038] By configuring in this way, it is possible to configure a three-dimensional measuring device that can ensure a wide measurement range within a predetermined temperature range.

[0039] Effects of the Invention

[0040] According to the present disclosure, it is possible to provide a three-dimensional measuring device capable of ensuring a large measurement range within a predetermined temperature region, and an optical unit for a three-dimensional measuring device provided in the three-dimensional measuring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of a three-dimensional measuring device according to an embodiment.

[0042] Figure 2 Yes means Figure 1 A schematic diagram of the structure of the functional blocks of the measuring head is shown.

[0043] Figure 3 Yes means Figure 1 A schematic diagram showing the concept of the specific structure of the measuring head is shown.

[0044] Figure 4 Yes means Figure 1 FIG. 1 is a schematic diagram of the structure of the functional blocks of the vision measuring device.

[0045] Figure 5 It means in Figure 1 FIG. 1 is a diagram showing an example of a projection pattern emitted from a measuring head in the three-dimensional measuring device shown.

[0046] Figure 6 It is used to illustrate Figure 1 The diagram shows the principle of three-dimensional measurement performed by the three-dimensional measuring device shown.

[0047] Figure 7 Yes means Figure 1 FIG. 2 is a diagram showing a measurement range on the imaging unit side of a three-dimensional measuring device.

[0048] Figure 8 Yes means Figure 1 The schematic perspective view of the external structure of the measuring head shown.

[0049] Fig. 9 Yes means Figure 1 A schematic three-dimensional view of the internal structure of the measuring head shown.

[0050] Fig.10 yes Fig. 9 A schematic three-dimensional view of the projection portion shown.

[0051] Fig.11 yes Fig. 9 A schematic cross-sectional view of the projection portion shown.

[0052] Fig.12 Yes means Fig. 9 An exploded perspective view of the assembly structure of the projection unit shown.

[0053] Fig.13 yes Fig. 9 A schematic three-dimensional diagram of the imaging unit shown.

[0054] Fig.14 yes Fig. 9 A schematic cross-sectional view of the imaging unit shown.

[0055] Fig.15 Yes means Fig. 9 An exploded perspective view of the assembly structure of the shooting unit shown.

[0056] Fig.16 Yes means Fig. 9 A schematic three-dimensional diagram of the heat dissipation structure of the projection unit and the imaging unit shown.

[0057] Fig.17 Yes means Figure 1 A schematic cross-sectional view of the sealed structure of the frame of the measuring head is shown.

[0058] [Explanation of Symbols]

[0059] 1: Three-dimensional measuring device

[0060] 10: Measuring head

[0061] 11: Processing Department

[0062] 11a: Control Unit

[0063] 12: Projection Department

[0064] 13: Photography Department

[0065] 14: Display unit

[0066] 15: Storage

[0067] 16: Communication I / F Department

[0068] 100: Frame

[0069] 101: Bottom plate

[0070] 101a: Groove

[0071] 102: Cover

[0072] 102a: protrusion

[0073] 110: Window for lighting

[0074] 111: Translucent board

[0075] 112: Lighting source

[0076] 120: Window for projecting light

[0077] 121: Translucent board

[0078] 130: Light receiving window

[0079] 131: Translucent board

[0080] 141, 142: Connection terminals

[0081] 150: Rack

[0082] 160: Circuit board

[0083] 171, 172: Heat sink

[0084] 180: Padding

[0085] 191~193: Screw

[0086] 200: Base

[0087] 201: First base

[0088] 202: Second base

[0089] 202a: Hollow

[0090] 210: Lens support

[0091] 211a: Hollow

[0092] 211: Assembling components

[0093] 212: Lens tube

[0094] 220: Light projection lens

[0095] 221-223: Lens

[0096] 230: Substrate

[0097] 241: Light Source

[0098] 242, 243: Lens

[0099] 244: Photomask

[0100] 245: Protective components

[0101] 250: Flexible Heater

[0102] 251: Heater

[0103] 252: Wiring department

[0104] 254: Temperature sensor

[0105] 256: Adhesive tape

[0106] 260: Cover member

[0107] 270: Air layer

[0108] 281-283: Screws

[0109] 300: Base

[0110] 310: Lens support

[0111] 311: Assembling components

[0112] 311a: Hollow

[0113] 312: Lens tube

[0114] 320: Light receiving lens

[0115] 321-323: Lens

[0116] 330: Substrate

[0117] 341: Photographic element

[0118] 342: Light shielding member

[0119] 350: Flexible Heater

[0120] 351: Heater

[0121] 352: Wiring department

[0122] 354: Temperature sensor

[0123] 356: Adhesive tape

[0124] 360: Cover member

[0125] 370: Air layer

[0126] 381, 382: Screws

[0127] 1000: Image measuring device

[0128] 1020: Processor

[0129] 1040: Main memory

[0130] 1060: Storage

[0131] 1061: OS

[0132] 1062: 3D measurement program

[0133] 1080: Input

[0134] 1100: Display unit

[0135] 1120: Optical drive

[0136] 1140: Lower I / F part

[0137] 1150: Recording medium

[0138] 1160: Upper I / F section

[0139] 1180: Processor bus

[0140] C: Conveyor

[0141] MR: Measuring range

[0142] P: Projection pattern

[0143] R: Primitive position

[0144] W1, W2, W3: character code

[0145] WK: Workpiece DETAILED DESCRIPTION

[0146] In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and their description will not be repeated.

[0147] <A. Three-dimensional measuring device>

[0148] Figure 1 3D measuring device according to the embodiment. Figure 1 The three-dimensional measuring device 1 according to this embodiment will be described.

[0149] like Figure 1 As shown, the three-dimensional measuring device 1 includes a measuring head 10 and an image measuring device 1000. The image measuring device 1000 is also called a sensor controller or a visual sensor.

[0150] The vision measuring device 1000 acquires an image (hereinafter also referred to as an "input image") obtained by photographing the object by the measuring head 10 while projecting a predetermined projection pattern from the measuring head 10 onto the object to be measured. Typically, a projection pattern based on structured illumination is used as the projection pattern. That is, a plurality of reference patterns to which inherent codes are respectively assigned are arranged according to a predetermined rule as the projection pattern (this method is referred to as an inherent code method).

[0151] The vision measuring device 1000 performs three-dimensional measurement processing using information of the projection pattern and information of the projection pattern appearing in the acquired input image, thereby acquiring a three-dimensional measurement result (three-dimensional measurement result image).

[0152] More specifically, the image measuring device 1000 searches for each reference pattern (hereinafter also referred to as "element") contained in the projected projection pattern in the input image, thereby obtaining the position of each irradiated element and the set of codes represented by the irradiated element. Furthermore, the image measuring device 1000 searches for a corresponding area (hereinafter also referred to as "grid code pattern") that presents the same arrangement of codes represented by a predetermined number of reference patterns contained in a unit area (hereinafter also referred to as "word") set for the projection pattern from the set of codes. Finally, the image measuring device 1000 calculates the distance from the irradiation reference plane of the projection pattern to each part of the object based on the search result of the grid code pattern. The set of calculated distances is expressed as a three-dimensional measurement result image.

[0153] The three-dimensional measuring device 1 can be used for various purposes, but in this example, it is used for measuring the three-dimensional shape of the workpiece WK and its surroundings conveyed on the conveyor C. Specifically, a projection pattern is projected from the projection unit 12 provided in the measuring head 10 toward the workpiece WK and its surroundings as a photographic object, and the workpiece WK and its surroundings on which the projection pattern is projected are photographed by the imaging unit 13 provided in the measuring head 10.

[0154] <B. Measuring head>

[0155] Figure 2 Yes means Figure 1 A schematic diagram showing the structure of the functional blocks of the measuring head is shown. Figure 3 Yes means Figure 1 The schematic diagram of the concept of the specific structure of the measuring head is shown below. Figure 2 as well as Figure 3 The structure of the measuring head 10 will be described.

[0156] like Figure 2 As shown, the measuring head 10 includes a processing unit 11, the projection unit 12 and the photographing unit 13, a display unit 14, a storage unit 15 and a communication interface (Interface, I / F) unit 16. As mentioned above, the projection unit 12 projects a projection pattern on the object, and the photographing unit 13 photographs the object projected with the projection pattern.

[0157] The processing unit 11 is responsible for the overall processing in the measuring head 10. Typically, the processing unit 11 includes a processor, a storage for storing command codes executed by the processor, and a memory for expanding the command codes. In this case, in the processing unit 11, the processor expands the command codes on the memory and executes them to implement various processes. All or part of the processing unit 11 can also be implemented using a dedicated hardware circuit (such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA)).

[0158] The display unit 14 notifies the outside of various information acquired or calculated by the measuring head 10 .

[0159] The storage unit 15 stores images captured by the imaging unit 13 , preset calibration parameters, and the like.

[0160] The communication interface 16 is responsible for data exchange between the measuring head 10 and the vision measuring device 1000 .

[0161] like Figure 3As shown in the figure, the projection unit 12 has: a light source 241 and a photomask 244 as optical devices, which are pattern illumination forming elements; a projection lens 220 as an optical lens; and a lens support unit not shown in the figure, which will be described later. That is, the projection unit 12 includes an optical assembly for a three-dimensional measurement device, which is formed by assembling the light source 241, the photomask 244, the projection lens 220, the lens support unit, etc., but the detailed structure thereof will be described later.

[0162] The light source 241 irradiates light of a predetermined wavelength toward the photomask 244. A predetermined pattern is formed on the photomask 244. The light that has passed through the photomask 244 is irradiated to the outside via the projection lens 220. Thus, the projection pattern is irradiated to the outside space.

[0163] On the other hand, the imaging unit 13 includes an imaging element 341 as an optical device, a light receiving lens 320 as an optical lens, and a lens support unit (not shown) described later, etc. That is, the imaging unit 13 includes an optical assembly for a three-dimensional measurement device constituted by assembling the imaging element 341, the light receiving lens 320, the lens support unit, etc., but the detailed structure thereof will be described later.

[0164] The imaging unit 13 captures an image of the subject on which the projection pattern is projected. Specifically, the imaging element 341 receives light that has passed through the light receiving lens 320 to thereby obtain an input image.

[0165] Here, if Figure 2 As shown, the projection unit 12 is provided with a temperature sensor 254 for detecting the temperature of the light projecting lens 220 , and the imaging unit 13 is provided with a temperature sensor 354 for detecting the temperature of the light receiving lens 320 .

[0166] Furthermore, the projection unit 12 is provided with a flexible heater 250 (see Fig.11 The imaging unit 13 is provided with a heater 251 for heating the light receiving lens 320, that is, a flexible heater 350 (see Fig.14 etc.) of the heater section 351.

[0167] On the other hand, the processing unit 11 is provided with a control unit 11a. The control unit 11a performs control for maintaining the temperature of the light projecting lens 220 and the temperature of the light receiving lens 320 at predetermined fixed temperatures during three-dimensional measurement.

[0168] Specifically, the control unit 11a controls the operation of the heater unit 251 based on the detection result of the temperature sensor 254, thereby maintaining the temperature of the light projecting lens 220 at a fixed temperature, and controls the operation of the heater unit 351 based on the detection result of the temperature sensor 354, thereby maintaining the temperature of the light receiving lens 320 at a fixed temperature. This point will be described in detail later.

[0169] <C. Image measuring device>

[0170] Figure 4 Yes means Figure 1 The schematic diagram of the structure of the functional blocks of the image measuring device shown in FIG. Figure 4 The structure of the functional blocks of the vision measuring device 1000 will be described.

[0171] like Figure 4 As shown, typically, the vision measuring device 1000 is implemented using a general-purpose computer. The vision measuring device 1000 includes a processor 1020, a main memory 1040, a storage 1060, an input unit 1080, a display unit 1100, an optical drive 1120, a lower interface unit 1140, and an upper interface unit 1160. These components are connected via a processor bus 1180.

[0172] The processor 1020 includes a central processing unit (CPU) or a graphics processing unit (GPU), etc., and realizes various processing as described later by reading out the program stored in the storage 1060 (as an example, an operating system (OS) 1061 and a three-dimensional measurement program 1062) and expanding and executing it in the main memory 1040.

[0173] The main memory 1040 includes a volatile storage device such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), etc. The storage 1060 includes a non-volatile storage device such as a hard disk drive (HDD) or a solid state drive (SSD), etc.

[0174] In the storage 1060 , in addition to the OS 1061 for realizing basic functions, a three-dimensional measurement program 1062 for providing functions as the vision measuring device 1000 is stored.

[0175] The input unit 1080 includes a keyboard, a mouse, etc., and receives user operations. The display unit 1100 includes a display, various indicators, a printer, etc., and outputs processing results from the processor 1020, etc.

[0176] The lower interface unit 1140 is responsible for data exchange with the measuring head 10. The upper interface unit 1160 is responsible for data exchange with an upper device (eg, a programmable logic controller (PLC) (programmable computer) etc.) not shown in the figure.

[0177] The vision measuring device 1000 includes an optical drive 1120 that reads a program stored in a recording medium 1150 (eg, an optical recording medium such as a digital versatile disc (DVD)) that stores a computer-readable program in a non-disposable manner, and installs the program in a storage device 1060 or the like.

[0178] The three-dimensional measurement program 1062 executed by the vision measuring device 1000 can be installed via the computer-readable recording medium 1150, but can also be installed in the form of downloading from a server device on the network. In addition, the functions provided by the three-dimensional measurement program 1062 of this embodiment may also be implemented in the form of a part of a module provided by the OS.

[0179] Figure 4 1 shows a configuration example in which the functions required as the vision measuring device 1000 are provided by executing a program on the processor 1020, but part or all of these provided functions may be realized using a dedicated hardware circuit (eg, ASIC or FPGA).

[0180] <D. Three-dimensional measurement>

[0181] Next, the three-dimensional measurement performed by the three-dimensional measurement device 1 of the present embodiment is described. In the present embodiment, the three-dimensional measurement is realized using a method called structured illumination. In the structured illumination method, a predetermined projection pattern is projected onto an object, and the position of each part of the object (the distance from the measuring head) is measured based on an image obtained by photographing the object in a state where the projection pattern is projected, thereby measuring the three-dimensional shape of the object.

[0182] In this embodiment, as an example of structured illumination, a method of irradiating measurement light having a predetermined projection pattern (typically a shading pattern) is adopted. In the following description, the irradiation surface of the projection unit 12 is regarded as the "irradiation reference surface" of the projection pattern.

[0183] In the three-dimensional measuring device 1, calibration is performed in advance between the projection unit 12 and the imaging unit 13 included in the measuring head 10, and the optical parameters of the projection unit 12 and the imaging unit 13 and the matrix that relates the two are predetermined. The optical parameters of the projection unit 12 and the imaging unit 13 are determined based on the same reference point, and as long as the height of the projection surface of the projection unit 12 is specified, it is possible to calculate which pixel on the imaging surface of the imaging unit 13 the projection pattern irradiated from the projection unit 12 corresponds to.

[0184] The projection pattern emitted from the projection unit 12 changes in size or position (expansion or contraction of the interval between adjacent elements) depending on the position or inclination of the object relative to the optical axis of the projection unit 12. Based on this information, the shape of the object can be measured according to the principle of triangulation.

[0185] Figure 5 This is a diagram showing an example of a projection pattern emitted from a measuring head in the three-dimensional measuring device according to the present embodiment. Figure 6 This is a diagram for explaining the principle of three-dimensional measurement performed by the three-dimensional measuring device according to the present embodiment.

[0186] From the projection unit 12 of the measuring head 10, for example, a light including Figure 5 The imaging unit 13 of the measuring head 10 images the object in a state where the projection pattern P is projected.

[0187] Figure 5 The projection pattern P shown is a spatial code arranged in a grid shape (hereinafter also referred to as a "grid code"), and a unique code that does not generate autocorrelation is assigned to a pattern of a predetermined length in a predetermined direction. More specifically, the projection pattern P is defined by a combination of multiple primitives (equivalent to reference patterns).

[0188] Figure 6 Four primitives are shown in (A). Each primitive represents a code ( Figure 6 In the example shown in (A), the four values ​​are 1 to 4). Each primitive includes four large squares Qa to Qd and a small square Qe located in the center. The squares Qa to Qd are arranged so that the primitive position R becomes a corner. The primitive position R is also the center position of the small square Qe.

[0189] like Figure 6 As shown in (A), the intersection point of the large squares Qa to Qd (a corner point of the grid) is defined as the primitive position R. There is no limitation on the size and shape of the primitive position R. Each primitive is restored to one three-dimensional point.

[0190] like Figure 6As shown in (A), when the primitive position R is "white", it is expressed as p0 = 1, and when it is "black", it is expressed as p0 = 0. When the large square Qb on the upper left of the primitive position R is "white", it is expressed as p1 = 1, and when it is "black", it is expressed as p1 = 0. The type of primitive can be expressed numerically as 2p1 + p0.

[0191] Figure 6 In (B), the projection pattern P is expressed numerically (refer to Figure 5 ) part. That is, by determining the type of each primitive contained in the projection pattern P and expressing the type of each determined primitive with a numerical value, a matrix K equivalent to the projection pattern P can be generated.

[0192] In the following description, the in-plane directions of the projection pattern P are defined as the X direction and the Y direction, and the optical axis direction (height) direction is defined as the Z direction.

[0193] Figure 6 (C) shows Figure 6 Here, it is assumed that the local matrix of the matrix K has a predetermined size (word height Hword×word width Wword) set for the matrix K. Such a local matrix is ​​also called a "word". That is, each word is a combination of a predetermined number of primitive types ( Figure 6 The projection pattern P is generated by arranging primitives in such a way that all the word codes are unique.

[0194] From the input image acquired by photographing the object with the projection pattern P projected onto it, all the characters included in the matrix K are extracted. The process of extracting primitives to determine or reconstruct characters is also called "decoding" (of characters).

[0195] Figure 6 The three extracted codes (codes W1, W2, and W3) are shown in (C). When all the codes are extracted from the pattern projected on the input image, as long as the arrangement of the values ​​of the local matrix in each extracted code is unique, the position of the code in the pattern can be determined. That is, the position in the projected pattern P (the position of the code) can be determined.

[0196] When the projection pattern P is irradiated from the measuring head 10 (projection unit 12 ), the position of the code specified by the projected image changes depending on the surface shape of the object.

[0197] Based on the size of the code specified by the primitives contained in the image obtained by photographing the object with the projection pattern P projected onto the object and the position deviation between adjacent code bits, the distance from the measuring head 10 to each part of the object and the three-dimensional shape of the object can be measured.

[0198] For example, Figure 6 In the example shown in (C), adjacent code words W1 to W3 share some primitives.

[0199] The vision measuring device 1000 performs a process of extracting primitives and a process of evaluating the position and size of a character code determined by the extracted primitives on the images output from each measuring head 10 , thereby outputting a measurement result of the three-dimensional shape of the object.

[0200] in addition, Figure 6 In (A), an example using four primitives is shown, but the number of primitives is not limited to four. Figure 6 The shape and color of the primitive shown in (A) can be any shape and color.

[0201] Furthermore, as a method for detecting primitives, pattern matching using each primitive as a model, or filtering processing using the black pixel direction / white pixel direction and the color of the central value as conditions, etc. can be adopted.

[0202] <E. Issues to be solved>

[0203] Next, the problem to be solved by the present disclosure will be described. To summarize the problem to be solved by the present disclosure, as described above, it is to prevent the measurement range from being extremely narrowed or the measurement range itself from disappearing within a predetermined temperature range.

[0204] Here, the so-called measurement range refers to the distance range along the optical axis between the measuring head and the object in which the three-dimensional shape of the object can be measured. If the measurement range becomes extremely narrow or the measurement range itself disappears, the three-dimensional shape of the object cannot be measured.

[0205] The measurement range includes a measurement range on the projection unit side and a measurement range on the imaging unit side. When the object is arranged outside the measurement range on the projection unit side, the projection pattern projected onto the object will become blurred, and the projection pattern in the input image will become unclear. Moreover, when the object is arranged outside the measurement range on the imaging unit side, the image formed on the imaging surface of the imaging element will become blurred, and the projection pattern in the input image will become unclear. Therefore, in either case, the primitive cannot be extracted from the acquired input image, and as a result, the three-dimensional shape of the object cannot be measured.

[0206] As described above, in the measuring head of the three-dimensional measuring device, there are provided an optical lens (light projection lens) for imaging the projection pattern on the object, and an optical lens (light receiving lens) for imaging the image of the state in which the projection pattern is projected on the object on the imaging surface of the imaging element. These optical lenses generally include a composite lens composed of a plurality of lenses, but usually have a property (temperature characteristic) that the focal position changes according to the temperature. The temperature characteristic of the optical lens greatly affects the presence and width of the measurement range.

[0207] Figure 7 Yes means Figure 1 The measurement range of the imaging unit side of the three-dimensional measuring device shown in FIG. Figure 7 Regarding the influence of the temperature characteristics of the optical lens on the measurement range of the three-dimensional measurement device 1, the light receiving side is taken as an example to explain in detail. In addition, for ease of understanding, Figure 7 In the figure, the light receiving lens 320 is shown to include a single lens, but it may also be as described later. Fig.14 As shown in , etc., the light receiving lens 320 includes a lens group including a plurality of lenses.

[0208] Here, Figure 7 (A) shows the state where the light receiving lens 320 is at temperature T. Figure 7 (B) shows the state where the light receiving lens 320 is heated to a temperature of T+ΔT. Figure 7 (C) shows a state where the temperature of the light receiving lens 320 is reduced to the temperature T-ΔT. In addition, as the light receiving lens 320 used, a lens whose focal position changes in a direction away from the focus as the temperature rises is exemplified.

[0209] like Figure 7 As shown in (A), the light receiving lens 320 forms an object plane and an image plane as a pair of conjugate planes in an optical conjugate relationship. The object distance A, which is the distance from the principal point of the light receiving lens 320 to the object plane, and the image distance B, which is the distance from the principal point of the light receiving lens 320 to the image plane, can be determined by the following formula (1) using the focal length f of the light receiving lens 320.

[0210] (1 / A)+(1 / B)=1 / f…(1)

[0211] Here, by placing the object on the object plane and placing the imaging element 341 on the image plane, a clear image of the object is formed on the imaging plane of the imaging element 341. In addition, the light receiving lens 320 has a focal depth δ determined by its permissible circle of confusion diameter Φ, and as long as the imaging element 341 is placed within the range of the focal depth δ, a clear image of the object can be formed on the imaging plane of the imaging element 341.

[0212] The measurement range on the light receiving side is determined by the depth of field (DOF). The depth of field DOF is the range along the optical axis direction on the side where the subject is arranged and clearly imaged on the image plane, and is expressed as the sum of the front depth of field Lf located on the light receiving lens 320 side as viewed from the object plane and the rear depth of field Lr located on the opposite side to the light receiving lens 320 side as viewed from the object plane. Generally speaking, the end point of the depth of field DOF on the light receiving lens 320 side is called the "near point", and the end point of the depth of field DOF on the opposite side to the light receiving lens 320 side is called the "far point".

[0213] Here, the distance from the principal point of the light-receiving lens 320 to the near point, i.e., the near point distance Sn, and the distance from the principal point of the light-receiving lens 320 to the far point, i.e., the far point distance Sf, are determined by the following equations (2) and (3), respectively, using the focal length f, object distance A, allowable circle of confusion diameter Φ, and brightness F of the light-receiving lens 320.

[0214] Sn=Φ×F×A 2 / (f 2 +Φ×F×A)…(2)

[0215] Sf=Φ×F×A 2 / (f 2 -Φ×F×A)…(3)

[0216] Therefore, in the imaging unit 13 where the distance along the optical axis between the imaging element 341 and the light receiving lens 320 (referred to as "inter-element distance") is the image distance B, a clear input image of the object can be obtained by arranging the object within a range from the light receiving lens 320 that is greater than the near point distance Sn represented by the above formula (2) and less than the far point distance Sf represented by the above formula (3). That is, the above range becomes the measurement range at the temperature T.

[0217] On the other hand, Figure 7 As shown in (B), when the light receiving lens 320 is relatively Figure 7 In the state shown in (A) of FIG. 1 , when the temperature is increased by ΔT, the focal position of the light receiving lens 320 moves in the direction away from the light receiving lens 320, and the object plane also moves away from the light receiving lens 320. If the distance away is ΔA, the object distance is A+ΔA. At this time, the near point distance Sn and the far point distance Sf are determined by the following equations (4) and (5), respectively.

[0218] Sn=Φ×F×(A+ΔA) 2 / (f 2 +Φ×F×(A+ΔA))…(4)

[0219] Sf=Φ×F×(A+ΔA)2 / (f 2 -Φ×F×(A+ΔA))…(5)

[0220] That is, the measurement range at the temperature T+ΔT is shifted from the measurement range at the temperature T in a direction away from the light receiving lens 320 .

[0221] In addition, as described above, when the object plane is far from the light receiving lens 320, the image plane will be close to the light receiving lens 320, and the image distance at this time is represented by B' in the figure. Here, based on the above formula (1), B' is f×(A+ΔA) / (A+ΔA-f).

[0222] On the other hand, Figure 7 As shown in (C), when the light receiving lens 320 is relatively Figure 7 In the state shown in (A) of FIG. 1 and cooled by the temperature ΔT, the focal position of the light receiving lens 320 moves toward the direction close to the light receiving lens 320, and the object plane also approaches the light receiving lens 320. If the approach distance is ΔA, the object distance is A-ΔA. At this time, the near point distance Sn and the far point distance Sf are determined by the following equations (6) and (7), respectively.

[0223] Sn=Φ×F×(A-ΔA) 2 / (f 2 +Φ×F×(A-ΔA))…(6)

[0224] Sf=Φ×F×(A-ΔA) 2 / (f 2 -Φ×F×(A-ΔA))…(7)

[0225] That is, the measurement range at the temperature T-ΔT is shifted from the measurement range at the temperature T toward a direction closer to the light receiving lens 320 .

[0226] In addition, as described above, when the object plane approaches the light receiving lens 320, the image plane will move away from the light receiving lens 320, and the image distance at this time is represented by B" in the figure. Here, based on the above formula (1), B" is f×(A-ΔA) / (A-ΔA-f).

[0227] According to the above, if it is assumed that a three-dimensional measuring device is produced in which the range from temperature T-ΔT to temperature T+ΔT is set as a measurable temperature range, the actual measurement range in the three-dimensional measuring device becomes a range where the distance from the light receiving lens 320 is greater than the near point distance Sn at temperature T+ΔT represented by the above formula (4) and less than the far point distance Sf at temperature T-ΔT represented by the above formula (7) (i.e., the range represented by the symbol MR in the figure). That is, in order to ensure the actual measurement range MR, at least the condition represented by (the right side of the above formula (4)) < (the right side of the above formula (7)) must be satisfied. In order to more fully ensure this condition, the far point distance Sf at temperature T-ΔT represented by the above formula (7) must be sufficiently greater than the near point distance Sn at temperature T+ΔT represented by the above formula (4).

[0228] However, the focal length f, the permissible circle of confusion diameter Φ, and the brightness F are all determined by the optical characteristics of the light receiving lens 320 used, and although a small amount of fine adjustment can be performed, they cannot be freely set due to various restrictions on achieving three-dimensional measurement. Therefore, the inventors of the present invention have assumed actual specifications and conducted various trial calculations. As a result, it was confirmed that it was very difficult to satisfy the optical characteristics required of the optical lens for achieving three-dimensional measurement while ensuring that the actual measurement range MR was sufficiently large, and it was determined that there was a problem that the actual measurement range MR was extremely narrow or the measurement range MR itself did not exist.

[0229] Although detailed description is omitted here, in the case where the light receiving lens 320 is a lens whose focal position changes in a direction approaching as the temperature rises, the same problem occurs for the same reason as described above. Moreover, for the same reason as the influence of the temperature characteristics of the light receiving lens 320 on the measurement range on the imaging unit 13 side of the three-dimensional measuring device 1, the temperature characteristics of the light projecting lens 220 provided in the projection unit 12 also affect the measurement range on the projection unit 12 side of the three-dimensional measuring device 1.

[0230] Therefore, the inventors have solved the above-mentioned problem by controlling the temperature of the light-projecting lens 220 and the temperature of the light-receiving lens 320 to be respectively maintained at a predetermined fixed temperature by the control unit 11a in the three-dimensional measuring device 1 of the present embodiment. The three-dimensional measuring device 1 of the present embodiment will be described in further detail below, including this point.

[0231] <F. Detailed structure of measuring head>

[0232] Figure 8 as well as Fig. 9 Respectively represent Figure 1The external structure of the measuring head and the schematic three-dimensional diagram of the internal structure are shown. Figure 8 as well as Fig. 9 The overall structure of the measuring head 10 in this embodiment is described below. Fig. 9 In the figure, some of the internal components are omitted.

[0233] like Figure 8 As shown, the measuring head 10 has a substantially rectangular parallelepiped shape, and includes a housing 100 , and a projection unit 12 and an imaging unit 13 as optical components for a three-dimensional measuring device accommodated in the housing 100 .

[0234] The frame 100 has a flat bottom plate 101 (see Fig. 9 ) and a box-shaped cover 102 with an opening on the lower surface, and the lower surface opening of the cover 102 is closed by the bottom plate 101, so that the whole has a substantially rectangular parallelepiped shape. The bottom plate 101 and the cover 102 are fixed by screws 191. The bottom plate 101 and the cover 102 both include a metal member with high thermal conductivity, preferably, formed of an aluminum alloy or the like.

[0235] The housing 100 has three windows, namely, a lighting window 110, a light-emitting window 120, and a light-receiving window 130, on its front surface. The lighting window 110, the light-emitting window 120, and the light-receiving window 130 are covered by light-transmitting plates 111, 121, and 131, respectively.

[0236] An illumination light source 112 including, for example, a light emitting diode (LED) is disposed inside the housing 100 and behind the illumination window 110. Light emitted from the illumination light source 112 passes through the light-transmitting plate 111, thereby irradiating from the illumination window 110 toward the outside space, thereby illuminating the measurement area. The illumination light source 112 is provided in consideration of the situation where there is no lighting equipment to illuminate the measurement area, and is used for illumination other than when the three-dimensional measurement is performed.

[0237] The projection unit 12 is disposed inside the housing 100 and behind the light projection window 120. Fig. 9 As described above, the projection unit 12 includes a light source 241, a photomask 244, a projection lens 220, a lens support unit 210, etc. (wherein the light source 241 and the photomask 244 are Fig. 9 An optical component for a three-dimensional measuring device composed of components (not shown) assembled together.

[0238] A lens barrel 212 that is a part of the lens support 210 is disposed in front of the projection unit 12. The lens barrel 212 supports a light projection lens 220 therein. Thus, the light projection lens 220 is disposed to face the light-transmitting plate 121 that covers the light projection window 120.

[0239] The light emitted from the projection unit 12 passes through the photomask 244 inside the projection unit 12 and then through the projection lens 220. The light is transmitted through the light-transmitting plate 121, and is irradiated toward the external space from the projection window 120. Thus, the projection pattern is irradiated toward the external space. As described above, the projection pattern irradiated from the projection unit 12 is projected onto the workpiece WK and its surroundings, thereby enabling three-dimensional measurement.

[0240] The imaging unit 13 is disposed inside the housing 100 and behind the light receiving window 130. Fig. 9 As described above, the imaging unit 13 includes an imaging element 341, a light receiving lens 320, a lens support unit 310, etc. (wherein the imaging element 341 is Fig. 9 An optical component for a three-dimensional measuring device composed of components (not shown) assembled together.

[0241] A lens barrel 312 that is a part of the lens support 310 is disposed in front of the imaging unit 13. The lens barrel 312 supports the light receiving lens 320 therein. Thus, the light receiving lens 320 is disposed to face the light transmitting plate 131 that covers the light receiving window 130.

[0242] The reflected light emitted from the workpiece WK on which the projection pattern is projected and its surroundings passes through the light-transmitting plate 131, thereby entering the imaging unit 13 from the light-receiving window 130, and irradiating the imaging element 341 via the light-receiving lens 320. Thus, as described above, the light is received by the imaging element 341, thereby enabling three-dimensional measurement.

[0243] Furthermore, connection terminals 141 and 142 are provided at predetermined positions on the side surface of the housing 100. The connection terminals 141 and 142 are used to electrically connect the measuring head 10 and the vision measuring device 1000, etc.

[0244] like Fig. 9 As shown, a chassis 150 including a metal plate-shaped member is provided inside the housing 100 and at a position behind the projection unit 12 and the imaging unit 13. The chassis 150 is provided in a manner of standing upright from the bottom plate 101 of the housing 100 toward the upper side, and a circuit substrate 160 is assembled on the front surface side of the chassis 150. Thus, the circuit substrate 160 is arranged in a standing posture in front of the chassis 150 and at a position behind the projection unit 12 and the imaging unit 13.

[0245] The circuit substrate 160 is provided with the processing unit 11, and is electrically connected to the projection unit 12 and the imaging unit 13 via a flexible wiring substrate (not shown) and the like. In addition, the circuit substrate 160 is provided with a control unit 11a for controlling the operation of the flexible heaters 250 and 350 described later, and is also electrically connected to the wiring units 252 and 352 of the flexible heaters 250 and 350.

[0246] <G. Structure of the projection unit>

[0247] Fig.10 as well as Fig.11 are respectively a schematic three-dimensional diagram and a schematic cross-sectional diagram of the projection portion, Fig.12 is an exploded perspective view showing the assembly structure of the projection unit. Fig. 9 With these Figures 10 to 12 The detailed structure of the projection unit 12 in this embodiment will be described.

[0248] Here, Fig.10 (A) shows a state where a cover member 260 described later has been assembled to the projection unit 12. Fig.10 (B) shows a state where the cover member 260 is removed from the projection unit 12. Fig.11 (A) and Fig.11 The (B) respectively represents along Fig.10 (A) shows a cross section along the line XIA-XIA and along the line XIB-XIB.

[0249] like Figures 9 to 12 As shown, the projection unit 12 mainly includes a base 200 , a lens support 210 , a projection lens 220 , a substrate 230 , a light source 241 , a photomask 244 , a flexible heater 250 , a temperature sensor 254 , and a cover member 260 .

[0250] The base 200 is a portion that serves as a stand for the projection unit 12 and is provided on the bottom plate 101 of the housing 100. The base 200 includes a first base 201 fixed to the bottom plate 101 by screws and a second base 202 fixed to the bottom plate 101 by screws 192 (see FIG. 1 ). Fig.12 ) is fixed to the second base 202 of the first base 201. The second base 202 is fixed in a state of being placed on the first base 201, and includes a cylindrical member having a hollow portion 202a extending in a direction parallel to the optical axis of the projection lens 220 and having a square shape.

[0251] like Fig.11 as well as Fig.12As shown, a substrate 230 is assembled on the rear end face of the second base 202 (i.e., the end face on the side where the circuit substrate 160 is located). More specifically, the substrate 230 is fixed to the rear end face of the second base 202 by screws 281, thereby the hollow portion 202a provided in the second base 202 is closed by the substrate 230.

[0252] A light source 241 is mounted on the surface of the substrate 230 that closes the hollow portion 202a, so that the light source 241 faces the hollow portion 202a. The light source 241, lenses 242, 243, and a photomask 244 constitute a pattern illumination forming element as an optical device, and in this embodiment, includes an LED.

[0253] The second base 202 supports lenses 242 and 243 inside. More specifically, the lenses 242 and 243 are fixed to the second base 202 by supporting the periphery thereof by the second base 202, and are thus arranged in front of the light source 241 in a manner facing the light source 241. These lenses 242 and 243 are so-called collimating lenses that collimate the light emitted from the light source 241, and together with the light source 241 and the photomask 244, constitute a pattern illumination forming element as an optical device.

[0254] A lens support part 210 is assembled at the front end of the second base 202 so as to cover the hollow part 202a. The lens support part 210 includes: an assembly member 211 whose end is embedded in the hollow part 202a and fixed to the second base 202 by screws 283; and a lens barrel 212 that supports the projection lens 220 and is fixed to the assembly member 211.

[0255] The assembly member 211 includes a member made of a metal having high thermal conductivity, such as an aluminum alloy, and includes a cylindrical member having a square shape and a hollow portion 211a extending in a direction parallel to the optical axis of the projection lens 220. As described above, the rear end portion of the assembly member 211 is fixed to the second base 202, and the photomask 244 and the protective member 245 are supported at a portion close to the rear end portion.

[0256] The photomask 244, together with the light source 241 and the lenses 242 and 243, constitute a pattern illumination forming element as an optical device, and is arranged opposite to the lenses 242 and 243 as collimating lenses supported by the second base 202. The protective member 245 is a member for protecting the photomask, and is made of glass, for example. The photomask 244 and the protective member 245 are fixed to the assembly member 211 by supporting their peripheries in a superimposed state.

[0257] The lens barrel 212 includes a cylindrical member made of a metal having high thermal conductivity, such as an aluminum alloy, and its rear end is fixed by being embedded in the hollow portion 211a of the assembly member 211. The front end of the lens barrel 212 protrudes forward from the assembly member 211, and is thus arranged in front of the projection unit 12.

[0258] Here, in more detail, a male thread is provided at the rear end of the outer circumference of the lens barrel 212, and a female thread is provided at the front end of the inner circumference of the hollow portion 211a of the assembly member 211. Thus, the lens barrel 212 is fixed by being screwed to the assembly member 211. This fixing method is generally referred to as a lens fixing method of S mounting.

[0259] The projection lens 220 includes a composite lens composed of a plurality of lenses 221 to 223, and the plurality of lenses 221 to 223 are arranged in a row along the axial direction of the lens barrel 212 in a manner that the optical axes overlap with each other. The peripheral edges of the plurality of lenses 221 to 223 are supported by the lens barrel 212. That is, the lens barrel 212 surrounds the projection lens 220 in a direction orthogonal to the optical axis of the projection lens 220 to support it.

[0260] According to the above, the light source 241, lenses 242 and 243 as collimating lenses, the photomask 244, and multiple lenses 221 to 223 as the projection lens 220 are arranged inside the projection unit 12 on the optical axis of the projection lens 220, so that the projection pattern can be irradiated from the projection unit 12 toward the outside.

[0261] Here, if Figures 10 to 12 As shown in the figure, the heater portion 251 of the flexible heater 250 is assembled on the outer peripheral surface of the mounting member 211 as a part of the lens support portion 210. More specifically, the flexible heater 250 includes a heating wire and a flexible substrate (such as a polyimide substrate) provided with wiring for energizing the heating wire, and the portion provided with the heating wire, that is, the heater portion 251, is attached to the outer peripheral surface of the mounting member 211 via an adhesive tape 256 with high thermal conductivity.

[0262] On the other hand, the wiring portion 252 of the flexible heater 250, which is a portion provided with the wiring, is led out from the upper surface of the projection unit 12 toward the outside, and its front end is connected to the circuit substrate 160, thereby being electrically connected to the control unit 11a. In addition, a temperature sensor 254 is installed at a predetermined position of the heater portion 251 of the flexible heater 250, and the temperature sensor 254 is also electrically connected to the control unit 11a via the wiring provided in the flexible heater 250.

[0263] Thus, when the flexible heater 250 is energized, the light projection lens 220 is heated via the mounting member 211 and the lens barrel 212. Furthermore, by energizing the flexible heater 250 over a predetermined period of time, the temperatures of the light projection lens 220, the lens barrel 212, the mounting member 211, and the heater portion 251 of the flexible heater 250 become equal, and thus the temperature of the light projection lens 220 can be detected by the temperature sensor 254.

[0264] In addition, in the present embodiment, the flexible heater 250 is not assembled to the portion of the outer peripheral surface of the attachment member 211 facing the first base 201 , but the flexible heater 250 may be further assembled to this portion as well.

[0265] like Figures 9 to 12 As shown, the projection unit 12 is provided with a cover member 260 so as to surround the mounting member 211 . Thus, the heater unit 251 of the flexible heater 250 and the temperature sensor 254 mounted on the heater unit 251 are covered by the cover member 260 .

[0266] In more detail, the cover member 260 has a roughly box shape that covers the portion of the outer peripheral surface of the assembly member 211 other than the portion facing the first base 201 and the front end surface, and the portion on the front end surface side is fixed to the assembly member 211 by screws 282, thereby being assembled to the assembly member 211.

[0267] Here, the cover member 260 covers the outer peripheral surface and the front end surface of the mounting member 211 over substantially the entire area except for the portion for leading out the wiring portion 252 of the flexible heater 250. Thus, the cover member 260 has a substantially sealed structure that conceals the mounting member 211.

[0268] like Fig.11 As shown, an air layer 270 is provided between the cover member 260 and the flexible heater 250 . The air layer 270 is formed by providing a predetermined gap between the inner surface of the cover member 260 and the exposed surface of the flexible heater 250 , and the air layer 270 is substantially sealed by the cover member 260 .

[0269] Furthermore, in the present embodiment, a predetermined gap is provided between the first base 201 and the attachment member 211 , thereby providing an air layer 270 , and the air layer 270 provided in the above portion is also sealed by the cover member 260 .

[0270] In this way, in the projection unit 12 , the lens barrel 212 and the assembly member 211 of the lens support unit 210 that surrounds and supports the projection lens 220 are surrounded by the cover member 260 via the air layer 270 , and the heater unit 251 and the temperature sensor 254 of the flexible heater 250 are both covered by the cover member 260 .

[0271] Here, as described above, in the three-dimensional measurement device 1 of the present embodiment, during the three-dimensional measurement, the control unit 11a performs control for maintaining the temperature of the light projection lens 220 at a predetermined fixed temperature. More specifically, the control unit 11a controls the operation of the heater unit 251 (e.g., whether or not power is supplied or the heater output is adjusted) based on the detection result of the temperature sensor 254, thereby maintaining the temperature of the light projection lens 220 at a fixed temperature.

[0272] Thus, the temperature of the light projection lens 220 can be maintained at a constant temperature, and thus the focus position of the light projection lens 220 can be substantially suppressed from changing during three-dimensional measurement. Therefore, by configuring in advance that the photomask 244 as a pattern illumination forming element is arranged at the focus position of the light projection lens 220 in a heated state, the photomask 244 can be maintained at the focus position of the light projection lens 220 during three-dimensional measurement. Therefore, by adopting the above configuration, the measurement range MR can be ensured to be large within a predetermined temperature range on the projection unit 12 side of the three-dimensional measurement device 1.

[0273] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, the temperatures of the mounting member 211 and the lens barrel 212 of the lens support portion 210 that supports the light projecting lens 220 can be maintained at a constant temperature, so that the distance between the light projecting lens 220 and the photomask 244 in the optical axis direction, that is, the distance between the elements can be substantially suppressed from changing during three-dimensional measurement. Therefore, the photomask 244 can be more reliably maintained at the focal position of the light projecting lens 220 during three-dimensional measurement.

[0274] In addition, as in the present embodiment, when the projector lens 220 includes a lens group including a plurality of lenses, the expansion and contraction caused by the temperature of the lens support portion 210 including the assembly component 211 and the lens barrel 212 will have a significant impact on the change in the focal position of the projector lens 220. Therefore, it is particularly effective to maintain the temperature of the lens support portion 210 fixed as described above.

[0275] That is, in the three-dimensional measuring device 1 of this embodiment, the light projection lens 220 is maintained at a predetermined fixed temperature during three-dimensional measurement, and is almost unaffected by the surrounding environment (especially the surrounding temperature) in which the three-dimensional measuring device 1 is installed. Therefore, as described above, on the projection unit 12 side, the measurement range MR can be ensured to be large within the prescribed temperature range.

[0276] Here, the first base 201 and the second base 202 of the base 200 preferably include a member having a thermal conductivity lower than that of the mounting member 211 and the lens barrel 212 of the lens support 210. By configuring in this way, the base 200 can provide a heat insulating effect.

[0277] Therefore, by adopting the above structure, the projector lens 220, the assembly member 211, and the lens barrel 212 can be efficiently heated, and their temperatures can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation required when the three-dimensional measurement device 1 is used can be shortened, and the photomask 244 can be more reliably maintained in a state where it is always arranged at the focal position of the projector lens 220 during three-dimensional measurement.

[0278] Furthermore, it is preferable that the cover member 260 includes a member having a thermal conductivity that is the same as or smaller than the thermal conductivity of the assembly member 211 and the lens barrel 212 that are the lens support portion 210. More specifically, when the air layer 270 is provided between the cover member 260 and the assembly member 211 as in the present embodiment, it is preferable that the thermal conductivity of the cover member 260 is the same as or smaller than the thermal conductivity of the lens support portion 210. Unlike the present embodiment, when a structure is adopted in which the cover member 260 is in close contact with the assembly member 211, etc., it is preferable that the thermal conductivity of the cover member 260 is smaller than the thermal conductivity of the lens support portion 210. By configuring in this way, a heat insulating effect is exerted by the cover member 260 or by the air layer 270 in addition thereto.

[0279] Therefore, by adopting the above structure, the projector lens 220, the assembly member 211, and the lens barrel 212 can be efficiently heated, and their temperatures can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation required when the three-dimensional measurement device 1 is used can be shortened, and the photomask 244 can be more reliably maintained in a state where it is always arranged at the focal position of the projector lens 220 during three-dimensional measurement.

[0280] In addition, based on the above viewpoint, it is preferred that the first base 201 and the second base 202 and the cover member 260 of the base portion 200 include a resin member represented by a polyphenylene sulfide (PPS) resin or a polycarbonate (PC) resin, or include a metal member with a relatively low thermal conductivity. However, in the case where an air layer 270 is provided between the cover member 260 and the assembly member 211 as in the present embodiment, a metal member (e.g., an aluminum alloy) with a relatively high thermal conductivity may be used as the cover member 260.

[0281] On the other hand, the temperature of the light projection lens 220 to be maintained constant by the control unit 11a is preferably a temperature that is higher than the maximum temperature that the light projection lens 220 can reach when the light projection lens 220 is not heated by the flexible heater 250 within the range of the ambient temperature allowed for the use of the projection unit 12 and lower than the upper limit of the operation guarantee temperature of the pattern illumination forming element. By configuring in this way, it is possible to configure a projection unit that can ensure a large measurement range MR within a predetermined temperature range, and a long life and high reliability, and a three-dimensional measurement device including the projection unit.

[0282] Here, in the case where the pattern illumination forming element includes a plurality of components, the upper limit of the guaranteed operation temperature of the pattern illumination forming element refers to the lowest temperature among the upper limits of the guaranteed operation temperatures of the plurality of components. Therefore, in the present embodiment, as described above, since the pattern illumination forming element includes the light source 241, the lenses 242, 243, and the photomask 244, the lowest temperature among the upper limits of the guaranteed operation temperatures of the light source 241, the lenses 242, 243, and the photomask 244 becomes the upper limit of the guaranteed operation temperature of the pattern illumination forming element. In addition, of course, the temperature of the projection lens 220 to be maintained fixed by the control unit 11a must be below the upper limit of the guaranteed operation temperature of the projection lens 220.

[0283] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, as described above, the light projecting lens 220, the assembly member 211, and the lens barrel 212 are heated by the flexible heater 250, and the temperature sensor 254 is mounted on the flexible heater 250. By configuring in this way, the light projecting lens 220, the assembly member 211, and the lens barrel 212 can be heated with a simple structure, and the temperature of the light projecting lens 220 can be measured with a simple structure, so that the assembly work becomes easy, and as a result, the manufacturing cost can be reduced.

[0284] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, a structure is adopted in which the flexible heater 250 is attached to the mounting member 211 via a highly thermally conductive adhesive tape 256. By configuring in this way, the thermal conductivity can be improved, and the flexible heater 250 can be easily assembled to the mounting member 211, and the temperature sensor 254 can be easily assembled to the mounting member 211 while more accurate temperature measurement can be performed. Therefore, in this respect, the manufacturing cost can also be reduced.

[0285] <H. Structure of the camera unit>

[0286] Fig.13 as well as Fig.14 are respectively a schematic stereoscopic diagram and a schematic cross-sectional diagram of the photographing unit, Fig.15 is an exploded perspective view showing the assembly structure of the camera unit. Fig. 9 With these Figures 13 to 15 The detailed structure of the imaging unit 13 in this embodiment will be described.

[0287] Here, Fig.13 (A) shows a state where a cover member 360 described later has been assembled to the imaging unit 13. Fig.13 (B) shows a state where the cover member 360 is removed from the imaging unit 13. Fig.14 (A) and Fig.14 The (B) respectively represents along Fig.13 (A) shows cross sections along the line XIVA-XIVA and along the line XIVB-XIVB.

[0288] like Fig. 9 as well as Figures 13 to 15 As shown, the imaging unit 13 mainly includes a base portion 300 , a lens support portion 310 , a light receiving lens 320 , a substrate 330 , an imaging element 341 , a flexible heater 350 , a temperature sensor 354 , and a cover member 360 .

[0289] The base portion 300 is a portion that serves as a stand for the imaging unit 13, and is provided on the bottom plate portion 101 of the housing 100. The base portion 300 is fixed to the bottom plate portion 101 by screws.

[0290] The lens support part 310 is fixed to the base part 300 in a mounted state. The lens support part 310 includes an assembly member 311, which is fixed to the base part 300 by screws 193 (see Fig.15 ) is fixed to the base portion 300; and a lens barrel 312, which supports the light receiving lens 320 and is fixed to the assembly member 311.

[0291] The attachment member 311 is made of a metal member having high thermal conductivity, such as aluminum alloy, and is a cylindrical member having a square outer shape and a hollow portion 311 a extending in a direction parallel to the optical axis of the light receiving lens 320 .

[0292] like Fig.14 as well as Fig.15 As shown, a substrate 330 is assembled on the rear end face of the assembly member 311 (i.e., the end face on the side where the circuit substrate 160 is located). More specifically, the substrate 330 is fixed to the rear end face of the assembly member 311 by screws 381, whereby the hollow portion 311a provided in the assembly member 311 is closed by the substrate 330.

[0293] An image sensor 341 is mounted on the surface of the substrate 330 that closes the hollow portion 311a, so that the image sensor 341 faces the hollow portion 311a. The image sensor 341 includes, for example, a complementary metal oxide semiconductor (CMOS) image sensor, a charge coupled device (CCD) image sensor, etc. A frame-shaped light shielding member 342 is provided on the surface of the substrate 330 and around the image sensor 341.

[0294] The lens barrel 312 includes a cylindrical member made of a metal having high thermal conductivity, such as an aluminum alloy, and its rear end is fixed by being inserted into the hollow portion 311a of the assembly member 311. The front end of the lens barrel 312 protrudes forward from the assembly member 311, and is thus arranged in front of the imaging unit 13.

[0295] Here, in more detail, a male thread is provided at the rear end of the outer circumference of the lens barrel 312, and a female thread is provided at the front end of the inner circumference of the hollow portion 311a of the assembly member 311. Thus, the lens barrel 312 is fixed by being screwed to the assembly member 311. This fixing method is generally called a fixing method of a lens of S mounting.

[0296] The light receiving lens 320 includes a composite lens composed of a plurality of lenses 321 to 323, and the plurality of lenses 321 to 323 are arranged in a row along the axial direction of the lens barrel 312 in a manner that the optical axes overlap with each other. The peripheral edges of the plurality of lenses 321 to 323 are supported by the lens barrel 312. That is, the lens barrel 312 surrounds the light receiving lens 320 in a direction orthogonal to the optical axis of the light receiving lens 320 to support it.

[0297] As described above, the imaging element 341 and the plurality of lenses 321 to 323 as the light receiving lens 320 are arranged on the optical axis of the light receiving lens 320 inside the imaging unit 13 , and the imaging element 341 receives light incident to the imaging unit 13 , thereby obtaining an input image.

[0298] Here, if Figures 13 to 15 As shown in the figure, the heater portion 351 of the flexible heater 350 is assembled on the outer peripheral surface of the assembly member 311 as a part of the lens support portion 310. In more detail, the flexible heater 350 includes a heating wire and a flexible substrate (such as a polyimide substrate) provided with wiring for energizing the heating wire, and the portion provided with the heating wire, that is, the heater portion 351, is attached to the outer peripheral surface of the assembly member 311 via an adhesive tape 356 with high thermal conductivity.

[0299] On the other hand, the wiring portion 352 of the flexible heater 350, where the wiring is provided, is led out from the upper surface of the imaging unit 13 toward the outside, and the front end thereof is connected to the circuit substrate 160, thereby being electrically connected to the control unit 11a. In addition, a temperature sensor 354 is mounted at a predetermined position of the heater portion 351 of the flexible heater 350, and the temperature sensor 354 is also electrically connected to the control unit 11a via the wiring provided in the flexible heater 350.

[0300] Thus, when the flexible heater 350 is energized, the light receiving lens 320 is heated via the mounting member 311 and the lens barrel 312. Furthermore, by energizing the flexible heater 350 over a predetermined period of time, the temperatures of the light receiving lens 320, the lens barrel 312, the mounting member 311, and the heater portion 351 of the flexible heater 350 become equal, and thus the temperature of the light receiving lens 320 can be detected by the temperature sensor 354.

[0301] In addition, in the present embodiment, a portion of the outer peripheral surface of the mounting member 311 facing the base portion 300 is in close contact with the base portion 300 , and therefore the flexible heater 350 is not mounted on the outer peripheral surface of the mounting member 311 in this portion.

[0302] like Fig. 9 as well as Figures 13 to 15 As shown in FIG. 1 , a cover member 360 is provided in the imaging unit 13 so as to surround the mounting member 311 . Thus, the heater portion 351 of the flexible heater 350 and the temperature sensor 354 attached to the heater portion 351 are covered by the cover member 360 .

[0303] In more detail, the cover member 360 has a roughly box shape covering the portion of the outer peripheral surface of the assembly member 311 other than the portion facing the base portion 300 and the front end surface, and the portion on the front end surface side is fixed to the assembly member 311 by screws 382, ​​thereby being assembled to the assembly member 311.

[0304] Here, the cover member 360 covers substantially the entire outer peripheral surface and the front end surface of the mounting member 311 except for the portion for leading out the wiring portion 352 of the flexible heater 350 . Thus, the cover member 360 has a substantially sealed structure that conceals the mounting member 311 .

[0305] like Fig.14 As shown, an air layer 370 is provided between the cover member 360 and the flexible heater 350 . The air layer 370 is formed by providing a predetermined gap between the inner surface of the cover member 360 and the exposed surface of the flexible heater 350 , and the air layer 370 is substantially sealed by the cover member 360 .

[0306] In this way, in the imaging unit 13 , the lens barrel 312 and the mounting member 311 of the lens support unit 310 that surround and support the light receiving lens 320 are surrounded by the cover member 360 via the air layer 370 , and the heater unit 351 and the temperature sensor 354 of the flexible heater 350 are both covered by the cover member 360 .

[0307] Here, as described above, in the three-dimensional measuring device 1 of the present embodiment, during the three-dimensional measurement, the control unit 11a performs control for maintaining the temperature of the light receiving lens 320 at a predetermined fixed temperature. More specifically, the control unit 11a controls the operation of the heater unit 351 (e.g., whether or not power is supplied, or adjustment of the heater output, etc.) based on the detection result of the temperature sensor 354, thereby maintaining the temperature of the light receiving lens 320 at a fixed temperature.

[0308] Thus, the temperature of the light receiving lens 320 can be maintained at a constant temperature, and thus the focus position of the light receiving lens 320 can be substantially suppressed from changing during three-dimensional measurement. Therefore, by configuring in advance that the imaging element 341 is arranged at the focus position of the light receiving lens 320 in a heated state, the imaging element 341 can be maintained at the focus position of the light receiving lens 320 during three-dimensional measurement. Therefore, by adopting the above configuration, the measurement range MR can be ensured to be large within a predetermined temperature range on the imaging unit 13 side of the three-dimensional measurement device 1.

[0309] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, the temperatures of the mounting member 311 and the lens barrel 312 of the lens support portion 310 supporting the light-receiving lens 320 can be maintained at a constant temperature, so that the distance between the light-receiving lens 320 and the imaging element 341 in the optical axis direction, that is, the inter-element distance can be substantially suppressed from changing during three-dimensional measurement. Therefore, during three-dimensional measurement, the imaging element 341 can be more reliably maintained in a state where it is always arranged at the focal position of the light-receiving lens 320.

[0310] In addition, as in the present embodiment, when the light receiving lens 320 includes a lens group including a plurality of lenses, the expansion and contraction caused by the temperature of the lens support portion 310 including the assembly component 311 and the lens barrel 312 will have a significant impact on the change in the focal position of the light receiving lens 320. Therefore, it is particularly effective to maintain the temperature of the lens support portion 310 fixed as described above.

[0311] That is, in the three-dimensional measuring device 1 of this embodiment, the light receiving lens 320 is maintained at a predetermined fixed temperature during three-dimensional measurement, and is almost unaffected by the surrounding environment (especially the surrounding temperature) in which the three-dimensional measuring device 1 is installed. Therefore, as described above, on the imaging unit 13 side, the measurement range MR can be ensured to be large within the prescribed temperature range.

[0312] Here, it is preferable that the base 300 includes a member having a thermal conductivity lower than that of the mounting member 311 and the lens barrel 312 as the lens support 310. With such a configuration, the base 300 exhibits a heat insulating effect.

[0313] Therefore, by adopting the above structure, the light receiving lens 320, the assembly member 311, and the lens barrel 312 can be efficiently heated, and their temperatures can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation required when the three-dimensional measuring device 1 is used can be shortened, and the state in which the imaging element 341 is always arranged at the focal position of the light receiving lens 320 can be more reliably maintained during three-dimensional measurement.

[0314] Furthermore, it is preferable that the cover member 360 includes a member having a thermal conductivity that is equal to or lower than the thermal conductivity of the assembly member 311 and the lens barrel 312 that are the lens support portion 310. More specifically, when the air layer 370 is provided between the cover member 360 and the assembly member 311 as in the present embodiment, it is preferable that the thermal conductivity of the cover member 360 is equal to or lower than the thermal conductivity of the lens support portion 310. Unlike the present embodiment, when a structure is adopted in which the cover member 360 is in close contact with the assembly member 311, etc., it is preferable that the thermal conductivity of the cover member 360 is lower than the thermal conductivity of the lens support portion 310. By configuring in this way, the heat insulating effect is exerted by the cover member 360 or by the air layer 370 in addition thereto.

[0315] Therefore, by adopting the above structure, the light receiving lens 320, the assembly member 311, and the lens barrel 312 can be efficiently heated, and their temperatures can be stably maintained at a fixed temperature. Therefore, the time required for the initial warm-up operation required when the three-dimensional measuring device 1 is used can be shortened, and the state in which the imaging element 341 is always arranged at the focal position of the light receiving lens 320 can be more reliably maintained during three-dimensional measurement.

[0316] In addition, based on the above viewpoint, it is preferred that the base portion 300 and the cover member 360 include a resin member represented by a polyphenylene sulfide (PPS) resin or a polycarbonate (PC) resin, or include a metal member with a relatively low thermal conductivity. However, when an air layer 370 is provided between the cover member 360 and the assembly member 311 as in the present embodiment, a metal member with a relatively high thermal conductivity (e.g., an aluminum alloy) may be used as the cover member 360.

[0317] On the other hand, the temperature of the light receiving lens 320 to be maintained constant by the control unit 11a is preferably a temperature that is higher than the maximum temperature that the light receiving lens 320 can reach when the light receiving lens 320 is not heated by the flexible heater 350 within the range of the ambient temperature of the use of the imaging unit 13 and lower than the upper limit of the operation guarantee temperature of the imaging element 341. By configuring in this way, it is possible to configure an imaging unit that can ensure a large measurement range MR within a predetermined temperature range, and has a long life and high reliability, and a three-dimensional measurement device including the imaging unit.

[0318] Here, as in the present embodiment, when the imaging element 341 includes a single component such as a CMOS image sensor or a CCD image sensor, the upper limit of the guaranteed operation temperature of the imaging element 341 refers to the upper limit of the guaranteed operation temperature of the single component, but when the imaging element includes a plurality of components, the upper limit of the guaranteed operation temperature of the imaging element 341 refers to the lowest temperature among the upper limits of the guaranteed operation temperatures of the plurality of components. In addition, of course, the temperature of the light receiving lens 320 to be maintained constant by the control unit 11a must be below the upper limit of the guaranteed operation temperature of the light receiving lens 320.

[0319] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, as described above, the light receiving lens 320, the assembly member 311, and the lens barrel 312 are heated by the flexible heater 350, and the temperature sensor 354 is mounted on the flexible heater 350. By configuring in this way, the light receiving lens 320, the assembly member 311, and the lens barrel 312 can be heated with a simple structure, and the temperature of the light receiving lens 320 can be measured with a simple structure, so that the assembly work becomes easy, and as a result, the manufacturing cost can be reduced.

[0320] Furthermore, in the three-dimensional measuring device 1 of the present embodiment, a structure is adopted in which the flexible heater 350 is attached to the mounting member 311 via a highly thermally conductive adhesive tape 356. By configuring in this way, the thermal conductivity can be improved, and the flexible heater 350 can be easily assembled to the mounting member 311, and the temperature sensor 354 can be easily assembled to the mounting member 311 while more accurate temperature measurement can be performed. Therefore, in this respect, the manufacturing cost can also be reduced.

[0321] <I. Heat dissipation structure of the projection unit and the imaging unit>

[0322] Fig.16 2 is a schematic perspective view showing the heat dissipation structure of the projection unit and the imaging unit in this embodiment. Fig. 9 With the Fig.16 The heat dissipation structure of the projection unit 12 and the imaging unit 13 in this embodiment will be described. Fig.16 In the figure, some of the internal components are omitted.

[0323] The light source 241 included in the projection unit 12 and the imaging element 341 included in the imaging unit 13 are both heat generating parts, and these light sources 241 and the imaging element 341 must be used within their guaranteed operating temperature range. At this time, if no heat dissipation structure is used, these light sources 241 and the imaging element 341 may exceed the upper limit of the guaranteed operating temperature.

[0324] In particular, in the three-dimensional measuring device 1 of the present embodiment, as described above, the light projection lens 220 included in the projection unit 12 and the light receiving lens 320 included in the imaging unit 13 are structures that are heated during three-dimensional measurement. Therefore, it is particularly necessary to efficiently dissipate the heat generated by these light sources 241 and imaging elements 341.

[0325] Therefore, in the three-dimensional measuring device 1 of the present embodiment, the heat generated by the light source 241 and the imaging element 341 can be efficiently dissipated by adopting the following heat dissipation structure.

[0326] like Fig. 9 as well as Fig.16 As shown, in the three-dimensional measuring device 1 of this embodiment, the circuit board 160 ( Fig.16 A heat sink 171 is provided in front of the projection unit 12 (not shown). The base of the heat sink 171 is fixed to the bottom plate 101 of the frame 100, and the portion erected from the base is pressed against the back of the substrate 230 located at the rear end of the projection unit 12.

[0327] Here, the back side of the substrate 230 to which the heat sink 171 is pressed corresponds to the portion where the light source 241 is mounted, and preferably, a heat sink sheet with high thermal conductivity is installed between the heat sink 171 and the substrate 230. In addition, the heat sink 171 preferably includes a metal member with high thermal conductivity, such as aluminum alloy or brass.

[0328] With this configuration, the heat generated by the light source 241 is conducted to the bottom plate 101 of the housing 100 via the substrate 230 and the heat sink 171. Therefore, the heat generated by the light source 241 can be efficiently dissipated, and the light source 241 can be used within its guaranteed operating temperature range.

[0329] On the other hand, in the three-dimensional measuring device 1 of the present embodiment, the circuit board 160 ( Fig.16 A heat sink 172 is provided in front of the camera 13 (not shown). The base of the heat sink 172 is fixed to the bottom plate 101 of the frame 100, and the portion erected from the base is pressed against the back of the substrate 330 at the rear end of the camera 13.

[0330] Here, the back side of the substrate 330 to which the heat sink 172 is pressed corresponds to the portion where the imaging element 341 is mounted, and preferably, a heat sink with high thermal conductivity is installed between the heat sink 172 and the substrate 330. In addition, the heat sink 172 preferably includes a metal member with high thermal conductivity, such as aluminum alloy or brass.

[0331] With this configuration, the heat generated by the imaging element 341 is conducted to the bottom plate 101 of the housing 100 via the substrate 330 and the heat sink 172. Therefore, the heat generated by the imaging element 341 can be efficiently dissipated, and the imaging element 341 can be used within its guaranteed operating temperature range.

[0332] <J.Sealed structure of the frame>

[0333] Fig.17 2 is a schematic cross-sectional view showing the sealed structure of the frame of the measuring head in this embodiment. Figure 8 as well as Fig.16 With the Fig.17 The sealed structure of the housing 100 of the measuring head 10 in this embodiment will be described. Fig.17 (A) shows the state of the frame 100 before assembly. Fig.17 (B) shows the assembled state of the frame body 100 .

[0334] In the measuring head 10, in the projection unit 12, a generally sealed structure is adopted in which the light-projecting lens 220 as the heating object and the lens support unit 210 supporting the light-projecting lens 220 are substantially sealed by a cover member 260, and in the imaging unit 13, a generally sealed structure is adopted in which the light-receiving lens 320 as the heating object and the lens support unit 310 supporting the light-receiving lens 320 are substantially sealed by a cover member 360.

[0335] However, these cover members 260 and 360 do not completely seal the heating object, so when the internal space of the frame 100 is connected to the external space, maintaining the heating object at a fixed temperature may become unstable. Furthermore, when the projection unit 12 and the imaging unit 13 are not provided with these cover members 260 and 360, it is more difficult to maintain the heating object at a fixed temperature.

[0336] Therefore, in the three-dimensional measuring device 1 of the present embodiment, by adopting the following sealed structure of the housing 100 , it is possible to stabilize the heating target by maintaining it at a constant temperature.

[0337] like Fig. 9 , Fig.16 as well as Fig.17 As shown, a groove 101a is provided on the bottom plate 101 of the frame 100 so as to extend along the periphery of the bottom plate 101. The groove 101a is provided so as to face the periphery of the lower end of the cover 102 of the frame 100. Fig.17 As shown, a gasket 180 is received in the groove 101 a.

[0338] On the other hand, Fig.17 As shown, a protrusion 102a is provided at the lower end of the cover 102 of the frame 100 and at a portion facing the groove 101a. The protrusion 102a is provided to extend along the periphery of the lower end of the cover 102 and has a width smaller than that of the groove 101a.

[0339] like Fig.17 As shown, when the frame 100 is assembled, the cover 102 overlaps the bottom plate 101. As a result, the gasket 180 accommodated in the bottom plate 101 is compressed by the protrusion 102a provided on the cover 102, and the gasket 180 is in close contact with both the bottom plate 101 and the cover 102. As a result, the gap that may be generated at the boundary between the bottom plate 101 and the cover 102 is sealed by the gasket 180, so that the internal space of the frame 100 is sealed from the external space.

[0340] In addition, although detailed description is omitted here, the portion of the cover 102 of the frame 100 where the lighting window 110, the light projection window 120, the light receiving window 130 and the connecting terminals 141 and 142 are provided also has gaskets installed between the light-transmitting plates 111, 121, 131 and the connecting terminals 141 and 142 and the periphery of the opening provided in the cover 102, thereby, in these portions, the internal space of the frame 100 is also sealed from the external space.

[0341] With such a configuration, the light projecting lens 220 and the lens support 210 supporting the light projecting lens 220 , as well as the light receiving lens 320 and the lens support 310 supporting the light receiving lens 320 , which are heating targets, can be stabilized by maintaining them at a constant temperature.

[0342] <K.Others>

[0343] The inventors of the present invention actually trial-produced the three-dimensional measuring device 1 of the above-described embodiment, and confirmed the extent of the difference in heating efficiency between the case where the cover members 260, 360 were attached to the projection unit 12 and the imaging unit 13 and the case where the cover members 260, 360 were removed from the projection unit 12 and the imaging unit 13. In addition, the fixed temperature to be maintained of the light projecting lens 220 and the light receiving lens 320 was set to about 60°C to 70°C.

[0344] As a result, it was confirmed that when the cover members 260, 360 were removed from the projection unit 12 and the imaging unit 13, the time required for the initial warm-up operation required when the three-dimensional measuring device 1 is used (i.e., the time until both the light projecting lens 220 and the light receiving lens 320 reach a predetermined fixed temperature) was about 10 minutes, and by attaching the cover members 260, 360 to the projection unit 12 and the imaging unit 13, the time required for the warm-up operation could be shortened to about 2 minutes.

[0345] Furthermore, it was confirmed that: when the cover members 260, 360 are removed from the projection unit 12 and the imaging unit 13, the time from stopping the heating of the flexible heaters 250, 350 until the temperature drops by 1°C is about 1 second, and by installing the cover members 260, 360 to the projection unit 12 and the imaging unit 13, the time can be delayed to about 10 seconds.

[0346] That is, the results of the former indicate that by installing the cover components 260 and 360 on the projection unit 12 and the imaging unit 13, the light projection lens 220 and the light receiving lens 320 can be heated very efficiently, while the results of the latter indicate that by installing the cover components 260 and 360 on the projection unit 12 and the imaging unit 13, the thermal insulation performance is improved, and the electricity consumed for heating during three-dimensional measurement can be greatly saved.

[0347] As described above, it has been confirmed through experiments that by adopting the three-dimensional measuring device 1 of the present embodiment, a three-dimensional measuring device that is also excellent in terms of heating efficiency can be configured.

[0348] <L. Notes>

[0349] The characteristic structures of the optical unit for a three-dimensional measuring device according to the present embodiment and the three-dimensional measuring device including the optical unit are summarized as follows.

[0350] [Structure 1]

[0351] An optical component for a three-dimensional measuring device, comprising:

[0352] The optical lenses 220 and 320 form a pair of conjugate surfaces in an optically conjugate relationship;

[0353] The optical device 244, 341 is arranged on one of the pair of conjugate surfaces;

[0354] Temperature sensors 254, 354, for detecting the temperature of the optical lens;

[0355] Heaters 251, 351, used to heat the optical lens; and

[0356] The control unit 11 a controls the operation of the heater based on the detection result of the temperature sensor so that the temperature of the optical lens becomes a constant.

[0357] [Structure 2]

[0358] The optical assembly for a three-dimensional measuring device according to structure 1 further includes:

[0359] The lens support parts 210 and 310 surround the optical lens and support it in a direction orthogonal to the optical axis of the optical lens.

[0360] The temperature sensor and the heater are assembled to the lens support portion.

[0361] [Structure 3]

[0362] The optical assembly for a three-dimensional measuring device according to structure 2 further includes:

[0363] The cover member 260, 360 surrounds the lens support portion and covers the temperature sensor and the heater.

[0364] The cover member has a thermal conductivity that is the same as or lower than a thermal conductivity of the lens support portion.

[0365] [Structure 4]

[0366] The optical component for a three-dimensional measuring device according to Structure 3, wherein

[0367] The lens support portion includes a lens barrel 212, 312 for supporting the optical lens and an assembly member 211, 311 for fixing the lens barrel.

[0368] The cover member has a substantially closed structure covering the fitting member.

[0369] [Structure 5]

[0370] According to the optical component for a three-dimensional measuring device according to structure 4,

[0371] An air layer 270, 370 is provided in at least a portion between the cover member and the fitting member.

[0372] [Structure 6]

[0373] The optical assembly for a three-dimensional measuring device according to any one of Structures 2 to 5 further includes:

[0374] The base parts 200 and 300 fix the lens support part.

[0375] The thermal conductivity of the base portion is the same as or lower than the thermal conductivity of the lens support portion.

[0376] [Structure 7]

[0377] An optical component for a three-dimensional measuring device according to any one of Structures 2 to 6, wherein

[0378] The heater includes a flexible heater 250 or 350 , wherein the flexible heater 250 or 350 includes a flexible substrate provided with a heating wire.

[0379] The temperature sensor is mounted on the flexible substrate.

[0380] The flexible heater is disposed on an outer peripheral surface of the lens support portion.

[0381] [Structure 8]

[0382] According to the optical component for a three-dimensional measuring device according to structure 7,

[0383] The flexible heater is attached to the lens support portion using adhesive tape 256 , 356 with high thermal conductivity.

[0384] [Structure 9]

[0385] An optical component for a three-dimensional measuring device according to any one of Structures 1 to 8, wherein

[0386] The optical device includes pattern illumination forming elements 241, 244 for forming pattern illumination,

[0387] The optical lens includes a light projection lens 220 for projecting pattern illumination onto the object disposed on the other of the pair of conjugate surfaces, thereby imaging the projection pattern.

[0388] [Structure 10]

[0389] According to the optical component for a three-dimensional measuring device according to structure 9,

[0390] The fixed temperature is a temperature that is higher than the maximum temperature that the projection lens can reach when the heater does not heat the projection lens within the range of ambient temperature that allows the use of the optical assembly for the three-dimensional measuring device, and is lower than the upper limit of the operation guarantee temperature of the pattern illumination forming element.

[0391] [Structure 11]

[0392] An optical component for a three-dimensional measuring device according to any one of Structures 1 to 8, wherein

[0393] The optical device includes a photographing element 341 having a photographing surface.

[0394] The optical lens includes a light receiving lens 320 for forming an image on the imaging surface of a projection pattern of the object projected onto the other of the pair of conjugate surfaces.

[0395] [Structure 12]

[0396] The optical component for a three-dimensional measuring device according to Structure 11, wherein

[0397] The fixed temperature is a temperature that is higher than the maximum temperature that the light receiving lens can reach when the heater does not heat the light receiving lens within a range of ambient temperature that allows use of the optical unit for a three-dimensional measuring device, and is lower than an upper limit of an operation guarantee temperature of the imaging element.

[0398] [Structure 13]

[0399] A three-dimensional measuring device includes the optical component for a three-dimensional measuring device according to structure 9 or 10 as a projection unit 12, and includes the optical component for a three-dimensional measuring device according to structure 11 or 12 as a photographing unit 13.

[0400] <M. Other forms, etc.>

[0401] In the above-mentioned embodiment, the case where the present disclosure is applied to a three-dimensional measuring device including a single projection unit and a single imaging unit and an optical component for a three-dimensional measuring device provided in the three-dimensional measuring device is illustrated, but the scope of application of the present disclosure is not limited to such a case. That is, the present disclosure can be applied to a three-dimensional measuring device including a single projection unit and a plurality of imaging units, a three-dimensional measuring device including a plurality of projection units and a single imaging unit, and a three-dimensional measuring device including a plurality of projection units and a plurality of imaging units, and further, can be applied to each of the optical components for a three-dimensional measuring device provided in these three-dimensional measuring devices.

[0402] Furthermore, in the above-mentioned embodiment, a three-dimensional measuring device that applies the intrinsic code method is exemplified and described as a three-dimensional measuring device, but in addition to this, there are three-dimensional measuring devices that apply the random dot method, the phase shift method, the spatial code method, etc. The present disclosure can be applied to these three-dimensional measuring devices and the optical components for three-dimensional measuring devices provided in the three-dimensional measuring devices, and its application is not limited to the three-dimensional measuring devices that apply the intrinsic code method and the optical components for three-dimensional measuring devices provided in the three-dimensional measuring devices.

[0403] Furthermore, in the above-described embodiment, as the use of the three-dimensional measuring device, the use of measuring the three-dimensional shape of the workpiece transported on the conveyor is exemplified, but of course, the present disclosure can also be applied to three-dimensional measuring devices used for various purposes and optical components for three-dimensional measuring devices provided in the three-dimensional measuring devices. Here, as other uses, for example, the following uses can be cited, that is, when the workpieces in a random state are picked up individually by a robot, the three-dimensional shapes of the workpieces in the random state are measured to individually identify the three-dimensional positions or postures of these workpieces.

[0404] Furthermore, in the above-described embodiment, a three-dimensional measuring device configured to project a projection pattern onto a subject using light of a specific wavelength is exemplified as a three-dimensional measuring device, but the present disclosure can of course also be applied to a three-dimensional measuring device configured to project a projection pattern onto a subject by using light of multiple wavelengths or using white light.

[0405] Furthermore, in the above-described embodiment, the case where the so-called S mount is adopted as the lens fixing method is exemplified and described, but it is of course possible to apply the present disclosure to the case where other lens fixing methods represented by the C mount are adopted.

[0406] Furthermore, in the above-described embodiment, as the light source of the pattern illumination forming element provided in the projection unit, the case of using LED is exemplified and described, but as the light source, for example, laser diode (LaserDiode, LD), mercury lamp, etc. can also be used. Furthermore, as the pattern illumination forming element, for example, a combination of the light source and a liquid crystal element, a combination of the light source and a micromirror array, organic electroluminescence (Electro-Luminescence, EL), etc. can also be used.

[0407] Moreover, in the above-mentioned embodiment, as mentioned above, it is preferable that the temperature of the light-projecting lens (the set temperature of the light-projecting lens) to be maintained fixed by the control unit is set to a temperature below the upper limit of the operation guarantee temperature of the pattern illumination forming element provided in the optical assembly for the three-dimensional measurement device as the projection part provided with the light-projecting lens, and the temperature of the light-receiving lens (the set temperature of the light-receiving lens) to be maintained fixed by the control unit is set to a temperature below the upper limit of the operation guarantee temperature of the imaging element provided in the optical assembly for the three-dimensional measurement device as the imaging part provided with the light-receiving lens, but the set temperature of the light-projecting lens and the set temperature of the light-receiving lens may be the same or different. Here, in the case where these set temperatures are set to the same, it is preferable that the lower temperature of the upper limit of the operation guarantee temperature of the pattern illumination forming element and the upper limit of the operation guarantee temperature of the imaging element is set as the set temperature. If it is configured in this way, a three-dimensional measurement device with a longer life and high reliability can be configured.

[0408] Furthermore, in the above-described embodiment, a case is illustrated in which a part of the projection part and a part of the imaging part are locally heated by respectively providing heaters in the projection part and the imaging part, but it is also possible to provide a heater in the internal space of the frame without providing a cover member in these projection part and the imaging part, and to heat the entire interior of the frame by the heater.

[0409] On the other hand, as a related form, it is also envisioned that: cooling components such as Peltier elements are respectively provided for the projection unit and the shooting unit, or, instead of providing a cover component for these projection units and the shooting unit, cooling components such as Peltier elements are provided in the internal space of the frame, and the driving of the cooling components is controlled by the control unit, thereby maintaining the light projection lens and the light receiving lens at room temperature. In the case of such a configuration, it is also possible to ensure that the measurement range is large within a specified temperature range, similarly to the above-mentioned embodiment.

[0410] The embodiments disclosed this time are intended to be illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. A three-dimensional measuring device, comprising an optical component as a projection part and an optical component as a photographing part, The optical component as the projection unit and the optical component as the shooting unit each include: An optical lens forms a pair of conjugate surfaces having an optical conjugate relationship; An optical device, disposed on one of the pair of conjugate surfaces; A temperature sensor, used to detect the temperature of the optical lens; A heater, used for heating the optical lens; a control unit that controls the operation of the heater based on the detection result of the temperature sensor so that the optical lens reaches a fixed temperature; as well as a lens support portion that surrounds the optical lens and supports the optical lens in a direction orthogonal to the optical axis of the optical lens, the temperature sensor and the heater being assembled to the lens support portion, The heater includes a flexible heater including a flexible substrate provided with a heating wire, the temperature sensor is mounted on the flexible substrate, and the flexible heater is arranged on the outer peripheral surface of the lens support portion, wherein In the optical component serving as a projection unit, the optical device includes a pattern illumination forming element for forming pattern illumination, and the optical lens includes a light projection lens for projecting pattern illumination onto an object disposed on the other surface of the pair of conjugate surfaces, thereby imaging the projection pattern.

2. The three-dimensional measuring device according to claim 1, further comprising: a cover member surrounding the lens support portion and covering the temperature sensor and the heater, The cover member has a thermal conductivity that is the same as or lower than a thermal conductivity of the lens support portion.

3. The three-dimensional measuring device according to claim 2, wherein The lens support portion includes a lens barrel for supporting the optical lens and an assembly member for fixing the lens barrel. The cover member has a substantially closed structure covering the fitting member.

4. The three-dimensional measuring device according to claim 3, wherein An air layer is provided in at least a portion between the cover member and the fitting member.

5. The three-dimensional measuring device according to any one of claims 1 to 4, further comprising: A base portion, fixing the lens support portion, The thermal conductivity of the base portion is the same as or lower than the thermal conductivity of the lens support portion.

6. The three-dimensional measuring device according to claim 1, wherein The flexible heater is attached to the lens support portion using an adhesive tape with high thermal conductivity.

7. The three-dimensional measuring device according to claim 1, wherein The fixed temperature is a temperature that is higher than the maximum temperature that the projection lens can reach when the heater does not heat the projection lens within the range of ambient temperature allowed for use of the optical component as the projection unit, and is lower than the upper limit of the operation guarantee temperature of the pattern illumination forming element.

8. The three-dimensional measuring device according to any one of claims 1 to 4, wherein In the optical assembly as the imaging unit, the optical device includes an imaging element having an imaging surface. The optical lens includes a light receiving lens for forming an image on the imaging surface of a projection pattern of an object projected onto the other of the pair of conjugate surfaces.

9. The three-dimensional measuring device according to claim 8, wherein The fixed temperature is a temperature that is not less than the maximum temperature that the light receiving lens can reach when the heater does not heat the light receiving lens within a range of ambient temperature that allows use of the optical component as the imaging unit and is not more than the upper limit of the operation guarantee temperature of the imaging element.

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