JP2011252866A - Three-dimensional shape measuring apparatus, three-dimensional shape measuring additional apparatus, and three-dimensional shape measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To derive a three-dimensional shape of a measured object with high accuracy and reliability without influencing the visibility of the measured object and work efficiency for a person while ensuring continuity of illumination light.SOLUTION: A three-dimensional shape measuring apparatus 110 comprises: a projection light source 150 which projects light of a specific color onto a measured object 102; a light receiving element 160 which receives reflected light of the specific color in reflected light reflected by the measured object and forms projection images; a signal generating unit 170 which generates a binarized control signal; an illumination controlling unit 162 which turns off an illumination device 120a which emits light including the specific color while the control signal indicates a first state, among a plurality of illumination devices 120a, 120b and 120c that emit illumination light to the measured object; a projection image formation controlling unit 172 which makes the light receiving element form projection images while the control signal indicates the first state; and a three-dimensional shape deriving unit 176 which derives the three-dimensional shape of the measured object based on the projection images formed by the light receiving element.

Description

  The present invention relates to a three-dimensional shape measurement apparatus, a three-dimensional shape measurement addition apparatus, and a three-dimensional shape measurement method for measuring a three-dimensional shape of a measurement object using reflected light when light is projected onto the measurement object.

  2. Description of the Related Art Conventionally, a three-dimensional shape measuring apparatus using a light cutting method is known as a three-dimensional shape measuring apparatus having a simple configuration and high measurement accuracy. In such a three-dimensional shape measuring apparatus using the light cutting method, first, slit light, which is slit-shaped light, is projected onto a measurement object to be measured, and a projection image is formed by projecting reflected light of the measurement object. Then, the three-dimensional shape measuring apparatus derives the three-dimensional shape of the object to be measured by specifying the position (three-dimensional position) of the light section image that is reflected light of the slit light, which appears in the projection image. To do.

  At the time of measuring a three-dimensional shape, the object to be measured is irradiated with illumination light for a person to perform a measurement operation in addition to the slit light for measurement described above. Then, since the illumination light is also reflected by the object to be measured and is superimposed on the reflected light of the slit light as background light (environmental light), the three-dimensional shape measurement apparatus uses the reflected light of the slit light from the formed projection image. It becomes difficult to extract only the light section image, and the measurement accuracy of the three-dimensional shape is lowered. Particularly in recent years, the intensity of illumination light tends to become stronger in order to improve human work efficiency and safety, and the extraction of a light section image is becoming more difficult.

  Therefore, the reflected light of one object to be measured is received by light receiving elements provided in two different directions, and one of the two projected images for which an effective measurement result cannot be obtained is interpolated on the other to be measured. A technique for measuring a three-dimensional shape of a measurement object is known (for example, Patent Document 1). Further, a technique has been proposed in which a projection image is acquired twice according to the presence or absence of light projection, and background light is eliminated by subtracting a projection image without projection from a projection image with projection (for example, Patent Document 2). ).

JP-A-2-223809 JP 2009-19884 A

  In the technique of Patent Document 1 described above, a projection image from which an effective measurement result cannot be obtained is excluded from two projection images formed at different timings on the same portion, so that the measurement accuracy is improved. be able to. However, such a technique only employs a projection image in which the influence of the reflected light of the illumination light is relatively small. For example, it is good when the intensity of the reflected light of the illumination light is uniformly strong regardless of time. I was not able to get a good result. In addition, as the number of projection processing and selection processing for projected images increases, the calculation processing load increases accordingly, resulting in higher costs. Furthermore, in the technique of Patent Document 2, since the acquisition timings of the projected image with projection and the projected image without projection are different, the measured object or its background is moved or deformed, or the reflected light of the illumination light When the intensity changes, the background light cannot be accurately excluded and an error occurs.

  Moreover, in order to reduce the influence of the reflected light of illumination light, it is also conceivable to completely turn off the illumination of the room where the three-dimensional shape measuring apparatus and the object to be measured are installed to make a dark room. However, in the dark room, not only the visibility of the object to be measured and the work efficiency of the person are significantly reduced, but also it becomes difficult to put the object to be measured in and out of the dark room.

  Therefore, the inventor of the present application pays attention to the timing of forming the projection image and the timing at which the illumination device irradiates illumination light, and turns off the illumination device only while the projection image is formed, thereby visually recognizing the object to be measured. It has been found that the three-dimensional shape of the object to be measured can be derived with high accuracy and reliability without affecting the performance and human work efficiency. Here, since the time for turning off the lighting device is set to be very short compared to the time during which the lighting device is turned on, the measurer is not aware that the lighting device is temporarily turned off.

  However, when other electrical equipment that shares the 3D shape measuring device and the lighting device is based on the premise of continuous illumination of the lighting device, if the technique for turning off the lighting device intermittently as described above is inadvertently adopted There may also be a situation where the electrical device does not perform its original function. Moreover, when it is not known that the lighting device is intermittently turned off, it is possible that the cause that the measurer does not perform the original function cannot be grasped against such other electric devices.

  In view of such a problem, the present invention ensures the continuity of illumination light, and does not affect the visibility of the object to be measured and the work efficiency of the person, and accurately and reliably the three-dimensional shape of the object to be measured. It is an object of the present invention to provide a three-dimensional shape measuring device, a three-dimensional shape measuring additional device, and a three-dimensional shape measuring method.

  In order to solve the above-described problems, a three-dimensional shape measuring apparatus of the present invention is a projection light source that projects light of a specific color onto an object to be measured, and reflected light of a specific color among reflected light reflected by the object to be measured. A light receiving element that receives light to form a projection image, a signal generation unit that generates a binarized control signal, and irradiates illumination light including a specific color among a plurality of illumination devices that irradiate the measurement object with illumination light The illumination device is formed by an illumination control unit that turns off while the control signal indicates the first state, a projection image formation control unit that forms a projection image on the light receiving element while the control signal indicates the first state, and the light receiving element. And a three-dimensional shape deriving unit for deriving a three-dimensional shape of the object to be measured based on the projected image.

  The illumination control unit may turn off the illumination device that emits illumination light that does not include the specific color for a time corresponding to the time when the control signal indicates the first state while the control signal does not indicate the first state. Good.

  The plurality of illumination devices may emit white light when irradiated with illumination light having different colors and additively mixed with illumination light.

  The three-dimensional shape deriving unit may derive the three-dimensional shape of the object to be measured based on whether or not the amount of received light of the projected image formed by the light receiving element is equal to or greater than a predetermined threshold.

  The illumination control unit may set the light emission amount of the illumination light including the specific color per unit time so as to offset the occupation ratio of the time to turn off the illumination device that irradiates the illumination light including the specific color with respect to the entire time. Good.

  In order to solve the above-described problem, a three-dimensional shape measurement addition device according to the present invention includes a light projecting light source that projects light of a specific color onto an object to be measured, and reflected light of a specific color among reflected light reflected by the object to be measured. 3 is added to a three-dimensional shape measuring apparatus having a light receiving element that receives the light and forms a projection image, and a three-dimensional shape deriving unit that derives the three-dimensional shape of the object to be measured based on the projection image formed by the light receiving element. Dimensional shape measurement addition device, a signal generation unit that generates a binarized control signal, and an illumination device that irradiates illumination light including a specific color among a plurality of illumination devices that irradiate the measurement object with illumination light And an illumination control unit that turns off while the control signal indicates the first state, and a projection image formation control unit that forms a projection image on the light receiving element while the control signal indicates the first state. .

  In order to solve the above-mentioned problem, another three-dimensional shape measuring apparatus of the present invention includes a light source that projects light of a specific color onto a measurement object, and a reflection of a specific color among reflected light reflected by the measurement object. A light receiving element that receives light, a signal generation unit that generates a binarized control signal, and an illumination device that irradiates illumination light including a specific color among a plurality of illumination devices that illuminate a measurement object with illumination light The illumination control unit that is turned off while the control signal indicates the first state, and while the control signal indicates the first state, the light source emits the light of the specific color and the light receiving element receives the reflected light of the specific color And a projection image formation control unit, and a three-dimensional shape deriving unit that derives a three-dimensional shape of the object to be measured based on a difference time between a projection time of the light projecting light source and a light reception time of the light receiving element.

  In order to solve the above problems, a light projecting light source that projects light of a specific color onto the object to be measured, and a light receiving element that receives the reflected light of the specific color among the reflected light reflected by the object to be measured and forms a projected image; The three-dimensional shape measuring method of the present invention for measuring a three-dimensional shape using a three-dimensional shape measuring apparatus including a signal generates a binarized control signal, and while the control signal indicates the first state, the measurement target Among the plurality of illumination devices that irradiate the object with illumination light, the illumination device that illuminates illumination light including a specific color is turned off and a projected image is formed by the light receiving element, and the specific color is displayed while the control signal indicates the second state. The illumination device for irradiating the illumination light is turned on, the formation of the projection image of the light receiving element is stopped, and the three-dimensional shape of the object to be measured is derived based on the projection image formed by the light receiving element.

  The above-described components based on the technical idea of the three-dimensional shape measuring apparatus and the description thereof can be applied to the three-dimensional shape measurement adding apparatus and the three-dimensional shape measuring method.

  According to the present invention, it is possible to secure the continuity of illumination light and derive the three-dimensional shape of the measurement object with high accuracy and reliability without affecting the visibility of the measurement object and the work efficiency of the person. It becomes possible.

It is explanatory drawing which showed the schematic connection relation of the three-dimensional shape measurement system. It is explanatory drawing for demonstrating the schematic structure of a three-dimensional shape measuring apparatus. It is explanatory drawing for demonstrating derivation | leading-out of the three-dimensional shape by a three-dimensional shape derivation | leading-out part. It is explanatory drawing explaining derivation | leading-out of the three-dimensional position of the arbitrary points on a to-be-measured object. It is a spectrum distribution figure for demonstrating the setting of a light transmissive filter. It is a time chart for demonstrating the light extinction timing of an illuminating device, and the timing which forms a projection image in a light receiving element. It is a time chart for demonstrating the extinction timing of an illuminating device, and the other timing which forms a projection image in a light receiving element. It is explanatory drawing which illustrated the three-dimensional shape measuring apparatus using the absolute value of received light quantity. It is a block diagram which shows schematic structure of a three-dimensional shape measurement addition apparatus. It is the flowchart which showed the whole flow of the three-dimensional shape measuring method.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  In order to measure the three-dimensional shape of the surface of the object to be measured, it is necessary to derive the three-dimensional positions (or three-dimensional coordinates) of arbitrary points on the surface of the object to be measured. Here, the three-dimensional position of the point on the surface of the object to be measured is obtained by applying, for example, a triangulation method. In the triangulation method, if one of the length of one side of a triangle and the length of two depressions at the end or the other two sides intersecting at the end is known, the other is also obtained. This is a measurement method capable of specifying a position.

  Here, the optical cutting method is given as an example of a method for measuring a three-dimensional shape using such a triangulation method, and it is highly accurate and reliable without affecting the visibility of the object to be measured and human work efficiency. A three-dimensional shape measurement system 100 for deriving the three-dimensional shape of the object to be measured is proposed, and then a specific three-dimensional shape measurement method is described in detail.

(3D shape measurement system 100)
FIG. 1 is an explanatory diagram showing a schematic connection relationship of the three-dimensional shape measurement system 100. As shown in FIG. 1A, the three-dimensional shape measurement system 100 includes a three-dimensional shape measurement device 110 and an illumination device 120.

  The three-dimensional shape measuring apparatus 110 projects slit light on the object 102 to be measured, forms a projection image 112 by reflected light of the object 102 to be measured, and determines the three-dimensional position of the light section image 114 that appears in the projection image 112. Identify. Further, in the three-dimensional shape measuring apparatus 110, such slit light transitions (swings) in a direction perpendicular to the longitudinal direction of the slit light (slit) as shown by a white arrow in FIG. And the projection image 112 is sequentially formed with respect to the entire object to be measured 102, thereby deriving the three-dimensional shape of the entire surface of the object to be measured 102. The installation location of the three-dimensional shape measuring apparatus 110 is not particularly limited.

  The illumination device 120 irradiates a work area including the device under test 102 so that a person can perform measurement work and various work. As such an illuminating device 120, a light source that can be switched on and off at a relatively high speed is used. Here, as a typical example, LED (Light Emitting Diode) illumination that has been widely used in recent years for reasons such as high-speed response, low power consumption, and long life is used. In the present embodiment, a plurality of illumination devices 120 (120a, 120b, 120c) each including LEDs having different emission colors are provided, and each is driven by an independent drive power source 122 (122a, 122b, 122c). . Specifically, as shown in FIG. 1B, the lighting device 120 includes, for example, light emitters of three primary colors of red (Red), green (Green), and blue (Blue) in one LED package. A plurality of the multi-chip type LEDs 124 are arranged in parallel. Such three primary color light emitters correspond to the illumination devices 120a, 120b, and 120c, respectively. Further, white light can be obtained as illumination light by additive color mixing because all three primary color light emitters emit light. In the following description, the lighting devices 120a, 120b, and 120c using the three primary colors of red, green, and blue are exemplified as the plurality of lighting devices 120. However, the number of the lighting devices 120 may be an arbitrary number of two or more. Can do. In addition, originally, the three lighting devices 120a, 120b, and 120c can be integrally formed as shown in FIG. 1B, but in order to facilitate understanding, each of the lighting devices 120a, 120b, It is described as 120c.

  The installation positions of the plurality of lighting devices 120a, 120b, and 120c may be indoor ceilings or arbitrary positions near the object to be measured 102, and the number is not limited. When the device under test 102 is relatively small, the devices under test 102 are arranged in a box that is shielded from light and darkened, and a plurality of illumination devices 120a, 120b, and 120c are provided so as to irradiate only the inside of the box. You may arrange.

  The plurality of drive power supplies 122 (122a, 122b, 122c) that supply power independently to each of the plurality of lighting devices 120a, 120b, 120c realize high-speed switching of each of the plurality of lighting devices 120a, 120b, 120c. Therefore, the power supply can open and close the supplied power at high speed. For example, when the three primary color LED lights are employed as the plurality of lighting devices 120a, 120b, and 120c, the same number (three) of driving power sources 122 are prepared, and the three driving power sources 122a, 122b, and 122c are commercial power sources, respectively. Power control, rectification and smoothing DC power or DC power from a constant voltage storage battery, semiconductor power control such as insulated gate bipolar transistor (IGBT) and power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) The DC power is opened and closed at high speed through the element. Here, when a plurality of lighting units in which three lighting devices 120a, 120b, 120c are combined are provided, a plurality of combinations of three driving power sources 122a, 122b, 122c for the lighting devices 120a, 120b, 120c are prepared, The semiconductor power control element is controlled by a common gate signal to synchronize the lighting and extinguishing timings of the lighting device 120 for the same emission color. Moreover, even if it is a case where LED is not used as several illuminating device 120a, 120b, 120c, by changing the structure and power supply system of the existing drive power supply, each of several illuminating device 120a, 120b, 120c Switching on and off can be performed at high speed.

  In the three-dimensional shape measurement system 100 of the present embodiment, the three-dimensional shape measurement device 110 measures the three-dimensional shape of the object 102 under irradiation with a plurality of illumination devices 120a, 120b, and 120c in parallel. Hereinafter, a detailed configuration of the three-dimensional shape measuring apparatus 110 will be described.

(3D shape measuring device 110)
FIG. 2 is an explanatory diagram for explaining a schematic configuration of the three-dimensional shape measuring apparatus 110. The three-dimensional shape measurement apparatus 110 includes a light projecting light source 150, a first optical system 152, a light projecting light source transition unit 154, a second optical system 156, an electronic shutter 158, a light receiving element 160, an illumination control unit 162, A holding unit 164 and a central control unit 166 are included. Although omitted here for convenience of explanation, the light projecting light source 150, the first optical system 152, the light projecting light source transition unit 154, the second optical system 156, the electronic shutter 158, the light receiving element 160 and the like are the housing of the three-dimensional shape measuring apparatus 110. It is fixed to.

  The light projecting light source 150 is composed of a specific color, for example, a red laser diode, and projects (emits) laser light onto the object to be measured 102. Here, the projection timing of the laser light can be continuous or intermittent. Here, red, which is generally employed for laser light, is used as the specific color, but the emission color is not limited. In addition, although a single color with one wavelength is employed here, a composite color with a plurality of wavelengths can be used.

  The first optical system 152 is formed of, for example, a cylindrical lens, and forms slit light that radiates the laser light emitted from the light projecting light source 150 in a fan shape. Here, the slit light is formed by diffusing the laser light, but the slit light may be formed by scanning the spot light of the laser light.

  The light projecting light source transition unit 154 shifts the slit light formed by the first optical system 152 through the power source 168 in a direction perpendicular to the longitudinal direction of the slit light, as indicated by a white arrow in FIG. Let For example, the light projecting light source 150 and the first optical system 152 are integrally formed and fixed to a gear (not shown), and a pinion (not shown) driven by a power source 168 is meshed with the gear so as to slit light. Or the slit light is reflected by a mirror (not shown), and the mirror is rotated by a power source 168 to change the slit light. In this way, it is possible to sequentially apply slit light to the entire object to be measured 102.

  The second optical system 156 is configured by combining one lens or a plurality of lenses, and forms reflected light (reflected image) reflected by the slit light on the surface of the measurement object 102 on the light receiving element 160. In the present embodiment, the second optical system 156 is provided with a light transmission filter that transmits only the reflected light of the specific color (blocks the reflected light other than the specific color) out of the reflected light of the laser light. . The setting procedure of the light transmission filter will be described in detail later. Further, a light transmission filter can be provided in the electronic shutter 158 and the light receiving element 160 described later, and the light receiving element 160 described later has sensitivity only to light of a specific color (detects only a specific color) due to its characteristics. In this case, this light transmission filter can be omitted.

  The electronic shutter 158 controls the light guide state (transmission state or non-transmission state) of the reflected light transmitted through the second optical system 156 to the light receiving element 160. In the present embodiment, while the lighting control unit 162 described later turns on the lighting device 120a that emits illumination light of a specific color, the electronic shutter 158 is in a non-transmissive state and the lighting device 120a is turned off. Only the transmission state. By limiting the transmission time of the electronic shutter 158 in this way, it is possible to reduce the influence of the reflected light of the object to be measured 102 due to the illumination light of a specific color in the illumination device 120a.

  The light receiving element 160 is constituted by a two-dimensional photoelectric conversion element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) with low power consumption, and while the electronic shutter 158 is in a transmissive state, the DUT 102 is measured. Among the reflected light generated on the surface of the light, the charge obtained by photoelectric conversion of the reflected light of a specific color (here, red) is accumulated. Such charge accumulation is performed in units of pixels of the light receiving element 160, for example, and a two-dimensional projection image 112 is formed by the entire pixels. In the present embodiment, in order to facilitate understanding, the expressions of the transmission state and the non-transmission state of the electronic shutter 158 are used. The transmission state of the electronic shutter 158 is a state in which the photoelectrically converted charges are accumulated in the light receiving element 160, and the light received in the transmission state of the electronic shutter 158 forms the projection image 112 in the light receiving element 160. Contribute to. On the contrary, the non-transmission state of the electronic shutter 158 is a state in which the photoelectric conversion charge is not accumulated in the light receiving element 160, and the light received in the non-transmission state of the electronic shutter 158 is the light receiving element. 160 does not contribute to the formation of the projected image 112.

  From the projection image 112 of the object to be measured 102 formed in this way, the three-dimensional shape deriving unit 176 described later can grasp the light reception angle of the reflected light incident on the light receiving element 160, and the light reception angle and projection A three-dimensional shape is derived using the projection angle of the light source 150. Here, the reflected light is precisely a part of the scattered light on the surface of the object 102 to be measured, but for convenience of explanation, the expression simply reflected light is used.

  In this embodiment, since the electronic shutter 158 is in a non-transmissive state while the lighting control unit 162 lights the three lighting devices 120a, 120b, and 120c, the light receiving element 160 receives the reflected light of the illumination light. In addition, since the electronic shutter 158 is in a transmissive state only while the illumination device 120a is turned off, only the light of a specific color from the light projecting light source 150 and the reflected light of the illumination light of the illumination devices 120b and 120c can be received. However, the reflected light of the illumination light from the illumination devices 120b and 120c is blocked by the light transmission filter described above. Therefore, since all the reflected light related to the illumination light can be excluded, the three-dimensional shape of the object 102 to be measured can be derived with high accuracy and reliability.

  The illumination control unit 162 irradiates illumination light including a specific color among the three illumination devices 120a, 120b, and 120c while the binarized control signal generated by the signal generation unit 170 described later indicates the first state. The lighting device 120a to be turned off is turned off. For example, when the control signal has a frequency of 50 Hz and the first state having a duration of 1 msec and the second state having a duration of 19 msec are alternately repeated, the illumination control unit 162 performs all the illumination while the control signal indicates the second state. The devices 120a, 120b, and 120c are turned on, and only the lighting device 120a is turned off once every 20 msec for 1 msec in the first state. At this time, the other lighting devices 120b and 120c maintain the lighting state. Here, since the illumination device 120a is turned off and the illumination devices 120b and 120c are lit for a very short time compared to the illumination devices 120a, 120b and 120c are all lit, only the illumination device 120a is turned off. The measurer is not conscious of the state that is doing. In addition, since the other lighting devices 120b and 120c are lit continuously even though they are turned off, it is possible to secure a sufficient amount of light emission as the lighting device 120, which affects the visibility of the object to be measured 102 and the human work efficiency. Will not affect.

  In addition, when there is an electrical device that shares the three-dimensional shape measuring apparatus 110 and the illumination device 120 and is premised on continuous illumination of the illumination device 120, for example, the illumination device 120 itself Functions as an optical space transmission device that modulates and performs continuous optical space transmission (communication), devices that continuously convert the energy of illumination light into other energy, and presence / absence of people by illumination light and its reflected light When there is a human sensor or the like for determining whether or not there is a case, irradiation of illumination light by the illumination device 120 may not be completely cut off (cannot be turned off). In the present embodiment, since the other lighting devices 120b and 120c are continuously turned on even while the lighting device 120a is turned off, the original function of the electric device as described above is not impaired. Therefore, the measurer can ensure the stable operation of other electric devices as well as his / her visibility.

  Here, when the lighting device 120a is turned on and off with a delay, the lighting control unit 162 delays the control signal from the time when the control signal is inverted from the second state to the first state in order to ensure the lighting time of the lighting device 120a. The lighting device 120a may be turned off quickly. By doing so, the illumination device 120a can be completely turned off while the control signal indicates the first state.

  The object of the present embodiment is to derive the three-dimensional shape of the device under test 102 without affecting the visibility of the device under test 102 or the work efficiency of a person. Therefore, the illumination control unit 162 ensures the lighting state of the lighting device 120a, that is, the lighting states of all the lighting devices 120a, 120b, and 120c for a relatively long time, thereby improving the visibility of the object 102 to be measured and the human work efficiency. In order to maintain and measure the three-dimensional shape of the device under test 102, only the illumination device 120a is turned off for a short time within a range that does not affect the visibility of the device under test 102 or the work efficiency of a person.

  Here, the illumination control unit 162 occupies the light emission amount of the illumination light of the illumination device 120a per unit time with respect to the total time including the illumination time of the illumination device 120a and the illumination time of the illumination device 120a. The rate (ratio) can be set to be large enough to cancel. For example, when the lighting device 120a is turned off for 1 msec at 50 Hz (cycle of 20 msec) described above, the occupation ratio (time for turning off the lighting device 120a / total time) becomes 1/20, and the lighting device 120a is simply turned off repeatedly. Then, the light emission amount focused only on the lighting device 120a is attenuated to (1-1 / 20) = 19/20. Therefore, the illumination control unit 162 is set to amplify only the light emission amount of the illumination device 120a by 20/19 times in order to cancel the influence of the extinction. Thus, as with the other lighting devices 120b and 120c, the lighting device 120a can secure the same amount of light emission as when the lighting device 120a is continuously turned on without turning off, and uniform white light can be obtained. It is possible to minimize the influence on the visibility of the object to be measured 102 and human work efficiency.

  The holding unit 164 includes a semiconductor memory, a non-volatile RAM, a flash memory, an HDD (Hard Disk Drive), and the like, and one or more transmitted from the central control unit 166 based on a control command of a storage control unit 174 described later. The projected image 112 of the image is held.

  The central control unit 166 manages and controls the entire three-dimensional shape measuring apparatus 110 by a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing a program, a RAM as a work area, and the like. In the present embodiment, the central control unit 166 also functions as the signal generation unit 170, the projection image formation control unit 172, the storage control unit 174, and the three-dimensional shape derivation unit 176.

  The signal generator 170 is binarized into a first state and a second state, and generates a rectangular control signal in which the occupation time of the first state is shorter than the occupation time of the second state. Specifically, when generating the periodic control signal as described above, the signal generation unit 170 sets a frequency and a duration for continuing the first state in a timer and a counter (not shown), and generates a one-shot rectangular impulse. When generating the control signal, a reversal time from the second state to the first state is set in a timer (not shown). Further, not only such a periodic control signal and one-shot control signal, but also various rectangular signals that change regularly or irregularly can be adopted as the control signal. Here, an example is given in which a timer and a counter are set and a control signal is generated by hardware. However, a control signal can also be generated in the central control unit 166 using a software interrupt. In this embodiment, the first state and the second state of the control signal are associated with the high level and low level (positive logic) of the discrete signal, but are associated with the low level and high level (negative logic). May be.

  When the signal generator 170 generates a periodic control signal, the time distribution can be determined as follows. First, according to the intensity of the laser light from the light projecting light source 150 and the distance to the object to be measured 102, the time required for forming the projection image 112 by the reflected light of the object to be measured 102 in the light receiving element 160 is determined. This is the duration of the first state of the control signal. In addition, the frequency is determined so that the projection image 112 can be acquired a sufficient number of times within a range in which turning off of the lighting device 120a does not affect the visibility of the object to be measured 102 or the human work efficiency.

  Therefore, if the intensity of the laser light of the light projecting light source 150 can be increased, the duration of the first state can be shortened accordingly, and as a result, the number of acquisitions per unit time of the projection image 112 is increased, and the total time until the measurement is completed. Can be shortened. At this time, the control signal may be set in consideration of a reaction speed of the electronic shutter 158, a delay time due to switching between lighting and extinguishing of the lighting device 120a, and the like.

  The projection image formation control unit 172 causes the light receiving element 160 to form the projection image 112 while the control signal indicates the first state. Here, an example in which the light guide state of the electronic shutter 158 is controlled to form the projected image 112 of the light receiving element 160 will be described. However, the present invention is not limited to this, and the projection image formation control unit 172 includes the light receiving element 160. The timing at which the light receiving element 160 forms the projection image 112 can be controlled by various methods, such as controlling the charge accumulation start timing by a reset signal of the accumulated charge.

  The turn-off timing of the illumination device 120a and the timing at which the light receiving element 160 forms the projection image 112 are synchronized through the control signal generated in this way.

  In addition, when the timing at which the light receiving element 160 forms the projection image 112 is determined in advance, the means for providing the timing at which the projection image 112 is formed corresponds to the signal generation unit 170. Therefore, the projection image formation control unit 172 receives the timing for forming a predetermined projection image 112 as a control signal provided from the signal generation unit 170, and causes the light receiving element 160 to form the projection image 112. . Further, the illumination control unit 162 turns off the illumination device 120a at the timing (control signal) at which the projection image 112 is formed.

  Furthermore, when the turn-off timing of the lighting device 120a is determined in advance as a reverse pattern, means for providing the turn-off timing of the lighting device 120a corresponds to the signal generation unit 170. Accordingly, the illumination control unit 162 turns off the illumination device 120a in response to a predetermined turn-off timing of the illumination device 120a as a control signal provided from the signal generation unit 170. Further, the projection image formation control unit 172 causes the light receiving element 160 to form the projection image 112 at the turn-off timing (control signal) of the illumination device 120a.

  The object of the present embodiment is to exclusively execute lighting of the illumination device 120a and formation of the projection image 112 of the light receiving element 160 on the time axis. Therefore, if the signal generation unit 170 can achieve such an object, the signal generation unit 170 can form a control signal based on various other timings. At this time, the signal generation unit 170 generates a control signal at another reference timing.

  Further, it has been described that the laser light from the light projecting light source 150 can be projected continuously. However, the laser light is intermittently projected onto the light projecting light source 150 in accordance with the timing at which the light receiving element 160 forms the projection image 112. You may let them. By reducing the emission time of the light projecting light source 150 in this way, useless power consumption can be reduced and the amount of light emission can be increased accordingly. In this case, a control signal is also provided to the driving power source of the light projecting light source 150, and the light projecting light source 150 stops the projection of the laser light while the electronic shutter 158 is in a non-transmissive state, and the electronic shutter 158 is in a transmissive state. Laser light projection starts (restarts) at the timing.

  In addition, when the light receiving element 160 starts to form the projection image 112 with a delay, in order to ensure the charge accumulation time, the delay time is earlier than the time when the control signal is inverted from the second state to the first state. The electronic shutter 158 can be in a transmissive state.

  After the control signal is inverted from the first state to the second state, that is, after the projection image formation control unit 172 sets the electronic shutter 158 in the non-transmissive state, the storage control unit 174 stores the projection accumulated in the light receiving element 160. The image 112 is read out and sequentially stored in the holding unit 164 in association with the projection angle of the projection light source 150 at that time.

  The three-dimensional shape deriving unit 176 performs a plurality of projections held by the holding unit 164 when the projection image 112 is formed a predetermined number of times in order to obtain the light section image 114 over the entire object to be measured 102. Based on the image 112, the three-dimensional shape of the DUT 102 is derived. Specifically, the three-dimensional shape deriving unit 176 performs only the light section image 114 based on whether or not the light reception amount (light reception intensity) in each pixel of the projection image 112 formed by the light receiving element 160 is greater than or equal to a predetermined threshold value. Is extracted, the three-dimensional position of the point on the light section image 114 is obtained from the relative position of the light section image 114 with respect to the projection image 112, and the three-dimensional shape of the object 102 to be measured is derived.

  FIG. 3 is an explanatory diagram for explaining the derivation of the three-dimensional shape by the three-dimensional shape derivation unit 176. Among the plurality of projection images 112 formed by the light receiving element 160, for example, it is assumed that an arbitrary projection image 112 when the projection angle of the slit light is in the state of FIG. 1 is as shown in FIG. To do. On the projected image 112, a light section image 114 that is a reflected light of the slit light on the object to be measured 102 is projected. At this time, the received light amount of each pixel in an arbitrary line 116 in the direction perpendicular to the longitudinal direction of the light section image 114 in the projection image 112 is as shown in FIG. In FIG. 3B, the horizontal axis is a position corresponding to the pixel of the line 116, and the vertical axis indicates the amount of light received for each pixel.

  Conventionally, reflected light of slit light includes reflected light of all three illumination devices 120a, 120b, and 120c, and only a specific color is transmitted by a light transmission filter provided in the second optical system 156. However, since the reflected light from the illumination device 120a that irradiates illumination light including the specific color is superimposed, the distribution of the amount of received light of the specific color is as shown in FIG. In the distribution of FIG. 3C, the reflected light of the slit light is added to the reflected light of the illumination light, particularly the illumination light of a specific color, in the pixel A corresponding to the light section image 114 (see FIG. 3A). However, the amount of reflected light of illumination light is difficult to predict in advance, and the amount of reflected light of illumination light oscillates and becomes irregular. Therefore, the threshold value for determining the position cannot be set uniquely, and it is difficult to extract only the reflected light of the slit light. In the present embodiment, as shown in FIG. 3B, since the reflected light of the illumination light of a specific color as a target is excluded from the illumination light in the formation of the projection image 112, only the light cut image 114 of the slit light is obtained. Appearing as a received light distribution, the measurer can assume the amount of light received by the light-cut image 114. Therefore, for example, as shown in FIG. 3B, by setting the threshold at a position that is half of the assumed amount of received light, the three-dimensional shape measuring apparatus 110 can extract only the light section image 114 reliably and easily. It is possible to measure a three-dimensional shape with high accuracy. Next, a flow for deriving a three-dimensional position from the extracted light section image 114 will be described.

FIG. 4 is an explanatory diagram for explaining the derivation of the three-dimensional position of an arbitrary point on the device under test 102. For example, when an arbitrary point A on the light section image 114 of the projection image 112 of FIG. 4A is targeted, the three-dimensional shape deriving unit 176 performs the Y-axis direction of the point A (see FIG. coordinates Y _a are shown) in 4 right _and makes a line segment connecting the points of the object to be measured 102 corresponding to the point a and the light receiving element 160, a line segment connecting the light receiving element 160 and the projection light source 150 is The light receiving angle θ _R that is the depression angle can be derived. Further, the projection image 112 includes a projection angle of a light projection angle of the light projecting light source 150 (a line segment connecting the point where the slit light hits and the light projecting light source 150 and a line segment connecting the light receiving element 160 and the light projecting light source 150) ) Θ _{S is} also associated and held. Therefore, if the distance L between the light receiving element 160 and the light projecting light source 150 is known in advance, the point A is one side (distance L) and the depression angle (light receiving angle θ) of one side (distance L) as shown in FIG. _{R 3} , the projection angle θ _S ) becomes the apex of the specified triangle, and the three-dimensional shape deriving unit 176 refers to the X-axis coordinate X _A and Z axis by referring to the calculation or the table based on the triangulation method. It becomes possible to derive the coordinate Z _A of the direction. Thus, coordinates (X _A , Y _A , Z _A ) are obtained as a three-dimensional position related to the point A. As described above, in the light cutting method, the three-dimensional shape of the DUT 102 can be obtained based on the projection image 112 formed by the light receiving element 160 and the relative position between the light projecting light source 150 and the light receiving element 160. .

  At this time, the depression angle formed by the line segment connecting the object to be measured 102 and the light receiving element 160 and the line segment connecting the object to be measured 102 and the light projecting light source 150 can be any angle less than 180 °. The larger the depression angle, the higher the accuracy of deriving the three-dimensional shape. However, the light section image 114 cannot be obtained because it is hidden behind the protruding structure of the object 102, and the width of the light section image 114 can be secured sufficiently. In this case, the depression angle is set to about 60 °.

  This embodiment is devised at the stage of forming the projection image 112, and generates a plurality of projection images for one projection angle, or selects or combines the plurality of projection images. Since there is no processing, the calculation processing load of the three-dimensional shape deriving unit 176 does not increase.

(Setting of light transmission filter provided in second optical system 156)
In the three-dimensional shape measuring apparatus 110 described above, a specific setting procedure of a light transmission filter used in the second optical system 156 will be described.

  FIG. 5 is a spectrum distribution diagram for explaining the setting of the light transmission filter. Here, the horizontal axis indicates the wavelength, and the vertical axis indicates the normalized output. First, when the color (specific color) of the laser light of the light projecting light source 150 is determined, the light emission distribution (182a) of the illuminating device 120a including the spectrum 180 of the specific color (here, red), the illumination light of the illuminating device 120a, and The light emission distributions 182b and 182c of the light emission colors (here, green and blue) of the illumination devices 120b and 120c that become white when additive color mixing is performed are determined. Therefore, the color of the lighting device 120a and the combined color of the other lighting devices 120b and 120c are complementary to each other.

  Here, it is sufficient to create a state in which illumination light having the same color as the laser light is not irradiated by some illumination devices 120. Therefore, it is also possible to determine a plurality of illumination devices 120 in advance, and adopt a color included in only one of the illumination devices 120 as the color of the laser light.

  The light transmission filter must transmit the laser light and block the irradiation light of the other illumination devices 120b and 120c. Therefore, the light transmission filter generally uses a band pass filter (BPF: Band Pass Filter) such as an interference filter or a filter using a pigment, and blocks the light emission distributions 182b and 182c of the other lighting devices 120b and 120c as much as possible. In addition, the pass band 184 is determined so that the spectrum 180 of the laser diode can be sufficiently transmitted (see FIG. 5).

  Here, an example in which white light is obtained by additive color mixing has been described, but the final composite color is not limited to white, and an arbitrary color can be set. In addition, although the illumination device 120a emits illumination light of a specific color, various light sources of a single color or a composite color can be used as long as the specific color of laser light is included. Furthermore, as long as the other illumination devices 120b and 120c do not include even the specific color of the laser light, the color and number of the illumination devices 120b and 120c are not limited.

(Measurement timing 1)
Next, the measurement timing in the three-dimensional shape measuring apparatus 110 will be specifically shown.

  FIG. 6 is a time chart for explaining the turn-off timing of the illumination devices 120a, 120b, and 120c and the timing at which the light receiving element 160 forms the projection image 112. In particular, FIG. 6A shows the overall timing until a three-dimensional shape is derived, and FIG. 6B shows a single projection image 112 when the projection light source 150 being measured is at an arbitrary projection angle. The read timing is shown.

  In the measurement of the three-dimensional shape, when the signal generation unit 170 generates a binarized control signal as shown in FIGS. 6A and 6B, the illumination control unit 162 indicates that the control signal indicates the second state. During this period, the lighting device 120a is turned on, and the lighting device 120a is turned off while the first state is indicated. At this time, the other lighting devices 120b and 120c maintain the lighting state. The projection image formation control unit 172 sets the electronic shutter 158 in the non-transmissive state while the control signal indicates the second state, and immediately before the control signal is inverted from the second state to the first state, The accumulation of light is reset, and the reflected light is guided to the light receiving element 160 in the transmissive state while the control signal indicates the first state. Thus, the light receiving element 160 can accumulate light of a specific color only while the electronic shutter 158 is in the transmissive state.

  Here, since the illumination device 120a is turned off while the control signal indicates the first state, the reflected light transmitted through the second optical system 156 and guided by the electronic shutter 158 includes slit light. Only the reflected light is included, and in the light receiving element 160, as shown in FIG. 3B, a projected image 112 in which the difference in the amount of received light is clear between the light section image 114 and other portions is accumulated. Further, in the present embodiment, such a projection image 112 is acquired by a single projection by the light receiving element 160, so that the measured object 102 or the background thereof is moved or deformed, or the reflected light of illumination light. Even when the intensity of the light changes, the light section image 114 can be extracted with high accuracy and reliability.

  Then, when the control signal is inverted from the first state to the second state, the storage control unit 174 reads the projection image 112 based on the electric charge accumulated in the light receiving element 160 and associates it with the light projection angle of the slit light to the holding unit 164. Hold. When the projected image 112 is formed a predetermined number of times and the light section image 114 over the entire object to be measured 102 is acquired, the three-dimensional shape deriving unit 176 is based on the plurality of projected images 112 held by the holding unit 164. A three-dimensional shape of the DUT 102 is derived. In addition, the three-dimensional shape deriving unit 176 does not wait for the completion of the acquisition of the light section image 114 over the entire object 102 to be measured, based on the acquired light section image 114, as needed. The shape can also be derived.

  Here, the example in which the lighting device 120a is turned off and the transmission state of the electronic shutter 158 is changed at the same time has been described. However, the present embodiment is not limited to this case, and the lighting state of the lighting device 120a and the electronic shutter 158 are changed. For example, the electronic shutter 158 may be in a transmissive state after the illumination device 120a is turned off and the reflected light is stabilized after the illuminating device 120a is extinguished.

  Here, it is assumed that the transmission state of the electronic shutter 158 and the formation of the projection image 112 of the light receiving element 160 are performed at the same time, but this is not limited to the simultaneous operation, and the transmission state of the electronic shutter 158 is also performed. The light receiving element 160 may form the projection image 112 therein, and the formation of the projection image 112 of the light receiving element 160 may be started after the electronic shutter 158 completely shifts from the non-transmissive state to the transmissive state. Further, when a mechanical shutter is used instead of the electronic shutter 158, it takes time for the mechanical shutter to be fully opened. Therefore, the projection image formation start time of the light receiving element 160 is delayed by the delay time or the mechanical shutter is not operated. You may respond by making the opening time point early. When a mechanical shutter is used in this way, a mechanism may be used in which a slit is provided in a rotating body instead of a shutter that is opened and closed, and a transmission state is provided only between the slits as the rotating body rotates.

  In addition, the lighting time of the illumination device 120a, the time for setting the electronic shutter 158 in the transmission state, and the time for forming the projection image 112 by the light receiving element 160 have been described as 1 msec. You may change the time at any time according to distance. For example, when the distance between the light projecting light source 150 and the light receiving element 160 and the object to be measured 102 is large, the amount of light reaching the object to be measured 102 is small, and the amount of reflected light received by the light receiving element 160 is also weakened. Therefore, the projection image formation control unit 172 increases the time for which the electronic shutter 158 is in the transmissive state and increases the time for accumulating light in the light receiving element 160 to ensure the amount of received light necessary for measurement. Further, even in the same object to be measured 102, when the distance from the light projecting light source 150 and the light receiving element 160 is different, the short distance is set to the transmission state for a short time, and the long distance is the transmission state for a long time. It can also be.

(Measurement timing 2)
In the example described above, the illumination control unit 162 turns off only the illumination device 120a that emits illumination light including a specific color during measurement by the three-dimensional shape measurement apparatus 110, but the illumination device 120b does not include a specific color. 120c may be turned off for a time corresponding to the time when the control signal indicates the first state while the control signal indicates the second state.

  FIG. 7 is a time chart for explaining the turn-off timings of the lighting devices 120a, 120b, and 120c and other timings at which the light receiving element 160 forms the projection image 112. As in FIG. 6, FIG. 7A shows the overall timing until a three-dimensional shape is derived, and FIG. 7B shows one time when the light source 150 being measured is at an arbitrary light projection angle. The readout timing of the projection image 112 is shown.

  In the measurement of the three-dimensional shape, when the signal generation unit 170 generates a binarized control signal as shown in FIGS. 7A and 7B, the illumination control unit 162 receives the control signal as in FIG. The lighting device 120a is turned on while two states are shown, and the lighting device 120a is turned off while showing the first state. The projection image formation control unit 172 sets the electronic shutter 158 in the non-transmissive state while the control signal indicates the second state, and immediately before the control signal is inverted from the second state to the first state, The accumulation of light is reset, and while the control signal indicates the first state, the reflected light of a specific color is guided to the light receiving element 160 in the transmissive state.

  At this time, the illumination control unit 162 lights the other lighting devices 120b and 120c while showing the first state, but only the time corresponding to the time when the lighting device 120a is turned off while showing the second state. The other lighting devices 120b and 120c are turned off. However, as shown in FIG. 7B, the turn-off time of the lighting device 120b and the turn-off time of the lighting device 120c are not overlapped. In this way, the three lighting devices 120a, 120b, and 120c are turned off uniformly so as not to overlap each other, so that the respective light emission amounts can be made equal and stable white light can be obtained. At this time, when the light emission color additively mixed by the three lighting devices 120a, 120b, and 120c is different from strict white, it can be made white by finely adjusting the turn-off time of the other lighting devices 120b and 120c. In addition, by exclusively configuring the turn-off times of the three lighting devices 120a, 120b, and 120c, the number of lighting devices 120 that are temporarily turned off is at most one. The illumination device 120a, 120b, 120c can be 2/3 times that when all the illumination devices 120a, 120b, and 120c are irradiated, and a sufficient amount of light emission that does not affect the visibility of the object to be measured 102 and human work efficiency can be ensured. It becomes possible.

  Since the illumination device 120a is turned off while the control signal indicates the first state, the reflected light that passes through the second optical system 156 and is guided by the electronic shutter 158 is similar to FIG. Only the reflected light of the slit light is included, and the light receiving element 160 accumulates a projection image 112 in which the difference in the amount of received light is clear between the light cut image 114 and other portions as shown in FIG. . Here, the turn-off timing of the lighting devices 120b and 120c overlaps the read timing of the projection image 112 of the storage control unit 174. However, the lighting devices 120b and 120c may be turned off while avoiding the read timing.

(Other three-dimensional shape measuring device by projection pattern)
In the above-described embodiment, in order to facilitate understanding, as a three-dimensional shape measuring apparatus that measures the three-dimensional shape of the device under test 102 using reflected light when laser light is projected onto the device under test 102, optical cutting is performed. The three-dimensional shape measuring apparatus 110 by the method has been described. However, the three-dimensional shape measurement apparatus according to the present embodiment is not limited to the light cutting method, but a measurement method using various light projection patterns that are common in that the reflected light of the illumination light of a specific color works disadvantageously, for example, The present invention can also be applied to spot methods, repetitive pattern methods, coding pattern methods (spatial coding methods), moire methods, and the like.

The spot method replaces slit light in the light cutting method with spot light, and can specify the three-dimensional position of one point for one projection image. In the repetitive pattern method, the slit light in the light cutting method is regularly arranged to be multi-slit light, the projection pattern is formed by regularly arranging squares and circles, or a regular projection pattern such as a checkered pattern is used. Then, the three-dimensional shape is specified by the reflected light. In the encoding pattern method, each point in the measurement space including the device under test 102 is encoded with a binary code, and pattern light in which the light and dark pitches are doubled in accordance with the code is projected to reduce the projected image. The three-dimensional shape is specified by the number of times of formation (an integer greater than or equal to log ₂ n where n is the number of space separations). In the moire method, a grating mask is arranged between the object to be measured 102 and the light projecting light source 150, and a light and dark pattern formed by light passing through the grating forms moiré fringes on a projected image by the light receiving element 160. A three-dimensional shape can be specified by the stripes.

(Three-dimensional shape measuring device by optical time difference)
Furthermore, the present embodiment is not limited to the above-described three-dimensional shape measurement that determines the presence or absence of reflected light and derives a three-dimensional shape using a triangulation method, and uses an optical time difference such as an optical laser method (optical time difference method). It can also be applied to 3D shape measurement. Specifically, in the optical laser method, unlike the triangulation method described above, the light projecting light source 150 and the light receiving element 160 are made as close as possible, and the emission direction of the light projecting light source 150 and the incident direction of the light receiving element 160 are arranged substantially coaxially. . In the optical laser method, light is emitted from the light projecting light source 150, and when the light receiving element 160 receives reflected light, the time from the light emission to the incidence (flight time) is measured, and the speed of light is set at the measured time. By multiplying, the sum of the distance from the light projecting light source 150 to the object to be measured 102 and the distance from the object to be measured 102 to the light receiving element 160 is obtained, and half of the sum is set as the distance of the object to be measured 102, so that The shape can be specified.

  At this time, if the reflected light of the illumination light of a specific color is mistaken as the reflected light of the laser light in specifying the reception time point of the reflected light, the accurate distance of the object to be measured 102 cannot be derived. Therefore, in this embodiment, the illumination device 120a is turned off at the timing when the reflected light is incident. Specifically, the projection image formation control unit 172 causes the light projecting light source 150 to project while the control signal indicates the first state, and causes the light receiving element 160 to receive the reflected light. At this time, the projection image formation control unit 172 keeps the electronic shutter 158 in a transmissive state for a predetermined time from when the light projecting light source 150 starts projection until the light receiving element 160 completes light reception. In addition, the illumination control unit 162 turns off the illumination device 120a while the control signal indicates the first state. The three-dimensional shape deriving unit 176 derives the three-dimensional shape of the measurement object 102 based on the difference time between the projection time of the light projecting light source 150 and the light reception time of the light receiving element. Here, since the reflected light of the illumination light is reduced, the reception time of the reflected light of the laser light can be accurately specified, and the accurate distance of the object 102 to be measured can be measured. In addition, since the time of flight of light is short, turning off the illumination device 120a does not affect the visibility of the object to be measured 102 or the human work efficiency.

(Further other three-dimensional shape measuring device)
Further, in the above-described three-dimensional shape measuring apparatus 110 using the light section method, the light section image 114 is extracted by comparing the light amount of the projection image 112 with a threshold value. The three-dimensional shape of the DUT 102 can also be derived based on the absolute value or wavelength of the amount of light received in the projection image 112 formed by the light receiving element 160.

  FIG. 8 is an explanatory diagram illustrating a three-dimensional shape measuring apparatus 190 using the absolute value of the amount of received light. As shown in FIG. 8A, the three-dimensional shape measuring apparatus 190 has substantially the same configuration as the above-described three-dimensional shape measuring apparatus 110, and although the first optical system 192 is a cylindrical lens, It is different from the three-dimensional shape measuring apparatus 110 in that the degree of shading differs step by step. Therefore, as shown in FIG. 8A, the laser light that has passed through the first optical system 192 becomes a plurality of slit lights having different amounts of light, although having a specific color, and is projected onto the surface of the object 102 to be measured. At this time, a striped pattern with different amounts of received light is formed in the projected image 112 as shown in FIG. Therefore, the amount of light received by each pixel in an arbitrary line 116 of the projected image 112 is as shown in FIG. In FIG. 8C, as in FIG. 3B, the horizontal axis represents the position corresponding to the pixel of the line 116, and the vertical axis represents the amount of received light for each pixel.

  In this embodiment, since the reflected light of the illumination light of a specific color is excluded in the formation of the projection image 112, only the reflected light of the slit light appears as a stepwise light reception distribution as shown in FIG. From the stepwise light distribution of the amount of received light, it can be easily specified by comparing with threshold values 1 to 4 which one of the measured objects 102 is irradiated with a plurality of slit lights having different light amounts. Further, in the case of the three-dimensional shape measuring apparatus 190, since it is possible to measure a plurality of slit lights with one projection image 112, it is possible to reduce the total time spent for measurement. In FIG. 8, the light amount of the slit light is shown in four stages for easy understanding, but more slit light can be formed according to the detection accuracy of the light emission amount of the light projecting light source 150 and the light reception amount of the light receiving element 160. Needless to say.

(Three-dimensional shape measurement additional device 200)
In the above-described embodiment, an example in which the three-dimensional shape measuring apparatus 110 is newly formed has been described. However, the present embodiment can be additionally applied to the existing three-dimensional shape measuring apparatus 10.

  FIG. 9 is a configuration diagram showing a schematic configuration of the three-dimensional shape measurement adding device 200. The three-dimensional shape measurement adding device 200 is configured by a computer such as a personal computer or a built-in board computer, and includes an illumination control unit 162, a signal generation unit 170 in the central control unit 202, and a projection image formation control unit 172. Consists of. Since the illumination control unit 162, the signal generation unit 170, and the projection image formation control unit 172 have substantially the same functions as the components of the three-dimensional shape measuring apparatus 110, the same reference numerals are given and redundant description is omitted. To do.

  The signal generation unit 170 operates using, for example, a timer and a counter of a personal computer as the three-dimensional shape measurement adding device 200, and is binarized into a first state and a second state, like the three-dimensional shape measurement device 110. The control signal is generated in which the occupation time of the first state is shorter than the occupation time of the second state. And while the control signal which the signal generation part 170 produced | generated shows the 1st state, the illumination control part 162 is only the illumination apparatus 120a which irradiates the illumination light containing a specific color among several illumination device 120a, 120b, 120c. Turns off. Further, the projection image formation control unit 172 controls the electronic shutter 158 and the like to form the projection image 112 on the light receiving element 160 of the existing three-dimensional shape measuring apparatus 10 while the control signal indicates the first state. Let Similarly to the three-dimensional shape measurement apparatus 110, the signal generation unit 170 forms the projection image 112 when the timing at which the light receiving element 160 forms the projection image 112 is predetermined in the existing three-dimensional shape measurement apparatus 10. In response to the timing (control signal) for forming the projection image 112 from the signal generation unit 170 corresponding to the means for providing the timing for the illumination, the illumination control unit 162 turns off the illumination device 120a at the timing for forming the projection image 112. .

  By connecting such a three-dimensional shape measurement additional device 200 to the existing three-dimensional shape measurement device 10, it is possible to reliably and accurately cover the object to be measured 102 without affecting the visibility of the object 102 and the work efficiency of a person. It is possible to derive the three-dimensional shape of the measurement object 102.

(Three-dimensional shape measurement method)
Also provided is a three-dimensional shape measurement method for measuring the three-dimensional shape of the measurement object 102 based on the projection image 112 of the reflected light when light is projected onto the measurement object 102. Hereinafter, such a three-dimensional shape measurement method will be described in detail.

  FIG. 10 is a flowchart showing the overall flow of the three-dimensional shape measuring method. As shown in FIG. 10, the signal generator 170 of the three-dimensional shape measuring apparatus 110 generates a binarized control signal (S200).

  Then, the illumination control unit 162 and the projection image formation control unit 172 determine whether or not the control signal indicates the first state (S202). If the control signal indicates the first state (YES in S202), the illumination control unit 162 turns off the illumination device 120a that irradiates illumination light including a specific color among the plurality of illumination devices 120a, 120b, and 120c that illuminate the object 102 to be measured (S204), and the projection image formation control unit 172 The projected image 112 is formed by the light receiving element 160 (S206). If the control signal does not indicate the first state, that is, if the control signal indicates the second state (NO in S202), the illumination control unit 162 turns on the illumination device 120a that emits illumination light including a specific color. Then, the projection image formation control unit 172 stops the formation of the projection image 112 by the light receiving element 160 (S210). When the control signal indicates the second state, the illumination control unit 162 may turn off the illumination devices 120b and 120c that do not include the specific color for a time corresponding to the time when the control signal indicates the first state. .

  Then, it is determined whether or not all the projection images 112 have been acquired (S212). If there is a projection angle that has not yet acquired the projection images 112 (NO in S212), the control signal generation step S200 is repeated. . When the projected image 112 is formed a predetermined number of times and a light section image of the entire object to be measured 102 is acquired, it is determined that all the projected image 112 has been acquired (YES in S212), and the three-dimensional shape deriving unit 176 receives the light. Based on the projection image 112 formed by the element, the three-dimensional shape of the DUT 102 is derived (S214).

  Thus, even in the three-dimensional shape measurement method, it is possible to derive the three-dimensional shape of the measurement object 102 with high accuracy and certainty without affecting the visibility of the measurement object 102 and the human work efficiency. .

  The above-described components based on the technical idea of the three-dimensional shape measuring apparatuses 110 and 190 and the description thereof can also be applied to the three-dimensional shape measurement adding apparatus 200 and the three-dimensional shape measuring method.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  Note that each step in the three-dimensional shape measurement method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or by a subroutine.

  The present invention is used in a three-dimensional shape measuring device, a three-dimensional shape measuring addition device, and a three-dimensional shape measuring method for measuring a three-dimensional shape of a measured object using reflected light when light is projected onto the measured object. be able to.

DESCRIPTION OF SYMBOLS 10, 110, 190 ... Three-dimensional shape measuring apparatus 102 ... Object to be measured 112 ... Projection image 120 (120a, 120b, 120c) ... Illuminating device 150 ... Projection light source 160 ... Light receiving element 162 ... Illumination control part 170 ... Signal generation part 172 ... Projected image formation control unit 176 ... 3D shape deriving unit 200 ... 3D shape measurement adding device

Claims (8)

A light source that projects light of a specific color on the object to be measured;
A light receiving element that receives the reflected light of the specific color among the reflected light reflected by the object to be measured, and forms a projected image;
A signal generator for generating a binarized control signal;
An illumination control unit that turns off the illumination device that emits illumination light including the specific color among the plurality of illumination devices that illuminate the object to be measured; and the control signal indicates the first state; and
A projection image formation control unit configured to form a projection image on the light receiving element while the control signal indicates the first state;
A three-dimensional shape deriving unit for deriving a three-dimensional shape of the object to be measured based on a projection image formed by the light receiving element;
A three-dimensional shape measuring apparatus comprising:   The illumination control unit is configured to illuminate an illumination device that emits illumination light that does not include the specific color, while the control signal does not indicate the first state, the time corresponding to the time when the control signal indicates the first state, The three-dimensional shape measuring apparatus according to claim 1, wherein the three-dimensional shape measuring apparatus is turned off.   3. The three-dimensional shape measuring apparatus according to claim 1, wherein the plurality of illuminating devices emit illumination light having different colors and become white light when the illumination light is additively mixed. 4.   The three-dimensional shape deriving unit derives the three-dimensional shape of the object to be measured based on whether or not the amount of received light of the projection image formed by the light receiving element is equal to or greater than a predetermined threshold value. Item 4. The three-dimensional shape measuring apparatus according to any one of Items 1 to 3.   The illumination control unit sets the light emission amount of the illumination light including the specific color per unit time so as to offset the occupation ratio of the time to turn off the illumination device that irradiates the illumination light including the specific color with respect to the entire time. The three-dimensional shape measuring apparatus according to claim 1. A light projecting light source that projects light of a specific color onto the object to be measured, a light receiving element that receives reflected light of a specific color among the reflected light reflected by the object to be measured, and forms a projected image, and the light receiving element. A three-dimensional shape measurement adding device for adding to a three-dimensional shape measuring device having a three-dimensional shape deriving unit for deriving a three-dimensional shape of the object to be measured based on the projected image,
A signal generator for generating a binarized control signal;
An illumination control unit that turns off the illumination device that emits illumination light including the specific color among the plurality of illumination devices that illuminate the object to be measured; and the control signal indicates the first state; and
A projection image formation control unit configured to form a projection image on the light receiving element while the control signal indicates the first state;
A three-dimensional shape measurement adding device comprising: A light source that projects light of a specific color on the object to be measured;
A light receiving element that receives the reflected light of the specific color among the reflected light reflected by the object to be measured;
A signal generator for generating a binarized control signal;
An illumination control unit that turns off the illumination device that emits illumination light including the specific color among the plurality of illumination devices that illuminate the object to be measured; and the control signal indicates the first state; and
While the control signal indicates the first state, a projection image formation control unit that causes the light source to project the light of the specific color and causes the light receiving element to receive the reflected light of the specific color;
A three-dimensional shape deriving unit for deriving a three-dimensional shape of the object to be measured based on a difference time between a projection time of the light projecting light source and a light reception time of the light receiving element;
A three-dimensional shape measuring apparatus comprising: A three-dimensional shape measuring apparatus including a light projecting light source that projects light of a specific color onto an object to be measured, and a light receiving element that receives the reflected light of a specific color among the reflected light reflected by the object to be measured and forms a projected image A three-dimensional shape measurement method for measuring a three-dimensional shape using
Generate a binarized control signal;
While the control signal indicates the first state, the illumination device that emits the illumination light including the specific color is turned off among the plurality of illumination devices that irradiate the measurement object with illumination light, and a projection image is displayed by the light receiving element. And turning on the illumination device that emits illumination light including the specific color while the control signal indicates the second state, and stopping the formation of the projection image of the light receiving element,
A three-dimensional shape measuring method, wherein a three-dimensional shape of the object to be measured is derived based on a projection image formed by the light receiving element.

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