JP2008191040A - Method of measuring cross sectional shape of workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of measuring a cross sectional shape of a workpiece for improving measurement precision of the cross sectional shape of the workpiece of a complicated shape at first and accelerating measurement of the cross sectional shape of the whole workpiece of the complicated shape at second. <P>SOLUTION: The method of measuring the cross sectional shape of the workpiece irradiates a plurality of slit lights onto the same line of the workpiece W from positions mutually differentiating inclination angles to the workpiece, and measures the cross sectional shape of the workpiece W by properly calculating each brightness value of each reflection light from the workpiece W. Therefore the method can accurately measure the cross sectional shape of the workpiece by the other slit lights even when one slit light generates halation, and in addition, can improve the measurement precision as compared with the conventional method having measured the cross sectional shape by one slit light by properly calculating each brightness value of each reflection light from the plurality of the slit lights. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a workpiece cross-sectional shape measuring method for measuring the cross-sectional shape of a workpiece by irradiating the surface of the workpiece with slit light, and more specifically, irregular reflection of slit light when measuring the cross-sectional shape of a workpiece having a complicated shape. The present invention relates to a cross-sectional shape measurement method for a workpiece that measures the cross-sectional shape accurately by reducing the influence of the above, and a cross-sectional shape measurement method for a workpiece that reduces the measurement time when measuring the cross-sectional shape of the entire workpiece.

  In general, in the production line of industrial products such as automobiles, there is a growing need to inspect parts etc. in-line in order to prevent defective products from flowing into the market, especially when inspecting the cross-sectional shape of workpieces. It is an important issue to improve the speed, and furthermore, the high speed is an important issue when 100% inspection of the cross-sectional shape of the workpiece is performed.

In view of the problem of improving the accuracy of measuring the cross-sectional shape of the former workpiece, the conventional cross-sectional shape measuring method, particularly, as shown in FIGS. The surface is irradiated and the diffuse reflected light is received by the light receiver 3, and the cross-sectional shape of the workpiece is measured by the principle of triangulation.
However, in this method, for example, when measuring the cross-sectional shape of a workpiece having a complicated shape such as an automobile body shape, a part shape, or a weld bead inspection, as shown in FIG. The slit light from 2 is specularly reflected by the inclined surface 10 or the like of the surface of the workpiece W, the brightness of the reflected light is excessive compared to the surroundings, the appropriate exposure amount of the light receiver 3 is exceeded, and halation occurs. The measurement of the part may be poor, and the measurement accuracy may deteriorate.

Further, in response to the problem of speeding up the measurement time of the cross-sectional shape of the entire workpiece, in the conventional cross-sectional shape measuring method, as shown in FIGS. 5 and 7, one projector 2 and one light receiver. 3 is sequentially moved along the longitudinal direction of the workpiece W for each scan, and the cross-sectional shape of the entire workpiece W is measured.
However, in this method, only the cross-sectional shape of one part of the workpiece W can be measured while the measuring unit 5 is stationary, and it takes a considerable time to measure the cross-sectional shape of the entire workpiece. The tact time of the production line cannot be shortened.

  By the way, as a conventional technique for the problem of improving the measurement accuracy of the cross-sectional shape of the former workpiece, Patent Literature 1 irradiates a side end portion of a corner member with slit light while changing the irradiation angle, and the irradiation location for each irradiation. Is used at predetermined intervals along the longitudinal direction of the corner member to measure the side surface shape of the corner shape based on the obtained captured image and to detect an abnormality of the corner portion such as a corner drop. A member shape measuring method is disclosed.

Further, as a conventional technique for the problem of speeding up the measurement time of the cross-sectional shape of the entire workpiece, Patent Document 2 discloses a light source unit that irradiates a surface of an object to be measured with slit light spreading in a fan shape in the main scanning direction And a photoelectric conversion element that receives reflected light from the surface of the object to be measured and outputs an electric signal corresponding to the brightness of the object to be measured, and sequentially moves the measurement unit in the sub-scanning direction, thereby converting the photoelectric conversion element A three-dimensional coordinate measuring device that calculates the coordinates of the surface shape of the object to be measured based on the electrical signal from the light source unit, the light source unit having a function of outputting a plurality of slit lights in the sub-scanning direction, sequentially or simultaneously A three-dimensional coordinate measuring apparatus is disclosed that performs main scanning in accordance with the number of slit light outputs when the measurement unit is moved once in the sub-scanning direction by irradiation.
JP 2002-131028 A JP-A-7-167617

  However, in the method for measuring the shape of a corner member disclosed in Patent Document 1, the first laser marker, the second laser marker, and the third laser marker are different from each other in inclination angles with respect to the workpiece in order to detect an abnormal portion of the edge. Since each slit light emitted from each laser marker is reflected at different parts of the edge where the angle has dropped, each reflection detection value is different, and it is determined that the edge is not normal. Even if the shape measuring method disclosed in Document 1 is adopted, only an abnormality in the edge portion is detected, and the former problem, that is, the cross-sectional shape of a workpiece having a complicated shape cannot be accurately measured.

  In addition, the three-dimensional coordinate measuring apparatus disclosed in Patent Document 2 shortens the measurement time for measuring the cross-sectional shape of the entire object to be measured by irradiating the workpiece surface with a plurality of slit lights by the light source unit in the measurement unit. However, when simultaneously irradiating a plurality of slit lights from the light source unit, the respective coordinates are calculated because there are three measurement signals in one main scan. However, in the three-dimensional coordinate measuring device of Patent Document 2, if the surface is flat and the workpiece has a simple shape, each reflected light of each slit light simultaneously irradiated from the projector is received by the light receiver with a time difference. However, when measuring a complex workpiece with an uneven surface, it is expected that each reflected light will be received by the receiver at the same timing. There is a possibility that measurement failure may occur because it is not possible to recognize whether the light is reflected from the part.

  The present invention has been made in view of such a point, and firstly, it aims to provide a method for measuring the cross-sectional shape of a workpiece that improves the measurement accuracy of the cross-sectional shape of a workpiece having a complicated shape. An object of the present invention is to provide a method for measuring a cross-sectional shape of a workpiece that speeds up the measurement time of the cross-sectional shape of the entire workpiece having a simple shape.

In order to solve the above first problem, the workpiece cross-sectional shape measurement method of the present invention irradiates a plurality of slit lights on the same line of the workpiece from positions where the inclination angles with respect to the workpiece are different from each other, It is characterized in that the cross-sectional shape of the work is measured by calculating each luminance value of each reflected light from the work.
Thereby, even if one slit light causes halation, the cross-sectional shape of the workpiece can be accurately measured by the other slit light. In addition, by appropriately calculating each luminance value of each reflected light from a plurality of slit lights, the measurement accuracy can be improved as compared with the conventional case where the cross-sectional shape is measured by one slit light. .

In order to solve the second problem, a method for measuring a cross-sectional shape of a workpiece according to the present invention is arranged in parallel with the workpiece in a plurality along the longitudinal direction of the workpiece, and on a non-identical line of the workpiece. The measuring unit including each light projector for irradiating each slit light so as to be distinguishable from each other and a light receiver for identifying and receiving each reflected light from the work is sequentially moved along the longitudinal direction of the work. It is characterized by measuring the entire cross-sectional shape.
As a result, the time required to measure the cross-sectional shape of the entire workpiece can be shortened and the speed can be increased, and even when the workpiece surface is uneven, the position (coordinates) of each irradiation site is accurately measured and each cross-sectional shape is measured. Can be measured accurately.
Various aspects of the cross-sectional shape measurement method of the present invention and their actions will be described in detail in the following section (Aspect of the Invention).

(Aspect of the Invention)
In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. In addition, each aspect is divided into a term like a claim, it attaches | subjects a number to each term, and is described in the format which quotes another term as needed. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description, embodiments, etc. accompanying each section, and as long as the interpretation is followed, there may be embodiments in which other constituent elements are added to the aspects of each section. In addition, an aspect in which the constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In the following items, each of items (1) to (3) corresponds to each of claims 1 to 3.

(1) A plurality of slit lights are irradiated on the same line of the work from positions where the inclination angles with respect to the work are different from each other, and each brightness value of each reflected light from the work is processed to obtain a cross-sectional shape of the work A method for measuring a cross-sectional shape of a workpiece, characterized by measuring
Therefore, in the method for measuring the cross-sectional shape of the workpiece of item (1), even if the irradiated portion of the workpiece surface is inclined and one reflected light causes halation due to the inclined surface, the luminance value of the other reflected light Thus, the position (coordinates) of the part can be measured, and the cross-sectional shape can be measured. In addition, even when no halation occurs, the position of the irradiated part can be measured and the cross-sectional shape thereof can be measured by performing arithmetic processing, for example, by averaging the luminance values of the reflected light, so that the luminance of one reflected light can be measured. The measurement accuracy is improved as compared with the conventional method in which the partial position is measured by the value.

(2) The method for measuring a cross-sectional shape of a workpiece according to (1), wherein the slit lights are irradiated so as to be distinguishable from each other.
Therefore, in the method for measuring the cross-sectional shape of the workpiece of item (2), particularly when each slit light is irradiated simultaneously, the measurement result by each slit light becomes clear.

(3) A plurality of projectors arranged substantially parallel to the workpiece and along the longitudinal direction of the workpiece, and irradiating each slit light on a non-identical line of the workpiece so as to be distinguishable from each other, and each reflected light from the workpiece A cross-sectional shape measurement method for a workpiece, comprising: measuring a cross-sectional shape of the entire workpiece by sequentially moving a measuring unit including a light receiver for identifying and receiving the light along the longitudinal direction of the workpiece.
Therefore, in the method for measuring the cross-sectional shape of the workpiece in (3), the measuring unit includes a plurality of projectors, and each of these projectors (N) is arranged substantially parallel to the workpiece and along the longitudinal direction of the workpiece. Because each slit light is emitted from each projector onto a non-identical line of the workpiece, the measurement unit is stationary compared to the conventional configuration in which one unit of light is used to measure one part of the workpiece. The number of times of measurement is 1 / N times, and the measurement time for measuring the cross-sectional shape of the entire workpiece is shortened compared to the conventional method.
In addition, since the slit light emitted from each projector is distinguishable from each other, each slit light from each projector can be identified by the light receiver even if the workpiece surface is uneven, and each slit light is emitted from each projector. The position of each irradiation part of each slit light can be recognized correctly, and each cross-sectional shape can be measured accurately.

(4) The method for measuring a cross-sectional shape of a workpiece according to (3), wherein the slit lights are irradiated simultaneously.
Therefore, in the workpiece cross-sectional shape measuring method of (4), when measuring with the measuring unit stationary, a plurality of positions of the workpiece can be measured simultaneously, and the measurement time can be further shortened.

(5) Each slit light is identified by a difference in color or by a difference in a dot pattern of light rays, and the cross-sectional shape of the workpiece according to (3) or (4) Measurement method.
Therefore, in the method for measuring the cross-sectional shape of the workpiece in (5), the method for identifying each slit light is appropriately selected based on the use environment and the like.

  ADVANTAGE OF THE INVENTION According to this invention, the cross-sectional shape measuring method of the workpiece | work which improves the measurement accuracy of the cross-sectional shape of the workpiece | work of a 1st complicated shape can be provided first, and the measurement time of the cross-sectional shape of the 2nd whole workpiece | work of a complicated shape It is possible to provide a method for measuring the cross-sectional shape of a workpiece that increases the speed of the workpiece.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.
The workpiece cross-sectional shape measurement method according to the first embodiment of the present invention is a method for accurately measuring the cross-sectional shape of a workpiece having an inclined surface or an uneven surface that causes irregular reflection or the like, The workpiece cross-sectional shape measuring apparatus 1 according to the first embodiment for embodying this method, as shown in FIG. 1, has the same line of the workpiece W from the position where the inclination angles with respect to the workpiece W are different from each other. A plurality of projectors 2a, 2b, and 2c that irradiate each slit light thereon, and a light receiver 3 that receives each reflected light formed by reflecting each slit light from each of the projectors 2a, 2b, and 2c on the workpiece W; Each luminance value of each reflected light detected by the light receiver 3 is appropriately calculated, and the position (coordinates) of one part of the workpiece W is calculated based on one luminance value derived from the calculation result. For one scan The W of the cross-sectional shape as the first arithmetic processing unit 4 for memory as data, and a measuring unit 5 with a.
The measuring unit 5 is sequentially moved at a predetermined pitch along the longitudinal direction of the workpiece W (the direction of the arrow in FIG. 1), and the cross-sectional shape is measured for each portion of the workpiece W. These cross-sectional shapes are integrated to construct a cross-sectional shape of the entire workpiece W.

As shown in FIG. 1, a plurality of projectors 2a, 2b, and 2c are radially provided on the moving body 6 that sequentially moves at a predetermined pitch along the longitudinal direction of the workpiece W (in this embodiment, in a side view). In this embodiment, three projectors) are arranged, and each slit light from each of the projectors 2a, 2b, 2c is irradiated on the same line of the workpiece W from a position where the inclination angles with respect to the workpiece W are different from each other. It has become.
In addition, each of the slit lights from each of the projectors 2a, 2b, and 2c may be applied in the form of being irradiated simultaneously or sequentially. In particular, when the slit lights from the projectors 2a, 2b, and 2c are simultaneously irradiated, the slit lights from the projectors 2a, 2b, and 2c are irradiated so as to be distinguishable from each other. For example, each slit light from each projector 2a, 2b, 2c is identified by a difference in color, or each slit light is identified by a difference in dot pattern of the light beam.

The light receiver 3 is disposed at a position adjacent to the projectors 2a, 2b, and 2c of the moving body 6 and includes a CCD camera or a CMOS sensor that is a work image pickup device, and each of the projectors 2a, 2b, and 2c. Each of the reflected lights formed by reflecting the slit light on the surface of the workpiece W is received, and the brightness value of each reflected light is detected and buffered. The arrangement of the light receiver 3 is appropriately determined along the groove 6 a provided along the longitudinal direction of the moving body 6.
In addition, when each of the light projectors 2a, 2b, and 2c emits the identifiable slit light as described above, the light receiver 3 is naturally identified and irradiated from each of the light projectors 2a, 2b, and 2c. Each slit light is identified and received, and each luminance value can be detected. For example, when each slit light is identified by a color difference, the light receiver 3 is supported by a color camera and a color filter, and each light is identified and received, and each luminance value is detected. .
The light projectors 2a, 2b, 2c and the light receiver 3 are equivalent to those used in the past, and basically calculate the position (coordinates) of the surface of the workpiece W by the principle of triangulation, and determine the cross-sectional shape thereof. It is to be measured.

The first calculation processing unit 4 is built in the moving body 6 and appropriately calculates each luminance value of each reflected light transmitted from the light receiver 3, and based on one luminance value derived from the calculation result. The position (coordinates) of the irradiation part of the workpiece W is calculated according to the principle of triangulation, and the cross-sectional shape of one part of the workpiece W for one scan is stored as data. Further, the first arithmetic processing unit 4 has a function of integrating the cross-sectional shapes of the respective parts to construct the cross-sectional shape of the entire workpiece W.
The calculation method for calculating each luminance value of each reflected light in the first calculation processing unit 4 is a first calculation method that averages and outputs each luminance value of each reflected light, or each luminance value equal to or greater than a predetermined value. Either the second calculation method for extracting only the extracted values and averaging and outputting the extracted values or the third calculation method for outputting the maximum value in each luminance value is employed. In the first, second, and third calculation methods, the reflected light that exceeds the appropriate exposure amount is excluded from the calculation processing target.

Next, the operation of the workpiece cross-sectional shape measuring apparatus 1 according to the first embodiment of the present invention will be described based on the flowchart of FIG.
The measurement unit 5 (moving body 6) is stopped at a predetermined position of the workpiece W, and measurement of the cross-sectional shape of the workpiece W is started.
First, in steps S1 to S3, each slit light is sequentially irradiated onto the same line at one part of the workpiece W from each of the projectors 2a, 2b, and 2c.
Subsequently, in step S4, in the light receiver 3, each brightness value of each reflected light sequentially irradiated from each projector 2a, 2b, 2c is detected and buffered.
Subsequently, in steps S5 to S7, each luminance value of each reflected light transmitted from the light receiver 3 in the first arithmetic processing unit 4 is any one of the first, second, or third arithmetic methods described above. Based on one luminance value derived from the calculation result, the position (coordinates) of the irradiated part of the workpiece W is calculated according to the principle of triangulation, and one scan of the workpiece W is calculated. The sectional shape of the part is output and the data is stored in memory.

Next, the measurement unit 5 is sequentially moved at a predetermined pitch along the longitudinal direction of the workpiece W, and the steps S1 to S7 are repeatedly performed, and the cross-sectional shape of each part of the workpiece W is measured.
In step S8, the first arithmetic processing unit 4 integrates the cross-sectional shapes of the respective parts that are sequentially measured along with the movement of the measuring unit 5 to construct the cross-sectional shape of the entire workpiece W.

  In steps S1 to S3, the slit lights from the projectors 2a, 2b, and 2c are sequentially irradiated. However, the slit lights from the projectors 2a, 2b, and 2c may be irradiated at the same time. In the case of this form, it is preferable that each slit light from each projector 2a, 2b, 2c is irradiated so that it can be distinguished from each other. From the viewpoint of shortening the measurement time, it is preferable to irradiate the slit lights from the projectors 2a, 2b, and 2c simultaneously so that they can be distinguished from each other.

  As described above, in the first embodiment of the present invention, a plurality of slit lights are placed on the same line of the workpiece W from the positions where the inclination angles with respect to the workpiece W are made different from each other by the projectors 2a, 2b, and 2c. Are simultaneously or sequentially irradiated, each reflected light from the workpiece W is received by the light receiver 3, and each brightness value is detected. Thereafter, each brightness value of each reflected light is detected by the first arithmetic processing unit 4. The cross-sectional shape of one part of the workpiece W is measured based on one luminance value derived from the calculation result by performing the calculation process by any one of the first, second, or third calculation processing methods described above. is doing.

Thereby, even when the inclined surface 10 is present on the surface of the workpiece W and slit light from one projector, for example, the projector 2c is regularly reflected by the inclined surface 10 of the workpiece W and received reflected light exceeding the appropriate exposure amount, Data from other projectors 2a and 2b can be used, and the position (coordinates) of the portion of the inclined surface 10 can be accurately measured.
In addition, even in a region where halation does not occur, the brightness value of each reflected light from each projector 2a, 2b, 2c is appropriately processed to measure the cross-sectional shape of the workpiece W. Compared with a mode in which the cross-sectional shape is measured by the projector 2, the measurement accuracy can be improved.

Next, the workpiece cross-sectional shape measuring method according to the second embodiment of the present invention is a method of measuring the cross-sectional shape of the entire workpiece W, which has an uneven surface and a complex shape, at high speed, As shown in FIG. 3, the cross-sectional shape measuring device 1 a according to the second embodiment for embodying the method is arranged in parallel with the workpiece W and arranged along the longitudinal direction of the workpiece W. Each of the projectors 2a, 2b, and 2c that irradiate each slit light on a non-identical line of W so as to be distinguishable from each other, and each reflected light that is reflected from the slit light from each of the projectors 2a, 2b, and 2c on the workpiece W And a plurality of parts of the workpiece W by calculating positions (coordinates) of a plurality of irradiation parts based on each luminance value of each reflected light detected by the light receiver 3. Second to memorize each cross-sectional shape as data And it includes an arithmetic processing unit 4a, the measuring unit 5a having a.
The measuring unit 5a is sequentially moved at a predetermined pitch along the longitudinal direction of the workpiece W (the direction of the arrow in FIG. 3), and the cross-sectional shape is measured for each portion of the workpiece W. These cross-sectional shapes are integrated to construct a cross-sectional shape of the entire workpiece W.
In the following, each component employed in the cross-sectional shape measuring apparatus 1a according to the second embodiment will be described. In the description, the cross-sectional shape measuring apparatus 1 according to the first embodiment will be used. Differences from the respective components made will be mainly described.

As shown in FIG. 3, the projectors 2 a, 2 b, and 2 c are substantially parallel to the workpiece W and move to the moving body 6 that sequentially moves at a predetermined pitch along the longitudinal direction of the workpiece W. A plurality (three in this embodiment) are arranged at predetermined intervals along the longitudinal direction, and each slit light from each of the projectors 2a, 2b, 2c is placed on a non-identical line of the workpiece W. Irradiated.
The slit light from each projector 2a, 2b, 2c is irradiated so that it can be distinguished from each other. For example, each slit light is identified by a difference in color, or each slit light is identified by a difference in dot pattern of the light beam. Identifying.

  On the other hand, the light receiver 3 is disposed at a position adjacent to each of the projectors 2a, 2b, and 2c of the moving body 6, and identifies each slit light that is radiated from each of the projectors 2a, 2b, and 2c. And configured to be able to detect each luminance value. For example, when each slit light is identified by a color difference, the light receiver 3 is supported by a color camera and a color filter, and each light is identified and received, and each luminance value is detected. .

  The second calculation processing unit 4a is built in the moving body 6 and calculates the positions of a plurality of irradiation parts by the principle of triangulation based on each luminance value of each reflected light received by the light receiver 3. In addition, each cross-sectional shape of a plurality of parts of the work W is stored as data, and each cross-sectional shape of each part is integrated to construct a cross-sectional shape of the whole work W.

Next, the operation of the workpiece cross-sectional shape measuring apparatus 1a according to the second embodiment of the present invention will be described with reference to the flowchart of FIG.
The measurement unit 5a (moving body 6) is stopped at a predetermined position of the workpiece W, and measurement of the cross-sectional shape of the workpiece W is started.
First, in steps S1a to S3a, slit lights that can be distinguished from each other from the projectors 2a, 2b, and 2c are simultaneously irradiated onto non-identical lines in a plurality of parts of the workpiece W.
Subsequently, in step S4a, the light receiver 3 identifies each reflected light from each of the projectors 2a, 2b, 2c, and detects and buffers each luminance value.
Subsequently, in steps S5a to S7a, in the second arithmetic processing unit 4a, the positions of a plurality of irradiation sites of the workpiece W are determined based on the triangulation principle based on the brightness values of the reflected lights transmitted from the light receiver 3. (Coordinates) are calculated, and cross-sectional shapes of a plurality of parts of the work W are output for one scan, and each data is stored in memory.

Next, the measuring unit 5a is sequentially moved at a predetermined pitch along the longitudinal direction of the workpiece W, the steps S1a to S7a are repeatedly performed, and the cross-sectional shape of each part of the workpiece W is measured.
In step S8a, in the second arithmetic processing unit 4a, the cross-sectional shapes of the respective parts sequentially measured along with the movement of the measuring unit 5 are integrated to construct the cross-sectional shape of the entire workpiece W.

  In steps S1a to S3a, each slit light from each of the projectors 2a, 2b, and 2c may be sequentially irradiated. However, from the viewpoint of shortening the measurement time, each slit light is simultaneously irradiated as in the present embodiment. Is preferred.

As described above, in the second embodiment of the present invention, a plurality of projectors 2a, 2b, 2c are arranged in the measurement unit 5a so as to be substantially parallel to the workpiece W and along the longitudinal direction of the workpiece W. In addition, each of the light projectors 2a, 2b and 2c irradiates each slit light onto non-identical lines of a plurality of parts of the workpiece W so that they can be distinguished from each other. At the same time, each brightness value is detected, and the second arithmetic processing unit 4a measures each cross-sectional shape of a plurality of parts of the workpiece W based on each brightness value.
As a result, while the measurement unit 5a is stationary, the cross-sectional shape of the N portions corresponding to the N projectors of the workpiece W can be measured, and the measurement unit 5a can be stationary as in the past. The number of times that the measurement unit 5a is stationary and measured is 1 / N times compared to a configuration in which only one cross-sectional shape of the workpiece W can be measured by one projector 2, while the entire workpiece W is measured. The measurement time for measuring the cross-sectional shape can be shortened compared to the conventional case. Furthermore, since each slit light is simultaneously irradiated from each projector 2a, 2b, 2c, further time reduction is achieved.

  Moreover, in the second embodiment of the present invention, each slit light from each of the projectors 2a, 2b, 2c is irradiated so as to be distinguishable from each other. Each reflected light from each light projector 2a, 2b, 2c can be identified correctly, and the cross-sectional shape of each irradiation part of each slit light can be measured accurately.

FIG. 1 is a schematic diagram of a cross-sectional shape measuring apparatus that embodies a cross-sectional shape measuring method for a workpiece according to a first embodiment of the present invention. FIG. 2 is a flowchart of the method for measuring the cross-sectional shape of the workpiece according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a cross-sectional shape measuring apparatus that embodies a cross-sectional shape measuring method for a workpiece according to a second embodiment of the present invention. FIG. 4 is a flowchart of the method for measuring the cross-sectional shape of the workpiece according to the second embodiment of the present invention. FIG. 5 is a schematic diagram showing a general method for measuring the cross-sectional shape of a workpiece. FIG. 6 is a schematic diagram for explaining the first problem in the conventional method for measuring the cross-sectional shape of a workpiece. FIG. 7 is a schematic diagram for explaining a second problem in the conventional method for measuring the cross-sectional shape of a workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Section shape measuring device, 2a, 2b, 2c Emitter, 3 Light receiver, 4 1st arithmetic processing part, 4a 2nd arithmetic processing part, 5, 5a Measuring unit, W work

Claims (3)

  A plurality of slit lights are irradiated on the same line of the workpiece from positions where the inclination angles with respect to the workpiece are different from each other, and each cross-sectional shape of the workpiece is measured by calculating each luminance value of each reflected light from the workpiece. A method for measuring a cross-sectional shape of a workpiece, characterized in that   2. The method for measuring a cross-sectional shape of a workpiece according to claim 1, wherein each of the slit lights is irradiated so as to be distinguishable from each other. A plurality of projectors arranged substantially parallel to the workpiece and along the longitudinal direction of the workpiece, and each projector that irradiates each slit light on a non-identical line of the workpiece so as to be distinguishable from each other, and each reflected light from the workpiece is identified. A cross-sectional shape measurement method for a workpiece, comprising: measuring a cross-sectional shape of the entire workpiece by sequentially moving a measurement unit including a light receiver for receiving light along the longitudinal direction of the workpiece.

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