JPS63108204A - Size measuring method - Google Patents

Abstract

PURPOSE:To accurately take a measurement of size even if respective cameras have different visual fields in case of the use of the plural cameras by inputting visual field correction data on sensors of the cameras and calibrating the actual measured size with the data. CONSTITUTION:A reference gauge 3 which is installed on a measurement reference surface 1 and has its X-directional size determined is irradiated with luminous flux D, the boundary between binarization black and white bits is extracted by arithmetic operation, and the visual field correction data on the sensors are calculated by arithmetic operation based on the relation between the extracted data and the determined size of the reference gauge 3 and stored in a memory 18 for the correction data. A body to be measured is irradiated with the luminous flux D, the boundary between binarization black and white bits is calculated as size data indicating the size of the irradiated part of the body to be measured, and the size of the object body is calculated by arithmetic operation based on the visual field correction data and outputted. Consequently, even if the cameras having deviation in the size (resolution) of a visual field, the influence of it is eliminated and the size is accurately measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dimension measuring method for measuring the dimensions of a stationary or moving object in a non-contact manner.

[Conventional technology]

Conventionally, as a non-contact dimension measurement method, a two-dimensional sensor, etc., in which the object to be measured is irradiated with slit illumination light whose light beams are parallel to each other and formed flat, and at least one camera has this irradiation point, etc. A so-called optical cutting method is known in which the dimensions of an object to be measured are calculated by taking an image with a two-dimensional sensor and calculating the output signal from the two-dimensional sensor.

[Problem that the invention seeks to solve]

However, since the measurement accuracy of this optical cutting method is not sufficiently high in practice, its use has been limited. Therefore, the inventor of the present invention conducted intensive research to find the cause of the lack of measurement accuracy, and as a result, it was found that the cause was on the camera side having the sensor.

In other words, one camera or several cameras may be used together.
Cameras are formed with lenses that have a predetermined f-number, but even if the cameras are manufactured in the same way by the same manufacturer, the f-number of the lens will vary slightly, and the camera It was found that the performance of the cameras varied, and furthermore, the distance from the measurement point to the camera lens varied depending on the direction in which the camera was mounted and the degree of mounting.

These variations cause a problem in that the field of view of the camera differs, and the resolution of the sensor also differs accordingly, making accurate measurement difficult.

[Means for solving problems]

The present invention is a one-dimensional camera that irradiates a reference gauge, which is installed on a measurement reference plane and has a determined dimension in the Projected onto a sensor or two-dimensional sensor,
After slicing the analog signal from this sensor using an arbitrary threshold voltage, dividing it into black and white bits, and converting it into binary data, the boundary between the binary black and white bits is extracted by calculation, and this extracted data is combined with the above reference gauge. The field of view correction data of the sensor is calculated based on the relationship with the determined dimensions and stored in the correction data memory, and then the object to be measured is irradiated with a beam of light, and the irradiated area is directed to the sensor. After projecting and slicing the analog signal from this sensor using an arbitrary threshold voltage and dividing it into black and white bits and binarizing it, the boundary of the binarized black and white bits is calculated to determine the irradiated location on the object to be measured. , and the dimensions of the object to be measured are calculated and output based on this dimension data and field of view correction data of the sensor stored in the memory. .

[Effect]

The measuring method and device equipped with the above-mentioned solving means installs a reference gauge on a measurement reference surface before starting measurement or temporarily suspends measurement, and irradiates the reference gauge on this reference surface with light from a light source. Then, the irradiated area is projected onto the camera sensor. Then, the analog signal from this sensor is divided into white bits and black bits with a threshold voltage as the boundary, and then binarized. Since the black and white bits binarized in this way are considered to be arranged in a matrix on the Panzer memory, next we need data indicating the boundaries of the black and white bits, that is, the X of the irradiated area on the reference gauge. After extracting the dimension along the direction by calculation,
Based on this extracted data and the dimensions specified in the reference gauge, we can determine how many meters actually corresponds to one bit within the field of view in the X direction of the sensor.
The field of view correction data corresponding to 2iIi is calculated and the data is taken into the correction data memory. The visual field correction data taken into this memory is stored until new visual field correction data is taken in thereafter. Thereafter, the object to be measured is irradiated with a light beam, and the irradiated location is projected onto the sensor. Then, after converting the analog signal from the sensor into black and white bits using the threshold voltage as the boundary,
The boundary between the black and white bits, that is, dimension data indicating the dimensions of the irradiated area on the object to be measured is extracted by calculation. Finally, the dimensions of the object to be measured are calculated based on this dimension data and the visual field correction data stored in the correction data memory. As described above, the field of view correction data of the sensor is imported using the reference gauge, and the actual measured dimensions are calibrated using this data. It is possible to eliminate the discrepancy between the camera's performance, such as the f-number, described in the specifications of the purchased camera and the actual field of view. In addition, when dividing the object to be measured into parts and photographing them using multiple cameras, even if there is a discrepancy in the field of view (size or resolution) of each camera, this effect can be eliminated and the dimensions can be accurately captured. Can be measured.

〔Example〕

First, an example of an apparatus for carrying out the method of the present invention will be explained with reference to FIGS. 1 to 10.

Reference numeral 1 in FIGS. 1 and 4 to 8 indicates a measurement reference surface, which is formed by, for example, the flat upper surface of a measurement table 2 fixedly or removably installed at a measurement location. A reference gauge 3 is removably installed on this reference surface 1, and an object to be measured 4 (see FIG. 8) is also removably installed. Note that when the object to be measured 4 is a moving object, the top of a roller or the like that guides its movement is placed on the measurement reference surface 1.
You can also use it as

The reference gauge 3 has two dimensions A and B determined along the X direction (lateral direction), and a dimension C along the Y direction (I direction) as required. , has an uneven shape as shown in FIG.

The object to be measured 4 includes a continuously moving strip-shaped object, such as an extruded tire tread, a weather strip for a window of a vehicle, an extruded material such as an aluminum alloy, a drawn material of metal, and a metal or resin medium. Various objects to be measured may be used, such as real wood, shaped steel, pressed A4 plates, bent steel plates, discontinuous synthetic resin molded products, and wooden objects. Further, the object to be measured 4 does not need to be moved on the measurement reference plane 1.

A floodlight 5 is disposed above the measurement reference plane 1 . The projector 5 is formed with at least one, for example, five, light sources 6 such as halogen lamps, and the light beams from the plurality of light sources 6 are transmitted through, for example, slits and lenses provided in the projector 5 to a flat surface. It is controlled to have a flat surface, and the flat surface crosses the measurement reference surface 1, so that each part of the measurement reference surface 1 is dividedly illuminated in the width direction.

Each light source 6 is connected to a dimming means 7, and by changing the voltage applied through this means 7, the brightness is automatically controlled according to the photographing level that varies depending on the object to be measured 4. In addition, through this control, it is determined by an AND circuit (not shown) that all cameras 9, which will be described later, have reached the appropriate shooting level, and when the AND is established, an output is output from the sensor 11 of each camera 9. It is configured.

Further, a light receiver 8 is disposed above the measurement reference plane 1 . The light receiver 8 consists of one or more cameras,
In the case of this embodiment, it is formed of seven cameras 9 and a synchronization signal generation circuit 10 that supplies synchronization signals to these cameras. The camera 9 has a built-in one-dimensional or two-dimensional sensor, and in this embodiment, the camera 9 has a built-in 244 x 320 bit MOS area array sensor (two-dimensional sensor).

These cameras 9 are for dividing and photographing the object 4 on the measurement reference plane 1 into each part, and by such divided photography, the entire object 4 to be measured can be photographed with only one camera 9. The resolution is improved compared to when Further, the photographing level of each camera 9 is fed back to the light source 6 via the light control means 7.

As shown in FIG. 1, the projector 5 and the camera 9 are connected to a perpendicular F made at the intersection of the optical axis of the light beam from the light source 6 and the optical axis E of the camera 9 on the object to be measured 4.
The optical axis of the light beam is tilted by α0, and the optical axis E of the camera 9 is tilted by β0, and these angles are respectively (45
±20) 0. Note that it is more desirable that α+β be 90°. In addition, instead of the light control means 7, each camera 9 is equipped with an automatic aperture mechanism, and this mechanism automatically controls the aperture to an appropriate value according to the photographing level that varies depending on the object to be measured 4. In addition, it is determined by an AND circuit (not shown) that all the cameras 9 have reached the appropriate shooting level through this control, and the AND circuit is used.
It may be configured such that the sensor 11 of each camera 9 outputs the output when the following is established.

The output end of each drive mechanism (not shown) that raster scans the sensor 11 of each camera 9 is connected to a sensor selector 12.
It is connected to the binarization means 14 built into the processing device 13 via the processing device 13 . The processing device 13 is provided with the binarization means 14, a buffer memory 15, an error erasure means 16, a boundary extraction means 17, a correction data memory 18, and a dimension correction means 19. It has been realized.

The binarization means 14 is configured to slice the analog signal from the sensor 11 using an arbitrary threshold voltage and divide it into black and white bits. Then, the binarization means 14 of the embodiment converts the analog output signal G from the sensor 11 as exemplified by the 9th @ middle upper waveform for each raster (in addition, in this embodiment, the sensor 11 has a two-dimensional The maximum voltage value VH and the minimum voltage value VL are determined for each raster (from one to more than ten rasters), and approximately 1/2 of these values VH and VL, that is, 1
/2±15% voltage value as threshold voltage sv (L
With this voltage, the analog signal from the sensor 11 related to the raster for which the same voltage was obtained or the next raster is sliced and divided into black and white bits as illustrated by the lower waveform in Fig. 9. It is designed to be binarized.

Such a binarization means 14 is a consideration for more reliable binarization regardless of light unevenness. Moreover, the reason why each raster is set to within one to ten or more in this example is based on empirical confirmation, and when using more than that number of rasters, the reliability of binarization is not practical. This is due to the fact that the above level has deteriorated to the extent that it causes problems. Note that this binarization means 14 may be replaced with a logic circuit consisting of an analog processing circuit, in which case the processing speed can be further increased.

The buffer memory 15 stores the binary data obtained as described above, and errors in the stored binary data are erased by the error erasing means 16. This means 16 stores black data b1 that is adjacent on both sides to a plurality of white bits (for example, within 10 bits) data in the black and white bit storage state illustrated in the upper part of FIG. ) If the data has white data b2 adjacent on both sides, these data b
1, b2 are determined to be error data and are assimilated into the data adjacent on both sides as shown in the black and white bit storage state illustrated in the lower part of FIG. be. By erasing this error, 2
This eliminates errors in the valued data, and the outline of the object to be measured 4 obtained as described later can be made clearer.

Note that this means 16 may be omitted if necessary.

Since the binarized data can be considered to be arranged in a matrix in the buffer memory 15, the boundary extracting means 17 detects the boundary between the black and white bits in this matrix, that is, the reference gauge 3 and the object to be measured 4. This means is configured to extract, by calculation, the dimensions of the irradiated locations that intersect at right angles. Further, this extraction means 17 extracts the reference gauge 3 which has been input in advance into the correction data memory 18 using the external keyboard 21.
The standard dimensions determined in (dimensions A and B).

C) and the dimension measurement data of the reference gauge 3 extracted by the above calculation, the field of view correction data of the sensor 11 is determined by calculation. Note that the functions for calculating the correction data for the field of view X-direction overlap and Y-axis direction below may be omitted, but in this example, the cross-sectional shape is also measured based on the dimensions of the object to be measured. The extraction means 17 extracts the dimension measurement data of the reference gauge 3 extracted by the above calculation and the reference dimensions (dimensions A, B, C) determined for the reference gauge 3 inputted in advance from the external keyboard 21. Based on the relationship, it is configured to calculate correction data for overlap in the field of view in the X direction of adjacent sensors 11 by calculation, and also calculates the relationship between the extracted data and the reference in the Y direction for each sensor 11. By calculation, each sensor 11
It is also configured to calculate Y-direction correction data.

Each of the above correction data is stored in the correction data memory 18.
Each of these correction data is stored until new correction data is stored.

Further, the workpiece q extracted by the boundary extraction means 17
Data indicating the dimensions of the irradiated portion of the fixed object 4 is taken into the dimension correction means 19.

This correction means 19 calculates the dimensions of the object to be measured 4 based on the captured data and the correction data stored in the correction data memory 18, and outputs it to the outside. It is configured as follows. The output end of the correction means 19 is connected to at least one of a printer 22, a monitor television 23, and a recording disk 24 such as a magnetic disk, which are provided outside the processing device 13. The monitor television 23 receives signals from the sensors 11 built into each camera 9 of the light receiver 8, 21B conversion data, and data output from the dimension correction means 19.
It is designed to be selectively input by a switching means (not shown).

The apparatus having the above configuration measures the dimensions of the object to be measured 4 in the order shown in FIGS. 11 and 12. In addition,
Since this embodiment uses a two-dimensional sensor 11, the cross-sectional shape is also measured at the same time.

That is, in step 1, each light source 6 of the projector 5 is turned on to irradiate the measurement reference surface 1 with a beam of light having a flat surface as shown in FIG. 7 so as to cross the measurement reference surface 1.

In step 2, the reference position of the sensor 11 of each camera 9 of the light receiver 8 in the Y direction is determined. This decision is made through the following steps (1) to (2). ■First, each sensor 1 on which the irradiated area of the measurement reference surface 1 is projected
1 drive mechanism is operated to raster scan each sensor 11 and output an analog signal. (2) These nine analog signals pass through the sensor selector 12 and are input to the binarization means 14 for each sensor 11 in turn. (2) The binarization means 14 determines the maximum voltage value VH and minimum voltage value VL for each rask with respect to the input analog signal, and approximately 1 of these values.
/2 is set as the threshold voltage S■, and the above analog signal is sliced with this voltage Sv, and the part where the light hits the measurement reference surface 1 becomes a white bit, and the part where the light hits the measurement reference surface 1 is set as a white bit. The parts that are not marked are divided into black bits and binarized. (2) This binary data is stored in the buffer 7 memory 15, and (2) the error data is corrected by the error erasing means 16 and then input to the boundary extracting means 17. ■This means 17 extracts the boundary between black and white pits (that is, in this case, the boundary 1it of light on the measurement reference plane 1 shown in FIGS. 7 and 8), and then The distance between an arbitrary pixel m (for example, the lowest raster) corresponding to one screen of a monitor television set is calculated. By this calculation, each sensor 1
1 reference position in the Y direction, that is, the correction data y in the Y direction
1 is obtained, and this correction data v1 is stored in the correction data memory 18.
is stored in Therefore, as shown in FIG. 8, the dimension y2 of the object to be measured 4 on the measurement reference plane 1 in the Y direction is
In the two-dimensional image captured by 1, the reference position and the object to be measured 4
By setting Y as the dimension between , it can be calculated using the formula V2-Y-Vl.

In step 3, the reference gauge 3 is placed on the upper surface of the measurement reference surface 1. Thereby, the process moves to step 4, and the reference gauge 3 is measured by the optical cutting method. This measurement is performed through steps 13 to 19 shown in FIG. That is, first, in step 13, each sensor receives light at the irradiated location of the reference gauge 3 (in other words, the irradiated location is imaged). Then, by operating the drive mechanism of each sensor 11, each sensor 1
1 is raster scanned and an analog signal is output. In step 14, the analog signal is input to the binarization means 14 for each sensor 11 in sequence through the sensor selector 12. In step 15, the input analog signal (that is, the two-dimensional video signal) is converted into a binary signal by the binarization means 14 to determine the maximum voltage value VH and minimum voltage value VL for each rask, and calculate these values. Approximately 1/2 of the voltage is set as the threshold voltage S, and this voltage S
The analog signal is sliced at V, and the portions where the reference measurement surface 1 is illuminated are treated as white bits, and the portions where the reference measurement surface 1 is not illuminated are divided into black bits and binarized. In step 16, the binarized data is stored in the buffer memory 15. And in step 17,
The above steps 15 and 16 are repeated for each sensor 11 analog signal input by the sensor selector 12. Thereafter, in step 18, error data regarding the binarized data stored in the buffer memory 15 is corrected by the error erasing means 16. Finally, in step 19, the boundary extraction means 17 extracts the binarized data corresponding to one screen of the monitor television stored in the buffer 7 memory 15 from the boundaries of black and white bits (in this case, the bottom of the concave part and the convex part in the reference gauge 3). , and the vertical boundary connecting these bottom and top surfaces).

Step 4 is executed above, and then the process moves to step 5 to obtain visual field correction data for each sensor 11. This data is calculated by the boundary extraction means 17. That is, in this case, the two-dimensional image of the reference gauge 3 captured by the sensor 11 is as shown by diagonal lines in FIG. 4, and the actual measured dimension in the X direction of the bottom of the recess in this image is H.
bit, and the actual measured dimension in the Y direction of the vertical boundary is I
Suppose it is a bit. In FIG. 3, if the resolution of the field of view of the sensor 11 at the left end is J bits in the X direction and bits in the Y direction on the two-dimensional image in the buffer memory, then the above calculation formula can be used to calculate the Visual field correction data for the leftmost sensor 11 is calculated.

Visual field correction data in the X direction x 1 -B/H (m/bit) Visual field correction data in the Y direction Y1 = C/I (ax/m/bit) Therefore, the X direction of the leftmost sensor 11, and the Y
The field of view in the direction is calculated by the following P14 formula.

The visual field in the X direction - JXB/H (am/bit) The visual field in the Y direction - KXC/I (m/bit) The visual field correction data Xi and Y1 obtained by the above calculation are stored in the correction data memory 18. Ru. This visual field correction data is obtained for the visual fields (1) and (2) of each sensor 11, respectively, and stored in the memory 18.

Thereafter, step 6 is carried out to obtain correction data for the overlap in the visual field X direction indicated by L in FIG. This data is calculated by the boundary extraction means 17. In other words, field of view overlap occurs when one of the adjacent sensors 11 captures the two-dimensional image in step 4 as shown in FIG. 5, and the other adjacent sensor 11 captures the two-dimensional image in step 4 above. If the two-dimensional images were as shown in FIG. 6, in these figures the (M1+N2-L) bit is equal to the dimension (A+8)#I of the reference gauge in the X direction. Here, Ml is the length obtained by subtracting the image length N1 of the non-overlapping convex portion from the total length 01 in the X direction of the two-dimensional image of the reference gauge 3 in the field of view located on the left side of the adjacent field of view, and M2 is L is the image length of the convex portions that overlap in the X direction in the two-dimensional image of the reference gauge 3 in the field of view located on the right side of the adjacent field of view, and L is the overlap dimension.

Therefore, overlap correction data L for these adjacent visual fields is calculated using the following equation.

L (bit) −(M1+N2)−(A+B)/X1 Then, the visual field overlap correction data L obtained by the above calculation is stored in the correction data memory 18.

This correction data L is obtained for each adjacent sensor 11 and stored in the memory 18.

Through steps 1 to 6 described above, storage of correction data regarding the dimension in the Y direction, field of view, and field of view overlap of each camera 9 is completed, and immediately after that, the process moves to step 7 to start measurement. Then, the apparatus is switched from the calibration mode to the measurement mode, and in step 8, the object to be measured 4 is placed on the measurement reference surface 1, and measurement is started. At the start of measurement, each light source 6 of the projector 5 is turned on, so that a beam of light having a flat surface is made to cross the measurement reference surface 1 on which the object to be measured 4 is placed, as shown in FIG. Then, step 9 is performed.

In the next step 10, steps 13 to 19 are repeated. The dimension data indicating the dimensions of the object to be measured 4 extracted in this step 10 is output to the dimension correction means 19 which carries out the next step 11 without being stored in the correction data memory 18. In step 11, the dimension correction means 19 calculates the dimension of the object to be measured 4 in the X direction based on the dimension data input thereto and various correction data stored in the memory 18. In addition, since the dimension correction means 19 in this embodiment also calculates the actual thickness dimension d1 of the object to be measured 4 in the Y direction based on the above-mentioned data, the cross-sectional shape can be calculated using both these X and Y dimensions. do. The actual thickness dimension d1 in the Y direction is calculated by the formula dl - (Y-yl> XB/I (alI). In this formula, Y, Vl,
and dl are shown in FIG.

The dimensions of the object 4 thus calculated and the cross-sectional shape obtained by recognizing the pattern of the actual thickness dimension d1 in the Y direction of the object 4 are printed on the printer 22, the monitor television 23, and the recorder by executing step 12. It is output to an external device such as the disk 24.

That is, the object to be measured is measured as described above.

In the above measurements, by importing the field of view correction data of each sensor 11 and calibrating the actual measured dimensions with this data, f@ of the camera 9 written in the instruction manual of the camera 9 purchased, etc. It is possible to eliminate the discrepancy between the performance and the actual field of view. Furthermore, even if there is a difference in the size of the field of view (that is, the resolution of each) of the plurality of cameras 9,
Regardless, since the field of view can be calibrated and measured, accurate measurements can be made.

Although the above embodiment is configured as described above, when implementing the present invention using only one camera, the sensor selector 12 may be omitted, and the sensor selector 12 may be omitted.
The measurement may be carried out by omitting steps 5, 14 and 17 above.

Further, the present invention can be implemented by omitting the error erasing means 16 and the step 18 for executing the error erasing means 16,
In that case, step 19 should be replaced with step 15 and step 1.
It may be implemented between 6 and 6.

Furthermore, in the present invention, if the position and orientation of each sensor 11 are manually adjusted accurately beforehand before measurement is performed, steps 2 and 6 may be omitted. .

Note that the present invention may be implemented by controlling the laser light to slit light and emitting it, and by using an ITV for the camera.

In addition, in the above embodiment, the camera receives reflected light, but the light source and camera are arranged on opposite sides of the object to be measured so that the camera receives transmitted light. Alternatively, the measurement may be performed by In this case, irradiation is performed with a normal light beam that does not have a flat surface.

Furthermore, the present invention may be implemented using a one-dimensional sensor such as an image sensor as a camera sensor. in this case,
A one-dimensional sensor is used instead of the two-dimensional sensor of the above embodiment, and step 2 of the above embodiment is omitted, and of course the dimension correction means has the function of calculating the cross-sectional shape. The present invention is carried out using the same apparatus configuration and measurement order as in the above-mentioned embodiment, except that the present invention is not equipped with the above-mentioned equipment. When using the -dimensional sensor in this way, the field of view of multiple adjacent sensors is shown in Figure 13, and the reference gauge (same configuration as shown in Figure 2) taken by the -dimensional sensor is shown in Figure 13. ) is shown in FIG. 14, so the X direction H field data X1 is X 1-8
The field of view in the X direction is calculated using the formula JXB/H. The one-dimensional images captured by adjacent one-dimensional sensors when there is overlap in the field of view in the X direction are shown in FIGS. 15 and 16, respectively.
As shown in the figure, (M1+N2-L
) bit is equal to the dimension 1 (A+8) of the reference gauge in the X direction, so that the correction data L for the overlap in the
+8)/Xi. Therefore, the dimension correction circuit corrects the dimension data of the object to be measured using the above correction data to calculate the actual dimension in the X direction.

In addition, it goes without saying that the present invention is not limited to the one embodiment described above, and can be implemented in various configurations as long as it does not go against the gist of the invention.

〔Effect of the invention〕

In the present invention, which has the gist of the configuration described in the claims, the field of view correction data of the camera sensor is taken in,
By calibrating the actual measured dimensions using this data, it is possible to eliminate the discrepancy between the performance of the camera, such as the f-number, described in the specifications of the purchased camera and the actual field of view, and also to avoid using multiple cameras. When carrying out measurements, dimensions can be accurately measured even if the field of view of each camera is different.

[Brief explanation of the drawing]

1 to 12 show one embodiment of the present invention, FIG. 1 is a block diagram showing the structure of the light cutting section, FIG. 2 is a perspective view of a reference gauge, and FIG. Figures showing the state of the field of view of the dimensional sensor, Figures 4 to 6 are diagrams showing two-dimensional images of different reference gauges captured by the two-dimensional sensor, and Figure 7 is a diagram showing the state of the measurement reference plane being irradiated with a light beam. A perspective view showing the state, FIG. 8 is a diagram showing a two-dimensional image of the object to be measured captured by the two-dimensional sensor, FIG. 9 is a waveform diagram showing the relationship between analog signal and binary data, and FIG. 10 11 is a flow chart showing the measurement step, and FIG. 12 is a flow chart showing the optical meter sub-step. Fig. 13 is a diagram showing the field of view of a plurality of adjacent one-dimensional sensors when the present invention is implemented using one-dimensional sensors, and Figs. It is a figure showing an original image. 1...Measurement reference plane, 3...Measuring gauge, A, B, C
...Dimensions determined on the measuring gauge, D... Luminous flux, 6
... Light source, 11 ... Sensor, 14 ... Binarization means, 15 ... Buffer memory, 17 ... Boundary extraction means, 18 ... Memory for correction data, 19 ... Dimension correction means. Applicant's representative Patent attorney Takehiko Suzue No. 1 Figure 2 In I

Claims (1)

[Scope of Claims] A camera that irradiates a reference gauge that is installed on a measurement reference plane and whose dimensions in the X direction are determined, and that places the irradiated area on the irradiation surface side or on the opposite side of the irradiation surface. After projecting onto a one-dimensional sensor or two-dimensional sensor, slicing the analog signal from this sensor using an arbitrary threshold voltage, dividing it into black and white bits, and binarizing it, the boundaries of the binarized black and white bits are determined by calculation. The field of view correction data of the sensor is calculated by calculation based on the relationship between this extracted data and the dimensions determined for the reference gauge, and the data is stored in the correction data memory. The irradiated area is projected onto the sensor, and the analog signal from this sensor is sliced at an arbitrary threshold voltage, divided into black and white bits, and binarized. The boundary is extracted as dimensional data indicating the dimensions of the irradiated part of the object to be measured by calculation, and the dimensions of the object to be measured are calculated based on this dimensional data and the field of view correction data of the sensor stored in the memory. A dimension measurement method characterized by calculating and outputting the result by calculation.