JPH11108625A - Surface shape measuring apparatus - Google Patents

Surface shape measuring apparatus

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Publication number
JPH11108625A
JPH11108625A JP9290290A JP29029097A JPH11108625A JP H11108625 A JPH11108625 A JP H11108625A JP 9290290 A JP9290290 A JP 9290290A JP 29029097 A JP29029097 A JP 29029097A JP H11108625 A JPH11108625 A JP H11108625A
Authority
JP
Japan
Prior art keywords
object
measured
interference
information
surface shape
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP9290290A
Other languages
Japanese (ja)
Inventor
Masaharu Okabe
正治 岡部
Original Assignee
Canon Inc
キヤノン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc, キヤノン株式会社 filed Critical Canon Inc
Priority to JP9290290A priority Critical patent/JPH11108625A/en
Publication of JPH11108625A publication Critical patent/JPH11108625A/en
Granted legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To measure, with high precision, the dimension of an object to be measured in the transversal direction, by obtaining the image information of a state that interference fringes are not formed on the object to be measured, and obtaining the information of the object to be measured in the transversal direction, by using an image processing means. SOLUTION: The luminous flux of a halogen lamp 17 is divided by a beam splitter 14. One part is reflected, passes through an objective 13, and inadiated an object k to be measured. The other part permeates the splitter, passes through an objective lens 15, and enters reference mirror 16. Reflected luminous fluxes on the respective surfaces are superposes again with each other by the beam splitter 14, and an interference image light is generates. The interference image light forms an image on the light receiving surface of a CCD camera set at the imagery position of the objective lens 13. A control computer 20 controls the driving of the vertical direction (the optical axis direction of the objective lens 13) on a precise stage 11, and changes the position of an object K. A plurality of interference images from the CCD camera 18 at each position of the object K to be measure are analyzed. and the solid form of the object K to be measured is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface shape measuring apparatus, which is suitable for inspecting, for example, an object having a complicated and fine structure, for example, a three-dimensional shape of a head of an ink-jet printer, using white light interference. The present invention relates to a simple surface shape measuring device.

[0002]

2. Description of the Related Art In recent years, manufacturing techniques such as molding and laser processing have been improved, and resin products having various shapes with submicron shape accuracy can be mass-produced. The processing shape of such a resin product also has a larger dimension in the depth direction than in the vertical and horizontal directions, and the measurement accuracy required for evaluating the shape of the processed product has been increasing.

A surface shape measuring device for measuring the three-dimensional shape of such a minute product (object) using white light interference has been proposed.
For example, the present applicant has proposed this in Japanese Patent Application No. 8-242609.

In the same publication, a white light source, a two-beam interference optical system for superposing and interfering a light beam from an object to be measured and a reference surface, an image pickup means for picking up an interference image, a two-beam interference optical system, A shape comprising moving means for relatively changing the distance between objects, image signal processing means for detecting interference fringes, and means for measuring the shape of an object to be measured by the interference fringes obtained by the image signal processing means A measuring device is proposed.

[0005] In particular, in the shape measuring device proposed in the same publication, the stage is moved in the height direction, and interference fringes of white light interference are detected for each pixel of the CCD camera by a change in light amount.
The measurement result is output as the height information of the work part corresponding to the pixel with the stage position where the change in the light amount becomes the maximum, and when the change in the light amount is equal to or less than a predetermined reference, the determination that measurement is impossible is output.

[0006]

In a surface shape measuring apparatus using a white light source, when the shape of an object to be measured is to be obtained only from interference fringe information, the height information of the object to be measured must be accurately obtained. it can. However, the detection of the measurement object in the horizontal direction is deteriorated because the amplitude of the interference fringes is more sensitive to the slight reflected light from the work than the normal resolution of the objective lens forming the detection system.

Therefore, the interference fringe signal is detected even outside the beam spot diameter in the light amount of the condensed spot of the objective lens. Therefore, the spot diameter at which interference fringes can be detected is larger than the beam spot diameter with respect to the light amount,
Lateral resolution decreases. As a result, when measuring the two-dimensional dimension of the measurement object, there has been a problem that the width in the lateral direction is measured wider than the actual one or the accuracy of the position is deteriorated.

According to the present invention, when measuring the three-dimensional shape of an object to be measured in the vertical direction, the horizontal direction, and the depth direction using interference, it is not possible to accurately measure the interference fringes alone. It is an object of the present invention to provide a surface shape measuring device capable of measuring a dimension of a measured object in a horizontal direction (longitudinal direction) with high accuracy.

Another object of the present invention is to provide a surface shape measuring apparatus capable of removing invalid data and measuring with high accuracy, particularly when measuring the depth direction of an object to be measured using interference. For the purpose of providing.

[0010]

The surface shape measuring apparatus according to the present invention comprises: (1-1) an interferometer which guides light emitted from a light source to an object to be measured and a reference surface, and interferes light beams from both. System, imaging means for imaging the interference information obtained by the interference optical system,
An image processing means for obtaining a surface shape from the object by using a signal from the imaging means, wherein the image information in an interference fringe non-formed state in which no interference fringes are formed on the object to be measured. Image acquisition means for obtaining the size of the object to be measured from the image information in the non-interference fringe non-formed state by the image processing means.

In particular, (1-1-1) the image obtaining means obtains the interference fringe non-formed state by adjusting the relative position of the interference optical system and the object to be measured in the optical axis direction. .

(1-1-2) The image obtaining means obtains a state in which no interference fringes are formed by using shutter means provided on a reference optical path of the interference optical system.

(1-1-3) The image acquisition means sets the interference fringe non-formed state from the interference state in which the light beam from the object to be measured and the light beam from the reference surface interfere with each other in both optical axis directions. And image data based on the area where the interference fringes are not formed is selected and obtained for each of a plurality of pixels of the imaging means.

(1-1-4) The lateral dimension information of the object to be measured is obtained by using a predetermined edge and a center of gravity of a luminance distribution in image information formed on the imaging means surface. . (1-
1-5) The light emitted from the light source is white light.

(1-1-6) To obtain validity / invalidity information of surface shape data for each pixel based on image data in a state where no interference fringes are formed. And so on.

(1-2) a first step of obtaining shape information of the object to be measured along a predetermined axial direction from information of the obtained interference fringes when an interference fringe is generated by light passing through the object to be measured. And a second step of obtaining a shape of the object to be measured in a direction perpendicular to the predetermined axis direction from video information of the object to be measured without interference fringes.

In particular, (2-1-1) the second stroke is a signal at a position different in the predetermined direction by a predetermined distance from the generation range of the interference fringes generated at the time of executing the first stroke. To be performed by obtaining intensity data.

(2-1-2) The second step is performed in a state where the interference fringes are not generated. And so on.

(2-2) When interference fringes are generated by light passing through the object to be measured, and when the surface shape information of the object to be measured is obtained based on the information of the obtained interference fringes, the interference fringes in a state where no interference fringes are present. It is characterized in that validity or invalidity of each part of the surface shape information is determined based on luminance information of each part of the device under test.

The storage medium of the present invention is characterized by storing a program for executing the surface shape measuring method of (3-1) Configuration (2-1) or Configuration (2-2).

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment of a surface shape measuring apparatus according to the present invention. In FIG. 1, reference numeral 10 denotes a manual stage movable in a three-dimensional direction, and on the surface thereof, a precision stage 11 on which an object K to be measured can be moved up and down.
Is placed. An interference microscope 12 as a two-beam interference optical system is arranged above the object K to be measured. In the interference microscope 12, the first
The objective lens 13 is disposed, and a beam splitter 14 is disposed behind the objective lens 13.

A second objective lens 15 and a reference mirror 16 are arranged in the direction via the beam splitter 14. Also, the second direction in the other direction via the beam splitter 14
A halogen lamp 17 as a white light source is provided in a direction opposite to the objective lens 15. A CCD camera (imaging means) 18 is fixed at a position where the first object lens 13 forms an image of the object K via the beam splitter 14. An output signal of the device under test K from the CCD camera 18 is connected to a control computer 20 via an image processing means 19. Here, the image processing means 19 and the computer 20 constitute one element of a control means for controlling the entire operation.

Referring to FIG. 1, a light beam from a halogen lamp 17 is split into two light beams by a beam splitter 14, one of which is reflected and irradiates an object to be measured K through a first objective lens 13, and the other one. The light beam passes through the second objective lens 15 and enters the reference mirror 16. The light beams reflected on the respective surfaces are superimposed again by the beam splitter 14 to generate interference image light. The interference image light is transmitted to the light receiving surface of the CCD camera 18 at the image forming position of the first objective lens 13. Form an image.

The control computer 20 is a precision stage 1
The position of the object to be measured K is changed by controlling the driving in the vertical direction (the optical axis direction of the first objective lens 13). The image processing means 19 analyzes a plurality of interference images from the CCD camera 18 at each position of the measured object K, and calculates a three-dimensional shape of the measured object K. The measurement results are output from the control computer 20 as shape data and dimension data.

The wavelength of the light beam emitted by the halogen lamp 17 is widely distributed in the visible light region, and the phase of the light beam is also random. Since the coherence length is about 2 μm, the range in which interference fringes occur in the CCD camera 18 in the two-beam interference microscope 12 of the present embodiment is about 2 μm in the range.

When the object K is made of glass or transparent resin, or when there is an adhered substance on the surface, the object K
Since the reflectivity of the light beam becomes low, simply increasing the light amount of the halogen lamp 17 only increases the offset of the video signal level of the obtained interference image, and does not contribute to the improvement of the contrast of the interference fringes. At this time, the reflectivity of the reference mirror 16 is changed, and the light amount is adjusted in accordance with the reflectivity of the device under test K to increase the contrast of the interference fringes.

The precision stage 11 is capable of transferring a light beam from the halogen lamp 17 with a resolution of 1/4 to 1/40 of the center wavelength λ. Since the wavelength of the luminous flux from the halogen lamp 17 has a predetermined wavelength width, here, for example, about 555 nm at the center of the wavelength width is set as the center wavelength of the halogen lamp 17.

The phase of the interference fringes obtained via the beam splitter 14 changes by 360 degrees when the distance from the beam splitter 14 to the device under test K changes (λ / 2). Therefore, it is necessary to perform sampling at least more than 180 degrees according to the Nyquist principle.
The moving resolution of 1 is shorter than (λ / 4).

When the precision stage 11 is sent at the step of λ / 40, the phase of the interference fringes changes at the step of π / 10, and when discretely measuring at this step, the signal peak theoretically becomes It can be detected within an error of 1%. Since there are error factors such as noise of the CCD camera 18 in the detection, even if sampling is performed more finely, it takes a long time for the measurement, and does not contribute to the improvement of the actual measurement accuracy.

If a CCD camera 18 for capturing an interference image is of a frame accumulation type, a single screen can be photographed every 1/30 second, so that the precision stage 11 can be moved every 1/30 second by using this. I have to. If a field storage type is used, one screen can be obtained every 1/60 second, so that the measurement time can be reduced to half.

FIG. 2A is a schematic view of an interference image when one area of the head 31 of the ink jet printer as shown in FIG. is there. In the figure, interference fringes appear only in the height direction (optical axis direction) where the optical distance coincides with the reference mirror 16, and the height range in which the fringes can be seen (range in the optical axis direction) is about 2 μm. . Therefore, in the CCD camera 18, X = 1 to X = 5 on the line AA in the image of the interference fringes.
Signal processing is performed on up to 12 512 pixels.

FIG. 3 shows a change in signal intensity of a certain X-th pixel in the CCD camera 18 when the precision stage 11 is sent to a height of 10 μm in steps of 0.1 μm in the height direction (Z direction). Represents.

In the figure, interference fringes appear at the position of height Z. Therefore, it is understood that the height of the surface of the device K to be measured is Z with respect to the pixel X, and in this embodiment, this is automatically obtained for each pixel, and as shown in FIG. The shape of K is required at a time.

FIG. 5 is an explanatory diagram of the horizontal resolution of the first objective lens 13 of FIG. In the figure, the graph shown by the solid line represents the ideal Gaussian light quantity distribution at the image forming position, and the maximum value at the center is normalized to 1. The graph shown by the dashed line represents the amplitude of the interference fringes, and the maximum value at the center is also normalized to 1. The graph shown by the dotted line is the square of the base e of the natural logarithm (1 / e 2 ),
Here, the beam diameter is defined as a diameter with 1 / e 2 as a threshold value. In the same figure, d1 is the beam diameter based on the light amount, and is the beam diameter where the amplitude of the interference fringes is 1 / e 2 based on the same concept.

The light quantity I is the dimension of the light power P, the square of the electric field E of the light, and the two-beam interference is the sum of the electric fields E1 and E2 of the two lights. From this, the light quantity I at the bright portion of the interference fringes is as follows: I = P = (E1 + E2) 2 = E1 2 + E2 2 + 2E1 × E2 cosΦ = P1 + P2 + 2E1 × E2 cosΦ ‥‥‥ (Equation 1) Here, Φ is the phase difference between the two lights. Where E
1 2 E2 2 can be observed separately as light amount P2 of the reference light and the light amount P1 of the probe light interference respectively, present as amount offset in the absence of interference fringes. Third
Term is an entity observed as interference fringes, cosΦ = 1
The maximum amplitude is obtained when the phase difference becomes In the two-beam interference, the reference light P2 is reflected back by the reference mirror 16 with a constant light amount. Only the probe light P1 is the DUT K
May vary depending on the surface condition of the surface. Therefore, the third term in equation 1 is

[0036]

(Equation 1) However, it can be rewritten as κ = 2E2 · cosΦ.

The amplitude of the interference fringes is proportional to the square root of the probe light P1 with respect to the light amount of only the probe light P1 shown by the solid line in FIG. Therefore, the graph of the interference fringe amplitude shown by the broken line in FIG. Therefore, the horizontal resolution of the interference fringes is lower than the horizontal resolution of the light quantity image.

Therefore, in the height direction, measurement is performed using interference fringes with high resolution, and in the horizontal direction, measurement is performed using the distribution of the amount of light reflected from the object K, so that the measurement is performed in any direction. It is also possible to measure with high resolution.

FIG. 6 is an explanatory diagram showing how the above phenomenon appears in actual measurement. FIG. 6A schematically shows a lateral shape of an ink flow path portion of the head 31 of the ink jet printer shown in FIG. 2B which is a measurement target, and has a trapezoidal structure on a plane. . Since the top Da of the trapezoid is as narrow as 10 μm or less, the spot diameter is too large to be measured by the optical micro measurement, and the bottom D of the groove is not measured.
Since b is a resin in a method such as a contact-type electric micro or the like, it is flawed and thus cannot be measured. The width of the bottom of the groove is 10
Since it has a depth of about 50 μm even though it is about μm, it is too deep to measure.

On the other hand, according to the method of the present embodiment, the measurement can be effectively performed. Here, when the width Da of the trapezoidal ink flow path is measured, the intensity of the obtained interference signal is expressed by light and dark, and the position Z of the precision stage (Z stage) 11 is taken on the vertical axis. ). If the Z stage is located at a position where the top of the trapezoid is in focus, interference fringes appear in the interference signal. On the other hand, if the precision stage 11 is located at a position where the bottom is focused, an interference signal appears on the bottom.

On the trapezoidal slope DC, the incident light is obliquely reflected and does not return to the first objective lens 13, so that it is dark when imaged by the CCD camera 18. The interference signal has such a spread as to seep into a dark portion at the edge portion for the reason described in FIG.

FIG. 6B shows the distribution of the luminance without interference fringes and the distribution of the amplitude of the interference fringes with interference fringes.
Shown in However, since the edge is blurred at the out-of-focus position, the signal intensity is shown schematically assuming that the top is trapezoidal and the bottom is bottom-focused. ing. The vertical axis is normalized with a maximum value of 1. Since there is no horizontal resolution of the interference fringes with respect to the luminance, the signal intensity distribution of the interference fringes has a slope of the graph at the edge.

Therefore, when measuring the width of the top, it is possible to measure with higher resolution by using a luminance signal without interference fringes that can obtain a sharp edge with respect to the threshold. Since the flow of ink is affected by the shape of the ink flow path of the ink jet printer, it is necessary to measure the shape of the edge of the flow path in order to obtain high-quality printing. It is effective for measuring the head shape of an ink jet printer as a measurement object.

FIG. 7 is a flowchart of the measurement according to the present embodiment. Hereinafter, a program for executing the flow shown in the flowchart is stored in a storage medium (not shown) in the computer 20. In the figure, first, in step S1, the precision stage 11 is set at an initial position.

Next, in step S2, while the precision stage 11 is stepped in the height direction at regular intervals, the interference image at that time is fetched for each step, and the data of the pixel X for one line is stored in the image processing means 19. Store in memory. Since this is a simple process, even software processing can be stored in the memory at high speed every 1/30 or 1/60 second.

Next, the shape is calculated by analyzing the data of the pixel X stored in step S3. Since this involves complicated processing, it is not included in step S2, and the calculation is performed after all the data has been fetched. In step S3, the height of the DUT K is calculated using the height information of the precision stage 11 when interference fringes appear in the corresponding image for each pixel and the obtained interference fringes, and the result is stored in an array. I do.

In step S4, an image free of interference fringes, that is, image luminance information is extracted from the captured image data having interference fringes by a method described later, and stored in an array. Then, in step S5, the data calculated in step S3 is set as valid data according to the data of the luminance information array (as image data in a state where no interference fringes are formed), or invalid data due to a small amount of reflected light from the device under test K. Is determined for each pixel. Then, in step S7, the precision stage 11 is returned to a predetermined position. Finally, in step S8, the shape data of the measurement result is output as a graph on a monitor.

More specifically, as shown in FIG. 13, as a graph of the shape data of the measurement results, pixels are plotted on the horizontal axis and heights are plotted on the vertical axis, and the valid / invalid judgment results obtained in step 5 are used. Only the measurement points for which the valid flag is 1 (that is, determined to be valid) are displayed. In this way, a cross-sectional shape graph in which only valid measurement values are displayed is obtained.

Further, the difference between the average value of the measured height of the portion Da in FIG. 6A and the average value of the measured height of the portion Db in FIG. 6A which is the bottom of the groove is determined. Thus, the depth of the groove can be obtained.

Further, in a luminance signal without interference fringes, by measuring a continuous width of a pixel having a luminance exceeding a predetermined luminance, a width of a top portion, that is, a Da portion in FIG. 6A can be obtained.

The graph obtained as described above, the depth of the groove and the width of the top are displayed on a monitor screen. Also print out on paper as needed.

FIG. 8 is a flow chart of the continuous image capturing of this embodiment. In the figure, first, step S
At 11, the repetition count value Y is set to the initial value 1. Next, in step S12, one screen data is fetched into the image memory.
Then, in step S13, the image processing means 19 transfers a predetermined line of pixel data from the image memory to the internal buffer memory.

Next, in step S14, the precision stage 11
Is stepped, and the distance between the object K and the interference microscope 12 is changed. Then, in step S15, the repetition count value Y is increased by one. Next, in step S16, if the image has not been captured a predetermined number of times, the process returns to A and repeats steps S12 to S15.

FIG. 9 is a flowchart of the shape calculation according to this embodiment. In the figure, from step S32 to step S39, the processing is repeated for each pixel X for the data stored in the buffer memory inside the image processing means 19. First, in step S21, the repetition count value Y is initialized to 1. Then, in step S32, the data is added to the pixel X in the Z direction, and the resultant value is divided by the added number to calculate the average value of the signal.

Subsequently, as shown in the original data D1 in FIG. 12A, the pixel X has a gentle swell in addition to the interference fringes, and the gradual fluctuation of the level is caused by the blur of the peripheral light due to the defocus. Since this is caused by the wraparound, it is necessary to avoid this effect in order to extract the interference fringe signal. Therefore, in step S23, first, a predetermined score, for example, 7 points or 1 point
If a moving average of one point is calculated, a gradual change in the intensity remains, and the waveform of the interference fringes is smoothed and disappears as in the smoothed data D2. Here, when the value obtained by taking this moving average is subtracted from the original data D1, the gentle low-frequency component disappears, and the waveform of the interference fringe can be left like the undulation removal data D3 in FIG. 12B.

Next, for the data D3 from which the undulation has been removed in step S34, the peak value and the position of the peak in the Z direction are obtained and stored as array data.

Next, in step S35, the repetition count value Y is set to 1
To increase. Then, in step S36, it is determined whether or not the count value Y exceeds a predetermined number of pixels.
Since all the operations have been completed, the process returns to the called position. If the number of pixels does not exceed the predetermined number, since there is still data to be calculated, the process returns to step B and step S3
Steps S36 to S36 are repeated.

By performing the above data processing, the height of each of the predetermined pixels X in the Z direction can be measured as shown in FIG. The measured value of the height in the Z direction at the multiple points can be obtained by one measurement.

FIG. 10 is a flow chart for generating luminance information according to the present embodiment. In the figure, the repetition count value Y is initialized to 1 in step S41. Next, step S42
According to the height data Z (Y) previously obtained for each pixel, image signal intensity data at a position different in height from Z (Y) by an offset OFS is stored in the luminance information R (Y). Here, it is assumed that the amount of the offset OFS is within the depth of focus of the interference microscope 12 being used and further away from the range in which interference fringes occur.

As a result, the data stored in the luminance information R (Y) becomes luminance data in a substantially focused state. In addition, it is also possible to take an average of data in a certain range not only at a point apart from the offset OFS but also in the height direction and use this as luminance data. This has the effect of reducing the amount of noise contained in the luminance information.

Next, in step S43, the repetition count value Y is incremented by 1. If the repetition count value Y is less than the predetermined number of pixels in step S44, the process returns to C and repeats steps S42 to S44. When the predetermined number of pixels have been repeated, the process returns to the called routine. In this way, luminance information R (Y) that is almost in focus for all the pixels can be obtained.

FIG. 11 is a flowchart of the measurement value validity determination according to the present embodiment. In the figure, step S51
Initializes the repetition count value Y to 1. Next, step S5
In step 2, the luminance information R (Y) previously obtained for each pixel is compared with a predetermined value. If there is a luminance exceeding the predetermined value for each pixel, the valid flag is set to 1 in step S53.
If the luminance is equal to or less than a predetermined value, the valid flag is set to 0.

In step S55, the repetition count value Y is incremented by one. In step S56, it is determined that a predetermined number of pixels are to be repeated.
After determining valid flags for all pixels, the process returns to the called routine.

In other words, the measurement method according to the present principle does not provide any interference fringes when there is no reflection surface of the object K in the measurement range and no interference fringes, or when the reflectance is low and sufficient contrast fringes are not obtained. In this case, a correct measurement result is not obtained, so whether the measurement result is reliable can be determined from the luminance information R (Y).

FIG. 14 is a schematic view of a principal part of a surface shape measuring apparatus according to a second embodiment of the present invention. This embodiment is different from the first embodiment shown in FIG. 1 in that a shutter 21 and a driving device 22 are newly provided, and other configurations are the same.

In this embodiment, the shutter 21 is driven by the driving device 22. The control computer 20 sends a control signal to the drive device 22 to open and close the shutter 21.

In the configuration of this apparatus, as in the first embodiment, first, image data having interference fringes is taken in with the shutter 21 opened, and the shape of the DUT K is calculated in the height direction. And shutter 2 to obtain luminance information
1 so as not to generate interference fringes, and instead of step S42 in FIG. 10, the stage height is set to Z (Y) + O
The image is moved to the position of FS, an image of the DUT K at that position is input by the microscope 12, and the image is stored as luminance information R (Y). Subsequent processing is the same as in the above embodiment.

Thus, the reference light does not enter the CCD camera 18. In particular, when the measured object K is a resin product or an uncoated glass surface or the like and the reflectance is lower than that of the reference surface 16, only a luminance signal with good contrast can be obtained. Therefore, the accuracy of the edge measurement in the horizontal direction of the DUT can be improved.

[0069]

As described above, according to the present invention, when measuring the three-dimensional shape of the object to be measured in the vertical direction, the horizontal direction, and the depth direction by using interference, the accuracy can be obtained only by interference fringes. well,
It is possible to achieve surface shape measurement capable of measuring a dimension in a horizontal direction (longitudinal direction) of an object to be measured that cannot be measured with high accuracy. This is particularly preferable when utilizing white light interference.

In particular, in the process of manufacturing the printer head using the apparatus of the present invention, the height and width of the flow path shape of the printer head, which is the object to be measured K, are measured and compared with a reference value. By inspecting products that fall within the specified range as good products and products that are out of the range as defective products, it is possible to accurately measure shapes that had low resolution in the horizontal direction and poor accuracy in edge measurement etc. And the quality assurance of the printer head can be improved.

Separately from this, it is possible to determine the validity / invalidity of the surface shape information based on the interference information based on the luminance information of each part of the object to be measured, thereby enabling highly accurate surface shape measurement excluding invalid data. Become.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of interference fringes obtained by the apparatus of FIG.

FIG. 3 is an explanatory diagram of a received light signal intensity obtained by the apparatus of FIG. 1;

FIG. 4 is an explanatory diagram showing a correspondence between an interference fringe signal of each pixel obtained by the apparatus of FIG. 1 and a measured shape;

FIG. 5 is an explanatory diagram of a relationship between a light amount distribution obtained by the apparatus of FIG. 1 and a spread of interference fringe amplitude.

FIG. 6 is an explanatory diagram of a relationship between a shape of an object to be measured and a measurement signal according to the present invention.

FIG. 7 is a flowchart of measurement according to the present invention.

FIG. 8 is a flowchart of image capture;

FIG. 9 is a flowchart of a shape calculation according to the present invention.

FIG. 10 is a flowchart of luminance information generation according to the present invention.

FIG. 11 is a flowchart of a measurement value validity determination in the present invention.

FIG. 12 is a graph showing a change in pixel level according to the present invention;

FIG. 13 is a graph of a measurement result in the present invention.

FIG. 14 is a schematic view of a main part of a second embodiment of the present invention.

FIG. 15 is a flowchart in a conventional surface shape measuring apparatus.

[Explanation of symbols]

 Reference Signs List 10 Manual stage 11 Precision stage 12 Interference microscope 13 First objective lens 14 Beam splitter 15 Second objective lens 16 Reference mirror 17 Halogen lamp 18 CCD camera 19 Image processing means 20 Computer

Claims (14)

[Claims]
1. An interference optical system for guiding light emitted from a light source to an object to be measured and a reference surface, and interfering light beams from both, and imaging means for imaging interference information obtained by the interference optical system. An image processing means for obtaining a surface shape from the object using the signal from the imaging means; and an image in an interference fringe non-formed state in which no interference fringes are formed on the object to be measured. A surface shape measuring apparatus comprising: an image acquiring unit for acquiring information; and obtaining, by the image processing unit, lateral dimensional information of the object to be measured from the image information in a state where the interference fringes are not formed. .
2. The image acquisition unit according to claim 1, wherein the interference fringe non-formed state is obtained by adjusting the relative position of the interference optical system and the measured object in the optical axis direction. Surface shape measuring device.
3. The surface shape measuring apparatus according to claim 1, wherein said image obtaining means obtains a state in which no interference fringes are formed using shutter means provided on a reference optical path of said interference optical system.
4. The image obtaining means changes the interference fringe non-formed state from an interference state in which a light beam from the object to be measured and a light beam from the reference surface interfere with each other by changing a relative position in both optical axis directions. 2. The surface shape measuring apparatus according to claim 1, wherein image data based on the area in which the interference fringe is not formed is selected and obtained for each of a plurality of pixels of the imaging unit.
5. The method according to claim 1, wherein lateral dimension information of the object to be measured is obtained by using a predetermined edge of a luminance distribution and a center of gravity of image information formed on the imaging means surface. Item 2. The surface shape measuring device according to Item 1.
6. The surface shape measuring apparatus according to claim 1, wherein the light emitted from the light source is white light.
7. A first step in which when interference fringes are generated by light passing through an object to be measured, shape information along a predetermined axis direction of the object to be measured is obtained from information on the obtained interference fringes;
Obtaining a shape of the object to be measured in a direction perpendicular to the predetermined axis direction from video information of the object to be measured without interference fringes.
8. The second step is performed by obtaining signal intensity data at a position different in the predetermined direction by a predetermined distance from a range in which the interference fringes are generated when the first step is performed. The method according to claim 7, wherein the measurement is performed.
9. The method according to claim 7, wherein the second step is performed in a state where the interference fringes are not generated.
10. A storage medium storing a program for executing the surface shape measuring method according to claim 7. Description:
11. The surface shape measuring apparatus according to claim 1, wherein information on the validity and invalidity of the surface shape data is obtained for each pixel based on the image data in a state where no interference fringes are formed.
12. In a surface shape measuring apparatus for obtaining surface shape information by imaging interference information obtained by interfering light from an object to be measured, luminance information of each part of the object to be measured without interference fringes. And determining whether each part of the surface shape information is valid or invalid.
13. An interference fringe is generated by light passing through an object to be measured, and when obtaining surface shape information of the object to be measured based on information on the obtained interference fringe, the object to be measured in a state without interference fringes. Determining whether each part of the surface shape information is valid or invalid based on the luminance information of each part.
14. A storage medium storing a program for executing the surface shape measuring method according to claim 13.
JP9290290A 1997-10-06 1997-10-06 Surface shape measuring apparatus Granted JPH11108625A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9290290A JPH11108625A (en) 1997-10-06 1997-10-06 Surface shape measuring apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9290290A JPH11108625A (en) 1997-10-06 1997-10-06 Surface shape measuring apparatus

Publications (1)

Publication Number Publication Date
JPH11108625A true JPH11108625A (en) 1999-04-23

Family

ID=17754235

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9290290A Granted JPH11108625A (en) 1997-10-06 1997-10-06 Surface shape measuring apparatus

Country Status (1)

Country Link
JP (1) JPH11108625A (en)

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US6377425B1 (en) * 1999-04-15 2002-04-23 Magnecomp Corporation One-piece load beam and gimbal flexure using flexible circuit
JP2007536539A (en) * 2004-05-04 2007-12-13 カール マール ホールディング ゲーエムベーハー Apparatus and method for detection based on a combination of geometric interference and imaging, especially in microsystem technology
JP2008299210A (en) * 2007-06-01 2008-12-11 Olympus Corp Interference objective lens, and interference microscope unit equipped with interference objective lens
JP2009198361A (en) * 2008-02-22 2009-09-03 Yokogawa Electric Corp Film thickness measuring device and method
JP2009300100A (en) * 2008-06-10 2009-12-24 Nikon Instech Co Ltd Shape measuring apparatus and its shape measuring method
JP2011519016A (en) * 2007-12-14 2011-06-30 インテクプラス カンパニー、リミテッド Surface shape measuring system and measuring method using the same
EP2840352A1 (en) 2013-08-23 2015-02-25 Canon Kabushiki Kaisha Interferometric apparatus combined with a non interferometric apparatus, and measuring method
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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6377425B1 (en) * 1999-04-15 2002-04-23 Magnecomp Corporation One-piece load beam and gimbal flexure using flexible circuit
JP2007536539A (en) * 2004-05-04 2007-12-13 カール マール ホールディング ゲーエムベーハー Apparatus and method for detection based on a combination of geometric interference and imaging, especially in microsystem technology
JP4644707B2 (en) * 2004-05-04 2011-03-02 カール マール ホールディング ゲーエムベーハー An apparatus for detection based on a combination of geometric interference and imaging, especially in microsystem technology
JP2008299210A (en) * 2007-06-01 2008-12-11 Olympus Corp Interference objective lens, and interference microscope unit equipped with interference objective lens
JP2011519016A (en) * 2007-12-14 2011-06-30 インテクプラス カンパニー、リミテッド Surface shape measuring system and measuring method using the same
JP2009198361A (en) * 2008-02-22 2009-09-03 Yokogawa Electric Corp Film thickness measuring device and method
JP2009300100A (en) * 2008-06-10 2009-12-24 Nikon Instech Co Ltd Shape measuring apparatus and its shape measuring method
EP2840352A1 (en) 2013-08-23 2015-02-25 Canon Kabushiki Kaisha Interferometric apparatus combined with a non interferometric apparatus, and measuring method
KR20150057997A (en) * 2013-11-18 2015-05-28 가부시기가이샤 디스코 Detecting apparatus
JP2015099026A (en) * 2013-11-18 2015-05-28 株式会社ディスコ Detector

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