JP2007232549A - Distance measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To respond to the variation of the measuring position of a measured object and to exactly measure a part to be measured. <P>SOLUTION: A changeover switch 15 is disposed in a controller 3, and the changeover switch 15 can select a reference for making the light receiving peak position of the light receiving distribution of the reflected light obtained by a CCD 6 correspond to the positions on front and rear faces of the measured object from the close side or separate side of a sensor head 2 (projection element 5). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a distance measuring device suitable for measuring various distances such as a distance (thickness) between front and back surfaces of a light-transmitting object to be measured such as a glass substrate and a gap distance between a plurality of objects to be measured. It is.

  There is a need to measure the thickness of each glass substrate and the distance between each glass substrate in a bonded substrate used for a flat panel display such as liquid crystal or plasma and having two glass substrates bonded together. Therefore, for example, Patent Document 1 proposes a distance measuring device that measures the distance (thickness) between the front and back surfaces of a glass substrate and the gap distance between a plurality of glass substrates in order to satisfy such a requirement.

  In the distance measuring device shown in Patent Document 1, a sensor head is arranged on the upper side of the bonded substrate, light is irradiated from the light emitting element provided in the sensor head toward the upper surface of the bonded substrate, Reflected light reflected on the front and back surfaces of the upper and lower glass substrates is received on the CCD by the CCD provided in the sensor head, and the front and back surfaces of each glass substrate in the received light distribution obtained on the CCD on the apparatus main body side. Based on the detection of each light receiving peak position corresponding to the reflected light, the thickness of each glass substrate and the gap distance between each glass substrate are calculated.

When measuring the thickness and gap distance, the first light receiving peak position on the near side of the sensor head (light projecting element) is recognized as a reference, that is, the surface position of the upper glass substrate, and the first light receiving peak position is recognized. And the thickness of an upper glass substrate is measured by the following 2nd light reception peak position (back surface position of an upper glass substrate). Next, the gap distance between the upper and lower glass substrates is measured at the second light receiving peak position and the next third light receiving peak position (surface position of the lower glass substrate). Next, the thickness of the lower glass substrate is measured at the third light receiving peak position and the next fourth light receiving peak position (back surface position of the lower glass substrate).
JP 2004-264082 A

  By the way, the bonding substrate may be displaced upward, that is, in the vicinity of the light projecting element, for example, when it is performed in the middle of the line for manufacturing the bonding substrate, and in some cases, the measurement range of the CCD is exceeded. May cause large movements.

  In such a case, for example, if the surface of the upper glass substrate is out of the measurement range, the light receiving peak corresponding to the surface reflected light does not appear in the light receiving distribution on the CCD. Using the peak as a reference, the received light peak position is erroneously associated with the surface position of the upper glass substrate.

  Therefore, although the next second light receiving peak corresponds to the front surface reflected light of the lower glass substrate, the measuring apparatus erroneously recognizes that it corresponds to the rear surface reflected light of the upper glass substrate. What originally measures the gap distance between the upper and lower glass substrates is erroneously measured as the thickness of the upper glass substrate. Similarly, even though the next third light receiving peak corresponds to the back surface reflected light of the lower glass substrate, the measuring apparatus misrecognizes that it corresponds to the surface reflected light of the lower glass substrate. Therefore, what originally measures the thickness of the lower glass substrate is erroneously measured as the gap distance between the upper and lower glass substrates.

  The present invention has been made to solve the above-mentioned problems, and its object is to provide a distance measuring device that can cope with fluctuations in the measurement position of an object to be measured and can accurately measure a measurement target portion. There is to do.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a light projecting means for irradiating light to a light-transmitting object to be measured, and the object to be measured based on light irradiation from the light projecting means. A light receiving distribution detecting means for detecting a light receiving distribution within a measurement range, and a plurality of light receiving peak positions in the light receiving distribution detected by the light receiving distribution detecting means. A distance measuring device comprising a measurement value calculating means for associating a front surface position and a back surface position of an object and calculating a measurement value of a measurement target portion related to the object to be measured from the light reception peak position, the light reception peak position It is necessary to include selection means for selecting a reference for associating the front surface position and the back surface position of the object to be measured from any of the surfaces of all the objects to be measured that are stored in advance. To.

  In the present invention, the selection means can select from any one of the surfaces of all the objects to be measured that are stored in advance as a reference for associating the light receiving peak position with the surface position and the back surface position of the object to be measured. It becomes possible. In other words, the measurement object is composed of a plurality of members, and each member has a plurality of front and back surfaces. For example, when the measurement object is used in an environment in which the measurement object is likely to be displaced near the light projecting means. A part of the object to be measured is out of the measurement range, and a part of the light receiving peak on the near side such as the surface of the object to be measured cannot be detected. Even in such a case, for example, the selection unit performs selection so that each surface of the measurement object and the light reception peak position are associated with each other on the basis of the back surface position of the measurement object positioned on the separation side of the light projecting unit. Thus, the light receiving peak position and each surface of the object to be measured are accurately associated with each other. In addition, when the object to be measured is used in an environment in which the position of the object to be measured is likely to be shifted to the separated side of the light projecting means, the selection means selects the surface position of the object to be measured on the near side. Thus, the light receiving peak position and each surface of the object to be measured are accurately associated with each other. Thereby, a measurement object part can be measured accurately.

The gist of the invention described in claim 2 is the distance measuring device according to claim 1, wherein the selection means is configured to be selectively switchable by an operation of an operator.
In this invention, since the selection means is configured to be selectable and switched by an operator's operation, it is not necessary to incorporate the determination to switch the selection automatically into the control configuration of the device, and the control configuration of the device is simplified. can do.

  According to a third aspect of the present invention, in the distance measuring device according to the first or second aspect, the measurement value calculating means includes a thickness of the measurement object or a gap between the plurality of measurement objects as the measurement target portion. The gist is to calculate the distance measurement.

  In this invention, the measured value calculation means accurately measures the thickness of the object to be measured or the gap distance between the plurality of objects to be measured.

  Therefore, according to the above-described invention, it is possible to provide a distance measuring device that can cope with a change in the measurement position of the object to be measured and can accurately measure the measurement target portion.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows a distance measuring apparatus 1 according to the present embodiment. The distance measuring device 1 is used for a flat panel display such as liquid crystal or plasma, and in a bonded substrate W in which two glass substrates W1 and W2 are bonded, the thicknesses D1 and D2 of the glass substrates W1 and W2 (see FIG. 3). ) And the distance L between the glass substrates W1 and W2 is measured. This distance measuring device 1 includes a sensor head 2 disposed above a measurement object (bonded substrate W) and a controller 3 that performs various controls when in use, and are electrically connected to each other by a cable 4. It is configured.

  As shown in FIGS. 1 and 2, the sensor head 2 includes a light projecting element 5 made of, for example, a red semiconductor laser diode, and an object to be measured (bonded substrate W) based on irradiation of light from the light projecting element 5. And a CCD 6 arranged so as to receive the reflected light. The sensor head 2 includes a light projecting element driving circuit 7 that supplies a driving current to the light projecting element 5 and a CCD driving circuit 8 that drives the CCD 6, and is controlled by the controller 3. Further, the sensor head 2 is provided with an indicator lamp 9 and performs various display operations based on the control of the controller 3.

  The controller 3 has a display 10 having a touch panel function as well as a display. The display 10 outputs various setting signals according to the touch operation of the operator to the CPU 11. For example, a mode for measuring the thicknesses D1 and D2 of the glass substrates W1 and W2 and the gap distance L between the glass substrates W1 and W2 can be selected by a touch operation, and a setting signal corresponding to this is output to the CPU 11. Based on this setting signal, the CPU 11 performs light projection control of the light projecting element drive circuit 7 (light projecting element 5), drive control of the CCD drive circuit 8 (CCD6), and lighting control of the display lamp 9, and various kinds of control. The measurement operation is performed.

  Further, the controller 3 is provided with a comparator 12 and an A / D converter 13 to which an output signal from the CCD 6 is input. The comparator 12 compares the output signal from the CCD 6 with a predetermined slice level and outputs the comparison result to the CPU 11. This is for distinguishing noise contained in the output signal from the CCD 6 from the peak level of the light reception distribution on the CCD 6, and in the CPU 11, the output from the comparator 12 is high level, that is, the light reception level of the CCD 6 is a predetermined level. Only at the above time, the output of the A / D converter 13 is captured as reflected light from the object to be measured (bonded substrate W).

  The CPU 11 acquires the light reception distribution of the CCD 6 based on the output of the A / D converter 13. In the case where the object to be measured is a bonded substrate W, when the bonded substrate W is located within a measurement range that can be measured by the CCD 6, the received light distribution includes the front surface a and the back surface b of the upper glass substrate W1. A light receiving peak is generated at a position corresponding to each reflected light reflected by the front surface c and the rear surface d of the lower glass substrate W2. CPU11 calculates | requires each position (for example, distance from the reference position set beforehand) of each of front surface a and back surface b of upper glass substrate W1, and front surface c and back surface d of lower glass substrate W2 based on the position of each received light peak, The measured values of the thicknesses D1 and D2 and the gap distance L are calculated from the positions of the surfaces a to d. Specifically, the thickness D1 is obtained from the difference between the position of the surface b and the position of the surface a, the thickness D2 is obtained from the difference between the position of the surface d and the position of the surface c, and the gap distance L is the position of the surface c. And the position of the surface b. In addition, the whole thickness etc. of the bonding board | substrate W can also be detected from the position of each surface ad. Incidentally, the memory 14 provided in the controller 3 is used for such calculation of the CPU 11. The CPU 11 displays the measured thicknesses D1 and D2 and the gap distance L on the display 10, and also displays the acquired light reception distribution and the like.

  In the present embodiment, a changeover switch 15 is added to the touch panel function of the display 10 so that the measurement mode of the CPU 11 can be selected and switched between “normal measurement mode” and “reverse measurement mode” stored in advance. Yes. That is, the measurement mode can be switched by a touch panel operation on the display 10.

  When the normal measurement mode is selected by the changeover switch 15, as shown in FIG. 3, the CPU 11 receives the first light receiving peak position on the proximity side of the sensor head 2 (light projecting element 5) (first on the left side of the light receiving distribution). As the reference, that is, the position of the surface a of the upper glass substrate W1, then the second light receiving peak position is the position of the back surface b of the upper glass substrate W1, and the third light receiving peak position is the surface of the lower glass substrate W2. The position c and the fourth light reception peak position are recognized as being associated with the position of the back surface d of the lower glass substrate W2. The CPU 11 calculates the positions (distances) of the surfaces a to d for calculating the measured values of the thicknesses D1 and D2 and the gap distance L from these.

  On the other hand, when the reverse measurement mode is selected by the changeover switch 15, as shown in FIG. 4, the CPU 11 is first on the separation side of the sensor head 2 (light projecting element 5) (first on the right side of the light reception distribution). Are matched with each other as the reference, that is, the position of the back surface d of the lower glass substrate W2, then the second light receiving peak position is the position of the surface c of the lower glass substrate W2, and the third light receiving peak position is the upper glass. The position of the back surface b of the substrate W1 and the fourth light receiving peak position are recognized in association with each other as the position of the surface a of the upper glass substrate W1. Similarly, CPU11 calculates the position (distance) of each surface ad from these.

  Here, when used in an environment in which the bonded substrate W, which is the object to be measured, is likely to be displaced upward from the measurement range, that is, closer to the sensor head 2 (light projecting element 5), as shown in FIG. For example, the surface of the upper glass substrate W1 may be out of the measurement range. Then, the light reception peak corresponding to the surface reflected light of the upper glass substrate W1 does not appear in the light reception distribution.

  In this case, when measurement is performed in the normal measurement mode as shown in FIG. 3, the CPU 11 recognizes the first light reception peak position on the left side of the light reception distribution as a reference, that is, the position of the surface a of the upper glass substrate W1. Therefore, although the actual position is the position of the back surface b of the upper glass substrate W1, the first light-receiving peak position on the left side is erroneously associated with the position of the surface a of the upper glass substrate W1. End up. Therefore, at the first left light receiving peak position (actually the position of the back surface b of the upper glass substrate W1) and the second light receiving peak position (actually the position of the surface c of the lower glass substrate W2), the CPU 11 The thickness D1 is calculated in an incorrect state. Further, the CPU 11 calculates the gap distance L between the glass substrates W1 and W2 in an incorrect state based on the second light receiving peak position and the third light receiving peak position (actually, the position of the back surface d of the lower glass substrate W2). End up.

  Therefore, in this embodiment, when used in the above environment, the measurement object (bonded substrate W) can be measured by switching to the reverse measurement mode by operating the changeover switch 15 of the operator. It is like that.

  That is, in the reverse measurement mode, as shown in FIG. 5, the CPU 11 normally associates the first light receiving peak position on the right side of the light receiving distribution with the reference, that is, the position of the back surface d of the lower glass substrate W2. Accordingly, the CPU 11 determines the thickness D2 of the lower glass substrate W2 at the first light receiving peak position on the right side (the position of the back surface d of the lower glass substrate W2) and the second light receiving peak position (the position of the surface c of the lower glass substrate W2). Is calculated accurately. Further, the CPU 11 accurately calculates the gap distance L between the glass substrates W1 and W2 based on the second light receiving peak position and the third light receiving peak position (the position of the back surface b of the upper glass substrate W1). That is, the thickness D1 of the upper glass substrate W1 is not measured because the light receiving peak of the surface reflected light of the upper glass substrate W1 is not obtained, but the remaining thickness D2 of the lower glass substrate W2 and the gap distance between the glass substrates W1 and W2 The portion to be measured such as L is accurately calculated.

  In the case where the object to be measured is used in an environment where the object to be measured is likely to be displaced downward from the measurement range, that is, to the side away from the sensor head 2 (light projecting element 5), the first light reception on the left side as shown in FIG. It is desirable to perform the measurement in the normal measurement mode based on the peak position because the measurement target portion can be accurately calculated.

  As described above, the distance measuring device 1 according to the present embodiment includes the change-over switch 15 that can cope with the change in the measurement position of the object to be measured (bonded substrate W), and the thicknesses D1 and D2 of the glass substrates W1 and W2. In addition, a measurement target portion such as a gap distance L between the glass substrates W1 and W2 can be accurately measured.

Next, characteristic actions and effects of the present embodiment will be described.
(1) In the present embodiment, the controller 3 is provided with a changeover switch 15, and the light receiving peak position of the received light distribution of the reflected light obtained by the CCD 6 by the changeover switch 15 and the front and back surfaces of the bonded substrate W as the object to be measured this time. The reference for associating the positions a to d can be selected from either the proximity side or the separation side of the sensor head 2 (light projecting element 5). That is, when the object to be measured is composed of a plurality of members and the bonded substrate W has a plurality of front and back surfaces of each member, for example, the bonded substrate W is displaced upward (closer to the sensor head 2). When used in an easy environment, a part of the bonded substrate W is removed from the measurement range, and a part of the light receiving peak on the near side such as the surface a of the upper glass substrate W1 of the bonded substrate W cannot be detected. . Even in such a case, the changeover switch is configured so that each surface a to d of the bonded substrate W and the light receiving peak position are associated with each other on the basis of the back surface d position of the lower glass substrate W2 positioned on the separation side of the sensor head 2. By switching (selecting) at 15, the light receiving peak position and each surface b to d (when the surface a is removed) of the bonded substrate W can be accurately associated with each other. Thereby, measurement object parts, such as thickness D2 of each glass substrate W2 and the clearance distance L between each glass substrate W1, W2, can be measured exactly.

  (2) Since the changeover switch 15 of the present embodiment is configured to be selectable and switched by an operator's operation, it is not necessary to incorporate the determination to automatically switch selection into the control configuration of the controller 3. The control configuration can be simplified.

  (3) In the present embodiment, the light projecting element 5 and the CCD 6 are provided in the same sensor head 2, while the CPU 11 and the changeover switch 15 are provided in the controller 3 separate from the sensor head 2. Thereby, it can contribute to size reduction of the sensor head 2, and the freedom degree of arrangement | positioning of the sensor head 2 can be improved. Further, in the case where the changeover switch 15 is provided on the controller 3 side as in the present embodiment, the operability is superior to the case where the changeover switch is provided on the sensor head 2 side that may be attached to a complicated place.

The embodiment of the present invention may be modified as follows.
In the above embodiment, the changeover switch 15 is added to the touch panel function of the display 10, but the changeover switch may have a mechanical contact and may be provided on the controller 3 side, for example.

  In the above embodiment, the selection means (switch 15) can be selected by the operator's operation. For example, the position of the object to be measured is shifted from the deviation of the light reception peak of the light reception distribution obtained by the CCD 6. The obtaining side may be determined by a circuit, and the selection may be automatically switched based on the determination result.

In the above embodiment, the light projecting element 5 and the CCD 6 are provided in the sensor head 2, but the configuration of the sensor head 2 is not limited to this.
For example, the light projecting element may be arranged at a location different from the sensor head, and light may be supplied to an irradiation unit provided on the sensor head with an optical cable, and the object to be measured may be irradiated from the irradiation unit.

Further, although the light projecting element 5 is a red semiconductor laser diode, other light projecting elements may be used.
Further, although the CCD 6 is used as the light reception distribution detecting means, it may be replaced with means other than the CCD that can obtain the light distribution.

  In the above embodiment, the light projecting element 5 and the CCD 6 are provided in the same sensor head 2, while the CPU 11 and the changeover switch 15 are provided in the controller 3 that is separate from the sensor head 2. You may comprise.

  -In the said embodiment, although the various distance measurement of the bonding board | substrate W which bonded two glass substrates W1 and W2 as a to-be-measured object was implemented, other than a bonding board | substrate (glass board | substrate) An object to be measured may be measured.

  In the above embodiment, the reference for associating the positions of the front and back surfaces a to d of the bonded substrate W is selected from either the proximity side or the separation side of the sensor head 2 (light projecting element 5). The reference may be selected from any one of the surfaces a to d of the measurement object stored in advance. In particular, the greater the number of objects to be measured is three or more, the greater the significance of being able to select a reference from a plurality of front and back surfaces.

Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below.
(A) In the distance measuring device according to any one of claims 1 to 3,
The distance measuring device, wherein the received light distribution detecting means is a CCD.

In this way, a suitable light distribution can be detected by the CCD.
(B) irradiating a light-transmitting object to be measured, receiving each reflected light on the front and back surfaces of the object to be measured based on the light irradiation, and detecting a light reception distribution within the measurement range; The distance measurement method associates the surface position and the back surface position of the object to be measured from a plurality of light reception peak positions in the light reception distribution, and calculates the measurement value of the measurement target portion related to the object to be measured from the light reception peak position. And
A distance measuring method, wherein a reference for associating the light receiving peak position with a front surface position and a back surface position of the object to be measured is selected from any one of the surfaces of the object to be measured.

  In this way, the same effect as in the first aspect can be obtained.

It is a perspective view of the distance measuring device of this embodiment. It is a block diagram which shows the electric constitution of a distance measuring device. It is explanatory drawing for demonstrating distance measurement. It is explanatory drawing for demonstrating distance measurement. It is explanatory drawing for demonstrating distance measurement.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Sensor head, 3 ... Controller, 5 ... Light projection element as light projection means, 6 ... CCD as light reception distribution detection means, 11 ... CPU as measurement value calculation means, 15 ... Changeover switch as selection means, D1 , D2: thickness as a measurement target portion, L: gap distance as a measurement target portion, W: a bonded substrate as a measurement object (W1: upper glass substrate, W2: lower glass substrate), a to d: plane ( front side, reverse side).

Claims (3)

A light projecting means for irradiating the object to be measured with light transmission;
A light distribution distribution detecting means that is arranged so as to be able to receive each reflected light on the front and back surfaces of the object to be measured based on the irradiation of light from the light projecting means, and detects a light reception distribution within the measurement range;
The surface position and the back surface position of the object to be measured are associated with each other from the plurality of light receiving peak positions in the light receiving distribution detected by the light receiving distribution detecting means, and the measurement value of the measurement target portion related to the object to be measured is calculated from the light receiving peak position. A distance measuring device comprising a measured value calculating means,
Selection means for selecting a reference for associating the light receiving peak position with the front surface position and the back surface position of the object to be measured from any of the surfaces of all the objects to be measured that are stored in advance. A distance measuring device characterized by. The distance measuring device according to claim 1,
The distance measuring device is characterized in that the selection means is configured to be selectable and switched by an operator's operation. In the distance measuring device according to claim 1 or 2,
The measurement value calculating unit calculates a measurement value of a thickness of the measurement object or a gap distance between the plurality of measurement objects as the measurement target portion.

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