JPH10300429A - Optical dimension measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust from clinging to a projecting window and a receiving window, without reducing a measuring space adapted to place an object for measurement. SOLUTION: On the opposite sides of the first casing 33 of a projecting portion 32 and the second casing 35 of a receiving portion 34 to a measuring space 4, the parts where a projecting window 38 or a receiving window 39 is provided are moved backward from the measuring space 4 to form steps 36, 37. The steps formed in the first and second casings are covered with a pair of covers 40, 41, slits 42, 43 for causing light passing through the projecting or receiving window to be input to and output from the measuring space are formed in the opposite sides of the covers to the measuring space, and air supply holes 44, 45 for air purging, preventing entrance of minute foreign matter into the covers via the slits, are provided in the covers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a measurement object with light having good directivity such as a laser beam, and utilizing the fact that a part of the measurement object is shielded from light. The present invention relates to an optical dimension measuring device for measuring dimensions.

[0002]

2. Description of the Related Art The size of a minute object such as the outer diameter of an electric wire is 10 ^-6.
As a dimension measurement device that measures with an accuracy of about m (micrometer), parallel scanning is performed along a measurement direction with a highly directional light such as a laser beam in a measurement space where a measurement target is placed, and the measurement target is measured. 2. Description of the Related Art An optical dimension measuring instrument for measuring a dimension of an object to be measured by utilizing the fact that a part thereof is shielded from light has been put to practical use.

FIG. 5 is a perspective view showing an optical dimension measuring device and a display device. The optical dimension measuring device 1 includes: a light projecting unit 2 that outputs a laser beam for measurement;
A light receiving unit 5 installed at a position facing the measurement space 4 where the measured object 3 is placed, and a base for setting the positional relationship between the light projecting unit 2 and the light receiving unit 5 to form the measurement space 4 6
It is composed of

[0004] The display device 7 supplies drive power to the light projecting unit 2 of the optical dimension measuring machine 1 and also takes in a detection signal related to the size of the measured object 3 output from the light receiving unit 5. Then, various arithmetic processes are performed on the captured detection signal to calculate the dimensions of the measured object 3 and digitally display it on the display unit 8.

FIG. 6 is a schematic diagram showing the internal configuration of the optical dimension measuring instrument 1. FIG. 6A is a top view of the optical dimension measuring device 1, and FIG. 6B is a side view of the optical dimension measuring device 1.

[0006] In the light projecting section 2, as shown in FIG. 6 (a), the first housing 9 mounted on the base 6
One area 9a and 9b are formed, an electronic circuit member is housed in a deep area 9a, and an optical system is housed in a near area 9b.

In the area 9b in front, the laser light source 1
The laser beam 11 output from the mirror 1 is deflected by a deflector 12 composed of, for example, a tuning fork or a rotating mirror.
3 is incident. The deflected laser beam 11 reflected by the reflecting mirror 13 is converted into a parallel scanning laser beam 16 by a collimator lens 14. Note that, other than using the deflector 12 to deflect the laser light 11, slit light may be used.

The laser beam 16 emitted from the collimator lens 14 and scanned in parallel is projected on the surface of the first housing 9 facing the measurement space 4 in the light projection window 1 formed in the scanning direction of the laser beam.
The light is emitted to the measurement space 4 via 5. The light emitting window 15
A transparent member such as glass or plastic is fitted into the first housing 9 so that minute foreign matters such as dust, dust, and dust do not enter the first housing 9.

The laser light 16 emitted from the light projecting window 15 to the measurement space 4 and scanned in parallel is partially shielded by the measurement object 3 while passing through the position of the measurement object 3. On the other hand, in the light receiving section 5, as shown in FIG. 6A, two regions 17 are provided in a second housing 17 mounted on the base 6.
a and 17b are formed, an electronic circuit member is accommodated in an area 17a at the back, and an optical system is accommodated in an area 17b on the near side.

[0010] The laser beam 16 that has passed through the measurement space 4 and is scanned in parallel enters a region 17 b in the foreground through a light receiving window 18 formed in a second housing 17 of the light receiving unit 5.
A transparent member such as glass or plastic is fitted into the light receiving window 18 so that minute foreign matters such as dust, dust, and dust do not enter the second housing 17.

The laser light 16 incident on the front area 17 b through the light receiving window 18 is reflected by the condenser mirror 19 by the condenser lens 19.
The light is condensed on the light receiving surface of the light receiver 21 through 0. Since the time when the parallel scanned laser light 16 crosses the measured object 3 is interrupted, the signal waveform of the detection signal of the photodetector 21 changes to the low level state for the time width corresponding to the dimension (outer diameter) of the measured object 3. Pulse signal.

The detection signal from the light receiver 21 is sent to the display device 7 shown in FIG. The display device 7 detects the time width of the low-level period of the detection signal using, for example, a counter or the like, converts the time width into a size, and digitally displays the size on the display unit 8.

Each of the housings 9 and 1 of the light projecting section 2 and the light receiving section 3 is provided.
In each of the optical systems housed in the regions 9b and 17b of FIG. 7, the optical axes of the laser beams 11 and 16 are bent using the reflecting mirrors 13 and 20, respectively. This is to reduce the size of the entire optical dimension measuring instrument 1 in a state where components are efficiently incorporated and the measurement space 4 has a predetermined volume.

[0014]

However, FIG.
The optical dimension measuring device 1 shown in FIG. 6 also has the following problems to be solved. That is, the light emitting window 15 and the light receiving window 18 in which a transparent member such as glass or plastic is fitted are provided at positions facing the measurement space 4 in the housings 9 and 17 of the light emitting unit 2 and the light receiving unit 5. ing. Therefore, when an operator who measures the dimensions of the measured object 3 by using the optical dimension measuring device 1 accidentally touches each transparent member of the light projecting window 15 and the light receiving window 18 with a finger, for example, a fingerprint is attached to the transparent member. Adheres, or when wearing gloves, the fibers of the glove adhere to the transparent member.

Even if the worker takes great care to prevent his / her hands from touching the transparent members of the light emitting window 15 and the light receiving window 18, depending on the working environment, dust and air in the air may not be present. Dust and dust adhere to the transparent members of the light emitting window 15 and the light receiving window 18.

As described above, the precision of the dimension measurement of the optical dimension measuring machine 1 with respect to the measured object 3 is required to be not less than μm (micrometer), and therefore, even if minute dust, dust and dirt are present. Even if there is, it greatly affects the measurement result.

Therefore, the operator needs to clean the surfaces of the transparent members of the light emitting window 15 and the light receiving window 18 before starting the actual measurement. As a result, not only does the work load on the operator increase, but even if the surface is cleaned before the start of the measurement, dust, dust and dirt adhering after the start of the measurement cannot be removed.

In order to eliminate such inconvenience, the light projecting window 1 and the light receiving window 18 are provided in front of the light projecting window 1.
It has been proposed to attach a cover for covering the light receiving window 5 and the light receiving window 18, to form a slit for inputting and outputting each laser beam 16 on the front surface of each cover, and to air purge the inside of the cover.

However, if an air purge cover is attached to the front of the light projecting window 15 and the light receiving window 18, the measuring space 4 for placing the object 3 to be measured becomes narrower, and the object to be measured in the optical dimension measuring instrument 1 becomes smaller. When the body 3 moves greatly, it is easy to make contact. In addition, there is a problem that it cannot be used when there is an obstacle such as a roller.

The present invention has been made in view of such circumstances, and an object to be measured is placed by forming a step in the light emitting window and the light receiving window of the light emitting unit and the light receiving unit. Without reducing the measurement space required for measurement, it is possible to prevent small foreign substances such as dust, dust, and dust from adhering to the light-emitting window and light-receiving window of the light-emitting and light-receiving parts, and to ensure that the measured object is always highly accurate. It is an object of the present invention to provide an optical dimension measuring instrument capable of measuring the dimension of a sheet.

[0021]

SUMMARY OF THE INVENTION The present invention comprises a light source and an optical system incorporated in a first housing, and transmits parallel scanning light or slit light to the first housing in which a transparent member is fitted. The light-emitting unit is provided through a light-emitting unit that emits light from the light-emitting window, and a measurement space for disposing the object to be measured with respect to the light-emitting unit. The parallel scanning light or the slit light, a part of which is shielded, is transmitted to the second
A light receiving unit that takes in a second housing through a light receiving window of the housing, guides the light to a light receiver with an optical system incorporated in the second housing, and obtains and outputs a detection signal relating to the dimensions of the measured object. This is applied to an optical dimension measuring device consisting of:

In order to solve the above-mentioned problem, in the present invention, a portion provided with a light emitting window or a light receiving window on a surface facing the measurement space of the first and second housings is retracted from the measurement space. And a pair of covers for covering the steps formed in the first and second housings, and a light-emitting window or a light-receiving window formed on a surface of each cover facing the measurement space. A slit is provided for allowing the passing light to enter and exit the measurement space, and an air supply port for air purging is provided on each cover and prevents minute foreign matter from entering the cover via the slit.

In the optical dimension measuring device thus constructed, the portion of the first and second housings provided with the light emitting window or the light receiving window on the surface facing the measurement space is retracted from the measurement space. Thus, a step is formed. The step is covered with a cover that is purged with air.

As a result, the front surface of the cover which covers the front of the light emitting window or the light receiving window is prevented from protruding into the measurement space. Therefore, it is possible to prevent dust, dirt, and dust from adhering to the transparent members inserted into the light emitting window and the light receiving window existing inside the cover, and to always maintain high measurement accuracy.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of an optical dimension measuring device according to an embodiment. The same parts as those of the conventional optical dimension measuring machine shown in FIG. Therefore, the detailed description of the overlapping part is omitted.

In the optical dimension measuring apparatus 31 of this embodiment, the first housing 33 of the light projecting section 32 and the light receiving section 3 sandwich a predetermined measuring space 4 in which the measured object 3 is placed on the base 6.
Four second housings 35 are attached. In each of the housings 33 and 35, steps including portions of the surfaces 33a and 35a that are in contact with the measurement space 4 and a portion of the front surface are cut out in a trapezoidal shape to form steps 36 and 37. A light transmitting window 38 and a light receiving window 39 in which a transparent member is fitted are formed on the surfaces of the steps 36 and 37 facing the measurement space 4.

That is, the light projecting window 15 and the light receiving window 18 on the surfaces of the housings 9 and 17 of the conventional optical dimension measuring device 1 shown in FIGS.
The steps 36 and 37 of the optical dimension measuring device 31 of the present embodiment in FIG.

The covers 40 and 41 that cover the steps 35 and 37 are attached to the steps 35 and 37 thus formed. The surfaces of the covers 40 and 41 facing the measurement space 4 are the surfaces 33 a and 3 of the housings 33 and 35 facing the measurement space 4.
The slits 42 and 43 are formed in the same plane as 5s and are respectively formed in the vertical direction. Furthermore, covers 40 and 4
1 is provided on the upper surface of the cover 4 through slits 42 and 43.
In order to prevent minute foreign substances such as dirt, dust and dust from entering the insides 0 and 41, air supply ports 44 and 4 for supplying compressed air into the covers 40 and 41 are provided.
5 are attached.

FIG. 2A, FIG. 2B and FIG.
FIG. 9 is a top view, a side view, and a perspective view showing the cover 40 in a state where the light emitting unit 32 is detached from the stepped portion 36 of the first housing 33. On the front surface 40a of the cover 40, the aforementioned slit 42 is provided.
The cover 40 is attached to the upper and lower horizontal portions 47 a and 47 b on the stepped portion 36 of the first housing 33 by bolts 49 a and 4.
Through holes 48a and 48b for fixing at 9b are formed. Further, inclined portions 51a, 51b are formed at the rear ends of the upper and lower horizontal portions 47a, 47b. Further, a step 50 is provided on the inner surface of the vertical portion in front of the cover 40. The above-described air supply port 44 is formed in the upper horizontal portion 47a.

FIG. 3 shows that the cover 40 is attached to the first housing 33.
FIG. 7 is a top view showing a state in which it is attached to a stepped portion of FIG. A protruding portion 36 a protruding into the cover 50 is formed at a central portion of the step portion 36 of the first housing 33.

Therefore, the light emitting window 38 of the first housing 33
The parallel scanning light or the slit light emitted from the cover 40 into the cover 40 passes through the narrow gap 53 in the scanning direction of the laser light in the cover 40 and is emitted to the measurement space 4 through the slit 42 of the front surface 40a.

In this case, compressed air is supplied into the cover 40 from an air supply source (not shown) via a hose and an air supply port 44. The compressed air supplied into the cover 40 passes through the narrow gap 53 in the scanning direction of the laser beam described above and flows out of the slit 42 of the front surface 40a into the measurement space 4.
Accordingly, dust, dust and dirt are prevented from entering the cover 40 from the slit 42 against the flow of compressed air, so that dust, dust and dirt adhere to the transparent member of the light emitting window 38 beforehand. Can be prevented.

Since the cover 40 is fixed to the stepped portion 36 of the first housing 33 with bolts 49a and 49b, the cover 40 is removed as necessary, for example, at the time of periodic inspection. It is also possible to clean the transparent member of the light emitting window 38.

The detailed structure of the cover 41 attached to the step portion 37 of the second housing 35 of the light receiving section 34 and the configuration prevents dust, dirt, and dust from entering the cover 41 due to this structure. The function and effect are substantially the same as those of the cover 40 attached to the step portion 36 of the first housing 33 of the light projecting portion 32, and the description thereof will be omitted.

FIG. 4 is a schematic diagram showing the internal configuration of the optical dimension measuring device 31 of the embodiment. 4A is a side view of the optical dimension measuring device 31 shown in FIG. 1 as viewed from behind, FIG. 4B is a top view as viewed from above, and FIG. 4C is a view as viewed from this side. FIG.

As shown in FIG. 4A, in the light projecting section 32, a first housing 33 mounted on the base 6 has two regions, a front region and a rear region. FIG.
As shown in (c), the electronic circuit member 5 is provided below the area in front.
4a is housed, and the optical system is housed in other areas.

In the deep area, the laser beam 11 emitted from the laser light source 10 is deflected by a deflector 12 composed of, for example, a tuning fork or a rotating mirror, and then reflected by a reflecting mirror 13a.
Incident on The reflecting mirror 13a reflects the incident laser light 11 in the direction of the reflecting mirror 13b in the area in front. The deflected laser beam 11 reflected by the reflector 13b in the front area
Is converted into laser light 16 that has been scanned in parallel by the collimator lens 14 disposed in front of the light projecting window 38 of the step portion 36 in the first housing 33.

The parallel scanning laser light 16 emitted from the collimator lens 14 is emitted into the cover 40 via a light projecting window 38 formed in the scanning direction of the laser light 16. The parallel scanning laser light 16 emitted from the light projecting window 38 of the first housing 33 into the cover 40 passes through a narrow gap 53 in the scanning direction of the laser light in the cover 40 and passes through the slit 42 of the front surface 40a. The light is emitted to the measurement space 4.

A part of the parallel scanning laser beam 16 emitted from the slit 42 to the measurement space 4 is shielded by the measured object 3 while passing through the position of the measured object 3. On the other hand, in the light receiving section 34, the second housing 3 mounted on the base 6
As shown in FIG. 4 (b), two regions of the front and the back are formed in 5, and the electronic circuit member 54b is housed below the front region as shown in FIG. 4 (c). The optical system is housed in another area.

Then, the laser beam 1 that has passed through the measurement space 4
Numeral 6 enters the cover 41 via the slit 43 of the cover 41 attached to the step portion 37 of the second housing 35 of the light receiving section 34. The laser light 16 incident on the cover 41 passes through the cover 41 and passes through the light receiving window 39 to the second housing 35.
Incident inside.

The parallel scanning laser beam 16 that has entered the area in front of the second housing 35 via the light receiving window 39 is narrowed down by the condenser lens 19 and is turned into two reflecting mirrors 20a and 20a.
At b, the light is guided to the light receiver 21 in the back area, and is focused on the light receiving surface of the light receiver 21.

Since the time when the parallel scanning laser beam 16 crosses the measured object 3 is interrupted, the signal waveform of the detection signal of the light receiver 21 is in a low level state for a time width corresponding to the dimension (outer diameter) of the measured object 3. Pulse signal.

The detection signal from the light receiver 21 is sent to the display device 7 shown in FIG. The display device 7 detects the time width of the low-level period of the detection signal using, for example, a counter or the like, converts the time width into a size, and digitally displays the size on the display unit 8.

As described above, in the optical dimension measuring device 31 of this embodiment, as shown in FIGS. 4A, 4B, and 4C, each of the housings 33, In each optical system housed in 35, each reflecting mirror 13a, 13
The optical axes of the laser beams 11, 16 are each bent twice using b, 20a, 20b. Therefore, by arranging the optical components over both the front and back regions of the housings 33 and 35, the positions of the collimator lens 14 and the condenser lens 19 are opposed to the measurement space 4 of the housings 33 and 35. It is possible to retreat from the surface.

The space created by this retreat is defined as steps 36 and 37, covers 40 and 41 are attached to the steps 36 and 47, and the insides of the covers 40 and 41 are purged with air, and the light projecting window 38 is provided. This prevents dust, dirt and dust from adhering to the transparent member fitted into the light receiving window 39.

Therefore, even if the light projecting window 38 and the light receiving window 3
Even if the air purging covers 40 and 41 are attached in front of 9, the measuring space 4 in which the measured object 3 is placed does not become smaller than that of the conventional optical dimension measuring instrument 1 shown in FIG.

[0047]

As described above, in the optical dimension measuring device of the present invention, a step is formed in the light emitting window and the light receiving window of the light projecting unit and the light receiving unit, and this step is covered with the cover. Wrap,
The inside of this cover is air purged.

Therefore, the cover for air purging does not protrude into the measuring space, and the measuring space for placing the object to be measured is not reduced, and the cover for the light projecting unit and the light receiving unit can be mounted on the light emitting window and the light receiving window. It is possible to prevent minute foreign matters such as dust, dust and dust from adhering, and it is possible to always measure the dimensions of the measured object with high accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an optical dimension measuring device according to an embodiment of the present invention.

FIG. 2 is a detailed configuration diagram showing a state where a cover incorporated in the optical dimension measuring instrument is removed.

FIG. 3 is a diagram showing details of a portion where the cover is attached to the housing in the optical dimension measuring device.

FIG. 4 is a side view and a top view of the internal structure of the optical dimension measuring instrument as viewed from various directions.

FIG. 5 is a perspective view showing a schematic configuration of a conventional optical dimension measuring device.

FIG. 6 is a side view and a top view of the internal structure of the conventional optical dimension measuring instrument as viewed from various directions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Measurement object 4 ... Measurement space 7 ... Display apparatus 10 ... Laser light source 11,16 ... Laser light 12 ... Deflector 13a, 13b, 20a, 20b ... Plane mirror 21 ... Receiver 31 ... Optical dimension measuring machine 32 ... Throw Light unit 33: First housing 34: Light receiving unit 35: Second housing 36, 37 ... Step 38: Light emitting window 39: Light receiving window 40, 41 ... Cover 42, 43 ... Slit 44, 45 ... Air Supply port

Claims (1)

[Claims] 1. A light source and an optical system incorporated in a first housing, and parallel scanning light or slit light is transmitted from a light emitting window (38) of the first housing into which a transparent member is fitted. A light projecting unit (32) for emitting light, and a measuring space (4) for disposing an object to be measured with respect to the light projecting unit are arranged via the light projecting window of the light projecting unit. The parallel scanning light or the slit light, a part of which is shielded by the measured object, is taken into the second housing through the light receiving window (39) of the second housing in which the transparent member is fitted, An optical system incorporated in the housing of the second case, guided to a light receiver, and a light receiving unit (34) for obtaining and outputting a detection signal relating to the size of the object to be measured; The portion of the housing (33, 35) facing the measurement space of the second housing (33, 35) provided with the light-emitting window or the light-receiving window may be retracted from the measurement space. A pair of covers (40, 41) covering the steps formed in the first and second housings; and a cover for each of the covers with respect to the measurement space. Slits (42, 43) formed on the opposing surface to allow light passing through the light emitting window or light receiving window to enter and exit the measurement space, and provided on each of the covers, and inside the cover via the slits An optical dimension measuring machine having air supply ports (44, 45) for air purging for preventing entry of minute foreign matter.