JPH0160765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an optical outer dimension measuring method in which the object to be measured is placed in a beam of light irradiating a light receiving element, and the dimensions of the object are measured based on the amount of light beam shielded by the object. Regarding.

In the optical external dimension measurement method, a charge-coupled device (hereinafter referred to as CCD) is usually used as a light-receiving element of a light-receiving section that receives parallel light beams, and the photosensitive area of this CCD becomes the object measurement range. Therefore, conventionally, when measuring the outer dimensions of a workpiece that exceeds this photosensitive area, the same CCD 1,
2 was placed in a straight line for measurement. However, as shown in FIG. 2, the length l1 of the photosensitive areas 1a and 2a of the CCDs 1 and 2 is shorter than the total length l2 of the CCD package, so the end surfaces of the CCDs 1 and 2 are brought into contact with each other and bonded. There are also blind regions 1b and 2b in which the parallel light beam φ cannot be sensed. As shown in Fig. 1, the large diameter object 3 is in the dead area 1
When arranged so as to cover the objects 1b and 2b, there is no need to sense the parallel light beam φ in the insensitive regions 1b and 2b, so the outer diameter of the large diameter object 3 can be measured by calculation processing. However, the small-diameter measured object 3a as shown by the dashed line in FIG.
When placed inside, measurement becomes impossible. In this case, the object to be measured 3a indicated by the dashed line must be moved to the photosensitive area of either CCD 1 or 2, and in FIG. The object to be measured was moved and placed like object 3a, and the range was switched to the CCD1 only measurement method.

However, as described above, in the conventional measurement method in which the end surfaces of multiple CCDs are simply joined together to extend the photosensitive area, there is a dead area, which causes the object to be measured (cable, hose, etc.) to vibrate. If you place the object to be measured while it is being pushed out, there is a risk that the measurement edge of the object will be located in the dead area, and if the object is small, both CCDs
There was an inconvenience that measurements could not be taken using the measurement range that uses the .

This invention was made in view of the above drawbacks.
Measurement of the object to be measured A continuous photosensitive area is configured in the length direction, and within this range, it is possible to directly measure objects from small to large diameters without having to move the installation position. The purpose is to provide an optical external dimension measurement method.

In summary, the present invention can be summarized by placing a plurality of charge-coupled devices at positions shifted in the width direction of the object to be measured so that their respective linear photosensitive areas are continuous on a plane substantially parallel to the length direction of the object to be measured. The device is characterized in that parallel light beams are irradiated from multiple directions and intersect at the measurement point of the object to be measured.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a schematic diagram of a measuring device for carrying out the optical outer dimension measuring method of the present invention, FIG. 5 is a top view thereof, and FIG. 6 is a side view thereof.

The light receiving section 4 has the same CCDs 1 and 2 having linear photosensitive areas at two locations on one plane, and their bottom surfaces are fixed at positions shifted in the width direction of the object to be measured 3 so that they are arranged parallel to each other. It is configured.

As is clear from the side view of FIG. 6, the dead area 1b of the CCD 1 is
is arranged so that it can be covered by a part of the photosensitive area 2a of the CCD, and the insensitive area 2b of the CCD2 can be covered by a part of the photosensitive area 1a of the CCD1. That is, the CCDs 1 and 2 are arranged so that the two linear photosensitive regions 1a and 2a are continuous on a plane parallel to the measurement length direction of the object 3. Therefore,
The photosensitive area, which is approximately twice as long as when using one CCD, is an allowable range in which the object to be measured 3 can be placed arbitrarily, and is the maximum diameter of the object to be measured 3 that can be measured.

This embodiment has two optical path systems,
The parallel light beams φ1 and φ2 irradiated toward the respective photosensitive regions 1a and 2a of the CCDs 1 and 2 have light beams in the measurement length direction of the object 3, and are at an angle θ at the dimension measurement point of the object 3. The beams are irradiated in an intersecting manner. That is, as shown in the top and side views of FIGS. 5 and 6, the two parallel light beams φ1 and φ2 are parallel to each other when viewed from the direction in which the measured length of the object to be measured 3 is projected, and They are set to intersect at the measurement point of the object to be measured 3 at an angle of θ (0°<θ<180°).

In the apparatus configured as described above, when the cylindrical measured object 3 as shown in FIG. 4 is arranged, the parallel light beams φ1 and φ
If the length of the photosensitive area in the measurement length direction of 2 is l3, the light receiving length measured by CCDs 1 and 2 is l4,
l5, and the diameter L of the object to be measured 3 is finally determined as L=l3-l4-l5. The object to be measured 3 is CCD1
It is possible to measure up to approximately twice the size compared to the case of a single object, and unlike the conventional measurement method shown in Fig. 1, the dead area is covered, so the object to be measured 3 is Continuous double sensitive area 1
It can be arbitrarily placed and measured anywhere within the range of a and 2a. In addition, in the conventional measurement method, the dead areas 1b and 2b are set to be calculated as part of the measurement length of the large-diameter object 3. object to be measured 3a
When measuring, change the range of the measuring instrument.
It used to be necessary to make measurements using only the CCD 1, but with this device, even small-diameter objects 3a can be directly measured in the same range because there is no dead area. Moreover, since this device uses two systems of parallel light beams φ1 and φ2 that intersect at an angle of θ at the dimension measurement point, even if the object to be measured is tilted in the measurement length direction, the area where the light beams intersect will be Since there is little variation in the measured length, measurement errors can be reduced.

In addition, in the above device, the two CCDs 1 and 2 arranged in the light receiving section 4 are arranged on one plane, but the CCDs 1 and 2 are arranged on one plane.
In order to improve the light receiving sensitivity of 2, the parallel light beams φ1 and φ2 may be tilted to an angle at which they are vertically received, as shown in FIG. In addition, parallel light beams that intersect at the measurement point were irradiated from two directions toward two CCDs.
By adding more CCDs, three
By irradiating parallel light beams that intersect at the dimension measurement point from different directions, measurement errors caused by inclination or twisting of the object to be measured can be further reduced. That is, as shown in Fig. 8, three CCDs 10 to 12 are arranged parallel to each other in an alternately shifted manner.
If you measure the light receiving lengths of 0 and 11 and find their average value, then measure the outer dimensions of the object 3 from that average value and the light receiving length of CCD 12, the above average value will be calculated by CCD 12. Since it is approximately equal to the light reception length measured by continuous virtual CCDs 13, when the object to be measured 3 is tilted, two CCDs 10,
12 or 11, 12, the external dimension measurement accuracy is further improved.

As described above, according to the present invention, multiple CCDs
are placed at positions shifted in the width direction of the object to be measured so that each linear photosensitive area is continuous on a plane substantially parallel to the length direction of the object to be measured, and parallel light beams are irradiated from multiple directions. Since they intersect at the measurement point of the object to be measured, it is possible to directly measure objects from small diameter objects to large diameter objects within the same measurement range, without having to change the placement position, as long as they are within a continuous photosensitive area. Therefore, the absolute value comparison becomes obvious at a glance, and the arithmetic circuit of the main body of the measuring instrument can be greatly simplified. Furthermore, since measurement is performed with the parallel light beams intersecting at the dimension measurement point of the object to be measured, measurement errors can be reduced even if the object to be measured is tilted or twisted.

[Brief explanation of drawings]

FIGS. 1 and 3 are diagrams for explaining a conventional optical external dimension measuring method, respectively, and FIG. 2 is a top view of a CCD. FIG. 4 is a schematic perspective view of an apparatus implementing the measuring method of the present invention, FIG. 5 is a top view thereof, and FIG. 6 is a side view thereof. FIG. 7 is a diagram showing an example of arrangement of CCDs for improving light receiving sensitivity. Also the 8th
9 show an example of the arrangement of CCDs for improving measurement accuracy, FIG. 8 is a front arrangement view, and FIG. 9 is a top arrangement view. 1, 2...CCD (charge coupled device), 1a, 2a...
Photosensitive area, 1b, 2b... Insensitive area, 3, 3a... Measured object, 4... Light receiving section, φ, φ1, φ2... Parallel light beam.

Claims (1)

[Scope of Claims] 1. A method in which a parallel light beam is irradiated from the front of the object to be measured, with the object to be measured being placed in front of a light-receiving section that includes a plurality of charge-coupled devices having linear photosensitive areas. In the optical external dimension measuring method of measuring the dimension of the object to be measured from the light receiving length of the plurality of charge-coupled devices, the linear photosensitive area of each of the plurality of charge-coupled devices A plurality of parallel light beams having a luminous flux in the measurement length direction of the object to be measured are connected to each other by charge coupling. It is characterized by irradiating a photosensitive area of the device from a plurality of directions so as to intersect at a dimension measurement point of the object to be measured, and measuring the dimensions of the object to be measured based on the light receiving length of the plurality of charge-coupled devices. Optical external dimension measurement method. 2. The optical external dimension measuring method according to claim 1, wherein the plurality of charge-coupled devices are tilted at an angle to perpendicularly receive the parallel light beams irradiated from a plurality of directions.