JPH1163925A - Image sensing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable clear image sensing of a plurality of measuring part positions, by a method wherein, in the state that a camera is forcused on one measuring part position of an object to be measured and is not focused on the other measuring part position, images of both part positions are picked up at the same time, and correction is so performed by using a transparent plate that the image of the other part position is formed on the imaging surface of the image sensing means. SOLUTION: A connector 4 is fixed to a holding member 3, and each pin 5 and reference segments 6 of the connector 4 are made to face a CCD camera 7. By moving the CCD camera 7 from one end of a guide rail 9 toward the other end, images of each pin 5 and the reference segments 6 of the connector 4 are picked up in order. The CCD camera 7 is adjusted to form the focus on the tips of the pins 5 of the connector 4, so that the images of the pins 5 are formed on the imaging surface of the CCD camera 7. By transparent plates 11 arranged between the CCD camera 7 and the reference segments 6, the focus of the CCD camera 7 is fitted to also the reference segments 6. Thereby the images of the reference segments 6 are formed on the imaging surface of the CCD camera 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an imaging apparatus for imaging at least two measurement sites of an object to be measured.

[0002]

2. Description of the Related Art When imaging two measurement sites U1 and U2 of an object to be measured using a conventional imaging apparatus, f is a focal length, m is an imaging magnification, e is an allowable confusion circle diameter, and F is a lens. , The depth of field U is given by the following equation.

U1 = −e ｛(1 / m) −1｝ / ｛(f /
F) m + e｝ × f U2 = −e ｛(1 / m) −1｝ / − ｛(f / F) m +
e｝ × f U = −U1 + U2 Here, the F value is calculated from the following equation: e = 2.44 × λ × effective F value Effective F value = F value × (magnification + 1) can get.

Now, e = 10 μm, m = 2, f = 35 mm
In the case of, when the depth of field U is calculated using the above formula, the effective F value = 0.01 / 2.44 / (590 × 10 ⁻⁶ ) =
6.9 F value = 6.9 / (2 + 1) = 4.6 U1 = −0.03 mm U2 = 0.03 mm U = −U1 + U2 = 0.06 mm

[0005]

As described above, when the depth of field U is extremely small as 0.06 mm, the difference between the positions of the respective measurement parts in the optical axis direction may be larger than the depth of field U. There were many. When the difference between the positions of the respective measurement parts in the optical axis direction is larger than the depth of field U, at least one of the measurement parts cannot be clearly imaged, which is a problem.

An object of the present invention is to solve such a problem and to provide an image pickup apparatus capable of clearly picking up images of at least two measurement sites.

[0007]

In order to solve the above-mentioned problems, an image pickup apparatus according to the present invention is an image pickup apparatus for simultaneously picking up at least two measurement sites of an object to be measured.
In a state where one of the measurement parts of the DUT is focused and the other measurement part is out of focus, imaging means for simultaneously imaging both of the measurement parts, and the other measurement part of the DUT A transparent plate that is provided between the imaging unit and the correction unit so that an image of the other measurement site is formed on the imaging surface of the imaging unit.

As described above, since the imaging means focuses on one measurement site of the measured object, a clear image of one measurement site is captured by the imaging means. In addition, the image of the other measurement site is corrected by the transparent plate provided between the other measurement site of the DUT and the imaging unit so that the image is formed on the imaging surface of the imaging unit. A clear image of the part is captured by the imaging means. As a result, clear images of both measurement sites of the object to be measured are simultaneously captured by the imaging unit.

Here, it is preferable that the transparent plate has a wedge shape. When such a configuration is employed, even when the other measurement site is protruding from the imaging surface of the imaging unit, the imaging position of the other measurement site is moved to the imaging surface of the imaging unit by the wedge-shaped transparent plate. And both measurement sites can be imaged simultaneously.

In order to solve the above-mentioned problems, an imaging apparatus according to the present invention is an imaging apparatus for simultaneously imaging at least two measurement sites of an object to be measured. An imaging unit that simultaneously captures both of the measurement sites in a displaced state and an image capturing unit that is provided between both the measurement sites and the imaging unit of the object to be measured. And a transparent plate that performs correction.

As described above, since the imaging unit is not focused on both measurement sites of the object to be measured, clear images of both measurement sites cannot be captured by the imaging unit. Therefore, the transparent plate provided between both the measurement sites of the DUT and the imaging unit corrects the images of both the measurement sites so that the images are simultaneously formed on the imaging surface of the imaging unit. A clear image of the measurement site is captured simultaneously by the imaging means.

In this case, it is preferable that the transparent plate includes a parallel plate-shaped portion for correcting an image of one measurement site and a wedge-shaped portion for correcting the image of the other measurement site. When such a configuration is adopted, the image of one measurement site can be clearly displayed by the parallel plate-shaped portion. Furthermore, even when the other measurement site is protruding from the imaging surface of the imaging unit, the imaging position of the other measurement site can be moved onto the imaging surface of the imaging unit by the wedge-shaped portion of the transparent plate,
Both measurement sites can be imaged simultaneously.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an imaging device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a view showing an image pickup apparatus 1 according to the present embodiment. As shown in FIG. 1, the imaging device 1 includes a holding member 3 arranged on a stage 2. Holding member 3
Can hold a connector 4 as an object to be measured. The connector 4 has a plurality of pins (one measurement site) 5 arranged in a row and a pair of reference pins arranged at both ends of the pins 5. A piece (the other measurement site) 6 is provided. Above the holding member 3, there is provided a CCD camera (imaging means) 7 which simultaneously images both the pin 5 and the reference piece 6 and has a very small depth of field of about 0.06 mm. The CCD camera 7 includes an imaging element 7a that captures an image of the connector 4 and an imaging lens 7b that forms an image of the connector 4 on an imaging surface of the imaging element 7a.

The CCD camera 7 is mounted on a pair of columns 8 standing upright from the stage 2 and is fixed to a guide rail 9 extending parallel to the upper surface of the stage 2. The driving motor 1 provided on the CCD camera 7
By driving 0, the CCD camera 7 moves in the left-right direction along the guide rail 9. Furthermore, CCD
Between the camera 7 and the connector 4, there is provided a parallel plate-shaped transparent plate 11 for adjusting the imaging position of the CCD camera 7. The transparent plate 11 includes a support 12 standing upright from the stage 2.
And extends to cover the reference piece 6 of the connector 4 from above. In addition, as the transparent plate 11, a transparent glass plate or a plastic plate that transmits light with a predetermined refractive index is used.

Here, the pins 5 of the connector 4 have substantially the same height, and the reference pieces 6 of the connector 4 also have substantially the same height. Further, each reference piece 6 is higher than each pin 5, and the height difference between the pin 5 and the reference piece 6 is 1 to 0.5 mm which is larger than the depth of field of the CCD camera 7. Therefore, pin 5
If any one of the reference piece 6 and the reference piece 6 is focused, the other image is blurred. And 1-0.5mm
In order to respond to the need to simultaneously and clearly visualize the pin 5 and the reference piece 6 having such a small dimensional difference, the image pickup apparatus 1 adjusts the focus of the CCD camera 7 with respect to the pin 5 and the CCD camera 7. A transparent plate 1 as a focus adjustment plate having two parallel planes between
1 is adjusted so that the imaging position of the reference piece 6 is substantially the same as the imaging position of the pin 5. As a result, a clear image of both the pin 5 and the reference piece 6 can be captured by the CCD camera 7, and the focused piece 6
, It is possible to recognize the relative positional relationship of the pin 5 with respect to.

Next, the operation of the imaging apparatus 1 according to the present embodiment will be described. First, the connector 4 is fixed to the holding member 3, and each pin 5 and each reference piece 6 of the connector 4 are
It is made to face the D camera 7. Then, the CCD camera 7 is moved from one end of the guide rail 9 to the other end, and the pins 5 and the reference pieces 6 of the connector 4 are sequentially imaged. As described above, the focus of the CCD camera 7 is adjusted so as to match the tip of the pin 5 of the connector 4. Therefore, the image of the pin 5 is formed on the imaging surface of the CCD camera 7. Also,
Transparent plate 1 placed between CCD camera 7 and reference piece 6
By 1, the CCD camera 7 is also focused on the reference piece 6. Therefore, an image of the reference piece 6 is formed on the imaging surface of the CCD camera 7.

As shown in FIG. 2, when the height of the pin 5 of the connector 4 is lower than the height of the reference piece 6 by h (h is C
Larger than the depth of field of the CD camera 7).
Assuming that 1 is not arranged, an image composed of clear pins 5 and blurred reference pieces 6 is captured by the CCD camera 7. An example of this video is shown in FIG. In fact, CC
Since the transparent plate 11 is disposed between the D camera 7 and the reference piece 6, an image of the reference piece 6 is formed on the imaging surface of the CCD camera 7. Here, the thickness t of the transparent plate 11 for forming the image of the reference piece 6 on the imaging surface of the CCD camera 7 is obtained by the following equation.

H = tt / nt t = h / (1-1 / n) (1) n: Refractive index of the transparent plate 11 at the used light source wavelength Thickness satisfying the condition of this formula (1) Transparent plate 11 with CCD
By arranging between the camera 7 and the reference piece 6, clear images can be obtained from both the pin 5 and the reference piece 6, as shown in FIG. The image obtained by the CCD camera 7 is displayed on, for example, a display (not shown).

Next, an example in which a wedge-shaped transparent plate 13 is used in place of the transparent plate 11 is shown in FIG. Here, the reference piece 6
Is located at a distance k from the optical axis of the CCD camera 7 and the reference piece 6 exists outside the imaging range j of the CCD camera 7, if the transparent plate 13 is not disposed, the sharp pins 5
Only the image (the reference piece 6 is not imaged) is imaged by the CCD camera 7. An example of this video is shown in FIG.

Further, the refractive index of the wedge-shaped transparent plate 13 with respect to the used light source wavelength is n, the wedge angle is θw, and the argument is θ.
Assuming that d, the relationship θd = sin ⁻¹ (n × sin θw) (2) holds. Reference piece 6 outside imaging range j
Is set to be within the imaging range j, and a wedge-shaped transparent plate 13 having a wedge angle θw is disposed between the CCD camera 7 and the reference piece 6 by using the equation (2). By doing so, the imaging position of the image of the reference piece 6 moves within the imaging range j of the CCD camera 7. Therefore, as shown in FIG. 5B, clear images of both the pin 5 and the reference piece 6 are captured by the CCD camera 7.

Next, FIG. 6 shows an example in which a transparent plate 14 composed of a parallel plate-shaped portion 14a and a wedge-shaped portion 14b is used instead of the transparent plate 11. Here, the reference piece 6 is separated from the optical axis of the CCD camera 7 by k and the pin 5 of the connector 4
Is higher than the height of the reference piece 6 by h (h is larger than the depth of field of the CCD camera 7), assuming that the transparent plate 14 is not disposed, only the blurred pin 5 An image (the reference piece 6 is not imaged) is imaged by the CCD camera 7. An example of this video is shown in FIG.

The thickness t of the parallel plate portion of the transparent plate 14 and the wedge angle θw of the wedge portion can be obtained based on the above-mentioned equations (1) and (2). By disposing the parallel plate-shaped portion 14a of the transparent plate 14 above the pin 5 and arranging the wedge-shaped portion 14b of the transparent plate 14 above the reference piece 6, the focus of the CCD camera 7 on the pin 5 is improved. Coincides with each other, and the imaging position of the image of the reference piece 6 moves within the imaging range j of the CCD camera 7. For this reason, as shown in FIG. 7B, both the pin 5 and the reference
The image is captured by the D camera 7.

It should be noted that the present invention is not limited to the above-described embodiment, and can be modified as follows, for example, without departing from the spirit of the present invention.

(1) In the above embodiment, two transparent plates 11, 13, and 14 are provided in accordance with the number of reference pieces 6 of the connector 4.
However, the number of the transparent plates 1 or 3 or more according to the number of the reference pieces 6 is not limited to this number.
1, 13, and 14 may be arranged.

(2) In the above embodiment, the CCD camera 7
Was used to simultaneously image the pin 5 and the reference piece 6,
The pin 5 and the reference piece 6 may be sequentially imaged while moving the CCD camera 7 along the guide rail 9. In this case, since the focus of the CCD camera 7 is on both the pin 5 and the reference piece 6, there is no need to adjust the focus when switching the imaging target.

[0027]

Since the imaging apparatus according to the present invention is configured as described above, the following effects can be obtained.

That is, imaging means for simultaneously imaging both measurement sites while one of the measurement sites is in focus and the other measurement site is out of focus; A transparent plate that is provided between the other measurement site and the imaging unit and that corrects an image of the other measurement site so that the image is formed on the imaging surface of the imaging unit; The site can be clearly imaged.

Further, an image pickup means for simultaneously picking up an image of both the measurement parts in a state where the focus is deviated with respect to both measurement parts of the object to be measured, and an image pickup means between both the measurement parts and the image pickup means of the object to be measured. The same effect can be obtained by providing a transparent plate that is provided and corrects the images of both measurement sites so that the images are formed on the imaging surface of the imaging unit.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an imaging device according to the present invention.

FIG. 2 is a diagram showing an example in which a transparent plate having a parallel plate shape is arranged between a CCD camera and a connector.

FIG. 3A is a diagram showing an image of a pin and a reference piece taken without a transparent plate, and FIG. 3B is a diagram showing an image of a pin and a reference piece taken with a transparent plate. It is.

FIG. 4 is a diagram showing an example in which a wedge-shaped transparent plate is arranged between a CCD camera and a connector.

FIG. 5A is a diagram showing an image of a pin and a reference piece taken without a transparent plate, and FIG. 5B is a diagram showing an image of a pin and a reference piece taken with a transparent plate placed. It is.

FIG. 6 is a diagram showing an example in which a transparent plate having a parallel plate-shaped portion and a wedge-shaped portion is arranged between a CCD camera and a connector.

7A is a diagram illustrating an image of a pin and a reference piece imaged without a transparent plate, and FIG. 7B is a diagram illustrating an image of a pin and a reference piece imaged with a transparent plate arranged. It is.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image pick-up device, 4 ... Connector (measurement object), 5 ... Pin (one measurement part), 6 ... Reference piece (the other measurement part)
7: CCD camera (imaging means), 11, 13, 14: transparent plate, 14a: parallel plate-shaped portion, 14b: wedge-shaped portion.

Claims (4)

[Claims] 1. An imaging apparatus for simultaneously imaging at least two measurement sites of an object to be measured, wherein one of the objects to be measured is in focus and the other is to be measured. Is displaced,
An imaging unit for simultaneously imaging both of the measurement sites; and an imaging unit provided between the other measurement site and the imaging unit of the object to be measured, and an image of the other measurement site is formed on an imaging surface of the imaging unit. An imaging device comprising: a transparent plate that corrects an image. 2. The imaging device according to claim 1, wherein the transparent plate has a wedge shape. 3. An imaging apparatus for simultaneously imaging at least two measurement parts of an object to be measured, wherein both of the measurement parts are defocused with respect to both of the measurement parts of the object to be measured. An image pickup unit that simultaneously picks up an image; and an image pickup unit that is provided between the measurement unit and the image pickup unit on both of the object to be measured so that images of both the measurement units are formed on the image pickup surface of the image pickup unit. An imaging device comprising: a transparent plate. 4. The apparatus according to claim 3, wherein the transparent plate includes a parallel plate-shaped portion for correcting an image of one of the measurement sites and a wedge-shaped portion for correcting the image of the other measurement site. An imaging device according to any one of the preceding claims.