JP3304533B2 - Pinhole element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinhole element. More specifically, the present invention relates to a pinhole element to be mounted on a device that requires the pinhole position and the focal position of the optical system to exactly match.

[0002]

2. Description of the Related Art Conventionally, the position of a pinhole element used in an apparatus such as a pinhole element of a scanning confocal optical microscope in which the pinhole position and the focal position or optical axis of an optical system must be exactly matched. Adjustment was not easy. In a case where a conventional apparatus of this type is used to match the position of a pinhole with a focal position or an optical axis in an optical system as shown in FIG.
The light flux emitted from the light source 1 and reflected by the mirror 2 and condensed at the focal position of the lens 3 is transmitted to the pinhole 5 of the pinhole element 4.
The paper 6 is placed in the vicinity of, and the degree of light hitting the paper 6 is detected to detect the position on the optical axis or the focus position. The position of the pinhole was adjusted according to the degree of the light hit.
Alternatively, a four-divided sensor 7 as shown in FIG. 6 is used instead of the paper 6, and four divided sensors 7a, 7b, 7c, 7
The center position was confirmed by comparing the output of d, and the position of the pinhole was moved so that the position of the pinhole was aligned with this.

[0003]

According to the conventional method using paper as described above, when adjusting the position of the pinhole to the focal position confirmed from the degree of light hitting the paper,
Replacement of both is indispensable, and an error accompanying the replacement has occurred. Also, depending on the method using the 4-split sensor, 4
Since the pinhole is positioned at the center position of the split sensor completely mechanically, no optical assurance can be obtained as to whether or not the two are arranged exactly correspondingly optically. Further, even if the position shifts during the operation of the apparatus, it has not been possible to detect this.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an optical guarantee for the position of an optical axis or a focal point, eliminates an error generated by replacing a pinhole with a position detecting tool, and adjusts the position during operation of the apparatus. It is an object of the present invention to provide a pinhole element capable of performing the following.

[0005]

In order to achieve the above-mentioned object, a pinhole element according to the present invention comprises a pinhole through which a light beam passes, and a light beam out of the light beam which is out of the pinhole around the pinhole. A light-shielding portion that shields the light, the light-shielding portion has an optical sensor that detects a light beam that has deviated from the pinhole, the pinhole has a circular shape, and the optical sensor of the light-shielding portion is a two-dimensional position sensor. There is a feature.

[0006]

[0007]

[Function] When the light beam that has deviated from the pinhole is shielded by the light-shielding portion, the light-shielding portion has an optical sensor, so that the deviation from the focal position of the pinhole is detected, and the position can be adjusted based on this. It is.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the pinhole element 8 is a substantially square plate-like photoelectric conversion element. A circular pinhole 9 is provided at the center, and a light beam can pass through this pinhole 9. The photoelectric conversion element includes four divided elements 10, 11, 12, and 13 divided into four crosses each having an intersection at the center of the pinhole 9. The splitting elements 10, 11, 12, and 13 individually photoelectrically convert incident light and output a light receiving signal. The luminous flux is divided by the splitting element 10,
Light is shielded at 11, 12, and 13.

The arrangement of the pinhole element 1 in the optical system will be described. FIG. 2 shows the main part of the optical system of the scanning confocal optical microscope. In the optical path of the light beam 14 emitted from the light source 1, the mirror 2 for adjusting the optical axis is arranged, and then the lens 3 is arranged. The lens 3 is a condenser lens for condensing the light beam 14, and is arranged so that the pinhole 9 of the pinhole element 8 matches the focal position. The pinhole element 8 is mounted on a two-dimensional positioning mechanism (not shown). The light detector 15 detects the light beam 14 that has passed through the pinhole 9 of the pinhole element 8.

Next, the adjustment operation will be described. First,
The pinhole element 8 is arranged so that the pinhole 9 substantially matches the focal position of the lens 3. Luminous flux 14 from light source
Is incident on any of the splitting elements 10, 11, 12, and 13, the splitting element that has received light outputs a light receiving signal. According to the magnitude of the received light signal, the two-dimensional positioning mechanism is operated to adjust the amount of received light of each divided element to be uniform and minimum.
At this time, the pinhole 9 exactly matches the focal position.

The adjustment of the focus position and the pinhole element 1 can also be performed by the automatic adjustment of the mirror tilt angle as follows. As shown in FIG. 3, the processing circuit 16 processes the outputs of the dividing elements 10, 11, 12, and 13, and compares the magnitude of each output signal. The control circuit 17 receives the output signal from the processing circuit 16 and outputs a control signal to the drive circuit 18. The mirror 2 controls the optical axis adjustment by the control of the drive circuit 18.

Next, a second embodiment will be described. First
The description of the same or similar points as in the embodiment is omitted. As shown in FIG. 4, the pinhole element 19 is a two-dimensional position detecting element. A circular pinhole 20 is provided at the center, and a light beam can pass through the pinhole 20 but is shielded from light at other portions. When the light beam enters a point other than the pinhole 20, the position of the incident point is detected. Therefore, the pinhole element 19 is moved in the direction in which the position of the incident point coincides with the pinhole 20 by operating the two-dimensional positioning mechanism.

In the embodiment, the four-division sensor and the two-dimensional position sensor have been described.
It goes without saying that, for example, a multi-division sensor such as a three-division or five-division sensor provided with a pinhole may be used. Further, since the optical path is not blocked even during operation of the apparatus, it is possible to detect and adjust the deviation between the pinhole and the optical axis or the focal position. It is needless to say that the present invention can be widely used not only in the scanning confocal optical microscope but also in an apparatus that requires the pinhole position and the focal position of the optical system or the pinhole position to exactly coincide with the optical axis.

[0014]

The present invention comprises a pinhole through which a light beam passes, and a light-shielding portion for shielding the light beam that has passed through the pinhole. Since the light-shielding portion is a pinhole element having an optical sensor, the optical axis or Adjusting the pinhole to match the focal position immediately sets the pinhole position. Therefore, optical assurance is given that the pinhole position coincides with the position of the optical axis or the focal point, and errors caused by replacing the pinhole element with the position detection tool can be eliminated. Moreover, there is an effect that the adjustment can be performed even during operation of the apparatus.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is an optical diagram showing a main part of an optical system equipped with the first embodiment.

FIG. 3 is a circuit diagram for automatic position adjustment according to the first embodiment.

FIG. 4 is a plan view of a second embodiment.

FIG. 5 is an optical diagram showing a main part of an optical system equipped with a conventional example.

FIG. 6 is a plan view of a conventional example.

[Description of Signs] 1... Light source 2... Mirror 3... Lens 8, 19... Pinhole element 9, 20. , 12, 13, .... Splitting element 14 ... Light flux 15 ... Photodetector

Claims (1)

(57) [Claims] A pinhole through which a light beam passes; and a light-shielding portion that shields a light beam out of the pinhole in the light beam around the pinhole, wherein the light-shielding portion is out of the pinhole. A pinhole element having an optical sensor for detecting a light beam, wherein the pinhole has a circular shape, and the optical sensor of the light shielding portion is a two-dimensional position sensor.