JPH0749210A - Pinhole element - Google Patents

Abstract

PURPOSE:To provide a highly accurate and convenient pinhole element by equipping a photo sensor having a pinhole to allow the passage of a light flux and a shading section to block a light flux outside the pinhole. CONSTITUTION:A mirror 2 and a lens 3 for optical axis adjustment are laid on the optical path of a light flux 14 emitted from an illuminant 1, so as to keep the pinhole 9 of a pinhole element 8 aligned with the focal point of the lens 3. Also, the element 8 is placed on a two-dimensional positioning mechanism. A photo detector 15 detects the light flux 14 transmitted through the pinhole 9 of the element 8. When the flux 14 is incident on any of divided elements, the element exposed thereto outputs a signal for the receipt of light. Also, the two-dimensional positioning mechanism is operated according to the magnitude of the signal, for adjusting the amount of luminous energy received with each divided element at uniform and minimum level. As a result, the pinhole 9 is accurately aligned with the position of the focal point.

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 mounted on an apparatus in which the pinhole position and the focal position of the optical system must be exactly matched.

[0002]

2. Description of the Related Art Conventionally, the position of a pinhole element used in a device such as a pinhole element of a scanning confocal optical microscope, which requires the pinhole position and the focal point of the optical system or the optical axis to exactly match. Adjustment was not easy. When a conventional device of this type is used in an optical system as shown in FIG. 5 to match the pinhole position with the focal position or the optical axis,
The light flux emitted from the light source 1, reflected by the mirror 2, and condensed at the focal position of the lens 3 is pinhole 5 of the pinhole element 4.
The paper 6 was placed in the vicinity of and the position of the focal point on the optical axis was detected by observing how the light hits the paper 6. The position of the pinhole was adjusted according to how the light hits.
Alternatively, instead of the paper 6, a four-division sensor 7 as shown in FIG. 6 is used, and four division sensors 7a, 7b, 7c, 7 are used.
The center position was confirmed by comparing the outputs 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 of using paper as described above, when the position of the pinhole is adjusted to the focus position confirmed from how the light hits the paper,
The replacement of both was indispensable and an error occurred due to the replacement. Also, depending on the method of using the 4-division sensor, 4
Positioning the pinhole by substituting it for the central position of the divided sensor is performed completely mechanically, so that it is not possible to optically obtain an optical guarantee as to whether or not the two are accurately arranged. Further, even if the position shift occurs during the operation of the apparatus, it is impossible to detect this.

In view of the above problems, the present invention gives an optical guarantee to the position of the optical axis or the focus, eliminates the error caused by the replacement of the position detection tool and the pinhole, and adjusts the position even while the apparatus is in operation. It is an object of the present invention to provide a pinhole device capable of

[0005]

According to the present invention, there is provided a pinhole through which a light beam passes, and a light-shielding portion which shields the light beam out of the pinhole out of the light beam around the pinhole. The section has an optical sensor that detects a light beam that has deviated from the pinhole.

The pinhole has a circular shape, and the light sensor of the light shielding portion is a divided sensor divided into four substantially in a cross shape having an intersection at the center of the circle, or the pinhole has a circular shape and has a circular shape. The optical sensor is preferably a two-dimensional position sensor.

[0007]

[Function] When the light beam that has deviated from the pinhole is blocked by the light-shielding portion, the light-shielding portion has an optical sensor, so that the deviation from the focus position of the pinhole can be detected and the position can be adjusted based on this. 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-shaped photoelectric conversion element. A circular pinhole 9 is provided in the center, and the light flux can pass through this pinhole 9. The photoelectric conversion element is composed of four dividing elements 10, 11, 12, and 13 which are divided into four substantially in a cross shape 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 reception signal. Also, the luminous flux is
The light is blocked 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, a mirror 2 for adjusting the optical axis is arranged, and then a lens 3 is arranged. The lens 3 is a condenser lens that condenses the light flux 14, and is arranged so that the pinhole 9 of the pinhole element 8 matches the focal position thereof. The pinhole element 8 is mounted on a two-dimensional positioning mechanism (not shown). The photodetector 15 detects the light flux 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 from the light source 14
Is incident on any of the splitting elements 10, 11, 12, and 13, the splitting element that receives the light outputs a light receiving signal. The two-dimensional positioning mechanism is operated according to the magnitude of the received light signal so that the amount of light received by each splitting element is uniform and minimized.
At this time, the pinhole 9 exactly matches the focal position.

The focus position and the pinhole element 1 can also be adjusted by automatically adjusting the tilt angle of the mirror 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 magnitudes of the respective output signals. 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 under the control of the drive circuit 18.

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

Although the four-division sensor and the two-dimensional position sensor are shown in the embodiments, position detecting sensors of other shapes,
It goes without saying that, for example, a multi-divided sensor such as 3-divided or 5-divided sensor provided with pinholes may be used. Further, since the optical path is not blocked even when the apparatus is in operation, it is possible to detect and adjust the deviation between the pinhole and the optical axis or the focus position. It is needless to say that the present invention can be widely used not only for the scanning confocal optical microscope, but also for an apparatus in which the pinhole position and the focal position of the optical system or the pinhole position must be exactly aligned with the optical axis.

[0014]

The present invention comprises a pinhole through which a light beam passes, and a light-shielding portion that shields the light beam that has deviated from the pinhole, and the light-shielding portion is a pinhole element having an optical sensor. Adjusting the pinhole so that it matches the focus position immediately sets the pinhole position. Therefore, an optical guarantee is given that the pinhole position matches the position of the optical axis or the focal point, and the error caused by the replacement of the position detection tool and the pinhole element can be eliminated. Moreover, there is an effect that adjustment can be performed even while the apparatus is in operation.

[Brief description of 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 the 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.

[Explanation of symbols]

 1 ... Light source 2 ... Mirror 3 ... Lens 8, 19 ... Pinhole element 9, 20 ... Pinhole 10, 11, 12, 13 ... .... Splitting element 14 ... Luminous flux 15 ... Photodetector

Claims (3)

[Claims] 1. A pinhole through which a light flux passes, and a light-shielding portion that shields a portion of the light flux that has deviated from the pinhole around the pinhole, and the light-shielding portion deviates from the pinhole. A pinhole element having an optical sensor for detecting a light flux. 2. The pinhole has a circular shape, and the optical sensor of the light-shielding portion is a crossed sensor divided into approximately four in a cross shape having an intersection at the center of the circle. Pinhole element. 3. The pinhole element according to claim 1, wherein the pinhole has a circular shape, and the light sensor of the light shielding portion is a two-dimensional position sensor.