JP5673376B2 - Spectroscopic optical adjustment method and adjustment jig - Google Patents

Description

  The present invention relates to an optical adjustment method and adjustment jig for a Zernitana spectrometer.

  A spectrophotometer irradiates a sample with measurement light that has been separated by a single wavelength with a spectroscope, and measures the transmitted or reflected light with a photodetector to obtain the spectral spectrum of the sample for quantitative or qualitative analysis. It is a device that performs. For example, a spectrophotometer using a Zellnitana type spectrometer as disclosed in Patent Document 1 and Patent Document 2 is known.

  FIG. 9 shows an optical path configuration of a general Zernitana spectrometer. Light introduced from the light source through the entrance slit 21 into the spectroscope is reflected as a parallel light beam by the first mirror 22 and sent to the plane diffraction grating (spectral element) 23. The light wavelength-dispersed by the planar diffraction grating 23 is reflected and collected by the second mirror 24 while being kept parallel, and sent to the exit slit 25. The light having a specific wavelength that has passed through the exit slit 25 passes through the sample in a subsequent sample chamber (not shown), and is then detected by a photodetector (not shown). The planar diffraction grating 23 is formed so as to be rotatable so that the reflection angle can be changed. By rotating the planar diffraction grating 23, the wavelength of the light reaching the opening position of the exit slit 25 changes, and a desired wavelength is obtained. Monochromatic light can be extracted.

  In order to obtain good wavelength resolution performance, the image at the entrance slit opening must be clearly formed on the exit slit surface. In order to adjust to such a state, it is necessary to perform the focus adjustment work by moving the first mirror 22 and the second mirror 24 in the optical path direction (referred to as the focus direction) of incident light and reflected light. Conventionally, in order to perform this focus adjustment, the focus adjustment has been completed by adjusting the displacement of only the second mirror 24 that receives the parallel light beam from the diffraction grating 23. Therefore, in such adjustment, the parallel light beam directed from the first mirror 22 to the diffraction grating 23 is not a perfectly adjusted parallel light beam but merely a substantially parallel light beam.

JP-A-8-145793 JP 2000-32136 A

  In this way, since the light flux from the first mirror is not a strictly adjusted parallel light flux, if the parallelism of the parallel light flux sent from the first mirror to the planar diffraction grating is out of order, even if the second mirror Even if only the adjustment was performed accurately and an accurate focus was obtained, the best wavelength resolution performance could not be exhibited.

  Accordingly, an object of the present invention is to provide an optical adjustment method that can be adjusted to a state in which the best wavelength resolution performance is exhibited, and an adjustment jig therefor.

In order to achieve the above object, the present invention takes the following technical means. That is, in the spectroscope optical adjustment method of the present invention, the light passing through the entrance slit is reflected by the first mirror and sent to the diffraction grating, and the light wavelength-dispersed by the diffraction grating is reflected by the second mirror and exit slit. Is a method for optically adjusting a spectroscope that transmits light to a light source and includes a light source and an optical element that converts light from the light source into a parallel light beam on a jig base, and the light emitted from the optical element is precisely parallel An adjustment jig for optical adjustment set in advance so as to obtain a light beam is prepared, and the adjustment jig is arranged on an optical path incident on the second mirror from the diffraction grating .
Then, the parallel light beam emitted from the adjustment jig is sent to the first mirror, the light reflected and collected by the first mirror is passed through the entrance slit, and the light beam pattern is displayed on the image observation member arranged in the vicinity thereof. The focus of the first mirror is adjusted by moving the first mirror or the entrance slit so as to obtain an appropriate light beam pattern based on the light beam pattern.
In the above-described invention, the image observation member may be a two-dimensional image sensor for displaying on a screen or a monitor.

  According to the method of the present invention, it is possible to accurately and easily adjust the parallel light flux from the first mirror, and it is possible to provide a spectrophotometer having high wavelength resolution performance.

In the second optical adjustment method of the present invention, the light passing through the entrance slit is reflected by the first mirror and sent to the diffraction grating, and the light wavelength-dispersed by the diffraction grating is reflected by the second mirror and exit slit. Is an optical adjustment method for a spectroscope that transmits light to a spectrometer and collects the parallel light beam from the first mirror of the spectroscope, and an image that displays an image or light beam pattern of the light collected by the optical element And an optical member that is set in advance so that an appropriate image or an appropriate light beam pattern is displayed on the image observation member when a precise parallel light beam is incident on the condensing optical element from the first mirror. Prepare an adjustment jig. The adjusting jig is arranged on the optical path, and the light or the light beam pattern incident on the entrance slit is displayed on the image observation member from the first mirror through the condensing optical element. Based on the image or the light beam pattern, The parallel light flux of the first mirror is adjusted by moving the first mirror or the entrance slit.
Here, the image observation member of the adjustment jig may be a two-dimensional imaging element for displaying on a screen or a monitor attached to an imaging position of light condensed by the condensing optical element.
In addition, the image observation member of the adjustment jig may be a slit-like opening attached to the imaging position of the light condensed by the condensing optical element.
Further, the image observation member of the adjustment jig is used for displaying on a screen or a monitor disposed behind the slit-like opening attached to the imaging position of the light condensed by the condensing optical element. A two-dimensional image sensor may be used.
Also by the second optical adjustment method, it is possible to accurately and easily adjust the parallel light flux from the first mirror, and it is possible to provide a spectrophotometer having high wavelength resolution performance.

In addition, an optical adjustment jig for a spectroscope according to another aspect of the present invention, which is made from another viewpoint, includes a light source, an optical element that converts light from the light source into a parallel light beam, and light that has been converted into a parallel light beam. The jig base is provided with a flat mirror that reflects the light as it is, and the jig base is detachably mounted on the base of the spectroscope by a fixing means so that the light emitted from the optical element is accurately collimated in advance. It has been set.

An optical adjustment jig for a spectroscope which is another aspect of the present invention made from another viewpoint includes an optical element for condensing a parallel light beam from a first mirror of the spectroscope, and the condensing optical element. An image observation member for displaying an image of the condensed light or a light flux pattern is provided on the jig base, and the jig base is detachably attached to the base of the spectroscope by a fixing means. An appropriate image or an appropriate light beam pattern is set in advance so that the image observation member is displayed when a precise parallel light beam is incident on the element.
According to these, it is possible to precisely adjust the parallel light flux from the first mirror, and it is possible to provide a spectrophotometer having a high wavelength resolution performance.
Further, it is possible to provide a jig capable of precisely adjusting the parallel light flux of the first mirror with a simple configuration.

1 is a schematic plan view of a spectroscope that performs optical adjustment using an adjustment jig according to the present invention. The perspective view which shows the attachment mechanism of the mirror of a spectrometer. Sectional drawing along the optical path direction in FIG. Sectional drawing of an attachment screw part. The perspective view which shows the state which attached the jig for optical adjustment which concerns on this invention to the spectrometer. Sectional drawing which shows the attachment part of the optical adjustment jig | tool of FIG. The top view which shows the optical adjustment method by the optical adjustment jig | tool of FIG. The top view similar to FIG. 7 which shows another Example of the optical adjustment method which concerns on this invention. Explanatory drawing which shows the optical path structure of the conventional spectrometer.

Hereinafter, the present invention will be described in detail with reference to the drawings showing examples.
FIG. 1 is a schematic plan view of a spectroscope that performs optical adjustment using an adjustment jig according to the present invention. The optical path configuration of this spectrometer employs a Zernitana type spectrometer.
That is, the entrance slit 1 that allows light from the light source to pass through, the first mirror (collimator mirror) 2 that reflects the light that has passed through the entrance slit 1 and is introduced into the spectroscope into a parallel light beam, and the first mirror 2. A plane diffraction grating (spectral element) 3 that reflects the light transmitted from the wavelength dispersion while maintaining parallelism, and a second mirror that reflects and condenses the light from the plane diffraction grating 3 and sends it to the exit slit 5 ( Camera mirror) 4.

The light having a specific wavelength that has passed through the exit slit 5 of the spectrometer is detected by a photodetector 6 provided outside. In an actual spectrophotometer, a sample chamber is also provided between the exit slit 5 and the photodetector 6, or an optical path switching element such as a sector mirror is provided. However, since it is a part that does not directly affect the optical adjustment method of the spectrometer according to the present invention, the illustration is omitted for convenience.
The planar diffraction grating 3 is rotatably mounted so that the reflection angle can be changed. By rotating the planar diffraction grating 3, the wavelength of light reaching the opening position of the exit slit 5 changes, and the photodetector 6, monochromatic light having a desired wavelength can be detected.

  As shown in FIGS. 2 to 4, the first mirror 2 and the second mirror 4 are attached to the base 12 (of the spectroscope) so that the mirror angle and position with respect to the optical path of incident light or reflected light can be adjusted. Yes. The configuration for making these optical elements adjustable with respect to the base 12 is not particularly limited, but an example of the configuration will be described based on these drawings.

  The first mirror 2 and the second mirror 4 are each fixed to a vertical piece 7a of the L-shaped holder 7 in a vertical posture. The holder 7 is attached to a flat base 8 through two front and rear adjustment screws 9 and 9. These two adjusting screws 9 and 9 are arranged substantially along the optical path direction of the reflected light (or incident light). By pushing or loosening these two adjusting screws 9 and 9, the holder 7 The elevation of the mirrors 2 and 4 (also referred to as the pitch angle) is adjusted by displacing the holder 7 like a seesaw using the protrusion 10 formed on the lower surface as a fulcrum.

  In addition, a pin 11 perpendicular to the lower surface of the base 8 is provided below the mirrors 2 and 4, and this pin 11 is rotatably inserted into a hole 13 formed in the base 12, and a mounting screw is provided. It is fixed to the base 12 via 14. The screw receiving hole 15 of the base 8 into which the mounting screw 14 is inserted is formed larger than the outer diameter of the mounting screw 14, and is formed so that an adjustment gap S is formed between the mounting screw 14 and the mounting screw 14. Therefore, the pedestal 8 can be rotated and adjusted with the pin 11 as a fulcrum by the gap S. Thereby, the angle (yaw direction) around the vertical axis of the mirrors 2 and 4 with the pin 11 as a fulcrum can be adjusted.

  Further, the hole 13 of the base 12 for receiving the pin 11 and the screw receiving hole 15 of the mounting screw 14 are formed in a long hole along the optical axis direction, whereby the base 8 is in the optical axis direction (focus direction). Can be adjusted to move.

  5 to 7 show an optical adjustment jig according to an embodiment of the present invention. This optical adjustment jig A is disposed on the optical path of the parallel light beam incident on the second mirror 4 from the diffraction grating 3 of the spectroscope, and the second mirror 4 is removed together with the base 8 to the base 12. It is attached.

  The adjustment jig A includes a light source 16, a lens 17 that converts the light from the light source 16 into a parallel light beam, a flat mirror 18 that reflects the parallel light beam from the lens 17, and the light source 16, the lens 17, and the flat mirror 18. It is comprised from the elongate plate-shaped jig | tool base 19 arrange | positioned on a straight line at intervals. The jig base 19 is detachably attached to the base 12 by fitting a pin 21 provided on the lower surface thereof into a receiving hole 20 formed at a predetermined position of the base 12 of the spectrometer and then tightening with a fixing screw 22. In this jig, the light emitted from the lens 17 is adjusted in advance so as to be strictly a parallel light beam by another optical device. The light source 16 is formed so that it can be finely adjusted in the optical path direction.

  When adjusting the parallel light flux from the first mirror 2, the optical adjustment jig A is attached to the base 12, and a screen 23 as an image observation member is disposed outside the entrance slit 1 to irradiate light from the light source 16. The irradiated light is reflected by the flat mirror 18 as a strict parallel light beam by the lens 17 and sent to the first mirror 2 while maintaining the parallel light beam. The light reflected by the first mirror 2 is collected and reaches the entrance slit 1, and the light that has passed through the entrance slit 1 projects a light flux pattern on the observation screen 23. While viewing the light beam pattern of the image projected on the screen 23 in real time, the first mirror 2 is displaced in the focus direction or the yaw direction and adjusted to a position where an appropriate light beam pattern (for example, a symmetrical pattern shape) is obtained. Thereby, the parallel light beam from the 1st mirror 2 can be adjusted precisely.

  After that, the adjustment jig A is removed and the second mirror 4 is attached to the original position. If adjustment is necessary, the parallel light flux of the second mirror 4 is also precisely adjusted by a conventional method to adjust the focus as a spectroscope. To complete.

FIG. 8 shows an adjustment method when an adjustment jig that performs optical adjustment with light traveling in the opposite direction to the above-described embodiment is used.
As in the previous embodiment, the adjustment jig A ′ is arranged on the optical path of the parallel light beam incident on the second mirror 4 from the diffraction grating 3 of the spectroscope, and the second mirror 4 is placed on its base. 8 is removed and attached to the base 12 of the spectrometer.

  The adjustment jig A ′ includes a flat mirror 18 ′ that reflects the parallel light beam from the first mirror 2 of the spectroscope, a lens 17 ′ that collects the parallel light beam from the flat mirror 18 ′, and a light beam that is collected by the lens 17 ′. A long plate-shaped jig base in which a screen 23 ′ as an image observation member for displaying a light beam pattern of the light, a lens 17 ′, a plane mirror 18 ′, and a screen 23 ′ are arranged on a straight line with predetermined intervals. 19 '. The jig base 19 'is detachably attached to the base 12 by the same attachment means as in the above embodiment. In the adjustment jig A ′, another appropriate light beam pattern (for example, a symmetrical pattern shape) is displayed in advance on the screen 23 ′ when a precise parallel light beam is incident from the first mirror 2 to the plane mirror 18 ′. It is set by the optical system equipment.

  In adjusting the parallel light flux from the first mirror 2, an adjustment jig A ′ is attached to the base 12, and light from the light source of the spectroscope is irradiated from the entrance slit 1. The irradiated light is sent to the plane mirror 18 ′ as an unadjusted parallel light beam by the first mirror 2, reaches the lens 17 ′ while keeping the unadjusted parallel light beam by the plane mirror 18 ′, and is condensed and slit 24. And a light flux pattern (an image out of focus) is projected onto the observation screen 23 '. The first mirror 2 is displaced in the focus direction or the yaw direction to a position where the light beam pattern projected on the screen 23 ′ becomes an appropriate light beam pattern (for example, a symmetrical pattern shape) while viewing in real time in the same manner as in the above embodiment. To adjust. Thereby, the parallel light beam from the 1st mirror 2 can be adjusted precisely.

  Thereafter, the adjustment jig A ′ is removed and the second mirror 4 is attached to the original position, and if necessary, the parallel light flux of the second mirror 4 is precisely adjusted by the conventional method to complete the focus adjustment as a spectrophotometer. To do.

  In the above-described embodiment, the screens 23 and 23 'are used as the image observation member. However, instead of this, a two-dimensional imaging element may be arranged and displayed on a monitor provided at another position via this element. . In the above embodiment, the first mirror 2 is displaced to adjust the optical path. However, the entrance slit 1 is formed so as to be movable in the optical path direction, and the entrance slit 1 is adjusted by moving the entrance slit 1. Is also possible.

Further, in the embodiment shown in FIG. 8, it is preferable to use a light source provided in a spectrophotometer itself having a spectroscope as a part of the adjustment as a light source for adjustment. You may make it use.
In the embodiment shown in FIG. 8, if there is a structure in which the adjuster has a space where the position of the slit 24 can be viewed from the horizontal direction with respect to the optical path of the spectrometer, a screen or A two-dimensional image sensor can be arranged and fine adjustment can be performed while observing the sharpness of the formed image itself. Furthermore, only the slit 24 can be provided, and the sharpness of the image generated at the position of the slit can be observed and finely adjusted.

Although typical examples of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and the object of the present invention is achieved and appropriately modified within the scope of the claims. It is possible to change.
For example, the condensing lens is not necessarily a lens, but may be a reflective condensing optical system such as a parabolic mirror or a toroidal mirror.
Since the plane mirror simply bends the optical path, it need not necessarily be provided.
In addition, the second mirror may not necessarily be removed. For example, if the optical path is bent with a plane mirror or the like in front of the second mirror, the same effect can be obtained without removing the mirror.

  The present invention can be used for optical axis adjustment in a Zernitana spectrometer.

A, A ′ Optical axis adjustment jig 1 Entrance slit 2 First mirror 3 Diffraction grating 4 Second mirror 5 Exit slit 6 Light detector 16 Light source 17, 17 ′ Lens 18, 18 ′ Planar mirrors 19, 19 'Jig base 23, 23' Screen as an image observation member

Claims (3)

This is an optical adjustment method for a spectrometer that reflects light that has passed through an entrance slit by a first mirror and sends it to a diffraction grating, and reflects light that has been wavelength-dispersed by the diffraction grating by a second mirror and sends it to an exit slit for spectroscopy. And
A light source and an optical element that converts the light from the light source into a parallel light flux are provided on a jig base, and are used for optical adjustment that is set in advance so that the light emitted from the optical element becomes a precise parallel light flux. Prepare the adjustment jig,
The adjusting jig is disposed on an optical path incident on the second mirror from the diffraction grating ;
The parallel light beam emitted from the adjustment jig is sent to the first mirror, the light reflected and collected by the first mirror is passed through the entrance slit, and the light beam pattern is displayed on the image observation member arranged in the vicinity thereof. An optical adjustment method in a spectroscope in which the focus of the first mirror is adjusted by moving the first mirror or the entrance slit so as to obtain an appropriate light flux pattern based on the light flux pattern.   The optical adjustment method for a spectroscope according to claim 1, wherein the image observation member is a two-dimensional image sensor for displaying on a screen or a monitor. A jig base is provided with a light source, an optical element that converts the light from the light source into a parallel light beam, and a flat mirror that reflects the parallel light beam as a parallel light beam, and the jig base is a base of a spectrometer. An optical adjustment jig for a spectroscope, which is detachably mounted on a fixing means and preset so that light emitted from the optical element becomes a parallel light beam precisely.

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