JPS59131123A - Spectrophotometer - Google Patents

Abstract

PURPOSE:To perform spectrophotometry over a wide measured wavelength range through simple constitution without spoiling high wavelength resolution nor speediness by performing the high order light removal of secondary light or higher between a light dispersing element, and a light source and a solid-state image pickup element. CONSTITUTION:A filter 1 removes short-wavelength light. A slit 2 allows the incidence of light passed through a filter 1. Then, 3 is a mirror and the light dispersing element 4 is composed of a concave grating. On the other hand, 5 is the solid-state pickup element and a microcomputer 6 processes the output signal of the solid-state image pickup element 5. An element 7 has a filter function for removing secondary light. Therefore, light from the light source is incident through the slit 2 after passing through the filter 1, reflected by the mirror 3, and then diffracted spectrally by the light dispersing element 4 to illuminate the solid-state image pickup element 5 through the element 7. Then, the output signal of the solid-state image pickup element 5 is processed by the microcomputer 6 to perform spectrophotometry.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spectrophotometric device using a solid-state image sensor,
By using a filter provided in the optical path on the incident side of the light dispersion element and an element provided between the light dispersion element and the solid-state image sensor, high-order light of F beyond the secondary light appearing on the solid-state image sensor is removed. purpose.

Spectrophotometers, especially instantaneous multi-photometers, are required to ensure high speed even when employing a method for removing two-dimensional or higher-order light.

However, when using a method in which the filter for removing higher-order light is switched depending on the wavelength range, as in the conventional spectrophotometer that rotates the light dispersion element, high speed cannot be achieved and the product value is reduced. cannot be increased.

In view of this, as shown in Japanese Patent Laid-Open No. 57-108766, a filter is installed in contact with the light-receiving surface of the element to remove higher-order light higher than secondary light. ing.

The present invention makes it possible to remove high-order light higher than secondary light while ensuring high speed through a different configuration.

In other words, in an instantaneous multi-photometer using one solid-state imaging probe, considering the resolution of the solid-state imaging probe, the measurement wavelength must be The range is only 500 nm culmability at most, and in order to obtain a wavelength resolution higher than 8I of self-recorded spectrophotometry, the measurement wavelength range must be further narrowed.

When running, a filter for removing short wavelength light is provided on the optical path on the incident side of the light dispersion element, and a filter function is also provided between the light dispersion element and the solid-state imaging element to remove secondary light. It was confirmed that the provision of the element provided a sufficient effect of 1q. In particular, in the measurement of bright lines and dark lines similar to emission analysis, higher wave resolution and high speed are required for separation of adjacent bright lines, standardization, etc., and the removal of higher-order light by the method of the present invention is This method was adopted for its simplicity and reliability without sacrificing wavelength resolution or high speed. below,
Embodiments will be described in detail with reference to the accompanying drawings, which show examples.

FIG. 1 is a system diagram showing the basic configuration of the device of the present invention,
(1) is a filter that removes short wavelength light, and (2)
is a slit through which the light passing through the filter (1) enters, (3) is a mirror, (/l) is a light dispersion element consisting of a concave grating, and (5) is a solid-state image sensor as a detector. and (6) is the solid-state image sensor (5
) is a microcomputer that processes the output signals of
(71 is an element having a filter function to remove secondary light.

Therefore, the light emitted from the light source passes through the filter (1), enters through the slit (2), and enters the mirror (3).
), the light is then dispersed by a light dispersion element (4), and is irradiated onto a solid-state imaging element (5) through the element (7). Then, by processing the output signal of the solid-state image sensor (5) with the microcomputer (6), spectrophotometry-4- can be performed.

To explain in more detail, the filter (1) has a measurement wavelength range x −y nm (x < y nm) of the solid-state imaging probe (5).
), it has the characteristic of being able to remove all light below a predetermined wavelength arv (a < x < 2a) that is shorter than the shortest measurement wavelength The following wavelength range does not include any higher order light than secondary light.

In other words, the filter (1) consists of solid m pixel elements (5)
This filter (1) is provided for the purpose of removing in advance high-order light higher than secondary light that appears between x~2a n-.
It is possible to irradiate only the primary light to the solid-state image sensor (9 x to 2 nm wavelength range).

However, higher-order light higher than secondary light appears in the wavelength range of 28 to vnI.

The element (71 is for removing high-order light higher than secondary light in the wavelength range of 2a to y nm), and is constructed by providing a filter function to a part of the substrate that does not have a filter function. Ru.

The specific configuration of this element (71 is, for example, transparent-5
− A quartz plate coated with a filter can be considered. Here, as a filter, an ordinary siV-put filter is sufficient. However, the boundary between the filter-coated part (7)' and the remaining part should be blurred to prevent a shadow from appearing on the light-receiving surface of the solid-state m pixel element and to prevent the transmitted light from scattering at the border. There is a need to.

In addition, as shown in Figure 2, the filter function of the element (71) is that it does not transmit any light below c nat;
Ni light has the characteristic of allowing long wavelength light to pass through easily and allowing light of d nm or more to pass through almost completely.

Therefore, light of Cnl11 or higher is transmitted through a portion having a filter function (7γ), and in a wavelength range of 2crv or higher, higher-order light higher than secondary light appears.

In other words, the practical wavelength range of the filter function (7γ) is from d to 2c nll, and in this practical wavelength range it is possible to remove higher order light or higher order light, so the filter (1) is By combining the element (71), it is possible to remove higher-order light higher than secondary light in the wavelength range of a to 2crv.

-6- Is the measurement wavelength range of the solid-state image sensor (5) x to y?
nm, one filter function should be selected such that y<2c.

The part with the filter function selected as above (
7) Installation of ' (◇ position is set as follows.

In other words, dispersed light including two-dimensional or higher-order light is irradiated2.
x~2a that is irradiated with dispersed light that covers the entire wavelength range of a~Vrllll and does not include higher order light of two or more dimensions.
It is necessary that the transmission of the dispersed light is not obstructed in any way in the nm wavelength range, and in order to satisfy these requirements, one end Afd of the part (7)' that has a filter function is
It must be located in a wavelength range through which primary light of ~2 nm passes, and the other end B must be located in a wavelength range through which received primary light of yr+m or more passes.

By setting the installation position of the part (7)' having a filter function in this way, it is possible to completely receive the primary light in the wavelength range of x to 2 nm, and also to
This makes it possible to reliably remove two-dimensional or higher-order light in the a-Vnll wavelength range.

-7- To give a specific example, if the measurement wavelength range by the solid-state R image element (5) is 300 to 700 nllll, for example, as the filter (1), a filter having a characteristic that can remove all light of 25 Onll1 or less, Element (one end of the part (7)' having the filter function, using a filter function that has the characteristic of not transmitting any light of 450 nm or less and almost completely transmitting light of 480 nm or more as the filter function of the sword) A from 480 to 500
It is sufficient to position the end portion 8 in a wavelength range where the primary light of n1ll passes through, and the other end 8 to be located in the wavelength range where the primary light of 70 Or+m or more passes.
In the wavelength range, the solid-state image sensor (71) can be irradiated with only the -order light.

Note that it is also possible to use a light dispersion element made of a plane grating in place of the mirror (3), and to use a concave mirror in place of the light dispersion element (4).

As described above, the present invention provides a method for disabling secondary light or more between a light dispersion element and a light source and between a light dispersion element and a solid-state image sensor.
Because it removes high-order light, it has a simple configuration without sacrificing high wavelength resolution and high speed
It has the unique effect of being able to perform spectrophotometry over a wide measurement wavelength range.

Furthermore, the present application uses a light dispersion element (4) using a filter (1).
), the wavelength range of the appearance of higher-order light that falls within the measurement wavelength range is considerably narrowed, so the cost can be reduced by arranging the force structure in the element (1).
Since only one boundary needs to be positioned, adjustments, maintenance, etc. can be easily performed.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing the basic configuration of the device 4A of the present invention, Fig. 2 is a diagram showing the transmission characteristics of the element (71) which has a filter function, and Fig. 3 is a diagram showing the transmission characteristics of the element (71) which has a filter function. A diagram showing the positional relationship between the solid mfN1 cord (5). (1)...Filter, (2)...Slit, (3
)...Mirror, (4)...Light dispersion element, (5)...
・Solid-state m-image element, (6)...micro combi coater,
(Force... an element that removes high-order light of two or more dimensions. -9- Figure 1

Claims (1)

[Claims] 1. In a device for detecting light incident through a slit with a solid-state image sensor after passing through a spectroscopic optical system, there is a space between the light source and the light dispersion element that is shorter than the short R measurement wavelength of the solid-state image sensor. 1. A spectrophotometric device comprising a filter that removes all light of a predetermined wavelength or less, and an element that removes two-dimensional or higher-order light between a light dispersion element and a solid-state image sensor. 2. An element that removes high-order light of two or more dimensions is constructed by giving a filter function to a part of the substrate that does not have a filter function, and t! Of the primary light of the light dispersed by the ambient light dispersion element, the wavelength is less than or equal to twice the wavelength of the light with the shortest wavelength, and the wavelength is longer than a predetermined wavelength that is greater than or equal to the practical shortest wavelength of the filter function, and the solid wA The spectrophotometric device according to claim 1, wherein the range is defined as a range through which primary light having a wavelength shorter than a predetermined wavelength greater than or equal to the longest measurement wavelength of the image element-1 passes.