JPH063185A - Light-receptor - Google Patents

Abstract

(57) [Summary] [Purpose] Arbitrary spectral responsivity such as standard relative luminosity required for measuring illuminance and brightness, and color matching function required for colorimetry can be realized with a simple configuration. Provide a light receiver. A wedge-shaped continuous interference filter (3) is provided with a first aperture (2) for restricting light incident on the wedge-shaped continuous interference filter (3) in front of a wedge-shaped continuous interference filter (3) that receives light emitted from a diffuser plate (1). A second aperture 4 having a window that spatially regulates the transmitted light of the wedge-shaped continuous interference filter 3 is located on the rear surface of the wedge-shaped continuous interference filter 3, and the aperture area of the second aperture 4 is arbitrarily changed to allow wedge continuous By changing the ratio of the light entering the light receiving element 5 from the interference filter 3 for each wavelength, the branching responsivity of the light receiver can be arbitrarily set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a simple structure for arbitrary spectral responsivity such as standard relative luminosity required for measuring illuminance and brightness, and color matching function required for colorimetry. The present invention relates to a light receiver that can be realized.

[0002]

2. Description of the Related Art Conventionally, the following method has been used to approximate the spectral responsivity of a light receiver to an arbitrary spectral responsivity such as a standard relative luminous efficiency and a color matching function. When it is attempted to approximate the spectral response of the light receiver to the standard relative luminous efficiency as shown in (FIG. 4), a plurality of color correction filters 7 having different spectral transmission characteristics are incident as shown in (FIG. 7). The spectral responsivity of the light receiving element 5 was corrected by superimposing the diffusion 1 receiving the light and the light receiving element 5.

[0003]

With such a conventional configuration, it is extremely difficult to accurately approximate the spectral responsivity of the light receiver to an arbitrary spectral responsivity. Further, in order to increase the degree of approximation, the number of color correction filters to be used must be increased, so that the light receiver becomes thick. Further, since the amount of light incident on the light receiving element is reduced, there is a problem that measurement in the low illuminance region becomes difficult.

The present invention solves the above problems, and an object of the present invention is to provide a photodetector which can realize an arbitrary spectral response with a simple structure.

[0005]

In order to solve the above-mentioned problems, a light receiver according to the present invention comprises a diffuser plate which receives light incident on the light receiver and a wedge-type continuous interference filter which receives light emitted from the diffuser plate. A first aperture located on the front surface of the wedge-shaped continuous interference filter for restricting incident light to the wedge-shaped continuous interference filter, and located on the rear surface of the wedge-shaped continuous interference filter, Second with a window that spatially regulates the transmitted light from the filter
And the continuous interference filter and a light receiving element that receives all the transmitted light of the first and second apertures, and the wedge continuous interference filter transmits light for each specific wavelength. , By arbitrarily changing the aperture area of the window of the second aperture, the spectral transmission characteristics of the light incident on the light receiving element from the wedge type continuous interference filter are changed, and the spectral responsivity of the light receiver is arbitrarily changed. This is set.

Further, the transmittance of the first or second aperture can be partially changed in accordance with the change of the opening area of the window of the second aperture, and the light is incident on the light receiving element from the wedge type continuous interference filter. The spectral transmission characteristics of light are changed to arbitrarily set the spectral response of the light receiver.

Further, by providing an incident light control means on the front surface of the first aperture, the light incident on the diffuser plate is directed to the light transmitting portion of the first aperture which does not transmit the light. The incident light is controlled so that all of the incident light enters the light receiving element.

[0008]

The present invention has the following operational effects due to the above respective configurations. (1) By providing a first aperture on the front surface of the wedge-shaped continuous interference filter, the incident light to the wedge-shaped continuous interference filter is regulated, and the opening area of the window of the second aperture is arbitrarily changed. Thus, the spectral responsivity of the light receiver can be arbitrarily set by changing the ratio of the light incident on the light receiving element from the wedge-shaped continuous interference filter for each wavelength.

(2) By changing the transmissivity of the first or second aperture partly in place of the change of the opening area of the window of the second aperture, the wedge type continuous interference filter enters the light receiving element. The spectral responsivity of the light receiver can be arbitrarily set by changing the ratio of the light to be emitted for each wavelength.

(3) By providing an incident light control means on the front surface of the first aperture, the light directed to the part of the first aperture that does not transmit light is directed to the part that transmits the light, and the incident light to the diffuser plate. Since all the light can be made incident on the light receiving element, it is possible to measure a wider illuminance range, particularly a low illuminance range.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing the configuration of a light receiver according to the first embodiment of the present invention. In FIG. 1, 1 is a diffuser plate that receives incident light, 2 is a first aperture in the form of vertical stripes that regulates incident light to a wedge-shaped continuous interference filter 3, and 3 is a wedge-shaped continuous aperture that transmits light at specific wavelengths. Interference filter, 4
Is a second aperture that spatially regulates the transmitted light of the wedge-shaped continuous interference filter 3, and 5 is a light receiving element.

In order to clarify the function of the first aperture 2, the case where the first and second apertures are not incorporated in the light receiver 5 will be described first. In FIG. 1, the light incident on the diffusion plate 1 uniformly illuminates the wedge-shaped continuous interference filter 3. Wedge type continuous interference filter 3
Since the wavelength of light that can be transmitted differs depending on the location of the filter surface, the transmittance when the front surface is uniformly irradiated with light is shown in FIG. 2 for each wavelength. All the light transmitted through the wedge-shaped continuous interference filter 3 is received by the light receiving element 5, and the spectral responsivity A of the spectroscope as shown in FIG. 4 is obtained. Here, when the spectral response A is to be approximated to the standard relative luminosity B as shown in FIG. 4, for example, the spectral transmission characteristic of the light incident on the wedge-shaped continuous interference filter 3 may be changed.

Therefore, a second aperture 4 is provided between the wedge-shaped continuous interference filter 3 and the light receiving element 5, and the aperture area of the aperture 4 is changed, whereby the ratio of the light incident on the light receiving element 5 for each wavelength. Can be changed. At this time, when it is desired to change the transmittance of the wedge-shaped continuous interference filter 3 at a specific wavelength, for example,
When it is desired to change the transmittance at the wavelength of 450 nm, the spectral transmittance of the wedge type continuous interference filter 3 is as shown in FIG. 2, and the second aperture 4 of the portion of the wedge type continuous interference filter 3 having a peak at the wavelength of 450 nm is used. If the opening area of is changed, it affects not only the wavelength of 450 nm but also the portion having a peak at another wavelength. Therefore, the design of the opening area of the second aperture 4 becomes complicated.

Therefore, a first aperture 2 is provided in front of the wedge-type continuous interference filter 3, the main transmission interval of the wedge-type continuous interference filter 3 is separated, and the transmission of the wedge-type continuous interference filter 3 is separated, as shown in FIG. By increasing the wavelength purity, the design of the second aperture 4 becomes easier. By such a method, the spectral responsivity of the light receiver can be arbitrarily set.

A second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the spectral transmission characteristic of the light entering the light receiving element 5 from the wedge-shaped continuous interference filter 3 is changed by changing the opening area of the second aperture 4, and the spectral responsivity of the light receiver is arbitrarily set. However, instead of changing the opening area of the second aperture 4, the first aperture 2 or the second aperture 4 can be changed.
Is realized by using a material whose transmittance can be partially changed, such as electrochromic or liquid crystal, to realize an aperture that partially transmits light. The same effect as changing the opening area of the second aperture 4 can be obtained, and moreover, fine adjustment for each wavelength can be electrically performed.

FIG. 5 is an exploded perspective view showing the structure of a light receiver according to the third embodiment of the present invention. In FIG. 5, when the light transmitted through the diffusion plate 1 is incident on the wedge-shaped continuous interference filter 3, the first aperture arranged on the front surface of the wedge-shaped continuous interference filter 3 as shown in FIG. 6A. Due to 2, several 10% of the light transmitted through the diffuser plate 1 is not incident on the wedge-shaped continuous interference filter 3, so that the amount of light incident on the light receiving element 5 is smaller than the light incident on the diffuser plate 1,
The measurement illuminance range is narrowed down. Therefore, the diffusion plate 1
Between the first aperture 2 and the first aperture 2, an incident light control means 6 for refracting light such as a lenticular lens to control the incident light to the first aperture 2 is arranged, and FIG.
As shown in (b), the structure is such that all the light transmitted through the diffusion plate 1 is incident on the light-transmitting portion of the first aperture 2. With such a structure, it becomes possible to measure a wide range, particularly in a low illuminance region, as compared with the case where the incident light control means 6 is not provided.

In FIG. 6 (b), if the distance between the incident light control means 6 and the first aperture 2 is increased and the focus of the lenticular lens of the incident light control means 6 is increased, wedge-shaped continuous interference occurs. The angle of incidence on the filter 3 is limited, and it becomes close to parallel light, and wavelength separation can be improved. Further, in FIG. 6B, a lenticular lens is described as an example of the incident light control means 6, but instead of this, a distributed index lens is used to prevent crosstalk between wavelength components adjacent to each other and to make a wedge shape. The incident light of the continuous interference filter can be effectively increased.

[0018]

As described above, according to the present invention, by providing the first aperture and the second aperture before and after the wedge type continuous interference filter, the light incident on the light receiving element from the wedge type continuous interference filter is provided. Since it is possible to change the spectral transmission characteristics of, the use of multiple color correction filters as in the prior art does not increase the thickness of the light receiver or decrease the amount of light incident on the light receiver. Arbitrary spectral responsivity can be realized by simple calibration.

[Brief description of drawings]

FIG. 1 is a configuration of a light receiver according to an embodiment of the present invention.

FIG. 2 is a diagram showing the transmittance of a wedge-type continuous interference filter in a light receiver according to an embodiment of the present invention.

FIG. 3 is a diagram showing another transmittance of the wedge-type continuous interference filter in the light receiver according to the embodiment of the present invention.

FIG. 4 is a diagram showing an example of a standard relative luminous efficiency and a spectral response of a light receiver.

FIG. 5 is a diagram showing a configuration of a light receiver according to another embodiment of the present invention.

FIG. 6 is a diagram illustrating how light is transmitted in a light receiver according to another embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a light receiver in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diffusion plate 2 1st aperture 3 Wedge type continuous interference filter 4 2nd aperture 5 Light receiving element 6 Incident light control means

Claims (3)

[Claims] 1. A wedge-type continuous interference filter, which is located in front of a diffuser plate that receives incident light to a light receiver, a wedge-type continuous interference filter that receives emitted light from the diffuser plate, and the wedge-type continuous interference filter. A first aperture that restricts light incident on the filter; and a second aperture that is located on the rear surface of the wedge-shaped continuous interference filter and that has a window that spatially restricts transmitted light from the wedge-shaped continuous interference filter. A light receiver comprising the continuous interference filter and a light receiving element that receives all the transmitted light of the first and second apertures. 2. The light receiver according to claim 1, wherein the transmittance of the first or second aperture can be varied for each part. 3. The light receiver according to claim 1, further comprising incident light control means located on the front surface of the first aperture and controlling incident light on the first aperture.