JPS62229115A - Filtering device - Google Patents

Abstract

PURPOSE:To optionally control the quantity of a transmission light by one piece of filtering plate, by constituting a filtering part for limiting a transmission of an incident light, of a liquid crystal element for generating coloring or polarization by impressing a voltage. CONSTITUTION:A liquid crystal plate 1 is used as a filtering plate, and an electric wiring is executed so that a voltage of a voltage impressing part 2 is impressed to the liquid crystal plate 1 through a controller part 3. The impressed voltage to the liquid crystal plate 1 can be varied by changing a resistance value of the controller part 3 by an adjusting knob 4, and accordingly, the transmission quantity of the incident light can be adjusted by the adjusting knob 4. That is to say, when a voltage is impressed to a liquid crystal, coloring or a polarizing phenomenon is generated, therefore, by adjusting a degree of coloring or polarization of the whole liquid crystal plate 1, the transmission quantity of the incident light can be varied continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a filtering device widely used in optical devices such as cameras and optical measurement devices.

[Prior Art] A filter plate is a so-called optical filter that absorbs incident light uniformly to weaken the whole, selectively absorbs light to change the spectral distribution of light, or in some cases, absorbs light in a particular way. It is used for the purpose of adjusting the amount of transmitted light, such as extracting light with a wavelength of . Solid filters include those that contain inorganic substances in glass, and those that contain dyes or pigments in gelatin or plastic membranes. Camera filters use colored glass, and several types are available with different amounts of tinting for different purposes.

[Problems to be solved by the invention] As mentioned above, conventional filters are compatible with l:l depending on the purpose and amount of transmission, so multiple filters can be used depending on the purpose of use. It was necessary to select and use one of the types, and the management was complicated. There are also cases where it is desired to use a filter with intermediate characteristics among the multiple types of filters available, but conventional filters have not been able to meet such requests.

In other words, the use of conventional filter plates is uniquely determined by their physical properties, and there is a problem in that the amount of transmitted light cannot be continuously adjusted. Therefore, an object of the present invention is to provide a filtering device that can arbitrarily adjust the amount of transmitted light using a single filtering plate.

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following configuration.

That is, in the filtering device according to the present invention, the filtering section that restricts the transmission of incident light rays is configured with a liquid crystal element that colors or polarizes light when a voltage is applied, and a controller is provided that adjusts the voltage applied to the liquid crystal element. It is characterized by

[Function] When a voltage is applied to a liquid crystal element, coloration (cloudiness) or polarization occurs. By changing the applied voltage using the controller, the degree of coloring or polarization changes, so the amount of transmitted light can be adjusted.

[Example] FIG. 1 is a schematic diagram showing the configuration of the main parts of an apparatus according to an example of the present invention, in which a liquid crystal plate 1 is used as a filter plate. Electrical wiring is provided to the liquid crystal plate l so that a voltage from a voltage applying section 2 is applied via a controller section 3. By changing the resistance value of the controller section 3 using the adjustment knob 4, the voltage applied to the liquid crystal plate 1 can be changed, and therefore the amount of transmission of incident light can be adjusted using the adjustment knob 4. In other words, if a voltage is applied to the liquid crystal,
Since a coloring or polarization phenomenon occurs, by adjusting the degree of coloring or polarization of the entire liquid crystal plate 1, the amount of transmitted light can be continuously changed.

FIG. 2 is a diagram showing an example in which the filtering device according to the present invention is applied to the optical system of a measuring instrument, in which the light irradiated from the light source 5 is
Next filter 6, lens 7, pass through slit 8 and lens 9
The parallel rays entering the lens 9 and exiting the lens 9 are passed through the secondary filter 1
0, enters the sample 13 through the aperture 11. The light passing through the sample 13 enters the photomultiplier tube 14, and the output signal from the photomultiplier tube 14 is inputted from the amplifier I5 to the detector 1G.

In such an optical system, the primary filter 6 and the secondary filter 1O are constituted by the apparatus of the embodiment described in 1 above, and the amount of transmission thereof is arbitrarily adjusted.

In the above-mentioned filtering device, if the voltage applied to the liquid crystal plate 1 is increased, the degree of coloring or polarization will become stronger and no light will be transmitted at all. Therefore, the filtering device of the present invention can also be used as a shutter. For example, in the optical system shown in FIG. 2, if the slit 8 is replaced with a filtering device that performs this shutter function, it can be used as a shutter of the optical system. in this case,
Since it is necessary to control the applied voltage so that light is transmitted only during the time the shutter is open, it is necessary to provide means for controlling the opening time. When used as a shutter by electrical control in this way, unlike conventional shutter mechanisms, a mechanical drive unit is not required, so failures and the like are less likely to occur.

Since the filtering device of the present invention can easily operate the filtering mechanism by an electric signal, it can be used with various optical measuring devices that require adjustment of the amount of transmitted light, such as a projection type microphotometer, a scattering device, etc. It can be easily incorporated into analytical instruments such as optical spectrometers, and since it can be controlled electrically, it can be used in a wide range of optical systems, such as being able to control in conjunction with other electrical components.

[Effects of the Invention] As is clear from the above description, according to the filtering device according to the present invention, the amount of transmission of incident light can be arbitrarily and continuously changed and adjusted. In addition, it can be electrically controlled easily, operates accurately, and consumes little power, so it can be suitably used in various optical systems, analytical instruments such as spectrophotometers, and other measuring devices. Depending on the design, this can also function as a shutter.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an example in which the embodiment device is applied to an optical system of a measuring machine. 1...Liquid crystal plate 2...Voltage application section 3...Controller section

Claims (1)

[Claims] (1) A filtration device in which a filtration unit that restricts the transmission of light rays is composed of a liquid crystal element that colors or polarizes light upon application of a voltage, and a controller that adjusts the voltage applied to the liquid crystal element.