JP2641184B2 - Ultraviolet reflection level indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a measuring instrument which simply and stably displays the reflectance of a sample from ultraviolet light as a level guide number. .

(Problems to be Solved by the Invention) In recent years, it has become necessary to measure the ultraviolet reflectance of a sample. In particular, there is a need for a measuring instrument that displays the level of the reflectance as a guide number. It is an object of the present invention to provide a simple and accurate reflection level indicator for ultraviolet light.

[Structure of the Invention] (Means for Solving the Problems) An ultraviolet reflection level indicator of the present invention uses a flash lamp as a light source in a measuring head, and diffuses and reflects flash light from the light source into a mixing box. The derived reference light and the data light obtained by reflecting the reference light on the measurement surface are transmitted through an ultraviolet positive filter that transmits in a predetermined wavelength range at an appropriate position in the optical path, and the reference photoelectric conversion element and the data photoelectric filter, respectively. The photoelectric conversion is performed by the light-receiving unit with the built-in conversion element, so that the simplicity and stability of the optical system measurement head are obtained. Data analog data obtained by arithmetically amplifying and holding each of a plurality of analog voltages divided by the resistance voltage divider and a signal of the data photoelectric conversion element. A simple and stable signal processing circuit that detects a switching voltage and a multilevel comparator and latches the digital output of the comparator to display the level of data light by means such as an LED. It is characterized by.

The predetermined ultraviolet wavelength range to be measured is to be determined according to the purpose of measurement or the standard of the object, and may include the visible light wavelength range in some cases. It is also natural that the voltage division of the resistance voltage divider is not limited to the linear division.

(Embodiment) The ultraviolet reflection level indicator of the present invention will be specifically described with reference to the embodiment shown in FIG.

In FIG. 1, the measuring optical system head is shown in a perspective view. 1 is a xenon flash lamp as a flash light source, 2 is a mixing box that diffuses and reflects the light emitted from the xenon lamp on the inner wall surface, and 3 is a projection that derives the reference light diffusely reflected in the mixing box and illuminates the sample surface. A guide 4 is a reference light receiving section for measuring a reference light amount, and 5
Denotes a sample surface, 6 denotes an incident guide for introducing data light reflected from the sample surface, and 7 denotes a data light receiving unit for measuring the amount of data guided from the incident guide.

In the reference light receiving unit 4, the reference light is photoelectrically converted by a photodiode through a filter that transmits only a predetermined ultraviolet wavelength range, and a reference photoelectric signal is obtained. On the other hand, the data light receiving section 7 removes the outside of a predetermined ultraviolet wavelength range through the same filter as the reference light receiving section filter, and performs photoelectric conversion by a photodiode to obtain a data photoelectric signal.

When the flash light source switch 11 of the power supply is closed, the strobe circuit 12 is boosted, and the xenon flash lamp 1 flashes. When the signal processing switch 13 is closed, a specified voltage for driving the circuit is obtained at the terminal 14 by a symmetric dual power supply system and a Zener diode stabilized power supply system (not shown).

21 is an operational amplifier configured in a non-inverting amplifier circuit,
Reference light electrical signal from the reference light receiving unit 4 is input to the Q _1.
The output voltage of Q ₁ is in the analog-hold circuit 22 is charged to a hold capacitor 22b through the diode 22a,
Charging voltage of the capacitor corresponding to the maximum reference amount of light is hold output by voltage follower Q _2.

23 is A / D operation circuit, hold output voltage of the first Q ₂ is the divider resistors, is pressed six stages bisection.

On the other hand, the data photoelectric signal from the data light receiving unit 7 is
Input to the operational amplifier Q _3, the output voltage of Q ₃ are charged in the hold capacitor 22d through another series of diode 22c, the charging voltage of the capacitor corresponding to the maximum data amount is hold output by voltage follower Q _4.

The partial divided voltage respectively applied to the pressure resistors of the reference light, both are compared by the multi comparators Q ₄ output voltage and the A / D calculation circuit 23 according to the data light, Q ₄ output voltage dividing resistors of the For example, if it corresponds to the voltage division level of the third stage, a 1-level digital signal is output to the outputs of the first to third stages of the comparator, and a 0-level digital signal is output to the outputs of the fourth to sixth stages.

The digital output of each stage of the multi-comparator is input to a data hold circuit 24 composed of a D latch. Pulse input for latch operation when the rise for Q ₁ output exceeds a predetermined voltage, obtained by the pulse generator 25. The output of each stage of the D latch is a guide number display 26 incorporating a current limiting resistor using an inverter as an interface.
Of the LEDs 1 to 6 are turned on to indicate that the data light is at level 3.

[Effects of the Invention] According to the ultraviolet reflection level indicator of the present invention, the flash lamp is used as a light source, and the level display of the diffusely reflected reference light and sample surface reflected light is made suitable for the characteristics of the flash signal. Since the signal processing circuit is configured, the ultraviolet reflection level can be displayed simply and accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the display of the present invention. DESCRIPTION OF SYMBOLS 1 ... Flash light source, 2 ... Mixing box, 3 ... Projection guide, 4 ... Reference light receiving section, 6 ... Incident guide, 7
…… Data light receiver, 12… Strobe circuit, 21, Q ₁ , Q ₃ …
… Op amp, 22, Q ₂ , Q ₄ … Hold circuit, 23… A / D
Arithmetic circuit, 24 data hold circuit, 25 pulse generator, 26 guide number display.

Claims (1)

(57) [Claims] 1. A flash lamp as a light source, a reference photoelectric conversion element for photoelectrically converting a reference light derived by diffusing and reflecting the flash light from the light source through an ultraviolet positive filter, and reflecting the reference light to a measurement surface. A data photoelectric conversion element that photoelectrically converts the obtained data light through an ultraviolet positive filter, a resistive voltage divider that amplifies and holds the signal of the reference photoelectric conversion element and divides the data light into a plurality of stages, and is divided by the resistance voltage divider A multi-level comparator for detecting each of the plurality of analog voltages and a data analog voltage obtained by amplifying and holding the signal of the data photoelectric conversion element, and displaying the level of data light by an output obtained by latching a digital output of the comparator. UV reflection level indicator comprising means.