JPH0611504A - Illuminating equipment for blood analyzer - Google Patents

Abstract

PURPOSE:To make it possible to light and extinguish a light source at a necessary time by using a cold cathode discharge tube for the light source, by detecting luminance by a light-detecting element just after lighting and by making it stable at a prescribed luminance. CONSTITUTION:When a lighting instruction signal is delivered from CPU 8, a variable driver 9 lights a cold cathode discharge tube 1. A light output thereof is sensed by a photosensor 2 and inputted to an amplifier 3. An output of the amplifier is subjected to A/D conversion 4 and inputted to the CPU 8 and a memory 5. In the memory 5, accordingly, the light output of the discharge tube 1 just after lighting is stored. The value thereof is read out and subjected to D/A conversion 6 and enters a reference terminal 10 of an operational amplifier 7. In the amplifier 7, the reference signal is always compared with the output of the amplifier 3 given to an input terminal 11 and an output of the amplifier 7 controls the variable output driver 9. According to this constitution, the discharge tube 1 can hold a photocurrent flowing just after the lighting and a light level becomes unvaried. Accordingly, it is unnecessary to wait for the light source to reach a steady state from the lighting and thus the time for a measuring operation can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for extending the life of a cold cathode fluorescent discharge tube used as a light source in a blood analyzer.

[0002]

2. Description of the Related Art Generally, in a blood analyzer, a tungsten lamp, a halogen lamp, a hydrogen discharge lamp or the like is combined with an optical filter in an illuminating section and used as a light source of a chemical analyzer. As an example of this, the “'86 ME Device Technical Handbook” issued by the Electronic Measuring and Publishing Company, P. 203 ~
An example is the chemical analyzer shown at 204.

[0003]

In the above-mentioned prior art,
Although the tungsten lamp or hydrogen discharge tube used for the light source is shown, it has a short life, and the user or service person must replace it with a good product at any time, which requires a lot of work and is very inconvenient. It was

In view of the above, the present invention employs a cold cathode fluorescent discharge tube whose light source is repeatedly turned on and off to shorten the life of the blood source in the blood analyzer, and further has a variable reference type light quantity stabilizing circuit. A lighting device for a container is provided.

[0005]

The present invention provides a cold cathode fluorescent discharge tube, a light receiving element, an A / D converter, a CPU, a memory and a D / D converter.
An A converter and an amplifier for detecting and amplifying light from the light receiving element are provided, and the light output of the cold cathode fluorescent discharge tube is set to a value immediately after lighting.

[0006]

In the illuminating device of the blood analyzer of the present invention, the cold cathode fluorescent discharge tube is first used as the light source, and the brightness is detected by the photodetector immediately after lighting the light source, so that the brightness is stabilized to a predetermined level. The advantage that the light source is turned off when the blood analyzer body is not used and the brightness is kept at a predetermined value when the blood analyzer is turned on is obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a lighting device of a blood analyzer of the present invention, FIG. 2 is a characteristic diagram of a cold cathode fluorescent discharge tube used in the device when the lighting device is on, and FIG. Shows a characteristic diagram when the discharge tube blinks. In the drawing, (1) is a cold cathode fluorescent discharge tube as a light source, (2) is a photosensor as a light receiving element, (3) is an amplifier for amplifying photocurrent, (4) is an A / D converter, (5) is a memory,
(6) is a D / A converter, (7) is a comparator operational amplifier,
(8) is a central information processing unit (CPU), and (9) is a variable output driver.

Next, the operation of the embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 2 and 3 showing characteristic diagrams.

First, a power switch (not shown) is operated based on an instruction from an operator (operator), power is supplied to each part, and then a lighting command signal is output from the CPU (8), which is changed. The output driver (9) lights the cold cathode fluorescent discharge tube (1) with a certain defined current.

The light output of the cold cathode fluorescent discharge tube (1) is received by a photo sensor (2) and amplified by an amplifier (3).

The output of the amplifier (3) is converted from an analog signal to a digital signal by the A / D converter (4) and input to the CPU (8) and the memory (5). C
The PU (8) stores the digital value of the digital signal in the memory (5) according to the digital signal corresponding to the optical output.

Therefore, the memory (5) stores the light output of the cold cathode fluorescent discharge tube (1) immediately after lighting. The digital value read from the memory (5) is converted from a digital signal to an analog signal by the D / A converter (6) and input to the reference terminal (10) of the operational amplifier (7). In the operational amplifier (7), the reference signal is constantly compared with the output of the amplifier (3) applied to the input terminal (11), and the output controls the variable output driver (9).

FIG. 2 shows a change in light output immediately after the cold cathode fluorescent discharge tube (1) itself is lit. The change in light output after lit is unsuitably large when used for measurement of various analyzers. In contrast, the cold cathode fluorescent discharge tube (1) having the configuration shown in FIG. 1 changes the light output in proportion to the photocurrent, so that the discharge tube (1) holds the photocurrent immediately after lighting. The light level is constant.

In FIG. 3, the characteristics of the cold cathode fluorescent discharge tube provided as a light source when blinking indicate the lighting period (T ₁ ,
T _2, the absolute value of the light output in the period of each of the T ₃₎ (P ₁
To P ₃₎ may vary depending on various conditions ambient temperature of each timing, said during each period is kept constant without light output changes.

[0015]

According to the illuminating device of the blood analyzer of the present invention, the cold cathode fluorescent discharge tube is used as the light source, the structure is such that it can withstand blinking, and the light output immediately after lighting is related to the magnitude of its absolute value. Since it can be held constant, it is not affected by changes over time during measurement.

Therefore, the apparatus of the present invention can perform optical analysis of the light output according to the light output immediately after lighting, without waiting until the light source reaches a steady state from the lighting, and the measurement work time can be shortened. As a result, the service life can be extended, and the frequency of replacement of light source parts, which is a drawback of the conventional device, can be drastically reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a lighting device of a blood analyzer of the present invention.

FIG. 2 is a characteristic diagram when the light source used in FIG. 1 is turned on.

FIG. 3 is a characteristic diagram when the light source used in FIG. 1 blinks.

[Explanation of symbols]

 (1) Cold cathode fluorescent discharge tube (2) Photo sensor (4) A / D converter (5) Memory (6) D / A converter (7) Operational amplifier (8) CPU (9) Variable output driver

Claims (3)

[Claims] 1. A cold cathode fluorescent discharge tube for irradiating a sample for a blood sample with light, a light receiving element for detecting light from the cold cathode fluorescent discharge tube, and an A / D connected to the light receiving element via an amplifier.
A converter, a central information processing device and a memory connected to the output side of the A / D converter, a variable output driver connected to the output side of the central information processing device, and a D / A from the memory
A comparator connected to one of the input terminals via a converter and having the output terminal of the amplifier connected to the other input terminal;
An illumination device for a blood analyzer, wherein an output terminal of the comparator is connected to the variable output driver, and an optical output of the cold cathode fluorescent discharge tube is set to an optical output immediately after lighting. 2. The illumination device for a blood analyzer according to claim 2, wherein a photo sensor is used for the light receiving element. 3. The blood according to claim 1, wherein a photosensor is used for the light receiving element, an operational amplifier is used for the comparator, and an analog signal output from the D / A converter is used as a reference. Lighting equipment for the analyzer.