Optical density detector

An optical density detector comprising:

• a light source;
• light receiving means for measuring a quantity of light belonging to a specific wavelength region, which is selectively detected from among lights having various wavelengths which are emitted from said light source and are transmitted through a sample;
• temperature measuring means for measuring the temperature of said light source and said light receiving means, or measuring the ambient temperature around said light source and said light receiving means;
• memory means for memorizing information concerned with a temperature characteristic of said light source and said light receiving means about said quantity of said light, a peak-wavelength of said light and an output of said light receiving means;
• and
• compensation means for compensating said quantity measured by said light receiving means on the basis of both said temperature measured by said temperature measuring means and said information memorized in said memory means, whereby a density of a specific material contained in said sample is detected by means of the difference of absorbence which said specific material possesses on the respective wavelengths.

An optical density detector comprising:

• a light source;
• light receiving means for measuring a quantity of light belonging to a specific wavelength region, which is selectively detected from among lights having various wavelengths which are emitted from said light source and are transmitted through a sample;
• temperature measuring means for measuring the temperature of said light source and said light receiving means, or measuring the ambient temperature around said light source and said light receiving means;
• memory means for memorizing information which represent a relationship between a peak-wavelength of said light at respective temperatures which include, at least, two values and said respective temperatures, and information which represent a relationship between said quantity of said light emitted from said light source at the respective temperatures which include, at least, two values as well as said respective temperatures;
• and
• compensation means for compensating said quantity measured by said light receiving means on the basis of both a measured temperature measured by said temperature measuring means and said information memorized in said memory means, whereby a density of a specific material contained in said sample is detected by means of the difference of absorbence which said specific material possesses on the respective wavelengths.

An optical density detector comprising:

• light source means comprising a light emitting diode for emitting a red color light and a light emitting diode for emitting an infrared light;
• emission control means for controlling emission of both said diodes so as to emit said red color light and said infrared light at difference times, respectively;
• light receiving means having a single light receiving element for receiving each light transmitted through a sample to be measured or each light reflected on said sample, wherein said each light is emitted from said both diodes respectively;
• and
• arithmetic means for calculating a difference of absorbence on the basis of output data of said light receiving means.

An optical density detector comprising:

• a first sample stage for arranging a green leaf, as a sample;
• a guide member for controlling a direction to insert said leaf and being arranged on said first sample stage;
• light source means comprising, at least, two light sources which emit, respectively, lights belonging to a different wavelength region and are arranged in a second sample stage facing said first sample stage, wherein said two light sources are on a straight line which makes a certain angle with said direction;
• and
• light receiving means arranged in said first sample stage, for detecting each quantity of lights of respective said light sources, which are transmitted through said leaf, whereby density of a specific material contained in said leaf is detected.

an optical density detector comprising:

• a light source;
• light receiving means for measuring a quantity of a light belonging to a specific wavelength region, which is selectively detected from among lights having various wavelengths which are emitted from said light source and are transmitted through a sample;
• calibration means for measuring said quantity of said light through said light receiving means at the time when said light source is actuated under a state without said sample or with a calibrating filter during a calibration stage;
• discrimination means for deciding whether or not said quantity measured by said calibration means is within a predetermined range;
• measurement control means for controlling to enable said light source and said light receiving means to be operated during a measuring stage when it is decided by said discrimination means that said quantity is within said predetermined range;
• and
• memory means for memorizing said quantity measured by said light receiving means when it is decided by said discrimination means that said quantity is within said predetermined range, whereby density of a specific material contained in said sample is detected by means of difference outputting a start signal for processing measurements when said measuring head comes in contact with said positioning member.

An optical density detector comprising:

• a light source;
• light receiving means for measuring a quantity of light belonging to a specific wavelength region, which is selectively detected from among lights having various wavelengths which are emitted from said light source and are transmitted through a sample;
• temperature measuring means for measuring the temperature of said light source and said light receiving means, or measuring the ambient temperature around said light source and said light receiving means;
• calibration means for measuring said quantity measured by said light receiving means and said temperature measured by said temperature measuring means at the time when said light source is actuated under a state without said sample or with a calibrating filter through said light receiving means and said temperature measuring means so as to obtain a calibrating value;
• memory means for memorizing said light quantity and said temperature measured, respectively, by said calibration means;
• discrimination means for deciding whether or not the difference between said temperature memorized in said memory means and a temperature measured by said temperature measuring means at a density measurement is within a predetermined range;
• and
• measurement control means for controlling said density measurement and starting said calibration means again when said discrimination means decides that said difference between said two temperatures is beyond said predetermined range, whereby the density of a specific material contained in said sample is detected by means of the difference of absorbence which said specific material possesses on respective wavelengths.

An optical density detector comprising:

• a first measuring head having a light source for illuminating a sample;
• a second measuring head which faces said first measuring head so that said sample is inserted between said first and said second measuring head, which have light receiving means for receiving a light illuminated from said light source and transmitted through said sample;
• and
• an optical path which is formed between said first and said second measuring heads so that said light may be transmitted through said sample and reaches said light receiving means,
• one of said first measuring head and said second measuring head being rotatably supported to a body with a joint in order to move from a first predetermined position for sandwiching said sample to a second predetermined position for releasing said sample, while the other being fixed to said body, and
• a shielding member with elasticity being arranged on one of said first and said second measuring heads so as to surround one of said light source and said light receiving means, correspondingly.