Apparatus for rapid colorimetry on different samples

• US 4,838,697 A
• Filed: 08/05/1987
• Issued: 06/13/1989
• Est. Priority Date: 08/05/1986
• Status: Expired due to Fees

• Current Assignee: Fritz Kurandt
• Original Assignee: Fritz Kurandt
• Inventors: Kurandt, Fritz
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US07/081,905
• Time in Patent Office: 678 Days
• Field of Search: 356/402, 356/406, 356/407, 356/409, 356/414, 356/416, 356/419, 356/420, 356/425, 250/226
• US Class Current: 356/406
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01J 3/501 Colorimeters using spectrally-selective light sources, e.g. LEDs
• CPC Class Codes: G01N 2021/3181 using LEDs

Abstract

An apparatus for rapid colorimetry on different samples which has a transmitter for irradiating or through-radiating the particular sample and a receiver for receiving the radiation reflected or transmitted by the sample, as well as a filter arrangement. Also included is a computer for evaluating the signals from the receiver. The transmitter is formed by several semiconductor radiation sources, which irradiate in different spectral ranges and whose optical radiation is combined by means of a filter unit and is deflected onto the sample by a lens arrangement. A control unit controls the semiconductor radiation sources in successive pulsewise intervals. The control unit also supplies a signal permitting an association of the receiver signals to the radiation emitted in the different spectral ranges.

Claims

1. An apparatus for rapid colorimetry on different samples comprising:

(a) a transmitter capable of irradiating or through-radiating the particular sample;

(b) three semiconductor radiation sources located in the transmitter which irradiate in the red, green and blue spectral ranges, respectively;

(c) a unitary photoelectric receiver capable of receiving the radiation reflected or transmitted by the sample and generating signals;

(d) a filter unit arrangement capable of combining optical radiation emitted from the semiconductors associated with the transmitter by means of two dichroic mirrors, each located at an angle of 45 degrees to the direction of the radiation emitted by one of the semiconductor radiation sources;

(e) a computer capable of evaluating the signal supplied by the receiver;

(f) a lens arrangement associated with the transmitter capable of focusing the combined optical radiation from the filter unit arrangement onto the particular sample;

(g) a control unit capable of providing successive pulses to control the semiconductor radiation sources, the control unit also capable of generating a signal permitting an association of the receiver signals with the radiation emitted in the different spectral ranges; and

(h) the semiconductor radiation sources, the filter unit and the lens arrangement adjusted in such a way that all the individual beams meet at one point forming an illuminating spot, the diameter of the illuminating spot being adaptable to the particular sample.

2. The apparatus according to claim 1, wherein the illuminating spot has a diameter of approximately 1 mm.

3. The apparatus according to claim 1, wherein the transmitter and receiver are placed in one casing, the receiver being at an angle of 45°

to the radiation directed onto the sample.

4. the apparatus according to claim 1, wherein exciting capacities for the individual semiconductor radiation sources of the transmitter can be separately predetermined.

5. The apparatus according to claim 1, wherein for one measuring cycle of the sample, each semiconductor radiation source is controlled at least once by one pulse.

6. An apparatus according to claim 1, wherein at least one of the dichroic mirrors reflects in the red spectral range and at least one dichroic mirror reflects in the blue spectral range.

7. The apparatus according to claim 1, wherein the semiconductor radiation sources are constructed as three light-emitting diodes which emit radiation in the red, green and blue spectral ranges respectively and the filter unit has at least two dichroic mirrors located at an angle of approximately 45°

to the respective directions of radiation emitted by the individual semiconductor radiation sources, wherein at least one dichroic mirror reflects light in the red spectral range and at least one other dichroic mirror reflecting light in the blue range.