Process and arrangement for detecting or recognizing an object

• US 6,744,514 B2
• Filed: 04/03/2001
• Issued: 06/01/2004
• Est. Priority Date: 04/03/2000
• Status: Active Grant

• Current Assignee: Sensopart Industriesensorik GmbH
• Original Assignee: Sensopart Industriesensorik GmbH
• Inventors: Kemmler, Manfred, Meinert, Thomas, Trüper, Dirk
• Primary Examiner(s): CHERRY, EUNCHA P
• Application Number:
  US09/824,577
• Publication Number:
  US 20020018208A1
• Time in Patent Office: 1,155 Days
• Field of Search: 356/402, 356/406, 356/407, 356/425, 356/405, 356/419, 250/226
• US Class Current: 356/425
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01J 1/0414 using plane or convex mirrors, parallel phase plates, or plane beam-splitters
• CPC Class Codes: G01J 1/0477 Prisms, wedges
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0205 Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• CPC Class Codes: G01J 3/0259 Monolithic
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/501 Colorimeters using spectrally-selective light sources, e.g. LEDs
• CPC Class Codes: G01V 8/12 using one transmitter and one receiver

Abstract

The invention relates to a process and a device for detecting or recognizing an object by means of color recognition or brightness evaluation, whereby radiation emitted by a radiation source on the object and radiation reflected from the object is recorded by a photosensitive element such as a color-recognizing sensor. In order to be able to detect objects with a higher measuring exactitude, whereby changes in distance between object and light-sensitive element should not basically lead to a measurement falsification, it is suggested that reflected radiation be guided to the photosensitive element by means of a light-guiding element tapering in the direction of the photosensitive element.

Claims

1. Process for detecting or recognizing an object by comparison of detected color of the object with a specified standard color, whereby radiation is emitted by a radiation source on the object and radiation reflected from the object are recorded by a color-recognizing sensor, characterized in that

the reflected radiation is guided to the color recognizing sensor by means of a truncated pyramid shaped light-guiding element tapering in the direction of the color-recognizing sensor, whereby the light-guiding element is developed for the reflected light such that the radiation falling into the light-guiding element is reflected a maximum of n times with n≦

2.

2. Process according to claim 1, characterized in that

the reflected radiation is guided lens-free to the color recognizing sensor.

3. Process according to claim 1, characterized in that

the reflected radiation is guided through the light-guiding element to (2×

n

     1)²−

1 virtual color-recognizing sensors as well as to the one real color recognizing-sensor whereby n is the number of reflections of the reflected radiation in the light-guiding element.

4. Arrangement for detecting or recognizing an object (10) by comparison of the detected color of the object with a specified standard color, including a radiation source (12) such as an LED emitting radiation on the object as well as a color-recognizing sensor (20) recording radiation reflected from the object, characterized in that

between the object (10) and the at least one color-recognizing sensor (20), a truncated pyramid shaped light-guiding element tapering in the direction of the color-recognizing sensor of light-permeable solid material is arranged, and in that the light-guiding element (18) is dimensioned for the reflected radiation such that radiation reflected from the object (10) and falling into the light-guiding element is reflectable maximally n times with n=2.

5. Arrangement according to claim 4, characterized in that

the light-guiding element (18) is made of Plexiglas or glass.

6. Arrangement according to claim 4, characterized in that

the radiation source (12) is a white light-emitting LED.

7. Arrangement according to claim 4, characterized in that

the radiation source is a white light-emitting laser.

8. Arrangement according to claim 4, characterized in that the radiation source (12) consists of at least a red, a green and a blue-emitting LED the emitted radiation of which is concentrated into a ray of white light.

9. Arrangement according to claim 4, characterized in that the radiation source (12) is at least a red light, green light and blue-emitting laser, the emitted irradiation of which is concentrated into a ray of white light.

10. Arrangement according to claim 4, characterized in that

the color-recognizing sensor (20) has a red, a blue and a green-sensitive surface.

11. Arrangement according to claim 4, characterized in that

the efflux area of the light-guiding element (18) is equal to the radiation-sensitive overall area of the color-recognizing sensor (20).

12. Arrangement according to claim 4, characterized in that

the object side influx side (22) of the light-guiding element has an extension that corresponds to at least 25 times the radiation-sensitive overall area of the color-recognizing sensor (20).

13. Arrangement according to claim 4, characterized in that

the color-recognizing sensor (20), reached by the radiation reflected by the object (10) and the radiation penetrating the light-guiding element (18), perceives a radiation energy that corresponds to the radiation received directly from the object from the one color-recognizing sensor corresponding to (2×

n

     1)²−

1 virtual color-recognizing sensors (24) plus the one real color-recognizing sensor (20), whereby n is the maximum number of reflections of radiation in the light-guiding element.

14. Arrangement according to claim 4, characterized in that

the radiation reflected by the object (10) into the light guiding element (18) penetrates an apparent aperture diaphragm, which is specified by the aperture fixed between the site of reflection on the object and the overall peripheral edge of the virtual color-recognizing sensor (24).

15. Arrangement according to claim 4, characterized in that

the object (10) is arranged in a receiving space usable for incident radiation which is bounded by an envelope which is fixed by the overall peripheral edge of the virtual color-recognizing sensors (24) as well as the peripheral edge of the influx area (22) of the light-guiding element (18).

16. Arrangement according to claim 4, characterized in that

intermediate space available between the sensor side surface of the light-guiding element (18), and the color-recognizing sensor (24) is filled with a material that has a refractive index, which corresponds to that of the light-guiding element.