Light measurement apparatus

• US 7,629,571 B2
• Filed: 06/29/2007
• Issued: 12/08/2009
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Ivoclar Vivadent AG
• Original Assignee: Ivoclar Vivadent AG
• Inventors: Plank, Wolfgang, Senn, Bruno
• Primary Examiner(s): Lee; John R
• Application Number:
  US11/824,257
• Publication Number:
  US 20080023625A1
• Time in Patent Office: 893 Days
• Field of Search: 250/227.11, 250/227.33, 250/208.2, 356/218, 356/222, 433/33
• US Class Current: 250/227.11
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01J 2001/4247 for testing lamps or other light sources

Abstract

The invention relates to a light measurement apparatus (34), having a light source to which a light guide apparatus (24) is connected, with the light guide apparatus (24) having a light outlet area (30) on the light output side and the light measurement apparatus (34) having a light sensor arrangement (36), and having a stop for the light guide apparatus (24) to make contact with. The light sensor arrangement (36) has at least two sensors (40a, 40b, 40c, . . . ), to which light from the light outlet area (30) can be applied.

Claims

1. A light measurement apparatus, for a light source on a hand-held dental light curing unit to which a light guide apparatus is connected, with the light guide apparatus having a light outlet area, and the light measurement apparatus being on a base unit having a light sensor arrangement (36) having at least two sensors (40a, 40b, 40c, . . .), to which light from the light outlet area (30) can be applied wherein the light sensor arrangement (36) measures not only the amount of light emitted per unit area from the light outlet area (30) but also the diameter of the light outlet area (30), whereby it can be determined if the optical characteristics of the light curing unit is or is not sufficient to properly cure a dental restoration.

2. The light measurement apparatus as claimed in claim 1, wherein a prefabricated light sensor arrangement (36), with a transparent cover (38), is installed in the base unit.

3. The light measurement apparatus as claimed in claim 1, wherein the base unit has a stop (42) for the light guide apparatus (24) to make contact with.

4. The light measurement apparatus as claimed in claim 1, wherein the light sensor arrangement (36) has light sensors (40a, 40b, 40c, . . .)which are arranged in a row, and wherein the longitudinal extent of the row is greater than the light outlet area.

5. The light measurement apparatus as claimed in claim 3, wherein the light outlet area (30) covers at least one light sensor when the light guide apparatus (24) is making free contact with the stop (42).

6. The light measurement apparatus as claimed in claim 1, wherein the light outlet area (30) is essentially circular, and the light sensors (40a, 40b, 40c, . . . ) each have a width which is less than the width of the light outlet area (30) that occurs, are arranged immediately adjacent to one another.

7. The light measurement apparatus as claimed in claim 1, wherein the light sensor arrangement (36) is an arrangement of light sensors (40a, 40b, 40c, 40d, . . . ) in the form of a strip of between three and five hundred light sensors.

8. The light measurement apparatus as claimed in claim 1, wherein each light sensor (40a, 40b, 40c, . . . ) has an aspect ratio (width/length ratio) of at least 2:

1 and at most 20;

1.

9. The light measurement apparatus as claimed in claim 1, wherein the light outlet area (30) is essentially circular, and wherein the light sensor arrangement (36) has a length of more than 10-times the diameter of the light outlet area.

10. The light measurement apparatus as claimed in claim 2, wherein the cover (38) is covered by a translucent or transparent filter which essentially compensates for the spectral sensitivity of the sensors in the light sensor arrangement (36).

11. The light measurement apparatus as claimed in claim 10 wherein a protective shutter is fitted to the filter or to the cover (38), which leaves free an area in the form of a slot above the light sensor arrangement (36) and covers areas to the side of this area.

12. The light measurement apparatus as claimed in claim 1, wherein the light outlet area (30) can be used for different light guide apparatuses (24).

13. The light measurement apparatus as claimed in claim 1, wherein a discriminator is connected to one light sensor (40a, 40b, 40c, . . . ) and emits an ON signal when the detected amount of light is above a predetermined threshold value, and emits an OFF signal when the amount of light is below the threshold value.

14. The light measurement apparatus as claimed in claim 1, wherein an evaluation circuit is connected to the light sensor arrangement (36) and forms the ratio of the amount of light detected by the light sensors (40a, 40b, 40c, . . . ) to the number of light sensors (40a, 40b, 40c, . . . ) which receive light and are adjacent to one another.

15. The light measurement apparatus as claimed in claim 14, wherein the light power which is emitted from the light outlet area (30) is calculated by the evaluation circuit on the basis of the ratio of the amount of light measured by the light sensors (40a, 40b, 40c, . . . ) over their area and the total light outlet area (30).

16. The light measurement apparatus as claimed in claim 3, wherein the light sensor arrangement (36) is in the form of a single-line or multiple-line bar, at one of whose ends the stop for the light guide apparatus (24) is arranged.

17. The light measurement apparatus as claimed in claim 1, wherein the number of sensors illuminated by the light guide apparatus (24) is determined by an evaluation circuit, and the average amount of light applied to the sensors is calculated in order to calculate the light power per unit area of a light source.