Safety light curtain to disable carousel rotation

1. A digital slide scanning apparatus, comprising:

a carousel comprising:

a carousel base, the carousel base configured to support a plurality of slide racks, the carousel base having an upper surface, a lower surface and a perimeter edge, the carousel base further configured to be rotated 360 degrees in either direction under control of at least one processor of the digital slide scanning apparatus;

a plurality of rack spacers extending upward from the carousel base, wherein adjacent pairs of rack spacers define a rack slot bordered on three sides by the carousel base, a first side of a first rack spacer and a second side of a second rack spacer, wherein each rack spacer comprises:

a perimeter edge extending upward from the carousel base proximal the perimeter edge of the carousel base, the perimeter edge having an upper portion and a lower portion; and

a recess in the perimeter edge positioned between the upper portion the lower portion, the recess configured to allow a hand of an operator to access a rack slot defined in part by the rack spacer;

a mount bracket positioned above the carousel;

a machine base positioned below the carousel and configured to support the carousel;

a plurality of transmitter and receiver pairs, wherein for each transmitter and receiver pair:

one of the transmitter or receiver is positioned on or in the mount bracket and the other of the transmitter or receiver is positioned on or in the machine base, wherein the transmitter and receiver are communicatively coupled via a direct wireless link and wherein the transmitter and receiver pair are configured to detect the presence of an object by interruption of the direct wireless link;

wherein the at least one processor of the digital slide scanning apparatus is configured to receive an indication from a first transmitter and receiver pair when the presence of an object in a first recess is detected, and

wherein the at least one processor of the digital slide scanning apparatus is configured to disable rotation of the base in response to the indication.

2. The digital slide scanning apparatus of claim 1 , wherein the at least one processor is further configured to enable rotation of the base in response to a termination of said indication.

3. The digital slide scanning apparatus of claim 1 , wherein the transmitter and receiver pair are offset at an angle.

4. The digital slide scanning apparatus of claim 3 , wherein the offset angle of the transmitter and receiver pair is equal to the angle of the upper surface of the carousel base.

5. The digital slide scanning apparatus of claim 1 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter onto the receiver.

6. The digital slide scanning apparatus of claim 1 , further comprising a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.

7. The digital slide scanning apparatus of claim 1 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter to the receiver and a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.

8. A digital slide scanning apparatus, comprising:

a carousel comprising:

a carousel base configured to support a plurality of slide racks, the carousel base having an upper surface, a lower surface and a perimeter edge, wherein at least a portion of the upper surface of the carousel base angles downward from an external region of the carousel base toward a central region of the carousel base; and

a plurality of rack spacers extending upward from the carousel base, wherein adjacent pairs of rack spacers define a rack slot bordered on three sides by the carousel base, a first side of a first rack spacer and a second side of a second rack spacer;

a mount bracket positioned over the carousel, the mount bracket having an upper surface, a lower surface and a perimeter edge;

a machine base positioned below the carousel and configured to support the carousel;

a plurality of transmitter and receiver pairs, wherein for each pair, one of the transmitter or receiver is positioned on or in the lower surface of the mount bracket proximal the perimeter edge of the mount bracket and the other of the transmitter or receiver is positioned on or in the upper surface of the machine base proximal the perimeter edge of the carousel base, wherein the transmitter and receiver are communicatively coupled via a direct wireless link and wherein the transmitter and receiver pair are configured to detect the presence of an object by interruption of the direct wireless link;

a housing comprising an opening configured to expose at least a portion of the carousel for continuous loading and unloading of slide racks;

at least one processor configured to rotate the carousel 360 degrees in either direction, the at least one processor further configured to receive an indication from a first transmitter and receiver pair when the presence of an object is detected, and wherein the at least one processor is further configured to disable rotation of the carousel in response to the indication.

9. The digital slide scanning apparatus of claim 8 , wherein the at least one processor is further configured to enable rotation of the carousel in response to a termination of said indication.

10. The digital slide scanning apparatus of claim 8 , wherein the transmitter and receiver pair are offset at an angle.

11. The digital slide scanning apparatus of claim 10 , wherein the offset angle of the transmitter and receiver pair is equal to the angle of the upper surface of the carousel base.

12. The digital slide scanning apparatus of claim 8 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter onto the receiver.

13. The digital slide scanning apparatus of claim 8 , further comprising a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.

14. The digital slide scanning apparatus of claim 8 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter to the receiver and a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.

15. A digital slide scanning apparatus, comprising:

a carousel configured to support a plurality of slide racks;

a mount bracket positioned over the carousel;

a plurality of transmitter and receiver pairs, wherein for each pair, one of the transmitter or receiver is connected to the mount bracket and the other of the transmitter or receiver is connected to the carousel, wherein the transmitter and receiver are communicatively coupled via a direct wireless link and wherein the transmitter and receiver pair are configured to detect the presence of an object by interruption of the direct wireless link;

at least one processor configured to rotate the carousel 360 degrees, the at least one processor further configured to receive an indication from a first transmitter and receiver pair when the presence of an object is detected, and wherein the at least one processor is further configured to disable rotation of the carousel in response to the indication.

16. The digital slide scanning apparatus of claim 15 , wherein the transmitter and receiver pair are offset at an angle equal to an angle of a portion of an upper surface of the carousel that supports the plurality of slide racks.

17. The digital slide scanning apparatus of claim 15 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter onto the receiver.

18. The digital slide scanning apparatus of claim 15 , further comprising a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.

19. The digital slide scanning apparatus of claim 15 , further comprising a first focusing means positioned relative to the transmitter and configured to focus the direct wireless link from the transmitter to the receiver and a second focusing means positioned relative to the receive and configured to focus the direct wireless link from the transmitter onto the receiver.