Endoscopic spectral illumination device having LEDS emitting different wavelengths of light

1 . An endoscope tip or capsule endoscope comprising

an illumination device configured to illuminate a scene and including a plurality of groups of light sources, each of the groups of light sources including a respective first light source configured to emit light with a first spectral distribution, and further including a respective second light source configured to emit light with a second spectral distribution;

an optical imaging device configured to image the scene, wherein each of said light sources are arranged in a circular pattern around and at the same radial distance from a center of the optical imaging device; and

a working channel outlet configured to accommodate an instrument therethrough, positioned adjacent to the optical imaging device and protruding into a path of the circular pattern such that an area between the working channel outlet and the optical imaging device is free of light sources, wherein:

the first spectral distribution is different from the second spectral distribution;

for each of the groups and for each two light sources A and B selected from the first light source of the respective group, the second light source of the respective group, the first light source of the group adjacent to the respective group, and the second light source of the group adjacent to the respective group, a clearance between the light sources A and B indicates a length of a shortest straight line segment which connects a point on the light source A with a point on the light source B; and

at least one of the following conditions is satisfied:

for each of the groups the clearance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to the clearance between the first light source of the respective group and the first light source of a group that is adjacent to the respective group; and

for each of the groups the clearance between the first light source of the respective group and the second light source of the respective group is smaller than the clearance between the second light source of the respective group and the second light source of the group that is adjacent to the respective group.

2 . The endoscope tip or capsule endoscope according to claim 1 , wherein in each of the groups the clearance between the first light source of the respective group and the second light source of the respective group is the same.

3 . The endoscope tip or capsule endoscope according to claim 1 , wherein in each of the groups the shortest straight line segment between a point of the first light source of the respective group and a point of the second light source of the respective group is smaller than twice a dimension among the dimensions of the first light source of the respective group perpendicular to the shortest straight line segment and the dimensions of the second light source of the respective group perpendicular to the shortest straight line segment.

4 . The endoscope tip or capsule endoscope according to claim 1 , wherein for each of the groups an edge of the first light source of the respective group and an edge of the second light source of the respective group lie on a line which is parallel to the shortest straight line segment.

5 . The endoscope tip or capsule endoscope according claim 1 , wherein at least one of the following conditions is satisfied for each of the groups:

the clearance between the first light source of the respective group and the second light source of the respective group is at least 20% smaller than the clearance between the first light source of the respective group and the first light source of the group that is adjacent to the respective group; and

the clearance between the first light source of the respective group and the second light source of the respective group is at least 20% smaller than the clearance between the second light source of the respective group and the second light source of the group that is adjacent to the respective group.

6 . The endoscope tip or capsule endoscope according to claim 1 , wherein at least one of the following conditions is satisfied:

the first light sources are disposed on a first circular segment having a first center around the optical imaging device; and

the second light sources are disposed on a second circular segment having a second center around the optical imaging device.

7 . The endoscope tip or capsule endoscope according to claim 6 , wherein at least one of the following conditions is satisfied:

when the first light sources are disposed on the first circular segment, for each of the groups an angle on the first circular segment between the first light source of the respective group and the first light source of the group adjacent to the respective group deviates from an ideal angle, wherein the deviation from the ideal angle is no more than 20%, and

when the second light sources are disposed on the second circular segment, for each of the groups an angle on the second circular segment between the second light source of the respective group and the second light source of the group adjacent to the respective group deviates from the ideal angle, wherein the deviation from the ideal angle is no more than 20%, and

the ideal angle is 360° divided by the number of groups.

8 . The endoscope tip or capsule endoscope according to claim 6 , wherein at least one of the following conditions is satisfied:

when the first light sources are disposed on the first circular segment, an angle between a straight line, which connects a barycenter of a light emission from the first light source of the respective group with a barycenter of a light emission from the second light source of the respective group, and a radius from the first center to the first light source of the respective group is the same in each of the groups, and

when the second light sources are disposed on the second circular segment, an angle between a straight line, which connects the barycenter of the light emission from the first light source of the respective group with the barycenter of the light emission from the second light source of the respective group, and a radius from the second center to the second light source of the respective group is the same in each of the groups.

9 . The endoscope tip or capsule endoscope according to claim 6 , wherein the first center is equal to the second center.

10 . The endoscope tip or the capsule endoscope according to claim 6 , wherein at least one of the following conditions is satisfied:

a center of a plan view of the optical imaging device is equal to the first center; and

the center of the plan view of the optical imaging device is equal to the second center.

11 . The endoscope tip or capsule endoscope according to claim 1 , wherein at least one of the following conditions is satisfied:

each of the first light sources is a light emitting diode or a laser diode or an emission end of a light guide; and

each of the second light sources is a light emitting diode or a laser diode or an emission end of a light guide.

12 . The endoscope tip or capsule endoscope according to claim 1 , wherein at least one of the following conditions is satisfied:

for each of the groups the clearance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to the clearance between the first light source of the respective group and the second light source of the group that is adjacent to the respective group; and

for each of the groups the clearance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to the clearance between the second light source of the respective group and the first light source of the group that is adjacent to the respective group.

13 . The endoscope tip or capsule endoscope according to claim 1 , wherein

for each of the groups the shortest straight line segment between a point on the first light source of the respective group and a point on the second light source of the respective group runs parallel to a straight line segment that connects a barycenter of a light emission from the first light source of the respective group with a barycenter of a light emission from the second light source of the respective group.

14 . The endoscope tip or capsule endoscope according to claim 1 , wherein

for each of the groups and for each two light sources C and D selected from the first light source of the respective group, the second light source of the respective group, the first light source of the group adjacent to the respective group, and the second light source of the group adjacent to the respective group, the distance between the light sources C and D indicates the length of a straight line segment that connects a barycenter of a light emission from the light source C with a barycenter of a light emission from the light source D, and at least one of the following conditions is satisfied:

for each of the groups a distance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to a distance between the first light source of the respective group and the first light source of the group that is adjacent to the respective group; and

for each of the groups a distance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to a distance between the second light source of the respective group and the second light source of the group that is adjacent to the respective group.

15 . The endoscope tip or capsule endoscope according to claim 1 , wherein at least one of the following conditions is satisfied:

for each of the groups the distance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to the distance between the first light source of the respective group and the second light source of the group that is adjacent to the respective group; and

for each of the groups the distance between the first light source of the respective group and the second light source of the respective group is smaller than or equal to the distance between the second light source of the respective group and the first light source of the group that is adjacent to the respective group.

16 . The endoscope tip or capsule endoscope according to claim 1 , wherein in each of the groups the respective first light source is electrically connected in parallel with the respective second light source, or in series with the respective second light source.

17 . The endoscope tip or capsule endoscope according to claim 1 , further comprising

a control unit configured to switch on or off, in each of the groups, the respective first light source together with the respective second light source.

18 . An endoscope tip or capsule endoscope comprising

an illumination device configured to illuminate a scene and including a plurality of groups of light sources, each of the groups of light sources including a respective first light source configured to emit light with a first spectral distribution and a respective second light source configured to emit light with a second spectral distribution, the first spectral distribution being different from the second spectral distribution;

a lens configured to image the scene, wherein each of said light sources are arranged in a circular pattern around and at the same radial distance from a center of the lens; and

a working channel outlet configured to accommodate an instrument therethrough, positioned adjacent to the lens and protruding into a path of the circular pattern such that an area between the working channel outlet and the lens is free of light sources, wherein:

a clearance between the first light source of a respective group and the second light source of the respective group is smaller than twice a dimension among the dimensions of the first light source and the dimensions of the second light source; and

the clearance between the first light source of the respective group and the second light source of the respective group indicates the length of a shortest straight line segment which connects a point on the first light source with a point on the second light source.

19 . The endoscope tip or capsule endoscope according to claim 18 , wherein the dimension among the dimensions of the first light source and the dimensions of the second light source is perpendicular to the shortest straight line segment which connects a point on the first light source with a point on the second light source.

20 . The endoscope tip or capsule endoscope according to claim 18 , wherein the first light source is electrically connected in parallel with the second light source, or in series with the second light source.

21 . The endoscope tip or capsule endoscope according to claim 18 , further comprising

a control unit configured to switch on or off the first light source together with the second light source.

22 . The endoscope tip or capsule endoscope according to claim 18 , wherein

a distance between the first light source and the second light source is smaller than twice the dimension among the dimensions of the first light source and the dimensions of the second light source; and

the distance between the first light source and the second light source indicates the length of a straight line segment which connects a barycenter of a light emission from the first light source with a barycenter of a light emission from the second light source.

23 . An endoscope comprising

the endoscope tip according to claim 1 ; and

a rigid or flexible shaft that is directly or indirectly connected with the endoscope tip.