Optical head for endoscope
An optical head for an endoscope is fitted with an imaging system comprising a solid state imaging sensor and with an illuminating system comprising illuminating means, e.g. LED's. At least one illuminating means is defined by a parameter, which value is different from the value of the same parameter of the remaining illuminating means. Among the parameters are luminous intensity, luminous intensity distribution angle, and direction of the longitudinal axis of the illuminating means.
1. An optical head for an endoscope, the optical head comprising:
an imaging system comprising
a CCD-chip or CMOS; and
an illuminating system comprising
an illuminating module fitted with a first illumination means and a second illumination means substantially simultaneously illuminating, wherein the first illumination means and the second illumination means have different luminous intensity distribution angles thereby exhibiting a uniform illumination,
wherein the first and second illuminating means are LEDs and the illuminating module comprises a mounting plate on which the LEDs are deployed, wherein the LEDs are divided into two groups located respectively at a left side and a right side of an imaginary longitudinal middle plane of the optical head, and
wherein the mounting plate has a saddle-like configuration and each of the groups of LEDs is located within a respective arched region provided at the left and the right side of the imaginary longitudinal middle plane.
2. The optical head according to claim 1 , wherein the mounting plate comprises a ceramic hybrid module.
3. The optical head according to claim 1 , wherein the LEDs are situated symmetrically with respect to the imaginary longitudinal middle plane.
4. The optical head according to claim 3 , wherein the LEDs are secured on the mounting plate such that their longitudinal axes are directed parallel to the longitudinal axis of the optical head.
5. The optical head according to claim 1 , wherein the first illumination means comprises a middle LED and the second illumination means comprises outside LEDs, and wherein the luminous intensity distribution angle of the middle LED is wider than the luminous intensity distribution angle of the outside LEDs.
6. The optical head according to claim 1 , wherein the first illumination means comprises a middle LED and the second illumination means comprises outside LEDs, and wherein the LEDs are secured on the mounting plate in such a manner that longitudinal axes of the outside LEDs are directed not parallel to the longitudinal axis of the optical head.
7. The optical head according to claim 6 , wherein the diameter of the middle LED is larger than the diameter of the outside LEDs.
8. The optical head according to claim 6 , wherein the luminous intensity distribution angle of the middle LED is narrower than the luminous intensity distribution angle of the outside LEDs.
9. The optical head according to claim 6 , wherein the luminous intensity of the middle LED is not equal to the luminous intensity of the outside LEDs.
10. The optical head according to claim 1 , further comprising a means for controlling the luminous intensity of the LEDs.
11. The optical head according to claim 10 , wherein the CCD-chip has a field of view, which is divided into virtual regions that are associated with respective LEDs and the means for controlling the luminous intensity comprises at least one current source supplying a current to a respective LED, the current depends on a preset value of the average illumination level of the virtual region associated with this LED.
12. The optical head according to claim 1 , further comprising a disposable cap detachably connectable to the optical head.
13. The optical head according to claim 12 , in which the optical head is detachably connectable to the cap by a snap connection.
14. The optical head according to claim 13 , wherein the snap connection comprises an elastically deflectable tongue for engagement with a hole.
15. A method for controlling an optical head of an endoscope, the optical head comprising an imaging system comprising a solid state imaging sensor, and an illuminating system comprising an illuminating module fitted with several illuminating means, including a first illumination means and a second illumination means substantially simultaneously illuminating, wherein the first illumination means and the second illumination means have different luminous intensity distribution angles, wherein the first and second illuminating means are LEDs and the illuminating module comprises a mounting plate on which the LEDs are deployed, wherein the LEDs are divided into two groups located respectively at a left side and a right side of an imaginary longitudinal middle plane of the optical head, and wherein the mounting plate has a saddle-like configuration and each of the groups of LEDs is located within a respective arched region provided at the left and the right side of the imaginary longitudinal middle plane, the method comprising:
dividing the field of view of the imaging sensor into virtual regions that are associated with respective illuminating means; and
supplying electrical current to a respective illuminating means depending on the average illumination level of the virtual region associated with the respective illuminating means.
16. An optical head for an endoscope, the optical head comprising:
an imaging system comprising
a CCD-chip or CMOS; and
an illuminating system comprising
an illuminating module fitted with a plurality of LEDs divided into two groups, each of the groups of LEDs consisting of two outside LEDs and a middle LED, at least one of the LEDs defined by a parameter value different from a value of the same parameter for remaining LEDs,
the illuminating module comprising a mounting plate on which the LEDs are secured such that their longitudinal axes are directed parallel to the longitudinal axis of the optical head, wherein the two groups of LEDs are located respectively at a left side and a right side of an imaginary longitudinal middle plane of the optical head,
wherein the mounting plate has a saddle-like configuration and each of the two groups of LEDs is located within a respective arched region provided at the left and the right side of the imaginary longitudinal middle plane,
wherein the LEDs are situated symmetrically with respect to the imaginary longitudinal middle plane, and
wherein the luminous intensity distribution angle of the middle LED is different from the luminous intensity distribution angle of the outside LEDs.
17. The optical head according to claim 16 , wherein the luminous intensity distribution angle of the middle LED is wider than the luminous intensity distribution angle of the outside LEDs.
18. An optical head for an endoscope, the optical head comprising:
an imaging system comprising
a CCD-chip or CMOS; and
an illuminating system comprising
an illuminating module fitted with a plurality of LEDs divided into two groups, each of the groups of LEDs consisting of two outside LEDs and a middle LED, at least one of the LEDs defined by a parameter value different from a value of the same parameter for remaining LEDs,
the illuminating module comprising a mounting plate on which the two groups of LEDs are secured in such a manner that longitudinal axes of the outside LEDs are directed not parallel to the longitudinal axis of the optical head, wherein the two groups of LEDs are located respectively at a left side and a right side of an imaginary longitudinal middle plane of the optical head,
wherein the mounting plate has a saddle-like configuration and each of the two groups of LEDs is located within a respective arched region provided at the left and the right side of the imaginary longitudinal middle plane,
wherein the LEDs are situated symmetrically with respect to the imaginary longitudinal middle plane, and
wherein the diameter of the middle LEDs is larger than the diameter of the outside LEDs.
19. An optical head for an endoscope, the optical head comprising:
an imaging system comprising
a CCD-chip or CMOS; and
an illuminating system comprising
an illuminating module fitted with a plurality of LEDs divided into two groups, each of the groups of LEDs consisting of two outside LEDs and a middle LED, at least one of the LEDs defined by a parameter value different from a value of the same parameter for remaining LEDs,
the illuminating module comprising a mounting plate on which the LEDs are secured in such a manner that longitudinal axes of the outside LEDs are directed not parallel to the longitudinal axis of the optical head, wherein the two groups of LEDs are divided located respectively at a left side and a right side of an imaginary longitudinal middle plane of the optical head,
wherein the mounting plate has a saddle-like configuration and each of the two groups of LEDs is located within a respective arched region provided at the left and the right side of the imaginary longitudinal middle plane,
wherein the LEDs are situated symmetrically with respect to the imaginary longitudinal middle plane, and
wherein the luminous intensity distribution angle of the middle LED is narrower than the luminous intensity distribution angle of the outside LEDs.