1. A robot arm assembly comprising:
a middle joint;
an upper arm rotatably connected to the middle joint;
a driver rotating the upper arm, wherein the driver is mounted on the middle joint and comprises an output shaft; and
a transmission mechanism transferring the power of the driver to the upper arm, wherein the transmission mechanism comprises a first gear coupled to the output shaft of the driver, a second gear mounted on the outer circumference of the upper arm, a third gear meshed with the first gear, and a fourth gear coinciding with the third gear and meshed with the second gear.
2. The robot arm assembly of claim 1, wherein the middle joint comprises a first support portion, the first support portion defining a first mounting hole therein and at least one first bearing received in the first mounting hole, wherein the upper arm is rotatably received in the first mounting hole and supported by the at least one first bearing.
3. The robot arm assembly of claim 2, wherein the middle joint further comprises a second support portion fixed to the first support portion, and wherein the first support portion and the second support portion cooperatively define a receiving space in which the transmission mechanism is partially received.
4. The robot arm assembly of claim 3, wherein the robot arm assembly further comprises a shaft seat secured in the second support portion.
5. The robot arm assembly of claim 4, further comprising a gear shaft, wherein the gear shaft is rotatably received in a second mounting hole defined in the shaft seat, and the third gear and the fourth gear are mounted on opposite ends of the gear shaft.
6. The robot arm assembly of claim 1, wherein the driver is an electric servo motor.
7. The robot arm assembly of claim 1, wherein the rotation axes of the output shaft of the driver, the second gear, the third gear, and the upper arm are parallel and mutually offset.
8. The robot arm assembly of claim 1, wherein the first, second, third and fourth gears are a plurality of straight-tooth involute gears.
9. An industrial robot comprising:
a robot arm assembly rotatable about a rotation axis, and
an end joint rotatably connected to the robot arm assembly, wherein the robot arm assembly comprises:
a middle joint;
an upper arm rotatably connected to the middle joint;
a driver rotating the upper arm, mounted on the middle joint and comprising an output shaft; and
a transmission mechanism transferring the power of the driver to the upper arm, wherein the transmission mechanism comprises a first gear coupled to the output shaft of the driver, a second gear mounted on the outer circumference of the upper arm, a third gear meshed with the first gear, and a fourth gear coinciding with the third gear and meshed with the second gear.
10. The industrial robot of claim 9, wherein the middle joint comprises a first support portion, the first support portion defining a first mounting hole therein and at least one first bearing received in the first mounting hole, wherein the upper arm is rotatably received in the first mounting hole and supported by the at least one first bearing.
11. The industrial robot of claim 10, wherein the middle joint further comprises a second support portion fixed to the first support portion, and the first support portion and the second support portion cooperatively define a receiving space in which the transmission mechanism is partially received.
12. The industrial robot of claim 11, wherein the robot arm assembly further comprises a shaft seat secured in the second support portion.
13. The industrial robot of claim 12, further comprising a gear shaft, wherein the gear shaft is rotatably received in a second mounting hole defined in the shaft seat, and the third gear and the fourth gear are mounted on opposite ends of the gear shaft.
14. The industrial robot of claim 9, wherein the rotation axes of the output shaft of the driver, the second gear, the third gear, and the upper arm are parallel and mutually offset.
15. The industrial robot of claim 9, wherein the first, second, third and fourth gears are a plurality of straight-tooth involute gears.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A semiconductor light emitting device comprising:
a stacked structure body including a first conductivity type first semiconductor layer, a second conductivity type second semiconductor layer facing a part of the first semiconductor layer, and a light emitting layer provided between the second semiconductor layer and the part of the first semiconductor layer, and having a first major surface on a side of the first semiconductor layer and a second major surface on a side of the second semiconductor layer;
a first electrode having a first contact part coming into contact with the first semiconductor layer on a side of the second major surface; and
a second electrode having a part coming into contact with the second semiconductor layer on the second major surface,
the first major surface having a first part and a second part, the first part having a part overlapping a contact surface with the first semiconductor layer in the first contact part when viewed in a stacking direction from the first semiconductor layer toward the second semiconductor layer, the second part having a part overlapping the second semiconductor layer when viewed in the stacking direction,
the second part having irregularity, the pitch of the irregularity being longer than a peak wavelength of emission light emitted from the light emitting layer, and
the first part having smaller irregularity than the second part.
2. The device according to claim 1, wherein
the pitch of the irregularity of the first part is shorter than the peak wavelength of the emission light.
3. The device according to claim 1, wherein
an outer edge of the first part when viewed in the stacking direction is located outside an outer edge of the contact surface when viewed in the stacking direction.
4. The device according to claim 3, wherein
reflectance to the emission light of the contact surface is lower than reflectance to the emission light of the surface facing the second semiconductor layer of the second electrode.
5. The device according to claim 1, further comprising a dielectric layer that covers the first part.
6. The device according to claim 1, wherein
the stacked structure body has a recess part reaching the first semiconductor layer from the second major surface, and
the first electrode comes into contact with the first semiconductor layer on a bottom surface of the recess part.
7. The device according to claim 1, wherein
the first semiconductor layer, the light emitting layer, and the second semiconductor layer include a nitride semiconductor.
8. The device according to claim 1, wherein
the peak wavelength of the emission light is 370 nanometers or more and 400 nanometers or less.
9. The device according to claim 1, wherein
the first electrode has a first bonding metal part, the first bonding metal part having a part being electrically connected to the first contact part, the first bonding metal part overlapping the second semiconductor layer when viewed in the stacking direction, and
further includes an insulating layer provided between the first bonding metal part and the second electrode between the first bonding metal part and the second semiconductor layer.
10. The device according to claim 1, wherein
the second electrode has a second contact part and a second bonding metal part, the second contact part coming into contact with the second semiconductor layer on the second major surface, the second bonding metal part having a part being electrically connected to the second contact part, the second bonding metal part overlapping the first electrode when viewed in the stacking direction, and
further includes an insulating layer provided between the second bonding metal part and the first electrode and between the second bonding metal part and the first semiconductor layer.
11. The device according to claim 10, further comprising a support substrate,
the support substrate being connected to the second bonding metal part.
12. The device according to claim 1, wherein
the first contact part and the first bonding metal part are provided integrally.
13. The device according to claim 12, wherein
the first contact part and the first bonding metal part are based on a material including aluminum.
14. The device according to claim 1, further comprising: a plurality of the first electrodes,
when viewed in the stacking direction, the plurality of the first electrodes being arranged in a matrix configuration.
15. The device according to claim 1, wherein
when viewed in the stacking direction, a shape of the first contact part and a shape of the first part are concentric, and
if a diameter in the shape of the first contact part is d and a thickness from the first contact part to the first part along the stacking direction of the stacking structure body is h, tan\u22121 (hd)>30 degrees is satisfied.
16. The device according to claim 1, wherein
the irregularity of the second part is twice or more in length of the peak wavelength of the emission light.
17. The device according to claim 1, wherein
the irregularity of the second part is ten times or more in length of the peak wavelength of the emission light.
18. The device according to claim 1, wherein
a surface of the irregularity of the second part is a surface etched along the crystal surface orientation of the first semiconductor layer.
19. The device according to claim 1, wherein
the second electrode includes silver.
20. The device according to claim 1, wherein
a shape of a protrusion part in the irregularity of the second part is a hexagonal pyramid.