1. A line printer comprising:
a printhead;
a platen;
a carriage including a head unit configured to support the printhead and a frame configured to movably support the head unit;
a carriage moving mechanism configured to move the carriage between an opposing position where the printhead is opposite the platen, and a standby position where the printhead is not opposite the platen;
a head unit moving mechanism configured to move the head unit in a direction toward the platen when the carriage is set to the opposing position; and
a bearing ball that is disposed between the head unit and the platen, and is configured to contact the head unit and the platen, and sets a constant gap between the head unit and the platen.
2. The line printer described in claim 1, wherein:
the frame is configured to support the head unit movably between a first position where the gap between the printhead and the platen is a first distance, and a second position where said gap is a second distance that is shorter than the first distance; and
the head unit moving mechanism is configured to move the head unit set to the first position to the second position.
3. The line printer described in claim 1, wherein:
the head unit moving mechanism is configured to move the carriage in a direction of opposition perpendicular to the direction.
4. The line printer described in claim 2, wherein:
the carriage has an urging member that produces an urging force that urges the head unit to the first position; and
the head unit moving mechanism moves the head unit in resistance to the urging force of the urging member from the first position to the second position.
5. The line printer described in claim 2, wherein:
the second position is a position where the printhead can print to recording paper on the platen.
6. The line printer described in claim 5, further comprising:
wherein the bearing ball is configured to set a specific gap between the printhead and the platen, and contact both the carriage and the platen when the head unit is at the second position.
7. The line printer described in claim 5, further comprising:
a gap-forming protrusion that is disposed to at least one of the head unit and the platen, and when the head unit is at the second position, contacts the other and sets a specific gap between the printhead and the platen.
8. The line printer described in claim 6, wherein:
the carriage comprises a guide mechanism that guides movement of the head unit; and
the guide mechanism comprises a guide channel disposed on one of the head unit and the frame, and a guide roller that is disposed on the other of the head unit and the frame and is inserted in the guide channel.
9. The line printer described in claim 8, wherein:
the guide channel extends in the direction extending between the printhead and the platen, and comprises a first channel section having a first channel width that is the same as the diameter of the guide roller, and a second channel section having a second channel width that is greater than the first channel width;
a first guide roller and a second guide roller are disposed as guide rollers; and
when the head unit moves between the first position and the second position, the first guide roller moves through the first channel section, and the second guide roller is configured to move through the second channel section.
10. A line printer comprising:
a platen opposite a printhead;
a head unit that holds the printhead; and
a bearing ball that is disposed between the head unit and the platen, and is configured to contact the head unit and the platen, and sets a constant gap between the head unit and the platen.
11. The line printer described in claim 10, further comprising:
a holding frame configured to hold the bearing ball so that the bearing ball can roll.
12. The line printer described in claim 11, wherein:
the holding frame is configured to hold the bearing ball movably in a direction of opposition perpendicular to a direction extending between the printhead and the platen.
13. The line printer described in claim 11, wherein:
there are at least three bearing balls disposed to mutually separated positions; and
the holding frame is configured to hold each of the bearing balls at a position not on a line joining the other two bearing balls.
14. The line printer described in claim 11, wherein:
the holding frame has a ball holding unit configured to hold the bearing ball; and
the ball holding unit has a through-hole that extends in the direction extending between the printhead and the platen to which the bearing ball is partially inserted, and a support member that spans the opening on one side of the through-hole in the direction of opposition at the edge of the opening, and can contact the bearing ball from the one side.
15. The line printer described in claim 11, further comprising:
a moving mechanism that moves the head unit between a first position where the gap is a first distance, and a second position where the gap is a second distance that is shorter than the first distance;
wherein the holding frame is configured to hold the bearing ball in contact with the platen; and
the head unit contacts the bearing ball when set to the second position.
16. The line printer described in claim 10, further comprising:
an urging member configured to urge either the head unit or the platen to the other through the bearing ball.
17. The line printer described in claim 11, further comprising:
a platen support mechanism configured to support the platen movably between a reference position opposite the printhead, and a retracted position that is different from the reference position;
the holding frame is set to a position causing the bearing ball to contact the platen when the platen is at the reference position, and separates the bearing ball from the platen when the platen is at the retracted position.
18. A printhead moving method of a line printer, comprising:
setting a printhead at a printhead standby position not opposite a platen to a head-opposing position opposite the platen;
moving the printhead in a direction toward the platen at the head-opposing position; and
setting a constant gap between the head unit and the platen with a bearing ball that is disposed between the head unit and the platen,
wherein the bearing ball contacts the head unit and the platen when the constant gap is set.
19. The printhead moving method of a line printer described in claim 18, further comprising:
moving the printhead while holding the gap between the platen and the printhead at a first distance; and
moving the printhead between the printhead and the platen to a second distance that is shorter than the first distance.
20. The printhead moving method of a line printer described in claim 18, further comprising:
moving the printhead in a direction perpendicular to the direction.
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 method of fabricating a backside-illuminated imaging structure, comprising:
providing a wafer having a frontside and a backside;
forming a device layer including one or more imager structures on the frontside of the wafer;
forming a metal and dielectric stack on the device layer;
providing electrical access from the backside of the wafer to the metal and dielectric stack;
providing one or more first alignment marks or features on the frontside of the wafer in respective one or more first positions; and
providing one or more second alignment marks or features on the backside of the wafer in respective one or more second positions different from the one or more first positions by using the one or more first alignment marks or features as a positioning guide for the second one or more alignment marks or features.
2. The method according to claim 1 further comprising deposition of a passivation layer on at least part of the backside of the wafer.
3. The method according to claim 1 further comprising heating the backside-illuminated imaging structure in an appropriate environment for passivation of interface traps and improving device performance.
4. The method according to claim 1 further comprising supporting the wafer on the frontside with a backing substrate.
5. The method according to claim 4 wherein the backing substrate is attached to the metal and dielectric stack.
6. The method according to claim 1 further comprising providing at least one of a color filter array and a microlens array on the backside of the wafer.
7. The method according to claim 1 further comprising providing at least one of a color filter array and a microlens array on the backside of the wafer and wherein the second alignment marks or features are used to align at least one of a color filter array and a microlens array so that at least one imager structure is optically aligned with at least one of a color filter and a microlens.
8. The method according to claim 1 further comprising one or more pads of conductive material on the backside of the wafer, at least one of the pads being in electrical connection to the backside of the wafer.
9. The method according to claim 8 wherein the one or more second alignment marks or devices comprise the one or more pads of conductive material.
10. The method according to claim 1 wherein the step of providing electrical access from the metal and dielectric stack to the backside of the wafer comprises forming a at least one cavity in the wafer between the metal and dielectric stack and the backside, providing one or more alignment marks in connection with the cavity, electrically isolating the cavity from the wafer, filling the cavity with a conductive material, and adding a conductive pad on the backside of the wafer in electrical communication with the conductive material.
11. The method according to claim 10 wherein more than one cavity is formed in the wafer between the metal and dielectric stack and the backside and each cavity is electrically isolated from each other as well as from the wafer.
12. The method according to claim 10 wherein the step of electrically isolating the cavity from the wafer comprises providing the cavity with a dielectric liner.
13. The method according to claim 10 wherein the cavity is formed by making a larger cavity opening on the frontside of the wafer and lining the larger cavity with a dielectric liner and further comprising providing one or more microcavities projecting from the cavity adjacent the backside of the wafer, wherein the cavity and the one or more projecting microcavities are filled with the conductive material, the filled one or more microcavities form one or more second alignment marks and are visible on the backside of the wafer, wherein the one or more second alignment marks are used to align the conductive pad.
14. The method according to claim 10 further comprising forming a larger cavity opening on the frontside of the wafer and filling the larger cavity with a dielectric and the one or more alignment marks are provided in the metal and dielectric stack, and further comprising forming the cavity in the dielectric from the backside in the dielectric and filling the second cavity with the conductive material.
15. The method according to claim 1 wherein the step of providing electrical access from the metal and dielectric stack to the backside of the wafer comprises forming at least one cavity in the wafer between the metal and dielectric stack and the backside to expose one or more metal traces in the metal and dielectric stack.
16. The method according to claim 15 wherein the cavity is formed in one or more stages.
17. The method according to claim 15 further comprising dicing the wafer at the cavity and expose the one or more metal traces to a side of the wafer formed by the dicing.
18. A method of fabricating a backside-illuminated imaging structure, comprising:
providing a wafer having a frontside and a backside;
forming a device layer including one or more imager structures on the frontside of the wafer;
forming a metal and dielectric stack on the device layer;
providing electrical access from the backside of the wafer to the metal and dielectric stack; and
providing one or more first alignment marks or features on the frontside of the wafer,
wherein providing electrical access from the metal and dielectric stack to the backside of the wafer comprises forming a at least one cavity in the wafer between the metal and dielectric stack and the backside, providing one or more alignment marks in connection with the cavity, electrically isolating the cavity from the wafer, filling the cavity with a conductive material, and adding a conductive pad on the backside of the wafer in electrical communication with the conductive material, and
wherein the cavity is formed by making a larger cavity opening on the frontside of the wafer and lining the larger cavity with a dielectric liner and further comprising providing one or more microcavities projecting from the cavity adjacent the backside of the wafer, wherein the cavity and the one or more projecting microcavities are filled with the conductive material, the filled one or more microcavities form one or more second alignment marks and are visible on the backside of the wafer, wherein the one or more second alignment marks are used to align the conductive pad.
19. A method of fabricating a backside-illuminated imaging structure, comprising:
providing a wafer having a frontside and a backside;
forming a device layer including one or more imager structures on the frontside of the wafer;
forming a metal and dielectric stack on the device layer;
providing electrical access from the backside of the wafer to the metal and dielectric stack; and
providing one or more first alignment marks or features on the frontside of the wafer,
wherein providing electrical access from the metal and dielectric stack to the backside of the wafer comprises forming a at least one cavity in the wafer between the metal and dielectric stack and the backside, providing one or more alignment marks in connection with the cavity, electrically isolating the cavity from the wafer, filling the cavity with a conductive material, and adding a conductive pad on the backside of the wafer in electrical communication with the conductive material,
the method further comprising forming a larger cavity opening on the frontside of the wafer and filling the larger cavity with a dielectric and the one or more alignment marks are provided in the metal and dielectric stack, and further comprising forming the cavity in the dielectric from the backside in the dielectric and filling the second cavity with the conductive material.