1. A biomaterial suitable for use in surgery in a human patient, comprising:
a coherent layer of non-human collagenous tissue which has been subjected to glutaraldehyde tanning so as to comprise cross-linked collagen fibrils, and
a reinforcement of synthetic material embedded within the coherent layer, said synthetic material having structure features for promoting said embedding, said synthetic material having on average in situ more than 50 of said features per square centimeter.
2. A biomaterial as claimed in claim 1 having more than 100 of said features per square centimeter.
3. A biomaterial as claimed in claim 1 wherein the synthetic material is a fibre mesh and the features for promoting said embedding are the reticulations of the mesh.
4. A biomaterial as claimed in claim 3 wherein the mesh is embedded in the coherent layer such that the mesh structure is in a loose unstretched state.
5. A biomaterial as claimed in claim 3 wherein the fibre mesh is constructed from polyester yarn.
6. A biomaterial as claimed in claim 5 wherein the polyester yarn is augmented with polyurethane.
7. A biomaterial as claimed in claim 6 wherein the polyurethane is in the form of strands of the polyester dipped in polyurethane.
8. A biomaterial as claimed in claim 6 wherein the polyurethane is in the form of strands of polyurethane wound around strands of the polyester.
9. A biomaterial as claimed in claim 1 wherein the synthetic material is particulate in nature.
10. A biomaterial as claimed in claim 9 wherein said features are constituted by individual particles of that material.
11. A biomaterial as claimed in claim 1 wherein the biomaterial is formed in the shape of a tube.
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. An image forming apparatus, comprising:
an image bearing member to bear a toner image;
a transfer member to form a transfer nip between the image bearing member and the transfer member;
a transfer power source to output a transfer bias to the transfer nip, the transfer power source including a DC power source, an AC power source, a first switch to connect and disconnect the DC power source to the transfer nip, and a second switch to connect and disconnect the AC power source to the transfer nip; and
a controller to control the transfer power source to output the transfer bias,
wherein the controller controls the first and second switches to switch modes between a first mode and a second mode,
wherein in the first mode the controller turns on both the first switch and the second switch so that the transfer power source outputs the transfer bias including an AC component superimposed on a DC component,
wherein in the second mode the controller turns on the first switch and turns off the second switch so that the transfer power source outputs the transfer bias including only the DC component, and
wherein the controller turns off both the first and second switches so as to turn off application of the transfer bias to the transfer nip when no sheet passes through the transfer nip.
2. The image forming apparatus according to claim 1, wherein the controller turns off application of the transfer bias to the transfer nip within a time period from when a trailing edge of the sheet passes through the transfer nip to when a leading edge of a successive sheet enters the transfer nip.
3. The image forming apparatus according to claim 1, wherein in the first mode the controller controls the transfer power source so that a polarity of the transfer bias is alternately inverted when the toner image is transferred to the sheet at the transfer nip.
4. The image forming apparatus according to claim 1, wherein the second switch is interposed between the DC power source and the AC power source.
5. The image forming apparatus according to claim 1, wherein the first switch is interposed between the DC power source and ground.
6. An image forming apparatus, comprising:
an image bearing member to bear a toner image;
a transfer member to form a transfer nip between the image bearing member and the transfer member;
a toner detector to detect a test toner image formed on the image bearing member;
a transfer power source to output a transfer bias to the transfer nip, the transfer power source including a DC power source, an AC power source, a first switch to connect and disconnect the DC power source to the transfer nip, and a second switch to connect and disconnect the AC power source to the transfer nip; and
a controller to control the transfer power source to output the transfer bias,
wherein the controller controls the first and second switches to switch modes between a first mode and a second mode,
wherein in the first mode the controller turns on both the first switch and the second switch so that the transfer power source outputs the transfer bias including an AC component superimposed on a DC component,
wherein in the second mode the controller turns on the first switch and turns off the second switch so that the transfer power source outputs the transfer bias including only the DC component, and
wherein the controller turns off both the first and second switches so as to turn off application of the transfer bias to the transfer nip when the test toner image passes through the transfer nip.
7. The image forming apparatus according to claim 6, wherein the toner detector detects the amount of toner of the test toner image formed on the image bearing member, and the controller adjusts image quality based on a detection result provided by the toner detector.
8. The image forming apparatus according to claim 6, wherein the controller turns off application of the transfer bias to the transfer nip within a time period from when a trailing edge of the sheet passes through the transfer nip to when a leading edge of a successive sheet enters the transfer nip.
9. The image forming apparatus according to claim 6, wherein in the first mode the controller controls the transfer power source so that a polarity of the transfer bias is alternately inverted when the toner image is transferred to the sheet at the transfer nip.
10. An image forming apparatus, comprising:
an image bearing member to bear a toner image;
a transfer member to form a transfer nip between the image bearing member and the transfer member;
a transfer power source to output a transfer bias to the transfer nip, the transfer power source including a first DC power source, a second DC power source, an AC power source, a first switch to connect and disconnect the first DC power source to the transfer nip, and a second switch to connect and disconnect both of the second DC power source and the AC power source to the transfer nip; and
a controller to control the transfer power source to output the transfer bias,
wherein the controller controls the first and second switches to switch modes between a first mode and a second mode,
wherein in the first mode the controller turns off the first switch and turns on the second switch so that the transfer power source outputs the transfer bias including an AC component superimposed on a DC component supplied by the second DC power source,
wherein in the second mode the controller turns on the first switch and turns off the second switch so that the transfer power source outputs the transfer bias including only a DC component supplied by the first DC power source, and
wherein the controller turns off both the first and second switches so as to turn off application of the transfer bias to the transfer nip when no sheet passes through the transfer nip.
11. The image forming apparatus according to claim 10, wherein the controller turns off application of the transfer bias to the transfer nip within a time period from when a trailing edge of the sheet passes through the transfer nip to when a leading edge of a successive sheet enters the transfer nip.
12. The image forming apparatus according to claim 10, wherein in the first mode the controller controls the transfer power source so that a polarity of the transfer bias is alternately inverted when the toner image is transferred to the sheet at the transfer nip.
13. The image forming apparatus according to claim 10, wherein a first branch including the first DC power source is in parallel with a second branch including both the second DC power source and the AC power source.
14. The image forming apparatus according to claim 10, wherein the first DC power source is interposed between the first switch and ground.
15. The image forming apparatus according to claim 10, wherein both the second DC power source and the AC power source are interposed between the second switch and ground.
16. The image forming apparatus according to claim 10, wherein the DC component of the bias that is output in the first mode and the DC component of the bias that is output in the second mode have the same polarity.
17. The image forming apparatus according to claim 6, wherein the second switch is interposed between the DC power source and the AC power source.
18. The image forming apparatus according to claim 6, wherein the first switch is interposed between the DC power source and ground.
19. An image forming apparatus, comprising:
an image bearing member to bear a toner image;
a transfer member to form a transfer nip between the image bearing member and the transfer member;
a toner detector to detect a test toner image formed on the image bearing member;
a transfer power source to output a transfer bias to the transfer nip, the transfer power source including a first DC power source, a second DC power source, an AC power source, a first switch to connect and disconnect the first DC power source to the transfer nip, and a second switch to connect and disconnect both of the second DC power source and the AC power source to the transfer nip; and
a controller to control the transfer power source to output the transfer bias,
wherein the controller controls the first and second switches to switch modes between a first mode and a second mode,
wherein in the first mode the controller turns off the first switch and turns on the second switch so that the transfer power source outputs the transfer bias including an AC component superimposed on a DC component supplied by the second DC power source,
wherein in the second mode the controller turns on the first switch and turns off the second switch so that the transfer power source outputs the transfer bias including only a DC component supplied by the first DC power source, and
wherein the controller turns off both the first and second switches so as to turn off application of the transfer nip when the test toner image passes through the transfer nip.
20. The image forming apparatus according to claim 19, wherein the toner detector detects the amount of toner of the test toner image formed on the image bearing member, and the controller adjusts image quality based on a detection result provided by the toner detector.
21. The image forming apparatus according to claim 19, wherein the controller turns off application of the transfer bias to the transfer nip within a time period from when a trailing edge of the sheet passes through the transfer nip to when a leading edge of a successive sheet enters the transfer nip.
22. The image forming apparatus according to claim 19, wherein in the first mode the controller controls the transfer power source so that a polarity of the transfer bias is alternately inverted when the toner image is transferred to the sheet at the transfer nip.
23. The image forming apparatus according to claim 19, wherein a first branch including the first DC power source is in parallel with a second branch including both the second DC power source and the AC power source.
24. The image forming apparatus according to claim 19, wherein the first DC power source is interposed between the first switch and ground.
25. The image forming apparatus according to claim 19, wherein both the second DC power source and the AC power source are interposed between the second switch and ground.
26. The image forming apparatus according to claim 19, wherein the DC component of the bias that is output in the first mode and the DC component of the bias that is output in the second mode have the same polarity.