1. An apparatus comprising:
a transmitter configured to receive an acknowledgment message comprising a plurality of data units, each data unit comprising a status bit indicative of a status of the data unit and a plurality of spacing bits, wherein the plurality of spacing bits from the plurality of data units together form a binary number, the binary number being the spacing between one incorrectly received datagram and a succeeding incorrectly received datagram and to determine from the acknowledgement message which of a plurality of datagrams have been incorrectly received.
2. An apparatus as claimed in claim 1 wherein the transmitter is configured to retransmit datagrams which have been incorrectly received.
3. An apparatus as claimed in claim 1 wherein the transmitter is configured to transmit datagrams comprising checksum information.
4. An apparatus as claimed in claim 1, wherein each data unit consists of four bits.
5. An apparatus as claimed in claim 1, wherein said acknowledgement message comprises at least one further data unit indicating a location of a first incorrectly received datagram.
6. An apparatus as claimed in claim 1, wherein one value of the status bit is indicative of its corresponding data unit not being the last data unit of said plurality of data units whose spacing bits together are said binary number.
7. An apparatus as claimed in claim 6, wherein said one value of the status bit indicative of its corresponding data units not being the last data unit is 0.
8. An apparatus as claimed in claim 1, wherein said acknowledgement message comprises a first data unit having predetermined binary bits to indicate a burst of incorrectly received datagrams and one or more burst data units indicating the length of the burst of incorrectly received datagrams.
9. An apparatus as claimed in claim 8, wherein said predetermined binary bits are 0001.
10. An apparatus as claimed in claim 1, wherein one value of the status bit is indicative of its corresponding data unit being the last data unit of said plurality of data units whose spacing bits are said binary number.
11. An apparatus as claimed in claim 10, wherein the one value of the status bit is 1.
12. An apparatus for determining which of a series of datagrams have been incorrectly received, the apparatus comprising:
means for receiving an acknowledgement message comprising a plurality of data units, each data unit comprising a status bit indicative of a status of the data unit and a plurality of spacing bits, wherein the plurality of spacing bits from the plurality of data units together form a binary number, the binary number being the space in between one incorrectly received datagram and a succeeding incorrectly receiving datagram; and
means for determining from the acknowledgement message which of a plurality of datagrams have been incorrectly received.
13. A method comprising:
receiving an acknowledgment message comprising a plurality of data units, each data unit comprising a status bit indicative of a status of the data unit and a plurality of spacing bits, wherein the plurality of spacing bits from the plurality of data units together form a binary number, the binary number being the spacing between one incorrectly received datagram and a succeeding incorrectly received datagram; and
determining from the acknowledgement message which of a plurality of datagrams have been incorrectly received.
14. A method as claimed in claim 13, comprising retransmitting datagrams which have been incorrectly received.
15. A method as claimed in claim 13, comprising transmitting datagrams, said datagrams comprising checksum information.
16. A method as claimed in claim 13, wherein each data unit consists of four bits.
17. A method as claimed in claim 13, wherein said acknowledgement message comprises at least one further data unit indicating a location of a first incorrectly received datagram.
18. A method as claimed in claim 13, wherein one value of the status bit is indicative of its corresponding data unit not being the last data unit of the plurality of data units whose spacing bits together are said binary number.
19. A method as claimed in claim 18, wherein said one value of the status bit indicative of its corresponding data unit not being the last data unit is 0.
20. A method as claimed in claim 13, wherein said acknowledgement message comprises a first data unit having predetermined binary bits to indicate a burst of incorrectly received datagrams and one or more burst data units indicative of the length of the burst of incorrectly received datagrams.
21. A method as claimed in claim 20, wherein said predetermined binary bits are 0001.
22. A method as claimed in claim 13, wherein one value of the status bit is indicative of its corresponding data unit being the last data unit of the plurality of data units whose spacing bits are said binary number.
23. A method as claimed in claim 22, wherein said one value of the status bit is 1.
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 liquid crystal display element comprising:
a liquid crystal layer made of cholesteric liquid crystal;
a first circularly polarizing plate for circularly polarizing light;
wherein the liquid crystal layer has the following relation:
dp<1.5, where d is a thickness of the liquid crystal layer and p is a helical pitch of the cholesteric liquid crystal, and
the liquid crystal layer selectively reflects incident light; and
wherein a rotating direction of a vibrating plane of the selectively reflected light is the same as that of a vibrating plane of light absorbed by the first circularly polarizing plate.
2. The liquid crystal display element according to claim 1,
wherein the liquid crystal layer has a planar shape and further includes a second surface; and
wherein a boundary of at least one of the first and second surfaces has an anchoring strength in relation to an axis to which the liquid crystal layer is easily aligned, the anchoring strength is not more than 1104 Jm2.
3. The liquid crystal display element according to claim 1,
wherein the liquid crystal layer has a planar shape and further includes a second surface;
wherein at least one of the first and second surfaces has a uniaxial orientation property; and
wherein a boundary of the at least one of the first and second surfaces has an anchoring strength in relation to the orientation axis smaller than 1104 Jm2.
4. The liquid crystal display element according to claim 1, further comprising a light reflection layer for reflecting light,
wherein the liquid crystal layer further includes a second surface;
wherein the first circularly polarizing plate is laminated on the first surface; and
wherein the light reflection layer is laminated on the second surface.
5. The liquid crystal display element according to claim 4, wherein the liquid crystal layer includes a first electrode on the first surface; and
wherein the light reflection layer is a second electrode.
6. A liquid crystal display element comprising:
a liquid crystal layer made of cholesteric liquid crystal;
a first circularly polarizing plate for circularly polarizing light;
wherein the liquid crystal layer has the following relation:
dp>1.5, where d is a thickness of the liquid crystal layer and p is a helical pitch of the cholesteric liquid crystal, and
wherein a retardation of the liquid crystal layer is not less than 220 nm and not more than 330 nm.
7. The liquid crystal display element according to claim 6,
wherein the liquid crystal layer has a planar shape and further includes a second surface; and
wherein a boundary of at least one of the first and second surfaces has an anchoring strength in relation to an axis to which the liquid crystal layer is easily aligned, the anchoring strength is not more than 1104 Jm2.
8. The liquid crystal display element according to claim 6,
wherein the liquid crystal layer has a planar shape and further includes a second surface;
wherein at least one of the first and second surfaces has a uniaxial orientation property; and
wherein a boundary of the at least one of the first and second surfaces has an anchoring strength in relation to the orientation axis smaller than 1104 Jm2.
9. A liquid crystal display element comprising:
a liquid crystal layer made of cholesteric liquid crystal;
a first circularly polarizing plate for circularly polarizing light;
wherein the liquid crystal layer has the following relation:
dp>1.5, where d is a thickness of the liquid crystal layer and p is a helical pitch of the cholesteric liquid crystal;
a phase compensating plate having an extraordinary light axis parallel to a normal axis of the first circularly polarizing plate,
wherein the phase compensating plate is laminated between the liquid crystal layer and the first circularly polarizing plate; and
wherein the phase compensating plate includes a positive uniaxial optical medium for optically compensating contrast in relation to oblique light, the positive uniaxial optical medium is equal to a plane developed by a director of the liquid crystal layer.
10. A liquid crystal display element comprising:
a liquid crystal layer made of cholesteric liquid crystal;
a first circularly polarizing plate for circularly polarizing light;
wherein the liquid crystal layer has the following relation:
dp>1.5, where d is a thickness of the liquid crystal layer and p is a helical pitch of the cholesteric liquid crystal;
wherein the circularly polarizing plate includes a lamination of a linearly polarizing plate for allowing light to uniaxially pass therethrough and a \xbc wavelength plate for retarding the phase of a vibrating plane of light; and
wherein refractive index of the \xbc wavelength plate in a thickness direction thereof is larger than refractive index of the \xbc wavelength plate in any direction on a plane, which is on the \xbc wavelength plate and contacts with the linearly polarizing plate.