What is claimed is:
1. A method for linking a status response from a printer to a host with a specific command issued by the host, the steps comprising:
a) generating a quasi-unique ID value and associating said quasi-unique ID value with a command to be issued by a host to a printer operatively connected thereto;
b) issuing said command and said associated quasi-unique ID value to said printer;
c) executing said command at said printer;
d) returning status information from said printer to said host, said status information comprising said quasi-unique ID value.
2. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 1, wherein said quasi-unique ID value comprises an integer generated by said host.
3. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 1, the steps further comprising:
e) storing said command in a buffer within said printer prior to attempting to execute said command step (c).
4. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 3, wherein said buffer comprises at least a current command pointer and a previous command pointer.
5. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 4, wherein said buffer comprises means for storing a last command status byte.
6. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 5, wherein said buffer comprises an input buffer adapted to receive and store a stream of data comprising commands and characters to be printed.
7. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 1, wherein said returning step (d) comprises said host issuing a printer command status (PCS) command to said printer.
8. A method for linking a status response from a printer to a host with a specific command issued by the host, the steps comprising:
a) providing a printer for receiving a stream of data comprising commands and characters to be printed from a host operatively connected to said printer;
b) issuing a plurality of commands from said host to said printer, each of said plurality of commands a quasi-unique ID value;
c) storing said plurality of commands in an input buffer within said printer;
d) parsing said commands in said input buffer; and
e) upon receipt of a PCS command, returning said quasi-unique ID value associated with the command most recently executed by said printer and at least a portion of the status information.
9. A method for restarting a print job in a POS printer, the steps comprising:
a) providing a host computer for supporting a POS printer connected thereto, said host issuing a plurality of commands to said POS printer, each of said commands having a first quasi-unique ID value associated therewith;
b) providing a POS printer connected to said host for receiving and storing said plurality of commands from said host;
c) establishing an identical starting value for both first and second quasi-unique ID values in said host and communicating said second quasi-unique ID starting value to said printer;
d) issuing a plurality of commands at said host and storing said plurality of commands at said printer; and
e) parsing and executing each one of said plurality of commands issued by said host and stored by said printer, as each command is executed, associating said second quasi-unique ID value with the command being executed;
whereby a print job at said POS printer may be restarted dependent upon which of said plurality of commands executed successfully there at.
10. The method for restarting a print job in a POS printer as recited in claim 9, the steps further comprising:
f) incrementing said second quasi-unique ID value upon completion of execution of each of said commands.
11. The method for restarting a print job in a POS printer as recited in claim 10, the steps further comprising:
g) upon request from said host, returning status information from said printer to said host, said status information including said second quasi-unique ID value.
12. The method for restarting a print job in a POS printer as recited in claim 11, the steps further comprising:
h) using said returned status information including said second quasi-unique ID value to determine which of said plurality of commands issued by said host executed properly at said printer.
13. A method for linking a status response from a printer to a host with a specific command issued by the host, the steps comprising:
a) generating a quasi-unique ID value and associating said quasi-unique ID value with a command to be issued by a host to a printer operatively connected thereto;
b) issuing said command and said associated quasi-unique ID value to said printer;
c) monitoring said printer for the occurrence of an abnormal condition which prevents execution of issued commands;
d) generating a unsolicited status response to said host, said unsolicited status response comprising said quasi-unique ID value associated with an issued command upon occurrence of said abnormal condition in said printer.
14. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 13, wherein said abnormal condition comprises at least one from the group: accidental opening of the printer cover during execution of said command, running out of media upon which to print, power failure, and printer input buffer overflow.
15. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 13, wherein said printer comprises means for periodically generating an unsolicited status response to said host.
16. The method for linking a status response from a printer to a host with a specific command issued by the host as recited in claim 15, wherein said period for providing said unsolicited status response to said host is programmable by said host.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An optical disk reproducing apparatus reproducing information from an optical disk having information recorded by formation of a string of a plurality of pits having at least two different depths, by irradiation of an optical beam, comprising:
a photoreceptor element detecting a quantity of reflected light of said optical beam from said optical disk;
a pit depth detecting unit detecting a depth of each pit formed on said optical disk, based on the quantity of reflected light detected by said photoreceptor element;
a servo signal generating unit, generating a tracking servo signal allowing said optical beam to track said pit string, by detecting deviation between said optical beam and said pit string, based on the quantity of reflected light detected by said photoreceptor element; and
an output control unit controlling an output of the tracking servo signal generated by said servo signal generating unit, based on the result of detection by said pit depth detecting unit.
2. The optical disk reproducing apparatus according to claim 1, wherein
said output control unit supplies the tracking servo signal generated by said servo signal generating unit for tracking by said optical beam, when a pit having such depth that is to be reproduced is being tracked, and holds and supplies for tracking by said optical beam the tracking servo signal generated at the time of tracking of said pit having the depth to be reproduced, when a pit of a different depth is being tracked, based on the result of detection by said pit depth detecting unit.
3. The optical disk reproducing apparatus according to claim 1, wherein
said pit depth detecting unit detects depth of each pit, based on a difference in the quantity of reflected light from said pit string along tangential direction.
4. The optical disk reproducing apparatus according to claim 3, wherein
said pit depth detecting unit includes a first detecting unit generating a first signal representing the quantity of reflected light from said pit string,
a second detecting unit generating a second signal indicative of the difference of the quantity of reflected light from said pit string along the tangential direction, and
a third detecting unit generating a third signal indicative of depth of each pit, based on said first and second signals.
5. The optical disk reproducing apparatus according to claim 4, wherein
said third detecting unit includes
a first comparing circuit comparing said second signal with a first reference value,
a second comparing circuit comparing said second signal with a second reference value, and
a holding circuit holding results of comparison by said first and second comparing circuits, at a time point of change of said first signal.
6. The optical disk reproducing apparatus according to claim 1, wherein
said servo signal generating unit generates said tracking servo signal, by detecting a phase difference in the quantity of reflected light detected by said photoreceptor element.
7. The optical disk reproducing apparatus according to claim 1, wherein
said servo signal generating unit generates said tracking servo signal, by detecting a difference in the quantity of reflected light detected by said photoreceptor element from an inner peripheral side and an outer peripheral side of said optical disk.
8. The optical disk reproducing apparatus according to claim 1, wherein
said photoreceptor element has a cross-shape, divided into two along the tangential direction and divided into two along the radial direction of said optical disk.
9. The optical disk reproducing apparatus according to claim 1, wherein
said photoreceptor element is divided into two along the tangential direction of said optical disk, one of the two-split photoreceptor element is further divided into two along the tangential direction of said optical disk, and the other is further divided into two along the radial direction of said optical disk.
10. An optical disk having a track including a plurality of recessed and protruded portions formed thereon, from which information is reproduced by optical beam irradiation, the recessed and protruded portions existing mixedly such that a signal indicative of a deviation between said optical beam and said track is detected with different polarity at each of the recessed and protruded portions, wherein
ratio of mixture of said recessed and protruded portions is set such that a tracking servo signal, obtained by time-averaging said detected signal in a time period shorter than a response time of tracking servo when said optical beam tracks said track, has one of said different polarities.
11. The optical disk according to claim 10, wherein
said formed recessed and protruded portions are pits.
12. The optical disk according to claim 10, wherein
said formed recessed and protruded portions include a recording mark.
13. The optical disk according to claim 10, wherein said formed recessed and protruded portions include a groove andor a land.
14. The optical disk according to claim 10, wherein
said detected signal is a signal detected based on a phase difference in the quantity of light reflected from said recessed and protruded portions of said optical beam.
15. The optical disk according to claim 10, wherein
said detected signal is a signal detected based on a difference in the quantity of light reflected from said recessed and protruded portions of said optical beam between an inner peripheral side and an outer peripheral side of said optical disk.
16. A optical disk reproducing apparatus reproducing information from an optical disk having information recorded by formation of a track formed of a plurality of recessed and protruded portions, by an optical beam irradiation, comprising:
a photoreceptor element detecting a quantity of reflected light of said optical beam from said optical disk;
a signal detecting unit detecting a signal indicative of a deviation between said optical beam and said track, based on the quantity of reflected light detected by said photodetector element, said optical disk having recessed and protruded portions existing mixedly, from which said signal is detected with the polarity being different in each of the recessed and protruded portions;
a servo signal generating unit generating a tracking servo signal by time-averaging said detected signal in a time period shorter than a response time of tracking servo when said optical beam tracks said track, ratio of mixture of said recessed and protruded portions being set such that said generated tracking servo signal has one of said different polarities; and
a gain changing unit changing gain of the tracking servo, in accordance with magnitude of said generated tracking servo signal.
17. The optical disk reproducing apparatus according to claim 16, wherein
the recessed and protruded portions formed on said optical disk are pits.
18. The optical disk reproducing apparatus according to claiml6, wherein
the recessed and protruded portions formed on said optical disk includes a recording mark.
19. The optical disk reproducing apparatus according to claim 16, wherein the recessed and protruded portions formed on said optical disk includes a groove andor a land.
20. The optical disk reproducing apparatus according to claim 16, wherein
said signal detecting unit detects said signal based on a phase difference in the quantity of light reflected from said recessed and protruded portions of said optical beam.
21. The optical disk reproducing apparatus according to claim 16, wherein
said signal detecting unit detects said signal based on a difference in the quantity of light reflected from said recessed and protruded portions of said optical beam between an inner peripheral side and an outer peripheral side of said optical disk.
22. A method of tracking an optical disk having a track including a plurality of recessed and protruded portions formed thereon, from which information is reproduced by optical beam irradiation, comprising the steps of:
detecting a quantity of reflected light of said optical beam from said optical disk;
detecting a signal indicative of a deviation between said optical beam and said track, based on said detected quantity of reflected light, wherein said optical disk includes recessed and protruded portions existing mixedly from which said signal is detected with the polarity being different in each of said recessed and protruded portions;
generating a tracking servo signal by time-averaging said detected signal in a time period shorter than a response time of tracking servo when said optical beam tracks said track, wherein ratio of mixture of said recessed and protruded portions is set such that said generated tracking servo signal has one of said different polarities; and
changing gain of the tracking servo in accordance with magnitude of said generated tracking servo signal.
23. The method according to claim 22, wherein
the recessed and protruded portions generated on said optical disk are pits.
24. The method according to claim 22, wherein
the recessed and protruded portions formed on said optical disk includes a recording mark.
25. The method according to claim 22, wherein the recessed and protruded portions formed on said optical disk includes a groove andor a land.
26. The method according to claim 22, wherein
in said step of detecting said signal, said signal is detected based on a phase difference in the quantity of light reflected from said recessed and protruded portions of said optical beam.
27. The method according to claim 22, wherein
in said step of detecting said signal, said signal is detected based on a difference in the quantity of light reflected from said recessed and protruded portions of said optical beam between an inner peripheral side and an outer peripheral side of said disk.