Image recording device and image recording method
View Patent ↗A control unit sets a head drive shortest cycle depending on a print mode, measures an encoder signal cycle, determines whether or not a measured encoder signal cycle is shorter than a head drive shortest cycle set in advance, switches a record synchronization signal to the head drive shortest cycle when it is determined that the measured encoder signal cycle is shorter (in YES), in No, corrects the position of superposed color dots and aligns record dots by a downstream recording unit to a dot position shift by an upstream recording unit when it is determined that the measured encoder signal cycle is longer (in NO), calculates and stores an amount of shift from an equal interval reference position by shifts of the head record synchronization signal and the measured encoder signal, and records an image in synchronization with a corrected record synchronization signal.
1. An image recording device having a conveyance mechanism for generating conveyance information about a record medium when the record medium is conveyed after being received upstream from a conveyance path, and a plurality of recording units, each of the plurality of recording units being provided with at least one nozzle array comprising a plurality of nozzles arranged in a direction orthogonal to a direction of conveyance of the record medium, and the plurality of recording units being arranged at predetermined intervals in the direction of conveyance so as to discharge ink by driving the plurality of nozzles of each recording unit, thereby performing a recording process on the record medium, the image recording device comprising:
an encoder signal cycle measuring device for measuring an encoder signal cycle as the conveyance information about the record medium;
a first nozzle drive cycle replacement device for replacing a nozzle drive cycle with a predetermined set cycle when the encoder signal cycle measured by the encoder signal cycle measuring device is shorter than the predetermined set cycle;
a second nozzle drive cycle replacement device for replacing a predetermined period of the nozzle drive cycle with an optimum cycle between the predetermined set cycle and the measured encoder signal cycle when the encoder signal cycle measured by the encoder signal cycle measuring device changes from a point at which it is shorter than the predetermined set cycle to a point at which it is longer than the predetermined set cycle; and
a third nozzle drive cycle replacement device for controlling a timing of a discharge drive of nozzle arrays subordinate to a recording unit downstream in the direction of conveyance depending on an image position recorded by nozzle arrays subordinate to a recording unit upstream in the direction of conveyance of the record medium.
2. The device according to claim 1 , wherein the predetermined set cycle is a head drive shortest cycle when data transfer for the recording process cannot be completed to the recording unit, or when a faulty ink discharge occurs in the nozzle array of the recording unit.
3. The device according to claim 1 , wherein the optimum cycle is a nozzle drive cycle appropriate for correcting a position of record dots by the nozzle drive cycle replaced with the predetermined set cycle when the measured encoder signal cycle is shorter than the predetermined set cycle.
4. The device according to claim 1 , wherein the third nozzle drive cycle replacement device comprises:
a storage device storing the nozzle drive cycle of the image position recorded by the nozzle array subordinate to the recording unit; and
a nozzle array control device controlling the discharge drive of the nozzle array subordinate to the recording unit downstream in the direction of conveyance by the nozzle drive cycle stored in the storage device when the image position reaches a discharge position of the nozzle array subordinate to the recording unit downstream in the direction of conveyance.
5. An image recording method for an image recording device having a conveyance mechanism for generating conveyance information about a record medium when the record medium is conveyed after being received upstream from a conveyance path, and a plurality of recording units, each of the plurality of recording units being provided with at least one nozzle array comprising a plurality of nozzles arranged in a direction orthogonal to a direction of conveyance of the record medium, and the plurality of recording units being arranged at predetermined intervals in the direction of conveyance so as to discharge ink by driving the plurality of nozzles of each recording unit, thereby performing a recording process on the record medium, the method comprising:
measuring an encoder signal cycle as the conveyance information about the record medium;
replacing a nozzle drive cycle with a predetermined set cycle when the measured encoder signal cycle is shorter than the predetermined set cycle;
replacing a predetermined period of the nozzle drive cycle with an optimum cycle between the predetermined set cycle and the measured encoder signal cycle when the measured encoder signal cycle changes from a point at which it is shorter than the predetermined set cycle to a point at which it is longer than the predetermined set cycle; and
controlling a timing of a discharge drive of nozzle arrays subordinate to a recording unit downstream in the direction of conveyance depending on an image position recorded by nozzle arrays of a recording unit upstream in the direction of conveyance of the record medium.
6. The method according to claim 5 , wherein the predetermined set cycle is a head drive shortest cycle when data transfer for the recording process cannot be completed to the recording unit, or when a faulty ink discharge occurs in the nozzle array of the recording unit.
7. The method according to claim 5 , wherein the optimum cycle is a nozzle drive cycle appropriate for correcting a position of record dots depending on the nozzle drive cycle replaced with the predetermined set cycle when the measured encoder signal cycle is shorter than the predetermined set cycle.
8. The method according to claim 5 , wherein controlling the timing of the discharge drive comprises:
storing the nozzle drive cycle of the image position recorded by the nozzle array subordinate to the recording unit upstream the direction of conveyance of the record medium; and
controlling the discharge drive of the nozzle array subordinate to the recording unit downstream in the direction of conveyance by the nozzle drive cycle stored in the storing step when the image position reaches a discharge position of the nozzle array subordinate to the recording unit downstream in the direction of conveyance.