Driver IC and optical print head
AssigneesSanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.
InventorMitsuhiro Omae
Life of this patent
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Abstract
A driver IC includes a first driver section for supplying driving signals to n output terminals and a second driver section for selectively switching one of m selection terminals (m≧3) to a predetermined potential. The first driver section includes a timing control circuit for generating timing signals that permit the second driver section to perform the selective switching. The timing control circuit generates the timing signals based on control signals fed thereto from outside by way of a number of signal lines fewer than m.
Claims22
A driver IC for supplying driving currents to m groups×n light-emitting diodes arranged in a row, the driver IC having n first output terminals each connected to first electrodes of m light-emitting diodes (where m≧3) and having m second output terminals each connected to second electrodes m light-emitting diodes, the driver IC comprising:
- a data signal storage circuit for storing temporarily and sequentially at least n×m data signals simultaneously, that are fed thereto;
- a second driver section for keeping one of the second output terminals at a predetermined potential so as to activate the light-emitting diodes connected to said one of the second output terminals;
- a control circuit for feeding the second driver section with designation signals for designating one of the second output terminals, and for selecting data signals corresponding to the light-emitting diodes connected to the one of the second output terminals kept at the predetermined potential from among the data signals stored in said data signal storage circuit;
- a first driver section for outputting the driving currents via the first output terminals in accordance with the data signals selected by the designation signals,
- wherein the control circuit outputs the designation signals on a basis of control signals fed thereto from outside by way of a number of signal lines fewer than m, and
- a number of the data signals stored temporarily and simultaneously in said data signal storage circuit is at least three times a number of said first output terminals.
A driver IC for supplying driving currents to m groups×n light-emitting diodes arranged in a row, the driver IC having n first output terminals each connected to first electrodes of m light-emitting diodes (where m≧2) and having m second output terminals each connected to second electrodes of n light-emitting diodes, the driver IC comprising:
- a shift register for receiving m×n data signals corresponding to the m groups×n light-emitting diodes from outside;
- a latch circuit for storing temporarily and simultaneously at least m×n data signals fed sequentially from the shift register;
- a data selection circuit for selecting and extracting sequentially, in batches of n data signals, the data signals stored in the latch circuit;
- a first driver section including a drive circuit for outputting the driving currents on a basis of the selected data signals via the first output terminals;
- and
- a second driver section for keeping one of the second output terminals at a predetermined potential so as to activate the light-emitting diodes connected to said one of the second output terminals,
- wherein a number of the data signals stored temporarily and simultaneously in said latch circuit is at least three times a number of said first output terminals.
An optical print head comprising a plurality of light-emitting devices, each having m groups×n light-emitting elements, and a plurality of driver ICs, each corresponding to each of the light-emitting devices, for supplying driving currents to the light-emitting elements,
- wherein the light-emitting device has n first electrodes each connected to first electrodes of m light-emitting elements (where m≧3) and m second electrodes each connected to second electrodes of m light-emitting elements,
- the driver IC comprises:
- n first output terminals connected individually to the first electrodes of the light-emitting device;
- m second output terminals connected individually to the second electrodes of the light-emitting device;
- a data signal storage circuit for storing temporarily and sequentially at least n×m data signals simultaneously, that are fed thereto;
- a second driver section for keeping one of the second output terminals at a predetermined potential so as to activate the light-emitting elements connected to said one of the second output terminals;
- a control circuit for feeding the second driver section with designation signals for designating one of the second output terminals and for selecting data signals corresponding to the light-emitting elements connected to the one of the second output terminals kept at the predetermined potential from among the data signals stored in said data signal storage circuit;
- and
- a first driver section for outputting the driving currents via the first output terminals in accordance with the data signals selected by the designation signals,
- wherein the control circuit outputs the designation signals on a basis of control signals fed thereto by way of a number of signal lines fewer than m, and
- a number of the data signals stored temporarily and simultaneously in said data signal storage circuit is at least three times a number of said first output terminals.
An optical print head comprising a light-emitting device, having m groups×n light-emitting elements, and a driver IC for supplying driving currents to the light-emitting elements of the light-emitting device,
- wherein the light-emitting device has n first electrodes each connected to first electrodes of m light-emitting elements (where m≧2) and m second electrodes each connected to second electrodes of m light-emitting elements,
- the driver IC comprises:
- n first output terminals connected individually to the first electrodes of the light-emitting device;
- m second output terminals connected individually to the second electrodes of the light-emitting device;
- a shift register for receiving m×n data signals corresponding to the m groups×n light-emitting elements from outside;
- a latch circuit for storing temporarily and simultaneously at least m×n data signals fed sequentially from the shift register;
- a data selection circuit for selecting and extracting sequentially, in batches of n data signals, the data signals stored in the latch circuit;
- a drive circuit for outputting the driving currents via the first output terminals on a basis of the extracted data signals;
- and
- a second driver section for keeping one of the second output terminals at a predetermined potential so as to activate the light-emitting elements connected to said one of the second output terminals,
- wherein a number of the data signals stored temporarily and simultaneously in said latch circuit is at least three times a number of said first output terminals.
A driver IC comprising n output terminals for driving a device, a first driver section connected to the individual output terminals, m group selection terminals, and a second driver section connected to the individual group selection terminals,
- wherein the first driver section comprises:
- a data signal storage circuit for storing simultaneously at least n×m data signals that are fed thereto sequentially;
- a data selection circuit for selecting and extracting sequentially m times, in batches of n data signals, the data signals stored in the data signal storage circuit on a basis of control signals fed thereto from outside by way of signal lines;
- and
- a drive circuit for outputting driving currents to the output terminals on a basis of the selected data signals, and
- wherein the second driver section is configured to switch the m group selection terminals sequentially in synchronism with timing with which the data selection circuit selects the data signals in batches of n data signals, and
- a number of the data signals stored simultaneously in said data signal storage circuit is at least three times a number of said output terminals.
A driver IC comprising n output terminals for driving a light-emitting device having light-emitting elements, a first driver section connected to the individual output terminals, m group selection terminals, and a second driver section connected to the individual group selection terminals, further comprising:
- a timing control circuit for generating m division timing signals on a basis of a number of control signals fewer than m fed thereto from outside,
- wherein the first driver section comprises:
- a data signal storage circuit for storing at least n×m data signals in order in which the data signals are fed thereto in order in which the light-emitting elements are arranged;
- a data selection circuit for selecting and extracting sequentially, in batches of n data signals, the data signals stored in the data signal storage circuit on a basis of the m division timing signals;
- and
- a drive circuit for outputting driving currents on a basis of the selected data signals, and
- wherein the second driver section is configured to switch the m group selection terminals sequentially in synchronism with timing with which the data selection circuit selects the data signals in batches of n data signals.
Dependencies are inferred from the claim text.