The present embodiments relates to a cue delay circuit for an ink jet printing system.
The ink jet printing industry has need for properly positioning data and printing information on print media. To accommodate the need for time to process the new data for proper insertion on the paper, the need for cue delays has arisen. Also, there is a need to control various peripheral devices simultaneously with printing and a cue delay has been become an easy fix to enable smooth incorporation of these devices with the printer.
So far, the cue delay systems have been cumbersome, slow, and inaccurate.
A need exists for a fast, instantaneous system which provides smooth, efficient operation of the printer while incorporating new information.
The need for such cue delay circuits is compounded on printing systems that employ a plurality of print heads which print on the print media sequentially. It is important to have separate cue delay signals so that each of the print heads can output properly when registered with an adjacent printhead.
Traditionally, the cues are highly programmed and it has been impossible to have a standard cue delay as each print job is different. Accordingly, the present invention provides the flexibility needed to provide a cue delay for different size jobs, different combinations of print heads, and for different types of print media.
The present embodiments described herein were designed to meet these needs.
A cue delay circuit for an ink jet printing system includes a state machine containing sequenced logic circuits that receive a start pulse for initializing the state machine. The state machine receives a tachometer input and generates buffered control signals. The state machine also contains a counter with sequenced logic circuits to count one of the buffered control signals from the state machine forming a read address. An adder receives the read address and a cue delay value and adds the read address to the cue delay value generating a write address.
The systems include a comparator that compares the cue delay value to the read address to determine if the read address is greater than the cue delay value and forms a comparator output. A multiplexer (MUX) receives the read address, the write address, and one of the buffered control signals. The MUX, the read address, or the write address forms a multiplexer output. A read-access memory (RAM) receives the multiplexer output, which serves as an address for the RAM. A cue signal and one of the buffered control signals serves as a read/write control for the RAM to provide a RAM output signal. At least one flip flop latches to the comparator output forming a latched comparator output. A gate circuit receives the latched comparator output and the RAM output signal forming a gated cue signal. A logic circuit receives one of the buffered control signals and the gated cue signal to output a delayed cue signal to the printing system.
In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings, in which:
The present embodiments are detailed below with reference to the listed Figures.
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that it can be practiced or carried out in various ways.
A key benefit of the present integrated circuits and methods is that the need to write out all prior RAM cue locations in the memory of an ink jet printhead to zero is eliminated, thereby saving significant amounts of time and additional logic circuits. The instant cue delay incorporated in the embodiments herein enable printers to restart immediately after stopping by not having to zero out the RAM. The printer simply starts with a new delay value that is more efficient than those systems known in the prior art.
Safety is improved using the embodied integrated circuits since all cues are proper and accounted, particularly for page correlation systems. Reliability for compiling a multicolor document printed by a number of printheads is increased using the embodied integrated circuits because the printheads do not have to be properly aligned off the same document.
With reference to the figures,
The integrated circuit includes a counter 32 with numerous sequenced logic circuits to count one of the buffered control signals 24 from the state machine 20 before forming a read address 34.
Continuing with
A comparator 42 compares the cue delay value 38 to the read address 34. If the read address 34 is greater than the cue delay value 38, the comparator 42 forms a comparator output 44.
A multiplexer (MUX) 46 receives the read address 34, the write address 40, and one of the buffered control signals 26 and, then, forms a multiplexer output 48 based upon the inputs. A read-access memory (RAM) 50 receives the multiplexer output 48. The multiplexer output 48 serves as a RAM address. The cue signal 52 and one of the buffered control signals 28 serves as a write/read control for the RAM to provide a RAM output signal 54.
The embodied integrated circuits include one or more flip flops 56 that latch to the comparator output 58 output forming a latched comparator output 64. An example of a flip flop 56 is a synchronous D flip flop with a chip enabler and a reset.
In an alternative embodiment, the embodied integrated circuits can include a cue pulse conditioning circuit 68. The cue pulse conditioning circuit 68 modifies the cue signal 52 by latching the cue signal 52 and synchronizing the transmission of the cue signal 52 with a buffered control signal. The cue pulse conditioning circuit 68 can further include numerous gates and flip flops.
Returning to
In an alternative embodiment, the embodied integrated circuits can include an oscillator 74 in communication the state machine 20, the counter 32, one or more flip flops 56, and the logic circuit 64.
The methods continue by inputting a first buffered control signal from the state machine to a counter to increment a read address by one (Step 104) and, then, the read address is input into the comparator and a multiplexer (Step 106). While inputting the cue delay value to the adder, the cue delay value is input to a comparator to set the comparator output to a logic high value if the read address is greater than the cue delay value (Step 108).
A second buffered control signal from the state machine causes the multiplexer to provide the write address to a RAM. The second buffered control signal also provides a multiplexer output that is equal the value of the write address (Step 110). The comparator output is latched using a gate circuit (Step 112) and a tachometer input is input into the state machine (Step 114).
The next steps in the methods than inputs a cue signal to a RAM and inputs a third buffered control signal from the state machine to the RAM (Step 116). The third buffered control signal causes the current state of the cue signal to be written to the address of the RAM and to correspond to the write address received from the multiplexer. The second buffered control signal from the state machine works in conjunction with the third buffered control signal to cause the output of the multiplexer to equal the value of the read address (Step 118).
The RAM output is sent to the gate circuit (Step 120) and the gated cue signal is passed to a logic circuit if the latched comparator output is set to logic high (Step 122). A fourth buffered control signal from the state machine enables the logic circuit to latch the gated cue signal to form the delayed cue signal (Step 124). The delayed cue signal is then transmitted to the ink jet printing system (Step 126).
The steps following the initializing step are repeated until a new start pulse is received by the state machine (Step 128).
In an alternative embodiment, the methods include a step of pulsing one or more buffered control signals.
In still another embodiment, the methods can optionally include the step of employing a cue pulse conditioner to latch the cue signal until the cue signal can be written to the RAM. If a cue pulse conditioner is used, a start pulse can be used to initialize a cue pulse conditioning circuit.
The embodiments have been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the embodiments, especially to those skilled in the art.
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