JP4254041B2 - Recording apparatus and recording control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus and a recording control method.
[0002]
[Prior art]
Conventionally, there is an ink jet recording apparatus as an apparatus for recording image data output from a personal computer, a facsimile machine or the like. This method is excellent in that it is quiet and can be recorded on paper of various materials.
[0003]
In such a recording apparatus, a carriage provided with a head unit and a recording medium (recording paper) are moved relative to each other, and the head unit forms an image on the recording medium. An outline of the periphery of this carriage is shown in FIG. The carriage 10 is movable along a fixed shaft 11 and is moved by driving a timing belt 15 spanned between pulleys 13 and 14 by a motor (not shown). A timing slit 16 is provided in parallel with the moving direction. The timing slit 16 is provided with a plurality of slits, and an encoder provided at the lower part of the carriage 10 reads the number of slits to generate a pulse signal used for timing the image forming operation.
[0004]
[Problems to be solved by the invention]
If the carriage 10 is moved at a constant speed, the pulse signal should be generated at regular time intervals. However, in practice, the pulse signal may not be generated at regular time intervals. This is illustrated in FIG. FIG. 2A is a graph showing the speed when the carriage 10 is stopped, and FIG. 2B is a pulse output from the encoder when the carriage 10 is moved as shown in FIG. It is. As shown in the figure, the speed of the carriage 10 is uneven to some extent even after reaching a steady state. As a result, the pulse signal that is originally desired to be generated at regular time intervals also becomes non-uniform.
[0005]
FIG. 3 shows this cause in detail. FIG. 3A shows an output signal from the encoder, and FIG. 3B shows a pulse signal generated based on this output signal. If the movement speed of the carriage 10 is uneven, the A-phase signal, which is one of the encoder output signals, has a duty ratio that should be 50:50 as shown in FIG. Become. In addition, the B phase output signal generated to detect the moving direction of the carriage 10 has a phase difference other than 90 ° with respect to the A phase, which should be 90 °, in addition to the duty ratio. turn into. As a result, the pulse output in FIG. 3B generated from the A phase and the B phase becomes non-uniform. In addition to the uneven speed of the carriage 10, the pulse output may be non-uniform due to variations in slit spacing.
[0006]
If the pulse output is non-uniform in this way, image formation may be hindered. This is shown in FIG. FIG. 4 is a time chart showing signals generated in the control circuit of the inkjet head based on the pulse signal. First, when a print start signal is received from a higher-level device of the control circuit (usually a CPU of a recording device equipped with the control circuit), an ejection request signal is generated based on the pulse output of the encoder. The ejection request signal is generated at a predetermined ejection cycle, and here, for simplicity, two ejection pulses constitute one ejection cycle. When a discharge request signal is generated, a discharge start signal is generated based on it. When the ejection start signal is generated, the control circuit generates a drive waveform corresponding to an image (dot) to be formed in the ejection cycle. The ink jet head that has received this drive waveform performs an ejection operation according to the drive waveform to form dots. The drive waveform is discharged in the process of transition from L to H in the figure.
[0007]
If the pulse output is non-uniform and the pulse interval is short in a certain period (for example, section A in the figure), the drive waveform may not fit within one ejection cycle. Then, the drive waveform in the section A protrudes into the next section B. Since the ejection start signal generated during the output of the drive waveform is ignored, the drive waveform that should be output in the section B is not output, and a dropout occurs. The same situation also occurs in recording apparatuses other than the ink jet system.
[0008]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus in which no missing occurs even when the pulse output of an encoder becomes short.
[0009]
[Means for Solving the Problems and Effects of the Invention]
The recording apparatus according to claim 1 of the present invention, which has been made in order to solve such a problem, is a sequential pulse signal corresponding to the position of the recording head that moves relative to the recording medium in the main scanning direction and the direction perpendicular thereto. Pulse signal output means for outputting,
A recording request signal output means for outputting a recording request signal based on the pulse signal output by the pulse signal output means;
A recording start signal output means for outputting a recording start signal based at least on the recording request signal output by the recording request signal output means;
When the recording start signal is input from the recording start signal output unit, a driving waveform signal output unit that outputs a driving waveform signal of a predetermined pattern to be supplied to the recording head;
A recording apparatus for recording while moving the recording head along a recording medium,
Each time the recording request signal is output by the recording request signal output means, the counter value is increased by a certain number, and each time the recording start signal is output by the recording start signal output means, the counter value is decreased by a certain number. The first condition is that the output is greater than an initial value and the output of the drive waveform signal by the drive waveform signal output means is terminated,
The second condition is that the output of the recording request signal by the recording request signal output means is the first signal in the main scanning direction,
Control means for permitting output of the recording start signal by the recording start signal output means when the first condition or the second condition is satisfied .
[0010]
According to this recording apparatus, since the recording start signal is not output until the output of the drive waveform signal is completed, the recording start signal is not ignored as described above .
[0011]
[0012]
Further, it is possible to drive the dynamic waveform signal is performed appropriately recording control even at early time points in the main scanning direction that is not generated.
[0013]
Furthermore, even when a situation such as loss if prior to occur continuously occurs, because the number of the generated recording request signal counter is stored, Ru can generate the recording start signal without exception. Therefore, according to the recording apparatus of the first aspect, no omission occurs even if the pulse signal is shortened. Note that the recording control method described in claim 2 describes the recording apparatus described in claim 1 as a method invention. Therefore, the same effect as that of the recording apparatus according to the first aspect can be obtained.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
First, FIG. 5 shows a block diagram of the main part of an ink jet printer to which the present invention is applied. In other words, this ink jet printer has an interface I / A for connection to a computer system PC such as a gate array circuit G / A for controlling printing operations such as print data processing, a CPU for controlling the entire other printer, and a personal computer. F, image memory for storing print data received from the computer system PC, CR motor (for carriage movement), LF motor (for paper conveyance), carriage origin sensor, printing connected to the CPU via respective drive circuits Various programs executed by the inkjet printer, such as a paper feed sensor for detecting whether or not a sheet is present, a carriage encoder for detecting a carriage position, printing and data communication, and data used in the program ROM with RAM for temporarily storing data during program execution, head driver, inkjet heads prepared for Y, M, C, K colors, head drive, logic voltage, power supply that is a voltage source for motor drive Yes.
[0015]
FIG. 6 shows an operation block diagram in the gate array circuit G / A. The pulse output circuit 20 outputs a pulse signal sequence from the encoder signal of the carriage 10. Upon receiving a print start signal from the CPU, the discharge request signal output circuit 21 outputs a discharge request signal based on the pulse signal output by the pulse output circuit 20. Counter A and counter B count this ejection request signal. The initial value of the counter A is 0, and the counter A is counted up every time there is a discharge request signal, and the output becomes H only when the count value is not 0. The counter B cumulatively counts all the ejection request signals for one scan of the carriage 10, and the output becomes H only when the count value = 1. In addition, it is cleared when the carriage 10 finishes one scan.
[0016]
The AND circuit 24 outputs H only when both the ejection request signal output circuit 21 and the counter B output, and the output is input to the ejection start signal output circuit 22 via the OR circuit 26. Therefore, when the first discharge request signal is output after receiving the print start signal in one scan of the carriage 10 as described above, the discharge start signal output is based on the discharge request signal and the H output of the counter B. The circuit 22 outputs a discharge start signal based on the input. Further, when the output of one drive waveform signal is completed, the waveform generation circuit 23 outputs a drive waveform output end signal.
[0017]
When the discharge start signal is output from the discharge start signal output circuit 22, the counter A subtracts 1 from the count value. The AND circuit 25 outputs H only when there is both an H output when the count value of the counter A is not 0 and an output of the drive waveform output end signal from the waveform generation circuit 23, and outputs the output to the OR circuit 26. To the discharge start signal output circuit 22. Therefore, when the first ejection request signal of one row is output as described above, the counter A decrements the count value by 1 and returns to 0. When the next ejection request signal is input, the counter A sets the output to H. On the other hand, since the first drive waveform output end signal is output from the waveform generation circuit 23, the AND circuit 25 sets the output to H, The discharge start signal output circuit 22 outputs a second discharge start signal. As a result, the waveform generation circuit 23 outputs a predetermined drive waveform signal to the head driver, and ejects ink droplets. Similarly, for the next and subsequent discharges, a discharge start signal is output based on the output of the counter A and the drive waveform output end signal.
[0018]
FIG. 7 shows an ejection control operation realized by such a gate array circuit G / A. FIG. 7 is a time chart for signals generated in the gate array circuit G / A shown in FIG. First, when there is a print start signal from the CPU, the discharge request signal output circuit 21 generates a discharge request signal based on the pulse output of the encoder. As in the case of FIG. 4, here, two pulses constitute one ejection cycle. When the discharge request signal is generated, in the case of the first discharge request signal in one row, the discharge start signal is output based on the discharge request signal and the output of the counter B as described above. The second and subsequent ejections are performed by the output of the counter A and the drive waveform output end signal.
[0019]
Here, it is assumed that the previous drive waveform has been generated (the drive waveform output end signal has not been output) when the next ejection request signal is generated. This is the state of section A in FIG. In this state, even when the value of the counter A is counted up by the discharge request signal, the discharge start signal is not generated. When the drive waveform output end signal is generated from the waveform generation circuit 23, the lower AND of FIG. 6 is output by the output of the counter A (H because the count value is 1 by the ejection request signal corresponding to the section B). The output of the circuit becomes H, and the discharge start signal output circuit 22 outputs a discharge start signal. If the drive waveform corresponding to the section B does not further fall within this section, the above processing is repeated in the same manner, so that the drive waveform is output without omission with respect to the generated ejection request signal.
[0020]
According to such a control method, even if the pulse output of the encoder is shortened and the drive waveform does not fit within one discharge cycle, the discharge start signal is generated after the output of the drive waveform is completed, and the next Since the drive waveform is output, there is no possibility of missing.
[0021]
Here, the correspondence between the present embodiment and the configuration of the present invention will be described. The pulse output circuit 20 in the gate array circuit G / A corresponds to the pulse signal output means of the present invention, the discharge request signal output circuit 21 also corresponds to the recording request signal output means of the present invention, and also the discharge start signal output circuit. 22 corresponds to the recording start signal output means of the present invention, the waveform generation circuit 23 corresponds to the drive waveform signal output means of the present invention, the counter A corresponds to the counter , and the AND circuits 24 and 25 and the OR circuit 56 are the main circuit. It corresponds to the control means of the invention.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the periphery of a carriage 10 of an ink jet recording apparatus.
FIG. 2 is a time chart showing pulse signals output from an encoder when a carriage 10 is moved.
FIG. 3 is a time chart showing pulse signals generated by an encoder when the moving speed of the carriage 10 is uneven.
FIG. 4 is a time chart showing a signal generated in a driver of an inkjet head based on a pulse signal.
FIG. 5 is a block diagram of a main part of an ink jet printer to which the present invention is applied.
FIG. 6 is an operation block diagram in the gate array circuit G / A.
FIG. 7 is a time chart showing an ejection control operation realized by the gate array circuit G / A.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Carriage 11 ... Shaft 13 ... Pulley 15 ... Timing belt 16 ... Timing slit G / A ... Gate array circuit

Claims (2)

Pulse signal output means for sequentially outputting a pulse signal according to the position of the recording head that moves relative to the recording medium in the main scanning direction and the direction perpendicular thereto,
A recording request signal output means for outputting the record request signal based on the pulse signal output by said pulse signal output means,
A recording start signal output means for outputting a recording start signal based at least on the recording request signal output by the recording request signal output means;
When the recording start signal is input from the recording start signal output unit, a driving waveform signal output unit that outputs a driving waveform signal of a predetermined pattern to be supplied to the recording head;
A recording apparatus for recording while moving the recording head along the recording medium ,
The recording request signal outputs the recording request signal by means are a certain number increased each time it is output, the value of the counter the being fixed number decreased every time the recording start signal by the recording start signal output means is output, The first condition is that the output is greater than an initial value and the output of the drive waveform signal by the drive waveform signal output means is terminated,
The second condition is that the output of the recording request signal by the recording request signal output means is the first signal in the main scanning direction,
A recording apparatus comprising: control means for permitting the recording start signal output means to output the recording start signal when the first condition or the second condition is satisfied . Pulse signal output means for sequentially outputting a pulse signal according to the position of the recording head that moves relative to the recording medium in the main scanning direction and the direction perpendicular thereto,
A recording request signal output means for outputting the record request signal based on the pulse signal output by said pulse signal output means,
A recording start signal output means for outputting a recording start signal based at least on the recording request signal output by the recording request signal output means;
When the recording start signal is input from the recording start signal output unit, a driving waveform signal output unit that outputs a driving waveform signal of a predetermined pattern to be supplied to the recording head;
In a recording control method for controlling a recording apparatus comprising :
The recording request signal outputs the recording request signal by means are a certain number increased each time it is output, the value of the counter the being fixed number decreased every time the recording start signal by the recording start signal output means is output, The first condition is that the output is greater than an initial value and the output of the drive waveform signal by the drive waveform signal output means is terminated,
The second condition is that the output of the recording request signal by the recording request signal output means is the first signal in the main scanning direction,
A recording control method characterized by permitting output of the recording start signal by the recording start signal output means when the first condition or the second condition is satisfied.

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