JPH08207399A - Serial printer - Google Patents

Abstract

PURPOSE: To provide a serial printer in which the throughput is improved by realizing a process for skipping a blank part at the printer side in the case of skipping process, and lessening a load applied to the line buffer retrieval of the software of a host machine side. CONSTITUTION: When a retrieval starting address is set to an address counter 21 by a host machine, a retrieval ending address is set to a comparator 25 and a start signal is generated to clear a D flip-flop 24, a DMA request L active is generated, data is read according to the address designated and indicated by the counter 21, and the read data is carried at a bus, and the address of the counter 21 is incrementally increased by one. If the output of the comparator 25 is 'H' or any bit of data bus DBUSn is 'H', the flip-flop 24 is set, thereby finishing the retrieving operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives serial print information for each dot row from a print information storage means which is connected to a host device for supplying print information and stores the print information of the host device, and prints out dot serially. Serial printer.

[0002]

2. Description of the Related Art The spread of personal computers in recent years,
Computer graphics, CAD (Computer Aidded)
Due to the spread of Sesign), the demand for printers as output devices is increasing. The printer recording method is also laser beam electrophotography, electrostatic photography, lithography recording, thermal transfer recording, wire dot recording,
There are various methods such as an inkjet recording method.

The printing speed is also increasing year by year due to the speeding up of processors and the optimization of software algorithms. However, since processing such as outline fonts that places a heavy burden on the processor has been mounted on the printer side, higher speed is desired. From such a background, the printer maker responds to the increase in speed by, for example, hardwareizing the processing conventionally performed by software.

As an example, there is DMA processing at the time of printing in a serial printer. This is an external memory C
This is a method of reducing the load on the software and improving the processing speed by directly accessing the ASIC without using the PU. FIG. 4 is given as an example of the DMA processing at the time of printing, and general control of the DMA processing will be described with reference to FIG.

In FIG. 4, reference numeral 11 denotes a heat pulse generator which generates a heat pulse for heating the head 16 at an appropriate timing in response to the movement of the head 16.
Reference numeral 12 denotes a head drive circuit 15 for driving the recording head by receiving a heat pulse from the heat pulse generator 11, and D
It is a heat control unit that controls each of the MA control units 14. 13 is R in which actual print data is stored
It is AM, and data is stored continuously in the order of the heat rows that are normally heated. 14 is the heat control unit 1
RAM the next heat data according to the control signal from 2
13 is a DMA control unit for reading from 13 and storing it in an internal register of the heat control unit 12. Reference numeral 15 denotes a head drive circuit, which is a portion that performs processing for actually printing the heat data stored in the register inside the heat control unit 12 according to a control signal from the heat control unit 12. Further, 16 is a head that performs recording corresponding to a heat pulse, 17 is a carriage, and 18 is a transport unit that transports the carriage 17 in the main scanning direction.

The operation during actual printing in the above circuit configuration will be described. Heat pulse generator 1
No. 1 starts moving the internal counter after the carriage 17 carrying the head 16 is transported by the transport unit 18 and starts moving, and if it is determined by the counter that the head 16 of the carriage 17 has reached the heat start position, A heat pulse is sent to the heat control unit 12.
The heat control unit 12 includes the heat pulse generation unit 11
When the heat pulse from the
Send MA start signal.

When the DMA control unit 14 receives this DMA start signal, it reads the heat data stored in the RAM 13 and stores it in a register inside the heat control unit 12, and outputs a pointer value indicating the position of the heat data in the RAM 13. Move to the next heat data position. Then, it prepares to receive the next DMA start signal from the heat control unit 12.

When the heat data is stored in the internal register by the DMA control unit 14, the heat control unit 12 outputs a heat start signal to the head drive circuit 15. Upon receiving the heat start signal from the heat control unit 12, the head drive circuit 15 performs a process for actually printing the heat data stored in the register inside the heat control unit 12. By such an operation, the first dot row is printed.

The heat pulse generator 11 continues to operate the internal counter after the heat pulse of the first dot row is generated,
When it is determined that the carriage has reached the second dot heating position based on the value of the counter, the second heat pulse is generated. The second dot is printed in the same manner as the first dot by the heat pulse of the second dot. Such an operation is repeated up to the final dot to print one line.

Skip processing is given as another example of processing that is often performed to improve throughput. The skip process is a process of moving the carriage to the position where actual printing should be performed by skipping a blank part that does not need to be printed, rather than moving the carriage to the left end (right end) of the printable area during LF. . By performing the skip processing, the carriage movement time from the LF to the actual printing position is shortened, and the throughput is improved.

[0011]

However, in the skip processing described in the above-mentioned conventional example, the line to be printed next by the software on the computer side controlling the recording device in order to perform the processing of skipping the blank portion. I was working on finding the blank part by examining the contents of the buffer. Therefore, in a printer with a large printable area, a high-resolution printer, a printer that prints multiple lines at the same time, or a printer with a large line buffer capacity, the load on the line buffer search of the software described above becomes large, and the throughput decreases. Could lead to.

[0012]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, in a serial printer that receives serial print information for each dot row from a print information storage unit that is connected to a host device that supplies print information and that stores the print information of the host device, and print out in dot serial, the host device Starting position holding means for holding the storage position information of the recording information dot to be printed at the beginning of one dot row to be printed in the recording information storage means, and printing of the recording information storage means from the host device. End position holding means for holding the storage position information of the print information dot to be printed at the end of the one dot row to be printed, and the start position holding means of the print information storage means of the host device when the one dot row is printed out. Only the print data in the area specified by the holding position above the end position holding means from the area specified by the holding position information Characterized by printout reading.

Further, for example, the holding information held by the starting position holding means and the ending position holding means is set by the host device. Alternatively, it is characterized in that blank information is automatically generated and output to the recording head before reaching the holding position of the start position holding means. Further, for example, the recording head is an inkjet recording head that ejects ink to perform recording. Alternatively, the recording head is a recording head that ejects ink by using thermal energy, and is provided with a thermal energy converter for generating thermal energy to be applied to the ink.

[0014]

With the above arrangement, it is possible to read out from the recording information dot to be dot printed at the beginning of one dot row to be printed to the recording information to be printed at the last dot to the printer side without searching by software. For example, there is no need to perform a blank search by software, which reduces the load on software and improves throughput.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings. <Schematic Description of Apparatus Main Body> FIG. 1 is an external perspective view showing the outline of the configuration of an inkjet printer IJRA which is a typical embodiment of the present invention. In FIG. 1, the drive motor 5
The driving force transmission gear 5011 is interlocked with the forward / reverse rotation of 013,
The carriage HC that engages with the spiral groove 5004 of the lead screw 5005 that rotates via 5009 has a pin (not shown) and is reciprocated in the directions of arrows a and b.
An inkjet cartridge IJC is mounted on the carriage HC. 5002 is a paper pressing plate,
The paper is pressed against the platen 5000 in the moving direction of the carriage. Reference numerals 5007 and 5008 denote photocouplers, which are home position detecting means for confirming the presence of the carriage lever 5006 in this area and switching the rotation direction of the motor 5013. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head. Reference numeral 5015 is a suction unit that sucks the inside of the cap, and performs suction recovery of the recording head through the in-cap opening 5023. Reference numeral 5017 is a cleaning blade, and 5019 is a member that allows this blade to move in the front-rear direction, and these are supported by a main body support plate 5018. Needless to say, a well-known cleaning blade can be applied to this example instead of this form.
Reference numeral 5012 denotes a lever for starting suction for suction recovery, which moves in accordance with the movement of the cam 5020 that engages with the carriage, and the movement of the driving force from the driving motor is controlled by a known transmission means such as clutch switching. To be done.

The capping, cleaning, and suction recovery are configured so that the desired processing can be performed at their corresponding positions by the action of the lead screw 5005 when the carriage comes to the area on the home position side. As long as the desired operation is performed at the timing, any of the above can be applied to this example. <Description of Control Configuration> Next, a control configuration for executing the recording control of the above-described apparatus will be described.

FIG. 2 is a block diagram showing the configuration of the control circuit of the ink jet printer IJRA. In the figure showing the control circuit, 1700 is an interface for inputting a recording signal, 1701 is an MPU, 1702 is an MPU 170.
Program RO for storing the control program executed by 1
M and 1703 are dynamic RAMs for storing various data (recording data, recording data supplied to the head, etc.), and correspond to the RAM 13 in the example of FIG.

Reference numeral 1704 denotes a gate array including a configuration corresponding to the above-described configuration of FIG. 4 for controlling the supply of print data to the print head 1708, and the interface 17
00, MPU 1701 and RAM 1703 are also controlled. Reference numeral 1710 is a carrier motor for carrying the recording head 1708, and 1709 is a carrying motor for carrying the recording paper. Reference numeral 1705 denotes a head driver for driving the head, and 1706 and 1707 denote the carry motor 1 respectively.
709, a motor driver for driving the carrier motor 1710.

The operation of the above control structure will be described. When a recording signal is input to the interface 1700, the gate array 17 will be described.
The print signal is converted between the print signal 04 and the MPU 1701 to print data for printing. Then, the motor driver 17
06 and 1707 are driven, and the head driver 1
The print head is driven according to the print data sent to 705, and printing is performed.

The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink, particularly in the ink jet recording system, and the thermal energy The printing apparatus of the type that causes a change in the state of ink has been described. According to such a method, the recording density is increased,
High definition can be achieved.

With regard to its typical structure and principle, for example, US Pat. Nos. 4,723,129 and 4740 are applicable.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which the liquid crystal is held, which corresponds to the recorded information and causes a rapid temperature rise exceeding film boiling. Since the electrothermal converter is caused to generate heat energy to cause film boiling on the heat-acting surface of the recording head, as a result, bubbles in the liquid (ink) corresponding to the drive signal in a one-to-one relationship can be formed. It is valid. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal in a pulse shape, because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed. As the structure of the recording head, in addition to the combination structure (straight liquid flow path or right-angled liquid flow path) of the ejection port, the liquid path, and the electrothermal converter as disclosed in the above-mentioned specifications, a heat acting surface is also provided. A configuration using US Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is arranged in a bending region, is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. Sho 5-5 discloses a configuration in which a common slot for a plurality of electrothermal converters is used as a discharge portion of the electrothermal converters.
Japanese Patent Application Laid-Open No. 9-123670 and Japanese Patent Application Laid-Open No. Sho 5 (1993) -58
The configuration may be based on Japanese Patent Publication No. 9-138461.

Further, as a full line type recording head having a length corresponding to the maximum recording medium width that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. Either of the structure satisfying the requirement or the structure as one recording head integrally formed may be used. In addition, the ink is integrated into the replaceable chip-type recording head, or the recording head itself, which can be electrically connected to the apparatus main body and can supply ink from the apparatus main body by being attached to the apparatus main body. A cartridge-type recording head provided with a tank may be used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a constituent of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. . Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. Alternatively, the device may be provided with at least one of full-color mixed colors. In the embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or lower, or one that softens or liquefies at room temperature may be used, or an ink jet system may be used. Generally, the temperature of the ink itself is adjusted within the range of 30 ° C to 70 ° C to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. Anything can be used.

In addition, in order to positively prevent the temperature rise due to thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state,
Alternatively, in order to prevent the ink from evaporating, an ink that solidifies in a standing state and liquefies by heating may be used. In any case, by applying heat energy, such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In such a case, the ink is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. It may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the recording apparatus according to the present invention, in addition to one provided integrally or separately as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and further transmission / reception It may take the form of a facsimile machine having a function. <Description of Configuration of Data Reading Portion of Gate Array 1704> DR in the gate array 1704 in FIG.
The basic configuration example of the portion for reading the recording information stored in the AM 1703 may be the same as the configuration shown in FIG. 4 described above, for example. However, in this embodiment, the DRAM 1 stored in the internal register under the control of the DMA controller 14 is
The control for outputting the print information from 703 (RAM 13 in FIG. 4) to the head driver 1705 (head drive circuit 15) is partly different, and the process of skipping the blank part in the skip process is directly achieved by hardware. As a result, the load on the software such as the MPU 1701 is reduced, and the original purpose of the skip processing is to improve the throughput.

The characteristic portion of this embodiment will be described in detail with reference to FIG. In FIG. 3, reference numeral 21 is an up / down counter, which is used as an address counter indicating the search position of the area allocated as a line buffer in the DRAM 1703 in this embodiment. Reference numeral 22 is a D flip-flop, the output Q of which is connected to the input terminal of the up / down counter 21 for selecting increment / decrement. As a result, by setting 0 (L) or 1 (H) in the D flip-flop 22 by the control program in the MPU 1701, for example, the up-down counter 21 is operated as an ascending order search or a descending order search. To do.

Reference numeral 23 is an OR circuit, one input of which is connected to the data bus DBUSn of the MPU 1701 and the other input of which is connected to the output of the comparison circuit 25, and only when all bits of the input are "L". "L" is output as the output. That is, the OR circuit 23 has the data bus DBU.
If there is even one bit of "H" in Sn, "H" is output as an output.

Reference numeral 24 is a D flip-flop with a clear function, whose input D is the output of the OR circuit 23 and the input CK.
Is a DMA start signal (D
MAACK signal). The input CL is connected to a signal (START signal) for starting the search, and its output Q is D of the DMA control unit 14.
The output Q is connected to the MA request input and the interrupt request input of an interrupt controller (not shown). Reference numeral 25 is a comparison circuit that outputs "H" only when the value of the address counter matches an arbitrary value set by software.

The procedure for searching the print start address of this embodiment having the above configuration will be described below. First MPU
The software 1701 sets the search start address in the address counter 21, the search end address in the comparison circuit 25, and 0 (L) in the D flip-flop. Then, when the above setting is completed, a start signal is generated.

Upon receipt of this start signal, the D flip-flop 24 shown in FIG. 3 is cleared, and the DMA controller 1
4 generates a DMA request (L active). Upon receiving the DMA request, the DMA controller 14 accesses the DRAM 1703, reads the data from the address indicated by the address counter 21, puts the read data on the data bus, and generates a DMA ACK signal.

The address counter 21 receiving the DMA ACK signal decrements the address by one. Also,
D flip-flop 24 receiving the DMA ACK signal
Indicates that the output of the comparison circuit 25 is "L" and all the bits of the data bus DBUSn (the contents of the data bus in the DMAACK indicate the contents of the address indicated by the address counter as described above) are " If it is “L”, the state of “L” is latched, and the DMA request is again issued to the DMA control unit 14.

On the other hand, when the output of the comparison circuit 25 is "H" or any bit of the data bus DBUSn is "H", the D flip-flop 24 latches "H" and requests DMA. Is negated to generate an interrupt request (defined as a falling signal) to the interrupt controller. By doing so, the search operation by hardware is ended when an interrupt occurs, and at that time, the address indicated by the address counter is the address at which the first non-blank data was found from the search start position + 1, or the entire area set by software. When it is blank, the search end address is +1. In this way, the print start address can be searched by the hardware with little software intervention.

A procedure for searching the print end address using the circuit configuration of FIG. 3 will be described. First, the search start address is set in the address counter 21 by software, the search end address is set in the comparison circuit 25, 1 (H) is set in the D flip-flop 24, and then a start signal is generated. When the start signal from the software is received, the D flip-flop 24 is cleared, and the DMA control unit 14 DMA
Make a request. When the DMA control unit 14 receives the DMA request, for example, the DRAM 1703 (ASIC external memory)
To read the data from the address pointed by the address counter 21, put it on the data bus DBUSn, and generate a DMA ACK. DMA
The address counter 21 receiving the ACK decrements the address. When the output of the comparison circuit 25 is "L" and all the bits of the data bus DBUSn are "L", the D flip-flop 24 which has received the DMA ACK latches this "L" and again the DMA control unit. A DMA request is issued to 14.

On the other hand, whether the output of the comparison circuit 25 is H,
Alternatively, if any bit of the data bus is "H", the D flip-flop 24 latches this "H", negates the DMA request, and issues an interrupt request to the interrupt controller. By doing so, the search operation by hardware ends when an interrupt occurs, and at that time, the address indicated by the address counter is the address -1 at which the first non-blank data was found from the search start position, or all areas set by software. Is blank, the search end address is -1. In this way, the print end address can be searched by the hardware with little software intervention.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0038]

As described above, according to the present invention, it is possible to perform a software search from the recording information dot to be printed at the beginning of one dot row to be printed to the recording information to be printed at the last dot. The data can be read out to the printer side without needing to perform, for example, a blank search by software, thereby reducing the load on software and improving throughput.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the outline of the configuration of an inkjet printer IJRA that is a typical embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control circuit of the inkjet printer IJRA.

FIG. 3 is a block diagram showing a configuration of a recording data read control unit according to an embodiment of the present invention.

FIG. 4 DM when printing one line in a serial printer
It is a conceptual diagram of A operation.

[Explanation of symbols]

 Reference Signs List 11 heat pulse generation unit 12 heat control unit 13 RAM 14 DMA control unit 15 head drive circuit 21 up-down counter 22 D flip-flop 23 OR circuit 24 D flip-flop 25 comparison circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G06K 15/00

Claims (5)

[Claims] 1. A serial printer, which is connected to a host device for supplying print information, receives serial print information for each dot row from a print information storage means for storing print information of the host device, and prints out in dot-serial, Starting position holding means for holding the storage position information of the recording information dot to be printed at the beginning of one dot row to be printed in the recording information storage means from the host device; and the recording information storage from the host device. End position holding means for holding the storage position information of the recording information dot to be dot printed at the end of the 1 dot row to be printed by the means, and the start of the recording information storage means of the host device at the time of printing output of the 1 dot row The print data of the area specified by the holding position above the end position holding means from the area specified by the holding position information of the position holding means. A serial printer that reads out only the data and prints it out. 2. The serial printer according to claim 1, wherein the holding information held by the start position holding means and the end position holding means is set by the host device. 3. The blank information is automatically generated and output to a recording head before the holding position of the start position holding means is reached. Serial printer. 4. The serial printer according to claim 3, wherein the recording head is an inkjet recording head that ejects ink to perform recording. 5. The recording head is a recording head which ejects ink by utilizing thermal energy, and is provided with a thermal energy converter for generating thermal energy applied to the ink. The serial printer according to Item 4.