JPH08224908A - Printer - Google Patents

Abstract

PURPOSE: To suppress a lowering of the printing speed of a printer when high density printing is performed by lowering a scanning speed without altering the drive frequency of a printing head in a printer scanning the printing head to perform printing. CONSTITUTION: A pattern detection part 4 detects a range performing high density printing and a processing line detection part 5 detects a line having to perform high density printing from the detected range to store the same. A timing generator 8 lowers the moving speed of a carriage 10 only when the line performing the high density printing stored in the processing line detection part is printed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device,
More specifically, the present invention relates to a printing device that prints based on print information from a host computer.

[0002]

2. Description of the Related Art A conventional printing apparatus which receives print information from a host computer and performs a printing operation based on the print information, particularly a print buffer which can store print data for one line, is used for printing one line. A device that performs a printing operation when print data is stored in the buffer performs the following processing.

That is, when print information including, for example, a control code and a character code is input from the host computer, the print information is temporarily stored in the memory, and then the control unit reads this print information from the memory and analyzes the content of the control code. To do. When the control code for starting printing is detected here, the control unit stores the print data corresponding to the character code in the character generator ROM (hereinafter referred to as CG).
-ROM) and write to the address of the print buffer corresponding to the print position indicated by the control code.

When the print data for one line is stored in the print buffer in this way, the control section sequentially reads the print data from the print buffer and outputs it to the print head. On the other hand, the print head is driven at a constant driving cycle while being scanned at a constant speed based on the print data. In this way, when the scanning speed and drive cycle of the print head are constant, the print density is determined according to the print density of the print data stored in the CG-ROM, and printing is performed at this density. When printing for one line is completed, the control unit
A drive pulse corresponding to the paper feed amount designated by the control code is output to the paper feed motor to feed a predetermined amount of paper.

As described above, the printing apparatus has one
A code indicating the print position on the line and a code indicating the print line interval (paper feed amount code) are analyzed, and the print head is driven and the paper is conveyed according to the information, and printing is performed at a predetermined position.

In such a printing apparatus, in principle, printing is performed according to the print density of the print data stored in the CG-ROM. However, in the case of performing higher density and smoother printing, the CG-ROM is printed. The high-density printing is realized by converting these into high-density data based on the print data of (1) and uniformly reducing the scanning speed while keeping the drive cycle of the print head at the normal cycle.

[0007]

However, in the conventional printing apparatus as described above, in order to increase the printing speed, the print cycle is maximized when the print head is driven at a normal print density. It is common to design For this reason, in the conventional printing apparatus, when performing high-density printing, if the scan speed is uniformly lowered while keeping the drive cycle of the print head as described above, it takes an extremely long time to print on the paper and the throughput decreases. There was a problem of doing.

The present invention has been made in view of the above-mentioned conventional problems, and when performing high-density printing, printing is performed while suppressing a decrease in print speed as compared with the case of printing at a normal density. It is to provide a printing device capable of performing the above.

[0009]

Therefore, according to the present invention,
In a printing apparatus that uses a head to scan the head to print on a print material, a carriage for scanning the head, and a density conversion unit that converts a print density of print data into high-density print data,
Pattern detecting means for detecting a pattern of data converted to high density by the density converting means, and data converted by the density converting means corresponding to the scanning of the head from a data pattern detected by the pattern detecting means. A data range detecting means for detecting the range, a carriage driving means for driving the carriage by changing the scanning speed of the carriage by scanning in which the data range detected by the data range detecting means corresponds and scanning in which the data range does not correspond, It is characterized by having.

More preferably, the carriage driving means reduces the scanning speed of the carriage in the corresponding scanning, and the printing device drives the head in both the corresponding scanning and the non-corresponding scanning. It is characterized by further comprising means for keeping the frequency constant.

[0011]

According to the above construction, whether or not to perform high-density printing is determined for each scan of the head, and the drive of the carriage can be controlled accordingly, so that high-density printing can be performed. The carriage speed can be reduced only when printing lines.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the circuit configuration of the printing apparatus, which applies the present invention to each line, as described above.

In FIG. 1, reference numeral 1 is a control unit for controlling the entire printing apparatus, 2 is a memory including a CG-ROM that stores print data relating to characters such as characters, and 3 is a high-density conversion of print density of print data. This is a high-density processing unit. For the conversion for increasing the density in the processing unit 3, known processing, for example, interpolation can be used. Reference numeral 4 is a pattern detection unit for detecting a pattern of data to be subjected to high-density conversion processing in print data received via the interface (I / F) 11, and 5 is a scanning line having data for high-density processing. It is a processing line detection unit for detecting. The pattern detection unit 4 has print pattern data required for high-density printing, and detects a pattern of print data to be densified by comparing with print data received via the interface 11. Further, the processing line detection unit 5 has a line detection flag, and monitors whether or not the pattern detection unit 4 has detected a high-density pattern in the print data creation line,
When a high density pattern is detected, the line detection flag is set. 6 is a print buffer that stores print data for one line; 7 is a print head; 8 is a timing generator that generates timing for driving the carriage; 9 is a carriage drive unit that drives the carriage;
Reference numeral 10 is a carriage on which a print head is mounted. Other components necessary for the recording device are omitted.

Next, the operation of the printing apparatus will be described.

Upon receiving the print information from the host computer, the control unit 1 stores the print information in the memory 2. After that, the control unit 1 reads out the print information from the memory 2 and analyzes the control code and the character code forming the information. When the print start code is detected from the control codes, the control unit 1 reads the print data corresponding to the character code from the CG-ROM of the memory 2 and outputs the print data to the high-density processing unit 3 and the pattern detection unit 4. The pattern detection unit 4 detects a data pattern, which is a range of data to be subjected to high-density processing, from the input print data, and outputs the information to the high-density processing unit 3 and the processing line detection unit 5. . It should be noted that this detection can be performed based on the content of the control data sent together with the character data.

The high-density processing unit 3 performs high-density processing on the data in the range for high-density processing based on the pattern information from the pattern detection unit 4, and then writes the data in the print buffer to perform processing. The data in the unnecessary range is written to the print buffer as it is. On the other hand, the processing line detection unit 5 determines, based on the pattern information from the pattern detection unit 4, whether each scanning line of the print head is a scanning line in which data to be subjected to high-density processing exists, and stores the information. .

When the print data for one line is stored in the print buffer, the printing operation is started. The timing generator 8 generates a signal necessary for driving the carriage 10 based on the basic clock from the control unit 1 and outputs the signal to the carriage driving unit 9. When the line to be printed is not the high-density print but the normal print, the timing signal corresponding to the normal drive speed is generated. When the line on which the printing operation is performed performs high density printing, a timing signal corresponding to the carriage drive speed capable of high density printing is generated.

For example, in the high density processing, when the print density is doubled, the scanning speed of the carriage 10 is 1.
Generate a timing signal such that / 2. The carriage drive unit 9 drives the carriage 10 based on this signal. On the other hand, the drive cycle of the head is a normal drive cycle. As a result, it is possible to print at a recording density twice as high as usual.

As described above, according to the present embodiment, it is determined whether or not each line is a line for performing high density printing, and the scanning speed is reduced only for the line for performing high density printing. It is possible to suppress a decrease in throughput of the entire device due to printing as much as possible.

FIG. 2 is a block diagram showing the circuit arrangement of a printing apparatus according to another embodiment of the present invention.

In the figure, reference numeral 12 is a processing range detecting section for detecting the position of the data to be subjected to the high density processing at the position on the scanning line from the information of the data pattern detected by the pattern detecting section 4. That is, the processing range detection unit 12
It has a line detection flag register and a register for storing the start position and the end position of high-density printing by the number of dots from the print start position, and whether the pattern detection unit 4 detects the high-density pattern in the print data creation line. A line detection flag is set when a high-density pattern is detected by monitoring whether or not it is detected, and the position where the high-density pattern is detected and the position where detection has been completed are stored in a register as the number of dots from the print start position. Is. The other components are the same as those shown in FIG. 1, and therefore their explanations are omitted.

Next, the operation based on the above configuration will be described.

When the print information is received from the host computer, the control unit 1 stores the print information in the memory 2. After that, the control unit 1 reads the print information from the memory 2 and analyzes the control code and the character code.
When the print start is detected by the control code, the control unit 1
Prints the print data corresponding to the character code in the memory C
The data is read from the G-ROM and output to the high-density processing unit 3 and the pattern detection unit 4, respectively. Pattern detector 4
Detects a data pattern to be subjected to high-density processing from the input print data, and outputs the information to the high-density processing unit 3 and the processing range detection unit 12, respectively. In the high-density processing unit 3, the high-density processing is performed on the portion to be subjected to the high-density processing based on the information from the pattern detection unit 4, and then,
The print data is written to the print buffer as it is at the portions that do not need to be processed.

On the other hand, the processing range detecting section 12 detects a range in which data to be subjected to high-density processing exists for each scanning line based on the information from the pattern detecting section 4 and stores the information.

When the print data for one line is stored in the print buffer as described above, the print operation is started. That is, the timing generator 8
A signal necessary for driving the carriage 10 is generated for each line based on the basic clock from the control unit 1 and is output to the carriage drive unit 9. However, information from the processing range detection unit 12 causes normal print density. A timing signal capable of realizing a carriage driving speed corresponding to each of the range for printing with and the range for printing with high density is generated. That is, a timing signal corresponding to a normal driving speed is generated in a range where high density printing is not performed in one line, and a timing signal corresponding to a carriage driving speed capable of high density printing is generated in a range where high density printing is performed. .

For example, in high density printing, when the print density is doubled, a timing signal is generated so that the moving speed of the carriage 10 becomes 1/2.

In order to switch the moving speed of the carriage 10 in one line, the following measures are required. For example, in a printing device that requires ramp-up and ramp-down operations, a range where ramp-up and ramp-down operations are possible is provided before and after the high-density printing range,
Further, the carriage drive timing signal is switched at a place where print data does not exist. Also,
If there are a range for printing at high density and a range for printing at high density in a narrow range, and there is no range for performing ramp-up and ramp-down operations, the high-density print timing signal for the narrow range is used to drive the carriage. Output to the department.

FIG. 3 is a perspective view showing an ink jet printer as an example of the printing apparatus according to each of the above-mentioned embodiments, excluding its outer case.

The ink jet print 100 comprises a rough paper feed section 102, a paper feed section (30, 34, 36, 37), a paper discharge section (41), a carriage section 5, and a cleaning section 106.

The paper feeding unit 102 is provided with a pressure plate 2 for the base 20.
1 is movably provided, whereby a spring (not shown)
Thus, it is possible to press the paper as the material to be printed placed on the pressure plate 21 against the paper feed roller (not shown) and feed the paper one by one. Here, the guide 23 is provided so as to be movable according to the size of the sheet.

The paper fed from the paper feed unit 102 is held by the pinch roller guide 30 by the pinch roller 37.
Is pressed by the transport roller 36 and is rotated by the driving force of a motor (not shown), so that the print area facing the inkjet head mounted on the carriage 105 is transported. Further, the printed paper is ejected to the front of the apparatus by the ejection rollers 41 and the like.

The carriage body 50 of the carriage portion 5 is provided with a contact portion for electrically connecting with the head when the ink jet cartridge is mounted. This electrical contact portion forms the end of the flexible cable 56, while the other end of the cable 56 is connected to the electrical board within the printer body. The carriage main body 50 is provided so as to be slidably engaged with the guide shaft 81 and movable by the driving force transmitted by the timing belt 83. As a result, the carriage body 50 can reciprocate along the guide shaft 81 in a direction perpendicular to the paper conveyance direction (also referred to as the sub-scanning direction). Then, during this movement, ink is ejected from the head to print on the paper.

The cleaning unit 6 includes a carriage body 50.
It has a cap 61 for covering the surface of the head mounted on the surface where the ejection port is provided, and a pump 60 for sucking ink from the ejection port and performing ejection recovery in a capping state by the cap 61. . Further, it is provided with a blade made of an elastic body for removing dust and ink droplets attached to the ejection port surface of the head. The blade is preferably made of non-hydrolyzable urethane rubber, HNBR rubber or the like because it has no reactivity with ink and further minimizes damage to the face surface of the head.

(Others) The present invention is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink even in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection 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 constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the electrical connection to the main body of the apparatus and the ink from the main body of the apparatus by being mounted on the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means and the like since the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change from the solid state of the ink to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. 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 this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. 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 the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may be a form or the like.

[0043]

As described above, according to the present invention,
Whether or not to perform high-density printing is determined for each scan of the head, and it is possible to control the drive of the carriage accordingly. Can be lowered.

As a result, high-density printing can be performed without significantly reducing the printing speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a printing apparatus according to another embodiment of the present invention.

FIG. 3 is a perspective view showing an example of a printing apparatus to which the present invention can be applied.

[Explanation of symbols]

 1 Control Section 2 Memory 3 High Density Processing Section 4 Pattern Detection Section 5 Processing Line Detection Section 6 Print Buffer 7 Recording Head 8 Timing Generator 9 Carriage Drive Section 10 Carriage 11 Interface (I / F) 12 Processing Range Detection Section

Claims (5)

[Claims] 1. In a printing apparatus that uses a head and scans the head to print on a print material, a carriage for scanning the head, and a print density of print data are converted into high-density print data. Density converting means, pattern detecting means for detecting a pattern of data converted to high density by the density converting means, and the density converting means corresponding to the scanning of the head from the data pattern detected by the pattern detecting means. The range of data converted by the data range detecting means, the scanning in which the range of the data detected by the data range detecting means corresponds, and the scanning in which the data range does not correspond, the scanning speed of the carriage is changed and the carriage is driven. A printing apparatus comprising: a carriage driving unit. 2. The carriage driving means reduces the scanning speed of the carriage in the corresponding scanning, and the printing device sets the drive frequency of the head in both the corresponding scanning and the non-corresponding scanning. 2. The printing apparatus according to claim 1, further comprising means for making it constant. 3. The printing apparatus according to claim 1, wherein the data range detecting unit detects a scan in which the converted data exists. 4. The printing apparatus according to claim 1, wherein the data range detecting unit detects a range in which the converted data exists for each scan. 5. The head according to claim 1, wherein the head uses the thermal energy to generate bubbles in the ink and ejects the ink based on the generation of the bubbles. The printing device described.