JPH03197048A - Ink jet recorder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a liquid jet recording device (hereinafter referred to as an inkjet printer) that performs recording by ejecting a recording liquid such as ink (hereinafter simply referred to as ink) onto a recording medium. )
In particular, the present invention relates to a serial type inkjet printer that performs recording while scanning an inkjet recording head in a predetermined direction on a recording medium.

[Prior Art] Conventional inkjet recording devices generally include a replaceable cartridge containing ink, that is, an ink cartridge, and ink is supplied from the ink cartridge to the recording head via a supply pipe. The arrangement is complicated, which not only affects the assembly cost of the device, but also makes it difficult to downsize the entire device.

Furthermore, if the supply pipe is a flexible pipe, if it is left unattended or shaken during transportation, air may enter the supply pipe.
Because of this, there is a possibility that ink may not be ejected, so it becomes necessary to provide a sub-tank as a trap near the print head. In addition, when replacing inks of different quality, for example color 9, with different concentrations, viscosity, and solvents, it is necessary to clean and dry not only the recording head but also the supply tube, which is a practical problem. It is difficult for the user to use the ink.

Therefore, as shown in FIG. 4, there is a print head unit in which a print head and an ink accommodating portion are integrally constructed and are detachably attached to a carriage so as to be replaceable. Fourth
In the figure, 101 is a disposable recording head unit in which an ink ejection part and an ink storage part are integrated;
IA is the ink ejection part, l0IB is the ink storage part, 1
10 is a carriage on which the recording head unit 101 is mounted and moves, and ill is a lock lever for fixing the recording head unit 101 to the carriage 110.

FIG. 5 is a schematic perspective view of an inkjet recording apparatus equipped with such a recording head unit.

In FIG. 5, a guide shaft 64 is placed in front of a sheet (recording medium such as paper or a thin plastic plate) 63 that is fed in the six directions of arrows through sheet feed rollers 61 and 62 installed at a predetermined interval vertically. A carriage 110 that moves along the recording head is provided, and a recording head unit 101 is removably mounted on the carriage 110.

This recording head unit lot has a fourth ink ejection opening (orifice) that ejects ink droplets on its front surface.
It is formed as shown in the figure, and is attached to the sheet 63 so as to scan in the printing digit direction at intervals of, for example, about 0.8 mm.

The carriage 110 is reciprocated in the direction of arrow P by a carriage drive motor 68 via a belt transmission mechanism 69.

A flexible cable 67 for power supply and signal transmission is connected between the carriage 110 and the control circuit of the recording apparatus.

During recording, in synchronization with the movement of the carriage 110 in the print digit direction, the driving elements (energy converters) of each ink ejection port of the recording head unit 101 are driven based on print data, thereby allowing the ink to flow from each ink ejection port. Image dots are recorded while forming flying ink droplets toward the sheet 63.

After the recording is completed, the recording head unit 101 is stopped at the home position HP outside the recording range. This home position HP is provided with a recovery device 70 that has a capping function for sealing the surface on which the ink ejection ports are formed and an ink recovery function that pumps and suctions ink from the ink ejection ports as needed. Here, the recording head unit 101 is attached to the carriage 110 in a detachable and electrically connected state.

FIG. 6 is a block diagram showing the configuration of a conventional logic unit and print head that control such a printing apparatus. In Figure 6, from the host system to the I/F
Based on the information sent via the control unit 34, the microprocessor unit (hereinafter referred to as MPυ) 31 generates bitmap pattern data constituting characters from a character generator (hereinafter referred to as CG) in the ROM 33 connected to the bus. After reading and writing one line of image data into the RAM 32, the carriage carrying the head is caused to scan in the horizontal direction. Then, when the head reaches the printing position, the MPU 31 reads out the contents of the RAM 32 for the nozzles of the head and stores them in the register 35.

The print pulse generation circuit 36 generates a pulse for driving the head, and the ANDN-gate group generates an ejection pulse for selectively driving the head element using an AND signal of this pulse and the output of the register 35. Then, the driver 39 drives each element 40 of the head according to this ejection pulse to perform a printing operation. As described above, the head shown in FIG. 6 is of a type that simply has only a driving element and the driver is disposed in a part other than the head. This method is used when the resolution of the head element and the number of nozzles are relatively small, or when the cost of the head increases due to having functional parts in the head, such as a disposable type head.

FIG. 7 is a block diagram showing another configuration of a conventional logic section and print head, and the same reference numerals as in FIG. 6 indicate the same components.

The system shown in FIG. 7 is a type in which, in addition to a driver 39, a latch shift register 37 and an ANDN gate group for transferring serial data are provided in the head. According to this method, data can be transferred to the head in a serial manner, so the number of wires connecting the head and the main body can be reduced compared to the method shown in FIG. The 0-hydraulic type is effective in reducing the number of wires, especially when the resolution of the head is high and the number of elements is large.

[Problem to be Solved by the Invention 1] The system shown in FIG. 6 has a relatively simple configuration, but when the resolution of the head is high and the number of driving elements is large, the MPU 31 uses the CG and RA in the ROM 33.
The number of accesses to M32 increases, requiring a high-speed MPU, and the capacity of RAM32 also increases as the number of head elements and resolution improves, resulting in higher costs and lower throughput. .

Furthermore, if you want to use a font other than the standard fonts built into the CG3:r, you will need a connector for the font cartridge 41 as shown in Figures 6 and 7, and you will also need a connector to store the font cartridge 41. In addition, there are problems in terms of cost and implementation, such as the need to provide space within the printer for the font cartridges, and the effort required for users to replace font cartridges.

The purpose of the present invention is to replace the disposable ink storage integrated recording head unit without the hassle of installing a font cartridge into the printer body, as if replacing the type wheel of a wheel typewriter. To provide an inkjet recording device that can easily exchange several types of fonts.

[Means for Solving the Problems] Character pattern generating means outputs a character pattern according to commands from a main control means, and the output of the character pattern generating means is inputted to a removably attached recording head to eject ink. The present invention is characterized by comprising an ejection signal forming means for forming a signal, and an ink ejecting means for ejecting ink in accordance with the output of the ejection signal forming means.

[Function] According to the present invention, by simply attaching a recording head equipped with a character generator of a font desired by the user to the printer, the font can be printed in the font desired by the user according to the character code sent to the recording head. can do.

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In Fig. 1, 1 is an MPU that controls the device, 2 is a RAM that buffers input data and stores one line of character code data, 3 is a ROM that holds the firmware of the MPU 1, and 4 is a connector that communicates with the host system. I/F control unit that performs an interface; 5 is a head I that performs an interface between the print head and the MPU 1;
/F part, 6 is a print pulse generation circuit that generates the drive timing of the head element, 7 is a CGROM containing a character pattern of a predetermined font with a word length for the drive element of the head, 8 is a CGROM 7 and print pulse generation A group of AND gates that generates an on/off signal to be supplied to the actual head element by the AND output of the output with the circuit 6; 9 is a driver array including a driver that drives the heater element 10 according to the output of the ANDN-gate group; 10 is a driver array for each nozzle. This heater element is provided for generating air bubbles and ejecting ink from the nozzle using the pressure generated from the air bubbles.

FIG. 2 is a block diagram showing the structure of the recording head unit used in this embodiment, and information is exchanged with the printer main body via a connector 75.

In the above configuration, the MPU 1 receives character codes to be printed from the host system through the I/F control section 4, and the data is stored in the RAM 2.

Next, MPU 1 searches the data in RAM 2,
When it is confirmed that the predetermined printing start conditions such as a line feed command and a carriage redundancy command, that is, one line of data has been received, the printing operation for that line is started.

First, the MPU 1 sequentially arranges character codes for one line in the RAM 2 according to the printing direction. Next, the carriage carrying the head is moved to start scanning in the horizontal direction. Then, before the head reaches the position to be printed, the address of the CGROM 7 corresponding to the character code to be printed is sent to the CGROM 7 via the head I/F unit 5.

Since the head I/F section 5 in this case is simply a register, it has a very simple configuration.

The CGROM 7 generates a character pattern according to the address input, and outputs a group of ANDN gates corresponding to the output of the CGROM 7 on a one-to-one basis. When the head reaches the printing position, an actual drive timing pulse is created by the pulse generated by the printing pulse generation circuit 6, the driver array 9 is selectively driven, and the heater element 10 is used to drive the driver array 9 in the vertical direction. For rows (1 force ram)
is printed.

At the next printing position, if the MPU i is in the next column of the same character, it adds 1 or subtracts l to the previous address of CGROM 7, depending on the head scanning direction, to the head. Transfer and print in the same way.

Repeat this operation, and when one character is printed, the MPU
i calculates the address value of CGROM 7 according to the character code edited in RAM 2, and stores it in CGROM.
By sending it to M7, the printing operation is performed as before.
This operation is performed continuously at each printing position, and when printing of one line is completed, the carriage is stopped and printing of this line is completed.

Here, CGROM? Generally, one character is arranged at consecutive addresses for each nozzle row of the head to facilitate access. In other words, in the printing operation of the same character, CGROM
A simple counter function is sufficient for access.

FIG. 3 is a block diagram showing the structure of another embodiment of the present invention in which access is further simplified by adding a (:GROM) address generation mechanism to the recording head unit.

In FIG. 3, the same reference numerals as in FIG. 1 indicate the same components, and 11 is a head I/F
A mode register 12 holds the print mode data sent through the section 5. An address counter 12 generates an address for the CGROM 7 constituted by an up/down counter.

In this embodiment configured as described above, before starting the printing operation, the MPU 1 sets information as to whether the printing direction is forward or reverse in the mode register 11. Then, before the carriage scans and the head reaches the printing position, the MPU 1 calculates an address in the CGROM 7 from the character code edited in the RAM 2 and loads it into the address counter 12. The output of the address counter 12 becomes the address input of the CGROM 7, and the CGROM
7 outputs a bitmap image of the specified character. Actual printing is performed using the output of the printing pulse generation circuit 6, as in the previously described embodiment.

Next, the address counter 12 performs an up or down operation at the trailing edge of the print pulse to access data in the next column. When one character is printed in this way, M
Before the next head drive, the PU 1 loads the address into the address counter 12 in order to access the beginning of the next character to be printed.
Each time a printing pulse is generated, the address of the CGROM 7 advances, and a character pattern of a predetermined font is printed.

It should be noted that the present invention provides excellent effects particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems.

This is because such a system can achieve higher recording density and higher definition.

Regarding typical configurations and principles, it is preferable to use the basic principles disclosed in U.S. Pat. No. 4,723,129 and U.S. Pat. No. 4,740,796. It can be applied to both continuous types, but in particular, in the case of on-demand type, electrothermal converters are placed corresponding to the sheet holding the liquid (ink) or the liquid path. To,
generating thermal energy in the electrothermal transducer to produce film boiling on the thermally active surface of the recording head by applying at least one drive signal corresponding to recorded information and providing a rapid temperature rise above nucleate boiling; This is effective because, as a result, bubbles in the liquid (ink) can be formed in pairs corresponding to the drive signals. The growth and contraction of these bubbles causes the liquid (ink) to be ejected through the ejection opening, forming a small droplet (at least one droplet).If this drive signal is in the form of a pulse, the growth and contraction of the bubbles can be carried out immediately and appropriately. Because you will be exposed to
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration compatible with an open discharge part that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently.

Further, the present invention is also effective when applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

[Effects of the Invention] As explained above, according to the present invention, a user can easily print in a desired font simply by attaching a recording head that prints the font selected by the user to the printer. I can do it.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the recording head unit of the embodiment shown in FIG. 3, and FIG. 3 is a block diagram showing the configuration of the recording head unit of the embodiment shown in FIG. FIG. 4 is a block diagram showing the configuration of a conventional recording head unit; FIG. 5 is a perspective view showing the configuration of an inkjet recording device; FIGS. 6 and 7 are diagrams of a conventional inkjet recording device. FIG. 2 is a block diagram showing the configuration. 1...Microprocessor unit 2...RAM. 3...ROM 1 4...I/F control unit, 5...Head I/F unit, 6...Print pulse generation circuit, (MPUI) 7...Character generator (CG), 8...・・A
NDN-gate group...driver array, lO...heater element, 11...print mode register, 12...address counter, 41...font cartridge, 75...connector.

Claims (1)

[Scope of Claims] 1) Character pattern generating means for outputting a character pattern according to commands from a main control means to a recording head that is equipped with an ink ejection section and is detachably attached to the main body of an inkjet recording apparatus; An inkjet comprising: an ejection signal forming means that inputs the output of the generating means and forms a signal for ink ejection, and an ink ejection means that ejects ink according to the output of the ejection signal forming means. Recording device. 2) The inkjet recording apparatus according to claim 1, wherein the recording head is mounted on a carriage, and the ink ejection section thereof is formed integrally with an ink storage section.