JPH04244875A - Recording apparatus - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus that performs printing by scanning a printing head, for example.

0002

2. Description of the Related Art During a recording operation in a serial printer such as an inkjet printer, recording is performed by synchronizing the movement of a carriage equipped with an inkjet head and the ejection of ink by driving the inkjet head. During such recording, since the ejection speed of ink from the inkjet head is constant, recording is performed with the carriage moving at a constant speed. In this type of carriage speed control, the carriage is accelerated and transported from a stopped state until it reaches a certain speed, so the carriage is transported from the position where recording starts by the distance required for acceleration. needs to be started.

On the other hand, in paper feed control for conveying a recording sheet, in order to convey the recording sheet by a length corresponding to a specified line spacing, a stepping motor with a constant rotation angle per pulse is used as a driving source. By applying a pulse corresponding to the desired rotation angle to this motor,
Controls the conveyance of recording sheets.

0004

Generally, in printer equipment, conveyance of a carriage for recording and conveyance of a recording sheet for a reversing operation are often carried out alternately. Therefore, in order to carry out the conveyance operation of the carriage and the conveyance of the recording sheet at the same time, near the end of conveyance of the recording sheet due to a changeover operation, etc., the carriage is moved without recording, for example, the carriage is accelerated, and the recording sheet is moved. It is conceivable to carry out conveyance and carriage movement at the same time. Execution of a part of the changeover operation and a part of the carriage transport operation in an overlapping manner is called an overlap operation. During such an overlap operation, the timing to start moving the carriage is determined based on the remaining number of pulses for conveying the recording sheet.

However, when conveying such a recording sheet,
If the pulse width for driving the conveyance of the recording sheet is constant, the remaining time required for conveying the recording sheet can be accurately determined from the number of remaining pulses, but the conveyance of the recording sheet is controlled by acceleration and deceleration. In such a case, the period and width of the drive pulse are changed, so it is no longer possible to predict the time until the end of conveyance of the recording sheet simply by the number of remaining pulses. For this reason, it is not possible to accurately determine the timing to start conveyance of the carriage during overlap operation, and for example, even if the conveyance of the recording sheet is finished, the acceleration control of the carriage is not finished, so the time to start recording operation may be delayed. Conversely, when the recording operation starts, the recording sheet feeding operation has not yet been completed, so there is a risk that the recording position may be shifted.

The present invention has been made in view of the above-mentioned conventional example, and it is possible to properly perform overlapping operations by accurately grasping the remaining time of the recording medium conveyance process and starting conveyance of the recording head. The purpose is to provide a recording device that can.

[0007]

Means for Solving the Problems In order to achieve the above object, the recording apparatus of the present invention has the following configuration. That is,
A recording apparatus that scans a recording head to record on a recording medium, the apparatus comprising: a conveyance means for conveying the recording medium; a calculation means for calculating the remaining time of the conveyance operation of the recording medium by the conveyance means; and timing determining means for determining a timing for starting conveyance of the recording head based on time.

[0008]

[Operation] In the above configuration, by calculating the remaining time of the recording medium conveying operation by the conveying means that conveys the recording medium, and determining the timing to start conveying the recording head based on the remaining time, the conveyance of the recording medium is calculated. and transport of the recording head at the same time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. <Explanation of inkjet printer (Figure 1, Figure 2)>
FIG. 1 is a block diagram showing a schematic configuration of an inkjet printer of this embodiment, and FIG. 2 is an external view showing an example of the configuration of a recording section of the inkjet printer of this embodiment.

First, with reference to FIG. 2, the configuration of the recording section of the inkjet printer of this embodiment will be explained. In FIG. 2, 1 is a recording head mounted on a carriage 2;
This carriage 2 is driven by a timing belt 15 (Fig. 1) stretched between an idler pulley 14 (Fig. 1) and a carriage motor 16 (Fig. 1), and the guide shaft 3 is moved back and forth along the Incidentally, ink is supplied to the recording head 1 from an ink cartridge 4 via an ink tube (not shown), and while the carriage 2 is moving from left to right, an ink discharge port (not shown) of the ink is supplied to the recording material. For example, record sheet 5
Recording is performed by ejecting ink toward. The ejection means of this recording head is described in US Pat.
, 723,129 and 4,459,600, the thermal energy causes a change of state in the liquid, including the rapid formation and contraction of bubbles, and An inkjet recording method (preferably one having an electrothermal transducer as a component) may be employed in which liquid is ejected as droplets in response to formation.

A fixed platen 6 holds the recording sheet 5 at a position facing the ejection surface of the recording head 1 at a predetermined distance. 7 is a feed roller for feeding the recording sheet 5; 8 is a pinch roller that is in pressure contact with the feed roller 7 and is driven to sandwich the recording sheet 5 therebetween; 9 is a roller that applies pressure to the pinch roller 8. This holder 9 is made of a stainless steel plate or the like, and its elastic force biases the pinch roller 8 toward the feed roller 7. Reference numerals 10 and 11 designate an upper guide and a lower guide for holding the manually fed recording sheet 5 and guiding it between the feed roller 7 and the pinch roller 8.

[0012] The upper guide 10 is provided with a guide rail 10A at its upper part, and a leaf spring portion 2A provided on the lower surface side of the carriage 2 is held slidably along this guide rail 10A. . In this way, the spring force of the leaf spring 2A urges the carriage 2 itself toward the fixed platen 6, and a part of the carriage 2 is slidably brought into contact with the sheet holding plate 13 provided on the front surface of the platen 6. Accordingly, a predetermined distance is maintained between the ink ejection surface 1A of the recording head 1 and the recording sheet 5. The part of the sheet presser plate 13 that a part of the carriage 2 comes into contact with is near the back side of the part of the sheet presser plate 13 that the feed roller 7 comes into contact with, and the sheet presser plate 1
When the carriage 3 moves back by that amount, the carriage 2 moves back as well. Therefore, regardless of the thickness of the recording sheet 5, by keeping the distance between the ink ejection surface 1A and the recording sheet 5 at a predetermined distance, a high-quality recorded image can be formed.

The recording sheet 5 fed by the feed roller 7 and the pinch roller 8 is held by a fixed platen 6 tilted rearward at an angle of approximately 30 degrees, so that the recording results are easy for the operator to read. It's easier to see. In this way, the recording sheet 5 that has been recorded is held between the discharge roller 12 and a spur (not shown) that is in pressure contact with the discharge roller 12 and is discharged. Further, on the left side of FIG. 2, 20 is a hollow needle that is inserted into the ink cartridge 4 when the ink cartridge 4 is inserted from the cartridge insertion port 21. 1 is supplied with ink.

A cap member 23 is attached to the ink ejection surface 1A of the recording head 1 when the recording head 1 is moved to the initial position (retracted position) to prevent the inkjet head from drying out. There is. A cap guide shaft 24 movably holds the cap member 23. 2
5 is a suction pump for performing a recovery operation via the cap member 23, and 26 is a pump cam for driving the pump 25. Reference numeral 27 denotes a recording sheet feeding motor that can rotate the feed roller 7 together with the discharge roller 12 via a gear train 28 and an idler pulley 29 to transport the recording sheet 5 by a predetermined amount.

Next, the configuration of the inkjet printer of this embodiment will be explained with reference to FIG. In Figure 1, 10
1 is a control unit for controlling the entire printer; for example, a CPU 110 such as a microcomputer, a control program for the CPU 110, a ROM 111 for storing various data such as constants described later, and a ROM 111 used as a work area for the CPU 110 and storing various data. RA for temporarily storing
It is equipped with M113 etc. This RAM 113 includes a memory area for storing a Tr for storing the total pulse width for conveying the recording sheet, which will be described later, and the width of each driving pulse when conveying the recording sheet. A timer 112 outputs an interrupt signal to the CPU 110 at every time t, which will be described later. Thereby, the CPU 111 can measure the elapsed time by counting the number of interrupts.

Reference numeral 114 denotes an input/output port for inputting and outputting signals between the control unit 101 and each mechanical unit of the printer (recording head 1, various motor drivers, etc.). A motor driver 17 rotates the carriage motor 16 according to instructions from the control unit 101. Similarly, reference numeral 18 is a motor driver that rotationally drives the recording sheet feeding motor 27 according to instructions from the control section 101. Further, 5 is a recording sheet which is a recording medium, and 7 is a feed roller that is rotationally driven by a recording sheet feeding motor 27 to convey the recording sheet 5.

With the above configuration, at the start of recording sheet feeding, the total time required for recording sheet feeding is calculated from all the pulse numbers for driving the recording sheet feeding motor 27 and their time intervals. Then, each time a pulse for feeding a recording sheet is output, the output pulse time is subtracted from this total time, and the timing to start transporting the carriage 2 is determined from the remaining time to perform an overlapping operation. <Explanation of the calculation process of the total time for feeding the record sheet (Figure 3)> Figure 3 shows the record sheet 5 performed in the rank change action.
FIG. 3 is a timing diagram showing an example of the conveyance timing.

As shown in FIG. 3, a total of 15 pulses are output for one changeover operation. In the figure,
Each of t0, t1, t2, t3, and t4 indicates a pulse width, and each of p0 to p14 indicates a pulse signal. Here, pulses p0 to p4 are an acceleration section in which the conveyance speed of the recording sheet 5 gradually increases, and pulse numbers p5 to p10 indicate recording sheet feeding at a constant speed. Further, pulse numbers p10 to p14 indicate deceleration sections in which the conveyance speed of the recording sheet 5 gradually slows down. Note that in these acceleration/deceleration sections, the ratio of acceleration and deceleration is the same in the acceleration section and the deceleration section. As a result, the total time Tr required to convey the recording sheet 5 for this line feed is Tr = 2 x (t0 + t1 + t2 +
t3) + number of pulses in constant velocity section (6 in Figure 3) x t
It is represented by 4.

In this way, before the conveyance of the recording sheet 5 is started, the total amount required for conveying the recording sheet 5 is determined based on the number of pulses for rotationally driving the recording sheet conveyance motor 27 and the width of each of these pulses. The transport time Tr is calculated and the total value Tr is stored in the RAM 113. <Description of recording sheet feeding process (FIG. 3)> FIG. 3 is a flowchart showing the recording sheet feeding process in the inkjet printer of this embodiment. A control program for executing this process is stored in the ROM 111.

This process is started by an instruction to transport the recording sheet 5, and first, in step S1, drive pulse data for the recording sheet feeding motor 27 is output to the motor driver 18. Next, the process advances to step S2 and waits for the time corresponding to this pulse width to elapse. This can be measured using the timer 112. When this time has elapsed, the process proceeds to step S3, and the pulse time width tn is subtracted from the total time Tr of the RAM 113. As a result, the remaining time for conveying the recording sheet 5 is set to Tr. In step S4, a predetermined number of drive pulses are output, and it is checked whether this recording sheet feeding process has been completed. If it has not been completed, the process returns to step S1 and the above-described process is executed.

The pulse width (tn) of each pulse signal of the recording sheet feeding motor 27 is, for example,
By storing the pulses as a table in the table, it is possible to sequentially set the pulses in the motor driver according to the order in which the pulses are output.

FIG. 4 is a flowchart showing another embodiment for determining the remaining time of the recording sheet feeding process.

[0023] Here, the timer interrupt is enabled at the same time as the conveyance of the recording sheet 5 is started, and the number of interrupts from the timer 112 is counted every time t to measure the remaining time of the recording sheet feeding process. That is, when a timer interrupt occurs in the CPU 110, the process advances to step S11, and it is determined whether this is the first interrupt immediately after the start of a recording sheet. If it is the first interrupt, do nothing and return to main processing.

If it is not the first interruption, the process advances to step S12, and the interruption period t is subtracted from the total time Tr required for transporting the recording sheet 5 in the RAM 113. This results in
By referring to this total time value Tr, the CPU 110 can determine the remaining time for the recording sheet feeding process whenever the recording sheet 5 is being conveyed. <Description of overlap operation (FIG. 6)> FIG. 6 is a flowchart for explaining the overlap operation in the printer of this embodiment.

This process is started by outputting a line feed command, and first in step S21, as explained with reference to FIG. 3, the number of pulses to drive the recording sheet feeding motor 27 during the line feed operation, From these pulse widths, the total time Tr required for transporting the recording sheet 5 is determined. Next, the process advances to step S22, and the conveyance process of the recording sheet 5 is started as shown in the flowchart of FIG. In step S23, in parallel with the conveyance process of the recording sheet 5, the total time Tr updated in step S3 of FIG. View. If the time is not substantially equal, the conveyance process for the recording sheet 5 is executed in step S22, and if the time is approximately equal to the time required for acceleration, the process proceeds from step S23 to step S24, where the rotation of the carriage motor 16 is started and acceleration of the carriage 2 is started. . When the acceleration ends in step S25, the feeding process of the recording sheet 5 has also ended, so step S26
Then, the carriage 2 is conveyed at a constant speed, and the inkjet head 1 starts recording on the recording sheet 5.

As explained above, according to this embodiment, the remaining time required for the recording sheet feeding process can be accurately calculated, so that the carriage movement start time during the overlap operation can be accurately set and efficiently carried out. Carriage conveyance processing and recording sheet conveyance processing can be performed in parallel.

[0027] The recording method used in the present invention is particularly applicable to the inkjet recording method, which uses a means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used to eject ink. This provides an excellent effect in a recording head and a recording apparatus that use the thermal energy to cause a change in the state of the ink. This is because such a system can achieve high recording speed.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It is applicable to both continuous types, but in particular, in the case of on-demand types, it is applicable to the electrothermal converter placed corresponding to the sheet holding the liquid (ink) and the liquid path. , by applying at least one drive signal corresponding to recorded information and providing a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to produce film boiling on the thermally active surface of the recording head. Let it happen,
This is effective because as a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal. Due to the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one liquid. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. No. 4,463,359 and US Pat. No. 4,345,262 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.

In addition to the configuration of the recording head that is a combination 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, , U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Patent Laid-Open No. 59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the recording head, according to the present invention, the time required for recording can be shortened and recording can be performed efficiently.

[0030] In the case of a serial type as in the above example, the recording head is fixed to the main body of the apparatus, or by being attached to the main body of the apparatus, electrical connection with the main body of the apparatus and supply of ink from the main body of the apparatus are possible. The present invention is also effective when using a replaceable chip-type recording head that allows the recording head to be replaced or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. Specifically, these are:
Capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or a different heating differential element, or a combination thereof, and ejection other than recording. It is also effective to perform a preliminary ejection mode for performing stable printing.

[0032] Also, the type and number of recording heads to be mounted. For example, in addition to a single ink corresponding to a single color ink, a plurality of inks may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode of only a mainstream color such as black, but may also include a recording head that is configured integrally or a combination of multiple colors; The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is explained as a liquid, but the ink that solidifies at room temperature or lower, and that softens or liquefies at room temperature, or the inkjet method. In general, the temperature of the ink itself is adjusted within the range of 30°C to 70°C to keep the viscosity of the ink within the stable ejection range. Any eggplant is fine. In addition, the temperature rise caused by thermal energy can be actively prevented by using the energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left standing is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, and the ink already begins to solidify by the time it reaches the recording medium.
The present invention is also applicable when using ink that is liquefied only by thermal energy. In such cases, the ink is held in a liquid or solid state in the recesses or through holes of the porous sheet, as described in JP-A-54-56847 or JP-A-60-71260. , it may also be in a form that faces the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the inkjet recording apparatus of the present invention can be used as an image output terminal of information processing equipment such as a computer, a copying machine combined with a reader, etc., and a facsimile machine having a transmitting/receiving function. It may also take a form.

As described above, this embodiment has the function of determining the speed during preparatory movement of the carriage in accordance with the degree of busyness of the equipment without substantially increasing the total recording time. This function allows some preparatory movement operations that previously operated at high speed to operate at low speed, which has the effect of reducing power consumption and reducing noise generated by carriage movement. A number of effects can be expected, including the effect of improving the sound environment by reducing noise, and the effect of extending the mechanical life of the equipment by reducing the sliding friction between the carriage and its guide shaft.

[0036]

As explained above, according to the present invention, by accurately grasping the remaining time of the recording medium conveyance process and starting conveyance of the recording head, it is possible to properly perform the overlapping operation. effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of an inkjet printer according to an embodiment.

FIG. 2 is an external view showing the configuration of a recording section of an inkjet printer according to an embodiment.

FIG. 3 is a timing chart showing an example of the conveyance timing of a recording sheet in the inkjet printer of the embodiment.

FIG. 4 is a flowchart showing recording sheet feeding processing in the inkjet printer of the embodiment.

FIG. 5 is a flowchart showing timer interrupt processing of the CPU of the inkjet printer of the embodiment.

FIG. 6 is a flowchart showing overlap processing associated with a changeover operation in the inkjet printer of this embodiment.

[Explanation of symbols]

1 Recording head 2 Carriage 5 Record sheet 16 Carriage motor 17, 18 Motor driver 27 Recording sheet feeding motor 101 Control section 110 CPU 111 ROM 112 Timer 113 RAM

Claims (4)

[Claims] 1. A printing apparatus that prints on a print medium by scanning a print head, comprising: a conveying means for conveying the recording medium; and a calculation for calculating the remaining time of the conveying operation of the recording medium by the conveying means. and a timing determining means for determining a timing to start transporting the recording head based on the remaining time, and transporting the recording medium and transporting the recording head are performed simultaneously. Recording device. 2. The calculation means calculates the remaining time of the conveyance operation by subtracting a time corresponding to the driving pulse width from the total conveyance time of the recording medium when the conveyance means drives the conveyance of the recording medium. 2. The recording device according to claim 1, wherein the recording device is configured to: 3. The printing apparatus according to claim 1, wherein the printing head is reciprocally scanned by a carriage that moves in a predetermined direction. 4. The recording head is a recording head that performs recording by generating thermal energy in an electrothermal transducer and causing film boiling in the ink. The recording device described in .