JPH0516370A - Image recorder - Google Patents

Abstract

PURPOSE:To provide an image recorder for producing a clear image with neither shear in color nor expansion and contraction. CONSTITUTION:Temperature of a drive roller 103 which drives a carrier belt 101 carrying a component to be recorded is detected with a temperature sensor 1, and a printing gap of a recording head 6 is controlled according to said temperature. When a number of the recording heads are plural (6C, 6M, 6Y, 6Bk), temperature of a head holder 610 is detected with temperature sensors (2a, 2b, 2c), and the printing gap is controlled according to an arranged gap of the head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus having functions such as a facsimile, a copying machine, a printer and the like, and an image recording apparatus used as an output device such as a multifunction machine or a workstation having these functions.

[0002]

2. Description of the Related Art Regarding an image recording apparatus, particularly an apparatus for recording an image on a cut sheet, a recording member as an object is fed from a sheet feeding section such as a sheet feeding cassette to an image discharging section through an image recording section. Although the recording material must be conveyed, one method of conveying the recording material is a method of sucking or adsorbing the recording material on an endless conveyor belt. An ink jet recording apparatus is an example of an image recording apparatus using this method.

Such an ink jet type image recording apparatus is
An optical scanner unit that converts information of the read document into an electric signal is provided, and the signal is sent to the recording head unit of the printer unit as a drive signal. Recording paper as an object is stored in the paper feeding unit, and the recording paper is conveyed one by one to the conveying device. At this time, the recording head portion supported by the head holder is moved to the printing position above the transport device. The recording paper passes between the conveyance belt and the suction roller, is adsorbed (held) on the outer peripheral surface of the belt, and is conveyed while maintaining the gap between the conveyance section and the recording head section. Is ejected and recording is performed. The plurality of recording heads are arranged at a predetermined pitch interval by the head holder, and the image recording is performed at the printing interval corresponding to the pitch interval and the transport speed of the transport device. The recording paper is sent to the tray via a fixing paper discharging unit that dries the printed image.

In the image recording apparatus having the above structure, since the recording head portion covers the entire width of the recording sheet, the recording sheet is fixed without scanning during printing, and the recording sheet only passes under the recording head. The entire image can be recorded (multi-nozzle method) and high-speed printing becomes possible.

Further, the above-mentioned conveying device is composed of a conveying belt for conveying a recording sheet, a driving roller for rotating the belt and a driven roller, and a supporting member for fixing and supporting the two rollers. The drive roller is connected to a drive motor to obtain a driving force.

[0006]

However, such a conventional example has the following problems.

That is, in the case of (1) continuous printing, the drive motor is continuously operated. In particular, when performing high-speed printing, a considerable load is involved, and as a result, the heat generated from the motor causes the temperature around the motor to rise and the driving roller is thermally deformed. In particular, the change in the roller diameter changes the transport speed of the transport belt that is rotationally driven.

(2) In the case of a recording head which ejects droplets by using thermal energy as the recording head, the temperature rises as it is used. As a result, the head holder, which is a supporting member of the recording head, is also heated and deformed. When a plurality of recording heads are arranged, the pitch interval between the heads changes due to thermal expansion.

(3) A fixing sheet discharging section is provided in front of the conveying device to dry the image after printing. A fan or a small heater is used as the drying means, and the latter is more effective in terms of time. Due to this heating, the adjacent drive rollers are affected by heat and undergo the same deformation as in (1) above.

As a result of the above, as the temperature rises, color misregistration and unexpected image expansion and contraction occur.

An object of the present invention is to solve the above problems and to provide an image recording apparatus capable of obtaining a clear image without color shift or image expansion / contraction.

[0012]

In order to achieve the above object, an embodiment of the present invention has a rotation driving member and conveys a recording member to a predetermined position; A recording head for recording an image on a member to be recorded,
It is characterized by further comprising: temperature detecting means for detecting the temperature of the rotary driving member; and control means for controlling the printing interval of the recording head according to the temperature detected by the temperature detecting means.

According to another aspect of the present invention, there is provided a rotation driving member, which conveys the recording member to a predetermined position, and performs image recording on the recording member which is being conveyed by the conveying unit and supports it. A plurality of recording heads supported by a member at predetermined intervals, a temperature detecting means for detecting the temperature of the supporting member, and an arrangement interval of the plurality of recording heads is detected based on the temperature detected by the temperature detecting means. And a control means for controlling the printing interval of the plurality of recording heads according to the arrangement interval detected by the detecting means.

[0014]

According to one embodiment of the present invention, the temperature detecting means detects the temperature of the rotation driving member which is a component of the conveying means for conveying the recording material. Then, the control unit controls the printing interval of the recording head in response to the transport speed of the transport unit that changes depending on the temperature, for example. Thus, a clear image can be obtained by controlling / correcting the printing interval.

According to another aspect of the present invention, the temperature of the support member that supports the plurality of recording heads is detected by the temperature detecting means. Then, the intervals between the plurality of recording heads are detected based on the temperature calculation processing. And
The printing intervals of the plurality of recording heads are controlled according to the arrangement intervals of the plurality of recording heads.

Thus, it is possible to obtain a clear image without color shift or image expansion / contraction.

[0017]

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

FIG. 1 shows an image recording device 60 as a device body.
0 is an example. In the figure, reference numeral 601 denotes an optical scanner unit that converts the information of the read document 600 a into an electric signal, which is the recording head unit 6 of the printer unit 602.
05 as a drive signal. A recording sheet (not shown) as an object is stored in the sheet feeding unit 603,
The sheets are conveyed one by one to the conveying device 604. At this time, the recording head unit 605 supported by the head holder 610 is moved to the printing position above the transport device 604. The recording paper passes between the conveyor belt 101 and the suction roller 609,
The conveyance unit 6 is attracted (held) to the outer peripheral surface of the belt 101.
04 and the recording head unit 605 while being conveyed while maintaining a gap D, the recording heads 6C, 6M, 6Y and 6Bk
Ink of each color is ejected from the printer to perform recording. And
The head holder 610 allows a plurality of recording heads 6C, 6
M, 6Y, and 6Bk are arranged at a predetermined pitch interval, and image recording is performed at a printing interval corresponding to the pitch interval and the transport speed of the transport device 604. Where the gap D is generally
Is set to 1 mm or less. The recording paper is passed through a fixing paper discharging unit 607 which dries the printed image, and then a tray 608.
Sent on. In addition, 606 is a recovery cap portion,
The recording head portion 605 is indicated by a chain double-dashed line in the figure.
It has a function of moving to the position of 5'and maintaining the printable state there.

In the image recording apparatus 600 having the above structure, since the recording head portion 605 covers the entire width of the recording paper, the recording paper is fixed during the printing without requiring the scanning operation, and the recording paper is below the recording heads 6C to 6Bk. The entire image can be recorded only by passing through (multi-nozzle method), and high-speed printing becomes possible.

A recording head applied to an ink jet recording apparatus generally has a fine liquid discharge port (orifice), a liquid flow path and an energy acting portion provided in a part of the liquid flow passage, and a liquid in the acting portion. It comprises energy generating means for generating the droplet forming energy to act.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or an electromagnetic wave such as a laser is radiated so that the liquid there absorbs the heat to generate heat. There are a recording method using an energy generating means for discharging and flying droplets by the action of heat generation, a recording method using an energy generating means for heating the liquid by an electrothermal converter, and discharging the liquid. Particularly in a recording head used in an inkjet recording method in which a liquid is ejected by thermal energy, liquid ejection ports (orifices) for ejecting recording liquid droplets to form flying liquid droplets may be arranged at high density. Therefore, it is possible to record high resolution.

The above-described transport device 604 includes a transport belt 101 for transporting a recording sheet, a driving roller 103 and a driven roller 104 for rotationally driving the belt 101, and a support member for fixedly supporting the two rollers 103, 104. And 105. The drive roller 103 is connected to a drive motor to obtain a driving force.

Next, referring to FIG. 2, an embodiment of the present invention will be described for the case where there is one recording head. In the figure, the same functional parts as those in the example using a plurality of recording heads described above are designated by the same reference numerals to avoid redundant description. 6 is a recording head for printing, 610 is a head holder for supporting the recording head 6, and the recording head 6 and the head holder 610 are collectively referred to as a recording head portion 605. The conveyor belt 102 on which the recording paper is placed and conveyed is driven by the driving roller 103 directly connected to the driving motor 107, and the driving roller 10 is driven.
3 and the driven roller 104 which is arranged in parallel and opposite to each other,
It is hung around. The drive motor 107 drives the drive roller 103 at a constant rotation speed. Drive roller 1
03 and the driven roller 104 are fixedly supported, a pair of side plates 105 as a supporting member is provided between the drive roller 103 and the driven roller 104. 106
Is a platen as a belt guide member, and rubs against the inner peripheral surface of the conveyor belt 102.

Reference numeral 108 denotes the recording head 6 and the conveyor belt 102.
The pins are abutted against the head holder 610 in order to keep the gap between them constant, and two pins (four pins in total) are provided on the front and rear portions of the platen 106. Reference numeral 1 denotes a first temperature sensor provided on the driving roller 103, which can use, for example, a thermistor or a thermocouple.
Detects the temperature of. The temperature sensor 1 calculates and controls an appropriate print interval of the recording head 6 according to the detected temperature.
Is connected to the control circuit 200 (see FIG. 3). The signal from the first control circuit 200 is synchronized with the image drawing position of the recording paper conveyed to the printing position (immediately below the recording head).

The first temperature sensor 1 and the first control circuit 200 will be described in detail below with reference to FIG. 3 showing a control system block. In FIG. 3, 110a and 110b are a pair of registration rollers for aligning the leading edge of the recording paper and correcting skew feeding, 111 is a pair of registration rollers 110a,
The detection sensor detects that the leading edge of the recording paper has reached the nip portion 110b.

The operation of this embodiment having the above configuration will be described. After the leading end of the fed recording paper reaches the nip portion of the registration roller pair 110a, 110b that is stopped,
The recording paper is further sent out by a rear conveyance roller (not shown) for some time, and the recording paper forms a loop by that amount. By the loop force at this time, the above-mentioned tip registration and skew correction are performed. Next, the registration roller pair 11
0a and 110b start rotating, and the recording paper is conveyed by the conveyor belt 1.
01 sent up. Registration roller pair 110a, 1
The rotation of 10b starts after a preset time period after the detection sensor 111 detects the leading edge of the recording paper. The recording paper sent out onto the conveyor belt 101 is brought into close contact with the surface of the conveyor belt 101 sequentially from its tip end by electrostatic attraction, passes directly under the recording head 6, and printing is performed. The printing interval of the recording head 6 is preset for a certain temperature of the driving roller 103. Here, the conveyance speed of the conveyance belt 101 is the registration roller pair 110a, 110.
It is slightly faster than the feeding speed of b, the electrostatic attraction force is stronger than the gripping force of the pair of registration rollers 110a and 110b, and the feeding speed of the recording paper is governed by the feeding speed of the feeding belt 101. The signal from the sensor 111 is the synchronous circuit 21.
The print head 6 sends a print start signal and an image information signal to the recording paper, which is sent to 0 and timed by the pair of registration rollers 110a and 110b. At this time, the first temperature sensor 1 detects the temperature of the drive roller 103, and the detected temperature is sent to the control circuit 200. Therefore, a change in the conveyance speed of the conveyor belt 101 due to a change in the diameter of the driving roller 103 is calculated, and the preset print interval is corrected to the print interval of the recording head 6 in response to the change in the transfer speed. A control signal is sent to the signal from the synchronizing circuit and is sent to the recording head 6 to control the printing interval.

The above is the print interval control during the image recording operation. Only the conveying device 604 is driven before the image recording, the temperature of the driving roller 103 at this time is detected, and the printing is performed in advance before the image recording. The interval may be controlled.

Next, referring to FIG. 4, an embodiment in which a plurality of recording heads are arranged will be described. 6 in the figure
C, 6M, 6Y, and 6Bk are recording heads for printing cyan, magenta, yellow, and black colors, respectively, as described above, and the arrangement intervals and printing intervals of the respective color recording heads are preset at predetermined temperatures. 610 is a head holder that integrally supports four recording heads 6C, 6M, 6Y and 6Bk, and 2a, 2b and 2c are recording heads 6C and 6M, 6M and 6Y and 6 in the head holder 610, respectively.
It is a second temperature sensor placed between Y and 6Bk. The temperature between the recording heads of the head holder 610 is detected by the second temperature sensors 2a, 2b and 2c.

FIG. 5 shows a block diagram of the control system. The relationship between the first control circuit 200 and the synchronizing circuit 210 is the same as that described in the previous embodiment with reference to FIG. 3 and duplicate description is avoided, but the recording head 6C is first controlled. next,
The temperature between the recording heads 6C and 6M of the head holder 610 is detected by the temperature sensor 2a, and the distance between the recording heads 6C and 6M due to this temperature is detected by the detection circuit 2A. In accordance with the interval detected here, the second control circuit 220 corrects the print interval of the recording head 6C in response to the print interval control from the first control circuit 200, and the print interval between the recording heads 6C and 6M is Controlled. Similarly, the second control circuit 220 corrects the print interval of the recording head 6M and controls the print interval between the recording heads 6M and 6Y according to the interval detected by the detection circuit 2B. Further, similarly, the printing interval of the recording head 6Y is corrected according to the detection interval of the detection circuit 2C, and the printing interval between the recording heads 6Y and 6Bk is controlled. Providing such control means is effective when a plurality of recording heads of respective colors are required for a color image.

(Others) 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. 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. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening 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 straight 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.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

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 or 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 because 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 or 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 method, it is common to control the temperature of the ink itself within the range of 30 ° C. or more and 70 ° C. or less 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 of the ink from the solid state 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 thermal energy such as ink that is liquefied by applying thermal 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 information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and further a facsimile apparatus having a transmission / reception function. It may be a form or the like.

[0039]

As is apparent from the above description, according to the first aspect of the present invention, the temperature of the rotation driving member of the conveying means for conveying the recording member to the predetermined position is detected and the detected temperature is detected. Since the print interval of the recording head is controlled according to this, the print interval corresponding to the change of the diameter of the rotary drive member that changes with the temperature of the equipment member and the environmental temperature, and by extension, the speed of the transport member driven by the rotary drive member. The image recording is carried out in, and a clear image without expansion and contraction of the image can be obtained.

Further, according to the second aspect of the present invention, the temperatures of the supporting members of the plurality of recording heads are detected, and the printing intervals of the plurality of recording heads are controlled according to the arrangement intervals of the plurality of recording heads. Therefore, it is possible to obtain a clear image without color shift or image expansion / contraction.

[Brief description of drawings]

FIG. 1 is a side view showing an image recording apparatus according to an embodiment of the present invention.

FIG. 2 is a side view showing the main part of the embodiment of the present invention, in the case of a single recording head.

FIG. 3 is a block diagram showing a control system of the embodiment of FIG.

FIG. 4 is a side view showing the main part of the embodiment of the present invention, in the case of a plurality of recording heads.

5 is a block diagram showing a control system of the embodiment of FIG.

[Explanation of symbols]

1st temperature sensor 2a, 2b, 2c Second temperature sensor 6 (6C, 6M, 6Y, 6Bk) recording head 101 conveyor belt 103 drive roller 610 head holder

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masatoshi Imai             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Masaharu Nemura             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation

Claims (4)

[Claims] 1. A transporting means for transporting a recording target member to a predetermined position, which has a rotation driving member, a recording head for recording an image on a recording target member being transported by the transporting means, and a rotation driving member of the rotation driving member. An image recording apparatus comprising: a temperature detecting unit that detects a temperature; and a control unit that controls a printing interval of the recording head according to the temperature detected by the temperature detecting unit. 2. The image recording apparatus according to claim 1, wherein the recording head uses the thermal energy to generate bubbles in the ink, and ejects the ink as the bubbles are generated. 3. Conveying means for conveying a recording medium to a predetermined position, which has a rotation driving member, and image recording on the recording medium being conveyed by the conveying mechanism, and the recording medium is separated from the supporting member by a predetermined distance. A plurality of supported recording heads; a temperature detecting means for detecting the temperature of the supporting member; a detecting means for detecting the arrangement interval of the plurality of recording heads based on the temperature detected by the temperature detecting means; An image recording apparatus, comprising: a control unit that controls a printing interval of the plurality of recording heads in accordance with an arrangement interval detected by the unit. 4. The image recording apparatus according to claim 3, wherein the recording head uses the thermal energy to generate bubbles in the ink and ejects the ink as the bubbles are generated.