JPS6347178A - Recorder - Google Patents

Abstract

PURPOSE:To maintain normal sheet feeding and recording quality even under a high humidity environment, by increasing the temperature of a platen stopper for contacting a sheet tightly with a platen at the upstream side of a recording head when the humidity exceeds over a setting level. CONSTITUTION:A platen stopper 12 at the upstream side (inlet side) of a recording head 5 is constituted with a freely rotatable driven roller, while a platen stopper 13 at the downstream side (outlet side) is constituted with a roller being driven with a slightly circumferential speed higher than that of a platen 2 so as to apply tensile force onto a sheet 1. The platen stopper 12 at the upstream side is provided with a heating means (heater) for increasing the circumferential face temperature, where the circumferential face temperature of the platen stopper 12 is set to 45-70 deg.C, for example, and the sheet 1 containing moisture is pressure heated between the platen 2 so as to dry the sheet and feed to a recording section. For the purpose of dehumidification of the sheet 1, automatic control may be started by a humidity sensor in the recorder only when the humidity is higher than a predetermined level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a recording apparatus equipped with a platen for backing up sheets.

[Conventional technology]

Recording devices such as printers, image creation machines, typewriters, and facsimiles generally have sheets (recording media such as paper or plastic thin plates) that are fed by a sheet conveyance mechanism and held in close contact with a platen. On the other hand,
It is configured to record using a recording head.

Printing devices can be divided into inkjet type, wire dot type, thermal type, or type type, depending on the recording method.Also, depending on the type, there are serial types that perform main scanning by reciprocating the recording head in a direction perpendicular to the line feed. The printing method can be divided into a line printing method, which records one line at a time, and a page printing method, which records one page at a time.

In addition to cut sheets cut into predetermined dimensions, continuous sheets such as roll sheets and fan-hold sheets are used as the sheets.

Conventionally, when this type of recording device is used in a high-humidity environment, the recording sheet absorbs moisture and becomes soft, causing wrinkles on the sheet and sheet jams during recording operations. Therefore, there is a problem in that normal sheet feeding becomes difficult.

Further, there was also the problem that the moisture content of the sheet increased, causing spots and smudges in the printed state, making it impossible to obtain normal recording quality.

Therefore, it has been difficult to use conventional recording devices in high humidity environments.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus that can solve the problems of the prior art described above and maintain normal sheet feeding and recording quality even in a high-humidity environment.

[Means to achieve the purpose]

The present invention provides a printing apparatus configured such that a printing head performs printing on a sheet that is fed in close contact with a platen, in which a platen presser is disposed upstream of the printing head so as to bring the sheet into close contact with the platen. The above object is achieved by providing a heating means for increasing the temperature.

In the above configuration, it is preferable that the heating means is activated when the humidity sensor detects that the humidity is higher than a set level.

[Example] 7 Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 4 shows a schematic configuration of a serial recording device suitable for implementing the present invention.

In FIG. 4, a guide rail 3 is installed parallel to the platen 2 in front of the platen 2 for backing up a sheet (recording medium such as paper or a thin plastic plate), and a recording head 5 is mounted on a carriage 4 that moves along the guide rail. is installed. In this way, by controlling and driving the carriage 4, the recording head 5 is configured to perform recording while main-scanning the sheet 1.

The illustrated platen 2 has a roller shape and also serves as a feed roller that conveys the sheet 1 in the line feeding direction.

In the illustrated example, the position of the carriage 4 is controlled by a drive system consisting of a carriage motor 6, a drive pulley 7, a driven pulley 8, and a timing belt 9 stretched around these pulleys.

FIG. 4 shows an example of a thermal recording device using a thermal transfer method, in which a plurality of (
For example, a printing means is provided in which electrothermal transducers (eg, 24 or 32 dots) of electrothermal transducers (heating resistor elements, etc.) are arranged in one or more vertical rows.

Furthermore, a ribbon cassette 11 for feeding the ink ribbon 10 between the recording head 5 and the sheet 1 is replaceably mounted on the carriage 4. During recording, the recording head 5 feeds the ink ribbon 10. The carriage 4 is moved in the direction of the arrow P, and while the ink ribbon 10 is fed at the same speed, a predetermined dot pattern is created by driving the printing means of the recording head 5 based on the data. will be recorded.

FIG. 1 shows a cross section of a main part of a recording apparatus according to an embodiment of the present invention.

In FIG. 1, the recording apparatus is configured so that a recording head 5 records on a sheet 1 that is conveyed in close contact with a roller-type platen 2. At desired positions on the upstream side and downstream side of the recording head 5 on the circumferential surface of the platen 2, platen pressers 12 and 13 are arranged for pressing the sheet 1 against the circumferential surface of the platen to bring it into close contact.

In the illustrated example, the platen 2 is composed of a platen roller that also serves as a sheet feeding roller, and by driving in the direction of arrow A, the sheet 1 is fed in the direction of arrow S.

The platen holder 12 on the upstream side of the recording head 5 has a function of guiding the sheet 1 to be fed into the area of the recording head 5, and the platen holder 13 on the downstream side has a function of pulling out the sheet 1 from the recording section. .

Therefore, the upstream side (inlet side) platen presser 12 is composed of a freely rotating driven roller, and the downstream side (exit side)
The platen presser 13 is composed of a roller driven at a circumferential speed slightly higher than the circumferential speed of the platen 2 in order to apply tension to the sheet 1.

However, the upstream platen holder I2 is provided with a heating means (heater) for increasing the temperature of its peripheral surface.

That is, by turning on the heating means and raising the peripheral surface temperature of the platen holder 12 (for example, 45 to 70° C.), the sheet 1 containing moisture is heated under pressure between it and the platen 2, and the sheet is heated. It is configured to be dried and sent to the recording section.

As the heating means, a heater that is always turned on during the recording operation or a heater that is turned on manually by the user can be used, but since the purpose is to dehumidify the sheet 1, a humidity sensor that detects humidity may be used in the recording device. Attach the
It is also possible to use a heater that is automatically controlled to turn on only when the humidity is above a predetermined value.

Figure 2 shows the humidity sensor turning on the heating means (heater).
FIG. 3 is a block diagram showing a control system when performing off control.

In FIG. 2, a signal indicating the value of environmental humidity detected by a humidity sensor 21 is transmitted to a control section 22, which determines whether the humidity is higher or lower than a set value (reference value).

When the humidity is lower than the set value, the controller 22 outputs an off signal to the heater power source 23, and no power is output through the output line 25 from the heater power source to the heater (heating means) 24. Therefore, the peripheral surface of the platen holder 12 (FIG. 1) is not heated, and the sheet 1 is fed as is and recorded without being dehumidified.

When the humidity is higher than the set value, the control section 22 determines this based on the signal from the humidity sensor 21, and the control section outputs a signal to turn on the heater power source 23. As a result, electric power is output to the heater 24 through the output line 25 of the heater power source 23, and the heater is heated (turned on).

In this state, the peripheral surface of the platen holder 12 (Fig. 1) is heated and the temperature has risen, so the sheet 12 that has absorbed moisture
is heated and pressurized between the platen presser 12 and the platen 2, and normal printing is performed by the recording head 5 on the dehumidified sheet 1.

FIG. 3 is a flowchart showing the operation of the control system shown in FIG.

In FIG. 3, when recording is started in step 100, the ambient humidity is detected by the humidity sensor +- 21 in step 101, and a humidity signal is transmitted to the control section 22.

In step 102, the humidity is set to a set value (
For example, if it is higher or lower than 60%), if it is higher than that, proceed to step 103, turn on the heater power supply 23, heat the platen presser 12, and record the sheet 1 in step 104 while feeding the sheet 1 in this state. go.

If the control unit 22 determines that the humidity is low in step 102, the process proceeds to step 105, turns off the heater power supply 23, and in this state, while feeding the sheet 1,
Record it with 04.

After recording in step 104, the process returns to step 101, and recording (printing) is continued while repeating the above operations at regular intervals.

In this way, by heating the platen holder 12 when the humidity is high, the sheet 1 sent to the recording section can be heated and pressurized to dehumidify it.
Normal printing (recording) could be easily achieved without wrinkles or jams on the sheet 1, and without stains or smudges on the print.

Although the illustrated embodiment shows a case in which the platen 2 is a rotary type that also serves as a sheet feeding roller, the present invention can be similarly implemented in the case of a fixed type platen.

Further, in the above embodiment, the platen holders 12 and 13 are rollers, but these platen holders can also be constructed of a member such as a leaf spring or a rod-shaped member that is slidably pressed against the platen 2. .

Furthermore, the present invention is applicable regardless of the recording method such as wire dot type, inkjet type or thermal type (including thermal transfer type and thermal type), and regardless of the type of recording device such as serial type, line print type or page print type. , can be widely applied to various recording devices.

In addition, the shape of the recording medium, such as cut sheets and continuous sheets (roll paper, fan-hold paper, etc.),
It can be widely implemented regardless of the material.

〔effect〕

As is clear from the above description, according to the present invention, it is possible to obtain a recording apparatus that can perform normal recording even in a high humidity environment with a simple configuration that includes a platen holder that is heated by a heating means.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view of a main part of an embodiment of a recording apparatus according to the present invention, FIG. 2 is a block diagram of a control system of a heating means of the recording apparatus of FIG. 1, and FIG. FIG. 4 is a flowchart showing the operation procedure of the control system of FIG. 1--------Sheet, 2--------Platen, 5------- Recording head, 12--
−−−−−−−−−Platen holder, 21−−−−−−−
Humidity sensor, 24-・-------・--heating means (heater>), 5---------1.-Sheet feeding direction. Agent: Patent attorney, Yasushi Ooto, Takeko 2

Claims (2)

[Claims] (1) In a recording apparatus configured to use a recording head to record on a sheet that is fed in close contact with a platen, the temperature of a platen presser located upstream of the recording head so as to bring the sheet in close contact with the platen. A recording device comprising heating means for raising the temperature. (2) The recording device according to claim 1, wherein the heating means is activated when a humidity sensor detects that the humidity is higher than a set level.