JPH0740573A - Printing device - Google Patents

Abstract

PURPOSE:To prevent erroneous operation which occurs due to rise of temperature and prevent a user from determining a breakdown by a printing device wherein all printings are performed when temperature of a thermal head reaches a first temperature and a normal printing is stopped till below the first temperature when the temperature of the head reaches a second temperature higher than the first temperature at completion of the printing and generates damage in the head and erroneous operation. CONSTITUTION:When there is an output T1 from a temperature sensor 12, a printing of a page which is under printing presently ends. When there is not an image data of a next page, the printing ends as it is. When there is the image data of the next page and there is not an output T2 from the sensor 12, reading of the image data of the next page starts and printing operation for the next page follows. As time elapses until a thermal head starts the printing of the next page and the temperature of the head lowers, stopping of the printing is unnecessary. When there is the output T2 from the sensor 12, as there are erroneous operation and inside damage of the head, a CPU 8 does not read out the image data of the next page from an image memory 11 until the temperature lowers and the output T1 from the sensor 12 runs out, and stops printing operation of a recording section K.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus which employs a thermal recording system or a thermal transfer system.

[0002]

2. Description of the Related Art In printers of word processors, personal computers, facsimile machines and the like, a thermal recording type printing device or a thermal transfer type printing device using a thermal head is generally adopted.

[0003]

Since the thermal head prints due to heat generation, there is a problem that when a document with many black portions is printed, the temperature rises, causing damage to internal parts and malfunction. The present invention solves the above problems,
It is an object of the present invention to provide a printing device which does not cause a malfunction even if the temperature of the thermal head rises and is not judged as a failure by the user.

[0004]

In order to achieve the above-mentioned object, the printing apparatus of the present invention can normally operate the temperature of the thermal head for the printing of about one page. When the temperature reaches the first temperature, the page being printed is printed. After all pages have been printed, and the temperature of the thermal head is higher than the first temperature at the end of printing of the page, and the temperature has reached the second temperature that may cause internal damage or malfunction of the thermal head, It is characterized in that normal printing is stopped until the temperature of the head becomes equal to or lower than the first temperature.

[0005]

According to the printing apparatus of the present invention having the above-described structure, when the thermal head reaches the first temperature at which printing can normally be performed for about one page, all the pages being printed are printed, and the printing of the page is performed. At the end, if the temperature reaches a second temperature which is higher than the first temperature and may cause internal damage or malfunction of the thermal head, normal printing is stopped until the temperature of the thermal head becomes equal to or lower than the first temperature.

That is, even if the temperature of the thermal head rises, printing of at least the page being printed is completed. At the end of printing, if the temperature of the thermal head has risen to the extent that internal damage or malfunction may occur, that is, if the temperature has reached the second temperature, printing is not performed immediately and the first temperature Normal printing is resumed when the following occurs.

Usually, when printing a plurality of pages, printing is stopped for a certain period of time between pages, so in many cases the temperature of the thermal head drops during that time, and printing of the next page is performed normally. However, if the temperature of the thermal head has risen above the second temperature at the end of printing on that page, normal printing cannot be guaranteed even if the temperature drops during the stoppage time between pages, so printing on the next page may not start. However, at least only the printing of the page is guaranteed, and the occurrence of troubles such as interruption of printing in the middle of the page can be suppressed. Even in the normal case, the printing is stopped for a while between pages, so that even in this case, it does not look unnatural to the user and it is not mistakenly judged as a failure.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a facsimile apparatus F to which a recording apparatus according to an embodiment of the present invention is applied. Reference numeral 1 denotes a box-shaped device case made of resin, and a recording paper P using heat-sensitive roll paper is rotatably supported by a main frame f provided inside the device case 1. A recording unit K for printing recording is provided along the conveyance direction of the recording paper P indicated by the one-dot chain line arrow in the figure. A document reading unit R is provided from the upper part of the apparatus F to the front part (left side in the drawing). On the upper part of the device case 1, there is provided a key operation unit 13 including communication keys, ten keys, a copy key and the like necessary for operating the device.

The document reading section R includes a document guide 6, a contact image sensor 4 for reading an image on the document D indicated by a two-dot chain line arrow in the drawing, and the document D on the contact image sensor 4.
The platen roller 5 is configured to convey the sheets in close contact with each other. The document guide 6 is rotatable via a hinge h,
It also serves as a lid for the document insertion port 6a. At the time of transmission, the document D is inserted through the document guide 6 which is in a one-dot chain line state.
The front end from a is in close contact with the platen roller 5 and the image sensor 4
Insert until it hits the contact part of.

When the reading is started, the document D is conveyed to the contact image sensor 4 by the platen roller 5 in a contact state. The contact image sensor 4 converts the image on the document D into image data which is an electric signal. The read image data is then sent to the communication partner device via the telephone line L or sent to the recording unit K for copying.

The recording unit K comprises a thermal head 2 for performing thermal recording, a platen roller 3 for positively rotating and conveying the recording paper P in close contact with the thermal head 2, and a document tray.
Based on the image data sent from the communication partner via the telephone line L or the image data read by the document reading unit R (during copying), the thermal head 2 prints on the recording paper P.
Thermal recording is performed on the sheet, and the sheet is ejected onto the original tray by the platen roller 3.

Next, the circuit configuration of this embodiment will be described. FIG. 2 is a block diagram showing the circuit configuration of the facsimile apparatus F. A read only memory (ROM) 9 and a random access memory (RAM) are provided to the CPU 8 (main control unit) that outputs a control signal to each circuit and controls the operation of the entire apparatus.
10, an image memory 11 for accumulating received image data or read image data, the document reading section R, the recording section K, the key operation section 13, the transmitting / receiving section 14, the temperature sensor 1.
2 are connected.

The ROM 9 stores fixed data such as programs required for control, and the RAM 10 temporarily stores various data required for control.

The transmission / reception unit 14 controls a network connection (NCU) 18, a tone signal generation circuit 15 for generating a tone signal such as a CNG signal, a 16 Hz call signal transmitted through a telephone line L, and a CNG. Tone signal detection circuit 17 for detecting tone signals such as signals and CED signals,
Modem 16 for modulating and demodulating image data and protocol signals
Consists of.

The temperature sensor 12 is provided in the thermal head 2 of the recording unit, and the temperature of the thermal head 2 is higher than the first temperature, that is, the temperature in the normal state, but normal printing is possible if printing is about one page. Output T1 when the temperature reaches
Is input to the CPU 8. Further, when the temperature reaches the second temperature, that is, the temperature at which the thermal head 2 may malfunction or be damaged internally when the temperature becomes higher than the second temperature, the detection output T2 is input to the CPU 8 together with T1.

Next, the operation control by the CPU 8 of this embodiment will be described with reference to the flowchart of FIG. This flowchart shows the case of memory reception. All the image data received from the communication partner via the telephone line L is temporarily stored in the image memory 11. When the accumulation is completed, C
The PU 8 reads the received image data from the image memory 11 and causes the recording unit K to start printing. In the recording unit K, the platen roller 3 rotates and the thermal head 2 starts printing based on the read image data (step S1). If there is no T1 output from the temperature sensor 12 during printing, the printing is terminated (steps S2, S).
3).

If there is T1 output from the temperature sensor 12, the printing of the page currently being printed is completed (step S4),
If there is no image data for the next page (step S5), printing ends. If there is image data for the next page and there is no T2 output from the temperature sensor 12 (step S6), the reading of the image data for the next page is started, and the operation proceeds to the printing operation for the next page (step S9), step S2. Return to. This is because there is no need to stop printing because a certain amount of time elapses before the thermal head 2 actually starts printing the next page and the temperature of the thermal head 2 drops to some extent during that time.

When there is T2 output from the temperature sensor 12, there is a risk of malfunction or internal damage of the thermal head 2. Therefore, the CPU 8 reads from the image memory 11 until the temperature drops and the T1 output from the temperature sensor 12 disappears. The printing operation of the recording unit K is stopped without reading the image data of the next page (steps S7 and S8).

In the above-mentioned flow chart, only the case of the memory reception is described, but the same control is performed at the time of copying, and the image on the original is once read as image data, stored in the memory, and then printed. In this case, it is determined in steps S6 and S7 whether the next page is read from the image memory. In the case of a normal copy, it is printed almost at the same time as it is read by the document reading unit R, but whether or not the document of the next page set by the document reading unit R is read is determined in S6 and S7.

By controlling as described above, even if the temperature of the thermal head 2 rises to the first temperature during printing, at least printing of the page being printed is guaranteed. Furthermore,
If the thermal head 2 has not reached the second temperature after printing of the page being printed, the printing operation of the next page is started. In this case, since it takes time to access the image memory 11 and to feed the recording paper by the platen roller 3 from the start of the printing operation to the time when the thermal head 2 actually starts printing, the temperature of the thermal head 2 is increased during that time. This is because it will be lowered and printing will not be hindered.

If the temperature of the thermal head 2 has reached the second temperature after the printing of the page being printed, the printing is stopped until the temperature falls below the first temperature in order to prevent malfunction and internal damage. . At this time, instead of stopping the printing, the temperature of the heating element of the thermal head may be lowered than usual to perform printing with a lower printing density. The above embodiment is for the case of the memory reception, but in the case of the normal reception, the MCF signal (message confirmation) sent from the reception side to the transmission side to notify the completion of reception of one page in the handshake between pages. By delaying the transmission timing of (signal), it is possible to delay the transmission of the image data of the next page from the transmission side and wait for the temperature of the thermal head 2 to drop.

Although the above embodiment is embodied as a recording unit of a facsimile apparatus, the printing apparatus of the present invention may use a thermal recording method using the thermal head 2 or a thermal transfer recording method as a printing method. It can also be embodied as a personal computer, a word processor printer, or the like.

[0023]

As described above, according to the printing apparatus of the present invention, even if the temperature of the thermal head rises to some extent during printing, printing of the page being printed is guaranteed, and printing is interrupted in the middle of the page. Trouble can be prevented. The temperature rises further,
When there is a risk of malfunction of the thermal head or internal damage, the normal printing of the next page is not started until the temperature drops, but even in the normal case, printing is stopped between pages, so the user is not judged to be a failure.

[Brief description of drawings]

FIG. 1 is a sectional view of a facsimile device F to which a printing device according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a circuit configuration of a facsimile device F.

FIG. 3 is a flowchart showing a control procedure of a printing operation of the facsimile device F.

[Explanation of symbols]

 1 Equipment Case 2 Thermal Head 3 Platen Roller 8 CPU 11 Image Memory 12 Temperature Sensor

Claims (1)

[Claims] 1. When the temperature of the thermal head reaches a first temperature at which printing can normally be performed if printing is about one page, all the pages being printed are printed, and at the end of printing of the page, the temperature of the thermal head is If the temperature exceeds the first temperature and reaches the second temperature that may cause damage or malfunction in the thermal head, normal printing is stopped until the temperature of the thermal head falls below the first temperature. Printing device.