JP2844576B2 - Recording method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method and apparatus for performing intermittent recording in a state where a recording cycle for each line is not constant, such as a recording apparatus such as a facsimile apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, in a thermal recording apparatus which performs recording by a thermal line head which performs recording for each line,
The energy (main heat) applied to the thermal head is controlled according to the recording cycle for each line. That is, when the recording cycle is short, the applied energy to the thermal head is reduced in consideration of the heat storage of the thermal head, and when the recording cycle is long and the thermal head is cooled, the applied energy to the thermal head is increased. I try to keep a record.

[0003]

However, in the prior art, the control of the applied energy is controlled by the pulse width of the main heat of the thermal head which actually performs the recording. Since it affects the speed, it cannot be made longer than a predetermined time. Further, after recording of one line, by applying an applied energy smaller than that of the main heat to the thermal head and performing an after heat for preventing the temperature from lowering, the temperature of the substrate of the thermal head can be kept almost constant. But,
The actual temperature of the heating resistor decreases as the recording interval increases. For this reason, if the recording interval becomes longer, the temperature of the heat-generating low antibody of the thermal head at the time of the next recording decreases, and the recording density of the line decreases. As described above, there is a problem that even if the pulse width of the main heat is controlled and the temperature of the thermal head is controlled by the after heat, the density unevenness of the image cannot be completely solved. .

The present invention has been made in view of the above conventional example, and has as its object to provide a recording method and apparatus capable of recording with a substantially constant recording density even when the recording cycle varies.

[0005]

In order to achieve the above object, a recording apparatus according to the present invention has the following arrangement. That is, a recording apparatus for recording an image on a recording medium by energizing the recording element of the recording head, and for causing the recording element of the recording head to generate heat with a smaller applied energy amount than at the time of recording immediately before actual image recording. Preheating means, heating means for applying a smaller energy to the recording element than at the time of recording at predetermined time intervals from the end of recording to the start of the next recording, and keeping the recording head warm, and the recording element by the heating means And an adjusting means for adjusting the amount of energy applied by the preheating means according to the driving amount determined by the determining means.

In order to achieve the above object, the recording method of the present invention has the following arrangement. That is, this is a recording method in which an image is recorded on a recording medium by energizing a recording element of a recording head, and a step of measuring a recording time interval from a previous recording to a next recording is performed. When the recording element is longer than the predetermined time, the applied energy to the recording element is made smaller than that at the time of recording to drive the recording element, and the recording element is applied to the recording element immediately before the start of recording according to the number of times of the after-heating step. Adjusting the amount of energy.

[0007]

In the above arrangement, the recording time interval from the previous recording to the next recording is measured, and when the recording time interval is longer than a predetermined time, the energy applied to the recording element is made smaller than that in the recording. Then, the recording element is driven. The amount of energy applied to the printing element is adjusted immediately before the start of printing according to the number of times of driving.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a schematic configuration of a facsimile apparatus according to the present embodiment.

In FIG. 1, reference numeral 1 denotes a main control unit for controlling the entire apparatus, 2 denotes an operation panel provided with various function instruction keys and a numeric keypad for inputting a telephone number, and a display unit for displaying various messages to an operator. An operation / display unit provided with: A reading unit 3 photoelectrically reads a document image, converts the read document image into a digital signal, and outputs the digital signal to the main control unit 1. A communication control unit 4 controls communication with a line via a network control unit (NCU) 5. 6 is RO
A recording control unit including a one-chip microcomputer having an M, a RAM, a timer, and the like controls a recording paper transport motor 7 for transporting a recording paper 7 as a recording medium and a thermal head 8 as a recording device. The temperature of the thermal head 8 is detected by a thermistor 9.

In the above configuration, during the recording operation, the image data read by the reading unit 3 or the image data demodulated by the communication control unit 4 via the line / NCU 5 is transmitted to the thermal head 8 by the main control unit 1. To a recordable format with
Each time a line is transferred to the thermal head 8, a print command is sent to the recording control unit 6 to perform recording. In response to this, the recording control unit 6 drives the recording paper transport motor 7 to start the movement of the recording paper, and also energizes the thermal head 8 and drives it to generate heat, thereby performing one-line recording. When recording one line, in order to reduce the number of simultaneously energized dots and downsize the power supply unit, one line is usually divided into a plurality of blocks of about 2 to 8 and recording is performed by sequentially energizing each block. It is carried out. The energization time for each block is called an applied pulse width.

At the time of recording for each line, one line depends on the state of the line, the capability of the modem (modulation / demodulation unit), the complexity of the image data (the number of black / white dot inversions), the encoding form, and the sub-scanning line density. The time until the image data for the line is completed is different, and the recording cycle is random intermittent recording.

FIG. 2 is a timing chart showing a recording operation in the facsimile apparatus of this embodiment. In this FIG.
The timing when one line of the thermal head 8 is divided into four blocks for recording is shown.

In FIG. 2, T1 and T2 indicate the timing of a print command output from the main control unit 1 to the recording control unit 6. At the same time, the recording control unit 6 advances the recording paper transport motor 7 by one line. The recording paper transport motor 7 is excited for this purpose. Subsequently, the thermal head 8 is sequentially preheated (P) from the first block, and then the main heat M (recording) is performed. After the end of the main heat M, a certain interval I is counted, and the after heat A1 or A2 is performed every time the time interval I (here, about 2 ms) elapses.
The after-heat at certain time intervals is repeated at time intervals I until a print command for the next line is received.

FIG. 3 is a diagram showing an example of data of the energization time (pulse width) to the thermal head 8. This figure shows the detected temperature T of the thermistor 9 of the thermal head 8.
(° C.) and applied energy (voltage) to the thermal head 8
The time value for determining the power-on time is stored in the ROM area of the one-chip microcomputer of the recording control unit 6. In FIG. 3, M is a pulse width of a main heat for recording, P1.
P4 indicates the preheat pulse width, A indicates the afterheat pulse width, and the higher the temperature of the thermal head 8, the smaller the pulse width.

Next, the recording operation in the facsimile apparatus according to the embodiment of the present invention will be described with reference to the flowchart of FIG.

In step S1, "11" is set in an AC (after-heat counter) as an initial value of the number of after-heats at the beginning of one page, so that the pulse width of the pre-heat is maximized. This afterheat counter AC is provided in the RAM of the recording control unit 6. Next, in step S2, when a print command is received from the main control unit 1, in step S3, the recording paper transport motor 7
, The recording paper is moved by one line.
Next, in step S4, the value of AC in which the number of times of after heat is set is determined. When the value of AC is smaller than 1 (AC ≦ 1), the process proceeds to step S5, and since the elapsed time from the end of the previous recording is short, the pulse width value designated by P1, which is the shortest pulse width, is changed to the value of preheating. The pulse width is selected, and the thermal head 8 is preheated in step S9.

The value of AC is 2 or more and 4 or less (2 ≦ AC ≦
If 4), the process proceeds to step S6, where the preheating pulse width indicated by P2 is selected, while if 5 ≦ AC ≦ 10, the preheating pulse width indicated by P3 is selected in step S7. Further, if 11 ≦ AC, the elapsed time from the end of the previous recording is longer, so the longest pulse width indicated by P4 is selected as the preheat pulse width.

In step S9, the after-heat counter AC is cleared to "0" and the thermal head 8 is energized for a shorter time than during recording to preheat the thermal head. This preheating is executed at the timing indicated by P in FIG.

Next, in step S10, an image is recorded by the main heat. During the main heat, the thermal head 8 is divided into four blocks, and recording is performed by energizing each block. In step S11, it is determined whether a print command for the next line has been received. If a print command has been received, step S3
Then, the recording paper is conveyed by driving the recording paper conveyance motor 7, and the above control steps are repeated. In this case, after-heating is not performed, and since AC = 0, the process proceeds from step S4 to step S5, where pre-heating is performed with the pulse width P1.

If no print command has been received in step S11, the flow advances to step S12 to determine whether or not one-page recording has been completed. If the recording of one page is completed, the recording process is terminated. On the other hand, if the recording of one page has not been completed, the process proceeds to step S13, and the timer starts recording a recording time interval (for example, about 2 ms).

While counting the recording time interval in step S14, it is determined in step S15 whether a print command for the next line has been received within a predetermined time. When the print command is received in step S15, the process proceeds to step S16, in which the time interval of the timer is stopped, the process returns to step S3, and the recording operation of the next line is repeated.

If the timer has finished measuring the recording interval before receiving the print command of the next line in step S14 (for example, when 2 ms has elapsed in the above-described case), the process proceeds to step S17, for example, as shown in FIG. After-heat for energizing the thermal head 8 is performed for a time indicated by A. Then, in step S18, the value of AC is incremented, and in step S19, counting of the recording interval time by the timer is started again, and the process proceeds to step S15.

In step S15, it is checked whether a print command has been received. If no print command has been received, steps S14 to S14 are executed.
Repeat step 19. When a print command is received, steps S16 and S3 are executed, a preheat value corresponding to the magnitude of AC at that time is selected, and a preheat of a time width corresponding to the value of AC is executed.

Incidentally, the thermal head 8 in each of the above-mentioned heats (pre-heat, main heat, after-heat).
The width of the energization pulse to is changed by the temperature of the thermal head 8 detected by the thermistor 9. That is, as shown in FIG. 3, for example, even if P1 is selected as the preheat pulse width, the pulse width is determined as shown in FIG. 3 according to the temperature of the thermal head 8 at that time.

In this embodiment, the case of thermal recording has been described as an example. However, the present invention is also effective in the case of thermal transfer recording in which an ink sheet is conveyed and recording is performed by a thermal transfer method. Further, the present invention is also effective for recording control such as bubble jet recording in which recording is performed by driving a recording element to generate heat and eject ink droplets.

In this embodiment, the recording control unit 6 has been described to control the energization of the thermal head 8, but the main control unit 1 may perform the control.

The number of preheat pulse width tables, the pulse width of each heat, and the intervals at which after heat is performed are not limited to those in this embodiment, but can be set arbitrarily. In particular, the after-heat interval may be varied by the thermistor 9 according to the detected temperature. The data stored in the thermal head 8 at the time of preheating and afterheating may be recording data of the previous line at the time of preheating, or inverted data at the time of recording of the previous line. The recording data stored in the thermal head may be used as all black data, or the most effective data may be selected and set for the recording section in any of the preheating and the afterheating. is there.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can also be applied to a case where the present invention is achieved by supplying a system or an apparatus with a control program for executing the processing specified in the present invention.

Further, in this embodiment, the adjustment of the applied energy applied to the thermal head 8 is controlled by the length of the energizing pulse width energizing the thermal head 8, but the present invention is not limited to this. For example, the applied energy may be adjusted by changing the voltage applied to the thermal head 8.

As described above, according to this embodiment, the pulse width of the preheat before the heat for recording is determined according to the number of the afterheats after the previous line is recorded, so that the afterheat is first determined. Thus, the temperature of the thermal head can be kept constant, and preheating can be performed in accordance with the recording cycle. This enables recording with less density unevenness corresponding to heat storage and heat radiation in the heat generating element portion of the thermal head. In addition, density unevenness in one page can be reduced simultaneously with density unevenness between pages of a recorded image.

Also, if the number of after-heats is counted, the number of timers of the microcomputer of the recording control unit can be reduced, so that it is possible to compensate for the shortage of the timer. In other words, you can use an inexpensive microcomputer with low capacity,
In addition, even when the main control unit directly controls, a timer with a small frequency can be used, or an interrupt with even intervals of after heat can be used, so that the efficiency of system design is improved, and the cost of the microcomputer or CPU is reduced. Become.

[0033]

As described above, according to the present invention, there is an effect that recording can be performed with the recording density kept substantially constant even if the recording cycle varies.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a facsimile apparatus of the present embodiment.

FIG. 2 is a timing chart showing heat generation drive timing of a thermal head in the facsimile apparatus of the present embodiment.

FIG. 3 is a diagram showing a value of a current supply time to a thermal head in the facsimile apparatus of the present embodiment according to a temperature of a thermistor.

FIG. 4 is a flowchart showing a recording process of one page in the facsimile apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main control part 2 Operation / display part 3 Reading control part 4 Communication control part 5 NCU 6 Recording control part 7 Recording paper conveyance motor 8 Thermal head 9 Thermistor

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/36 B41J 2/38 B41J 2/32-2/325

Claims (2)

(57) [Claims] 1. A recording apparatus for recording an image on a recording medium by energizing a recording element of a recording head, wherein the recording element of the recording head generates heat with an applied energy smaller than that during recording immediately before actual image recording. A preheating means for causing
From the end of printing to the start of the next printing, a heating means for applying a smaller energy to the printing element than at the time of printing at predetermined time intervals to keep the print head warm, and a driving amount of the printing element by the heating means. A recording apparatus, comprising: a determination unit; and an adjustment unit configured to adjust an amount of energy applied by the preheating unit according to a driving amount determined by the determination unit. 2. A recording method for recording an image on a recording medium by energizing a recording element of a recording head, comprising: a step of measuring a recording time interval from a previous recording to a next recording.
When the recording time interval is longer than a predetermined time, the after-heating step of driving the recording element by making the applied energy to the recording element smaller than during recording, and according to the number of times of the after-heating step, Adjusting the amount of energy applied to the recording element.