JPS6012862A - Control method of facsimile equipment - Google Patents

Abstract

PURPOSE:To uniform recording density by preheating a recording head during the movement of a carriage from a home position to a recording start position at the time of recording. CONSTITUTION:A CPU40 turns on an output signal TAB of an I/O circuit 45 at first to actuate a pulse width controller 60 driving a thermal head array 9 and then output signal PSL of the circuit 45 is turned on to limit the pulse width of an output pulse from a controller 60 to a latch circuit 59. Subsequently, data heating an array 9 are stored in a shift register 58. When a controller 60 is triggered at the trailing edge of a scanning end signal EOS from a photodiode array 7 immediately after said storage, the data in the register 58 are latched by the circuit 59 and the array 9 is preheated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a control method for a so-called shuttle type facsimile apparatus during recording.

[Prior Art] Conventionally, a reading head (for example, a storage type photodiode array) has been used in which multiple light-receiving elements are arranged in a sub-scanning method for a document.
In addition, a recording head (thermal head array) in which multiple thermal recording elements are arranged in the sub-scanning method of the recording paper is mounted on the same carriage of the main scanning mechanism. A so-called shuttle type facsimile machine that performs scanning is known.

In this shuttle type facsimile machine, during recording, the recording is performed on the recording paper during the main scan, and when returning, the recording head is raised above the recording paper and returned to the home position (carriage reference position) at high speed. There is.

As mentioned above, the recording head consists of a heat-sensitive recording element, and when recording, it generates heat and colors the recording paper, so it is necessary to keep the temperature of the recording head constant in order to keep the density of the recording constant. It is. Therefore, in the past, a temperature detection element (for example, a thermistor) was attached to the recording head, and the pulse width of the recording pulse applied to the recording head was controlled by feeding back the detection output of this temperature detection element.

However, because the print head has a heat storage effect and is cooled down when returning, the temperature of the print head is higher at the end of printing than at the start of main scanning, and as a result, the print density decreases. This resulted in non-uniformity.

[Objective] The present invention solves the above-mentioned disadvantages and provides a control method for a facsimile machine that can make the recording density uniform during recording by preheating the recording head while the carriage moves from the home position to the recording start position. The purpose is to provide

[Configuration] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a facsimile device F according to an embodiment of the present invention.
It shows AX. In the figure, 1 and 2 are rollers that move the document SP in the sub-scanning direction, 3 is a roller that moves the recording paper BP in the sub-scanning direction, 4 is a step motor that drives the roller 1, and 5 is a roller that drives the roller 3. It is a step motor, and rollers 1 and 2 are interlocked by a belt 6.

7 is a photodiode array (PDA) in which 32 photodiodes are arranged in a straight line along the sub-scanning direction.
), 8 PD is the image corresponding to the reading position PR of the document sp.
The lens 9 that forms an image on A7 is a thermal radar array (THA) in which 16 thermal heads are arranged in a straight line along the sub-scanning direction and a thermistor (not shown) for temperature detection is attached. Yes, PDA7 and TI
The IA's 9 are each fixed to the carriage 12 via attachment members 10.11, and the lens 8 is likewise fixed to the carriage 12.

A timing belt 13 is connected to a leg portion 12a protruding from the lower part of the carriage 12, and this timing belt 13 meshes with a gear 15 attached to the shaft of a step motor 14. The carriage 12 also includes a facsimile machine FA.
It is guided by rails 16 and 17 installed between both side plates of X so as to be parallel to the main scanning direction of the document SP. Therefore, the carriage 12 is driven back and forth in the main scanning direction of the original SP and the recording paper RP by the step motor 14, and thereby the PDA 7 and the THA 9 main scan the original SP and the recording paper RP, respectively.

Further, 18 is a pair of photosensors for detecting the document SP;
Reference numeral 19 is a back plate for pressing the recording paper RP onto the THA 9, and 20 is a support plate for supporting the back plate 19.

In this embodiment, when the 1"IIA9 is not actually recorded on the recording paper RP, such as when the carriage 12 returns when the facsimile machine FAX performs a transmission operation or during recording (copy or reception mode), , TIIA9 is raised from the recording paper RP to prevent it from coming into contact with the recording paper RP.

FIG. 2 illustrates the control unit DP of the device according to the present invention, and as shown in the figure, in the present invention, the central processing unit (CP) 40
The control unit DP is configured using the following.

In the figure, 41 is a ROM (read-only memory) that stores processing programs, etc., which will be described later, and 42 is an RA.
M (random access memory), 43 is CPU 40
A programmable timer 44 controls the period of its output pulse P2 by dividing the reference period pulse signal outputted from the built-in crystal oscillator to generate a reference clock P1,
CPU clock CP t , PDA clock CP2 . Modem clock CPs and interrupt signal INT3 with a predetermined period
A frequency divider 45 is an input/output circuit of the CPU 40.

46 is a latch circuit that temporarily stores 8-bit transmission data, 47 is a shift register whose input/output mode changes depending on the state of its control input/output T/π, and 48 is a three-channel transistor that temporarily stores 8-bit receive m data. 1 ~ Output latch circuit, 4
9 is a counter that counts the clock CP3, and every time the H1 value exceeds 8, the output signal INT2 is changed to the old logic level and self-resets; 50 is a communication section;

This communication section 50 is composed of a modem 50a and an NCU 30b. Transmission data from the shift register 47 is added to the output terminal TD of the modem 50a, and received data is output to the shift register 47 from the output terminal RD.

Furthermore, 51, 52 and 53 are motor drive circuits that drive the step motors 4, 5 and 14, respectively.

54 outputs a start pulse Ps (see FIGS. 3(a) and 3(b)) in synchronization with the rise of the pulse signal P2, and a shift clock CPs (see FIG. 3(C)) in synchronization with the pulse signal Pi.
) and a sun ring pulse (see (e) in the same figure) synchronized with the shift clock CPs and the PDA clock CP2 (see (d) in the same figure), respectively.
Signal E output after PDA7 executes 32 shifts
A PDA clock generator that generates a PDA blank signal Pa (see (g) in the same figure) that rises in synchronization with the rising edge of the OS (see (f) in the same figure) and falls in synchronization with the fall of the pulse signal P2. be. Note that the pulse signal PR is a reset signal for the PDA 7.

The output video signal Sv of the PDA 7 is passed through the amplifier 55 to 2
After being applied to the digitization circuit 56 and binarized, it is applied to a 32-bit shift register 57, and the output of this shift register 57 is applied to the CP[I40 serial input port SI.

58 is a 16-bit shift register that temporarily stores data to be applied to TI (A9), 59 is a latch circuit including a driver that drives Tl1A9, and 60 is a latch circuit 59 that is connected to T1A9.
A pulse width controller that changes the pulse width of the pulse signal P5 that controls the driving time of the IIA 9 according to the temperature detection signal DT output from the THA 9; 64 is a resistor R1°R2 that sets the operating time constant of the pulse width controller 60;
This is an analog switch that shorts out resistor R2.

Next, an outline of the operation of the control section needle will be explained.

When reading the image of the original sp, the logic level of the signal P4 is rLJ in the initial state as shown in FIG. 3(g).
Therefore, the sampling pulse P3 is applied to the register 57 as a shift clock CP4 (see FIG. 3(j)) via the AND circuit 61 and the OR circuit 62, so that the data of the PDA 7 is sequentially stored in the shift register 57.

When 32 sampling pulses P3 are output and one scan of the PDA7 is completed, the PDA7 outputs the signal EO5.
, which causes PDA clock generator 54 to set the logic level of signal P4 to "old".

The rising edge of this signal P4 is detected at the interrupt input terminal INI of the CPU 40, and the processing of the CPU 40 shifts to the restartable interrupt processing R5T7.5, which has the first priority.
The PU 40 outputs a pulse signal P6 as shown in FIG. 3(i) from the input/output circuit 45.

The pulse signal P6 is supplied to an AND circuit 63 and an OR circuit 62.
is applied to the shift register 57 as a shift clock CP4, whereby the 32-bit data D1 stored in the shift register 57 is sequentially applied to the input terminal SI of the CPU 40.

In this embodiment, the magnification of the lens 8 described above is set so that each element of the PDA 7 decomposes the image of the document sp into 7.7 Q/mm in the sub-scanning direction, so the CPU 40 reads the 32-bit data input sequentially. The data D1 is converted into data D2 of 16 bits 1 to 16 by using the correlation between the data of the preceding and following bits, thereby effectively reducing the decomposition ring of the PDA 7 to 3.
Convert to 85 Q/na.

When the facsimile machine FAX is in the transmission mode, the CPL 140 stores data D2 at a predetermined address in a buffer area set in the RAM 42. Furthermore, when in the copy mode, the CPU 40 connects the serial data output terminal S to the serial data output terminal S every time data D2 is formed one bit at a time.
At the same time, a pulse signal P7 as shown in FIG. 3(k) is applied to the clock input terminal CK of the shift register 58 via the input/output circuit 45, and the data D2 is sequentially stored in the shift register 58. As a result, the 16-bit data row 2 is latched in the latch circuit 59 when the next signal EO5 rises, and when the signal EO3 falls, the pulse width controller 60 is triggered and the signal P
When s (see figure (ff)) is output, 1 cho 1 (A
9, an image corresponding to the 16-bit data D2 is recorded on the recording paper RP.

On the other hand, when the facsimile machine FAX is in the reception mode, the data for recording is stored in the buffer area of the RAM 42, so the CPU 40 receives a short-cycle pulse signal Py' as shown in FIG. 3(m). Pulse signal P7
Instead, 16 data are output, and the recording data D3 is stored in the shift register 58.

The step motor 14 that moves the carriage 12 in the main scanning direction is controlled as shown in FIG. 4(a) in synchronization with image reading by the PDA 7 and image recording by the THA 9. In this embodiment, as described above, the operation of the PDA 7 and THA 9 is controlled by including the drive control process of the step motor 14 in the interrupt process R5T7.5 executed by the CPU 40 at the rise of the signal P4 synchronized with the signal P2. The operation of the step motor 14 is synchronized.

For the sake of simplicity, the explanation below assumes that since the signal P4 is synchronized with the signal P2, the step motor 14 is directly excited and driven by the signal P2 actually outputted by the CPυ40.

During forward scanning of the carriage 12 from the home position, which is the standby position, to the scan end position, the CPU 40 maintains the period of the signal P2 at a constant value and operates the step motor 14 at a constant speed, that is, from time t1 to L2. The carriage 12 is moved at a constant speed.

After that, when returning the carriage 12 to the home position between time points L3 and ty, the period of the signal P2, that is, the speed of the step motor 14 is changed according to a predetermined pattern to move the carriage 12 at high speed, and perform the re-scanning. This reduces the time required.

Furthermore, before and after the forward scan, in order to reliably stop the carriage 12, the step motor 14 is stopped for a predetermined period of time, and the carriage 12 is placed in a wait state in which it does not actually move. From time t1 to t2 when the carriage 12 is actually moved
During this period, 1060 signals P2 are output, and therefore the carriage 12 is moved 1060 steps. Assuming that the main scanning dust decomposition is set to 5pe Q/-, the carriage 12 will move 212mm and will be able to handle up to A4 size paper, satisfying the Gn standard recommended by the CCITT (International Telegraph and Telephone Consultative Committee). ing.

By the way, FIGS. 4(b) to 4(h) show various flags for storing the state of movement of the carriage 12 when the CPt 140 controls the movement of the carriage 12.
A high level corresponds to a set state. These flags are set by the interrupt processing R5T7.5 described above by the CPt140.
managed within.

The dummy scan flag F [IMSC
N corresponds to both ends of the paper that are not actually read or written during main scanning (that is, dummy scan areas), and the effective screen width flag FTABUL shown in FIG. The weight flag FvAITIIE shown in FIG.
This corresponds to the above-mentioned wait state.

Through-up flag FTIIRI shown in the same figure (, 3)
JP increases the return speed of the carriage 12 from point 3 at the beginning of the return scan to point L4 (through-up), and the slew flag FSLE%l shown in FIG. Carriage 1 between 4 and L5
The through-down flag FTHRDN shown in FIG.
Corresponding to the state in which the return speed of the carriage 12 is reduced between time points 5 and 76, the constant return flag FCNSRT shown in FIG. (Same speed as forward scan) It corresponds to the state where it returns to the home position.

Note that the subscan flag FStl shown in FIG.
BSC corresponds to the state in which the sub-scan paper is fed during the salt scan described above.

The counter 4 transfers data between the communication unit 50 and the CPU 40.
9 outputs the interrupt signal INT2, CP[I40 output 1 is executed in the second priority restartable interrupt processing R5T6.5.

To explain the outline of the data transmission procedure in this interrupt processing R5T6.5, in the transmission mode, the transmission data is G II
The latch circuit sequentially stores data D2 from the first byte of the first line every time the 8-bit data stored in the shift register 47 is transferred to the modem 50a. 46 and stored in the shift register 47.

In the reception mode, conversely, the 8-bit data D3 added to the shift register 47 from the modem 50a is transferred to the latch circuit 4.
8, and sequentially writes the data into the buffer of the RAM 42 via the pass line SB starting from the first byte of the first line.

Furthermore, when the interrupt signal INT3 is applied, the CPυ40 executes the restartable interrupt process R3T5.5, which has the third priority. This interrupt process R5T5.5 is a sub-scanning process.

It consists of a plurality of processes with relatively small time constraints, such as recording paper remaining confirmation processing and paper ejection processing.

The dummy scan job DLIMSCN shown in FIG. 5 forms part of the main scanning process executed in the above-mentioned interrupt process R5T7.5, and is a job when the carriage 12 moves between both ends of the paper. .

In the figure, a scan counter 5CNCNT indicates each stage of the main scanning process (that is, the front and rear wait states).

The counter is used to control the front/rear dummy scan state, effective scan state, return state, etc.), and the step amount of the step motor 14 at each stage is preset. The flag FPRDUM is set when performing a pre-scan immediately after the start of a forward scan. Flag FPRHEX is T
This flag indicates that the preheating process of HA9 has been performed. In addition, other unexplained abbreviations (FSOR5T
, TR5TCN, etc.) are not directly related to the gist of the present invention, so their explanation will be omitted.

In addition, the signal TAB is transmitted from the input/output circuit 45 to shift 1 to register 58, from shift 1 to input terminal R (rising edge sense).
and enable input E of pulse width controller 60
N (see FIG. 2), and at the falling edge of this signal TAB, the shift register 58 is reset, and the signal TAB
The pulse width controller 60 is activated when the signal PSL is turned on and the logic level is "old". The signal PSL is applied to the analog switch 64, and when the signal PSL is turned on and the logic level is "!1" The analog switch 64 is turned on, and as a result, the time constant of the pulse width controller 60 becomes smaller, and the pulse width of its output pulse P5 becomes smaller. Note that the pulse width τ1 of the pulse P5 when the time constant is controlled to be small is set to a small value to the extent that the thermal paper (recording paper RP) does not develop color due to the TIIA9.

- Now, in the present invention, in the copy mode and at the time of reception, THA9 is preheated in the previous dummy scan immediately after the start of the forward scan, and in this case, the flag FPRDUM is set, and the In the state, scan counter 5CNC
The step amount of the step motor 14 corresponding to the width of the previous dummy scan is preset in NT.

In this state, control by the CPU 40 is started, and first, the CPU 40 switches the excitation phase of the step motor 14 in the forward rotation direction and operates it one step (process 101).After this, since the step motor 14 has moved one step, it decrements the counter 5CNCNT. Process 102), it is determined whether the flag FPRDUM is set (determination 103).

In this case, as described above, flag FPRDuM is
Therefore, the result of judgment 103 is YES, and again.

Since it is not the transmission mode, the result of judgment 104 is NO, and since the flag FPRHEX is not set in the first process of the previous dummy scan, the result of judgment 105 is NO, and the CPU 40 executes the preheat process.

That is, first, since processing from PRI-1 to PRI is performed, the flag FPRIIEX should be set (Process 106), THA, 9
Process 107) to turn on the signal TAB to operate the pulse width controller 60 that drives the pulse width controller 60, Process 108) to turn on the signal PSL to limit the pulse width of the output pulse P5 of the pulse width controller 60, and Process 109 to judgment. At part 113, 16 bits of continuous black information, ie, data that causes THA9 to generate heat, is stored in the shift register 58. As a result, when the pulse width controller 60 is triggered at the falling edge of the signal EO5 that occurs immediately after this, the data in the shift register 58 is transferred to the latch circuit 59.
is latched and THA9 is preheated.

In addition, in the dummy scan job DUMSCN in the subsequent interrupt processing R3T7.5, the flag FPR
Since HEX is set, the result of judgment 105 is YE.
until the value of the counter 5CNCNT, which is decremented by 1 in step 102, becomes ``0'' (decision 114).
(while the result is NO), only the carriage 12 feed control is performed.

Then, finish the previous dummy scan and start the counter 5CNC.
When the value of NT becomes 0'' and the result of 1 judgment 114 becomes YES, flags F P I D U M and F D M
S CN is reset and the flag FTABUL is set in preparation for the next step (115), and the signal TA
Process 1 to turn off B and reset the shift register 58
16), reset the flag FPRHEX (processing 117)
After that, the signal TAB is turned on again (process 118), and the signal PSL is turned off to return the pulse width of the output pulse P5 of the pulse width controller 60 to the normal state (process 1
19).

FIGS. 6(a) to 6(h) show the states of each signal and the value of the scan counter 5CNCNT before and after the previous dummy scan ends. Note that the pulse width τ2 in the figure is the standard pulse width of the output pulse P5 of the pulse width controller 60 when the analog switch 64 is turned off. Furthermore, time T1 indicates the job processing time of the CPU 40, and time T2 indicates the gap in which the recording data of the first line is transferred.

Note that if the result of the first judgment 103 is NO, it is a post-dummy scan after completing the scan of the effective screen width.
The explanation will be omitted.

By the way, in the preheat processing described above, T
Although preheating of HA9 is executed, for example, a counter for managing the number of preheating times may be set to allow preheating to be executed several times.

[Effect] As explained above, according to the present invention, since the thermal recording head is preheated in the previous dummy scan, the difference between the temperature of the thermal recording head at the start of recording and that at the end of recording can be reduced. This has the advantage that recording density can be made uniform.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a facsimile machine according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control section of the facsimile machine shown in FIG. m)
2 is a waveform diagram for explaining the operation of each part of the control section, FIGS. 4(a) to (i) are waveform diagrams showing carriage movement control and the status of each flag, and FIG. A flowchart illustrating a dummy scan job including processing, and FIGS. 6(a) to 6(h) are waveform diagrams showing the states of each signal when the control shown in FIG. 5 is executed. 40...CPU (central processing unit), 41...RO
M (read-only memory), 42...RAM
(Random access memory), 43... Programmable timer, 45... Input/output circuit, 60... Pulse width controller, 64... Analog switch.

Claims (1)

[Claims] A reading head in which a plurality of light-receiving elements are arranged in the sub-scanning direction of a document and a recording head in which a plurality of heat-sensitive recording elements are arranged in the sub-scanning direction of a recording paper are both mounted on a carriage forming a main scanning mechanism. However, in a method for controlling a facsimile machine that performs main scanning for a plurality of lines with one reciprocating movement of the carriage, during recording. A method for controlling a facsimile apparatus, characterized in that the plurality of heat-sensitive recording elements are preheated while the carriage moves from a standby position to an actual recording start position.