JP2940971B2 - Control circuit operation matching method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an operation matching method for a control circuit, for example,
A control circuit suitable for matching the operation of a control circuit of the printer mounted on an impact printer and a control circuit for controlling a feeding operation of a cut sheet feeder used for feeding a cut sheet to a printing unit. And an operation control method.

2. Description of the Related Art In recent years, various devices have been required to have advanced functions, and it is not technically or cost-effective to cover all the functions with a single device. In many cases, an oscillation circuit for operating the device is provided to be unitized and attached to the parent device as an optional device.

An example of this is a combination of an impact printer and a cut sheet feeder. That is, only the printing is performed in the main body of the impact printer, and the separation and feeding of the cut sheet and the setting in the printing section of the main body of the impact printer are performed by the optional cut sheet feeder.

The cut sheet feeder includes a hopper section for storing cut sheets to be printed, a feed mechanism for feeding out the cut sheets one by one from the hopper section and feeding the cut sheets to a printing section of a printer, a motor for driving the feed mechanism, A power transmission mechanism for transmitting the power of the motor to the feeding mechanism, and a control circuit for transmitting and receiving an operation control signal to and from the printer body and controlling the feeding operation of the cut sheet are provided. The cut sheet feeder is activated by receiving a sheet feed command signal from the printer body.

When a cut sheet is set on the printing unit using the cut sheet feeder, the sheet feeding command signal is sent from the control unit of the printer body to the control circuit unit of the cut sheet feeder. Upon receiving this signal, the control circuit of the cut sheet feeder drives the motor to operate the feeding mechanism to feed one cut sheet from the hopper. The fed cut sheet travels along the sheet traveling path in the cut sheet feeder, enters the printing portion of the printer from obliquely above the rear, and reaches the outer periphery of the platen of the printing portion. The platen of the printing unit supports the printing paper from behind, has the function of receiving the shock during the printing operation, has the function of sending the printing paper by rotating itself, and is also extended when cutting paper is set in the printing unit. The cut sheet is wound around the outer periphery and rotated, and stops when the first print position of the cut sheet reaches the front of the print head. Therefore, the cut sheet is set in the printing section by receiving a feed operation by two mechanisms, a feed mechanism of the cut sheet feeder and a paper feed mechanism of the printer body.

Incidentally, the paper feed speed in the printer is set to a predetermined speed, and the platen rotates at this set speed. On the other hand, the feed speed of the feed mechanism on the cut sheet feeder side is also set to match the set speed. However, there is some variation in the paper feed speed of the feed mechanism on the cut sheet feeder side, and the paper feed speed does not match the paper feed speed by the platen of the printer. In such a case, the paper becomes slack between the cut sheet feeder and the platen, or on the other hand, the paper is pulled, thereby causing a paper jam or breakage of the paper.

The variation in the feeding speed of the cut sheet feeder is caused by the variation in the oscillation frequency of the clock signal that is the basis of the control of the feeding operation. In general, a stepping motor is used as a motor serving as a power source of the cut sheet feeder because of easy control. The stepping motor rotates at a speed corresponding to a cycle of a drive signal provided from a control circuit of the cut sheet feeder, and the drive signal is generated in the control circuit based on a clock signal.

The control circuit of the cut sheet feeder is composed of a microcomputer, etc.
), Various memories, input / output ports (hereinafter referred to as I / O ports), timers, clock signal generators, and the like. The drive signal of the stepping motor is generated each time the CPU counts the clock signal and reaches a predetermined count value.

On the other hand, as the clock signal generator, an inexpensive CR oscillation circuit is used for cost reduction. For this reason, the clock signal generator may not generate a clock signal at a predetermined standard frequency due to variations in the resistance value of the resistor and the capacitance value of the capacitor. Further, the frequency of the clock signal also fluctuates due to the fluctuation of the power supply voltage and the influence of the ambient temperature.

Therefore, the present invention is to prevent the measurement time from being shifted between units even when the control circuit is operated by clock signals having different frequencies generated by separate clock signal generators in a plurality of units. The purpose of the present invention is to make it possible to match the operation timing between units.

More specifically, even if the frequency of the clock signal of the control circuit of the cut sheet feeder is not the standard frequency, a speed difference occurs between the feed speed of the cut sheet feeder and the paper feed speed of the printer platen. The purpose is to prevent jamming and breakage of cut paper.

Another object of the present invention is to provide a control method for making the feed speed of the cut sheet feeder and the paper feed speed of the platen of the printer match with a simple configuration.

DISCLOSURE OF THE INVENTION In the control method of the cut sheet feeder of the present invention, when a power supply of the printer and the cut sheet feeder is turned on, a correction signal of a preset pulse width is input from the printer to the cut sheet feeder. Has become. The pulse width of the correction signal is counted by a timer in the cut sheet feeder, and the counted value is read.

The count value is compared with a preset standard value to determine a difference. This difference value is added to each value of the timer table stored in the ROM. The value obtained as a result is used to correct the drive pulse generation cycle of the paper feed stepping motor, and the rotation speed of the stepping motor is adjusted so that the cut sheet feed speed of the cut sheet feeder matches the paper feed speed of the printer. Is controlled.
As a result, there is no difference in the paper feeding speed between the cut sheet feeder and the printer, and the feeding of the cut sheet to the printing position is stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of a cut sheet feeder to which the present invention is applied, FIG. 2 is a schematic side view explaining an operation of setting a cut sheet from a cut sheet feeder to a printer, FIG. 3 is a block diagram showing an example of the configuration of the control unit of the present invention, FIG. 4 is a time chart illustrating the temporal relationship of the control operation of the present invention, and FIG. 5 is a control operation procedure of the present invention. FIG. 6 is a block diagram functionally explaining some of the operations shown in FIG. 5 in more detail, and FIG. 7 is a diagram showing the relationship between the fluctuation of the clock frequency and the difference between the timer count values in the present invention. FIG. 8 is a diagram showing the relationship between the variation of the clock frequency and the correction value of the timer table. FIG. 9 is a diagram showing the relationship between the variation of the clock frequency and the variation of the rotation speed of the stepping motor.

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 shows a cut sheet feeder according to the present invention.

1 is a paper hopper, 2 is a stacker for storing paper printed by a printer, 3a and 3b are nails for attaching a cut sheet feeder to a printer platen collar, 4
Is a stepping motor for driving the cut sheet feeder, which drives a one-way gear (not shown) and a hopping roller via gears 5 and 6 to feed out one of the sheets in the hopper section 1 to the printer. Feed.
Reference numerals 7, 8, 9 and 10 denote gears mounted on the platen shaft of the printer for transmitting the driving force to drive a stacker roller (not shown). The stacker roller follows the rotation of the platen when printing is performed, and the printed paper is stored in the stacker unit 2.

FIG. 2 illustrates the operation of feeding paper to the printing unit of the printer by the cut sheet feeder.
Is a platen of the printer, 12 is an impact printhead for printing on paper via an ink ribbon, 13 and 14 are clamp rollers for pressing the paper against the platen, 15a and 15
Reference numeral b denotes a stacker roller for discharging printed paper to the stacker unit 2. Reference numeral 16 denotes a hopping roller of the cut sheet feeder, which feeds out the sheet 17 set in the hopper 1 from the uppermost one. Reference numeral 18 denotes claws for separating the sheets 17 fed from the hopper 1 one by one.

The operation of the cut sheet feeder will be described. First, a plurality of sheets cut into a desired size to be printed are loaded into the hopper unit 1. When the paper 17 is set between the platen 11 and the print head 12 of the printer, the hopping roller 16 rotates and the paper 17 is fed out of the hopper. The fed paper 17 advances along a paper guide path (not shown) inside the cut sheet feeder, and the platen 11 and the clamp roller
Enter between 14. At this time, the platen 11 is rotating, and conveys the paper 17 in the direction of the printing position while sandwiching the paper 17 between its outer periphery and the clamp roller 14. Then the paper 17 is the platen
The paper 11 travels along a paper guide (not shown) provided along the outer periphery of the print head 11, is further sandwiched between the clamp roller 13 and the platen 11, and reaches the front of the print head 12. When the first line to be printed on the paper 17 advances to the printing position, the platen 11 stops rotating, and the printer starts the printing operation by the print head 12. The platen 11 rotates by a predetermined amount each time a printing operation for one line is completed, and feeds the paper 17 line by line. The printed paper 17 is guided by a paper guide (not shown) and advances between the stacker rollers 15a and 15b. When printing is completed, the rotation of the stacker rollers 15a and 15b and the platen 11 causes the stacker unit 2 of the cut sheet feeder to rotate. Sent to

FIG. 3 shows an electrical control configuration of the cut sheet feeder that performs such an operation. In FIG. 3, reference numeral 21 denotes a microcontroller built in the printer, and reference numeral 22 denotes a crystal oscillator for oscillating the clock frequency of the microcontroller. Reference numeral 23 denotes an interface signal line for transmitting a control signal between the printer and the cut sheet feeder, and a microcontroller for controlling the stepping motor 4 of the cut sheet feeder via the I / O port 24.
Connected to 25.

The microcontroller 25 has a CPU 26, a ROM 27 for storing programs, a RAM 28 for storing intermediate data, an I / O port 29, and a timer 30, in addition to the I / O port 24. Then, the microcontroller 25 counts the clock signal oscillated by the resistor 31 and the capacitor 32 connected to the CPU 26, generates a drive pulse timing of the stepping motor 4, and drives the hopping roller 16 of the cut sheet feeder.

33 is the microcontroller 2 via I / O port 29
5 is a driver circuit for driving the stepping motor 4.

In the above configuration, when the power of the printer and the cut sheet feeder is turned on, the microcontroller 21 of the printer sends the microcontroller 25 of the cut sheet feeder to the microcontroller 25 of the cut sheet feeder as shown in FIG. and sends a correction signals S ₁ of the pre Ji because the pulse width set T. The corrected signals S ₁ is cut even when the frequency of the sheet feeder side of the clock signal is shifted from the standard frequency, since the paper feeding speed of the cut sheet feeder side is corrected to match the printer side Buraten chart speed Used for

Here it will be described in accordance with FIG. 5 how to control the sheet feeding rate by using the correction signal S _1.

The microcontroller 25 of the cut sheet feeder
After the power is turned on, the apparatus waits for the input of the correction signal for the sheet feeding speed (step 101). When CPU26 detects the input of the correction signal S _1, and starts the counting operation of the timer 30 (step 102). The timer 30 continues counting the clock signal generated by the CR oscillator having the resistor 31 and the capacitor 32, and waits for the correction signal to expire (step 10).
3). When the CPU 27 detects the end of the correction signal, the timer 30
Is stopped (step 104). Next, the CPU 27 reads the count value of the timer 30 (step 105). On the other hand, R
Standard values obtained by counting the pulse width of the correction signals S ₁ by using the clock signal of the pre Ji fit standard frequency is stored in the OM27. The CPU 27 reads this standard value from the ROM 27 and compares it with the count value of the timer 30 to determine the difference (step 10).
6). If the difference is 0, the clock signal frequency of the microcontroller 25 is the same as the standard frequency, and it is not necessary to correct the sheet feeding speed due to the frequency shift. If the count value of the timer 30 is larger than the standard value, the clock signal frequency is higher than the standard frequency. Conversely, if the count value of the timer 30 is smaller, the clock signal frequency is higher than the standard frequency. Will be lower. The CPU 27 calculates the difference between the count value of the timer 30 and the standard value as positive or negative, and then adds this difference to each speed control value of the standard speed timer table previously stored in the ROM 27, and calculates the correction timer table value. And generate this correction timer table.
It is stored in the RAM 28 (step 107). The above is the timer table correction processing operation of the microcontroller in the cut sheet feeder. This operation period is shown in FIG.
As shown.

When the timer table correction process is completed, a feed command signal _Sf is transmitted from the microcontroller 21 on the printer side as shown in FIG. This feed command signal
S _f is supplied by the same signal line 23 and the correction signal S _1. CPU2
6 receives the feed command signal, refers to the correction timer table stored in the RAM 28, and sends a drive signal to the I / O port 29 to drive the stepping motor 4 according to the correction value (step 108). ). Note that in FIG. 4, (a) represents but shows control signals sent to cut sheet feeder side from the printer side, S _f is a sheet feeding command signal and (b) the sheet of cut sheet feeder while indicating feeding speed, D _f is for command S _f feeding each sheet feeding, also T _f is each represent a one sheet feeding operation period.

The correction of the sheet feeding speed based on the correction value of the timer table will be described in more detail with reference to FIG. 6. The correction timer table value 50 is read from the RAM 28 and temporarily stored in the temporary storage unit 51.
Is held. On the other hand, the clock signal 52 is supplied to the counting means 53 and counted. The correction timer table value in the temporary storage unit 51 and the count value of the counting unit 53 are both supplied to the comparison coincidence detection unit 54, and when they match, a guidance command 55 for the stepping motor 4 is transmitted. At the same time, the counting means 53 is cleared by the driving command 55, returns to 0, and repeats counting of the clock signal again.

Therefore, the larger the correction timer table value 50, the longer the cycle at which the drive command 55 of the stepping motor 4 is issued, and conversely, the smaller the value, the shorter the cycle at which the drive command 55 is issued. As is well known in the rotation control of the stepping motor, the stepping motor switches the excitation phase every time a drive command signal is given, and rotates by a predetermined angle step. Therefore, if the period at which the drive command is issued becomes longer, the rotation speed of the stepping motor 4 becomes slower, and the paper feeding speed of the cut sheet feeder becomes slower. In the opposite case, the paper feeding speed increases.

In the present invention, as can be understood from the above description, when the clock signal frequency of the microcontroller 25 of the cut sheet feeder is higher than the standard, the drive command transmission cycle of the stepping motor 4 is lengthened, and when it is low, the drive command transmission cycle is Is shortened, and the sheet feeding speed of the cut sheet feeder is corrected to match the sheet feeding speed of the printer.

FIG. 7 is a diagram showing the relationship between the difference in the count value of the timer and the variation value of the clock frequency, and FIG. 8 is also a diagram showing the relationship between the correction value of the timer table and the variation value of the clock frequency. Here, the upper limit of the correction value is set so that the added value after correcting the timer table does not overflow. FIG. 9 is a diagram showing the relationship between the fluctuation value of the clock frequency and the fluctuation of the rotation speed of the stepping motor 4. By performing the above correction, it can be seen that the fluctuation of the rotation speed of the stepping motor 4 is set to 0 for a slight fluctuation of the oscillation frequency of the clock within a certain range.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
These do not exclude the present invention from the scope.

INDUSTRIAL APPLICABILITY As described above, the present invention uses the reference time output by one device to match the operation between a plurality of devices that are unitized for each function. The time measured by the local device can be matched with the time measured by the local device, so that the operation of the local device can be matched to the operation of one device, especially from the cut sheet feeder to the printer of the printer. Paper can be fed at a speed that matches the feed speed, and when automatically feeding cut paper to the printing unit, it is useful for achieving stable feeding without causing paper jams and paper damage. It is suitable for use in the cut sheet feeder to be equipped.

Continuation of the front page (72) Inventor Akira Nanun 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) H02P 8/00 B41J 13/00 B65H 7/00-7/20

Claims (5)

(57) [Claims] A first unit including a first oscillation circuit, a control circuit including a first CPU operated by a first clock signal generated by the first oscillation circuit, and a second oscillation circuit. When the circuit and a second unit including a control circuit including a second CPU operated by a second clock signal generated by the second oscillation circuit are operated in cooperation with each other, the second unit Transmitting a correction signal corresponding to a predetermined time generated by the first clock from the first unit to the second unit, comprising: a reference time memory; Measuring a time corresponding to a time based on the second clock; storing a value corresponding to the measured number of clocks as a reference time in the reference time memory; Operation method of matching control circuit; and a step of operating the second unit Te. 2. The method according to claim 1, wherein the correction signal and an operation command signal for instructing the second unit to drive are sent over a single signal line, and the power supply is turned on and the correction signal is sent before the operation command signal is sent. 3. The method according to claim 1, wherein the operation is transmitted to the control circuit. 3. The driving device controlled by the second control circuit is a stepping motor provided in the second unit, and the reference time determines a driving speed of the stepping motor specific to the second unit. 2. The operation matching method for a control circuit according to claim 1, wherein: 4. The second unit counts the second clock signal when a drive command for the stepping motor is given, and each time the counted value reaches a value corresponding to the reference time, the second unit counts the second clock signal. 4. The operation matching method for a control circuit according to claim 3, wherein said step rotation drive command is transmitted and counted again. 5. A first unit comprising a first oscillation circuit, a control circuit including a first CPU operated by a first clock signal generated by the first oscillation circuit, and a second oscillation circuit. When operating a circuit and a second unit including a control circuit including a second CPU operated by a second clock signal generated by the second oscillation circuit in cooperation with each other, Sending a correction signal having a pulse width corresponding to a predetermined time generated by the first clock to the second unit; and the second unit changing the pulse width of the correction signal to the second signal.
Measuring with a clock of the following; obtaining a difference between the measured value and a previously stored standard value; and driving a standard speed drive of a second unit driving the difference previously stored in a standard speed drive control value. Obtaining a correction drive control value by adding to the control value; and driving the second unit using the correction drive control value.