JP4137322B2 - Printer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printer device, and more particularly to a printer device including a paper feeding device driven by a DC motor.
[0002]
[Prior art]
Various printer apparatuses are known as output apparatuses such as information processing apparatuses. As a drive source for driving the printer device, there is a device using a DC motor suitable for a small printer device. In this printer apparatus, a printing mechanism unit that prints on paper and a paper feeding unit that feeds paper are provided, and paper feeding is performed by driving the paper feeding unit with a DC motor.
In general, in order to reduce a printing deviation in a printer device, it is required that a speed difference between a printing speed by a printing mechanism unit and a paper feeding speed by a paper feeding unit is small. For example, if the paper feed speed of the paper feed unit is faster than the print speed of the print mechanism unit, the paper feed will be performed before the print mechanism unit side prepares the print for one line. Therefore, a printing misalignment occurs.
Normally, in a small printer device, the mechanism for speed control is omitted, and only the initial setting of the printing speed of the printing mechanism section and the paper feed speed of the paper feeding section is performed to reduce the size at the expense of printing accuracy. It is carried out.
[0003]
FIG. 19 is a schematic block diagram of a conventional printer. In FIG. 19, the printer apparatus 1 ′ includes a printing mechanism unit 2 for performing printing and a paper feeding unit 5 for feeding paper 11. The printing mechanism unit 2 includes a printing unit 3 having a type roller and a platen unit 4 that presses the paper 11 against the type roller with an ink ribbon (not shown) interposed therebetween. The paper feed unit 5 includes a paper feed roller 5A, and the paper feed roller 5A is rotationally driven by a DC motor 6 via a transmission mechanism 7 such as a gear. The DC motor 6 is supplied with power by the power supply unit 8.
[0004]
[Problems to be solved by the invention]
In a printer apparatus using a DC motor as a drive source, the DC motor is usually low in the initial state, and the rotational speed tends to gradually increase as time passes. This is because the load seen from the DC motor is reduced with the lapse of time and the characteristics of the DC motor change.
Loads seen from the DC motor include a transmission mechanism such as a gear provided between the DC motor and the paper feed roller, and friction of a bearing portion such as the paper feed roller. The load on these mechanical parts tends to gradually decrease with time. Therefore, when the DC motor is driven with a constant torque, the rotational speed increases due to a decrease in load.
Further, the brush portion provided in the DC motor is worn by rotation and the contact point is shifted to cause a phase shift, and the electric characteristics of the DC motor change. This change in electrical characteristics increases the speed.
[0005]
Normally, in a small printer, the paper feed speed of the paper feed unit is set so that the speed deviation from the speed of the print mechanism unit is within an allowable range with respect to the aging of the speed of the paper feed unit. . When the paper feed speed is low, it is possible to limit the speed deviation due to aging within the allowable range, but when the paper feed speed becomes high, it becomes difficult to limit the speed deviation within the allowable range. . This is because the speed deviation occurs at a ratio to the speed and becomes larger as the speed increases.
Therefore, in a printer apparatus using a DC motor as a drive source, there is a problem that the rotational speed gradually increases as time passes, and printing misalignment occurs, and this printing misalignment increases particularly when performing high-speed printing. There's a problem.
[0006]
In order to solve such a problem, it has been proposed to control the paper feed speed to be constant. FIG. 19B is an example of a configuration for controlling the paper feed speed to be constant. In this configuration example, the speed of the paper feed roller is detected, and feedback control is performed by adding and subtracting a current value corresponding to the deviation from the reference value to the DC motor. The encoder 13 controls the rotational speed of the paper feed roller 5A. Based on the detection signal, the control unit 14 controls the voltage supplied by the power supply unit 8 to control the rotation speed of the DC motor 6 to be constant.
However, in the configuration that performs such feedback control, an encoder that detects the rotation speed of the paper feed roller 5A, a comparator that forms a control signal based on the encoder signal, a processing circuit, and a conversion circuit that converts the drive current to the motor There is a problem that an expensive device other than the components originally provided in the printer device, such as a control device such as the above, is required.
[0007]
In particular, in a small printer device, increasing the number of components increases the size of the device and complicates the device configuration.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the conventional problems and to reduce printing deviation caused by a speed change due to aging in a printer device with a simple configuration.
[0008]
[Means for Solving the Problems]
The present invention detects a change in the paper feed speed based on an interval signal, and lowers the rotational speed of the DC motor by lowering the voltage of the DC motor drive power supply, thereby causing a speed deviation between the printing mechanism section and the paper feeding section. This suppresses printing deviation.
Therefore, the printer apparatus of the present invention has a DC motor and a paper feed unit and a print mechanism unit including a paper feed roller using the DC motor as a drive source, and a print mechanism unit for paper fed by a predetermined amount by the paper feed unit. In the printer device that performs printing, a power supply unit that supplies a predetermined current to the DC motor so that the voltage value can be switched, and a switching unit that switches a voltage value output from the power supply unit based on an interval signal output from the printing mechanism unit It is set as the structure provided with.
[0009]
FIG. 1 is a schematic block diagram of a printer apparatus of the present invention. In FIG. 1, the printer apparatus 1 includes a printing mechanism unit 2 for performing printing and a paper feeding unit 5 for feeding paper 11. The printing mechanism unit 2 includes a printing unit 3 having a type roller and a platen unit 4 that presses the paper 11 against the type roller with an ink ribbon (not shown) interposed therebetween. The printing mechanism unit 2 includes an interval signal generation unit 9, and the generated interval signal is used as a character signal for selecting a type.
The paper feed unit 5 includes a paper feed roller 5A, and the paper feed roller 5A is rotationally driven by a DC motor 6 via a transmission mechanism 7 such as a gear. The DC motor 6 is supplied with power by the power supply unit 8. The printer device 1 of the present invention includes a switching unit 10 that switches the voltage of the power supply unit 8, and the switching unit 10 makes a switching determination based on an interval signal. The paper feed unit and the print mechanism unit use a common DC motor as a drive source, the paper feed unit drives the paper feed roller to feed a predetermined amount of paper, and the print mechanism unit selects the selected character on the paper fed. Is printed.
[0010]
The power supply unit of the present invention supplies a predetermined current to the DC motor, and the voltage value can be switched. The configuration for switching the output voltage value is a circuit configuration in which a series circuit of a plurality of constant voltage diodes is connected between both terminals of the DC power supply, and the constant voltage diode connected to the output terminal side is selected by a switching signal. Can do.
The switching unit outputs a switching signal based on the interval signal output from the printing mechanism unit. The power supply unit switches the voltage value output to the DC motor by this switching signal. The interval signal is a timing signal used when the printing mechanism unit selects a type, and is a signal that is normally formed by the printing mechanism unit to achieve its function. Normally, after the power is turned on, the printer apparatus performs various processes for initialization settings called initialization. The interval signal is fixed to non-active from when the power is turned on until initialization is started, and becomes active after initialization.
The power supply unit of the present invention can also serve as a power supply for the printer apparatus. By combining the power supply, the printer device can be reduced in size.
[0011]
FIG. 2 is a flowchart for explaining the operation of the printer apparatus of the present invention, and FIG. 3 is a change diagram showing changes in the rotational speed v and the supply voltage V of the DC motor. The printer device of the present invention measures an interval signal inherently provided in the printing mechanism (step S2), and determines a change in the rotational speed of the DC motor using this interval signal (step S3), thereby increasing the paper feed speed. This is detected and the voltage value output from the power supply unit that drives the DC motor is changed (step S4), so that the rotation speed of the DC motor is adjusted to the paper feed speed, thereby causing the printing deviation caused by the speed change due to secular change. Is reduced with a simple configuration.
[0012]
When the power supply unit of the present invention detects that the paper feed speed is increased by the interval signal, the power supply unit supplies a low voltage to the DC motor to reduce the rotational speed of the DC motor, thereby reducing the paper feed speed.
The switching unit of the present invention obtains a change in the rotational speed v of the DC motor based on the interval signal, determines that the paper feed speed has been detected to increase when the speed exceeds the set speed v0, and detects an increase in the paper feed speed. When this occurs, a switching signal for lowering the output voltage is output to the power supply unit. The power supply unit switches the voltage for the DC motor from the high voltage VH to the low voltage VL by the switching signal.
[0013]
The paper feed speed increase detection based on the interval signal performed by the switching unit can be performed in the following plurality of modes.
In the first aspect, the switching signal is output when the signal interval of the interval signal becomes shorter than the predetermined interval. The interval signal is a plurality of signals formed for selecting a type, and is output at a predetermined time interval. The time interval of each signal of the interval signal depends on the rotational speed (paper feed speed) of the DC motor. Therefore, the time interval is detected and compared with a predetermined interval, and it is determined that the paper feed speed has increased when the interval becomes shorter than the predetermined interval.
In the second aspect, the switching signal is output when the number of interval signals counted within a predetermined time becomes larger than the predetermined number. In the second mode, while the first mode detects a time interval, the number of interval signals counted within a predetermined time is counted and compared with a predetermined number. Is determined to have increased, the paper feed speed has increased.
[0014]
In the third aspect, an interval signal within a predetermined time is integrated by a capacitor, and the obtained voltage signal is used as it is as a switching signal. In the third aspect, the power supply unit switches the output voltage according to the voltage value of the switching signal. The output voltage can be switched by selecting a constant voltage diode provided in the power supply unit by a switching signal. Therefore, in the third aspect, the comparison process with the predetermined value is not necessary, and the paper feed speed increase determination is performed by the cooperative operation of the switching unit and the power supply unit.
In the first and second modes, the output voltage of the power supply unit is switched without performing comparison processing with a predetermined value by taking out the switching signal as a voltage value, as in the third mode. Can do. Further, a function for holding a switching signal or output voltage after switching can be provided in the switching unit or the power supply unit so that the voltage of the power supply unit does not change after switching.
[0015]
Further, the switching unit of the present invention is configured to make the switching determination only when the printer device is powered on. The speed change targeted by the present invention is a secular change and does not change greatly during the operation of the printer apparatus. Therefore, it is not necessary to always make the switching determination, and it can be sufficiently determined at a relatively long time interval. Therefore, the printer apparatus of the present invention does not always perform the voltage switching determination, but only when the printer apparatus is turned on (step S1), and by using the interval signal output at initialization when the power is turned on. The processing operation can be simplified, the processing of the CPU of the printer apparatus can be made more efficient, and the power consumption can be reduced.
[0016]
In the present invention, the interval signal can be obtained by the interval signal generator. The interval signal generation unit includes a rotating plate and a detector that rotate in synchronization with a type roller that supports a plurality of print wheels, each having a type on the outer periphery, supported by a rotation shaft. The rotating plate has a position index for selecting the type of the print wheel, and the detector detects a position index included in the rotating plate. The detected signal interval of the position index depends on the rotational speed of the type roller.
[0017]
The detector of the present invention can use any detection means such as detection by light and detection by magnetism. In the case of detecting using light, for example, a light having a light-transmitting part such as an LED and a light-receiving part such as a phototransistor is formed on the rotating plate as a position index corresponding to a type or the like. The structure which detects this translucent part with a detector can be used.
In addition, the printing mechanism of the present invention includes a type roller that supports a plurality of print wheels each having a type provided on the outer periphery thereof on a rotation shaft, and a platen roller that presses the paper against the type roller via an ink ribbon. can do.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, an embodiment of the printer apparatus of the present invention will be described with reference to the schematic configuration of FIG. 4 and the flowcharts of FIGS. 5 and 7 and the time charts of FIGS. 6 and 8.
4, the printer apparatus 1 includes a printing unit 3, a printer unit 4, a paper feeding unit 5, a power supply unit 8, and a switching unit 10, and the printing unit 3 and the printer unit 4 constitute a printing mechanism unit.
[0019]
The printing unit 3 includes a type roller 3 </ b> A in which a plurality of print wheels 3 </ b> B are arranged on the same axis. In order to perform printing with this type roller 3A, a type for one line is set by sequentially performing an operation of selecting a type to be printed while rotating the print wheel 3B for a plurality of print wheels 3B, and the type is set. The type roller 3A is pressed by the platen roller 4B with the ink ribbon 12A and the paper 11 interposed therebetween.
The type of the print wheel 3B is selected by a selection claw 3D and a selection mechanism 3E. The selection pawl 3D is arranged corresponding to each print wheel 3B. The pawl portion is separated from the print wheel 3B when not selected, and the type is selected by abutting the pawl portion against the print wheel 3B when selected. The selection mechanism 3E is a mechanism that rotates the selection pawl 3D to perform a selection operation, and when the print wheel 3B is rotated, the selection pawl 3D is rotated toward the print wheel 3B. The type selection is performed by stopping the rotation.
[0020]
The selection operation by the selection mechanism 3E is performed based on the interval signal from the interval signal generator 9. The interval signal includes a character signal for selecting a type and a stop signal for stopping the current supply to the DC motor.
The interval signal generator 9 generates an interval signal using the main gear 3F. The main gear 3F is driven by the DC motor 6 via the gear mechanism 3I, and moves the type wheel 3A etc. by a cam mechanism (not shown) that rotates in synchronization with the main gear 3F to perform a printing operation. The main gear 3F includes a plurality of holes used for forming an interval signal on the circumference thereof. There are a plurality of character signal holes 3G for forming character signals and one stop signal hole 3H for forming stop signals. The photodetector 9A provided in the interval signal generator 9 forms an interval signal by detecting light transmitted through the holes 3G and 3H.
[0021]
By performing the type selection using the interval signal, the timing of the type selection in the print wheel 3B and the printing operation performed via the cam mechanism can be matched. Further, since the signal interval of the interval signal depends on the rotation speed of the main gear 3F, and the main gear 3F depends on the rotation of the DC motor 6, the state of the rotation speed of the DC motor 6 is determined from the signal interval of the interval signal. Can be detected.
[0022]
The platen unit 4 includes a platen roller 4B that presses the paper 11 and the ink ribbon 12A against the type roller 3A, and a guide portion that guides the paper 11 to the platen carrier.
The paper feed unit 5 includes a paper feed roller 5A, and feeds the paper 11 to the platen carrier side by a predetermined amount by rotating the paper feed roller 5A. The paper feed roller 5A is rotationally driven by a DC motor 6 via a transmission mechanism 7 such as a pinion 7A or a reduction gear 7B. Therefore, the paper feed speed depends on the rotational speed of the DC motor 6.
[0023]
The power supply unit 8 is configured so that the output voltage can be switched between a high voltage and a low voltage, and this voltage switching is performed by a switching signal from the switching unit 10. The switching unit 10 takes in the interval signal, obtains a change in the rotational speed of the DC motor 6 based on the interval signal, determines that the paper feed speed has been detected to increase when the set speed is exceeded, and determines the paper feed speed. When the increase is detected, a switching signal for decreasing the output voltage is output to the power supply unit. The power supply unit 8 switches the voltage for the DC motor 6 from a high voltage to a low voltage by this switching signal.
[0024]
A first mode for detecting an increase in paper feed speed based on an interval signal performed by the switching unit will be described with reference to FIGS. 5 and 6, a second mode will be described with reference to FIGS. 7 and 8, and a third mode will be described. Will be described with reference to FIGS. 9 and 10. FIG.
In the first aspect, the switching signal is output when the signal interval of the interval signal becomes shorter than the predetermined interval.
The switching unit 10 takes in the interval signal from the interval signal generation unit 9. FIG. 6A is an example of an interval signal, T0 to Tn indicate character signals, and Ts indicates a stop signal. Each time the main gear 3F makes one revolution, a series of signals T0 to Tn and Ts are output (step S12a). The switching unit 10 measures the time interval T of the captured interval signal. As shown in FIG. 6A, the time interval T includes a time interval between adjacent character signals, a time interval until an arbitrary plurality of character signals are output, and a time from the character signal T0 to the stop signal Ts. It can be obtained by measuring an interval or a time interval from a character signal T0 to a stop signal Ts over a plurality of periods. Note that the measurement accuracy can be increased by increasing the measurement time width (step S12b).
[0025]
The switching unit 10 determines a time interval T0 for performing voltage switching in advance, and compares the obtained time interval T with T0. Note that the time interval T0 can be determined according to the paper feed speed at which printing deviation occurs and the rotational speed of the DC motor corresponding to the speed. As shown in FIG. 6B, when T is larger than T0, it is determined that the paper feed speed does not cause printing deviation, and the high voltage set in the initial state is supplied from the power supply unit 8 to the DC motor. 6 to output.
On the other hand, as shown in FIG. 6C, when T is smaller than T0, it is determined that the paper feed speed has reached the speed at which printing deviation occurs, and a switching signal is output to the power supply unit 8 (step). S <b> 14 a), a low voltage is output from the power supply unit 8 to the DC motor 6. 6D and 6E show changes over a long period of time. If the supply voltage is switched from the high voltage VH to VL when the paper feed speed increases due to secular change and the time interval T becomes smaller than T0, the paper feed speed decreases and the time interval becomes larger than T0 (step) S14b).
[0026]
Note that the above-described determination operation is performed once at the time of initialization associated with power-on (step S11), and is not performed while the printer device is normally driven, thereby increasing the efficiency of the CPU of the printer device. In addition, power consumption can be reduced. The switching unit of the present invention is configured to make the switching determination only when the printer device is powered on.
[0027]
In the second aspect, the switching signal is output when the number of interval signals counted within a predetermined time becomes larger than the predetermined number.
The switching unit 10 takes in the interval signal from the interval signal generation unit 9. FIG. 8A is an example of an interval signal as in FIG. 6A, T0 to Tn indicate a character signal, and Ts indicates a stop signal. Each time the main gear 3F makes one rotation, a series of signals T0 to Tn and Ts are output (step S22a). The switching unit 10 counts the number N of captured interval signals. As shown in FIG. 8A, the signal number N can be obtained by counting the number of character signals or character signals and stop signals within an arbitrary predetermined time interval. Note that the measurement accuracy can be increased by increasing the time width for counting (step S22b).
[0028]
The switching unit 10 determines a count value N0 for voltage switching in advance, and compares the calculated count value N with N0. Note that N0 can be determined according to the paper feed speed at which printing deviation occurs and the rotational speed of the DC motor corresponding to the speed. As shown in FIG. 8B, when N is smaller than N0, it is determined that the paper feed speed does not cause printing deviation, and the high voltage set in the initial state is supplied from the power supply unit 8 to the DC motor. 6 to output.
On the other hand, as shown in FIG. 8C, when N is greater than N0, it is determined that the paper feed speed has reached a speed causing a printing deviation, and a switching signal is output to the power supply unit 8 (step S24a), a low voltage is output from the power supply unit 8 to the DC motor 6.
[0029]
FIGS. 8D and 8E show changes over a long period of time. If the supply voltage is switched from the high voltage VH to VL when the paper feed speed increases due to secular change and the count value N becomes larger than N0, the paper feed speed decreases and the count value N becomes smaller than N0 ( Step S24b).
Note that the above determination operation is performed once at the time of initialization upon power-on (step S21), and is not performed while the printer device is normally driven, thereby improving the efficiency of the processing of the CPU of the printer device. In addition, power consumption can be reduced. The switching unit of the present invention is configured to make the switching determination only when the printer device is powered on.
[0030]
In the third aspect, the interval signal output within a predetermined time is integrated, and the voltage value is used as the switching signal.
The switching unit 10 takes in the interval signal from the interval signal generation unit 9. The example of the interval signal in FIG. 9A is the same as that in FIGS. 6A and 8A (step S32a). The switching unit 10 integrates the acquired interval signal within a predetermined time Ta to obtain an integral value S. The integral value S represents the frequency of occurrence of the interval signal, and represents the number of rotations of the DC motor and the paper feed speed. The integral value S increases as the paper feed speed increases. The predetermined time Ta can be set to an arbitrary time interval as described with reference to FIG. 6A, and the measurement accuracy can be increased by taking a long time width for integration (step S32b).
[0031]
The switching unit 10 outputs a voltage signal representing the integral value to the power supply unit 8 as a switching signal. By integrating the interval signal in the capacitor, the integral value can be taken out as the voltage value of the capacitor, and this voltage value can be used as the switching signal.
Assuming that the integral value corresponding to the paper feed speed to be switched is S0, when the paper feed speed is equal to or lower than the set speed, the integral value S is smaller than S0 as shown in FIG. When the speed is equal to or higher than the set speed, the integral value S is larger than S0 as shown in FIG. 10C (step S34a).
[0032]
  The power supply unit 8 switches the output voltage according to the voltage value of the switching signal. FIG. 11 is a diagram illustrating a configuration example of the power supply unit 8.FIG.In (a), the rectifier diode 8A and the capacitor 8B constitute a rectifier circuit and output a DC voltage from an AC power supply. Constant voltage diodes at both ends of the rectifier circuit8D1,8D2And Darlington-connected transistor 8CAndConstant voltage diode connected in series8D1There is a switch transistor8GAnd resistance circuit8E,8FConnect. resistance8EA switching signal is input to one end of the resistor and one end is grounded.8FA voltage corresponding to the voltage value of the switching signal is generated at the connection point. Transistor8GInputs this voltage as a switch signal. Transistor8GIs turned off when the input voltage value is equal to or lower than a predetermined voltage, and is turned on when it is equal to or higher than the predetermined voltage.
[0033]
  If the paper feed speed does not reach high speed, the voltage value of the switching signal is low, so the transistor8GIs in the off state. At this time, the constant voltage diode8D1Voltage value and constant voltage diode8D2Is added to the DC motor 6 and the selection mechanism 3E, which are loads. On the other hand, when the paper feed speed becomes high, the voltage value of the switching signal becomes a high voltage.8GIs turned on. At this time, the constant voltage diode8D1Is disconnected from the constant voltage circuit, the constant voltage diode8D2Is output and supplied to the DC motor 6 and the selection mechanism 3E, which are loads.
[0034]
  Therefore, constant voltage diode8D1And constant voltage diode8D2The voltage value to be supplied can be switched by determining the voltage value corresponding to the high voltage value and low voltage value supplied to the DC motor 6. For example, constant voltage diode8D1Constant voltage of 2 (V), constant voltage diode8D2If the constant voltage is 16 (V), the DC motor 6 can output 18 (V) as a high voltage and 16 (V) as a low voltage. Here, a configuration including two constant voltage diodes is shown, but an arbitrary number of constant voltage diodes are connected in series, and a switching transistor is connected to selectively drive according to the voltage value of the switching signal. Also, it can be configured to output a predetermined voltage.
[0035]
Figure11 (b) is a configuration example of a conventional power supply unit. This circuit configuration does not have a series circuit of a plurality of constant voltage diodes that are selectively driven by a switching signal provided in the power supply unit of the present invention. Therefore, the output voltage value is a single voltage value, and a separate voltage conversion circuit is required to switch the voltage value supplied to the DC motor.The
[0036]
In addition to the above configuration, the switching unit 10 previously determines an integral value S0 for performing voltage switching, compares the obtained integral value S with S0, and when the integral value S is smaller than S0, It is determined that the paper feed speed does not cause printing deviation, and the high voltage set in the initial state is output from the power supply unit 8 to the DC motor 6. When S is larger than S0, the paper feed speed is printed. It is also possible to determine that the speed causing the deviation has been reached, and to output a switching signal to the power supply unit 8 so that a low voltage is output from the power supply unit 8 to the DC motor 6 (step S33).
[0037]
FIGS. 10D and 10E show changes over a long period of time. If the supply voltage is switched from the high voltage VH to VL when the paper feed speed increases due to secular change and the integrated value S becomes larger than S0, the paper feed speed decreases and the integral value S becomes smaller than S0 ( Step S34b).
Note that the above determination operation is performed once at the time of initialization upon power-on (step S31), and is not performed while the printer device is normally driven, thereby improving the efficiency of the processing of the CPU of the printer device. In addition, power consumption can be reduced. The switching unit of the present invention is configured to make the switching determination only when the printer device is powered on.
[0038]
Next, a configuration example of each part of the printer apparatus of the present invention will be described. FIG. 12 is a schematic block diagram seen from above the printer apparatus of the present invention. The print wheel 3B and the platen carrier 4A are opposed to each other with a paper guide 4E that guides the paper at the printing portion. A wheel gear 3C that meshes with the main gear 3F is attached to the shaft of the print wheel 3B, and a platen gear 4C that meshes with the intermediate gear 7C is attached to the platen roller shaft of the platen carrier 4A. The main gear 3F and the platen gear 4C mesh with the pinion 7A of the DC motor 6 via gears such as the reduction gear 7B and are driven by the DC motor 6.
[0039]
On the print wheel 3B side, there is a selection block including a selection pawl 3D, a leaf spring 3L, a spring plate 3J, and the like, which are driven by a cam (not shown) that rotates in synchronization with the main gear 3F. Further, a photodetector 9A is installed adjacent to the main gear 3F, detects an opening such as a hole provided in the main gear 3F, and outputs a character signal and a stop signal.
[0040]
The paper 11 passes from the upper paper guide 4D between the pressing roller 5D and the paper feed roller (not shown) to the paper guide 4E, and printing is performed at a position where the print wheel 3B and the platen roller face each other.
The ink ribbon is disposed so as to return from the ribbon unit 12 to the ribbon unit 12 through the space between the print wheel 3B and the platen roller, and is controlled by a feeding ribbon lever 12B, a ribbon shift lever 12C, and the like.
[0041]
FIG. 13 is a diagram for explaining the selection operation of the type roller.
The type roller 3A includes a plurality of print wheels 3B on the same axis along the print line, and the type is provided on the outer peripheral surface of the print wheel 3B. Selection of the type is performed by sequentially repeating the operation of stopping at the type position where the rotating print wheel 3B is selected for each print wheel 3B for each character signal such as TO, T1, T2, and the like. The selection of the print wheel 3B is performed by driving the selection pawl 3D by a selection mechanism 3E constituted by a solenoid or the like and stopping the print wheel 3B at the type position.
By performing type selection for all the print wheels 3B (including the print wheel 3B that does not select a type) included in the type roller 3A, the type for one line is selected, and the preparation for the printing operation is completed.
[0042]
FIG. 14 is a partial side view for explaining the configuration of the printing unit, the platen unit, and the paper feeding unit. The printing mechanism unit and the paper feeding unit are attached to a base 1A including a bottom plate 1B of the printer device.
The printing unit includes a plurality of print wheels 3B held by friction springs 3Q on the wheel shaft 3P, and rotates in the direction of the arrow by a drive mechanism (not shown) to select a type. A series of selection pawls 3D, a selection mechanism 3E, and a spring guide mechanism 3R for resetting the selection pawls 3D are provided for type selection.
The selection mechanism 3E includes a selection core 3Ed having a holding permanent magnet 3Eg and a yoke plate 3Eh attached to one end thereof, and a coil 3Ed wound around the selection bobbin 3Ec. The coil 3Ed is driven via the selection circuit board 3Ea. Is done.
[0043]
The selection pawl 3D comes into contact with the selection core 3Ed by the attractive force of the permanent magnet 3Eg, and is biased in the opposite direction by a force from the leaf spring 3L that is weaker than the attractive force. Further, the spring plate 3J presses the selected pawl 3D at the axial position.
[0044]
Note that one of the leaf springs 3L is attached to the spring guide mechanism 3R by a holding plate 3M and a tap screw 3N. The selected core 3Ed is positioned on the core shaft 3Ee with the core spacer 3Ef interposed therebetween, and a slide pin 3Ej is attached to the selected core 3Ed.
The paper feed roller 5A is attached to the reduction gear shaft 7D and includes a clutch pawl 5C. The pressing roller 5D is attached to the roller shaft 5E and feeds paper with the paper sandwiched between the paper feeding roller 5A.
[0045]
Next, the operation of the printing unit will be described with reference to FIG.
With the rotation of the DC motor, the main gear 3F and the print wheel 3B rotate in the direction of the arrow and start a type selection operation.
The cam of the main gear 3F drives the spring guide mechanism 3R as follows. The protrusion (a) of the cam pushes up the spring guide mechanism 3R counterclockwise, and the (d) portion of the selected pawl is separated from the large ratchet portion (e) of the print wheel 3B. As a result, the ratchet portion (e) passes through the portion (d) of the selected claw. When the projection (a) of the cam passes through the (d) portion, the selection pawl 3D returns to the state shown in FIG.
[0046]
The type selection operation is performed in the portion (b) of the cam. The ratchet portion (e) of the print wheel 3B passes through the selected (d) portion. When the position corresponding to the type selected by the ratchet is reached, the coil is driven by the signal. When the corl is driven, the electromagnetic force of the coil is balanced with the magnetic force of the permanent magnet, and the selected pawl 3D is released from the selected core 3Ed. The selection pawl 3D meshes with the ratchet of the print wheel 3B by a spring force. The type selection is sequentially performed in the same manner.
[0047]
When the selection operation is completed, the characters are arranged in a line facing the print roller 4B. The print roller 4B performs printing by pressing a letter with a paper and an ink ribbon between them. When printing is completed, the portion (c) of the cam pushes up the spring guide mechanism 3R, and at the same time, the selection pawl 3D opens the ratchet of the print wheel 3B. The lower part of the selection pawl 3D comes into contact with the selection core 3Ed by the magnetic force of the permanent magnet.
The print wheel 3B stops in a standby state after rotating until the ratchet portion (e) of the print wheel 3B hits the selected (d) portion, and prepares for the next print cycle.
[0048]
Next, the interval signal generator will be described with reference to FIG. FIG. 16A shows the positional relationship between the main gear 3F and the photodetector 9A from the cross-sectional direction, and FIG. 16B shows the axial direction.
The main gear 3F includes a plurality of openings formed by the character signal holes 3G and a single opening formed by the stop signal holes 3H.
In the photodetector 9A, the light emitting means and the light receiving means are arranged to face each other so that the opening of the main gear 3F passes through the optical axis. The light emitting means can use LED 9Aa, and the light receiving means can use photodiode 9Ab. The LED 9Aa and the photodiode 9Ab supply a current for light emission and extract a detection signal via the circuit board 3Ea.
The LED 9Aa detects the light of the photodiode 9Ab that has passed through the opening of the main gear 3F, thereby forming an interval signal of a character signal and a stop signal.
[0049]
Next, the operation of the platen unit will be described with reference to FIG. The platen unit performs printing by pressing against the print wheel type with paper and an ink ribbon interposed therebetween. A platen roller 4E is attached to the platen carrier shaft 4G. The electromagnetic bearing 4H provided at each end of the platen carrier shaft 4G is fixed to the holes (1 to 4) provided in the base 1A, and the pressing force is adjusted by changing the fixing holes by 1 to 4. can do. The position of the hole 1 is a weak pressing force, and the position of the hole 4 is a strong pressing force. The platen gear 4C attached to the platen carrier shaft 4G rotates in the direction of the arrow, and printing is performed by the mechanical pressure of the platen roller.
[0050]
FIG. 18 is a time chart showing the position and signal state of each part described above. During the rotation of the main gear (0 ° to 360 °), in addition to the generation of the interval signal of the character signal and the stop signal, the formation of the selection pulse signal by the character signal, each signal related to ribbon shift and paper feed is formed. Perform print cycle operation for printing.
[0051]
According to the embodiment of the present invention, the DC motor, which is the drive source of the printer device, can suppress printing deviation due to an increase in rotational speed caused by secular change by reducing the output voltage of the power supply unit. In particular, it is possible to obtain a larger printing shift suppression effect for high-speed printing.
According to the embodiment of the present invention, the printer device can be configured without using a minimum configuration required for printing only and without adding a configuration required for feedback control such as an encoder for detecting the rotation speed of the paper feed roller. And a small and simple printer device.
According to the embodiment of the present invention, the processing operation is simplified and the processing of the CPU of the printer apparatus is made efficient by not performing the voltage switching determination constantly but only when the printer apparatus is powered on. In addition, power consumption can be reduced.
[0052]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce printing deviation caused by speed change due to secular change with a simple configuration in the printer apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a printer apparatus of the present invention.
FIG. 2 is a flowchart for explaining the operation of the printer apparatus of the present invention.
FIG. 3 is a change diagram showing changes in the rotational speed v and the supply voltage V of the DC motor.
FIG. 4 is a schematic view of an embodiment of a printer apparatus of the present invention.
FIG. 5 is a flowchart of a first operation mode of the printer apparatus according to the embodiment of the present invention.
FIG. 6 is a time chart of a first operation mode of the printer apparatus according to the embodiment of the invention.
FIG. 7 is a flowchart of a second operation mode of the embodiment of the printer apparatus of the present invention.
FIG. 8 is a time chart of a second operation mode of the printer apparatus according to the embodiment of the invention.
FIG. 9 is a flowchart of a third operation mode of the embodiment of the printer apparatus of the present invention.
FIG. 10 is a time chart of a third operation mode of the embodiment of the printer apparatus of the present invention.
FIG. 11 is a diagram illustrating a configuration example of a power supply unit of the printer apparatus of the present invention.
FIG. 12 is a schematic block diagram of the printer apparatus of the present invention as viewed from above.
FIG. 13 is a diagram for explaining a type roller selection operation of the printer device of the invention.
FIG. 14 is a partial side view for explaining a configuration of a printing unit, a platen unit, and a paper feeding unit of the printer apparatus of the present invention.
FIG. 15 is a schematic diagram for explaining the operation of the printing unit of the printer apparatus of the present invention.
FIG. 16 is a schematic diagram illustrating an interval signal generation unit of the printer apparatus of the present invention.
FIG. 17 is a schematic diagram for explaining the operation of the platen unit of the printer apparatus of the invention.
FIG. 18 is a time chart showing the position and signal state of each part of the printer apparatus of the present invention.
FIG. 19 is a schematic block diagram of a conventional printer device.
[Explanation of symbols]
1, 1 ', 1 "printer device
1A substrate
1B Bottom plate
2 Printing mechanism
3 Print section
3A type roller
3B print wheel
3C wheel gear
3D selection claw
3E selection mechanism
3Ea selection circuit board
3Eb coil
3Ec selection bobbin
3Ed selection core
3Ee core shaft
3Ef core spacer
3Eg holding magnet
3Eh York plate
3Ei transistor
3Ej Slide pin
3F main gear
3G character signal hole
3H Stop signal hole
3I gear mechanism
3J Spring plate
3K guide spring
3L leaf spring
3M holding plate
3N tap screw
3P wheel shaft
3Q friction spring
3R spring guide
4 Platen section
4A platen carrier
4B Platen roller
4C platen gear
4D upper paper guide
4E Paper Guide
4F Print roller carrier
4G printer carrier shaft
4H electromagnetic bearing
5 Paper feeder
5A Paper feed roller
5B Paper feed gear
5C crunch claw
5D pressing roller
5E Roller shaft
6 DC motor
6A transistor
7 Transmission mechanism
8 Power supply
8A diode
8B capacitor
8C, 8G transistor
8D, 8D1, 8D2 constant voltage diode
8E, 8F resistance
9 Interval signal generator
9A photodetector
9Aa LED
9Ab phototransistor
10 Switching section
11 paper
12 Ribbon unit
12A ink ribbon
12B Feeding ribbon lever
12C Ribbon shift lever
13 Encoder
14 Control unit

Claims (5)

In a printer apparatus that includes a DC motor and a paper feed unit and a print mechanism unit including a paper feed roller that uses the DC motor as a drive source, and performs printing by the print mechanism unit on paper fed by a predetermined amount by the paper feed unit.
A rotary plate having a position index for selecting a print wheel type by rotating in synchronization with a type roller supporting a plurality of print wheels having a type on the outer periphery thereof on a rotation shaft, and the position index And an interval signal generator having a detector that forms an interval signal by detecting
A switching unit that performs a comparison determination between the signal interval of the interval signal output from the interval signal generation unit and a predetermined interval, and outputs a switching signal when the signal interval of the interval signal becomes shorter than the predetermined interval; ,
Wherein the switching signal outputted from the switching unit, a printer apparatus wherein said <br/> comprising a power supply unit for the voltage supplied to the DC motor switches from a high voltage to a low voltage. In a printer apparatus that includes a DC motor and a paper feed unit and a print mechanism unit including a paper feed roller that uses the DC motor as a drive source, and performs printing by the print mechanism unit on paper fed by a predetermined amount by the paper feed unit.
A rotary plate having a position index for selecting a print wheel type by rotating in synchronization with a type roller supporting a plurality of print wheels having a type on the outer periphery thereof on a rotation shaft, and the position index And an interval signal generator having a detector that forms an interval signal by detecting
A comparison is made between the number of signals counted within a predetermined time of the interval signal output from the interval signal generator and a predetermined number, and when the number of signals becomes larger than the predetermined number, a switching signal is generated. A switching unit for outputting;
Wherein the switching signal outputted from the switching unit, <br/> features and to pulp printer apparatus further comprising a, a power supply unit for switching the voltage supplied to the DC motor from a high voltage to a low voltage. In a printer apparatus that includes a DC motor and a paper feed unit and a print mechanism unit including a paper feed roller that uses the DC motor as a drive source, and performs printing by the print mechanism unit on paper fed by a predetermined amount by the paper feed unit.
A rotary plate having a position index for selecting a print wheel type by rotating in synchronization with a type roller supporting a plurality of print wheels having a type on the outer periphery thereof on a rotation shaft, and the position index And an interval signal generator having a detector that forms an interval signal by detecting
A switching unit that outputs, as a switching signal, a voltage signal representing an integrated value obtained by integrating the interval signal output from the interval signal generation unit within a predetermined time;
When the voltage value of the switching signal output from the switching unit is equal to or higher than a predetermined voltage, the power source unit switches the voltage supplied to the DC motor from a high voltage to a low voltage by turning the transistor from an off state to an on state. If, <br/> features and to pulp printer apparatus further comprising: a. The printing mechanism section includes a type roller that supports a plurality of print wheels, each having a type on the outer periphery, and a platen roller that presses the paper against the type roller via an ink ribbon. Item 4. The printer device according to any one of Items 1 to 3 . 3. The printer apparatus according to claim 1 , wherein the switching unit performs the comparison determination based on the interval signal only when power is supplied to the printer apparatus.

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