JPH09150561A - Serial recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a serial recording device provided with an inexpensive carriage motor misoperation prevention means to be operated securely. SOLUTION: A recording position sensing slit of an encorder sheet 29 is formed only within the range of the movement of a carriage 3 at the time of regular recording to sense the pulses issued from the encorder only within the range of the formation of slit, and in the case the pulses are not input, the carriage 3 is regarded as moving in the abnormal operation range and a carriage motor 5 is stopped forcibly to eliminate the necessity of a sensor for sensing the carriage position, and the carriage motor misoperation prevention means which is inexpensive and space-saving and not affected by external noises can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial type recording apparatus in which recording means moves perpendicularly to a recording material carrying direction and performs recording while detecting a recording position.

[0002]

2. Description of the Related Art Conventionally, a recording device such as a printer, a copying machine or a facsimile connected to a computer or a word processor forms an image on a recording material such as paper or a plastic thin plate based on image information. Is configured.

The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type and the like according to the recording method. In either method, a recording material such as ink is attached to a recording material such as paper or a plastic thin plate to form an image. In the case of the wire dot type, a wire is projected by an electromagnetic force or the like, a ribbon impregnated with ink is hit on a recording material, and the ink is transferred to the recording material to form an image. Further, the ink-jet type utilizes the pressure change caused by the generation and contraction of bubbles due to film boiling formed by the thermal energy applied by the electrothermal energy converter by the recording means (inkjet head), and the ink is recorded on the recording material. An image is formed by using a device configured to eject and record, or an ink ejecting unit that ejects ink onto a recording material by changing the volume of the ink chamber by an electromechanical transducer such as a piezo element. What is formed is general.

Further, the recording apparatus has a recording means mounted on a carriage, and a serial type for recording while reciprocating the front surface of a recording material, and a direction (main scanning direction) perpendicular to a recording material conveying direction (sub-scanning direction). ), A large number of recording means are arranged on a straight line, and the recording material is conveyed while the recording means is fixed, and the recording type can be classified into a line type.

The line type recording apparatus is provided with recording means corresponding to the recordable range in the main scanning direction, and at the same time, it is possible to record a large range, so that there is an advantage that very high speed recording is possible. On the other hand, since the recording means is required over the entire recordable range, the cost of the recording means becomes very high, and the maximum resolution in the main scanning direction is determined by the mounting pitch of the recording means element, and the recording pitch is higher than the mounting pitch. It has the disadvantage that the resolution cannot be achieved. On the other hand, since the serial type recording apparatus performs recording while moving a small number of recording means within the recording range, it has a disadvantage that it takes time to complete recording, but it is low in price because the number of recording means is small. In addition, since the maximum resolution can be changed relatively freely by providing a position detection unit according to the resolution and recording according to the recording signal generated by this position detection unit, it is a serial as a low-cost and high-resolution recording device. Mold recorders are the mainstream.

In the serial type recording apparatus, as described above, recording is performed while moving the recording means within the recording range. However, since this operation is generally performed by the central processing means such as a microcontroller controlling the motor, If the central processing means falls into an uncontrollable state (hereinafter, this state is called "runaway") due to external noise such as static electricity, lightning surge, power source impulse noise, etc. during the recording operation, the motor cannot be controlled. Even if the carriage moves beyond the range of movement for normal recording, the recording means continues to move, and eventually collides with the side plate of the recording apparatus, seriously damaging the recording means, the motor, and the recording apparatus itself. Therefore, generally, in the serial type recording apparatus, when the central processing unit runs out of control, a malfunction prevention unit is used for forcibly stopping the operation of the recording unit for safety.

A conventional serial type ink jet recording apparatus will be described below. 7 is an external view of a conventional serial type recording apparatus, FIG. 8 is a partial structural view of the same carriage, FIG. 9 is a block diagram of the same apparatus, FIG. 10 is a flowchart for explaining the same recording operation, and FIG. 11 is for explaining the same recording operation. Various waveform diagrams, FIG. 12 is an explanatory view of the carriage motor malfunction prevention means, FIG. 13 is an explanatory view of the carriage motor malfunction prevention means, FIG. 14 is an explanatory view of the carriage motor malfunction prevention means, and FIG. 15 is the carriage motor malfunction operation. It is a defect explanatory drawing of a prevention means. FIG. 7 is an external view of the serial type ink jet recording apparatus as seen from the front side. 1 is a recording means in which an ink tank and an ink jet head for ejecting ink are integrated, 2 is a recording medium, and 3 is a recording means 1. Then, the carriage 4 that moves in the direction perpendicular to the transport direction of the recording material 2 is arranged parallel to the moving direction of the carriage 3 and transmits light at a pitch corresponding to the actual recording position on the recording material 2. Encoder sheets 5 in which alternating portions and slits that do not pass through are alternately arranged, a carriage motor 5 for reciprocating the carriage 3 in the arrow direction via a power transmission belt 6, and a recording apparatus side plate 7 to which the encoder sheet 4 is fixed. Is.

FIG. 8 is a view of the carriage 3 seen from the direction perpendicular to FIG. 8 is a carriage shaft that is arranged in parallel with the moving direction of the carriage 3 and supports the carriage 3.
Reference numeral 9 denotes an encoder sensor that detects a portion of the encoder sheet 4 that transmits light and a portion that does not transmit light, and outputs "high" and "low" signals corresponding to the print pitch, and is fixed to the carriage 3.

In FIG. 9, a computer 10 outputs image information and character information to be recorded to an ink jet recording apparatus. A central processing unit (CPU) 11 processes input information and controls the entire apparatus.
A storage unit 12 stores a program for information processing performed by the central processing unit 11 and control of the apparatus, and provides the program to the central processing unit 11. Reference numeral 13 is an inkjet head for ejecting ink, and 14 is a head driving means for driving the inkjet head 13.

A carriage position detector 16 receives a signal from an encoder sensor 9 for generating a signal corresponding to the slit position of the encoder sheet 4 as the carriage 3 moves and counts the signal to detect the carriage position. It is a counter. Reference numeral 15 is a recording start signal generating means for inputting a signal from the encoder sensor 9 and generating a recording start signal at a change point of the signal. Reference numeral 5 denotes a carriage motor used to move the carriage 3, 17 denotes a carriage motor driver for driving the carriage motor 5, and 18
Is a recording material conveying motor used for conveying the recording material 2, and 19 is a recording material conveying motor driver for driving the recording material conveying motor 18. Reference numeral 20 denotes a power supply unit, which rectifies a general household AC power supply and supplies it as a DC power supply with electric power necessary for an electric block of the entire apparatus. 2
Reference numeral 1 is a limit switch for detecting that the carriage 3 has deviated from the recording operation range, and 22 is the central processing means 11 when the central processing means 11 runs out of control and the carriage motor 5 enters the abnormal operation range. It is a carriage motor malfunction prevention means for forcibly stopping without a command.

Next, the operation will be described with reference to the flowchart of FIG. When printing is performed, the central processing means 11 outputs a motor drive signal to the carriage motor driver 17 to move the carriage motor 5 toward the position where printing is started (step 1). Central processing means 11
Reads the value of the carriage position detection counter 16 to which the encoder signal is input (step 2), and the carriage 3
Detects whether the recording start position has reached (step 3). When the carriage 3 reaches the recording start position, the recording start generation signal corresponding to the change point of the encoder signal is generated by the recording start signal generation means 15, ink is ejected according to this signal, and recording is performed (step 4). At the same time, the central processing means 11 reads the value of the carriage position detection counter 16 (step 5) and judges whether or not the carriage motor 3 has reached the recording end position (step 6). When the point at which recording is completed is reached, the central processing means 11 outputs a motor stop signal to the carriage motor driver 17 to stop the carriage motor 5 (step 7). Here, it is judged whether or not the printing sequence is finished (step 8), and if it is finished, the printing operation is finished (step 9), and if the printing is to be continued, the moving direction of the carriage motor 3 is reversed (step 1).
0), the same operation is repeated from step 1 again.

FIG. 11A is a signal waveform of the encoder sensor 9 from when the carriage 3 starts moving to when it stops in the flowchart of FIG. 10, and FIG. 11B shows FIG.
A carriage for detecting the position of the carriage 3 by counting the number of recording position signals corresponding to the change point of the signal waveform of the encoder sensor 9 in FIG. 1A, and FIG. 11C in FIG. 11C. The change in the content of the position detection counter 16 is shown (in this example, counting is performed from 1 to 3000). FIG. 11D is a counter value increase curve showing how the contents of the carriage position detection counter 16 increase with time.

As described above, since the central processing means 11 starts and stops the operation of the carriage motor 5 while reading the value of the carriage position detection counter 16, static electricity, lightning surge, and power source impulse noise are generated during the recording operation. When the central processing means 11 runs out of control due to external noise such as, the stop signal of the carriage motor 5 is not issued, and the range over which the carriage 3 moves for normal recording (hereinafter referred to as "normal operation range") is exceeded (hereinafter normal). Even if the range from the operation range to the recording device side plate 7 is called the “abnormal operation range”), the carriage 3 continues to move, and finally it collides with the recording device side plate 7 and seriously affects the carriage 3, the carriage motor 5, and the recording device itself. Cause serious damage.

Therefore, conventionally, in order to prevent such a malfunction, the carriage motor 5 is forcibly stopped without a motor stop command of the central processing means 11, so that the carriage motor malfunction prevention means 22 in FIG. 9 is used. To be As a concrete example of the carriage motor malfunction prevention means 22, conventionally, the methods shown in FIGS. 12 to 14 have been used.

FIG. 12 shows a first example of the carriage motor malfunction prevention means 22, and its operation is shown in FIG.
This will be described with reference to (c). In FIG. 12 (a), 23
Is a carriage stop position setting register that sets the value of the carriage position detection counter 16 at which the carriage motor 5 is stopped.
It is set by 1. Reference numeral 24 is a comparator that compares the values of the carriage position detection counter 16 and the carriage stop position setting register 23, and outputs a "low" signal if they match, and 25 is a 2-input AND circuit. FIG. 12B shows changes in the contents of the carriage position detection counter 16 and the carriage stop position setting register 23. As is apparent from the figure, if external noise is applied at the time of the arrow in the figure and the central processing means 11 runs away, the value of the carriage position detection counter 16 continues to increase even if it exceeds the normal operation range, and the carriage 3 moves. When it enters the abnormal operation range, it matches the value of the carriage stop position setting register 23. Then, the output of the comparator 24 changes from "high" to "low" as shown in FIG. 12 (c), and the output of the 2-input AND circuit 25 does not depend on the content of the motor control signal of the central processing means 11. When it becomes "low", the carriage motor 5 is forcibly stopped.

FIG. 13 shows a second example of the carriage motor malfunction prevention means 22 in which sensors such as the limit switch 21 are provided within the abnormal operation range. The operation will be described. In FIG. 13A, 26 is a 3-input A.
It is an ND circuit. When external noise is applied at the time point of the arrow in FIG. 13B and the central processing means 11 runs away, the carriage 3 continues to move beyond the normal operation range, and finally contacts the limit switch 21 in the abnormal operation range. . Then, the output of the limit switch 21 changes from "high" to "low", and the output of the 3-input AND circuit 26 also becomes as shown in FIG.
As shown in (b), the carriage motor 5 becomes "low" regardless of the contents of the motor control signal of the central processing means 11.
Is forcibly stopped.

FIG. 14 shows a third example of the carriage motor malfunction prevention means 22, and its operation is shown in FIG.
This will be described with reference to (c). In FIG. 14 (a), 2
7 is a voltage dividing resistor that creates a reference voltage when determining whether the winding current of the carriage motor 5 is normal or abnormal. 28 is a comparison between the reference voltage and a voltage proportional to the value of the winding current of the carriage motor 5. However, it is a comparator that outputs "low" when the winding current becomes larger. When external noise is applied at the time of the arrow in FIG. 14C and the central processing means 11 runs away, the carriage 3 continues to move beyond the normal operating range and finally reaches the recording device side plate 7. Then, the carriage motor 5 is locked and more winding current flows than during normal operation, and the voltage proportional to the winding current (the voltage at point A in FIG. 14A) is the reference voltage ( 14 (a) voltage (point B in FIG. 14A)
The output of 8 changes from "high" to "low" as shown in FIG. 14 (c). Therefore, the output of the 2-input AND circuit 24 is irrespective of the content of the motor control signal of the central processing means 11.
When it becomes "low", the current flowing through the carriage motor 5 is forcibly cut off and the carriage motor 5 is stopped.

[0018]

However, the conventional carriage motor malfunction preventing means shown in FIGS.
There are the following problems. First, in the first example, if the external noise is such that the central processing means 11 malfunctions, both the contents of the carriage position detection counter 16 and the contents of the carriage stop position setting register 23 are destroyed, and malfunction prevention is prevented. The means may not work properly.
This will be described with reference to FIG. FIG.
It is assumed that the external noise is applied at the same time point as in (b), the value of the carriage stop position setting register 23 is larger than that before the external noise is applied, and the value of the carriage position detection counter 16 is small and becomes 0. After the external noise is applied, the central processing means 11 runs away and the carriage 3 continues to move. Therefore, the value of the carriage position detection counter 16 starts to increase again, but the content of the carriage position detection counter 16 which is once cleared to 0 is the content of the carriage 3. Does not become a sufficiently large value even if it enters the abnormal operation range, and the carriage stop position setting register 23 is also large, so that the carriage 3
However, the carriage 3 may collide with the recording device side plate 7 at last because the values of the two registers do not match even when the recording medium reaches the recording device side plate 7, and the forced stop signal to the carriage motor 5 cannot be generated. There is.

Next, in the second example, the carriage motor 5 can be reliably stopped without being affected by noise, but two limit switches 21 are provided near the left and right recording device side plates 7. In addition to the need for sensors such as the above, not only the cost is greatly increased, but also the switch mounting space must be secured, which is an obstacle to downsizing the entire recording apparatus.

Further, in the third example, the carriage motor 5 is locked, and the overcurrent flows in the motor winding after the carriage 3 crashes into the printing apparatus side plate 7 and the motor is locked. Although it is possible to prevent the motor from burning due to the continuous flow of current to the carriage motor 5, it is impossible to prevent damage to the carriage 3 and the recording apparatus itself.

Therefore, in the conventional carriage motor malfunction prevention means, the method which does not use the sensor such as the limit switch 21 is not effective enough to protect the carriage 3 and the recording apparatus from the malfunction of the carriage motor 5.
The method using a sensor such as the limit switch 21 has problems such as an increase in cost and a space for mounting the sensor.

Therefore, an object of the present invention is to provide a serial type recording apparatus equipped with a carriage motor malfunction preventing means which is inexpensive and operates reliably.

[0023]

To this end, the serial type recording apparatus of the present invention comprises a recording means for recording while moving in the main scanning direction, and a recording position only within the maximum range in which the recording means moves during normal operation. And a detection means for detecting that the signal from the position detection means has disappeared when the recording means moves out of the normal operation range, and the recording means is out of the normal operation range. If the recording medium is erroneously moved, the recording medium has a malfunction preventing means capable of immediately stopping the movement of the recording means.

[0024]

According to the present invention, although the carriage position detecting sensor such as the limit switch is not used, it can be surely detected that the carriage is moving within the abnormal operation range, and the central processing means. Even if the printer runs out of control, the carriage motor can be reliably stopped without damaging the carriage, the carriage motor, and the recording apparatus.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a serial type recording apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged view of the encoder sheet and an encoder output signal waveform diagram, FIG. 3 is a block diagram of the carriage motor malfunction preventing means, and FIG. FIG. 5 is an operation explanatory view of the carriage motor malfunction prevention means, FIG. 5 is an operation explanatory view of the carriage motor malfunction prevention means, and FIG. 6 is a block diagram of the apparatus. The same elements as those in the conventional example are designated by the same reference numerals.

FIG. 1 is an external view when a slit is provided only in the normal operation range of the carriage and an encoder sheet 29 having a full solid abnormal operation range is attached to the recording apparatus. 2A is an enlarged view of the encoder sheet 29, FIG.
(B) is an encoder signal waveform obtained from the encoder sheet 29, and the portion where the slit is provided as shown in FIG.
Although a pulse-like signal is obtained from the encoder sensor 9 when the carriage moves, a "low" signal is always output in the full-solid portion, that is, in the abnormal operation range of the carriage 3.

Next, the basic operation of the carriage motor malfunction prevention means 30 using the encoder signal obtained from the encoder sheet 29 will be described with reference to FIGS. 3 and 4, it is assumed that the value of the internal counter does not change due to external noise. In FIG. 3, 30
Is a carriage motor malfunction prevention means, 31 is a free-run counter which automatically counts up when the reference clock 32 is input, and is cleared to zero when the reset input becomes "high", 33 is an encoder sensor 9 Edge detection circuit for detecting the change point of the input signal pulse of
Is compared with the value of the free-run counter 31 to determine the count value for stopping the motor, the carriage stop reference value, 3
Reference numeral 5 is a comparator which compares the value of the free-run counter 31 with the value of the carriage stop reference value 34, and outputs "low" when they are equal.

First, the operation when the carriage 3 is moving within the normal operation range will be described. FIG. 4A shows a waveform at point A in FIG. 3, which represents the output signal of the encoder sensor 9. When the carriage 3 is moving within the normal operation range, pulses are output at regular intervals as shown in the figure. When this signal is input to the edge detection circuit 33, the waveform at point B in FIG. 3 outputs a thin pulse as shown in FIG. 4B corresponding to the change point of the encoder sensor 9 signal pulse.
Since this signal is connected to the reset input of the free-run counter 31, the free-run counter 31 is reset at regular intervals, the counter value does not exceed a certain fixed value, and matches the carriage stop reference value 34. Nothing (Fig. 4 (c)). Therefore, the output D of the comparator 35 remains "high" within the normal operation range as shown in FIG.
The input AND circuit 25 passes the motor control signal of the central processing means 11 as it is.

Next, the operation when the carriage 3 is moving within the abnormal operation range will be described. Carriage 3
Is moving within the abnormal operation range, the encoder sheet 29 is full solid, so the output of the encoder signal is always "low" as shown in FIG.
The waveform of the point will also continue to be "low" (Fig. 4
(A)). Then, since the free-run counter 31 is not reset, the counter value continues to increase and finally becomes the same as the carriage stop reference value 34 (FIG. 4).
(C)). At this point, the output point D of the comparator 35 is "low".
(FIG. 4 (d)), the output of the 2-input AND circuit 25 becomes "low" regardless of the output of the central processing means 11,
The carriage motor 5 is forcibly stopped.

Next, a case where the contents of the free-run counter 31 are changed by external noise will be described. If the carriage 3 receives external noise within the normal operation range and the content of the free-run counter 31 changes so as to be larger than the motor stop reference value, the output of the comparator 35 becomes "low" at that time. The carriage motor 5 stops. Next, the case where the value of the free-run counter 31 becomes much smaller than the value before receiving the external noise is shown in FIG.
This will be described with reference to (a) to (d). In FIG. 5, FIG. 5 (c)
It is assumed that the contents of the free-run counter 31 have become 0 due to the influence of external noise at the time indicated by the arrow. Since the carriage stop reference value 34 is a fixed value, it does not change due to noise. In FIG. 5C, the contents of the free-run counter 31 are temporarily cleared to 0 due to the influence of external noise.
Start counting up again. Since it is within the normal operation range, the free-run counter 31 is reset by the reset signal generated from the output of the edge detection circuit 33 corresponding to the change point of the encoder sensor 9 although the value is smaller than usual. Becomes Then, the free-run counter 31 starts counting up again, but at this time, since it becomes exactly the same as that in FIG. 4C when no external noise is received, the central processing means 11 runs away due to the external noise, If the carriage 3 moves within the abnormal operation range,
The carriage motor 5 is stopped in the same procedure as described with reference to FIG.

In this embodiment, the encoder sheet 29 in the portion corresponding to the abnormal operation range is full solid (all black).
The case has been described above, but since it is sufficient if there is no slit in the abnormal operation range, the same effect can be obtained even if the full solid part is made transparent.

FIG. 6 shows an apparatus block diagram of a serial type ink jet recording apparatus using the encoder sheet 29 and the carriage motor malfunction prevention means 30 used in this embodiment. As is clear from comparison with FIG. 9, sensors such as the limit switch 21 are unnecessary.

[0033]

According to the present invention, even if the central processing means goes out of control due to the influence of external noise and the carriage deviates from the normal operating range, the carriage motor can be reliably stopped without using a sensor such as a limit switch. Because you can
It is possible to realize a malfunction prevention means for a carriage motor that is inexpensive and does not require a sensor mounting space.

[Brief description of the drawings]

FIG. 1 is an external view of a serial type recording apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of an encoder sheet and an encoder output signal waveform diagram of a serial type recording apparatus according to an embodiment of the present invention.

FIG. 3 is a block diagram of carriage motor malfunction prevention means of the serial type recording apparatus according to the embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of a carriage motor malfunction prevention unit of the serial type recording apparatus according to the embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of a carriage motor malfunction prevention unit of the serial type recording apparatus according to the embodiment of the present invention.

FIG. 6 is a device block diagram of a serial type recording device according to an embodiment of the present invention.

FIG. 7 is an external view of a conventional serial type recording device.

FIG. 8 is a partial structural diagram of a carriage of a conventional serial type recording apparatus.

FIG. 9 is a device block diagram of a conventional serial type recording device.

FIG. 10 is a flowchart illustrating a recording operation of a conventional serial type recording device.

FIG. 11 is various waveform charts for explaining a recording operation of a conventional serial type recording device.

FIG. 12 is an explanatory diagram of a carriage motor malfunction prevention unit of a conventional serial type recording apparatus.

FIG. 13 is an explanatory diagram of a carriage motor malfunction prevention unit of a conventional serial type recording apparatus.

FIG. 14 is an explanatory diagram of a carriage motor malfunction prevention unit of a conventional serial type recording apparatus.

FIG. 15 is an explanatory diagram of defects of the carriage motor malfunction prevention means of the conventional serial type recording apparatus.

[Explanation of symbols]

 1 Recording Means 2 Recording Material 3 Carriage 4 Encoder Sheet 5 Carriage Motor 6 Power Transmission Belt 7 Recording Device Side Plate 8 Carriage Shaft 9 Encoder Sensor 10 Computer 11 Central Processing Means 12 Storage Means 13 Inkjet Head 14 Head Driving Means 15 Recording Start Signal Generation Means 16 Carriage Position Detection Counter 17 Carriage Motor Driver 18 Recording Material Conveying Motor 19 Recording Material Conveying Motor Driver 20 Power Supply Unit 23 Carriage Stop Position Setting Register 24 Comparator 25 2 Input AND Circuit 26 3 Input AND Circuit 27 Voltage Dividing Resistance 28 Comparator 29 Encoder sheet 30 Carriage motor malfunction prevention means 31 Free-run counter 32 Reference clock 33 Edge detection circuit 34 Carriage stop reference value

Claims (1)

[Claims] 1. A recording means for recording while moving in the main scanning direction, a position detecting means capable of detecting a recording position only within a maximum range in which the recording means moves during normal operation, and a normal operating range for the recording means. And a detection means for detecting that the signal from the position detection means has disappeared when the recording means moves outside, and immediately stops the movement of the recording means when the recording means accidentally moves outside the normal operation range. A serial type recording apparatus having a malfunction prevention means capable of performing the operation.