JPS5887964A - Carriage control system - Google Patents

Abstract

PURPOSE:To quickly detect a failure in a carriage, by providing a home stop position of the carriage at the left side of the set position of an original and a recording paper, and measuring the time from the host stop position to the set position. CONSTITUTION:When a start/stop control signal S1 of a servo motor and a command signal S2 indicating forward drive are given to a driver 17 from a control section 21, a servo motor 3 is driven forward and a carriage 1 starts moving right. A home stop position sensor 7 generates a sense signal when the carriage 1 leaves the home stop position. A distance between the home stop position and the left end position for an original is set in the ''256'' step of the servo motor 3. When the counted value of an up-down counter 19 goes to zero and all binary outputs go to logical zero, it is detected that the carriage 1 has come to the left end of the original.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carriage control system for facsimile machines, printers, etc. that performs document reading and recording operations while moving the carriage in a direction perpendicular to the conveying direction of the document or recording paper. If an abnormality occurs in the servo motor that drives the carriage, the carriage mechanism, etc., and the carriage is not moved at the specified speed and scanning is not performed correctly, the entire system is immediately stopped to reduce the impact compared to the impact placed on the carriage. This invention relates to a carriage control method that improves the safety of equipment by preventing mechanical shock to vulnerable components and burnout of motors.

2. Description of the Related Art Facsimile machines, printers, and the like that perform document reading and recording operations while moving a carriage in a direction perpendicular to the direction in which the document or recording paper is conveyed have been used in the past.

FIG. 1A is a perspective view showing an example of a conventional facsimile machine that performs document reading and recording operations while moving a carriage in a direction perpendicular to the conveying direction of the document or recording paper;
FIG. 1B is also a side view thereof. In the drawing,
/ is the carriage, /a is the reading section, /b is the recording section, -
is a guide rail, 3 is a servo motor, da is a rotary encoder, S is a pulley, O is a wire, 7 is a home stop position sensor %ga and gb are document start edge detection sensors, 9 is a document feed roller, 10 is a document, // indicates recording paper,
Also, arrows indicate the direction of movement.

In the facsimile machine shown in FIGS. 1A and 1B, the document 10 and recording paper // are transported in the direction of the arrow, and the carriage / is moved in a direction perpendicular to the transport direction. That is, the wire B is driven in accordance with the rotation of the servo motor 3, and the carriage / on which the reading section /a and the recording section /b are mounted reciprocates on the guide rail a.

This carriage/ is provided with a plurality of reading elements and recording elements with respect to the conveyance direction of the original 10 and the recording paper //, and as the carriage/ is moved seven times in the direction of the arrow, Reading and recording operations for multiple lines are performed simultaneously.

Please note that read data and received recorded data are
The data is temporarily stored in a memory (not shown), converted in an appropriate order, and then read out.

The home stop position sensor 7 is a sensor that detects the presence or absence of the carriage at the start of each reading or recording operation or scan. When the carriage stops driving and leaves its home stop position, the sensor output is reversed. The time point at which the carriage starts moving is detected.

Further, the current position of the carriage is detected by an encoder output from a rotary encoder coaxially attached to the servo motor 3. That is, seven pulse signals are outputted from the encoder for each step of the servo motor 3, and are given to a control section (not shown), such as a μCPU, for counting.

In this case, from the home stop position to the starting edge position MV of the original 10 or recording paper //, for example, the paper width of the original /θ is 7.72g steps, in the case of the header width, the paper width is 7.72g steps, B
In the case of 4 widths: z, ottg steps are predetermined.

When the carriage / passes the end position of the document 10 or the recording paper //, the servo motor 3 is rotated in the opposite direction, and the carriage / is returned to the home stop position again. At the same time, manuscript 1
0 and recording paper // are also conveyed in the direction of the arrow l\, and preparation for the next / scan is completed.

The above explanation assumes that the facsimile machine operates normally and that the carriage is moved at a predetermined speed.

However, in reality, various abnormalities occur due to various causes.

In other words, if the servo motor 3 breaks down, an abnormality occurs in the rotary encoder, or an abnormal condition occurs such as poor contact or disconnection of the connector of these circuits or disconnection of the wiring while the facsimile machine is operating. , the carriage/ is moved at high speed in the direction of the arrow and collides with the side plate. Therefore, the reading element, illumination lamp, and other components mounted on the carriage that are susceptible to mechanical shock may be damaged.

In addition, problems with the carriage mechanism, that is, the mechanism that holds or moves the carriage, such as oil leaks, etc.
Wire breakage, wire stretching, aging of the wire tensioning spring, contamination of foreign objects, scattering of originals and recording paper, reduction in motor driving force, failure of the drive device, abnormality in the control system, excessive or insufficient motor load. When this occurs, the carriage/carriage is not moved at a predetermined speed, and especially if an abnormal load is applied to the servo motor, there is a risk that not only the motor will be burned out but also the equipment may be damaged.

In these cases, the speed of the carriage differs from the predetermined speed, so correct scanning will not be performed.

Therefore, the carriage control method of the present invention solves these inconveniences in the conventional key carriage drive device, and uses a simple circuit.If it is predicted that correct scanning will not be performed, the system can be By stopping the entire system, the purpose is to improve the safety of the device by preventing mechanical shock to components mounted on the carriage and from burning out the motor and the like, which are relatively vulnerable to shock.

For this purpose, in the carriage control system of the present invention, a home stop position of the carriage is provided to the left of the position where the original or recording paper is set, and the carriage starts moving to the right from this home stop position, and then moves to the home stop position. For example, a range such as the distance from the left end position of a set document, etc. is set in advance, and when the preset time to move within this range has elapsed, the carriage moves to the position of the set range. For example, the presence or absence of an instruction signal instructing that the left end position of a set document or the like has been reached is detected, and if no instruction signal is detected, movement of the carriage is immediately stopped.

FIG. 2 is an example of a schematic top view of the periphery of the carriage used to implement the carriage control method of the present invention and a block diagram showing the main parts of its control circuit. The numbers in the drawings are the same as those in Figure 1 A and B above, and 7, 2
is the side plate, /3 is the end position sensor, /lI is the mono multivibrator, /S is the integrator, /6 is the analog comparator, / is the driver, 7g is the reference voltage switching section, /q
is an up/down counter, 20 is a first gate circuit, 2
/ is the control unit, UU is the upper limit setter 1.23 is the lower limit setter 5
．． 2da is a comparator, S is a gate circuit, U6 is a mono multivibrator, Near is a start sensor, 2g is an AND gate circuit, S/ is a servo motor 0 start/stop control number, and 82 is a Servo motor forward/reverse instruction signal, S3 is reading/recording enable signal, SII is count range display signal, St is paper size designation signal for original or recording paper, S6 is gate signal, S7 is home stop position sensor 7 start sensor output signal generated by,
sg is the output signal of the AND gate circuit 2g, Sq is the preset signal, S70 is the end position sense signal, S// is the output signal of the lees separator/S, S7.2 is the output signal of the up/down counter/q, and S73 is the output signal of the up/down counter/q. The output signal of the upper limit setter 2.2 indicates the upper limit count of the normal range; S/lI is the output signal of the lower limit setter 2.2 that indicates the lower limit count of the normal range;
El and E indicate reference voltages when the carriage moves forward and backward, respectively, and A4' and BII indicate the paper width of the original or recording paper to be set. Note that the white arrow indicates the conveyance direction of the original or recording paper.

The area around the carriage shown in FIG. 2 is basically the same as that of the facsimile machine shown in FIGS. 1A and 1B.

That is, by means of a wire 6 that transmits the rotation of the servo motor 3, the carriage on which the reading section and the recording section are mounted reciprocates on the guide rail a supported by the side plate to perform scanning. , carriage/ starts moving rightward from the left home stop position, and is accelerated to a constant speed until it reaches the left end position of the document or recording paper.

FIG. 3 is a time chart for explaining the operation of the circuit shown in FIG. 2 using the carriage control method of the present invention.

The symbols attached to each signal waveform in the drawing correspond to the symbol positions in FIG. It is the center count value of the position of the set range, +α indicates the upper limit count value, and -β similarly indicates the lower limit count value.

When the carriage starts moving, it is stopped at a Baum stop position to the left of the position where the original or recording paper is set.

Then, when the servo motor start 1/stop control signal S/ and an instruction signal 82 instructing forward rotation are given to the driver/7 from the control unit 2/ consisting of a μCPU, the servo motor 3 rotates in the forward direction. The carriage starts moving to the right.

The home stop position sensor 7 generates a sense signal when the carriage leaves the home stop position and transmits it to the start sensor 27. Therefore, the output signal S7 of the start sensor core is changed to the L level as shown in S7 in FIG.

This start sensor output signal S7 is applied to the AND gate circuit 2 together with the gate signal S generated from the control section 2/.
Enter it into g. Further, this start sensor output signal S7 is used to determine whether the carriage / is located at the home stop position or whether the carriage / has returned to the home stop position after one movement. I can't help but feel strong. The output signal S of the AND gate circuit 2g is
The preset signal Sq is applied to the multivibrator octopus B to generate a preset signal Sq. As a result, the up/down counter/
In this case, q is "-" like Count in Figure 3.
23A”.

Further, as the servo motor 3 rotates, the rotary encoder also rotates, and for each step of the motor, for example, seven pulse signals are generated as encoder outputs.

This encoder output is a mono multivibrator/II
The signal is input to the up/down counter /q and the integrator 15 through the .

The up/down counter /9 is a counter that indicates the current position of the carriage /.When the carriage starts moving from the home stop position, its count value becomes [-,25Aj
It is said that The count is sequentially counted up as the servo motor 3 rotates in the normal direction, and the count value is designed to become "0" when the carriage reaches the left end position of the document or the like. Note that when the paper size of the original is "AIl", the right end position is "/, 72g", and when the paper size is l'-111, it is "2.O'1g".

The integrator /S controls the speed of the servo motor 3 together with the next analog comparator /6, and the output signal S// of the integrator /S is , reference voltage E, to control the output of driver/7.

When the carriage starts moving, the speed of the servo motor 3 is slower than the constant speed v1, so it is accelerated, and by the time the carriage reaches the left end position of the set original, etc., the 0 servo motor 3 is at a constant speed v. When the speed of the motor 3 is constant V and the moving speed of the carriage is also constant,
When the left end position of the document, etc. is reached, the count value of the up/down counter /q becomes "θ".0 As already explained, in this embodiment, the home stop position of the carriage / and the left end position of the set document, etc. The distance between the servo motor 3 and the
'', and when all binary outputs become logic 10', it is detected that the carriage / has reached the left end position of the set document, etc. This binary output, all of which is logic '0', is used as the arrival indication signal.

The binary output of the up/down counter /q is given to the first gate circuit 20, and all signals indicating that the carriage / has reached the left end of the document etc. are determined by the arrival instruction signal of logic 'θ' 73 - read/write enable signal S from the first gate circuit θ;
3 is generated and given to the control section 2/ and other units such as a reading section and a recording section (not shown).

This reading/recording enable signal S3 starts the /scan reading operation or recording operation, and the carriage /
is further moved to the right while performing a reading or recording operation.

If the paper size of the manuscript is [Adar-1, then the count of the uptown counter /q (direct is "/.

72 becomes -1, the control unit 2/ switches the servo motor forward/reverse instruction signal S2 to a reverse instruction, and the driver/
7 to the reference voltage switching unit/g.

Therefore, the servo Tanabata 3 is rotated in the opposite direction at a speed as indicated by ◯ in FIG. 3, and the carriage is returned to the left home stop position.

Under normal conditions, such reciprocating motion of the carriage is repeated until the removal or recording operation is completed for all rows of the original b or recording paper.

-/dar- However, for some reason, the servo motor... If the movement speed of the carriage does not fall within the specified range due to a malfunction in the carriage or encoder, or an abnormality occurs in the carriage holding mechanism or movement mechanism, such carriage reading operations will not be possible. .

For example, a case where the moving speed of the carriage becomes abnormally high has a relatively high probability of occurring because the motor system becomes uncontrollable immediately after the carriage starts moving from the left home stop position. The carriage / is accelerated and moved to the right at a high speed, collides with the right side plate /2, and stops.

End position sensor installed in front of the right side plate/
3 operates when such an abnormality occurs and generates an end position sense signal S70, thereby notifying the driver 7 and the control unit 7 to that effect.

In response to this sense signal S70, the output of the driver/7 is stopped to prevent burnout of the servo motor 3, etc., and the control unit 2/ stops the operation of the facsimile machine or takes internal prevention measures such as cutting off the power supply. become.

However, since the weight of the carriage / is relatively large and its moving speed is high, the right side plate /
, 2, the carriage/ receives a large impact. As a result, the reading element mounted on the carriage, the original axis illumination lamp, etc. may be damaged, and the entire carriage mechanism may be subjected to unexpected physical distortion.
In some cases, damage may be beyond repair.

On the other hand, a case in which the moving speed of the carriage becomes abnormally slow can be considered, for example, when the mechanical load on the servo motor 3 becomes large for some reason.

In this state, the control system of the servo motor 3 controls the servo motor 3 to reach a predetermined speed, and an excessive drive current flows. However, when the load is large, the carriage / does not reach the right end, so the end position sensor / 3 is not activated, and the driver / 7 continues to generate output, which may cause the servo motor 3 to burn out.

Furthermore, an excessive load is placed on the economically designed servo motor 3's driver/driver and the power supply (not shown), so the effects of such an abnormality spread in many directions, and losses occur over an unexpectedly wide range. There is a possibility that.

Therefore, in the carriage control method of the present invention, the moving speed of the carriage is detected using a simple circuit, and when the moving speed is abnormally fast, the carriage is prevented from colliding with the right side plate. This protects the reading element, document illumination lamp, and other components that are susceptible to mechanical shock, and also prevents physical distortion from occurring. Conversely, when the movement speed is abnormally slow, excessive motor The drive is avoided to avoid mechanical and electrical damage to the drive system.

As described above, the distance between the home stop position of the carriage and the left end position of the set document, etc. is predetermined, for example, by the step [2S677-'' of the servo motor 3.

Further, the time required for the carriage to move through this period is also determined in advance based on the starting characteristics of the servo motor 3, inertia due to the load, and the like.

Therefore, when the carriage starts moving from the home stop position, under normal operating conditions, it will reach the left end position of the document or the like after a predetermined time has elapsed. Then, when the carriage / reaches the left end position of the original, etc., in the case of the circuit shown in Figure 1, all the binary outputs from the up/down counter /q become logic 10', and the first gate circuit, 20 Output to.

At this point, the first gate circuit 20 outputs a read/write enable signal S3 at H level and is applied to the control section 2/, and the read/write operation is started.

In the carriage control system of the present invention, in order to detect the moving speed of the carriage /, the output signal S7.2 of the up/down counter /q is applied to the comparator 2, as shown in FIG. This output signal -7g - signal S72 is output on a plurality of lines, and when the contents of the counters are all logic 10', all of these signals become logic 10''.

This comparator 21I, unlike the first gate circuit C0 described above, can detect the value of the output signal S72 even when the output signal S72 is not all logic 10'.

For this purpose, the comparator 2+ is given an output signal S73 from the upper limit setter 23 which indicates the upper limit count of the normal range, and an output signal S/4' from the lower limit setter 23 which also indicates the lower limit count. It will be done. Note that the comparator 2'l is composed of an extremely simple gate circuit, and the upper limit setter 2.2 and the lower limit setter 23 are set to a fixed logic '/' or '0' so that a predetermined value can be obtained. ′ by connecting it to the signal source.

Therefore, the output signal S/ of up/down counter /q
The count value input as l is the upper limit signal S73.
and a lower limit signal S/+, and when the count value is within the upper and lower limits, an output signal is generated from the comparator to the third gate circuit 3. Then, the count in-range display signal S<Z, as shown at Sll in FIG. 3, is output from the first gate circuit 2 to the control section 2.

FIG. 3 shows a case where the count value T at the center of the comparator 24 is positive, the lower limit value is 'T-β', and the upper limit value is '''
It becomes T ten α1. Note that the upper limit value α and lower limit value β are αNβ
or α-β.

However, the center value T does not necessarily have to be positive, and may be set to 10', which corresponds to the left end position of the document or the like. Also,
It is also possible to choose a negative value.

Here, the case where the center count value T is positive as shown in FIG. 3 will be explained.

A timer is built into the control unit 2/ consisting of a μCPU, and this timer is set when the start/top control signal S/ of the servo motor 3 is generated, and the carriage/ is moved from the home stop position to a predetermined count. It is activated when the time required to move to the position corresponding to the center value T has elapsed.

For example, the gate signal S6 necessary for generating the preset signal S9 of the up/down counter /q is
Controlled by timer.

In the time chart of Fig. 3, the scale at the start of the servo motor is shown on a slightly enlarged scale, but when the gate signal S set in the timer falls, the control unit
determines whether or not the count range indication signal Sg is generated from the third gate circuit U.

If the count in-range display signal SII is not generated at this point, it is assumed that an abnormality has occurred in the control system of the servo motor 3, and the start and top control signals S/ are generated as shown by the dotted line. Stop immediately. As a result, the servo motor 3 is stopped and the movement of the carriage is also stopped.

As described above, in the carriage control method % type % of the present invention, the pulses output from the encoder tag in response to the movement of the carriage are counted by the up/down counter/9, and the moving distance on the needle side is determined based on the count value. . Then, a range is given to the count value T centered on C1, and an in-count range display signal Sda is generated between the upper limit value T+α and the 1 limit value T−β.

In addition, the carriage / is the upper and lower limit count value T + α ~ T
- An instruction to set in advance the required time to reach β, and when this time elapses, determine whether the carriage / has reached within the range of the count value, and indicate that it has arrived. If no signal is detected, it is determined that the moving speed of the carriage is abnormal and the carriage is stopped immediately.

The following are possible causes of the progress of the count value counted by the up/down counter /q deviating from its design value.

First of all, if the count value advances more than the other, this is because the motor rotates faster than normal or the rotational speed changes faster. When the load on the motor becomes lighter due to changes in the voltage, transmission thread slipping, etc. (2) Abnormality in driver/7, abnormality in analog comparator/O, failure in integrator/S, reference voltage switching section/g
(3) A malfunction in the drive system due to a defect in the comparison voltage provided by the servo motor, a defect in the servo motor start/stop control signal S/ or a forward/reverse instruction signal S2, (3) a defect in the mono multivibrator 26 or an up/down counter. Control system malfunction due to /q reset failure, etc. On the other hand, if the count value progresses to a lower value, that is, the motor rotates slower than normal or does not rotate at full heat. (1) Carriage (2) When the load on the motor becomes heavy due to lack of oil in the mechanism, contamination of dust or foreign matter, scattering of originals or recording paper, defective bearings, increased frictional resistance due to wear, etc. (2) Due to dirt or a decrease in light source brightness, or when the receiver Encoder system caused by decreased sensitivity, poor contact or disconnection of the connector, disconnection, misadjustment, encoder non-rotation due to loose shaft installation, etc. Malfunction of the motor itself due to a decrease in driving force due to defective brushes, soiled armatures, lack of oil, defective bearings, etc. (4) Abnormality in driver/7, abnormality in power supply, defective analog comparator/6, integrator/ failure of the comparison voltage given from the reference voltage switching unit /g, failure of the servo motor start/stop control signal S/ or forward/reverse rotation instruction signal S2, sense signal S generated by the end position sensor /3. Problems on the 1st drive side due to defects in /θ, etc.

And in these cases, as already explained, the carriage is not moved at a given speed, so that correct scanning does not occur and, in some cases, mechanical damage to the relatively shock-sensitive components mounted on the carriage. There is a risk of severe shock, physical distortion of the device, burnout of the motor, damage to the power supply, etc.

However, in the carriage control method of the present invention, when the moving speed of the carriage deviates from the predetermined speed as described above, the movement of the carriage is immediately stopped, thereby preventing a serious problem from occurring.

In the above embodiment, the up/down counter /9 is set to r-2 when the carriage / leaves the home stop position.
, t4J, and when the left end position of the document, etc. is reached, the count value is set to [0-1]. By doing this, all the instruction signals indicating that the carriage / has reached the left end position of the document etc. will be logic 1.
θ", which is easy to detect.

However, the home stop position is not necessarily [-J,! 1-
There is no need to set it to a negative value like 61, but -,2 for rol.
5-- It goes without saying that you may choose. In this case,
Since it takes 1.256'' steps to reach the left end position of the document, etc., the count value of the up/down counter/q is r, 2. When it is detected that tAJ has been reached, an instruction signal indicating that the carriage / has reached the left end position of the document etc. is obtained. Also, if the paper size is [A+j], the right edge position of the document, etc. is 231. + 7,72g
= /, 9 zada, if "BII", 2&A
+ 2,011g = 2.30'l.

In order to detect the entire current position of the carriage, the count value of the up/down counter/9 is input to the comparator 2 and μ.
The control unit 2/ consisting of a CPU may perform the comparison, and the operation of the servo motor 3 may be controlled according to the comparison result.

Regarding the configuration of facsimile machines, a belt-type encoder using a graduated film or the like is known instead of a rotary encoder, and the means for transmitting drive to the carriage is a timing belt in addition to the wire 6. Other means are known.

Therefore, the carriage control method of the present invention can be applied to all facsimile apparatuses to which these known means have been added and modified. Furthermore, the present invention can be similarly applied to dot printers and other printers, and is not limited to the case described as an embodiment.

As explained in detail above, in the carriage control method of the present invention, a home stop position of the carriage is provided to the left of the position where the original or recording paper is set, and the carriage starts moving to the right from this home stop position. The preset time required to move from the home stop position to a position within a range determined corresponding to the count value as shown by the count value T-β to T+α in FIG. When the time has elapsed, the presence or absence of an instruction signal indicating that the carriage has arrived within the set range is detected, and if no instruction signal is detected, movement of the carriage is immediately stopped.

Therefore, according to the carriage control method of the present invention,
If the carriage is not moved at a predetermined speed, that is, if it becomes abnormally faster or slower than the predetermined speed, the occurrence of an abnormal condition is immediately detected and the carriage movement is stopped. . For example, abnormalities in servo motors and encoders that occur during carriage operation, poor contact with connectors of these circuits, disconnections, etc.
Even if the moving speed of the carriage becomes abnormally fast due to a break in the wiring, etc., the carriage will be prevented from colliding with the right side plate, etc., and the reading element mounted on the carriage, document illumination lamp, and The purchasing element, which is relatively weak against mechanical shock, is reliably protected, and the occurrence of physical distortion due to the shock is also prevented. Also, on the contrary,
Even if the moving speed of the carriage becomes abnormally slow due to an increase in motor load or malfunction of the motor itself, excessive drive is prevented and burnout of the servo motor, drive system power supply, etc. can be prevented. becomes possible. Moreover, the circuits added for this purpose include a timer that sets the time required for the carriage to move from the home stop position to the position corresponding to the center value T set by the count value, and a simple gate. It is extremely simple and requires only a comparator and a means for detecting and comparing the presence or absence of an instruction signal indicating that the carriage has reached a position within the range corresponding to the upper and lower limits α and β of the center value T. Excellent effects such as cost reduction and cost advantages can be achieved.

[Brief explanation of drawings]

FIG. 1A is a perspective view showing an example of a conventional facsimile machine that performs document reading and recording operations while moving the carriage in a direction perpendicular to the conveyance direction of the document or recording paper, and FIG. 1B is a side view of the same. , FIG. 2 is an example of a schematic top view of the periphery of the carriage and a block diagram showing the main parts of the control circuit used to implement the carriage control method of the present invention, and FIG. 3 is an example of the carriage control method according to the present invention. 29 is a time chart for explaining the operation of the circuit of FIG. 2. FIG. In the drawing, / means carriage, ko means guide rail, 3
is a servo motor, d is a rotary encoder, y is a pulley, ot is a wire, 7 is a home stop position sensor, /,
2 is the side plate, /3 is the end position sensor, /4' and 26 are the mono multivibrators, /S is the integrator, /B is the analog comparator, /7 is the driver, / is the reference voltage switching section, /q is the up Down counter, 20 is the first gate circuit 1.2/ is the control unit, 22 is the upper limit setter, 23 is the lower limit setter, moss is the comparator, =5 is the second gate circuit, and core is the start sensor. . 30-

Claims (1)

[Claims] In an apparatus that reads or records a document while moving a carriage in a direction perpendicular to the conveying direction of the document or recording paper, a home stop position of the carriage is provided to the left of the position where the document or recording paper is set, and The carriage starts moving rightward from the stop position, and when a preset time required for moving the carriage a distance from the home stop position to a position within a predetermined range has elapsed, the carriage is moved to the right. If no indication signal is detected indicating that the position within the specified range has been reached,
A carriage control method characterized by stopping the movement of the carriage.