JP2000203115A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optimum method for driving a carriage corresponding to all combinations by variably controlling a drive system for energizing a motor of a drive source and a profile of accelerating, decelerating or the like based on a type of a unit mounted on the carriage and an identification of the combinations. SOLUTION: A recording head has three terminals 71 to 73, which are respectively pulled up by resistors 74 to 76 and selectively connected to a ground potential by patterns 77 to 79 when the heads are mounted in a body. Thus, eight types of combinations are generated by three signals A, B and C. Combinations of the units mounted on a carriage are identified, and a current profile conducting with a main scanning motor is decided from causes such as combinations of the units, printing mode, ink residue or the like. The motor is driven according to the decided profile. Energy conservation, noise reduction and settling characteristics can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus,
In particular, the present invention relates to a printing apparatus that can optimally drive a scan motor that drives and scans a printhead housing carriage in accordance with various combinations of a plurality of printheads.

[0002]

2. Description of the Related Art In a recording apparatus, for example, an ink jet recording apparatus, one or a plurality of recording heads each including an ink tank are mounted on a carriage and reciprocated in a main scanning direction to achieve printing. In general,
A stepping motor is used as a driving source for the main scanning.

FIG. 1 shows a driving circuit of a typical two-phase bipolar motor. Reference numeral 101 is a two-phase bipolar, having two windings A and B. The motor 101 is driven by a motor driving device (also referred to as a “motor driver”) 102 in this specification. Motor driver 10
2 is controlled by a combination of the control signals shown in FIGS. In particular, FIG. 2 shows control signals (IN1 to 4) for determining the direction of the current flowing through the winding of the motor, that is, the rotation direction of the motor, and FIG. 3 shows the control signals (IO) for determining the level of the current flowing to the motor. , I1).

[0004] FIG. 4 shows a driving method generally called a 2-2 phase drive. In FIG.
The currents flowing through the respective windings A and B and the directions thereof are shown. FIG. 5 is a diagram expressing the rotation of the motor in a vector manner. The vector positions indicated by circle numbers in the figure correspond to the circle numbers shown at the bottom of the current waveform in FIG.

[0005] The 2-2 phase drive as shown in FIG. 4 described above is simple in driving method, but disadvantageous in terms of noise (operation sound) because the current waveform is a square wave. In order to improve such disadvantages, recent printers and facsimile machines tend to cope with low noise by adopting a sine wave drive (also called micro step drive) as shown in FIG. However, in order to realize such micro-step driving, control becomes more complicated, and a control block such as that shown in FIG. 7 has conventionally been used. Before describing FIG. 7 in detail, the transition of the motor current will be described with reference to FIG.

While the motor current waveform shown in FIG. 6 which has already been referred to is a current waveform when the motor is driven at a constant speed, the current waveform shown in FIG. up), that is, the drive cycle and the drive current during acceleration. In a normal motor starting method, as shown in the figure, the rotation of the motor is gradually accelerated at the time of ramp-up, so as to approach the rotation speed at a constant speed. Therefore, the driving cycle is gradually shortened, and a method of reducing the driving current continuously or stepwise is also adopted. Here, “continuous” and “gradual”
Referring to FIG. 8, one step period T1, T2, T3
.. Change continuously, or the period is shortened every half cycle or one cycle. Further, with respect to the current, a method is adopted in which the current is reduced continuously for each step, or stepwise for each half cycle or each cycle. The effect of such control contributes not only to the reduction in noise as described above, but also to an improvement in settling performance (in short, a smooth transition to constant velocity motion).

In order to realize the drive control of the stepping motor as shown in FIG. 8, for example, a control circuit shown in FIG. 7 is used. FIG. 7 is briefly described as follows.
Are prepared, and the table 701 stores the control step intervals T1, T2, T3... Of the stepping motor shown in FIG. As shown, the interval is continuously or stepwise shortened in the ramp-up region as described above,
When it reaches the constant velocity region, it repeats in the same tone. Also,
At the time of ramp down, that is, at the time of deceleration, the motor can be stopped without any problem by controlling the table to generally proceed in the opposite direction to the ramp up. Therefore, the storage capacity of the table is selected so that data corresponding to ramp-up and data corresponding to constant speed can be accommodated.

A table 702 is an A-phase current table, and stores current value data S1 and S1 of a control curve A_i 803 in FIG.
S2, S3... Are stored. This current value is generally attenuated every half cycle, every cycle, or every predetermined plurality of cycles to reach a constant velocity region.

A table 703 is a B-phase current table forming a pair with the table 702, and has a control curve B_i80 shown in FIG.
., S3 ′,... Are stored. A table 704 is a phase table, and A__ in FIG.
Waveforms corresponding to ph801 and B_ph802, and their inverted waveforms ("bar" in table 704 in FIG. 7)
) Is stored. Here, A_ph 801 matches the phase of the A-phase current waveform A_i 803, and B_ph 802
Coincides with the phase of the B-phase current waveform B_i804. These waveforms A_ph801 and B_ph802, and their inverted waveforms, correspond to the control signals IN1 to IN4 (reference numbers 112 to 115) that control the conduction of the eight output power transistors 104 to 111 in FIG.

The data of the four tables shown in FIG. 7 are transferred to the corresponding registers 705, 710, 712, and I / O port 718 by the match signal 708 of the comparator 707. Here, the comparator 707 compares the current interval value in the register 705 with the count value of the counter 706, and when a match occurs, generates a transfer trigger signal 709 (in the figure, a match signal 708, a transfer trigger signal 709 and a transfer trigger signal 709). Are the same signal). Such a transfer method from a table to a register generally includes a DMA.
(Direct memory access) transfer was used.
That is, the tables 701 to 704 are configured in a memory in the system, for example, in a ROM or a RAM, and the ROM or the RAM is connected to the illustrated CPU bus 725.
(Not shown) to write data. When the transfer trigger 709 is generated, the CPU bus is temporarily released, and the corresponding registers 705, 710, 712 and I / O are read from these tables 701 to 704, respectively.
The next data is transferred to the O port 718.

Incidentally, in the ink jet recording apparatus,
As shown in FIG. 9, generally, recording heads 46, 47, 48, and 49 corresponding to four color inks of black (BK), yellow (Y), magenta (M), and cyan (C) are prepared, and these are carriages. 40 are attached to respective predetermined positions (pockets). Then, the rear lower end portion of the carriage 40 is penetrated so as to be movable on the rail 42, and further connected to the timing belt 45. The timing belt 45 is hung on a pulley or a motor shaft 44, and is rotated in synchronization with the rotation of the motor 43, whereby the rotation of the motor is transmitted to the carriage 40 through the timing belt 45, and as a result, the carriage is moved to the rail 42. Reciprocate above.

In FIG. 9, the ink capacity of the black head 46 is set to be larger than the ink capacities of the other three recording heads 47 to 49. This is because the consumption of black ink is usually the largest. By setting the ink capacity of the black head large as shown in the figure, the frequency of black ink replenishment or the number of times of black head replacement is reduced, and Can be less complicated.

In FIG. 10, in addition to the three types of recording heads shown in FIG. 9, a recording head 52 having cyan light-density ink and magenta light-density ink is added and mounted in an additional pocket 54. Is shown as However, the two are not provided separately as in other recording heads, but are provided as an integrated type. The significance of these heads being integrated is to avoid confusing the user by increasing the types of recording heads too much,
It is not limited to this. The role of these light-density inks is to provide rich gradation expression especially when assuming a photographic image, and these types of recording devices are already sold by multiple manufacturers and will be installed simultaneously in the future. By further increasing the types of recording heads, a tendency to pursue high definition images is expected.

In FIG. 11, instead of the light density ink head 52 of FIG. 10, a reading scanner is shown added and mounted in an additional pocket 64. Although a printer that functions as a sheet-only (ie, does not correspond to a book) reading scanner by mounting a reading scanner in place of a recording head is already on the market, the example of FIG. This is a printer device in which both can be mounted at the same time, and can save the user from having to replace these units.

Although various combinations of the recording head and reading scanner shown in FIGS. 9 to 11 and others are possible, it is necessary to mount these units on a carriage and reciprocate in the main scanning direction. The appropriate power can of course vary depending on the particular combination. For example, in FIG.
A case where only the black head (Bk) is mounted, and a case where black (Bk), yellow (Y), magenta (M), cyan (C), light density magenta (M ') and cyan (C') are mounted When mounted, the total weight is significantly different, and the torque required to move the carriage accordingly varies significantly.

Therefore, in order to smoothly reciprocate the carriage with respect to all possible combinations of all units including all recording heads and other units such as reading scanners in a given recording apparatus, it is necessary to always perform A current that satisfies the load torque of the heaviest combination must be supplied to the motor. However, such a driving method has some disadvantages as follows.
That is, at the time of light load torque such as when only the black head (Bk) is mounted, 1) energy saving cannot be performed 2) noise (operating sound) increases due to excessive current supplied to the motor 3) acceleration For example, the setting performance when shifting from the region to the constant velocity region is deteriorated.

[0017]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to mount all or part of other units such as a plurality of types of recording heads and reading scanners on a carriage,
It is an object of the present invention to provide an operable recording apparatus which can realize an optimum carriage driving method for each possible combination of these units.

[0018]

SUMMARY OF THE INVENTION The present invention comprises means for identifying the types of units currently mounted on a carriage and their combinations, and based on the identified combinations,
A profile of a current supplied to a motor serving as a drive source for carriage scanning is variably controlled. Elements constituting such a profile include drive methods such as the above-described square wave drive and sine wave drive; envelopes of current peaks in each of an acceleration region, a constant velocity region, and a deceleration region; and a repetition period (cycle). It is.

[0019]

FIG. 12 shows an embodiment of the identification means of the recording head 70 of the present invention. The recording head has three terminals 7
1 to 73 are provided, and each terminal is pulled up by resistors 74 to 76 on the main body side when the recording head is mounted on the main body. Further, the terminals 71 to 73 are selectively connected to the ground potential by patterns 77 to 79. In practice, the patterns 77 to 79 are selectively cut by laser according to the mounting position of the ink head or the like. Therefore, the terminals 71 to 73 which have been subjected to the pattern cutting are maintained at the Vcc potential, and the terminals which are not subjected to the pattern cutting are maintained at the ground potential. As a result, a combination of eight types of signals is generated by the three signal lines A, B, and C. However, the recording head 70
Are not attached, these three signal lines A, B, C
Are all logical 1, so that the number of actually identifiable mounting units is seven.

FIG. 13 is a diagram schematically showing a current supplied to one of the two windings A and B of the main scanning motor 43 over the entire main scanning area in the apparatus shown in FIG. 10, for example. . As shown, the scanning area is divided into three areas: an acceleration area, a constant velocity area, and a deceleration area. In the acceleration region, the rotation of the motor is gradually accelerated from a stationary state toward a target speed, and during this time, the current supplied is gradually reduced according to the torque required for acceleration, and finally shifts to the constant velocity region. In the constant velocity region, the supplied current is kept constant. When the printing scan of the predetermined length is completed, it shifts to the deceleration area next,
Slowly reduce the rotation of the motor. Normally, cycle control in the deceleration region is symmetrical to that in the acceleration region except for the current value to be supplied. In the example of FIG. 13, the current flowing through the motor in the deceleration region is shown as being maintained constant.
It is not limited to this.

FIG. 14 schematically shows various profiles of the current supplied to the main scanning motor, and best illustrates the features of the present invention. In the figure, three types of current profiles I
1, I2 and I3 are shown, respectively (142, 14
2 '), (144, 144'), (146, 146 ')
Are shown in pairs. Each of these pairs represents the current flowing through the winding and the envelope of its peak value. In FIG. 14, the cycle of each cycle of the three types of current profiles is drawn the same, but the present invention is not limited to this. The current profile I1 shows a case where the current value is controlled to be small, which corresponds to a case where only the black head 46 or only the reading scanner is mounted on the carriage 40 in the apparatus shown in FIG. In contrast, the current profiles I2 and I3 have a larger current amplitude than I1, and for example, in FIG. 10, BK, Y, M, C,
All five recording heads M '/ C'
It corresponds to the case where it is mounted on the top. Here, the difference between the current profiles I2 and I3 is that the envelope of I2 attenuates exponentially, whereas the envelope of I3 attenuates in an inverted S-shape.

These choices depend on the settling characteristics, ie, FIG.
As shown in FIG. 5, it is determined depending on the degree of goodness of the speed unevenness when shifting from the acceleration region to the constant velocity region. For example, FIG.
In the example of the curve 150, although the carriage speed smoothly shifts from the acceleration region to the constant speed region, the curve 152 has a ringing in the speed, and this ringing does not stop even at the start of the printing region. . In such a situation, the image at the left end of the print result is distorted, and the print quality is significantly deteriorated. Therefore, it is necessary to select a current profile that does not cause such ringing. However, such a settling performance usually cannot be determined completely depending on the mechanical configuration of the drive system and the target speed. It is.

For example, a large current such as I2 or I3 in FIG.
When used in a light load situation where only k) is mounted, ringing as shown in FIG. 15 may occur due to excessive input power. Conversely, a small current like I1 in FIG. 14 is applied to all the heads 46 as shown in FIG.
When used in a situation where -52 is mounted,
Insufficient motor torque can cause a step-out operation (poor rotation) of the stepping motor. Further, the remaining amount of ink of each recording head can be one factor for determining the current profile. The procedure for determining the current profile described above is shown in the flowchart of FIG.

That is, the combination of the units mounted on the carriage is identified (step S1). next,
A current profile to be conducted to the main scanning motor is determined based on factors such as a unit combination, a printing mode, and a remaining amount of ink (step S2). Then, the main scanning motor is driven according to the determined current profile (Step S).
3).

In FIG. 14, for the sake of illustration, each current profile shows relatively few current cycles included in the envelope, but actually includes more current cycles. Is common.

In the above-described embodiment, the selection of the current profile mainly due to the current peak envelope and the magnitude relation of the current has been described. However, it is needless to say that the change of the period is also included in the current profile. Needless to say.
For example, in a light load situation where only a black head (Bk) is mounted, the carriage can be reciprocated at a high speed, thereby controlling the current cycle high and rotating the motor at a high speed. In situations where a recording head is mounted, the speed may be reduced, i.e., the current cycle may be kept lower than with a single head.

The selection of the current profile is determined by several factors, such as the condition of the head mounted on the carriage, the operation sound, and the quality required for a recorded image.

In the above description, the recording head is mainly described as a unit mounted on the carriage. However, as described above, these units include a reading scanner and the like other than the recording head. Units are also included.

[0029]

As described above, according to the present invention, according to the combination of the recording head and other units mounted in the carriage of the recording apparatus, the current profile of the main scanning motor is selected from among a plurality of current profiles. By selecting a corresponding profile, it is possible to achieve energy saving, low noise, improvement of settling characteristics, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit block of a conventional motor driver.

FIG. 2 is a truth table showing a relationship between an input control signal and an output of the motor driver shown in FIG. 1;

FIG. 3 is a truth table of power supply switching of the motor driver of FIG. 1;

FIG. 4 is a diagram showing a current waveform in a typical 2-2 phase drive.

FIG. 5 is a diagram showing rotation vectors in the case of 2-2 phase driving.

FIG. 6 is a diagram showing a current waveform in the case of micro-step driving.

FIG. 7 is a diagram showing a conventional architecture for realizing micro-step driving.

FIG. 8 is a diagram showing control of a ramp-up area in micro-step driving.

FIG. 9 is a diagram showing an embodiment of a recording apparatus to which the present invention can be applied.

FIG. 10 is a diagram showing another embodiment of the recording apparatus to which the present invention can be applied.

FIG. 11 is a diagram showing still another embodiment of a recording apparatus to which the present invention can be applied.

FIG. 12 is a diagram showing a unit for identifying a unit mounted on a carriage.

FIG. 13 is a diagram schematically showing a current flowing through a motor in each of three divided areas in a scanning area.

FIG. 14 is a diagram showing examples of various current profiles.

FIG. 15 is a diagram for explaining settling characteristics.

FIG. 16 is a flow diagram of a current profile determination procedure according to the present invention.

[Explanation of symbols]

 101 Motor 102 Motor Driver 701-704 Table 707 Comparator 705, 710, 712 Register 46-49 Recording Head 40 Carriage 52 Recording Head

Claims (4)

[Claims] 1. A printing apparatus capable of mounting a plurality of types of print heads on a carriage and performing printing while reciprocating the carriage in a scanning direction, comprising: a driving unit including a motor for reciprocating the carriage. Means for performing printing in various modes by a plurality of combinations including a part or all of the plurality of types of recording heads; and a plurality of currents supplied to the motor corresponding to each of the plurality of combinations. Means for preparing a different profile; means for detecting a combination of the recording heads currently mounted on the carriage; means for selecting the corresponding current profile according to the detected combination; Means for driving the motor according to the profile. 2. The plurality of combinations include: 1) only a black head 2) three types of heads of cyan, magenta and yellow 3) four types of heads of black, cyan, magenta and yellow 4) In addition to the above 3) , A head containing light-density ink such as light cyan, light magenta, etc. 5) Only other units such as a reading scanner 6) Combination of any one of the above 1) to 4) with other units such as the reading scanner The recording apparatus according to claim 1, wherein the recording apparatus is selected from a group including the group. 3. A recording apparatus according to claim 1, further comprising means for determining said current profile in consideration of a printing mode including normal printing, high-definition printing, high-speed printing, and the like. 4. The recording apparatus according to claim 1, further comprising means for determining said current profile in consideration of the remaining amount of ink in said recording head.