JPH04341881A - Recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the generation of noise and an increase in power consumption by making the detection of the feed quantity of a sheet, the accurate feed of the sheet and the use of a motor low in generated torque possible by providing a sheet feed quantity detection means of the necessary min. constitution. CONSTITUTION:In a recording apparatus having sheet feed mechanisms 6a, 6b, 5 driven by a motor 6, a detection means 9 detecting the tooth part of the transmission gear 6b constituting the sheet feed mechanisms and the control means 30 connected to the detection means are mounted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a sheet feeding mechanism driven by a motor.

0002

2. Description of the Related Art Conventionally, recording apparatuses have been known that have a sheet feeding mechanism driven by a motor and use various recording means. For example, in a serial recording device in which the recording unit performs main scanning sequentially in the lateral direction of a sheet, which is a recording medium, the motor that drives the carriage is equipped with a linear encoder that detects the amount of movement of the carriage in the scanning direction. Some types have an encoder installed directly on the carriage motor. The position and speed of the carriage are controlled based on the output of the encoder thus provided.

On the other hand, in a sheet feeding mechanism driven by a motor, a pulse motor is often used as a drive source, which is capable of open drive control and can generate sufficient rotational torque.

[0004] In this way, the high cost of detecting and controlling the rotation of the sheet feed motor like the above-mentioned carriage motor is prevented, and this tendency is particularly noticeable in low-priced models.

[0005]

[Problem to be Solved by the Invention] However, in the above conventional example, when a pulse motor is used for sheet feeding, the sheet feeding amount cannot be detected when the pulse motor loses synchronization due to excessive load, etc. As a result, it becomes impossible
There is a problem that accurate sheet feeding is not possible.

Furthermore, conventionally, excessive loads have been handled by using pulse motors that generate sufficient torque, resulting in noise generation and increased power consumption.

[0007]Additionally, adding rotation amount detection means such as an encoder to the pulse motor to detect the sheet feed amount has the problem of increasing costs, and has not been implemented.

[0008] Therefore, the recording device of the present invention has been made in view of the above-mentioned problems, and its purpose is to provide a means for detecting the sheet feed amount having the minimum necessary configuration. To enable accurate sheet feeding by making it possible to detect the sheet feeding amount even when the motor is out of synchronization, and to prevent the generation of noise and increase in power consumption by making it possible to use a motor that generates a small torque.

[0009]

[Means for solving the problem] Achieving the above objectives,
In order to solve the problems, a recording apparatus of the present invention has the following configuration, that is, in a recording apparatus having a sheet feeding mechanism driven by a motor, transmission of driving force of the motor constituting the sheet feeding mechanism is provided. The present invention is characterized in that it comprises a detection means for detecting the tooth portion of the transmission gear for the transmission gear, and a control means connected to the detection means.

[0010] Preferably, the detection means detects a disc that is provided integrally with the transmission gear and that forms a slit consisting of a through hole.

Preferably, the recording apparatus is a serial inkjet type recording apparatus, and the motor is commonly used for scanning by the serial recording means.

0012

[Operation] In the above-described configuration, the recording device having a motor-driven sheet feeding mechanism detects the teeth of the transmission gear by the detection means when the motor is driven, and detects the predetermined value of the motor drive and the detection. A comparison of the detected values by the means is made in the control means to operate the sheet feeding mechanism to normally drive the motor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an external perspective view of a main part showing one embodiment of a recording apparatus according to the present invention. In this figure, the recording head 1 is mounted on a carriage 2 that is slidably supported by a carriage shaft 3 that extends over the longitudinal direction of a frame 20, and is driven by a drive source of a carriage motor (not shown). 2, it reciprocates in the main scanning direction in the direction of arrow S in the figure to perform recording on the recording medium 4.

In the figure, as shown by broken lines, a feed roller 5 including a plurality of integrally provided rubber rollers is disposed parallel to the carriage shaft 3, and is attached to the frame 2.
It is rotatably supported by 0. This feed roller 5
is driven by the driving force of a feed motor (paper feed motor) 6 transmitted through a transmission mechanism consisting of transmission gears 6a and 6b, and conveys the recording medium 4 according to the recording situation.

The feed motor 6 and the transmission mechanism are used to move the recording head 1 and the carriage 2 to a position outside the range of reciprocating movement of the recording head 1 and the carriage 2 during the recording operation, and to a position where the recording head 1 and the carriage 2 are moved during the cleaning operation of the recording head 1. are placed in each.

The feed motor 6 is also used as a drive source for an automatic paper feeder (not shown) when an automatic paper feeder (not shown) is attached to a recording apparatus equipped with an inkjet recording head.

Next, the cap cartridge 7 is slidably mounted on a guide shaft 8 disposed on the frame 20 parallel to the above-mentioned cartridge shaft 3, and is guided by the guide shaft 8 to move the recording head. It is designed to be able to reciprocate in a direction parallel to the movement direction of the carriage 1 and the carriage 2.

As shown in the figure, this cap cartridge 7 is provided with an arm portion 7a protrudingly provided, and a protrusion 2a provided on the left side of the carriage 2 in the figure can be fitted into the tip portion of this arm portion 7a. A hole 7b is formed. When the recording head 1 and the carriage 2 move to the left in the figure and the protrusion 2a is inserted into the hole 7b, the carriage 2 is inserted into the hole 7b.
It is formed in order to stably perform capping, pressurization, suction, etc. of the ejection surface of the recording head 1 by preventing it from rotating in the vertical direction.

On the other hand, a photo interrupter 9 consisting of a light-receiving and light-emitting element is fixed to the frame 20, and is configured to optically detect the tooth portion of the transmission gear 6b. As a result, the feed motor (paper feed motor) 6
The amount of rotation of the feed motor (paper feed motor) 6 can be detected by detecting the amount of rotation of the transmission gear 6b that is meshed with. For this purpose, the photointerrupter 9 is connected to a control board 30 and performs drive control, which will be described later.

FIG. 2 is a diagram showing the relative positional relationship between the transmission gear 6b and the photo interrupter 9, in which (a) is a plan view and (b) is a central sectional view taken along a breaking line passing through the photo interrupter 9. They are shown respectively. In this figure, as the feed motor 6 rotates, the transmission gear 6b meshing with the feed motor 6 rotates, and the light transmission path of the photo interrupter 9 is blocked by the ridges H of the teeth of the gear 6b. , will be transmitted through the valley portion V of the tooth. (Figure b
) FIG. 3 is an output waveform diagram obtained by the detection means having the configuration shown in FIG. 2, in which "low" indicates a state in which light is transmitted, and "high" indicates a state in which light is blocked. In FIG. 3, time T0
The period from T1 to T2 is the rest time range of the feed motor 6, and the period from time T1 to T2 is the time range in which the paper feeding feed motor 6 is rotating.

From this figure, in the time range T0 to T1 before the motor moves, the photo interrupter 9 is in a state of detecting the valley portion V of the gear teeth, and is "low".

Subsequently, when the feed motor 6 begins to rotate, the transmission gear 6b rotates, and the photo interrupter 9 is detected by detecting the peaks H and valleys V of the teeth of the gear.
The output of is in the state shown in the time range from T1 to T2 in the figure.

When the feed motor 6 stops rotating after completing the drive for a predetermined number of steps, the photo interrupter 9
The output remains in a “high” or “low” state. In FIG. 3, when the motor 6 stops rotating, the photointerrupter 9 is in a state where the valley portions V of the teeth of the transmission gear 6a are detected on the optical path.

Here, the step angle of the feed motor 6 is a (degrees), the deceleration rate from the feed motor to the transmission gear 6b is b, the number of teeth of the transmission gear 6b is c, and the number of motor steps for one tooth of the transmission gear 6b is When x is assumed, the following formula (1) holds true.

x=360×b/(a×c)...(1) As shown in FIG. When setting the number of steps of the motor so that it is in the state of detecting part V, if the number of steps of the motor exceeds x and the output of the photo interrupter 9 remains in the "high" state, then Since the feed motor 6 cannot be driven by a predetermined amount of steps, it is determined that a step-out has occurred in the pulse motor.

Normally, when the number of steps of the motor exceeds x, outputs such as T1 to T2 in FIG. 3 must be obtained.

FIG. 4 is a flowchart showing an example of controlling the feed motor configured as described above.
This is executed by In this figure, when paper feeding is started, in step S1, the teeth of the transmission gear are detected by the photo interrupter 9 as described above before the feed motor 6 is driven, and "high" and "low" are detected. and sends the detection results to the RA on the control board 30.
Temporarily stored in M etc. Subsequently, in step S2, the feed motor 6 is driven by a predetermined number of steps, and the process proceeds to step S3, where it is determined whether or not the output of the photo interrupter 9 has changed. If so, proceed to step S4. In step S4, detection for a predetermined number of steps in step S2 is performed. Subsequently, in step S6, the predetermined step and the detected step are compared, and if they match, it is determined that the feed motor has been driven normally, and the process proceeds to the next step.

On the other hand, in step S3, if it is determined that there is no change even though the feed motor 6 has been driven by a predetermined number of steps, the process proceeds to step S5, and if there is some abnormality in the motor drive, the process proceeds to step S5. A flag is raised to indicate that this has occurred. Further, even if the predetermined step and the detected step are compared in step S6 and they do not match, the process proceeds to step S5 and a flag indicating that some kind of abnormality has occurred in the motor drive is set, so the drive current of the feed motor 6 is changed. The device automatically takes measures such as increasing the

By configuring and controlling the means for detecting the rotation amount of the feed motor at low cost as described above, when a pulse motor is used for the feed motor, a motor with the minimum necessary specifications can be used.

Next, FIG. 5 is a diagram showing the relative positional relationship between the linear encoder and the photo interrupter 9, which are integrally formed with the transmission gear 6b, in which (a) is a plan view and (b) is a broken line passing through the photo interrupter 9. Each figure shows a central sectional view cut away at . In this figure, the above-mentioned transmission gear 6b is integrally formed with a linear encoder 10 having a large number of thin slits 10a formed at equal intervals in the radial direction as shown. These slits 10a are detected by the photo interrupter 9 described above.

As described above, by integrating the transmission gear 6b and setting the number of slits to c, it becomes possible to detect out-of-step of the motor in the same manner as in the first embodiment described above.

As explained above, in order to detect the rotation of the paper feed motor, the paper feed motor can be easily and inexpensively installed by providing a sensor in the teeth of the gear or in the slit part integrated with the gear. It is possible to detect out-of-step.

[0033] Especially recently, the noise emitted by recording devices has become a big problem, but it is known that it is effective to set the rotation speed or current value of the paper feed motor close to the load torque in order to reduce the noise. However, due to environmental changes or abnormal situations, a large load is generated, the torque margin of the paper feed motor is lost, the paper feed motor tends to lose synchronization, and conveyance abnormalities occur immediately, resulting in jams and printing defects. .

However, by operating the structure as described above, it is possible to set the rotational speed or current value of the paper feed motor close to the load torque for normal usage conditions, thereby reducing noise. In addition, only when the paper feed motor is detected to be out of step, the motor speed is lowered or
By changing the ramp-up curve or increasing the current value, the motor can be rotated normally, eliminating jams and printing defects.

In other words, a recording device with low noise and high reliability can be provided at low cost.

[0036]

[Effects of the Invention] As explained above, according to the present invention, by providing a means for detecting the paper feed amount with the minimum necessary configuration, it is possible to detect the paper feed amount even when an abnormality occurs in the sheet feed mechanism. As such, it enables accurate paper feeding,
Furthermore, it is possible to use a motor that generates less torque, thereby preventing noise generation and increased power consumption.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a main part of a recording device according to an embodiment.

FIG. 2 is a diagram showing the relative positional relationship between a transmission gear 6b and a photo interrupter 9.

FIG. 3 is an output waveform diagram obtained by the detection means.

FIG. 4 is a flowchart showing an example of controlling a feed motor.

FIG. 5 is a diagram showing the relative positional relationship between a linear encoder and a photo interrupter 9 that are integrally formed with a transmission gear 6b.

[Explanation of symbols]

1 Recording head 2 Carriage 6 Feed motor 6b Transmission gear 9 Photo interrupter 10 Linear encoder 10a Slit 30 Control board

Claims (3)

[Claims] 1. A recording apparatus having a sheet feeding mechanism driven by a motor, comprising: detecting means for detecting teeth of a transmission gear for transmitting the motor driving force constituting the sheet feeding mechanism; A recording device comprising: a control means connected to a detection means. 2. The recording apparatus according to claim 1, wherein said detecting means detects a disk that is provided integrally with said transmission gear and that forms a slit consisting of a through hole. 3. The recording device according to claim 1 or 2, wherein the recording device is a serial inkjet type recording device, and the motor is commonly used for scanning by the serial recording means. .