JPH09251227A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the vibration of a driving system from a motor to an exposing means as less as possible and to always obtain uniform and excellent image quality by controlling the acceleration of the motor in accordance with a pattern specified by an operating means. SOLUTION: At the time of reciprocating a carriage, a pulse motor 55 is accelerated for the first specified time. This acceleration time corresponds to a nonimage forming period. When the acceleration period is completed, the pulse motor 55 is moved at a uniform speed. This movement at the uniform speed is executed for a specified time including a whole image forming period. At the time of manufacturing a main body, a worker inspects the inspection report of the pulse motor 55, to recognize the measured value of the holding torque of the pulse motor 55 and judges the degree of the dispersion of the measured value with respect to a normal value Then, the worker operates the input part 54a of an operation display part 54, in accordance with the judged 'dispersion', at the time of executing a trial operation after manufacturing is completed. Thus, an arbitrary acceleration pattern is specified.

Description

Detailed Description of the Invention

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, an exposing means is driven to reciprocate along a document table by driving a motor, for example, a pulse motor, and at the time of the forward movement, the document table is exposed and scanned to read an image on the document. The read image is formed on a copy sheet which is an image forming medium.

The exposure means is composed of an exposure lamp and a carriage on which the exposure lamp is mounted. The carriage is provided so as to be reciprocally movable along the platen, and is connected to the shaft of the pulse motor via a power transmission mechanism such as a belt or a wire, and reciprocates for each copy by driving the pulse motor.

During the forward movement for exposure scanning, the pulse motor is first accelerated for a predetermined time and distance (slew up), then moved at a constant speed, and finally decelerated. The image forming period corresponds to the constant-velocity period of the pulse motor.

[0005]

When the pulse motor is accelerated, the vibration generated by the pulse motor is transmitted to the carriage via the power transmission mechanism. On the other hand, the torque exerted by the pulse motor includes a holding torque for holding the rotation stop position and a normal torque during operation. The two torques are in proportion to each other, and if the holding torque is large, the normal torque is also large.

The holding torque has a "variation" of about ± 5% for each pulse motor product. This "variation" appears as a difference in the magnitude of vibration transmitted to the carriage. When the vibration is large, it does not stop even during the image forming period due to the constant velocity motion, and the image quality at the leading end portion of the image formation deteriorates.

That is, the "variation" of the torque of the pulse motor appears as it is as the quality of the image formed, and depending on the product, there are good and bad image quality.

The present invention takes the above circumstances into consideration,
It is an object of the present invention to provide an image forming apparatus capable of suppressing the vibration of the drive system from the motor to the exposure unit to be small, thereby always obtaining a uniform and good image quality.

[0009]

According to another aspect of the present invention, an image forming apparatus reads an image of an original by moving an exposing unit along an original table by driving a motor and exposing and scanning the original table during the movement. , Which forms a read image on an image forming medium, and specifies a control means for accelerating the motor first and then a constant speed when the exposure means moves, and a pattern for accelerating the motor. And a control means for controlling the accelerating motion of the motor according to the pattern designated by the operating means.

In the image forming apparatus according to the second aspect of the present invention, the exposure means is moved along the document table by driving the motor, and at the time of the movement, the document table is exposed and scanned to read the image of the document, and the read image is received. The image forming medium is formed on an image forming medium, and when the exposure means is moved, a control means for accelerating the motor first and then moving the same at a constant speed, and a plurality of types for determining a pattern of the accelerating movement of the motor. A storage unit storing the acceleration pattern data, an operating unit for designating an arbitrary acceleration pattern data among the acceleration pattern data in the storage unit, and a motor according to the acceleration pattern data designated by the operating unit. Control means for controlling the acceleration of
Is provided.

In the image forming apparatus according to the third aspect of the present invention, the exposure means is reciprocated along the document table by driving the motor, and at the time of the forward movement, the document table is exposed and scanned to read the image of the document.
The read image is formed on an image forming medium, and when the exposure unit moves forward, the motor is first accelerated for a predetermined time, then moved at a constant speed, and finally decelerated. Control means, operation means for designating a pattern of acceleration movement of the motor, and control means for controlling the acceleration movement of the motor according to the pattern designated by the operation means.

According to another aspect of the invention, the image forming apparatus reciprocates the exposure means along the document table by driving the motor, and at the time of the forward movement, the document table is exposed and scanned to read the image of the document.
The read image is formed on an image forming medium, and when the exposure unit moves forward, the motor is first accelerated for a predetermined time, then moved at a constant speed, and finally decelerated. Control means, storage means for storing a plurality of types of acceleration pattern data for determining the pattern of acceleration motion of the motor, and for specifying any acceleration pattern data among the respective acceleration pattern data in this storage means An operating means and a control means for controlling the acceleration movement of the motor according to the acceleration pattern data specified by the operating means are provided.

In the image forming apparatus according to the present invention, the carriage on which the exposure lamp is mounted is moved along the document table by driving the pulse motor, and the document table is exposed and scanned during the movement to read the image of the document. , A means for forming a read image on an image forming medium, and a control means for accelerating the pulse motor first and then moving at a constant speed when the carriage moves, and a pattern for accelerating the pulse motor. An operating means for designating and a control means for controlling the acceleration motion of the pulse motor according to the pattern designated by the operating means are provided.

According to another aspect of the image forming apparatus of the present invention, the carriage on which the exposure lamp is mounted is moved along the document table by driving the pulse motor, and at the time of the movement, the document table is exposed and scanned to read the image of the document. , A means for forming a read image on an image forming medium, and a control means for accelerating the pulse motor first and then moving at a constant speed when the carriage moves, and a pattern for accelerating the pulse motor. Storage means storing a plurality of types of acceleration pattern data for determination, operation means for designating arbitrary acceleration pattern data among the respective acceleration pattern data in this storage means, and this operation means Control means for controlling the acceleration of the pulse motor according to the acceleration pattern data.

In the image forming apparatus according to the invention of claim 7, the carriage on which the exposure lamp is mounted is reciprocated along the document table by driving the pulse motor, and the document table is exposed and scanned at the time of the forward movement to form an image of the document. And the read image is formed on the image forming medium. When the carriage moves forward, the pulse motor is first accelerated for a predetermined time, then moved at a constant speed, and finally. Control means for decelerating,
An operating means for designating a pattern of the acceleration movement of the pulse motor and a control means for controlling the acceleration movement of the pulse motor according to the pattern designated by the operating means are provided.

In the image forming apparatus according to the present invention, the carriage on which the exposure lamp is mounted is reciprocated along the document table by driving the pulse motor, and the document table is exposed and scanned at the time of the forward movement to image the document. And the read image is formed on the image forming medium. When the carriage moves forward, the pulse motor is first accelerated for a predetermined time, then moved at a constant speed, and finally. Control means for decelerating,
Storage means for storing a plurality of types of acceleration pattern data for determining a pattern of acceleration motion of the pulse motor; and operation means for designating arbitrary acceleration pattern data among the respective acceleration pattern data in the storage means. Control means for controlling the acceleration movement of the pulse motor in accordance with the acceleration pattern data designated by the operating means.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 5 shows the internal structure of an image forming apparatus such as a copying machine. A document table 2 is provided above the main body 1, and an automatic document feeder 3 is mounted at a position corresponding to the document table 2. The automatic document feeder 3 automatically feeds the set documents one by one to the document table 2.

The photoconductor drum 20 is provided at a substantially central portion of the main body 1.
Are provided rotatably. Around the photosensitive drum 20, a charging charger 21, an exposure unit 22a, a developing unit 23,
Transfer charger 25, peeling charger 26, cleaner 2
7. The static eliminator 28 is sequentially arranged.

An exposure system 22 is provided in the upper part of the main body 1. The exposure system 22 includes an exposure lamp 41, first to third reflecting mirrors 42a, 42b and 42c, a variable magnification lens block 43, and fourth to sixth reflecting mirrors 42d and 4c.
2e, 42f.

The exposure lamp 41 is mounted on a reciprocating carriage 40, and together with the carriage 40 constitutes an exposing means. The carriage 40 is connected to a shaft of a pulse motor 55, which will be described later, via a power transmission mechanism (not shown) such as a belt or a wire.
By the drive of 5, it reciprocates for each copy. By the forward movement of the carriage 40 in the right direction in the drawing and the light emission of the exposure lamp 41, the exposure scanning is performed over the entire surface of the document table 2.

By this exposure scanning, a reflected light image of the document placed on the document table 2 is obtained, and the reflected light image is obtained by the reflecting mirrors and the variable magnification lens block 43.
projected on a.

A plurality of paper feed cassettes 10 are provided at the bottom of the main body 1 as paper feed means. These paper feed cassettes 1
In No. 0, a large number of copy sheets P having different sizes are accommodated as image forming media.

The copy sheets P are taken out one by one from any one of the paper feed cassettes 10 in response to an ON operation of a copy key (not shown) and a detection result of a document size sensor (not shown). To be done. For taking out this,
A pickup roller 30 is provided.

The picked-up copy paper P is separated from the paper feed cassette by the separator 31 and sent to the registration rollers 32, where the rotation of the photosensitive drum 20 is awaited.

The charging charger 21 applies a high voltage supplied from a high voltage power source (not shown) to the photoconductor drum 20 to charge the surface of the photoconductor drum 20 with an electrostatic charge.
An electrostatic latent image is formed on the photoconductor drum 20 by this charging and the image formation from the exposure system 22 on the photoconductor drum 20.

The electrostatic latent image on the photosensitive drum 20 is developed by the developing device 2.
At 3, the toner of the developer is received to make it visible, and the image is transferred to the transfer charger 25. This transfer charger 25
The copy paper P is sent from the registration roller 32 in synchronization with the rotation of the photoconductor drum 20, and the visible image on the photoconductor drum 20 is transferred onto the copy paper P.

The copy sheet P on which the visible image has been transferred is peeled off from the photosensitive drum 20 by the peeling charger 26 and sent to the fixing roller 34 by the conveyor belt 33. Then, the fixed copy paper P is discharged by the discharge roller 35 to the discharge tray 36 on the side of the main body. After the transfer, the photoconductor drum 20 passes through the cleaner 27 and the static eliminator 28 to prepare for the next copy.

The developing device 23 is provided with a toner cartridge 24 attached thereto, and the toner replenished from the toner cartridge 24 is attached to the surface of the photosensitive drum 20 by the developing magnet roller 23a. The toner cartridge 24, which contains a predetermined amount of toner 24a, is prepared as a new product, and can be freely attached to and detached from the developing device 23.

On the other hand, the main part of the control circuit is shown in FIG. 5
Reference numeral 0 is a control unit for controlling the entire copying machine. This control unit 5
A scan motor drive circuit 51, a main motor drive circuit 52, a memory 53, and an operation display unit 54 are connected to 0.

The scan motor drive circuit 51 includes a controller 5
A pulse motor 55, which is a scan motor, is driven according to a control command from 0. Pulse motor 55
Is for driving the carriage 40.

The main motor drive circuit 52 includes a control unit 50.
The main motor 56 is driven according to the control command from. The main motor 56 is for driving the photosensitive drum 20 and various rollers.

The memory 53 stores a program for controlling the entire copying machine and also stores a plurality of types of acceleration pattern data from the first to the Nth. These acceleration pattern data are for determining the pattern of acceleration movement of the pulse motor 55 when the carriage 40 moves forward.

Several examples of acceleration pattern data are shown in FIGS.
It is shown in FIG. The acceleration pattern data in Fig. 2 shows the acceleration from the initial speed of 100mm / sec to the constant speed of 500mm / sec for 20ms
It is meant to be done during the ec period. Carriage 4
A displacement of 0 corresponds to 20 mm.

The acceleration pattern data shown in FIG.
This is for accelerating from 0 mm / sec to a constant velocity of 500 mm / sec in a period of 50 msec. The movement amount of the carriage 40 corresponds to 30 mm.

The acceleration pattern data shown in FIG.
This is for accelerating from 5 mm / sec to a constant velocity of 500 mm / sec in a period of 70 msec. The movement amount of the carriage 40 corresponds to 35 mm.

The operation display unit 54 is provided on the upper surface of the main body 1, and sets various copy conditions (the number of copies, paper size, density, magnification, etc.), a copy start instruction, and display of information related to copying. It has an input unit 54a and a display unit 54b. In particular, by operating the input unit 54a, it is possible to specify any acceleration pattern data among the acceleration pattern data in the memory 53.

The control unit 50 has the following [1] to [5] as main functional means. [1] The carriage 40 is reciprocated along the document table 2 by driving the pulse motor 55, the document table 2 is exposed and scanned by the exposure lamp 41 during the forward movement, the image of the document is read, and the read image is read on the paper P. Copying means formed on top.

[2] A control means for accelerating the pulse motor 55 for a predetermined time during the forward movement of the carriage 40, then moving it at a constant speed, and finally decelerating it. [3] Designating means for designating arbitrary acceleration pattern data among the respective acceleration pattern data in the memory 53 in accordance with the operation of the input unit 54a in the operation display unit 54 (for example, the operation of the numeric keypad for inputting numerical values).

[4] Reading means for reading the designated acceleration pattern data from the memory 53. [5] Control means for controlling the acceleration movement of the pulse motor 55 according to the read acceleration pattern data.

Next, the operation of the above configuration will be described. When the print key is turned on at the input unit 54a of the operation display unit 54, the pulse motor 55 is driven to drive the carriage 4
0 reciprocates along the document table 2, and during the forward movement, the exposure lamp 41 emits light and the document table 2 is exposed and scanned. The image of the original is read by this exposure scanning and is formed on the paper P.

When the carriage 40 moves forward, the pulse motor 55 is accelerated in the first predetermined time. The time of this acceleration movement corresponds to the non-image forming period. When the acceleration period ends, the pulse motor 55 is moved at a constant speed.
This constant velocity motion is performed in a predetermined time including the entire image forming period.

When the time of constant speed motion is over, the pulse motor 5
5 is decelerated. Due to this deceleration motion, the carriage 41
The forward movement of will end soon. After the forward movement of the carriage 41 is completed, the pulse motor 55 is reversely operated, and the carriage 41 is returned. During this return movement, the pulse motor 55
Acceleration, constant velocity, and deceleration are performed at a speed higher than the forward movement.

By the way, the pulse motor 55 incorporated in the main body 1 is attached with an inspection result table in advance at the stage of product delivery. This inspection result table records inspection data relating to the characteristics of the pulse motor 55, and one of the inspection data is a measured value of the holding torque.

At the time of manufacturing the main body 1, the worker grasps the actually measured value of the holding torque of the pulse motor 55 by looking at the inspection result table, and the measured value has "variation" with respect to the standard value. To determine.

Then, in the test run after the manufacturing is completed, the worker operates the operation display unit 5 according to the "variation" judged above.
By operating the input unit 54a of No. 4, an arbitrary acceleration pattern is designated.

For example, if the actually measured value of the holding torque is larger than the standard value and there is "variation" on the + side, from the viewpoint that a large vibration will be generated in the carriage 40 due to the acceleration motion, the vibration area will be changed. The acceleration pattern of FIG. 2 having a high initial speed and a short period is specified from the viewpoint of wanting to pass through quickly.

When the actually measured value of the holding torque is smaller than the standard value and there is a "side variation",
From the viewpoint that the vibration of the carriage 40 accompanying the acceleration motion is small, and from the viewpoint that the period of the acceleration motion can be extended (effective for reducing the vibration), the initial speed is low and the period is long. The acceleration pattern of FIG. 4 is designated.

When the measured value of the holding torque is near the standard value and the "variation" is small, the acceleration pattern of FIG. 3 having an intermediate element between the acceleration pattern of FIG. 2 and the acceleration pattern of FIG. 4 is designated. It

Since the acceleration motion pattern can be freely selected in this manner, even if the torque of the pulse motor 5 has a "variation", the vibration of the carriage 40 due to the acceleration motion is moved at a constant speed (image formation) regardless of the variation. Can be converged before entering the period).

Therefore, the image quality of the leading edge of the paper P is improved. A uniform and good image quality is always obtained over all of a plurality of copiers manufactured one after another. It is conceivable that the torque of the pulse motor 55 may be “varied” during use to deteriorate the image quality at the leading edge of the paper P. In this case, copying can be performed each time while repeatedly specifying the acceleration pattern. By checking the condition,
The image quality can be corrected to a good condition.

In the above embodiment, three acceleration patterns in which the speed changes linearly are shown, but other various acceleration patterns such as one in which the speed changes in a curve can be adopted. In addition, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

[0052]

As described above, the image forming apparatus of the present invention is provided with means for designating the pattern of the acceleration movement of the motor during the exposure scanning, and the acceleration movement of the motor is designated according to the designated pattern. Is controlled, the vibration of the drive system from the motor to the exposure unit can be suppressed to a small level, whereby uniform and good image quality can always be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a control circuit according to the first embodiment.

FIG. 2 is a diagram showing an example of an acceleration pattern in the same embodiment.

FIG. 3 is a diagram showing another example of an acceleration pattern in the same embodiment.

FIG. 4 is a diagram showing still another example of the acceleration pattern in the same embodiment.

FIG. 5 is a cross-sectional view showing the overall configuration of the same embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main body 2 ... Manuscript stand 20 ... Photosensitive drum 22 ... Exposure system 40 ... Carriage 41 ... Exposure lamp 50 ... Control part 51 ... Scan motor drive circuit 53 ... Memory 54 ... Operation display part

Claims (8)

[Claims] 1. An image forming apparatus for moving an exposing unit along a document table by driving a motor, exposing and scanning the document table to read an image of a document, and forming the read image on an image forming medium. In the apparatus, when the exposure means is moved, a control means for accelerating the motor first and then a uniform speed, an operating means for designating an acceleration motion pattern of the motor, and an operating means for designating the pattern. An image forming apparatus comprising: a control unit that controls the acceleration movement of the motor according to the pattern. 2. An image forming apparatus for moving an exposing device along a document table by driving a motor, exposing and scanning the document table during the movement to read an image of a document, and forming the read image on an image forming medium. In the apparatus, when the exposure means is moved, a control means for accelerating the motor first and then a uniform speed, and a plurality of types of acceleration pattern data for determining an acceleration movement pattern of the motor are stored. Storage means, operation means for designating arbitrary acceleration pattern data among the respective acceleration pattern data in the storage means, and controlling the acceleration of the motor in accordance with the acceleration pattern data designated by the operation means. An image forming apparatus comprising: a control unit. 3. An exposure unit is reciprocated along a document table by driving a motor, and at the time of the forward movement, the document table is exposed and scanned to read an image of the document, and the read image is formed on an image forming medium. In the image forming apparatus, when the exposure unit moves forward, the motor is first accelerated for a predetermined time, then is moved at a constant speed, and finally is decelerated, and a control unit for accelerating the motor. An image forming apparatus comprising: an operation unit for designating a pattern; and a control unit for controlling acceleration movement of the motor according to the pattern designated by the operation unit. 4. The exposure means is reciprocated along a document table by driving a motor, and when the document is moved forward, the document table is exposed and scanned to read an image of a document, and the read image is formed on an image forming medium. In the image forming apparatus, when the exposure unit moves forward, the motor is first accelerated for a predetermined time, then is moved at a constant speed, and finally is decelerated, and a control unit for accelerating the motor. Storage means for storing a plurality of types of acceleration pattern data for determining a pattern, operation means for designating arbitrary acceleration pattern data among the acceleration pattern data in this storage means, and designation by this operation means An image forming apparatus, comprising: a control unit that controls the acceleration movement of the motor according to the acceleration pattern data. 5. A carriage, on which an exposure lamp is mounted, is moved along a document table by driving a pulse motor, the document table is exposed and scanned at the time of the movement, the image of the document is read, and the read image is an image forming medium. In the image forming apparatus formed above, a control means for accelerating the pulse motor first and then a constant velocity when the carriage is moved, and an operating means for designating an accelerating pattern of the pulse motor. An image forming apparatus comprising: a control unit configured to control an acceleration movement of the pulse motor according to a pattern designated by the operation unit. 6. A carriage on which an exposure lamp is mounted is moved along a document table by driving a pulse motor, the document table is exposed and scanned when the carriage is moved, the image of the document is read, and the read image is an image forming medium. In the image forming apparatus formed above, when the carriage is moved, a control unit that first accelerates the pulse motor and then moves at a constant speed, and a plurality of types for determining a pattern of the acceleration movement of the pulse motor. Of the acceleration pattern data stored in the storage means, operation means for designating arbitrary acceleration pattern data among the acceleration pattern data in the storage means, and acceleration pattern data designated by the operation means. An image forming apparatus comprising: a control unit that controls acceleration of the pulse motor. 7. A carriage on which an exposure lamp is mounted is reciprocated along a document table by driving a pulse motor, and the document table is exposed and scanned at the time of the forward movement to read an image of the document,
In an image forming apparatus for forming a read image on an image forming medium, when the carriage moves forward, the pulse motor is first accelerated for a predetermined time, then moved at a constant speed, and finally decelerated. A control means for moving the pulse motor, an operating means for designating a pattern of the acceleration movement of the pulse motor, and a control means for controlling the acceleration movement of the pulse motor according to the pattern designated by the operation means. An image forming apparatus characterized by the above. 8. A carriage on which an exposure lamp is mounted is reciprocated along a document table by driving a pulse motor, and the document table is exposed and scanned during the forward movement to read an image of the document.
In an image forming apparatus for forming a read image on an image forming medium, when the carriage moves forward, the pulse motor is first accelerated for a predetermined time, then moved at a constant speed, and finally decelerated. Control means for moving, a storage means for storing a plurality of types of acceleration pattern data for determining the acceleration motion pattern of the pulse motor, and an arbitrary acceleration pattern data among the respective acceleration pattern data in the storage means. An image forming apparatus comprising: an operating unit for designating; and a control unit for controlling the acceleration movement of the pulse motor according to the acceleration pattern data designated by the operating unit.