JP2688218B2 - Image processing device - Google Patents

Description

The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus using a stepping motor as a drive source for a load.

[Prior Art] Conventionally, as an image processing apparatus such as a copying apparatus, for example, there is one in which a single stepping motor drives a plurality of loads arranged in a reading system for reading an image. In such a case, normally, only the load of the scanner or the like is driven, and when the load is switched by an appropriate switching device, the load of the lens or the like may be driven instead of the scanner or the like.

[Problems to be Solved by the Invention] However, in the conventional image processing apparatus, since the same driving method is adopted regardless of the type of load, it is necessary to perform optimum control according to the load torque and the driving speed. In some cases, which may cause problems in terms of noise and load driving speed.

An object of the present invention is to enable optimum drive control according to each of a plurality of loads, thereby solving the above problem.

[Means for Solving the Problem] Therefore, the present invention is an image processing apparatus including means for independently driving a plurality of loads by a single stepping motor, and selects a load to be driven and selects the stepping motor. And a drive switching means for switching the drive system of the stepping motor according to the load to be driven.

[Operation] According to the present invention, when different loads are independently driven by a single stepping motor, the drive system of the stepping motor is switched according to the load, so that appropriate drive control suitable for the load can be performed. .

Examples Hereinafter, the present invention will be described in detail with reference to the drawings.

 The present embodiment will be described by taking a copying machine as an example.

FIG. 1 is a sectional view of the entire copying apparatus according to this embodiment. In FIG. 1, the drive system is divided into a main drive system that drives the paper feed unit, the transport unit, the photoconductor, and the fixing unit, and an optical drive system that drives the optical system. An AC synchronous motor 25 is used as the main drive source, and a stepping motor (pulse motor) 26 is used as the optical drive source.

The paper feed method can be selected from the paper feed from the cassette 23 and the paper feed from the manual feed section 24. When feeding from cassette 23,
The state is managed by a switch for detecting the presence / absence of the cassette 23, a switch group 31 for detecting the size of the cassette, and a switch 37 for detecting the presence / absence of paper in the cassette,
When an abnormality is detected by the above switch, it is displayed on the display unit described later. Switch 32 that detects the status of the manual feed guide 24
The state is managed by, and when an abnormality is detected, it is displayed on the display unit described later.

The photoconductor 12 rotates clockwise in the drawing. The potential charged on the photoconductor 12 by the primary charger 13 is exposed at an exposure position, which will be described in detail later, developed by the developing unit 15, and transferred by the transfer unit 14 from the paper feeding unit. Transfer the image to (transfer paper). The residual toner is removed from the photoconductor 12 after transfer by the cleaning unit 38, and the residual potential is removed by the pre-exposure lamp 16.
The process of forming an image again is repeated.

The transfer sheet on which the image has been transferred is carried on the conveyor belt of the conveyor unit 20 and sent to the fixing unit 21. The fixing unit 21 is composed of a heat roller 35 'on the surface of which a temperature detecting element 35 such as a thermistor is arranged, and a roller of which pressure is brought into contact and the surface of which has elasticity. The heat roller 35 'uses a halogen lamp as a heat source, and this halogen lamp is incorporated in the roller axial direction. The halogen lamp is controlled by a thermistor so that the surface temperature of the heat roller 35 'becomes a predetermined temperature.

The paper that has passed through the fixing unit 21 is discharged from the fixing unit 21 by the paper discharge roller 22 and is stacked on the paper discharge tray 39. Further, 34 is a paper discharge sensor for detecting whether or not the transfer paper has normally passed through the fixing unit 21.

The drive source of the optical drive system is the pulse motor 26 as described above.
It is. The pulse motor 26, which is the drive source, is configured to drive a completely different load by operating the drive switching solenoid 27, which will be described in detail later with reference to FIG. One load is a unit that constitutes the exposure lamp 4 and the first mirror 5, the second mirror 6, and the third mirror 7, and the other load is a unit that constitutes the zoom lens 8. These loads that do not need to be driven synchronously can be driven by a common drive source.

The apparatus according to this example uses a pulse motor 26 of an optical drive unit to control the position of the zoom lens 8, a multi-step magnification selection function by controlling the speed of the lamp systems 4 to 7, and the reflection of an original placed on the original glass 3 surface. A function that automatically selects the density by the light sensor 40 that detects light, a function that automatically selects the copy magnification by connecting through communication means with an external device (not shown), and in the unlikely event that an abnormality such as a paper jam occurs. Various coping functions, for example, a memory backup function for storing the remaining number of sheets, a magnification value, abnormality information, etc., a page continuous shooting function by controlling the position of the exposure lamp 4 by the pulse motor 26, and further, the developing unit 15 is replaced. By doing so, it is possible to form a plurality of color images, and by providing a switch 36 for detecting the replacement of the developing unit 15, a function for switching control depending on this state is provided. It is.

 Next, the operation of this device will be described.

FIG. 2 shows an operation panel of this apparatus, which is arranged on the upper surface of the apparatus shown in FIG. When the I side of the power switch 51 is pressed, power is supplied to this device. At the same time as the power indicator
52 is lit up.

The thermistor 35 of the fixing unit 21 detects that the heat roller 35 'has not reached a predetermined temperature in the initial state after the power is turned on, and controls the lighting of a fixing heater (not shown) as a heat source. When the power is turned on, the display on the operation panel is set in the standard mode as follows, for example. Number display 59
Indicates "1", the magnification display 67 displays the equal magnification, and A of the automatic density adjustment display 76 is turned on.

In addition, the display of the start key 56 is displayed in red when the temperature inside the fixing unit has not reached the fixable temperature, and when it reaches the fixable temperature, it is switched to the green display and the copying operation becomes possible. Display that. Normally, all other indicators are turned off.

The fixable temperature of the fixing unit 21 differs depending on the type of the developing unit 15, and the type of the developing unit 15 is discriminated by the switch 36 provided in the developing unit 15 to switch the set temperature. Further, when it is necessary to lower the temperature from a high temperature, a forced cooling means such as an in-machine cooling fan 28 is provided so that the fixing temperature can be reached quickly.

Transmission and reception of these signals related to the operation panel, temperature control, and control operations for the optical drive system and the like described below are controlled by the one-chip microcomputer shown in FIG. Q in FIG. 3 shows a one-chip microcomputer with built-in ROM and RAM, and this one-chip microcomputer Q executes control operation according to a microcomputer program whose basic configuration is shown in FIG.

Next, the operation of the optical drive system after the power is turned on will be described. The exposure lamp systems 4 to 7 move the original on the original glass 3 to the first position.
The document image is moved in the right direction from the left end of the figure, and the original image is passed through the first mirror 5, the second mirror 6, the third mirror 7, the zoom lens 8, the fourth mirror 9, the fifth mirror 10 and the sixth mirror 11. Photoconductor 12
Exposure of the document to That is, the movement start point is set to the left end. This position is the home position (hereinafter referred to as HP). An HP sensor 29 is provided to detect this HP. When the HP sensor does not detect the position of the exposure lamp 4 when the power is turned on, for example, a control unit in the form of a one-chip microcomputer as shown in FIG. It moves to the HP side (a known technique can be used for the forward / reverse rotation control of the pulse motor).

The start of the rotation control will be described with reference to FIG. Fifth
The figure shows an example of the configuration of a drive system in which two loads (optical system and lens) can be driven independently.

Here, is a lamp driving gear integrally formed with a pulley for driving an optical load (exposure lamp system 4 to 7), 26 'is a motor output gear provided on the output shaft of the pulse motor, and is meshed with a gear 26'. At the same time, a switching gear that selectively meshes with the gear or switches the load, 27 is a solenoid for causing the gear to perform a switching operation via a link, and a lens driving gear.

First, when the drive switching solenoid 27 is off (there is no force b '), the switching gear moves in the A direction by the spring pressure. As a result, the output of the pulse motor 26 is connected to the lamp driving gear via the switching gear, and the exposure lamp units 4 to 7 are driven. When the gears are connected, the pulse motor 26 is controlled so that the rotation speed is sufficiently lowered when the switching gear and the lamp driving gear are meshed.

If the exposure units 4-7 are located on the HP,
The pulse motor 26 drives the zoom lens unit 8.
That is, the position of the zoom lens before the power is turned on is unknown. As described above, when the power is turned on, the equal magnification value is selected as the standard mode. Therefore, the operation of temporarily returning to the reference position and setting a predetermined position from that point is executed.

The reference position above is the zoom lens home position (Z.
HP). A Z.HP sensor 30 for detecting this position is provided.

 The operation will be described with reference to FIG.

When the drive switching solenoid 27 is turned on, the solenoid 27
Plunger moves in the b direction. Therefore, the force of b ′ causes the switching gear to move in the B direction against the spring force. This movement disengages the switching gear and the lamp driving gear. By further moving in the B direction, the switching gear meshes with the lens driving gear. The rotation control at the time of gear engagement is the same as that described above.

The zoom lens 8 uses the Z.HP sensor as a reference position, and the zoom ratio is 200 when the lens position is near the Z.HP sensor.
The position is controlled within the range of the reduction rate of 50% when moving to the right from%.

The operation is as follows depending on the Z.HP state when the zoom lens drive is started.

(1) When the position of the zoom lens 8 is detected by the Z.HP sensor.

(1) -1 Once move the zoom lens 8 to the right and bring it out of the range not detected by the Z.HP sensor and stop.

(1) -2 Move to the left side and move for a predetermined distance from the time when the Z.HP sensor detects it, then stop.

However, if the Z.HP sensor has not detected the position of the zoom lens, execution is started from the operation (1) -2.

The above operation is the control necessary to prevent the setting position error due to the backlash of the gears.

Thereafter, the zoom lens 8 is moved to the right again, and the zoom lens 8 is moved from the position where the Z.HP sensor is released to a predetermined position.
In other words, in the case of the setting of the standard mode, it moves to the position corresponding to the equal magnification and stops. Thereafter, the drive switching solenoid 27 is turned off. As a result, as described above, the switching gear moves in the direction in which it meshes with the lamp driving gear. However, in order to smoothly engage with each other, it is necessary to rotate the switching gear as described above. At this point, the exposure lamp units 4 to 7 are at H.P29. Therefore, the pulse motor 26 rotates the exposure lamp units 4 to 7 in the direction to move them to the right. As a result, when the exposure lamp units 4 to 7 are disengaged from the HP sensor 29 (that is, the fitting of the switching gear and the lamp driving gear is completed), the rotation is stopped, and the HP sensor 2 is rotated again in the opposite direction.
After detecting 9, stop at the specified position.

The initial operation of the optical drive system described above and the fixing unit 21
, The preparation for the copying operation of this apparatus is completed.

Next, a copying operation by feeding paper from the cassette 23 will be described.

When the copy start key 56 is pressed, the transfer paper size data by the input signal of the switch group 31 for detecting the cassette size, the number data set by the number key 54, and the magnification selection keys 61, 62, 64, 65, 66 The copying operation is started based on the magnification data and other various mode selection means data.

When the copy start key 56 is accepted, the display changes from green to red, the numeric key 54, the magnification keys 61, 62, 64, 65, 66
And the like, mode input is prohibited. The main drive motor 25 starts rotating, and the driving force is transmitted to the paper feed roller 18, the photoconductor 12, the transport unit 20, the fixing unit 21, and the like.

Further, when the copy key 56 is received, the fixable temperature of the fixing unit 21 is switched according to the cassette size data.

A sheet feeding solenoid (not shown) operates 0.5 seconds after the rotation of the main drive motor 25 starts, and the sheet feeding roller 17 rotates accordingly, and the transfer sheet in the cassette 23 is sent out to the sheet feeding roller 18 direction. . The transfer paper feed amount of the paper feed roller 17 is controlled by the cassette size data. That is, when the transfer paper is larger than the predetermined value, the feed amount is increased. When the transfer paper reaches the paper feed roller 18, the transfer paper is
It is stopped by the time when it is sent to the registration roller 19 by 18 and reaches it. A manual feed switch 33 installed between the paper feed roller 18 and the registration roller 19 detects the transfer state of the transfer paper.

The exposure lamp units 4 to 7 are allowed to start scanning the document at a predetermined timing until the transfer sheet is fed on the sheet feeding path and reaches the registration roller 19. At this time, the exposure lamp is at a position detected by the HP sensor 29.
More specifically, during the initial operation or the backward movement of the copy operation, the vehicle stops at a position backward from the position detected by the HP sensor by a distance according to the selection magnification at that time.

When the document scanning is started, the pulse motor 26, which is the optical system drive source, causes the pulse rate until the drive pulse rate corresponding to the selected magnification value is reached in the forward direction (right direction) of the exposure units 4 to 7. Gradually increases (called slow-up control). That is, the moving speed is gradually accelerated and reaches the target speed. Although not particularly shown, the pulse motor drive circuit of the present device employs a constant current control method and a configuration in which the drive current value can be switched to a plurality of stages (two stages in the embodiment) (see FIG. 3). It is selected by the PB4 output signal of the optical drive pulse motor control signal).

In general, the characteristics of the pulse motor are such that the pull-in torque decreases as the pulse rate increases. Therefore, means for switching the constant current set value is provided, and the current value is switched as necessary.

In this device, the set current is lowered during the relatively low pulse rate from the start of movement, and the set current value is controlled to increase when the speed exceeds a predetermined value, and after reaching the target speed, a predetermined time is reached. The control for lowering the set current value is performed again with the passage of. This is mainly intended to prevent noise, temperature rise, and step-out phenomenon of the pulse motor.

Next, with reference to FIG. 6, a method for forming a margin at the leading edge of the image and a method for aligning the leading edge with the transfer paper will be described.

LED as a means to prevent toner adhesion in non-image areas
A static elimination means using a light source such as a lamp or a fuse lamp is generally used, but in this apparatus, the same effect is realized by controlling the voltage value of the grid 13 'provided in the primary charging unit 13. This is an important method in the present situation where it is difficult to arrange a plurality of members around the photoconductor due to downsizing of the apparatus. Since the distance e between the exposure point and the grid cannot be arranged sufficiently short compared to the distance b between the HP sensor 29 and the original contact position, it is necessary to form a 2 mm margin at the leading edge of the original from the start of the movement of the exposure lamp 4. The grid is switched from the L level to a predetermined voltage after a predetermined time corresponding to the magnification selection value. In other words, when the grid voltage is at the L level, the toner image is not formed because the photoconductor is not charged with the electric potential, and the image is formed from the timing when the voltage is switched to the above-mentioned predetermined voltage. A margin is formed on the.

Next, regarding the leading edge of the image with the transfer paper, the distance c between the exposure point and the transfer section is shorter than the distance d between the registration roller 19 and the transfer section. For this reason, it is necessary to re-feed the transfer paper waiting on the above-mentioned registration roller 19 before the image of the front end of the original is exposed on the photoconductor 12 and feed it toward the transfer section.

In this apparatus, the exposure lamp 4 starts moving and the exposure lamp 4
Is reached by the HP sensor 29 when the vehicle reaches the target speed. The time required for the exposure lamp 4 to reach the edge of the white plate after passing the HP sensor 29 is the value obtained by dividing the value of the distance b + 2 mm by the selected magnification from the timing of passing the HP sensor 29. And this time is x
And

Further, y is a value obtained by subtracting the time required for the image at the exposure point of the photoconductor 12 to reach the transfer portion from the time from the start of re-feeding by the registration roller 19 to the transfer portion. , The time required to feed the transfer paper 2 mm to this y (2
mm ÷ 100mm / s = 0.02sec… Transport speed = 100mm / s) The above values are calculated by the following equation.

x− (y + 0.02) = Z (sec) In other words, if the registration roller 19 is operated at the timing when the above formula value z has passed from the time when the HP sensor 29 was passed and re-feeding is executed, the selected magnification is selected. 2mm depending on the margin
The formed transfer paper image is obtained.

The scanning distance of the exposure units 4 to 7 moves a predetermined distance according to the cassette size data, the magnification data, etc., and when the target position is reached, the pulse rate is gradually reduced (called slowdown control) and stopped, and then the HP sensor is restarted. Slow-up control and constant-speed control are performed in 29 directions to move backward. And HP sensor 2
When 9 is detected, slowdown control for stopping at a position corresponding to the selected magnification is performed and the exposure units 4 to 7 are stopped.

The operation of the manual feed copy is started when the manual feed sensor 33 detects the inserted transfer paper. The main drive motor 25 starts rotating, whereby the paper feed roller 18 rotates. Thus, the inserted transfer paper is fed by the paper feed roller 18 toward the registration roller 19.
Further, after a predetermined time from the time when the manual feed sensor 33 detects the transfer paper, the exposure lamp units 4 to 7 are permitted to start scanning the original document. Subsequent operations of the exposure lamp system and the front end of the transfer paper are the same as those in the case of feeding the cassette, and therefore the description thereof is omitted. Next, from the time when the trailing edge of the transfer paper passes the manual feed sensor 33, the manual feed sensor 33 operates the registration roller 19 when the time x ′ required for the transfer paper to pass the distance between the transfer portions elapses. Stop. However, when the above x'is measured, the manual feed sensor 33
When the next paper is detected, the operation of the registration roller 19 is stopped when the time required for the transfer paper to pass the distance between the manual feed sensor 33 and the registration roller 19 has elapsed.

Further, control of the document scanning distance is also executed by the trailing edge signal of the transfer paper.

As described above, the pulse motor 26 drives the exposure lamp units 4 to 7 and the zoom lens 8 independently, but in this example, in order to perform the optimum drive control corresponding to the load, the following is performed. Performs pulse motor control.

As is well known, the pulse motor rotates according to the excitation pattern input to each phase. In case of 2-phase pulse motor,
There are the following three excitation patterns.

a) 1-phase excitation b) 2-phase excitation: Large output torque c) 1-2-phase excitation: Can be driven in half steps.

In this example, a two-phase pulse motor 26 is used, and driving is performed by two-phase excitation and one-two phase excitation. In other words, for the drive of the optical system (exposure lamp units 4 to 7, 1-2 phase excitation capable of half step is selected. This is because the movement of the optical system affects the image, so it is smoother. Two-phase excitation with a large output torque is selected for driving the lens so that the lens can be driven even with a large load.

FIG. 7 shows an example of the control section according to the main part of this embodiment. Here, 101 is a controller for driving a motor 26 for driving an optical system as a load and a lens and a load switching solenoid 27, and is a simplified view of a one-chip microcomputer Q for executing a series of copy sequences. . 102 is a constant current driver for driving the pulse motor according to the excitation signals A, B.

A mode in which the excitation method is switched according to the load in the above configuration will be described.

FIG. 8A shows an example of the control procedure when the power is turned on. When the power is turned on, first, in step S121, it is determined whether or not the optical system (exposure lamp units 4 to 7) is at the home position. If a negative determination is made, 1-
The pulse motor 26 is driven by the two-phase excitation to set the optical system to the home position (step S131).

Thereafter, in order to position the zoom lens 8 at the set position, the optical system / lens switching solenoid 4 is turned on (step S122), and a predetermined time is waited until the solenoid 4 is completely turned on (step S123). Then, the lens 8 is moved toward the lens home position (Z · HP) by two-phase excitation (step S124), and is driven by a distance corresponding to the set magnification from Z · HP (step S125). After completing this setting, the optical system / lens switching solenoid 4 is turned off by waiting for a predetermined time (step S126) (step S126).
S127). After waiting for a predetermined time (step S128), 1-
The optical system is once taken out from the detection position of the home position sensor by two-phase excitation (step S129), and the optical system is stopped at the home position where the home position sensor detects again (step S130).

Next, the operation when the copy key 56 is turned on will be described with reference to FIG. Copy start key
When 56 is pressed (step S132), it is determined whether or not there is a change in the set magnification, and if a positive determination is made, step S1
At 34, the same processing as steps S122 to S130 is performed. Then, an appropriate series of copy processing as described above (step S13
Do 5).

As described above, according to the present embodiment, the pulse motor that drives the optical system and the lens independently is driven by the phase excitation method according to the driving target. Optimal drive control can be performed without causing any problems.

In the above description, the case where the present invention is applied to the image reading system of the image processing device in the form of a copying machine has been described, but it goes without saying that the present invention can be applied to appropriate parts of the image processing device in an appropriate form.

[Effects of the Invention] As described above, according to the present invention, by providing the switching means of the excitation method of the stepping motor (pulse motor) which is the drive source, the optimum driving according to the load can be performed with a simple configuration. There is an effect that control can be performed and noise can be suppressed. Further, such control can be performed using a single motor, which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a copying machine according to an embodiment of the present invention, FIG. 2 is a plan view showing a configuration example of an operation panel of the apparatus shown in FIG. 1, and FIG. 3 is a view showing the apparatus shown in FIG. FIG. 4 is a block diagram showing a one-chip microcomputer for performing all controls, FIG. 4 is an explanatory diagram showing a basic configuration example of a program of the one-chip microcomputer shown in FIG. 3, and FIG. 5 is a switching for switching a load driven by a pulse motor. 6 is an explanatory diagram showing a configuration example of a system, FIG. 6 is a diagram for explaining margin formation of an image leading end portion, and leading edge alignment with a transfer sheet, and FIG. 7 is a control system relating to a main portion of the present embodiment. Block diagrams, FIGS. 8A and 8B are flowcharts showing an example of the control procedure of this embodiment. 4 ... exposure lamp, 5,6,7,8,9,10,11 ... mirror, 12 ... photoreceptor, 13 ... primary charger, 14 ... transfer unit, 15 ... development unit, 20 ... … Transport unit, 21… Fixing unit, 26… Pulse motor, 27… Drive switching solenoid, 29… HP sensor.

Claims (2)

(57) [Claims] 1. An image processing apparatus comprising means for independently driving a plurality of loads by a single stepping motor; load switching means for selecting a load to be driven and connecting the load to the stepping motor; And a drive switching means for switching the drive system of the stepping motor according to the load. 2. An optical system comprising reading means for reading image information from a manuscript, the reading means having an optical system for scanning the manuscript at the time of reading and a zoom lens for changing a reading magnification. A system and the zoom lens as the plurality of loads, the stepping motor has a form of a two-phase stepping motor, and the drive switching means drives the optical system and the zoom lens.
The image processing apparatus according to claim 1, wherein the two-phase stepping motor is driven by a 1-2-phase excitation method and a 2-phase excitation method, respectively.