JP2783730B2 - Copier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine in which a document table is reciprocated by a document table driving device during a copying operation.

[0002]

2. Description of the Related Art In a copying machine that performs copying by moving a platen, when a document on the platen is scanned by an optical system, the platen first moves from a standby position to a scanning start position in a return direction. Then, after moving in the feed direction to the scanning end position to scan the original, the scanning unit moves from the scanning end position to the original standby position in the return direction.

A conventional platen driving device 51 for moving a platen as described above is provided below a platen 52 as shown in FIG. 9 and has a structure as shown in FIG. In the platen driving device 51, when the platen 52 is moved in the feed (F) direction from the scanning start position, the feed solenoid 53 is turned on, whereby the latch 54 is turned on by the clutch brake of the feed spring clutch 55. , And the feed spring clutch 55 is brought into a connected state. Accordingly, the driving force input to the input gear 57 is transmitted to the output gear 58 and further transmitted to the platen drive gear 59, and the platen 52 provided with a rack that meshes with the platen drive gear 59 is fed (F). ) Direction.

After that, when the document table 52 reaches the scanning end position, this state is detected by the detection switch 60 shown in FIG. 9, and the feed solenoid 53 is turned off and the return solenoid 61 is turned on. As a result, the latch 62 is engaged with the clutch brake 63 of the return spring clutch 67, and the return spring clutch 6
7 is connected. Accordingly, the driving force input to the input gear 57 is transmitted to the platen drive gear 59 via the gear 64, the input gear 65, the output gear 66, and the output gear 58, and the platen 52 is moved in the return (R) direction. It moves to the standby position.

However, in the above-described conventional configuration, the original table 5
In order to reciprocate 2, the feed spring clutch 55, the return spring clutch 67, the feed solenoid 53, the return solenoid 61, and other devices are required. In a copying machine, the ratio of the cost occupied by each device as described above increases, resulting in an increase in the cost of the device.

Further, in the above configuration, since a plurality of clutches and solenoids are used, the control timer is likely to vary, which causes a situation in which the leading edges of the images are not aligned and the image quality deteriorates. This is particularly noticeable when the rotation speed of the motor is increased and the return speed of the document table 52 is extremely increased in order to shorten the time required for copying.

On the other hand, in Japanese Utility Model Publication No. Sho 56-22205, a moving body having a stepped endless gear extending along the moving direction of the document table is attached to the document table. An original table moving device of a copying machine has been disclosed in which an endless gear is reciprocated in a horizontal direction by rotating a pinion gear that meshes with the original table, whereby the original table is reciprocated.

According to this, the transmission of the driving force from the driving source to the pinion gear for moving the platen is directly performed without the intervention of the clutch mechanism, so that the structure is simplified and the cost of the apparatus can be reduced. In addition, since the clutch, the solenoid and the like are not used, the deterioration of the image quality due to the variation in the time of the control timer can be avoided.

[0009]

However, in the apparatus disclosed in Japanese Utility Model Publication No. Sho 56-22205, the structure is simplified and the cost of the apparatus can be reduced. Not implemented and there is room for improvement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying machine which has a simple structure, is low in cost, and has a short copying time.

[0011]

In order to achieve the above object, a copying machine according to the present invention has a platen driving device for reciprocating a platen in a linear direction, and a platen position detecting device for detecting a position of the platen. Means for transmitting a driving force from a driving source to a driving unit of the platen driving device directly without passing through a clutch mechanism. With one copy operation, a document for scanning a document is provided. The copying operation is started when the platen moves one cycle and the state where the platen has reached the scanning start position is detected by the platen position detecting means. The speed is controlled to be higher than the rotation speed during the copying operation until the document table reaches the scanning start position and the copying operation is started. Control means for controlling speed It is characterized in that is provided.

[0012]

According to the above arrangement, there is provided a platen driving device for reciprocating the platen in a linear direction, and platen position detecting means for detecting the position of the platen. The transmission of the driving force from the driving source is directly performed without going through the clutch mechanism, and with one copying operation,
One cycle of movement of the platen for document scanning is performed,
Since the copying operation is started when the state in which the platen has reached the scanning start position is detected by the platen position detecting means, various mechanisms are provided for transmitting the drive to the platen. The structure is simplified and the cost is lower than when the clutch is provided.

The control means controls the rotational speed of the drive source to be higher than the rotational speed during the copying operation until the document table reaches the scanning start position and the copying operation is started. On the other hand, since the control is performed so that the rotation speed at the time of the copying operation is at the same time as the start of the copying operation, the movement of the document table is speeded up, and the time required for copying can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, the copying machine of the present embodiment has a document table 2 on the top surface of a substantially rectangular box-shaped copying machine main body 1. The platen 2 is formed by a transparent member such as a glass plate at a central portion, and is driven by a platen driving device 3 described later to linearly move in the horizontal direction.

A copy lamp 1 is provided above the copying machine body 1.
An optical system 20 including a lens 5 and a rod / lens array 24 is disposed, and a drum-shaped photoconductor 13 is disposed below the optical system 20. The photoreceptor 13 is driven to rotate by a main motor 43, which will be described later, and is exposed to the reflected light of the light emitted from the copy lamp 15 toward the document 25, and the residual charge is generated by the direct light from the copy lamp 15. Is to be neutralized.

Around the photosensitive member 13, the photosensitive member 13
And a stirrer 26, a supply roller 27, a stirring roller 28, a magnet roller 29, and the like. The electrostatic latent image formed on the photoconductor 13 by the exposure operation of the optical system 20 is developed with toner. Developing device 30
And a transfer roller 12 for transferring the toner image formed by the developing operation onto transfer paper, a cleaning device 18 for collecting residual toner on the surface of the photoconductor 13 by a blade 17, and the like.

A transfer section 32 is provided on the side of supplying the transfer paper to the photoconductor 13, and a feed section 33 is further provided on the supply side.
Is provided. The paper feed unit 33 includes a manual feed tray 34 on which transfer paper is placed, a paper feed roller 35 that feeds out the transfer paper one by one from the manual feed tray 34, and a later-described paper feed solenoid 44 that operates the paper feed roller 35. And the transfer paper is supplied to the transport unit 32.

On the other hand, the transport section 32 includes a paper input sensor 36 which is turned on when the transfer paper is detected, a registration roller 16 for temporarily stopping the transfer paper, and a registration roller solenoid 45 for operating the registration roller 16 which will be described later. The transfer paper supplied from the paper supply unit 33 is transported between the transfer roller 12 and the photoconductor 13 at a predetermined timing.

Further, in the transport direction of the transfer paper from the photoconductor 13, jam sensors 38 and 39 for detecting the position of the jam paper when a paper jam occurs, that is, when a jam occurs, and for fixing the toner image on the transfer paper. A fixing device 19 and a sheet discharge sensor 37 for detecting that the transfer sheet has passed through the fixing device 19 and reached a sheet discharge unit (not shown) are provided.

At the time of the copying operation, the original table 2 is driven by the original table driving device 3, and the end in the return direction (R) substantially coincides with the end of the copying machine main body 1, that is, the standby position. from B _1, first, it moved to the scanning start position B ₂ of the return direction (R), then, for the document scanning by the optical system 20, and moved to the scanning end position B ₃ of the feed direction (F), then moves to the original standby position B _1.

On the other hand, while the original table 2 moves from the scanning start position B ₂ to the scanning end position B ₃ , the original 25
Is performed. That is, the document 2 placed on the platen 2
5 is irradiated by the copy lamp 15, and the reflected light is incident on the photoconductor 13 via the rod lens array 24. At this time, the photoreceptor 13 is uniformly charged by the main charger 14 and is exposed by the reflected light,
An electrostatic latent image is formed on the photoconductor 13.

This electrostatic latent image is developed with toner supplied from the developing device 30, and a toner image corresponding to the image of the original 25 is formed on the photoconductor 13. This toner image is
The transfer roller 35 and the registration
The image is transferred by the transfer roller 12 to the transfer paper conveyed via the roller 16. Thereafter, the toner image on the transfer paper is fixed on the transfer paper by a heating and pressurizing operation by the fixing device 19, and the transfer paper passing through the fixing device 19 is transferred to the copying machine main body 1.
Is discharged to the outside.

On the other hand, after the transfer operation, the transfer roller 12
The toner adhering to the surface moves onto the photoconductor 13 by applying a voltage having a polarity opposite to that of the toner to the transfer roller 12, and is collected by the cleaning device 18 together with the residual toner on the surface of the photoconductor 13. Further, the surface of the photoreceptor 13 after the transfer operation is uniformly discharged by the direct light of the copy lamp 15 to be in a standby state. In addition, the above-mentioned original scanning
A document table sensor 2 provided in a document table driving device 3 described later.
2 is started based on the output signal from the control unit 2.

Before starting copying, the copying machine
In order to obtain a high-quality image, pre-rotation including a series of operations such as charging, exposure, development, cleaning, and charge elimination of the photoconductor 13 is performed, and the photoconductor 13 is initialized. The platen 2 is also driven by the platen driving device 3 to perform one cycle of operation.

The platen driving device 3 for moving the platen 2 as described above is provided on the rear side of the copying machine main body 1 and is provided with
The configuration is as shown in FIG. In FIG. 1, a document table driving device 3 includes a main support 4 on which an endless gear 8 is provided.
have. The main support 4 has a vertical wall shape, is vertically connected to the document table 2, and moves along with the document table 2 along the side surface of the copying machine main body 1. Main support 4
An oval concave portion is formed at the center of the
The above-mentioned endless gear 8 having internal teeth and forming an annular shape is provided.

The endless gear 8 connects the upper rack portion 5 and the lower rack portion 6 provided in parallel with the tooth surfaces facing each other, and the respective end portions of the two rack portions 5 and 6 to form a semicircular shape. Return side semicircle internal gear 7a having aligned internal teeth
And a feed side semicircle internal gear 7b.
The upper rack portion 5 is formed such that the gear pitch is smaller than that of the lower rack portion 6 and the gear width is substantially half.
The side surface extends along the copying machine main body 1 side, and is disposed inside the endless gear 8 with a step relative to the return side semicircle internal gear portion 7a and the feed side semicircle internal gear portion 7b.

Inside the endless gear 8, a sun gear 9 is fixedly provided at an intermediate portion between the upper and lower racks 5 and 6, and a small diameter is provided between the sun gear 9 and the endless gear 8. A large-diameter planetary gear 10b is provided integrally and concentrically with the planetary gear 10c and the small-diameter planetary gear 10c. The small-diameter planetary gear 10c is a large-diameter planetary gear 1
The large-diameter planetary gear 10 b is arranged on the side of the copying machine main body 1, and is meshed with the upper rack portion 5. On the other hand, the large-diameter planetary gear 10b meshes with the lower rack 6, the return-side semicircle internal gear 7a, and the feed-side semicircle internal gear 7b. In other words, the sun gear 9, the small-diameter planetary gear 10c, and the small-diameter planetary gear 10c constitute a driving unit of the document table driving device 3 of the present invention.

The main support 4 includes an endless gear 8.
A groove 4a for passing the input shaft 9a, which is the rotation shaft of the sun gear 9, during the movement of the sun gear 9, is formed in parallel with the upper and lower rack portions 5,6. Driving force from a main motor 43, which is a driving source shown in FIG. 6, is transmitted to the input shaft 9a.

The gear shaft 10a as the gear shaft of the large-diameter planetary gear 10b and the small-diameter planetary gear 10c is
1 is rotatably connected to the vicinity of the center. An input shaft 9a of the sun gear 9 is rotatably connected near one end of the connection plate 11. The connecting plate 11 has a sliding member (not shown) connected thereto slides in a sliding guide groove (not shown) provided on the back side of a protective cover (not shown) of the main support 4. Thus, the rotation is made along the endless gear 8.

As shown in FIGS. 4 and 5, the platen driving device 3 has large and small planetary gears 10b and 10b.
A light-shielding plate 21 and a document table sensor 22 constituting a document table position detecting means for detecting the position of the document table 2 by detecting the position detection of c are provided. The light shielding plate 21 has a semicircular shape centered on the input shaft 9 a of the sun gear 9, is provided integrally with the connection plate 11, and rotates with the rotation of the connection plate 11. The platen sensor 22 has a light-emitting element 22a such as a light-emitting diode and a light-receiving element 22b such as a phototransistor arranged opposite to each other with a rotation space of the light-shielding plate 21 therebetween. This platen sensor 2
2 is held at a fixed position with respect to the input shaft 9a.

On the other hand, the copying machine main body 1 has a control device 31 as control means shown in FIG. This control device 3
1 comprises a microcomputer, as described below,
On the basis of input signals from the main power switch 40, the print switch 23, the paper input sensor 36, the document table sensor 22, the paper discharge sensor 37, the encoder sensor 47, and the like of the copying machine body 1, the main motor 43 and the The operation of a ready lamp 41, a copy lamp 42, a paper feed solenoid 44, a registration roller solenoid 45, and a high voltage unit 46 for supplying a high voltage to the main charger 14 and the transfer roller 12 provided on a display panel (not shown) is performed. Control.

The encoder sensor 47 is provided in the vicinity of the main motor 43 and generates pulses corresponding to the rotation of the main motor 43. The rotation speed of the main motor is detected and the speed is controlled based on the number of pulses.

In the above configuration, as shown in FIG.
The small-diameter planetary gear 10c of the platen driving device 3 is
When the sun gear 9 rotates in the direction A due to the input to the input shaft 9a when the input shaft 9a is engaged, the small-diameter planetary gear 10c rotates in the direction B, and the platen 2 moves in the feed direction (F) together with the endless gear 8. I do. Thereafter, when the small-diameter planetary gear 10c reaches the end of the upper rack portion 5 on the side of the return-side semicircular internal gear portion 7a, the engagement between the small-diameter gear 10c and the upper rack portion 5 is released, while the large-diameter planetary gear is released. Gear 10b
Meshes with the return side semicircle internal gear 7a. In this state, the large-diameter planetary gear 10b and the connecting plate 11
180 ° around the sun gear 9 around the input shaft 9a
Rotate. And the large-diameter planetary gear 10b is
And the endless gear 8 moves the document table 2 in the return (R) direction opposite to the above. afterwards,
When the large-diameter planetary gear 10b meshes with the feed-side semicircle internal gear 7b, the large-diameter planetary gear 10b rotates 180 ° around the sun gear 9 about the input shaft 9a of the sun gear 9 together with the connecting plate 11. Then, it reaches the upper rack section 5.

Here, when the document table 2 is at the standby position B ₁ , the large-diameter planetary gear 10 b meshes with the substantially central portion of the lower rack 6. In one copying operation, that is, in one cycle movement of the document table 2, the large-diameter planetary gear 10
When b reaches the point α ₁ shown in FIG. 5, the document table 2 reaches the scanning start position B ₂ in the return direction with respect to the standby position B ₁ . Then, while the large径遊star gear 10b is meshed with the return-side semicircular internal gear portion 7a, the document table 2 is held in the scan start position B _2, the small-diameter planetary gears 10c reaches alpha ₂ points When it is engaged with the upper rack part 5, the movement in the feed direction is started. Then, when the small-diameter planetary gears 10c reaches alpha ₃ points, the document table 2 has reached the scanning end position B _3. Then, while the large径遊star gear 10b is meshed with gear portion 7b in the feed side semicircle, platen 2 is held to the scanning end position B _3, large径遊star wheel 10b reaches the alpha ₄ When the lower rack part 6 meshes with the lower rack part, it starts moving in the return direction.
When the large-diameter planetary gear 10b reaches the initial position, the standby position B
It reaches _1. Note that α _{1 to} α ₄ indicate the start point or end point of the bending in the endless gear 8.

As described above, as long as the sun gear 9 is rotating, the document table 2 alternately repeats the movement in the return direction and the feed direction. The large-diameter and small-diameter planetary gears 10b and 10c rotate only in the direction B, and make one rotation around the sun gear 9 by moving the document table 2 in one cycle. At this time, the connecting plate 11 also makes one rotation.

In this copying machine, since the operation of the document table 2 is controlled only by turning on / off the main motor 43, the document table 2 is moved to the standby position B in one copy operation.
Before returning to step ₁ , the transfer paper on which the original image was copied
The paper passes through the fixing device 19 and is discharged from the copying machine main body 1.

Next, the operation of detecting the position of the document table 2 based on the output from the document table sensor 22 will be described. The light-shielding plate 21 is used to move the connecting plate 1 when the platen 2 is moved for one cycle.
One rotation is made around the sun gear 9 together with 1, and the output of the document table sensor 22 changes accordingly. For example, as shown in FIG. 5, when the small-diameter planetary gear 10c meshes with the upper rack portion 5, the light path between the light emitting element 22a and the light receiving element 22b is blocked by the light shielding plate 21, so that the document table Sensor 2
The output of No. 2 is OFF. Then, the large-diameter planetary gear 10b
Is meshed with the return-side semicircular internal gear 7a and passes through the intermediate point Q, the light path between the light emitting element 22a and the light receiving element 22b is opened by the rotation of the light shielding plate 21. Therefore, the output of the document table sensor 22 is turned ON. Thereafter, when the large-diameter planetary gear 10b meshes with the lower rack section 6, the ON state of the document table sensor 22 is continued. Then, when the large-diameter planetary gear 10b meshes with the feed-side semicircle internal gear 7b and passes through a point O which is an intermediate point therebetween,
The light emitting element 22a and the light receiving element 22 are rotated by the rotation of the light shielding plate 21.
Since the optical path between the platen b is shut off, the output of the document table sensor 22 is turned off. The point O is the start position of the large-diameter planetary gear 10b when copying is started.

Accordingly, the output of the document table sensor 22 when the document table 2 is moved for one cycle is as shown in FIG. 8, and based on this output, the control device 31 determines that the document table 2 has moved to the scanning start position B ₂ reached state, the state has reached the scanning end position B _3, the large径遊star gear 10b is adapted to sense the state has reached the start position. The input means for detecting the position of the document table 2 is replaced with the optical means described above,
A switch that is turned on / off by a contact may be used.

Next, the operation of the copying machine under the control of the control device 31 will be described with reference to FIGS. First, when the main power switch 40 is turned on (S1), an initial operation such as a check operation of a voltage and a remaining amount of toner at each part is performed (S2), and then the fixing device 19 is warmed up. (S3). Thereafter, the warm-up is completed and the preparation for the copying operation is completed (S4), and when the print switch 23 for instructing the start of copying is turned on (S5), the bias for the developing device 30, etc., the main motor 43, The lamp 15 and the paper supply solenoid 44 are turned ON to start the pre-rotation (S6). At this time,
The rotation speed of the main motor 43 is set to a high speed, which is higher than the normal rotation speed.

Thereafter, when the transfer paper is fed and the paper input sensor 36 is turned on (S7), the paper feed solenoid 44 is turned off.
Then, the output of the high-pressure unit 46 is started (S8).

When the large-diameter planetary gear 10b reaches point O, which is the start position, and the document table sensor 22 is turned off (S9), the rotation speed of the main motor 43 is returned to the original normal speed, and the encoder sensor 47 is returned. A pulse count P1, which counts the number of pulses detected at ( _1), is started (S10).

[0042] Thereafter, the number of pulses are counted by the pulse counting P ₁ may determine whether or not reached a certain number P _S which is set in advance (S11), if reached, ON the registration roller solenoid Then, the transfer paper is discharged (S1
2) When the copy is completed (S13), the process returns to S2, and when the completion is not confirmed, the copy process is continued until the completion is confirmed (S14).

As described above, in this copying machine, the control device 31 sets the rotation speed of the main motor 43 to high speed together with ON, and the large-diameter planetary gear 10b is set at the start position by the platen sensor 22. When it is detected that a certain point O has been reached, the copying operation is started, and the speed is returned to the normal speed during the copying operation.

Therefore, since the movement of the document table 2 from the standby position B ₁ to the scanning start position B ₂ is performed at a high speed, the time required for copying can be reduced.

In addition, the control device 31 of this embodiment sets the timing of turning on the registration roller solenoid 45 as follows.
Since the number of pulses from the encoder sensor 47 that directly detects the rotation of the main motor 43 is counted and performed, even in a configuration in which the rotation speed of the main motor 43 is switched, variation in the tip due to the switching does not occur. In addition, it is possible to prevent a decrease in image quality.

In the document table driving device 3 of this embodiment, the small-diameter planetary gear 10c has fewer teeth than the large-diameter planetary gear 10b, and the upper rack 5 has a smaller pitch than the lower rack 6. The moving speed of the document table 2 in the return (R) direction is faster than the moving speed in the feed (F) direction, which can also reduce the time required for copying. However, even if only the speed of the main motor 43 is switched by the control device 31 without employing the above configuration, a sufficient time reduction effect can be obtained.

In the above embodiment, the method of driving the document table 2 using the endless gear 8 has been described. However, the present invention is not limited to this. If the transmission of the driving force from the main motor 43 is directly performed without going through the clutch mechanism,
It is applicable to other configurations.

Further, as the means for detecting the position of the document table, a means comprising a light-shielding plate 21 and a document table sensor 22 is used, but the present invention is not limited to this.
A switch actuating part is provided at a predetermined position of the endless gear 8.
A configuration in which a pressing switch is provided in the vicinity, or a configuration in which a conduction state between the connection plate 11 and the endless gear 8 is detected may be used.

[0049]

As described above, the copying machine of the present invention comprises a platen driving device for reciprocating the platen in a linear direction, and platen position detecting means for detecting the position of the platen. The transmission of the driving force from the driving source to the drive unit of the table drive device is directly performed without the intervention of the clutch mechanism. With one copy operation, the movement of the document table for scanning the document in one cycle is performed. The copying operation is started when the state in which the platen has reached the scanning start position is detected by the platen position detecting means, and the rotation speed of the drive source is further adjusted by scanning the platen. Until the start position is reached and the copying operation is started, the rotation speed is controlled so as to be higher than the rotation speed during the copying operation, while the rotation speed during the copying operation is controlled simultaneously with the start of the copying operation. The control means is provided.

As a result, the structure is simplified, the cost is reduced, and the speed of moving the platen is increased, as compared with the case where various mechanisms are provided in the mechanism for transmitting the drive to the platen. There is an effect that the time required for copying can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an operation of a copying machine according to an embodiment of the present invention.

FIG. 2 is a schematic overall configuration diagram of a copying machine that performs the above operation.

FIG. 3 is a perspective view showing a main part of a platen driving device provided in the copying machine.

4 is a longitudinal sectional view showing a configuration for detecting the positions of the large-diameter and small-diameter planetary gears shown in FIG.

FIG. 5 is an explanatory diagram of the operation of the document table shown in FIG. 2;

FIG. 6 is a block diagram showing a control unit in the copying machine.

FIG. 7 is an explanatory diagram of a rotation operation of the light shielding plate accompanying movement of the large-diameter and small-diameter planetary gears shown in FIG.

FIG. 8 is an explanatory diagram showing a change in an output signal from a document table sensor due to the movement of the large-diameter and small-diameter planetary gears.

FIG. 9 is a front view showing a structure near a document table in a conventional copying machine.

FIG. 10 is a front view of a main part showing a platen driving device in the copying machine.

[Explanation of symbols]

 2 Platen 3 Platen Drive 9 Sun Gear (Drive) 10b Large Diameter Planetary Gear (Drive) 10c Small Diameter Planetary Gear (Drive) 21 Light Shield (Document Plate Position Detecting Means) 22 Document Plate Sensor (Document Plate Position) Detecting means) 22a Light emitting element 22b Light receiving element 31 Controller (control means) 43 Main motor (drive source) O Start position (scan start position)

Claims (1)

(57) [Claims] An original platen driving device for reciprocating the original platen in a rectilinear direction; and an original platen position detecting means for detecting a position of the original platen. The transmission of the driving force is directly performed without the intervention of the clutch mechanism, and one cycle of the original table for scanning the original is performed with one copy operation. The copying operation is started when it is detected that the platen has reached the scanning start position, and the rotation speed of the drive source is further increased, and the copying operation is started when the platen reaches the scanning start position. Up to this point, control means is provided for controlling the rotation speed to be higher than the rotation speed at the time of the copying operation, while controlling the rotation speed at the time of the copying operation at the same time as the start of the copying operation. Copy machine.