JPH10211730A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of contact noises and motor load by a cam mechanism for rocking a rocking mirror by providing a one-direction clutch on a power transmission system for transmitting the rotation driving force of a motor to a rotating shaft. SOLUTION: A rotating shaft of a motor 12 is connected with a rotating shaft 16 of a cam mechanism by a claw clutch 15 through a pulley 14. The rotating force from the rotating shaft of the clutch is transmitted to the rotating shaft 16 by the clutch 15 at the time of forward rotation of the motor 12, while the transmission of the rotating force from the rotating shaft to the rotating shaft 16 is set to be impossible by the clutch at the time of counterrotation of the motor 12. The counterrotation of a cam mechanism member for rocking the rocking mirror 5 is prevented by the claw clutch 15. Namely, when a sub- scanning mechanism is returned to the print starting state by counterrotating the motor 12, the rotation of the rotating shaft 16 is se to be impossible by the clutch 15 to prevent the generation of load torque of the motor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer,
In particular, the present invention relates to a printer that irradiates a photoreceptor with a light beam from an LED light source or the like to create a print.

[0002]

2. Description of the Related Art Conventionally, there has been known a printer for producing a print by irradiating a photoreceptor with a light beam from an LED light source or the like. In this type of conventional printer, as a main scan, a light beam from an LED light source is reflected on a mirror that swings by a cam mechanism to scan the light beam, and a linear light beam (hereinafter, referred to as a line beam) in the main scanning direction. .)
And irradiates the photoconductor, and as a sub-scan,
A unit (stage) on which a photoconductor is set (hereinafter, referred to as a sub-scanning unit) is moved horizontally in the sub-scanning direction,
The line beam from the LED light source is scanned in the sub-scanning direction. Thus, the light beam from the LED light source is scanned on the photoconductor in the main scanning direction and the sub-scanning direction, and a print is created on the photoconductor.

[0003]

However, in such a printer, when the cam mechanism for swinging the mirror and the sub-scanning unit for setting the photosensitive member are driven by the same motor, the sub-scanning unit is moved. After the print is made, when the sub-scanning unit is efficiently and quickly returned to the start position, the mirror is also swung by the cam mechanism at the same time (for example, a swing pin for swinging the mirror is attached to a cam member such as a face cam). However, there is a problem in that a large load is applied to the driving power, and the contact noise of the cam mechanism (the swing pin and the face cam) is generated sharply by the high-speed rotation.

The present invention has been made in view of such circumstances, and a light beam is scanned in a main scanning direction by an oscillating mirror, and a photosensitive member and a means for emitting the light beam to the photosensitive member are relatively positioned. In a printer that moves and scans a light beam in the sub-scanning direction to perform printing, after the printing is completed, the contact sound from the cam mechanism that swings the swinging mirror when the motor is rotated in the reverse direction to return to the start position It is an object of the present invention to provide a printer that prevents generation of a motor load.

[0005]

According to the present invention, in order to achieve the above object, a cam member provided on a first rotating shaft is rotated by a motor, and a mirror is swung in conjunction with the rotation of the cam member. To move the light beam in the main scanning direction via the mirror, and rotate the second rotating shaft with a lead screw by the motor, so that the photosensitive member and the means for emitting the light beam to the photosensitive member are auxiliary. In a printer that performs printing on the photoconductor by relatively moving in a scanning direction, a one-way clutch is provided in a power transmission system that transmits a rotational driving force of the motor to the first rotation shaft,
When the motor is rotating in a direction to return to the print start position, the one-way clutch prevents the rotational driving force of the motor from being transmitted to the first rotating shaft.

According to the present invention, when the motor is rotating in the printing direction, the one-way clutch transmits the rotational driving force of the motor to the first rotating shaft and rotates the cam member to rotate the cam member. The light beam is scanned in the main scanning direction by swinging the mirror. When printing is completed and the motor is rotating in a direction to return to the print start position, the rotation driving force of the motor is not transmitted to the first rotation shaft, and the rotation of the cam member is prohibited. Thus, when the photosensitive member or the means for emitting a light beam to the photosensitive member is returned to the print start position after printing is completed, contact noise in the cam member is prevented, contact friction is not generated, and the load torque of the motor is reduced. Decrease.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the printer according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing the structure of the printer according to the present invention. The printer shown in FIG. 3 is a main scanning mechanism for generating a line beam by oscillating a beam in a main scanning direction (x direction in the drawing), and a photoconductor 27 mounted on a sub-scanning unit 28.
Is moved in the sub-scanning direction (y direction in FIG. 3) to sequentially scan the line beam in the sub-scanning direction.

First, the main scanning mechanism will be described. As shown in FIG. 1, an LED (light emitting diode) light source 3, an illumination lens 4, a swing mirror 5,
The reflection mirror 6 and the like are arranged. The LED light source 3 is, for example, 3
It comprises three light emitting diodes, and outputs light of three wavelengths according to the color development wavelength of the photoreceptor 27, respectively. Also, LE
The intensity of the LED light output from the D light source 3 is modulated according to the print image. LED output from LED light source 3
The light becomes a light beam focused on the photoreceptor 27 by the illumination lens 4 and is incident on the reflection surface of the oscillating mirror 5. The oscillating mirror 5 oscillates left and right by a cam mechanism described later, and the light beam is scanned by the oscillating mirror 5 in the main scanning direction (x direction in FIG. 3). The light is irradiated to the placed photoconductor 27.

The oscillating mirror 5 is fixed to an oscillating lever 7, and the oscillating lever 7 is rotatably supported on a bottom surface 2 of the printer main body 1 via a column 8. And the swing lever 7
A swing pin 11 is provided at the tip of the swing pin 1.
1 is held between the face cam 19 and the holding cam 21.
FIG. 2 is a side sectional view of the printer showing a cam mechanism for swinging the swing mirror 5. As shown in FIG. 1, a bearing 17 (FIG.
), And the other end of the rotating shaft 16 is connected to the rotating shaft 13 of the motor 12 via a meshing clutch 15 and a pulley 14.
The face cam 19 is fixed to the rotating shaft 16 and a pressing cam 21 is provided adjacent to the face cam 19.
Are rotatably fitted. The holding cam 21 has a pair of rotation preventing pins 2 fixed to the face cam 19.
2 and 22 are fitted so as to be freely fitted, and the holding cam 21 rotates in conjunction with the face cam 19. A spring 23 is attached to the holding cam 21, and the spring 23 is fixed by a spring holding member 24. As a result, the holding cam 21 becomes the face cam 19
And the swing pin 11 is securely pressed against the cam surface 19A of the face cam 19. The spring holding member 24 is fixed to the rotating shaft 16 by a set screw 25.

The cam surface 21A of the pressing cam 21 facing the cam surface 19A of the face cam 19 has the same cam curve as that of the face cam 19 so that the distance from the face cam 19 is constant at any position. It is formed by a curve. That is, the cam surface 21A of the pressing cam 21 is formed so as to be parallel to the cam surface 19A of the face cam 19. Thus, when the motor 12 rotates, the pressing cam 21 hardly moves in the axial direction, and
3, the biasing force is kept constant. Therefore, the swing pin 1
The pressing force exerted on the face cam 19 by the motor 1 is kept substantially constant, so that the urging force of the spring 23 can be reduced and the torque of the motor 12 can be reduced.
The motor 12 can be reduced in size.

On the other hand, a ball bearing 9 having a different diameter is provided at the tip of a swing pin 11 mounted on the tip of the swing lever 7.
10 is mounted. The ball bearing 9 contacts only the cam surface 19A of the face cam 19, and the ball bearing 10 contacts only the cam surface 21A of the pressing cam 21. Accordingly, the pressing cam 21 urges the swing pin 11 in the direction of the face cam 19 via the ball bearing 10 by the urging force of the spring spring 23, and the urging force urges the ball bearing 9 to the cam surface 19A of the face cam 19. Press against. Therefore, the swing pin 11 moves following the cam surface 19A of the face cam 19.

The rotating shaft 13 of the motor 12 and the rotating shaft 16 of the cam mechanism are connected by a meshing clutch 15 via a pulley 14. The meshing clutch 15 transmits the rotational force from the rotating shaft 13 to the rotating shaft 16 when the motor 12 rotates in the forward direction.
Of the rotating shaft 13 during the reverse rotation of the rotating shaft 16
To be unable to communicate.

FIG. 3 is a sectional view of the meshing clutch 15 (a sectional view taken along the lines A and A 'in FIG. 2). As shown in the figure, the engagement latch 15 is fitted into the pulley 14, and the outer peripheral ring 35 of the engagement clutch 15 rotates in conjunction with the pulley 14. A wedge surface 35 is provided on the inner peripheral surface of the outer ring 35.
A, 35A, 35A, 35A are formed at an equal angle, and a clockwise curved surface 35B is formed at an equal angle.
Each wedge surface 35A is formed so as to narrow the gap between the rotating shaft 16 inserted at the center in a counterclockwise direction, and rollers 36, 36, 3 are provided between each wedge surface 35A and the rotating shaft 16.
6, 36 are arranged. Also, these rollers 36,
36, 36, 36 and curved surfaces 35A, 35A, 35A,
The springs 37, 37, 37, 37 are inserted between 35A.

As a result, when the motor 12 rotates forward (direction A in FIG. 2) and the pulley 14 rotates forward via the rotating shaft 13, the roller 36 is sandwiched between the wedge surface 35A and the rotating shaft 16, and the rotating shaft 16 rotates. The shaft 16 rotates forward with the pulley 14. On the other hand, the motor 12 rotates in the reverse direction (the direction B in the figure).
Then, when the pulley 14 rotates reversely via the rotation shaft 13,
The roller 36 is shifted toward the spring 37 between the curved surface 35B, and a gap is generated between the roller 36 and the center rotating shaft 16 due to the expansion and contraction of the spring 37, and the rotating shaft 16 becomes free.
Stand still without reverse rotation.

The meshing clutch 15 prevents the cam mechanism member that swings the swing mirror 5 from rotating in the reverse direction.
That is, as described later, when the motor 12 is rotated in the reverse direction to return the sub-scanning mechanism to the printing start state, the rotating shaft 1
6 cannot be rotated by the engagement clutch 15, the face cam 19 and the pressing cam 21 are stopped, and contact friction between the cam surfaces of the face cam 19 and the pressing cam 21 and the swing pin 11 is not generated. No load torque is generated.

Next, the sub-scanning mechanism will be described. As shown in FIG. 1, a sub-scanning unit (U-shaped box as shown) 28 having an aperture (inner groove) 28A provided on the upper surface
Is mounted on a rail 29 provided on the bottom surface 2 of the printer 1 so as to be movable in the sub-scanning direction (the y direction in the drawing). Then, the photoconductor 27 is set on the aperture 28A.

A rotary shaft 30 having a feed screw formed on a bearing 34 fixed in the wall surface 2 of the printer body 1.
Are rotatably supported. A connecting member 31 fixed to the sub-scanning unit 28 is attached to the feed screw of the rotating shaft 30.
Is screwed. A pulley 14 is fixed to the rotating shaft 13 of the motor 12, a pulley 32 having a larger diameter than the pulley 14 is fixed to the rotating shaft 30, and a belt 33 is stretched between the pulley 14 and the pulley 32. Thus, when the motor 12 rotates, the rotation of the motor 12 is reduced and transmitted to the rotating shaft 30, and the rotating shaft 30 rotates. Then, the rotation of the rotation shaft 30 causes the sub-scanning unit 28 to move horizontally in the sub-scanning direction via the connecting member 31.

With the above-described sub-scanning mechanism, the sub-scanning unit 28 reciprocates according to the forward / reverse rotation of the motor 12.
Next, the operation of the printer configured as described above will be described. The sub-scanning unit 28 is at the front end (start position)
Switch on when stationary (not shown)
When the LED light source 3 emits light, the motor 12 starts (forward rotation), the pulley 14 rotates forward, and the rotating shaft 16 rotates forward via the meshing clutch 15.
As a result, the rotation shaft 30 rotates and the sub-scanning unit 28
Starts moving backward, the face cam 19 and the holding cam 21 start rotating, and the reflection surface of the swing mirror 5 swings right and left.

The light beam output from the LED light source 3 and incident on the reflection surface of the oscillating mirror 5 via the illumination lens 4 is oscillated by the oscillating mirror 5 so that the sub-scanning unit 2
Scanning is performed in the main scanning direction on the photoconductor 27 set on the upper surface of the photoconductor 8, and scanning is performed in the subscanning direction on the photoconductor 27 by the movement of the sub-scanning unit 28. When the sub-scanning unit 28 moves to the rear end in this way and printing is completed, next, the motor 12 starts reverse rotation at high speed. When the motor 12 rotates in the reverse direction, the meshing clutch 1
5, the rotation of the rotation shaft 16 is stopped, and only the rotation shaft 30 rotates. Then, the sub-scanning unit 28 moves forward, returns the sub-scanning unit 28 to the start position at a high speed, and prepares for printing of the next photosensitive member.

When the next printing is started after the sub-scanning unit 28 returns to the start position, the direction of the swing mirror 5 (or the rotation angle of the rotating shaft 16) is detected and the swing is performed. The orientation of the mirror 5 is synchronized with the print signal by the light beam. In this way, the sub-scanning unit 28 is moved backward from the sub-scanning start position to
When the sub-scanning unit 28 is returned to the start position at a high speed after the printing of
5, the reverse rotation of the cam mechanism is prevented, so that, for example, even if the motor 12 sends the sub-scanning unit 28 at 1,000 rotations per minute and returns at 2,000 rotations per minute, the motor 12 has no load. It rotates sufficiently, does not generate cam jumps, and has low noise.

As described above, in the above-described embodiment, the case of the printer which performs the sub-scanning by moving the sub-scanning unit 28 on which the photosensitive member 27 is mounted has been described.
For example, even in the case of a printer that performs sub-scanning by moving the reflection mirror 6, the reverse rotation of the cam mechanism that swings the swing mirror 5 is prevented by using the meshing clutch 15 as in the above-described embodiment. Can be.

FIGS. 4 and 5 are a side cross-sectional view and a top cross-sectional view showing the configuration of an embodiment of a printer that scans a light beam in the sub-scanning direction by moving a mirror. FIG.
The printer shown in FIG. 5 oscillates a beam in a main scanning direction (x direction in FIG. 5) to generate a line beam, and sequentially scans the photoreceptor 66 set on a stage 65 by sub-scanning the line beam. And a sub-scanning mechanism for scanning in the direction. The main scanning mechanism is configured in the same manner as the main scanning mechanism of the printer shown in FIGS.

As shown in FIGS. 4 and 5, the LED light output from the LED light source 42 becomes a light beam focused on the photoreceptor 66 by the illumination lens 43, and reflected by the swing mirror 45 via the reflection mirror 44. Incident on the surface. The swing mirror 45 swings left and right by a cam mechanism described later, and the light beam is scanned in the main scanning direction by the swing mirror 45 and enters the mirror box 71. The mirror box 71 has mirrors 68 and 69 mounted thereon.
The light beam incident on 1 is reflected by mirrors 68 and 69,
The light enters the mirror box 72. A mirror 70 is mounted on the mirror box 72, and the light beam incident on the mirror box 72 is irradiated on the photoconductor 66 by the mirror 70. The mirror box 71 and the mirror box 72
Moves in the sub-scanning direction while keeping the optical path length from the LED light source 42 to the photoreceptor 66 constant, and makes the light beam sub-scan.

First, the main scanning mechanism will be described. LE
A swing mirror 45 that swings the light beam output from the D light source 42 in the main scanning direction is fixed to a swing lever 46.
The swing lever 46 is rotatably supported by the holding member 90 fixed to the printer main body 41 with the support member 47. A swing pin 50 is attached to the tip of the swing lever 46, and the swing pin 50 is held between the face cam 58 and the holding cam 60. Ball bearings 48 and 49 having different diameters are mounted on the tip of the swing pin 11, and the ball bearings 48 come into contact with the cam surface 58 </ b> A of the face cam 58, and the ball bearing 49 contacts the cam surface 6 of the holding cam 60.
Touch OA.

The face cam 58 and the pressing cam 60 are disposed on the rotating shaft 55, and the pressing cam 60 is
1 and 61, it rotates in conjunction with the face cam 58 fixed to the rotating shaft 55, and is urged in the direction of the face cam 58 by a spring spring 62 fixed to a spring holding member 63. The spring holding member 63 is fixed to the rotating shaft 55 by a set screw 64.

The rotating shaft 55 is rotatably supported by a bearing 56 fixed in the wall surface of the printer main body 41, and is connected to the rotating shaft 52 of the motor 51 via a meshing clutch 54 and a pulley 53. Mesh clutch 5
4 transmits the torque from the rotating shaft 52 to the rotating shaft 55 when the motor 51 rotates forward, and disables the rotating force from the rotating shaft 52 to the rotating shaft 52 when the motor 51 rotates reversely.

At the time of reverse rotation of the motor 51 after printing by the main scanning mechanism (return operation to the start position by sub-scanning), the engagement clutch 54
The rotation shaft 55 becomes free and rotation stops, and the pulley 53
Rotates in the reverse direction to operate only the sub-scan described later, so that there is no occurrence of contact friction on the cam surface or load torque of the drive motor.

Next, the sub-scanning mechanism will be described. FIG.
As shown in FIGS. 5 and 6 (FIG. 6 is a sectional view taken along line A and A ′ in FIG. 4), a pulley 7
3 and 74 are attached, and the belt 7 is
5 is fitted. One end of the belt 75 is fixed on a pedestal provided on the mirror box 72 with a fixing screw 77,
The other end is fixed with a fixing screw 77 on a pedestal provided on the inner wall surface of the printer main body 41.

When the mirror box 72 is moved by the belt 75, the mirror box 71 moves in conjunction with this movement.
Moves, and the moving distance of the mirror box 71 becomes １ ／ of the moving distance of the mirror box 72.
As a result, the line beam is guided to the photoconductor 66 on the stage 65 with a constant optical path length (path). On the other hand, an elastic belt 76 is fitted in the outer peripheral groove of the pulley 74, and one end of the elastic belt 76 is fixed on a pedestal of the mirror box 72 with a fixing screw 77. The other end of the telescopic belt 76 is connected to the printer main body 4 via a rotating member 78 on a pedestal provided on the inner wall surface of the printer main body 41.
It is fixed with a fixing screw 77 on another pedestal provided on one inner wall surface.

By the elastic belt 76, the cooperative relationship between the mirror box 71 and the mirror box 72 is reliably maintained, and both mirror boxes 71 and 72 move on the rail 67. The mirror box 72 is disposed so as to be able to move directly along the rail 67, and is screwed to a rotary shaft 80 provided with a feed screw. The rotation shaft 80 is rotatably supported by a bearing 84A provided on the inner wall surface of the printer main body 41 and a bearing 84B supported by the holding member 92. A rotating shaft 79 is rotatably provided on a bearing 84C provided on the inner wall surface of the printer main body 1 and a bearing 84D supported by the holding member 94. A pulley 81 and a pulley 82 having a larger diameter than the pulley 53 fixed to the rotation shaft 52 of the motor 51 are fixed to the rotation shaft 79.
A pulley 83 having the same diameter as the pulley 82 is fixed to the rotating shaft 80.

A belt 85 is stretched between a pulley 53 fixed to the rotating shaft 52 of the motor 51 and a pulley 81 fixed to the rotating shaft 79, and the pulley 81 fixed to the rotating shaft 79 and the rotating shaft 80 Pulley 8 fixed to
3, the belt 86 is fixed. Thus, when the motor 51 rotates, the rotating shaft 79 rotates and the rotating shaft 80 rotates, and the mirror box 72 reciprocates on the rail 67, and the mirror box 71 moves on the rail 67 in conjunction with the mirror box 72. To reciprocate.

According to this embodiment, when the motor 51 rotates forward, the swing mirror 45 swings by the cam mechanism to scan the light beam in the main scanning direction, and the mirror boxes 71 and 72 move in the sub-scanning direction. And the light beam is scanned in the sub-scanning direction. Then, when the sub-scanning of the light beam is completed and the printing of the photoconductor 66 is completed, the motor 51 starts reverse rotation. When the motor 51 starts the reverse rotation, the rotational force from the rotating shaft 52 of the motor 51 cannot be transmitted to the rotating shaft 55 of the cam mechanism by the meshing clutch 54, and the swinging mirror 45 is stopped, and the mirror box 7 is stopped.
Only 1, 72 move and return to the start position.

Although the LED light source is used in the above embodiment, the present invention is not limited to this, and the present invention can be applied to a printer using another light source such as a laser.

[0034]

As described above, according to the printer of the present invention, the motor rotates in the direction for returning the photosensitive member or the means for emitting a light beam to the photosensitive member to the print start position after printing is completed. In this case, the rotation driving force of the motor is not transmitted to the rotation shaft of the cam member, and the rotation of the cam member is prohibited. Load torque decreases. Further, even when the rotation speed of the motor is increased for efficiency in returning to the print start position, cam jumps and the like do not occur.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a printer according to the present invention.

FIG. 2 is a side sectional view of the printer according to the present invention.

FIG. 3 is a sectional view showing a configuration of a meshing clutch. is there.

FIG. 4 is a side sectional view showing another embodiment of the printer according to the present invention.

FIG. 5 is a top sectional view showing another embodiment of the printer according to the present invention.

FIG. 6 is a cross-sectional view of the printer of FIG.

[Explanation of symbols]

1 Printer body 2 Bottom surface 3 L
ED light source 4 ... Illumination lens 5 ... Swing mirror 6 ... Reflection mirror 7 ... Swing lever 8 ... Support 9 ... Ball bearing 10 ... Ball bearing 11 ... Swing pin 12
... Motor 13 ... Rotary shaft 14 ... Pulley 15
... meshing clutch 16 ... rotating shaft 17 ... bearing 19
... Face cam 21 ... Holding cam 26 ... Stage 27
... Photoconductor 28 ... Sub-scanning unit 29 ... Rail 30
... Rotating shaft 31 ... Connecting member 32 ... Pulley 33
... belt 34 ... bearing 35 ... wedge surface 36
… Roller 37… Spring

Claims (1)

[Claims] A cam member disposed on a first rotating shaft is rotated by a motor, a mirror is swung in conjunction with the rotation of the cam member, and a light beam is moved in the main scanning direction via the mirror. While scanning, the motor rotates a second rotating shaft with a lead screw, and relatively moves the photosensitive member and a means for emitting a light beam to the photosensitive member in the sub-scanning direction, thereby printing on the photosensitive member. In a printer that performs, when a one-way clutch is provided in a power transmission system that transmits the rotational driving force of the motor to the first rotating shaft, and the motor is rotating in a direction to return to a print start position, The printer according to claim 1, wherein the one-way clutch does not transmit the rotational driving force of the motor to the first rotating shaft.