JPH01195416A - Supporting device for optical beam deflector - Google Patents

Abstract

PURPOSE:To prevent shifting of the writing position to a photosensitive body and variation of the beam diameter resulting in unsharp by supporting an optical beam deflector in a state where the deflector is floated and is not brought into contact with its supporting member. CONSTITUTION:An optical beam deflector 13 with a built-in mirror vibrator which deflects an optical beam by swinging a mirror 4 and a supporting member 70 which supports the deflector 13 are provided. An air flow is blown out from the central part of the supporting member 70 in the direction from the down side to the top side of the figure and the air flow supports the optical beam deflector 13 in a state where the deflector 13 is floated and is not brought into contact with the member 70. Therefore, transmission of outside disturbances and vibrations to the mirror vibrator can be prevented and, as a result, shifting of the writing position to a photosensitive body and variation of the beam diameter resulting in unsharp can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a support device for a light beam deflector suitable for image forming apparatuses such as facsimile copiers and printers, and in particular for supporting devices for deflecting laser beams. The present invention relates to a support device for a light beam deflector that is optimal for mounting and fixing a light beam deflector that writes on a photoreceptor with a beam.

(2) Prior Art Image forming apparatuses such as facsimile machines, copying machines, and printers are increasingly using laser beams to write on photoreceptors. In such an image forming apparatus, a rotating polygon mirror, a mirror oscillator, or the like has conventionally been used as an optical deflector for deflecting a laser beam.

In recent years, mirror resonators have come into widespread use while solving a number of problems due to demands for smaller size, lower noise, lower cost, etc. This mirror resonator generally uses a thin insulating substrate made of crystal or the like and having a thickness of about 0.1 to 0.5 mm.

(3) Problems to be Solved by the Invention As mentioned above, the mirror oscillator has 0. 1~0゜5mm
Due to the use of a relatively thin crystal substrate, mirror resonators have a problem in that they are extremely susceptible to external vibrations. In particular, the motor that rotates the photoreceptor,
When a mirror oscillator is used in a copying machine that has a motor etc. that drives the scanning optical system that reads the original, the vibrations from these motors etc. are transmitted to the mirror oscillator, which may cause the writing position on the photoreceptor to shift. Or the beam diameter may fluctuate, causing blur. Therefore, there is a problem that the resolution and contrast are lowered and the image quality is deteriorated.

(4) Means for Solving the Problems The present invention has been made in view of the above-mentioned points.When disturbance vibrations are transmitted to the mirror oscillator, the writing position on the photoreceptor may shift or the beam diameter may vary. In order to achieve this purpose, we have developed a light beam deflector that includes a mirror oscillator that deflects the light beam by rotating and vibrating the mirror, and a light beam deflector that deflects the light beam by rotating and vibrating the mirror. The optical beam deflector has a support member that supports the beam deflector, and is configured to support the optical beam deflector in a non-contact state by floating it from the support member.

(5) Examples Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a perspective view showing an embodiment of a support device for a light beam deflector according to the present invention.

In FIG. 1, a light beam deflector 13 having a substantially cylindrical shape is shown.
A cylindrical support member 70 is provided at the bottom of the support member 70, and an air flow is ejected from the center of the support member 70 from the bottom to the top of the drawing. The support member 70 is fixed to an optical base 27, and the optical base 27 is fixed to a housing 30, which will be described later in conjunction with FIG. As a result, the airflow ejected from the support member 70 supports the light beam deflector 13 in a floating state from the support member 70 in a non-contact state.

Inside the light beam deflector 13, a reflecting mirror 4 and the like, which will be explained next with reference to FIG. 5, are provided.

In FIG. 1, only the reflection mirror 4 is shown through an opening 24a provided in a part of the cylindrical housing 24. As shown in FIG.

In FIG. 5, a mirror vibrator 1 is placed on an L-shaped member 3 at the center of a fixing member 2 whose cross section is substantially horseshoe-shaped. The horseshoe-shaped fixing member 2 is
The mirror oscillator 1 is covered by a cylindrical housing 24 (see Fig. 1), and the mirror oscillator 1 is
to ensure that they are not adversely affected.

The mirror vibrator 1 includes a reflecting mirror 4, a driving coil 5, a ligament 6, and a frame part 7. The reflecting mirror 4 and the driving coil 5 are connected to each other and are fixed to the frame part 7 by the ligament 6. The reflecting mirror 4, drive coil 5, ligament 6, and frame part 7 are made of a single insulating substrate such as a crystal substrate (thickness is 0.1 mm to 0.5 mm).
The reflective surface of the reflective mirror 4 and A coil pattern of the drive coil 5 is formed.

The lower horizontal part of the frame part 7 is placed on the L-shaped member 3, and the left vertical part is attached to the block member 8, and the block member 8 is further attached to the vertical part of the L-shaped member 3. It is fixed to the L-shaped member 3 by being attached.

This mirror oscillator 1 is placed in a DC magnetic field formed by an excitation permanent magnet 10 and an excitation permanent magnet 11 provided on the inner peripheral surface of the fixed member 2. When a drive current is supplied to the drive coil 5 from the outside, a torsion torque is generated in the drive coil 5 around the ligament 6, and the connected reflecting mirror 4 rotates back and forth. The period of the reciprocating rotation of the reflecting mirror 4 is determined by the frequency of the drive current supplied to the drive coil 5, and the deflection angle is determined by the amplitude of the drive current. Lead wire 71 shown in FIG. 1 supplies drive current to drive coil 5. Lead wire 71 shown in FIG.

Therefore, the laser beam is reflected from the right side of Figure 5 by the reflecting mirror 4.
By irradiating the laser beam, the laser beam is deflected as will be described later with reference to FIG.

The L-shaped member 3 for fixing the mirror vibrator 1 is attached to a vibration isolating material 12 which is also formed in an L-shape. Vibration isolation material 1
2, its horizontal portion is connected to the fixing member 2 through the block member 8.
At the same time, the vertical portion is directly bonded to the fixing member 2. Note that the block member 8 and the L-shaped member 3 can also be formed integrally.

In this way, by interposing the vibration isolating material 12 made of urethane-based shock-absorbing elastomer or the like between the L-shaped member 3 that fixes the mirror vibrator l and the fixing member 2 (and the block member 9), mirror vibration can be prevented. It becomes possible to attenuate the external disturbance transmitted to the element l with a small amount of vibration isolating material.

The light beam deflector 13 described in FIG. 5 is arranged with other optical components as shown in FIG.

In FIG. 6, the laser beam emitted from the semiconductor laser 14 is corrected in beam shape by the collimator lens 15, and then passes through the cylindrical lens 16 and the reflection mirror 17 to the reflection mirror 4 of the light beam deflector 13. is irradiated.

The reflecting mirror 4 deflects the laser beam as explained in FIG. The laser beam deflected by the reflection mirror 4 is irradiated onto the photosensitive drum 20 via the scanning lens 18 and the cylindrical lens 19 .

The cylindrical lens 16 and the cylindrical lens 19 are used to correct vertical tilting of the reflecting mirror 4, but can be omitted when the tilting is small. Further, the scanning lens 18 is used for the purpose of scanning the laser beam at a constant speed to form an image at a correct position on the surface of the photoreceptor drum 20. Instead of this scanning lens 18, the scanning lens 18 can be omitted by controlling the waveform of the drive current supplied to the drive coil 5 shown in FIG.

Note that the index sensor 21 and the reflecting mirror 22 in FIG. 6 detect that the laser beam deflected by the reflecting mirror 4 is reflected by the reflecting mirror 22 and irradiated to the index sensor 21, and start or end scanning. I am trying to detect the timing of this.

FIG. 7 is a front view showing an embodiment in which the light beam deflector support device according to the present invention is applied to a copying machine. In the figure, the first
Components that are the same as those in the figures to FIG. 6 are given the same reference numerals and their explanations will be omitted.

In FIG. 7, the copying machine is arranged as described below.

The copying machine is roughly divided into an image reading system A, a laser writing system B, and an image forming section C1 paper feeding section. The image reading system A is housed in a casing 29, and the other laser writing system B, image forming section C1, paper feeding section, etc. are housed in a casing 30 independent of the casing 29. The image signal read by the image reading system A as described later is sent to the housing 30 via a group of flexible cables.
is supplied to

Further, within the housing 30, with the photosensitive drum 20 in the center, a drive coil 56, a drive coil 57, and a drive coil 58 are arranged on the right side, and a charger 55 and a cleaning device 59 are arranged on the left side. Photosensitive drum 20, drive coil 56
, the drive coil 57, the drive coil 58, the charger 55, and the cleaning device 59 are supported by a supporting member 54 that is removably inserted into the housing 30, or are removably attached to the housing 30.

The copying process by this copying machine is performed as described below.

In image reading system A, a document to be copied is placed on document table 31 . Carriage 3
A reading light is emitted from a halogen lamp 33 attached to the original document, and the reflected light from the original is reflected by a reflecting mirror 34 to the left in FIG.

A movable mirror unit 35 is arranged on the left side of the carriage 32. The movable mirror unit 35 includes a mirror 3
6 and a mirror 37 are attached, and the reading light reflected by the reflecting mirror 34 is reflected by the mirror 36 and the mirror 37 and guided to a lens reading section 40 described later.

The carriage 32 and the movable mirror unit 35 are driven by a wire 49 wound around a stepping motor 48 to horizontally move in the left-right direction in FIG. The horizontal movement of the carriage 32 and the movable mirror unit 35 is set so that when the carriage 32 moves at a speed of 2, the moving speed of the movable mirror unit 35 is V/2. Even if the lens moves, the optical path length of the reading light from the document surface to the lens reading section 40 remains constant.

The lens reading section 40 includes a lens 41, a prism 42, a first reading board 44, a red channel CCD 45, a second
It is composed of a reading board 46 and a cyan channel CCD 47, and the above-mentioned reading light is converted into an image signal here.

The reading light guided to the lens reading section 40 passes through the prism 42
The images are focused by a dichroic mirror (not shown) in the prism 42 and separated into a red channel image and a cyan channel image.
The image is formed on the light receiving surface 7 and converted into an image signal.

Red channel CCD45 and cyan channel C
From the image signal output from the CD 47, a color signal separated according to the color of the toner used is extracted and supplied to a laser writing system B, which is an exposure means.

In laser writing system B, the optical base 2 shown in FIG.
7 is fixed to the housing 30. The optical base 27 forms a housing, and the optical base 27 includes the light beam deflector 13 and the cylindrical lens 19 described in FIG. It is provided inside 27. In the configuration described in FIG. 6, the semiconductor laser 14, the light beam deflector 13, the cylindrical lens 19, and the like other than the photosensitive drum 20 are all housed inside the optical base 27.

As explained in FIGS. 5 and 6, the laser beam is deflected in the light beam deflector 13, and the reflection mirror 2
After changing its direction, the photoreceptor drum 20 is irradiated with light.

The photoreceptor drum 20 is charged in advance by a charger 55, and a latent image is formed on the circumferential surface of the photoreceptor drum 20 by being irradiated with a laser beam. Irradiation of the laser beam onto the photosensitive drum 20 is performed as described below.

When the scanning of the laser beam by the reflection mirror 4 explained in FIGS. A color signal of 1 (in this case, red) is supplied to a laser writing system B, which is an exposure means. by this,
Modulation of the laser beam with the first color signal begins.

The modulated laser beam is deflected by the semiconductor laser 14 and scans the circumferential surface of the photoreceptor drum 20 . Along with the main scanning of the laser beam by this semiconductor laser 14,
Sub-scanning is performed by rotationally driving the photoreceptor drum 20 by a motor (not shown), and a latent image for the first color signal (red) is formed on the circumferential surface of the photoreceptor drum 20.

The latent image on the photosensitive drum 20 is developed by a drive coil 56 loaded with red toner, and the latent image on the photosensitive drum 200 is developed by a drive coil 56 loaded with red toner.
A toner image is formed on the surface. The obtained red toner image passes under the cleaning device 59 while being held on the surface of the photosensitive drum 200, and enters the next copy cycle.

In the next copy cycle, the photosensitive drum 2o is moved to the charger 5.
5 and then the cyan channel CC
A second color signal (blue in this case) color-separated from the image signal output from the D47 is supplied to the laser writing system B, which is an exposure means.

This starts modulating the laser beam with the second color signal. The modulated laser beam is deflected by the semiconductor laser 14 and scans the circumferential surface of the photoreceptor drum 20 . Along with the main scanning of the laser beam by the semiconductor laser 14, the photoreceptor drum 20 is rotationally driven by a motor (not shown) to perform sub-scanning, and a second color signal (blue) is applied to the circumferential surface of the photoreceptor drum 20. A latent image is formed.

The latent image on the photoreceptor drum 20 is developed by a drive coil 57 loaded with blue toner, and a toner image is formed on the surface of the photoreceptor drum 20. This blue toner image is formed on top of the red toner image already formed on the photoreceptor drum 20. The obtained blue toner image passes under the cleaning device 59 while being held on the surface of the photosensitive drum 20, and enters the next copy cycle.

In the next copy cycle, a black toner image is formed in the same manner as the red and blue toner images described above. The development at this time is performed by the drive coil 58 loaded with black toner.

AC and DC bias voltages are applied to the sleeves 56a1, 57a, and 58a of the drive coils 56, 57, and 58, respectively, and jumping development using a so-called two-component developer is performed. Therefore, development is performed without contacting the grounded photosensitive drum 20.

A three-color image consisting of a red toner image, a blue toner image, and a black toner image formed on the photoreceptor drum 20 is transferred to the transfer pole 6.
At 0, the image is transferred to recording paper (not shown). The recording paper is transported from the paper feed section to a paper feed belt 61 and a paper feed roller 62.
Powered by.

The recording paper onto which the toner image has been transferred is separated from the surface of the photoreceptor drum 200 by a separation electrode 63, and transferred to a conveyor belt 64.
The paper is transported to the fixing device 65 via the fixing device 65, where fixing is performed.

After fixing, the recording paper is ejected from the machine and the series of copying operations ends. At this time, the blade 59a and roller 59b of the cleaning device 59 remove the toner remaining on the photosensitive drum 20 in preparation for the next copying process.

When the mirror oscillator 1 is used in such a copying machine,
The above-mentioned stepping motor 48 and photosensitive drum 2
Vibrations and shocks from the motor driving the 0, clutch, gears, etc. cannot be avoided. however,
According to the support device for a light beam deflector according to the present invention, the airflow ejected from the support member 70 is transmitted to the mirror resonator l via the fixing member 28 due to vibrations from the stepping motor 48, the motor of the photoreceptor drum 20, etc. By attenuating this, a shift in the writing position on the photoreceptor drum 20 is prevented,
It also prevents the beam diameter from changing and causing blur.

FIG. 2 is a side view and a top view showing another embodiment of a support device for a light beam deflector according to the present invention. In the figure, the first
Components that are the same as those in the figures and FIGS. 2 to 6 are given the same reference numerals, and explanations thereof will be omitted.

In FIG. 2(a), a cylindrical support member 70 is provided at the bottom of the light beam deflector 13 having a substantially cylindrical shape.
A disk-shaped permanent magnet 73 is attached to the center portion of the inner bottom surface of the support member 70 .

Further, a magnetic shielding plate 74 made of a permalloy plate or the like is attached to the bottom surface of the light beam deflector 13, and a disk-shaped permanent magnet 72 is attached to the lower surface of the magnetic shielding plate 74. Permanent magnet 72 and permanent magnet 73 are placed in positions facing each other and are magnetized to have the same polarity (for example, N pole). That is, permanent magnet 72 and permanent magnet 73
The repulsive force between the two supports the light beam deflector 13 in a floating state from the support member 70 in a non-contact state. The magnetic shielding plate 74 performs magnetic shielding to prevent the magnetic forces of the permanent magnets 72 and 73 from having an adverse effect on the magnetic fields of the excitation permanent magnets 10 and excitation permanent magnets 11 shown in FIG. ing.

For example, six permanent magnets 75 are attached to the inner peripheral surface of the support member 70, as shown in FIG. 2(b). Further, for example, six permanent magnets 76 are attached to the outer peripheral surface of the light beam deflector 13 at positions facing the permanent magnets 75. That is, the light beam deflector 13 is supported in a non-contact state separated from the support member 70 by the repulsion or attraction force between the permanent magnets 75 and 76. When using repulsive force, the permanent magnets 75 and 76 have the same polarity (for example, N poles), and when using attractive force, they have different polarities (N pole and S pole).

As a result, while the light beam deflector 13 is suspended by the repulsive force between the permanent magnet 72 and the permanent magnet 73, the permanent magnet 7
The light beam deflector 13 is separated from the support member 70 by the repulsive force (or attraction force) between the magnet 5 and the permanent magnet 76, and the light beam deflector 13 is supported from the support member 70 in a non-contact state. .

FIG. 3 is a side view showing another embodiment of the support device for a light beam deflector according to the present invention. In the figure, Figures 2 and 1
Components that are the same as those in the figures to FIG. 6 are given the same reference numerals and their explanations will be omitted.

In FIG. 3, a light beam deflector 13 having a substantially cylindrical shape is shown.
A cylindrical support member 77 is provided on the upper part of the support member 77, and on the inner peripheral surface of this support member 77, for example, six permanent magnets 78 are mounted, similar to the permanent magnets 75 shown in FIG. 2(b). It is affixed. Although not shown, the support member 77 is fixed to the optical base 27. Similarly to the permanent magnets 76 shown in FIG. 2(b), for example, six permanent magnets 79 are attached to the upper outer peripheral surface of the light beam deflector 13 at positions facing the permanent magnets 78. That is, permanent magnet 7
The light beam deflector 13 is supported in a non-contact state separated from the support member 77 by the repulsion or attraction force between the permanent magnet 8 and the permanent magnet 79. When using repulsive force, the permanent magnets 78 and 79 have the same polarity (for example, N poles), and when using attractive force, they have different polarities (N pole and S pole).

As a result, while the light beam deflector 13 is suspended by the repulsive force between the permanent magnet 72 and the permanent magnet 73, the permanent magnet 7
The light beam deflector 13 is separated from the support member 70 by the repulsive force (or attractive force) between 5 and the permanent magnet 76, and the light beam is deflected by the repulsive force (or attractive force) between the permanent magnet 78 and the permanent magnet 790. The light beam deflector 13 is separated from the support member 77, and the light beam deflector 13 is supported by the support member 70 and the support member 77 in a non-contact state.

By providing the permanent magnets 78 and 79 in this manner, the inclination of the light beam deflector 13 can be regulated.

FIG. 4 is a side view showing another embodiment of the support device for a light beam deflector according to the present invention. In the figure, Figures 2 and 1
Components that are the same as those in the figures to FIG. 6 are given the same reference numerals and their explanations will be omitted.

In FIG. 4, a light beam deflector 13 having a substantially cylindrical shape is shown.
A pivot 80 is attached to the upper surface of the pivot 80.
A pivot receiver 81 is provided on the upper part of 0. The pivot receiver 81 is adhesively fixed to a support member 83 via a vibration isolating material 82 made of urethane-based shock absorbing elastomer or the like.
Although not shown, the support member 83 is fixed to the optical base 27.

As a result, while the light beam deflector 13 is suspended by the repulsive force between the permanent magnet 72 and the permanent magnet 73, the permanent magnet 7
The repulsive force between the light beam deflector 1 and the permanent magnet 73
The light beam deflector 13 is supported by separating the light beam deflector 3 from the support member 70 and regulating the position of the light beam deflector 13 by the pivot 80 and the pivot receiver 81. By providing the pivot 80 and the pivot receiver 81 in this way, the inclination of the light beam deflector 13 can be easily regulated and stabilized during use, compared to the embodiments shown in FIGS. 1 and 2. can be achieved.

Although the present invention has been described above using examples, various modifications are possible according to the technical idea of the present invention. For example, in the embodiments shown in FIGS. 2 to 4, the space between the light beam deflector 13 and the support member 70 has been described, but the support member 70 may be filled with magnetic fluid. Dissipating heat from the light beam deflector 13 via magnetic fluid,
The temperature of the light beam deflector 13 can also be controlled.

Furthermore, in the embodiment, the permanent magnets 72, 73, etc. have been described as permanent magnets, but they can also be used as electromagnets.

Furthermore, a lead wire 7 for driving current to be supplied to the reflecting mirror 4 is provided.
1 is taken out from the circumferential surface of the cylindrical housing 24, but it is also possible to provide a through hole passing through the cylindrical housing 24, the permanent magnet 72, and the permanent magnet 73, and take out the lead wire 71 from this through hole. Moreover, the cylindrical housing 24 can also be used as the fixing member 2.

(6) Effects of the Invention As explained above, the present invention provides a light beam deflector incorporating a mirror oscillator that deflects a light beam by rotating and vibrating a mirror, and a support member that supports the light beam deflector. and is configured to support the light beam deflector in a non-contact manner in a floating manner from the support member. By supporting the light beam deflector in a non-contact manner by floating it from the support member, it is possible to prevent external vibrations from being transmitted to the mirror oscillator. It is possible to prevent the image from fluctuating and causing blur.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of a support device for a light beam deflector according to the present invention, and FIG. 2 is a side view and a top view showing another embodiment of a support device for a light beam deflector according to the present invention. 3 is a side view showing another embodiment of the support device for a light beam deflector according to the present invention, and FIG. 4 is a side view showing another embodiment of the support device for a light beam deflector according to the present invention. 5 is a perspective view showing the inside of the light beam deflector shown in FIG. 1, and FIG. 6 shows an embodiment in which the support device for the light beam deflector shown in FIG. 1 is applied to a copying machine. The plan view, FIG. 7, is a front view of a copying machine showing an embodiment in which the light beam deflector support device shown in FIG. 1 is applied to the copying machine. 1...Mirror vibrator 2...Fixing member 3...L-shaped member 4...Reflecting mirror 5...Drive coil 6...Ligament 7...Frame Part 8...Block member 9...Block member 10...Permanent magnet for excitation 11...Permanent magnet for excitation 12...Vibration isolator 13...Light beam deflector 14 Semiconductor laser 15 Collimator lens 16 Cylindrical lens 17 Reflection mirror 18 Scanning lens 19 Cylindrical lens 20 Photosensitive Body drum 21 ... Index sensor 22 ... Reflection mirror 23 ... Reflection mirror 24 ... Cylindrical housing 27 Assembly ... Optical base 70 ... Support member 71 ... Lead wire 72... Permanent magnet 73... Permanent magnet 74... Magnetic shielding plate 75... Permanent magnet 76... Permanent magnet 77... Support member 78... Permanent magnet 79... Permanent magnet 80... Pivot 81 φ... Pivot receiver 82... Vibration isolating material 83... Supporting member

Claims (4)

[Claims] (1) A light beam deflector incorporating a mirror oscillator that deflects a light beam by rotating and vibrating a mirror, and a support member that supports the light beam deflector, the light beam deflector being supported by the support member. A support device for a light beam deflector, characterized in that it is supported in a non-contact state while suspended from a member. (2) The light beam deflector according to claim 1, wherein a gas/fluid is interposed between the light beam deflector and the support member, and the light beam deflector is supported by the gas/fluid. Support device. (3) A support device for a light beam deflector according to claim 1, wherein a magnet is provided in the light beam deflector and the support member, and the light beam deflector is supported by the magnetic force between the magnets. . (4) A magnetic fluid is interposed between the light beam deflector and the support member, and heat conduction is performed between the light beam deflector and the support member via the magnetic fluid. 4. A support device for a light beam deflector according to claim 3.