JP2011257471A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixation apparatus-cum-optical apparatus that can use one beam light source both for writing an electrostatic latent image in a photosensitive drum and for fixing a toner on a recording paper separately as well as simultaneously.SOLUTION: An image forming apparatus of the present invention has a beam splitter that divides beam light irradiated from a light source into beam light for writing an electrostatic latent image to a photosensitive drum and beam light for fixing a toner on a recording paper.

Description

  The present invention relates to a fixing device and optical device used in an electrophotographic image forming apparatus such as a copying machine or a printer.

  As a fixing device used in an electrophotographic image forming apparatus such as a copying machine or a printer, a heat roller fixing type fixing device is frequently used. A fixing device of a heat roller fixing system includes a fixing roller and a pressure roller which are a pair of rollers in pressure contact with each other, and the roller is heated by a heating unit including a halogen lamp or the like disposed inside or both of the roller pair. After the pair is heated to a predetermined fixing temperature, a recording medium such as a recording sheet on which an unfixed toner image is formed is fed to a fixing nip portion that is a pressing portion of the roller pair, and is passed through the pressing portion. The unfixed toner image is fixed on the recording paper by heat and pressure.

  However, in the conventional roller pair system, the surface temperature of the roller pair is at room temperature immediately after the power is turned on, and thus it has been necessary to warm up for a long time in order to increase the temperature to a predetermined fixing temperature. Further, even when the copying operation is not being performed, it is necessary to maintain the surface temperature of the roller pair at a predetermined fixing temperature, which causes a problem of consuming large power consumption.

  In order to solve such a problem, a laser fixing type fixing device that performs fixing by irradiating a laser beam to an unfixed toner image formed on a recording paper and melting the unfixed toner image is a special feature. It has been proposed in, for example, Kaihei 2-221984 (Patent Document 1). In this laser fixing method, since the unfixed toner image is directly heated and melted by the laser light emitted from the light source, it is not necessary to heat the roller pair to a predetermined fixing temperature, and the warm-up time is greatly shortened. be able to. Further, since the entire area of the recording paper is not heated but the portion of the unfixed toner image is selectively heated, power consumption can be greatly reduced.

  However, the optical device for writing the electrostatic latent image on the photosensitive drum also has a light source that emits laser light, and is arranged separately from the light source for fixing by the laser fixing method. There was a problem that the structure was complicated.

  In order to solve this problem, Japanese Patent Application Laid-Open No. 59-95570 (Patent Document 2) discloses a method in which the traveling direction of laser light is changed by moving a mirror and fixing is performed by a laser fixing method. And a light source for writing an electrostatic latent image on a photosensitive drum.

JP-A-2-221984 JP 59-95570 A

  However, the configuration of Patent Document 2 merely switches the traveling direction of the laser light by simply moving the mirror, and directly without changing the output of the laser light necessary for fixing. The photosensitive drum is irradiated. Usually, the output of laser light required for fixing is about 50,000 times stronger than the output of laser light required for writing an electrostatic latent image on the photosensitive drum. Therefore, if the photosensitive drum is directly irradiated without changing the output of the laser beam necessary for fixing, the photosensitive drum is damaged by the heat of the laser beam.

  The present invention has been made in view of the above-described problems, and an object thereof is to write an electrostatic latent image on a light source and a photosensitive drum for fixing by a laser fixing method without damaging the photosensitive drum. It is an object of the present invention to provide a fixing device and optical device that can be used simultaneously with a light source.

  The present invention is an image forming apparatus that fixes toner using a light beam, and the image forming apparatus includes at least a light source, a beam splitter, a fixing device, and a photosensitive drum, and is irradiated from the light source. The light beam is incident on the beam splitter and then split by the beam splitter, and one of the light beams split by the beam splitter becomes a light beam for writing an electrostatic latent image on a photosensitive drum, The other one of the divided light beams is a light beam for fixing the toner onto a recording sheet.

  In the present invention, it is preferable that an ND filter for attenuating the light beam is disposed between the beam splitter and the photosensitive drum.

  Further, according to the present invention, a light modulation element that controls ON / OFF of a light beam based on image information is disposed between the beam splitter and the photosensitive member and between the beam splitter and the recording paper. It is preferable.

  According to the present invention, the light beam emitted from the light source is split by the beam splitter into the light beam for writing the electrostatic latent image on the photosensitive drum and the light beam for fixing the toner on the recording paper, It is possible to provide a fixing device and an optical device that can be used simultaneously and simultaneously with a light source of beam light for writing an electrostatic latent image on a photosensitive drum and a light source of beam light for fixing toner on a recording sheet.

  According to the present invention, an ND filter for attenuating the light beam is disposed between the beam splitter and the photosensitive drum, so that the intensity of the beam light for writing an electrostatic latent image on the photosensitive drum is appropriately set. Can be attenuated.

  Furthermore, according to the present invention, an optical switch for controlling ON / OFF of the light beam based on image information is arranged between the beam splitter and the photosensitive member and between the beam splitter and the recording paper. Accordingly, the control for writing the electrostatic latent image on the photosensitive drum and the control for fixing the toner on the recording paper can be performed simultaneously.

1 is a schematic sectional view of a monochrome copying machine of the present invention. 1 is a schematic configuration diagram of a fixing device of the present invention. 1 is a schematic cross-sectional view of a fixing device of the present invention. It is a schematic block diagram of the optical apparatus of this invention. It is the schematic which shows control of the laser beam by the optical switch of this invention. FIG. 3 is a control block diagram of the monochrome copying machine of the present invention. 3 is a flowchart showing control of the monochrome copying machine of the present invention. It is the schematic block diagram which looked at the laser head of this invention from the front. It is the schematic block diagram which looked at the laser head of this invention from the side. It is a schematic block diagram of the optical apparatus of other embodiment of this invention.

  An embodiment of a monochrome copying machine, which is an image forming apparatus equipped with a fixing device and optical device of the present invention, will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a monochrome copying machine, and FIGS. 2 and 3 are schematic sectional views of a fixing device of a laser fixing system.

  As shown in FIG. 1, a monochrome copying machine 100 according to an embodiment of the present invention includes an optical device E, an image forming unit P, a transfer unit 14, a fixing device 15, a paper feeding unit 16, and a manual paper feeding unit 17. ing.

  In the image forming unit P, a charging unit 102, a developing unit 103, and a cleaning unit 104 are disposed around a photosensitive drum 101 serving as a toner image carrier. The charging unit 102 is disposed to face the photosensitive drum 101. The optical device E is arranged so that image information from the light source 200 reaches the photosensitive drum 101. The laser fixing type fixing device 15 includes a sheet conveying device 150 and the like, and is disposed downstream of the transfer unit 14.

  The image forming process is as follows. After the surface of the photosensitive drum 101 is uniformly charged by the charging unit 102, the surface of the photosensitive drum 101 is exposed by the laser light from the light source 200 according to image information by the optical device E, and an electrostatic latent image is obtained. Form. As the charging unit 102, a charging roller is used to charge the surface of the photosensitive drum 101 uniformly and without generating ozone as much as possible. Thereafter, the developing unit 103 develops the toner image with respect to the electrostatic latent image on the photosensitive drum 101. The visualized toner image is transferred onto the recording paper fed from the paper feeding unit 16 or the manual paper feeding unit 17 by applying a bias voltage having a polarity opposite to that of the toner by the transfer unit 14. The recording paper is conveyed to the fixing device 15 at a predetermined fixing speed. In the monochrome copying machine 100 of the present invention, the fixing speed is 225 mm / sec at the maximum, and the fixing speed can be variably controlled by image information. The transferred toner image is heated by laser light irradiation from the light source 200 and fixed on the recording paper. Thereafter, the recording paper is discharged to the paper discharge unit 18.

  Next, the fixing device 15 of the present invention will be described in detail with reference to FIGS. As shown in FIG. 2, the laser light from a single light source 200 is scanned by rotating the polyhedral mirror 111 in the main scanning direction (arrow A) of the recording paper 110, and then aberrations caused by the deflection of the laser light. The recording paper 110 is irradiated with laser light by a correction lens 112 such as an fθ lens or a condensing lens. Thereafter, the recording paper 110 is conveyed rightward in FIG. 2 by the conveying member 15b, so that the entire surface of the recording paper 110 is irradiated with laser light.

  The unfixed toner image T1 shown in FIG. 3 is developed with, for example, a non-magnetic one-component developer containing non-magnetic toner, a non-magnetic two-component developer containing non-magnetic toner and a carrier, and a magnetic developer containing magnetic toner. It is formed with toner contained in the agent. Since the present invention is a monochrome copying machine, the toner is a monochrome toner to which a pigment such as carbon black is added, and an infrared absorber is unnecessary. However, when color toners (yellow, magenta, cyan) are used, it is necessary to add an infrared absorber because the absorption rate of laser light is lower than that of monochrome toner. For example, 1 to 5 parts by weight of phthalocyanine, which is an infrared absorber, is internally added to 100 parts by weight of the binder resin of the color toner. In addition to phthalocyanine, polymethine, cyanine, onium, nickel complex and the like can be used, or can be used in combination. Thereby, the absorption rate of the laser beam equivalent to the monochrome toner can be secured.

  As shown in FIG. 3, the fixing device 15 includes a paper transport device 150, a suction charger 15d, a separation charger 15e, a static elimination charger 15f, a separation claw 15g, and a drive motor (not shown). It comprises a member 15a, a drive member 15b, and a conveying member 15c.

The conveying member 15c is made of a polyimide resin having a thickness of 75 μm and a volume resistivity of 10 ¹⁶ Ω · cm, and is stretched between the driven member 15a and the driving member 15b. The drive member 15b is configured to be driven to rotate at an arbitrary speed by a drive motor, and the transport member 15c is transported at an arbitrary speed in the arrow Y direction by the rotation of the drive member 15b. Further, an adsorption charger 15d, a separation charger 15e, a charge removal charger 15f, and a separation claw 15g are provided around the transport member 15c.

  The recording paper 110 onto which the unfixed toner image T1 from the transfer unit 14 shown in FIG. 1 is transferred is conveyed from the right direction in FIG. 3, and first, between the conveyance member 15c on the driven member 15b and the suction charger 15d. It is conveyed to. At this time, the driven member 15b is made of a conductive material and is grounded, and the recording paper 110 is given a charge by the suction charger 15d. As a result, the recording paper 110 and the transport member 15c each cause dielectric polarization, and the recording paper 110 is electrostatically adsorbed on the transport member 15c. Thereafter, the recording paper 110 is conveyed to the place S where the laser beam is irradiated by driving the driving member 15b. The unfixed toner image T1 on the recording paper 110 conveyed to the place S where the laser beam is irradiated is irradiated with the laser beam from the light source 200 of FIG. 2 according to the image information, and heated. Fixing is performed.

  Thereafter, the recording sheet 110 having the fixed toner image T2 is conveyed between the separation charger 15e and the driving member 15b while being electrostatically attracted to the conveying member 15c. At this time, the drive member 15b is made of a conductive material and grounded, and the charge on the recording paper 110 is removed by the separation charger 15e. Thereby, the electrostatic attraction between the conveying member 15c and the recording paper 110 is weakened. Since the conveying member 15c rotates with a large curvature along the driving member 15b, the leading end of the recording paper 110 is lifted from the conveying member 15c, and the recording paper 110 is completely removed from the conveying member 15c by the separation claw 15g. To separate. The conveying member 15c from which the recording paper 110 has been separated is discharged to the position of the suction charger 15d again after the outer surface and the inner surface are discharged by the discharging charger 15f.

As a first embodiment, an optical apparatus E according to the present invention will be described in detail with reference to FIG. As shown in FIG. 4, the laser light emitted from the light source 200 is divided into two by the beam splitter 201. The beam splitter 201 has a function of reflecting part of the light incident on the beam splitter 201 and transmitting part of the light. The beam splitter 201 includes a prism type, a planar type, and a wedge substrate type. In the prism type, two right angle prisms are bonded together, and the joint surface is coated with a dielectric multilayer film or a metal thin film. A simple one is made of a thin glass film. In this embodiment, two prism molds are bonded, and the intensity of transmitted light and the intensity of reflected light are set to a ratio of 1:50. As long as the laser beam is divided into two and the intensity of one of the divided laser beams can be attenuated to an attenuation factor of about 1/50 of the intensity of the other laser beam, other than the prism type may be used. As the laser light source 200, a semiconductor laser or the like is used.

  First, the intensity of the laser light output from the light source 200 is set to 150 W (wavelength 780 nm, beam diameter 50 μm, spot diameter 50 μm). Of the two laser beams divided by the beam splitter 201, the intensity of one laser beam is set to 3W, and the intensity of the other laser beam is set to 147W.

  The degree to which the intensity of one of the divided laser beams is attenuated compared to the intensity of the other laser beam is not limited to 1/50, and is appropriately adjusted in consideration of the performance of the ND filter 202. . The ND filter 202 is a filter capable of greatly attenuating the intensity of the laser beam. In this embodiment, ND1000 (manufactured by NS Lighting, model number: NS-ND0152) capable of attenuation to about 1/1000 is used. did. Note that the attenuation factor of the ND filter 202 that can be used is determined by the intensity of the laser light emitted from the light source 200, the attenuation factor of the intensity of the laser light by the beam splitter 201, and the like, and is not limited to the ND1000. .

  With the above configuration, the laser light emitted with the intensity of 150 W from the light source 200 is attenuated to 1 / 50,000 by the beam splitter 201 and the ND filter 202, and is attenuated to about 3 mW when reaching the photosensitive drum 101. . This is almost the same as the intensity of the laser beam used for writing image information on a normal photosensitive drum 101 such as an organic photosensitive drum, so that writing is performed according to image information without imposing a load on the photosensitive drum 101. The electrostatic latent image can be formed on the photosensitive drum 101. In the above description, the attenuation rate is described as 1/50000, for example. However, this is merely an example, and it is needless to say that an appropriate attenuation rate can be selected as necessary.

  Laser light for writing image information to the photosensitive drum 101 attenuated by 1 / 50,000 is applied to the polyhedral mirror 111a, and the laser light is scanned in the main scanning direction of the photosensitive drum 101 by the rotation of the polyhedral mirror 111a.

  On the other hand, the laser beam divided for laser fixing is irradiated to the polyhedral mirror 111b with almost no attenuation by the beam splitter 201, and the recording of the fixing device 15 shown in FIG. 3 is performed by the rotation of the polyhedral mirror 111b and the correction lens 112. It reaches the unfixed toner image T1 on the paper 110, and the unfixed toner image T1 is heated and melted and fixed on the recording paper 110.

  Optical switches 203a and 203b, which are light modulation elements, are provided between the beam splitter 201 and the photosensitive drum 101 and between the beam splitter 201 and the fixing device 15, respectively. This makes it possible to control the laser beam for each pixel simply by turning on / off the optical switches 203a and 203b, which are light modulation elements, based on the image information. The optical switch 203a allows the image on the photosensitive drum 101 to be controlled. Information writing can also be controlled for each pixel.

  The optical switch 203b turns on / off the laser beam to the fixing device 15 for each pixel even when the recording paper 110 shown in FIG. 3 is not conveyed on the conveying member 15c shown in FIG. This is to prevent the conveyance member 15c, which is resin, from being directly irradiated with the laser beam and to prevent the conveyance member 15c from being deteriorated by the heat of the laser beam.

Note that the light modulation element utilizes the fact that the refractive index changes when an electric field is applied to the electro-optic crystal, and can control whether or not the inputted light goes straight as it is by an electric signal. The electro-optic crystal is a ferroelectric crystal typified by LiNbO ₃ or LiTaO _{3. In} this example, LiTaO ₃ was used.

  On the other hand, in the direct control method in which the laser light source 200 is directly turned on / off, it is impossible to irradiate laser light for laser fixing and laser light for writing image information to the photosensitive drum 101 at the same time. Need to switch. However, with the optical switches 203 a and 203 b and the configuration provided at two locations, it is possible to simultaneously control the irradiation of the laser beam for laser fixing and the irradiation of the laser beam for writing image information to the photosensitive drum 101.

  The optical switches 203a and 203b are roughly classified into a mechanical type and an electronic type. The mechanical type includes a prism moving type and a lens rotating type. Specifically, the optical path is switched by moving a prism, a mirror or the like using an electromagnet. However, since the mechanical type is inferior in responsiveness, the electronic type was used in this example.

  The electronic type includes a total reflection type, a branch type, a distributed coupling type, a branch interference type, and the like. It is preferable to use a total reflection type. In this embodiment, the optical switches 203a and 203b are used. However, any optical switch can be used as long as it can control whether or not the input laser light travels straight as it is.

  FIG. 5 is a diagram conceptually illustrating laser light control by the optical switches 203a and 203b. Image information detected by a reading unit 401 such as a scanner for reading a document image shown in FIG. 6 is first transmitted to the control unit 301 and then transmitted to the optical switches 203a and 203b. The optical switch 203a performs ON / OFF control as to whether or not the laser beam to the photosensitive drum 101 is allowed to pass. Similarly, the optical switch 203b performs ON / OFF control as to whether or not the laser beam to the fixing device 15 is allowed to pass.

  FIG. 6 is a control block diagram of the monochrome copying machine 100 according to the present embodiment. A reading unit 401 such as a scanner that reads a document image, an image processing unit 402 that converts the read document image into an electrical signal to generate image information, an image forming unit 403 that prints out the generated image information, and an optical control to be described later A unit 404, a fixing control unit 405, a storage unit 406, a peripheral device control unit 407, an input unit 408, and a display unit 409. The peripheral device control unit 407 controls peripheral devices such as finishers and sorters (not shown) that are post-processing devices. The input unit 408 is an operation unit of the monochrome copying machine 100 and can input characters, and the display unit 409 can display the printing state of the monochrome copying machine 100.

  The optical control unit 404 controls the irradiation of the laser beam applied to the photosensitive drum 101 shown in FIG. 1, and the fixing control unit 405 controls the irradiation of the laser beam that causes the fixing device 15 shown in FIG. . The fixing control unit 405 monitors a signal of an actuator (not shown) that detects a conveyance start signal of the recording paper 110 in FIG. 3, and applies a bias voltage to the conveyance member 15c shown in FIG. 3 based on this signal. Control is also performed.

  The storage unit 406 reaches the place S where the recording paper 110 is irradiated with the laser beam in the fixing device 15 of FIG. 3 based on a signal of an actuator (not shown) that detects a conveyance start signal of the recording paper 110 of FIG. I remember the time until.

  The control unit 301 transmits to the optical control unit 404 and the fixing control unit 405 based on the print position information of the image information received from the image processing unit 402. Note that the print position information indicates information on which position on the recording paper 110 is to be printed. After that, based on the received printing position information and the output value of the laser beam, the optical switch 203a shown in FIG. 3 controls the laser beam to the photosensitive drum 101 shown in FIG. At the same time, the conveying member 15c shown in FIG. 3 is driven to control the laser light by the optical switch 203b shown in FIG.

  FIG. 7 is a flowchart showing the control in this embodiment. First, the image information received from the image processing unit 402 shown in FIG. 6 is analyzed by the control unit 301 <Step S1>. Next, based on the analyzed result, it is determined whether or not the laser light is turned ON / OFF for each pixel by the optical switches 203a and 203b which are light modulation elements. This is done by determining whether or not the laser light to the photosensitive drum 101 shown in FIG. 1 is turned on / off for each pixel <step S2> and turning on / off the laser light to the fixing device 15 shown in FIG. This corresponds to the determination <step S3>.

  When it is determined whether to turn on / off the laser beam to the photosensitive drum 101 for each pixel, the determined instruction signal is transmitted to the optical control unit 404 <step S4>, and the laser beam to the fixing device 15 is transmitted. When it is determined whether to turn on / off for each pixel, the determined instruction signal is transmitted to the fixing control unit 405 <step S5>.

  The optical control unit 404 performs ON / OFF control of the laser light for each pixel by the optical switch 203a based on the transmitted instruction signal <Step S6>, and the fixing control unit 405 performs based on the transmitted instruction signal. Then, the laser light is turned on / off for each pixel by the optical switch 203b <step S7>.

  As a second embodiment, the light source is different from that of FIG. 4, and a laser head L in which laser light sources 200a are arranged in a line so that a plurality of laser beams are emitted as shown in FIG. 8 is used. ,explain. FIG. 8 is a configuration diagram of the laser head L viewed from the front, and FIG. 9 is a configuration diagram of the laser head L viewed from the side.

  By using a plurality of laser light sources 200a arranged in a line instead of a single one as shown in FIG. 4, the light source 200a emitting a very large laser light with a single laser light intensity of 150 W is bothered. No need to prepare. By arranging a plurality of light sources in a single row, the intensity of the light sources 200a of the individual laser beams can be reduced, so that the laser head L can be configured with the light source 200a having high versatility.

  The laser head L has a plurality of laser light sources 200a arranged in a line perpendicular to the conveyance direction of the recording paper 110 shown in FIG. 3, and laser light is applied to the unfixed toner image T1 shown in FIG. Is fixed to the recording paper 110. As shown in FIG. 8, the laser head L has a configuration in which a plurality of light sources 200a of a plurality of laser beams are arranged in a line, and includes a heat radiating plate 509 and a temperature sensor 510 shown in FIG. In the present embodiment, 1,000 light sources having a wavelength of 780 nm and individual laser light sources 200a having an intensity of 150 mW are used. The arrangement pitch M of the individual laser light sources 200a is 0.3 mm, and the spot diameter N of the laser light is 0.3 mm. The heat radiating plate 509 was made of an aluminum alloy and had a size of 30 mm square, a thickness of 20 mm, and a heat resistance of 1.6 ° C./W (manufactured by Alpha, model number: UB30-20B). The thermal resistance is 0.16 ° C./W.

  Further, the detailed configuration of the laser head L will be described with reference to FIG. In each silicon substrate 503, a photodiode 502 and a control circuit (not shown) are integrally formed. The photodiode 502 is a light receiving element that monitors the intensity of the laser light, and the control circuit changes the intensity of the laser light or keeps the intensity of the laser light constant based on the signal of the photodiode 502. The connection between the laser light source 200a and the plurality of silicon substrates 503 and the connection between the surface electrode 505 of the ceramic substrate 506 and the electrode on the silicon substrate 503 after the silicon substrate 503 is mounted on the ceramic substrate 506 are performed by wire bonding. Electrical connection is made with a line 504 or the like. Then, after attaching the heat sink 509 to the ceramic substrate 506, the lens holder 507 holding a plurality of convex lenses 508 for condensing the laser light from the light source 200a is attached.

  The plurality of convex lenses 508 and the lens holder 507 use an ion-exchanged product in which a convex lens 508 and a lens holder 507 are integrally formed of resin, or flat glass is used in a lens shape, rather than an individual convex lens 508 incorporated in a resin holder or the like. A flat microlens or the like obtained in this way is more advantageous in terms of assembly accuracy. It is also possible to directly irradiate the unfixed toner image T1 shown in FIG. 3 with laser light in the state of parallel light by eliminating the plurality of convex lenses 508 for condensing the laser light from the light source 200a.

  Further, as shown in FIG. 9, a temperature sensor 510 composed of a thermistor or the like for measuring the temperature of the laser head L is attached on the ceramic substrate 506. The temperature sensor 510 is disposed at the center with respect to the longitudinal direction of the laser head L. Based on the temperature data detected by the temperature sensor 510, the control circuit controls the voltage applied to the laser head L.

  FIG. 10 shows the optical device E. A plurality of laser beams with a laser beam intensity of 150 mW are emitted from the light source 200a of the laser head L, and the beam splitter 201 divides the laser beam intensity into 1:50. In this case, since the intensity of the laser light applied to the photosensitive drum 101 is attenuated to 3 mW, the ND filter 202 shown in FIG. 4 is not necessary, but when the attenuation factor of the beam splitter 201 is small, the beam splitter 201 and An ND filter 202 may be provided between the photosensitive drums 101. In other configurations, a beam splitter 201 and optical switches 203a and 203b are provided in the same manner as in FIG.

  In the present invention, laser light has been described. However, any light beam may be used, and an LED (Light Emitting Diode) or the like can also be used.

  Although the present invention relates to a monochrome copying machine, it can also be applied to a color copying machine.

  The image forming apparatus according to the present invention can be widely applied to all apparatuses such as a copy / scanner / printer / facsimile.

14 Transfer unit 15 Fixing device 15a Follower member 15b Conveying member 15c Conveying member 15d Adsorption charger 15e Separating charger 15f Discharging charger 15g Separating claw 16 Paper feeding unit 17 Manual paper feeding unit 18 Paper discharging unit 100 Monochrome copier 101 Photosensitive drum 102 Charging unit 103 Development Unit 104 Cleaning Unit 110 Recording Paper 111 Polyhedral Mirror (111a, 111b)
112 Correction Lens 150 Paper Conveying Device 200 Light Source 200a Light Source 201 Consisting of Multiple Laser Lights Beam Splitter 202 ND Filter 203a, 203b Optical Switch 301 Control Unit 401 Reading Unit 402 Image Processing Unit 403 Image Forming Unit 404 Optical Control Unit 405 Fixing Control Unit 406 Storage unit 407 Peripheral device control unit 408 Input unit 409 Display unit 502 Photodiode 503 Silicon substrate 504 Wire bond line 505 Surface electrode 506 Ceramic substrate 507 Lens holder 508 Convex lens 509 Heat sink 510 Temperature sensor E Optical device L Laser head M Array pitch N Spot diameter P Image forming unit S Location T1 Unfixed toner image T2 Fixed toner image

Claims (3)

An image forming apparatus that fixes toner using a light beam,
The image forming apparatus includes at least a light source, a beam splitter, a fixing device, and a photosensitive drum.
After the light beam emitted from the light source is incident on the beam splitter,
Split by the beam splitter,
One of the light beams divided by the beam splitter becomes a light beam for writing an electrostatic latent image on a photosensitive drum,
The other one of the divided light beams is a light beam for fixing the toner onto a recording sheet.   The image forming apparatus according to claim 1, wherein an ND filter is disposed between the beam splitter and the photosensitive drum.   An optical modulation element that controls ON / OFF of a light beam based on image information is provided between the beam splitter and the photosensitive member, and between the beam splitter and the recording paper, respectively. Item 3. The image forming apparatus according to Item 1 or 2.