JPS6366572A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To resolve a danger of touch or the like to improve the safety by providing an interlock switch, which is operated when an upper unit and a lower unit are divided, with an inner cover. CONSTITUTION:An interlock switch 164 is provided on the right of the front of a lower frame 78, and the power is supplied to a power supply part for a main controller from a power input part through the interlock switch 164. The interlock switch 164 is normally turned off; and when an upper unit 1 is closed, the switch 164 is depressed by a depresser provided on the upper frame and is turned on. The interlock switch 164 is covered with a switch cover 171 of an inner cover 170, and a hole 172 of the switch cover 171 is formed into a cross shape to allow only the depresser to insert to the hole 172 so that the interlock switch 164 is not turned on when the upper unit 1 is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to electrostatic recording devices such as copying machines, facsimile machines, printers, and the like.

In the above electrostatic recording device, the electrostatic recording device is divided into two units, upper and lower, in consideration of maintenance work, jammed paper disposal, etc., and the upper unit is separated from the lower unit and rotated. In some machines, when the upper unit is lifted, the inside of the machine is exposed to the outside. in this case,
It is dangerous if each device continues to operate after that, so it is convenient to turn off the interlock switch and stop each device when the unit is lifted.

However, if this interlock switch remains exposed to the outside, there is a risk that a person may accidentally touch it, and the danger cannot be completely eliminated.

Purpose In view of the above points, it is an object of the present invention to ensure double safety of a divisible type electrostatic recording device.

In order to achieve the above object, the present invention has splittable units, and when the units are split, an interlock switch is turned off to cut off the power supply path. This electrostatic recording device is characterized in that it includes an inner cover that covers an interlock switch.

Hereinafter, the present invention will be explained based on Examples.

FIG. 1 shows the appearance of a laser printer, which is an example of an electrostatic recording device. This laser printer.

It prints characters, etc. on a transfer material such as a sheet of paper or an envelope based on instructions from a host computer (not shown). Further, this laser printer can be roughly divided into an upper printer unit 1 and a lower printer unit 2. A paper feed tray 3 is removably attached to the lower unit 2, and a paper discharge switching knob 4 is also provided. The upper unit 1 is provided with an operation panel 5, a font cartridge insertion slot 6, and a Nimure Rayon card insertion lower. In addition, a cover 8 which is one of the components of the upper unit 1
The upper surface constitutes an upper paper discharge tray 9.

Transfer materials to be printed are stacked and held on a paper feed tray 3. In this embodiment, it is possible to print on a wide variety of transfer materials, from large-sized paper such as so-called legal size to small-sized paper such as envelopes. Upper guide plate 25
Guide each size paper by moving 4 as shown by the arrow 0
Both guide plates 254, 254 are linked together on the bottom surface of the tray so that when one is moved in either direction, the other is automatically moved in the other direction. The operation panel 5 includes switches for setting the size of the transfer material and various other printing conditions. The font cartridge insertion slot 6 is a font cartridge,
That is, by inserting a ROM cartridge in which several types of font information are stored, the font information is sent to a character controller, which will be described later. The emulation card insertion lower is for connecting an emulation card (ROM card) to the character controller for matching the host computer and this laser printer, depending on the type of the host computer (not shown). The paper ejection switching knob 4 is used to select whether to eject the transfer material that has finished printing in the laser printer to the upper paper ejection tray 9 or
Alternatively, as shown by arrow A, it is possible to switch between ejecting to the outside of the laser printer to the left.

The upper printer unit 1 and the lower printer unit 2 are hinged together on the back side of the figure, and are fixedly held to each other on the front side by a locking mechanism to be described later. By pushing up the lock lever knob 10 protruding from the front surface of the cover 8 to release the locking mechanism, the printer upper unit 1 can be rotated and lifted from the printer lower unit 2, as shown in FIG. The reason why the upper and lower units 1 and 2 are constructed so that they can be separated from each other is to facilitate maintenance work or to facilitate replacement of photoreceptors, developer, etc., which will be described later.

Figure 3 shows printer upper unit 1 and printer lower unit 2.
FIG. 3 is a side sectional view of the laser printer in a state in which the two are coupled together. Hereinafter, an outline of the operation of the laser printer will be described using this diagram.

A drum-shaped photoreceptor 11 disposed approximately in the center of the printer lower unit 2 is driven and rotated in a clockwise direction, and is first subjected to a discharging action by an electrostatic charger 12 .

The charge wire 13 of the electrification charger 12 is shown in FIG.
As shown in a), it is stretched parallel to the photoreceptor 11,
Therefore, due to the discharge from the charge wire 13, the photoreceptor 11
The surface of is charged uniformly in the axial direction.

The thus charged photoreceptor 11 is then exposed to a laser exposure device 14.
The image is exposed by the image. As shown in FIG. 5, the laser exposure device 14 includes a polygon mirror 16 rotated clockwise by a scanner motor 15, a laser diode (LD) unit 17, a first cylindrical lens 18, and a first mirror 19. , a spherical lens 20, and a second mirror 21.

The LD unit 17 has a built-in laser diode (LD), and this LD emits a laser beam for writing an image signal based on an image signal, which will be described later. This laser beam is transmitted through the first cylindrical lens 18 as shown in FIG.
, and enters the spherical lens 2o via the first mirror 19. The laser beam is focused by the spherical lens 20 and refracted upward by about 5 inches, and then reflected by the polygon mirror 16.
It is incident on a surface and reflected by the mirror surface. Since the light incident on the polygon mirror 16 is refracted upward by the spherical lens 20, the reflected light passes above the incident light. The reflected laser beam is further passed through the second mirror 21
The light is reflected by the beam, passes through the second cylindrical lens 22, is guided onto the photoreceptor 11, and is irradiated dot by dot. At this time, according to the rotation of the polygon mirror 16, the laser beam is scanned on the second mirror 21 and therefore on the photoreceptor 11 as shown by arrow B (main scanning).During this main scanning, a dot line is created by the laser beam on the photoreceptor. is formed. This optical scanning is repeated for each surface of the polygon mirror 16, and at the same time the photoreceptor 11 is moved in a direction perpendicular to the main scanning direction (sub-scanning direction).
and the result.

In this embodiment, an electrostatic latent image corresponding to an image signal on the surface of the photoreceptor 11 is formed, and the dot density of this electrostatic latent image is 30.
Main scanning and sub-scanning are performed to achieve 0 dots/inch. When printing is performed based on such a high-density dot image, it is possible to obtain a clear print image equivalent to that of the so-called type impact method. Further, in this embodiment, each surface of the polygon mirror 16 is curved to form the second mirror 2.
The scanning image plane on 1 is made flat.

Therefore, the so-called f-theta lens that was conventionally disposed between the polygon mirror 16 and the second mirror 21 is unnecessary. This makes it possible to significantly reduce the size of the entire laser optical device 14.

The image signal written in the LD in the LD unit 17 is reflected by the polygon mirror 16 and then enters the optical fiber 25 via the third mirror 23 and the third cylindrical lens 24. The optical fiber 25 is connected to a main controller (described later) that controls all operations of the printer, and the image signal writing laser is controlled by a synchronization detection laser beam sent to the main controller via the optical fiber 25. Controls the timing at which the beam starts emitting light.

In FIG. 3, a photoreceptor 1 is exposed by a laser exposure device 14.
The electrostatic latent image formed on the photoreceptor 11 is carried to the developing roller 26 as the photoreceptor 11 rotates.6 In this embodiment, a so-called contact developing method is adopted, and the electrostatic latent image formed on the developing roller 26 is transported to the developing roller 26.
6 is driven and rotated counterclockwise while lightly contacting the photoreceptor 11. Further, the developing roller 26 is supplied with non-magnetic toner 29 contained in the developing tank 28 by a toner replenishing roller 27 that is disposed at the bottom of the developing tank 28 and rotates counterclockwise. Therefore, developing roller 2
The electrostatic latent image on the photoreceptor 11 that has been carried to the position 6 is developed into a visible image by the toner carried by the developing roller 26. In the contact development method in which the photoreceptor 11 and the developing roller 26 are brought into contact, a one-component developer made of non-magnetic toner is used, and there is no need to use magnetic toner.

The toner composition is the front car. Furthermore, since no carrier is used, carrier replacement, which is required when conventional so-called two-component developers are used, can be omitted. Furthermore, non-magnetic toner can easily perform the fixing operation described below, and the fixing device can be manufactured with a simple structure and small size. Furthermore, when a non-magnetic toner is used, the outline of the toner image obtained by development can be clearly defined, and a higher quality image can be obtained than a single-component developer using a magnetic toner.

This toner image is then conveyed to a transfer position, which is a position opposite transfer charger 30. 64 is a toner thickness regulating blade, and 65 is a toner cartridge.

While the above process is being executed, the topmost sheet of the transfer materials stacked on the paper feed tray 3, for example, the sheet-shaped transfer paper 31, is rotated counterclockwise. The paper is separated from other paper by the roller 32 and the friction pad 33 in pressure contact with it, and is transferred to the upper and lower conveyance rollers 34 and 35.
The photoreceptor 11 is further transported to a transfer position on the photoreceptor 11 by these transport rollers.

The transfer paper transported in this manner is superimposed on the toner image on the photoreceptor 11 at the transfer position, and is subjected to a discharge action by the transfer charger 3o.

Due to this discharge, the toner image on the photoreceptor 11 is transferred onto the transfer paper. When the transfer work is finished, the transfer charger 30
Light from a charge eliminating lamp 54 consisting of an LED arranged next to the transfer paper is irradiated onto the photoreceptor 11 to eliminate both the surface potential of the photoreceptor and the charged potential of the transfer paper.

The transfer paper whose potential has been weakened is reliably separated from the photoreceptor 11 by its own weight, and is sent to a heat fixing device in which a heating roller 36 and a pressure roller 37 are offset. The transfer paper and the toner image transferred thereon are heated by the heating roller 36 and are subjected to pressure from above and below by both rollers 36, 37, and as a result, the toner image is fused and fixed onto the transfer paper. A heater 38 is provided inside the heating roller 36 to heat the heating roller 36.

The transfer paper that has undergone the fixing operation is peeled off from the heating roller 36 by a peeling claw 39 and sent to a paper discharge roller 40. A paper ejection switching claw 41 is provided at the downstream position of the paper ejection roller 40, and this switching claw 41 can be switched between the solid line position in FIG. 3 by turning the paper ejection switching knob 4 shown in FIGS. 1 and 2. Switch with the dashed line position. When the switching claw 41 is in the solid line position, the transfer paper coming out of the paper ejection roller 40 passes through the conveyance path formed by the paper ejection guide member 42 and the paper ejection guide plates 43 and 44, and is transferred by the upper paper ejection roller 45. The paper is discharged to the upper paper discharge tray 9. On the other hand, when the switching claw 41 is at the broken line position, the paper ejection roller 4
The transfer paper that comes out from 0 is ejected straight out of the printer as shown by arrow A.

The manner in which the transfer paper is to be discharged is determined by the operator's operation of the switching knob 4. Generally, pages are printed on weak plain paper transfer paper, and when it is desired to stack pages, the paper is discharged to the upper paper discharge tray 9.

On the other hand, when printing on envelopes or other stiff transfer materials, the paper is ejected in a straight line.

Toner that did not contribute to the transfer remains on the photoreceptor 11 after the transfer is completed. This residual toner is neutralized along with the photoreceptor 11 by the charge removal lamp 54, and scraped off from the photoreceptor 11 by the cleaning blade 55. The scraped off toner is sent into a toner collection tank 57 by a toner collection roller 56, and the photoreceptor 11, which is collected there and cleaned by the cleaning blade 55, is again subjected to the charging action by the charging charger 12.

The surface of the fixing roller 36 in the embodiment is electrically conductive. In this way, the charge on the transfer paper is removed via the fixing roller during the fixing operation. Conventionally, in order to improve the stacking properties of the transfer paper, the transfer paper that is sent to the outside was charged with a special charge-eliminating brush before being ejected, but in this embodiment, the charge-eliminating brush is not necessary6. In order to impart conductivity to the fixing roller, for example, a method can be used in which carbon is mixed into the base of the roller such as Teflon. Since carbon has a relatively high hardness, this method can also increase the durability of the roller.

The general operation of the laser printer according to the embodiment has been described above. Details of each part will be explained below.

Image forming section In this embodiment, the photoreceptor 11, charger 12, and toner collection tank 57 in FIG. 3 are configured as one two-unit (photoreceptor unit 58) as shown in FIG. 4(a). has been done. Further, the developing roller 26. The toner replenishing roller 27° and the developing tank 28 are also integrated into one unit (developing unit 59) as shown in FIG.
). The photoreceptor unit 58 and the developing unit 59 are each detachably supported by an image forming unit case 60.

The photoreceptor unit 58 has a box-shaped case 61, and the photoreceptor 11 is supported in this case 61*! i62 is rotatably and detachably supported. Also, this case 61
663 into which the rape beam from the laser optical system W14 (FIG. 3) is incident is formed, and furthermore, the toner recovery tank 57 (FIG. 3) mentioned earlier is defined by the case 61 itself, and the charger 12 A casing (a wall surrounding the charge wire 13) is configured. The cleaning blade 55 and the toner collection roller 56 are each supported by a case 61. Photoconductor 11 in case 6
1. Therefore, the reason why it is made detachable from the toner collection tank 57 is as follows. That is, generally when the toner recovery tank 57 becomes full of waste toner, it is replaced with a new one. in this case.

When the photoreceptor 11 and the toner collection tank 57 are integrated,
Along with replacing the toner collection tank, the photoreceptor will also be replaced. However, the lifespan of recent photoreceptors has been significantly extended due to improvements in materials, manufacturing methods, and the like. Therefore, if the photoreceptor is to be used until the end of its life, a very large-capacity toner collection tank will be required, making the entire printer unnecessarily large. In order to avoid this, the toner collection tank for one photoreceptor can be replaced, thereby reducing the size of the printer and effectively utilizing the photoreceptor.

The developing unit 59 has a case 66, which defines a developing tank 28 (FIG. 3), and further rotatably supports the developing roller 26 and the toner replenishing roller 27. The toner cartridge 65 is removably mounted on the case 66. When the amount of toner remaining in the developing tank 28 becomes low,
The previously installed cartridge 65 is replaced with a new cartridge, and toner is replenished into the developing tank 28.

The image forming unit case 60 is disposed within the printer lower unit 2. Therefore, the photoreceptor unit 58 and the developing unit 59 are also arranged within the printer lower unit 2. When the upper printer unit 1 is lifted as shown in FIG. 2, the upper portions of both the photoreceptor unit 58 and the developing unit 59 are exposed.

As shown in FIG. 4, the image forming unit case 60 is formed into a box shape with an open top, and has front and rear walls 60a, 6.
A groove-shaped support portion 67.67 for supporting the support shaft 62 of the photoreceptor 11 is formed in 0b. The photoreceptor unit 58, supported on one side by the support portion 67, is pressed against the other side by a stop claw 69. The developing unit 59 is also pressed by the stop claw 70 while being housed in the image forming unit case 60 . These stop claws 69, 70 are made of a flexible material, and when each unit 58, 59 is inserted into the imaging unit case 60, they expand outward so as not to interfere with the insertion.

When the photoreceptor unit 58 is attached to the image forming unit case 60, a portion of the lower side of the photoreceptor 11 enters the opening lower 1 formed on the bottom wall of the case 6o, and the gear 72 attached to the support shaft Enter booth lower 3.

When the developing unit 59 is viewed from the direction of the arrow (2) as shown in FIG. 7, a gear 74 is attached to the shaft end of the developing roller 26. As shown in FIG. When the developing unit 59 is attached to the image forming unit case 60, this gear 74 projects outward from the recess 75 in the rear wall 60b of the image forming unit case in FIG.

A pair of pivot pins 76 and 77 are protruded from the left side wall 60d of the image forming unit case 60, and these pivot pins are connected to each frame 78 (FIGS. 1 and 3) of the printer lower unit 2. Support grooves 79.7 provided in side plates 78a, 78b
9 is fitted. Therefore, as shown by arrow E in FIG. 2, the image forming unit case 6o can be lifted up by rotating around the pivot pins 76 and 77 while housing the photoreceptor unit 58 and the developing unit 59. In this case, as shown in FIG. 3, the lower part of the case 60 is the conveyance path for the transfer paper, so when the case 60 is lifted as described above, the paper conveyance path is exposed to the outside, and the paper conveyance path is exposed to the outside. Transfer paper (so-called jammed paper) can be easily removed.

The entire image forming unit case 60 can also be removed from the printer lower unit 2 if necessary.

In FIG. 4, a pair of support pins 81 and 81 are protruded from the right end of the image forming unit case 60, and a rotating member 82 is rotatably supported by these support pins. A pair of lock claws 83, 83 and a knob 84 are integrally formed on this member 82. In addition, a compression spring 87 is press-fitted between a receiving portion 85 formed by cutting and bending a part of the rotating member 82 and the right-end horizontal portion 86 of the image forming unit case 60, and these springs 87 cause the rotating member to rotate. The member 82 is urged toward the image forming unit case 60 around the support pin 81 .

A pair of locking holes 88 are provided in the lower frame side plates 78a and 78b.
88 is formed, and the image forming unit case 60 is the third
When installed in the mounting position shown in the figure.

The locking claws 83 are respectively engaged in the locking holes 88 by the action of the springs 87. In this case, as shown in FIG. 3, a compression spring 89 is provided at the lower right end of one image forming unit case 60, and the lower end of this spring 89 comes into pressure contact with the lever 90, so that the case 60
When the case 6o is placed in the mounting position, the case 6o is urged counterclockwise by the spring 89 around the pivot pins 76 and 77. Therefore, the lock claw 83 comes into pressure contact with the upper surface of the locking hole 88, and the case 60 is reliably locked.

Note that the lever 90 is connected to the lower frame 7 by the bin 91.
8, and rotatably supports an upper conveyance roller 34 for conveying the transfer paper 31. When the image forming unit case 60 is installed in the predetermined position shown in FIG. 3, the spring 89 presses the lever 90 as described above.

As a result, the upper and lower transport rollers 34 and 35 press against each other to transport the transfer paper. Place the image forming unit case 6o in the second
When lifted as shown in Figure E, the spring 8
9 is released, the upper and lower transport rollers 34 and 35
When transfer paper gets jammed in between, it can be easily removed.

In FIG. 4, another frame side plate 78c is fixed to the lower frame side plate 78b on the rear side.

A main motor unit 93 having a main motor 92 is attached to this frame side plate 78c. A drive gear 94 is fixed to the output shaft of the main motor 92, and a photoreceptor drive gear 95 and a developing roller drive gear 96 are rotated by this drive gear via an appropriate gear train.

When the image forming unit case 60 is installed in the predetermined position shown in FIG. 74 (FIG. 7) meshes with the developing roller drive gear 96. When the main motor 92 rotates in this state, the photoreceptor 1
1 and the developing roller 26 rotate.

When the image forming unit case 6o is attached, the contact state between the photoreceptor 11 and the developing roller 26 and the developing roller shaft end gear 7
8 and the developing roller drive gear 96 are as shown in FIG. 8. By setting the positional relationship as shown in FIG. The acting force P on the shaft end gear 74 and therefore on the developing roller 26 is in the vertical direction. Since the force of the drive system is thus prevented from acting in the horizontal direction, the pressure force between the developing roller 26 and the photoreceptor 11 is no longer adversely affected by the force of the drive system.

On the other hand, in addition to the gear 74, a lock lever 101 is rotatably attached to the shaft of the developing roller 26, as shown in FIG. A tension spring 10 is attached to the top of the lock lever 101.
2 is attached and the developing unit 59 is not attached to the image forming unit case 60 (FIG. 4), the lock lever 101 is lifted and rotated to the upper position by the spring force of the spring 102. .

When the developing unit 59 is placed in the predetermined position shown in FIG.
1 and push it down. Then, the lock lever
As shown in FIG. 10, the recessed portion 104 of 101 is caught by a lock pin LO5 fixedly arranged near the developing roller drive gear 96, and as a result, vertical movement of the developing unit 59 is restrained. The pin 106 and elongated hole 107 shown in FIG. 10 are used to determine the rotation range of the lock lever 101.

As described above, by setting the acting force P on the developing roller 26 only in the vertical direction and further regulating the vertical movement of the developing unit 59 with the lock lever 101, the contact pressure between the developing roller 26 and the photoreceptor 11 is stabilized. Furthermore, the vibration of the developing roller 26 has been reduced. When the vibration of the developing roller 26 decreases, the uneven rotation of the photoreceptor 11 decreases accordingly. In this way, jitter in the photoreceptor rotation direction (sub-scanning direction) was significantly reduced. In this case, the spring 10 of the lock lever 10L
The rotation by 2 does not impede the operability when attaching and detaching the developing unit 59.

In the case of the above configuration, the developing unit 59 is pressed downward by the spring force of the leaf spring 103 when the above-described printing process is executed. Generally, this configuration alone is sufficient, but in order to more reliably prevent the occurrence of jitter, it is convenient to adopt the following configuration.

A compression spring 108 is provided in the printer upper unit 1 in addition to the leaf spring 103. When the printer upper unit 1 is closed, the lock lever 101 first releases the leaf spring 103 and the compression spring 10.
8 until it is caught on the lock bin 105.

When the lock lever 101 is further caught on the lock pin 105, a gap is created between the lock lever unit 05 and the spring 108, and the spring force of the spring 108 no longer applies to the lock lever 108. That is, the lock lever 105 is connected to the leaf spring 103.
According to /71, it engages with the lock bin 105 only by the spring force. In this case, the pressing force by the compression spring 108 is Pl,
When the pressing force by the leaf spring 103 is P2, if Pl is too small, the lock lever 101 will not be able to rotate sufficiently, and locking failure by the lock lever 101 will likely occur, which may cause problems such as gear locking. There is. Further, if P2, that is, the pressing force during the printing operation is too large, the contact pressure between the photoreceptor 11 and the developing roller 26 will be adversely affected, and there is a risk of image plate cracking or jitter. Therefore, Pl
When selecting P2 and P2, it is necessary to select the best combination. In the example, P = 2.0 kg, P = 300 g
And so.

(Left space below) In Fig. 3, compression springs 109 and 110 are provided on the inner surface of the right end wall of the image forming unit case 60.In Fig. 1, there appear to be only one compression spring, but there are two in total, one on the front side and one on the back side. Each is provided. These springs.

As shown in FIG. 4(b), both ends of the case 66 of the developing unit 59 are pressed by spring forces p, , p, respectively.

On the other hand, a compression splash 1 is applied to a portion of the printer upper unit 1 corresponding to the non-driving side (the side without the gear 74) of the developing unit 59.
11 will be provided. When the upper printer unit 1 is closed, the spring 111 presses the developing unit 59 downward at a portion on the non-drive side with a spring force P.

In this way, the developing unit 59, and therefore the developing roller 26, are pressed horizontally in the direction toward the photoreceptor 11 at two points, and the developing roller 26 is further pressed downward by a part on the non-driving side, so that the photoreceptor 11 The contact pressure with the developing roller 26 has become even more stable, making it possible to obtain a toner image with uniform density.

Note that appropriate values for P, , P, , P, are selected depending on the developing unit 59 and other parts to which it is applied.

Incidentally, in the example, P==700g, p4=1o.

gp Pi = 1000g.

The developing roller shaft end gear 74 shown in FIG. 7 includes an oil seal 112, a retainer 113 (press-fitted), a cushion 114, and the like, as shown in FIG. It is attached to the developing roller 26 via a bracket 116 in which side seals 115 and the like are housed. The developer roller 26 rotates during the printing process. If no precautions are taken, toner may spill from between the bracket 116 and the developing roller 26. Therefore, in this embodiment, one end 118 of the seal 117 is made of a thin material such as polyethylene film.
(the shaded part) is fixed to the bracket 116, and the bracket 1
The seal 117 covers the joint between the developing roller 16 and the developing roller 26, and the other end 119 is pulled out above the developing unit 59 as shown in FIG. 7 and further fixed. The fixation is performed by applying an adhesive to the seal in the shaded area Q in advance and adhering it to the case 66 of the developing unit 59. To ensure complete fixation,
Further apply the plate 120 on the adhesive part Q, and tape 1
It is preferable to fold back the tip 119 of the printer 17 and carry it to the top of the plate 120, and then press the plate 120 in this state with the upper printer unit l.

Radial leakage of toner is thus prevented.

In order to completely prevent toner from leaking in the axial direction, a seal plate 12 is installed between the side seal 115 and the developing roller 26.
This seal plate 121 preferably has small protrusions 122a on both the front and back sides.

122b are provided in a protruding manner, and these small protrusions further improve the sealing performance of the side seal 115.

In the embodiment, the casing of the charger 12 is integrally molded with the photoreceptor unit 58 from resin. This has the advantage of reducing the number of parts and manufacturing man-hours.

By the way, the resin used here is generally an insulating material. If the charge wire 13 is covered only with such an insulating material, the voltage at which the charge wire 13 starts discharging becomes abnormally high.

As a result, there is an inconvenience that, prior to normal discharge to the photoreceptor 11, leakage of current in an unspecified direction, so-called leakage, occurs. Further, even after the discharge to the photoreceptor 11 has started, the discharge becomes unstable.

In conventional chargers, the above-mentioned disadvantages were avoided by making the casing surrounding the charge wire from a grounded conductive material, but in this example, the casing is made of resin integrally molded, so some kind of compensation is required. is necessary.

Therefore, as shown in FIGS. 3 and 4(a), an opening 296 is made in the upper part of the casing of the charger 12, and a grounding plate made of a conductive material is placed on the bottom of the printer upper unit 1 in a portion corresponding to the opening. 297 is provided.

In this way, the ground plate 297 functions similarly to the conductive casing in the conventional device, and therefore the above-mentioned disadvantages such as leakage or unstable discharge do not occur.

As shown in FIG. 2, the ground plate 297 has a protrusion 297a formed on its front side (the side where the operation panel 5 is located). When the printer upper unit 1 and printer lower unit 2 are combined, the protrusion 297a is formed on the photoreceptor unit 58.
A conductive plate 299 connected to the axis of the photoreceptor 11 is disposed in the opening 298, which fits into the opening 298 provided in the opening 298, as shown by the broken line in FIG.
The earth plate protrusion 297a protruding into the ground plate 98 is electrically connected to the shaft of the photoreceptor 11 via a conductive plate 299. in general,
Since the axis of the photoreceptor 11 is grounded, the ground plate 29
7 will also be grounded.

It has already been explained in connection with FIG. 4 that the drive system photoreceptor 11 and the developing roller 26 are driven by the main motor 92. However, in this embodiment, what is driven by the main motor 92 is not limited to these two members.

FIG. 18 shows the gear train driven by the main motor 92 in detail. In addition to the photoreceptor drive gear 95 and the developing roller drive gear 96, it also drives a conveyance roller drive gear 97, a paper feed roller drive gear 98, a heating roller drive gear 99, a paper discharge roller drive gear 100, and the like. The conveyance roller drive gear 97 drives the lower conveyance roller 35 in FIG.

Paper feed roller drive gear 98 drives paper feed roller 32 .

The heating roller drive gear 99 drives the heating roller 36 'PJA!'
! Illll. A paper discharge roller drive gear 100 drives upper and lower paper discharge rollers 40 and 45.

The main motor unit 93 includes a main motor driver 139 in addition to the main motor 92 described above. The main motor 92 includes a crystal oscillator that generates a reference signal for constant speed control, an encoder that indicates the actual motor speed that also serves as a control amount for constant speed control, a power circuit, and a servo circuit that performs constant speed control. It becomes necessary. The main motor driver 139 has the above-mentioned devices mounted on a board, and is fixedly attached to the main motor 92 and integrated therewith. The reason why such an integrated structure is adopted is to minimize the number of cables connecting the above-mentioned devices and the main motor 92, thereby achieving compactness.

Ozone ゛, Cooling Generally, ozone is generated by the discharge of the charger 12 or the like. If this ozone accumulates in a specific location near the photoreceptor 11 inside the printer, it will cause deterioration of the photoreceptor, which is undesirable.
Further, in this embodiment, the following ozone discharge device is provided to eliminate the inconvenience that causes discomfort to the operator when lifting the printer upper unit 1.

In FIG. 3, an ozone blowing fan 46 is disposed above the electrification charger 12. As shown in FIG. 13, this ozone blower fan 46 is installed approximately in the center of the upper unit frame 47 made of synthetic resin, from the front surface 47a toward the back side (the third
(direction perpendicular to the paper of the figure) is fixed. Ozone blower fan 46
A plurality of air blowing openings 48 are opened in the frame 47 to which the air blower is fixed. When the ozone blower fan 46 rotates, air is uniformly sent into the vicinity of the photoreceptor 11 in the axial direction through the individual blower openings 48, as shown in FIG. As a result, ozone near the photoreceptor is blown away, and deterioration of the photoreceptor due to ozone is prevented. The ozone blower fan 46 starts at the latest at the same time as the photoreceptor 11 rotates. This is because the rotation of the photoreceptor 11 and the lighting of the charger 12, which is an ozone generation source, are generally synchronized.

Further, the timing for stopping the ozone blowing fan 46 is set 8 to 10 seconds after the photoreceptor 11 stops.

When the photoreceptor 11 stops, the discharge from the charger 12 also stops, but if the ozone blowing fan 46 is also stopped at the same time, the ozone accumulated around the photoreceptor 11 cannot be sufficiently blown away.

Therefore, the fan 46 is continuously rotated for 8 to 10 seconds to ensure that the ozone is blown away. Note that the period of 8 to 10 seconds is for the structure of the embodiment, and if the structure is different, the appropriate time is set accordingly.

In FIG. 3, a suction fan unit 49 is provided to the left of the ozone blower fan 46. As shown in FIG. 15, the suction fan unit 49 includes a suction fan 50 and an ozone filter 52 supported by a holder 51 fixed to the casing of the suction fan 50. When the suction fan 50 rotates, ozone blown off from the photoreceptor 11 by the ozone blowing fan 46 is attracted to the suction fan 50 and discharged to the outside of the machine via the ozone filter 52. In this way, ozone does not accumulate inside the printer, and since it passes through the ozone filter 52,
Ozone is not released to the outside.

As shown in FIG. 16, the filter holder 51 is made of a thin metal material, and a holding piece 53 is formed on one side thereof. The filter 52 is formed into a cylindrical shape by winding a corrugated paper tape in a spiral shape and fixing the outermost surface with adhesive tape, and the paper used as the material is impregnated with carbon. The holding piece 53 of the holder 51 is indicated by the arrow C.
It can be manually pushed outward as shown, and from the pushed out state it elastically returns inward as shown by the arrow. When attaching the filter 52 to the holder 51, first push the holding pieces 53 apart to press the filter 52 against the holder 51, and then return the holding pieces 53 in the direction D. As a result, the filter 52 is attached to the holding pieces 53 and the frame. It is held and fixed in position by the portion 47b. Since no special fixing tools are required, the cost is low and attachment/detachment work is easy.

In FIG. 12, a large number of air holes 123 are formed in the paper conveyance rib 124 of the lower frame 78 (details will be described later), and in FIG. is opened (details will be explained later). Therefore, when the suction fan 50 rotates, these holes 1
Outside air flows into the fixing device such as the fixing roller 36 and the toner recovery tank 57 via the fixing rollers 23 and 125, and is then discharged to the outside from the suction fan 50. Therefore, the fixing device and tank 57 are efficiently cooled.

The purpose of cooling the fixing device is to prevent the fixing device itself and other devices around it from overheating. Toner collection tank 5
The purpose of cooling the tank 7 is to prevent the waste toner in the tank 57 from melting and sticking due to heat.

In order to improve cooling efficiency, it is desirable to provide an appropriate space between the image forming unit case 60 and the fixing device in FIG. 3. Cooling is efficiently performed by air flowing through this space. The suction fan 50 also serves to cool the fixing device and the like, so unlike the ozone blower fan 46, it is constantly rotated.

Each component of the printer case and printer is surrounded by a cover 8 and a lower frame 78. Each of these uses 1 glass fiber.
It is integrally molded with a synthetic resin 1 containing 0 to 20%, such as Noryl (trade name). In particular, lower frame 7
8 is a transfer paper conveyance path as shown in Fig. 12 (see Fig. 3).
It has a large number of ribs 124 arranged in parallel in a direction perpendicular to the paper conveyance direction. These ribs are also made by integral molding. Further, among these ribs, the one located below the toner recovery tank 57 of the photoreceptor unit 58 is provided with the above-mentioned large number of air holes 123. Note that the paper discharge guide plate 44 in FIG. 3 is also integrally molded with the lower frame 78.

The paper discharge guide member 42 is fixed to the side surface 47c of the upper unit frame 47 as shown in FIG.

This paper ejection guide member 42 is also molded from synthetic resin.
Also, the many air holes 125 mentioned above are provided at the bottom.

The paper discharge guide plate 43 shown in FIG. 3 is integrally molded with the upper cover 8.

As shown in FIG. 17, drive rollers 45a and 40a of the upper paper discharge roller 45 and the lower paper discharge roller 4o are detachably and rotatably supported on the upper and lower sides of the paper discharge guide member 42, respectively, and have nine roller shafts. 126. It is a rubber shaft fitted in a predetermined position on 127. A gear 128 is fixed to the shaft end of the lower roller shaft 127, and this gear meshes with the paper discharge roller drive gear 1oO (see FIG. 18). This drive gear 100 is supported by an arm 129 rotatably attached to a lower roller shaft 127, and a compression spring 130 is further attached to this arm.

As mentioned above, the paper ejection guide member 42 is attached to the upper unit frame 47 (FIG. 13) of the printer upper unit 1, but when the printer upper unit 1 is closed with the paper ejection guide member 42 attached, the paper ejection roller Drive gear 10
0 meshes with the heating roller driving gear 99 shown in FIG. 18. At this time, the spring 130 is compressed by a predetermined amount, and the pressure necessary for transmitting the driving force is applied between the gears 100 and 99. Thus, when the main motor 92 rotates, the lower roller shaft 127 rotates, and the drive sheet discharge roller 40a rotates.

The lower roller shaft 127 and the upper roller shaft 126 are connected to pulleys 131, 131 and a belt 132 that is passed between them.
, and thus the lower drive roller 40
When a rotates, the upper drive roller 45a also rotates at the same time.

The paper discharge drive rollers 40a and 45a are in pressure contact with driven rollers 40b and 45b, respectively, as shown in FIG. In this embodiment, the driven rollers 40b and 45b are connected to the lower frame 78 by a holder 133 made of spring material, as shown in FIG.
Alternatively, it is fixed to the cover 8. Drive port -ra 40
When the driven rollers 40b, 45bL are pressed against each other, the arm 136 of the holder 133 is bent to generate a spring force, which generates the pressing force necessary to drive the paper.

A slot 134 is formed in the fixing portion of the holder 133, and the holder 133 is fixed to the lower frame 78 or the like by press-fitting the slot 134 into a pin 135 protruding from the lower frame 78 or the cover 8. No fasteners such as screws are required. Further, the driven rollers 40b and 45b are supported by inserting their support shafts into the curved end portion of the arm 136.

Incidentally, it is preferable that the upper and lower roller shafts 126 and 127 be molded from non-conductive synthetic resin. This is because there is no need for grounding. Further, it is preferable that the details of the locations where the rubber shafts as the paper ejection rollers 40a and 45a are provided have a step with respect to other shaft portions.
This is to prevent the rubber shaft from shifting.

In FIG. 17, a paper feed ring 137 is lightly press-fitted approximately in the center of the upper roller shaft 126. This ring has small projections 138 on its outer periphery, as shown in FIG. This small protrusion.

This is to push out the rear end of the transfer paper discharged to the upper paper discharge tray 9 (FIG. 3) to improve the stackability of the primary discharge paper.

The relationship between the paper discharge switching claw 41 (FIG. 3) and the paper discharge switching knob 4 (FIG. 2) for switching the paper discharge path is as follows. In FIG. 21, the paper discharge switching claw 41 and the paper discharge switching knob 4 are connected by a shaft 140. As shown in FIG. This ll1140
A cam 141 having two recesses is fixed in the middle (of course, inside the lower frame 78). The concave portion of the cam 141 fits into the convex portion of a locking member 142 that is fixed to the lower frame 78 and is formed of a spring material. In this fitted state, the rotation of the cam 141, that is, the rotation of the switching pawl 41, is restricted.

When the knob 4 is turned in the direction of arrow F from the illustrated state, the locking member 142 is once pushed and bent, and when the upper concave portion of the cam 141 is brought to the convex portion of the locking member 142, the two are fitted again. Fixed position. The upper recessed portion and lower recessed portion of the cam 141 correspond to the solid line position and the broken line position of the switching pawl 41 in FIG. 3, respectively.

The size of the concave portion of the cam 141 (for example, the radius of curvature) is preferably smaller than the size of the convex portion of the locking member 142, since the position can be securely fixed.

As described above, the printer upper unit 1 can be lifted and rotated from the printer lower unit 2.

This rotation is performed by rotating the upper unit frame 47 of the upper printer unit 1 about a hinge pin 238 fixed to the lower frame 78 of the lower printer unit 2, as shown in FIG. When lifting the upper unit 1, there are cases where it is not necessary to lift it at such a large angle, such as when removing jammed paper or performing simple maintenance work. In consideration of such a case, a stop pin 246 is arranged inside the lower frame 78 on the back side of the hinge pin 238 (on the right side in the figure), and when the bracket 247 of the upper frame 47 hits this stop pin 246, It is convenient if the rotation of the upper frame 47 is restricted.

Further, the stop pin 246 is made removable from the lower frame 78, and when it is necessary to lift up the printer upper unit 1 greatly, such as when replacing the photoconductor unit 58 and the developing unit 59, the stop pin 246 can be removed from the lower frame 78.
46 from the lower frame 78 so that the upper frame 47 can be lifted up to a substantially right angle as shown by the chain line.

By adopting such a two-stage rotation structure, convenience for the operator can be achieved.

UPPER UNIT LOCK STRUCTURE In FIG. 2, when the printer upper unit 1 is closed from the open position shown in the figure as shown by arrow G, the printer becomes in the state shown in FIG. 3 and is ready to print.

However, when actually printing, it is necessary to lock the upper and lower units 1 and 2 in this state. The mechanism for this will be explained below.

In FIG. 13, the front surface 47a of the upper unit frame 47
Lever support brackets 143, 143 and lever press plates 144, 144 are provided by integral resin molding. The lever support brackets 143, 143 support support shafts 146, 146 at both ends of the lock lever 145. At this time, the upper side of the support shaft 146, 146 is
4 is pressed downward. Since the presser foot Fi 144 is made of resin and has flexibility, when inserting the support 0146 into the bracket 143, the insertion operation is performed while pushing the -2 presser plate 144 upwardly. Support shaft 146
When the locking plate 144 enters the recessed portion of the bracket 143, the holding plate 144 automatically moves downward and holds the entire lock/<-145. In order to facilitate the assembly of the lock lever 145 to the upper unit frame 47, the support shaft 146 may be provided with an axial slot.

At this time, the lock lever 145 is rotatable about the support shaft 146, but since spring members 147, 147 are attached in advance to the upper part of the lock lever 145 so as to protrude toward the frame 47, The lock lever 145 attached to the lock lever 145 is urged to rotate in the direction of arrow H.

The spring material 147 may be a leaf spring, or may be integrally molded with the entire lock lever 145 from a resilient resin.

Lock claws 1 are provided at the bottom of both ends of the lock lever 145.
48 and 148 are integrally formed. 12th
As shown in the figure, hooks 149, 149 are integrally formed at positions corresponding to the lock claws 148 on the lower frame 78.

When the printer upper unit 1 is closed, the lock pawl 148 of the lock lever 145 is moved to the hook 1 by the action of the spring material 147.
49, and the upper unit 1 is locked, that is, fixed. When lifting the printer upper unit 1, first grasp the lock lever knob 10 and rotate it upward against the spring force of the spring member 147. Then, the lock pawl 148 and the hook 149 are disengaged, and the printer upper unit 1 can be lifted without any trouble. The lock lever knob 10 projects outward from an opening 248 provided on the front surface of the cover 8.

Conventionally, when creating such a locking mechanism, a composite structure was often used, in which a knob, pawl, etc. were attached to a metal shaft. In contrast, this embodiment has an integral resin structure, so it is lightweight and easy to manufacture. Also, grounding is not required. The stopper 312 is integrally formed with the entire lock lever 145, and protrudes toward the case 47 like the spring member 147. This is the lock lever
This is to limit the rotation of the lock lever 145 to a certain amount in order to prevent the spring material 147 from weakening due to excessive rotation of the lock lever 145.

Below the support brackets 143, 143, positioning protrusions 150, 150 in the paper transport direction and positioning protrusions 151 in the photoconductor axis direction are provided. ．． 131 is integrally molded with the frame 47. Of these protrusions, one set on the right side in Fig. 13 engages with the hook 149 on the right side in Fig. 12, and the manner of engagement is shown in Fig. 22. By engaging with the hook 149, it is possible to reliably prevent the upper unit frame 47 from shifting in the photoreceptor axial direction (laser main scanning direction) and paper conveyance direction (laser sub-scanning direction).

The general operation of the laser optical device 14 (FIG. 3) has been explained using an example in FIGS. 5 and 6. In this example, in order to maintain the optical path of the laser beam in a normal state, the first mirror 19 and the third mirror 23 are connected to the case 1.
55 must be fixed exactly vertically.

'In this actual flow example, as shown in Fig. 23, case 155 (
The first mirror 19 and the like are fixed by a support portion 156 integrally molded with the mirror (FIG. 5) and a presser plate 157 made of a spring material. In this case, the surface 156a of the support portion 156 against which the first mirror 19 is pressed is precisely finished precisely.

The mirror 19 is pressed against this vertical surface 156a, and the mirror 19 is pressed against the vertical surface 156a from behind by the arms 157a, 157a of the presser plate 157. Presser plate 15
When the holding plate 157 is screwed into a predetermined position of the case 155 through the hole 158, the arm 157a of No. 7 presses the mirror 19 by bending and deforming. At this time, the arm 157a is provided in advance with small protrusions 159, 159 that protrude toward the mirror 19, so that the mirror 19 is suppressed at two points via these small protrusions. Due to this two-point suppression, the mirror 19 is
6a ensures reliable positioning.

The second cylindrical lens 22, which is briefly shown in FIGS. 3 and 6, has an overall shape as shown in the lower position of FIG. 13. This is made entirely of resin together with the lens part. This cylindrical lens 22 can be inserted into a predetermined position in the upper unit frame 47 shown in FIG. 3 through an opening 249 provided in the front surface 47a of the upper unit frame 47, and can be pulled out from there. Cylindrical lens 2 inserted in a predetermined position
2 acts as an optical lens and optical device 14
It also acts as a sealing member to prevent toner and other dust from entering the inside. Therefore, it is desirable that the fitting between the cylindrical lens 22 and the corresponding portion of the upper unit frame 47 be as airtight as possible.

(The following is a blank space) An example of a means for attaching the second cylindrical lens 22 is as follows. As shown in FIG. 33, the second cylindrical lens 22 is arranged inside two parallel side walls 304, 304 that define the hole 303 of the upper unit frame 47. As shown in FIG. Upper and lower support parts 305 and 306 that slidably guide the respective side edges 22b and 22b in the longitudinal direction of the second cylindrical lens 22 are provided on both sides of each side wall 304 integrally formed with the upper unit frame 47. The second cylindrical lens 22 is molded integrally with the frame 47, and the second cylindrical lens 22 is
It is supported while being sandwiched between 06.

The upper and lower support portions 305 and 306 of each side wall 304 are arranged in a staggered pattern, but this is to make it easier to cut out the mold when molding the upper unit frame 47. For example, the support portion may be formed in an appropriate shape, such as a parallel guide rail shape.

When the second cylindrical lens 22 is set, the third
As shown in FIG. 4, an elastic piece 308 integrally molded on the upper unit frame 47 engages with both locking portions 307, 307 formed at the tip of the second cylindrical lens, so that the second cylindrical lens 22 Extraction is prevented. In addition, the regulating piece 310 protruding from the second cylindrical lens 22 comes into contact with the stopper 309 that is integrally bridged with the both side walls 304, and prevents the second cylindrical lens 22 from being pushed deeper than the predetermined setting position. Ru.

For cleaning or replacing the second cylindrical lens 22,
To pull it out, just grab the knob 22a and pull it in the direction of arrow T. As a result, both elastic pieces 308 are elastically expanded by the bulge 311 at the tip of the second cylindrical lens 22, and the second cylindrical lens 22 is pulled out through the opening 249 of the upper unit frame 47.

The knob 22a, like the lock lever knob 1o, is exposed to the outside through the opening 248 of the cover 8 when the second cylindrical lens 22 is mounted in a predetermined position. Since the opening 248 can be shared in this way, the appearance is not impaired and workability is also good.

A beam shutter 258 provided on the right side of the ozone fan 46 in FIG. 3 is rotatable about a pin 259. When the upper and lower units 1 and 2 are closed as shown in FIG. 3, this beam shutter 258 is pushed up and rotated by the protrusion 250 (FIG. 4(a)) on the photoreceptor unit 58, and the laser beam is irradiated. Mouth 251 is open.

When the upper printer unit 1 is lifted, the engagement between the protrusion 250 and the beam shutter 258 is released, and the beam shutter rotates to the right to close the laser beam irradiation port 251.

In this embodiment, when the printer upper unit 1 is lifted up, the power supply to the laser optical device 14 is cut off and the laser beam is not irradiated due to the action of an interlock switch, which will be described later. The beam shutter 258 is provided in consideration of malfunctions to ensure safety.

Further, rubber,
A shielding member 252 made of an elastic material such as sponge is fixed (see Fig. 2). When the upper and lower units 1 and 2 are closed, the lower end of the shielding member 252 is attached to the lower printer unit as shown in Fig. 3. Developing unit 58 in 2 (Fig. 4)
(see a)), and thus the area around the laser irradiation port 251 is sealed by this shielding member. As a result, the laser optical system S! This prevents toner and other dust from entering the inside 14, leakage of laser light, and light from outside.

The second paper feed tray 3 is detachable from the printer lower unit 2. As can be seen from FIG. 1, this paper feed tray 3 has a portion 153 provided with a pressing lever 152 that protrudes downward, so the bottom is not flat. If the tray 3 is left unattended, the rear part of the tray 3 may fall downward like a seesaw, and the transfer paper may slide backward. In order to prevent this, it is preferable to provide a protrusion 154 on the rear bottom surface of the protrusion 153 as shown in FIG. 3.

The seating of the paper feed tray 3 is improved and paper slippage is eliminated.

A manual feed guide plate 255 is attached to the upper part of the paper feed tray 3, and the transfer material can be manually fed from above this manual feed guide plate 255 (
Figure 3 arrow M). If plain paper transfer paper is loaded on the paper feed tray 3 and envelopes are manually fed from the manual feed guide plate 255, printing of letters and addresses on envelopes should be performed alternately one set at a time. You can also do it.

Further, in the printer according to this embodiment, a paper feed unit 266 can be detachably connected to the lower part of the printer lower unit 2, as shown in FIG.

A preliminary paper feed tray 267 is included in this paper feed unit 266.
A plurality of transfer papers 268 are stacked on the tray 267. These transfer sheets 268 are fed into the lower printer unit 2 one by one in the direction of arrow N by a feed roller 269 and a conveyance roller 270.

The fed transfer paper undergoes the printing process described above in the same way as the transfer paper 31 on the paper feed tray 3.

Whether paper is to be fed from the paper feed tray 3 or the preliminary paper feed tray 267 is determined by providing a selection switch on the operation panel 5 or by an instruction from the host computer. It will be done.

As can be seen from the figure, the paper transport distance from the sketch paper tray 267 to the upper and lower transport rollers 34, 35 in the printer lower unit 2 is the same as that of the paper feed tray 3.
On the other hand, in order to execute the printing process, the time required for the transfer paper from both paper feed trays 3 and 267 to reach the upper and lower transport rollers 34 and 35 is equal. There must be. Therefore, the preliminary paper feed roller 269 of the embodiment feeds the transfer paper 26 at a faster feeding speed than the paper feed roller 32 in the printer lower unit 2.
7 is sent out.

After printing is completed, the transfer sheets are discharged to the upper paper discharge tray 9 and stacked. The deeper the upper paper ejection tray 9, the height h from the upper paper ejection tray 9 to the upper paper ejection roller 45.
The higher the value, the more sheets of transfer paper can be stacked. However, if this depth is too deep, the stacked transfer papers will be disturbed and the printer as a whole will become unnecessarily large. Therefore, depending on the depth, there is a limit to the number of transfer paper stacks.

However, in the case of the above-mentioned embodiment using the preliminary paper feed tray 267, it is conceivable that the number of transfer sheets to be stacked on the upper paper discharge tray 9 increases significantly.

For this reason, it is convenient to adopt the following configuration.

As shown in FIG. 30, the printer's upper and lower units 1,
A paper discharge unit 271 is attached to the left side of 2. This paper ejection unit 271 includes a main body case 272 and a pin 2 attached thereto.
73, and a cover 274 which is rotatably supported in the direction of arrow P. Cover 274 is normally held in the vertical position shown in FIG. 30 by a locking device, not shown. The cover 274 and main case 272 are provided with a plurality of ribs 275, 276, and 277 arranged at intervals in the direction perpendicular to the plane of the paper in FIG. 30, and these ribs form a transfer paper discharge path 278. The main body case 272 supports transport rollers 279, 280 and a paper discharge roller 281, and the transfer paper is transported and discharged by each of these rollers.

When conveying the transfer paper through the paper discharge unit 271, the paper discharge switching claw 41 is switched to the position shown by the broken line. As a result, the transfer paper sent out from the paper ejection roller 40 is transferred to the transport roller 279.
The paper is sent to the paper discharge unit 271 via the paper.

The height H from the paper ejection tray 9 to the paper ejection roller 281 of the paper ejection unit 272 is higher than the height h from the upper paper ejection roller 45 (H>h). If the transfer paper is ejected from the paper ejection unit 271, it is possible to stack more transfer paper. In this case, as a paper ejection method, the upper paper ejection roller of the printer upper unit 4
5 is used to eject the paper, and the transfer paper is then ejected using the paper ejection roller 4.
When the paper is stacked to the height of 5, the paper output unit 2
The paper ejection roller 281 of 71 is started to eject the paper. In this way, the situation where the transfer paper discharged from the paper discharge unit 271 falls to a deep position can be avoided, and irregularities will not occur in the stacked transfer paper.

In some cases, only the paper ejection roller 281 of the paper ejection unit 271 or only the upper paper ejection roller 45 of the printer upper unit 1 may be used. Further, these paper ejection rollers 281 and 45 can also be used alternately.

The printer upper unit 1 in the embodiment is the printer lower unit 2.
It is lifted and rotated. However, as shown in FIG. 30, the upper part of the paper ejection unit 271 is
If it is located above the paper output unit 2,
The printer upper unit 1 cannot be lifted up because the 71 becomes an obstacle. Therefore, in the illustrated example, the paper ejection unit 271 is supported by the paper feed unit 266 (which may be the printer lower unit 2) via the bin 282 so as to be rotatable in the direction of the arrow Q. When opening and closing the printer upper unit 1, a paper discharge unit 271 is rotated in the Q direction with respect to the upper and lower units 1°2, and is retracted to a position where it does not interfere with the opening and closing of the printer upper unit 1. In addition, the paper ejection unit 27
1 can be configured to be detachable from the paper feed unit 266 or the like, so that it can be removed when the printer upper unit 1 is opened or closed.

When the transfer paper jams in the paper discharge path 278 of the paper discharge unit 271, the cover 274 is rotated in the P direction about the pin 273 and moved to the position shown in FIG. 31. This exposes the paper discharge path 278 to the outside, so that jammed paper can be easily removed.

A preliminary switching pawl 283 is provided at a downstream position of the lower conveyance roller 279. This switching pawl 283 is switched between the position shown in FIG. 30 and the position shown in FIG. 31. When the preliminary switching claw 283 is in the position shown in FIG. 30, the paper is ejected to the upper paper ejection tray 9 described above. On the other hand, the preliminary switching claw 28
3 is in the position shown in FIG. 31, the transfer paper is discharged onto the cover 274 from the lower conveyance roller 279. This paper ejection mode is adopted when it is not desired to eject the transfer paper in reverse. Since the cover 274 itself can also be used as a paper discharge tray, the number of parts can be reduced.

Further, it is advantageous if the preliminary switching claw 283 is configured to perform switching operation in conjunction with the opening and closing of the cover 274, since the operation becomes simple. For example, a switch (not shown) that turns on and off as the cover 274 is opened and closed is provided, and when the cover 274 is opened to the position shown in FIG. 31, this switch is turned on, thereby causing a motor (not shown) to Activate a drive device such as a solenoid to move the preliminary switching pawl 283 to the third position.
When operating from the position shown in Figure 0 to the position shown in Figure 31, and conversely closing the cover 274, the preliminary switching pawl 283 is returned to the position shown in Figure 1 by the operation of the drive device.

There is also the following method. As shown in FIGS. 3o and 31, a cam member 284 is fixed to the cover 274, and when the cover 274 is closed, the preliminary switching pawl 283 is held in the position shown in FIG. 30 by the action of a toggle spring 285. When the cover 274 is opened, a cam member 284 integrated with the cover 274 comes into contact with the preliminary switching pawl 283, pressurizes it, and rotates it to the position shown in FIG. 31. The preliminary switching pawl 283 is held in this state by a toggle spring 285.

The paper ejection roller 281 of the paper ejection unit 271 can be constructed in the same manner as the paper ejection rollers 40 and 45 in the upper and lower printer units 1 and 2, as shown in FIG. Moreover, it is even more convenient to do as shown in FIG.

In the figure, the paper discharge roller 281 is composed of a drive roller 286 and a driven roller 287, and the drive roller 286 is rotationally driven via a driven gear 289 fixed to a support shaft 288 thereof and a drive gear 290 that meshes with the driven gear 289. A connecting member 291 is mounted on the support shaft 288 so as to be rotatable but not slidable in the axial direction. A nut 292 is provided at the other end of the connecting member 291, and this nut 292 connects the reversible motor 2.
It is engaged with a feed screw 294 rotationally driven by 93.

It is assumed that the position of the transfer paper when the transfer paper is discharged to the upper paper discharge tray 9 with the motor 293 stopped is the position shown by the chain line in FIG. After stacking several sheets of transfer paper in this state, the motor 293 is activated and the feed screw 294
Rotate. Then, the nut 292 connects to the feed screw 294.
, and the drive roller 286 accordingly moves in the same direction, so that the rollers 286 and 287
The transfer paper sandwiched between is shifted (shifted) by δ as shown by the broken line.

The transfer paper shifted by δ in this way is transferred to the upper paper output tray 9.
If the paper is ejected to the tray 9, it can be distinguished from the group of transfer sheets that have been ejected onto the tray 9 before. In other words, a plurality of transfer papers can be divided into several bundles.

Actually, as shown in FIG. 30, a sensor 295 is provided upstream of the paper ejection roller 281, and when an external signal to shift the transfer paper is input to the main controller (described later), the sensor 295 detects the transfer paper. When the rear end is detected, the motor 293 is operated based on the detection signal to shift the drive roller 286.

In FIG. 24, 160 is a power input section, which is connected to a commercial power source via an AC plug 161. In FIG.

This includes a main switch 162 and a noise filter 16.
3 is included. The power input section 160 is arranged at the back side of the lower frame 78, as shown in FIG. The main switch 162 penetrates the side wall of the lower frame 78 to the outside, and can be operated by an operator from the outside. Noise filter 163 removes external noise from the supplied power.

One side of power from the power supply input unit 160 is supplied to the main controller power supply unit (main PS'U) 165 via an interlock switch 164, and the other side is supplied to the character controller power supply unit (character PSU).
) 166.

The main PSUI 65 is located on the left side of the upper unit frame 47 as shown in FIG.
SR) 169. The constant voltage circuit 168 is mainly A
Perform C/DC conversion.

5SR169 turns on and off the power supply for controlling the temperature of the heater 38 (FIG. 3) in the heating roller 36. As can be seen from FIG. 3, a thermistor 235 for temperature control is attached to the heater 38, but this thermistor 235 is used when a minimum width transfer material such as an envelope is used as the transfer material.
It is arranged at an upper position corresponding to the conveyance path of the minimum width transfer material.

The reason for this is that envelopes are generally made by gluing, so if the fixing temperature is too high, the glue will melt, causing problems. Therefore, the purpose is to arrange the thermistor 235 closest to the position where the minimum width transfer material such as an envelope will pass, thereby enabling accurate heater temperature control.

The interlock switch] 64 is disposed on the front right side of the lower frame 78, as shown in FIG. 12, and is normally off, but turns on when pressed downward. When the printer is assembled, a resin inner cover 170 is attached to the right end of the lower frame 78. Thereby, the interlock switch 164 is covered by the switch cover 171 of the inner cover 170. A cross-shaped hole 172 is formed in the switch cover 171.

Although a human finger cannot enter this cross recess, a suppressor 17 of an appropriately shaped shape is provided in a corresponding part of the upper unit 1 of the printer.
3 (Figure 2) is large enough to fit inside. Therefore, as shown in Fig. 2, the printer upper unit 1
When the is lifted, interlock switch 16
4 is off and power is not being supplied to the main PSU,
When the upper unit 1 is closed, the interlock switch 164 is turned on by the suppressor 173, and power is supplied. The cross recess 172 is designed so that a person's finger cannot pass through it to prevent the interlock switch 164 from being accidentally turned on when the upper unit 1 is opened. As described above, when the interlock switch 164 is turned off, the power supply to the laser optical device 14 is cut off and the laser beam irradiation is interrupted.

When the inner cover 170 is attached, it covers the paper feed roller 32, as shown in FIG. This prevents dust and the like from being attached to the paper feed roller 32, and furthermore prevents the paper feed roller 32 from being attached to the paper feed roller 32 when the upper unit 1 is lifted.
will be protected.

The character PSU 166 is disposed on the right back side of the upper unit frame 47 in FIG. 13, and a noise tweeter 174 and a constant voltage circuit 175 are provided inside thereof as shown in FIG. 24.

The main PSU 165 drives the main controller 176, the charging charger 12 and the power back for developing bias (charging/developing PP) 177, the power back for the transfer charger 30 (transfer PP) 178, the main motor 92, various operating devices 179, and the like. It also drives fans such as the ozone fan 46 and the suction fan 5o, and the fixing unit heater 38. Character PSU 166 drives character controller 180.

The charging/developing PP 177 is disposed on the back side of the upper unit frame 47 as shown in FIG. On the other hand, this charging
Charger 12 driven by developer PP 177
The developing roller 26 and the developing roller 26 are arranged in the printer lower unit 2 together with the photoreceptor unit 58 and the developing unit 59, respectively, as described above in connection with FIG. 3 or FIG. In order to electrically connect the units disposed across both units 1 and 2, the following configuration is adopted.

First, a terminal 195 is provided on the charger 12 as shown in FIG. 4(a), and a terminal 196 is provided on the shaft end of the developing roller 26 as shown in FIG. In correspondence with these terminals, power supply terminals 197 and 198 of the charging/developing PPI 77 protrude from the bottom surface of the printer upper unit 1 (ie, the bottom surface of the upper unit frame 47) (FIG. 2). Power terminals 197 and 198 are the 25th
As shown in the figure, a circular recess 200 provided with a claw portion 199;
The spring terminal 201 is housed in the recess in a state where a preload is generated in advance. When the upper and lower units 1 and 2 are closed, the terminals 195 and 196 of the 1F electric charger enter into the spring from the lower end of the spring terminal 201, and the spring terminals 201 are wrapped around the terminals 195 and 196. are connected, and high voltage is applied to the terminals 195 and 196.

Since the spring terminal 201 has a shape that widens toward the lower end, the terminals 195 and 196 can enter without fail. Further, the contact between the spring terminal and the terminals 195, 196 is also good. Furthermore, since the spring terminal 201 is preloaded by the claw portion 199, there is no contact failure.

The transfer PP 178 is attached to the lower frame 78 as shown in FIG.
It is fixed adjacent to the paper transport rib 124 of , and therefore to the right of the transfer charger 30 in FIG. The high voltage terminal from the transfer PP is configured as a spring terminal 202 as shown in FIG.
A high voltage is applied to the charge wire 205 connected to 3. The casing 206 of the transfer charger 30 is grounded by an integral spring terminal 207 having two spring parts 207a and 207b.

As is clear from FIG. 3, an image forming unit case 60 is placed above the transfer charger 30.

As shown in FIG. 26, spacer members 208, 2.08 are provided at the top of both ends of the transfer charger 3o, and the transfer charger 30 is connected to the image forming unit case 6o by spring terminals 202 and 207a via these spacer members 208. is pressed from below. Spacer member 208
is integrally molded with resin together with the end block 204, and its height can be accurately determined. Therefore, the transfer charger 30
The distance between the image forming unit case 60 and the image forming unit case 60 is always maintained reliably by the height of the spacer member 208. This allows constant transfer work to be performed at all times.

The main controller 176 is connected to an electrical chassis 181 in the printer unit 1 as shown in FIGS. 13 and 3.
The character controller 180, which controls the overall printer process such as charging, exposure, development, and transfer, as described in connection with FIG. 3, is attached to the electrical chassis 181 in the same way as the main controller 176. host computer 182 (
Figure 24) to Centronics interface (S)
Alternatively, character information sent via the R3232C(R) is sent to the CPU 184 via the interface 183, where a character signal corresponding to the character information is formed. At this time, the font cartridge 18 inserted into the font cartridge insertion slot 6 shown in FIG.
As described above, the font is formed in accordance with the content of 5.

Information from the host computer 182 is typically transmitted to the character controller 180 via an interface cable.
The data is transmitted to the main controller 176 (in some cases, the main controller 176). In this embodiment, as shown in FIG. 13, a connector 253 is provided on the system controller 180 attached to the electrical chassis 181 in the printer unit 1, and the interface cable is directly connected to the character controller 180 via this connector. There is. Since the interface cable is not routed inside the printer, there is no need to worry about noise entering the information from the host computer and causing printing defects.

The main controller 176 includes a CPU 186, a phase synchronization section 187 composed of a gate array, a display drive section 188,
Scanner synchronization detection section 189, scanner motor driver 1
90 and a video interface section 191.

The display drive section 188 drives the operation panel 5. In this embodiment, as shown in FIG. 1, the operation panel 5 displays the size of the transfer paper placed on the paper feed tray 3.
Rotary type switch 19 that instructs PU 186
2. A button switch group 193 for issuing various instructions to the character controller 180 and an LED group 194 for various displays are provided. This operation panel 5
As shown in FIG. 13, it is attached to the front surface of the electrical equipment chassis 181 in a transparent manner and is exposed to the outside through the opening 2.9 of the cover 8. If the installation position of the operation panel 5 on the chassis 181 is made variable, and the opening 209 of the cover 8 is opened in another location accordingly, the operation panel 5 can be freely moved and the operation surface can be changed. can be changed. In this case, it is convenient to cover the separate opening 209 with a cap.

The button switch group 193 includes the following switches.

(Font Selection Switch) As mentioned above, a font cartridge (ROM) storing several types of fonts is inserted into the font cartridge insertion slot 6. The font selection switch is operated when selecting a desired font from among these.

(Line on/off switch) This is used to turn on/off information transmission from the host computer 182 to the character controller 180. When the line is turned on, information is transmitted. When line-off occurs, information transmission begins. By providing line-off, it is possible to prevent information from the host computer from being input when the printer performs test printing or when replacing font cartridges, emulation cards, etc.

(Left below) The phase synchronization unit 187 synchronizes the laser optical device 14 with the print process executed by the CPU 186.
drives the laser diode LD inside. Furthermore, the synchronization detection laser beam (described above) is received from the optical fiber 25 via the synchronization detection section 189 to control the light emission timing of the LD. Control phase.

The video interface section 191 exchanges image information and control data with the character controller 180, and also transmits a clock signal that serves as a reference for control to the character controller 180.

Inside the main controller 176, there are two voltage converters 2 consisting of a three-terminal regulator, a DC/DC converter, etc.
10 and 211 are provided, and voltages of +24V, +12V, +5V, and -12V are generated by these voltage converters. These voltages control the drive motors, solenoids, laser diodes, polygon motors, etc. of each device, and also drive each logic circuit. The reason why the control voltage is specially created in the main controller 176 in this way is to perform control using a clean power source with little urine flow. As a result, the printing process such as light emission of the laser diode, rotation of the polygon mirror, etc. is executed without malfunction, and a printed product with good print quality can be obtained.

The option interface 300 is connected to the paper feed unit 2
66 (Fig. 30), the paper feed unit 2
This is used to instruct the timing of starting and stopping the paper feed roller 269 in the paper feed roller 66.

Power supply unit is main PStJ165 and character PSU
The reason for dividing into 166 parts is as follows.

- Since the interlock switch 164 is provided, when the printer upper unit 1 is lifted, the power supply from the power input section 160 is automatically stopped.

In this case, the CPU 18 of the character controller 180
It would be bad if the memory contents of 4 were also erased at the same time. Therefore, a separate power supply section was provided for the character controller.

■ Depending on the printer, the character controller 180
In some cases, the character PSU 166 is not required as an interior, but as an exterior, and in this case, the character PSU 166 is made separately.

The various operating devices 179 shown in FIG. 24 will be described in detail as follows. The paper feed clutch 212 controls the rotation of the paper feed roller 32. Paper transport latch 213 controls rotation of lower transport roller 35 . The total counter solenoid 214 counts up a total counter 215 (located at the back right of the lower frame 78 in FIG. 12 and visible through the window 216 of the inner cover 170) that displays the number of prints. In this embodiment, each time the transfer charger is turned on during the print process by the CPU 186 of the main controller 176, the solenoid 214 is activated and the count is incremented by 1 based on 6 transfer operations. The reason for this is to ensure that the number of printed products corresponds accurately to the count value on a one-to-one basis.

If some step prior to the transfer operation in the printing process is used as a reference, when the transfer paper is removed midway due to a jam or the like, the number of printed products and the count value will not correspond one-to-one.

The latching solenoid 217 is assembled as one component of the suction fan unit 49 in FIG.
The action itself is not directly related to the suction fan 50), and the detailed action will be described later.

In FIG. 24, the CPU of the main controller 176
Input device 21 that sends a signal serving as a reference for the process to 186
8, a registration sensor 219, a paper discharge sensor 220,
Toner over sensor 221°Paper end sensor 2
22, a latch sensor 223, and a toner end sensor 224 are provided.

The registration sensor 219 is connected to the conveyance roller 34 in FIG.
．． It is located on the right side of 35. The lower conveyance roller 35 is activated based on the timing when the transfer paper passes the registration sensor.
The starting timing is determined.

The paper discharge sensor 220 is arranged at a downstream position of the fixing device in FIG.

The toner over-sensor 221 is arranged above the detection filler 225 provided at the top of the toner recovery tank 57 in FIG. is accumulated in the toner collection tank 57, and when it becomes full, the detection filler 225 is lifted upward by the waste toner and is detected by the toner over-sensor 221.

The vapor end sensor 222 is arranged on the right side of the paper feed roller 32 in FIG. 3, that is, above the tip of the paper feed tray 3. When there is no transfer paper on the tray 3, it is detected.

Latch sensor 223 is located above latching solenoid 217 in FIG. The solenoid 217
It turns off when the optical path is blocked by the plunger.

The toner end sensor 224 is a microswitch located at the bottom of the printer upper unit 1, above the cam mechanism 226 provided at one end of the developing unit 59, as shown in FIG. Figure 2). The cam mechanism 226 includes a toner stirring member 227 (
It has a cam 228 mounted on the rotating shaft (FIG. 2) and a lever 230 that comes into contact with the outer peripheral surface of the cam 228 and swings about a pin 229. The lever 230 is the spring 23
1 against the cam 228.

In FIG. 3, the toner stirring member 227 is connected to the developing tank 2.
Stir the toner in 8. The cam 228 consists of two cam plates each having a concave portion (details are not shown), and when the stirring resistance of the stirring member 227 is large (when there is a sufficient amount of toner), the concave portions of the two cam plates are different from each other. and
L//<-230, which is in contact with it, is always lifted upward and turns on the toner end sensor 224. When the agitation resistance decreases (when the toner runs out), one of the cam plates rotates out of alignment, and the concave parts of both cam plates overlap.
The lever 230 falls into the recess, the toner end sensor 224 is turned off, and the toner end is detected.

As is clear from the above explanation, the toner end is located at lever 2.
It is detected by turning on and off the microswitch by upward movement of 30. Therefore, the distance between the lever 230 and the microswitch actuator must always be kept constant. Therefore, in this embodiment, as shown in FIG. 7, a toner end sensor 224, which is a microswitch, is mounted on a holder 23 formed by bending a spring material.
2, the holder 232 is fixed to the printer upper unit 1, and the actuator portion of the microswitch is configured to protrude from the printer upper unit 1 toward the printer lower unit 2 (see FIG. 2).

When the printer upper unit 1 and lower unit 2 are closed, the projecting pieces 233° 233 of the t3 unit 59 as shown in FIG.
While bending the holder 232 upward, push up the projecting pieces 234 on both sides of the microswitch. When the upper and lower units 1 and 2 are locked, the face protrusions 233 and 234 apply pressure to each other, and the switch protrusions 234
The position is fixed with an interval equal to the height of . Thus, the distance between the lever 230 and the microswitch actuator is maintained constant.

Line 236 in FIG. 24 indicates a ground line connected between each electrical device. In the embodiment, the ground board 237 is fixedly installed on the lower frame 78 of the printer lower unit 2, as shown in FIG. However, many of the devices shown in FIG. 24 are installed in the printer unit 1 as described above. Since the upper and lower units 1 and 2 rotate with respect to each other around the hinge pin 238, some ingenuity is required to connect the ground lines of each device in the printer upper unit 1 to the ground board 237 of the printer lower unit 2.

In the embodiment, a rigid conductive metal plate 2 is attached to the ground substrate 237.
39 is connected to extend the metal plate 239 to above the lower frame 78, and the metal plate 239 and the earth plate 240 of the printer upper unit 1 are electrically connected via the connection plate 241. The connection plate 241 is formed by bending a thin plate of a conductive and flexible material, such as phosphor bronze. Also, both ends 241 of the connection plate 241
a + 241b are curved as shown, and electrical connection is achieved by screwing these curved terminals to the ground plate 240 and metal plate 239, respectively, with stepped screws 242.

By using the stepped screw 242, the connecting plate 241
The ground plate 240 and the gold RFi 239 are not connected by screw force, but by the curved terminal portions 241a, 241.
Contact is ensured by the springiness of b itself. This prevents the contact state of the contact portion from deteriorating over time and permanently provides a good contact state. In addition, since the entire connecting plate 241 is finished in a curved shape, even if the upper and lower units 1 and 2 rotate relative to each other, the connecting plate 241 can freely follow the rotation, and the terminal portion 241 a
, 24 lb without placing a large burden on it.

Note that when the printer upper unit 1 is lifted and rotated, there is a possibility that the connection plate 241 may collide with the screw 242 or the like depending on the shape of the curved portion 241c of the connection plate 241. In order to prevent the connection plate 241 from being damaged even in such a case, a guide plate 2 is provided at the screw 242 that extends perpendicular to the plane of the paper and has a smoothly curved surface facing the connection plate 241.
It is good to set 43.

The power input section 160 in FIG. 24 is provided in the printer lower unit 2. On the other hand, a main PSU 165 and a character PSU 166 connected to the power input section 160 are provided in the printer upper unit 1. Therefore, the cable connecting these units will be routed between the upper and lower units. This cable is surrounded by a metal spring tube 24, as shown at 244 in FIG.
5 to be covered and protected. Since it is a spring tube, it is flexible and does not restrict the degree of freedom in bending the cable 244. Also, since the tube is made of metal, the printer upper unit 1 is repeatedly opened and closed, and the spring tube 245
Even if the cable 244 rubs against the lower frame 78 or the cover 8 (FIG. 13), the cable 244 will not be damaged.

Control process In this embodiment, the main controller 176 shown in FIG.
The PU 186 controls and executes the print process and various processes associated therewith. The above-mentioned printing process, which includes steps such as charging, exposure, development, and transfer, is as explained in connection with FIG. 3.

We will now discuss some other important processes that accompany the printing process.

(Irregular Size Paper Print) In this embodiment, as shown in FIGS. 1 and 24, a rotary switch 192 for specifying the size of the transfer material is provided on the operation panel 5. This switch 192 specifies a paper size such as BEzA4. In addition, in consideration of printing on envelopes of various sizes, it is also possible to specify an irregular size so that the size is not specified. When the operator selects this size switch 192
When you adjust the size to the desired size such as B O, A4, etc., the settings for conveying the transfer material for the printing process and the character arrangement settings (settings such as whether double characters can be printed on one page) will be adjusted to the respective size. It is done together. For example, regarding transfer material jam detection, after the leading edge of the transfer material is detected by the registration sensor 219, paper ejection sensor 220, etc., the trailing edge of the transfer material is detected by the same sensor after a conveyance time commensurate with the size of the transfer material. It is determined that a jam has occurred when the jam does not occur. When an irregular size is specified, various timing settings for the printing process are performed based on the maximum size among the sizes that can be specified.

The above jam detection is performed when the size switch 192 is set to B5 or A4.
This can be done without any problem if the paper is adjusted to a standard size such as . However, when an operator tries to print envelopes of various sizes and selects an irregular size, the size of the envelopes, etc. is generally quite small, so the jam detection described above using the registration sensor 219 etc. does not work properly. There is a possibility that it will not be carried out. Therefore, in this embodiment, when an irregular size is specified by the paper size switch 192, the jam detection operation is not performed to ensure smooth progress of the printing process.

In this case, the fact that jam detection is omitted is displayed by lighting the LED on the operation panel 5.

Incidentally, when printing on an envelope with the size switch 192 set to an irregular size, the temperature of the heating roller 36 of the fixing device can be programmed to be slightly lower than during normal printing. This is because envelopes are generally made by gluing, so if the fixing temperature is too high, the glue will melt. However, even in this case, care must be taken because lowering the temperature too much may result in poor fixing. Generally, a reduction of about 20% can prevent melting of the glue while maintaining sufficient fixing performance.

In the above explanation, when the irregular size is selected, the printing process is executed based on the maximum size transfer material, and the jam detection function is omitted.

Apart from this control method, when an irregular size is specified, the process for the first transfer material is performed based on the largest size material, but the first transfer material is not conveyed. After the size of the transfer material is detected during the printing process, the printing process can be performed for the second and subsequent transfer materials based on the detected size. According to this method, high-speed printing can be performed in accordance with the size of the transfer material.

(Transfer material size abnormality notification) The operator can specify the paper size using the paper size switch 192. This designation is performed by selecting the same size as the transfer material placed on the paper feed tray 3. Therefore, normally the size specified by the switch 192 and the size of the transfer paper on the paper feed tray 3 are the same.

However, it is conceivable that the two sizes may be different due to an operator's mistake in setting the switch. In this case, if the printing process is executed without any compensation, for example, B5-size printing may be executed on A4-size paper, resulting in too large margins, or the paper size may be insufficient for the number of prints. Sometimes it disappears.

In order to solve this problem, in this embodiment, when the printing process is started and the first sheet of transfer paper is conveyed into the printer, the size of the first sheet of transfer paper is checked, and the detected size of the first sheet of transfer paper is checked. If the size is different from the size specified by the switch 192, an LED display to that effect is displayed on the operation panel 5, and the printing operation is stopped.

This makes it possible to minimize the number of defective printed products.

In this case, the first sheet of transfer paper once sent into the printer is directly discharged to the outside by the paper discharge roller 4o or 45. In addition, how to detect the transfer paper size.

A special sensor for this purpose may be prepared, or an existing sensor such as the registration sensor 219 may be used.

When an abnormality in the transfer paper size is reported as described above,
At the same time, the CPU 186 of the main controller 176 instructs the CPU 184 of the character controller 180 to keep the print information that is currently being printed. Otherwise, the print information that has been created will be lost due to an error in specifying the paper size.

(Photoconductor unit replacement instruction control) The OPC counter 250 disposed above the suction fan unit 49 in FIG. The number of prints for each part (cleaning unit) related to cleaning, such as the blade 55, is counted.

The OPC counter 250 counts up in response to a transfer command signal from the main controller 176, and when the count reaches 10,000, a signal to that effect is sent to the main controller 176 (Fig. 24), and the main controller 176 controls the operation panel 5. A message to replace the photoconductor unit is displayed.

Furthermore, if the toner over sensor 221 (Figs. 3 and 24) detects toner over before the oPC counter 250 reaches 10,000, a notification to that effect is sent to the main controller 176, and the photoconductor is activated in the same way as above. A unit replacement message is displayed.

On the other hand, in FIG. 4A, a protrusion 301 for identifying the unit is formed on the upper surface of the case 61 of the photoreceptor unit 58 that supports a new photoreceptor 11. As shown in FIG. This protrusion is the second
In the figure, when the photoconductor unit replacement display is displayed, if the unit identification protrusion 301 is detected by the type sensor 302 (that is, the photoconductor 11 has not yet been used 10,000 times), "1" is displayed along with a photoconductor unit replacement display.

At the same time as the message "Replace photoconductor unit rlJ" is displayed, the latching solenoid 217 is turned on and its plunger is pulled down.
3 is turned on. As long as the latch sensor 223 is on, the message "Replace photoconductor unit rlJ" continues to be displayed. Once the latch sensor 223 is turned on, the OP
Reset lever 251 that resets C counter 250
When is reset as shown by arrow J, it turns off at the same time (
initial state).

For convenience, the display ``Photoconductor unit replacement r I J'' indicates that the photoconductor has been used 10,000 times (although there may be cases where the toner is over before counting 10,000 times, the toner collection tank 57 (third (Figure) is designed to have a capacity that is full of waste toner after 10,000 printings are performed.Therefore, before the 10,000th printing is performed, toner overflow is detected and the photoconductor unit is replaced. If this message appears, it is assumed that the photoreceptor has been used 10,000 times.) After seeing this display, the operator replaces the cleaning unit of the photoreceptor unit 58. The lifespan of the photoreceptor 11 is 20,000 cycles in the case of the example, so it will not be replaced because it still has 10,000 cycles left. The photoreceptor 11 is removed from the photoreceptor unit 58, and only the cleaning unit is discarded.

When replacing the cleaning unit, replace the old photoconductor unit 58 with a new photoconductor unit 58 whose toner collection tank 57 is empty, and replace the photoconductor 11 that has been used 10,000 times.
Attach the photoconductor unit to the lower unit 2 of the printer.
Attach it to the specified position. Note that the case 61 of the new photoreceptor unit is selected not to have the unit identification protrusion 301. After that, when the operator presses the reset lever 251, the latch sensor 223 is initialized.
At the same time, the OPC counter is reset.

Therefore, from now on, the OPC counter starts counting again from zero. Even if the unit is replaced, the reset lever 25
The latch sensor 223 is not initialized unless 1 is pressed, and therefore the display of "Photoconductor unit replacement '1'" continues.In other words, the latch sensor 223 prevents forgetting to reset the OPC counter after replacing the unit. There is.

Thereafter, printing is repeated, and when the oPC counter counts 10,000 times again or when toner overflow is detected, the photoreceptor unit replacement display is displayed again. However, since there is no unit identification protrusion 301 this time, the type sensor 302 will not detect it. Therefore, the display at this time will be something like "Photoconductor unit replacement "2". This display indicates that the unit has been replaced for the second time, that is, the photoconductor has been used 20,000 times or close to it. This indicates that the photoconductor itself has reached the end of its life.Therefore, ``Replace the photoconductor unit.'' Q J
``'' is displayed, the operator replaces the entire photoconductor unit 58 including the photoconductor 11 with a new one.

Transfer/Static Elimination Cleaner In this embodiment, as shown in FIG. 3, a static elimination lamp 54 and a transfer charger 30 are arranged adjacent to each other. By using the cleaner 252 shown in FIG. 29, both can be cleaned at the same time. The top transparent plate 253 of the static elimination lamp 54 is made of felt 2
It is cleaned at 54. The charge wire 205 of the charger 30 is cleaned with a polishing cloth 255 made of polyurethane rubber or the like. When cleaning, place the felt 254 on the transparent plate 253.
Then apply the polishing cloth 255 to the charging wire 20.
5 at the same time, and in that state apply cleaner 25.
2. Move the entire object in the direction perpendicular to the page. This removes toner and other debris. The clip 256 is used to hang the cleaner 252 at an appropriate location within the printer. The guide protrusion 257 is attached to the lower frame 78 (the third
It engages with the protruding portion (not shown) of the figure).

Effects According to the present invention, even if the two units are divided, the interlock switch is protected by the inner cover, so the risk of malfunction is eliminated.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a laser printer according to an embodiment;
2 is a perspective view showing the upper unit of the laser printer shown in FIG. 1 in an open state, FIG. 3 is a side sectional view of the laser printer, and FIG. 4 is an exploded perspective view of the image forming unit of the laser printer. Fig. 5 is a plan view of the laser optical device, Fig. 6 is an optical path diagram of the laser optical device, Fig. 7 is a perspective view of a part of the developing unit, Fig. 8 is a diagram of the meshing state of gears, and Fig. 9 is a diagram of the optical path of the laser optical device. A perspective view of another part of the developing unit, FIG. 10 is a view taken along arrow X in FIG. 9, FIG. 11 is an exploded perspective view for explaining the sealing means of the developing roller, and FIG. 12 is a view of the printer. Fig. 13 is an exploded perspective view showing a part of the printer upper unit, Fig. 14 is a front view of a part of the ozone discharge device, and Fig. 15 is a perspective view of the suction fan unit. 16 is an exploded perspective view of a part of the suction fan unit, FIG. 17 is a perspective view of the paper discharge guide member, and FIG.
The figure is a front view of the drive system, Figure 19 is a perspective view of the paper ejection roller,
Fig. 20 is a perspective view of the paper ejection ring, Fig. 21 is a perspective view of the paper ejection path switching means, Fig. 22 is a perspective view of a part of the positioning means of the printer upper unit, and Fig. 23 is a perspective view of the laser optical device. A perspective view of the mirror fixing means, FIG. 24 is a control circuit diagram, and FIG.
Figure 5 is a side cross-sectional view of the high voltage connection terminal section, Figure 26 is a diagram showing the installation state of the transfer charger, Figure 27 is a cross-sectional view of one means of grounding the upper and lower units, and Figure 28 is the top of the printer. A sectional view showing the two-stage rotation structure of the unit, Fig. 29 is an explanatory diagram of the transfer/static elimination cleaner, Fig. 30 is a side sectional view showing the optional paper feed unit installed, and Fig. 31 is the optional paper ejection unit. 32 is a perspective view of an example of a paper ejection roller, FIG. 33 is a perspective view of an example of a support means for the second cylindrical lens, and FIG. 34 is a perspective view of the second cylindrical lens in a state where the tip is attached. It is. 1...Unit (printer lower unit) 2...Unit (printer lower unit) 164...Interlock switch 170...Inner cover agent Patent attorney Takeshi Ito "X (flijn) Figure 17 Procedural Amendment (Part 1, October 23, 1986)

Claims (1)

[Claims] In an electrostatic recording device that has two units that can be divided, and when these units are divided, an interlock switch is turned off and the power supply path is cut off,
An electrostatic recording device characterized by having an inner cover that covers an interlock switch.