JPH0727318B2 - Electrostatic recording device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrostatic recording device such as a copying machine, a facsimile, or a printer.

2. Description of the Related Art In the electrostatic recording apparatus described above, there is an electrostatic recording apparatus in which a photosensitive member, a charging device, an image exposure device, a developing device, a transfer device, a fixing device and other components are appropriately divided and arranged in upper and lower units that can be divided.

When actually performing a printing operation with this apparatus, the upper and lower units are coupled to each other and further locked (fixed) to each other. In this case, a locking device is needed.

A conventional locking device is configured by individually attaching an engaging claw, a hook, a knob, or the like to one of upper and lower units. This increases the number of parts and makes the manufacturing cumbersome.

Aim of the Invention In view of the above points, an object of the present invention is to provide an electrostatic recording device in which a lock mechanism can be assembled easily and inexpensively.

According to the present invention to achieve the above object, in an electrostatic recording device having two units that can be separated from each other, a lock lever that is detachably provided in one of the units and includes a first engaging portion, The second engaging portion provided on the other unit and fitted to the first engaging portion, and particularly the first engaging portion which is integrally attached to the lock lever and is attached to the unit, is the second engaging portion. And an elastic body that urges the lock lever to rotate so as to urge the lock lever toward the direction.

Hereinafter, the present invention will be described based on examples.

FIG. 1 shows the appearance of a laser printer which is an example of an electrostatic recording device. This laser printer prints characters and the like on a transfer material such as a sheet of paper and an envelope based on an instruction from a host computer (not shown).
The laser printer is roughly divided into an upper printer unit 1 and a lower printer unit 2. A paper feed tray 3 is detachably attached to the lower unit 2 and a paper discharge switching knob 4 is provided. Upper unit 1
An operation panel 5, a font cartridge insertion slot 6, and an emulation card insertion slot 7 are provided in the. or,
The upper surface of the cover 8 which is one of the constituent elements of the upper unit 1 constitutes an upper paper discharge tray 9.

Transfer materials to be printed are stacked and held on the paper feed tray 3. In the embodiment, printing can be performed over various transfer materials from large size paper such as so-called legal size to small size paper such as envelopes. When applying transfer materials of different sizes as described above, the paper feed tray 3 is used. Upper guide plate 254
Is moved as indicated by arrow K to guide each size paper. The two guide plates 254, 254 are linked to each other on the lower surface of the tray so that when one of the guide plates is moved in one of the K directions, the other is automatically moved in the other of the K directions. The operation panel 5 is provided with switches and the like for setting the size of the transfer material and various other printing conditions. The font cartridge insertion port 6 is for inserting a phone cartridge, that is, a ROM cartridge in which several types of font information are stored, and sending the font information to a character controller described later. The emulation card insertion slot 7 is for connecting an emulation card (ROM card) for matching the host computer and the laser printer to a character controller according to the type of the host computer (not shown). The discharge switching knob 4 switches between discharging the transfer material, which has been printed in the laser printer, to the upper discharge tray 9 or discharging the transfer material to the left outside the laser printer as indicated by arrow A. .

The upper printer unit 1 and the lower printer unit 2 are hinged to each other on the back side of the drawing, and are fixedly held to each other on the front side by a lock mechanism described later. When the lock lever knob 10 protruding from the front surface of the cover 8 is pushed up to release the lock mechanism, the upper printer unit 1 can be rotated and lifted from the lower printer unit 2 as shown in FIG. Upper and lower units like this
The structure in which 1 and 2 are separable from each other is for facilitating maintenance work or for facilitating replacement of a photoconductor, a developer and the like which will be described later.

FIG. 3 shows a printer upper unit 1 and a printer lower unit 2.
FIG. 3 is a side sectional view of the laser printer in which the and are coupled to each other. The outline of the operation of the laser printer will be described below with reference to this figure.

The drum-shaped photoconductor 11 disposed substantially in the center of the printer lower unit 2 is driven and rotated in the clockwise direction, and is first subjected to the discharging action by the charger 12. The charger wire 13 of the charger 12 is a photosensitive member as shown in FIG. 4 (a).
The surface of the photoconductor 11 is uniformly charged in the axial direction by the discharge from the charge wire 13.

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

A laser diode (LD) is built in the LD unit 17, and the LD emits a laser beam for writing an image signal based on an image signal described later. This laser beam is the sixth
As shown in the figure, it enters the spherical lens 20 through the first cylindrical lens 18 and the first mirror 19. The laser beam is narrowed down by the spherical lens 20, refracted upward by about 5 °, enters the one surface of the polygon mirror 16, and is reflected by the mirror surface. Since the incident light 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 reflected by the second mirror 21, passes through the second cylindrical lens 22, is guided onto the photoconductor 11, and is irradiated for each dot. At this time, according to the rotation of the polygon mirror 16, the laser beam is scanned on the second mirror 21, that is, on the photoconductor 11 as shown by arrow B (main scanning). By this main scanning, dot lines formed by the laser beam are formed on the photoconductor. This main scanning is repeated for each surface of the polygon mirror 16, and at the same time, the photoconductor 11 rotates in the direction orthogonal to the main scanning direction (sub-scanning direction), and as a result, the static image corresponding to the image signal on the surface of the photoconductor 11 is obtained. A latent image is formed. In this embodiment, main scanning and sub scanning are performed so that the dot density of this electrostatic latent image becomes 300 dots / inch. When printing is performed based on such a high-density dot image, it is possible to obtain a clear printed image equivalent to the so-called type impact method. Further, in this embodiment, each surface of the polygon mirror 16 is curved so that the scanning image surface on the second mirror 21 becomes flat. Therefore, conventional polygon mirror
The so-called f- that is arranged between the 16 and the second mirror 21.
The θ lens is unnecessary. As a result, the laser optical device 14
The overall shape can be greatly reduced.

The LD in the LD unit 17 detects the synchronization detection laser beam once for each scanning, separately from the image signal writing laser beam. This beam is reflected by the polygon mirror 16, and then enters the optical fiber 25 through the third mirror 23 and the third cylindrical lens 24. The optical fiber 25 is connected to a main controller (which will be described later) that controls the entire operation of the printer, and the synchronization detection laser beam sent to the main controller via the optical fiber 25 causes the laser for writing the image signal described above. Controls the emission start timing of the beam.

In FIG. 3, the electrostatic latent image formed on the photoconductor 11 by the laser exposure device 14 is carried to the developing roller 26 as the photoconductor 11 rotates. In this embodiment, a so-called contact developing method is adopted, and the developing roller 26 is a photosensitive member.
While lightly touching 11, it is rotated counterclockwise.
The non-magnetic toner 29 contained in the developing tank 28 is supplied to the developing roller 26 by a toner replenishing roller 27 which is arranged at the bottom of the developing tank 28 and rotates counterclockwise. Therefore, the electrostatic latent image on the photoconductor 11 carried to the developing roller 26 is developed by the toner carried by the developing roller 26 to be a visible image. Photoconductor
In the contact image method in which 11 and the developing roller 26 are brought into contact with each other, a one-component developer made of a non-magnetic toner is used, and a magnetic toner is not used. Further, since no carrier is used, it is possible to omit carrier exchange in the case of using a conventional so-called two-component developer. Further, the non-magnetic toner can easily carry out the fixing operation described later, and the fixing device can be made small in size with a simple structure. In addition, when the non-magnetic toner is used, the contour of the toner image obtained by the development can be clearly displayed, and a high quality image can be obtained as compared with the one-component developer using the magnetic toner.

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

While the above process is being executed, a transfer material stacked on the paper feed tray 3, for example, the uppermost one of the sheet-shaped transfer papers 31 is driven and rotated in the clockwise direction.
Further, it is separated from other papers by the friction pad 33 that is pressed against it and sent to the nip portion of the upper and lower carrying rollers 34 and 35, and is further carried to the transfer position of the photoconductor 11 by these carrying rollers.

The transfer paper conveyed in this way is transferred onto the photosensitive member at the transfer position.
11 The toner image on top and the transfer charger
Receives discharge action by 30. By this discharge, the toner image on the photoconductor 11 is transferred onto the transfer paper. When the transfer work is completed, the light from the static elimination lamp 54 formed of an LED arranged next to the transfer charger 30 is irradiated onto the photoconductor 11 through the transfer paper, and the static elimination lamp 54 irradiates the light while overlapping the transfer paper. The surface potential of the photoconductor passing through the position is eliminated.

When the potential of the photoconductor is weakened, the electrostatic attraction between the photoconductor and the transfer paper is weakened, the transfer paper is reliably separated from the photoconductor 11 by its own weight, and sent to the heating and fixing device equipped with the heating roller 36 and the pressure roller 37. To be The transfer paper and the toner image transferred onto the transfer paper are heated by the heating roller 36 while being heated by the rollers 36, 37.
Receives pressure from above and below, and as a result, the toner image is fused and fixed on the transfer paper. In order to heat the heating roller 36, a heater 38 is provided inside the heating roller 36.

The transfer paper that has undergone the fixing operation is heated by a peeling claw 39 to a heating roller.
It is peeled from 36 and sent to the paper discharge roller 40. Paper ejection roller
A paper discharge switching claw 41 is provided at the downstream position of 40, and the switching claw 41 is turned to the solid line position and the broken line position in FIG. 3 by turning the paper discharge switching knob 4 in FIGS. 1 and 2. Switch with. When the switching claw 41 is in the solid line position, the transfer paper output from the paper discharge roller 40 passes through the conveyance path formed by the paper discharge guide member 42 and the paper discharge guide plates 43 and 44, and is transferred by the upper paper discharge 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 position of the broken line, the transfer paper output from the paper discharge roller 40 is linearly discharged to the outside of the printer as indicated by arrow A.

Which mode of the transfer paper is ejected is determined by the operation of the switching knob 4 by the operator. Generally, printing is performed in the order of pages on a weak transfer plain paper transfer sheet, and when it is desired to stack these in page order, the sheets are discharged to the upper discharge tray 9.
On the other hand, when printing is performed on an envelope or other transfer material having a strong elasticity, the sheet is ejected linearly.

After the transfer is completed, the toner that has not contributed to the transfer remains on the photoconductor 11. The residual toner is discharged with the photoconductor 11 by the charge removal lamp 54, and is scraped off from the photoconductor 11 by the cleaning blade 55. The toner scraped off is collected by the toner collecting roller 56 in the toner collecting tank 57.
It is sent in and stored here. Cleaning blade
The photoconductor 11 cleaned by 55 is again charged by the charger 12.
It is used for the charging effect.

The fixing roller 36 of the embodiment has a conductive surface. In this way, the electric charge on the transfer paper is removed through the fixing roller during the fixing operation. Conventionally, in order to improve the stackability of the transfer paper, the transfer paper discharged to the outside was discharged by a dedicated static elimination brush before the discharge, but this static elimination brush is not necessary in this embodiment. In order to give conductivity to the fixing roller, a method of mixing carbon with the roller base such as Teflon can be used. Since carbon has a relatively high hardness, the durability of the roller can be improved by this method.

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

Image forming unit In this embodiment, the photoconductor 11, the charger 12 and the toner recovery tank 57 in FIG. 3 are combined into one unit (photoconductor unit 5) as shown in FIG.
8) is configured as. Further, the developing roller 26, the toner replenishing roller 27, and the developing tank 28 are also configured as one unit (developing unit 59) as shown in FIG. The photoconductor unit 58 and the developing unit 59 are detachably supported in the image forming unit case 60, respectively.

The photoconductor unit 58 has a box-shaped case 61, and the support shaft 62 of the photoconductor 11 is rotatably and detachably supported by the case 61. Further, a hole 63 into which the laser beam from the rage optical device 14 (Fig. 3) is formed is formed in the case 61, and the toner recovery tank 57 (Fig. 3) described above is partitioned by the case 61 itself. And the casings of the charger 12 (the wall surrounding the charge wire 13) are constructed. The cleaning blade 55 and the toner collecting roller 56 are supported by the case 61, respectively. The photoconductor 11 is detachably attached to the case 61, and hence the toner recovery tank 57, for the following reason. That is, generally, when the toner recovery tank 57 is full of waste toner, it is replaced with a new one. In this case, if the photoconductor 11 and the toner recovery tank 57 are integrated, the photoconductor is also replaced when the toner recovery tank is replaced. However, the life of recent photoconductors has been remarkably extended due to improvements in materials, manufacturing methods and the like. Therefore, if the photoconductor is to be used until it reaches the end of its life, a very large capacity toner recovery tank is required, and the entire printer becomes rather large. In order to avoid this, the toner recovery tank can be exchanged and used for one photoconductor to reduce the size of the printer and effectively use the photoconductor.

The developing unit 59 has a case 66.
The developing tank 28 (FIG. 3) is partitioned and formed, and the developing roller 26 and the toner replenishing roller 27 are rotatably supported by the case 66. The toner cartridge 65 is detachably mounted on the case 66. Development tank 28
When the remaining amount of toner in the developing tank 28 becomes low, the cartridge 65 that has been attached up to that point is replaced with a new cartridge and toner is replenished into the developing tank 28.

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

As can be seen from FIG. 4, the image forming unit case 60 is formed in a box shape with an upper opening, and front and rear walls 60a and 60b are groove-shaped supports for supporting the support shaft 62 of the photoconductor 11. Part 6
7,67 are formed. The photoconductor unit 58, one of which is supported by the support portion 67, is pressed by the stop claw 69 on the other. 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 each unit 58, 59 is attached to the image forming unit case 6
When it goes into 0, it spreads out so that it doesn't interfere with the insertion.

When the photoconductor unit 58 is attached to the image forming unit case 60, a part of the lower side of the photoconductor 11 protrudes into the opening 71 formed in the bottom wall of the case 60, and the gear 72 attached to the support shaft is small. Plunge into the opening 73.

When the developing unit 59 is viewed in the direction of arrow VII, it is as shown in FIG. 7, and a gear 74 is attached to the shaft end of the developing roller 26. Develop unit 59 image forming unit case
When mounted on 60, the gear 74 projects outward from the recess 75 in the rear wall 60b of the image forming unit case shown in FIG.

A pair of pivot pins 76 and 77 are provided on the left side wall 60d of the image forming unit case 60 so as to project from the frame 78 (FIGS. 1 and 3) of the printer lower unit 2. Side plate
It fits into the support grooves 79, 79 provided in 78a, 78b. Therefore, as indicated by arrow E in FIG. 2, the image forming unit case 60 is provided with the pivot pin 7 while the photoconductor unit 58 and the developing unit 59 are accommodated.
It can be lifted by rotating around 6,77.
In this case, as shown in FIG. 3, the lower side of the case 60 is the transfer sheet conveyance path. Therefore, when the case 60 is lifted as described above, the sheet conveyance path is exposed to the outside and is thus jammed here. Transfer paper (so-called jam paper) can be easily removed. If necessary, the entire image forming unit case 60 can be removed from the printer lower unit 2.

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

The lower frame side plates 78a, 78b are formed with a pair of locking holes 88, 88, and when the image forming unit case 60 is stored in the device position shown in FIG. The action of spring 87 engages each. In this case, as shown in FIG. 3, a compression spring 89 is provided at the lower right end of the image forming unit case 60, and the lower end of the spring 89 is pressed against the lever 90. The spring 60 is biased counterclockwise by the spring 89 about the pivot pins 76 and 77. Therefore, the lock claw 83 is pressed against the upper surface of the locking hole 88,
The case 60 is securely locked.

The lever 90 is rotatably supported by the lower frame 78 by a pin 91, and rotatably supports the upper transport roller 34 for transporting the transfer paper 31. When the image forming unit case 60 is mounted at the predetermined position 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 are pressed against each other to transport the transfer paper. When the image forming unit case 60 is lifted as shown in FIG. 2E, the pressure of the spring 89 against the lever 90 is released.
When the transfer paper is jammed between the upper and lower transport rollers 34, 35, it can be easily removed.

In FIG. 4, another frame side plate 78c is fixed to the lower frame side plate 78b on the back side. This frame side plate 78c
A main motor unit 93 having a main motor 92 is attached to. A drive gear 94 is fixed to the output shaft of the main motor 92, and a photoconductor drive gear 95 and a developing roller drive gear are provided by this drive gear via an appropriate gear train.
96 is rotated.

When the image forming unit case 60 is mounted at the predetermined position in FIG. 3, the shaft end gear 72 (a in FIG. 4) of the photoconductor 11 meshes with the photoconductor drive gear 95, while the shaft end gear of the developing roller 26. 74 (FIG. 7) meshes with the developing roller drive gear 96. When the main motor 92 rotates in this state, the photoconductor 11 and the developing roller 26 are rotated.
Rotates.

When the image forming unit case 60 is mounted, the contact state between the photoconductor 11 and the developing roller 26 and the meshing state between the developing roller shaft end gear 74 and the developing roller drive gear 96 are as shown in FIG. When the developing roller shaft end gear 74 is driven by the drive gear 96 due to the positional relationship shown in the drawing, the acting force P from the drive gear 96 to the shaft end gear 74 and thus to the developing roller 26 is in the vertical direction. In this way, since the acting force of the drive system is prevented from acting in the horizontal direction, the pressure contact force between the developing roller 26 and the photoconductor 11 is not adversely affected by the acting force from 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 102 is attached to the upper part of the lock lever 101, and the developing unit 59 is attached to the image forming unit case 60.
When the lock lever 101 is not mounted (see 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 at the predetermined position in FIG. 3 and the printer upper unit 1 is closed, the leaf spring 103 provided in advance on the printer upper unit 1 contacts the lock lever 101 and pushes it down. Then, the recess 104 of the lock lever 101 is caught by the lock pin 105 fixedly arranged near the developing roller drive gear 96 as shown in FIG. 10, and as a result, the vertical movement of the developing unit 59 is restricted. To be done.
The pin 106 and the slot 107 in FIG. 10 are for determining the rotation range of the lock lever 101.

As described above, since the acting force P on the developing roller 26 is limited to the vertical direction and the vertical movement of the developing unit 59 is restricted by the lock lever 101, the contact pressure between the developing roller 26 and the photoconductor 11 is stabilized, Further, the vibration of the developing roller 26 is reduced.
When the vibration of the developing roller 26 decreases, the uneven rotation of the photoconductor 11 correspondingly decreases. Thus, the jitter in the photoconductor rotating direction (sub-scanning direction) was greatly reduced. Further, in this case, the rotation of the lock lever 101 by the spring 102 does not impair the operability when the developing unit 59 is attached and detached.

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

In addition to the leaf spring 103, the compression spring 108 is attached to the printer upper unit 1.
To provide. When the printer upper unit 1 is closed, the lock lever 101 first rotates while being pressed by both the leaf spring 103 and the compression spring 108 until it is caught by the lock pin 105. Once the lock lever 101 is caught on the lock pin 105, a gap is created between the lock lever 101 and the spring 108,
The spring force of 108 does not reach the lock lever 101. That is, the lock lever 101 engages with the lock pin 105 only by a small spring force of the leaf spring 103. In this case, the compression spring 108
When the pressing force by P is ₁ and the pressing force by the leaf spring 103 is P ₂ , if P ₁ is too small, the lock lever 101 cannot be rotated sufficiently, and the lock lever 101 is liable to malfunction. However, there is a possibility that inconveniences such as gear jumps may occur. _{On the} other hand, if P2, that is, the pressing force during the printing operation is too large, the contact pressure between the photoconductor 11 and the developing roller 26 is adversely affected, and there is a risk of pixel removal or jitter. Therefore, P ₁
And it is necessary to select the best combinations when selecting the P _2. In the examples, P ₁ = 2.0 kg and P ₂ = 300 g.

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. Although it looks like one in the figure, two are provided, one on the front side and one on the back side.
These springs are used in the developing unit 59 as shown in FIG.
Both ends of the case 66 are pressed by spring forces P ₃ and P ₄ , respectively.
On the other hand, the compression spring 111 is provided in the portion of the printer upper unit 1 corresponding to the non-driving side (the side without the gear 74) of the developing unit 59. When the printer upper unit 1 is closed, the spring 111 presses the developing unit 59 downward with a spring force P ₅ at a part on the non-driving side.

In this way, the developing unit 59, and thus the developing roller 26, is horizontally pressed in the direction toward the photoconductor 11 at two points, and
Since 26 is pressed downward by a part of the non-driving side, the contact pressure between the photoconductor 11 and the developing roller 26 is further stabilized, so that a toner image of uniform density can be obtained. Appropriate values are selected for the values of P ₃ , P ₄ , and P ₅ in accordance with the developing unit 59 and other parts to which it is applied.

In the examples, P ₃ = 700 g, P ₄ = 100 g, P ₅ = 1000 g.

The developing roller shaft end gear 74 shown in FIG. 7 has a developing roller via a bracket 116 in which an oil seal 112, a retainer 113 (press fit), a cushion 114, a side seal 115 and the like are housed as shown in FIG. Mounted on 26. The developing roller 26 rotates during the printing process.
If you do not take any measures, the bracket 116 and the developing roller 2
Toner may spill from between 6 and. Therefore, in this embodiment, one end 118 (shaded portion) of a seal 117 made of a thin material such as polyethylene film is fixed to the bracket 116, and the seal 116 covers the joint between the bracket 116 and the developing roller 26, and is circulated. As shown in FIG. 7, the other end 119 is pulled out to above the developing unit 59 and further fixed. The fixing is performed by applying an adhesive agent to the seal in the shaded portion Q and adhering the adhesive agent to the case 66 of the developing unit 59. In order to fix completely,
It is preferable that the plate 120 is further applied on the adhesive portion Q, the tip 119 of the tape 117 is folded back and carried to the top of the plate 120, and the plate 120 in this state is pressed by the printer upper unit 1.

Thus, radial leakage of toner is prevented. In order to completely prevent the toner from leaking in the axial direction, a seal plate 121 may be interposed between the side seal 115 and the developing roller 26. This seal plate 121 has small protrusions 1 on both sides.
22a and 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 charging charger 12 is integrally molded with the photoconductor unit 58 by resin. This has the advantage of reducing the number of parts and the number of manufacturing steps.

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 the start of discharge by the charge wire 13 becomes abnormally high, and as a result, prior to normal discharge to the photoconductor 11, the charge wire 13 moves in an unspecified direction. There is an inconvenience of current leakage, so-called leakage. Further, even after the discharge to the photoconductor 11 is started, the discharge becomes unstable. In the conventional charging charger, the above-mentioned inconvenience was avoided by making the casing surrounding the charge wire from a grounded conductive material, but in this embodiment the casing is made of resin integral molding, so some compensation is required. is necessary.

Therefore, as shown in FIGS. 3 and 4 (a), an opening 296 is opened in the upper part of the casing of the charging charger 12, and a ground plate made of a conductive material is formed on the bottom surface of the printer upper unit 1 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 inconvenience such as unstable leakage or discharge does not occur.

As shown in FIG. 2, the ground plate 297 has a protrusion 297a formed on the front side thereof (the side where the operation panel 5 is located). The protrusion 297a is an opening provided in the photoconductor unit 58 when the upper print unit 1 and the lower printer unit 2 are combined.
Fit in 298. A conductive plate 299 connected to the shaft of the photoconductor 11 is disposed in the opening 298 as shown by the broken line in FIG. 4, and thus the ground plate protrusion 297a that has entered the opening 298 is conductive. It is electrically connected to the shaft of the photoconductor 11 via the plate 299. Generally, since the shaft of the photoconductor 11 is grounded, the ground plate 297 is also grounded.

Drive System It has already been described with reference to FIG. 4 that the photoconductor 11 and the developing roller 26 are driven by the main motor 92. However, in this embodiment, the main motor 92 is not limited to being driven by these two members.

FIG. 18 shows the gear train driven by the main motor 92 in detail. In addition to the photoconductor drive gear 95 and the developing roller drive gear 96, the transport roller drive gear 97, the paper feed roller drive gear 98, the heating roller drive gear 99, the paper discharge roller drive gear 100 and the like are also driven. The transport roller drive gear 97 is the third
The lower conveyance roller 35 in the figure is driven. Feed roller drive gear 98
Drives the paper feed roller 32. The heating roller drive gear 99 drives the heating roller 36. The paper ejection roller drive gear 100 drives the upper and lower paper ejection rollers 40, 45.

The main motor unit 93 has a main motor driver 139 in addition to the main motor 92. Main motor 9
2 requires a crystal oscillator that generates a reference signal for constant speed control, an encoder that also indicates the actual motor speed that is the control amount for constant speed control, a power circuit, and a servo circuit that performs constant speed control. Become. The main motor driver 139 is one in which each of the above devices is mounted on a board, and is fixedly mounted on the main motor 92 to be integrated. The reason why such an integrated structure is adopted is that the cables connecting the above-mentioned devices and the main motor 92 are pressed down to a minimum size to achieve a compact structure.

Ozone discharging device, cooling device In general, ozone is generated by discharge of the charging charger 12 or the like. If this ozone accumulates in a specific portion near the photoconductor 11 in the printer, the photoconductor is deteriorated, which is not preferable. or,
When the printer upper unit 1 is lifted, the operator feels uncomfortable. In this embodiment, by providing the following ozone discharge device, these disadvantages are eliminated.

In FIG. 3, an ozone blower fan 46 is arranged above the charger 12. As shown in FIG. 13, the ozone blower fan 46 is fixed substantially at the center of the upper unit frame 47 made of synthetic resin from the front surface 47a toward the rear side (perpendicular to the paper surface of FIG. 3). A plurality of ventilation openings 48 are opened in the frame 47 where the ozone blowing fan 46 is fixed. When the ozone blower fan 46 rotates, air is blown into the vicinity of the photoconductor 11 uniformly in the axial direction through the individual blower openings 48 as shown in FIG. As a result, the ozone in the vicinity of the photoconductor is blown off and deterioration of the photoconductor due to ozone is prevented. The ozone blower fan 46 starts at the same time as the photoconductor 11 rotates. This is because, in general, the rotation of the photoconductor 11 and the lighting of the charging charger 12, which serves as an ozone generation source, are synchronized. The timing of stopping the ozone blowing fan 46 is set 8 to 10 seconds after the stop of the photoconductor 11. When the photoconductor 11 stops, the discharge from the charger 12 also stops, but if the ozone blowing fan 46 also stops at the same time, the ozone accumulated around the photoconductor 11 cannot be sufficiently blown off. Therefore, the fan 46 is continuously rotated for a period of 8 to 10 seconds to surely blow off the ozone. It should be noted that 8 to 10 seconds later is the case of the structure of the embodiment, and when the structure is different, it is set to an appropriate time according to it.

In FIG. 3, a suction fan unit 49 is provided on the left side of the ozone blowing fan 46. As shown in FIG. 15, the suction fan unit 49 includes a suction fan 50 and the suction fan 50.
The ozone filter 52 is supported by a holder 51 fixed to the casing. When the suction fan 50 rotates, the ozone blown off from the photoconductor 11 by the ozone blowing fan 46 is sucked by the suction fan 50 and discharged to the outside of the machine through the ozone filter 52. As a result, ozone does not accumulate in the printer, and since it passes through the ozone filter 52, it does not diffuse 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 in a cylindrical shape by winding a corrugated paper tape in a spiral shape and fixing the outermost peripheral surface with an adhesive tape, and the material paper is impregnated with carbon. The holding piece 53 of the holder 51 can be pushed outward by a hand as shown by an arrow C, and can be elastically returned to the inside as shown by an arrow D from the pushed state. When attaching the filter 52 to the holder 51, first hold the holding piece.
The filter 52 is pressed against the holder 51 by spreading 53, and the holding piece 53 is returned in the D direction. This causes the filter 52 to
The holding piece 53 and the part 47b of the frame sandwich the holding piece 53 and fix the position. Since no special fixtures are required, the cost is low and it is easy to attach and detach.

In FIG. 12, a large number of air holes 123 are opened in the paper carrying rib 124 of the lower frame 78 (details will be described later). Also, thirteenth
In the figure, a large number of air holes 12 are also provided below the paper ejection guide member 42.
5 is open (details below). Therefore, when the suction fan 50 rotates, the outside air flows through the holes 123 and 125 toward the fixing device such as the fixing roller 36 and the toner recovery tank 57, and is discharged from the suction fan 50 to the outside. Therefore, the fixing device and the tank 57 are efficiently cooled. The fixing device is cooled to prevent the fixing device itself and other devices around it from overheating. The toner recovery tank 57 is cooled in order to prevent the waste toner in the tank 57 from being melted and fixed by heat.

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

Printer case, paper transport system Each component of the printer is surrounded by a cover 8 and a lower frame 78. Each of these contains 10 to 10 glass fibers.
It is a synthetic resin containing 20%, such as Noryl (trade name) or the like, which is integrally molded. In particular, the lower frame 78 is the 12th
As shown in the figure, it has a large number of ribs 124 that are arranged along the paper transport direction while forming a transfer paper transport path (see FIG. 3). These ribs are also made by integral molding. Further, among the ribs, which are located below the toner recovery tank 57 of the photoconductor unit 58, the above-described many air holes 123 are opened. The paper ejection guide plate 44 in FIG. 3 is also integrally formed with the lower frame 78.

The paper ejection 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 made of synthetic resin, and the above-mentioned many air holes 125 are provided in the lower part.

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

Drive roller of the upper paper ejection roller 45 and the lower paper ejection roller 40
As shown in FIG. 17, 45a and 40a are rubber rings fitted to predetermined positions on roller shafts 126 and 127 that are rotatably supported on the upper and lower sides of the paper discharge guide member 42, respectively. A gear 128 is fixed to the shaft end of the lower roller shaft 127, and this gear is the discharge roller drive gear 100 (see FIG. 18).
Is meshing with. This drive gear 100 has a lower roller shaft 127.
It is supported by an arm 129 which is rotatably attached to the arm, and a compression spring 130 is attached to this arm.

As described 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 rollers The drive gear 100 meshes with the heating roller drive gear 99 of FIG. At this time, the spring 130
Is contracted by a predetermined amount, and the pressure required to transmit 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 paper discharge roller 40a rotates. The lower roller shaft 127 and the upper roller shaft 126 are drivingly connected by the pulleys 131, 131 and the belt 132 wound around them, so that when the lower drive roller 40a rotates, the upper drive roller 45a also rotates at the same time.

The discharge driving rollers 40a and 45a are in pressure contact with the driven rollers 40b and 4tb, respectively, as shown in FIG. In this embodiment, the driven rollers 40b and 45b are fixed to the lower frame 78 or the cover 8 by a holder 133 made of a spring material as shown in FIG. When the drive rollers 40a, 45a are brought into pressure contact with the driven rollers 40b, 45b, the arm 136 of the holder 133 bends to generate a spring force, which causes a pressing force necessary for driving the paper.

A slot 134 is formed in the fixing portion of the holder 133, and the holder 13 is fixed to the lower frame 78 and 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 supporting shafts into the curved end of the arm 136.

The upper and lower roller shafts 126, 127 should be molded of non-conductive synthetic resin. This is because there is no need for grounding.
Further, it is preferable that the shaft portion where the rubber rings are provided as the paper discharge rollers 40a and 45a has a step with respect to the other shaft portions. This is to prevent displacement of the rubber ring.

In FIG. 17, a paper feed ring 137 is lightly press-fitted into the center of the upper roller shaft 126. This ring is the 20th
As shown in the figure, it has a small protrusion 138 on its outer circumference.
The small protrusions are provided to push out the rear end of the transfer paper discharged to the upper paper discharge tray 9 (FIG. 3) and improve the stackability of the transfer paper to be discharged next.

The relationship between the discharge switching claw 41 (FIG. 3) for switching the discharge path and the discharge switching knob 4 (FIG. 2) is as follows. 21st
In the figure, the paper ejection switching claw 41 and the paper ejection switching knob 4 are shown as shafts 14.
Connected by 0. In the middle of this axis 140 (of course,
Inside the lower frame 78) A cam 141 having two recesses is fixed. The concave portion of the cam 141 is fixed to the lower frame 78 and is a locking member 142 formed of a spring material.
It fits into the convex part of. In this fitted state, the rotation of the cam 141, that is, the rotation of the switching claw 41 is restricted.

When the knob 4 is turned as shown by the arrow F from the state shown in the drawing, the locking member 142 is once pushed and bent, and when the upper concave portion of the cam 141 is carried to the convex portion of the locking member 142, the two are fitted again. The position is fixed. The upper concave portion and the lower concave portion of the cam 141 correspond to the solid line position and the broken line position of the switching claw 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. This is because the position can be surely fixed.

As described above, the printer upper unit 1 can be lifted and rotated from the printer lower unit 2. This rotation is
In FIG. 28, this is performed by rotating the upper unit frame 47 of the printer upper unit 1 around the hinge pin 238 fixed to the lower frame 78 of the printer lower unit 2. When the upper unit 1 is lifted, there is a case where it is not necessary to lift it at such a large angle as when removing jammed paper or when performing a simple maintenance work.
In consideration of such a case, the stop pin 246 is arranged in the lower frame 78 on the inner side of the hinge pin 238 (on the right side in the figure), and when the bracket 247 of the upper frame 47 hits the stop pin 246. It is convenient to restrict the rotation of the upper frame 47.

If the stop pin 246 is detachable from the lower frame 78 and the printer upper unit 1 needs to be greatly lifted, such as when replacing the photoconductor unit 58 and the developing unit 59, the stop pin 246 It is even more convenient to remove the lower frame 78 from the lower frame 78 so that the upper frame 47 can be lifted up to a substantially right angle as indicated by the dashed line.

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

Upper and Lower Units / Locking Mechanism In FIG. 2, when the printer upper unit 1 is closed from the illustrated open position as indicated by arrow G, the printer is in the state shown in FIG. However, in actual printing, it is necessary to lock the upper and lower units 1 and 2 in this state. The mechanism for that will be described below.

In FIG. 13, lever supporting brackets 143, 143 and lever pressing plates 144, 144 are provided on the front surface 47a of the upper unit frame 47 by resin integral molding. The lever support brackets 143, 143 are the support shafts 146, 146 for both ends of the lock lever 145.
Support. At this time, the upper side of the support shafts 146, 146 is attached to the holding plates 144, 1
Pressed down by 44. Since the holding plate 144 is made of resin and has flexibility, the support shaft 146 is attached to the bracket 1.
When inserting into 43, the inserting work is performed while pushing the holding plate 144 upward. Support shaft 146 is bracket 143
When it enters the recessed portion, the holding plate 144 automatically restores and moves downward, and holds the entire lock lever 145. Lock lever 1
In order to facilitate the assembling of the 45 to the upper unit frame 47, the support shaft 146 may be provided with an axial slit.

At this time, the lock lever 145 is rotatable around the support shaft 146, but since the spring members 147, 147 are preliminarily attached to the upper portion of the lock lever 145 so as to project toward the frame 47, the lock lever 145 is attached to the frame front surface 47a. Locked lever 1
45 is urged to rotate in the direction of arrow H. Spring material 14
7 may be a leaf spring, or may be integrally formed with the lock lever 145 by a resin having a spring property.

At the bottom of both ends of the lock lever 145, lock claws 148, 1 respectively.
48 is formed by integral molding. As shown in FIG. 12, hooks 149, 149 are integrally formed at positions corresponding to the lock claws 148 of the lower frame 78.
When the printer upper unit 1 is closed, the spring claw 147 automatically fits the lock claw 148 of the lock lever 145 into the hole of the hook 149, and the upper unit 1 is locked, that is, fixed. When the printer upper unit 1 is lifted, first, the lock lever knob 10 is pinched, and it is rotated upward against the spring force of the spring member 147. Then, the lock claw 14
The engagement between 8 and the hook 149 is released, and the printer upper unit 1 can be lifted without any trouble. Lock lever knob
Reference numeral 10 projects to the outside from an opening 248 provided on the front surface of the cover 8.

In the past, when making such a lock mechanism, there were many complex structures in which a knob, a claw, etc. were attached to a metal shaft. On the other hand, in this embodiment, since the resin integrated structure is used, it is lightweight and easy to manufacture. Also, no grounding is required. The stopper 312 is integrally formed with the entire lock lever 145, and projects in the direction of the case 47 like the spring member 147. This is to limit the rotation of the lock lever 145 to a certain amount in order to prevent the spring material 147 from sagging due to the rotation of the lock lever 145 too much.

Below the support brackets 143, 143, the positioning protrusions 150, 150 in the paper transport direction and the positioning protrusions 151, 151 in the photoconductor axial direction are provided.
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 as shown in FIG. By engaging both protrusions with one hook 149 respectively, the upper unit frame 47 moves the photosensitive member axial direction (laser main scanning direction) and the paper transport direction (laser sub-scanning direction).
It is possible to reliably prevent the position from being shifted.

Laser Optical Device Regarding the laser optical device 14 (FIG. 3), the schematic operation has been described with reference to one example in FIGS. 5 and 6.
In this example, in order to keep the optical path of the laser light in a normal state, the first mirror 19 and the third mirror 23 must be fixed exactly perpendicular to the case 155.

In this embodiment, as shown in FIG. 23, the case 155 (the fifth
The first mirror 19 and the like are fixed by a support portion 156 integrally formed with the drawing) and a holding plate 157 made of a spring material. In this case, in the support portion 156, the surface 156a against which the first mirror 19 is pressed is accurately finished vertically. The mirror 19 is pressed against this vertical surface 156a, and the holding plate is pressed from behind.
Arms 157a, 157a of 157 press mirror 19 against vertical surface 156a. The arm 157a of the holding plate 157 has a hole in the holding plate 157.
When the case 155 is screwed to a predetermined position via the 158, the mirror 19 is pressed by the bending deformation. At this time, the arm 157a is provided beforehand with small projections 159, 159 projecting toward the mirror 19, so that the mirror 19 is pressed by two points through these small projections.
By this two-point pressing, the mirror 19 is reliably positioned by the vertical surface 156a.

The second cylindrical lens 22 shown simply in FIGS. 3 and 6 has an overall shape shown in the lower position in FIG. This is made by resin integral molding together with the entire lens portion. The cylindrical lens 22 has an opening 249 provided on the front surface 47a of the upper unit frame 47.
It can be inserted into a predetermined position in the upper unit frame 47 shown in FIG. The cylindrical lens 22 inserted at a predetermined position acts as an optical lens and also as a sealing member for preventing toner and other dust from entering the optical device 14. Therefore, the cylindrical lens 22 and the upper unit frame
It is desirable that the mating with the corresponding part of 47 is as airtight as possible.

The following is an example of a mounting means for the second cylindrical lens 22. As shown in FIG. 33, the second cylindrical lens 22 is arranged inside the two parallel side walls 304, 304 that define the hole 303 of the upper unit frame 47.
Upper and lower support portions 305 and 306 for slidably guiding the side edges 22b, 22b in the longitudinal direction of the second cylindrical lens 22 are provided on both surfaces of each integrally formed side wall 304 of the upper unit frame 47. The second cylindrical lens 22 is formed integrally with the frame 47, and is supported by being sandwiched between these supporting portions 305 and 306.

The upper and lower support portions 305, 306 of each side wall 304 are arranged in a zigzag pattern, but this is for facilitating die-cutting when molding the upper unit frame 47, and if the frame 47 can be molded, The supporting portion may be formed in an appropriate shape such as a parallel guide rail shape.

When the second cylindrical lens 22 is set, as shown in FIG. 34, the elastic pieces 308 integrally formed with the upper unit frame 47 are engaged with both locking portions 307, 307 formed at the tip of the second cylindrical lens. Accordingly, the second cylindrical lens 22 is prevented from coming out. Further, the stopper 309 integrally bridged to both side walls 304 is hit by the restricting piece 310 protruding from the second cylindrical lens 22 to prevent the second cylindrical lens 22 from being pushed deeper than the predetermined set position. It

In order to clean or replace the second cylindrical lens 22, when pulling it out, it is sufficient to grasp the knob 22a and pull it in the direction of the arrow T. In this way, 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 is similar to the lock lever knob 10 when the second cylindrical lens 22 is mounted at a predetermined position.
It is exposed to the outside from the opening 248 of. Since the opening 248 can be shared in this way, the appearance is not impaired and workability is good.

In FIG. 3, a beam shutter 258 provided on the right side of the ozone fan 46 is rotatable about a pin 259. When the upper and lower units 1 and 2 are closed as shown in FIG.
The upper projection 250 (FIG. 4 (a)) pushes and turns the laser beam irradiation port 251 to open. When the printer upper unit 1 is lifted, the protrusion 250 and the beam shutter 258.
Is disengaged and the beam shutter is rotated to the right to close the laser beam irradiation port 251.

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

Further, a shielding member 252 made of an elastic material such as rubber or sponge is fixed to a portion of the upper unit frame 47 of the printer upper unit 1 corresponding to the laser beam irradiation port 251 (see FIG. 2). When the upper and lower units 1 and 2 are closed, as shown in FIG. 3, the lower end of the shielding member 252 causes the developing unit 58 in the printer lower unit 2 (see FIG. 4A).
The upper surface of the laser irradiation port 251 is pressed against the upper surface of the laser irradiation port, so that the shielding member seals the periphery of the laser irradiation port 251. This prevents toner and other dust from entering the laser optical device 14, leakage of laser light, and intrusion of light from the outside.

Feeding / Discharging Section The feeding tray 3 is detachable from the printer lower unit 2. As can be seen from FIG. 1, this paper feed tray 3 has an uneven bottom because the portion 153 provided with the pressing lever 152 projects downward. Therefore, if the paper feed tray 3 is detached from the lower unit 2 and left as it is, the tray 3
There is a risk that the rear part of the transfer paper will fall downward like a seesaw and the transfer paper will slip backward. In order to prevent this, it is advisable to provide a protrusion 154 on the bottom surface at the rear of the overhang 153, as shown in FIG. As a result, the paper feeding tray 3 can be comfortably seated and the slipping of the paper can be 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 the manual feed guide plate 255 (third part).
Diagram arrow M). If plain paper transfer sheets are stacked on the paper feed tray 3 and the envelope is manually fed from the manual feed guide plate 255, letter printing and address book to the envelope will be alternated 1
It can also be done in groups.

Further, in the printer according to this embodiment, as shown in FIG. 30, a paper feeding unit 266 can be detachably connected to the lower portion of the printer lower unit 2. A preliminary paper feed tray 267 is arranged in the paper feed unit 266, and a plurality of transfer papers 268 are stacked on the tray 267. These transfer papers 268 are fed into the printer lower unit 2 one by one as indicated by an arrow N by a paper feed roller 269 and a conveyance roller 270. The fact that the transferred transfer paper is subjected to the above-described print process is the same as that of the transfer paper 31 on the paper feed tray 3.

Whether to feed paper from the paper feed tray 3 or from the auxiliary paper feed tray 267 is determined by providing a selection switch for that on the operation panel 5 or by an instruction from the host computer. Be done.

As can be seen from the figure, the paper transport distance from the lower paper feed tray 267 to the upper and lower transport rollers 34 and 35 in the printer lower unit 2 is greater than the paper transport distance from the paper feed tray 3 to the rollers 34 and 35. long. On the other hand, in order to execute the printing process, it is necessary for the transfer sheets output from both the sheet feeding trays 3 and 267 to reach the upper and lower conveying rollers 34 and 35 in the same time. Therefore, the auxiliary paper feed roller 269 of the embodiment feeds the transfer paper 267 at a feeding speed higher than that of the paper feed roller 32 in the printer lower unit 2.

The transfer paper after printing is discharged to the upper paper discharge tray 9 and stacked. The deeper the upper paper ejection tray 9, that is, the higher the height h from the upper paper ejection tray 9 to the upper paper ejection roller 45, the larger the number of transfer sheets that can be stacked. However, if it is too deep, the transfer sheets stacked will be disturbed, or the entire printer will be oversized. Therefore, there is a limit to the number of transfer paper stacks depending on the degree of depth.

However, in the case of the embodiment using the above-mentioned auxiliary paper feed tray 267, it is considered that the number of transfer papers to be stacked on the upper paper discharge tray 9 is significantly increased. Therefore, it is convenient to adopt the following configuration.

As shown in FIG. 30, a paper discharge unit 271 is attached to the left side of the upper and lower units 1 and 2 of the printer. The paper discharge unit 271 has a main body case 272 and a cover 274 pivotally supported by a main body case 272 via a pin 273 in the arrow P direction. The cover 274 is normally held in the vertical state shown in FIG. 30 by a locking device (not shown). Cover 27
A plurality of ribs 275, 276, 277 arranged at intervals from each other are attached to the 4 and the main body case 272 in the direction perpendicular to the paper surface of FIG. 30, and a transfer paper discharge path 278 is formed by these ribs. Conveying rollers 279 and 280 and a discharge roller 281 are supported by the main body case 272, and the transfer sheet is conveyed and discharged by these rollers.

When the transfer sheet is conveyed through the sheet discharge unit 271, the sheet discharge switching claw 41 is switched to the broken line position. As a result, the transfer paper sent from the paper discharge roller 40 is sent to the paper discharge unit 271 via the carry roller 279.

Paper discharge rollers 281 of the paper discharge unit 272 from the paper discharge tray 9
Is higher than the height h to the upper paper discharge roller 45 (H> h). Therefore, when the transfer paper is ejected from the paper ejection unit 271, it is possible to stack more transfer papers. In this case, as a paper discharge method, the upper discharge roller 45 of the printer upper unit 1 is first used to discharge the paper, and when the transfer paper is stacked up to the height of the upper discharge roller 45, the paper discharge unit 271 Paper ejection roller 281
Start to eject the paper by. In this way, it is possible to avoid the situation where the transfer sheets discharged from the sheet discharge unit 271 drop to a deep position, so that the stacked transfer sheets do not become misaligned.

Depending on the case, the discharge roller 281 of the discharge unit 271
Only, or the upper ejection roller 45 of the printer upper unit 1
You can use only. In addition, these discharge rollers 281 and 4
5 can be used alternately.

The printer upper unit 1 of the embodiment is a printer lower unit 2
It is lifted and rotated with respect to. However, the paper discharge unit
When the upper portion of 271 is located above the printer upper unit 1 as shown in FIG. 30, the paper discharge unit 271 interferes and the printer upper unit 1 cannot be lifted as it is. Therefore, in the illustrated example, the paper discharge unit 271 is connected to the paper feed unit 266 (which may be the printer lower unit 2).
It is supported rotatably in the direction of arrow Q via a pin 282. When the printer unit 1 is opened or closed, the paper discharge unit 27
Rotate 1 in the Q direction with respect to the upper and lower units 1 and 2, and retract it to a position where it does not interfere with the opening and closing of the printer upper unit 1. The paper discharge unit 271 may be detachably attached to the paper feed unit 266 or the like, and may 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 about the pin 273 in the P direction and moved to the position shown in FIG. As a result, the paper discharge path 278 is exposed to the outside, and the jammed paper can be easily removed.

A preliminary switching claw 283 is provided at the downstream position of the lower transport roller 279. The switching claw 283 is switched between the position shown in FIG. 30 and the position shown in FIG. Preliminary switching claw 283 is the third
When in the position shown in FIG. 0, the above-described upper sheet discharge tray 9 is discharged. On the other hand, when the preliminary switching claw 283 is at the position shown in FIG. 31, the transfer sheet is ejected from the lower conveying roller 279 onto the cover 274. Such a paper discharge mode is adopted when the reverse discharge of the transfer paper is not desired. Since the cover 274 itself can also be used as a paper discharge tray, the number of parts can be reduced.

In addition, it is advantageous to configure the switching operation of the preliminary switching claw 283 in conjunction with opening and closing of the cover 274, which is advantageous because the operation is simple. For example, a switch (not shown) that is turned on / off when the cover 274 is opened / closed is provided, and when the cover 274 is opened to the position shown in FIG. 31, this switch is turned on, whereby a motor (not shown), When the drive device such as a solenoid is operated to operate the preliminary switching claw 283 from the position of FIG. 30 to the position of FIG. 31, conversely when the cover 274 is closed, the preliminary switching claw 283 is moved to the first position by the operation of the driving device. Return to the position shown.

There is also the following method. As shown in FIG. 30 and FIG. 31, the cam member 284 is fixed to the cover 274, and when the cover 274 is closed, the preliminary switching pawl 283 is operated by the action of the toggle spring 285.
To the position shown in FIG. When the cover 274 is opened, the cam member 284 integrated with the cover 274 hits the preliminary switching claw 283 to press it and rotate it to the position shown in FIG. The preliminary switching claw 283 is held in this state by the toggle spring 285.

The paper discharge rollers 281 of the paper discharge unit 271 can be configured similarly to the paper discharge rollers 40 and 45 in the upper and lower printer units 1 and 2 as shown in FIG. Further, it is 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 its supporting shaft 288.
A driven gear 289 fixed to and a drive gear 2 meshing with the driven gear 289.
It is rotationally driven through 90. Connecting member 291 on support shaft 288
However, it is mounted so that it can rotate but cannot slide in the axial direction. A nut 292 is provided at the other end of the connecting member 291, and the nut 292 is engaged with a feed screw 294 that is rotationally driven by a reversible motor 293.

With the motor 293 stopped, transfer paper is placed on the upper discharge tray 9
It is assumed that the position of the transfer paper when ejected to is the position shown by the chain line in FIG. After stacking several sheets of transfer paper in this state, the motor 293 is operated to rotate the feed screw 294. Then, the nut 292 moves in the axial direction of the feed screw 294, and the drive roller 286 accordingly moves in the same direction,
As a result, the transfer paper nipped by the rollers 286 and 287 is displaced (shifted) by δ as shown by the broken line.

The transfer paper thus displaced by δ is transferred to the upper discharge tray 9
If the sheet is discharged to the tray 9, it can be distinguished from the transfer sheet group that has been discharged onto the tray 9 before that. That is, a plurality of transfer sheets can be divided into several bundles.

Actually, as shown in FIG. 30, a sensor 295 is provided on the upstream side of the paper discharge roller 281, and when an external signal for shifting the transfer paper is input to the main controller described later,
When the sensor 295 detects the trailing edge of the transfer sheet, the motor 293 is operated based on the detection signal to shift the drive roller 286.

Electrical Equipment In FIG. 24, reference numeral 160 is a power supply input unit, which is connected to a commercial power supply via an AC plug 161. A main switch 162 and a nozzle filter 163 are included in this. Power input section
160 is arranged on the inner side of the lower frame 78 as shown in FIG. The main switch 162 penetrates the side wall of the lower frame 78 and extends to the lower portion, so that an operator can perform a switching operation from the outside. The noise filter 163 removes external noise from the supplied power.

One of power supplied from the power input unit 160 is supplied to the main controller power supply unit (main PSU) 165 via the interlock switch 164, and the other one is supplied to the character controller power supply unit (character PSU) 166. To be done. The main PSU 165 is arranged on the left side of the upper unit frame 47 as shown in FIG. 13, and has a noise filter 167, a constant voltage circuit 168, and a semiconductor relay (SSR) 169. The constant voltage circuit 168 mainly performs AC / DC conversion. SSR1
Reference numeral 69 turns on / 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, the heater 38 is additionally provided with a thermistor 235 for temperature control. This thermistor 235 is used when a minimum width transfer material such as an envelope is applied as the transfer material. Is disposed at an upper position corresponding to the transport path of the. The reason is,
Since the envelope is generally made by gluing, if the fixing temperature is too high, the glue will melt and cause a problem. Therefore, the thermistor 235 is arranged closest to the position where the minimum width transfer material such as an envelope will pass to enable accurate heater temperature control.

The interlock switch 164 is disposed on the right front side of the lower frame 78 as shown in FIG. 12, is normally off, and is turned on when pushed down. When the printer is assembled, an inner cover 170 made of resin is attached to the right end of the lower frame 78. As a result, the interlock switch 164 is set to the switch cover 17 of the inner cover 170.
Covered by 1. Switch cover 171 has a cross-shaped hole
172 is formed. The cross hole has a size such that a human finger cannot be inserted therein, but an appropriately-shaped pressing member 173 (FIG. 2) provided in a corresponding portion of the printer upper unit 1 can be inserted therein. Therefore, as shown in FIG. 2, when the printer upper unit 1 is lifted, the interlock switch 164 is turned off and power is not supplied to the main PSU, but when the upper unit 1 is closed, the interlock switch 173 is pressed by the pressing element 173. 164 is turned on and power is supplied. The reason why the cross hole 172 is not able to pass through a human finger is 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 irradiation of the laser beam is interrupted.

As shown in FIG. 3, the inner cover 170 covers the paper feed roller 32 in the mounted state. This prevents dust and the like from adhering to the paper feed roller 32, and further protects the paper feed roller 32 when the upper unit 1 is lifted.

The character PSU166 is the upper unit frame in Fig. 13.
It is arranged on the right back side of 47, and inside the
As shown, a noise filter 174 and a constant voltage circuit 175 are provided.

The main PSU 165 includes a main controller 176, a charging charger 12, and a developing bias power pack (charging / developing P
P) 177, power pack for transfer charger 30 (transfer PP) 17
8. Drives the main motor 92, various operating devices 179, etc.
Further, the fan such as the ozone fan 46 and the suction fan 50 and the fixing unit heater 38 are driven. The character PSU 166 drives the character controller 180.

The charging / developing PP 177 is arranged on the inner side of the upper unit frame 47 as shown in FIG. On the other hand, this charging / development PP17
Charger 12 and developing roller 2 driven by 7
6 is arranged in the printer lower unit 2 together with the photoconductor unit 58 and the developing unit 59, as described above with reference to FIG. 3 or FIG. Both of these units 1
The following configuration is adopted to electrically connect the components arranged over the lines 2 and 2.

First, the charging charger 12 is provided with a terminal 195 as shown in FIG. 4 (a), and as shown in FIG.
A terminal 196 is provided at the shaft end of the. Then, from the bottom surface of the printer upper unit 1 (that is, the bottom surface of the upper unit frame 47), the charging / developing PP is made to correspond to these terminals.
The power supply terminals 197 and 198 of 177 are projected (Fig. 2).
As shown in FIG. 25, the power supply terminals 197 and 198 each have a circular recess 200 having a claw 199, and a spring terminal 201 which is housed in the recess in a state where preload is generated in advance. The terminals 195 and 196 such as the charging charger enter the spring from the lower end of the spring terminal 201 when the upper and lower units 1 and 2 are closed, and the spring terminal 201 is wound around the terminals 195 and 196 and both are connected. A high voltage is applied to the terminals 195 and 196 side. Since the spring terminal 201 has a shape that widens toward the lower end, the terminals 195 and 196 can definitely enter. Also, the contact between the spring terminal and the terminals 195 and 196 is good. In addition, the spring terminal 2
Since 01 is preloaded by the claw 199, there is no contact failure.

The transfer PP 178 is located next to the paper carrying rib 124 of the lower frame 78 as shown in FIG. 12, and therefore, the transfer charger 3 in FIG.
Fixed to the right of 0. High voltage terminal from transfer PP is No. 26
As shown in the figure, it is configured as a spring terminal 202, which comes into pressure contact with the terminal 203 embedded in the end block 204 of the transfer charger 30, and applies a high voltage to the charger wire 205 connected to the terminal 203. The casing 206 of the transfer charger 30 is grounded by an integrally formed spring terminal 207 having two spring portions 207a and 207b.

An image forming unit case 60 is placed above the transfer charger 30 as is apparent from FIG. As shown in FIG. 26, spacer members 208, 208 are provided on both upper ends of the transfer charger 30.
The transfer charger 30 is pressed from below the image forming unit case 60 by the spring terminals 202 and 207a via these spacer members 208. The spacer member 208 is integrally molded with the end block 204,
The height can be accurately produced. Therefore, the transfer charger 30
The distance between the image forming unit case 60 and the image forming unit case 60 is always the spacer member 20.
It is securely kept only for the height of 8. As a result, a constant transfer operation can be performed at all times.

The main controller 176 is attached to the electrical equipment chassis 181 in the printer upper unit 1 as shown in FIGS. 13 and 3, and the charging, exposure, development, transfer, etc. described with reference to FIG. Control all printer processes. Like the main controller 176, the character controller 180 is attached to the electrical equipment chassis 181 and can be connected to the Centronics interface (S) or RS232C from the host computer 182 (Fig. 24).
The character information sent via (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 is formed according to the contents of the font cartridge 185 inserted in the font cartridge insertion opening 6 of FIG. 1 as described above.

Information from the host computer 182 is typically transmitted to the character controller 180 (possibly the main controller 176) via an interface cable.
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 upper 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 distributed within the printer, there is no risk of noise from the information from the host computer causing printing defects.

The main controller 176 has a CPU 186, a phase synchronization unit 187 including a gate array, a display drive unit 188, a scanner synchronization detection unit 189, a scanner motor driver 190, and a video interface unit 191.

The display drive unit 188 drives the operation panel 5. In the case of the present embodiment, as shown in FIG. 1, the operation panel 5 displays the size of the transfer paper placed on the paper feed tray 3 as CP.
A rotary type switch 192 for instructing the U186, a button switch group 193 for making various instructions to the character controller 180, and an LED group 194 for making various displays are provided. This operation panel 5, as shown in FIG. 13,
It is detachably attached to the front surface of the electrical equipment chassis 181, and is exposed to the outside through the opening 209 of the cover 8. If the mounting position of the operation panel 5 on the chassis 181 can be changed and the opening 209 of the cover 8 is opened at another location accordingly, the operation panel 5 can be freely moved to move the operation surface. Can be changed. In this case, it is convenient to cover the opening 209 at a separate place with a cap.

The button switch group 193 includes the following switches.

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

(Line On / Off Switch) This is for turning on / off the information transmission from the host computer 182 to the character controller 180. When the line is turned on, information is transmitted. When the line is turned off, information transmission is interrupted. By providing the line-off, it is possible to prevent information from being input from the host computer at the time of test printing of the printer or at the time of replacing the font cartridge, the emulation card, or the like.

The phase synchronization unit 187 drives the laser diode LD in the laser optical device 14 in synchronization with the print process executed by the CPU 186. Further, it receives the laser beam for synchronization detection (described above) from the optical fiber 25 via the synchronization detection unit 189 and controls the light emission timing of the LD. Further, the scanner motor 15 is phase-controlled via the scanner motor driver 190.

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

In the main controller 176, a three-terminal regulator, D
Two voltage converters 210 and 211 including C / DC converters
Is provided, and by these voltage conversion units, + 24V,
Each voltage of + 12V, + 5V, -12V is made. The drive motor, solenoid, laser diode, polygon motor, etc. of each device are controlled by these respective voltages, and each logic circuit is driven. As described above, the main controller 176 specially generates the control voltage because the control is performed by a clean power source with a small pulsating current. As a result, laser diode emission, polygon mirror rotation, and other printing processes can be executed without malfunction.
A printed product with good print quality can be obtained.

Optional interface 300 is a paper feed unit 266
When (Fig. 30) is attached, it is used when instructing the start and stop timings of the paper feed roller 269 in the paper feed unit 266.

The power supply unit is divided into the main PSU 165 and the character PSU 166 for the following reasons.

Since the interlock switch 164 is provided, when the printer upper unit 1 is lifted, the power input section is automatically
Power supply from 160 stops. In this case, the contents stored in the CPU 184 of the character controller 180 should not be erased at the same time. Therefore, a separate power supply unit for the character controller is provided.

Depending on the printer, the character controller 180 may be external rather than internal. In this case, the character PSU 166 is not particularly necessary, so the character PS
The U166 is separate.

The various operating devices 179 shown in FIG. 24 will be described in detail below. The paper feed clutch 212 controls the rotation of the paper feed roller 32. The paper transport clutch 213 controls the rotation of the lower transport roller 35. The total counter solenoid 214 is
A total counter 215 that displays the number of prints (provided on the right rear side of the lower frame 78 in FIG. 12 and visible from the window 216 of the inner cover 170) is counted up. In this embodiment, the CPU 186 of the main controller 176
The solenoid 214 is programmed to count up by "1" each time the transfer charger is turned on in the printing process of FIG. The reason for counting up based on the transfer operation is to ensure that the number of printed products and the count value correspond exactly to one-to-one. If some process before the transfer operation in the print process is taken as a reference, when the transfer paper is removed on the way due to a jam or the like, the number of printed products and the count value do not have a one-to-one correspondence.

The latching solenoid 217 is assembled as one component of the suction fan unit 49 in FIG. 15 (the operation itself is not directly related to the suction fan 50). Detailed operation will be described later.

In FIG. 24, a registration sensor 219, a paper discharge sensor 220, a toner over sensor 221, a paper end sensor 222, a latch sensor 223, and an input device 218 that sends a signal serving as a process reference to the CPU 186 of the main controller 176.
A toner end sensor 224 is provided.

The registration sensor 219 is arranged on the right side of the transport rollers 34, 35 in FIG. The start timing of the lower conveyance roller 35 is determined based on the timing when the transfer paper passes through the registration sensor.

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

The toner over sensor 221 is arranged above the detection filler 225 provided in the upper part of the toner recovery tank 57 in FIG. 3 (attached to the printer upper unit 1). Waste toner cleaned from above the photoconductor 11 accumulates in the toner recovery tank 57, and when it is full, the detection filler 225 is lifted upward by the waste toner,
It is detected by the toner over sensor 221.

The paper end sensor 222 is the paper feed roller 3 in FIG.
It is arranged on the right side of 2, that is, above the leading end of the paper feed tray 3. When the transfer paper runs out on the tray 3, it is detected.

The latch sensor 223 is arranged above the latching solenoid 217 in FIG. It is turned off when the optical path is blocked by the plunger of the solenoid 217.

The toner end sensor 224 is a micro switch arranged at the bottom of the printer upper unit 1 so as to be located above a cam mechanism 226 provided at one end of the developing unit 59 as shown in FIG. (Fig. 2). Cam mechanism 226
Has a cam 228 mounted on the rotary shaft of a toner stirring member 227 (FIG. 2) in the developing tank 28, and a lever 230 that abuts on the outer peripheral surface of the cam 228 and swings around a pin 229. ing. The lever 230 is pressed against the cam 228 by the spring 231.

In FIG. 3, the toner stirring member 227 stirs the toner in the developing tank 28. The cam 228 is composed of two cam plates each having a recess (not shown in detail), and when the stirring resistance of the stirring member 227 is large (when there is a sufficient amount of toner), the recesses are different from each other. The lever 230 abutting against it is always lifted upward to turn on the toner end sensor 224. When the agitation resistance decreases (when the toner runs out), one cam plate rotates and the recesses of both cam plates overlap, and the lever is inserted into that recess.
230 falls, the toner end sensor 224 turns off, and the toner end is detected.

As is clear from the above description, the toner end is the lever 23
It is detected by turning on / off the micro switch due to the upward movement of 0. Therefore, the distance between the lever 230 and the actuator of the micro switch needs to be always kept constant. Therefore, in this embodiment, as shown in FIG. 7, the toner end sensor 224, which is a micro switch, is supported by a holder 232 formed by bending a spring material, and the holder 232 is fixed to the printer upper unit 1. At the same time, the actuator portion of the microswitch is configured to project from the printer upper unit 1 toward the printer lower unit 2 (see FIG. 2).

When the upper unit 1 and the lower unit 2 of the printer are closed, the protrusions 233, 233 of the developing unit 59 in FIG. 7 cause the protrusions 233, 233 of the microswitch while bending the holder 232 upward.
Push up 4. When the upper and lower units 1 and 2 are locked, the two protruding pieces 233 and 234 are fixed in position with a distance corresponding to the height of the switch protruding piece 234 while exerting pressure on each other. Thus, the distance between the lever 230 and the actuator of the micro switch is kept constant.

A line 236 in FIG. 24 shows a ground line connected between the electric devices. In the embodiment, as shown in FIG. 27, the ground substrate 237 is the lower frame 78 of the printer lower unit 2.
It is fixedly installed in. However, most of the devices shown in FIG. 24 are arranged in the printer upper unit 1 as described above. Since the upper and lower units 1 and 2 rotate about the hinge pin 238, it is necessary to devise a means for connecting the ground line of each device in the printer upper unit 1 to the ground substrate 237 of the printer lower unit 2.

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

By using the stepped screw 242, the connection plate 241 is not connected to the ground plate 240 and the metal plate 239 by screw force, but contact is secured by the spring property of the curved terminal portions 241a, 241b themselves. There is. This prevents the contact state of the contact portion from deteriorating with time, and a good contact state can be permanently obtained. Further, since the entire connecting plate 241 is finished in a curved shape, the connecting plate 241 can freely follow the rotation even when the upper and lower units 1 and 2 rotate with each other, and the terminal portion 241a, It does not put a heavy burden on 241b.

When the printer upper unit 1 is lifted and rotated, depending on the shape of the curved portion 241c of the connection plate 241, the connection plate 241 may be changed.
May hit the screw 242. Even in such a case, a guide plate 243 that extends in the direction perpendicular to the paper surface and has a smooth curved surface for the connection plate 241 may be provided at the screw 242 so that the connection plate 241 is not scratched.

The power input unit 160 in FIG. 24 is the printer lower unit 2
It is provided in. On the other hand, the main PSU 165 and the character PSU 166 connected to the power input unit 160 are the printer upper unit 1
It is provided in. Therefore, the cable connecting these is wired between the upper and lower units. This cable is protected by being surrounded by a metal spring tube 245 as indicated by reference numeral 244 in FIG.
Flexible and cable because it is a spring tube
Does not constrain the bending freedom of 244. In addition, since the printer upper unit 1 is repeatedly opened and closed because it is a metal tube, the cable 244 may be rubbed against the lower frame 78 or the cover 8 (FIG. 13) by the sprinter tube 245.
Will not be damaged.

Control process In this embodiment, the CPU 186 of the main controller 176 shown in FIG. 24 is used.
This controls and executes the print process and various processes associated with it. The above-mentioned printing process including the steps of charging, exposing, developing, transferring, etc. is as described in the operation relating to FIG.

In the following, some other important processes associated with the printing process will be explained.

(Printing Custom Size Paper) In this embodiment, the operation panel 5 is provided with a rotary switch 192 for designating the size of the transfer material as shown in FIGS. With this switch 192 B5,
A paper size such as A4 is specified. Further, in consideration of the case of printing on envelopes of various sizes, it is possible to specify an irregular size for not specifying the size. When the operator adjusts the size switch 192 to the desired size such as B5, A4, etc., the transfer material conveyance timing setting for the printing process and the character arrangement (setting such as how many characters can be printed on one page) can be set. It is done according to each size. For example, regarding the jam of the transfer material, after the leading edge of the transfer material is detected by the registration sensor 219, the paper discharge sensor 220, etc., the rear end of the transfer material is detected by the same sensor after the conveyance time corresponding to the size of the transfer material. If not, it is determined that a jam has occurred. When a custom size is specified, various timing settings for the print process are made based on the maximum size of the sizes that can be specified.

If the size switch 192 is fitted to a standard size paper such as B5 or A4, the jam detection is performed without any trouble. However, when the operator selects an irregular size to print on envelopes of various sizes, the size of the envelope is generally quite small.
The jam detection using the 219 or the like may not be performed normally. Therefore, in this embodiment, the paper size switch
When the irregular size is designated by 192, the jam detection work is not performed, and the smooth progress of the printing process is ensured.

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

Note that when the size switch 192 is set to an irregular size and printing is performed on the envelope, the temperature of the heating roller 36 of the fixing device can be programmed to be slightly lower than that during normal printing. This is because the envelope is generally made by gluing, and if the fixing temperature is too high, the glue will melt. However, even in this case, it should be noted that if the temperature is lowered too much, fixing failure may occur. Generally, a reduction of about 20% can prevent the adhesive from melting while maintaining sufficient fixability.

In the above description, when the irregular size is selected, the printing process based on the maximum size transfer material is performed and the jam detection function is omitted.
Separately from this control method, when an irregular size is specified, the process with the maximum size material as the reference is executed for the first transfer material, but the first transfer material is conveyed. After the size of the transfer material is detected during this period, the printing process can be performed on the second and subsequent transfer materials based on the detected size. According to this method, high-speed printing can be performed in conformity with the transfer material size.

(Transfer Material Size Abnormality Information) The operator can specify the paper size with the paper size switch 192. This designation is made by selecting the same size as the size of the transfer material placed on the paper feed tray 3. Therefore, normally, the size designated by the switch 192 and the transfer paper size on the paper feed tray 3 are the same. However, there is a possibility that both 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, printing for B5 size is performed on A4 size paper and the margin becomes too large, or conversely, several sizes are printed for the number of prints. It may be insufficient.

In order to solve this, in this embodiment, when the print process is started and the first transfer sheet is conveyed into the printer, the transfer sheet size of the first transfer sheet is confirmed and detected. When the size and the size designated by the switch 192 are different, the fact is displayed on the operation panel 5 by an LED and the printing operation is stopped. This minimizes defective print products.

In this case, the first transfer sheet once sent into the printer is discharged outside by the discharge rollers 40 or 45.
A special sensor for detecting the transfer paper size 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 notified 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 retain the print information that is about to be printed. Otherwise, the print information that has been formed will be lost due to a paper size designation error.

(Replacement instruction control of photoconductor unit) It is arranged above the suction fan unit 49 of FIG.
The OPC counter 250 is a photoconductor unit 58 (Fig. 4 (a)).
The number of prints for each portion (cleaning unit) related to cleaning such as the toner recovery tank 57 and the cleaning blade 55 in the inside is counted.

The OPC counter 250 counts up in response to a transfer command signal from the main controller 176. When the count reaches 10,000, the main controller 17 sends a signal to that effect.
6 (FIG. 24), and the main controller 176 displays a photoconductor unit replacement display on the operation panel 5. or,
If the toner over sensor 221 (Figs. 3 and 24) detects toner over before the OPC counter 250 counts to 10,000, the fact is sent to the main controller 176, and the photoconductor unit is replaced in the same manner as above. Display is made.

On the other hand, in FIG. 4A, a unit identification projection 301 is formed on the upper surface of the case 61 of the photoconductor unit 58 carrying the new photoconductor 11. This protrusion is a type sensor 30 provided on the bottom surface of the printer upper unit 1 in FIG.
Detected by 2. When the above-mentioned photoconductor unit replacement display is made, the unit identification protrusion 301 is attached to the type sensor 302.
If it is detected (that is, if the photoconductor 11 has not been used 10,000 times), "1" is displayed together with the photoconductor unit replacement display.

Simultaneously with the display of "photoconductor unit replacement" 1 "", the latching solenoid 217 is turned on and the plunger is pulled down, which turns on the latch sensor 223. As long as the latch sensor 223 is turned on , "Photoconductor unit replacement" 1 "" continues to be displayed.Once the latch sensor 223 is turned on, the OPC counter
When the reset lever 251 for resetting 250 is reset as indicated by arrow J, it is simultaneously turned off (initial state).

The display of "photoconductor unit replacement" 1 "" indicates that the photoconductor has been used 10,000 times for convenience (the toner may be over before counting 10,000 times, but the toner recovery tank 57 (3rd In the figure, the capacity is designed so that the waste toner will be full when general printing is performed 10,000 times.Therefore, when the toner is detected over 10,000 times, the "photoreceptor unit replacement" 1 "is detected. When "is displayed, it is considered that the photoconductor has been substantially used 10,000 times." Therefore, the operator who sees this display replaces the cleaning unit of the photoconductor unit 58. The life of 11 is 20,000 times in the embodiment, and therefore, there is still 10,000 more lives, so it is not replaced.Remove the photoconductor 11 from the photoconductor unit 58, and discard only the cleaning unit.

To replace the cleaning unit, replace the old photoconductor unit 58 with a new photoconductor unit 58 that has an empty toner recovery tank 57, and mount the photoconductor 11 that has been used 10,000 times.
The photoconductor unit is attached to the printer lower unit 2 at a predetermined position. The case 61 of the new photoconductor unit is selected without the unit identification projection 301. After that, when the operator pushes the reset lever 251, the latch sensor 223 is initialized, and at the same time, the OPC counter is reset. Therefore, after that, the OPC counter starts counting from zero again. Even if the unit is replaced, the latch sensor 223 is not initialized unless the reset lever 251 is pressed, so that the display of "photoconductor unit replacement" 1 "" is continued. That is, the latch sensor 223 is the OPC counter after the unit replacement. Prevents forgetting to reset.

After that, printing is repeated and the OPC counter is set to 1 again.
When counting ten thousand times or when toner over is detected, the photoconductor unit replacement display is again displayed. However,
This time there is no unit identification protrusion 301 so type sensor 3
02 does not detect this. Therefore, the display at this time is a display such as "photoreceptor unit replacement" 2 "".
This display indicates that the unit has been replaced for the second time
This means that the photoconductor has been used ten thousand times or nearly the same number of times, which means that the life of the photoconductor itself has expired. Therefore, the operator replaces the entire photoconductor unit 58 together with the photoconductor 11 with a new one by displaying "photoconductor unit replacement" 2 "".

Transfer / Electrification Removal Cleaner In this embodiment, as shown in FIG. 3, an electricity removal lamp 54 and a transfer charger 30 are arranged adjacent to each other. Both can be cleaned simultaneously by using the cleaner 252 shown in FIG. The upper transparent plate 253 of the static elimination lamp 54 is cleaned with a felt 254. The charge wire 205 of the charging charger 30 is a polishing cloth 25 made of polyurethane rubber or the like.
Cleaned at 5. When cleaning, attach felt 254 to transparent plate 253 and polishing cloth 255.
Are simultaneously pressed against the charge wires 205, and in that state, the entire cleaner 252 is moved in the direction perpendicular to the paper surface.
This removes toner and other dust. The clip 256 is for hooking the cleaner 252 at an appropriate place in the printer. The guide protrusion 257 is provided on the lower frame 78 so as not to push the charge wire 205 or the like too much.
It engages with a projecting portion (not shown) of FIG.

Effect According to the present invention, the first engaging portion and the elastic body for biasing are integrated with the lock lever so that the elastic body automatically biases the first engaging portion when the lock lever is mounted on the unit. It has become. Therefore, the assembly of the lock mechanism is very simple.

[Brief description of drawings]

FIG. 1 is an external perspective view of a laser printer according to an embodiment,
2 is a perspective view showing a state where the upper unit of the laser printer of FIG. 1 is opened, FIG. 3 is a side sectional view of the laser printer, and FIG. 4 is an exploded perspective view of an 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 gear meshing state, and FIG. FIG. 10 is a perspective view of another part of the developing unit, FIG. 10 is a view taken along the 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 printer. FIG. 13 is an exploded perspective view showing a part of the lower unit, 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. Figure, 16th
The figure shows an exploded perspective view of part of the suction fan unit.
Figure is a perspective view of the paper ejection guide member, Figure 18 is a front view of the drive system, Figure 19 is a perspective view of the paper ejection roller, Figure 20 is a perspective view of the paper ejection ring, and Figure 21 is the paper ejection path. FIG. 22 is a perspective view of the switching means, FIG. 22 is a perspective view of a part of the positioning means of the printer upper unit,
FIG. 23 is a perspective view of the mirror fixing means of the laser optical device,
FIG. 24 is a control circuit diagram, FIG. 25 is a side sectional view of the high-voltage connecting terminal portion, FIG. 26 is a diagram showing the installation state of the transfer charger, 27
The figure is a cross-sectional view of one means of grounding the upper and lower units.
FIG. 28 is a sectional view showing a two-stage rotation structure of the printer upper unit, FIG. 29 is an explanatory view of a transfer / static elimination cleaner, and FIG. 30 is a side sectional view showing a state in which an optional paper feeding unit is mounted,
FIG. 31 is a side sectional view of an optional paper discharging unit, FIG. 32 is a perspective view of an example of a paper discharging roller, FIG. 33 is a perspective view of an example of a supporting means of a second cylindrical lens, and FIG. 34 is a second cylindrical. It is a perspective view of the state of the tip device of a lens. 1 …… Unit (upper printer unit) 2 …… Unit (printer lower unit) 145 …… Lock lever 147 …… Elastic body 148 …… First engaging part (lock claw) 149 …… Second engaging part (hook) )

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Makita 1-3-3 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Co., Ltd. (72) Yoshiro Tanaka 1-3-3 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Inventor Takahiro Yanagishita 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company (72) Inventor Takanori Yamaki 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company ( 72) Inventor Takeshi Motohashi 1-3-6 Nakamagome, Ota-ku, Tokyo, within Ricoh Co., Ltd. (72) Inventor Masayoshi Miyamoto 1-3-6 Nakamagome, Ota-ku, Tokyo In-Ricoh, Inc. (72) Inventor Hisao Ishizu 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Yasuhiro Sagawa 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company In Ricoh (72) Inventor Tadaaki Sugano 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Tomoo Sanoda 1-3-6 Nakamagome, Ota-ku, Tokyo In Ricoh Co., Ltd. (72 ) Inventor Hiroshi Hosokawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (1)

[Claims] 1. An electrostatic recording apparatus having two units that can be separated from each other, wherein one of the units is detachably provided with a lock lever having a first engaging portion, and the other unit is provided with the lock lever. The second engaging with the first engaging portion
The lock lever is rotationally biased so that the first engaging portion is biased in the direction toward the second engaging portion when the lock lever is attached to the unit integrally with the engaging portion and the lock lever. An electrostatic recording device having an elastic body.