JPH02245772A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To always precisely regulate the positional relation among an electrostatic latent image carrier, a transfer electrifier, and a transfer unit by providing an electrostatic recorder with an elastic holding means for holding a cartridge in a lower housing part and with a positioning means for positioning the cartridge in a prescribed position when an upper housing part is closed. CONSTITUTION:The electrostatic recorder is provided with the elastic holding means 50 and 52, both of which hold the cartridge 48 in the lower housing part 42a, and the positioning means 66, 68, 70, and 72, all of which position the cartridge in the prescribed position in relation to the upper housing part 42b when the part 42b is closed. In this way, when the upper housing part 42b is closed, the cartridge is positioned in the prescribed position in relation to the upper housing part 42b by the positioning means 66, 68, 70, and 72 all of which are provided between the upper housing part 42b and the cartridge 48, therefore the electrostatic latent image carrier, the transfer electrifier, and the fixing unit, all of which are in the cartridge, can be positioned always under the prescribed, proper relation in terms of arrangement.

Description

[Detailed Description of the Invention] [Summary] An electrostatic recording device that uses, for example, a photosensitive drum or a dielectric drum as an electrostatic latent image carrier, in which at least the electrostatic latent image carrier and a toner developing section are integrated into a unit. Regarding an electrostatic latent image device configured so that a cartridge can be replaced, the electrostatic latent image device is configured so that the mutual positional relationship of the electrostatic latent image carrier, transfer charger, and transfer device can be strictly regulated at all times. In order to provide an electrostatic recording device, the housing is divided into a lower housing part and an upper housing part, the upper housing part can be opened and closed with respect to the lower housing part, and the lower housing part has at least A cartridge containing an electrostatic latent image carrier and a toner developing section is housed in a unit, a transfer charger and a fixing device are housed in the upper housing part, and when the upper housing part is closed, the transfer charger and fixer are attached to the bottom side. In an electrostatic recording device adapted to be positioned in a predetermined position with respect to a housing part, an elastic retaining means is provided for retaining the cartridge in an elastically suspended state within the lower housing part, and a resilient retaining means for retaining the cartridge in a resiliently suspended state within the lower housing part; An electrostatic recording device is constructed, comprising positioning means provided between the upper housing part and the cartridge to position the cartridge at a predetermined position with respect to the upper housing part.

[Industrial application field]

The present invention is an electrostatic recording device that uses, for example, a photosensitive drum or a dielectric drum as an electrostatic latent image carrier, and in which at least a cartridge in which the electrostatic latent image carrier and a toner developing section are integrated is replaceable. The present invention relates to a constructed electrostatic latent image device.

[Conventional technology]

In an electrostatic recording device, an electrostatic latent image is formed on the surface of a photosensitive drum or dielectric drum that is an electrostatic latent image carrier, and this electrostatic latent image is developed with charged toner to become a visible image. .

A recording medium, ie, paper, is then applied to the toner image, and the paper is charged from the back side with a polarity opposite to that of the charged toner, thereby electrostatically transferring the toner image to the paper. The paper having such a transferred toner image is separated from the drum and sent to, for example, a heat fixing device.
The transferred toner image is then thermally fixed onto the paper.

In recent years, such electrostatic recording devices have become popular as printers for personal computers, word processors, etc., and as recorders for facsimiles, and in particular, printers used for personal use are becoming smaller and easier to use. considered a problem. Therefore, an electrostatic recording apparatus has been developed in which a cartridge in which an electrostatic latent image carrier and a toner developing section, which are the heart of the electrostatic recording apparatus, are integrated into a unit can be replaced.

In other words, by using such a cartridge system, not only can the electrostatic recording device itself be made more compact, but also the troublesome maintenance of the electrostatic latent image carrier and the time-consuming toner replenishment can be eliminated. .

Referring to FIG. 2(a) and FIG. 2(b), a conventional electrostatic recording device employing such a cartridge system is shown, and this electrostatic recording device is configured as a printer applying the principle of electrophotography. , this printer is indicated generally by the reference numeral 10.

The printer 10 includes a generally rectangular housing 12, which is composed of a lower housing portion 12a and an upper housing portion 12b that are divided horizontally. On one end side of the housing 12, the lower housing part 12a and the upper housing part 12b are designated by the reference numeral 1.
The upper housing portion 12b is pivotally connected to each other as shown at 4, so that the upper housing portion 12b can be opened and closed with respect to the lower housing portion 12a.

A cartridge 18 in which an electrostatic latent image carrier, that is, a photoreceptor drum 16, and a toner developing section (not shown) are integrated into a unit is installed in the lower housing portion 12a. is positioned in a predetermined position. Also, the second
Although not shown in Figures (a) and 2(b),
A charger for applying a negative charge to the photosensitive layer of the photosensitive drum 16, and a photo array for writing an electrostatic latent image on the charged area of the photosensitive layer are also installed at predetermined locations within the lower housing portion 12a. Furthermore, a control unit, a power source, etc. are also accommodated within the lower housing portion 12a.

On the other hand, inside the upper housing portion 12b is a photosensitive drum 1.
A transfer charger 20 is installed to charge the paper in order to electrostatically transfer the toner image (an electrostatic latent image developed with toner) held on the paper onto the paper.
is supported suspended from the upper housing portion 12b by suitable resilient means, such as a swivel spring 22.

When the upper housing portion 12b is placed in the closed position as shown in FIG. 2(b), the transfer charger 20 abuts a positioning member (not shown) provided on the lower housing portion 12a or the cartridge 18, As a result, the transfer charger 20 is positioned at a predetermined position relative to the photosensitive drum 16.

Moreover, as shown in FIG. 2(a) and FIG. 2(b),
A paper feed hopper 24 is integrally formed in the upper housing portion 12b, in which paper, ie cut sheet paper P
is accommodated. A pick roller 26 is provided in the paper feed hopper 24 so as to be constantly engaged with the paper P.
The paper P is sequentially fed out from the paper feed hopper 24 by the pink roller 26 during printing operation. A pair of registration rollers 28 are provided in the upper housing portion 12b near the paper discharge port of the paper hopper 24, and the pair of registration rollers 28 once catch the paper fed out from the paper hopper 24, and then transfer it to the photoreceptor drum 16. It has a function of feeding the sheet of paper toward the transfer charger 20 in accordance with the electrostatic latent image writing timing. As best shown in FIG. 2(b), a pair of guide rollers 30 are arranged on the front side of the transfer charger, and the paper fed by the pair of registration rollers 28 passes through the pair of guide rollers 30 to be transferred and charged. It is introduced between the container 20 and the photosensitive drum 16.

As is clear from FIG. 2(a), a pair of guide rollers 3
0 is supported on the lower housing portion 12a side, and the other guide roller 30 is supported on the upper housing portion 1
2b side, and when the upper housing portion 12b is closed, both guide rollers 30 function as a pair.

Furthermore, a heat roller 3 is disposed within the upper housing portion 12b.
2 and a backup roller 34 is installed, and like the transfer charger 20, this heat fuser is also supported in a suspended state from the upper housing portion 12b by suitable elastic means, such as a coil spring 36. be done. As shown in the figure, the heat fixing device is disposed downstream from the transfer charger 20, and the paper (having the transferred toner image) discharged from the transfer charger 20 is placed between the heat roller 32 and the bank up roller 34. The transferred toner image is thereby thermally fixed onto the paper. Note that the paper after thermal fixing is discharged to the outside of the printer 10 by a pair of discharge rollers 38, and the pair of discharge rollers 38 are also installed on the upper housing portion 12b side.

[Problem to be solved by the invention]

By the way, in the above-mentioned cartridge type printer, in order to obtain a high-quality recorded image, one cartridge is required.
It is important to strictly control the mutual positional relationship of the photosensitive drum 16, the transfer charger 20, and the thermal transfer device (32, 34) in the image forming apparatus 8. This is because unless the transfer charger 20 is accurately positioned with respect to the photoreceptor drum 16, the toner image will not be properly transferred from the photoreceptor drum 16 to the paper.゜34) If the positioning is not performed accurately, the paper with the transferred toner image will be moved between the heat roller 32 and the backup roller 3.
This is because it will not be possible to smoothly introduce it between the two. Needless to say, the transferred toner image is simply electrostatically adhered to the paper, and if the smooth introduction of the paper into the heat fixing device is obstructed, so-called transfer misalignment may occur.

Therefore, in conventional cartridge type printers, as described above, the transfer charger and heat fixing device are suspended by coil springs, etc., and the transfer charger and heat fixing device are brought into contact with the positioning member when the upper housing portion is closed. This allows accurate positioning of these objects to be obtained at all times.

However, in the configuration of conventional cartridge printers, the cartridge is simply positioned at a predetermined position relative to the lower housing part, and this allows the upper housing part to, for example, pivot at the lower housing part. If it is displaced relative to the lower housing part due to so-called backlash, accurate positioning of the transfer charger and heat fixing device with respect to the photosensitive drum in the cartridge cannot be guaranteed, and as a result, high-quality recording cannot be achieved. It becomes difficult to constantly obtain images.

Therefore, an object of the present invention is to provide an electrostatic recording device that employs the cartridge system as described above, in which the mutual positional relationship of the latent image carrier, transfer charger, and transfer device is always strictly maintained. An object of the present invention is to provide an electrostatic recording device configured to be regulated.

According to US Pat. and positioning means provided between the upper housing part and the cartridge for positioning the cartridge in a predetermined position.

[Means to solve the problem]

In order to achieve the above object, in the electrostatic recording device according to the present invention, the housing is divided into a lower housing part and an upper housing part, and the upper housing part can be opened and closed with respect to the lower housing part. . The lower housing part accommodates a cartridge in which at least an electrostatic latent image carrier and a toner developing section are integrated, and the upper housing part accommodates a transfer charger and a fixing device. A charger and a fuser are positioned in position relative to the lower housing portion. [Function] of the present invention As is clear from the above configuration, in the electrostatic recording device according to the present invention, the cartridge in which at least the electrostatic latent image bearing member and the toner developing section are unitized is held in the lower housing part by the elastic holding means. When the upper housing part is closed, it is positioned in a predetermined position relative to the lower housing part by positioning means provided between the upper housing part and the cartridge. The electrostatic latent image carrier, the transfer charger, and the fixing device are always positioned in a predetermined proper arrangement relationship.

〔Example〕

Next, an embodiment of an electrostatic recording apparatus according to the present invention will be described with reference to FIGS. 1(a) and 1(b) of the accompanying drawings. The electrostatic recording device shown in FIGS. 1(a) and 1(b) is a printer that applies the principle of electrophotography as in the case of FIGS. 2(a) and 2(b). The printer is generally designated by the reference numeral 40.

Similar to the conventional case shown in FIGS. 2(a) and 2(b), the printer 40 also includes a substantially rectangular housing 42, which is horizontally divided into a lower housing portion 42a. and an upper housing portion 42b. Further, on one end surface side of the housing 42, a lower housing portion 42a and an upper housing portion 42b are provided.
are pivotally connected to each other as indicated by reference numeral 44, whereby the upper housing portion 42b is connected to the lower housing portion 4.
The same applies to the point that it can be opened and closed freely with respect to 2a.

A cartridge 48 in which an electrostatic latent image carrier, that is, a photosensitive drum 4G, and a toner developing section (not shown) are integrated into a unit is installed in the lower housing portion 42a. Unlike the case shown in FIG. Specifically, the bottom of the lower housing portion 42a is provided with elastic retaining means consisting of a pair of coil springs 50 and a support plate element 52 mounted on each coil 50. The cartridge 48 is placed on top, and thereby the cartridge 48 is held in an elastically floating state.

As is clear from FIG. 1(a) and FIG. 1(b),
The central part of the bottom of the cartridge 48 (that is, the part between the pair of coil springs 50) is recessed inward, and within this recess is a charger for applying a -like charge to the photosensitive layer of the photoreceptor drum 46, and a photosensitive member therefor. e.g. a photoarray (none of which is shown) for writing an electrostatic latent image in the charged areas of the layer.
will be installed. Note that reference number 54 indicates a casing portion disposed within the lower housing portion 42a, and this casing portion 54
A power supply, control circuit, etc. are housed inside.

Furthermore, this photoarray, for example, an LED array head, has gap rollers at both ends, and these gap rollers are brought into contact with the non-image areas at both ends of the photoreceptor drum 46, and the entire LED array head is placed on the photoreceptor drum 46. It has means such as a leaf spring that biases the cartridge 48 in the direction.
It is configured to have a predetermined positional relationship with the photoreceptor drum 46 inside.

On the other hand, a transfer charger 56 is provided in the upper housing portion 42b.
2(a) and 2(b), this transfer charger 56 is also separated from the upper housing portion 42b by suitable elastic means (not shown). The transfer charger 56 is supported in a suspended state, and when the upper housing portion 42b is closed, the transfer charger 56 is attached to the cartridge 4 housed in the lower housing portion 42a.
8 is positioned at a predetermined position. Further, a heat fixing device consisting of a heat roller 58 and a backup roller 60 is provided in the upper housing portion 42b, and the support mode of this heat fixing device is also similar to that shown in FIGS. 2(a) and 2(b).
), and when the upper housing portion 42b is closed, the thermal fuser is positioned at a predetermined position relative to the lower housing portion 42a. Furthermore, a pair of rollers 62 held on the upper housing portion 42b side are similar to the ejection rollers 38 shown in FIGS. It has the function of ejecting water from the Note that the sheets sequentially discharged from the housing 42 are held on a paper tray 64 extending from the lower housing portion 42a.

Printer 40 shown in FIG. 1(a) and FIG. 1(b)
In this case, the paper feed hopper 65 is also integrally formed in the upper housing portion 42b, but its internal structure is shown in FIG.
This is similar to the case of the paper hopper 24 shown in a) and FIG. 2(b). In addition, Fig. 1(a) and Fig. 1(b)
Both the pair of registration rollers 28 and the pair of guide rollers 30 shown in FIG. 1A and FIG. 1B are omitted from the printer 40 of FIGS. 1A and 1B for the purpose of simplifying the illustration.

As already mentioned, the printer 40 according to the present invention is characterized in that the cartridge 48 is held in an elastically floating state, and the printer 40 according to the present invention holds the cartridge 48 in the lower housing portion when the upper housing portion 42b is closed. It is also characterized by positioning means provided between the upper housing part 42b and the cartridge 48 for positioning it in a predetermined position relative to the part 42a. Specifically, such positioning means are located on both side walls of the upper housing portion 42b (FIG. 1(a) and FIG. 1(b)).
two notches 66 and 68 formed in the lower edge of each
In order to abut and engage with each of these notches 66 and 68, both side walls of the cartridge 48 (only one side wall can be seen in FIGS. 1(a) and 1(b)). When the upper housing portion 42b is closed (FIG. 1(a)), the locating pin elements 70 and 72 protrude from the upper edge of the corresponding side wall (see FIG. 1(a)). 66 and 68, thereby positioning cartridge 48 in position relative to lower housing portion 42a.

In the embodiment described above, the cutouts 66 and 68 are formed on the upper housing portion 42b side and the locating pin elements 70 and 72 are provided on the cartridge 48 side, but it goes without saying that the arrangement relationship can be reversed. Further, the positioning means may be configured in other ways instead of the notch and the positioning pin element, for example, a patterned protrusion provided on either the upper housing portion or the cartridge, and the other. It can also be configured with an engaging recess formed in the.

Further, in the above-described embodiment, a coil spring is used as an elastic holding means for holding the cartridge in an elastically floating state, but other elastic elements such as a leaf spring, a rubber material, a sponge material, etc. can be used as the elastic holding means. may be configured.

〔Effect of the invention〕

As is clear from the above description, in the electrostatic recording device according to the present invention, when the upper housing portion is closed, the cartridge is always positioned at a predetermined position with respect to the lower housing portion, so that the electrostatic recording device in the cartridge is Since a predetermined proper arrangement relationship is obtained for the latent image carrier, transfer charger, and fixing device, even if there is a so-called looseness at the pivot joint between the lower housing part and the upper housing part, It becomes possible to stably obtain high-quality recorded images over a long period of time.

[Brief explanation of drawings]

FIG. 1(a) is a side view of a printer embodying the present invention, showing the upper housing portion of the printer in an open state and showing the lower housing portion of the printer so that the interior of the printer can be observed. FIG. 1(b) is a side view similar to FIG. 1(a), with most of the side wall cut away, and FIG. a) is a side view of a conventional printer showing the upper housing portion of the printer in an open state and sectionalizing the side walls of the lower and upper housing portions of the printer to enable observation of the interior of the printer; FIG. 2(b) is a side view similar to FIG. 2(a), showing the upper housing portion in a closed state. 40...Printer, 42...Housing, 4
2a... Lower housing part, 42b... Upper housing part, 44... Pivot part, 46... Photosensitive drum, 4
8...Cartridge, 50...Coil spring, 52.
...Support plate element, 56...Transfer charger, 58...
Heat roller, 60... Backup roller, 66, 68... Notch, 70, 72... Positioning pin element. (Q) (b) Side view of the printer according to the present invention No. 1 (b) Side view of the conventional printer No. 28

Claims (1)

[Claims] 1. The housing (42) is attached to the lower housing portion (42a).
) and an upper housing part (42b), the upper housing part can be opened and closed with respect to the lower housing part, and the lower housing part contains at least an electrostatic latent image carrier (46) and a toner developer. A transfer charger (56) and a fixing device (58, 6) are housed in the upper housing part.
0), and the transfer charger and the fixing device are positioned at predetermined positions with respect to the lower housing portion when the upper housing portion is closed, the electrostatic recording device (40) comprising: Resilient retention means (50, 52) for retaining the cartridge in an elastically floating state within the lower housing portion.
and positioning means (66, 68, 70, 7) provided between the upper housing part and the cartridge for positioning the cartridge in a predetermined position relative to the upper housing part when the upper housing part is closed.
2) An electrostatic recording device comprising: