JPS62971A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To reduce the size, weight and cost of a titled device by irradiating light from the rear of an original through the slit of a light shielding member in a transparent cylinder which rotates in tight contact with a photosensitive body or while facing the same apart at a gap smaller than the thickness of the original. CONSTITUTION:Various operation timings are controlled when the insertion of the original 6 is detected by a transmission type optical sensor 8. The inserted original 6 is then conveyed downward between a supporting roller 4 under rotation and the transparent cylinder 9 while the original is held in tight contact with the photosensitive body 5. A light source 10 for original exposure is fixed and disposed in the transparent cylinder 9 under rotation and the light from a light source 10 is irradiated from the rear side of the original 6 toward the photosensitive body 5 side while the optical path thereof is controlled by the slit 11 of the light shielding member 12 fixed and disposed around said light source. The electrostatic latent image corresponding to the original image is eventually transferred and formed on the electrostatically charged photosensitive body 5.

Description

[Detailed description of the invention] Technical field The present invention relates to an electrophotographic reproduction apparatus.

2. Description of the Related Art In general, an electrophotographic copying machine uses an imaging lens or a focusing light transmitting member (for example, a SELFOC lens array) to form an electrostatic latent image by focusing an original image on a photoreceptor. It uses an optical system that includes As a result, the cost is high for personal use.

It cannot be said to be a personal item suitable for desk-side use within a company.

Purpose The present invention was made in view of the above points.
It is an object of the present invention to provide an electrophotographic copying device that is lightweight, inexpensive, and suitable for personal use.

Structure In order to achieve the above object, the present invention brings a sheet-like original into close contact with a charged photoconductor, irradiates light from the back side of the document, and forms an electrostatic latent image on the photoconductor by the transmitted light. In an electrophotographic copying device that uses an original contact type exposure method, a light source that irradiates light from the back side of the original is provided, and a slit is formed around this light source to regulate the direction of light irradiation in the area where the original and the photoreceptor are in close contact. The present invention is characterized in that a light-shielding shield member is provided, and a transparent cylinder that rotates around the light-shielding member in close contact with the photoreceptor or facing the photoreceptor with a gap less than the thickness of the document is provided.

Hereinafter, one embodiment of the present invention will be described based on the drawings. First, FIG. 2 shows the external appearance of the copying machine 1 according to this embodiment, in which one removable leg 2 is attached. FIG. 3 shows a schematic internal configuration of such a copying machine 1, and FIG. 1 shows an enlarged view of its main parts. A belt-shaped photoreceptor 5 is provided approximately at the center of the copying machine 1 and is rotated clockwise while being supported by support rollers 3 and 4 provided above and below. With respect to such a photoconductor 5, a lower insertion lower portion for inserting a sheet-like original 6 is formed, which is directed from an obliquely upper part of the front side toward the support roller 4 side. A transmission type optical sensor 8 for detecting insertion of the original 6 is provided on the insertion lower.

A transparent cylinder 9 is rotatably provided in close contact with the photoreceptor 5 (or facing the photoreceptor 5 with a gap smaller than the thickness of the document 6) at the support roller 4 portion.

A light source 10 for exposing the original is fixedly arranged inside the transparent cylinder 9. or.

A light-shielding shield member 12 is provided between the light source 10 and the transparent cylinder 9 in a fixed position and has a slit 11 formed therein to restrict the direction of irradiation by the light source 10 to the area where the transparent cylinder 9 and the photoreceptor 5 are in close contact with each other. . Here, the support roller 4 that supports the photoreceptor 5 in close contact with the transparent cylinder 9 is made of an elastic material such as a rubber roller having a rubber hardness of about 50 to 80 or a foam roller having the same hardness, as shown in FIG. The body roller 4a is the main body. and,
The outer periphery of this elastic roller 4a is coated with a resin layer 4b having a low coefficient of friction. Furthermore.

A photoreceptor 5 is connected to both ends of such an elastic roller 4a.
A stop collar 40 is provided for the movement.

Further, a charger 13 is disposed on the front side of the transparent cylinder 9 and facing the photoreceptor 5 . A developing device 14, a transfer charger 15, . A cleaning device 16 and the like are provided. Here, a transfer paper cassette 18 containing transfer paper 17 is provided below the developing device 14 so as to be freely attachable from the outside of the copying machine 1 . A fixing roller 20 fixes the transfer paper 17 fed by the paper feed roller 19 and transferred by the transfer charger 15 section.
．． A paper discharge roller 21 and a copy discharge port 22 are provided above the transfer charger 15. A sensor 23 for detecting the ejection of the transfer paper 17 is located near the copy ejection port 22.
is provided. On the other hand, a discharge guide plate 25 serving as a document discharge port 24 is provided from between the transparent cylinder 9 and the developing device 14 toward the front side downward. and.

Near the upper end of this ejection guide plate 25 is a separation brush 2 that separates the photoreceptor 5 and original document 6 conveyed by the transparent cylinder 9 from the photoreceptor 5 and directs it toward the ejection guide plate 25 side.
6 is provided so as to be rotated clockwise at a predetermined timing. At this time, a notch 25 is provided at the upper end of the discharge guide plate 25 so as not to hinder the rotation of the separation brush 26.
a is formed. Furthermore, as the material for this separation brush 26, an insulating brush, for example, a Teflon brush, is effective.

Note that a copy button 27 is provided on the top surface of the copying machine 1.

In such a configuration, a copy operation is started by pressing the copy button 27. As a result, the charger 13 starts operating, the main motor is driven, and the photoreceptor 5 and the like start rotating. Therefore, first, the sheet-like original 6 is inserted into the insertion lower. The document 6 may be set by an operation such as allowing it to fall naturally to the insertion lower. The insertion of the document 6 is detected by the transmission type optical sensor 8, thereby controlling various operation timings. At this time, since the photoreceptor 5 and the transparent cylinder 9 are rotating in the conveying direction, the inserted original 5 is successively conveyed downward while being brought into close contact with the photoreceptor 5 by the transparent cylinder 9. At this time, the photoreceptor 5 is charged to the charger 1
3 has already been uniformly charged. Then, the light source 10 irradiates light from the back side of the document 6 toward the photoreceptor 5 side to perform an exposure process. As a result, the light transmitted through the image-free portion is irradiated onto the photoreceptor 5, and an electrostatic latent image corresponding to the original image is transferred and formed on the charged photoreceptor 5. In this exposure step, the document 6 is in close contact with the photoreceptor 5 through the transparent cylinder 9, so that the resolution does not deteriorate.In particular, in this embodiment, the support roller 4 in this part is an elastic roller 4a. , the adhesion of the original 6 to the photoreceptor 5 is further improved, resulting in a transferred latent image with good resolution. Furthermore, the outer periphery of the elastic roller 4a is coated with a resin layer 4b having a low coefficient of friction, and the end portion is provided with a collar 40 to prevent the belt from shifting. It never happens. On the other hand, on the light source 10 side, a light shielding member 12 is provided around the light source 10, and the irradiation light from the light source 10 is regulated by the slit 11, and the light emitted from the light source 10 is regulated by the slit 11, and
Since exposure is performed only in the areas in close contact with the surface, a latent image with good image resolution is formed in this respect as well.

The original 6 that has been exposed in close contact with the photoreceptor 5 is separated from the photoreceptor 5 after this exposure. At this time, since the original 6 is electrostatically in close contact with the photoreceptor 5, separation of the original 6 is forcibly performed by the separation brush 26. First, as shown in FIG. 7(a), the separating brush 26 normally stands still with its tip not in contact with the photoreceptor 5. As shown in FIG. Then, under detection by the transmission type optical sensor 8, etc., the separation brush 26 is rotated clockwise as shown in FIG. It rotates while contacting the body 5 and the original 6, peels off the leading edge of the original 6 from the photoreceptor 5, and guides it to the ejection guide plate 25 side. By using such a separating brush 26, it is possible to reliably separate the original 6 without damaging the photoreceptor 5. The original 6 separated from the photoreceptor 5 is placed on the ejection guide plate 2
The document is discharged to the document discharge port 24 while being guided by the document document discharge port 5 .

In other words, if you look at the overall flow of the document 6, the feeding direction is from top to bottom, and the document 6 uses natural falling.
A set and discharge method is adopted.

On the other hand, as the rotation of the photoreceptor 5 from which the original 6 has been peeled off progresses, the electrostatic latent image is developed by the developing device 14 to become a visible image, and a transfer charger 15 It is transferred by the action of This transfer paper 17 is fixed by a fixing roller 20 and then discharged to a copy discharge port 22 by a paper discharge roller 21. on the other hand,
Residual toner and the like on the photoreceptor 5 are cleaned and removed by a cleaning device 16.

The copy operation is performed in this manner, and a timing chart thereof is shown in FIG. In this timing chart, 1 hour T1 to T5 indicate each control timing. Further, the length Q corresponds to the length of the document 6.

In the copying machine 1 configured as described above, when considering common originals on the market, most of them are standard size and single-sided originals, and considering personal use, the size of the transfer paper 17 to be copied is A4 size. Alternatively, it is possible to limit the size to one type of the most common size such as B5 size, thereby making it possible to downsize the copying machine 1 and significantly reduce the cost. and.

This transfer paper 17 can be supplied by a transfer paper cassette 18 or a universal tray.

In this way, according to this embodiment, an electrostatic latent image is formed by exposure transfer in close contact with the original without using an imaging lens, so that copying is possible at extremely low cost and suitable for personal use. It can be said to be a machine.

Moreover, it can also be made smaller and lighter. As a result, if the copying machine 1 is used with legs 2 as shown in FIG. 9(a), it can be placed on the side of a desk 28 or the like.
Alternatively, as shown in FIG. 2(b), if the legs 2 are removed, the device can be hung on a desk 28, a wall, or the like.

Effects The present invention uses a method in which a sheet-like original is brought into close contact with a charged photoreceptor as described above, light is irradiated from the back side of the original, and an electrostatic latent image is formed on the photoreceptor by the transmitted light. To form an electrostatic latent image corresponding to the original image, there is no need to use an optical system including an imaging lens, etc., making it possible to achieve miniaturization and weight reduction (extremely low cost).
The present invention provides a copying machine suitable for personal use, but in this case, the direction of light irradiation from the light source is regulated by a slit in the light-shielding shield member in the exposed portion of the document, and the portion where the photoreceptor and the document are in close contact with each other. only, and
Since the document is in close contact with the photoreceptor through the transparent sleeve, an electrostatic latent image can be formed with extremely high resolution, and copy quality can be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal side view showing an enlarged view of the main parts, FIG. 2 is a perspective view of the overall appearance,
FIG. 3 is a longitudinal sectional side view of the same, FIG. 4 is an exploded perspective view of the vicinity of the exposure section, FIG. Figure 7(a),
9(b) is a side view showing the separation operation, FIG. 8 is a timing chart, and FIGS. 9(a) and 9(b) are perspective views showing an example of how the copying machine is installed. 5... Photoreceptor, 6... Sheet-like original, 9... Transparent cylinder, 10... Light source, 11... Slit, 12
...Light shielding material applicant Ricoh Co., Ltd. - (a)
(b) 56

Claims (1)

[Claims] Electrophotographic copying that uses an original contact type exposure method in which a sheet-like original is brought into close contact with a charged photoreceptor, light is irradiated from the back side of the original, and an electrostatic latent image is formed on the photoreceptor by the transmitted light. In the apparatus, a light source that irradiates light from the back side of the original is provided, and a light-shielding shield member is provided around the light source in which a slit for regulating the direction of light irradiation is formed in a portion where the original and the photoconductor are in close contact with each other, and the light-shielding member An electrophotographic copying apparatus characterized in that a transparent cylinder is provided around the shield member and rotates in close contact with the photoreceptor or in opposition to the photoreceptor with a gap less than the thickness of the original.