JPH0738727A - Image forming device - Google Patents

Abstract

PURPOSE:To facilitate the storage of image information and to shorten copy time by using a reversible thermosensitive film as an image information storing means of the image forming device. CONSTITUTION:This device is provided with a platen (13) for mounting an original to be copied, reading means (14 and 14d) for this original, reversible thermosensitive film (15) for reversibly forming transparent and opaque states while passing a part through the upside of the platen (13), intermediate image recording head (16) for recording information read by the original reading means onto the thermosensitive film as an intermediate image composed of transparent and opaque parts, exposing means (22) for converting the intermediate image to an electrostatic latent image on the photosensitive body, eraser head (17) for erasing the intermediate image on the thermal film, developing means (23) for the electrostatic latent image, means (24) for transferring the visible image on the photosensitive body to transfer paper, and means (34) for fixing the visible image on the transfer paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a so-called reversible thermosensitive film (hereinafter referred to as "thermosensitive film") capable of reversibly forming a transparent state and an opaque state by heating as an image information storage medium. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying apparatus or a facsimile apparatus, image information of a document to be copied which is read by a scanner is temporarily stored in an image information storage means, and image processing such as editing is performed. After going,
An image forming technique has been proposed in which image information is read from the image information storage unit to form an image, or image information read by one scan is repeatedly read from the image information storage unit to form an image of a plurality of copies. ing.
As image information storage means, a semiconductor memory is used in a copying machine, and a storage medium such as an optical disk or a magnetic disk is used in a facsimile machine.

[0003]

The semiconductor memory used in the copying apparatus has a high processing speed for writing and reading the read image information, but the semiconductor memory is generally expensive, which is a problem in the image forming apparatus. It is a factor of cost increase. Especially when the pixel density read by the scanner is increased to improve image quality,
Along with this, the required memory capacity increases as the amount of image information increases, which further increases the cost. On the other hand, a storage medium such as an optical disk or a magnetic disk used in a facsimile machine is advantageous in cost as compared with the above-mentioned semiconductor memory, but has a problem in processing speed of writing and reading image information. Therefore, although these storage media are adopted in the facsimile machine, they are not suitable for the copying machine which is required to immediately output the read original image.
The present invention is intended to solve the problems in the conventional image forming apparatus using the image information storage means by using a film made of a reversible thermosensitive recording medium as the image information storage means.

[0004]

According to the present invention, in an image forming apparatus, there are provided a document placing table made of a contact glass for placing a document to be duplicated, a document reading means for reading a document on the document placing table, and a plurality of document reading units. The belt-shaped heat-sensitive film, which is wound around the roller of which part is located on the upper surface of the document placing table and can reversibly form a transparent state and an opaque state, and information read by the document reading means. ,
An intermediate image recording means for recording on the heat-sensitive film as an intermediate image consisting of a transparent portion and an opaque portion, and an intermediate image on the heat-sensitive film obtained by the intermediate image recording means are formed as an electrostatic latent image on the photoreceptor. Latent image forming means, an intermediate image erasing means for erasing the intermediate image on the heat-sensitive film after forming the intermediate image as an electrostatic latent image on the photoreceptor, and an electrostatic image formed on the photoreceptor. It comprises a developing means for converting the latent image into a visible image, a transfer means for transferring the visible image on the photoreceptor to a transfer paper, and a heat fixing means for fixing the visible image on the transfer paper.

[0005]

The document read by the document reading means is
An intermediate image recording means records an intermediate image composed of a transparent portion and an opaque portion on the reversible thermosensitive film. The intermediate image on the reversible heat-sensitive film is formed as an electrostatic latent image on the photoconductor by the latent image forming means, the electrostatic latent image is visualized by the developing means, and then transferred onto the transfer paper by the transfer means. Transcribed. On the other hand, the intermediate image on the reversible thermosensitive film that has passed through the latent image forming means is erased by the intermediate image erasing means and the image of the next original is reversible by the intermediate image recording means when the intermediate image is not repeatedly used. Recorded on a thermosensitive film. The intermediate image on the reversible thermosensitive film can be used repeatedly.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, an image forming apparatus generally designated by reference numeral 10 is mainly composed of an intermediate image forming means 11 and a visible image forming means 12. The intermediate image forming unit 11 is
A document placing table 13 made of transparent glass, a scanning optical system 14 arranged below the document placing table 13, a reversible heat sensitive film 15 which becomes transparent or becomes cloudy when heat is applied, and a thermal for writing image information on the heat sensitive film 15. A heat sensitive film 15 having a recording head 16 having an element and an intermediate image erasing head 17 also having a thermal element.
Is located above the document placing table 13, and an automatic document feeding device 18 is arranged on the upper surface of the document placing table 13 with the thermosensitive film 15 interposed therebetween.

The visible image forming means 12 includes a photoconductor 20, a charging means 21 composed of a corona discharger sequentially arranged around the photoconductor, an exposure means 22 having a light source 22a such as an LED and a reflecting plate 22b, and a developing means. It comprises a means 23, a transfer means 24 composed of a corona discharger, a separating means 25, a photoconductor cleaning means 26, and a charge eliminating means 27. Below the visible image forming means 12, a paper feeding device 28 for supplying the transfer paper to the image forming means is arranged. The paper feeding device 28 has a plurality of paper feeding cassettes 29, and one of the paper feeding cassettes 29 feeds the transfer paper to a conveyance path 31 by a paper feeding roller 30. A pair of registration rollers 32 is arranged in front of the transfer means 24 on the conveyance path 31. The registration roller pair 32 includes a registration driving roller 32a and a registration driven roller 32b. Behind the transfer means 24, the paper transport belt 3
3, a fixing unit 34 including a heating roller 34a and a pressure roller 34b, a paper discharge roller pair 35, and a paper discharge tray 36 are arranged. Immediately after the discharge roller pair 35, a path switching member 19 that switches the path of the paper sent by the discharge roller pair 35 is provided.

The optical system 14 includes a scanning mirror 14a, an optical path folding mirror pair 14b which moves at a speed half that of the scanning mirror 14a, an imaging lens 14c, and a charge-coupled image sensor 14d (hereinafter simply referred to as "image sensor"). ) And an illumination lamp 14e that moves integrally with the scanning mirror 14a. The visible image forming means 12 including the paper feeding device 28 is well known as an electrophotographic copying machine except for the exposing means 22. The automatic document feeder 18 itself is also well known, and is openably and closably attached to the document placing table 13 to open the document placing surface, that is, the surface of the heat sensitive film 15 on the document placing table 13. I'm supposed to get it. It

In FIG. 2, the heat-sensitive film 15 constituting the intermediate image forming means 11 has an endless belt shape, and a pair of rollers 37a, 3a arranged on both sides of the document placing table 13 are provided.
7b, a pair of rollers 38a and 38b arranged on both sides of the recording head 16, and a photoconductor 20.
A pair of rollers 39a, 39b for contacting a part of the heat sensitive film 15 with the surface of the photoconductor 20 and an idler 40.
a, 40b and tension roller 41. The roller 40b is a heat sensitive film driving roller driven by the motor M. Since the heat sensitive film 15 is in contact with the photoconductor 20, a transparent protective layer is provided on the surface of the photoconductor 20 to protect the photoconductor.

Blowers 42 and 43 for cooling the heat-sensitive film 15 are arranged between the tension roller 41 and the roller 39a and between the roller 40b and the roller 37b, respectively. Further, between the roller 39b and the idler 40a, a film cleaning means 45 for bringing the tip of the blade 44 into contact with the heat sensitive film 15 to clean the surface of the heat sensitive film 15 is arranged.

The heat-sensitive film 15, which is called a thermochromic film, is a reversible film that changes from a transparent state to a cloudy state or from a cloudy state to a transparent state when heat is applied. FIG. 3 shows the characteristics of the heat sensitive film when heat is applied to the heat sensitive film.
In the figure, the vertical axis represents the transparency of the heat sensitive film, and the horizontal axis represents the temperature at which the heat sensitive film is heated.
When a transparent thermosensitive film (referred to as “transparent thermosensitive film”) is heated to T ₃ (90 ° C.), the transparent thermosensitive film begins to turn cloudy and becomes a semitransparent state at an intermediate concentration at T ₄ , from that point until T _1. When the temperature is lowered, the white turbidity further progresses, and the white turbidity occurs at room temperature T ₀ . A turbid heat-sensitive film (referred to as "white turbid heat-sensitive film") is produced from T ₁ to T ₂ (7
It becomes transparent up to 0 ° C. and maintains the transparent state at a temperature around T ₃ or lower. When the heating is stopped during the period from T ₁ to T ₂ , the heat-sensitive film maintains the translucent state.

The operation based on the above configuration will be described.
1 and 2, when a copy start button (not shown) of the image forming apparatus is pressed, the automatic document feeder 18 causes
One of the originals to be copied is placed on the original placing table 13 while sandwiching the transparent heat-sensitive film 15 which is stationary, and immediately after that,
As the optical system 14 scans the document, the image information of the document is read by the image sensor 14d. During the image reading process by the image sensor 14d, the recording head 16 in which the heating element selected according to the image information is heated to 90 ° C. or more is moved to the right side in the figure by the length of the document (16
Thermal film 1 that has moved and is stationary (position A)
Image information (hereinafter, referred to as “white turbid image”) that is opaque to an intermediate density is recorded in 5. Instead of moving the recording head 16 with respect to the stationary heat sensitive film 15, the recording head 16 may be placed in a stationary state and the heat sensitive film 15 may be moved. Further, the document reading means and the recording head 1
6 may be moved synchronously with respect to the stationary thermal film. A portion of the recording head 16 which is not heated by the heating element, that is, a non-image area of the heat sensitive film 15 maintains a transparent state. After that, the heat sensitive film 15 and the photoconductor 2
0 rotates synchronously in the directions of arrows A and B, the heat-sensitive film 15 is cooled down to room temperature T ₀ by the blower 42, and the intermediate image that has been clouded to an intermediate density is sufficiently clouded, while The surface of the photoconductor 20 is uniformly charged by the charging unit 21.

The intermediate image on the heat-sensitive film 15 is exposed by the exposing means 2.
2, when the light source 22a reaches the photosensitive member 2 for an intermediate image.
Exposure to 0 is performed, and an electrostatic latent image corresponding to the intermediate image is formed on the photoconductor 20. The electrostatic latent image is developed by the developing unit 2.
3 is developed on the photoconductor 20. The developing means 23 has a developing electrode, and the electrostatic latent image is developed by applying a bias potential between the potential of the cloudy image portion and the potential of the non-image portion (background portion) of the photoconductor 20 to the developing electrode. Done by

On the other hand, when the copy start button is pressed, one sheet of transfer paper is sent out from one of the paper feed cassettes 29 of the paper feed device 28 by the paper feed roller 30 to the conveyance path 31, and is transferred to the registration roller pair 32. Arrive The registration roller pair 32 sends the transfer paper to the transfer means 24 at the timing when the developed image on the photoconductor 20 and the transfer paper coincide with each other in the transfer means 24. The transfer paper on which the image is transferred by the transfer means 24 is separated from the photoconductor 20 by the separation means 25, and then sent to the fixing means 34 by the paper carrying belt 33, where it is heated and fixed and then discharged to the paper discharge tray 36. To be done. When making a copy on the back side of the transfer paper (duplex copy), the transfer paper is guided to the paper reversing section by the path switching member 19, and then the registration roller pair 3 is again provided.
Then, the image forming process similar to the above is repeated.

The heat-sensitive film 15 which has been exposed to the photoconductor 20 has its static electricity removed by the static elimination brush 101, its surface is cleaned by the blade 44 of the cleaning means 45, and T ₀ to T ₂ (at the erasing head 17). 70 ° C.) and the intermediate image becomes transparent, and the transparent heat-sensitive film 15
Is cooled to about room temperature T ₀ by the blower 43 and reaches the document table 13. When it is desired to leave the intermediate image on the thermal film 15, the erasing head 17 is separated from the thermal film 15 or the erasing head 17 is de-energized to disable the erasing head 17 function. If the erasing head 17 is arranged immediately after the exposing means 22, the distance between the erasing head and the document table 13 becomes long and the heat radiation time becomes long, so that the heat sensitive film 15 is cooled effectively.

The recording head 16 can also be used as an erasing head by controlling the driving of the heat-sensitive film 15 such that the heat-sensitive film 15 is rotated twice or switched back to erase the intermediate image. On the transparent heat-sensitive film 15 on the document mounting table 13, a heating pen having a temperature-adjustable heating element at its tip can be used to correct or record an intermediate image. in this way,
The document table 13 corrects and records intermediate images, and
An image display unit that displays an intermediate image is configured.

Recording head 1 constituting intermediate image recording means
A heating element 6 is arranged in a row in the main scanning direction orthogonal to the running direction of the heat-sensitive film 15. The heating element 6 is supported by a carriage 60 in a vertically movable manner by a guide member 61, as shown in FIG. A lever 63 pivotally attached to the carriage 60 by a shaft 62 is connected to one end of the lever via a link 64. The other end of the lever 63 is connected to the solenoid 65. The link 64 is pulled up by a tension spring 66 to a position where the lever 63 comes into contact with the stopper 67, the recording head 16 is placed in a state of being plain and separated from the heat sensitive film 15, and an intermediate image is formed on the heat sensitive film 15. When recording, the solenoid 65 operates and comes into contact with the heat sensitive film 15. The carriage 60 is supported by guide rods 68 and 69 parallel to the heat sensitive film 15, and is driven by a drive mechanism (not shown) along the guide rods 68 and 69 in the sub-main scanning direction orthogonal to the main scanning direction. It is designed to move back and forth. The document reading optical system 14a and the recording head 16 can be mounted on the carriage 60 together with the recording head 16 as means for moving the document reading optical system 14a and the recording head 16 synchronously with respect to the stationary thermosensitive film. By mounting the optical system 14a and the recording head 16 on one carriage 60, it is possible to prevent the occurrence of jitter between the optical system 14a and the recording head 16.

Erasing head 1 constituting an intermediate image erasing means
A heating element 7 is provided in the main scanning direction, and this erasing head 17 is also a stationary support by a mechanism similar to the above-mentioned vertical movement mechanism of the recording head 16 including a lever, a link and a solenoid. It is supported so that it can move up and down,
When the intermediate image is erased from the heat sensitive film 15, the heat sensitive film 15 is brought into contact with the heat sensitive film 15. Such a head contact / separation mechanism
This helps prevent deformation of the heat-sensitive film due to the head always contacting the heat-sensitive film 15.

FIG. 5 shows an embodiment in which an endless heat sensitive film 315 having both ends wound around a film take-up roller is used instead of the endless heat sensitive film. In the figure, one end of the heat sensitive film 315 is wound around the roller 316 and the other end is wound around the roller 317.
By reciprocally moving 16, 317, necessary processing on the heat sensitive film 315 and formation of an electrostatic latent image on the photoconductor are performed. By using the endless heat-sensitive film 315, the amount of information recorded on the heat-sensitive film can be significantly increased as compared with the endless heat-sensitive film. In this embodiment, the structure other than the structure using the heat-sensitive film 315 having an end is the same as that of the embodiment shown in FIG. 1, and therefore, the same components are designated by the same reference numerals as those of the embodiment of FIG. The explanation is omitted.

When the original to be duplicated is conveyed by the automatic original conveying device 18 onto the heat sensitive film 15 on the original placing table 13, the heat sensitive film 15 is soiled by the original,
In order to prevent the scratches caused by the original document from being attached to the heat sensitive film 15, as shown in FIG. 6, the original document suction means 101 for separating the original document 100 fed onto the heat sensitive film 15 upward from the heat sensitive film 15 is automatically conveyed. It is arranged inside the document conveying belt 118 of the apparatus.

When the original 100 is conveyed to a fixed position on the heat-sensitive film 15 on the original placing table 13 by the automatic original conveying device 18, the original 100 is sucked by the original suction means 101.
8 has a function as a document pressing unit that presses against the heat-sensitive film 15, as shown in FIG. By pressing the document against the heat sensitive film 15, the flatness of the document is favorably supported. As shown in FIG. 7, the document suction means 101 blows and sucks air through an opening 118a formed in the document transport belt 118.

When reading a document to be duplicated, the heat sensitive film 15 is run on the document placing table 13 in a direction for feeding the document, and the heat sensitive film 15 is used as a document transporting means, as shown in FIG. The document is read by moving the document with respect to the optical system 114b fixedly arranged at the position,
On the other hand, the intermediate image is recorded on the thermosensitive film 15 by the recording head 116 fixedly arranged at a fixed position. As described above, when the heat-sensitive film 15 is used as the document conveying means, the document conveying belt is not required in the automatic document conveying device 218, and the document discharging roller 119 is provided on the document discharging end side of the document mounting table 13. There is. The structure of the automatic document feeder is simplified. In the figure, a scraper 120 for removing dust such as paper powder attached to the heat sensitive film is in contact with the surface of the heat sensitive film 15 which is in contact with the roller 37a. The scraper 120 is useful for peeling the document from the heat sensitive film 15 when the discharged document is electrostatically adsorbed to the heat sensitive film 15.

FIG. 10 shows a recording head 16 and an erasing head 17.
Next, an example will be described in which and are integrally moved to the dotted line positions 16A and 17A, and the intermediate film is recorded while the thermal film 15 is initialized. The erasing head 17 is arranged on the side preceding the recording head 16 in the moving direction. Both heads 16 and 17 can be mounted on the carriage 60 (FIG. 4) together with the document reading optical system 14a.

[0024]

According to the present invention, which uses a heat-sensitive film capable of reversibly forming a transparent state and an opaque state by heating as an image information storage medium, an intermediate image is formed on the heat-sensitive film. When making a plurality of copies from one sheet of original, it is not necessary to individually operate the optical system for scanning the original for each copy, so that the copying time can be shortened. Further, since a part of the heat sensitive film passes through the upper surface of the original placing table, not only the information to be copied on the heat sensitive film can be written independently or together with the intermediate image, but the intermediate image can be corrected. It also has an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic side view of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is an enlarged side view showing a main part of the present invention.

FIG. 3 is a characteristic diagram showing a change in transparency of a heat-sensitive film with respect to temperature.

FIG. 4 is a side view of the carriage showing the mounting structure of the recording head.

FIG. 5 is a schematic side view of an image forming apparatus showing another embodiment of the present invention.

FIG. 6 is a side view showing an upward suction unit for a document on a document table.

FIG. 7 is a perspective view showing a document suction / press means on the document table.

FIG. 8 is a side view showing a document pressing unit on the document table.

FIG. 9 is a schematic side view of an image forming apparatus showing still another embodiment of the present invention.

FIG. 10 is a schematic side view of an image forming apparatus showing still another embodiment of the present invention.

[Explanation of symbols]

 10 image forming apparatus 11 intermediate image recording means 12 visible image forming means 13 document placing table 14, 114b optical system for document scanning 14d image sensor 15,315 reversible thermosensitive film 16,116 recording head 17 erasing head 18,218 automatic Document feeder 20 Photoreceptor 22 Exposure device as latent image forming device 22a Light source 23 Developing device 24 Transfer device 34 Fixing device 100 Document 101 Document suction device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G09F 9/00 7610-5G H04N 1/04 107 B 7251-5C 1/21 7232-5C (72) Inventor Masumi Sato 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Yasuo Ogata, 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd.

Claims (10)

[Claims] 1. An original placing table made of a contact glass for placing an original to be duplicated, an original reading means for reading an original on the original placing table, and a plurality of rollers partially wound around the above-mentioned rollers. A belt-shaped heat-sensitive film, which is located on the upper surface of the original placing table and is capable of reversibly forming a transparent state and an opaque state, and the information read by the original reading means is used as an intermediate image consisting of a transparent portion and an opaque portion. An intermediate image recording means for recording on a heat sensitive film, a latent image forming means for forming an intermediate image on the heat sensitive film obtained by the intermediate image recording means as an electrostatic latent image on a photoconductor, and the intermediate image for light exposure Intermediate image erasing means for erasing the intermediate image on the heat-sensitive film after forming it as an electrostatic latent image on the body, and developing for visualizing the electrostatic latent image formed on the photoreceptor. Image forming apparatus comprising stage and, a transfer unit for transferring the transfer sheet to a visible image on the photosensitive member and the heat-fixing means for fixing the visible image on the paper the transfer, the. 2. An automatic document feeder arranged on the upper surface of the document table via the thermosensitive film, and when the document is conveyed on the thermosensitive film by the automatic document feeder, the document is automatically transferred by the automatic document feeder. The image forming apparatus according to claim 1, further comprising a document suction unit that sucks toward the document transport device. 3. The image forming apparatus according to claim 1, further comprising a document pressing unit that presses a document placed on the document table via the heat sensitive film against the heat sensitive film. 4. The image forming apparatus according to claim 1, wherein the document reading unit and the intermediate image recording unit are fixedly provided. 5. The image forming apparatus according to claim 1, wherein said document reading means and said intermediate image recording means move in synchronization with a stationary thermosensitive film. 6. The image forming apparatus according to claim 1, wherein the heat sensitive film on the document placing table conveys a document. 7. The image forming apparatus according to claim 1, further comprising means for removing dust adhering to the heat sensitive film. 8. The image forming apparatus according to claim 5, wherein the document reading unit and the intermediate image recording unit are supported by the same carriage. 9. The image forming apparatus according to claim 5, wherein the intermediate image erasing means is arranged on the downstream side in the moving direction of the intermediate image recording means. 10. The image forming apparatus according to claim 6, wherein the document reading unit and the intermediate image recording unit are fixedly provided.