JPS63250967A - Original feeding device - Google Patents

Abstract

PURPOSE:To read a translucent original during an automatic feeding at a favorable condition by fixing and installing a light source at a position above an original conveying path so as to face in the direction, in which the translucent original, placed on an original platen, can be illuminated. CONSTITUTION:When the translucent original is set in an original feeding table 68, the moving carriages such as a first carriage 118, a second carriage 121, etc., are fixed, and the conveyance of the translucent original by an original feeding device 54 is started. The conveyed translucent original is conveyed on the original conveying path toward an illuminating part, in which the light source 58 is provided, by a conveying belt 62, rotating in an arrow mark direction. The light of the light source 58 is transmitted through a diffusion plate 61 and the translucent original, and reaches a photosensitive body drum 80 through a first mirror 116, a second mirror 122, third mirror 124, a focusing lens 126, a fourth mirror 128, a color separation filter 130 and so on, and a latent image bearing is processed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a document feeding device, and more particularly to a document feeding device that can be applied to a color copying machine or a color scanner for transparent documents.

(Prior art) Documents used in color copying machines, color scanners, etc. are generally non-light-transparent, and are configured to provide good reproducibility for such reflective documents. .

However, among the originals used as originals, there are not only the so-called reflective type described above, but also originals that transmit light (hereinafter referred to as transparent originals).

An example of such a transparent document is a document used with an overhead projector. When making a copy from a transparent original, if you put a reflector on the back side and expose it in the same way as a normal reflective original, it may not be possible to reproduce it with good image quality because the light reflection conditions are different from the 1A case of a normal reflective original. There is a problem.

Therefore, for reading transparent originals, a measure is taken to use light that passes through the original, and a unit exclusively for transparent originals is provided.

FIG. 20 explains one example. In the figure, reference numeral 2 indicates a light source with a red filter, reference numeral 4 indicates a light source with a green filter, and reference numeral 6 indicates a light source with a blue filter. Each of these light sources is fixed to the main body of the image reading device @8, and a contact glass 10 is provided above it so as to be movable back and forth.

When copying a reflective original, the contact glass 10 on which the original is placed moves, the light from the light source is reflected by the original, the reflected light passes through the mirrors 12, 14, 16, and then the imaging lens 18. After that, the image is formed on the solid-state image sensor 20 and the document information is read.

When using a transparent original, a transparent original reading unit 22 is mounted on one image reading device 8 .

Mirrors 24 and 26 are fixedly installed in the transparent original reading unit 22 at positions facing the mirrors 12 and 16, respectively, and the light from the light source is transmitted through the transparent original on the contact glass 10 to the mirrors 24 and 26. After that, head to Mirror 16.

Note that the position of the mirror 14 is changed in advance so as not to obstruct the progress of the transmitted light. Therefore, the transmitted light passes through the mirror 16 and the imaging lens 18 and is imaged on the solid-state image sensor 20.

Thus, the transparent original can be read satisfactorily.

However, in the above example, the transparent original reading unit 22 must be attached and detached from the main body of the image reading device@8 as necessary, which is cumbersome, and a switching means is also required for the mirror 14, which complicates the device configuration. There are problems such as restrictions on the document size because the contact glass 10 crosses the optical path between the mirrors 26 and 16.

FIG. 21 illustrates another conventional example of a transparent original reading means, which is constructed as a projector type.

In this example, in the case of a reflective type original, it is placed on a contact glass 30 and covered with a pressure plate from above, and a light source fixed on the carriage is moved while a carriage 32 provided below the contact glass is moved. At 34, the original is sequentially irradiated and the reflected light is read by the solid-state image sensor 38 via the lens array 36.

On the other hand, in the case of a transparent original, the microfilm original 40
Light is emitted from a light source 42 at the rear of the document, and the transmitted light of the document is projected onto a contact glass via an imaging lens 44 and a mirror 46.

This projected image is then read by the circular image sensor 38 via the lens array 36.

However, in this example, in addition to requiring a large mirror 46,
The entire device is also larger, requires a high amount of light, and there are problems with power consumption and temperature rise.Furthermore, it is difficult to provide uniform illumination, and depending on the type of document, a unit consisting of a mirror 46, a light @ 42, etc. must be attached and detached. There are problems such as being complicated and complicated.

Furthermore, what is common to each of the sides shown in FIGS. 20 and 21 is that it is difficult to install an automatic document feeder.

(Objective) Accordingly, it is an object of the present invention to provide a document feeding device which solves the problems of the prior art described above and which allows a transparent document to be read under favorable conditions during automatic feeding.

(Structure) In order to achieve the above-mentioned object, the present invention has a document feeding section, a document conveying means, and a document discharging section, and is mounted on a document table of an image reading device. A light source is fixed at a position above the document conveyance path by the document conveyance means, which faces the document table of the image reading device when installed in the image reading device, and the light source illuminates the transparent document placed on the document table. It is characterized by being provided in a direction that allows for

Hereinafter, a specific explanation will be given based on one embodiment of the present invention.

Embodiment 1 (See Fig. 1) The example shown in Fig. 1 is a color copying machine 5 which is one image reading device.
The configuration is shown in which a document feeding device M54 according to the present invention is mounted on a document table 52 of No. 0.

In this example, the document table 52 is made of so-called contact glass.

Document feeder! 54 is assembled within a frame 56. A light source 5B and a reflector 60 are attached to the right end of the frame 56, and a diffuser plate 61 made of a lath or the like is provided between the light source 58 and the document table 52.

When a high temperature source such as a halogen lamp is used as the light source 58, a cooling fan is attached.

The reflector 60 surrounds the light source 58 above the light 'g58, and has an opening facing the document table 52, so that the light source 58 faces the document table 52.

The center portion of the frame 56 faces the document table 52,
A conveyor belt 62 as a document conveyor is provided in this section.

The lower surface of the conveyor belt 62 is close to or in contact with the document table 52, and the document is transferred to the document table 52 according to the rotation of the document table 52.
It is transported along with the Therefore, the narrow gap between the conveyance belt 62 and the document table 52 constitutes a document conveyance path.

A guide 64 is disposed close to the left end of the conveyor belt 62, and the other end of the guide 64 is connected to a document feed table 68 via a group of rollers 66 for document feed. Here, the opening extending from the document feeding table 68 to the roller group 66 is referred to as a document feeding section.

On the document conveyance path, a document leading edge detection switch (hereinafter referred to as sIJ) 69 is provided between the right end of the conveyance belt 62 and the diffusion plate 61.

Furthermore, there is a curved guide 70 on the right side of the diffusion plate 61, and inside thereof there is a group of paper feeding rollers and a document trailing edge detection 5W72.
is the provision.

After passing the diffusion plate 61, the document conveyance path goes inside the guide 70, and is connected to a tray-shaped document discharge section 74 located above the conveyance belt 62.

The color copying machine 50 equipped with such a document feeder 54 is based on the well-known transfer type electrophotographic method.
To avoid complexity, the explanation will be limited to the main component names and θ operation.

Reference numeral 80 indicates a photosensitive drum, and chargers 82 . eraser 84,
Magenta developing unit 86. cyan developing unit 88,
A yellow@fine unit 90, a pre-transfer static elimination lamp 92, a transfer drum 94, a cleaning charger 96, a cleaning unit 98, a static elimination charger 100, etc. are arranged.

Here, the photosensitive drum between the eraser 84 and the magenta developing unit 86 is irradiated with exposure light and constitutes an exposure section.

Further, a portion on the photosensitive drum 80 facing the transfer drum 94 constitutes a transfer portion, and a transfer charger 102 is provided inside the transfer drum in this portion.

The transfer drum 94 is configured to be rotated in the direction of the arrow, and a pair of separate chargers 10 are located downstream of the transfer section.
4 are arranged facing each other with the peripheral surface of the transfer drum in between.

There is a separation claw 106 downstream of the separation charger 104,
It is connected to a fusing unit 110 via a belt 108.

A guide 112 is provided at a position further downstream of the separation claw 106 on the circumferential surface of the transfer drum 94, and this guide 112 is connected to a pair of registration rollers 114.

This pair of registration rollers 114 includes a paper feed cassette 116.
, 118, the transfer paper is selectively fed.

Next, an optical system is provided between the photosensitive drum and the document table 52. The optical system consists of the following staff members.

First, the first mirror 116 is located directly below the diffuser plate 61. This first mirror 116 is connected to the first carriage 118.
and the first carriage has a second one.

A light source 120 is fixed.

Here, there are cases where there is a reflective original and a transparent original on the original table 52, and in each of the above cases, there are cases where the original is kept stationary and the first carriage 118 is scanned while moving. There are cases where the first carriage 118 remains stationary at the illustrated home position and scans the document while moving it.

Whichever scanning mode is adopted, the light source 58 is used as a scanning light source in the case of a transparent original, and the light source 120 is used in the case of a reflective original, depending on the type of the original.

The light from the light source 58 or the light source 120 contains document information on the way and reaches the first mirror 116 .

Then, after being reflected by the first mirror 116, the second
It reaches a second mirror 123 and a third mirror 124 fixed to the carriage 121, and is sequentially reflected by these mirrors to an imaging lens 126. The light passes through the fourth mirror 128 and the color separation filter 130 and reaches the exposed tip portion on the photoreceptor drum 80.

When scanning a document while it is stationary, the first carriage 118 and the second carriage 121 are moved in the direction of the arrow.

The color separation filter 130 includes a blue filter and a green filter.
, consists of a red filter, and when copying from a color original, these filters are switched and image creation processes such as exposure and development are performed for each separated color, and the color images are overlaid and transferred onto transfer paper to synthesize a color image. be done.

In FIG. 1, reference numeral 132 indicates a cooling fan for the optical system.

Next, we will explain the process of reading the manuscript in Figures 1 and 14.
This will be explained based on the diagram.

Suppose now that it becomes necessary to obtain a copy of a transparent manuscript. In this case, the transparent original is set on the original feeding tray 68. When the print switch is turned on in step (2), the determining means determines whether the document on the document feed tray 68 is a transparent document, a reflective document, or a cup in step 0. If it is a transparent manuscript,
In step (■, the moving carriages such as the first carriage 118 and the second carriage 121 are fixed. Then, in step α), conveyance of the transparent original by the original feeding device 54 is started. That is, the transparent original is conveyed to the original feeding device 54 by the action of the roller group 66 via the original feeding section.

The transparent original transported in this manner is transported along the original transport path toward the illumination section where the light source 58 is provided by the transport belt 62 rotating in the direction of the arrow.

On the other hand, the image forming process is started in steps and (2), the photosensitive drum 80 starts rotating, and charging by the charging charger 82 starts.

When the document leading edge detection unit 5W69 detects the leading edge of the transparent document in step (2), the light source 58 is turned on in step (2) by the function of the control section that receives the detection information. By turning on the light source 58, the transparent original is illuminated from the back side (above).

At this time, the image forming process related to the photoreceptor drum 80 has already been started in step 'D, and the portion of the photoreceptor that is uniformly charged by the charger 82 is located in the exposure section.

Further, the transfer paper is already waiting to be fed to the registration roller 114, and in step (3), the registration roller 114 starts rotating in synchronization with the timing of conveyance of the transparent original to send out the transfer paper.

The transparent original is transported by the transport belt 62 at a predetermined transport speed. At this time, the first carriage 118 and the second carriage 121 are each stationary at the position shown in FIG. 1, and the reading position is constant.

The light from the light source 58 is transmitted through the diffuser plate 61 and the transparent original to the first
Mirror 116. Second mirror 122. third mirror 124,
Imaging lens 126. The light passes through the fourth mirror 128, color separation filter 130, etc., and reaches the photosensitive drum 80, where a latent image is carried. The latent image is developed into a color corresponding to the filter of the color separation filter 130 and then transferred to transfer paper.

In this way, for example, when the image forming process using the blue filter is completed, if the copy is made in only one color, the original is sent out according to the procedure shown in FIG. 14. Also, the transfer paper is also fixed in the fixing unit 1.
Sent out on 10th. When obtaining a full-color copy, after the image creation process using the blue filter is completed,
After the conveyor belt 62 is reversed to return the leading edge of the transparent original to the left of the original leading edge detector 5W69, the green filter is switched and the image forming process is executed according to the above procedure. Further, the red filter is switched to and the same image forming process is performed to obtain a composite color image on the transfer paper.

Thereafter, the transfer paper is separated from the transfer drum 94 by a five-minute decoupling claw 106, passes through a bell 108, reaches a fixing unit 110, is fixed thereon, and is discharged.

On the other hand, when the trailing edge of a transparent original is detected by the original trailing edge detection 5W72 in step ip), the step 0 timer is set, the light source 58 is turned off in step 0, and the registration roller 114 is stopped in step O. , step ◎
The image creation process ends. Transparent originals are sent to the original output section 74.
is discharged. Next, due to the time-up of the set timer in step 10 (step Q), it is determined that a sufficient amount of time has elapsed for the document to be sent to the document discharge section 74, and the document feeding by the document feeder 54 is stopped (
Step @).

Next, the case of obtaining a copy from a single reflection type original will be explained.

In this case, the reflective original set on the original feed table 68 is determined to be a reflective original in step ◯, and is sent to the conveyor belt 62 via the roller group 6d in step ◯. In step O, the leading edge of the document is detected by the document detection unit 5W69, a timer is set in step O, and the first mirror 116 is moved slightly until the time is amplified in step O, and the first mirror 116 is at the home position.
The vehicle stops at a predetermined position after a predetermined run-up distance (step O).

At the same time, the image creation process starts on the STETSU X9, and the light source 1
20 is turned on (Step O), and in Step O, the first carriage 118 and the second carriage 121 are started to move leftward (Step O) to start scanning the original.

At the time of this scanning, the image forming process related to the photoreceptor drum 80 has already started, and the transfer paper is also moved to the registration roller 114.
Waiting in the copy is the same as in the case of the transparent original. Then, in step O, the registration roller 11
Transfer paper is sent out from step 4.

The first carriage 118 and the second carriage 121 repeatedly scan in response to switching of the color separation filter 130 (Step O), and when they return to the home position (Step O), they are stopped (Stella type D).

Then, the registration roller 114 is also stopped (step O
), step O) of turning off the light source 120, transfer drum 94
The color image is composited onto the upper transfer paper, and the fixing unit 11
0 and the imaging process ends.

On the other hand, the feeding of the 1M document is started in step O, and after the trailing edge is detected by the document trailing edge detection 5Ii 172 (step O), the document is sent out to the document discharging section 74 after a predetermined time (step O
, Step O, Stetz).

In this example, a diffuser plate 61 is provided between the light source 58 for illuminating the transparent original and the document table 52 on which the transparent original is placed and passed.This is because the light source 58 does not directly illuminate the transparent original. It is.

If direct light from a light source is used, defective images such as partially white images will be produced.

In this point, if the diffuser plate 61 is used, the light will be diffused and the original will be uniformly illuminated, thereby preventing the occurrence of defective images.

The diffusion plate 61 may have small protrusions as shown in FIG. 6, or may have a hemispherical surface as shown in FIG. 7. Furthermore, it is also possible to cause diffuse reflection inside by including a dye or the like inside.

Embodiment 2 (See FIG. 2) The example shown in FIG. 2 is a configuration in which a document feeding device 154 according to the present invention is mounted on a document table 152 of a color scanner 150, which is an image reading device.

In this example, the main components of the document feeder 154 are similar to the document feeder 54 in FIG. 1 described above.

Therefore, the common constituent parts are indicated by the same reference numerals and the explanation thereof will be omitted, and only the different parts will be explained.

The document sent out by the conveyor belt 62 is transferred to the roller 166.
Accordingly, the document is discharged to a document discharge section 174 located on an extension of the document table 152.

Although various sources can be used as the light source 58, a halogen lamp is used in this example. Since the halogen lamp reaches a high temperature, a cooling fan 183 is provided above to cool the light source and document table 152.

On the other hand, regarding the color scanner 150, the original platen 15
A first carriage 118 is movably provided with a home position facing the light source 58 below the light source 58, and a light source 120 and a first mirror 116 are attached thereto, similar to the example shown in FIG. Also, the second carriage 121
This is similar to the example shown in FIG. 1 in that a second mirror 123 and a third mirror 124 are attached and are movable.

In this example, the light from the third mirror 124, which has passed through the imaging lens 126, is transferred to the prism 188 and is divided into blue and green.

Spectral with red filter 182.1.84.186,
The light receiving element 18211.1 receives each of these separated lights.
82G.

182R to read each color.

If such a configuration is adopted, and a halogen lamp is used as the light source 58 as described above, the intensity level of each color will differ greatly because the halogen lamp has a larger infrared light than blue light in the light intensity distribution of each wavelength. (See Figure 5). Therefore, in order to adjust this, a filter 190 that cuts infrared light is provided between the light source 58 and the document table 152. The light transmission characteristics of this filter 190 are as shown in FIG. 4, for example.

By providing such a filter, the light intensity level of each color approaches uniformity, making it possible to read each color information accurately.

In the illustrated example, the filter 190 is provided separately from the diffuser plate 61, but instead of this, for example, a single layer of the infrared cut filter may be deposited on the diffuser plate 61, or the infrared cut filter itself may be coated on its surface. It would also be possible to roughen the parts and integrate them into one piece.

Note that the i-image is the light receiving element 18211.182G, 18
In this example, where the image is formed on 2B, etc., even if the light source 58 is slightly off due to manufacturing variations, poor imaging (for example, a completely black image) will result, so it is important to provide the enlarged i'a temporary 61. It is.

In this example, similarly to the previous example, the operating modes of the light source and carriage are switched between when reading a transparent original and when reading a reflective original. A determining means determines whether the original is a transparent original or a reflective original.

When reading a transparent original, the first carriage 11B and the second carriage 121 are each fixed at the home position shown in the figure, and the transparent original is transported at a predetermined speed by the conveyor belt 62 while the light from the light source 58 is transmitted through the original. , light receiving elements 182R, 182G, and 18213 at once.

Therefore, unlike the above-mentioned example, reading of each color of a transparent original is completed by passing through the original transport path once.

In the case of a reflective type document, the light source 120 is used to move the first carriage 118 and the second carriage 121 to read the document that is stationary on the document table 152.

The original after being read is ejected to an original ejection 9174.

The details of the reading process for each of the above-mentioned transparent originals and reflective originals are shown in FIG.

Embodiment 3 (See FIG. 3) The example shown in FIG. 3 is a configuration in which one document feeding device 254 according to the present invention is mounted on a document table 252 of a color scanner 250, which is one image reading device.

In this example, the main components of the document feeder 254 are similar to the document feeder 54 shown in FIG. 1 above.

Therefore, the common constituent parts are indicated by the same reference numerals and the explanation thereof will be omitted, and only the different parts will be explained.

In this example, a fluorescent lamp is used as the light source 58. Since a fluorescent lamp does not emit as much infrared light as a halogen lamp, there is no need for the filter 190 for cutting off infrared rays as in the example shown in FIG.

On the other hand, regarding the color scanner 250, the original platen 25
A guide 280 is installed parallel to 2, and this guide 280
A carriage 218 is configured to be movable above.

On the carriage 218 is a light source 220 consisting of a fluorescent lamp,
A lens array 226 as an imaging element, a light receiving element 282, etc. are provided.

The relative positions of the lens array 226 are set so that the light receiving element 282 forms an image of the original on the original platen 252 at the same magnification.

The light receiving element 282 has a structure in which solid-state image sensing elements 282B are arranged on a substrate 282 as shown in FIG.

Further, as shown in an enlarged view in FIG. 9, the solid-state image sensor 282B has blue, blue, and blue light for each light-receiving area 282B-1 corresponding to each pixel.
It has green and red spectral filters. Solid-state image sensor 2
82B is covered with a protective glass 290 as shown in FIG. Since this type can read each color information in one reading operation, there is no need to repeat the reading operation multiple times as in the first embodiment even when obtaining a full color copy.

In this example as well, similar to the above-mentioned respective sides, when reading a transparent original, the carriage 218 is fixed, and image information is read by illumination from the light source 58 while conveying the transparent original to the original feeding device 254. Also, when reading a reflective type original, the carriage 21 is moved while the original is stationary on the original platen 252.
Image information is read by illumination from a light source 220 while moving the camera 8. The details of the reading process for each of the transmissive originals and reflective originals in this example are also shown in FIG.

In this way, in each of the embodiments described above, the transparent original is read while being conveyed by the original feeding means in the original feeding device, so there is no need to move the light source.

It can be fixedly provided.

In addition, in the case of reflective type originals, the document feeder can be left as is.
Documents can be read using the same functions as a normal automatic document feeder, and there is no need for complicated operations such as attaching and detaching the device.

That is, by providing a light source for illuminating a transparent document in the document feeder, the document feeding function of the document feeder can be used to read the transparent document under favorable conditions during automatic feeding.

As described above, in each of the embodiments (FIGS. 1, 2, and 3), the operating modes of the document feeding device and the image reading device differ depending on whether the document is a transmissive document or a reflective document.

The above switching depending on whether the document is transparent or reflective can be done manually based on the operator's judgment to identify the document, but it can also be done automatically by installing document discrimination means (for example, a sensor). Switching control may also be used.

Regarding each of the embodiments (Figs. 1 to 3) in which transmissive originals and reflective originals can be read easily without the need for attaching and detaching the original feeder, when reading transmissive originals, the movable carriage must be stabilized. The document is fixed at a fixed position, and the document information is read while the document feeder transports the document at a predetermined speed.1 In the case of a reflective type document, the document is transported to a fixed position on the document table by the document feeder, and then the document is read. It has been described that the document is read by fixing the document and moving the movable carriage.

In each of the embodiments shown in FIGS. 1 to 3, the following various aspects regarding the document feeding speed are determined depending on the document feeding mode 1, for example, when using a transparent original and 1 when using a reflective type original. It is possible to perform the operation in

Example 1: The document feeding speed of the document feeding device is different between when a transparent document is being used and when a reflective document is being sent.

Embodiment 2 In Embodiment 1 above, the original feeding speed for reflective originals is made faster than the feeding speed for transparent originals.

Aspect 3゜The original feeding speed for transparent originals is made different between when feeding the original and when reading the original, or when ejecting the original and when reading the original.

Embodiment 4 In Embodiment 3 above, the document feeding speed at the time of document feeding or document ejection is made faster than the document feeding speed during reading of the transparent document.

Aspect 5: In Aspects 1 to 4 above, the document feeding speed when reading a transparent document is switched depending on the magnification ratio.

Embodiment 6 In Embodiment 5 above, when the document feeding speed at the same magnification is V, the document feeding speed at the variable magnification ratio m (m=1 at the same magnification) is V/m.

Embodiment Example 7 In the case of Embodiment 1 (see FIG. 1), when performing so-called frame-sequential scanning of a full-color transparent original, in which the original definition is repeated several times while replacing the color separation filter 130. , After reading all the transparent originals for each filter, before ejecting them from the original feeder,
Switching the original feeding direction to the opposite direction and transporting the original to a position in front of the light source in the original feeding device.

Embodiment 8 In Embodiment 7 above, the speed at which the original is reversely conveyed is higher than the original feeding speed when reading the original.

Details of each of these embodiments will be described below.

Example 4 (A case where the above embodiment is applied to the embodiment 1) In this example, the above embodiment is applied to the apparatus shown in FIG. 2, but the apparatus shown in FIG. Applicable. This will be explained below with reference to FIGS. 2 and 16.

In step ○, determine whether it is a transparent original or a reflective original.
In the case of a transparent original, the moving carriage is fixed (step o). Next, in step ◎, feeding and conveyance of the original from the original feeding table 68 of the original feeding device 154 is started. The transport speed at this time is V=90+nm/S, which is the image reading speed.

Then, as shown in FIG. 11, when the document leading edge GF is detected by the document leading edge detection 5W69 (step [phase]), the cooling fan 183 and light source in the document feeder 154 are turned on, and the document is illuminated from the back side. (step [phase].

Step ○). And light receiving elements 182'R, 182G,
Reading of image information is started at 182B (step @).

At this time, the document continues to be conveyed at V=90 mm/S.

The document is further conveyed and reaches the trailing edge of the document GT as shown in FIG.
is detected by the document leading edge detection 5IJ72 (step O)
When the reading of one image is completed (step 0), the light source 58 and cooling fan 183 in the document feeder 154 are turned off (step [phase], step @). Document feeder] 54 is then operated for a predetermined period of time (step@).

Step 0) Continue to feed the original and send the original to the original output section 174.
After the document is ejected, feeding of the document is stopped (step 0).

In the case of a reflective type original, the original is fed from the original feeding table 68 in the same manner as described above, and conveyance of the original is started at a speed of V = 300 mm/S (step (E)). And the 11th
As shown in the figure, after the document leading edge GF is detected by the document leading edge detection 51169, the document is conveyed until a predetermined period of time has elapsed.

After the predetermined time has elapsed, the document stops at a position suitable for scanning on document table 152 (step O).

Then, the first carriage 118. Second carriage 12
The light source 120 on the side of the first moving carriage is turned on, and the moving carriage scans a predetermined distance and returns to the home position, which is the position shown in FIG.
154 starts conveying the document again and sends it to the document discharge section 174.
Send the manuscript towards /S. Although this speed does not have to be the same as the speed when using <ki paper as described above, it was made the same because controlling the motor etc. is simple.

In this way, the document is sent toward the document discharge section 174: 11
, as shown in FIG. 12, after a predetermined period of time has elapsed for the trailing edge GT of the document to reach the document leading edge inspection/discharging section 174 (Step In the above process, the document feeding speed for transparent documents is set to V, = 90
mm/S, document feed speed when using reflective type document is V = 3
00nv/S is set, but this means that in the case of a transparent original, the original must be transported at a predetermined readable speed according to the reading speed of the light receiving elements 182G, 182B, and 182It, but in the case of a reflective original, The document feed speed is simply the speed at which the document is fed onto the document table 152. When one image is being read, the document is stationary and the image is read at the speed of the moving carriage, so the document is moved as fast as possible. This is because it is more advantageous to bring in items at a faster speed in order to reduce the copying time.

Embodiment 5 This example is a modification of the above-mentioned Embodiment 4, and although the apparatus shown in FIG. 2 will be explained, the same applies to the apparatus shown in FIG. 3 as well.

This will be explained below with reference to FIGS. 2 and 17.

The major flow is the same as that shown in FIG. 16 above, but the document feed speed is switched when transparent H and 5 documents are processed.

In the case of a transparent original, the original 3 is fed from the interleaved sheet tray 68 and is fed 1 m at the transport speed/ffi V = 300:nun/S (Step ◎). Then, as shown in No. 1101, when the document leading edge GF reaches the document leading edge detection 5III69 (step), the conveyance speed becomes V:=90/
m, mm/S (step ◎
). Here, m is the variable S rate and n]=1 when equal to 1.

Therefore, at the same magnification, the conveyance speed is 90nv1/S,
As mentioned above, this is the light receiving element 182G.

The value is set according to the reading speed of 1.82B and 182t't.

If the ``non'' character is between rn''0.5 and 2, the conveyance speed V will be set between 1.80 and 45 mm/S.Then, the image information will be read at this speed ( Step 0. Step ・) As shown in FIG. 12, when the document trailing edge GT reaches document trailing edge detection 5W72 (Step
)2 Step ◎ to finish reading the image.

step [phase]), the conveyance speed is switched again and V = 30
It becomes 0 piece S (step [phase]). and a predetermined time (
Step [Phase], Step O) The M document continues to be fed, and when the document is completely discharged to the document discharge section 174, the document feeding device is stopped (Step O).

Since the process is the same as the process after step O in FIG. 16, the explanation will be omitted.

Embodiment 6 This embodiment relates to the case where the above embodiment is applied to the apparatus shown in FIG. This will be explained below with reference to FIGS. 1, 18, and 19.

In this example, since it is so-called field sequential, the yellow, magenta, and cyan processes are repeated three times as the fi:9 process.

First, in the case of a transparent original, the original is fed from the original feeding table 68, and V = 90 mm/S, which is determined by the process speed.
Please send Q. At that time, yellow and magenta.

Determine which process of cyan and use color separation filter 1
30 blue filters, recording filters, and red filters are each activated, the image forming process is started, and as shown in FIG.
When reaching step S69 (step 0), the light source in the document feeder 54 is turned on and the image of the document begins to be formed on the photosensitive drum 80.

Then, as shown in FIG. 12, the document continues to be transported.
When the document trailing edge GT reaches the document trailing edge detection 5W72.

The light source 58 and the imaging process are turned off, and it is determined whether all yellow, magenta, and cyan processes are completed.

If it has not yet finished, stop feeding the document (
Step O0 At this time, the document has not been completely ejected, and its rear end is caught between the rollers of the guide 70 section. In this state, the motor is rotated in the opposite direction to transport the document in the opposite direction.

This conveyance speed is the speed at the time of reading V = 90mm
/S is set to V = 300mm/S, which is faster than the other
).

At the same time, the yellow, magenta, and cyan processes are also switched to the next step.

When the document is conveyed in the reverse direction as shown in 2 and the leading edge CF of the document passes the document leading edge detection unit 5W69 (step 0) as shown in FIG. Start transporting the M document. Image formation in the next step of the yellow, magenta, and cyan process is then started.

In this way, when all processes for yellow, magenta, and cyan are completed, the original is continued to be conveyed in the normal direction for a predetermined period of time, and then the original is ejected to the original ejection section 74.

Stop document transport.

In the case of a reflective type original, the original is transported to a predetermined position on the original platen 52 (step O) and fixed, and in this state, the three processes of yellow, magenta, and cyan are performed as shown in FIG. After completing all the yellow, magenta, and cyan processes, document feeding is restarted and the document is ejected.

In this way, by carrying out reverse conveyance and reading the document during transmission in a field-sequential manner without ejecting it for each process, it is possible to easily and quickly read the transmission document without any effort.

(Effects) According to the present invention, even a transparent original can be easily read to obtain a high-quality image, which is advantageous.

[Brief explanation of drawings]

1 to 3 are diagrams illustrating the document feeding device according to the present invention together with a document reading device, FIG. 4 is a light transmission characteristic diagram of a filter, FIG. 5 is a spectral distribution diagram of a halogen lamp, and FIG. Fig. 7 is a diagram specifying the surface condition of the diffuser plate, Figs. 8 to 10 are explanatory diagrams of the light receiving element, Figs. Figures 14 to 1
Figure 9 is a flowchart explaining the present invention in detail, Figure 20, and Figure 2.
FIG. 1 is an explanatory diagram of the prior art. 52, 152, 452...Original table, 54.154.
254...Document feeder, 58...Light source. Enemy 9 Mocking Fence $ 1 勺zenkankan-3 No. /q ♀

Claims (1)

[Scope of Claims] A document feeding device that includes a document feeding section, a document conveying means, and a document discharging section and is mounted on a document table of an image reading device, which reads the image when mounted on the document reading device. A light source is fixed at a position facing the document table of the apparatus and above the document conveyance path by the document conveyance means, and the light source is oriented so as to illuminate the transparent document placed on the document table. Characteristic document feeder.