JPH04211563A - Document reader - Google Patents

Abstract

PURPOSE:To improve the reading accuracy of the document reader by exactly detecting the transporting position of a document and the opening and closing states of a pressure plate while reducing the cost of the document reader. CONSTITUTION:The light introduced via a light guide 515 from an energization display light source 517 provided in the pressure plate 516 into document detection regions 510b, 510c of a photoelectric conversion means 510 is shielded by actuators 511, 512 energized by the document 515. The presence or absence of the setting of the document 515 and the front end and rear end of the document 515 are thus detected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading device, and more particularly to a document reading device that has improved methods for detecting the presence or absence of a document and the leading and trailing edges of a document.

0002

2. Description of the Related Art A document reading device is used as a standalone document reading device, a scanner for a facsimile machine, or a copying machine. The documents are conveyed one by one to the document reading section and read. Therefore, a document presence/absence detecting means for detecting that a document is set on the document table and a document leading and trailing edge detecting means for detecting the leading and trailing edges of the document being conveyed to the document reading section are required.

[0003] Therefore, in the conventional document reading device,
As shown in FIG. 49, when applied to the facsimile machine 1, the document reading device 2 is provided with a document presence/absence detection sensor 3 and a document front/back edge detection sensor 4, and the document on the document table is automatically transported. The device 5 transports the documents to the document reading section 6 one by one. When the document reading device 2 detects the document set on the document table using the document presence/absence detection sensor 3, the document is conveyed to the document reading section 6 by the automatic document feeder 5, and the leading and trailing edges of the document are placed behind the leading edge of the document. It is detected by the edge detection sensor 4. When the document leading and trailing edge detection sensor 4 detects the leading edge of the document, the document reading section 6 starts reading the document.
When the document leading edge and trailing edge detection sensor 4 detects the trailing edge of the document,
After the document reading operation is performed until the rear end of the document is read, the document reading operation is ended. Furthermore, Figure 49
, the document reading section 6 includes a light source 7, a discharge roller 8, mirrors 9, 10, 11, a lens 12, and a photoelectric conversion means 1.
3, etc., and the facsimile device 1 includes:
Facsimile control unit 14, roll recording paper 15, thermal head 16, and platen roller 17
etc. Further, in FIG. 49, arrows indicate the conveyance direction of the document and the conveyance direction of the rolled recording paper.

Conventionally, a photocoupler is used as the document presence/absence detection sensor 3 and document front/back edge detection sensor 4, and the photocoupler projects light directly onto the document and detects the presence or absence of the document based on the presence or absence of the reflected light. The leading and trailing ends of the are being detected. Also, although a photocoupler is used in the same way,
As described in Japanese Utility Model Publication No. 47314 and Japanese Utility Model Publication No. 63-29332, by moving the detection lever, actuator, etc. with the document, and detecting the movement of the detection lever, actuator, etc. with a reflective photocoupler, Detects the presence or absence of a document and the leading and trailing edges of the document.

[0005]

[Problems to be Solved by the Invention] However, in such conventional document reading devices, a photocoupler is used to detect the presence or absence of a document and to detect the leading and trailing edges of the document. There are problems in that it is expensive, requires a photocoupler-specific harness, circuit board, etc., is too expensive to detect the presence or absence of a document, and detects the leading and trailing edges of a document, and that the document reading device itself becomes expensive.

[0006] Therefore, the present applicant has previously filed an application for a method for detecting the presence or absence of an original using a solid-state image sensor similar to the conventional solid-state image sensor for reading originals instead of a photocoupler. As described in Japanese Patent Application Laid-Open No. 59-37763, this method for detecting the presence or absence of a document is performed separately from an image reading photoelectric conversion element for reading the image of the document. A photoelectric conversion element for detecting the presence or absence of a document is placed at a position where the detection signals of the photoelectric conversion element for image reading and the photoelectric conversion element for detecting the presence or absence of a document are serially extracted, and the presence or absence of the document and the reading of the image are determined based on the results. I am doing it.

However, in this method, the photoelectric conversion element for image reading and the photoelectric conversion element for detecting the presence or absence of a document as solid-state image sensors are provided separately, and each solid-state image sensor is fixed as an IC chip. , it is necessary to provide two separate solid-state image sensors. As a result, there is still room for improvement in terms of cost reduction, and there is a problem in that the degree of freedom in designing the document reading device is restricted.

[0008] In addition, in the conventional document leading edge/trailing edge detection method, once the leading edge or trailing edge of the document is detected, even if an abnormality occurs in the conveyance status of the document, such as a slip, the abnormality cannot be detected. There has been a problem in that it is not possible to detect this, and it is not possible to properly read the document.

[0009]

[Means to solve the problem]

The invention according to claim 1 includes: a light source that projects light over a predetermined reading width in the main scanning direction onto a document being conveyed to a document reading position; a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over the predetermined width; A document reading device comprising: a reduction optical system that reduces light reflected by a document and introduces the reduced light into a photoelectric conversion means; An image reading area for reading the image of the original, and an original detection area for detecting the presence or absence of the original and/or the leading and trailing edges of the original. The invention according to claim 2 is characterized in that, in the invention according to claim 1, the light source is formed by disposing a plurality of independent light emitting elements in the document width direction,
The light emitting elements are divided into an image light emitting element group for illuminating the image reading area, and an original detection light emitting element group for illuminating the document detection area, and each light emitting element group is made independent. The invention according to claim 3 is characterized in that in the invention according to claim 2, the light projected from the image light emitting element group is irradiated onto the image reading area of the photoelectric conversion means. The optical path through which the light projected from the document detection light emitting element group is irradiated onto the document detection area of the photoelectric conversion means is characterized in that at least part of the optical path passes through different optical paths, The invention according to claim 4 provides a document table on which a plurality of documents are placed, a document conveyance path in which the documents on the document table are conveyed to a document reading position, and a document conveying path in a main scanning direction for conveying the documents to the document reading position. a light source that projects light over a predetermined reading width; a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width; and a reduction optical system that reduces light reflected by the document and introduces it into the photoelectric conversion means; In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and The light source is divided into an image reading area for reading an image of the document, and a document detection area for detecting the presence or absence of a document and the leading and trailing edges of the document, and the light source is provided by disposing a plurality of light emitting elements in the width direction of the document. and dividing the light emitting elements into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area,
It is rotatably provided, and its detection end protrudes to a position where it is urged by the document on the document table, and its light-blocking end illuminates the document detection area of the photoelectric conversion means from the document detection light emitting element group. A document presence/absence detection mechanism protrudes from a position that blocks a portion of the light transmitted, and a detection end thereof is rotatably provided, and the detection end is attached to the document conveyed on the document conveyance path at a predetermined position on the document conveyance path. a document leading edge and trailing edge detection mechanism that protrudes to a position where the document detection area of the photoelectric conversion means is exposed to light, and whose light-shielding end portion protrudes to a position that blocks a portion of the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means; , a lighting cycle control means for controlling the lighting cycle of the image light emitting element group, and determines the conveyance status of the document based on the output of the document detection area of the photoelectric conversion means, and controls the image light emitting element group. The invention according to claim 5 is characterized in that the lighting period of the group is controlled, and includes: a document table on which a plurality of documents are placed; a document conveyance path through which the documents on the document table are conveyed to a document reading position; A light source that projects light over a predetermined reading width in the main scanning direction onto a document being conveyed to a reading position, a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width, and a photoelectric conversion means that reduces light reflected by the document. and a reduction optical system that introduces the photoelectric conversion element of the photoelectric conversion means into the photoelectric conversion means, the optical path width is such that the reflected light of the readable width is reduced by the reduction optical system and introduced. The light source is divided into an image reading area for reading the image of the original and an original detection area for detecting the presence or absence of the original and the leading and trailing edges of the original. light-emitting elements arranged in the document width direction, and the light-emitting elements are combined into an image light-emitting element group for illuminating the image reading area, and a group of image light-emitting elements for illuminating the document detection area, which are always turned on when the power is turned on. A group of light emitting elements for image detection, and a light emitting element group for image detection, which is located closer to the light source than the document transport path near the document reading position, in the sub-scanning direction with respect to the light irradiated from the image light emitting element group to the reading position. The light emitted from the document detection light emitting element group is located on the same plane and outside the readable width in the main scanning direction, and the photoelectric conversion means detects the document through the reduction optical system. A reflective member for irradiating an area, a detecting end thereof protruding to a position biased by the document on the document table, and a light-shielding end of the reflective member being rotatably provided, and a light-shielding end of the reflective member is rotatably provided. and protrudes to a position that blocks part of the light irradiated onto the document detection area of the photoelectric conversion means through the reduction optical system, and when the document pushes the detection end, the light blocking end blocks part of the light. A document presence/absence detection mechanism that blocks or transmits light is rotatably provided, and its detection end protrudes to a predetermined position on the document conveyance path, and its light-shielding end is connected to the light-emitting element group for document detection by a reflecting member and a reduction optical system. The system protrudes to a position that blocks part of the light that is irradiated onto the document detection area of the photoelectric conversion means, and when the document pushes the detection end, the light blocking end blocks or transmits part of the light. The invention as set forth in claim 6 is characterized in that a document leading edge and trailing edge detection mechanism is provided, and the conveyance status of the document is detected based on the output of the document detection area of the photoelectric conversion means. In the invention, the rotating surfaces of the document presence/absence detection mechanism and the document leading and trailing edge detection mechanism are parallel to the optical path direction of the light blocked by these mechanisms, and the light blocking end of each mechanism is parallel to the direction of the light path of the light blocked by each of these mechanisms. It has a curved shape with a concave surface on the moving center side, and is located outside with respect to the optical axis of the light projected from the image light emitting element group at the light-shielding end of the document presence/absence detection mechanism and the document leading and trailing edge detection mechanism. The angle between the surface of the light-emitting device and the optical axis is θa1, the angle between the surface of the light-shielding end on the optical axis side and the optical axis is θa2, and the light emitted from the document detection light emitting element group is θa2. Let θb1 be the angle between the optical axis of the light from the imaging light emitting element group at the shielded end of the light flux and the optical axis, and the light flux on the optical axis side of the light flux is defined as θb1. When the angle between the surface and the optical axis is θb2, θa1
≧θb1 θa2≧θb2 The invention according to claim 7 is characterized in that it has a document table on which a plurality of documents are placed, and a document conveyance path through which the documents on the document table are conveyed to a document reading position. , on the opposite side of the original reading position across the original reading position, is provided so as to be removable from the original reading position, and a predetermined empty space is formed between the cover and the upper cover, and the original is transported to the original reading position. A pressure plate that is conveyed in close proximity to the reading position, an image reading light source that projects light over a predetermined reading width in the main scanning direction onto the original that is transported to the original reading position, and a plurality of photoelectric conversion elements are arranged over the predetermined width. a reduction optical system that reduces the light emitted from the image reading light source and reflected by the original and introduces it to the photoelectric conversion means; and a reduction optical system that is provided in the empty space of the pressure plate and is always turned on when the original reading device is energized. an energized display light source for indicating that the light source is energized; and a photoelectric conversion element of the photoelectric conversion means, in which the reflected light of the readable width is reduced by a reduction optical system and introduced into the photoelectric conversion element. The optical path width of the document is divided into an image reading area for reading the image of the document, and a document detection area for detecting the presence or absence of the document and the leading and trailing edges of the document. In the space between the pressure plate and the upper cover near the reading position, the light irradiated from the image light source to the reading position is on the same plane in the sub-scanning direction and the readable width in the main scanning direction. is located outside the range of the energized display light source, receives the light irradiated from the energized display light source from its entrance surface, introduces it into the reduction optical system from its exit surface, and enters the original detection area of the photoelectric conversion means through the reduction optical system. Along with irradiating
A light guide is rotatably provided with a dispersion surface for dispersing the light of the energized display light source on at least one of its entrance surface or exit surface, and its detection end is biased by the document on the document table. The light-shielding end protrudes to a position where it blocks part of the light irradiated from the energized display light source to the document detection area of the photoelectric conversion means through the light guide and reduction optical system, so that the document is detected. A document presence/absence detection mechanism that allows a part of the light to pass through a light-shielding end when the detection end is pushed; The part protrudes to a position that blocks part of the light irradiated from the energized display light source to the document detection area of the photoelectric conversion means through the light guide and reduction optical system, and the document blocks light by pushing the detection end. A document leading edge/back edge detection mechanism whose edge portion transmits a portion of the light is provided, and the presence or absence of the document and the conveyance status of the document are detected based on the output of the document detection area of the photoelectric conversion means. The invention according to claim 8 is the invention according to claim 7, wherein the photoelectric conversion element of the photoelectric conversion means has a predetermined width smaller than the optical path width through which the reflected light having the readable width is reduced by the reduction optical system. An image reading area for reading an image of a document, a document detection area for detecting the presence or absence of a document and the leading and trailing edges of the document, and a pressure plate detachment detection area for detecting the detachment state of the pressure plate. The light guide moves with the separation of the pressure plate, stops introducing the light of the energized display light source into the reduction optical system, and changes the state of separation of the pressure plate to the separation state of the pressure plate of the photoelectric conversion means. The invention according to claim 9 is characterized in that the detection is performed based on the output result of the detection area, and the detection state of the original detection area of the photoelectric conversion means is set to a state of no original. a document conveying path through which the document on the document table is conveyed to the document reading position; a light source that projects light over a predetermined scanning width in the main scanning direction onto the document being conveyed to the document reading position; and a plurality of photoelectric conversion units over the predetermined width. In a document reading device comprising a photoelectric conversion means in which an element is arranged, and a reduction optical system that reduces light reflected by the document and introduces it into the photoelectric conversion means, the photoelectric conversion element of the photoelectric conversion means is A predetermined width is provided wider than the optical path width into which the reflected light having the readable width is reduced by the reduction optical system and introduced, and an image reading area for reading the image of the document and the leading and trailing edges of the document are detected. The original detection area is divided into
The light source is formed by a plurality of light emitting elements arranged in the document width direction, and the light emitting elements are combined with an image light emitting element group for illuminating the image reading area and a group of image light emitting elements for illuminating the document detection area. A light emitting element group for image detection is divided into a group of light emitting elements for document detection, and the light emitting element group for image is divided into a group of light emitting elements for image detection on the light source side of the document conveyance path near the document reading position, and in the sub-scanning direction with respect to the light irradiated to the reading position from the light emitting element group for image. The photoelectric conversion means is located on the same plane and outside the readable width in the main scanning direction, and introduces the light emitted from the light emitting element group for document detection into the reduction optical system and passes it through the reduction optical system. a light introducing means for irradiating a document detection area of the document, the detection end of which is rotatably provided, protrudes to a predetermined position on the document conveyance path, and is biased by the document in accordance with the conveyance position of the document; The light-shielding end protrudes to a position that shields the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means through the light introduction means and the reduction optical system, and the detection end is biased. A document leading edge and trailing edge detection mechanism that changes the light blocking range in multiple stages according to the situation is provided, and the conveyance status of the document is detected based on the output of the document detection area of the photoelectric conversion means. As a feature,
The invention according to claim 10 provides: a document table on which a plurality of documents are placed; a document conveyance path in which the documents on the document table are conveyed to a document reading position; a light source that projects light over a predetermined reading width; a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width; and a reduction optical system that reduces light reflected by the document and introduces it into the photoelectric conversion means; In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and It is divided into an image reading area for reading the image of the document, and a document detection area for detecting the leading and trailing edges of the document.
The light source is formed by a plurality of light emitting elements arranged in the document width direction, and the light emitting elements are combined with an image light emitting element group for illuminating the image reading area and a group of image light emitting elements for illuminating the document detection area. A light emitting element group for image detection is divided into a group of light emitting elements for document detection, and the light emitting element group for image is divided into a group of light emitting elements for image detection on the light source side of the document conveyance path near the document reading position, and in the sub-scanning direction with respect to the light irradiated to the reading position from the light emitting element group for image. The photoelectric conversion means is located on the same plane and outside the range of the readable width in the main scanning direction, and the light irradiated from the document detection light emitting element group is introduced into the reduction optical system and transmitted through the reduction optical system. a light introducing means for irradiating a document detection area of the document, the detection end of which is rotatably provided, protrudes to a predetermined position on the document conveyance path, and is biased by the document in accordance with the conveyance position of the document; The light-shielding end protrudes to a position that shields the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means through the light introduction means and the reduction optical system, and the detection end is biased. A document leading and trailing edge detection mechanism that changes the amount of light in multiple stages according to the situation is provided, and the conveyance status of the document is detected based on the output of the document detection area of the photoelectric conversion means. It is said that

0010

[Operation] In the invention as claimed in claim 1, the photoelectric conversion element is arranged to be wider by a predetermined width than the optical path width of the readable width of the original, and has an image reading area for reading the image of the original, the presence or absence of the original, and ( or) a document detection area for detecting the leading edge and trailing edge of the document. Therefore, a single photoelectric conversion means can read the image of the original, determine the presence or absence of the original, and/or the leading edge of the original.
The trailing edge can be detected, these circuit systems can be simplified, costs can be reduced, and the degree of freedom in designing the document reading device can be improved.

In the invention as set forth in claim 2, a plurality of independent light emitting elements are arranged as light sources in the document width direction, and these plurality of light emitting elements are combined into a group of light emitting elements for reading an image of the document; The light emitting element group is divided into a light emitting element group for document detection, and each light emitting element group can be controlled independently. Therefore, the lighting timing of the light emitting elements can be changed, the life of the light emitting elements can be extended, and a group of light emitting elements can be simultaneously mounted on the same substrate. Further, the difference in light amount between the image light emitting element and the document detection light emitting element can be kept below a certain value, and the processing of the output signal from the photoelectric conversion means can be facilitated.

[0012] According to the third aspect of the present invention, the arrangement location of the light emitting element group for document detection can be changed, and the degree of freedom in designing the document reading device can be further improved. In the invention according to claim 4, the photoelectric conversion element of the photoelectric conversion means is disposed wider by a predetermined width, and an image reading area for reading the image of the original, and an area for detecting the presence or absence of the original and the leading and trailing edges of the original are provided. A document detection area is divided into a document detection area, and multiple light emitting elements are used as light sources.
an image light emitting element group for illuminating the image reading area;
a group of light-emitting elements for detecting a document for illuminating the document detection area; and a group of light-emitting elements for detecting a document that is rotated by the document on the document table and illuminates the document detection area of the photoelectric conversion means. A document presence/absence detection mechanism that blocks (or transmits) a portion of the light emitted by the document; A document leading and trailing edge detection mechanism that blocks (or transmits) part of the light irradiated to the document detection area, and a lighting cycle control means that controls the lighting cycle of the image light emitting element group, and the photoelectric Based on the output of the document detection area of the converting means, the conveyance status of the document is determined and the lighting period of the image light emitting element group is controlled. Therefore, it is possible to read the image of the document, detect the presence or absence of the document, and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. Further, the lighting cycle of the image light emitting element at times other than the original reading time can be made slower than the lighting cycle during the original reading time,
It is possible to simplify these circuit systems, reduce costs, and increase the degree of freedom in designing the document reading device.In addition, it is possible to prevent deterioration of the image light emitting element and extend the life of the image light emitting element. can do.

In the invention described in claim 5, the photoelectric conversion element of the photoelectric conversion means is disposed wider by a predetermined width, and an image reading area for reading the image of the original, the presence or absence of the original, and the leading and trailing edges of the original are detected. A document detection area for illuminating the image reading area, an image light emitting element group for illuminating the image reading area, and a document detection light emitting element for illuminating the image reading area. an element group, and a reflection device located near the original reading position, which reflects the light emitted from the original detection light emitting element group and irradiates it to the original detection area of the photoelectric conversion means via the reduction optical system. A part of the light that is rotated by the document on the document table, is projected from the light emitting element group for detecting the document, is reflected by the reflector, and is irradiated to the document detection area of the photoelectric conversion means is blocked (or transmitted). )
a document detection mechanism for detecting the presence or absence of a document, which is rotated by the document conveyed on the document conveyance path at a predetermined position on the document conveyance path, is projected from the light emitting element group for detecting the document, is reflected by the reflection plate, and is transmitted to the photoelectric conversion means. A document leading edge and trailing edge detection mechanism that blocks (or transmits) part of the light irradiated to the detection area is provided,
The conveyance status of the document is detected based on the output of the document detection area of the photoelectric conversion means. Therefore, it is possible to read the image of the document, detect the presence or absence of the document, and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, the light projected from the document detection light emitting element can be efficiently introduced into the document detection area of the photoelectric conversion means, which simplifies these circuit systems.
It is possible to reduce costs and improve the degree of freedom in designing the document reading device, and it is also possible to improve the detection accuracy of the leading edge and trailing edge of the document.

In the invention as set forth in claim 6, the photoelectric conversion element of the photoelectric conversion means is disposed wider by a predetermined width, and the image reading area for reading the image of the original, the presence or absence of the original, and the leading and trailing edges of the original are detected. A document detection area for illuminating the image reading area, an image light emitting element group for illuminating the image reading area, and a document detection light emitting element for illuminating the image reading area. an element group, and a reflecting member located near the document reading position that reflects the light emitted from the document detection light emitting device group and irradiates it to the document detection area of the photoelectric conversion means via the reduction optical system. and,
A document that blocks (or transmits) part of the light that is rotated by the document on the document table, is projected from the group of light emitting elements for detecting the document, is reflected by the reflector, and is irradiated to the document detection area of the photoelectric conversion means. a presence/absence detection mechanism; and a detection area of the photoelectric conversion means that is rotated by the document conveyed on the document conveyance path at a predetermined position on the document conveyance path, is projected from the document detection light emitting element group, and is reflected by the reflector; A document front/rear edge detection mechanism that blocks (or transmits) part of the light irradiated to the document is provided, and the shapes of the parts of the document presence/absence detection mechanism and the document front/rear edge detection mechanism that block light are appropriately configured. The shape of the light shielding member is such that it blocks a certain amount of light and prevents a decrease in the strength of the light shielding member, and the conveyance status of the document is detected based on the output of the document detection area of the photoelectric conversion means. Therefore, it is possible to read the image of the document, detect the presence or absence of the document, and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. Furthermore, the light projected from the document detection light emitting element is efficiently introduced into the document detection area of the photoelectric conversion means, and the light is made suitable for detection, thereby simplifying these circuit systems and reducing costs. It is possible to improve the degree of freedom in the design of document reading devices and document reading devices.
The detection accuracy of the leading edge and trailing edge of the document can be further improved.

In the invention as set forth in claim 7, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. The system is divided into an image reading area for reading the image of the original, and an original detection area for detecting the presence or absence of the original and the leading and trailing edges of the original. An energization display document is disposed in the empty space of the pressure plate, which is conveyed by the document reader and is removable from the reading position. The light emitted from the energized display light source is received from the entrance surface of the light guide, is introduced into the reduction optical system from the exit surface, and is irradiated onto the original detection area of the photoelectric conversion means through the reduction optical system. A dispersion surface for dispersing the light from the energized display light source is formed on either the entrance surface or the exit surface of the guide. Further, it is rotatably provided, and its detection end protrudes to a position where it is urged by the document on the document table, and its light-shielding end is connected to the photoelectric conversion means from the energized display light source through the light guide and the reduction optical system. A document presence detection mechanism that protrudes to a position that blocks part of the light that is irradiated to the document detection area of the document detecting area, and allows the light blocking edge to transmit part of the light when the document pushes the detection edge, and is rotatable. The detection end protrudes at a predetermined position on the document transport path, and the light-shielding end detects part of the light irradiated from the energized display light source to the document detection area of the photoelectric conversion means via the light guide and reduction optical system. a document leading and trailing edge detection mechanism that protrudes to a light-blocking position so that when the document pushes the detection edge, the light-blocking edge transmits a portion of the light;
is provided to detect the presence or absence of a document, the conveyance status of the document, and the detachment state of the pressure plate based on the output of the document detection area of the photoelectric conversion means.

[0016] Therefore, it is possible to read an image of an original, detect the presence or absence of an original, and detect the leading and trailing edges of the original using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, since a energized display light source is used as the light source for document detection, the number of parts can be reduced.
The cost of the document reading device can be reduced, and power consumption can be reduced. Furthermore, since the light guide has a dispersion surface that disperses the light on at least one of the entrance and exit surfaces, it is possible to accurately detect the presence or absence of a document and the leading and trailing edges even if the optical axis is misaligned. This makes it possible to further improve the detection accuracy of the leading edge and trailing edge of the document.

According to an eighth aspect of the invention, in the seventh aspect of the invention, the photoelectric conversion element of the photoelectric conversion means is further provided with a pressure plate detachment detection area for detecting the detachment state of the pressure plate, and the light guide When the pressure plate is removed, it moves and stops introducing the light from the energized display light source to the reduction optical system.

Therefore, in addition to the effect of claim 7,
The separation state of the pressure plate can be detected based on the output result of the pressure plate separation detection area of the photoelectric conversion means, and the detection state of the document detection area of the photoelectric conversion means can be set to the state of no document, so that the separation state of the pressure plate can be detected. This can be easily detected, and it is also possible to prevent the document from being inadvertently conveyed or read when the pressure plate is removed. As a result, the usability of the document reading device can be improved.

In the invention as set forth in claim 9, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. , an image reading area for reading the image of the original, an original detection area for detecting the leading and trailing edges of the original,
The light source is formed by a plurality of light emitting elements arranged in the document width direction, and the light emitting elements are combined with an image light emitting element group for illuminating the image reading area and a light emitting element group for illuminating the document detection area. It is divided into a group of light-emitting elements for document detection, and a group of light-emitting elements for document detection. The light emitted from the light emitting element group for document detection is introduced into the reduction optical system by the light introduction means, and is irradiated onto the document detection area of the photoelectric conversion means via the reduction optical system, and the light introduction means is used to detect the photoelectric conversion means. A document leading and trailing edge detection mechanism is disposed on the optical path that illuminates the document detection area. This document front/back edge detection mechanism is rotatably provided, and its detection end protrudes to a predetermined position on the document conveyance path and is biased by the document in accordance with the conveyance position of the document. The portion protrudes to a position that blocks the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion device via the light introduction device and the reduction optical system, and also The light blocking range is changed in multiple stages.

[0020] Therefore, it is possible to read an image of a document and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, the document leading edge and trailing edge detection mechanism changes the light blocking range of the light irradiated to the document detection area of the photoelectric conversion means in multiple stages according to the document conveyance status, so that the document is conveyed to the document reading position. The transport position can be detected accurately, and the reading operation of the document reading device can be performed accurately.

In the tenth aspect of the invention, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. , the document is divided into an image reading area for reading the image of the document and a document detection area for detecting the leading and trailing edges of the document, and a light source is formed by a plurality of light emitting elements arranged in the width direction of the document, The light emitting elements are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area. The light emitted from the light emitting element group for document detection is introduced into the reduction optical system by the light introduction means, and is irradiated onto the document detection area of the photoelectric conversion means via the reduction optical system, and the light introduction means is used to detect the photoelectric conversion means. A document leading and trailing edge detection mechanism is disposed on the optical path that illuminates the document detection area. This document front/back edge detection mechanism is rotatably provided, and its detection end protrudes to a predetermined position on the document conveyance path and is biased by the document in accordance with the conveyance position of the document. The portion protrudes to a position that blocks the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion device via the light introduction device and the reduction optical system, and also The amount of light is changed in multiple stages.

[0022] Therefore, it is possible to read an image of an original and detect the leading and trailing edges of the original using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, since the document leading edge and trailing edge detection mechanism changes the amount of light irradiated to the document detection area of the photoelectric conversion means in multiple stages according to the document conveyance status, the document is conveyed to the document reading position. The position can be detected accurately, and the reading operation of the document reading device can be performed accurately.

[0023]

[Example] Hereinafter, a detailed explanation will be given based on an example. 1 to 11 are diagrams showing a first embodiment of a document reading device according to the invention according to claims 1, 2, and 3. FIG. 1 is a side view of a facsimile device 20 to which the document reading device is applied, and the facsimile device 20 includes a document reading device 21, a recording device 22, a control device 23, and the like.

The document reading device 21 includes a document table (not shown),
Actuator 24 for detecting the presence or absence of a document, automatic document feeder 25, actuator 26 for detecting the front and rear edges of the document, and light source 2
7, a discharge roller 28, mirrors 29, 30, 31, a lens 32, a photoelectric conversion element array 33, and the like. The actuator 24 for detecting the presence or absence of a document is rotatably supported via a support pin 24a, and one end 24b of the actuator 24 projects above the document table. Further, the other end 24c of the document presence/absence detection actuator 24 protrudes onto the optical path, which will be described later, and the document presence detection actuator 24 is pushed by the support pin 2 by its one end 24b on the document table side being pressed by the document.
Rotate around 4a as a fulcrum. The automatic document feeder 25 has a conveyance roller 25a and a separation plate 25b.The conveyance roller 25a feeds out the lowest document on the document table and separates the documents one by one using the separation plate 25b.

The document leading edge and trailing edge detecting actuator 26 is rotatably supported via a support pin 26, and one end 26b of the actuator 26 projects onto the document conveyance path. Also,
The other end 26c of the document front/back edge detection actuator 26 protrudes onto an optical path, which will be described later, and the document front/back edge detection actuator 26 is moved around the support pin 26a as a fulcrum when its one end 26b on the document transport path side is pushed by the document. Rotate.

The light source 27 projects light onto the original at the reading position P on the original transport path, and the light reflected by the original is reflected by the mirror 29.
, 30 and 31, the light is irradiated onto a photoelectric conversion element array 33 via a lens 32. As shown in FIG. 2, at the position where the light source 27 is projected, a pressure plate 34 is disposed on the opposite side of the light source 27 across the document transport path.
As shown in FIG. 3, is formed wider by a predetermined width than the maximum width of the fed document (document reading width W1). Furthermore, although the surface of the pressure plate 34 facing the light source 27 is painted white, a striped pattern 34a may be applied to the portion beyond the original reading width W1, as shown in FIG. In FIG. 3, of the portion of the pressure plate 34 that exceeds the document reading width W1, the portion indicated by W2 is the portion where the reflected light passes through the optical path where the other end 24c of the document presence detection actuator 24 is located. , and a portion indicated by W3 is a portion where the reflected light passes through the optical path where the other end 26c of the document leading and trailing edge detection actuator 26 is located.

As the light source 27, an LED (Light
A plurality of independent light-emitting elements such as Emitting Diodes are arranged in the document width direction, and these plurality of light-emitting elements are used to emit images for illuminating the document reading width W1 portion of the pressure plate 34. Light emitting element group 2
7a, and a document detection light emitting element group 27b for illuminating a portion of the pressure plate 34 for detecting the presence or absence of a document and for detecting the leading and trailing edges of the document. The image light emitting element group 27a and the document detection light emitting element group 27b are connected to terminals of separate control circuits, for example, as shown in FIG. 5, and can be controlled independently. . In FIG. 5, the image light emitting element group 27a is divided into five blocks, and a plurality of light emitting elements (LED1 to LED8) are connected to each block. Further, all of the light emitting elements (LED1 to LED) of the document detection light emitting element group 27b are connected, and R1 to R6 represent resistances. Note that the pressure plate 34
The method of dividing the light sources 27 is not limited to the above-mentioned method. For example, as shown in FIG.
The document reading width W1 is set at the center of the pressure plate 34, and a portion W2 for the document presence/absence detection actuator 24 and a portion W3 for the document leading/rear end detection actuator 26 are set at both end portions of the pressure plate 34. In the light source 27, an image light emitting element group 27a is located in the center, a light emitting element group 27b for document detection is connected to an actuator 27c for detecting the presence or absence of a document, and an actuator 26 for detecting the front and rear edges of a document.
In addition to dividing the light source 27d into two parts, they may also be set at both ends of the light source 27.

The light reflected at the reading position P is reflected by the mirror 2.
After being reflected by 9, 30, and 31, it is irradiated onto the photoelectric conversion element array 33 by the lens 21. As the photoelectric conversion element array 33, for example, a CCD (Charge Co., Ltd.
(Updated Device) etc. are used, in which a plurality of photoelectric conversion elements are arranged in a row. The photoelectric conversion element array 33 is arranged to be wider by a predetermined width than the width to which the light reflected by the document reading width W1 of the pressure plate 34 is irradiated, and has an image reading area W1' for reading the image of the document, and an image reading area W1' for reading the image of the document. It is divided into a document presence/absence detection area W2' for detecting the presence or absence of a document, and a leading/rear end detection area W3' for detecting the leading edge and trailing edge of the document. In this photoelectric conversion element array 33, as shown in FIG.
The light reflected from the portion corresponding to the original reading width W1 is applied to the image reading area W1' by the actuator 24 for detecting the presence or absence of the original.
The light reflected from the original portion W2 is detected as the document presence/absence detection area W2'.
, and the light reflected by the portion W3 for the document leading edge/back edge detection actuator 26 enters the leading edge/back edge detection area W3'.
Each is irradiated. Generally, CCDs for B4, which are wider, are cheaper than those for A4, and in the facsimile machine 1 for A4, by using a CCD for B4, the image reading area W1' and the presence/absence of a document can be detected. It is possible to secure the area W2' and the leading and trailing edge detection area W3'.

That is, if the resolution of the facsimile device 1 is 8 lines/mm, the B4 width has 2048 pixels, whereas the A4 width requires only 1728 pixels as the image reading area W1'. By using the remaining 320 pixels for the document presence/absence detection area W2' and the leading and trailing edge detection area W3', the photoelectric conversion element array 33 wider than the image reading area W1' can be provided at low cost. This photoelectric conversion element array 33 is conceptually divided into an image reading area W1', a document presence/absence detection area W2', and a leading edge/back edge detection area W3', but the wiring and circuit system can be shared and used in the conventional manner. Similarly, the wiring and circuit system are simpler and cheaper than providing dedicated photocouplers for detecting the presence or absence of a document and for detecting the leading and trailing edges of a document. Note that the method of dividing the photoelectric conversion element array 33 is not limited to the above method. When the pressure plate 34 is set with the document reading width W1 at the center as shown in FIG. , the photoelectric conversion element array 33 also has an image reading area W1' disposed at the center, and a document presence/absence detection area W2' and a leading edge/back edge detection area W3' at both ends.

The recording device 22 has a thermal head 40, a platen roller 41, a roll recording paper 42, etc.
A roll of recording paper 42 is fed between a thermal head 40 and a platen roller 41. The platen roller 41 conveys the rolled recording paper 42 while pressing it against the thermal head 40, and the thermal head 40 records on the rolled recording paper 42. The control device 23, as shown in FIG.
CPU (Central Processing Un
) 50, and the CPU 50 has a power supply device 51.
The photoelectric conversion element array 33 and the light source 2
7, the document transport motor 52, and the like.

Note that in FIG. 1, arrows indicate the direction of conveyance of the document, the direction of conveyance of the rolled recording paper 42, and the direction of travel of the light projected from the light source 27. Next, the effect will be explained. When transmitting or copying, the facsimile machine 20 starts reading the original when the original is set on the original table and the start button is pressed. That is, as shown in FIG.
When the facsimile machine 20 is powered on (step S1), the light source 27 is turned on (step S2). The light source 27 that is turned on at this time may light all the light emitting element groups of the light source 27, or in the case of FIG. 3, it may light only the document detection light emitting element group 27b, or the In this case, only the document detection light emitting element groups 27c and 27d may be turned on. By lighting only the light emitting element group for document detection in this manner, power consumption can be reduced and deterioration of the light source 27 can be prevented.

When the presence or absence of an original is detected using the light from the light source 27 and it is detected that an original is set (steps S3 and S4), the state enters a standby state for reading the original (
Step S5). That is, when the document presence/absence detection actuator 24 is not set on the document table, the other end 24c is connected to the document detection light emitting element group 27b.
, 27c, 27d are located on the optical path of the light projected from the document detection light emitting element groups 27b, 27c, 27d.
From the document presence/absence detection area W2 of the photoelectric conversion element array 33
' to block the projection.

Therefore, it can be determined from the output of the document presence/absence detection area W2' of the photoelectric conversion element array 33 whether or not a document is set on the document table. In addition, the pressure plate 34
When the striped pattern 34a as shown in FIG. 4 is applied to the document presence detection area W2', the movement of the other end 24c of the document presence detection actuator 24 can be detected more accurately.

Thereafter, when the start button of the facsimile machine 20 is pressed (step S6), the document conveyance motor 42 is driven to start conveying the document (step S7).
, the detection of the leading edge and trailing edge of the original is started, and when the leading edge of the original is detected (steps S8 and S9), the original is transported and read (steps S10 and S11). That is, the actuator 26 for detecting the leading and trailing edges of the original is located at its one end 26b.
is located in the document conveyance path, and when the document is not conveyed, the other end 26c is located from the document detection light emitting element group 27b, 27c, 27d of the light source 27 to the leading and trailing edge detection area W3' of the photoelectric conversion element array 33. located in the path of light incident on the Furthermore, when the document is conveyed, one end 26b of the document front/back edge detection actuator 26 is pressed by the document, the document front/back edge detection actuator 26 rotates around the support pin 26a, and the other end 26c is exposed to light. Off the road. Therefore, the photoelectric conversion element array 33
The leading edge and trailing edge of the document can be detected by the output of the leading edge and trailing edge detection area W3'. Furthermore, when a striped pattern 34a as shown in FIG. 4 is applied to the front/back edge detection area W3' of the pressure plate 34, the movement of the other end 26c of the document front/back edge detection actuator 26 can be more accurately detected. can be detected.

In reading this document, if only the document detection light emitting element groups 27b, 27c, and 27d of the light source 27 are turned on when the facsimile machine 20 is powered on as described above, when the leading edge of the document is detected. The image light emitting element group 27a may be turned on. While reading the original, it is checked whether or not the trailing edge of the original is detected (step S12), and when the trailing edge of the original is detected, it is far from the trailing edge detection position of the original to the original reading position P.
The document is read for a predetermined period of time, that is, the remainder of the document being read is read (step S13), and the document is ejected (step S14). The presence or absence of the document on the document table is checked (steps S15, S16), and if the document remains on the document table, the process returns to step S7 and similarly detects and reads the leading and trailing edges of the document. . When all the originals have been read, a standby state is entered, and this flow ends (step S17).

In the control method shown in FIG. 10, at least the document detection light emitting element groups 27b, 27c, and 27d are turned on when the facsimile machine 20 is powered on; however, the control method is not limited to this, and as shown in FIG. Alternatively, the light source 27 may be turned on after the start button of the facsimile machine 20 is pressed. That is, in the facsimile machine 20, the light source 27 does not turn on only when the power is turned on, and when a document is set on the document table (step P1) and the start button is pressed (step P2), the CPU 4
0 starts energizing the light source 27 and lights it up (step P3).

Even in this case, all the light emitting elements of the light source 27 may be turned on, or only the document detection light emitting element groups 27b, 27c, and 27d may be turned on. When the light source 27 is turned on, the presence or absence of a document is first detected (steps P4 and P5). If no document is detected, there is no document to be read, so error processing is performed and the process returns to the standby state ( Step P6, P
17). When it detects that there is a document, it starts transporting the document (
Step P7) When the leading edge of the document is detected (Step P7),
8, P9), the document is read while being transported (steps P10, P11). After that, when the trailing edge of the document is detected (step P12), the remainder of the document being read is read, and then it is checked whether there is a document on the document table (steps P15, P16). Returning to step P7, similar processing is performed. When reading all the originals and discharging the read originals is completed, the process returns to the standby state and ends this flow (step P17).

According to this method, since the light source 27 is turned on after the start button is pressed, deterioration of the light source 27 can be prevented. In this case, if only the document detection light emitting element groups 27b, 27c, and 27d are turned on first, and the image light emitting element group 27a is turned on when the leading edge of the document is detected in step P9, the light source 27 will be further degraded. can be prevented.

FIGS. 12 to 14 are diagrams showing a second embodiment of the document reading device according to the invention according to claims 1, 2, and 3. In explaining this embodiment, FIGS. Components similar to those of the document reading device 21 shown in FIG. In FIG. 12, the document reading device 60 sends out the document set on the document table one by one using the conveying roller 25a and the separation plate 25b, reads it at the document reading position P, and then sends the document out of the document reading device 60 by the discharge roller 28. Discharge. Light is projected from the light source 27 onto the original reading position P, and the light reflected at the original reading position P is reflected by the mirror 61 and then irradiated onto the photoelectric conversion element array 33 via the lens 32. This photoelectric conversion element array 33 has a plurality of photoelectric conversion elements arranged in a row as in the above embodiment, and the photoelectric conversion element array 33 receives light reflected by the document reading width W1 of the pressure plate 34. It is disposed a predetermined width wider than the width to which the image is irradiated, and is divided into an image reading area W1', a document presence/absence detection area W2', and a leading and trailing edge detection area W3'.

The document reading device 60 is provided with an actuator 62 for detecting the presence or absence of a document, and the actuator 62 for detecting the presence or absence of a document is rotatably supported by a support pin 62a. Actuator 62 for detecting the presence or absence of a document
One end 62b protrudes above the document table, and the other end 62c of the document presence detection actuator 62 protrudes near the optical path of the light reflected at the document reading position P, as shown in FIG. In addition, this actuator 6 for detecting the presence or absence of a document
2 is connected to one end 62 by a screw spring or the like (not shown).
b is urged in a direction to protrude above the document table, and is regulated to stop at a predetermined position by a stopper or the like (not shown).

An actuator 63 for detecting the leading and trailing edges of the original is provided between the conveyance roller 25a and the document reading position P, and the actuator 63 for detecting the leading and trailing edges of the original is rotated via a support pin 63a. Possibly supported. One end 63b of the actuator 63 for detecting the leading and trailing edges of the document
protrudes onto the document transport path, and the other end 63c of the document leading edge and trailing edge detecting actuator 63 protrudes near the optical path of the light reflected at the document reading position P, as shown in FIG. The leading and trailing edge detection actuator 63 is biased by a screw spring (not shown) in a direction in which its one end 63b protrudes onto the document conveyance path, and by a screw spring (not shown) or the like, its one end 63b is biased toward the document conveyance path. It is biased in the direction of protruding onto the road, and is regulated to stop at a predetermined position by a stopper or the like (not shown).

A light emitting port of a light guide 64 is directed toward the other end 62c of the actuator 62 for detecting the presence or absence of a document, and a light receiving port of the light guide 64 is directed toward a light source 65 for detecting the presence or absence of a document. Therefore, the light emitted from the light source 65 for detecting the presence or absence of an original is irradiated onto the other end 62c of the actuator 62 for detecting the presence or absence of an original through the light guide 64, and is further transmitted through the lens 32 to the photoelectric sensor as shown in FIG. The conversion element array 33, especially the document presence/absence detection area W2' thereof, is irradiated with light. Further, a light emitting port of a light guide 66 is directed toward the other end 63c of the actuator 63 for detecting the leading and trailing edges of the document, and a light receiving port of the light guide 66 is directed toward the light source 67 for detecting the leading and trailing edges of the document. There is. Therefore, the light emitted from the light source 67 for detecting the leading and trailing edges of the original is irradiated to the other end 63c of the actuator 63 for detecting the leading and trailing edges of the original through the light guide 66, and further,
As shown in FIG. 13, the light is irradiated through the lens 32 to the photoelectric conversion element array 33, particularly to its front and rear end detection regions W3'. The light source 65 for detecting the presence or absence of a document and the light source 67 for detecting the leading and trailing edges of the document are provided on the board of the control device 23 .

Next, the operation will be explained. The light projected from the original 27 in the direction of the original reading position P of the pressure plate 34 is reflected at the original reading position P, as shown in FIG. The reading area W1' is irradiated. In addition, the light projected from the document presence/absence detection light source 65 is
Light that passes through the other end 62c of the actuator 62 for detecting the presence or absence of a document through the light guide 64 and illuminates the detection region W2' of the document presence/absence of the photoelectric conversion element array 33, and is projected from the light source 67 for detecting the front and rear edges of the document. The light passes through the light guide 66, passes through the other end 63c of the document leading and trailing edge detection actuator 63, and is irradiated onto the leading and trailing edge detection area W3' of the photoelectric conversion element array 33.

Assuming that the document reading device 60 is powered on and the document presence/absence detection light source 65 and the document leading and trailing edge detection light source 67 are turned on, when no document is set on the document table, As shown in FIG. 14(a), the output signals (video signals) of each area W1', W2', and W3' of the photoelectric conversion element array 33 are output from the document presence/absence detection area W2' and the front/back edge detection area W3'. The output signal from the image reading area W1' is high, and the output signal from the image reading area W1' is low. Therefore, the output signals of the document presence/absence detection area W2' and the leading and trailing edge detection area W3' of the photoelectric conversion element array 33 are compared with a predetermined specified value Vt, and both areas W1', W
When the output signal of 2' exceeds the specified value Vt,
It can be determined that there is no original on the original table or on the original transport path. That is, when there is no original, the actuator 62 for detecting the presence of an original and the actuator 63 for detecting the leading and trailing edges of the original are urged toward the document table and the document transport path by screw springs, etc. The light from the light source 67 is not blocked by the other ends 62c and 63c of the actuator 62 for detecting the presence or absence of a document and the actuator 63 for detecting the leading and trailing edges of the document. Therefore, the output signals of the document presence/absence detection area W2' and the leading and trailing edge detection area W3' of the photoelectric conversion element array 33 have values higher than the specified values, as shown in FIG. 14(a).

After that, when the original is set on the original table,
The actuator 62 for detecting the presence or absence of a document is pushed by the document and rotates, and the other end 62c blocks the light from the light source 65 for detecting the presence or absence of a document. Therefore, the output signal of the document presence/absence detection area W2' of the photoelectric conversion element array 33 becomes lower than the specified value Vt, as shown in FIG. 14(b), and it is possible to detect that the document is set on the document table. I can do it.

When the conveyance of the document is started and the document reaches the document leading edge and trailing edge detecting actuator 63, the document leading edge and trailing edge detecting actuator 63 is pushed by the document and rotates. Therefore, the other end 63c of the document leading and trailing edge detection actuator 63 blocks the light from the document leading and trailing edge detection light source 67, and the output signal of the leading and trailing edge detection area W3' of the photoelectric conversion element array 33 is as shown in FIG. As shown in c), it becomes lower than the specified value Vt. As a result, the leading edge of the document can be detected, and the document reading device 60 starts reading the document at the time when the document arrives at the document reading position P. The output signal of the photoelectric conversion element array 33 during this document reading is as shown in FIG. 14(d).

As the document progresses and the trailing edge of the document comes to the position of the leading/backing edge detection actuator 63, the leading/backing edge detection actuator 63 is no longer pressed by the original, and the leading/backing edge detection actuator 63 is no longer pressed. 63 is rotated in the direction of the document conveyance path by a screw spring or the like. Therefore, the light from the document leading and trailing edge detection light source 67 is irradiated onto the leading and trailing edge detection area W3' of the photoelectric conversion element array 33 without being blocked by the other end 63c of the document leading and trailing edge detection actuator 63. As a result, the output signal of the photoelectric conversion element array 33 becomes higher than the specified value Vt, as shown in FIG. 14(e), and the trailing edge of the document can be detected.

Therefore, since the photoelectric conversion element array 33 is divided and used as an image reading area W1', a document presence/absence detection area W2', and a leading edge/back edge detection area W3',
The wiring system and circuit system can be used in common for document reading, making it possible to simplify the wiring and circuit system and reduce costs. Furthermore, in this example,
Since the light source 27 for reading the original, the light source 65 for detecting the presence of the original, and the light source 67 for detecting the front and rear edges of the original are provided separately, the degree of freedom in designing the original reading device 60 can be improved. . Furthermore, if the presence or absence of a document and the leading and trailing edges of the document are detected using the light reflected from the pressure plate 34, it is necessary to use a mirror that is correspondingly wider, but in this embodiment, the mirror can be made smaller. , the entire document reading device 60 can be downsized.

12 and 13, between the other end 62c of the document existence detection actuator 62 and the light guide 64, and between the other end 63c of the document front/back edge detection actuator 63 and the light guide 66. To,
As shown in FIG. 15, a dot-line conversion light guide 68 is provided, and the light projected from the light guide 64 and the light guide 64 to the document presence detection actuator 62 and the document leading edge/back edge detection actuator 63 is transmitted to the light source 27. The light projected from the document reading position P and reflected at the document reading position P may be expanded in a direction perpendicular to the optical path plane. This dot-to-line conversion light guide 68 has a rotationally symmetrical cross-section in which the light intake ports on the light guides 64 and 66 side take in the emitted light from the light guides 64 and 66 with high efficiency, and the actuator of the dot-to-line conversion light guide 68 The light projected on the actuator 62 for detecting the presence or absence of a document and the actuator 63 for detecting the leading edge and trailing edge of the document on the sides 62 and 63 is expanded in the direction perpendicular to the optical path plane of the light projected from the light source 27 and reflected at the document reading position P. You may let them. This point-line conversion light guide 68 is the light guide 6
It has a rotationally symmetrical cross section that takes in the light emitted from the light guides 64 and 66 with high efficiency, and the light exit on the actuators 62 and 63 side of the point-to-line conversion light guide 68 is the light intake port on the side of the light source 27. It has a long surface shape in the direction perpendicular to the optical path.

Therefore, even if the photoelectric conversion element array 33 is adjusted vertically by adjusting the image reading position, the light for detecting the presence or absence of a document and for detecting the leading and trailing edges is always located on the photoelectric conversion element array 33, There is no need to adjust the optical axis for presence/absence and tip/back end detection. As a result, the document reading device 6
A document reading device 60 that simplifies the zero adjustment work and can always appropriately detect the presence or absence of a document and the leading and trailing edges.
can be provided at low cost.

FIG. 16 is a diagram showing a third embodiment of the invention according to claims 1, 2, and 3. This embodiment is a diagram showing the light source for detecting the presence or absence of a document and the leading edge of the document in the second embodiment. This is a modified version of the light source for rear edge detection. In describing this embodiment, the same components as in the second embodiment are given the same reference numerals, and the explanation thereof will be omitted. In FIG. 16, reference numeral 70 denotes a light source for detecting the presence or absence of a document, and the light source 70 for detecting the presence or absence of a document is attached to a printed circuit board 71. A light source 72 for detecting the leading and trailing edges of the document is further attached to the printed circuit board 71, and these light sources 70, 72
Power is supplied through a harness 73. The document presence/absence detection light source 70 is directed toward the other end 62c of the document presence/absence detection actuator 62, and its light is projected onto the document presence/absence detection area W2' of the photoelectric conversion element array 33. Further, the light source 72 for detecting the leading and trailing edges of the original is directed toward the other end 63c of the actuator 63 for detecting the leading and trailing ends of the original, and its light is projected onto the leading and trailing edge detection area W3' of the photoelectric conversion element array 33.

Therefore, the presence or absence of a document and the leading and trailing edges of the document can be detected without providing the light guides 64 and 66, and costs can be reduced. Figure 1
7 is a diagram showing a fourth embodiment of the invention according to claims 1, 2, and 3, and this embodiment is a diagram showing a light source for detecting the presence or absence of a document and a light source for detecting the leading and trailing edges of a document in the second embodiment. The light source part has been changed. In describing this embodiment, the same components as in the second embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 17, reference numeral 80 denotes a light source for detecting the presence or absence of an original, and the light source 80 for detecting the presence or absence of an original is connected to the separating plate 2 of the original table.
It is attached to the 5b side. Opposed to this light source 65 for detecting the presence or absence of a document, a light entrance of a light guide 81 is provided on the conveying roller 25a side of the document table, and a projection port of the light guide 81 is connected to a photoelectric conversion element through a lens 32. It is directed toward the document presence/absence detection area W2' of the array 33. Further, a light source 82 for detecting the leading edge and trailing edge of the original is attached to the pressure plate 34 side of the document transport path, and a light guide 83 is installed on the light source side of the document transport path opposite to this light source 82 for detecting the leading and trailing edge of the original. A lighting opening is provided. light guide 83
The projected light passes through the lens 32 to the photoelectric conversion element array 33.
The leading and trailing ends are oriented toward the detection area W3'.

Therefore, in this embodiment, by blocking the light from the light source 80 for detecting the presence of a document and the light source 82 for detecting the leading and trailing edges of the document, the actuator 62 for detecting the presence of the document and the actuator 63 for detecting the leading and trailing edges of the document are It is possible to detect the presence or absence of a document and the leading and trailing edges of the document without using . As a result, the reading device can be made smaller and the degree of freedom in design can be further improved.

FIG. 18 is a diagram showing a fifth embodiment of the invention as claimed in claims 1, 2, and 3. This embodiment is a diagram showing the light source for detecting the presence or absence of a document and the leading edge of the document in the fourth embodiment. The light source part for rear edge detection has been changed. In describing this embodiment, the same components as in the fourth embodiment are given the same reference numerals, and the explanation thereof will be omitted. A reflection plate 85 is disposed on the separation plate 25b side of the document table, and a light source 86 for detecting the presence or absence of a document is provided on the conveyance roller 25a side across the document table.
and a light guide 81 are provided. A light source 86 for detecting the presence or absence of a document projects light onto a reflecting plate 85 , and the light reflected by the reflecting plate 85 is incident on a light receiving port of a light guide 81 . Further, a reflection plate 87 is provided on the pressure plate 34 side of the document transport path, and a light source 88 for detecting the leading and trailing edges of the document and a light guide 83 are provided on the light source 27 side across the document transport path. . The light source 87 for detecting the leading edge and the trailing edge of the original projects light onto the reflecting plate 87 , and the light reflected by the reflecting plate 87 is incident on the light receiving port of the light guide 83 .

Therefore, in this embodiment, the actuator 62 for detecting the presence of a document and the actuator 63 for detecting the leading and trailing edges of the document are activated by blocking the light from the light source 86 for detecting the presence of a document and the light source 87 for detecting the leading edge and trailing edge of the document. It is possible to detect the presence or absence of a document and the leading and trailing edges of the document without using it. As a result, the reading device can be made smaller and the degree of freedom in design can be further improved.

FIG. 19 is a diagram showing a sixth embodiment of the recording device according to the invention according to claims 1, 2, and 3, in which a light guide is used instead of a lens as an optical system. be. In the description of this embodiment, the same components as those of the fourth embodiment shown in FIG. 18 are given the same reference numerals, and the explanation thereof will be omitted. In FIG. 19, a light source 80 for detecting the presence or absence of a document is provided on the side of the separation plate 25b of the document table, and a light guide 90 for detecting the presence or absence of a document is provided opposite to this light source 80 for detecting the presence or absence of a document with the document table in between. A lighting opening is provided. The projection opening of the light guide 90 for detecting the presence of a document is provided near the photoelectric conversion element array 33 and is directed toward the document presence/absence detection area W2' of the photoelectric conversion element array 33. Further, a light source 82 for detecting the leading and trailing edges of the original is provided on the pressure plate 34 side of the document transport path, and a leading and trailing edge of the original is located at a position across the transport path opposite to this light source 82 for detecting the leading and trailing edges of the original. A light opening for a detection light guide 91 is provided. The projection opening of the document leading edge/back edge detection light guide 91 is provided near the photoelectric conversion element array 33 and is directed toward the leading edge/back edge detection area W3' of the photoelectric conversion element array 33. Further, a light entrance of an image light guide 92 is provided at a position facing the document reading position P of the pressure plate 34, and a projection port of the image light guide 92 is provided near the photoelectric conversion element array 33. There is. The projection opening of this image light guide 92 is directed toward the image reading area W1' of the photoelectric conversion element array 33. Note that as the document presence detection light guide 90, the document leading and trailing edge detection light guide 91, and the image light guide 92, for example, a linear-circular conversion light guide or a linear-plane conversion light guide is used.

Therefore, by blocking the light from the light source 80 for detecting the presence of a document and the light source 82 for detecting the leading and trailing edges of the document, the presence or absence of the document and the leading and trailing edges of the document can be detected. The light from the light source 80 for detecting the front and rear edges of the document and the light source 82 for detecting the leading and trailing edges of the original is transmitted to the light guides 90 and 9.
1, the light can be directly projected onto the photoelectric conversion element array 33. Further, the light projected from the light source 27 and reflected by the original can be directly irradiated onto the photoelectric conversion element array 33 by the image light guide 92. As a result, the lens can be omitted, the reading device can be downsized, and the degree of freedom in design can be further improved. Note that in FIGS. 17, 18, and 19, the light sources for detecting the presence or absence of a document and for detecting the leading and trailing edges of the document are arranged at positions facing each detection light guide.
It is not limited to this, and it is sufficient if the secondary light emitting point is located at that position. Therefore, the actual light source may be disposed at a different position, and the light may be guided to the light source positions in FIGS. 17, 18, and 19 using a light guide or the like.

FIGS. 20 to 24 are diagrams showing an embodiment of the document reading device according to the fourth aspect of the invention. FIG. 20 is a configuration diagram of the main parts of the document reading device 100. ) 102 , document guide plate 103 , document presser plate 104 , conveyance roller 105
, light source 106 , discharge roller 107 , lens 108 ,
It includes a photoelectric conversion element array (photoelectric conversion means) 109, a stepper motor 110, and the like.

[0060] Original guide plate 103 and original pressing plate 1
04 is the document table 1 on which a plurality of documents 111 are set.
12 and the document conveyance path 11 through which the document 111 is conveyed.
3 is formed. Actuator 1 for document presence detection
01 is rotatably supported via a support pin 101a, and its detection end 101b protrudes above the document table 112. In addition, the actuator 1 for detecting the presence or absence of a document
The light-shielding end 101c of 01 protrudes onto the optical path, which will be described later.
The document presence detection actuator 101 rotates about the support pin 101a as the detection end 101b on the document table side is pushed by the document.

The conveyance roller 105 separates and sends out the lowest document 111 set on the document table 112 one by one, and conveys it to the reading position P on the conveyance path 113. Light is projected from the light source 106 onto the document 111 conveyed to the reading position P to read the image, and the document 111 with the image read is discharged onto a document tray (not shown) by the discharge roller 107 . Ru.

[0062] Actuator 102 for detecting leading edge and trailing edge of document
is rotatably supported via a support pin 102a, and its detection end 102b projects onto the conveyance path 113. In addition, actuator 1 for detecting the leading edge and trailing edge of the document
The light-shielding end 102c of 02 protrudes onto the optical path, which will be described later.
The document leading edge and trailing edge detecting actuator 102 rotates about the support pin 102a as a fulcrum when its detection end 102c on the document transport path side is pushed by the document 111.

The light source 106 projects light onto the original 111 located at the reading position P on the original transport path 113, and
The light reflected by the photoelectric conversion element array 109 is irradiated through the lens 108. This light source 106
A document holding plate 104 is disposed on the opposite side of the light source 106 across the document transport path 113 at the position where the light from the document is projected.
The sides are painted white. In addition, this original presser plate 10
4 is arranged so that its width in the main scanning direction is wider than the maximum document width.

The light source 106 is an LED (Light E
As shown in FIG. It is divided into an image light emitting element group 106a for illuminating the reading width, and an original detection light emitting element group 106b for illuminating the outside of the maximum original reading width of the document holding plate 104. These image light emitting element group 106a and document detection light emitting element group 106b
is controlled by a control circuit shown in FIG.

[0065] Furthermore, the light reflected at the reading position P is
The photoelectric conversion element array 109 is irradiated by the lens 108 . As the photoelectric conversion element array 109, for example, a CCD (Charge Coupled Dev)
(ice) etc. are used, and a plurality of photoelectric conversion elements are arranged in a row. This photoelectric conversion element array 109 is arranged to be wider by a predetermined width than the width to which the light reflected by the maximum document width portion of the document holding plate 104 is irradiated, and as shown in FIG. an image reading area 109a for reading the document; and a document detection area 109b for detecting the presence or absence of a document and the leading and trailing edges of the document.
It is divided into In this photoelectric conversion element array 109, light reflected from the maximum original width portion of the original holding plate 104 is directed to the image reading area 109a, and light reflected from the outside of the maximum original width of the original holding plate 104 is sent to the original detection area. 10
9b, respectively. As mentioned above, generally
CCDs for B4, which are wider, are cheaper than those for A4, and in the A4 document reading device 100, by using a CCD for B4, the image reading area 109a and the document detection area 109b are can be ensured.

That is, if the resolution of the document reading device 100 is 8 lines/mm, the B4 width has 2048 pixels, whereas the A4 width requires only 1728 pixels as the image reading area 109a. By using the remaining 320 pixels for the original detection area 109b,
The photoelectric conversion element array 109, which is wider than the image reading area 109a, can be provided at low cost. Although this photoelectric conversion element array 109 is conceptually divided into an image reading area 109a and an original detection area 109b, its wiring and circuit system can be shared and used for detecting the presence or absence of an original and for detecting the leading edge and trailing edge of an original. The wiring and circuit system are simpler than installing a dedicated photocoupler for detection, and
It will be cheap.

[0067] Actuator 101 for detecting the presence or absence of the original document
The light-shielding end 101c and the light-shielding end 102c of the leading and trailing edge detection actuator 102 of the document are connected to the light source 10.
It is located on the optical path of the light emitted from the original detection light emitting element group 106b of No. 6 to the original detection area 109b of the photoelectric conversion element array 109, and each of the light-shielding end portions 101c and the light-shielding end portion 102c are used for detecting the presence or absence of a document. Actuator 10
The detection end 101b of the document 111 and the detection end 102b of the document leading and trailing edge detection actuator 102 are
When not pressed, this light is blocked and each detection end 1
When the detection end 101b and the detection end 101b are pushed by the original 111, they are removed from the optical path and no longer block the light.

The control circuit 120 is configured as shown in FIG. 22, and includes a detection circuit 121, a drive circuit 122, a lighting cycle control circuit 123, a driver 124, and the like. Photoelectric conversion element array 109
The output signal Vo is output to the detection circuit 121, and this output signal Vo is applied to the document presence detection actuator 101 in the document detection area, as shown in FIG.
And when the document front/back edge detection actuator 102 blocks the light from the light source 106, the output values S1 and S2 of the portion blocked by both actuators (S1 is the document presence/absence detection S2 is due to the actuator 101 for detecting the leading edge of the document, and S2 is due to the actuator 102 for detecting the leading edge and trailing edge of the document. As shown in , there is no decrease in the output value due to both actuators. Based on the output Vo of the photoelectric conversion element array 109, the detection circuit 121 activates the actuator 1 for detecting the presence or absence of a document.
01 and actuator 102 for detecting the leading edge and trailing edge of the document
Actuator 10 for detecting the presence or absence of a document by detecting the operation of
The system control circuit 12 uses the detection results of the signal S1 by 1 and the signal S2 by the document leading and trailing edge detection actuator 102 as detection signals S1D and S2D, respectively.
At the same time, the lighting signal LG is output to the lighting cycle control circuit 123. The lighting signal LG is the detection signal S
Based on this lighting signal LG, the lighting cycle control circuit 123 outputs a control signal LC to the driver 124 that controls the driving of the light source 106. The driver 124 outputs the drive signal LD to the light source 106 and
control the drive of the Therefore, the lighting period control circuit 12
3 controls the output cycle of the control signal LC to the driver 124 based on the lighting signal LG from the detection circuit 121, and controls the lighting cycle of the light source 106 by the driver 124.

On the other hand, the drive circuit 122 supplies the photoelectric conversion element array 109 with a shift pulse φSH and a transfer pulse φ
1, φ2 and a reset pulse φR, a signal LT is output to the detection circuit 121, and a lighting time width signal LDT synchronized with the shift pulse φSH is output to the lighting cycle control circuit 123. The photoelectric conversion element array 109 converts the image reading area 109a and the document detection area 10 based on each signal from the drive circuit 122.
The input light of 9b is photoelectrically converted and an output signal Vo is output.

Next, the operation will be explained. In the document reading device 100 , in a standby state in which the document 111 is not set on the document table 112 , the document presence detection actuator 101 and the document front/back edge detection actuator 102 are not pushed by the document 111 , and each document presence detection actuator As shown in FIG. 20 and FIG.
Original detection area 10 of photoelectric conversion element array 109 from b
9b is located on the optical path of the light introduced into the document detection area 1.
The light projected onto 09b is blocked by the light-shielding end 101c of the actuator 101 for detecting the presence or absence of a document and the light-shielding end 102c of the actuator 102 for detecting the leading and trailing edges of the document.

Therefore, the photoelectric conversion element array 109
As shown in FIG. 23(a), the output signal Vo of
The portions that are shielded from light by the light-shielding end 102c of the leading and trailing edge detection actuator 102 of the document are signals S1 and S2.
The detection circuit 121 sends this detection result to the system control circuit 12 as detection signals S1D and S2D.
Output to 5. Based on the values of the detection signal S1D and the detection signal S1D, the system control circuit 125 determines whether the original 111 is set on the original table 112 and whether the original 111 has been conveyed to a predetermined position on the original conveyance path 113. can be determined. Therefore, the system control circuit 125 can control the reading operation based on the detection signal S1D and the detection signal S2D. In addition, the detection circuit 12
1 outputs the lighting signal LG to the lighting cycle control circuit 123 based on the detection signal S1D, and this lighting signal LG
As shown in FIG. 24, changes in synchronization with the detection signal S1D. In this standby state, the lighting cycle control circuit 1
23 outputs to the driver 124 a control signal LC with a lighting cycle longer than that required for normal reading, and the driver 124 outputs a drive signal LD with a longer lighting cycle according to this control signal LC.
is output to the light source 106 , and the light source 106 is turned on.

Now, when the original 111 is set on the original table 112 , the original 11 set on the original table 112 is
1 presses the detection end 101b of the actuator 101 for detecting the presence or absence of a document, and the actuator 1 for detecting the presence or absence of a document
01 is rotated around the support pin 101a. When the document presence/absence detection actuator 101 rotates around the support pin 101a, its light-shielding end 101c comes off the optical path of the document detection light-emitting element group 106b and no longer blocks light.

Therefore, as shown in FIG. 24, the signal S1 portion of the output Vo of the photoelectric conversion element array 109 by the actuator for detecting the presence or absence of an original 101 no longer decreases, and accordingly, the lighting signal LG changes as shown in FIG. , it switches from low (L) to high (H). When the lighting signal LG switches from low (L) to high (H), the lighting cycle control circuit 123 changes the output cycle of the control signal LC to the driver 124 from the output cycle during standby, as shown in FIG. It is also fast and outputs by switching to the lighting cycle required for normal reading. For example, set the output cycle during standby to 20
If it is 0 mms, when the lighting signal LG becomes high (H), the output cycle is switched to 10 mms. As a result, during standby, the lighting cycle is approximately 20 times longer than during reading, thereby preventing deterioration of the light source 106 and extending the life of the light source 106. At the time of reading, the lighting cycle is approximately 20 times longer than when reading an image. can be controlled.

After that, the original 111 is transferred to the transport roller 105.
When the document 111 is conveyed on the conveyance path 113 by the document 111 and presses the detection end 102b of the document leading and trailing edge detecting actuator 102, the document leading and trailing edge detecting actuator 102 rotates around the support pin 102a. The light-shielding end 102c is removed from the optical path. Therefore, as shown in FIGS. 23(b) and 24, the output Vo of the photoelectric conversion element array 109 is no longer reduced by the actuator 101 for detecting the presence or absence of a document and the actuator 102 for detecting the front and rear edges of the document, and the system control circuit 125 performs a reading operation of the original 111 .

As described above, according to the invention as set forth in claim 4, the lighting period of the light source can be controlled by checking the transportation status of the document, so that deterioration of the light source can be prevented and the light source It can extend the lifespan. Furthermore, in the above embodiment, until the document presence/absence detection actuator 101 detects the document on the document table 112, the light source 106
When the actuator 101 detects that a document is set on the document table 112, the light source 106 is illuminated at a faster rate, so that it can be used for document presence detection, which does not require high detection accuracy. The actuator 101 can perform sufficient detection, and the actuator 102 for detecting the front and rear edges of the document
Therefore, sufficient detection accuracy can be obtained, and the original 111 can be read with high accuracy.

FIGS. 25 to 35 are diagrams showing an embodiment of the original reading device according to the fifth and sixth aspects of the invention. 25 and 26 are a perspective view and a side view of essential parts of the document reading device 200. The document reading device 200 includes a document guide plate 201, an ADF roller 202, a separation pad 203, an ejection roller 204, a light source 205, and a mirror. 206 , 207 , 208 , a lens 209 , a photoelectric conversion element array 210 , a reflection plate 211 , an actuator 212 for detecting the presence or absence of a document, an actuator 213 for detecting the leading and trailing edges of a document, and the like.

[0077] The document guide plate 201 is connected to the document table 214.
It also constitutes an original transport path 215 , and a plurality of originals 216 are stacked on the original table 214 . Original table 214 Original 216 placed on top
The documents are separated one by one by the ADF roller 202 and the separation pad 203, sent out onto the document conveyance path 215, and conveyed to the reading position P on the document conveyance path 215. The light source 20 is placed on the document 216 conveyed to the reading position P.
The light is emitted from the document 216 and is reflected by the mirrors 206, 207, and 208, and then is irradiated onto the photoelectric conversion element array 210 through the lens 209. Original 21 whose image has been completely scanned at reading position P
6 is the document reading device 200 by the ejection roller 204.
The document is ejected onto the external document tray. At the reading position P, a document holding plate 217 is disposed on the opposite side of the light source 205 across the document transport path 215, and a white color is provided on the light source side surface of the document holding plate 217 for shading correction. is applied.

[0078] Also, the reflector 211 is located at this reading position P.
It is provided nearby on the side of the light source 205 with the document conveyance path 215 in between, and reflects the light from the light source 205 and irradiates it onto the mirror 206 , passing through the mirrors 207 , 208 and the lens 209 to the photoelectric conversion element array 210 . is irradiated with light from a light source 205. The surface of the reflection plate 211 may be formed like a normal mirror, but
Illuminance can be efficiently obtained even if the color is white or has a metallic luster. In addition, the surface of the reflecting plate 211 is shown in FIG.
As shown in FIG. 2, the finely grained surface allows the specularly reflected light to become diffused light, and it is possible to reliably detect the document presence/absence detection actuator 212 and the document front/back edge detection actuator 213, which will be described later. . Furthermore, if the surface of the reflection plate 211 is formed into an uneven surface shape extending in the main scanning direction, as shown in FIG.
As shown in FIG. 29, the light from the document can be diffused only in the sub-scanning direction without being diffused in the main scanning direction. Detection can be performed reliably and efficiently. Note that when the surface of the reflector plate 211 has an uneven surface shape extending in the main scanning direction, if the angle of the uneven line is changed as necessary, the diffusion component can be adjusted and the detection accuracy can be further improved. I can do it.

The light source 205 projects light onto the original 216 located at the reading position P on the original transport path 215, and
The light reflected by 6 is irradiated onto a photoelectric conversion element array 210 through a lens 209. This light source 205
A document holding plate 217 is disposed on the opposite side of the light source 205 across the document transport path 215 at the position where the light from the light source 205 is projected.
The sides are painted white. In addition, this document pressing plate 21
7 is arranged so that its width in the main scanning direction is wider than the maximum document width.

The light source 205 is an LED (Light E
A device in which a plurality of independent light emitting elements such as diodes (mitting diodes) are arranged in the width direction of the document is used, and as in the above embodiment, these light emitting elements An image light emitting element group 205a having a width sufficient for reading, and the reflecting plate 211
a document detection light emitting element group 205b for irradiating;
It is divided into

The photoelectric conversion element array 210 may be, for example, a CCD (Charge CCD) as in the above embodiment.
A photoelectric conversion device is used, in which a plurality of photoelectric conversion elements are arranged in a row. This photoelectric conversion element array 210 is connected to the original holding plate 2
As shown in FIG. 30, the image reading area 210a is arranged to be wider than the width to which the light reflected by 17 is irradiated, and as shown in FIG. Document detection area 210b for detecting
It is divided into. This photoelectric conversion element array 210
In this case, the light reflected at the reading position P of the original holding plate 217 is applied to the image reading area 210a, and the light reflected from the reflecting plate 211 is applied to the original detection area 210b. This photoelectric conversion element array 210 is conceptually divided into an image reading area 210a and a document detection area 210b, but the wiring and circuit system can be shared.
The wiring and circuit system are simpler and cheaper than the conventional method, in which dedicated photocouplers are provided for detecting the presence or absence of a document and for detecting the leading and trailing edges of a document.

Further, the lighting state of the image light emitting element group 205a and the original detection light emitting element group 205b of this light source 205 can be controlled independently, and the image light emitting element group 205a is used to control the conveyance of the original 216. The light-emitting element group 205b for document detection is lit at all times when the power of the document reading device 200 is turned on, and is used to detect the presence or absence of the document 216 and the leading and trailing edges thereof, although it is turned on at appropriate times depending on the situation. Furthermore, the document detection light emitting element group 2 of the light source 205
As 05b, the light of the indicator light indicating that the document reading device 200 is powered on may be introduced through an optical fiber or the like.
Alternatively, a separately prepared light such as an LED may be used.

The actuator 212 for detecting the presence or absence of a document is rotatably supported via a support pin 212a, and its detection end 212b protrudes to a position where it is pushed by the document 216 set on the document table 214. In addition, the light-shielding end 2 of the actuator 212 for detecting the presence or absence of a document
Reference numeral 12c projects on the optical path of the light from the document detection light emitting element group 205b, and is an actuator 212 for document presence/absence detection.
When the detection end 212b is pushed by the document 216, the detection end 212b rotates about the support pin 212a as a fulcrum.

[0084] Actuator 213 for detecting leading edge and trailing edge of document
is rotatably supported via a support pin 213a, and its detection end 213b protrudes above the document transport path 215. Further, the light-shielding end 213c of the document front/back edge detection actuator 213 protrudes onto the optical path of the light from the document detection light emitting element group 205b, and the document front/back edge detection actuator 213 has its detection end 213b on the document 216. By being pushed, it rotates about the support pin 213a as a fulcrum.

These actuators 21 for detecting the presence or absence of originals
As shown in FIG. 25, the light-shielding end portion 212c of the light source 205 and the light-shielding end portion 213c of the actuator 213 for detecting the leading and trailing edges of the document are connected to the light-emitting element group 205 for document detection of the light source 205.
Each actuator 212, 213 is located on the optical path of the light irradiated from b and reflected by the reflecting plate 211.
The detection end portion 212b and the detection end portion 213b are connected to the original 21
6, when not pressed by the light shielding end 212c
and the light-shielding end 213c blocks light reflected by the reflector 211 and irradiated onto the photoelectric conversion element array 210 through the mirrors 207 and 208 and the lens 209,
The detection end portion 212b and the detection end portion 213b are connected to the original 21
6, the light-shielding end 212c and the light-shielding end 213c are removed from the optical path of the light from the document detection light emitting element group 205b, and no longer block the light. In FIG. 25, the optical path is indicated by diagonal lines when the light is blocked by the actuator 212 for detecting the presence or absence of a document and the actuator 213 for detecting the leading and trailing edges of the document.

[0086] In addition, the actuator 21 for detecting the presence or absence of a document
2 and actuator 213 for detecting the front and rear edges of the document
The support pins 212a and 213a are arranged perpendicularly to the optical axis of the light from the reflection plate 211, and each actuator 212 and 213 has its light-shielding end 21
2c and the light shielding end 213c rotate in a direction parallel to the optical path direction of the light to be shielded. Further, as shown in FIGS. 25 and 26, the light-shielding end 212c of the document presence detection actuator 212 and the light-shielding end 213c of the document leading and trailing edge detection actuator 213 are connected to the support pins 212a and 213a of each actuator 212 and 213, respectively. side(
In other words, the light-shielding end 212c of the actuator 212 for detecting the presence or absence of a document does not reflect light even if its detection end 212b is pushed by the document 216 and rotates. While blocking the light from the plate 211, the light blocking end 212c always blocks the light at the same position. Similarly, the light-shielding end 213c of the document leading and trailing edge detection actuator 213 is connected to its detection end 213b.
Even if it is pushed by the original 216 and rotates, the reflector 211
The light-shielding end portion 213c always shields light at the same position. Therefore, it is possible to reliably detect whether this light is blocked by the photoelectric conversion element array 210.

[0087] In addition, the actuator 21 for detecting the presence or absence of a document
As shown in FIG. 30, the light-shielding end portion 212c of No. 2 and the light-shielding end portion 213c of the document leading and trailing edge detection actuator 213 have the following characteristics: The angle between the outer surface of each light-shielding end 212c and 213c and the optical axis PL is θa1, and the angle between the surface of each light-shielding end 212c, 213c on the optical axis PL side and the optical axis PL is θa1. The angle is θa2, the outer luminous flux surface of the light beam PS projected from the document detection light emitting element group 205b at the light shielding ends 212c, 213c, and the optical axis PL of the light from the image light emitting element group 205a.
Let θb1 be the angle between the light beam PS and the optical axis PL, then θa1≧θb1 θa2≧θb2 …(1) It is in.

Therefore, the range of the light-shielding end 212c of the document detection actuator 212 and the light-shielding end 213c of the document leading and trailing edge detection actuator 213 that blocks light from the document detection light emitting element group 205b is larger than necessary. In addition, it is possible to prevent the spread of the document detection area 210b from the document detection light emitting element group 205b.
It is possible to prevent a decrease in the intensity of light irradiated to the area.

Next, the operation will be explained. When the document 216 is not set on the document table 214, the document detection actuator 212 and the document front/back edge detection actuator 213 have their detection ends 212b and 213b not pressed by the document 216, and their light-shielded ends portion 212c and light shielding end portion 21
3c is located on the light beam PS (optical path) of the light from the original detection light emitting element group 205b;
Original detection area 21 of photoelectric conversion element array 210 from b
The light irradiated to 0b is blocked. At this time, the light-shielded end 212c of the document presence/absence detection actuator 212 and the light-shielded end 213c of the document front/back edge detection actuator 213 have the relationship expressed by equation (1) above. It is possible to prevent the light from being blocked more than necessary or from lowering the light intensity. As a result, based on the output of the photoelectric conversion element array 210, the operation of the document presence/absence detection actuator 212 and the document front/back edge detection actuator 213 can be reliably detected.
12 and actuator 213 for detecting the leading edge and trailing edge of the document
Accordingly, the presence or absence of the original 216 on the original table 214 and the transport position of the original 216 on the original transport path 215 can be accurately detected.

Now, when the original 216 is set on the original table 214, the detection end 212b of the original presence/absence detection actuator 212 is pushed by the original 216.
The actuator 212 for detecting the presence or absence of a document has the support pin 2
It rotates around 12a. As described above, the support pin 212a of the actuator 212 for detecting the presence or absence of a document is
It is arranged in a direction perpendicular to the light beam PS from the document detection light emitting element group 205b, and its light-shielding end 212
c is formed in a curved shape with a concave surface on the side of the support pin 212a, so that the document presence detection actuator 212
As shown in FIG. 31, the light shielding end portion 212c always shields the light from the document detection light emitting element group 205b at the same position.

Therefore, by rotating the actuator 212 for detecting the presence or absence of a document, the photoelectric conversion element array 210
It is possible to prevent the width and intensity of the light irradiated onto the original detection area 210b from being disturbed, and the detection end 212b of the original presence/absence detection actuator 212
6, it is possible to accurately detect the position where the light shielding end portion 212c no longer blocks light from the document detection light emitting element group 205b. As a result, the original platen 2
It is possible to accurately detect the setting of the original 216 on top of the original 216 .

[0092] Thereafter, when the original 216 is conveyed sheet by sheet onto the original transport path 215 by the ADF roller 202 and the separation pad 203, the detection end 213b of the actuator 213 for detecting the leading and trailing edges of the original is pushed by the original 216. Then, the document leading edge and trailing edge detecting actuator 213 rotates around the support pin 213a. Similarly to the actuator 212 for detecting the presence or absence of a document, this actuator 213 for detecting the front and rear edges of a document has a support pin 213a disposed in a direction perpendicular to the light beam PS, and a light-shielding end 213c thereof faces the side of the support pin 213a. Since it is formed in a curved shape with a concave surface, the light-shielding end portion 213c is formed in a curved shape with a concave surface.
The light from 5b is always blocked at the same position. therefore,
When the detection end 213b of the document front/back edge detection actuator 213 is pressed by the document 216, the position where the light blocking end 213c no longer blocks light from the document detection light emitting element group 205b can be accurately detected. ,
The leading edge and trailing edge of the document 216 conveyed on the document conveyance path 215 can be detected with high accuracy.

Furthermore, since the reflective plate 211 is disposed near the reading position P and closer to the light source 205 than the original guide plate 201, the original 216 can be reliably read without being affected by the skew of the original 216. can be detected. Therefore, according to the inventions recited in claims 5 and 6, it is possible to reliably and precisely control whether or not a document is set on the document table and the leading and trailing edges of the document being conveyed on the document conveyance path. Therefore, it is possible to precisely control the driving state of the document reading device 200 corresponding to the set state and conveyance state of the document.

Note that in the above embodiment, the reflector 211
Although a plate-shaped plate is used, the present invention is not limited to this. For example, as shown in FIG. 32, a reflecting plate 300 with a concave surface facing the light source 205 may be used. The light from 205b can be efficiently introduced into the document detection area 210b of the photoelectric conversion element array 210. Further, as shown in FIGS. 33 to 35, the reflection plate may be a polygonal reflection plate 400 and may be arranged to surround the document detection light emitting element group 205b of the light source 205. In this case as well, the document detection light emitting element group 205
The light from the source b can be efficiently introduced into the document detection area 210b of the photoelectric conversion element array 210. The bottom surface of this polygonal reflecting plate 400 may be flat or concave.

Furthermore, in the reflecting plates 300 and 400 shown in FIGS. 31 and 32 to 35, the grained surface shown in FIG. 27 or the textured surface shown in FIGS. It may also be an uneven surface in the main scanning direction as shown in FIG. In this case, the photoelectric conversion element array 2
10 can be further improved. 36 to 38 are diagrams showing an embodiment of the document reading device according to the seventh and eighth aspects of the invention.

FIGS. 36 and 37 show the document reading device 50.
0 is a perspective view and a side view of main parts of the document reading device 50.
0 has a document guide plate 501 and an ADF on its main body side.
Roller 502, separation pad 503, discharge roller 5
04, light source 505, mirror 506, 507, 5
08, a lens 509, a photoelectric conversion element array 510, an actuator 511 for detecting the presence or absence of a document, an actuator 512 for detecting the leading and trailing edges of a document, and the like.

[0097] The document guide plate 501 is connected to the document table 513.
It also constitutes an original transport path 514, and a plurality of originals 515 are stacked on the original table 513. Original table 513 Original 515 placed on top
The documents are separated one by one by the ADF roller 502 and the separation pad 503, sent out onto the document conveyance path 514, and conveyed to the reading position P on the document conveyance path 514. A light source 50 is placed on the document 515 that has been conveyed to the reading position P.
The light emitted from the original 515 is reflected by the mirrors 506, 507, and 508, and then passes through the lens 509 to the photoelectric conversion element array 510.
is irradiated. The document 515 whose image has been completely read at the reading position P is discharged onto a document tray (not shown) outside the document reading device 500 by a discharge roller 504 .

At the reading position P, the original transport path 51
A pressure plate 516 is disposed on the opposite side of the light source 505 with 4 in between, and the surface of the pressure plate 516 on the light source side is painted white for shading correction. The pressure plate 516 is provided at a fulcrum S formed in the main body of the document reading device 500 so that it can be opened and closed, that is, it can be removed from the reading position (original reading position) P, and it moves the original conveyed to the original reading position to the reading position P. Transport in close contact. In addition, the pressure plate 516
A predetermined empty space is formed between the upper cover 516a and the energized display light source 51 in this empty space 516b.
7 are installed. The energization indicator light source 517 is a light source for indicating that the power is turned on to the document reading device 500, and is always lit when the power is turned on to the document reading device 500. Further, a light guide 518 is provided on the pressure plate 516 , and the light guide 518 introduces the light projected from the energized display light source 517 to the mirror 506 .
The photoelectric conversion element array 510 is irradiated through the lens 509 and the photoelectric conversion element array 510. That is, mirror 5
06 , 507 , 508 and the lens 509 collectively constitute a reduction optical system 518 that introduces the reflected light of the light projected onto the original 515 from the light source 505 into the photoelectric conversion element array 510 , and the light guide 518
The light projected from the energized display light source 517 is introduced into the reduction optical system 518. In addition, the light guide 518 is connected to the energization display light source 51.
7 side surface (incident surface) or (and) document reading device 5
A textured surface (dispersion surface) for dispersing the light from the energized display light source 517 is formed on one or both surfaces of the 00 side surface (output surface). Therefore, the document reading device 5
00 is formed with a hole 501a into which the exit surface of the light guide 518 enters when the pressure plate 516 is closed. Incidentally, a hole 516c is formed in the upper cover 516a of the pressure plate 516 to enable visual recognition of the lighting of the energization indicator light source 517.

The light source 505 projects light onto the original 515 located at the reading position P on the original transport path 514, and
The light reflected by mirrors 506, 507, 5
08 and the photoelectric conversion element array 510 through the lens 509. At the position where light is projected from the light source 505 (reading position), the pressure plate 516 is disposed on the opposite side of the light source 505 across the document transport path 514, and the pressure plate 516 has a width in the main scanning direction. is wider than the maximum document width. The light source 505 is, for example, an LED (Light Emitting Diode).
A device in which a plurality of independent light-emitting elements such as de) are arranged in the document width direction is used, and these plurality of light-emitting elements have a width sufficient to read the document 515 having the maximum document reading width. are doing.

As the photoelectric conversion element array 510, for example, a CCD (Charge CCD) is used as in the above embodiment.
A photoelectric conversion device is used, in which a plurality of photoelectric conversion elements are arranged in a row. This photoelectric conversion element array 510 includes the pressure plate 516
As shown in FIG. 36, an image reading area 510a is provided which is wider than the width of the original 515 at the reading position P by a predetermined width than the width illuminated with light reflected from the original 515 at the reading position P. As shown in FIG.
, a document front/back edge detection area 510b for detecting the leading/back edge of the document, and a document presence/absence detection area 510c for detecting the presence/absence of the document. In this photoelectric conversion element array 510, the pressure plate 51 at the reading position P
6 and the original 515, the light reflected from the image reading area 510
A, the light projected from the energized display light source 517 detects the leading edge and trailing edge of the document detection area 510b and the document presence/absence detection area 510c.
are irradiated respectively. This photoelectric conversion element array 51
0 is conceptually divided into an image reading area 210a, a document leading and trailing edge detection area 510b, and a document presence/absence detection area 510c, but the wiring and circuit system can be shared and used for document presence detection and document presence detection area 510c as in the past. The wiring and circuit system are simpler and cheaper than providing a dedicated photo coupler for detecting the leading edge and trailing edge of the document.

[0101] The actuator 511 for detecting the presence or absence of a document is
It is rotatably supported via a support pin 511a,
The detection end portion 511b protrudes to a position where it is pushed by the document 515 set on the document table 513. Further, the light-shielding end 511c of the actuator 511 for detecting the presence or absence of a document is connected to the reduction optical system 5 from the energized display light source 517.
The document presence/absence detecting actuator 511 protrudes onto the optical path of the light introduced into the document 515, and when its detection end 511b is pushed by the document 515, it rotates about the support pin 511a as a fulcrum.

[0102] Actuator 512 for detecting leading edge and trailing edge of document
is rotatably supported via a support pin 512a, and its detection end 512b protrudes above the document transport path 514. Further, the light-shielding end 512c of the document front/back edge detection actuator 512 protrudes onto the optical path of the light introduced from the energized display light source 517 to the reduction optical system 518, and the document front/back edge detection actuator 512 has its detection end 512c.
b is pushed by the document 515, the support pin 51
Rotates around 2a as a fulcrum.

[0103] Actuator 51 for detecting the presence or absence of these documents
The light-shielding end 411c of 1 and the light-shielding end 512c of the document leading and trailing edge detection actuator 512 are located on the optical path of the light emitted from the energized display light source 517 and introduced into the reduction optical system 518 by the light guide 518.
The light introduced into the mirror 506 by the light guide 518, further reflected by the mirror 506, and projected onto the mirror 507 is located on the optical path of the light projected from the mirror 507 onto the mirror 508,
, 213 are the detection end 511b and the detection end 5
12b is not pressed by the original 515, its light-shielding end 212c and light-shielding end 213c touch the mirror 50.
7 to the mirror 508 , that is, the light from the energized display light source 517 , and the detection end 51
1b and the detection end 512b are pushed by the original 515, the light-shielding end 511c and the light-shielding end 511c
The light from the energized display light source 517 is removed from the optical path, and the light is no longer blocked. In FIG. 36, the optical path is indicated by diagonal lines when the light is blocked by the actuator 511 for detecting the presence of a document and the actuator 512 for detecting the leading and trailing edges of the document.

[0104] Also, the actuator 51 for detecting the presence or absence of a document
1 and actuator 512 for detecting the front and rear edges of the document
The support pins 511a and 512a are arranged perpendicularly to the optical axis of the light introduced from the mirror 507 to the mirror 508, and the support pins 511a and 512a of the actuators 511 and 512
rotates in a direction parallel to the optical path direction of the light blocked by the light blocking end 511c and the light blocking end 512c. Therefore, the photoelectric conversion element array 510 causes the energization display light source 5 to
It is possible to reliably detect whether the light from 17 is blocked.

Next, the operation will be explained. When the document 515 is not set on the document table 513, the document existence detection actuator 511 and the document leading and trailing edge detection actuator 512 have their detection ends 511b and 512b not pressed by the document 515, and their light-shielding ends portion 511c and light shielding end portion 51
2c is located on the optical path of light from the energized display light source 517, and is connected from the energized display light source 517 to the photoelectric conversion element array 51.
0 to the original detection areas 510b and 510c. At this time, all outputs of the photoelectric conversion element array 510 are at the black level, as shown in FIG. 38(a). As a result, the photoelectric conversion element array 510
Actuator 51 for detecting the presence or absence of a document based on the output of
1 and actuator 512 for detecting the front and rear edges of the document
The actuator 511 for detecting the presence of a document and the actuator 512 for detecting the leading and trailing edges of the document can reliably detect the operation of the document 51 on the document table 513.
5 is not set and the document transport path 514
It is possible to accurately detect that the original 515 does not exist above.

Now, when the original 515 is set on the original table 513, the detection end 511b of the original presence/absence detection actuator 511 is pushed by the original 515.
The actuator 511 for detecting the presence or absence of a document is the support pin 5
11a, the light from the energization display light source 517 is no longer blocked. Therefore, by rotating the actuator 511 for detecting the presence or absence of a document, the energized display light source 51
7 is irradiated onto the original presence/absence detection area 510c of the photoelectric conversion element array 510, and the light from the photoelectric conversion element array 5
38 (
b) As shown in FIG.
The setting of the original 515 on top can be detected by the output of the photoelectric conversion element array 510.

[0107] Thereafter, when the original 515 is conveyed one by one onto the original transport path 514 by the ADF roller 502 and the separation pad 503, the detection end 512b of the original leading and trailing edge detection actuator 512 is pushed by the original 515. Then, the document leading edge and trailing edge detecting actuator 512 rotates around the support pin 512a. Therefore, the actuator 512 for detecting the leading and trailing edges of the document
38(c) to 38(e), the detection end 512b of the sensor is pressed by the original 515, so that the light-shielding end 512c no longer blocks the light from the energized display light source 517.
As shown in FIG. 3, the output of the document leading light edge detection area 510b of the photoelectric conversion element array 510 is at the white level. As a result, the leading edge and trailing edge of the document 515 conveyed on the document conveyance path 514 can be detected with high accuracy by the output of the photoelectric conversion element array 510.

[0108] Furthermore, since a dispersion surface for dispersing the light is formed on at least one of the incident surface and the exit surface of the light guide 518 that introduces the light from the energized display light source 517 into the reduction optical system 518, it is possible to detect whether there is an original or not. Detection actuator 511 and document front/back edge detection actuator 51
If the mounting position of 2 is slightly shifted or the energization indicator light source 517
Even if the optical axis of the document is slightly deviated, the rotation of the document detection actuator 511 and the document front/back edge detection actuator 512 can be accurately detected by the output of the photoelectric conversion element array 510, and the presence or absence of the document can be detected. The detection accuracy of the leading edge and trailing edge can be improved.

Further, an energized display light source 517 as a light source for detecting the presence or absence of a document and the leading and trailing edges of the document is attached to the pressure plate 516 constituting the document transport path 514, and when the pressure plate 516 is open, it is not energized. Since the light from the display light source 517 is not introduced into the reduction optical system 518, when the pressure plate 516 is opened and a jammed original is removed or a book type original is set, it may be accidentally It is possible to prevent the document 515 from being conveyed, and the safety of the work can be improved.

[0110] After that, when the conveyance of the original 515 is started and the light source 505 is turned on to start reading the pressure plate 516, the light reflected by the white surface of the pressure plate 516 is reflected onto the image reading area 210a of the photoelectric conversion element array 510. As shown in FIG. 38(c), the image reading area 21
White level output is also performed from 0a. Further manuscript 5
When the original 515 reaches the reading position P, the original 515 is irradiated with light from the light source 505 and reading of the original 515 is started (FIG. 38(d)).
reference). When the next original 515 is read while this original 515 is being read, the photoelectric conversion element array 5
10, the white level is also output from the document presence/absence detection area 510c, as shown in FIG. 38(e). The original 515 is further conveyed, and the original 515 is
When the rear end passes the detection end 511b of the document presence detection actuator 511, the photoelectric conversion element array 51
The output of the document leading edge light edge detection area 510b of 0 is shown in FIG.
As shown in (f), the black level is obtained. Furthermore, when the document 515 being read is ejected when the next document is available, the output of the photoelectric conversion element array 510 is as shown in FIG. 38(g).
As shown in FIG. 3, only the document presence/absence detection area 510c has a white level.

On the other hand, when the original 515 is conveyed to the reading position P and the next original 515 is not set on the original platen 513 while the original 515 is being read, as shown in FIG. 38(h)
As shown in , the output of the document presence/absence detection area 510c of the photoelectric conversion element array 510 is at the black level, and in this state, the document 515 is further conveyed, and the document 515 is further conveyed during reading.
The rear end of 5 is an actuator 511 for detecting the presence or absence of a document.
When the light passes through the detection edge 511b of the photoelectric conversion element array 510, the outputs of the document presence/absence detection area 510c and the document leading edge light edge detection area 510b become black level, as shown in FIG. 38(i).

As described above, according to the invention as set forth in claims 7 and 8, it is possible to determine whether or not an original is set on the original platen and the leading and trailing ends of the original being conveyed on the original conveyance path. It is possible to accurately control the driving state of the document reading device corresponding to the document setting state and conveyance state, as well as the presence or absence of the document, leading edge and trailing edge. There is no need for a dedicated light source for detecting, and the number of parts can be reduced, reducing costs.

[0113] Furthermore, since a dispersion surface for dispersing the light is formed on at least one of the entrance surface and the exit surface of the light guide that introduces the light from the energized display light source into the reduction optical system, the actuator for detecting the presence or absence of an original is formed. Even if the mounting position of the document front/rear edge detection actuator is slightly shifted, or the optical axis of the energized display light source is slightly shifted, the rotation of the document presence/absence detection actuator and the document front/rear edge detection actuator will not be controlled by the photoelectric conversion element array. The output allows accurate detection,
The accuracy of detecting the presence or absence of a document and the leading and trailing edges of the document can be improved.

Furthermore, according to the invention as set forth in claim 8, the energized display light source as a light source for detecting the presence or absence of a document and the leading and trailing edges of the document is attached to the pressure plate constituting the document conveyance path. When the light guide is open, the light guide moves along with the pressure plate, and the light from the energized display light source is not introduced into the reduction optical system.This makes it easy to open the pressure plate to remove jammed originals or to set book-type originals. It is possible to prevent the document from being inadvertently carried out during work, etc., and to improve the safety of the work.

FIGS. 39 and 40 show claims 9 and 1.
1 is a diagram showing an embodiment of a document reading device according to the invention described in No. 0; FIG. 39 and 40 are a perspective view and a side view of the main parts of the document reading device 600. The document reading device 600 includes a document guide plate 601, an ADF roller 602, a separation pad 603, an ejection roller 604, a light source 605, and a mirror. 606 , 607 , 608 , a lens 609 , a photoelectric conversion element array 610 , a reflection plate 611 , an actuator 612 for detecting the leading edge and trailing edge of a document, and the like.

[0116] The document guide plate 601 is connected to the document table 613.
It also constitutes an original transport path 614, and a plurality of originals 615 are stacked on the original table 613. Original plate 613 Original 615 placed on top
The documents are separated one by one by the ADF roller 602 and the separation pad 603, sent out onto the document conveyance path 614, and conveyed to the reading position P on the document conveyance path 614. The light source 60 is placed on the original 615 that has been conveyed to the reading position P.
The light is emitted from the document 615 and is reflected by the mirrors 606, 607, and 608, and then is irradiated onto the photoelectric conversion element array 610 through the lens 609. Original 61 whose image has been completely scanned at reading position P
5 is a document reading device 600 by a discharge roller 604.
The document is ejected onto an external document tray (not shown). At the reading position P, there is a light source 60 across the document transport path 614.
A document holding plate 616 is disposed on the opposite side of the document holding plate 5, and the light source side surface of the document holding plate 616 is painted white for shading correction.

[0117] Also, the reflection plate 611 is located at this reading position P.
It is provided nearby on the side of the light source 605 across the document conveyance path 614, and reflects the light from the light source 605 and irradiates it onto the mirror 606. is irradiated with light from a light source 605. The surface of the reflection plate 611 may be formed like a normal mirror, but
Illuminance can be efficiently obtained even if the color is white or has a metallic luster. Note that the surface of the reflection plate 611 is shown in FIG.
As shown in FIG. 2, by providing a finely textured surface, the specularly reflected light can be converted into diffused light, and detection by an actuator 612 for detecting the leading edge and trailing edge of the document, which will be described later, can be performed reliably. Furthermore, if the surface of the reflection plate 611 is formed into an uneven surface shape extending in the main scanning direction, as shown in FIG. This makes it possible to reliably and efficiently perform detection by an actuator 612 for detecting the leading edge and trailing edge of a document, which will be described later.

[0118] The light source 605 projects light onto the original 615 located at the reading position P on the original transport path 614, and
The light reflected by 5 is irradiated onto a photoelectric conversion element array 610 through a lens 609. This light source 605
The document holding plate 616 is disposed on the opposite side of the light source 605 across the document transport path 614 at the position where the light from the document is projected.
5 The side surface is painted white. Further, the width of the original holding plate 616 in the main scanning direction is wider than the maximum original width.

[0119] The light source 605 is, for example, an LED (Light
A plurality of independent light emitting elements such as ht Emitting Diodes are arranged on a substrate in the document width direction, and these light emitting elements are
It has a width sufficient to read an original 615 having the maximum original reading width. A document detection light source 617 is provided on the substrate of the light source 605. The document detection light source 617 illuminates the reflecting plate 611 and is used to detect the leading and trailing edges of the document.

[0120] Note that the light source 617 for detecting the original is as follows:
The light source 605 for reading the document is formed wider than the document 615 having the maximum document reading width, and the photoelectric conversion element array 610 is divided into an image reading area and a document detection area, and the lighting state of each is controlled independently. It may also be controlled. In this case, it is possible to deal with this by lighting the image reading area at appropriate times depending on the conveyance status of the original 615, and lighting the original detection area at all times when the original reading device 600 is powered on.

[0121] As the photoelectric conversion element array 610, for example, a CCD (Charge Coupled Dev)
(ice) etc. are used, and a plurality of photoelectric conversion elements are arranged in a row. This photoelectric conversion element array 610 is arranged to be wider by a predetermined width than the width to which the light reflected by the document holding plate 616 is irradiated.
As shown in FIG. 39, it is divided into an image reading area 610a for reading the image of the original, and an original detection area 610b for detecting the leading and trailing edges of the original. In this photoelectric conversion element array 610, the light reflected at the reading position P of the document holding plate 616 is irradiated onto the image reading area 610a, and the light reflected at the reflection plate 611 is irradiated onto the original detection area 610b. This photoelectric conversion element array 610
conceptually corresponds to the image reading area 610a and the document detection area 6.
Although it is divided into 10b, its wiring and circuit system can be shared, making the wiring and circuit system simpler and cheaper than the conventional method of providing a dedicated photo coupler for detecting the leading edge and trailing edge of the document. Become something.

[0122] Actuator 612 for detecting leading edge and trailing edge of document
is rotatably supported via a support pin 612a, and its detection end 612b protrudes above the document transport path 614. Further, the light-shielding end 612c of the document front/back edge detection actuator 612 protrudes onto the optical path of the light from the document detection light source 617, and the document front/back edge detection actuator 61
2 rotates about the support pin 612a as a fulcrum when its detection end 612b is pushed by the document 615.

Further, as shown in FIGS. 39 and 40, the detection end portion 612b of the document leading and trailing edge detecting actuator 612 has a portion where the leading edge of the document 615 comes into contact with,
A front inclined surface SI is formed which is inclined in the conveying direction of the original 615, and an actuator 612 for detecting the leading and trailing edges of the original is formed.
The original 61 is placed on the front inclined surface SI of the detection end 612b.
When the leading edge of the document 615 comes into contact with the document 615, its rotation angle changes in accordance with the conveyance position of the leading edge of the document 615. Further, the detection end 612b of the document leading edge/back edge detection actuator 612 has a rear inclined surface SK inclined in the opposite direction to the conveyance direction of the document 615 at the portion where the trailing edge of the document 615 contacts. , the document leading and trailing edge detection actuator 612 detects the document 615 by positioning the document's trailing edge on the rear inclined surface SK of the detection end portion 612b.
The rotation angle changes depending on the conveyance position of the rear end. Therefore, the actuator 61 for detecting the leading and trailing edges of the document
2 changes its rotation angle in multiple stages depending on the conveyance position of the leading edge and trailing edge of the document 615.

[0124] Actuator 612 for detecting leading edge and trailing edge of document
The detection end 612b is held by the spring 618.
is biased in the direction of protruding into the document transport path 614 , and due to the bias of the spring 618 , the light-shielding end 612 c of the document front/back edge detection actuator 612 is irradiated by the document detection light source 617 and is illuminated by the reflection plate 611 . It is located out of the optical path of reflected light. When the detection end 612b of the document leading and trailing edge detection actuator 612 is not pressed by the document 615,
The light-shielding end 612c is located at a position off the optical path of the light reflected by the reflector 611 and irradiated onto the photoelectric conversion element array 610 through the mirrors 607, 608 and the lens 609, and the detection end 612b Manuscript 61
5, the light-shielding end 612c enters the optical path of the light from the document detection light source 617 depending on the rotation angle. In FIG. 39, a document detection light source 617
The optical path of the light projected from the photoelectric conversion element array 610 and introduced into the photoelectric conversion element array 610 is indicated by diagonal lines.

Furthermore, as shown in FIG.
It is formed in such a shape that the surface facing perpendicularly to the optical path of the document detection light source 617 becomes narrower toward the tip. Therefore, the light-shielding end 61 of the actuator 612 for detecting the leading and trailing edges of the document
2c rotates when its detection end 612b is pressed by the document 615, and the light-shielding range that blocks the light from the document detection light source 617 changes in multiple stages according to the rotation angle.

Although not shown in FIGS. 39 and 40, an actuator for detecting the presence or absence of a document is installed to detect whether or not a document 615 is set on the document table 613. The same actuator for detecting the presence or absence of a document as shown in each of the above embodiments can be applied. Next, the effect will be explained.

[0127] When the original 615 is not set on the original table 613, the actuator for detecting the presence or absence of an original and the actuator for detecting the leading and trailing edges of the original 612 have their detection ends 612b etc. not pressed by the original 615, and their light-shielding ends 612c etc. are off the optical path of the light from the original detection light source 617 , and the light from the original detection light source 617 is irradiated onto the original detection area 610 b of the photoelectric conversion element array 610 . Therefore, the photoelectric conversion element array 610
It can be detected by the output that the document 615 is not set on the document table 613 and is not being conveyed on the document conveyance path 614 .

Now, an original 615 is set on the original table 613, and the ADF roller 602 and separation pad 603 move the original 615 one by one into the original transport path 6.
14 When the document 615 is conveyed upward, the detection end 61 of the document leading and trailing edge detection actuator 612 is detected by the document 615.
2b is pressed, and the actuator 61 for detecting the leading edge and trailing edge of the document is pressed.
2 rotates around the support pin 612a. Detection end 61 of this actuator 612 for detecting the leading and trailing edges of the document
2b is formed with the front inclined surface SI that is inclined in the conveyance direction of the document 615, so that the document leading and trailing edge detection actuator 612 is moved at an angle corresponding to the conveyance position of the leading edge of the document 615. Rotate. In addition, the light-shielding end 61 of the actuator 612 for detecting the leading and trailing edges of the document
2c, as described above, is formed in a shape that becomes thinner toward the tip, so that the range of light shielding from the document detection light source 617 is changed in multiple stages in accordance with the position of the tip of the document 615. .

Therefore, the range of light from the document detection light source 617 that enters the document detection area 610b of the photoelectric conversion element array 610 changes in a multi-step manner in accordance with the transport position of the leading edge of the document 615. A change in the light-blocking range is detected as a change in the number of bits of the output of the photoelectric conversion element array 610. When this change in the number of bits is processed by a logic circuit, the position of the leading edge of the document 615 can be detected accurately. That is, the photoelectric conversion element array 61
The leading edge position of the transported document 615 can be accurately detected based on the output of 0. As a result, the original 615 slips, etc.
Even if an abnormality occurs in the conveyance of the document 615, the leading edge position of the document 615 can be accurately detected based on the output of the photoelectric conversion element array 610, and the time when the document 615 is conveyed to the reading position P can be accurately recognized. can do. In particular, when a pulse motor is used as a drive source for transporting the original 615, the original 615 being transported
By calculating the position of the leading edge of the document 615 and the number of pulses of the pulse motor, it is possible to recognize the slip situation of the document 615. Therefore, reading the original 615 is performed using the original 615.
The reading accuracy of the document reading device 600 can be improved.

[0130] When the original 615 is further conveyed and the rear end of the original 615 reaches the detection end 612b of the front/rear end detection actuator 612, the original 615 is
Actuator 612 for detecting the leading edge and trailing edge of the document by the trailing edge
The biasing of the detection end portion 612b of is released. As described above, the detection end 612b of the document leading and trailing edge detection actuator 612 is formed with the rear inclined surface SK that is inclined in the opposite direction to the conveying direction of the document 615. Actuator 612 for
The rotation angle of the original 615 is changed by the rear edge of the original 615.
It changes in multiple stages corresponding to the transport position of 15. In addition, the light-shielding end 612c of the document leading and trailing edge detection actuator 612 is formed in a shape that becomes thinner toward the leading edge as described above, so that the light source for document detection corresponds to the position of the leading edge of the document 615. 617 to change the range of light shielding in multiple stages.

Therefore, the shielding range of the light from the original detection light source 617 that enters the original detection area 610b of the photoelectric conversion element array 610 changes in a multi-step manner in accordance with the transport position of the rear end of the original 615. Based on the output of the photoelectric conversion element array 610, the position of the trailing edge of the transported document 615 can be accurately detected. As a result, even if an abnormality occurs in the conveyance of the original 615 due to a slip of the original 615, the rear edge position of the original 615 can be accurately detected based on the output of the photoelectric conversion element array 610, and the original 615 is It is possible to accurately recognize the timing of conveyance to the reading position P. therefore,
It is possible to accurately read up to the rear end of the original 615, and the reading accuracy of the original reading device 600 can be improved.

[0132] In the above embodiment, the light-shielding end 612c of the leading and trailing edge detection actuator 612 of the document detecting light source 617 has a light-shielding end 612c with respect to the optical path of the light. Although both sides in the right angle direction are tapered, the present invention is not limited to this. For example, as shown in FIG.
An inclined surface is formed on only one surface perpendicular to the optical path of the light from the document detection light source 617 , and the document front/back edge detection actuator 612 rotates to detect the light shielding end 65 .
0 moves in the direction shown by the arrow in FIG.
The range of light shielding from the original detection light source 617 may be changed. In this case, by moving the light-shielding end 650 of the document leading and trailing edge detection actuator 612, the photoelectric conversion element array 6 is moved as shown in FIG.
The amount of light irradiated onto the original detection area 610b of 10 and the width of the light-shielding bit that is shielded by the light-shielding end 650 can be shown as shown in FIG. Therefore, the leading edge of the original 615 is connected to the leading and trailing edge detection actuator 6 of the original.
By energizing the detection end 612b of 12, the amount of light irradiated from the original detection light source 617 to the photoelectric conversion element array 610 is changed, and the shading bit width of the photoelectric conversion element array 610 becomes the same as that of the original 615. It changes as shown in FIG. 43 depending on the amount of movement. Note that FIG. 43 shows a case where the light-shielding bit width W changes from W1 to W2 when the leading edge of the document 615 changes from P1 to P2. As a result, the conveyance position of the document 615 can be accurately detected based on the output of the photoelectric conversion element array 610.

Furthermore, in the above embodiment, the original detection light source 6
Although the leading and trailing edge positions of the original 615 are detected by changing the shielding range of light from the original detection light source 617, the present invention is not limited to this. The amount of light may be changed. For example, as shown in FIG. 44, the light-shielding end 660 of the document front/back edge detection actuator 612 is placed between the object point (document surface) and the entrance pupil 609a of the lens 609, as shown in FIG. The light-shielding end 650 has a shape that changes the diameter (φd) of the light beam that shields the light from the document detection light source 617 . Further, the focal point of the lens 609 is set so that the object point (document surface) is imaged onto the image point (photoelectric conversion element array 610). In this case, although the outline of the light-shielding end 660 is blurred, the detection end 612b of the document leading and trailing edge detection actuator 612 is biased toward the document 615, so that the light beam diameter (φd) of the light from the document detection light source 617 is )
changes, and the amount of light at the photoelectric conversion element array 610, which is the image plane, changes. That is, the amount of light blocked (the light blocked end 660
45) and the amount of light at the photoelectric conversion element array 510 change as shown in FIG. Therefore, by analyzing the output of the photoelectric conversion element array 510 over several gradations using a predetermined image processing means, it is possible to accurately detect the leading and trailing edge positions of the original 515 based on the output of the photoelectric conversion element array 510. I can do it. In this case, the document detection area 610b of the photoelectric conversion element array 510 has a minimum of 1 bit (1 pixel).
The photoelectric conversion element array 510 can be used effectively. In addition, in FIG. 44, 609b
is the exit pupil of the lens 609.

Furthermore, the device for changing the amount of light from the document detection light source 617 is not limited to the one shown in FIG. 44, but as shown in FIG. As the light-shielding end 670 , the base material of the light-shielding end 650 may be made of a transparent material, and the tip of the light-shielding end 650 may be printed with gradation in the direction of movement of the light-shielding end 650 . In this case, the amount of light blocked (the amount of movement of the light blocked end 660) and the amount of light at the photoelectric conversion element array 510 are
The gradation of the 0 printing changes as shown in FIG. 47, although it also depends on how the printing is applied. Therefore, even in this case, by analyzing the output of the photoelectric conversion element array 510 over several gradations using a predetermined image processing means, the positions of the leading and trailing edges of the original 515 can be determined based on the output of the photoelectric conversion element array 510. Can be detected accurately.

[0135]

According to the invention as set forth in claim 1, the photoelectric conversion element is arranged to be wider by a predetermined width than the optical path width of the readable width of the original, and the image reading area for reading the image of the original and the width of the optical path of the original can be read. A document detection area for detecting the presence or absence of a document and (or) the leading edge and trailing edge of the document. Therefore, these circuit systems can be simplified and costs can be reduced, and the degree of freedom in designing the document reading device can be improved.

According to the second aspect of the invention, a plurality of independent light emitting elements are arranged as light sources in the document width direction, and a group of light emitting elements for reading an image of the document and a light emitting element group for detecting the document are formed. Since each light-emitting element group can be controlled independently, the lighting timing and installation location of the light-emitting elements can be changed at any time, and the life of the light-emitting elements can be extended. In addition, by mounting a group of light emitting elements on the same substrate at the same time, the difference in light intensity between the image light emitting element and the document detection light emitting element can be kept below a certain value, making it easier to process the output signal from the photoelectric conversion means. can do.

According to the third aspect of the invention, the arrangement location of the light emitting element group for document detection can be changed freely, and the degree of freedom in designing the document reading device can be further improved. According to the invention described in claim 4, the photoelectric conversion element of the photoelectric conversion means is disposed wider by a predetermined width, and an image reading area for reading the image of the original, the presence or absence of the original, and the leading and trailing edges of the original are detected. A document detection area for
an image light emitting element group for illuminating the image reading area;
a group of light-emitting elements for detecting a document for illuminating the document detection area; and a group of light-emitting elements for detecting a document that is rotated by the document on the document table and illuminates the document detection area of the photoelectric conversion means. A document presence/absence detection mechanism that blocks (or transmits) a portion of the light emitted by the document; A document leading and trailing edge detection mechanism that blocks (or transmits) part of the light irradiated to the document detection area, and a lighting cycle control means that controls the lighting cycle of the image light emitting element group, and the photoelectric Based on the output of the document detection area of the conversion means, the conveyance status of the document can be determined and the lighting period of the image light emitting element group can be controlled. The light-emitting element used can read the image of the original, detect the presence or absence of the original, and detect the leading and trailing edges of the original.The lighting cycle of the image-use light-emitting element at times other than the original reading time can also be changed to the lighting cycle during the original reading time. It is possible to simplify the circuit system, reduce costs, and improve the degree of freedom in the design of the document reading device, and prevents deterioration of the image light emitting element. The life of the image light emitting element can be extended.

According to the fifth aspect of the invention, the photoelectric conversion elements of the photoelectric conversion means are disposed wider by a predetermined width, and
an image reading area for reading the image of the original, an original detection area for detecting the presence or absence of the original and the leading and trailing edges of the original;
A plurality of light emitting elements as light sources are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area. , a reflecting member located near the document reading position, which reflects the light emitted from the document detection light emitting element group and irradiates it onto the document detection area of the photoelectric conversion means through the reduction optical system; and the document on the document table. an original presence/absence detection mechanism that blocks (or transmits) part of the light that is rotated by the original detection light emitting element group, is reflected by the reflector, and is irradiated onto the original detection area of the photoelectric conversion means; Light that is rotated at a predetermined position on the document conveyance path by the document conveyed on the document conveyance path, is projected from the document detection light emitting element group, is reflected by the reflection plate, and is irradiated onto the document detection area of the photoelectric conversion means. A document leading and trailing edge detection mechanism that blocks (or transmits) a part of light is provided, and based on the output of the document detection area of the photoelectric conversion means,
By detecting the conveyance status of the document, it is possible to read the image of the document, detect the presence or absence of the document, and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. At the same time, the light projected from the light emitting element for document detection can be efficiently introduced into the document detection area of the photoelectric conversion means, which contributes to simplifying these circuit systems, reducing costs, and improving the design of the document reading device. It is possible to improve the degree of freedom of the document, and to improve the detection accuracy of the leading edge and trailing edge of the document.

According to the sixth aspect of the invention, the photoelectric conversion elements of the photoelectric conversion means are disposed wider by a predetermined width, and
an image reading area for reading the image of the original, an original detection area for detecting the presence or absence of the original and the leading and trailing edges of the original;
A plurality of light emitting elements as light sources are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area. , a reflecting member located near the document reading position that reflects the light emitted from the document detection light emitting element group and irradiates it to the document detection area of the photoelectric conversion means via the reduction optical system; and the document on the document table. a document presence/absence detection mechanism that blocks (or transmits) a portion of the light that is rotated and projected from the document detection light emitting element group, reflected by the reflection plate, and irradiated onto the document detection area of the photoelectric conversion means; At a predetermined position on the conveyance path, light is rotated by the document conveyed on the document conveyance path, is projected from the document detection light emitting element group, is reflected by the reflection plate, and is irradiated onto the document detection area of the photoelectric conversion means. A document front/rear edge detection mechanism that partially blocks (or transmits) light is provided, and the shape of the part that blocks the light of the document presence/absence detection mechanism and the document leading/rear edge detection mechanism is adjusted to block an appropriate amount of light. At the same time, it has a shape that prevents a decrease in light intensity, and the conveyance status of the document can be detected based on the output of the document detection area of the photoelectric conversion means, so it can be mounted on one photoelectric conversion means and one board. The light-emitting element can be used to read the image of the original, detect the presence or absence of the original, and detect the leading and trailing edges of the original.The light emitted from the original-detecting light-emitting element can also be used to efficiently detect the original by the photoelectric conversion means. introduced into the area,
In addition, the light can be made suitable for detection, simplifying the circuit system, reducing costs, and improving the degree of freedom in designing the document reading device. - The detection accuracy of the rear end can be further improved.

According to the seventh aspect of the invention, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. At the same time, the document is divided into an image reading area for reading the image of the document, and a document detection area for detecting the presence or absence of the document and the leading and trailing edges of the document. An energization display light source for displaying the energization state of the document reading device is disposed in the empty space of the pressure plate that is conveyed in close contact with each other and can be removed from the reading position. The light emitted from the energized display light source is received from the entrance surface of the light guide, is introduced into the reduction optical system from the exit surface, and is irradiated onto the original detection area of the photoelectric conversion means through the reduction optical system. A dispersion surface for dispersing the light from the energized display light source is formed on one of the entrance surface and the exit surface of the guide. Further, it is rotatably provided, and its detection end protrudes to a position where it is urged by the document on the document table, and its light-shielding end is connected to the photoelectric conversion means from the energized display light source through the light guide and the reduction optical system. A document presence detection mechanism that protrudes to a position that blocks part of the light that is irradiated to the document detection area of the document detecting area, and allows the light blocking edge to transmit part of the light when the document pushes the detection edge, and is rotatable. The detection end protrudes at a predetermined position on the document transport path, and the light-shielding end detects part of the light irradiated from the energized display light source to the document detection area of the photoelectric conversion means via the light guide and reduction optical system. a document front/back edge detection mechanism that protrudes to a light-shielding position and allows the light-shielding edge to transmit part of the light when the document pushes the detection edge, and outputs the document detection area of the photoelectric conversion means. Based on this, the presence or absence of a document, the conveyance status of the document, and the detachment state of the pressure plate are detected.

[0141] Therefore, it is possible to read an image of an original, detect the presence or absence of an original, and detect the leading and trailing edges of the original using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, since a energized display light source is used as the light source for document detection, the number of parts can be reduced.
The cost of the document reading device can be reduced, and power consumption can be reduced. Furthermore, since a dispersion surface that disperses light is formed on at least one of the entrance surface and the exit surface of the light guide, it is possible to accurately detect the presence or absence of a document and the leading and trailing edges even if the optical axis is misaligned. This makes it possible to further improve the detection accuracy of the leading edge and trailing edge of the document.

According to the invention set forth in claim 8, in the invention set forth in claim 7, the photoelectric conversion element of the photoelectric conversion means is further provided with a pressure plate detachment detection area for detecting the detachment state of the pressure plate, and the light guide , moves as the pressure plate is removed, and stops introducing the light from the energized display light source to the reduction optical system.

[0143] Therefore, in addition to the effect of claim 7,
The separation state of the pressure plate can be detected based on the output result of the pressure plate separation detection area of the photoelectric conversion means, and the detection state of the document detection area of the photoelectric conversion means can be set to the state of no document, so that the separation state of the pressure plate can be detected. This can be easily detected, and it is also possible to prevent the document from being inadvertently conveyed or read when the pressure plate is removed. As a result, the usability of the document reading device can be improved.

According to the ninth aspect of the invention, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. At the same time, it is divided into an image reading area for reading the image of the original, and an original detection area for detecting the leading and trailing edges of the original, and the light source is formed by multiple light emitting elements arranged in the width direction of the original. The light emitting elements are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area. The light emitted from the light emitting element group for document detection is introduced into the reduction optical system by the light introduction means, and is irradiated onto the document detection area of the photoelectric conversion means via the reduction optical system, and the light introduction means is used to detect the photoelectric conversion means. A document leading and trailing edge detection mechanism is disposed on the optical path that illuminates the document detection area. This document front/back edge detection mechanism is rotatably provided, and its detection end protrudes to a predetermined position on the document conveyance path and is biased by the document in accordance with the conveyance position of the document. The portion protrudes to a position that blocks the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion device via the light introduction device and the reduction optical system, and also The light blocking range is changed in multiple stages.

[0145] Therefore, it is possible to read an image of a document and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, the document leading edge and trailing edge detection mechanism changes the shielding range of the light irradiated to the document detection area of the photoelectric conversion means in multiple stages according to the document conveyance status, so that the document is conveyed to the document reading position. The transport position can be detected accurately, and the reading operation of the document reading device can be performed accurately.

According to the tenth aspect of the invention, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having a document readable width is reduced by the reduction optical system and introduced. At the same time, it is divided into an image reading area for reading the image of the original, and an original detection area for detecting the leading and trailing edges of the original, and the light source is formed by multiple light emitting elements arranged in the width direction of the original. The light emitting elements are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area. The light emitted from the light emitting element group for document detection is introduced into the reduction optical system by the light introduction means, and is irradiated onto the document detection area of the photoelectric conversion means via the reduction optical system, and the light introduction means is used to detect the photoelectric conversion means. A document leading and trailing edge detection mechanism is disposed on the optical path that illuminates the document detection area. This document front/back edge detection mechanism is rotatably provided, and its detection end protrudes to a predetermined position on the document conveyance path and is biased by the document in accordance with the conveyance position of the document. The department is
The light emitting element group for document detection projects to a position that blocks the light irradiated onto the document detection area of the photoelectric conversion means through the light introduction means and the reduction optical system, and the light is Changes the amount of light in multiple stages.

[0147] Therefore, it is possible to read an image of a document and detect the leading and trailing edges of the document using one photoelectric conversion means and a light emitting element mounted on one substrate. In addition, since the document leading edge and trailing edge detection mechanism changes the amount of light irradiated to the document detection area of the photoelectric conversion means in multiple stages according to the document conveyance status, the document is conveyed to the document reading position. The position can be detected accurately, and the reading operation of the document reading device can be performed accurately.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a facsimile apparatus to which a first embodiment of a document reading apparatus according to the invention is applied.

FIG. 2 is an enlarged view of the reading portion of the facsimile machine in FIG. 1;

FIG. 3 is a configuration diagram of a pressure plate and a light source of the facsimile machine of FIG. 1;

FIG. 4 is a diagram showing a pattern applied to the pressure plate of the facsimile machine of FIG. 1;

FIG. 5 is a diagram showing a control circuit for a light source of the facsimile machine in FIG. 1;

FIG. 6 is a configuration diagram showing another embodiment of the pressure plate and light source of the facsimile machine of FIG. 1;

FIG. 7 is an explanatory diagram showing the relationship between area divisions of the pressure plate and area divisions of the photoelectric conversion element array of the facsimile machine in FIG. 1;

8 is an explanatory diagram of another embodiment corresponding to FIG. 6 of the relationship between the area divisions of the pressure plate and the area divisions of the photoelectric conversion element array of the facsimile machine of FIG. 1;

FIG. 9 is a block diagram showing the circuit configuration of main parts of the facsimile machine of FIG. 1;

FIG. 10 is a flowchart of document presence/absence and leading/back edge detection processing of the facsimile machine of FIG. 1;

FIG. 11 is a flowchart of another embodiment of document presence/absence and leading/back edge detection processing of the facsimile machine of FIG. 1;

FIG. 12 is a configuration diagram of a main part of a second embodiment of the document reading device according to the invention as claimed in claim 1, claim 2, and claim 3;

FIG. 13 is a configuration diagram of an optical system of the document reading device shown in FIG. 12;

14] Each time point (a) (b) (c) (d) (from before the document is set in the document reading device in FIG. 12 until the trailing edge of the document is detected)
The figure which shows the output signal of the photoelectric conversion element array in e).

15 is a diagram illustrating a main part configuration of another embodiment of the light guide for detecting the presence or absence of a document and the leading and trailing edges of the document in the document reading device shown in FIGS. 12 and 13; FIG.

FIG. 16 is a configuration diagram of a main part of a third embodiment of the document reading device according to the invention according to claims 1, 2, and 3;

FIG. 17 is a configuration diagram of a main part of a fourth embodiment of the document reading device according to the invention as claimed in claim 1, claim 2, and claim 3;

FIG. 18 is a configuration diagram of a main part of a fifth embodiment of a document reading device according to the invention as claimed in claims 1, 2, and 3;

FIG. 19 is a configuration diagram of a main part of a sixth embodiment of the document reading device according to the invention according to claims 1, 2, and 3;

FIG. 20 is a configuration diagram of main parts of an embodiment of the document reading device according to claim 4;

21 is a detailed view of the optical system, the actuator for detecting the presence or absence of a document, and the actuator for detecting the leading and trailing edges of the document of the document reading device shown in FIG. 20;

22 is a block diagram of a control circuit of the document reading device shown in FIG. 20. FIG.

23 is a diagram showing the output of the photoelectric conversion element array of the document reading device of FIG. 20 when the document is not detected (FIG. 23(a)) and the output when the document is detected (FIG. 23(b)).

24 is a timing diagram for explaining a lighting period control effect based on the output of the photoelectric conversion element array of the document reading device of FIG. 20. FIG.

FIG. 25 is a perspective view of essential parts of an embodiment of the document reading device according to claim 5;

26 is a side view of a main part of the document reading device shown in FIG. 25. FIG.

27 is a diagram showing another example of surface treatment of the reflecting plate of the document reading device shown in FIG. 25. FIG.

28 is a diagram showing still another example of surface treatment of the reflecting plate of the document reading device of FIG. 25. FIG.

29 is a diagram for explaining the effect of the surface treatment of the reflector in FIG. 28,

30 is a diagram for explaining the shape of the light-shielding end portions of the actuator for detecting the presence or absence of a document and the actuator for detecting the leading and trailing edges of the document of the document reading device shown in FIG. 25;

31 is a diagram illustrating how light is blocked at the light-blocking end portions of the actuator for detecting the presence or absence of a document and the actuator for detecting the leading and trailing edges of the document of the document reading device in FIG. 25;

32 is a diagram showing another example of the shape of the reflector of the document reading device shown in FIG. 25. FIG.

33 is a diagram showing still another example of the shape of the reflector of the document reading device shown in FIG. 25; FIG.

34 is a partially cross-sectional perspective view of the reflector of FIG. 33. FIG.

FIG. 35 is an explanatory diagram of the effect of the reflector in FIG. 33;

FIG. 36 is a perspective view of a main part of an embodiment of the document reading device according to the invention according to claims 7 and 8;

37 is a side view of main parts of the document reading device shown in FIG. 37. FIG.

38 is a diagram showing the output of the photoelectric conversion element array corresponding to the document setting and conveyance state of the document reading device in FIG. 36 (
(a) to (i)).

FIG. 39 is a perspective view of a main part of an embodiment of the document reading device of the invention according to claims 9 and 10;

40 is a side view of main parts of the document reading device shown in FIG. 40. FIG.

41 is a diagram showing a second embodiment of the light-shielding end portion of the actuator for detecting the leading and trailing edges of a document in the document reading device of FIG. 39; FIG.

42 is a diagram showing the relationship between the light-shielding bit width and the amount of light when the light-shielding end portion of the document front/back edge detection actuator in FIG. 42 is used; FIG.

43 is a diagram showing the relationship between the document leading edge position and the light shielding bit width when the light shielding end of the document leading and trailing edge detection actuator of FIG. 42 is used; FIG.

44 is a diagram showing a third embodiment of the light-shielding end portion of the actuator for detecting the leading and trailing edges of a document in the document reading device of FIG. 39; FIG.

45 is a diagram showing the relationship between the amount of light blocked and the amount of light at the photoelectric conversion element array when the light-shielded end portion of the actuator for detecting the leading and trailing edges of the document shown in FIG. 44 is used.

46 is a diagram showing a fourth embodiment of the light-shielding end portion of the actuator for detecting the leading and trailing edges of a document in the document reading device of FIG. 39; FIG.

47 is a diagram illustrating the relationship between the amount of light blocked and the amount of light at the photoelectric conversion element array when the light-shielded end portion of the actuator for detecting the front and rear edges of the document shown in FIG. 46 is used.

FIG. 48 is a schematic configuration diagram of a facsimile machine to which a conventional document reading device is applied.

[Explanation of symbols]

20 facsimile device, 21 document reading device, 22 recording device, 23 control device, 24 actuator for detecting document presence, 24a
Support pin, 24b one end, 24c other end, 25 automatic document feeder, 25a transport roller, 25b separation plate, 26 actuator for detecting leading and trailing edges of document, 26
a support pin, 26b one end, 26c other end, 27 light source, 27a image light emitting element group, 27b document detection light emitting element group, 27C
Light emitting element group for actuator for document presence detection, 27d
Light-emitting element group for actuator for detecting leading and trailing edges of originals, 28 Ejection roller, 29, 30, 31 Mirror, 32 Lens, 33 Photoelectric conversion element array, 34 Pressure plate, 40 Thermal head, 41 Platen roller, 42 Rolled recording paper, 50 CPU, 51 power supply device, 52 document conveyance motor, 60 recording device, 61 mirror, 62 document presence detection actuator, 62a
Support pin, 62b one end, 62c other end, 63 Actuator for detecting leading and trailing edge of document, 63
a support pin, 63b one end, 63c other end, 64 light guide, 65 light source for detecting the presence or absence of a document, 66 light guide, 67 light source for detecting the leading edge and trailing edge of the document, 68 point-line conversion light guide, 70 light source for detecting the presence or absence of the document, 71 Printed circuit board, 72 Light source for detecting leading edge and trailing edge of original, 73 Harness, 80 Light source for detecting existence of original, 81 Light guide, 82 Light source for detecting leading edge and trailing edge of original, 83 Light guide, 85 Reflector, 86 Light source for detecting existence of original , 87 Reflector plate, 88 Light source for detecting leading and trailing edge of original, 90 Light guide for detecting presence/absence of original, 91 Light guide for detecting leading and trailing edge of original, 92 Light guide for image, 100, 200, 500, 600 Original reading device, 101 , 212, 511 Original presence detection actuator, 101a, 212a, 511a
Support pin, 101b, 212b, 511b Detection end, 101c, 212c, 511c Light shielding end, 102, 213, 512, 612 Actuator for detecting leading edge and trailing edge of document, 102a, 213a, 512a, 612a Support pin, 102b, 213b, 512b, 612b
Detection end, 102c, 213c, 512c, 612c
Light shielding end, 103, 201, 501, 601
Original guide plate, 104, 217, 616
Document holding plate, 105 Conveyance roller, 106, 205, 505, 605 Light source, 10
6a, 205a image light emitting element group, 106b,
205b Light emitting element group for document detection, 107, 2
04, 504, 604 discharge roller, 108,
209, 509, 609 lens, 109, 2
10, 510, 610 photoelectric conversion element array, 1
09a, 210a, 510a, 610a Image reading area, 109b, 210b, 510b, 510c, 6
10b Original detection area, 110 Taper motor, 111, 216, 515, 615 Original, 11
2, 214, 513, 613 Original table, 113
, 215, 514, 614 Original transport path, 12
0 Control circuit, 202, 502, 602 ADF roller, 20
3, 503, 603 Separated Pat, 206, 2
07, 208, 506, 507, 508, 606, 6
07, 608 Mirror, LC control signal, LD drive signal, LG lighting signal, S1D detection signal, S2D detection signal, LDT lighting time width signal, PL optical axis, PS luminous flux. 515 Light guide 517 Original detection light source 611 Reflector

Claims (10)

[Claims] 1. A light source that projects light over a predetermined reading width in the main scanning direction onto a document being conveyed to a document reading position; a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over the predetermined width; a reduction optical system that reduces the generated light and introduces it into a photoelectric conversion means,
The photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light having the readable width is reduced by a reduction optical system and introduced, and has an image reading area for reading an image of the document. , and a document detection area for detecting the presence or absence of a document and/or the leading and trailing edges of the document. 2. The light source is formed by a plurality of independent light emitting elements arranged in the document width direction, and the light emitting elements are a group of image light emitting elements for illuminating the image reading area;
2. The document reading device according to claim 1, wherein the document reading device is divided into a document detection light emitting element group for illuminating the document detection area, and each light emitting device group can be controlled independently. 3. An optical path in which light projected from the image light emitting element group is irradiated onto an image reading area of the photoelectric conversion means, and a light path projected from the document detection light emitting element group is irradiated to the photoelectric conversion means. 3. The document reading device according to claim 2, wherein at least a part of the light path of the light beam irradiating the document detection area is different from the light path of the light beam. 4. A document table on which a plurality of documents are placed, a document conveyance path in which the documents on the document table are conveyed to the document reading position, and a predetermined reading width in the main scanning direction for the documents conveyed to the document reading position. A light source that projects light over a wide area, a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width, and a reduction optical system that reduces the light reflected by the original and introduces it into the photoelectric conversion means. In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and the image of the document is divided into an image reading area for reading and a document detection area for detecting the presence or absence of a document and the leading and trailing edges of the document, and forming the light source by arranging a plurality of light emitting elements in the width direction of the document; The light emitting elements are divided into an image light emitting element group for illuminating the image reading area and a document detection light emitting element group for illuminating the document detection area, and are rotatably provided. A detection end protrudes to a position where it is biased by the document on the document table, and its light-shielding end blocks part of the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means. a document presence/absence detecting mechanism protruding at a position where the document is detected;
a document leading and trailing edge detection mechanism whose light-shielding end protrudes to a position that blocks part of the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means; and the image light emitting element group. lighting period control means for controlling the lighting period of the image light emitting element group, and determining the conveyance status of the document based on the output of the document detection area of the photoelectric conversion means, and controlling the lighting period of the image light emitting element group. A document reading device characterized by: 5. A document table on which a plurality of documents are placed, a document conveyance path in which the documents on the document table are conveyed to a document reading position, and a predetermined reading width in the main scanning direction for conveying the documents to the document reading position. A light source that projects light over a wide area, a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width, and a reduction optical system that reduces the light reflected by the original and introduces it into the photoelectric conversion means. In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and the image of the document is It is divided into an image reading area for reading and a document detection area for detecting the presence or absence of a document and the leading and trailing edges of the document, and the light source is formed by a plurality of light emitting elements arranged in the width direction of the document, The light emitting elements are divided into an image light emitting element group for illuminating the image reading area, and a document detection light emitting element group for illuminating the document detection area, which is always turned on when the power is turned on. Near the reading position. A position on the light source side of the document transport path, on the same plane in the sub-scanning direction with respect to the light irradiated to the reading position from the image light emitting element group, and outside the range of the readable width in the main scanning direction. a reflecting member that reflects the light irradiated from the document detection light emitting element group and irradiates the document detection area of the photoelectric conversion means through the reduction optical system; protrudes to a position where it is urged by the document on the document table, and its light-shielding end is irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means via the reflection member and the reduction optical system. A document presence/absence detection mechanism that protrudes to a position that blocks part of the light and causes the light blocking end to block or transmit part of the light when the document pushes the detection end; The end portion protrudes to a predetermined position on the document transport path, and the light-shielding end portion receives part of the light irradiated from the document detection light emitting element group to the document detection area of the photoelectric conversion means via the reflection member and the reduction optical system. A document front/back edge detection mechanism is provided, which protrudes to a position where the photoelectric conversion means detects the document by protruding to a position where the photoelectric conversion means detects the document. A document reading device characterized by detecting the conveyance status of a document based on the output of a region. 6. The rotating surfaces of the document presence/absence detection mechanism and the document leading and trailing edge detection mechanism are parallel to the optical path direction of the light blocked by these mechanisms, and the light blocking end of each mechanism is parallel to the light path direction of the light blocked by each of these mechanisms. It has a curved shape with a concave surface on the rotation center side, and is aligned with the optical axis of the light projected from the image light emitting element group at the light-shielding end of the document presence/absence detection mechanism and the document leading and trailing edge detection mechanism. The angle between the outer surface and the optical axis is θa1, and the angle between the optical axis side surface of the light-shielding end and the optical axis is θa.
2, and the angle formed by the optical axis and the outer light beam surface with respect to the optical axis of the light from the imaging light emitting element group at the light-blocking end of the light beam projected from the document detection light emitting element group. of,
The document reading device according to claim 5, characterized in that, when θb1 is an angle between the light beam surface on the optical axis side of the light beam and the optical axis, θb2 holds the following relationships: θa1≧θb1 θa2≧θb2 Device. 7. A document table on which a plurality of documents are placed; a document conveyance path through which the documents on the document table are conveyed to a document reading position; a pressure plate that is removable from the reading position and has a predetermined empty space between the top cover and the pressure plate that transports the original to be transported to the original reading position in close contact with the original reading position; an image reading light source that projects light onto a document over a predetermined reading width in the main scanning direction; a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width; a reduction optical system that reduces the light and introduces it into the photoelectric conversion means, and an energization indicator light source that is provided in the empty space of the pressure plate and lights up at all times when the document reading device is energized to indicate that it is energized. In the original document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and the image of the document is an image reading area for reading the document, and a document detection area for detecting the presence or absence of the document and the leading and trailing edges of the document; The light emitted from the energized display light source is located on the same plane in the sub-scanning direction and outside the readable width in the main scanning direction with respect to the light emitted from the image light source to the reading position. The light is received from the entrance surface and introduced into the reduction optical system from the exit surface and irradiated onto the original detection area of the photoelectric conversion means through the reduction optical system, and at least one of the entrance surface or the exit surface is provided with an energized display light source. a light guide provided with a dispersion surface for dispersing the light; the light guide is rotatably provided, its detection end protrudes to a position where it is biased by the document on the document table, and its light-shielding end serves as the energization indicator. It protrudes to a position that blocks part of the light irradiated from the light source to the document detection area of the photoelectric conversion means through the light guide and reduction optical system, and when the document pushes the detection end, the light blocking end A document presence/absence detection mechanism that transmits a portion of the document is rotatably provided, the detection end thereof protrudes to a predetermined position on the document conveyance path, and the light shielding end portion of the document detection mechanism transmits a portion of the document from the energized display light source to the light guide and the reduction optical system. A document leading edge protrudes to a position that blocks part of the light that is irradiated onto the document detection area of the photoelectric conversion means through the photoelectric conversion means, and when the document presses the detection end, the light blocking end transmits part of the light. What is claimed is: 1. A document reading device comprising: a trailing edge detection mechanism; and detecting the presence or absence of a document and the conveyance status of the document based on the output of the document detection area of the photoelectric conversion means. 8. The photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system, and the photoelectric conversion element is arranged to read an image of the document. The scanning area, the presence or absence of a document, and the leading edge of the document.
The light guide is divided into a document detection area for detecting the trailing edge and a pressure plate detachment detection area for detecting the detachment state of the pressure plate, and the light guide moves as the pressure plate leaves and detects the energization indication light source. The introduction of the light into the reduction optical system is stopped, and the detachment state of the pressure plate is detected by the output result of the pressure plate detachment detection area of the photoelectric conversion means, and the detection state of the document detection area of the photoelectric conversion means is changed to the state of no document. The document reading device according to claim 7, characterized in that: 9. A document table on which a plurality of documents are placed, a document conveyance path in which the documents on the document table are conveyed to a document reading position, and a predetermined reading width in the main scanning direction for conveying the documents to the document reading position. A light source that projects light over a wide area, a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width, and a reduction optical system that reduces the light reflected by the original and introduces it into the photoelectric conversion means. In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and the image of the document is The light source is divided into an image reading area for reading and an original detection area for detecting the leading and trailing edges of the original, and the light source is formed by disposing a plurality of light emitting elements in the width direction of the original, and the light emitting elements are , an image light emitting element group for illuminating the image reading area, and a document detection light emitting element group for illuminating the document detection area, and On the light source side, with respect to the light irradiated from the image light emitting element group to the reading position, the light source is located on the same plane in the sub-scanning direction and outside the range of the readable width in the main scanning direction, and is used for detecting the document. a light introduction means for introducing the light irradiated from the light emitting element group into the reduction optical system and irradiating it onto the original detection area of the photoelectric conversion means through the reduction optical system; It protrudes to a predetermined position on the document conveyance path and is biased by the document in accordance with the conveyance position of the document, and its light-shielding end is photoelectrically transmitted from the document detection light emitting element group through the light introduction means and the reduction optical system. a document leading and trailing edge detection mechanism that protrudes to a position that blocks the light irradiated on the document detection area of the conversion means and changes the light blocking range in multiple stages according to the energization status of the detection end; What is claimed is: 1. A document reading device comprising: a device for detecting a conveyance status of a document based on an output of a document detection area of the photoelectric conversion means; 10. A document table on which a plurality of documents are placed, a document conveyance path in which the documents on the document table are conveyed to a document reading position, and a predetermined reading width in the main scanning direction for conveying the documents to the document reading position. A light source that projects light over a wide area, a photoelectric conversion means in which a plurality of photoelectric conversion elements are arranged over a predetermined width, and a reduction optical system that reduces the light reflected by the original and introduces it into the photoelectric conversion means. In the document reading device, the photoelectric conversion element of the photoelectric conversion means is arranged to be wider by a predetermined width than the optical path width through which the reflected light of the readable width is reduced by the reduction optical system and introduced, and the image of the document is The light source is divided into an image reading area for reading and an original detection area for detecting the leading and trailing edges of the original, and the light source is formed by disposing a plurality of light emitting elements in the width direction of the original, and the light emitting elements are , an image light emitting element group for illuminating the image reading area, and a document detection light emitting element group for illuminating the document detection area, and On the light source side,
With respect to the light emitted from the image light emitting element group to the reading position, the light emitting element group for document detection is located on the same plane in the sub-scanning direction and outside the range of the readable width in the main scanning direction. a light introduction means that introduces the irradiated light into a reduction optical system and irradiates the document detection area of the photoelectric conversion means through the reduction optical system; It protrudes to a predetermined position and is biased by the document in accordance with the conveyance position of the document, and its light-shielding end is exposed to the light of the photoelectric conversion means from the document detection light emitting element group through the light introduction means and the reduction optical system. A document leading and trailing edge detection mechanism is provided, which protrudes to a position that blocks the light irradiated to the document detection area, and changes the amount of light in multiple stages according to the energization status of the detection end. A document reading device characterized in that a document conveyance status is detected based on an output of a document detection area of a converting means.