JP3179840B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus capable of reading a transparent original such as a reflective original and a film with high accuracy by a single apparatus.

[0002]

2. Description of the Related Art There have hitherto been proposed many image reading apparatuses capable of selecting a mode for reading a reflection original and a mode for reading a transparent original such as a film. A film projector projects and forms a film image on the original platen surface, and it is possible to select both a mode to read the projected image and a mode to read the original placed on the original surface. An example of a readable image reading apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-174462, entitled "Image Reading Apparatus".
In this case, a mode in which a document placed on a document table is scanned by a reading optical system and read, and a film image is projected and formed on the document surface by a film projector, and the projected image is read by the reading optical system. In an apparatus having a selection mode for selecting a reading mode, the reading optical system is stopped in the scanning direction in the film reading mode, and the reading scan is performed by moving the film.
Accordingly, in the film reading mode, since the scanning is performed by moving the film while the reading optical system is fixed, the projection optical system includes a projection lens and a mirror as compared with a conventional apparatus that projects and reads the entire surface of the film at once. The optical system can be made compact, and only the slit-shaped region needs to be illuminated, so that the illumination system can be made compact.

[0003] In addition, a reflection and transmission type in which a mode in which a transparent original such as a film is read by illuminating the original from the side opposite to the imaging lens or the image sensor and a mode in which an original placed on the original surface is read can be selected. With respect to an image reading apparatus capable of reading an original by one unit, for example, an "image reading apparatus" in JP-A-3-46864, an "image reading apparatus" in JP-A-3-55961, and a JP-A-3-58566 are disclosed. Each is disclosed in the gazette under the title of “image reading device”.

First, in Japanese Patent Application Laid-Open No. 3-46864, an "image reading apparatus" is used for reading a transparent original such as a film in an image reading apparatus which scans an original placed on an original table by scanning a reading optical system. Is capable of mounting a device for illuminating from the opposite side of the image forming lens and image sensor for the transparent original, and expanding the transparent original such as film by making the imaging lens movable within the reading optical system. This makes it possible to read the document. This allows
A mode for reading a reflection original and a mode for reading a transmission original can be selected, and a transmission original such as a film can be read with high accuracy.

Japanese Patent Application Laid-Open No. 3-55961 discloses an "image reading apparatus" which scans a document placed on a document table by scanning a reading optical system to read a transparent document such as a film. Has a document moving table for moving a transparent document such as a film across the optical path between the image forming lens of the reading optical system and the document surface. As a result, it is possible to select a mode for reading a reflection original and a mode for reading a transmission original, and also to read a transmission original at a high magnification because the distance from the transmission original to the imaging lens is shortened, that is, High-precision reading can be performed.

Further, in the "image reading apparatus" of JP-A-3-58566, when reading a transparent original such as a reflective original or a film with a single image reading apparatus, separate light sources and originals are used for reflection reading and transparent reading. A mode for reading a document placed on a platen and scanning an optical system to read the document,
A reading mode in which a transparent original such as a film is moved so as to cross the optical path between the image forming lens of the reading optical system and the original surface. Here, when reading a transparent original, one of the reflection mirrors of the reading optical system is movable. As a result, a mode for reading a reflection original and a mode for reading a transmission original can be selected, and the distance between the transmission original and the imaging lens is shortened, so that the transmission original reading at a high magnification, that is, a high-precision reading, Reading can be performed.

[0007] In addition to the various image reading apparatuses having the selection mode as described above, there are also those filed by the present applicant as described in the following two apparatuses. First, as the first device, in the image reading device capable of selecting a mode for reading a reflective original and a mode for reading a transparent original such as a film, each has a separate light source and a platen for reflection reading and transmission reading, Furthermore, by configuring an optical system that forms an image on the same photoelectric conversion element with a different imaging lens, a mode in which a reflection original placed on a platen is scanned by a reading optical system to read, and a mode in which a transparent original is placed. A mode for reading a transparent original can be selected by moving another original platen with respect to another fixed reading optical system. As a result, a mode for reading a reflection original and a mode for reading a transmission original can be selected, and since the imaging lens for reading is different between the reflection original reading and the transmission original reading, the transmission original reading at high magnification, that is, , High-precision reading becomes possible.

Next, as a second apparatus, a mode for reading a reflection original and a mode for reading a transmission original such as a film can be selected, and a separate light source and a document table are provided for reflection reading and transmission reading. In an image reading apparatus that forms an optical system that forms an image on different photoelectric conversion elements with different image forming lenses, a moving means of a second traveling mirror also functions as a transmitting original moving means, and furthermore, an imaging magnification of a reflective original and a transmitting original. Is set to 2: 1.

[0009]

First, Japanese Patent Laid-Open No. 2-17 / 1990
In No. 4462, a film image is projected and formed on a document surface by a film projector, and when the projected image is read by a reading optical system, the image projected on the diffusion plate is read through a Fresnel lens. Magnification is possible, but high quality reading is difficult. In this case, since the film projector is separately installed, the apparatus becomes complicated, and the overall configuration becomes large.

Further, Japanese Patent Application Laid-Open Nos. Hei 3-46864 and Hei 3
According to the inventions disclosed in JP-A-55961 and JP-A-3-58566, when reading a transparent original such as a film, the position of an imaging lens commonly used for reflection and reading of a transparent original is changed to enlarge the image. Reading is in progress. Therefore, in order to obtain an accurate magnification, it is necessary to accurately determine the position (including the six-dimensional posture) of the imaging lens before and after the movement. In general, it is difficult to move the imaging lens to set its position within the lens aberration range, and a high-precision drive system is required to perform this.

Further, the first and second apparatuses of the present applicant have been proposed in order to solve the various problems as described above. Is reflected four times. By the way, in a reflection original, light from a light source is diffused on the original surface, and a part thereof is imaged and read. Therefore, since the loss of the light amount from the light source is large, it is desired to minimize the loss in the optical path. It is considered that the reflection mirror actually has a reflectance of not about 100% due to the properties of the deposited material and the like, but has a loss of about 10% in aluminum deposition generally used for an image reading device or the like. For this reason, it is necessary to minimize the number of reflections in the reading optical path. By the way, the minimum number of reflections required in the reduction optical system is three. Therefore, this device has a drawback that the loss of the light amount due to the reflection mirror is larger than that of a normal reading system.

[0012]

[0013]

According to the first aspect of the present invention, a light source for reading a reflective original or a transparent original, an original table on which the original is placed, a sub-scanning traveling system, and an imaging lens are connected to the reflective original. A reading optical system or a transparent original reading optical system, images are separately formed on the same photoelectric conversion element by the different imaging lenses, and a mode for reading the reflective original and a mode for reading the transparent original. Wherein the platen for reading the transparent document is provided in the reflection document reading optical system to read the reflection document.
And the reflected light from the original surface of the reflective original.
It was connected to a first traveling body having a reflecting mirror for reflecting .

According to a second aspect of the present invention, a light source for reading a reflection document or a transmission document, a document table on which the document is placed, a sub-scanning traveling system, and an imaging lens are connected to a reflection document reading optical system or Provided in a transmission original reading optical system, images are separately formed on the same photoelectric conversion element by the different imaging lenses, and a mode for reading the reflection original and a mode for reading the transmission original are selected. In a possible image reading apparatus, the platen for reading the transparent document is provided in the reflection document reading optical system, and the reflection plate reflects the reflection document from the document surface.
It was connected to a second traveling body provided with two reflection mirrors for reading a reflection original for reflecting light .

According to the third aspect of the present invention, the first or second aspect is provided.
In the invention described above, the ratio of the maximum reading width in the main scanning direction between the reflective original and the transparent original is set to the reciprocal of the maximum reading density ratio in the main scanning direction between the reflective original and the transparent original.

According to a fourth aspect of the present invention, in the third aspect of the invention, the ratio of the maximum reading density between the reflective original and the transmissive original in the main scanning direction and the sub-scanning direction is set to 1: 2, and In each of the main scanning direction and the sub-scanning direction, the ratio of the maximum reading width between the reflection original and the transmission original was set to 2: 1.

[0017]

[0018]

According to the first aspect of the present invention, an original plate for reading a transparent original such as a film is provided on a first traveling body for reading a reflective original, so that a reflective original reading optical system and a transparent original reading optical system are provided. And a common sub-scanning traveling system to reduce the size of the entire image reading apparatus and reduce the cost of the apparatus.

According to the second aspect of the present invention, an original platen for reading a transparent original such as a film is provided on the second traveling body of the reflective original reading optical system, so that the reflective original reading optical system and the transparent original reading optical system are provided. A common sub-scanning traveling system is used to reduce the size of the entire image reading apparatus, reduce the cost of the apparatus, and narrow the control range of the speed required for the common sub-scanning traveling system. It is possible to do.

According to the third aspect of the present invention, the first or second aspect is provided.
In the invention described, by setting the ratio of the maximum reading width in the main scanning direction between the reflective original and the transmissive original to the reciprocal of the maximum reading density ratio in the main scanning direction between the reflective original and the transparent original,
The signal processing system after reading by the photoelectric conversion element used for the reflection original reading and the transmission original reading can be made the same.

According to the fourth aspect of the invention, the ratio of the maximum reading density between the reflection original and the transmission original is set to 1: 2.
In the main scanning direction, the ratio of the maximum reading width between the reflection original and the transmission original is set to 2: 1 so that the photoelectric conversion used for reading the reflection original and reading the transmission original in the main scanning direction. By making the pixel reading clock of the element and the signal processing system after reading the same, the electric circuit system can be simplified, and in the sub-scanning direction, the reflection original reading optical system and the transmission original reading optical system are necessary. Common sub-scanning traveling system (traveling distance and speed range, etc.)
Can be achieved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a configuration which is a premise of the present invention will be described with reference to FIG. Here, the image reading apparatus shown in FIG. 1 will be described as an example of an apparatus capable of selecting a mode for reading a reflective original and a mode for reading a transparent original.

A contact glass 2 as a document table is mounted on the upper surface of the main body 1, and a reflection document 3 is placed on the surface of the contact glass 2. Below the contact glass 2, a light source 4 for illuminating the reflective original 3 is disposed with its longitudinal direction in the main scanning direction X. Then, the reflection original 3 illuminated by the light source 4
Is reflected by the reflection mirrors 6, 7, and 8 constituting the reflection original reading optical system 5 sequentially, and then passes through the imaging lens 9 to form an image on the surface of the photoelectric conversion element 10. Is done. The photoelectric conversion element 10 is mounted on an electrical system circuit board 11 for converting a signal detected thereby into an electric signal. An optical path switching mirror 12 for switching an optical path is rotatably mounted between the imaging lens 9 and the photoelectric conversion element 10. When reading the reflection original 3, the optical path switching mirror 12 is arranged at a position P substantially parallel to the optical axis a.

In the reflection original reading optical system 5 having such a configuration, when reading the reflection original 3, the first traveling body 13 on which the light source 4 and the reflection mirror 6 are mounted and the reflection mirrors 7 and 8 are mounted. The unillustrated second traveling body moves at a speed of 2: 1 so that the entire surface of the reflection original 3 can be read. Note that the traveling system in the sub-scanning direction Y of the image reading apparatus driven at the two-to-one speed is considered to be well-known, and the description thereof is omitted.

In the main body 1, a transparent original 15 is placed on a contact glass 14 serving as an original table.
A light source 16 for illuminating the transmissive original 15 is disposed above the transmissive original 15. The direct light from the light source 16 and the reflected light from the reflector 17 are reflected by the reflector 18 and further diffused. By being diffused by the plate 19a, uniform illumination is provided. And
The transmitted original 1 which has been uniformly illuminated by passing through the diffusion plate 19a
The transmitted light 5 is reflected by the reflection mirror 20 constituting the transmission original reading optical system 19, passes through the imaging lens 21, passes through the reflection mirror 22, and the optical path switching mirror 12, and is common to the reflection original reading. An image is formed on the photoelectric conversion element 10.

In the transparent original reading optical system 19 having such a configuration, when reading the transparent original 15, the transparent original 15 and the contact glass 14 are driven in the direction of the arrow (the sub-scanning direction Y). Can be read. The driving in the sub-scanning direction Y can be performed using, for example, a linear motor, a rotary motor, and a transmission system that converts rotation to linear.

As described above, the reflection original reading optical system 5
Is constituted by three reflections by the reflection mirrors 6, 7, and 8, and the transmission original reading optical system 19 is constituted by three reflections. As a result, the loss of the light amount due to the reflection of the mirror in the reflection original reading optical system 5 requiring the power of the light source 4 can be suppressed to the minimum necessary, and the number of reflections is the same for both reflection and transmission. If the light amount loss due to the reflection of the mirror in the system is also obtained, the light amount loss due to the reflection in the mirrors of both optical systems can be obtained.

Next, a description will be given based on an embodiment of the invention of claim 1, wherein in Figure 2. It should be noted that , based on the premise of the present invention described above ,
The same reference numerals are used for the same parts as in the configuration example (see FIG. 1), and the description of the same parts is omitted.

In the above-described configuration example on which the present invention is based ,
The sub-scanning traveling systems of the reflection original reading optical system 5 and the transmission original reading optical system 19 are controlled by separate drive systems. In this embodiment, however, in the apparatus shown in FIG. A glass 14 is fixed to a first traveling body 13 including a light source 4 for reading a reflection original and a reflection mirror 6, thereby newly forming a sub-scanning first traveling body 23.

In this case, the sub-scanning direction Y when reading the reflected original
The scanning method is the same as that described in the configuration example which is the premise of the present invention, but also at the time of reading the transparent document, the moving speed of the sub-scanning first traveling body 23 is the same as that at the time of reading the transparent document. The sub-scanning traveling system of the reflection original reading optical system 5 is driven so as to have the same speed. At this time, the sub-scanning first traveling body 23 for reading the reflection document also functions as a traveling body for reading the transmission document.

As described above, the transparent original reading optical system 19
Can be omitted and the sub-scanning traveling system of the reflection original reading optical system 5 and the transparent original reading optical system 19 can be shared, so that the size of the image reading apparatus itself can be reduced, and
It is possible to reduce the cost of the image reading device.

A description will now be given with reference to an embodiment of the second aspect of the present invention in FIG. It should be noted that , based on the premise of the present invention described above ,
Using the same symbols for the same parts configuration example becomes and claim 1 Symbol placing the invention (see FIGS. 1 and 2), it will not be described here again the same parts.

In the above-described configuration example on which the present invention is based ,
The sub-scanning traveling systems of the reflective original reading optical system 5 and the transparent original reading optical system 19 are controlled by separate drive systems. In the present embodiment, however, in the apparatus shown in FIG. The glass 14 is fixed to the second traveling body 24 holding the reflection mirrors 7 and 8 for reading the reflection original,
Thus, the sub-scanning second traveling body 25 is newly configured.

In this case, the sub-scanning direction Y when reading the reflected original
The scanning method is the same as that described in the configuration example which is the premise of the present invention. However, also at the time of reading the transparent document, the moving speed of the sub-scanning second traveling body 25 is set at the time of reading the transparent document. The sub-scanning traveling system of the reflection original reading optical system 5 is driven so as to have the same speed. At this time, the sub-scanning second traveling body 25 for reading the reflection document also functions as a traveling body for reading the transmission document.

The first traveling body 13 and the second traveling body 24 of the sub-scanning traveling system at the time of reading the reflected original are moved at a speed of 2: 1. Now, assuming that the speed range of the sub-scanning traveling system necessary for reading the reflected original is V _{1 to} V ₂ (V ₁ <V ₂ ), the first
Speed range of the traveling member 13 whereas a V ₁ ~V _2, the speed range of the second running body 24 becomes V ₁ / 2~V _2/2. Therefore, if the contact glass 14 for reading the transmissive document is attached to the sub-scanning second traveling body 25 for reading the reflective document, the sub-scanning traveling system for reading the reflective document alone can be used to read the sub-scan for the reflection and transmissive document. This means that a speed range of V _{1/2 to} V ₂ is prepared as the scanning traveling system. That is, this means that the speed range is expanded to a lower speed region than when the contact glass 14 for reading the transparent original is attached to the first sub-scanning traveling body 23 for reading the reflective original, and the enlarged reading is performed. , Which is advantageous for reading a transparent original.

The speed range of the sub-scanning traveling system required for reading the reflection original is V _{1 to} V ₂ , and the speed range of the sub-scanning traveling system required for reading the transparent original is V _{3 to} V ₄ (V ₃ <V _4). <V ₁ <V ₂ )
If, while the speed range of the first carriage 13 required to both document reading the first aspect of the present invention is a V ₃ ~V _2, in this embodiment, 2 La V ₃ ~V ₂ or V ₁ ~V ₂ becomes, thereby it can be seen that the speed range required is more of this embodiment is narrow.

As described above, the transparent original 1 such as a film
The sub-scanning traveling system of the reflection original reading optical system 5 and the transmission original reading optical system 19 is made common by installing the contact glass 14 for reading the original 5 on the second traveling body 24 of the reflection original reading optical system 5. The size of the entire image reading apparatus can be reduced, and the control range of the speed required for the common sub-scanning traveling system can be narrowed.

Next, it will be described with reference to an embodiment of the invention of claim 3 according to FIG. It should be noted that , based on the premise of the present invention described above ,
The same reference numerals are used for the same components as those of the configuration example and the inventions described in claims 1 and 2 (see FIGS. 1 to 3), and the description of the same components is omitted.

In this embodiment, the reflection original 3 or the transmission original 1
5 a light source 4 and 16 read the, the contact lens 2 and 14 as a document table on which an original is placed, and the sub-scanning driving system (not shown), reflecting an imaging lens 9 and 21 document scanning optical system 5 or transmission A mode for reading the reflective document 3 and a mode for reading the transparent document 15 are provided in a document reading optical system 19, wherein images are separately formed on the same photoelectric conversion element 10 by the different imaging lenses 9 and 21, respectively, and the reflection document 3 is read. In the image reading apparatus as shown in FIGS. 1 to 3 in which the mode can be selected, as shown in FIGS. 4A and 4B, the main scanning direction of the reflection original 3 and the transmission original 15 as shown in FIGS. The ratio of the maximum reading width of X is set to the reciprocal of the ratio of the maximum reading density of the reflective original 3 and the transparent original 15 in the main scanning direction X. Hereinafter, the reason for setting such conditions will be described.

FIG. 4A shows the relationship between the maximum reading width of the original in the main scanning direction X and the reading width of the photoelectric conversion element 10 when reading the reflection original 3, and FIG. Shows the relationship between the maximum reading width of the original in the main scanning direction X and the reading width of the photoelectric conversion element 10 when the transparent original 15 is read.

Now, the maximum reading width of the reflection original 3 is set to Xr (m
m), the maximum reading width of the transparent original 15 is Xf (mm), the maximum reading density of the reflective original 3 is α (dpm), and the maximum reading density of the transparent original 15 is β (dpm). The number Dr of dots read by the photoelectric conversion element 10 and the number Df of dots read by the photoelectric conversion element 10 when reading a transparent original are as follows.

Dr = α × Xr (1) Df = β × Xf (2) Here, the ratio of the maximum reading width in the main scanning direction X of the reflection original 3 and the transmission original 15 is N ₁ , and the photoelectric conversion element 10 Xr = N ₁ × Xf (3) α = (1 / N ₂ ) × β (4) where N ₂ is the maximum reading density ratio of

From (1) to (4), (Dr / Df) = (N ₁ / N ₂ ) (5)

In the prior art, N ₁ and N ₂ are completely arbitrarily determined. For example, when N ₁ <N ₂ , first, the number Df of dots read by the photoelectric conversion element 10 at the time of reading a transparent original is determined. determined, in the time of reading reflective originals, the number of different dots from that, i.e., was read in dots by multiplying the N ₁ / N ₂ in Df ((5) formula). Conversely, N ₁ >
For N _2, it was determined the number of reading dots in the reverse order. For this reason, a circuit for signal processing after the photoelectric conversion element 10 is complicated.

Therefore, in this embodiment, the ratio of the maximum reading width in the main scanning direction X between the reflection original 3 and the transmission original 15 is determined by the inverse ratio of the reading density of the photoelectric conversion element 10 between the reflection original 3 and the transmission original 15. Set to. That is, N ₁ = N ₂ (6) is set.

Here, when the expression (6) is substituted into the expression (5), Dr / Df = 1, that is, Dr = Df, and the photoelectric conversion element 10 when reading the reflection original 3 and the transmission original 15 is obtained.
Can be made equal in the number of read dots. Accordingly, since the signal processing system after reading by the photoelectric conversion element 10 used for the reflection original reading and the transmission original reading can be made the same, the signal processing system can be simplified as compared with the related art. it can.

Next, FIG 5 an embodiment of the invention described in claim 4, will be described with reference to FIG. It should be noted that the above-described present invention
Example of a prerequisite configuration and the invention described in claims 1 to 3 (FIGS. 1 to 3 )
4) are used for the same parts, and the description of the same parts is omitted.

In this embodiment, in the image reading apparatus having the structure described in the second aspect of the present invention (see FIG. 3),
In both the main scanning direction X and the sub-scanning direction Y, the ratio between the maximum reading densities of the reflection document 3 and the transmission document 15 is set to 1: 2, and
In both the main scanning direction X and the sub-scanning direction Y, the reflection original 3
The ratio of the maximum reading width of the transparent document 15 to that of the transparent document 15 is set to 2: 1. Hereinafter, a specific example will be described.

FIGS. 5A and 5B show reading in the sub-scanning direction Y by the image reading apparatus of this embodiment.
(A) shows a reading start position, and (b) shows a reading end position. Here, Pa is a reading start position of the reflection original 3, and Pb is a reading end position thereof. Similarly, Pc indicates the reading start position of the transparent original 15, and Pd indicates the reading end position. In the present embodiment, as described above, the ratio of the distance between Pa and Pb, ie, the maximum reading width of the reflective original 3, and the distance between Pc, Pd, ie, the maximum reading width of the transparent original 15, is set to 2: 1. At this time, the reading density ratio between the reflective original 3 and the transparent original 15 in the sub-scanning direction Y is set to 1: 2.

FIGS. 6A and 6B show the maximum reading width of a document in the main scanning direction X and the reading width of the photoelectric conversion element 10 in the image reading apparatus of this embodiment. (A) shows the time of reading a reflective original, and (b) shows the time of reading a transparent original. In this embodiment, the maximum reading width Xr (m
m) is set to twice the maximum reading width Xf (mm) of the transparent original 15. At this time, the maximum reading density β (dpm) of the transparent original 15 is equal to the maximum reading density α of the reflective original 3.
(Dpm).

In such a configuration, since the reading density ratio between the reflective original 3 and the transmissive original 15 in the sub-scanning direction Y is set to 1: 2, the photoelectric conversion element 10 at the time of reading each original is set. If the pixel reading clocks in the main scanning direction X are the same, the moving speed of the sub-scanning traveling system required for reading the original of the reflective original 3 and the original of the transparent original 15 becomes 2: 1. At this time, in this embodiment, since the contact glass 14 for reading the transparent original is fixed to the second traveling body 24 for the sub-scanning for reading the reflective original, the sub-scanning traveling system for reading the reflective original is moved at a certain speed. , It is possible to obtain half the speed of the movable table necessary for reading the transparent original. In the present embodiment, the ratio of the maximum reading width of the reflective original 3 to the maximum reading width of the transparent original 15 is set to 2: 1. The scanning width of the transparent original 15 at this time naturally satisfies the optimum condition. That is, only the sub-scanning traveling system (traveling distance, speed range, etc.) necessary for reading the reflected original can secure the sub-scanning traveling system required for reading both originals.

In the sub-scanning direction Y, the present embodiment satisfies the setting conditions of the invention described in claim 3 , and the reading density of the reflective original 3 and the transmissive original 15 in the sub-scanning direction Y due to the set ratio to 1: 2, a pixel read clock of the photoelectric conversion element 10 at the time of reading of each of the reflective original 3 and the transparent original 15 can be the same, thereby the invention of claim 3, wherein In addition to the effect, the pixel reading clock of the photoelectric conversion element 10 can be shared.

As described above, the reflection original 3 and the transmission original 1
5 is set to 1: 2, and the ratio of the maximum reading width between the reflective original 3 and the transparent original 15 is set to 2: 1 in both the main scanning direction X and the sub-scanning direction Y. In the main scanning direction X, the electrical circuit system can be simplified by using the same pixel reading clock and the same signal processing system for the photoelectric conversion element 10 used for the reflection original reading and the transmission original reading. In the sub-scanning direction Y, the reflection original reading optical system 5 and the transmission original reading optical system 19
The common sub-scanning traveling system (traveling distance and speed range, etc.) required for the above can be achieved.

[0054]

[0055]

According to the first aspect of the present invention, a light source for reading a reflection document or a transmission document, a document table on which the document is placed, a sub-scanning traveling system, and an imaging lens are connected to a reflection document reading optical system or <br/> Provided in a transparent original reading optical system, images are separately formed on the same photoelectric conversion element by the different image forming lenses, and a mode for reading the reflective original and a mode for reading the transparent original. In the image reading apparatus selectable, the platen for reading the transparent document is provided in the reflection document reading optical system, and the light source for reading the reflection document and the light source for reading the reflection document are provided.
A reflective mirror that reflects light reflected from the original surface of the reflective original
Having continuously to the first traveling body having a can be shared in the sub-scanning driving system for reflective original reading optical system and the transparent original reading optical system, thereby reducing the size of the entire image reading apparatus In addition, the cost of the apparatus can be reduced.

According to a second aspect of the present invention, a light source for reading a reflective original or a transparent original, an original table on which the original is placed, a sub-scanning traveling system, and an imaging lens are connected to a reflective original reading optical system or a transparent original. An image reading optical system is provided, and images are separately formed on the same photoelectric conversion element by the different image forming lenses, and a mode for reading the reflective original and a mode for reading the transparent original are provided. In the selectable image reading device, the platen for reading the transparent document is provided in the reflection document reading optical system to reflect the reflection document from the document surface.
The sub-scanning traveling system of the reflection original scanning optical system and the transmission original scanning optical system is common because it is connected to the second traveling body provided with two reflection mirrors for reflecting the original. This makes it possible to reduce the size of the entire image reading apparatus, reduce the cost of the apparatus, and narrow the control range of the speed required for the common sub-scanning traveling system. Can be done.

The third aspect of the present invention provides the first or second aspect.
In the image reading apparatus, the ratio of the maximum reading width in the main scanning direction between the reflective original and the transparent original is set to the reciprocal of the maximum reading density ratio in the main scanning direction between the reflective original and the transparent original. Therefore, the signal processing system after reading by the photoelectric conversion element used for the reflection original reading and the transmission original reading can be made the same, whereby the signal processing system can be simplified.

According to a fourth aspect of the present invention, in the third aspect of the invention, the ratio of the maximum reading density between the reflective original and the transmissive original in the main scanning direction and the sub-scanning direction is set to 1: 2, and In both the main scanning direction and the sub-scanning direction, the ratio of the maximum reading width between the reflective original and the transparent original is set to 2: 1. By using the same pixel read clock and the same signal processing system after reading, the electrical circuit system can be simplified, and in the sub-scanning direction, both the reflective original reading optical system and the transparent original reading optical system are required. This makes it possible to achieve a common sub-scanning traveling system.

[Brief description of the drawings]

FIG. 1 is a front view of an image reading apparatus which is a configuration example on which the present invention is based .

FIG. 2 is a front view showing one embodiment of the invention described in claim 1 ;

FIG. 3 is a front view showing an embodiment of the invention described in claim 2 ;

FIG. 4 shows an embodiment of the invention according to claim 3, wherein FIG. 4 (a) is an optical path diagram showing a state when reading a reflection original;
FIG. 4B is an optical path diagram showing a state when reading a transparent original.

FIGS. 5A and 5B show an embodiment of the invention according to claim 4 , wherein FIG. 5A is a front view at a reading start position and FIG. 5B is a front view at a reading end position.

FIGS. 6A and 6B show an embodiment of the invention according to claim 4, wherein FIG. 6A is an optical path diagram showing a state when reading a reflection original;
FIG. 4B is an optical path diagram showing a state when reading a transparent original.

[Explanation of symbols]

 2 Document table 4 Light source 5 Reflected document reading optical system 6-8 Reflecting mirror 9 Imaging lens 10 Photoelectric conversion element 13 First traveling body 14 Document table 16 Light source 19 Transparent document reading optical system 21 Imaging lens 24 Second traveling body X Main scanning direction Y Sub scanning direction

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H04N 1/107 H04N 1/12 Z 1/19 (72) Inventor Makoto Hino 1-6-6 Nakamagome, Ota-ku, Tokyo, Japan Inside Ricoh Company (72) Inventor Yutaka Kaneko 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (56) References JP-A-4-157964 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03B 27/50 G03G 15/04-15/047 H04N 1/04-1/207

Claims (4)

(57) [Claims] A light source for reading a reflection document or a transmission document;
A document table on which a document is placed, a sub-scanning traveling system, and an image forming lens are provided in a reflection document reading optical system or a transmission document reading optical system, and images are separately formed by the different image forming lenses into the same photoelectric sensor. In an image reading apparatus which forms an image on a conversion element and is capable of selecting a mode for reading the reflective original and a mode for reading the transparent original, the original platen for reading the transparent original is provided with a reflection original reading optical system. Provided within the anti
From the light source for reading the reflected original and the original surface of the reflective original.
An image reading apparatus, wherein the image reading apparatus is connected to a first traveling body including a reflection mirror for reflecting reflected light . 2. A light source for reading a reflection document or a transmission document,
A document table on which a document is placed, a sub-scanning traveling system, and an image forming lens are provided in a reflection document reading optical system or a transmission document reading optical system, and images are separately formed by the different image forming lenses into the same photoelectric sensor. In an image reading apparatus which forms an image on a conversion element and is capable of selecting a mode for reading the reflective original and a mode for reading the transparent original, the original platen for reading the transparent original is provided with a reflection original reading optical system. Before being provided in
Reflected originals that reflect light reflected from the original surface
An image reading apparatus, wherein the image reading apparatus is provided in series with a second traveling body having two reflecting mirrors for taking . That the wherein the ratio of the maximum reading width in the main scanning direction before and Symbol reflective original and the transparent original was set to the reciprocal of the ratio of the maximum reading density in the main scanning direction between the transmissive original and the reflective original The image reading device according to claim 1, wherein: 4. The ratio of the maximum reading density between a reflective original and a transmissive original in the main scanning direction and the sub-scanning direction is set to 1: 2, and the reflective original and the transparent original are both set in the main scanning direction and the sub-scanning direction. 4. The image reading apparatus according to claim 3, wherein the ratio of the maximum reading width to the original is set to 2: 1.