JPH088629B2 - Image reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention reads a document using reflected light or transmitted light, and outputs the read image signal to an external device such as a computer. The present invention relates to an image reading device.

(Prior Art) Recently, with the improvement of functions of personal computers and the like, image reading apparatuses for inputting various image information to computers have come into general use.

However, in the existing image reading apparatus, either the original is read using reflected light or the original is read using transmitted light, and there is no apparatus that can read either of them. Therefore, there is a demand for a document that can be arbitrarily read with either reflected light or transmitted light.

As described above, as an apparatus capable of arbitrarily reading a document with either reflected light or transmitted light, for example, Japanese Patent Application Laid-Open No. 61-1748.
There is one as shown in Japanese Patent No. 68.

However, in such an apparatus, the document is read by moving the document regardless of the type of the document to be read and irradiating the fixed light source with light. Therefore, not only the space of the main body of the apparatus but also the space accompanying the movement of the document is required, and there is a drawback that the operating space of the apparatus is large.

(Problems to be Solved by the Invention) The present invention solves the conventional problem that not only the space of the main body of the apparatus but also the operation space of the apparatus is large by moving and reading the document with respect to the fixed light source. ,
It is an object of the present invention to provide an image reading apparatus capable of arbitrarily reading either reflected light or transmitted light from a document only in the space of the apparatus body and reducing the operation space of the apparatus.

[Structure of the Invention] (Means for Solving the Problems) In the image reading apparatus of the present invention, which reads image information of a document placed on a document table, the document is read from above the document table. A first light source for irradiating light to the original, first supporting means for supporting the first light source so as to be movable in a predetermined direction along the original placing table, and a lower portion of the original placing table with respect to the original. Second light source that irradiates light
Transmitted light that is provided on the same side as the second light source with respect to the original placing table and that is emitted from the first light source and transmitted through the original document or reflected light that is emitted from the second light source and reflects the original document. A photoelectric conversion means for receiving light and converting it into an electric signal, and a second light source and a photoelectric conversion means for movably supporting the second light source and the photoelectric conversion means in the same direction as the first supporting means along the document table. Second supporting means, a first scanning motor that reciprocates the first light source supported by the first supporting means along the document mounting table, and is supported by the second supporting means. A second scanning motor that reciprocally moves the second light source and the photoelectric conversion means along the document mounting table, a designation means that designates whether the document is for reflected light or transmitted light, and The above by specified means Is designated for transmitted light, the first light source is turned on, and the first light source and the photoelectric conversion means are moved in synchronization with each other along the document table. , The second scanning motor is controlled to turn on the second light source when the original is designated by the designating means for reflected light, and the second light source and the photoelectric conversion means are turned on. Is composed of control means for controlling the second scanning motor so as to move along the document placing table.

(Operation) According to the present invention, in reading image information of a document placed on a document table, the first light source irradiates the document with light from above the document table, and Is supported by a first supporting means so as to be movable in a predetermined direction along the original placing table, and light is emitted from a lower portion of the original placing table to the original by a second light source, so that the original is placed. The photoelectric conversion means provided on the same side as the second light source with respect to the mounting table transmits the light emitted from the first light source and transmitted through the original document or the reflection light emitted from the second light source and reflects the original document. The light is received and converted into an electric signal, and the second light source and the photoelectric conversion means can be moved by the second support means along the document placing table in the same direction as the first support means. Supported and supported by the first supporting means The first light source is reciprocally moved along the document table by the first scanning motor, and the second light source supported by the second supporting means and the photoelectric conversion means are moved to the second position. In the case where the scanning motor is reciprocally moved along the document placing table, the designation unit designates whether the document is for reflected light or transmitted light, and when the designation designates the document as transmitted light. The first light source is turned on and the first and second scanning motors are controlled so that the first light source and the photoelectric conversion means move synchronously along the document placing table. When the document is designated by the designating means for reflected light, the second light source is turned on, and the second light source and the photoelectric conversion means are moved so as to move along the document mounting table. Controlled the second scanning motor Than it is.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

2 and 3 show an image reading apparatus of the present invention, which reads an original for reflected light (ordinary original) or an original for transmitted light (positive, negative film, OHP paper), and an external device such as a computer. 2 shows a scanner for outputting the read image signal. That is, 1 is a scanner body, and an operation panel (not shown) is provided on the front part of the upper surface of the body 1. An original placing table (platen glass) 2 made of transparent glass is fixed to the upper surface of the main body 1.

Further, the main body 1 is provided with a document scanning section 5 composed of a first scanning device 3 and a second scanning device 4 which are provided with the document mounting table 2 interposed therebetween. The first scanner 3 is provided above the document table 2 and reciprocates in the direction of arrow a in the figure along the upper surface thereof to move the document table 2.
The original O set above is optically scanned, and an illumination lamp (first light source; fluorescent lamp) 6 for illuminating the original O and a carriage 7 for supporting the irradiation lamp 6 are provided.
It is composed by.

As shown in FIG. 3, the carriage 7 is guided by a guide rail 8 and a guide shaft 9 so as to be reciprocally movable in the direction of arrow a. A drive pulley 11 driven by a scanning motor (for example, a pulse motor) 10 capable of forward and reverse rotations is provided on one end side of the guide shaft 9, and a driven pulley 12 is provided on the other end side thereof. A timing belt 13 is stretched between 11 and 12. One point of the timing belt 13 is fixed to the carriage 7 via a fixing member (not shown). This enables the scanning motor
The carriage 7 is linearly moved by the forward or reverse rotation of 18.

Further, the second scanner 4 is provided below the document placing table 2 and reciprocates along the lower surface thereof in the direction of the arrow a in the figure to read the document O set on the document placing table 2. An illumination lamp (second light source; fluorescent lamp) 21 for optically scanning the document O, a photoelectric converter (photoelectric conversion means) for receiving reflected light from the document O or transmitted light from the document O. ) 22, an optical system (light converging lens) 23 for guiding the reflected light or the transmitted light from the original O to the photoelectric converter 22;
And a carriage 24 supporting them.

The photoelectric converter 22 outputs the image of the original O as an electric signal by photoelectrically converting the reflected light or the transmitted light from the original O, and is mainly composed of, for example, a CCD type line image sensor.

The carriage 24 is a guide rail as shown in FIG.
It is guided by 25 and a guide shaft 26 so as to be reciprocally movable in the direction of arrow a. A drive pulley 28 driven by a scanning motor (for example, a pulse motor) 27 capable of forward and reverse rotation is provided on one end side of the guide shaft 26, and a driven pulley 29 is provided on the other end side thereof. A timing belt 30 is stretched between 28 and 29. Timing belt
One point of 30 is fixed to the carriage 24 via a fixing member 31. As a result, the carriage 24 linearly moves when the scanning motor 27 rotates forward or backward.

Further, a scale 41, which serves as a reference surface on which the original O is placed, a transmission reference plate 42, and a reflection reference plate 43 are provided on the upper surface of the end portion of the original placing table 2.

The transmission reference plate 42 is provided on the document placing table 2 and is made of a thick material. As a result, dust does not adhere to the optical focusing surface Q, and the transmission reference plate
Even if dust adheres to the upper surface P of 42, it is not an optical focus surface, so that it does not adversely affect the transmission reference data.

Therefore, since the dedicated thick transparent reference plate is provided on the upper end surface of the document placing table 2, it is possible to prevent the transparent document from entering the transparent reference data reading area.
Even if dust adheres to the transmission reference plate, the transmission reference data can be read stably because it is not on the optical focus surface.

FIG. 1 schematically shows the overall control system. That is, the CPU 51 as a control unit for controlling the whole
Is an operation panel (designating means) 52, standardization circuit 53, memory
54, light source control units 55 and 56, motor drive units 57 and 58, and A /
Each is connected to the D converter 59.

The operation panel 52 is for instructing to start reading the original,
It is composed of a key for designating (selecting) whether the original to be read is for reading by reflected light or for reading by transmitted light. The normalization circuit 53 detects the reflected light or transmitted light from the original.
The A / D-converted image data and the reflection reference data or the transmission reference data stored in the memory 54 are used for normalization (shading correction, that is, correction of variations in the photoelectric converter 22). The memory 54 stores the reflection reference data obtained by A / D converting the reflection light from the reflection reference plate 43 or the transmission reference data obtained by A / D conversion of the transmission light from the transmission reference plate 42.

The light source control unit 55 is connected to the illumination lamp 6,
The lighting control and the light amount control are performed. Light source control unit
Reference numeral 56 is connected to the illumination lamp 21 and performs lighting control and light amount control thereof. The motor drive unit 57 is connected to the scanning motor 10 and drives it. The motor drive unit 58 is connected to the scanning motor 27 and drives it. The A / D converter 59 is connected to the photoelectric converter 22, converts an electric signal from the photoelectric converter 22 into a digital signal, and outputs the digital signal to the CPU 51.

Next, the operation of the above configuration will be described. For example, now, whether the original O is for reflection or transmission is selected by the operation panel 52, the original O is placed on the original placing table 2, and a reading start key (not shown) is pressed.

Then, when the reflection mode is selected, the CPU51
The carriage 24 is moved by turning on the illumination lamp 21 and driving the scanning motor 27. As a result, the light from the illumination lamp 21 is applied to the reflection reference plate 43 and the original O via the original table 2. Light reflected from the reflection reference plate 43 and the original O is guided to the photoelectric converter 22 via the optical system 23. The photoelectric converter 22 converts the light into an electric signal and sends it to the A / D converter 59. A / D converter 59
Converts this analog signal into a digital signal.

The signal from the A / D converter 59 by the reflection reference plate 43 is stored in the memory 54 as reflection reference data. And
The signal from the document O from the A / D converter 59 is standardized by the standardization circuit 53 using the reflection reference data stored in the memory 54, and is output as read data to an external device (not shown). .

When the transmission mode is selected, the CPU 51 turns on the illumination lamp 6 and drives the scanning motors 10 and 27 to move the carriages 7 and 24 in synchronization. At this time, the illumination lamp 6 and the photoelectric converter 22 move in synchronization. As a result, the light from the illumination lamp 6 is applied to the transmission reference plate 42 and the original O. The light transmitted through the transmission reference plate 42 and the original O is guided to the photoelectric converter 22 via the original table 2 and the optical system 23. The photoelectric converter 22 converts the light into an electric signal and sends it to the A / D converter 59. The A / D converter 59 converts this analog signal into a digital signal.

The signal from the A / D converter 59 by the transmission reference plate 42 is stored in the memory 54 as transmission reference data. And
The signal from the original O from the A / D converter 59 is standardized by the standardizing circuit 53 using the transparent reference data stored in the memory 54, and is output as read data to an external device (not shown). .

As described above, the original placing table on which the original is placed is fixed, and the light source is moved inside the device to irradiate the original with light, so both the reflective and transparent originals can be read only in the space of the main body of the device. The operating space of the device can be reduced. Further, by designating the type of the original placed on the original placing table by the designation means, the lighting control of the light source according to the original can be controlled, and the accurate original can be always read.

Further, since the transmission illumination lamp and the photoelectric converter are synchronously moved and controlled by the scanning motor, and the reflection illumination lamp and the photoelectric converter are both movably supported so that the movement is controlled. The operator can easily read the originals placed on the original placing table by specifying the type of the original placed on the original placing table from the operation panel. The result can be obtained.

It should be noted that the above embodiment does not include a device for pressing the original document, but as shown in FIG. May be. In this case, the document pressing cover 60 can remove wrinkles, warpage, and the like of the document, and can also guide the light from the illumination lamp 6 to the document. The document pressing cover 60 is positioned, for example, at one end with the document mounting table 2 by a hinge or the like. Further, when reading with reflected light, the transparent cover can be replaced with a non-transparent cover (not shown).

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to arbitrarily read either the reflected light or the transmitted light from a document with only the space of the apparatus body, and it is possible to reduce the operation space of the apparatus. It is possible to provide an image reading device that can do so.

[Brief description of drawings]

The drawings are for explaining one embodiment of the present invention. FIG. 1 is a block diagram schematically showing an entire control system, FIG. 2 is a side view schematically showing an internal configuration, and FIG. FIG. 4 is a perspective view showing a scanner moving mechanism of a document scanning section, and FIG. 4 is a schematic configuration diagram for explaining another embodiment. 2 ... Operation panel, 3 ... First scanner, 4 ... Second scanner, 5 ... Original scanning unit, 6, 21 ... Illumination lamp, 1
0, 27 ... Scanning motor, 22 ... Photoelectric converter, 51 ... CP
U, 52 ... Operation panel.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04N 1/107

Claims (1)

[Claims] 1. An image reading apparatus for reading image information of an original placed on an original placing table, comprising: a first light source for irradiating the original with light from above the original placing table; First supporting means for supporting the light source of FIG. 1 so as to be movable in a predetermined direction along the document mounting table, a second light source for irradiating the document with light from the lower portion of the document mounting table, and the document mounting table. The transmitted light, which is provided on the same side as the second light source with respect to the table and is emitted from the first light source and transmitted through the document, or the reflected light, which is emitted from the second light source and reflected from the document, is received. Second support for movably supporting the photoelectric conversion means for converting into an electric signal, the second light source and the photoelectric conversion means along the document mounting table in the same direction as the first supporting means. Means and supported by said first supporting means A first scanning motor for reciprocating the first light source, which is moved along the document mounting table, the second light source supported by the second supporting means, and the photoelectric conversion means. A second scanning motor that reciprocates along the document mounting table, a designation unit that designates whether the document is for reflected light or transmitted light, and the designation unit determines that the document is for transmitted light. When specified, the first and second scanning motors are turned on so that the first light source is turned on and the first light source and the photoelectric conversion means move synchronously along the document placing table. And the second light source is turned on and the second light source and the photoelectric conversion means are arranged along the original table when the original is specified by the specifying means for reflected light. Second scan to move Image reading apparatus characterized by comprising a control means for controlling the motor.