JPH07254972A - Image reader - Google Patents

Abstract

PURPOSE:To provide an image reader for arbitrarily and selectively reading an original with both reflected light and transmitted light. CONSTITUTION:A scanner 1 for reading the image information of the original placed on an original platen 2 is provided with a first scanner 4 for irradiating the original with light from the upper part of the original platen 2 and a second scanner 4 for irradiating the original with light from the lower part of the original platen 2. The light transmitted from the first or second scanner 3 or 4 through the original or reflected on the original is received and converted to an electric signal by a photoelectric converter 22 but this device is provided with a control panel to selectively designate whether the original is provided for reflection or transmission and according to the designation with this control panel, either transmission or reflection is processed.

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 for reading an original using reflected light or transmitted light and outputting the read image signal to an external device such as a computer.

[0002]

2. Description of the Related Art Recently, with the improvement of functions of personal computers and the like, image reading devices for inputting various image information to computers have come into general use.

However, existing image reading devices either read a document using reflected light or read a document using transmitted light, and there is a device that can read either of them arbitrarily. There wasn't. So, the reflected light,
Alternatively, there is a demand for a document that can be read with either transmitted light.

The above-mentioned one using reflected light is a normal black-and-white original, and the one using transmitted light is a positive image and a negative image original drawn on a transparent film or OHP paper. When a positive image of the transparent film is read using reflected light, fine lines and the like are blurred or blurred due to diffusion of the document cover surface (white surface), that is, light wraparound, and the resolution is degraded. Therefore, reading is performed using transmitted light.

[0005]

As described above, there is a demand for a document that can be arbitrarily read with either reflected light or transmitted light, and the original can be read with either reflected light or transmitted light. It is an object of the present invention to provide an image reading apparatus capable of selectively reading, and in either case of reading, a document can be read without wrinkles or warpage.

[0006]

An image reading apparatus of the present invention is an image reading apparatus for reading image information of an original placed on an original placing table, wherein light is applied to the original from above the original placing table. A first light source for irradiating, a second light source for irradiating the original with light from the lower portion of the original placing table, the first
Photoelectric conversion means for receiving the light transmitted from the light source from the light source or the light reflected from the light source from the second light source and converting the light into an electric signal. Designating means to selectively designate whether it is transparent or transparent,
According to the selection made by the operation panel, the control means for turning on the first light source when the original is for transmission and for turning on the second light source when the original is for reflection, a predetermined transmittance and a predetermined transmittance. The white cover is provided with an optical characteristic of reflectance, and also serves as a white cover for pressing the reflection original or the transmission original placed on the original placing table against the original placing table.

[0007]

According to the present invention, an arbitrary original is read by transmitting light by turning on the first light source provided on the upper side of the original placing table, or the second light source provided on the lower side of the original placing table. The reading by the reflected light by turning on is selectively performed by the designating means. Further, when performing the above reading, the reflective original or the transparent original placed on the original placing table is pressed against the original placing table by the white cover having the optical characteristics of the predetermined transmittance and the predetermined reflectance. To do.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an image reading apparatus according to the present invention, which reads an original for reflected light (normal original) or an original for transmitted light (positive, negative film, OHP paper), a computer, etc. 2 shows a scanner for outputting the read image signal to an external device. Ie 1
Is a scanner body, and an operation panel 61 is provided on the front portion 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 placing table 2, that is, in a document cover 62 to be described later, and reciprocates along the upper surface of the document placing table 2 in the direction of the arrow a, so that the document is placed. The document O set on the table 2 is optically scanned, and is composed of an illumination lamp (first light source; fluorescent lamp) 6 for illuminating the document O, and a carriage 7 supporting the illumination lamp 6. There is.

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 scanning motor (for example, a pulse motor) capable of rotating in the forward and reverse directions is provided on one end side of the guide shaft 9.
A drive pulley 11 driven by 10 and a driven pulley 12 are arranged on the other end side, and a timing belt 13 is stretched between these pulleys 11 and 12. One point of the timing belt 13 is fixed to the carriage 7 via a limiting member (not shown). As a result, the carriage 7 linearly moves when the scanning motor 10 rotates forward or backward.

Further, the second scanner 4 is provided below the original document table 2 and along the lower surface thereof, an arrow a shown in the figure.
The document O set on the document table 2 is optically scanned by reciprocating in the direction.
An illumination lamp (second light source; fluorescent lamp) 21 for illuminating the light source, a photoelectric converter (photoelectric conversion means) 22 for receiving reflected light from the document O or transmitted light from the document O, reflected light from the document O or transmitted An optical system (light converging lens) 23 that guides light to the photoelectric converter 22 and a carriage 24 that supports these are configured.

The photoelectric converter 22 photoelectrically converts the reflected light or transmitted light from the original O to output the image of the original O as an electric signal. For example, a CCD.
Mainly composed of a line image sensor.

As shown in FIG. 3, the carriage 24 is guided by a guide rail 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 forward / reverse scan motor (for example, a pulse motor) 27 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. One point of the timing belt 30 is fixed to the carriage 24 via a fixing member 31. As a result, the carriage 24 moves linearly when the scanning motor 27 rotates forward or backward.

Further, on the upper surface of the end portion of the document placing table 2,
A scale 41 is provided as a reference surface on which the document O is placed.

Further, an original cover 62 which can be opened and closed by a hinge (not shown) is provided on the upper portion of the main body 1.
A white plate (or reflective paper) 63 is provided as a white cover for both reflection and transmission on the document mounting table 2 side of the document cover 62.
Is provided so that when a reflecting or transmissive original O is placed on the original placing table 2, the original O is closed and used to remove wrinkles, warps, and the like.

The white plate 63 has the functions of a transmission plate and a reflection plate by having a predetermined reflectance and a predetermined transmittance. For example, the reflectance is 80% to 90% and the transmittance is 2%.
The reflectance is 0% to 10%, and as an example, the reflectance is 85%.
%, And a transmittance of 15% is used. In this case, if the transmittance is high, a double image may be formed, and if the reflectance is high, the original O is not irradiated with the light of the illumination lamp 6 for transmission, and the above value is determined. ing.

FIG. 4 schematically shows the whole control system. That is, the CPU 51 as a control unit that controls the entire operation includes the operation panel 52, the standardization circuit 53, the memory 54, the light source control units 55 and 56, the motor drive units 57 and 5.
8 and an A / D converter 59, respectively.

The operation panel 52 is composed of keys for instructing the start of reading of a document and designating (selecting) whether the document to be read is for reading by reflected light or reading by transmitted light. The standardization circuit 53 is provided with a memory 54 and image data obtained by A / D converting the reflected light or the transmitted light from the document.
Standardization (shading correction, that is, variation correction of the photoelectric converter 22) is performed based on the reflection reference data or the transmission reference data stored in. The memory 54 stores reflection reference data obtained by A / D converting the reflection light from the reflection reference plate (not shown) or transmission reference data obtained by A / D conversion of the transmission light from the transmission reference plate (not shown). To do.

The light source control section 55 includes the illumination lamp 6
It is connected to and controls the lighting and the amount of light. The light source control unit 56 is connected to the illumination lamp 21,
The lighting control and the light amount control are performed. 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.

The operation of the above arrangement will be described below. 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, the original cover 62 is closed, and then a reading start key (not shown) is pressed.

Then, when the reflection mode is selected, the CPU 51 turns on the illumination lamp 21 and drives the scanning motor 27 to move the carriage 24. As a result, the light from the illumination lamp 21 is applied to the document O via the document mounting table 2. The reflected light from 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. The A / D converter 59 converts this analog signal into a digital signal.

The signal from the original 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 read out as an external device (not shown). Is output to.

When the transmission mode is selected, the CPU 51 turns on the illumination lamp 6 and drives the scanning motors 10 and 27 to drive the carriage 7,
The carriage 24 moves synchronously. 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 document O. The light transmitted through the original O is placed on the original table 2 and the optical system 23.
Is introduced to the photoelectric converter 22 via. This photoelectric converter 2
2 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 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 read as external data (not shown) by an external device (not shown). Is output to.

As described above, depending on the type of the original placed on the original placing table, either the reflected light from the original or the transmitted light can be read.

Further, when reading a reflection original or a transmission original, it is possible to read the original without wrinkles or warp by pressing the original cover.

In the above embodiment, the case where the illumination lamp 6 is turned off when the reflection original is read is described. However, the present invention is not limited to this, and the illumination lamp 21 and the illumination lamp 21 are turned on. The white plate 63 may be illuminated with the backlight by moving in synchronization. In this case, the white plate 63 becomes more positively white, and the total light amount increases, so that the contrast can be improved.

[0029]

As described above in detail, according to the present invention,
It is possible to provide an image reading apparatus which can arbitrarily and selectively read a document with either reflected light or transmitted light, and can read the document without wrinkles or warpage in either case.

[Brief description of drawings]

FIG. 1 is an external view showing the overall configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a side view schematically showing a main part of the configuration of the image reading apparatus according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a scanner moving mechanism of a document scanning unit of the image reading apparatus according to the embodiment of the present invention.

FIG. 4 is a block diagram schematically showing an overall control system of the image reading apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 2 Document Placement Table 3 First Scanner 4 Second Scanner 5 Document Scanning Section 6, 21 Illumination Lamp 10, 27 Scanning Motor 22 Photoelectric Converter 51 CPU 52 Operation Panel 62 Original Cover 63 White Plate

Claims (2)

[Claims] 1. An image reading apparatus for reading image information of a document placed on a document table, wherein a first light source for irradiating a document with light from above the document table and the document table A second light source that irradiates the original with light from below, and transmitted light from the first light source that has passed through the original or light from the second light source that has reflected the original. When the original is for transmission, the photoelectric conversion means for receiving the reflected light and converting it into an electric signal, the designation means for selectively designating whether the original is for reflection or transmission, A control means for turning on the first light source and turning on the second light source when the original is for reflection; and an optical characteristic of a predetermined transmittance and a predetermined reflectance. Place the reflective or transparent original placed on the original table. An image reading apparatus comprising: a white cover that also presses against. 2. The white cover has a reflectance of 80% to 9%.
The image reading apparatus according to claim 1, wherein the image reading apparatus has a transmittance of 0% and a transmittance of 20% to 10%.