JP2005311948A - Image scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image scanner with small deterioration in image and a small noise influence on the exterior, by making an operation optical unit wireless in the image scanner and also a circuit unit, which is fixed in the image reader, wireless. <P>SOLUTION: Power feeding to a mobile optical unit is carried out without a cable or by using a mechanical component, such as a guide rail, and data transmission is carried out by wireless transmission. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus capable of reading an original image with an electrical analog image signal and transferring the digitally converted image signal to an external device.

  2. Description of the Related Art Conventionally, in this type of document image reading apparatus, a read document image is obtained from digital data after the reflected light of the document by the illumination means is read by the image sensor and then digitally converted by the A / D converter or from the image sensor. The output analog signal is sent as it is to the image processing means that performs some kind of image processing, or to the communication means with an external device (mainly PC), by the control means that controls the entire apparatus. . At this time, it is common to use a connecting cable such as FFC or wire (for example, see Patent Document 1).

At the same time, the illuminating means, the image sensor and the A / D converter are usually fed by using the same connection cable as described above or by preparing a separate cable.
JP 2001-77983 A

  However, in the above-described prior art, when an original image is transmitted as an analog signal output from an image sensor, image deterioration due to the connection cable cannot be avoided. In addition, when digital signals are transmitted through the connection cable after being digitally converted by an A / D converter, the influence of noise on a peripheral portion from a digital signal having a higher electrical signal level than that of an analog signal is large. It was necessary to consider means for avoiding the problem. In addition, when the same power supply cable as the digital data transmission cable is used as the illumination means, the image sensor, and the A / D converter, the influence from the data signal and the control signal is unavoidable, and the power supply is separately dedicated to the power supply. Even when this cable is used, there is no influence from the data signal or the control signal, but the apparatus configuration becomes large and wasted.

  Therefore, in the present invention, the object is achieved by providing an image reading apparatus according to any one of the following items (1) to (10).

(1) In an image reading apparatus that is connected to an external device and reads a document image,
Illumination means for illuminating the image original;
An image sensor that converts the read document image into an electrical image signal;
An A / D converter for converting the image signal into a digital signal;
Moving means for moving a relative position between the image original and the image sensor;
Power supply means for supplying power to the illumination means, the image sensor and the A / D converter;
Communication means for transferring an image signal digitally converted by the A / D converter to an external device;
Wireless communication means inside the apparatus for wirelessly communicating the digitally converted image signal to the communication means;
An image reading apparatus capable of wirelessly communicating a document image read by the image sensor to the communication unit.
(2) The image reading apparatus according to claim 1, wherein the wireless communication unit is a communication unit that enables data communication using infrared rays as in the IrDA standard.
(3) The image reading apparatus according to claim 1, wherein the wireless communication means is communication means that enables data communication using radio, as in the Bluetooth standard.
(4) The image reading apparatus according to claim 1, wherein the power supply means is a cable mainly used for connection to an operating part, such as a flexible flat cable (hereinafter FFC).
(5) The image reading apparatus according to claim 1, wherein the power supply means is a metal mechanical part that holds an operating part, such as a guide rail, and is not a connection cable or the like originally intended for electrical connection. apparatus.
(6) The image reading apparatus according to (1), wherein the power supply means is a power supply means that uses a transformer or the like and enables cableless power supply.
(7) The image reading apparatus according to (1), wherein the wireless communication means performs only one-way transmission to the communication means with the external device.
(8) The image reading apparatus according to claim 1, wherein the wireless communication means performs bidirectional transmission / reception with the communication means with the external device.
(9) The image reading apparatus according to claim 2, wherein the wireless communication means has a plurality of channels to enable higher-speed infrared data communication.
(10) The image reading apparatus according to (3), wherein the wireless communication means has a plurality of channels to enable higher-speed wireless data communication.

(Function)
According to the present invention as described above, while the original image read by the image sensor and converted into digital data by the A / D converter is transmitted to the image processing means or the communication means with the external device via the wireless communication means, The power supply to the image sensor and A / D converter is not required to be equipped with a cable such as FFC or wire, and has good anti-noise performance that does not deteriorate the quality of the read image, and there is little noise influence on the surroundings. An image reading apparatus can be realized.

  As described above, according to the present invention, the image reading apparatus is configured such that the power feeding means to the moving optical unit is cableless or uses mechanical parts such as a guide rail, and data transmission is performed by wireless communication such as infrared rays. It is possible to wirelessly connect the operating unit part and the circuit part fixed in the device, and there is less image degradation and less external noise influence than the conventional FFC or wire connection configuration. A reading device can be realized.

(Example 1)
FIG. 1 shows an example of an image reading apparatus used in an image reading system according to the present invention, and is a cross-sectional view of the image reading apparatus.

  In FIG. 1, 1 is a scanner body, 2 is a document presser, and 3 is a read document. The scanner 1 is connected to a host computer (hereinafter referred to as a host) by an interface cable (not shown). Further, the scanner 1 has a moving optical unit 4, an original table glass 5, electric boards 6 and 35, a pulse motor 7, an endless belt 8, pulleys 9 and 10, a gear train 11, a guide rail 12, and a white reference plate 13. Yes. The optical unit 4 and the pulse motor 7 are electrically connected by cables (not shown). The optical unit 4 is slidably mounted on the guide rail 12 by the mounting means 14. Further, the placing means 14 is fixed to the endless belt 8.

  The moving optical unit 4 includes a light source 15, a plurality of reflecting mirrors 16 and 17, a combining mirror 18 that is an image combining unit, an imaging lens 19, and a line sensor 20 that is an imaging unit.

  A document image reading operation of the scanner 1 will be briefly described. The reading operation in the scanner 1 is started by a read command from the host. The scanner 1 turns on the light source 15 of the optical unit 4, reflects the reflected light by a plurality of mirrors 16, 17, and simultaneously receives a plurality of images read through the composite mirror 18 in the line sensor 20. Are synthesized so as to have the same offset as the offset of the sensor unit for each color arranged in the image, and then imaged on the line sensor via the imaging lens 19, thereby image of one line in the main scanning direction Read. Further, by driving the endless belt 8 with the power of the pulse motor 7 by the gear train 11, the optical unit 4 placed on the guide rail 12 by the placing means 14 moves on the guide rail in the sub-scanning direction of the arrow X. To move. The scanner 1 repeats reading the above-described line image in the main scanning direction while moving the optical unit 4 in the sub-scanning direction. The scanner 1 can scan the entire surface of the platen glass by moving the optical unit 4 of FIG. 1 to a position indicated by a dotted line while performing a reading operation. However, it is possible to read a partial image of a document on the platen glass in accordance with the content of a read command from the host. In that case, with respect to the read image range designated by the host, the pixel range to be adopted among the sensor outputs in the main scanning direction and the movement range of the optical unit in the sub scanning direction are controlled as described later on the electric board. It is realized by defining by means.

  An embodiment of each functional block will be described below with reference to FIG. 2 and with reference to FIG. 2 below. First, in the optical unit 4, 24 is a light source lighting circuit for lighting the light source 15, and when a cold cathode tube is used as the light source 5, it becomes a so-called inverter circuit. In the electric board 6, reference numeral 25 denotes a motor drive circuit for the pulse motor 7, which outputs an excitation switching signal for the pulse motor 7 in response to a signal from a system controller 26 that is a system control means of the scanner 1. Reference numerals 27R, 27G, and 27B denote analog gain adjusters that can variably amplify the analog image signal output from the line sensor 20. An A / D converter 28 converts the analog image signal output from the variable analog gain adjuster 27 into a digital image signal. Reference numeral 29 denotes an image processing means for performing image processing such as image compression for offset correction, shading correction, digital gain adjustment, color balance adjustment, masking, resolution conversion in the main and sub-scanning directions for a digital image signal. Do. A line buffer 30 is a part for temporarily storing image data, and is realized by a general-purpose random access memory. Reference numeral 31 denotes an interface unit for communicating with the host 15. Here, it is realized by a SCSI controller, but other interfaces such as Centronics and USB can also be adopted. A offset RAM 32 is used as a working area when performing image processing. The offset RAM 32 is used for correcting the offset between the RGB lines because the line sensor 20 has the RGB line sensors arranged in parallel with a predetermined offset. The offset RAM also temporarily stores various data such as shading correction. Here, it is realized by a general-purpose random access memory. A gamma RAM 33 stores a gamma curve and performs gamma correction. A system controller 26 stores the entire sequence of the scanner, and performs various controls in accordance with commands from the host 21. A system bus 34 connects the system controller 26, the image processing means 29, the line buffer 30, the interface unit 31, the offset RAM 32, and the gamma RAM 33, and includes an address bus and a data bus. Reference numeral 33 denotes a communication system conversion bridge including wireless communication transmission / reception means inside the scanner, communication means 22 with an external host, and conversion means for converting the communication system between the wireless transmission / reception means. As a result, the image data subjected to the image processing is buffered in the line buffer 30, and then transmitted to the communication system conversion bridge 33 mounted on the electric board 35 via the wireless communication 36 by the wireless interface unit 31. Sent.

  The communication system conversion bridge 33 performs only communication system conversion regardless of the data contents. Data is transmitted to the host 21 via the communication means 22. The command from the host 21 to the scanner 1 is also converted by the communication system conversion bridge 33 in the reverse procedure, and transmitted to the system controller 26 via the wireless communication means 36.

  FIG. 3 is a view of the scanner 1 as viewed from above, and FIG. 4 is a simple circuit diagram. As described above, the movable optical unit 4 moves on the guide rail 12. In the figure, the power supplied from the outside is supplied to one of the guide rails 12 through the electric board 35, and the other of the guide rails 12 is connected to GND. At the same time, the electrical board 6 mounted on the movable optical unit 4 and each guide rail 12 are electrically connected while being operable, so that the movable optical unit 4 can be connected via the guide rail 12. It is possible to supply power to the electric board 6 mounted on the board.

  As described above, by supplying power to the electric substrate 6 mounted on the movable optical unit 4 via the guide rail 12, it is not necessary to supply power via a cable such as FFC or wire, and further, reading is performed by the line sensor 20. The A / D converter 28 performs image processing on the original image converted to digital data, wirelessly transmits it via the wireless communication means 36, and then transmits it to the host via the communication means conversion bridge 33. A completely wireless / cableless structure can be formed between the optical unit 4 and the electric board 35. Thereby, it is possible to realize an image reading apparatus that does not deteriorate the image and has less noise influence from the digital signal to the power source and the like.

(Example 2)
Hereinafter, an embodiment of Example 2 will be described with reference to FIG. On the electric board 6 mounted on the moving optical unit 4, a line sensor 20, a variable analog gain adjuster 27, an A / D converter 28, a plurality of wireless communication means 36 and a power supply receiving means are mounted.

  Since the outline of the document image reading operation of the scanner 1 in the second embodiment is substantially the same as that of the first embodiment, only the differences will be described. In the first embodiment, the original image is read by the line sensor 20, converted into digital data by an A / D converter, subjected to various image processing, and then communicated on the electric board 35 from the movable optical unit 4 by wireless communication. Data is transmitted to the system conversion bridge, and then transmitted to the host 21 via the communication means 22. Also, the command from the host 21 to the scanner 1 is converted by the communication system conversion bridge 33 in the reverse procedure, and transmitted to the system controller 26 via the wireless communication means 36. Therefore, the wireless communication means is bidirectional communication. On the other hand, in the second embodiment, immediately after the original image is read by the line sensor 20 and converted into digital data by the A / D converter, wireless reception on the electric board 35 from the moving optical unit 4 is performed by the wireless transmission means. Data transfer to the means. Here, the line sensor 20 and the A / D converter can be started from the system controller by adopting a configuration in which image reading can be started directly from the outside of the scanner by a button arranged on the movable optical unit 4 or a remote control receiving means. The image reading operation can be started without the need for the above control. As a result, the wireless communication means between the moving optical unit 4 and the electric board 35 may have a one-way communication function, and the moving optical unit 4 side can be a transmitting means and the electric board 35 side can be a receiving means.

  Here, if the wireless communication means is configured with IrDA which is an infrared communication standard, the data communication rate is 4 Mbps at the maximum. As a result, the data communication rate of the entire apparatus becomes 4 Mbps. Therefore, in this embodiment, a plurality of wireless transmission / reception means are mounted, and signals for each of the RGB colors from the line sensor 20 are output independently, and then the image data for each of the RGB colors of the image data from the A / D converter is independently provided. By transmitting, the data rate can be increased.

  FIG. 5 is a detailed view of the power supply means in the present embodiment. A transformer circuit is configured between the electric substrate 6 disposed on the moving optical unit 4 and the circuit disposed on the guide rail 12. As a result, power can be stably supplied to the electric substrate 6 when the movable optical unit 4 is not performing an image reading operation and during the image reading operation. However, since power is supplied by a transformer circuit, it is necessary to supply AC power, and it is necessary to configure a rectifier circuit from AC to DC on the electric board 6, and an example thereof is shown in FIG. As described above, it is possible to supply power to the electric board 6 mounted on the movable optical unit 4 without using a cable such as FFC or a wire and without using the guide rail 12 as in the first embodiment. Become.

  As described above, it is not necessary to supply power via a cable such as FFC or wire by supplying power to the electric board 6 mounted on the movable optical unit 4 by using a transformer circuit, and further guide rails 12 are provided. The document image read by the line sensor 20 and converted into digital data by the A / D converter 28 is transmitted wirelessly via a plurality of wireless communication means 36, and then subjected to image processing and communication. With the configuration of transmitting to the host via the means, it is possible to form a completely wireless / cable structure between the moving optical unit 4 and the electric board 35. As a result, it is possible to realize a high-speed image reading apparatus that does not deteriorate the image and has little noise influence on the power supply from the digital signal.

1 is an internal configuration diagram of a document image reading apparatus according to Embodiment 1. FIG. 1 is a hardware configuration diagram of Embodiment 1. FIG. FIG. 3 is a configuration diagram of a power feeding unit according to the first embodiment. FIG. 3 is a circuit diagram of a power feeding unit according to the first embodiment. FIG. 6 is a hardware configuration diagram of Embodiment 2. FIG. 6 is a configuration diagram of a power feeding unit according to the second embodiment. FIG. 6 is a circuit diagram of a power feeding unit according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scanner main body 2 Original pressing 3 Reading original 4 Moving optical unit 5 Original plate glass 6 Electric board 7 Pulse motor 8 Endless belt 9, 10 Pulley 11 Gear train 12 Guide rail 13 White reference board 14 Mounting means 15 Light source 16, 17 Reflection Mirror 18 Composite mirror 19 Imaging lens 20 Line sensor 21 Host 22 Host communication means 24 Light source control circuit 25 Motor drive circuit 26 Image processing working memory 27R, 27G, 27B Analog gain adjuster 28 A / D converter 29 System controller And image processing means 31 wireless interface 33 communication system conversion bridge 34 system system bus 36 wireless communication means 37 host interface 38 wireless transmission part 39 wireless reception part 101 power supply means from the guide rail to the electric board 6 02 power supply means from the electric substrate 35 to the guide rail 103 power circuit 105 feeding transformer 106 power cable

Claims (10)

In an image reading device that connects to an external device and reads a document image,
Illumination means for illuminating the image original;
An image sensor that converts the read document image into an electrical image signal;
An A / D converter for converting the image signal into a digital signal;
Moving means for moving a relative position between the image original and the image sensor;
Power supply means for supplying power to the illumination means, the image sensor and the A / D converter;
Communication means for transferring an image signal digitally converted by the A / D converter to an external device;
Wireless communication means inside the apparatus for wirelessly communicating the digitally converted image signal to the communication means;
An image reading apparatus capable of wirelessly communicating a document image read by the image sensor to the communication unit.   The image reading apparatus according to claim 1, wherein the wireless communication unit is a communication unit that enables data communication using infrared rays as in the IrDA standard.   The image reading apparatus according to claim 1, wherein the wireless communication unit is a communication unit that enables data communication using radio, as in the Bluetooth standard.   The image reading apparatus according to claim 1, wherein the power feeding unit is a cable mainly used for connection to an operating unit, such as a flexible flat cable (hereinafter referred to as FFC).   2. The image reading apparatus according to claim 1, wherein the power supply means is a metal mechanical part that holds an operating part, such as a guide rail, and is not a connection cable or the like originally intended for electrical connection.   The image reading apparatus according to claim 1, wherein the power supply unit is a power supply unit that uses a transformer or the like and enables cableless power supply.   The image reading apparatus according to claim 1, wherein the wireless communication unit performs only one-way transmission to the communication unit with the external apparatus.   The image reading apparatus according to claim 1, wherein the wireless communication unit performs bidirectional transmission / reception with the communication unit with the external apparatus.   3. An image reading apparatus according to claim 2, wherein said wireless communication means has a plurality of channels to enable higher-speed infrared data communication.   4. The image reading apparatus according to claim 3, wherein said wireless communication means has a plurality of channels to enable higher-speed wireless data communication.

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