JP2010141664A - Reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reading apparatus capable of increasing the permissible range of an angel between an image formation surface of a medium on which an image to be read is formed and an indication direction of a position for the image formation surface of the medium from the image reading apparatus. <P>SOLUTION: A pen nib 69a of an electronic pen 60 points out the position on the medium 50 on which a code pattern image is formed. An irradiation section 63 irradiates a predetermined range for the position of the medium 50 pointed out by the pen nib 69a with a light. Light-receiving sections 641a, 641b receive reflection lights of the lights irradiated from the irradiation section 63. A control section 61 selects any one of the plurality of light-receiving sections 641a, 641b, and uses an output image signal generated in response to the reflection light received by the selected light-receiving section to read position information or identification information included in the code pattern image recorded in the medium 50. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a reader.

  In recent years, attention has been paid to a technology that converts characters and figures written on paper into electronic data, transfers them to a personal computer, mobile phone, etc., and saves the written content as it is or sends it as an e-mail. Yes. In such a technique, a sheet on which a large number of fine dot images are formed in a certain arrangement pattern, and a pen-type reading device having an image sensor, for example, are used. When the user performs writing by using the pen-shaped reading device and successively specifying the position on the paper surface, a dot image on a locus connecting the specified positions is displayed on the image sensor of the reading device. Is read. The reading device specifies the position coordinates of the trajectory based on the mutual positional relationship between the read dot images. As a result, it is possible to generate an electronic document composed of written characters, graphics, etc., and to add characters, graphics, etc. to a predetermined electronic document (for example, see Patent Document 1). Further, Patent Document 2 proposes a barcode reader including a plurality of image sensors.

Japanese Patent Laying-Open No. 2004-94907 (pages 12-14) Japanese Patent Laid-Open No. 2-183879

  An object of the present invention is to widen an allowable range of an angle between an image forming surface of a medium on which an image to be read is formed and an indication direction of a position of the medium with respect to the image forming surface of the medium. .

  According to a first aspect of the present invention, there is provided a reading device that indicates in advance a position on a medium on which a read image to be read is formed, and a position on the medium that is instructed by the instruction section. An irradiation unit that irradiates light within a predetermined range, a plurality of light receiving units that are provided at different positions and receive reflected light of the light irradiated onto the medium by the irradiation unit, and the light receiving units Based on the received reflected light, an image to be read is picked up, an image pickup means for generating a signal representing the read image and a plurality of light receiving means are selected, and the selected light receiving means receives the light. And a selection output unit that outputs a signal representing the read image captured by the imaging unit based on reflected light.

  According to a second aspect of the present invention, there is provided the reading device according to the first aspect, wherein the plurality of light receiving units pass through different optical paths among the reflected lights of the light irradiated on the medium by the irradiation unit. The reflected light that is reflected in this way is provided at a position for receiving the reflected light.

  According to a third aspect of the present invention, there is provided the reading device according to the first or second aspect, wherein the plurality of light receiving means are two light receiving means provided at symmetrical positions with the pointing portion as a center. It has a certain configuration.

  According to a fourth aspect of the present invention, there is provided the reader according to the third aspect, wherein the irradiating means is one irradiating means provided at a position where the distance from each of the two light receiving means is equal. Have

  According to a fifth aspect of the present invention, there is provided the reader according to the third aspect, wherein the irradiating means is two irradiating means provided at symmetrical positions with the pointing portion as a center.

  According to a sixth aspect of the present invention, there is provided a reader according to any one of the first to fifth aspects, wherein the plurality of light receiving means are integrally formed.

  According to a seventh aspect of the present invention, in the configuration according to any one of the first to sixth aspects, the selection output means switches the light receiving means to be selected according to a predetermined selection order. .

  According to an eighth aspect of the present invention, in the configuration according to any one of the first to sixth aspects, the selection output unit sets the read recognition rate of the read image captured by the imaging unit. And calculating one of the plurality of light receiving units based on the calculated reading recognition rate.

  According to a ninth aspect of the present invention, in the reading apparatus according to any one of the first to sixth aspects, the selection output means detects an inclination angle of the self-reading apparatus, and based on the detected inclination angle. In this case, any one of the plurality of light receiving means is selected.

According to the first aspect of the present invention, in the reading apparatus that reads an image on the medium, the allowable angle between the pointing direction of the pointing unit and the medium surface can be widened.
According to the second aspect of the present invention, it is possible to widen the allowable range of the angle between the pointing direction of the pointing unit and the medium surface, and it is possible to reduce reading errors due to regular reflection.
According to claim 2 of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be further increased.
According to claim 3 of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be further widened.
According to claim 4 of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be further increased.
According to claim 5 of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be further increased.
According to the sixth aspect of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be widened, and the configuration can be simplified.
According to the seventh aspect of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be widened, and information on the medium can be read more accurately.
According to the eighth aspect of the present invention, the allowable range of the angle between the indication direction of the indication unit and the medium surface can be widened, and information on the medium can be read more accurately.
According to the ninth aspect of the present invention, it is possible to widen the allowable range of the angle between the indication direction of the indication unit and the medium surface, and it is possible to read information on the medium more accurately.

<A: First Embodiment>
<A-1: Configuration>
FIG. 1 is a diagram illustrating an example of a configuration of a system according to the present embodiment. In the drawing, an electronic pen 60 is an example of a reading device that has a function of writing characters and figures on a medium 50 such as paper and reads a code pattern image (read image) formed on the medium 50. The information processing apparatus 10 is a personal computer, for example, and is an example of a writing information generation apparatus that generates writing information representing writing contents in accordance with a signal output from the electronic pen 60.

  The code pattern image formed on the medium 50 is an image obtained by encoding identification information for identifying the medium 50 and position information indicating coordinate positions on the medium 50. Here, an example of the code pattern image formed on the medium 50 will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a code pattern image formed on the medium 50. The code pattern image represents the above-described identification information and position information by the mutual positional relationship between a plurality of dot-like dot images. As the areas where these dot images can be arranged, areas A1 to A9 are preliminarily provided. It has been established. In the example shown in FIG. 2, black areas A1 and A2 indicate areas where dot-like dot images are arranged, and hatched areas A3 to A9 indicate areas where dot images are not arranged. The identification information and the position information are expressed depending on which region the dot image is arranged. The code pattern image is formed on the entire medium 50 by an electrophotographic image forming apparatus (not shown) such as a printer. The code pattern image is read by the electronic pen 60, and the code pattern image is analyzed, whereby the position of the pen tip of the electronic pen 60 is detected.

  In addition to the above-described code pattern image, the medium 50 may be formed with an image such as a document or a figure intended to convey information to a person. Hereinafter, this image is referred to as a “document image”, but this is not limited to an image representing a document including text, and includes, for example, an image such as a picture, a photograph, or a graphic, and other images. When forming a code pattern image, the image forming apparatus uses K (black) toner to form an image, while when forming a document image, C (cyan), M (magenta), and Y (yellow). Image formation is performed using toner. On the medium 50, a document image and a code pattern image are superimposed and formed. As described above, since the toner is different between the code pattern image and the document image, the electronic pen 60 reads only the code pattern image. The “medium” in the present embodiment is not limited to so-called paper, and may be a plastic such as an OHP sheet, a sheet of other materials, or the like. Moreover, what is called electronic paper which can electrically rewrite display content may be used. In short, the medium 50 may be any medium on which at least a code pattern image is formed by an image forming apparatus or the like.

  The electronic pen 60 is a writing instrument having a function of writing characters, figures, and the like on the medium 50 and is a reading device that reads a code pattern image formed on the medium 50. The electronic pen 60 transmits information indicating the code pattern image read from the medium 50 to the information processing apparatus 10.

  Here, an example of a functional configuration of the electronic pen 60 will be described with reference to the drawings. FIG. 3 is a block diagram schematically illustrating an example of a functional configuration of the electronic pen 60. In the figure, a control unit 61 is a control unit that controls the overall operation of the electronic pen 60. The pressure sensor 62 is a detection unit that detects a writing operation by the electronic pen 60 by a pressure applied to the pen tip 69. The irradiation unit 63 is, for example, an LED, and is an example of an irradiation unit that irradiates the medium 50 with infrared light. The imaging unit 64 is an example of an imaging unit that captures an image on the medium 50 in accordance with the reflected infrared light emitted from the irradiation unit 63.

  The information memory 65 is a storage unit that stores identification information and position information. The communication unit 66 is a communication unit that controls communication with an external device. The battery 67 is a rechargeable power supply unit that supplies power for driving the electronic pen 60 to each unit. The pen ID memory 68 is a storage unit that stores identification information (pen ID) of the electronic pen 60. The pen tip 69 is a so-called pen shaft, and a pen tip 69a is provided at the tip. The pen tip 69a is an example of an instruction unit that indicates a position on the medium 50 on which a code pattern image (read image) to be read is formed when a writing operation is performed by the user. When the writing operation is performed by the user, the irradiation unit 63 irradiates light in a predetermined range with respect to the position on the medium 50 indicated by the pen tip 69a. The switch 75 is a switching unit that switches various settings. Each of these units is connected to the control unit 61.

  Next, the configuration of the imaging unit 64 will be described with reference to the drawings. 4 is an example of a side sectional view of the electronic pen 60, and FIG. 5 is an example of a transverse sectional view of the electronic pen 60 as viewed from above in FIG. In the figure, light receiving portions 641a and 641b are lenses, respectively, and are examples of light receiving means for receiving reflected light of light emitted from the irradiation portion 63. As shown in FIG. 5, the light receiving portions 641a and 641b are provided at different positions. The prism 642 reflects the light received by the light receiving unit 641a and the light receiving unit 641b and supplies the reflected light to the image sensor 643. In the following description, for convenience of description, when it is not necessary to distinguish between the light receiving portions 641a and 641b, they will be referred to as “light receiving portions 641”.

  The image sensor 643 captures a code pattern image based on the reflected light reflected by the prism 642, and outputs a signal representing the captured code pattern image. As shown in FIG. 5, the reflected light received by the light receiving unit 641a is incident on the lower region 643a of the image sensor 643 in the drawing, and the light receiving unit 641b receives the reflected light on the upper region 643b of the image sensor 643 in the diagram. The reflected light is incident. In the example shown in FIG. 5, the configuration in which the reflected light received by each of the plurality of light receiving units 641a and 641b is incident on different regions of one imaging element 643 is shown. However, the light receiving unit 641a receives the light. A configuration in which two image pickup devices, that is, an image pickup device that receives reflected light and an image pickup device that receives reflected light received by the light receiving unit 641b, are arranged side by side.

  Here, as the image sensor 643, a CMOS sensor having a sensitivity in the infrared region and capable of simultaneously transferring captured images is used. The image sensor 643 captures an image according to an image capture signal (frame rate) with a period of about 70 fps to 100 fps (frame per second). Accordingly, the irradiating unit 63 is configured to perform pulse lighting in synchronization with an image capture signal to the image sensor 643 in order to reduce power consumption. Here, a CMOS sensor is used as the image sensor, but the image sensor is not limited to a CMOS sensor, and other image sensors such as a CCD may be used.

  As shown in FIG. 5, the light receiving portion 641 a and the light receiving portion 641 b have their optical axes (indicated by a one-dot chain line in FIG. 5) on the surface on which an image is formed on the medium 50 (hereinafter referred to as the medium surface). They are arranged to intersect at different angles. Further, both the light receiving units 641a and 641b receive the reflected light of the light emitted from the irradiation unit 63. As described above, the light receiving units 641a and 641b are provided at positions where the reflected light reflected through the different optical paths among the light irradiated on the medium 50 by the irradiation unit 63 is received.

  Next, the positional relationship among the irradiation unit 63, the light receiving units 641a and 641b, and the pen tip 69a will be described with reference to FIG. FIG. 6 is a diagram schematically illustrating an example of the configuration of the electronic pen 60 viewed from the pen tip 69a side. In the example shown in FIG. 6, the two light receiving portions 641a and 641b are provided at symmetrical positions with the direction indicated by the pen tip 69a as the center. Moreover, in the example shown in FIG. 6, the irradiation part 63 is provided in the position where the distance between each of the two light-receiving parts 641a and 641b is equal. In other words, the light receiving parts 641a and 641b are provided at positions on a straight line that is substantially orthogonal to the straight line connecting the pen tip 69a and the irradiation part 63. The indication direction of the pen tip 69a is the indication direction of the position from the electronic pen to the medium surface when the user writes on the medium with the electronic pen, and the direction along the longitudinal direction of the electronic pen It is.

  Next, an example of a functional configuration of the control unit 61 will be described with reference to FIG. FIG. 7 is a block diagram illustrating an example of a functional configuration of the control unit 61. In the figure, a selection control unit 611 selects any one of a plurality of light receiving units 641 and outputs a signal representing a code pattern image captured by the image sensor 643 based on reflected light received by the selected light receiving unit 641. 7 is an example of a selection output unit that outputs to a code detection unit 612. Here, when the light receiving unit 641a is selected, the selection control unit 611 is based on reflected light received by the light receiving unit 641a (reflected light incident on the lower region 643a in FIG. 5 of the image sensor 643). The generated signal is output. On the other hand, when the light receiving unit 641b is selected, the selection control unit 611 generates based on the reflected light received by the light receiving unit 641b (reflected light incident on the region 643b on the upper side in FIG. 5 of the image sensor 643). The signal is output. Here, the selection control unit 611 switches the light receiving unit 641 to be selected in accordance with a predetermined selection order, but here, the light receiving unit 641 to be selected is switched alternately.

  The code detection unit 612 detects a code pattern image from a signal output from the selection control unit 611 (a signal representing a captured image). The data processing unit 613 extracts identification information and position information from the code pattern image detected by the code detection unit 612. The illumination control unit 614 transmits an illumination control signal for illuminating the irradiation unit 63 to the irradiation unit 63 to cause the irradiation unit 63 to perform pulse lighting. The imaging control unit 615 supplies the imaging unit 64 with an image capture signal synchronized with the pulse lighting transmitted to the irradiation unit 63.

  Next, an outline of the operation of the control unit 61 in the electronic pen 60 will be described. FIG. 8 is a diagram illustrating an output timing chart relating to an illumination control signal for controlling the pulse lighting of the irradiation unit 63, an image capture signal in the imaging unit 64, and an output image signal. When writing with the electronic pen 60 is started, the pressure sensor 62 connected to the pen tip 69 detects the writing operation. Thereby, the control part 61 starts the reading process of identification information and position information. First, the illumination control unit 614 of the control unit 61 transmits an illumination control signal (FIG. 8A) for turning on the irradiation unit 63 in a pulsed manner to the irradiation unit 63, and turns on the irradiation unit 63 in a pulsed manner.

  The imaging unit 64 captures an image on the medium 50 in synchronization with the image capture signal (FIG. 8B). At that time, the irradiation unit 63 is pulse-lit in synchronization with the image capture signal to the imaging unit 64. The imaging unit 64 captures an image on the medium 50 illuminated by the irradiation unit 63 that performs pulse lighting. Therefore, in the imaging unit 64, image signals (output image signal: FIG. 8C) relating to the image on the medium 50 illuminated by the irradiation unit 63 are generated in order.

  Output image signals sequentially generated by the imaging unit 64 are sent to the selection control unit 611. The selection control unit 611 is based on the output image signal output from the imaging unit 64, the output image signal generated based on the reflected light received by the light receiving unit 631a, and the reflected light received by the light receiving unit 631b. The generated output image signal is alternately output to the code detection unit 612. The code detection unit 612 that has received the output image signal processes the output image signal and detects a code pattern image from the image captured by the imaging unit 64. The code pattern image acquired by the code detection unit 612 is sent to the data processing unit 613. Upon receiving the code pattern image, the data processing unit 613 decodes the code pattern image and acquires identification information and position information embedded in the code pattern image.

<A-2: Operation>
Next, the operation of this embodiment will be described. When writing with the electronic pen 60 is started, the pressure sensor 62 connected to the pen tip 69 detects the writing operation. Thereby, the control part 61 starts the reading process of identification information and position information. First, the illumination control unit 614 transmits an illumination control signal for pulse-lighting the irradiation unit 63 to the irradiation unit 63 to turn on the irradiation unit 63 in pulses. Further, the imaging control unit 615 of the electronic pen 60 supplies the imaging unit 64 with an image capture signal synchronized with the pulse lighting transmitted to the irradiation unit 63. The imaging unit 64 captures the code pattern image based on the reflected light received by the light receiving unit 641a and the light receiving unit 641b in accordance with the image capture signal supplied from the imaging control unit 615, and the captured code pattern image is captured. The output image signal to be expressed is output to the selection control unit 611.

  Next, operations of the code detection unit 612 and the data processing unit 613 will be described with reference to the flowchart shown in FIG. The code detection unit 612 receives an output image signal representing an image on the medium 50 from the selection control unit 611 (step S601). The code detection unit 612 performs processing for removing noise included in the output image signal (step S602). Here, the noise includes variations in CMOS sensitivity, noise generated by an electronic circuit, and the like. What processing is performed to remove noise is determined according to the characteristics of the imaging system of the electronic pen 60. For example, sharpening processing such as blurring processing or unsharp masking can be applied. Next, the code detection unit 612 detects a dot pattern (a position of the dot image) from the image (step S603). Further, the code detection unit 612 converts the detected dot pattern into digital data on a two-dimensional array (step S604). For example, on a two-dimensional array, a position where there is a dot is converted to “1”, and a position where there is no dot is converted to “0”. The digital data (code pattern image) on the two-dimensional array is transferred from the code detection unit 612 to the data processing unit 613.

  The data processing unit 613 detects a dot pattern composed of a combination of two dots shown in FIG. 2 from the delivered code pattern image (step S605). For example, the dot pattern can be detected by moving the boundary position of the block corresponding to the dot pattern on the two-dimensional array and detecting the boundary position where the number of dots included in the block is two. When the dot pattern is detected in this manner, the data processing unit 613 detects the identification code and the position code based on the type of the dot pattern (step S606). Thereafter, the data processing unit 613 acquires the identification information by decoding the identification code, and acquires the position information by decoding the position code (step S607). In the processing shown in FIG. 9, when the light amount received by the light receiving unit 641 is too small, or conversely, when the received light amount is too large, the dot pattern is not detected from the captured image, and the electronic pen 60 is identified. Information and position information may not be acquired. When the identification information and the position information cannot be acquired as described above, the data processing unit 613 acquires information indicating a reading failure instead of the identification information and the position information.

  The electronic pen 60 transmits the identification information and position information acquired by the processing of FIG. 9 to the information processing apparatus 10. At this time, if the reading of the identification information and the position information fails, the electronic pen 60 transmits information indicating the reading failure to the information processing apparatus 10. The information processing apparatus 10 receives identification information and position information from the electronic pen 60, and generates writing information based on the received position information. When the information processing apparatus 10 receives information indicating a reading failure from the electronic pen 60, the information processing apparatus 10 generates writing information by interpolating the identification information and position information before and after the information.

  By the way, when writing is performed with respect to the medium 50 with the electronic pen 60, the angle between the electronic pen 60 and the medium 50 sequentially changes with the user's writing operation. At this time, for example, when the angle between the electronic pen 60 and the medium 50 has the positional relationship shown in FIG. 10, the depth of focus of the light receiving unit 641 a becomes deep, so the aperture needs to be reduced. The amount of reflected light received at 641a is reduced. For this reason, in the case of the positional relationship illustrated in FIG. 10, the light receiving unit 641a cannot secure the necessary minimum amount of light and cannot perform accurate imaging, and the electronic pen 60 may not obtain identification information and position information. . On the other hand, since the depth of focus of the light receiving unit 641b is shallow, the aperture can be increased, and imaging is performed even when the amount of light emitted from the irradiation unit 63 is small. Therefore, the electronic pen 60 can obtain identification information and position information from this captured image. As described above, in the case of the positional relationship illustrated in FIG. 10, there is a possibility that the light receiving unit 641a does not receive a sufficient amount of light, but the light receiving unit 641b arranged on the opposite side secures a sufficient amount of light. As described above, even when the angle between the electronic pen 60 and the medium 50 is wide as illustrated in FIG. 10, a sufficient amount of light is secured by any one of the light receiving units 641.

As another example, for example, when the angle between the electronic pen 60 and the medium 50 has the positional relationship shown in FIG. 11, the focal depth of the light receiving unit 641a is opposite to the case illustrated in FIG. On the other hand, the depth of focus of the light receiving portion 641b becomes deeper as it becomes shallower. For this reason, since it is necessary to reduce the aperture in the light receiving unit 641b, the minimum necessary amount of light for imaging cannot be secured, and imaging may not be performed appropriately. Even in this case, a sufficient amount of light is secured in one of the light receiving portions 641.
Thus, even if the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is large, a sufficient amount of light for imaging is ensured in any of the plurality of light receiving units 641. .
In particular, in the present embodiment, since the plurality of light receiving units 641 are alternately selected, even if any of the light receiving units 641 does not receive the reflected light suitably, the reading failure of the code pattern image continues. It does not occur.

  Further, as described above, when writing is performed on the medium 50 with the electronic pen 60, the angle between the electronic pen 60 and the medium 50 sequentially changes with the writing operation. As shown in FIG. 22, in the conventional electronic pen 160, the angle between the electronic pen and the medium may be close to 90 degrees. Since the electronic pen is required to have an elongated shape like a pen that is a normal writing instrument, the irradiating unit 163 and the light receiving unit 1641 are disposed at relatively close positions in a direction orthogonal to the longitudinal direction of the electronic pen. I have to. Because of such arrangement restrictions, when the angle between the electronic pen and the medium is close to 90 degrees, as shown in FIG. 18, the reflected light of the light emitted from the irradiation unit 163 is mainly positive. The reflected light component is received by the light receiving unit 1641. At this time, depending on the type of toner that forms the code pattern image, the intensity of the reflected light is too strong, and the reflected light that exceeds the upper limit of the received light intensity that can be covered by the light receiving unit 1641 reaches the light receiving unit 1641 so that the code pattern image is accurately displayed. There are cases where it cannot be read. On the other hand, the plurality of light receiving units 641 in the electronic pen 60 of the present embodiment are provided such that the light receiving directions (optical axes) of the reflected light with respect to the irradiation direction of the irradiation unit 63 are different from each other. At the same time, the regular reflection light component is not mainly received by the light receiving unit 641. Therefore, even if one of the light receiving units 641 mainly receives the regular reflection light component, the light receiving units 641 are alternately selected, so that the failure of reading the code pattern image does not continue.

  From the above, the code pattern image is read by the electronic pen 60 even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is relatively large such as close to 180 °. In addition, even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is relatively small such as close to 90 °, the code pattern image is read by the electronic pen 60. That is, the allowable range of the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is widened.

<B: Second Embodiment>
Next explained is the second embodiment of the invention. FIG. 12 is a diagram schematically illustrating an example of the configuration of the electronic pen 60B according to the present embodiment as viewed from the pen tip 69a side. FIG. 12 is a diagram corresponding to FIG. 6 in the first embodiment described above. The electronic pen 60 </ b> B according to the present embodiment is different from the electronic pen 60 according to the first embodiment described above in that irradiation units 63 a and 63 b are provided instead of the irradiation unit 63. In the following description, the same components as those of the electronic pen 60 described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 12, the electronic pen 60B includes two irradiation units 63a and 63b. Further, the plurality of light receiving portions 641a and 641b are provided at different positions. The light receiving unit 641a is provided at a position for receiving the reflected light of the light emitted from the irradiation unit 63a. On the other hand, the light receiving unit 641b is provided at a position for receiving the reflected light of the light emitted from the irradiation unit 63b. As described above, the light receiving units 641a and 641b are provided at positions that receive the reflected light reflected through the different optical paths among the reflected light of the light irradiated by the irradiation units 63a and 63b, respectively.

  In this embodiment, the control unit 61 of the electronic pen 60 </ b> B alternately selects the light receiving units 641 and alternately selects the irradiation units 63 a and 63 b as the light receiving unit 641 is selected. That is, the illumination control unit 614 of the electronic pen 60B alternately supplies illumination control signals to the irradiation units 63a and 63b, and turns on the irradiation units 63a and 63b alternately. More specifically, the control unit 61 turns on the irradiation unit 63a corresponding to the light receiving unit 641a when the light receiving unit 641a is selected, and corresponds to the light receiving unit 641b when selecting the light receiving unit 641b. The irradiation unit 63b is pulse-lit.

  Also in this embodiment, the code pattern image is read by the electronic pen 60B even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is relatively large such as close to 180 °. In addition, even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is relatively small, such as 90 °, the code pattern image is read by the electronic pen 60B. That is, the allowable range of the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is widened.

<C: Third Embodiment>
Next explained is the third embodiment of the invention. FIG. 13 is a diagram schematically illustrating an example of the configuration of the electronic pen 60C according to the present embodiment as viewed from the pen tip 69a side. FIG. 13 is a diagram corresponding to FIG. 6 in the first embodiment described above. The electronic pen 60 </ b> C according to the present embodiment is different from the electronic pen 60 according to the first embodiment described above in that irradiation units 63 c and 63 d are provided instead of the irradiation unit 63. In the following description, the same components as those of the electronic pen 60 described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 13, the electronic pen 60C includes two irradiation units 63c and 63d. Further, the plurality of light receiving portions 641a and 641b are provided at different positions. The light receiving unit 641a is provided at a position for receiving the reflected light of the light emitted from the irradiation unit 63d. On the other hand, the light receiving unit 641b is provided at a position for receiving the reflected light of the light emitted from the irradiation unit 63c. As described above, the light receiving units 641a and 641b are provided at positions that respectively receive the reflected light reflected through the different optical paths among the reflected light of the light irradiated by the 63c and 63d. Further, as shown in the figure, the two irradiation parts 63c and 63d are provided at symmetrical positions around the pen tip 69a.

  In this embodiment, the control unit 61 of the electronic pen 60C alternately selects the light receiving units 641 and alternately selects the irradiation units 63c and 63d as the light receiving unit 641 is selected. That is, the illumination control unit 614 of the electronic pen 60C alternately supplies illumination control signals to the irradiation units 63c and 63d, and turns on the irradiation units 63c and 63d alternately. More specifically, when selecting the light receiving unit 641a, the control unit 61 pulses the irradiation unit 63c corresponding to the light receiving unit 641a, while selecting the light receiving unit 641b corresponds to the light receiving unit 641b. The irradiation part 63c is pulse-lit.

  Also in this embodiment, the code pattern image is read by the electronic pen 60C even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is relatively large such as close to 180 °. In addition, even when the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is close to 90 °, the code pattern image is read by the electronic pen 60C. That is, the allowable range of the angle between the indication direction of the pen tip 69a and the medium surface of the medium 50 is widened.

<D: Modification>
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. An example is shown below. In addition, you may combine each following aspect.
(1) In the above-described embodiment, a plurality of light receiving portions may be integrally formed. Specifically, for example, the configuration illustrated in FIG. 14 may be used. FIG. 14A is an example of a side cross-sectional view of the electronic pen 60D of this embodiment, and FIG. 14B is an example of a cross-sectional view of the electronic pen 60D as viewed from above in FIG. 14A. In FIG. 14, the imaging unit 64B is configured integrally with two light receiving units (corresponding to the light receiving units 641a and 641b in the first embodiment) and two prisms that guide light received by these light receiving units. By using the imaging unit 64B, the configuration of the electronic pen can be simplified.

(2) In the first embodiment described above, the configuration including one irradiation unit 63, two light receiving units 641a and 641b, and one image sensor 643 has been described. However, the number of irradiation units and image sensors is not limited thereto. Absent. For example, as illustrated in FIG. 15A, one irradiating unit 63, two light receiving units 641a and 641b, and two imaging elements 643a and 643b may be provided. Further, for example, the configuration illustrated in FIG. In the example shown in FIG. 15B, the light received by the light receiving unit 641a is reflected by the mirror 644a and the prism 644c and supplied to the imaging device 643c, and the light received by the light receiving unit 641b is reflected by the mirror 644b. The light is reflected by the prism 644c and supplied to the image sensor 643c. In the first embodiment described above, the area of one imaging element 643 is divided into two areas. However, the present invention is not limited to this. As shown in FIG. 15C, a plurality of irradiation units 63a and 63b are used. In contrast, one region of one image sensor 643d may be used in combination. Moreover, it is good also as a structure which comprises not only these but three image pick-up elements, for example.

(3) In the above-described embodiment, the electronic pen having the two light receiving units 641a and 641b has been described. However, the number of the light receiving units included in the electronic pen is not limited to two, and may be larger. In short, it is only necessary that the electronic pen has a plurality of light receiving portions provided at different positions.

(4) In the first embodiment described above, the irradiation unit 63 is provided at a position where the distances between the two light receiving units 641a and 641b are equal to each other, but the irradiation unit 63 and the light receiving unit 641a, The positional relationship with 641b is not limited to this.

  Further, in the above-described embodiment, the plurality of light receiving units 641 are provided at positions that respectively receive the reflected light reflected through the different optical paths among the reflected light of the light irradiated to the medium 50 by the irradiation unit 63. However, the positional relationship between the light receiving unit 641 and the irradiation unit 63 is not limited to this.

(5) In the above-described embodiment, the selection control unit 611 alternately switches the light receiving unit 641 to be selected. However, the selection mode by the selection control unit 611 is not limited to this. For example, the selection control unit 611 The selected light receiving unit may be switched so that the selection ratio of the light receiving unit 641a and the light receiving unit 641b is 2: 1. Further, for example, the selection control unit 611 may randomly switch between the light receiving unit 641a and the light receiving unit 641b according to a predetermined random function. In short, the selection control unit 611 may switch the light receiving unit 641 to be selected in accordance with a predetermined selection order.

  The selection mode by the selection control unit 611 is not limited to that described above. For example, the code detection unit 612 calculates the read recognition rate of the code pattern image captured by the imaging unit 64, and the selection control unit 611 calculates One of the plurality of light receiving units 641 may be selected based on the read recognition rate. The configuration of the control unit of the electronic pen 60 in this case will be described with reference to the drawings.

  FIG. 16 is a diagram illustrating an example of a functional configuration of the control unit 61B in this aspect. FIG. 16 corresponds to FIG. 7 in the first embodiment described above. The configuration of the control unit 61B shown in FIG. 16 is different from the control unit 61 shown in FIG. 7 in the first embodiment described above in that the processing contents of the selection control unit and the code detection unit are different. Therefore, in the following description, the same code | symbol is attached | subjected about the structure and process similar to 1st Embodiment mentioned above, and the description is abbreviate | omitted.

  In FIG. 16, the code detection unit 612B detects a code pattern image based on the output image signal supplied from the imaging unit 64, and also detects a detection accuracy signal indicating the detection accuracy (reading recognition rate) of the detected code pattern image. Is generated. More specifically, the code detection unit 612B performs pattern matching with a plurality of code pattern images prepared in advance for the detected code pattern image. Thereby, the similarity to each of the code pattern images prepared in advance for each code pattern image is calculated. Then, a detection accuracy signal representing the calculated similarity of each code pattern image is generated and sent to the selection control unit 611B.

  Note that the code detection unit 612B may divide the output image signal received from the imaging unit 64 into a plurality, and generate a detection accuracy signal from the divided output image signal. That is, the code detection unit 612B may divide the output image signal received from the imaging unit 64 into a plurality of parts and detect a code pattern image for each of the divided output image signals. Then, the code detection unit 612B may perform the above-described pattern matching on each code pattern image and integrate the results to generate a detection accuracy signal representing the similarity of each code pattern.

  The selection control unit 611B compares the detection accuracy signals received from the code detection unit 612B, and selects the light receiving unit 641 corresponding to the code pattern image indicating high detection accuracy from the detection accuracy signals. That is, in this aspect, the code detection unit 612B and the selection control unit 611B each calculate the read recognition rate of the code pattern image captured by the imaging unit 64, and a plurality of light receptions based on the calculated read recognition rate. It functions as a selection output unit that selects one of the units 641. In this way, in the cycle for acquiring the identification information and the position information, the light receiving unit 641 determined to have the highest detection accuracy of the code pattern image is selected and used.

  Here, when the identification information and position information acquisition cycle is executed, the light receiving unit selection cycle may be executed at all times or in a predetermined time cycle. That is, the code detection unit 612B calculates detection accuracy at all times or in a predetermined time cycle, generates a detection accuracy signal, and sends the detection accuracy signal to the selection control unit 611B. Then, the selection control unit 611B monitors whether or not the detection accuracy signal received from the code detection unit 612B falls below a predetermined level (threshold value). Then, when the received detection accuracy signal falls below the threshold value, the light receiving unit selection cycle described above may be executed again to reset the light receiving unit 641.

  In this aspect, when writing with the electronic pen 60 is performed, the light receiving unit 641 that is determined to have high detection accuracy of the code pattern image is selected and used. Thereby, even when various changes in the situation occur when the user writes with the electronic pen 60, the identification information and the position information are acquired from the medium 50.

(6) As another example of the selection mode of the light receiving unit 641, for example, the light receiving unit 641 may be selected based on the tilt angle of the electronic pen 60. The configuration of the control unit in this case will be described with reference to the drawings. FIG. 17 is a diagram illustrating an example of a functional configuration of the control unit 61C in this aspect. FIG. 17 corresponds to FIG. 7 in the first embodiment described above. The configuration of the control unit 61C shown in FIG. 17 is different from the control unit 61 shown in FIG. 7 in the first embodiment described above in that the inclination detection unit 615 is different from the processing of the selection control unit. It is. In the following description, the same reference numerals are given to the same configurations and processes as those in the first embodiment described above, and the description thereof is omitted.

  In FIG. 17, the inclination angle detection unit 616 is an example of an inclination angle detection unit, and includes a sensor that detects an inclination angle of the electronic pen 60 from a predetermined plane (for example, a horizontal plane). The selection control unit 611C selects the light receiving unit 641 based on the detection value (level of the tilt detection signal) in the tilt angle detection unit 616. That is, since the reflected light incident on the imaging unit 64 changes from the code pattern image formed on the medium 50 depending on the incident angle of the light that irradiates the medium 50, the selection control unit 611C responds to the inclination of the electronic pen 60. Thus, the optimum light receiving unit 641 is selected. In other words, in this aspect, the tilt angle detection unit 616 and the selection control unit 611C detect the tilt angle of the electronic pen 60, and based on the detected tilt angle, select one of the plurality of light receiving units 641. It functions as a selection output means for selecting.

  When writing with the electronic pen 60 is started, the pressure sensor 62 connected to the pen tip 69 detects the writing operation. Accordingly, the tilt angle detection unit 616 starts detecting the tilt angle of the electronic pen 60 and generates a tilt detection signal representing the tilt angle of the electronic pen 60. Then, the generated inclination detection signal is sent to the selection control unit 611C. Upon receiving the tilt detection signal, the selection control unit 611C selects the light receiving unit 641 according to the level of the tilt detection signal.

(7) As another example of the selection mode of the light receiving unit, for example, the light receiving unit 641 may be selected based on both the detection accuracy of the code pattern image and the tilt angle of the electronic pen. In this case, for example, the selection control unit may weight each of the detection accuracy of the code pattern image and the inclination angle of the electronic pen 60, and may select the light receiving unit 641 in consideration of the weighting.

(8) In the above-described embodiment, a configuration in which imaging is always performed in both the two areas 643a and 643b of the image sensor 643, and the selection control unit 611 outputs an output image signal corresponding to the selected area to the subsequent stage. It was. Instead of this, the imaging element 643 may perform imaging based on reflected light received by the selected light receiving unit 641. An example of the configuration and an example of the operation in this case will be described with reference to the drawings. FIG. 18 is a block diagram illustrating an example of a functional configuration of the control unit 61D in this aspect, and FIG. 19 is a flowchart illustrating a processing flow of the electronic pen in this aspect. In the example illustrated in FIG. 18, a configuration in the case where the electronic pen includes two irradiation units 63a and 63b will be described. In this example, as in the second embodiment described above, the light receiving unit 641a receives the reflected light of the light emitted from the irradiation unit 63a, and the reflected light of the light emitted from the light receiving unit 641b from the irradiation unit 63b. Is received. In the following description, an area on the medium 50 imaged by the irradiation light of the irradiation unit 63a is defined as an imaging area Ra (see FIG. 18), and an area on the medium 50 imaged by the irradiation light of the irradiation unit 63b is defined as an imaging area Rb. (See FIG. 18).

  The selection control unit 611D illustrated in FIG. 18 selects one of the plurality of imaging regions Ra and Rb according to the signal supplied from the code detection unit 612D (that is, selects one from the plurality of light receiving units 641). Then, an imaging region setting signal for setting the selected imaging region is supplied to the illumination control unit 614D and the imaging control unit 615D (step S701 in FIG. 19). The illumination control unit 614D selects the irradiation unit 63 corresponding to the imaging region setting signal supplied from the selection control unit 611D, and applies the illumination control signal for pulse-lighting the selected irradiation unit 63 to the irradiation unit 63 selected. The selected irradiation unit 63 is pulse-lit. In addition, the imaging control unit 641D supplies an image capture signal corresponding to the imaging region setting signal supplied from the selection control unit 611D to the imaging unit 64. The imaging element 643 captures an image based on any reflected light of the light receiving unit 641 according to the selection result of the selection control unit 611D, and outputs an output image signal indicating the imaging result to the code detection unit 612 (step S702). .

  The code detection unit 612D detects a code pattern image based on the output image signal supplied from the image sensor 643 and outputs the code pattern image to the data processing unit 613, and the detection accuracy (reading recognition rate) of the detected code pattern image. A detection accuracy signal is generated and supplied to the selection control unit 611D (step S703). The generation process of the detection accuracy signal performed by the code detection unit 612D is the same as the process performed by the code detection unit 612B shown in the modified example (6), and detailed description thereof is omitted here.

The selection control unit 611D determines whether or not to end imaging (step S704). When the imaging ends (step S704; YES), the processing ends. On the other hand, when shooting is continued (step S704; NO), the selection control unit 611D determines whether the detection accuracy signal received from the code detection unit 612D is below a predetermined reference value (step S705). When the detection accuracy signal falls below a predetermined reference value (step S705; YES), the imaging region is switched to another imaging region (that is, the selected light receiving unit 641 is switched) (step S706). When the detection accuracy signal received from the code detection unit 612D is not less than a predetermined reference value, the selection control unit 611D continues to use the selected imaging region without switching the imaging region. In step S705, the selection control unit 611D may determine whether or not the occurrence frequency of regular reflection is equal to or higher than a predetermined frequency, and both the detection accuracy and the occurrence frequency of regular reflection are determined. You may make it determine.
As described above, in this aspect, the imaging device 643 captures only one of the plurality of optical paths, and when the detection accuracy of the captured code image falls below a predetermined reference value, Switch to another.

(9) In the example shown in FIG. 18 and FIG. 19, the selection control unit 611D switches the light receiving unit 641 based on the detection accuracy signal detected from the code detection unit 612D. The selection control unit may be switched to another area every time shooting is performed. An example of the configuration and an example of the operation in this case will be described with reference to the drawings. FIG. 20 is a block diagram illustrating an example of a functional configuration of the control unit 61E in this aspect, and FIG. 21 is a flowchart illustrating a processing flow of the electronic pen in this aspect. 20 and FIG. 21 correspond to FIG. 18 and FIG. 19 shown in the above-described modification (8), respectively, and in the following description, the same configuration and processing as shown in FIG. 18 and FIG. About the thing, the same code | symbol is provided and the description is abbreviate | omitted.

  The selection control unit 611E switches the shooting area to another area every time shooting is performed. That is, as shown in FIG. 21, the selection control unit 611E does not determine the detection accuracy (without performing the process of step S705 shown in FIG. 19) and continues shooting (step S704; NO). Then, the imaging region is switched (that is, the selected light receiving unit 641 is switched) (step S706). That is, in this aspect, the selection control unit 611E alternately switches and selects a plurality of optical paths, and the image sensor 643 performs imaging using the selected optical path.

(10) In the first to third embodiments described above, the electronic pen that writes characters, graphics, and the like on the medium 50 has been described. However, the electronic pen is not limited to this, for example, a pointing device (mouse) function or A stylus function that reads information (for example, command information) recorded corresponding to an area on the medium may be provided.

(11) In the above-described embodiment, an LED that emits infrared light is used as the irradiation unit 63. However, the irradiation unit 63 is not limited to this, and an LED having different characteristics may be used. In short, the irradiating unit 63 only needs to irradiate the code pattern image formed on the medium 50 with light that can be read by the reflected light.

(12) In the first embodiment described above, information that uniquely identifies a medium is used as identification information. However, the identification information is not limited to this, and for example, information that uniquely identifies an electronic document is used as identification information. You may make it use. When information that uniquely identifies a medium is used as exemplified in the first embodiment, different identification information is assigned to different media when a plurality of copies of the same electronic document are formed. On the other hand, when information that uniquely identifies an electronic document is used as identification information, the same identification information is given to different media when the same electronic document is formed.

  In the above-described embodiment, the code pattern image representing the position information and the identification information is read. However, the information represented by the code pattern image is not limited to the position information and the identification information. For example, the information represents text data or a command. May be. Alternatively, the image may represent only position information.

(13) In the image forming apparatus described above, the code pattern image is formed using K toner. This is because the K toner has a larger amount of infrared light absorption than the C, M, and Y toners, and the code pattern image can be read by the electronic pen 60. However, the code pattern image can also be formed using special toner. Here, as the special toner, an invisible toner having a maximum absorption rate of 7% or less in the visible light region (400 nm to 700 nm) and an absorption rate of 30% or more in the near infrared region (800 nm to 1000 nm) is exemplified. . Here, “visible” and “invisible” are not related to whether they can be recognized visually. “Visible” and “invisible” are distinguished based on whether or not an image formed on the formed medium can be recognized by the presence or absence of color development due to absorption of a specific wavelength in the visible light region. Further, “invisible” includes those that have some color developability due to absorption of a specific wavelength in the visible light region but are difficult to recognize with human eyes. The invisible toner preferably has an average dispersion diameter in the range of 100 nm to 600 nm in order to increase the near infrared light absorption capability necessary for machine reading of an image.
Further, the image forming apparatus is not limited to the electrophotographic system, and any other system such as an ink jet system may be used.

(14) A computer program executed by the control unit 61 of the electronic pen 60 according to the above-described embodiment includes a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, and a semiconductor. It may be provided in a state stored in a computer-readable recording medium such as a memory. It is also possible to download to the electronic pen 60 via a network such as the Internet. Various devices other than the CPU can be applied as the control means for performing the above-described control. For example, a dedicated processor or the like may be used.

It is a figure which shows an example of the whole structure of a writing information processing system. It is a figure which shows an example of the content of a code pattern image. It is a block diagram which shows an example of a functional structure of an electronic pen. It is a sectional side view which shows an example of a structure of an electronic pen. It is a cross-sectional view which shows an example of a structure of an electronic pen. It is a figure which shows an example of the structure seen from the pen point of the electronic pen. It is a block diagram which shows an example of a functional structure of the control part of an electronic pen. It is the figure which showed the output timing chart regarding an illumination control signal, an image capture signal, and an output image signal. It is the figure which showed the flowchart which showed the operation | movement in the code | cord | chord detection part and data processing part of an electronic pen. It is a figure which shows an example of the angle between the instruction | indication direction of an electronic pen, and a medium surface. It is a figure which shows an example of the angle between the instruction | indication direction of an electronic pen, and a medium surface. It is a figure which shows an example of the structure seen from the pen point of the electronic pen. It is a figure which shows an example of the structure seen from the pen point of the electronic pen. It is sectional drawing which shows an example of a structure of an electronic pen. It is a figure which shows an example of a structure of an electronic pen. It is a block diagram which shows an example of a functional structure of the control part of an electronic pen. It is a block diagram which shows an example of a functional structure of the control part of an electronic pen. It is a block diagram which shows an example of a functional structure of the control part of an electronic pen. It is the figure which showed the flowchart which shows the flow of a process of an electronic pen. It is a block diagram which shows an example of a functional structure of the control part of an electronic pen. It is the figure which showed the flowchart which shows the flow of a process of an electronic pen. It is a sectional side view which shows an example of a structure of an electronic pen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Information processing apparatus, 50 ... Medium, 60, 60B, 60C, 60D, 160 ... Electronic pen, 61 ... Control part, 62 ... Pressure sensor, 63 ... Irradiation part, 64 ... Imaging part, 64B ... Imaging unit, 611 ... Selection control unit, 612 ... code detection unit, 612 ... data processing unit, 614 ... illumination control unit, 615 ... imaging control unit, 616 ... tilt angle detection unit, 616 ... illumination switching unit, 641 ... light receiving unit, 642 ... prism, 643 ... Image sensor.

Claims (9)

An instruction unit for instructing a position on a medium on which a read image to be read is formed;
Irradiating means for irradiating light in a predetermined range with respect to the position on the medium instructed by the instruction unit;
A plurality of light receiving means which are respectively provided at different positions and receive reflected light of the light irradiated on the medium by the irradiation means;
An imaging unit that captures an image to be read based on reflected light received by each of the light receiving units, and generates a signal representing the image to be read;
Selection output means for selecting one of the plurality of light receiving means and outputting a signal representing the read image captured by the imaging means based on reflected light received by the selected light receiving means. A reading device. The plurality of light receiving means are provided at positions that respectively receive reflected light reflected through different optical paths among the reflected light of the light irradiated to the medium by the irradiating means. The reading device according to claim 1.   3. The reading apparatus according to claim 1, wherein the plurality of light receiving units are two light receiving units provided at symmetrical positions around the instruction unit. 4. The reading device according to claim 3, wherein the irradiating unit is one irradiating unit provided at a position where the distance from each of the two light receiving units is equal. The reading device according to claim 3, wherein the irradiating means is two irradiating means provided at symmetrical positions with the pointing unit as a center. The reading device according to any one of claims 1 to 5, wherein the plurality of light receiving units are integrally formed. The reading apparatus according to claim 1, wherein the selection output unit switches the light receiving unit to be selected in accordance with a predetermined selection order. The selection output unit calculates a reading recognition rate of each read image captured by the imaging unit, and selects one of the plurality of light receiving units based on the calculated reading recognition rate. The reading apparatus according to any one of claims 1 to 6. The selection output means detects an inclination angle of the reading device, and selects any one of the plurality of light receiving means based on the detected inclination angle. The reading device according to item 1.

Images