JP4938697B2 - Line scanner device - Google Patents

Description

  The present invention relates to a line scanner device that irradiates a reading object with light and reads reflected light.

  As a device for reading a color image, a pattern, or the like, a color scanner that irradiates a reading object with light and reads the reflected light is widely used (for example, see Patent Document 1). An apparatus that reads and records a pattern of an object and displays it is also known (see Patent Document 4).

A fluorescent lamp is generally used as the light source of the color scanner, but a simple scanner is also known in which a red light emitting diode is used for both light emission and light reception (see Patent Documents 2 to 5). In general, a light emitting diode has a basic element structure equivalent to that of a light receiving element, and is used as a light receiving element that receives light having a wavelength shorter than the light emitting wavelength of the light emitting diode by reversing the bias to the pn junction. be able to. In particular, by using an inexpensive red light emitting diode as a light receiving element, a small, inexpensive, and simple structure scanner can be realized.
Japanese Patent Laid-Open No. 9-135327 Patent registration No. 2823436 JP 2001-1119063 A JP 2001-197253 A JP 2004-264440 A

  However, when the light emitting diode is used for both light emission and light reception, the object is read only with red, and the color of the object cannot be known.

  An object of the present invention is to provide an inexpensive and simple line scanner that can read a color pattern using a light emitting diode as a light receiving element.

  The line scanner of the present invention is a line scanner that scans an object to be read and reads a color pattern of the object, and includes a red light emitting diode, a green light emitting diode, and a blue light emitting diode for light emission along the scanning direction. A red light-emitting diode is provided as an element that receives light emitted from each light-emitting diode and reflected by an object to be read.

  A plurality of red light emitting diodes for light emission and red light emitting diodes for light reception are arranged in a row along the scanning direction, the green light emitting diodes are arranged in a staggered manner with one row of red light emitting diodes in between, and the blue light emitting diodes are The green light emitting diodes are preferably disposed between a pair of staggered and green light emitting diodes facing each other to form a row with the green light emitting diodes.

  The red light emitting diode for light emission and the red light emitting diode for light reception may be separate, but it is also possible to adopt a configuration in which these are combined and switched to time division.

  Other light emitting diodes can be arranged in a direction different from the scanning direction, and the other light emitting diodes can be used to determine the timing of scanning in the scanning direction with respect to the movement of the reading object along that direction.

  In general, a light emitting diode has a basic element structure equivalent to that of a light receiving element, and can be used as a light receiving element that receives light having a wavelength shorter than the light emitting wavelength of the light emitting diode by reversing the bias to the pn junction. Can do. That is, the blue light emitting diode is sensitive to blue light, the green light emitting diode is sensitive to green and blue light, and the red light emitting diode is sensitive to blue, green and red light. Therefore, by using a red light emitting diode as a light receiving element, it is possible to have sensitivity to light from any of the blue, green, and red light emitting diodes, and read the intensity of the reflected light from each object. Thus, the color pattern of the object can be known.

[Constitution]
1 and 2 are diagrams showing a first embodiment of the present invention. FIG. 1 shows an example of an arrangement of light emitting diodes, and FIG. 2 shows a configuration of a drive circuit.

  This line scanner is a device that scans an object to be read and reads a color pattern of the object, and emits red light emitting diodes R00, R02, R04,..., Green light emitting diodes G00, G01 for light emission along the scanning direction. , G02,..., And blue light emitting diodes B00, B01, B02,... , ... are provided.

  Here, each set of three light emitting diodes of red, green and blue for light emission and one red light emitting diode for light reception is defined as a light emitting diode group 10, and this light emitting diode group 10 is arranged along the scanning direction. It is assumed that a plurality of light emitting diode units 10A are arranged. In the adjacent light emitting diode group 10, it is desirable to reverse the arrangement of the green light emitting diode and the blue light emitting diode. That is, the light emitting red light emitting diodes R00, R02, R04,... And the light receiving red light emitting diodes R01, R03, R05,. , G01, G02,... Are arranged in a staggered manner with one row of red light emitting diodes R00, R01, R02,. The green light emitting diodes G00, G01, G02,... Are arranged between a pair of staggered and green light emitting diodes G00, G01, G02,. Form.

  Light emitting red light emitting diodes R00, R02, R04,..., Green light emitting diodes G00, G01, G02,... And blue light emitting diodes B00, B01, B02,. The light receiving circuit 14 is connected to the red light emitting diodes R01, R03, R05,. FIG. 2 shows only one light emitting diode group 10 and a corresponding circuit configuration. The light emitting circuits 11, 12, 13 and the light receiving circuit 14 are controlled by the control circuit 15.

[Color judgment]
The color determination will be described using the operations of the red light emitting diode R00, the green light emitting diode G00, the blue light emitting diode B00, and the red light emitting diode R01 as an example. A light emitting diode for light emission is composed of a combination of the three primary colors of light (red, blue, green). When the object is irradiated with the red light emitting diode R00, the green light emitting diode G00, and the blue light emitting diode B00, for example, when the object surface is red, the red light is reflected and the blue light and the green light are absorbed. Similarly, when the object surface is green or blue, green light or blue light is reflected, and the others are absorbed. The red light emitting diode R00, the green light emitting diode G00, and the blue light emitting diode B00 emit light in time series, and the red light emitting diode R01 reads the intensity of the reflected light of each RBG.

  By sequentially performing this reading operation, color scanning can be performed in one direction (in the above example, the horizontal direction in FIG. 1). That is, the light emitting diode group 10 is sequentially operated from the left side to the right side in FIG. After the end of the scan, the object or the light emitting diode unit 10A is moved in the direction perpendicular to the scan direction to perform the next slacking. By repeating this, a full scan of the object is executed.

In a light emitting diode, electrons in a conduction band and holes in a valence band are recombined and emitted as photons (light). Between the emission wavelength λ (nm) of photons and the band gap ε (eV), λ = hc / ε = (1.2398 / ε (eV)) 10 ³ (nm)
h: Planck constant, c: speed of light. Therefore, the emission wavelength (color) is determined by the type of semiconductor. In the case of a red light emitting diode, the forbidden band width is about 1.9 eV.

On the other hand, the light emitting diode also functions as a light receiving element due to the phenomenon of light absorption, which is the reverse process. That is, when the incident light energy Eg is larger than the forbidden band energy ε, Eg ≧ ε, the electrons in the valence band are excited to the conduction band, and the photons are absorbed.
Eg = hc / λ ≧ ε
Due to the generation of electrons in the conduction band and holes in the valence band excited by light absorption, a voltage difference is generated between the anode and the cathode of the light emitting diode. The stronger the light (the more light absorption), the greater the voltage difference. In the case of a red light emitting diode, if the band gap ε = 1.9 eV, light absorption occurs when an incident light wavelength λ ≧ 650 nm is incident. That is, when viewed as a light receiving element, the red light emitting diode has sensitivity to blue, green and red. However, it has no sensitivity to infrared light. Therefore, it is possible to read the intensity of the reflected light from the blue light emitting diode, the green light emitting diode, and the red light emitting diode.

[Second Embodiment]
3 and 4 are diagrams showing a second embodiment of the present invention. FIG. 3 shows an arrangement example of light emitting diodes, and FIG. 4 shows a configuration of a drive circuit.

  This line scanner is a device that scans an object to be read and reads a color pattern of the object, and emits red light emitting diodes R10, R11, R12,..., Green light emitting diodes for each pixel along the reading line. G10, G11, G12,..., And blue light emitting diodes B10, B11, B12,..., And the red light emitting diode described above as an element that receives the light emitted from each light emitting diode and reflected by the object to be read Also used as R11, R12,.

  Here, as in the first embodiment, each set of three light emitting diodes of red, green and blue for light emission and one red light emitting diode for light reception is defined as a light emitting diode group 20, and this light emission It is assumed that a plurality of diode groups 20 are arranged along the scanning direction to constitute the light emitting diode unit 20A. However, a red light emitting diode is also used between adjacent light emitting diode groups 20. FIG. 3 shows a state where the red light emitting diode R14 is also used.

  The light emitting and light receiving circuits 21 and 24 are connected to the red light emitting diodes R11, R12,..., And the light emitting circuits 22, 23 are respectively connected to the green light emitting diodes G10, G11,. Connected. The light emitting / light receiving circuits 21 and 24 and the light emitting circuits 22 and 23 are controlled by the control circuit 24. In FIG. 4, the light emitting / receiving circuits 21 and 24 are shown as separate circuits, but these are shared between adjacent light emitting diode groups 20. FIG. 4 shows only one light emitting diode group 20 and a circuit configuration corresponding thereto.

[Color judgment]
The color determination in the present embodiment is performed by sequentially switching each red light emitting diode between light emission and light reception. That is, first, the red light emitting diode R10, the green light emitting diode G10, and the blue light emitting diode B10 emit light in time series, and the red light emitting diode R11 reads the intensity of the reflected light of each RBG. Next, the red light emitting diode R11, the green light emitting diode G11, and the blue light emitting diode B11 emit light in time series, and the red light emitting diode R12 reads the intensity of the reflected light of each RBG. Next, the red light emitting diode R12, the green light emitting diode G12, and the blue light emitting diode B12 emit light in time series, and the red light emitting diode R13 reads the intensity of the reflected light of each RBG. In this way, one column is scanned from the left side to the right side in FIG. The object is scanned by moving the object to be scanned in a direction perpendicular to the scanning direction, that is, by moving the object or the light emitting diode unit 20A.

[Third Embodiment]
FIG. 5 is a diagram showing a third embodiment of the present invention, and shows an example of the arrangement of light emitting diodes. In this arrangement example, the light emitting diode group 30 equivalent to the above-described light emitting diode group 10 or 20 is arranged in the first direction to constitute the light emitting diode unit 30A, and the light emitting diode LED1 in a direction different from the first direction. , LEDs 2,... Are arranged to constitute a light emitting diode unit 40. As the light-emitting diodes LED1, LED2,..., Red light-emitting diodes are sufficient if they are used only for position detection as will be described later. Can also be done. In this example, the two light emitting diode units 30A and 40 are arranged in a T-shape in which the arrangement direction of the light emitting diode units 30A is a vertical direction and the light emitting diode unit 40 is a horizontal direction.

  The light emitting diode unit 40 is used to determine the scanning timing of the light emitting diode unit 30A with respect to the movement of the reading object along the direction. This will be described in detail below.

[Operation]
6 is a diagram for explaining an operation of reading an object using the light emitting diode array shown in FIG. 5, and FIG. 7 is a flowchart of the operation. The end of the object 50 to be read is placed on the intersection of the light emitting diode units 30A and 40, and the object 50 is moved along the light emitting diode units 40 in the vertical arrangement (in the order of the light emitting diodes LED1, LED2,...). During this time, sampling scans are repeated at regular time intervals by the light emitting diode units 30A and 40 (steps S1 and S3). Thus, as the object 50 moves, the front end position is detected by the light emitting diode units 40 arranged vertically (step S2), and the object 50 is scanned horizontally by the light emitting diode units 30A arranged horizontally. The scan result when the tip position of the object 30 is detected by the light emitting diode unit 40 is stored in the memory (step S4).

[Speed guide]
Simultaneously with the above-described scanning control, a speed guide can be shown to the user. Referring to FIG. 1 again, for example, when an object passes through the LED 1 of the light emitting diode unit 40, the LED 2 (or all of LEDs 0 to 2) is caused to emit light. Subsequently, when the object passes through the LED 2, the LED 3 (or all of the LEDs 0 to 3) is caused to emit light. The user advances the scanning movement with the LED emission as a guide. If the light emitting diode LED does not move, the head position of the light emitting diode LED is not moved forward. If the moving speed exceeds the light emitting diode LED lighting position, the user turns on the light emitting diode LED ahead. By waiting for the movement until it is done, the user himself / herself is assisted in controlling the movement speed.

  The light emitting diode LED is capable of high-speed dimming control, and scans by switching the control to the light receiving mode during the extinction period. When the scanning is completed, the light emitting diode LED is turned on in the light emission mode. By switching this at a high speed, it is possible to receive the light while it remains lit.

  By scanning scan control by speed and speed guide instructions to the user, the vertical and horizontal dimensions of the object can be accurately measured, and the color pattern on the two-dimensional plane can be read.

[Scan by trigger]
In the above example, scanning in the horizontal direction is performed at regular time intervals, but this can also be performed using the detection of the tip position of the object 50 by the light emitting diode unit 30 as a trigger. That is, when the tip of the object 50 is first on the intersection of the light emitting diode units 30A and 40, the object 50 is moved, and the signal level of the light emitting diode LED1 changes from “low” to “high” as a trigger. Scanning is performed by the light emitting diode units 30A in the horizontal arrangement. In the same manner, scanning is sequentially performed using a change in the signal level of the light emitting diodes LED2, LED3,.

  As mentioned above, although embodiment of invention was described, this invention can be variously changed unless the summary is changed. For example, the light emitting diode units 10A and 20A have a configuration in which three rows of light emitting diodes are arranged in one row as one set, but a plurality of sets of three rows can be arranged.

  In addition, each of the three primary color light emitting diodes of red, green, and blue is not individually configured, and each of the three primary color light emitting diodes is mounted on a single chip, and the individual red light emitting diodes. You may make it form the thing corresponded to 10 A of light emitting diode units. In the above-described embodiment, the red light emitting diodes are arranged in one row, and the green light emitting diodes and the blue light emitting diodes are alternately arranged in the column direction on both sides thereof, but the green light emitting diodes are parallel to the red light emitting diodes. The blue light emitting diodes may be arranged so as to be parallel to the red light emitting diodes. As described above, when the red, green, and blue are arranged in a total of three rows, or in the arrangements shown in the first, second, and third embodiments, the red light emitting die auto row is in the center. However, depending on the form of use, it may be an upper row or a lower row other than the center.

  The line scanner of the present invention can be used in any field where it is necessary to read a color pattern of an object. Furthermore, since this line scanner uses a light emitting diode as a light emitting element, an apparatus as shown in Patent Document 5, that is, an application for displaying information read by a scanner using an afterimage due to light emission of the light emitting diode. Can also be used. In particular, in the configuration shown in the second embodiment, the resolution can be matched between reading and afterimage display by using almost all red light emitting diodes for light emission.

It is a figure which shows the example of an arrangement | sequence of the light emitting diode in the 1st Embodiment of this invention. It is a figure which shows the structure of the drive circuit in the 1st Embodiment of this invention. It is a figure which shows the example of an arrangement | sequence of the light emitting diode in the 2nd Embodiment of this invention. It is a figure which shows the structure of the drive circuit in the 2nd Embodiment of this invention. It is a figure which shows the example of an arrangement | sequence of the light emitting diode in the 3rd Embodiment of this invention. It is a figure explaining the operation | movement which reads an object using the example of an arrangement | sequence of the light emitting diode in the 3rd Embodiment of this invention. It is a flowchart of the operation | movement which reads an object using the example of an arrangement | sequence of the light emitting diode in the 3rd Embodiment of this invention.

Explanation of symbols

R00 to R07, R10 to R17 Red light emitting diodes G00 to G03, G10 to G16 Green light emitting diodes B00 to B03, B10 to B16 Blue light emitting diodes LED1 to LED10 Light emitting diodes 10, 20 Light emitting diode groups 10A, 20A, 30 Light emitting diode units 11 -13, 22, 23 Light emitting circuit 14 Light receiving circuit 21, 24 Light emitting / light receiving circuit 15, 24 Control circuit

Claims (4)

It is a line scanner that scans the reading object and reads the color pattern of the object,
Provided with red light emitting diode, green light emitting diode and blue light emitting diode for light emission along the scanning direction,
A line scanner comprising a red light emitting diode as an element for receiving light emitted from each light emitting diode and reflected by an object to be read.   The light emitting red light emitting diodes and the light receiving red light emitting diodes are arranged in a plurality of rows along the scanning direction, and the green light emitting diodes are arranged in a staggered manner with the one row of red light emitting diodes interposed therebetween, 2. The blue light emitting diodes are disposed between a pair of staggered and green light emitting diodes facing the green light emitting diodes arranged in a staggered manner to form a row with the green light emitting diodes. The line scanner described.   3. The line scanner according to claim 1, wherein the red light emitting diode for light emission and the red light emitting diode for light reception are used in combination and switched to time division.   Other light emitting diodes are arranged in a direction different from the scanning direction, and the other light emitting diodes are used to determine the timing of scanning in the scanning direction with respect to the movement of the reading object along the different direction. The line scanner according to claim 1, 2 or 3.

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