JP2741760B2 - Optical follower - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical image reading apparatus that is used in a facsimile machine and a copying machine and reads a color image described on a document or the like.

[Prior Art] This type of optical reading apparatus includes a plurality of types of light-emitting elements (hereinafter, referred to as LEDs) each emitting light of a different color, and a first optical component for irradiating an original with light emitted from the light-emitting elements. (For example, a light-emitting side fiber or an irradiation mirror) and a second optical component (1) that receives and transmits reflected light from a document.
An optical system including a light-receiving fiber as an example), a light-receiving element (hereinafter also referred to as a PD) for receiving light transmitted through the light-receiving fiber, and a detecting unit for detecting an output of the light-receiving element in the optical system. A member having a constant reflectance at a position of the original with respect to the optical system is disposed relative to the optical system, the LED is made to emit light, and the output of the PD is detected by the detecting means; Control means for adjusting the light amounts of the plurality of types of LEDs or the outputs of the PD so that the output of the PD becomes a predetermined value.

In the optical image input device, in order to accurately read a color image on a document, a plurality of types of LEs each emitting light of a different color so that the output signal from the PD is at a constant level.
It was necessary to adjust the brightness of D. Conventionally, a so-called white level check method has been used as this adjustment method. This is because the light emitted from each LED is emitted to the white reference material (white member) via the light emitting side fiber, the light received through the light receiving side fiber is received by the PD, and the PD outputs a signal corresponding to the light amount. In this case, the detection means determines the brightness of each LED so that the input signal is constant.

[Problems to be Solved by the Invention] Conventionally, this type of white level check performs each LE on a white reference material placed in a reading unit before starting document reading.
Performed every D. In the case of this optical reading apparatus, after a white level check is performed, a light emitting element that emits a plurality of colors selectively emits light to irradiate an image on a document placed in a reading unit and receive light. The element receives the reflected light from the document, and the color of the image on the document is determined based on the detection result of the detecting means connected to the light receiving element. When the color of the image is determined based on the detection result of the detection means, the detection result corresponding to the light emitting element of a certain color is preferentially used, and the detection result corresponding to the light emitting element of another color is used. Used subordinately.

For example, in the case of an optical reading device that has red and yellow LEDs and distinguishes red, white, and black on a document, the yellow LED
Detects the presence of white and other colors (black and red) on the document by preferentially using the detection result when the light is illuminated, and uses the detection result when the red LED irradiates based on that to determine the The upper red and black colors are determined. However, when the color of the original is a gray original that is not white and the yellow portion of the original is illuminated by a yellow LED for determining the presence of the color, the output voltage of the light receiving element is used as a reference voltage used in the detecting means. And become very close. Further, when the red LED is irradiated, the output of the light receiving element receiving the red reflected light also becomes very close to the reference voltage, and it may be determined that there is a red image on the document.

The present invention has been made in order to solve the above-mentioned drawbacks of the related art. After performing a white level check with a reference member having a constant reflectance, a light emitting element emits light using data from the white level check. Alternatively, when the light receiving element outputs, the light emitting element of a specific color is corrected so as to be relatively small data as compared with the preset data, so that the specific color of the image on the document surface can be accurately read. And an optical reading device.

[Means for Solving the Problems] In order to achieve this object, according to the present invention, as shown in FIG. 1, a plurality of types of light emitting elements L ₁ L ₂ respectively emitting light of a plurality of colors. And an optical component T for receiving light emitted to a reading unit R for reading the light emitted from the light emitting element, and an optical component T for transmitting reflected light from the reading unit to the light receiving element. System, detecting means K for detecting the output of the light receiving element, and arranging means C ₁ for arranging a member W having a constant reflectance at a position of the reading section with respect to the optical system relative to the optical system. And arranging the arranging means to emit light of each of the plurality of types of light emitting elements after the arranging of the arranging means and detecting the output of the light receiving element by the detecting means so that the input of the detecting means has a predetermined value. Light intensity or light reception And adjusting means C ₂ to adjust the output of the child, the stores the output of light intensity or the light receiving element of the adjusted light emitting device according to adjusting means and a storage means C _3, the light emitting stored in said storage means Optical reading that selectively emits the plurality of types of light emitting elements using the light amount of the element or the output of the light receiving element and reads a color image on a document placed in a reading unit based on a detection result of the detection unit. In the apparatus, an original M
And illuminating one of the plurality of types of light emitting elements to determine the presence of an image on a document based on the detection result of the detection means using the output stored in the storage means. 1 discriminating means C ₄ , the document M is arranged in the reading section, and when the other light emitting element of the plurality of types of light emitting elements emits light, the output is stored relatively to the output of the storage means. A second determination step of determining the presence of an image of a color corresponding to the emission color of the other light-emitting element in the image on the document based on the detection result of the detection means together with the determination result of the first determination means using a small output. and means C _5.

[Operation] In the optical reading device having the above configuration, a detection result corresponding to a light emitting element of a certain color is preferentially used to determine an image on a document, and a light emitting element of another color is used. When the corresponding detection result is used subordinately to determine the color of the image, an output relatively smaller than the output stored in the storage means is used for the light emitting element used subordinately. Therefore, even if there is a slight variation in the detection result of the light emitting element used preferentially, the detection result of the light emitting element used preferentially is used so as not to determine that the color exists in the detection result. Erroneous determination of an image of a color corresponding to the emission color of the used light emitting element is unlikely to occur.

[Embodiment] Hereinafter, a specific embodiment of a red, black, and white three-color image input device provided with two red and yellow LEDs using the present invention as a light source will be described with reference to the drawings.

 FIG. 2 shows a block diagram of this embodiment.

In the figure, 1 is a multiplexer, 2 is a photoelectric conversion element as a light receiving element, 3 is a voltage comparator (comparator), 4 is D /
A converter, 5 is a RAM, 6 is a ROM storing a light amount data table and other programs, 7 is a CPU, 8 is a display device, D _{1 to} Dn are reading points, C _{1 to} Cn are drive control circuits, Lr ₁
~Lrn red LED that emits red light, Ly ₁ ~Lyn yellow LED, T ₁ to Tn-emitting optical fiber which emits yellow light, R ₁ ~Rn is the light receiving side optical fiber as an optical component.

The CPU 7 adjusts the respective light amounts of the plurality of light sources Lr _{1 to} Lrn and Ly _{1 to} Lyn based on the light amount data input from the ROM 6 according to a command sent according to a program stored in the ROM 6. That, CPU 7 sends the light quantity data to the D / A converter 4, the output signal from the D / A converter 4 is output to the drive control circuit C ₁ to Cn through the multiplexer 1 in charge of the time-division control, drive The control circuits C _{1 to} C ₂ n are each red LED Lr _{1 to} Lrn and each yellow L
EDLy _{1 to} Lyn are selectively turned on. The light illuminates points D _{1 to} Dn to be read on the document surface through the corresponding light emitting side optical fibers T _{1 to} Tn. The reacted light is received at the document-side end of the corresponding light receiving side optical fibers R _{1 to} Rn, and the fibers R _{1 to} Rn are transmitted to the photoelectric conversion element 2 connected thereto. The output from the photoelectric conversion element 2 is compared with a reference value by a comparator 3, and when the reference value is reached, the data input to the D / A converter 4 is converted into a plurality of light emitting elements Lr.
_The CPU 7 stores in the RAM 5 for each of _{1 to} Lrn and Ly _{1 to} Lyn.

FIG. 3 is a flowchart showing the operation of the white level check as the adjusting means and the setting of the light emission amounts of the light emitting elements Lrn and Lyn in this embodiment.

First, in step 1, 1 is input to an N register used to specify a light emitting element for counting and an M register used to specify the amount of light emission. Move to a white reference value with a percentage. This corresponds to the arrangement means. In step 3, the n-th drive control circuit Cn is designated based on the contents of the N register, and the ROM 6 is designated based on the contents of the M register.
And reads and outputs the m-th test data (step 4). In step 5, the output of the comparator is set to the reference value (SG
= 1) If not, the test data at that time is stored as appropriate light amount data in the RAM 5 as storage means in step 6. In step 7, register N is 16 (in this case,
Assume that the total number of red light emitting elements is eight and the total number of yellow light emitting elements is eight. If not, this operation is repeated until N = 16 as shown in step 8. At this time,
As shown in step 8, the M register is reset to "1". If N = 16 in step 7, the CPU 7 turns to yellow LE
For DLyn, use the appropriate light emission data as the emission data
It is stored in the RAM 5 (step 9). For the red LED Lrn, the CPU 7 stores in the RAM 5 a light amount two steps smaller than the appropriate light amount light emission data as light emission data (step 10). The start-on switch can be input (step 11). If the output of the comparator to which the m-th test data is input does not exceed the reference value in step 5, as shown in step 10, the light amount of the light-emitting element is increased until m = 13, as shown in step 10. 20, Steps 4 and 5 are repeated. If the value does not match the reference value when m = 13, a failure is displayed on the display device 8 in step 21 and END is given.

When the start switch is turned on, the CPU 7 sets the N register to 1 (step 12). In step 13, the n-th drive control circuit Cn is designated based on the contents of the N register. In step 14, the CPU 7 reads and outputs light emission data for the yellow LEDLyn and the red LEDLyn, respectively. The CPU 7 stores the output of the comparator 3 in the RAM 5 in step 15. The CPU 7 determines the color based on the output of the comparator 3 (step 16). Then, it is determined whether or not N is 16 (Step 17), and Step 13 is performed until N reaches 16.
Steps 17 to 17 are repeated (step 18).

In this case, step 14 and step 15 correspond to a first determination unit and a second determination unit.

Next, a reading operation for reading red and black on a document by the optical reading device will be described.

After the original is set, the yellow LED Lyn attached to the reading head irradiates the background color portion of the original, receives the reflected light by the photoelectric conversion element 2 and performs photoelectric conversion to obtain an output. Also,
An output is similarly obtained for the red LED Lrn. As a result, the reading results shown in the following table are obtained.

Here, conventionally, each of the LEs is controlled so that the output voltage of the light receiving element PD with respect to both the light emitting elements becomes a certain constant value.
Although the light amount of DLyn and Lrn was adjusted, the CPU5 was designed so that the light amount of the red LED Lrn was narrowed to the light amount of the yellow LEDLyn.
Is red LEDL for light emission data smaller than proper light emission data
Given for r _{1 to} Lrn. Thus, when irradiated with yellow LEDLy ₁ ~Lyyn the image gray (small black density), even closer to the output voltage if the reference voltage, red LE
Since the output voltage of DLyn is much smaller than the reference voltage, it is not erroneously identified as "red".

Note that the present invention is not limited to the above-described embodiment, and the light emitting elements other than red and yellow LEDs as the light emitting elements of a plurality of colors, for example, red, green, red, green, It may be configured to read a black image. Further, a reflecting mirror may be used instead of the plurality of light emitting fibers, a lens may be used instead of the plurality of light receiving fibers, and a light receiving element (white light level check) may be used instead of light quantity adjustment of the light emitting element. (Including AMP). Further, an A / D converter may be used instead of the comparator 3 as the detecting means. Further, the display device 8 constituting the detection means may be a buzzer for outputting a sound, or may be an LED lamp.

[Effects of the Invention] As described above, according to the optical reading apparatus of the present invention, an image of a specific color on a document can be accurately read, and clear reading can be performed.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram, FIG. 2 is a block diagram of an embodiment embodying the present invention, and FIG. 3 is a flowchart showing the operation of this embodiment. In the figure, 1 is a multiplexer, 2 is a photoelectric conversion element, 3 is a voltage comparator (comparator), 4 is a D / A converter, and 5 is R
AM, 6 are ROM, 7 is CPU, 8 is display device, D _{1 to} Dn are reading points, C _{1 to} Cn are drive control circuits, L _{1 to} Ln are LEDs, T _{1 to} Tn are light emitting side optical fibers, R _{1 to} Rn are light receiving side optical fibers.

Continued on the front page (72) Inventor Takayuki Matsumoto 9-35, Hotta-dori, Mizuho-ku, Nagoya-shi, Aichi Prefecture Inside Brother Industries, Ltd. (72) Inventor Murai Sushiro 9-35, Horita-dori, Mizuho-ku, Nagoya, Aichi, Japan In Brother Industries, Ltd. (72) Inventor Koji Takeyama 9-35, Horitadori, Mizuho-ku, Nagoya-shi, Aichi Examiner, Brother Industries, Ltd. Shoichi Shimizu (56) References JP-A-62-91069 (JP, A) )

Claims (1)

(57) [Claims] 1. A plurality of types of light emitting elements for emitting light of a plurality of colors, respectively, and a light receiving unit for irradiating irradiation light from the light emitting element to a reading unit to be read and receiving light from the reading unit. An optical system including an element and an optical component that transmits light from the reading unit to a light receiving element; a detecting unit that detects an output of the light receiving element; and a constant reflectance at a position of the reading unit with respect to the optical system. Arranging means for arranging a member having a relative position with respect to the optical system; and arranging the arranging means to cause the plurality of types of light emitting elements to emit light and to detect outputs of the light receiving elements by the detecting means. Adjusting means for adjusting the light amount of the light emitting element or the output of the light receiving element so that the input of the detecting means becomes a predetermined value; and the light amount of the light emitting element or the light receiving amount adjusted by the adjusting means. Storage means for storing an output of the optical element, wherein the detection means selectively emits the plurality of types of light-emitting elements using the light amount of the light-emitting element or the output of the light-receiving element stored in the storage means. An optical reading device that reads a color image on a document placed in a reading unit based on a detection result of: when placing a document in the reading unit and causing one of the plurality of types of light emitting elements to emit light A first determining unit that determines the presence of an image on a document based on a detection result of the detecting unit using an output stored in the storage unit; and arranging the document on the reading unit; When the other light emitting element among the elements emits light, an output relatively smaller than the output stored in the storage means is used, and the other light emission of the image on the document is detected by the detection result of the detection means. Light emission of device An optical reading device, characterized in that the presence of the corresponding color image and a second determining means for determining with a determination result of the first determination means.