JPH0626418B2 - Optical reader - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical reading device that is used in a facsimile device, a copying device, or the like, and reads an image described on a document or the like.

[Prior Art] Conventionally, an optical reading device of this type has a light emitting element (hereinafter, L
ED), a light-emitting side fiber that irradiates the document with light emitted from the light-emitting element, a light-receiving side fiber that receives and transmits reflected light from the document, and light transmitted through the light-receiving side fiber. Light receiving element for receiving light (hereinafter referred to as SPD)
A plurality of optical system members, detecting means for detecting the output of the light receiving element in the optical system members, and a member having a constant reflectance at the position of the original document with respect to the optical system members, and the LED is caused to emit light. The detecting means detects the output of the SPD, and the adjusting means adjusts the light amount of the LED or the output of the SPD so that the output of the detecting means in each optical system member becomes a predetermined value.

In such an optical reading device, in order to read an image on a document accurately, it is necessary to adjust the brightness of each LED so that the output signal from the SPD has a constant level.

Conventionally, a so-called white level check method has been used as this adjustment method. This is to illuminate the white reference member (white member) with the light emitted from the LED through the light emitting side fiber, and to emit the light through the light receiving side fiber with SP.
When the D receives light and the SPD outputs a signal according to the amount of light, the adjusting means changes the LED brightness stepwise to determine the LED brightness at which the signal input to the detecting means becomes constant. Alternatively, the brightness of the LED is fixed to a constant value, and the signal output from the SPD is gradually amplified by the adjusting means by an amplifier (AMP) or the like so that the signal input to the detecting means becomes constant. Is a method of determining.

This white level check is performed by reading the white level of the white reference member arranged in advance in the reading unit immediately before reading the original. Then, the optical reading device adjusts the reading level and then sequentially conveys the document to the reading unit to read the document.

[Problems to be Solved by the Invention] However, in the conventional optical reader, the background color of the original is white when the original is not white in color, for example, in the case of an original such as a newspaper with a yellowish mottled tone. Not so
The image on this document could not be read accurately (clearly).

In particular, when this optical reading device is used in a facsimile device, when the original document is accurately read, the paper of the destination facsimile device is output in a totally contaminated state and the transmitted original document is The content becomes difficult to grasp.

[Object of the Invention] The present invention has been made in order to solve the drawbacks of the prior art. After performing a level check with a reference member having a constant reflectance, the document is placed in the reading unit and the document surface is placed. Provide an optical reading device that can read the image on the original surface clearly by correcting the level check data on the reference member based on the level check data on the original surface. The purpose is to do.

[Means for Solving the Problems] In order to achieve this object, an optical reading device of the present invention includes a light emitting element that irradiates a reading section with irradiation light and a light receiving element that receives reflected light from the reading section. A plurality of optical system means having :, a detecting means for detecting the output of the light receiving element, and a reference member having a constant reflectance at the position of the reading section with respect to the optical system means, relative to the optical system means. And the first arranging means for arranging the first arranging means, and after the arranging of the first arranging means is completed, each light emitting element is caused to emit light in order and the output of each light receiving element is detected by the detecting means, and the input to the detecting means in each optical system means Adjusting means for adjusting the light quantity of each light emitting element to a predetermined value, first storing means for storing the light quantity of each light emitting element adjusted by the adjusting means, and an optical system after the adjusting operation by the adjusting means is completed. Reading for means In the position of the take part,
Second arranging means for arranging the background portion of the document, second memorizing means for executing the adjusting operation by the adjusting means after arranging the second arranging means, and storing the light amount of each light emitting element in that case; 1 correction means for correcting the data stored in the storage means on the basis of the data stored in the second storage means to enable reading with the background portion of the document as a reference.

[Operation] In the optical reading device of the present invention having the above configuration, the reference member having a constant reflectance is arranged relatively to the optical system means in the reading section for the optical system means by the first arrangement means. After that, the adjusting means causes each light emitting element to emit light in order, and the detecting means detects the output of each light receiving element, so that the input to the detecting means in each optical system means becomes a predetermined value. Adjust the light intensity. Also, the first
The storage means stores the light amount of each light emitting element adjusted by the adjusting means. Then, after the adjusting operation by the adjusting means,
The second arranging unit arranges the background portion of the document at the position of the reading unit with respect to the optical system unit, and the adjusting operation is executed again by the adjusting unit, and the second storing unit stores the light amount of each light emitting element in that case. To do.

Subsequently, the correction unit corrects the reference data stored in the first storage unit based on the background portion data of the original document stored in the second storage unit, and uses the corrected data as a reference to obtain the background portion. It becomes possible to clearly distinguish between the image part and the image part for reading.

Embodiments Embodiments embodying the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of this optical reader.

The CPU 7 adjusts the light amount of each of the plurality of light sources L _{1 to} L _n based on the light amount data input from the ROM 6 according to a command sent according to the program stored in the ROM 6.
That is, the CPU 7 sends the light amount data to the D / A converter 4, and the output signal from the D / A converter 4 is passed through the multiplexer 1 which is in charge of the time division control, to the drive control circuit C.
_{1 to} C _n , and the drive control circuits C _{1 to} C _n turn on the LEDs L _{1 to} L _n as the light emitting elements of the present invention.
The light illuminates the points D _{1 to} D _n to be read on the document surface through the corresponding light emitting side optical fibers T _{1 to} T _n . The reflected light is received by the ends of the corresponding light-receiving side optical fibers R _{1 to} R _{n on} the side of the document, and the optical fibers R _{1 to} R _n are photoelectric conversion elements as the light-receiving element of the present invention connected thereto. 2 to transmit. The CPU 7 compares the output from the photoelectric conversion element 2 with a reference value by the 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 receiving side fibers R ₁ to R _n is stored in the RAM5 of the first and second storage means of the present invention separately.

FIG. 2 is a flow chart showing the white level check processing operation as the adjusting means of the present invention.

First, 1 is set in the N and M registers for counting in step 1, and then the reader is moved to a white reference plate having a constant reflectance in step 2. Then, in step 3, the nth drive control circuit is designated based on the contents of the N register, and then in step 4, the mth test data is read out from the ROM 6 based on the contents of the M register and output.

If the output of the comparator 3 is equal to or greater than the reference value (SG = 1) in step 5, the test data at that time is stored in the RAM 5 as appropriate light amount data in step 6. Next, when it is determined in step 7 that the N register is not 16, the operations of steps 3 to 7 are repeated until N = 16 in the process of step 8. At this time, in step 8, the M register is reset to "1".

On the other hand, if N = 16 is determined in step 7, it is determined whether or not the start switch is on (step 9). In this case, the start switch is on (step 9: (YES), proceed to the next process.

By the way, in the step 5, the output of the comparator 3 to which the m-th test data is input is the reference value (SG =
1) If it is determined that the above is not the case, it is determined in step 10 whether or not the test data is the thirteenth data (m = 13).

Then, the operations of step 12 [increment the value of m by 1], step 4 and step 5 are performed so that the light amount of the light emitting element (LED) increases until it is determined in step 10 that m = 13. Execute repeatedly.

If the output of the comparator 3 does not exceed the reference value even when m = 13 (step 5: NO, step 10: YES), a failure display is displayed on the display device 8 in step 11, and this process ends. To do.

Next, the operation of adjusting the reading level of the optical reading apparatus thus configured will be described with reference to the flowchart of FIG.

Since the white level check process is performed for all the LEDs L _{1 to} L _n , first, in step 21, the P register for counting the number of LEDs is designated, and the first LE is added to it.
“1” indicating D is set. Next, at step 22, just before the reading of the document, the above-mentioned white level check process shown in FIG. 2 for the white reference plate is performed.

Then, in step 23, the CPU 7 executes the white level check process to obtain the proper data X ₁ obtained in the RAM 5
Remember. Then, in step 24, all LEDs
(In this case, the number of LEDs is 104) It is determined whether the white level check process has been performed. Then, step 25 [increment the value of P by one], step 22, step 23, and step 24 are repeatedly executed until the white level check processing is executed for all the LEDs.

When the white level check process is performed for all the LEDs (step 24: YES), the white part (background part, that is, the base part) of the document is read if there is no abnormality (step 26).

Then, when the reading process of the white portion of the document is completed, in step 27, the LED count P register is reset, and "1" is set again. Then step 28
In the second part of the white part of the document (the part without the image)
Perform the same processing as the white level check processing shown in the figure,
In step 29, the appropriate light amount data X ₂ obtained by the white level check process is stored in the RAM in the same manner as the white level check process for the white reference plate immediately before reading the original.
Store in 5. Repeating these respective processes for each LEDL ₁ ~L _n (Step 28 to Step 31).

Further, when the white level check process for the white part of the document is completed for all the LEDs (step 30: YE
S) In step 32, the P register for the LED count is reset again and "1" is set. Then, in step 33, the difference X between the proper light quantity X ₁ obtained by the white level check processing for the white reference plate and the proper light quantity X ₂ obtained by the white level check processing for the white portion (background portion) of the document. ₁₂ is obtained, and the difference X ₁₂ is obtained in the next step 34, and this difference X ₁₂ is obtained in the next step 34.
It is determined whether ₁₂ is within the allowable range (q ₁ <X ₁₂ <q ₂ ). Note that each of these processes is repeatedly executed for all LEDs (step 33 to step 36).

Then, even if it is determined that the difference X ₁₂ is out of the allowable range even for one LED (step 34: NO),
Immediately, those processes are interrupted, and a warning is displayed on the display device 8 in step 37.

Further, when it is confirmed that the difference X ₁₂ between the proper light quantities X ₁ and X ₂ for all the LEDs is within the allowable range (step 35: YES), the average value n of the difference X ₁₂ is calculated in step 38. calculate. Next, the P register for LED counting is reset and "1" is set again. Next, at step 40, the average value n of the differences X ₁₂ is added to the proper light amount X ₁ obtained by the white level check process for the white reference plate of the LED, and the proper light amount data Z for the original document is added.
Correct to i. Then, in step 41, all LEs are
It is determined whether or not D has been corrected to the proper light amount data Zi at the original level. Then, step 42 [increment the value of P by one], step 40, and step 41 are repeatedly executed until all the LEDs are corrected to the proper light amount data Zi of the original level.

When all the LEDs are corrected to the proper light amount data Zi at the document level (step 41: YES), the LEDs are caused to emit light based on the proper light amount data Zi in step 43 to start reading the document. As a result, no matter what the color of the background portion of the document, that is, the color of the base, is, for example, a manuscript such as a newspaper with a yellowish mottled tone, the proper light amount X ₁ for the white reference plate and Since the average value n of the difference X _{12 from} the proper light amount X ₂ is added to the proper light amount X ₁ with respect to the white reference plate, the image on the document surface can be clearly read.

The present invention is not limited to the above-mentioned embodiment,
A reflecting mirror may be used in place of the plurality of light emitting side fibers, and a lens may be used in place of the plurality of light receiving side fibers. Further, instead of the voltage comparator 3 as the detection means, A /
A D converter may be used. Further, the display device 8 constituting the detection means may be a buzzer that outputs a sound or an LED lamp.

[Effects of the Invention] As described above, the optical reading apparatus of the present invention checks the level of the reference member so that the reading level is adjusted to the original even when the background portion (base portion) of the original is not white. Since the data is corrected based on the level check data for the background portion of the document, clear reading is possible.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment embodying the present invention, and FIG.
FIG. 3 is a flowchart showing the white level check of this embodiment, and FIG. 3 is a flowchart showing the read level correction control of this embodiment. In the figure, 1 is a multiplexer, 2 is a photoelectric conversion element (light receiving element), 3 is a voltage comparator (comparator), 4 is a D / A converter, 5 is RAM, 6 is ROM, 7 is CPU, 8 is a display device, D _{1 to} D _n are reading points, C _{1 to} C _n are drive control circuits, L _{1 to} L _n are LEDs (light emitting elements), and T _{1 to} T.
_n is a light emitting side optical fiber, and R _{1 to} R _n are light receiving side optical fibers.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Atsushi Hatamura Atsushi Hatamura 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Brother Industries, Ltd. (72) Inventor Otobe 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Brother Industries, Ltd. (72) Inventor Hideaki Takahashi 9-35, Hotta-dori, Mizuho-ku, Nagoya, Aichi Pref. Tadao Yuhara, Examiner, Brother Industries Ltd. (56) Reference JP-A-60-52159 (JP, A) Special Kai 61-256865 (JP, A) JP 61-256866 (JP, A) JP 62-45270 (JP, A)

Claims (1)

[Claims] 1. A plurality of optical system means having a light emitting element for irradiating a reading section with irradiation light and a light receiving element for receiving reflected light from the reading section, and a detecting means for detecting an output of the light receiving element. First arranging means for arranging a reference member having a constant reflectance at the position of the reading section with respect to the optical system means, relative to the optical system means; Adjusting means for causing the light emitting elements to sequentially emit light, detecting the output of each of the light receiving elements by the detecting means, and adjusting the light quantity of each of the light emitting elements so that the input to the detecting means in each of the optical system means becomes a predetermined value. A first storage unit that stores the light amount of each light emitting element adjusted by the adjustment unit; and a background portion of the document at the position of the reading unit with respect to the optical system unit after the adjustment operation by the adjustment unit is completed. Distribution Second arranging means, a second memorizing means for executing the adjusting operation by the adjusting means after arranging the second arranging means, and storing the light amount of each light emitting element in that case, and the first memorizing means. And a correction unit that corrects the data stored in the second storage unit based on the data stored in the second storage unit and enables reading with the background portion of the original as a reference. apparatus.