JPS6043960A - Optical picture reading device - Google Patents

Abstract

PURPOSE:To perform the same reading under the same condition without adjusting operating condition of a light emitting element one by one by providing a digital/analog converting means for controlling the quantity of light of plural light sources basing on inputted data. CONSTITUTION:A driver shaft 11 both ends of which are supported by a frame of an optical reading device is installed parallel to a supporting drum 13 that feeds and controls an original 12, and a spiral cam groove 15 is cut on its outer peripheral face. The basal part of a holder 16 is supported movably by a guide shaft 17 provided parallel to the supporting drum 13 in the lower rear of the driver shaft 11, and at the same time, its detaining piece 18 is fitted to the spiral cam shaft 15 and supported. When the driver shaft 11 is rotated by a DC motor 14, the holder 16 reciprocates along the guide shaft 17 in the direction of left and right. The optical picture reading device 19 is attached to the holder 16, and reads pictures recorded in the original 12 successively in lateral direction with movement of the holder 16.

Description

[Detailed Description of the Invention] Technical Field This invention involves arranging a plurality of optical fibers, shining light onto an image original, receiving the reflected light with each optical fiber, and calculating the amount of light received by each optical fiber. Image D)
The present invention relates to an optical image reading device for reading images recorded on paper.

Prior Art Conventionally, this type of optical image reading device, as shown in FIG. Reciprocal light is received by the light receiving side optical filter R, and the light is converted into an electrical signal proportional to the amount of light by the electrical conversion element P, and then the image information at that reading point is read based on the value (level) of the electrical signal. It is 6.

In the shell-shaped reading device, as shown in FIG. 2, a plurality of light-emitting side optical fibers T1 to Tn are arranged in a row, and a
The light emitted from the light emitting elements L1 to Ln is irradiated to each of the reading points D1 to Dn on the document surface in front, and on the other hand,
The light-receiving side optical fibers R1-Rn are arranged in a line corresponding to the optical fibers T1-Tn and receive the repulsed light from the reading points D1-Dn, respectively.
There is a configuration that receives the reflected light of the light irradiated to Dn.Then, the light received by the light-receiving side optical fibers R1 to Rn is transmitted to the photoelectric conversion element D1 rl, and the light 11 is transmitted to the photoelectric conversion element D1 by the conversion element P1. ) is converted into electricity No. 1.1 proportional to ), amplified by the next stage amplifier A1, and output to the microcomputer M.

On the other hand, each drive control circuit C1-C of each light emitting element L1 to Ln
n is 1J as shown in FIG. 3, and a -C transistor 2 is turned on based on a drive control signal from a microcomputer M via a resistor 1. A light emitting diode 3 as a light emitting element is turned on.
61. It was composed of sea urchins.

However, if the -C operating characteristics of each of the light emitting elements L1 to Ln change due to changes over time, for example, if the light emitting elements L1 to Ln do not emit light under the same conditions (for example, the same applied voltage),
↓The amount of light emitted by B and B is different. For example, when nothing is recorded (each reading point 1 on a blank white background document) 1-Dn is irradiated with each sound and light, 11.1 , the level of the electrical signal based on the anti-OJ light at reading points 1)1 to ])n is the same level (b1) as shown in Fig. 4(a).
), and as shown in FIG. 4(b), the level of the electrical signal varies relative to the light h) irradiated to each reading point D1 to Dn, and each reading point D1 to Dn Even under the same conditions, electrical signals of different levels are output, so each reading point D1 to Dn can be read using a microphone. was occurring. Therefore, each light emitting element L1
When the light output from ~Ln irradiates the corresponding reading points D1 to Dn, the third reading point D1 to Dn is set so that the same level of electric signal is obtained when the reading points D1 to Dn are under the same conditions. As shown in the figure, a variable resistor 4 is connected in series to the light emitting element and the diode 3 (), and the variable resistor 4 is used to adjust the applied threshold voltage (J selected) for each light emitting element L1 to Ln. -(There was.

However, (the second adjustment work requires time to be adjusted one by one), and even if the adjustment is done once, the light emitting element L
1 to Ln, line 1 of photoelectric conversion element P1 or amplifier A1
．． There is a problem that if the conditions are changed due to a change in the reading point or a relative positional shift between the light-receiving optical fiber and the light-receiving optical fiber relative to the reading point, and if the conditions are adjusted again, the result will not be correct.

Purpose This invention was made to solve the above-mentioned problems, and its purpose is to control the amount of light from each light-emitting element without adjusting the operating conditions of the light-emitting elements one by one, so that the reading point can always be read under the same conditions. The same reading can be done,
An object of the present invention is to provide an optical image reading device that can read images accurately and reliably.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment embodying the present invention will be described with reference to the drawings.

In FIG. 5, a driver shaft 11 whose both ends are supported by a frame (not shown) of an optical reader is connected to a document 12.
A spiral cam groove 5 is formed on the outer circumferential surface of the drum, which is disposed parallel to the support drum 13 for feeding and controlling the frame, and whose end protruding from the frame is drivingly connected to the DC motor 14.

As shown in FIG. 6, the holder 16 has its proximal end disposed parallel to the support drum 13 at the lower front of the driver shaft 11, and is movably supported by the Iζ guide shaft 17 (along with its distal end). A locking piece 18 formed on the rear surface is fitted and supported in the spiral cam groove 15.
When the driver shaft 11 or the DC motor 14 rotates the holder 16, the holder 16 reciprocates in the left-right direction along the guide shaft 17 based on the engagement between the spinor cam groove 15 and the locking piece 18.

Optical image reading device (hereinafter referred to as reading device) 1
9 is attached to the front surface of the tip of the holder 16, and its front surface faces the document surface 12a on the support J, drum 13. Therefore, the reading device 19 is stagnant as the holder 16 moves and sequentially reads the images recorded on the document 12 in the horizontal direction.

Next, the reading device 19 will be explained according to FIG. It should be noted that each member disposed in the reading device 19 is the same as the member explained in the conventional example, so for convenience of explanation 1? The following description uses the same reference numerals.

Inside the reading device 19, first to nth light emitting side optical fibers T1 to Tn each having first to nth light emitting elements L1 to Ln such as light emitting diodes as light sources at their base ends are arranged. C relative to the moving direction of the reading device 19.
The optical fibers are arranged in order from the first light emitting side optical fiber T1 in the surface angle direction, and each irradiation surface is arranged on the original surface 12a as shown in FIG.
It is tilted approximately 60 degrees with respect to C. And each light emitting element L1
For the light from ~Ln, each optical fiber T1~Tn is used.
The light is irradiated onto the original surface 12a through the rays, and each irradiated point is designated as the first to nth reading points on the original surface 12a.

The first to nth light receiving side optical fibers R1 to 1 are installed on opposite sides of the first to nth light emitting side optical fibers T1 to Tn.
Rn connects each tip to the same light-emitting side optical fibers T1 to Tn.
are arranged in parallel with the tips of the first light-receiving side optical fibers R1, and the light-receiving surfaces of the tips are connected to the respective light-emitting side optical fibers T1 to T1.
Tilt it at an angle of 60 degrees to the irradiation surface of Tn (
There is. The light irradiated to each of the reading points D1 to Dn becomes reflected light and is received by the corresponding first to n-th light receiving side optical fibers R1 to Rn.

The base ends of the first to n-th light receiving side optical fibers R1 to Rn are respectively connected to a photoelectric conversion element P1 such as a phototransistor provided in the reading device 9, and transmit the received reflected light to the conversion element. . And photoelectric conversion element P
1 converts the reflected light transmitted from each light-receiving side optical fiber R1 to Rn into an electric signal proportional to the amount of light, and outputs it as a detection signal SG1 to the central processing unit 21, which will be described later, via the next stage amplifier A1. do.

Central processing unit (hereinafter referred to as CPU) 21 as each means
operates based on the control program 11 stored in a read-only memory (hereinafter referred to as ROM) 22, and outputs an operation control signal to the multiplexer 23 to control the light emission timing of each of the light emitting elements L1 to Ln. In order to do this, a data signal (digital amount) for controlling the amount of light emitted from each of the light emitting elements L1 to Ln is outputted to the D/A converter 24 as a digital/analog conversion means. The D/A converter 24 controls the amount of light emitted from each of the light emitting elements L1 to Ln, converts the data signal into an analog signal with a voltage proportional to the digital amount, and outputs it.

Each drive control circuit C1 to Cn of each light emitting element L1 to Ln is C
Based on the operation control signal from the PU 21, the jlL-marzi brake 23 operates! A predetermined one of the D/A converter 24 is selected from time to time, and the analog signal output from the D/A converter 24 at the time of selection is input. Each of the drive control circuits C1 to Cn has a voltage follower operational amplifier 25J as shown in FIG. A voltage proportional to the value is applied to the light emitting element and the light emitting diode 17 through the resistor 26.
〜27〕”Runoru. Therefore, the amount of light emitted from the light emitting diode 27, that is, each of the light emitting elements L1 to Ln increases in proportion to the applied voltage value.

The data signal input to the D/A converter 24 may be various test data stored in advance in the ROM 22 or stored in a readable and rewritable memory (hereinafter referred to as RAM) 28. It is output from the CPU 21 based on the appropriate light amount data. The test data stored in the ROM 22 is transferred from the D/A converter 24 to VM from 0 to 1 as shown in FIG.
M pieces (13 pieces in this example) that differ in stages up to the bolts
This data is for sequentially outputting the voltage from 0 volts as an analog signal, and when selecting the optimal light IIi for each light emitting element L1 to Ln,
It is used when creating appropriate light amount data for 1 to Ln. Further, the RAM 28 stores appropriate light amount data corresponding to the number of light emitting elements L1 to Ln, and allows the light emitting elements L1 to Ln to emit light with the optimum light amount.
There is data C that determines the voltage value of the analog signal output from the front nD/A converter 24 in order to determine the voltage value of the analog signal output from the front nD/A converter 24.

In addition, the CPU 21 determines whether the detection signal SG output from the amplifier A1 is based on irradiation of light onto the ground color of the original [, takodo] or whether it is based on irradiation of light onto an image recorded on the original. When the level of the detection signal SG1 is higher than the preset reference value k, it is determined that no image is recorded at the reading point on the document surface 12a. If it is less than that, it is determined that an image is recorded at the reading point on the document surface 12a. Note that the reference value k is stored in advance in the ROM 22 and is read out every time a determination is made.

The working memory 29 stores the reading data of the image information in each reading D1 to Dn on the document surface 12a from time to time based on the detection signal SG1 outputted from the amplifier A1. When the CPU 21 detects that each of the light emitting elements L1 to Ln does not emit the appropriate amount of light, the display device 30 displays the number of the failed light emitting element based on a control signal output from the CPU 21. It has become.

Next, the operation of the reading device 19 configured as described above will be explained.

Now, after setting the document 12 with the image stored on the document surface 12a on the support drum 13, when the power switch (not shown) of the reading device 19 is turned on, the CPU 21 operates according to the flowchart shown in FIG. Let's start. For convenience of explanation, it is assumed that the number of reading points is 16 and the number of each drive control circuit is 16.
The OM22 stores 13 types of data and has a capacity of 1J.

The CPU 21 first inputs the contents of the N register for specifying each of the 16 drive control circuits C1 to C16 provided within the CPU 21, and the M register for specifying each of the 13 types of drive control circuits stored in the R0M22. After initial setting to "1", the DC motor 14 is driven and controlled to move the reading device 19 to a position on the original surface 12a in a ground-colored cylindrical section on which nothing is recorded.

Next, the CPU 21 outputs an operation control signal to the multiplexer 23 based on the content "1" of the N register to designate the first drive control circuit C1, and also specifies the content "1" of the M register.
1", the first test data stored in the ROM 22 is read out and the data signal is sent to the D/A converter 2.
Output to 4.

The analog signal that the D/A converter 24 outputs to the first drive control circuit C1 based on this data signal is at 0 halt as shown in FIG. 9, so the first light emitting element L1 emits light.
- Yes. On the other hand, at the same time as this data signal is output, the CPU 21
has a detector bow SG1 from amplifier A1. At this time, since the light emitting element L1 is not emitting light, there is no reflected light transmitted to the photoelectric conversion element P1, and as a result, the detection signal SG1 output from the photoelectric conversion element P1 and amplified by the amplifier A1 becomes 0 volts.

The CPU 21 determines the level of this detected Shinkyu SG1 in the ROM 22.
It is determined whether or not it matches the criterion k stored in . Then, the CPU 21 determines that they do not match at this point, and immediately changes the contents of the backward M register, which has determined that the contents of the M register are not “13”, from “1” to “2”.
”.

Based on the contents of "2" in the M register, the CPU 21 reads out the second test data stored in the ROM 22 and outputs the data signal to the D/A converter 24.
Ru. The D/A converter 24 outputs an analog signal based on this new data signal to the first drive control circuit C1. From then on, this operation will be performed until the contents of the M register are "13".
'' or until the level of the detection signal SG1 matches the reference value k during the process, and the analog signal is shown in FIG. 9 every time the contents of the M register are added by 1. As the voltage value increases step by step, the light emitting element L
1.

Then, as the applied F becomes larger, the amount of light emitted from the light emitting element L1 increases.
The light is irradiated via the light-emitting optical fiber L1 to the reading point D1 of the ground color where nothing is recorded. Therefore, since the amount of received light reflected from the light irradiated onto the reading point D1 received by the light-receiving side optical fiber L1 also increases in proportion to the amount of light emitted, that is, in proportion to the analog signal, the photoelectric conversion element P1 generates electricity. After being converted into a signal, the level of the detection signal SG1 output from the amplifier A1 also becomes relatively large.

Preferably, when the level of the odor-C detection signal SG1 in the coating matches the reference value k, the CPU 21 outputs the test data stored in the ROM 22 read out based on the contents of the M register at that time in the first light emission. The appropriate light amount data of the light emitting element L1 is stored in the RAM 28, and then the data of the next second light emitting element L2 is stored.
Proceed to the processing operation to obtain the appropriate light amount data.

On the other hand, even if all the analog signals based on the test data in the ROM 22 are applied to the first light emitting element L1, the output will still be output (if the detection signal SG1 does not reach the reference value k)
J determines that the CPU 21 is malfunctioning and immediately switches on the display device 3.
0 to display the number of the corresponding first light-emitting cable L1, and also activate an alarm device (not shown) [↓ to issue an alarm and perform its maintenance work.

When the proper light amount data of the first light emitting element L1 is stored in the RAM 28, the CPU 21 next stores the contents of the N register as "
16'', that is, all light emitting elements L1 to L1
After determining whether the appropriate light amount data in step 6 has been achieved, the content of the Nl nozzle is set to "2". Based on the content "2" of this N register, the CPU 21 outputs an operation control signal to the multiplexer 23 to designate the second drive control circuit C2, based on the test data stored in the ROM 22 in the same manner as described above. Then, the analog signals shown in FIG. 9 are again sequentially output to the second drive control circuit C2 via the D/A converter 24.

Then, the same operation as described above is repeated, and the appropriate light amount data for the second light emitting element L2 is selected from among the test data in the ROM 22 and stored in the RAM 28. Thereafter, appropriate light amount data is similarly obtained for each of up to the 16th light emitting element L16 and stored in the RAM 28.

Appropriate light amount data of the last 16th light emitting element L16 or RO
iLRAM28 selected from each test data of M22
When the content of the N register is output to
16'', that is, all light emitting elements L1-L
16 is determined based on the appropriate light amount data, and waits for the ON operation of a start switch (not shown) for reading the image recorded on the document surface 12a, and the operation for creating the appropriate light amount data is completed.

Therefore, even if the operating characteristics of each of the light emitting elements L1 to Ln differ due to fragmentation over time, an analog signal based on each appropriate light amount data is transmitted via the D/A converter 24 to each corresponding drive control circuit C1. ~C16, the light emitted from each light emitting element L1~L16 is a detection signal SG1 of a constant level with the same value if each reading point is under the same conditions at each reading point D1~D16. is converted to

Then, when the start switch is turned on to start reading the image on the document surface 12a, the CPU 21 moves the DC motor 14 to the document surface 12a on which the image is recorded and starts reading the image. Start operation. Then, the CPU 21 specifies in a predetermined order from the first drive control circuit C1 to the sixteenth drive control circuit C16 in a time-division manner, and sequentially causes each of the light emitting elements L1 to L16 to blink. At this time, the CPU 21 uses the RAM 28
The appropriate light amount data of each light emitting element L1 to L16 stored in
data signal based on the appropriate amount of light.
Output to A converter 24. Then, the D/A converter 24 outputs an analog signal based on appropriate light amount data of the corresponding light emitting elements L1 to L16 to each of the light emitting elements L1 to L16, thereby causing each of the light emitting elements L1 to L16 to emit light.

Therefore, from each light emitting element L1 to L16, each reading point D1
~ D16 is irradiated with light whose light intensity is controlled, each reading point D1 at each reading point D1 to D16.
If D16 to D16 are under the same conditions, the detection signal SG1 of the same constant level will always be output for each of them, and accurate and reliable image reading will be possible within the CPU 21.

In this way, each detection signal SG1 at each reading point D1 to D16 is output to the CPU 21, and
1 compares this detection signal SG1 with the reference value K to determine the presence or absence of an image, converts the result into a numerical value, and stores the result in a working memory 29.
are memorized in sequence.

Note that in this embodiment, one light-receiving optical fiber is used for one light-emitting optical fiber, but even if there are m light-receiving optical fibers for one light-receiving optical fiber, m light-emitting elements are used for the same light-emitting element. Even if the appropriate light amount data is created and the same light emitting element is driven M times based on the appropriate light amount data, image reading can be performed in the same manner as described above.

Effects As detailed above, this invention provides a digital-to-analog conversion means for controlling the light intensity of a number of light sources based on manually inputted data, and sequentially changes the light emission intensity of each light source in advance. , I wonder about the change in the amount of light from the light source.)
When the output output from the C photoelectric conversion element reaches a predetermined reference value, the data input to the digital-to-analog conversion means when the reference value is reached is stored in a storage device, and the stored data is stored in the storage device. By using the data to be output to the digital-to-analog conversion means when reading the image on the document surface, the light intensity of each light emitting element is controlled based on the data without having to adjust the light intensity of the light source one by one, so that the reading point is always the same. Under these conditions, the same reading can be performed and the image reading can be performed accurately and reliably, which has an excellent effect.

[Brief explanation of drawings]

Fig. 1 is a principle diagram showing the principle of image reading, Fig. 2 is an electric block circuit diagram of a conventional optical image reading device, Fig. 3 is a conventional drive control circuit diagram, and Fig. 4 a and b are from an amplifier. 5 is a plan view of an optical image reading device embodying the present invention, FIG. 6 is a side view, and FIG. 7 is an electric block circuit diagram.
Fig. 8 is a drive control circuit diagram, Fig. 9 is an output waveform diagram showing the output waveform of an analog signal output from the D/A converter based on test data, and Fig. 10 is a flowchart showing the operation of the central processing unit. It is a diagram. Optical image reading device 19, central processing unit (CPU) 21 as means, multiplexer 23, D/A converter 24 as digital-to-analog conversion means, readable and rewritable memory (RAM) as storage device
28, light emitting elements L1 to Ln as light sources, light emitting side optical fibers T to Tn, photoelectric conversion element P1, reading points D1 to
Dn, receiving side optical fibers R1 to Rn, amplifier A1. Patent applicant Brother Industries, Ltd. Representative Patent attorney Hiroshi Onda

Claims (1)

[Claims] A plurality of light sources (L1 to Ln) based on input data.
digital-to-analog conversion means (24) for controlling each light amount; a plurality of light-emitting side optical fibers (T1 to Tn) provided opposite to each of the light sources (L1 to Ln); It is provided facing the optical fibers (T1 to Tn), and emits light from the light-emitting side optical fibers (T1 to Tn) to illuminate the document surface (
12a); a plurality of photoreceptor photometric fibers (R1 to Rn) for receiving the light reflected from the decile; a photoelectric conversion element (P1) connected to the light receiving side optical fibers (R1 to Rn); means (21) for sequentially changing the light UIi emitted from the light source (L1-Ln) for each of the light sources (L1-Ln) by changing the data input to the analog-to-video conversion means (24); , the photoelectric conversion element (P1)
Detects the output from the light source and inputs it to the digital-to-analog conversion means (24) when the output reaches a certain reference value (k) as the light amount of the light source <L1 to Ln) changes. means (21) for storing data in a storage device (28) for each of the plurality of light-receiving side optical fibers (R1 to Rn); An optical image characterized in that it comprises means (21) for sequentially reading data stored in the device (28) and inputting the read data to the digital-to-analog conversion means (24). reading device.