JPH0818726A - Device for identifying recording medium - Google Patents

Abstract

PURPOSE:To stabilize the identification of a number of media by detecting a recording medium by the combination of reflected light and transmitted light, converting a shape difference on the surface of the medium into an electric output difference by a reflected light detecting means and converting the thickness and density differences of the medium into electric output differences by a transmitted light detecting means. CONSTITUTION:Output difference between a reflected light receiving element 202 and a transmitted light receiving element 203 and the sum of then are respectively found out by a difference circuit 204 and an adder circuit 205 and the output of the circuit 204 is divided by the output of the circuit 205 through a divider circuit 206. Thus the generation of error decision due to the displacement of a medium and the tolerance of fixing positions between both light emitting and receiving elements can be prevented by obtaining such a relative value. An output from the circuit 206 is quantized by an A/D converter 207 and sent to a main CPU 100, which compares previously registered medium data with the output of the converter 207 to identify the medium. Then optimum picture processing and paper feeding is applied to the identified medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium identification device used in an image recording device.

[0002]

2. Description of the Related Art Conventionally, a recording medium is identified by arranging a light emitting element and a light receiving element on the printing surface side of the recording medium and reading the reflected light.

[0003]

However, the above-mentioned conventional example has the following problems.

Since the recording medium is identified only by the reflected light,
Only data was obtained on whether the surface of the recording medium was smooth or rough. Therefore, when the number of types of recording media has increased, it has not been possible to deal with it. Further, since the identification is performed directly from the read value, the identification result may be influenced by the displacement of the recording medium.

An object of the present invention is to provide a recording medium identification device capable of stably identifying various types of recording media.

[0006]

In order to achieve the above object, the invention according to the present application is characterized by detection by a combination of reflected light and transmitted light. In the above structure, the reflected light detecting means operates so as to convert the difference in the shape of the recording medium surface into the electrical output difference. Further, the transmitted light detecting means operates so as to convert the difference in thickness and density of the recording medium into an electrical output difference.

[0007]

【Example】

(First Embodiment) A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 is an external view of the digital color copying machine of this embodiment and the computer connected thereto.

The digital color copying machine 10 is roughly composed of two elements. That is, a color image scanner unit (hereinafter abbreviated as “reader unit”) 12 located above is a first major element. The reader unit 12 reads a document image in color and outputs digital color image data. The reader unit 12 includes a controller unit 14 that performs various image processing of digital color image data and has a processing function such as an interface with an external device. Further, there is a printer section 20 as a second major element, which is located below the reader section 12 and outputs a color digital image signal output from the controller section 14 of the reader section 12 to a recording medium. I am recording.

The reader unit 12 is placed on a document table (not shown) below the document holding plate 16 and faces downward. Images from documents of various shapes and sizes such as three-dimensional, sheet-shaped or large-sized sheet-shaped documents. It also has a built-in mechanism for reading information. In addition, on one side of the upper surface of the reader unit 12,
An operation unit 18 connected to the controller unit 14 is provided. The operation unit 18 is for inputting various information and operation instructions for the copying machine. Further, the controller unit 14 is configured to issue an operation instruction to the reader unit 12 and the printer unit 20 according to the information input via the operation unit 18. Then, when it is necessary to perform a complicated editing process or the like, a digitizer or the like is attached instead of the document pressing plate 16 and is connected to the controller unit 14, whereby more advanced image processing can be performed.

On the other hand, in the printer section 20 of this embodiment, a full-color ink jet using a recording head of an ink jet recording system using thermal energy as described in JP-A-54-59936 is used. -A printer is used. Note that the above-mentioned two main elements can be separated from each other, and can be set at positions separated from each other by extending the connection cable.

The reader unit 12 has an I / F cut such as GPIB, SCSI, etc., and is connected to the computer 12 via an I / F cable.

FIG. 4 is a side sectional view schematically showing the internal structure of the digital color copying machine 10 shown in FIG.

First, the structure of the reader unit 12 of the copying machine 10 will be described.

In the reader unit 12, the exposure lamp 2
2, an image of a document placed on the platen glass 28 by a lens 24, and an image sensor 26 (a CCD sensor is used in this embodiment) capable of reading a line image in full color, a projected image by a projector, or ,
The image of the sheet-shaped document is read by the sheet feeding mechanism 30. Next, various image processing for the image information read by the reader unit 12 in this manner is performed by the reader unit 1.
2 and the controller unit 14, and then read,
The image-processed information is sent to the printer unit 20 where it is recorded on a recording medium.

Next, in the printer section 20, the recording medium is a small-sized standard size (in the present embodiment, A4 size to A3 size) cut paper cassette 32 for storing cut sheets, and a large size (in this embodiment, A2 size). It is selectively supplied from the roll paper 34 for recording the size (A1 size to A1 size).
Paper feeding is started by a print start instruction from the controller unit 14, and is first conveyed to the position of the first paper feeding roller 44 through the following path. In the present embodiment, it is also possible to perform manual paper feeding (paper feeding from outside the apparatus) by manually inserting the recording media one by one from the manual feeding port 36 along the paper feeding unit cover 38. ing.

In the case of feeding a recording medium from the paper feed cassette 32 mounted in the printer unit 20, the paper feed cassette 32
A pick-up roller 40 for picking out cut sheets one by one from the sheet feeding cassette 32 is arranged on the upper surface of the sheet feeding end of the recording medium cassette. Therefore, by rotating the pick-up roller 40, the uppermost recording medium set in the paper feed cassette 32 is taken out, sent to the cut paper feed roller 42, and further fed by the roller 42. It is conveyed to the roller 44.

On the other hand, in the case of the roll paper 34, it is continuously sent out by a roll paper feed roller 46, this roll paper is cut into a standard length by a cutter 48, and is conveyed to the above-mentioned first paper feed roller 44 position. To be done.

Similarly, when the paper is manually fed from the manual feed port 36, the manually fed recording medium 50 is conveyed to the first paper feed roller 44.

Here, the pick-up roller 40, the cut paper feed roller 42, the roll paper feed roller 46, the first paper feed roller 44, and the manual feed roller 50 are a paper feed motor (not shown) (DC in this embodiment). It is driven by a servo motor), and an electromagnetic clutch attached to each roller allows ON / OFF control of the rotation drive at any time.

The recording medium selectively fed from any one of the above-mentioned paper feeding paths is conveyed to the position of the first paper feeding roller 44. The skew of the recording medium
In order to remove the above, when feeding, a predetermined amount of paper loop is formed on the recording medium, and then the feeding first roller 44 is turned on and driven to rotate, and then the recording medium is conveyed to the feeding second roller 45. Will be done.

Paper feed first roller 44 and paper feed second roller 45
Between the recording medium identification unit 209 and the recording medium identification unit 209
Is arranged. Here, the recording medium identification unit 209 will be described with reference to FIG. The recording medium 20 as shown in FIG.
On the print surface side of 0, the inclination θ of the optical axis of the light emitting element a201 (for example, b, c, and d below the LED is the same) is 0 <θ <90.
The light emitting element a201 is installed so as to be (degrees). At this time, the print surface side of the normal line of the recording medium 200 is set to θ = 0.
A light receiving element a202 for detecting specular reflection light (for example, a phototransistor or a photodiode, b, c, d below
The same applies) to the position of −θ, and the light receiving element b203 for detecting transmitted light is set to the position of θ + 180 °. These three elements are arranged on the same plane orthogonal to the recording medium. By arranging each element in this way, the light receiving element a2
In 02, the difference in surface roughness of the recording medium can be identified, and in the light receiving element b203, the difference in thickness and density of the recording medium can be identified.

Next, FIG. 2 shows a system of the recording medium identification unit. The difference between the output of the light receiving element a202 and the light receiving element b203 (in this embodiment, the output of the light receiving element a202 is subtracted from the output of the light receiving element b203) and the sum are obtained by the difference circuit 204.
Then, it is obtained from the addition circuit 205 and the output of the difference circuit 204 is divided by the output of the addition circuit 205 in the division circuit 206. By thus obtaining the relative values, it is possible to prevent erroneous judgments due to the displacement of the recording medium and the tolerance of the mounting positions of both the light emitting element and the light receiving element. The output result at this time is as shown in FIG. In FIG. 9, the horizontal axis represents the amount of displacement from the reference position, and the vertical axis represents the relative output obtained by calculation. Recording medium 1 of FIG.
The characteristics of light reflection and transmission of light from Nos. 6 to 6 will be briefly described below in relative terms. The recording medium 1 reflects light very much and hardly transmits it. The recording medium 2 reflects well and hardly transmits. Recording media 3 and 4 are medium reflective and medium transparent. The recording medium 5 is moderately reflective and relatively well transparent. The recording medium 6 is very well reflected and very well transmitted. From Fig. 9, the relative output difference of each recording medium is at least 10%.
Even if there is a difference in output, a sufficient threshold value can be set, so that a plurality of recording media can be identified. The output of the division circuit 206 is A /
It is quantized by the D converter 207 and sent to the main CPU 100. The main CPU 100 compares the data of the recording medium registered in advance with the output of the A / D converter 207 to identify the recording medium. Optimal image processing and paper feeding for the recording medium identified in this way is performed by the main image processing unit 106 and the printer control CPU 102 in FIG.
By.

Paper feed second roller 45 and paper feed third roller 52
In order to perform accurate paper feeding operation between the paper feeding roller 64 disposed on the upper side of the recording head 56 and the paper feeding third roller 52 disposed on the lower side, The medium is slackened by a predetermined amount to form a buffer. The buffer amount detection sensor 54 for detecting the buffer amount as the slack amount of the recording medium is provided in this buffer.
Is provided. By constantly forming a buffer in the recording medium conveyance path in this way, it is possible to reduce the load on the paper feed roller 64 and the third paper feed roller 52, particularly when a large-sized recording medium is conveyed. Accurate paper feed operation is possible.

In the printer section 20 having the recording medium conveying system as described above, when printing by the recording head 56, the scanning carriage 58 on which the recording head 56 is mounted scans the carriage rail 60. The motor 62 is configured to reciprocate in the front and back directions in the drawing to scan the recording medium in the main scanning direction. Then, in the forward scan, the image is printed on the recording medium by the recording head 56, and in the backward scan, the paper feeding roller 64 performs a feeding operation in the sub-scanning direction for feeding the recording medium by a predetermined amount.

Here, the feed amount in the sub-scanning direction is defined as a constant movement amount which will be described later, and here, the length corresponding to the width of the recording head 56 in the sub-scanning direction, that is, the figure is shown. Although not provided, it is formed over the surface portion of the platen 74 facing the recording head 56 and has a length corresponding to the width of the suction port. The suction port is for bringing the recording medium into close contact with the platen 74.
Further, in the conveyance drive control of the recording medium by the scanning motor 62 during the backward scanning, the buffer amount of the recording medium is detected by the buffer amount detection sensor 54, and the recording medium always has a predetermined buffer amount. Controlled by. Then, the recording medium thus printed is discharged to the paper discharge tray 66, and the series of printing operations described above is completed.

Next, referring to FIG. 5, the scanning carriage 58
The peripheral configuration will be described in detail. In FIG. 5, 6
Reference numeral 8 is a paper feed motor as a drive source for intermittently feeding the recording medium in the sub-scanning direction. The paper feed motor 68 is capable of setting / changing its rotation amount as desired, and it is provided with the paper feed roller 64 and the paper feed second roller clutch 7.
The sheet feeding second roller 52 is driven via 0. The above-mentioned scanning motor 62 is a drive source for reciprocally scanning the scanning carriage 58 along the main scanning direction indicated by arrows A and B via the scanning belt 72.

In this embodiment, pulse motors are used as the paper feed motor 68 and the scanning motor 62 because accurate paper feed control with an arbitrary feed amount is required. Further, in the present embodiment, a paper pressing member (not shown) is disposed at a position facing the lower end of the platen 74, and the paper pressing member is fixed to the platen during scanning of the scanning carriage 56, so that the recording medium The movement is controlled so that it does not occur.

When the recording medium reaches the second sheet feeding roller 52, the second sheet feeding roller clutch 70 and the sheet feeding motor 68 are turned on, and the leading end of the recording medium is nipped by the pair of sheet feeding rollers 64. Until it is conveyed, it is conveyed on the platen 74. Then, the conveyed recording medium is the platen 7
4 by the paper detection sensor 76 provided on the platen 7
It is detected that the sheet has been conveyed after passing through 4. This sensor information is used for position control, jam control, and the like. When the leading end of the recording medium reaches the paper feed roller 64 in this way, the second paper feed roller clutch 70 and the paper feed roller 68 are turned off, and then the inner space of the platen 74 is negatively activated by the activation of a suction motor (not shown). The pressure is applied and the suction operation is started. By such a suction operation, the recording medium is moved to the platen 7
4 will be closely attached. At this time, at the same time, the above-mentioned paper pressing member also fixes the recording medium to the platen.

Here, prior to the image printing operation on the recording medium, the scanning carriage 58 is moved to the home position.
It is moved to the position where the sensor 78 is installed, and then the arrow A
The forward scan is performed along the direction. In this forward scan, cyan "C", magenta "M",
Yellow (Y) and black (K) inks are appropriately ejected from the recording head 56 to record (print) an image. Then, when the image recording operation for a predetermined length in the main scanning direction is completed, the rotation direction of the scanning motor 62 is reversed to move the scanning carriage 58 in the reverse direction, that is, in the direction indicated by the arrow B, and then in the return path. Start scanning. At this time, the scan motor 62 moves the scan carriage 58 home.
It is reversely driven until it returns to the position where the position sensor 78 is provided.

During this backward scan, the paper feed motor 6
By driving 8 to rotate the paper feed roller 64, the paper feed operation is performed by the length in the sub-scanning direction (the width of the print head 56) recorded by the print head 56 indicated by the arrow C. . In this embodiment, the paper feed amount, that is, the movement amount in the sub-scanning direction is not limited to the constant movement amount corresponding to the width of the recording head 56 described above, but is defined by the final line width. It may be set to the one-sided movement amount.

In this embodiment, the recording head 56 is an ink
It is a jet nozzle with a total of 256 nozzles Y,
It is assembled for each color of M, C and K. The color printed in one scan can be arbitrarily selected.

On the other hand, when the scanning carriage 58 stops at the home position defined by the home position sensor, the recovery operation of the recording head 56 is performed. This recovery operation is a process for performing a stable recording operation,
This is a process for preventing unevenness at the start of ejection, which is caused by a change in viscosity of ink remaining in the nozzles of the recording head 56. In this process, a pressurizing operation is performed on each nozzle of the recording head 56 according to pre-programmed conditions such as a sheet feeding time, a temperature inside the apparatus, and an ejection time, and an idle ejection operation of ink is performed from each nozzle.

By repeating the operation described above, desired image recording is performed over the entire surface of the recording medium.

Next, the processing and control of the image signal of the control system in the digital color copying machine 10 of this embodiment will be described with reference to FIG.

In FIG. 6, reference numeral 100 is a main CPU that controls the entire apparatus.
Includes a printer control CPU 1 that controls the printer control operation.
02, reader control CPU 10 that controls the reading control operation
4, the main image processing unit 106 for processing the image display operation,
An operation unit 108 as an input unit by an operator, an I / F unit 123 for exchanging images and information with an external device (here, the computer 125), and an image storing an image sent via the I / F The memory unit 122 is connected. Here, the printer control CPU 102 and the reader control CPU 104 respectively control the operation of the printer unit and the reader unit, and are set in a master-slave relationship with the main CPU 100.

The main image processing unit 106 described above performs image processing such as masking, black extraction, binarization, and γ correction.
In addition, the printer control CPU 102 and the main image processing unit 10
6, a synchronous memory 110 is connected. The synchronous memory 110 is for absorbing the time variation of the input operation and correcting the delay due to the mechanical arrangement of the recording heads described above. The output of the synchronous memory 110 is connected to the recording head 56. Printer control CP
The U 102 is connected to a printer unit drive system 114 that controls the input drive of the printer unit. Also, the reader control unit C
The PU 104 is an input system image processing unit 11 that performs necessary correction processing in a reading system such as shading correction and color correction Y correction.
6 and a reader unit drive system 1 for controlling the input drive of the reader
18 is connected to. Furthermore, the input system image processing unit 11
A CCD line sensor 26 is connected to 6, and the input system image processing unit 116 is connected to the main image processing unit 106. Here, the reader unit 12 is the main CPU 1
00, reader control CPU 104, main image processing unit 10
6, operation unit 108, input system image processing unit 116, reader unit drive system 118, and CCD as an image sensor
It is composed of a line sensor 26.

Further, the printer section 20 has a printer control CP.
The U 102, the synchronous memory 110, the recording head 56, and the printer unit driving system 114. The synchronous memory is for absorbing the time variation of the input operation and correcting the delay due to the mechanical arrangement of the recording heads described above. The synchronous memory can store images for one band, and the stored images can be read out for each color at any time. Printer control CPU selects colors to read and print
Performed by 102.

(Second Embodiment) In the first embodiment, the recording medium is identified by two light receiving elements for one light emitting element. In the second embodiment, the light emitting element is as shown in FIG. One of the light receiving elements is used to identify the two. In FIG. 7, a light emitting element b21 for regular reflection light is provided on the printing surface side of the recording medium 200.
1. A light receiving element c210 is provided, and a light emitting element c212 for transmitted light is provided on the back side. The installation angle is the same as in the above-mentioned embodiment. The system at this time is shown in FIG. In this configuration, two data of specular reflection light and transmitted light
The difference circuit 204, the addition circuit 205, and the division circuit 20 which can be read every time and which are necessary in the first embodiment described above.
6 can be replaced with one of the amplifier circuits 213, and the cost can be suppressed.

(Other Embodiments) Although the present invention is applied to a digital color copying machine in the above-mentioned embodiments, the present invention is not limited to this and can be applied to all apparatuses that handle recording media.

[0041]

As described above, according to the present invention,
By identifying the recording medium from the relative relationship between the specular reflection light and the transmitted light, it is possible to stably identify many recording media.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a recording medium identification device according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of a recording medium identification device according to the first embodiment of the present invention.

FIG. 3 is an external view of a digital color copying machine having a recording medium identification device of the present invention.

FIG. 4 is a side sectional view showing an internal configuration of the digital color copying machine shown in FIG.

FIG. 5 is a configuration diagram around a scanning carriage of the digital color copying machine shown in FIG.

FIG. 6 is a block diagram of the digital color copying machine shown in FIG.

FIG. 7 is a configuration diagram of a recording medium identification device according to a second embodiment of the present invention.

FIG. 8 is a block configuration diagram of a recording medium identification device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between a displacement amount of a recording medium from a reference position and a relative output.

[Explanation of symbols]

 10 Digital Color Copier 12 Color Image Scanner 14 Controller Section 20 Printer Section 16 Original Press Plate 18 Operation Section 22 Exposure Lamp 24 Lens 26 Image Sensor 28 Original Plate Glass 30 Sheet Feed Mechanism 32 Paper Feed Cassette 34 Roll Paper 36 Manual Feed Port 38 Supply Paper cover 40 Pickup roller 44 Paper feed first roller 45 Paper feed second roller 46 Roll paper feed roller 48 Cutter 50 Manual feed roller 52 Paper feed third roller 54 Buffer amount detection sensor 56 Recording head 58 Operation carriage 60 Carriage rail 62 Scan Motor 64 Paper feed roller 66 Waste paper tray 68 Paper feed motor 70 Feeding second roller clutch 72 Scan belt 74 Platen 76 Paper detection sensor 78 Home position sensor 100 Main CPU 102 Printer control CPU 104 Reader control CPU 106 Main image processing unit 110 Synchronous memory 114 Printer unit driving system 116 Input system image processing unit 118 Reader unit driving system 122 Image memory unit 123 I / F unit 125 Computer 200 Recording medium 201 Light emitting element a 202 Light receiving element a 203 Light receiving element b 204 Difference circuit 205 Addition circuit 206 Dividing circuit 207 A / D converter 209 Recording medium identification section 210 Light receiving element c 211 Light emitting element b 212 Light emitting element c 213 Amplifying circuit

Claims (3)

[Claims] 1. A light emitting means for emitting light used for identifying a recording medium, a reflected light detecting means for reading light emitted from the light emitting means and reflected by the recording medium, and a recording medium emitted from the light emitting means. Transmitted light detecting means for reading the light transmitted through, a calculating means for calculating the data read by the reflected light detecting means or the transmitted light detecting means, and a memory for recording the data of the recording medium in advance. And a comparing means for comparing the data read by the both detecting means with the data in the memory. 2. A light emitting diode is arranged as a light emitting element in the vicinity of a surface of a recording medium, and a phototransistor or a photodiode is arranged as a light receiving element for reflected light on the same surface side, and a light emitting element is arranged through the recording medium. Is a phototransistor or photodiode as a light receiving element for transmitted light on the opposite side, and an arithmetic unit for calculating the outputs from the two light receiving elements to identify the recording medium and the data (threshold value) of the recording medium. 2. The recording medium identification device according to claim 1, further comprising a memory for storing the element, the element for reflected light and the element for transmitted light are combined, and the recording medium is identified by the relative value of the output. 3. A phototransistor or a photodiode is arranged near a surface of a recording medium as a light receiving element for simultaneously reading reflected light and transmitted light, and a light emitting diode is arranged on the same surface side as a light emitting element for reflected light. , A light emitting diode is arranged as a light emitting element for transmitting light on the side opposite to the light receiving element through the recording medium, and an arithmetic unit for identifying the recording medium by the output of the light receiving element, and the data (threshold value) of the recording medium A recording medium identification device, characterized by comprising a memory for storing, and identifying a recording medium by combining reflected light and transmitted light.