JPH0940227A - Device for identifying medium for printing, and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and surely identify the kind of a medium for printing. SOLUTION: A sensor 112A located on the front side of a medium 110 for printing includes a light emitting diode 201 and a photocell 202, and a sensor 112B located on the back side of the medium 110 for printing includes a light emitting diode 203 and a photocell 204; the photocells 202, 204 sense the light reflected from and transmitted through the medium 110 for printing, respectively, and the kind of the medium 110 for printing is identified according to the results.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discriminating apparatus for discriminating the type of a print medium and a printing apparatus having the discriminating apparatus.

[0002]

2. Description of the Related Art A printing apparatus, depending on its printing method, includes an electrophotographic method, a thermal transfer method, a wire dot method,
The method can be roughly classified into an ink jet method and the like. In any of the methods, printing is carried out by adhering a pigment-based powder or ink called toner on a recording material such as paper or film. The print quality in such a printing apparatus largely depends on the print medium.

Therefore, conventionally, a method has been proposed in which the type of the print medium is discriminated and the print control is performed according to the ink absorption speed of the type to perform the optimum printing according to the type of the print medium. (JP-A-6-15861).

[0004]

However, the above proposed method is intended for paper as a print medium having different glossinesses on the front and back surfaces, and is applicable only to a limited type of print medium. It was possible. Therefore, so-called plain paper and OHP that are generally commercially available
(Overhead projector) It was not possible to cope with a large number of types of print media such as paper. Further, it is not configured to automatically determine the type of print medium.

It is an object of the present invention to provide a print medium discriminating apparatus which can discriminate the type of the print medium automatically and surely, and a printing apparatus provided with the discriminating apparatus.

[0006]

A discriminating apparatus for a print medium according to the present invention detects a characteristic on one side of a print medium and a characteristic on the other side of the print medium. It is characterized by comprising a second detecting means for detecting and a determining means for determining the type of the print medium based on the detection results of the first and second detecting means.

A printing apparatus of the present invention is characterized by comprising the above-mentioned printing medium discriminating apparatus, a carrying means for carrying the printing medium, and a print head for printing on the printing medium. .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic perspective view of a main part when the present invention is applied to an ink jet printer. In FIG. 1, 101 is a print head for ink jet printing, which is black or cyan. , Magenta, and heads for four colors of yellow are integrated. 102K, 102C, 102M, and 1
02Y is an ink tank for four colors of black, cyan, zenta, and yellow, 103 is a carriage, and 1 is an ink tank.
Reference numerals 04 and 105 are guide shafts of the carriage 103, 106 is a belt for moving the carriage 103, and 107 is a carriage motor for driving the carriage belt 106.

Reference numeral 108 is a flexible printed card (FPC) that connects the printer control board 111 and the print head 101, 109 is a paper feed roller, and 110
Is a paper as a print medium. Reference numeral 111 denotes a control board that controls printer functions such as the print head 101 and the carriage motor 107, and as shown in FIG. 2, the print head 101, the mechanism control means 211, and the notification means 212 are connected. 112A, 112
B is a sensor of the print medium arranged at a position facing the front and back surfaces of the paper 110.

FIG. 2 is a diagram for explaining the sensors 112A and 112B, in which the description of the same reference numerals as those in FIG. 1 is omitted.

Reference numerals 201 and 203 are light emitting diodes as light emitting elements, 202 and 204 are photodiodes as light receiving elements, and the sensor 112A is a light emitting diode 2
01 and the photodiode 202 are housed in the same package. Similarly, the sensor 112B is
The light emitting diode 203 and the photodiode 204 are formed in the same package. 20
5, 206 are drive circuits for the sensors 112A and 112B, 2
07 is a micro processing unit (hereinafter referred to as "MP
"U"), 208 and 209 are input terminals of an analog-digital converter (hereinafter referred to as "AD converter") provided in the MPU 207. Reference numeral 210 is a printer control circuit for controlling the print head 101, the carriage motor 107, and the like. Reference numeral 211 denotes a mechanism control unit that controls a mechanism such as a paper feed motor and an operation switch (not shown) of the carriage motor 107,
Is a notification means for the user, which includes a buzzer and a display element.

FIG. 3 is an explanatory diagram of the drive circuits 205 and 206 of the sensors 112A and 112B. In the figure, the former drive circuit 205 is shown as a representative. 301 is an operational amplifier for amplifying a photocurrent as a detection signal of the photodiode 202, 302 is a feedback resistor for determining the amplification factor of the operational amplifier 301, 303 is an output line for outputting the amplification result, and 304 is a light emitting diode 201. Is the current limiting resistance of.

Next, the operation of this embodiment will be described with reference to FIGS.

First, when the printer control board 111 receives print data sent from a host computer (not shown), the print data is expanded, and at the same time, a paper feed motor (not shown) is driven to serve as a print medium. Paper 110 is fed. In this process, the paper 110 is fed by the two sensors 112A and 112A.
Pass the detection position of B. At that time, the light emitting diode 20
3 is turned off and the light emitting diode 201 is caused to emit light, and the paper 1
The photodiode 202 detects the amount of reflected light from the sheet 10, and at the same time, the photodiode 204 detects the amount of transmitted light of the paper 110. Then, conversely, the light emitting diode 201 is turned off and the light emitting diode 203 is caused to emit light, and the amount of light reflected from the paper 110 is measured by the photodiode
4 and at the same time, the amount of light transmitted through the paper 110 is detected by the photodiode 202.

Then, the photodiodes 202 and 204
The detected signal of 1 is amplified by the corresponding drive circuits 205 and 206, and then read as a voltage change by the AD converters 208 and 209 provided in the MPU 207.

FIGS. 4 to 7 are views for explaining an example of detection when the paper 110 is plain paper.

Reference numeral 110 in the drawing denotes a plain paper which is a paper to be detected, and as shown in the drawing, the front surface and the back surface are relatively rough due to the fiber component of the paper. In FIG. 4, 401 is incident light emitted from the light emitting diode 201, and 402 is reflected light that is reflected by the surface of the paper 110 and is detected by the photodiode 202. Most of the incident light 401 is reflected as reflected light 402, and depending on the surface roughness of the paper 110, as shown in FIG.
As shown in (a), the detection signal of the reflected light 402 has a magnitude difference and a periodic fluctuation. In FIG. 4, reference numeral 403 denotes transmitted light from the front surface to the back surface of the paper 110, which is detected by the photodiode 204. The transmitted light 403 is a portion of the incident light 401 that has been transmitted, and the detection signal thereof undergoes periodic fluctuations having the same tendency as the reflected light 402 as shown in FIG. 5B.

Similarly, in FIG. 6, 404 is the incident light emitted from the light emitting diode 203, and 405 is the paper 1.
It is the reflected light that is reflected by the back surface of 10 and detected by the photodiode 204. The reflected light 405 is the incident light 4
Most of 04 is reflected, and depending on the roughness of the back surface of the sheet 110, a difference in detection signal and periodic fluctuation occur as shown in FIG. 7A. Reference numeral 406 denotes transmitted light from the back surface to the front surface of the paper 110, and the photodiode 202
Is detected by The transmitted light 406 is the incident light 40
A small part of 4 is transmitted, and the detection signal is
As shown in FIG. 7B, periodic fluctuations having the same tendency as the reflected light 405 occur.

FIGS. 8 to 11 are views for explaining an example of detection when the paper 110 is an OHP paper.

In FIG. 8, 110 is an O to be detected.
It is HP paper, and as shown in the figure, its front and back surfaces are relatively flat, and its transparency is high in its application. In FIG. 8, 501 is incident light emitted from the light emitting diode 201, and 502 is reflected light reflected from the surface of the paper 110 and detected by the photodiode 202. The reflected light 502 is a reflection of only a small part of the incident light 401, and since the surface of the OHP paper 110 is flat, the detection signal thereof has a small fluctuation and a small output as shown in FIG. 9A. Reference numeral 503 denotes transmitted light from the front surface to the back surface of the paper 110, which is detected by the photodiode 204. Most of the incident light 501 is transmitted as the transmitted light 503, and the detection signal thereof is as shown in FIG.
As shown in (b), the fluctuation is small and the output is large.

Similarly, reference numeral 504 in FIG. 10 denotes incident light emitted from the light emitting diode 203, and 505 denotes reflected light from the back surface of the paper 110, which is detected by the photodiode 204. The reflected light 505 is a reflection of a small part of the incident light 504, and since the back surface of the OHP paper 110 is flat, its detection signal has a small fluctuation and a small output as shown in FIG. 11A. Reference numeral 506 denotes transmitted light from the back surface to the front surface of the paper 110, which is detected by the photodiode 202. The transmitted light 506 is the incident light 504.
Is transmitted, and the detection signal is as shown in FIG.
1 (b), the fluctuation is small and the output is large.

12 to 15 are diagrams for explaining an example of detection when the paper 110 is a coated paper.

In FIG. 12, reference numeral 110 denotes a coated paper as a detection target, and the coating layer 601 is formed by applying silica or the like to the surface of the plain paper shown in FIG. 4 to improve the ink adhesion. It is a thing. Therefore, the surface of the coated paper 110 is flat due to the coating layer 601, and the back surface thereof is relatively rough due to the fiber component like the plain paper.

In FIG. 12, 602 is a light emitting diode 201.
The incident light 603 emitted from the device is reflected light which is reflected by the surface of the coated paper 110 and detected by the photodiode 202. The reflected light 603 is a reflection of most of the incident light 602, and the detection signal thereof has a small fluctuation as shown in FIG. 13A because the surface of the paper 110 is flat. Reference numeral 604 denotes transmitted light from the front surface to the back surface of the paper 110, which is detected by the photodiode 204. A small part of the incident light 602 is transmitted through the transmitted light 604, and the detection signal thereof is small as shown in FIG. 13B, and is caused by uneven thickness of the plain paper portion of the paper 110. Some periodic fluctuations are confirmed.

Similarly, reference numeral 605 in FIG. 14 denotes incident light emitted from the light emitting diode 203, and 606 denotes the paper 110.
Is the reflected light that is reflected from the back surface of the and detected by the photodiode 204. The reflected light 606 is the incident light 605.
Is reflected, and the detection signal thereof is, as in FIG. 15A, similar to the reflected light 405 described above,
Differences in size and periodic fluctuations occur depending on the roughness of the back surface of the sheet 110. Reference numeral 607 denotes transmitted light from the back surface to the front surface of the paper 110, which is detected by the photodiode 202. The transmitted light 607 is a portion of the incident light 605 that has been transmitted, and the detection signal thereof is small as shown in FIG. 15B, and has periodic fluctuations similar to those of the transmitted light 604 of FIG. 12 described above. Is confirmed.

As described above, the two sensors 205, 20
The reflected light and the transmitted light when the paper 110 passes between 6 are detected, and the type of the paper 110 is detected from the difference between the output level of the detection signal and the fluctuation cycle. And
The printing method is changed according to the type of the paper 110. For example, the print mode is switched in consideration of the difference in ink absorption speed for each type of paper 110.
The print mode is, for example, Japanese Patent Laid-Open No. 6-400.
No. 38, the number of scans for one image area is changed, the mask for masking the print area divided for each scan is changed, and the size of the divided print area is changed. By changing or appropriately selecting divided unidirectional printing (printing is performed only when the carriage 103 scans in one direction) or bidirectional printing (printing is performed when the carriage 103 reciprocally scans), the paper 110 of the paper 110 is changed. By setting a printing method according to the ink absorption speed and the like, it is possible to prevent bleeding due to the attraction of ink and print a high-quality image.

(Other Embodiments) FIG. 16 shows a second embodiment of the present invention. The present embodiment has a configuration including phototransistors 701 and 702 in place of the photodiodes 202 and 204 in the first embodiment described above, and has a detection accuracy higher than that of the first embodiment described above. Drive circuits 205, 20 including the operational amplifier 301, etc.
Since 6 is not necessary, the cost can be reduced.

FIG. 17 shows a third embodiment of the present invention.
In this embodiment, contact type detection means is provided in place of the sensors 112A and 112B as the optical detection means in the first embodiment described above. That is, in the figure, reference numerals 801 and 804 are contact elements that contact the front and back surfaces of the sheet 110, 802 and 805 are permanent magnets mechanically coupled to the contact elements 801 and 802, 803 and 806 are detection coils, and 80.
Reference numerals 7 and 808 are amplifiers.

The operation of the third embodiment will be described below.

In the process of feeding the paper 110, the contacts 801 and 804 are vertically displaced together with the permanent magnets 802 and 805 according to the roughness of the front and back surfaces of the paper 110. The induced power generated in the coils 803 and 806 due to such displacement of the permanent magnets 802 and 805 is generated by the amplifier 8
After being amplified by 07 and 808, they are input to AD converters 208 and 209 provided in the MPU 207, whereby the roughness of the front surface and the back surface of the paper 110 is detected. Then, the type of the sheet 110 is determined based on the detected content. In the case of the present embodiment, detection of OHP paper becomes somewhat difficult.

FIG. 18 shows a fourth embodiment of the present invention.
In this embodiment, the optical detecting means in the first embodiment and the contact detecting means in the third embodiment are combined. In this embodiment, since the transmitted light of the paper 110 is detected by the optical detecting means, the OHP paper can be easily detected.

If either the front or back of the coated paper is designated as the print surface,
The front and back sides are identified, and the paper 1 as a print medium
It is possible to recognize that 10 is erroneously set on the front and back, or recognize that a sheet 110 other than the designated type is set, and notify the user of the result.

Further, the printing method is not limited to the ink jet method at all, and the electrophotographic method, thermal transfer method,
Of course, it can be applied to various types of printers such as the wire dot type. Furthermore, the present invention is not limited to a printer, but can be applied to a recording device such as a copying machine.

Further, the number of the detection means of the print medium is not limited to two at all, and by providing two or more detection means or a combination of a plurality of types of detection means, higher accuracy can be obtained. It is possible to detect various things.

[0035]

As described above, the present invention discriminates the type of the print medium by using a plurality of detecting means for detecting the control of both sides of the print medium, so that the so-called plain paper or OHP is used. It is possible to reliably discriminate a large number of types of print media such as paper and perform various functions based on the discrimination result.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a printing apparatus according to the present invention.

FIG. 2 is a circuit configuration diagram of a detection unit in the first embodiment of the present invention.

FIG. 3 is a circuit configuration diagram of the drive circuit shown in FIG.

FIG. 4 is a side view for explaining one state of the plain paper detection operation by the detection means shown in FIG.

5 is an explanatory diagram of a detection result by the detection operation of FIG.

6 is a side view for explaining another state of the plain paper detection operation by the detection means shown in FIG. 2. FIG.

FIG. 7 is an explanatory diagram of a detection result by the detection operation of FIG.

FIG. 8 is a side view for explaining one state of the detection operation of the OHP sheet by the detection unit shown in FIG.

9 is an explanatory diagram of a detection result by the detection operation of FIG.

10 is a side view for explaining another state of the OHP sheet detection operation by the detection means shown in FIG.

11 is an explanatory diagram of a detection result by the detection operation of FIG.

FIG. 12 is a side view for explaining one state of the detection operation of the coated paper by the detection means shown in FIG.

13 is an explanatory diagram of a detection result of the detection operation of FIG.

14 is a side view for explaining another state of the detection operation of the coated paper by the detection means shown in FIG.

15 is an explanatory diagram of a detection result by the detection operation of FIG.

FIG. 16 is a circuit configuration diagram of a detection unit according to a second embodiment of the present invention.

FIG. 17 is a circuit configuration diagram of a detecting means in a third embodiment of the present invention.

FIG. 18 is a circuit configuration diagram of a detection means in a fourth embodiment of the present invention.

[Explanation of symbols]

 101 print head 102 ink tank 103 carriage 110 print medium 112A, 112B detection sensor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Noriyuki Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Uemura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Nobuyuki Tsukada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (9)

[Claims] 1. A first detecting means for detecting a characteristic of one side of a print medium, a second detecting means for detecting a characteristic of the other side of the print medium, and the first and second aspects. And a discriminating unit for discriminating the type of the print medium based on the detection result of the detecting unit. 2. The first and second detection means continuously detect the characteristics of one surface side and the other surface side of the print medium while being relatively displaced with respect to the print medium. The apparatus for discriminating a print medium according to claim 1. 3. The method according to claim 1, wherein at least one of the first and second detection units has a detection unit that detects reflected light of the light emitted to the print medium. Device for discriminating printed medium. 4. The method according to claim 1, wherein at least one of the first and second detection units has a detection unit that detects the transmitted light of the light with which the print medium is irradiated. Device for discriminating printed medium. 5. The at least one of the first and second detecting means has a contactor which is in contact with one surface or the other surface of the print medium to detect the surface roughness. Alternatively, the print medium determination device according to the second aspect. 6. The apparatus for discriminating a print medium according to claim 1, further comprising display means for displaying a discrimination result of the discrimination means. 7. A print medium discriminating apparatus according to claim 1, a transport unit for transporting the print medium, and a print head for printing on the print medium. A printing device characterized by. 8. The printing apparatus according to claim 7, further comprising means for changing a drive system of the print head based on a determination result of the determination means. 9. A front / back surface detecting unit for detecting a front / back direction in a set state of the print medium based on a result of the judgment by the discriminating unit, and a detection result of the front / back detecting unit is a regular front / back surface of the print medium. 9. The printing apparatus according to claim 7, further comprising a notification unit that notifies that the print medium is in an erroneous set state when the direction is different.