JP2006218802A - Printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing device which accurately performs the paper kind discrimination between regular papers and coated papers. <P>SOLUTION: A detecting means for the kind of a medium to be recorded is constituted in such a manner that a plurality of different points can be sampled on the same medium to be recorded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing apparatus including a recording medium type detection device.

  2. Description of the Related Art Conventionally, devices such as printers and printing machines that perform recording on a recording medium such as recording paper with ink have been widely used.

  In recent years, the types of recording media have diversified with market demands and the development of recording equipment. Recording paper, postcards and other thick paper with improved ink quality by providing an ink-receiving layer on the paper surface, fabrics that can be recorded with a printer, etc. A wide variety of recording media have been put into practical use.

  An ink jet printer is a representative device that supports these various recording media.

  In an ink jet printer, the degree of bleed and color development on the ink medium varies depending on the type of recording medium. Therefore, in order to obtain the best image quality, the ink discharge amount and the number of ink discharges are set according to the medium, and this setting is performed by the user instructing the medium type from the instruction means of the host computer or printer.

  As the types of recording media increase, the number of options for this instruction increases, which adds complexity to the user and makes it impossible to warn the user from the printer even if an incorrect instruction is given. Despite the use of special paper that can be printed, it is possible to output a recorded material with inferior image quality.

  Also, when there is no printer near the user, such as a network printer that is shared by multiple people, it is necessary to go to the printer location to check what type of recording medium is stored in the recording medium storage unit. After checking, it is necessary to indicate the medium type, which is inefficient.

  In order to solve such problems, a device for detecting the type of the recording medium has been devised, and a representative one is to measure the difference in reflectance on the surface of the recording medium as described in Patent Document 1, In this method, the type is determined by the threshold method.

  However, in this discrimination method, even when discrimination between plain paper and OHP sheet or glossy paper is possible, for example, when discrimination by a very small difference in reflectance is required, such as plain paper and coated paper, Accurate discrimination was difficult because the measurement values sometimes overlapped.

Therefore, a device for discriminating the type of recording medium in more detail has been devised. A typical one is to measure a multidirectional reflectance coefficient using a plurality of light receiving elements as disclosed in Patent Document 2. This method is also a method for discriminating a genuine OHP sheet by reading a detection mark portion and other portions on the same sheet as disclosed in Patent Document 3.
Japanese Patent Laid-Open No. 2-138805 Japanese Patent Laid-Open No. 8-48438 JP-A-7-175369

  However, in the method described in Patent Document 2, in the case of discrimination between plain paper and coated paper, the measurement value may exceed the threshold value and may not be accurately discriminated. In addition, the method described in Patent Document 3 may be inconvenient because it cannot be determined in detail other than genuine paper with a specific mark.

  The present invention has been made in view of the above circumstances, and a printing apparatus provided with a recording medium type detection device that can accurately determine the type of recording medium even in the case of discrimination between plain paper and coated paper. It is intended to provide.

  For this reason, the present invention aims to achieve the above object by providing a recording medium type detection means comprising an illumination means and a photoelectric conversion means so that a plurality of different points on the same recording medium can be sampled. To do.

  That is, the technical contents of the present invention can solve the above-described problems by including the following configuration.

  (1) A recording medium storage unit capable of storing a plurality of recording media to be printed, a feeding means for feeding the recording media one by one from the recording medium storage unit, In a printing apparatus provided with a recording medium type detecting means capable of discriminating the type of recording medium, the recording medium type detecting means receives illumination light for irradiating the recording medium and reflected light from the recording medium. A printing apparatus comprising photoelectric conversion means for performing photoelectric conversion and configured to sample a plurality of different points on the same recording medium.

  According to the present invention, a recording medium storage unit that can store a plurality of recording media to be printed, a feeding unit that feeds the recording media one by one from the recording medium storage unit, and the same recording target By providing a recording medium type detection means configured to sample a plurality of different points on the medium, it is possible to accurately determine the type of recording medium even in the case of discrimination between plain paper and coated paper. A printing apparatus provided with a medium type detection apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, what attached | subjected the same code | symbol has the same structure or effect | action, The duplication description about these shall be abbreviate | omitted suitably.

<Embodiment 1>
FIG. 1 is a perspective view of a printing apparatus 1 provided with a recording medium type detection apparatus according to the present invention. Here, 2 is a recording medium storage unit, and 3 is a recording medium stored in the recording medium storage unit 2.

  FIG. 2 is a longitudinal sectional view of the printing apparatus 1 including a recording medium type detection device.

  A case where printing is performed will be described with reference to FIG. First, the type of the recording medium 3 at the top of the recording medium storage unit 2 is discriminated by the recording medium type detection unit 4, and conditions for optimal printing are prepared.

  Next, when a printing instruction is issued, the recording medium 3 stored in the recording medium storage unit 2 is fed one by one from the recording medium storage unit 2 by rotation of a paper supply roller (not shown). 21 is inserted into the nip portion between the transport rollers 22 and 23 and transported to a designated printing position, then printing by the print head 24 on the carriage (not shown) is performed along with the line feed of the recording medium 3. Subsequently, the paper is discharged in the Z direction through the paper discharge roller 25 and the spur 26 which is a pressing portion.

  Here, the recording medium type detection unit 4 is rotatably attached to a chassis (not shown) of the printing apparatus 1 at a point P and is urged in the A direction by a spring (not shown) and the supporting member. 5 and the recording medium type detection unit 4 on the recording medium storage unit 2 by a spring 6 that adjusts the position of the recording medium type detection unit 4 according to the difference in the remaining amount of the recording medium 3. When the recording medium 3 is fed, it is supported by the shaft 7 that moves in the B direction in conjunction with the rotation of a feeding roller (not shown). Since the member 5 is rotated in the C direction, the bias to the surface of the recording medium 3 is released, and smooth paper feeding can be performed.

  Further, when the recording medium 3 is set in the recording medium storage unit 2, the spring 6 is moved by a force for setting the recording medium 3 that has entered below using the inclined surface portion 4 c of the recording medium type detection unit 4. In addition to being able to be contracted, rollers 47 and 48 that are pivotally supported by the recording medium type detection unit 4 and rotate in accordance with the movement of the recording medium 3 are provided, so that the setting can be performed smoothly. .

  FIG. 3 shows the recording medium type detection unit 4 that is detecting the type of the recording medium 3. Here, for example, when the light emitting unit 41 made of LED is caused to emit light, the light emitted from the light emitting unit 41 is formed on the surface of the recording medium 3 by a light guide 42 made of a transparent resin suitable for transmitting light. The angle from the vertical direction, the so-called normal angle, is branched left and right into two angles of θ1, and the surface of the recording medium 3 is illuminated. Here, it is assumed that the illumination in the two directions is adjusted so that the amount of light is equal.

  Reference numerals 43 and 44 denote photodiodes or phototransistors that receive light diffusely reflected from the recording medium 3 at a normal angle of 0 degrees, perform photoelectric conversion according to the amount of incident light, and output an electrical signal. Here, it is assumed that the sensors 43 and 44 are selected or adjusted so as to have equivalent sensitivity characteristics.

  Reference numerals 45 and 46 denote sensors composed of photodiodes or phototransistors that receive light regularly reflected from the recording medium 3 at the normal angle θ1, and perform photoelectric conversion according to the amount of incident light and output electric signals. Here, it is assumed that the sensors 45 and 46 are selected or adjusted so as to have equivalent sensitivity characteristics.

  It is possible to determine the type of the recording medium 3 by combining the electrical signal output by the diffuse reflected light and the electrical signal output by the regular reflected light and comparing the value with each recording medium stored in advance as data. I can do it.

  FIG. 4 shows the specular reflection sensor output when plain paper ([1], [2], [3]) and coated paper ([1], [2], [3]) are used as the recording medium 3. The value divided by the diffused light sensor output is shown. Here, a value using 43 and 45 sensors is A, and a value using 44 and 46 sensors is B.

  In this case, the difference between the values of the plain paper and the coated paper is small, and depending on the media, the vertical relationship of the values may be reversed, and the discrimination cannot be made well.

  This is the same as the system configuration for sampling only one normal location.

  FIG. 5 shows the specular reflection sensor output when the recording medium 3 is plain paper ([1], [2], [3]) and coated paper ([1], [2], [3]). The value divided by the diffused light sensor output and the variation of the values (A, B) are shown. Here, a value using 43 and 45 sensors is A, and a value using 44 and 46 sensors is B.

  In this case, the surface of the plain paper is rough due to the fiber of the paper, so that the variation is large. However, the surface of the coated paper is smooth and small because of the coating treatment. By checking this variation, it is possible to accurately discriminate between plain paper and coated paper.

<Embodiment 2>
In the first embodiment described above, the light guide 42 that branches light may be branched in multiple directions, not more than two directions, and may be realized using a prism. Alternatively, it may be realized using a mirror.

<Embodiment 3>
In the above-described first embodiment, as means for sampling a plurality of different points on the same recording medium 3, the light branch using the light guide 42 and a plurality of diffused light sensors and regular reflection light sensors are used. As described above, a configuration using a plurality of recording medium type detection units 4 having equivalent characteristics, a configuration in which the recording medium type detection unit 4 is moved for each sampling, and a plurality of point data are collected, or sampling is performed. The recording medium 3 may be moved every time to collect a plurality of point data.

1 is a perspective view of a printing apparatus including a recording medium type detection device according to the present invention. 1 is a longitudinal sectional view of a printing apparatus provided with a recording medium type detection device according to the present invention. It is explanatory drawing of the recording medium kind detection unit which concerns on this invention. It is data and a graph of sensor output concerning the present invention. It is data and a graph of sensor output concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing apparatus main body provided with recording medium type detection apparatus 2 Recording medium storage part 3 Recording medium 4 Recording medium type detection unit 4c Slope part 5 Support member 6 Spring 7 Shaft 21 Paper feed port 22, 23 Conveyance roller 24 Print head 25 Paper discharge roller 26 Spur 41 Light emitting part 42 Light guides 43, 44 Light receiving parts 45, 46 for diffused light Light receiving parts 47, 48 for specularly reflected light

Claims (2)

A recording medium storage unit capable of storing a plurality of recording media to be printed; and
A feeding means for feeding the recording medium one by one from the recording medium storage unit;
A recording medium type detecting means capable of determining the type of the recording medium at the top;
In the printing apparatus provided with
The recording medium type detecting means is an illuminating means for irradiating the recording medium;
It consists of photoelectric conversion means that receives reflected light from the recording medium and photoelectrically converts it,
A printing apparatus configured to be able to sample a plurality of different points on the same recording medium. In the illuminating means constituting the recording medium type detecting means,
The printing apparatus according to claim 1, wherein the printing apparatus is configured so that light from one light source can be branched to irradiate a plurality of points on the recording medium.

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