JP3293878B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for identifying the size and type of a recording medium and recording the data in an appropriate manner according to the result of the identification.

[0002]

2. Description of the Related Art Conventionally, a recording device such as a printer uses a dedicated roll paper or a designated cut paper. Also,
In a copying machine, cassettes corresponding to fixed size paper of each size are prepared, and the type of the cassette is generally identified by a microswitch or the like, thereby indirectly recognizing the paper size.

[0003]

However, a recent trend of printers is that rolled paper tends to be shunned due to a demand that the recorded output result can be used as it is as an official document. Is often used. In the case of using fixed-size paper, it is necessary to provide a discriminating means corresponding to the size of the cassette, which has been a factor of cost increase from the viewpoint of productivity.

In a color ink jet printer, since a plurality of colors of ink are ejected onto a recording medium, O
For a medium having poor ink absorption such as an HP (overhead projector) sheet, only a limited type of ink may be ejected at the same time, and the recording sequence is different from that of ordinary paper. Especially needed to be identified.

Further, even when non-standard paper is used, the width of the paper being used is accurately detected, ink is prevented from being ejected to unnecessary areas, and the inside of the machine is designed not to be stained. There is a need.

The present invention has been made in view of the above conventional example, and provides a recording apparatus capable of detecting the size and material of a medium used as a recording medium and the presence or absence of a recording medium with a simple configuration. The purpose is to do.

[0007]

To achieve the above object, the recording apparatus of the present invention has the following arrangement.

A recording medium supporting member for supporting a recording medium;
A light emitting means for irradiating light; a light receiving means for receiving light;
After irradiation from the light emitting means toward the recording medium support member,
It does not receive the specularly reflected light,
The light emitting means and the light receiving means so as to receive the reflected light.
And scanning for scanning over the recording medium support member.
Inspection means; and light receiving means for receiving light emitted from the light emitting means.
A part of the recording medium supporting member is provided so as to reflect light to the step.
And a light receiving means from the reflecting surface.
The reflected light reaching the recording medium support member and the recording medium
From the recording medium supported by the body support member to the light receiving means.
This is reflected light that is closer to regular reflection than reflected light.

[0009]

With the above arrangement, the recording apparatus of the present invention optically detects the type of the recording medium at the detection position, and recognizes whether or not there is a recording medium at the detection point, and if so, recognizes the type.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet printer will be described as an embodiment of the present invention. The configuration of the present embodiment is shown in FIGS.

[Structure of Printer] FIG. 1 is a view particularly illustrating a portion related to the present invention. The carriage 1 on which the ink jet recording heads 2 of four colors (black, cyan, magenta, and yellow) are mounted moves on the recording medium 7 in the direction of the arrow S, and the ink is printed on the recording medium in the recording area shown in FIG. Is ejected to record an image. Here, the movement of the carriage 1 is defined as main scanning. When one main scan is completed, the recording medium 7 is conveyed by a paper feed mechanism (not shown in FIG. 1) on the black painted sheet metal 4 by a predetermined distance (8 mm in the present invention) in a direction perpendicular to the paper surface. Is done. At the same time, the carriage 1 is returned to the position shown in FIG. Then, the above-described operation is repeated again to realize the recording corresponding to the length of the medium.

The carriage 1 is provided with a sensor unit 3 for sensing the width of the medium. This sensor detects the type, effective width, and presence / absence of the medium by a prescan performed before recording based on an optical idea described later.

FIG. 2 shows the structure of the printer of this embodiment. The control unit and the like are not included.

In the drawing, reference numeral 809 denotes a head cartridge having an ink jet recording head 2, and 1 denotes a carriage for mounting the head cartridge 809 and the sensor unit 3 and scanning in the S direction in the drawing. Reference numeral 813 denotes a hook for attaching the head cartridge 809 to the carriage 1, and reference numeral 815 denotes a lever for operating the hook 813. The lever 815 is provided with a marker 817 for indicating a scale provided on a cover, which will be described later, so as to be able to read a print position, a set position, and the like of the recording head 2 of the head cartridge. A support plate 819 supports an electrical connection to the head cartridge 809. Reference numeral 821 denotes a flexible cable for connecting the electrical connection unit and the main body control unit.

Reference numeral 823 denotes a guide shaft for guiding the carriage 1 in the S direction, and is inserted through a bearing 825 of the carriage 1. Reference numeral 827 denotes a timing belt to which the carriage 1 is fixed and which transmits power for moving the carriage 1 in the S direction, and pulleys 829 arranged on both sides of the apparatus.
A.829B. One pulley 829B
Is connected to the carriage motor 83 via a transmission mechanism such as a gear.
1 transmits the driving force.

Reference numeral 833 denotes a platen roller for regulating the recording surface of a recording medium such as paper (hereinafter also referred to as recording paper) and for transporting the recording medium during recording and the like. 837, a paper pan for guiding the recording medium to the recording position from the paper feed tray side;
Reference numeral denotes a feed roller which is disposed in the middle of the recording medium feeding path, presses the recording medium toward the platen roller 833, and conveys the recording medium. A discharge roller 841 is disposed downstream of the recording position in the recording medium transport direction and discharges the recording medium toward a discharge port (not shown). 8
Reference numeral 42 denotes a spur provided corresponding to the paper discharge roller 841, which presses the roller 841 via the recording medium to generate a conveyance force of the recording medium by the paper discharge roller 841. 843
Is a feed roller 839 for setting a recording medium, etc.
It is a release lever for releasing the urging of the holding plate 845 and the spur 842.

Reference numeral 845 denotes a pressing plate for suppressing the floating of the recording medium in the vicinity of the recording position and ensuring the close contact with the platen roller 833. In this embodiment, an ink jet recording head that performs recording by discharging ink from the recording head 2 is employed. Therefore, the distance between the ink discharge port forming surface of the recording head 2 and the recording surface of the recording medium is relatively small, and the distance must be strictly controlled to avoid contact between the recording medium and the discharge port forming surface. Therefore, the arrangement of the holding plate 845 is effective. Reference numeral 847 denotes a scale provided on the holding plate 845, and reference numeral 849 denotes a marker provided on the carriage 1 corresponding to the scale. The markers 847 can also read the print position and set position of the recording head 2.

Reference numeral 851 denotes a cap formed of an elastic material such as rubber which faces the ink ejection port forming surface of the recording head 2 in the home position, and is supported so as to be able to come into contact with / separate from the recording head 2. This cap 851
Is used for protection of the recording head at the time of non-recording or the like, and for ejection recovery processing of the recording head. In the ejection recovery process, ink is ejected from all ejection openings by driving an energy generating element provided inside the ink ejection openings and used for ink ejection, thereby causing bubbles, dust, and thickening. This is a process for removing the cause of ejection failure of ink or the like that is no longer suitable for printing (preliminary ejection), or a process for removing the cause of ejection failure by forcibly discharging ink from the ejection port separately from this.

Reference numeral 853 denotes a suction force for forcibly discharging ink, and a cap 85 for discharge recovery processing by such forced discharge and discharge recovery processing by preliminary discharge.
1 is a pump used to suck the ink required. Reference numeral 855 denotes a waste ink tank for storing the waste ink sucked by the pump 853, and reference numeral 857 denotes a tube for communicating the pump 853 with the waste ink tank 855.

Reference numeral 859 denotes a blade for wiping the discharge head forming surface of the recording head, which protrudes toward the recording head 2 and does not engage with the discharge port forming surface during wiping in the process of moving the head. It is movably supported to the retracted position. 861 is a recovery motor, and 863 is a pump 853 receiving power transmitted from the recovery motor 861.
And a cam device for moving the cap 851 and the blade 859, respectively.

FIG. 3 is a cross-sectional view showing an example of the positional relationship between the carriage 1 and the platen roller 833 in the printer having the structure described with reference to FIG. In this figure, the sensor unit 3 is located below the head 2 and a black painted sheet metal 4 is provided opposite thereto.

FIG. 4 is a block diagram of a part related to control of the sensor 3 and the printer. Control unit 31 of the printer body
Controls the printer by the operation of the CPU 311.
An A / D converter 312 is provided. Print data and control data are exchanged between the control unit 31 and the mechanism unit 32 shown in FIG. 2, and data obtained by the sensor 3 provided in the mechanism unit is also input to the control unit 31. This data is input to the A / D converter 312, converted into a digital signal, and then input to the CPU 311. CPU
Performs sequence control based on the value.

For example, if it is determined that there is no medium, the recording is not performed even if a recording instruction is given from the printer user, and a warning is output to the display unit to notify the user. . Further, even when irregular-sized paper is used, the width can be sensed by the mechanism and an optimum recording area can be set. Further, the OHP sheet can be identified by a detection method described later.

[Explanation of Sensor Unit] Now, the sensor unit 3 will be described. This unit is shown in FIG.
And a circuit shown in FIG. 6. The terminal indicated by V ₀ which 6 are inputted and processed to the A / D converter 312 of the control unit 31 as a detection output.

The reflection-type sensor unit 8 shown in FIG. 5 includes a light-emitting element 8A and a light-receiving element 8B, and slits 9A and 9B are provided as shown in FIG. Angle θ from perpendicular to recording medium 7
Are formed to emit light (referred to as a light projection angle) and to enter light at an angle θ (referred to as a light receiving angle). For example, an LED is used as the light emitting element 8A, and a phototransistor is used as the light receiving element 8B. Light exiting from the light emitting element 8A enters the recording medium 7 at a projection angle θ. The reflected light is received by the light receiving element 8B, and a current corresponding to the energy of the received light flows as a base current of the transistor Q1. As a result, the detection output V ₀ is output according to the energy received by the light receiving element. VR1 is a variable resistor for adjusting the gain of the circuit.

[Detection of Recording Medium] When the sensor unit as described above is used for a recording medium, if the recording medium is close to a regular reflector, the regular reflection light 10 having the same reflection angle as the incident angle is the main component. And the diffuse reflection component 11 is small. However, the surface of the paper is generally microscopically uneven with fibers as shown in FIG. 7, and the irregular reflection component 11 becomes large.

FIG. 9 shows a graph in which the detection output V ₀ is measured by the sensor unit 8 while changing the type of the recording medium and the mounting angle of the sensor. FIG. 9 shows a comparison between an OHP sheet and a coated paper used in the present embodiment (a paper having a surface on which a coating process is performed so that the ink is properly blurred). Here, the output V _{0 in} the case of coated paper is 3 V
Is adjusted by VR1 so that the output of the OHP sheet is measured in this state. As is apparent from this figure, when the measurement was made at several sensor mounting angles, the output level in the case of OHP paper was 1.8.
It can be seen that it has a width of V to 4.2V. The cause of this is shown in FIG.
0 to FIG. FIGS. 10 to 12 show the reflection characteristics of the sensor unit 3 for three types of media, ie, a mirror, an OHP sheet, and coated paper, and FIG. 13 shows a measurement system thereof. However, only for the mirror of FIG. 10,
Variable resistor VR compared to OHP sheet or coated paper
1 is the result of measurement with the circuit gain reduced. This is because, since the mirror has a high light reflectance, the detection output V ₀ is minimized in a region where the rotation angle α in FIG. 10 is a negative value, but the saturation voltage of the circuit is reached even in that case. That's why.

In the figure, 1 (ell) is the distance between the medium and the sensor.
The horizontal axis α is the distance between the medium and the sensor as shown in FIG.
Angle about a point at a distance of 35 mm
Every time( ^o ). Positive clockwise, My counterclockwise
The direction is eggplant. However, the circuit gain (VR1 in FIG. 3)
Value) is changed between the case of the mirror and the case of the other two types. Ma
The sensor used here has an emission angle smaller than the reception angle.
It is the one formed.

[0029] It can be seen from FIGS. 10 to 12, it OHP sheet to the first is almost the same characteristic as that of the mirror, i.e. specular reflection is mainly in the second coated paper output V ₀ is That is, there is little relation to the rotation angle α, that is, irregular reflection is mainly performed. 10 and 11
As described above, in the sensor used, α is 6
It has a peak output level around °. This will be described with reference to FIG. FIG. 14 is a diagram illustrating a light path from the light emitting unit 8A to the light receiving unit 8B. If θ _Tr = θ _LED , the light emitted from the light emitting unit 8A is reflected at the point d along the chain line and reaches the light receiving unit 8B. However, since θ _Tr > θ _LED , the light emitted from the light emitting unit 8A is incident on the point P on the medium along the line 121. Reference numeral 120 denotes a case where the inclination angle of the recording medium is 0.
And does not reach the light receiving section 8B. But,
By tilting the medium surface by the angle α as in the illustrated medium 123, the reflected light is incident on the light receiving element 8B along the line 124, and the maximum output can be obtained. For this reason, in the case of a regular reflection medium such as a mirror or an OHP sheet, the output V ₀ becomes maximum when the rotation angle of the medium is set at a certain angle in the plus direction.

It can be said from the above results that detecting the presence / absence, type, and effective width of the recording medium with one reflection type sensor 8 is not dependent on the mounting accuracy of the sensor (distance, horizontal position, etc.) or the characteristic (sensor specific). for reasons such as differences in directivity, etc.), it is that it is difficult to do based only on the absolute value of the output V ₀ level.

For this purpose, as a first feature, in the present embodiment, as shown in FIG. 1, a window 6 is provided in a part of a black painted sheet metal 4, and this part is a pseudo mirror surface 5 plated with Ni.
By doing so, the reflectance at the portion of the mirror surface 5 increases, and FIG.
Output characteristics such as 0 will be exhibited. Further, it is also effective to incline this pseudo mirror surface from a horizontal plane by an angle 取 り 付 け for mounting a sensor described later, so that the relationship between light emission and light reception of the sensor approaches regular reflection.

Further, as a second feature, FIG. 10 and FIG.
As described in 2, the directivity of the sensor 8 is preset so that the point shifted by a predetermined angle (6 ^{° in} this embodiment) has the highest sensitivity. That is, the sensor 8 was designed such that the highest sensitivity was obtained when the sensor 8 was rotated in the “+” direction in FIG.

A third feature of the present invention is that, as shown in FIG. 8, the relationship between the sensor and the recording medium is inclined by a predetermined angle に in the direction opposite to the direction in which the maximum sensitivity is obtained. This corresponds to the region where the rotation angle is “α <0” in FIG. 10, and as a result, the magnitude relationship between the absolute output levels of the OHP sheet and the coated sheet is set to “OHP sheet <
"Coated paper".

Due to the three characteristics described above, the detection output level for each recording medium by the apparatus of this embodiment is as shown in FIG.
It becomes as shown in. In the case of coated paper, it is indicated by a broken line in the figure,
As described above, the output level is set to 3.0 V in FIG.
Is adjusted. At this time, if the surface of the black painted sheet metal shown in FIG. 1 is sensed without placing any recording medium,
The output is about 0.3V. In the case of coated paper,
The output level of the window 6 is 3.0 V over the entire effective width of recording because the coated paper does not transmit light.

On the other hand, in the case of the OHP sheet, as shown by the solid line in the figure, about 70% of the light from the sensor 8 is transmitted through the window 6, and the transmitted light is reflected by the Ni-plate pseudo mirror surface. Most of the light passes through the OHP paper again and enters the light receiving element of the sensor 8. As described in the description of FIG. 10, since the pseudo mirror surface has an extremely high reflectance, the detection output of the sensor unit 3 is saturated. In the circuit of FIG. 6 used in this embodiment, the output level reaches the upper limit at 4.2 V, and the output level higher than this saturates at this voltage. Therefore, in the case of an OHP sheet, the output level at the window 6 is saturated as shown in FIG. In the portion other than the portion that hits the window 6 of the OHP sheet, as shown in FIG.
= 6 ^°, it corresponds to the point of α = -6 ^{° in} FIG. 11 and is about 1V. However, as described above, the value of 1 V has a variation due to a variation in directivity inherent in the sensor, a mounting accuracy of the sensor, and the like. Therefore, in this embodiment, as shown in FIG. Are determined to be OHP when the level difference ΔV ₀ between the output level in the portion corresponding to the above and the output level in other portions is equal to or larger than the predetermined value C. As described above, if the pseudo-mirror surface is also inclined by ψ so that the relationship between the pseudo-mirror surface and the light emission / reception of the sensor approaches regular reflection, the detection output level at the window is further assured.

When the recording medium is not present due to lack of paper or the like, the output is indicated by a one-dot chain point in FIG. 15, the output of the window portion is saturated at the upper limit, and the other portion (the normal recording medium is present) Effective area) is the output level of the black painted portion.

As can be understood from the above description, according to the printer of this embodiment, the material of the recording medium can be determined and the effective recording width of the recording medium can be detected. Not painted black sheet metal 4 in Fig. 1
It is possible to avoid a situation in which recording is performed erroneously on the top and the inside of the apparatus is stained with ink.

Further, according to the present embodiment, it is also detected whether or not the front end of the recording medium has been fed to a predetermined position, and whether or not the rear end of the recording medium has passed the predetermined position. It is possible.

By providing one sensor in this way, it is possible to determine the presence or absence of a recording medium to be used in the recording apparatus, to determine the type, and to detect the effective recording width. -Cost reduction can be achieved and cost performance can be improved.

The ink jet printer of the present embodiment may be an aero-jet type printer which discharges ink using an air flow, but is a type called a bubble jet type, the principle of which will be described below. You may.

[Explanation of Bubble Jet] FIG. 16 is an exploded view of the recording head 2 constituting the recording means, and FIGS. 17 (a) to 17 (g) are explanatory views of the bubble jet recording principle. The typical configuration and principle are described in, for example, U.S. Pat.
740,796.

In FIG. 16, reference numeral 209a denotes a heater board, which is an electrothermal converter (discharge heater) on a silicon substrate.
209b and an electrode 209c made of aluminum or the like for supplying electric power thereto are formed and disposed. A liquid path (nozzle) 2 for the recording liquid is provided to the heater board 209a.
It is constituted by bonding a top plate 209e having a partition wall for partitioning 09d. At a predetermined position of the apparatus, an ink cartridge for supplying ink to the recording head 209 is exchangeably mounted.

The ink supplied from the ink cartridge via the conduit is filled into a common liquid chamber 209g in the recording head 209 through a supply port 209f provided in the top plate 209e, and the common liquid output 209g is supplied to each nozzle 209g.
Guided into d. These nozzles 209d are provided with ink discharge ports 209h.
h is formed at a predetermined pitch in the sheet conveying direction so as to face the recording sheet of the recording head 209.

In this embodiment, the recording head 2 having the above-described configuration is mounted on a reciprocally movable carriage, and recording is performed by ejecting and flying ink from the recording head 2 in synchronization with the movement of the carriage.

Here, the principle of ink flying in the bubble jet recording system will be described with reference to FIGS. In the steady state, as shown in FIG. 17A, the surface tension and the external pressure of the ink 40 filled in the nozzle 209d are balanced at the ejection port surface. In this state, the ink 40
In the case of flying, the electric heat converter 209d in the nozzle 209d is energized, and the ink in the nozzle 209d exceeds the nucleate boiling and causes a rapid temperature rise. Then
As shown in FIG. 17 (b), the ink adjacent to the electrothermal converter 209b is heated to generate micro bubbles,
The ink in the heated portion is vaporized to cause film boiling, and FIG.
As shown in (c), the bubbles 41 grow rapidly.

When the bubble 41 grows to the maximum as shown in FIG. 17D, the ink droplet 42 is pushed out from the discharge port in the nozzle 209d. And the electrothermal converter 209b
When the power supply to the nozzle 209 is completed, the grown bubble 41 is cooled by the ink 40 in the nozzle 209d and contracts as shown in FIG. 17 (e), and the ink droplet is discharged by the growth and contraction of the bubble. Fly from. Further, as shown in FIG. 17 (f), the ink comes into contact with the surface of the electrothermal transducer 209b, is rapidly cooled, and the bubbles 41 disappear or shrink to a volume that can be almost ignored. When the bubble 41 contracts, as shown in FIG. 17 (g), ink is supplied from the common liquid chamber 209g into the nozzle 209d by the capillary action to prepare for the next energization.

Accordingly, the carriage on which such a recording head is mounted is reciprocated and, at the same time, a current is supplied to the electrothermal converter 209b in accordance with an image signal in synchronism with the movement, whereby an ink image is formed on the recording sheet. Is recorded.

As a configuration of the recording means, in addition to the above-described combination of the discharge port, the liquid path, and the electrothermal converter, US Pat.
333, JP-A-59-123670 and the like can also be employed.

The above-mentioned recording means may supply ink to the recording head from an ink cartridge mounted on the recording apparatus, or provide an ink storage chamber in the recording head so that the ink storage chamber has no ink. In such a case, a replaceable recording head that replaces the recording head may be used.

The operating principle of the bubble jet method is as described above.

In this embodiment, the recording head of the recording means is a recording head for performing recording by an ink jet method. However, the present invention is not limited to this. For example, a heat sensitive method, a thermal transfer method, a wire dot recording method Of course, a recording head for performing recording by an electrostatic recording method or the like may be used.

The recording apparatus is not limited to a printer, and the present invention can be applied to a facsimile apparatus, a copying machine, and the like.

[0053]

As described above, the recording apparatus of the present invention
The width and material of the medium used as the recording medium, as well as the presence or absence of the recording medium can be detected with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a recording unit of a recording apparatus according to an embodiment of the present invention.

FIG. 2

FIG. 3 is a structural diagram of the ink jet printer of the embodiment.

FIG. 4 is a block diagram of a control unit of the printer according to the embodiment.

FIG. 5 is a diagram illustrating a reflection type optical sensor according to an embodiment.

FIG. 6 is a diagram of a sensor circuit.

FIG. 7 is a diagram illustrating a diffuse reflection medium.

FIG. 8 is a diagram showing a state in which the sensor is attached at an angle according to the embodiment.

FIG. 9 is a diagram illustrating a relationship between a type of a recording medium and a detection output.

FIG. 10 is a graph showing detection output characteristics when a mirror is used as a recording medium.

FIG. 11 is a diagram showing detection output characteristics when an OHP sheet is used as a recording medium.

FIG. 12 is a detection output characteristic diagram when coated paper is used as a recording medium.

FIG. 13 is a view for explaining a measurement jig for changing a relative positional relationship between a sensor and a recording medium.

FIG. 14 is a diagram for explaining a directional characteristic of a sensor;

FIG. 15 is a comparison diagram of detection output characteristics of each recording medium according to the embodiment.

FIG. 16 is a structural diagram of a recording head of a bubble jet printer.

FIG. 17 is a diagram illustrating the principle of operation of a bubble jet printer.

Claims (7)

(57) [Claims] 1. A recording medium supporting member for supporting a recording medium.
When a light emitting means for irradiating light, a light receiving means for receiving light, after the irradiation toward the recording medium supporting member from said light emitting means
The light emitting means and the light receiving means are configured to receive the irregularly reflected light without receiving the specularly reflected light among the reflected light.
By arranging the stage and scanned over the recording medium support member
Scanning means for reflecting light emitted from the light emitting means to the light receiving means;
As described above, a countermeasure provided on a part of the recording medium support member is provided.
And a morphism surface, the reflected light reaching to the light receiving means from the reflecting surface, the recording
A medium support member and a recording medium supported by the recording medium support member
Closer to regular reflection than reflected light from the recording medium to the light receiving means.
A recording device, which is a reflected light . 2. The recording medium supporting member supports a recording medium.
2. The recording apparatus according to claim 1 , wherein the holding surface is black . 3. The recording medium supporting member according to claim 2 , wherein
2. The recording apparatus according to claim 1 , wherein the recording apparatus is a pseudo-mirror surface disposed in a window provided in a part . Wherein said light emitting means and said light receiving means, by moving by the scanning means while maintaining the positional relationship of that, and characterized by recognizing the width of presence and the recording medium of said recording medium Any one of claims 1 to 3
The recording apparatus according to. Wherein said recording medium is a recording of the recording paper and OHP (overhead Project) sheet and any one to <br/> of claims 1 to claim 4, characterized in that it comprises a cardboard apparatus. 6. The recording apparatus, a recording apparatus according to any one of claims paragraphs 1 through 5, wherein, characterized in that performing the recording by Inkujietsuto method for performing printing by discharging ink. 7. The recording apparatus according to claim 6 , wherein said ink jet system is a bubble jet system for performing recording by discharging ink by growing bubbles.