JPH0568991U - Print medium transport device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a print medium conveyance device capable of improving conveyance accuracy by preventing slippage when the conveyance roller enters and kick when the conveyance roller comes out even if a thick booklet is inserted. [Structure] Before and after the transport roller 3, the medium detectors 14, 1
5 is provided, and a mechanism is provided for separating the movable roller 2 from the fixed roller 1 when the print medium enters the transport roller 3 and when the print medium exits.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a print medium carrying device used in a printer, and more particularly, to a print medium carrying device for carrying print media such as passbooks and notebooks that are relatively thick and have different thicknesses.

[0002]

[Prior Art]

 In printers that print passbooks, notebooks, etc., it is necessary to carry print media of different thicknesses depending on the type of print media and even on the same media depending on the print page. FIG. 1 is a side view of a conventional print medium carrying device applied to the printer described above, and FIG. 2 is a front view of the same. In FIGS. 1 and 2, 1 is a fixed roller whose shaft is fixed, and 2 is a movable roller which abuts against the fixed roller 1. These both constitute a conveying roller 3, and the conveying roller 3 is an upper and lower guide plate. Are arranged at appropriate places on the transport path 4 consisting of.

Reference numeral 5 denotes a carry motor, and a timing belt (hereinafter, simply referred to as a belt) 6 hung between a pulley of the carry motor 5 and a pulley of the fixed roller 1 causes a rotational force of the carry motor 5 to the fixed roller 1. It is being transmitted. Reference numeral 7 is a hook-shaped rocking lever, which rocks around a support shaft 8, and the movable roller 2 is attached to the tip thereof. A coil spring 9 is provided at the lower end of the swing lever 7, and the movable roller 2 is urged clockwise by the action of the coil spring 9 to be pressed against the fixed roller 1.

In this state, when the print medium is inserted or conveyed from the upstream side of the conveying path 4 and gripped in the nip of the conveying roller 3, the movable roller 2 is coiled according to its thickness. It is arranged to be separated from the fixed roller 1 in the counterclockwise direction against the tensile force of the spring 9. As shown in FIG. 2, the fixed roller 1 and the movable roller 2 are provided on each of the shafts 1S and 2S in pairs (two in the illustrated example).

[0005]

[Problems to be solved by the device]

 As described above, the movable roller 2 is constantly pressed against the fixed roller 1 by the coil spring 9 via the swing lever 7. In this state, when the thick booklet (print medium) 13 plunges between the transport rollers 3 as shown in FIG. Further, when the thick booklet 13 comes out of the transport roller 3, it is kicked by the restoring force of the movable roller 2 as shown in FIG.

That is, when the thick booklet 13 shown in (a) of the figure enters the conveying roller 3, a conveyance delay occurs, while the thick booklet 13 shown in (b) of the figure comes out of the conveying roller 3. In this case, there is a problem in that the conveyance progresses, and the conveyance accuracy is distorted when entering or exiting. Such a deviation of the conveyance accuracy is affected when a medium processing means for performing, for example, printing, bar code reading, OCR reading or the like on the medium is provided upstream or downstream of the conveying roller 3. Will be given.

The present invention solves the above-mentioned drawbacks of the conventional apparatus, and even when a thick booklet is inserted, a slide at the time of plunging into a transport roller (particularly, a transport roller arranged immediately before or immediately after the medium processing means). An object of the present invention is to provide a print medium conveying device capable of preventing the kick when the lip and the conveying roller are pulled out and improving the conveying accuracy.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a media detector is provided in front of and behind the transport roller, and the movable roller is separated from the fixed roller when the print medium enters and exits the transport roller. A roller contacting / separating means is provided.

[0009]

[Action]

 When the first medium detector provided on the front side of the transport roller (upstream side in the medium transport direction) detects the leading edge of the print medium, the movable roller contact / separation unit separates the movable roller from the fixed roller. As a result, slippage of the print medium when it enters the transport roller is prevented. Then, when the second medium detector on the rear side of the transport roller detects the leading edge of the print medium, the movable roller contact / separation unit presses the movable roller against the fixed roller. Thereafter, the print medium is transported by the transport roller until the trailing edge of the print medium is detected by the first medium detector.

When the first medium detector detects the trailing edge of the print medium, the movable roller contact / separation unit again separates the movable roller from the fixed roller. When the trailing edge of the print medium completely comes out of the transport roller (at this time, the leading edge of the print medium is transported by another transport roller at the rear) and is detected by the second medium detector Then, the movable roller contact / separation means brings the movable roller into contact with the fixed roller again. This eliminates the kick when the print medium exits the transport roller.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. It should be noted that members that are the same as or can be regarded as the same as those in the conventional example are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 3 is a block diagram of a print medium conveying device according to an embodiment of the present invention, in which a medium processing means P, for example, a conveying roller 3 arranged upstream of a printing section, a bar code reading section or an OCR reading section. Before and after the above, first and second medium detectors 14 and 15 composed of photosensors (a transmissive type is shown in the drawing, but may be a reflective type) are provided. Further, a solenoid 16 is provided below the swing lever 7 at a position facing the coil spring 9. In addition, 17 is an upstream side conveyance roller.

As will be described later, the solenoid 16 is turned on / off by a medium front / rear end detection signal from the first medium detector 14 and the second medium detector 15, and the swing lever 7 is swung to print. The movable roller 2 is separated from the fixed roller 1 when the medium enters the transport roller 3 and when the medium exits the transport roller 3.

In the apparatus having such a configuration, the solenoid 16 is attached to the swing lever 7 as described above.

FIG. 4 is a block diagram of a control unit that controls the solenoid 16, and FIG. 5 is a timing chart of the same. The medium detection signals a 1 and b 2 of the first medium detector 14 and the second medium detector are input to the control circuit 19, and the output c of the control circuit when both signals satisfy a predetermined condition of the control circuit 19 The solenoid 16 is controlled to be turned on and off.

As is apparent from FIG. 5, the control circuit 19 outputs the drive pulse c1 and turns on the solenoid 16 at the output timing of the medium front end detection signal a1 of the first medium detector 14. When the solenoid 16 is turned on, the plunger is pulled, so that the swing lever 7 swings counterclockwise about the support shaft 8, thereby separating the movable roller 2 from the fixing roller 1. Therefore, when the print medium plunges into the transport roller 3, the transport roller 3 is open, and the print medium can smoothly enter without slipping. Then, the control circuit 19 stops the output of the drive pulse c1 at the output timing of the medium leading edge detection signal b1 of the second medium detector 15, turns off the solenoid 16 and closes the conveyance roller 3. As a result, the print medium is conveyed downstream.

Next, the control circuit 19 outputs the drive pulse c2 and turns on the solenoid 16 again at the output timing of the medium rear end detection signal a2 of the first medium detector 14, to open the conveying roller 3 again. This state continues until the trailing edge of the print medium is detected by the second medium detector 15, that is, until the trailing edge detection signal b2 is output. Therefore, the print medium can come out of the transport roller 3 without kicking. After that, the transport roller 3 is closed again.

In the above embodiment, a normal bistable solenoid is used as the solenoid 16, and the control circuit 19 determines whether the first and second medium detectors 14 and 15 satisfy the EX / OR (exclusive OR) condition. The solenoid 16 is turned on so that the movable roller 2 is separated from the fixed roller 1 when the print medium enters the transport roller 3 and when the print medium exits.

However, the present invention is not limited to this, and when a monostable latching solenoid is used as the solenoid, there is a change in the output of each medium detector 14, 15 as shown in FIG. Each time, that is, every time the leading edge or the trailing edge of the medium is detected, the control circuit 19 is provided so as to apply drive pulses c3 and c4 for alternately applying current to the suction side coil and the recovery side coil of the monostable latching solenoid. It can also be configured. When using a single-stabilizing latching solenoid, the state is maintained even when the power is off, which has the advantage of low power consumption.

Further, in the example of FIG. 5, the control circuit 19 turns on the solenoid 16 based on the satisfaction of the EX / OR condition of the medium detection signals of the medium detectors 14 and 15 to open the closed conveyance roller 3. However, as shown in FIG. 7, the control circuit 19 may be configured to close the transport roller 3 only while the medium detection signals of the medium detectors 14 and 15 satisfy the AND condition. .. That is, in this case, when the medium enters between the transporting rollers, the roller is opened from the beginning, and when the medium leading edge of the second medium detector 15 is detected, that is, after the medium leading edge enters between the rollers, The roller is closed, and the roller is opened when the trailing edge of the medium is detected by the first medium detector 14.

Therefore, also in this embodiment, it is possible to prevent the slip at the time of entry and the kick at the time of exit.

In FIG. 3, on the downstream side of the medium processing means P, a movable roller contacting means having the same structure as the upstream side is arranged. The members corresponding to the upstream side are indicated by adding E to the same reference numerals. Reference numeral 18 denotes a transport roller on the downstream side.

The present invention is particularly effective when the movable roller contacting / separating means is provided on both the upstream side and the downstream side of the medium processing means, as shown in FIG. Is.

[0024]

[Effect of the device]

 As described above, according to the present invention, the movable roller is separated from the fixed roller when the print medium enters the transport roller and when the print medium exits from the transport roller. It is possible to provide a print medium conveyance device that prevents the conveyance pitch from being disturbed and can obtain high printing accuracy and reading accuracy even in a thick booklet.

[Brief description of drawings]

FIG. 1 is a side view of a print medium conveying device according to a conventional example.

FIG. 2 is an explanatory diagram showing a defect of a conventional example when a thick booklet is conveyed.

FIG. 3 is a configuration diagram of a print medium conveying device according to an embodiment of the present invention.

FIG. 4 is a block diagram of a control unit of a movable roller contacting / separating unit.

FIG. 5 is a time chart showing an example of solenoid control conditions by the control unit.

FIG. 6 is a time chart showing another example of solenoid control conditions by the control unit.

FIG. 7 is a time chart showing still another example of solenoid control conditions by the control unit.

[Explanation of symbols]

 1 Fixed Roller 2 Movable Roller 3 Conveying Roller 7 Swing Lever 8 Spindle 11 Driven Gear 12 Drive Gear 13 Thick Booklet 14, 15 First and Second Medium Detector 16 Solenoid 19 Control Circuit

Claims (4)

[Scope of utility model registration request] 1. A printing medium carrying device for carrying a printing medium having various thicknesses by a carrying roller including a fixed roller and a movable roller whose gap between the fixed roller and the fixed roller changes depending on the thickness of the printing medium. First and second medium detectors provided before and after the roller, and the movable roller is separated from the fixed roller by a medium leading edge detection signal of the first medium detector, and the second medium detector The movable roller is pressed against the fixed roller by a medium leading edge detection signal, and the movable roller is separated from the fixed roller again by a medium trailing edge detection signal of the first medium detector, and the second medium detector is detected. 2. A print medium conveying device, comprising movable roller contacting / separating means for pressing the movable roller to the fixed roller in response to the medium rear end detection signal. 2. The printing according to claim 1, wherein the movable roller contacting / separating means is arranged on both the upstream side and the downstream side of the medium processing means such as the printing section, the bar code reading section or the OCR reading section. Medium transport device. 3. The first and second medium detectors are composed of photosensors, and the movable roller contact / separation means inputs the medium detection signals from the respective medium detectors to satisfy a predetermined condition. 3. The print medium transport according to claim 1, wherein the control circuit outputs a drive signal in this case, and a solenoid which receives the drive signal and separates or abuts the movable roller from the fixed roller. apparatus. 4. The print medium conveying device according to claim 3, wherein the solenoid is a monostable latching solenoid.