KR100787083B1 - printer - Google Patents

Abstract

The conveyance path conveys the print medium in the first direction. The guide member forms part of the conveying path and has an opening. The photosensor includes a light emitting element and a light receiving element and is disposed in the opening. The protrusion projects from a portion of the first guide member proximate at least the first edge of the opening, which is arranged upstream with respect to the first direction. The protrusion shields the light receiving element from ambient light entering the transport path.

Printer, recording paper conveyance path, first guide member, photosensor, protrusion

Description

Printer {printer}

1 is a perspective view of a printer according to a first embodiment of the present invention showing a state in which a door cover is closed;

2 is a perspective view of the printer showing a state where the door cover is opened;

3 is a cross-sectional view taken along line III-III of FIG. 2;

4A is an enlarged cross-sectional view of the recording paper conveyance path of the printer;

4B is a plan view of the recording sheet guide and photosensors provided in the recording sheet conveying path;

5 is a schematic side view of a printer according to a second embodiment of the present invention.

The present invention relates to a printer having a reflective photosensor for detecting recording paper conveyed along a recording paper conveying path.

In a printer which prints on roll paper, the load portion on which the roll paper is loaded is opened when the door cover attached to the casing body is opened. After the roll paper (recording paper) is loaded in the loading section, the leading edge of the roll paper is drawn out and inserted into the inlet arranged upstream of the recording paper conveying path. The inserted roll paper is detected by a recording paper detector arranged near the inlet, and a paper feed roller disposed downstream of the recording paper detector is rotated to supply the tip of the roll paper to a predetermined position along the recording paper conveying path. By this, the print waiting state is achieved.

Reflective photosensors are commonly used as recording paper detectors. In the absence of recording paper, the light receiving amount of the photosensor is below a predetermined threshold. When the recording paper passes, the light receiving amount of the photosensor is switched to the state exceeding the threshold by the light reflected from the recording paper surface. Therefore, the presence or absence of the recording paper is detected based on the change in the amount of received light.

In such a printer, when loading or replacing roll paper, the door cover is opened to open the loading section and the entrance of the recording paper conveying path.

Therefore, ambient light such as sunlight can enter the recording paper conveyance path from the entrance. When ambient light directly or indirectly irradiates the light receiving surface of the photosensor arranged on the recording paper conveyance path, the light receiving amount of the photosensor may exceed the threshold. Then, erroneous detection of the insertion of the recording sheet can be done even if the recording sheet is not inserted.

Accordingly, it is an object of the present invention to provide a printer capable of preventing the reflective recording paper detector (photo sensor) from being malfunctioned by disturbance light.

In order to achieve the above object, according to the present invention,

A conveying path for conveying the printing medium in the first direction;

A first guide member forming a first portion of the conveying path and having an opening;

A photosensor including a light emitting element and a light receiving element and disposed in the opening; And

A protruding portion protruding from a part of the first guide member proximate to the first edge of the opening at least disposed upstream with respect to the first direction, the protruding portion shielding the light receiving element from ambient light entering the conveyance path; There is provided a printer comprising a.

At least a second edge of the opening disposed downstream of the first direction may have an inclined surface that reflects light incident thereon to be deflected from the light receiving element.

The light receiving element may be disposed near the protrusion.

The printer further includes a second guide member forming a second portion of the conveying path. A portion of the second guide member facing the photosensor may be recessed.

The printer further includes a cover movable between a first position that opens the upstream end of the conveyance path and a second position that covers the upstream end. A line extending in parallel from the upstream end to the conveying path crosses the cover located at the first position.

The opening portion may be disposed near the upstream end of the conveyance path.

In the above configuration, the light receiving element of the photosensor may be shielded from direct incidence of ambient light by the protrusion. In addition, the light receiving element may be shielded from indirect incidence of reflected light of ambient light entering the carrier path by an inclined surface.

Therefore, it is possible to surely prevent the photosensor from malfunctioning by the ambient light.

The above objects and advantages of the present invention will become more apparent by describing the preferred and exemplary embodiments in detail with reference to the accompanying drawings.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

The printer 1 according to the first embodiment of the present invention includes an extended box-shaped body 2. The main body 2 includes a casing main body 3 and a door cover 4. This door cover 4 is hinged to the casing body 3 with its rear end pivoting a pivot axis extending in the printer width direction, and thus a fully open position shown in FIG. 2 from the closed position 4A shown in FIG. It is possible to turn between (4B). The recording paper discharge slot 4a is formed in the center of the door cover 4.

The printing unit 5 is attached to the casing main body 2 in the first half, and the roll paper loading part 6 is formed in the latter half. When the door cover 4 is opened, the roll paper loading unit 6 is exposed to the outside so that the roll paper (not shown) may be loaded from the top of the roll paper loading unit 6.

The recording paper conveyance path 7 is formed in the printing unit 5. As shown in Fig. 3, the recording sheet conveying path 7 is defined at its upstream side by a pair of upper and lower recording sheet guides 8 and 9 inclined so that its tip is positioned downward. These recording sheet guides 8 and 9 have an upstream end opened to form an inlet 7a for receiving the recording sheet 10 (indicated by the dashed-dotted line) fed from the roll sheet loading section 6. In the position near the inlet 7a in the lower recording paper guide 9, an opening 11 on which the reflection type photo sensor 12 for detecting the recording paper 10 is mounted is formed.

At the downstream end of the recording sheet guides 8 and 9, a paper feed roller 13 is disposed above, and the press roller 14 is in contact with the paper feed roller 13 from the lower side. The recording paper guide 15 extends upward from the paper feed roller 13 and serves as a platen 16 opposite the print head 17. The recording sheet discharge slot 4a is located above the upper end of the recording sheet guide 15.

The manual cutter 18 is provided at a position near the recording paper discharge slot 4a. The tip of the recording sheet 10 ejected from the recording sheet ejecting slot 4a is cut along the blade (or cutting position) 19 of the manual cutter 18 extending in the printer width direction.

The recording paper 10 introduced from the roll paper loaded in the roll paper loading unit 6 is guided to the recording paper conveying path 7 through the inlet 7a. Then, the recording sheet 10 is conveyed along the recording sheet conveying path 7 by the sheet feeding roller 13 and guided to the recording sheet discharge slot 4a through the printing position defined by the print head 17. Finally, the recording sheet 10 is discharged upward from the recording sheet discharge slot 4a.

The print head 17 of this embodiment is a dot impact head. The print head 17 is mounted on the head carriage 21 which can reciprocate along the guide shaft 22 connected in the printer width direction. The cassette mounting portion 23 is formed on the front side of the head carriage 21. When the door cover 4 is opened, the cassette mounting portion 23 is exposed so that the ink ribbon cassette 24 is detachable from the upper side.

As shown in Figs. 4A and 4B, the surface 9a of the recording paper guide 9 is formed with ribs arranged at a fixed pitch and extending in the recording paper conveying direction, the upper surface of which is the lower recording paper guide surface. Regulate.

The surface of the upper recording paper guide 8 provides a flat recording paper guide surface as a whole except for the portion on the downstream side. The portion 8a of the recording sheet guide surface 8 opposite the photosensor 12 is recessed. Moreover, the downstream end part 8b which continues downward from the recessed part 8a protrudes toward the recording paper conveyance path 7 so that the front-end | tip of the recording paper 10 may not be caught.

The recording paper guide 9 is formed by the opening 11 which is a rectangular through hole. The detection part 12c of the photosensor 12 provided with the light emitting element 12a and the light receiving element 12b is fitted into a through hole from the lower side. The transparent window 12d of the detection unit 12c faces the inside of the recording paper conveying path 7 through the opening 11. In this embodiment, the light receiving element 12b is disposed upstream with respect to the recording sheet conveyance direction, and the light emitting element 12a is disposed downstream. In addition, the window 12d of the detection unit 12c slightly retracts from the surface 9a of the recording sheet guide 9.

The inner surfaces 11a, 11b, 11c and 11d of the opening 11 are perpendicular to the surface 9a of the recording paper guide 9. A projection 11e (hatched portion A in FIG. 4B) raised from the surface 9a near the upstream inner surface 11a of the opening 11 is formed. The protrusion 11e extends to connect the rib 9b. That is, it extends along the entire width of the opening 11.

As shown by the dashed-dotted line in FIG. 4A, the height of the projection portion 11e, when the ambient light L enters the recording paper conveyance path 7, the ambient light L is the light receiving element 12b of the photosensor 12 It is set so that irradiation of the light-receiving surface of () is impossible. In this embodiment, the projection 11e is the same height as the rib 9b so that the conveyance of the recording paper 10 cannot be prevented.

As shown in FIG. 4A, the upper end of the downstream inner surface 11b is fully tapered to form an inclined surface 11f (hatch B of FIG. 4B) inclined from the normal of the surface 9a at about 45 degrees. Although the ambient light L entering the recording paper conveying path 7 collides with the inclined surface 11f, the light reflected from the inclined surface 11f is directed in a direction different from the light receiving surface of the photosensor 12. As a result, the ambient light reflected at the edge of the opening 11 does not enter the light receiving surface of the photosensor 12.

Here, the protrusion 11e may be formed adjacent to the side inner surfaces 11b and 11c of the opening 11. In addition, the upper ends of the side inner surfaces 11b and 11c may be tapered. The region forming the protrusion 11e and the inclined surface 11f may be appropriately determined according to the incident state of the ambient light.

In this embodiment, the door cover 4 is opened at the time of loading the roll paper 10 (recording paper). When the door cover 4 is opened, as shown in Fig. 2, the loading portion 6 and the inlet 7a of the recording paper conveying path 7 are opened. In this state, the roll paper 10 is loaded in the loading section 6. Then, the operator pulls out the leading end of the roll paper 10 and inserts it into the recording paper conveying path 7 from the inlet 7a.

When the leading end of the recording paper 10 reaches the nipping portion of the paper feed roller 13, it is detected by the photosensor 12. In the absence of the recording sheet 10, in particular, the light emitted from the light emitting element 12a of the photosensor 12 is not received by the light receiving element 12b, so the extinction amount is lower than the threshold value. When the recording paper 10 is inserted, the emitted light is reflected by the surface of the recording paper 10 and is incident on the light receiving element 12a. As a result, the light receiving amount exceeds a threshold value, and the excess amount into which the recording sheet 10 is inserted is detected based on this.

Then, the sheet feeding operation by the sheet feeding roller 13 starts at a predetermined timing, and the recording sheet 10 is placed on the recording sheet conveying path until the tip thereof is positioned at the cutting position 19 of the manual cutter 18. It is conveyed by a predetermined stroke along 7). This is a print ready state.

Here, this roll paper loading operation is performed with the door cover 4 open. As a result, ambient light such as sunlight can reach the recording paper conveying path 7 from the inlet 7a of the recording paper conveying path 7 in the open state. However, in this embodiment, the protrusion 11e is formed near the upstream edge of the opening 11 in which the photosensor 12 is mounted. As a result, the ambient light toward the light receiving surface of the photosensor 12 is shielded by the protrusion 11e.

On the other hand, the ambient light reaching the downstream edge of the opening 11 is reflected by the inclined surface 11f in a direction different from the light receiving surface of the photosensor 12. As a result, ambient light entering the inside of the recording paper conveying path 7 is also prevented from indirectly entering the light receiving surface.

In addition, when loading the recording paper 10, the front end portion of the recording paper 10 is reflected by the ambient light reflected from the inclined surface 11f or the loaded recording paper 10 before covering the light receiving surface of the photosensor 12. The ambient light thus reflected can be reflected by the upper recording paper guide 8a and is incident on the light receiving surface. However, since the portion 8a of the upper recording paper guide 8 facing the photosensor 12 is recessed, it is possible to reduce the influence of the reflected light from the upper recording paper guide 8 on the photosensor 12. It is possible. In particular, in this embodiment, the depth of the concave portion 8a is not larger than the clearance of the recording sheet conveying path 7, so the influence can be almost ignored.

Therefore, even when ambient light enters the recording paper conveyance path 7 when the recording paper 10 is loaded, the ambient light will not be incident on the light receiving surface of the photosensor 12. As a result, it is possible to accurately detect whether or not the recording sheet 10 is inserted into the recording sheet conveying path 7.

In this embodiment, since the light receiving element 12b is disposed on the side close to the protrusion 11e, even if the protrusion 11e is not high, it is possible to more reliably prevent the ambient light from entering the light receiving surface of the light receiving element 12b. Can be.

Next, a second embodiment of the present invention will be described. The same components as in the first embodiment are denoted by the same reference numerals and the repetitive description thereof will be omitted.

In this embodiment, as shown in Fig. 5, the door cover 4 in the open state serves to shield ambient light that may otherwise enter the recording paper conveying path 7.

In particular, in the printer 1A of this embodiment, the extension line 7A extending upstream of the recording paper conveying path 7 is set to intersect the upper end of the door cover 4 in the open position 4B. That is, ambient light from the direction which enters the recording paper conveyance path 7 is shielded by the upper end part of the door cover 4. Therefore, the disturbance light can be prevented from entering the light receiving surface of the photosensor 12, thereby preventing the malfunction of the photosensor due to the disturbance light more reliably.

As described above, since the light receiving element of the photosensor can be shielded from the direct incidence of the ambient light by the protrusion and can be shielded from the indirect incidence of the reflected light of the ambient light entering the carrier path by the inclined surface. There is an effect of reliably preventing the photosensor from malfunctioning by the ambient light.

Claims (6)

A conveying path 7 for conveying the printing medium in the first direction; A first guide member (9) forming a first portion of the conveying path (7) and having an opening (11); A photosensor 12 including a light emitting element 12a and a light receiving element 12b and disposed in the opening 11; And The conveying path (11e) protruding from a part of the first guide member 9 proximate to at least the first edge 11a of the opening 11 arranged upstream with respect to the first direction. 7) a projection (11e) for shielding the light receiving element (12b) from ambient light (L) entering. The method of claim 1, At least the second edge 11b of the opening 11 arranged downstream from the first direction has an inclined surface 11f for reflecting light incident thereon to be deflected from the light receiving element 12b. Featuring a printer. The method of claim 1, The light receiving element (12b) is disposed near the projecting portion (11e). The method of claim 1, It further comprises a second guide member 8 for forming a second portion of the conveying path (7), A part of the second guide member (8) facing the photosensor (12) is recessed. The method of claim 1, A cover 4 movable between a first position that opens the upstream end of the conveying path 7 and a second position that covers the upstream end; A printer which is characterized in that a line extending in parallel from the upstream end to the conveying path (7) intersects a cover (4) located at the first position. The method of claim 5, The said opening part (11) is arrange | positioned in the vicinity of the said upstream end of the said conveyance path (7).

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