JP2529791Y2 - Media thickness detection mechanism of printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium thickness detecting mechanism of a printing apparatus, and more particularly, to a medium thickness detecting mechanism for detecting a thickness of a printing medium passing between a pair of sensing rollers by a sensor.

2. Description of the Related Art Conventionally, in a medium thickness detecting mechanism of a printing apparatus of this type, as shown in FIG.
It slides on a guide shaft 15 held by 16.

The lower sensing roller 2 mounted on the carrier 14 is urged by a spring 17 and pressed against the upper sensing roller 3.

In such a conventional medium thickness detecting mechanism, since the carrier 14 for mounting the sensor 1 and the lower sensing roller 2 slides on the guide shaft 15,
There is a disadvantage that a large space is occupied by the guide shaft 15 and the guide frame 16 holding the guide shaft 15.

Further, since the carrier 14 slides on the guide shaft 15, it is required that the carrier 14 be made of a material having a small linear expansion coefficient, so that there is a disadvantage that the mechanism itself becomes expensive.

Object of the Invention The present invention has been made to eliminate the above-mentioned drawbacks of the conventional device, and aims to provide a medium thickness detecting mechanism of a printing apparatus which can be manufactured at a low cost and saves space. And

Configuration of the Invention The medium thickness detection mechanism of the printing apparatus according to the present invention is arranged such that when a printing medium is inserted between a fixed first roller and a movable second roller, the printing medium is perpendicular to the printing medium. A print medium thickness detection mechanism for detecting the thickness of the print medium by a sensor that moves integrally with the second roller that moves together with the second roller, wherein the sensor integrally supports the second roller and the sensor. A supporting member, an elastic member, and one end rotatably supported by the supporting member, and the other end is urged by the elastic member in a direction of pressing the second roller against the first roller. A link member, a fixed shaft that rotatably supports the link member between the one end and the other end, and a unit that guides the support member in the vertical direction.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. First
FIG. 1A is a side view of an embodiment of the present invention.
FIG. 1B is a front view of one embodiment of the present invention.

In these figures, an optical sensor 1 and a lower sensing roller 2 are mounted on a sensing bracket 4.

The sensing bracket 4 is held by link members 5 and 6.

One end of the link member 5 is rotatably supported on the sensing bracket 4, and the other end is a spring stay 8.
Is connected to a tension spring 7 which is fixed to the tension spring 7.

The link member 5 is rotatably supported by a link bracket 9 between one end and the other end.

On the other hand, one end of the link member 6 is connected to the sensing bracket 4.
The other end is rotatably supported by a link bracket 9, and one end and the other end thereof are arranged so that the link member 6 is parallel to the link member 5.
Sensing bracket 4 and link bracket 9 respectively
It is pivoted on.

Thus, when the link member 5 is pulled by the tension spring 7, the sensing bracket 4 is pushed up by the link member 5, and the lower sensing roller 2 mounted on the sensing bracket 4 is pressed against the upper sensing roller 3. That is, the lower sensing roller 2 is urged by the tension spring 7 and pressed against the upper sensing roller 3.

FIG. 2 is a diagram showing the operation of one embodiment of the present invention. FIG. 2A is a side view of the operation of the embodiment of the present invention, and FIG. 2B is a front view of the operation of the embodiment of the present invention.

The operation of the embodiment of the present invention will be described with reference to FIGS.

First, the medium thickness detecting mechanism according to one embodiment of the present invention is the first one.
When the print medium 13 is conveyed in the state shown in the drawing, that is, when the print medium 13 is not conveyed, the lower sensing roller 2 is pushed down by the print medium 13 and the thickness of the print medium 13 is reduced. The sensing bracket 4 is pushed down by the amount of.

At this time, the sensing bracket 4 is connected to the link members 5, 6
Move in parallel in the medium thickness detection direction (the direction of arrow A), but also move slightly in the lateral direction, and a lateral displacement Δα occurs between the lower sensing roller 2 and the upper sensing roller 3 [ 2 (a)].

However, even if the deviation Δα occurs, the printing medium 13
If the pitch between the optical sensor 1 and the lower sensing roller 2 does not change in the medium thickness detection direction (the direction of arrow A) when the sensing bracket 4 is pressed down, the detection of the thickness of the print medium 13 is affected. I will not give.

When the printing medium 13 is transported to the printing position and stopped, the platen 10 is raised until the plate 11 shuts off the optical sensor 1 and is brought into contact with the lower side of the printing medium 13.

In this state, printing on the print medium 13 is performed by the printer head.
12 [see FIG. 2 (b)].

In this manner, the link member 5 whose one end is pivotally supported on the sensing bracket 4 for mounting the optical sensor 1 and the lower sensing roller 2 and whose other end is urged by the tension spring 7 is connected between the one end and the other end. 9
, And the other end of the link member 6 whose one end is supported on the sensing bracket 4 is supported by the link bracket 9 so as to be parallel to the link member 5, and the conveyed printing is performed. Since the sensing bracket 4 pushed down by the medium 13 is moved in parallel in the medium thickness detecting direction by the link members 5 and 6, the material of the medium thickness detecting mechanism can be made of a sheet metal, so that it can be manufactured at low cost. can do.

Also, by incorporating the parallel link mechanism, the space of the mechanism itself can be reduced, so that the space can be saved.

In the embodiment of the present invention, the parallel link mechanism using the link members 5 and 6 is used. However, instead of the link member 6, a projection is provided on the sensing bracket 4 and the projection is guided vertically. A guide plate having a long hole may be provided so that the sensing bracket 4 does not largely move in the lateral direction, but is not limited thereto.

Effect of the Invention As described above, according to the present invention, the roller that moves in the vertical direction by the transported print medium and the sensor for detecting the thickness of the print medium are integrally supported by the support member. One end is rotatably supported by the support member, and the other end is rotatably supported by a fixed shaft between the one end and the other end with a link member urged by an elastic member. Is guided in the vertical direction, it is possible to manufacture the device at low cost and to save space.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing an operation of one embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional example. Description of Signs of Main Parts 1 ... optical sensor, 5,6 ... link member 2 ... lower sensing roller 3 ... upper sensing roller 4 ... sensing bracket 7 ... tension spring 8 ... spring stay 9 ... link bracket

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B65H 7/12 B41J 25/30 K

Claims (1)

(57) [Scope of request for utility model registration] 1. A fixed first roller and a movable second roller.
A printing device that detects the thickness of the printing medium by a sensor that moves integrally with the second roller that moves in a direction perpendicular to the printing medium when the printing medium is inserted between the printing medium and the rollers. A medium thickness detecting mechanism, wherein the supporting member integrally supports the second roller and the sensor, an elastic member, and one end is rotatably supported by the supporting member and the other end is the elastic member. A link member urged by a member in a direction to press the second roller against the first roller, a fixed shaft rotatably supporting the link member between the one end and the other end, Means for guiding the support member in the vertical direction.