JPS6242863A - Platen holder - Google Patents

Abstract

PURPOSE:To attain miniaturization, wt. reduction, the enhancement of assembling property and cost reduction, by constituting a platen holder fixing a platen of a material having elasticity such as a thin sheet metal. CONSTITUTION:Because a platen holder 10 is formed of a thin sheet metal extremely rich in elasticity, a platen 9 is freely twisted to the E-direction around an x-axis in such a state that the platen holder 10 was fixed to a chassis by screws 28 and can freely move to the direction shown by an arrow F of a z-axis. However, because the deformation of the platen to which a platen base 27 is adhered. As a result, the close contact surface of the platen 9 is certainly and closely contacted with the surface of a thermal head printer by the force of a spring 21 and no accuracy is required in the assembling of the platen 9 and the platen holder 10 and the number of parts can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a platen having a flat or curved surface with a large radius of curvature (hereinafter referred to as a flat platen) used in a printer equipped with a linear thermal head.
This invention relates to a platen holder for fixing the platen.

BACKGROUND OF THE INVENTION In recent years, printers have become rapidly popular due to their role as terminals for various systems.As printers become more widespread, printers are rapidly becoming cheaper, faster, smaller and lighter. The present invention relates to a printer using a line-shaped thermal head that records at high speed among printers, and relates to a method for fixing a flat platen used in the printer, and aims to reduce the price, reduce size and weight, and improve ease of assembly. That is. Furthermore, although the flat platen for a printer using a linear thermal head was proposed by the present inventor in Patent Application No. 59-125959, the present invention does not cover a flat platen that is not mentioned in the patent application. This paper describes a method for fixing a platen of the type shown in FIG.

Conventionally, there were no flat platens at all, and there were no platen holders in the world to fix them. Here, a platen holder that does not exist at all, but has a structure that can easily be considered for fixing a flat platen, will be taken as an example and explained as a conventional technique. In order to make it easier to understand the structure of a conventional thermal head printer and its problems, an example will be shown in which a linear thermal head and a flat platen are applied to a small and lightweight copying machine.

An example in which a linear thermal head and a flat platen are used in a small and lightweight copying machine will be described with reference to FIGS. 5 and 6.

Before explaining the conventional technology, first, a small and lightweight copying machine will be explained 17, and then a conventional platen holder will be explained.

Fig. 5 is an external view and an operation diagram of a small and lightweight copying machine. 1 is a copying machine, and as shown in the figure, the copying machine 1 is held with one hand, and the bottom of the copying machine is placed on top of the original 2 to be copied. While touching the copy paper 3 that comes out from the bottom of the copy machine 1 with the other hand,
(Here, thermal paper is used as the copy paper, but it will be referred to as copy paper hereinafter.) One end is fixed to the original 2, and the copy machine 1 is manually moved in parallel in the direction of arrow A to copy the contents of the original 2. This is to be copied onto copy paper 3.

Next, the specific structure of the copying machine 1 and its copying principle will be explained below. FIG. 6 is a structural sectional view of the copying machine 1,
Figure 6(a) is an x-"x cross-sectional view of Figure 6(b).
FIG. 6(a) is a YY cross-sectional view of FIG. 6(b). Inside the copying machine 1, there are a roll of copy paper 3 (the starting end is 3A), an opening 4, a transparent glass plate 5, a lens 6, and a -dimensional image sensor 7 (for example, - Charge-coupled device in which photosensitive elements are arranged in a row...ChargeCo
An upgraded device, ie, a CCD, etc. is suitable. ), a linear thermal head 8, a rubber platen 9 that supports the copy paper 3 and brings it into close contact with the thermal head 8, a platen holder 10 that holds the platen 9, and a linear illumination 11 that illuminates the original 2. have.

By operating the copying machine 1 as described earlier, the light from the illumination 11 illuminates the original 2 in a line, and the reflected light is imaged and read by the image sensor 7 through the aperture 4 and the lens 6, and at the same time, it is read by the thermal head 8. Copies are sequentially made onto copy paper 3, and the copied copy paper 3 is outputted from the copying machine 1 in the direction of arrow B. Note that there is a control section between the image sensor 7 and the thermal head 8 that processes the data read by the image sensor 7 and sequentially sends it to the thermal head 8, but it is not shown here. The feed speeds of the original 2 and the copy paper 3 can be synchronized by holding the starting edge 3A of the copy paper 3 against the original 2 by hand and moving the copying machine 1 in parallel in the direction of the arrow A. Copy paper 3 having a length equal to the moving distance of copying machine 1 in direction A is fed out in the direction of arrow B, so that mutual synchronization can be achieved.

The above is the operating principle of a copying machine.

Further, to explain the structure of the copying machine 1 in detail, in order to make the lighting 11 compact, an LED array in which a plurality of light emitting diodes are arranged in a row is used.

Further, considering the portability of the copying machine, a plurality of batteries 12 are provided, and the present copying machine is battery-powered. In order to convey the copy paper 3 to the thermal head printer 8, there is a conveyance path 13 from top to bottom at the rear of the moving direction of the copying machine j, and a guide 14 and a chassis 15 transport the copy paper 3, The battery 12, image sensor 7, and lens 6 are separated to prevent the copy paper 3 from being damaged when it is transported. The chassis 15 is made of metal casting such as aluminum, and has an image sensor 7 and a lens 6.
, illumination 11, and other optical system components are firmly fixed, and the structure is such that there is no misalignment of the optical axis.

Further, as described above, there is a platen 9 for bringing the copy paper 3 into close contact with the thermal head printer 8, and after passing through the conveyance path 13, the copy paper 3 is copied while passing between the thermal head 8 and the platen 9. , exits from the copying machine 1 through the paper ejection port 16. When loading copy paper 3,
A part of the detachable cover 18 of the outer shell 17 of the copying machine 1 is removed, and copy paper 3 is loaded. Further, since the copy paper 3 must be passed between the thermal head 8 and the platen 9, the thermal head 8, together with the base 19 to which it is attached, is placed at a seventh
It has a structure that opens and closes as shown in the figure.

Furthermore, the platen 9 is attached to the platen holder 10 with adhesive (
(not shown), and the copy paper 3 is brought into close contact with the thermal head 8 by the repulsive force of a spring 21 that is locked between the chassis 15 and the platen holder 10. Note that the surface of the platen is coated with a fluorine-based resin (not shown) in order to improve the sliding contact with the copy paper 3.

The above is the structure of this copying machine. Conventionally, line-type thermal head printers only have cylindrical platens, and this is the first time the inventor has proposed a flat platen. Conventionally, there was no technology for a button holder for fixing.

Therefore, as mentioned above, in the present invention, when fixing a flat platen, a general configuration of a platen holder that can be easily considered will be explained and replaced with the conventional technique. Now, as shown in FIG. 8, a generally considered configuration of the platen holder 10 is to bend a thick sheet metal as shown in the figure to form the platen holder 10, and use a part of it as a fulcrum 20, 22 to hold the platen holder. 10 is rotated in the direction of arrow C about a fulcrum 22, and the copy paper 3 is brought into close contact with the thermal head 8 by the force of a spring 21.

Problems to be Solved by the Invention However, in this structure, the line connecting the fulcrums 20 and 22, the recording surface 23 of the thermal head 8, and the contact surface 24 of the platen 9 to the thermal head 8 (this surface is also connected to the copy paper 3). In order to improve the sliding of the parts, they must be parallel to each other (as mentioned above, they must be coated with fluororesin), and the dimensional accuracy of the parts and the precision of assembly of the parts must be strictly maintained. . If this was not followed, as a result, the copy paper 3 would not come into close contact with the thermal head 8, resulting in incomplete copying.

In addition, in FIG. 9(a), a platen holder 10 is made of aluminum or the like in the shape shown in the figure, and pins 25 are attached to both ends of the platen holder 10.
Here is another example with In this example, a part of the chassis 15 is used as a platen guide 26, and this guides the pin 24 in the direction of the arrow. In this case, the thermal head of the platen 9 is The contact surface 24 to the thermal head 8 becomes parallel to the recording surface 23 of the thermal head 8 by itself, and does not require much assembly precision. However, the number of parts is large and the structure is complicated. , it was unsuitable for making copying machines smaller and lighter.

The present invention provides a new type of platen holder for a flat platen for a line-type thermal head printer, which has not been available in the past. The purpose is to lower prices.

Means for Solving the Problems The present invention provides a planar platen used in a printer using a line-shaped thermal head, in which a platen holder for fixing the platen is made of an elastic material such as a thin sheet metal. ing. Further, a part of the platen holder is formed into a U-shape, and the platen is fixed to this part. Further, one or more holes are formed in the platen mounting portion of the platen holder, and a protrusion is provided on the opposite platen, which fits into the hole of the platen holder to fix the platen. Finally, in the platen, between the surface facing the thermal head and the part attached to the platen holder, a slope is formed in the direction in which the thermal paper enters with respect to the direction of travel of the thermal paper, and the part where the slope of the platen begins. The U-shaped end of the platen holder covers the platen holder, making the platen holder smaller and lighter, easier to assemble, easier to operate, and lower in price.

Effect: By using the above means, in the platen mechanism of a printer using a line-shaped thermal head, the platen holder can be made smaller and lighter, easier to assemble, easier to operate, and lower in price.

Embodiment As an embodiment of the platen boulder of the present invention, an example in which the platen holder of the present invention is applied to a small and lightweight copying machine will be explained based on this example.

The structure of the copying machine of this embodiment is the same as that of the above-mentioned conventional technology, so a description thereof will be omitted. Furthermore, since the operating method and principle of operation of the copying machine of this embodiment are the same, the explanation will be omitted.

Therefore, in FIG. 1, only the portion of the platen holder 10 of the copying machine of this embodiment, which is different in configuration from the conventional example, is shown in an enlarged manner. In the figure, there is a platen base 27 between the platen holder 10 and the platen 9 that connects them.The platen base 27 is made of metal such as aluminum, and the platen holder 10 is made of stainless steel or the like. This is made from a thin sheet of metal.

The platen holder 10 is attached to the chassis 15 by screws 28.
(See FIG. 7 for the conventional example). This makes it possible to solve various problems that have been difficult to solve with conventional techniques.

That is, in the example of FIG. 8, the fulcrums 20 and 22 are parallel,
Care had to be taken to keep the recording surface 23 and contact surface 25 parallel,
In this embodiment, the platen holder 10 is made of a thin sheet metal with extremely high elasticity, so that the platen 9 can move freely and firmly adhere to the thermal head printer 8, as will be explained below. That is, in FIG.
When the upper direction parallel to the platen holder IQ is the X axis, the longitudinal direction of the platen 9 is the y axis, and the direction perpendicular to the platen holder 10 is the two axes, the platen holder 10 is fixed to the chassis 15 with the screws 28. The platen 9 can be freely twisted in the E direction around the X axis and freely moved in the direction of the arrow F on the two axes. However, the platen base 27
Deformation in the longitudinal direction of the platen does not occur in the areas where the platen is bonded. Therefore, due to the force of the spring 21, the contact surface 25 of the platen 9 is surely brought into close contact with the surface of the thermal head printer 8, and as a result, the copy paper 3 is brought into complete contact with the recording surface 23. Parallelism is no longer required. This eliminates the need for precision in assembling the platen 9 and the platen holder 10, greatly improving assembly efficiency and stabilizing copy quality.

It has also become possible to reduce the number of parts, allowing the structure of this part to be made smaller, lighter, and cheaper.

Further, another embodiment of the platen holder IO is shown in FIG. As shown in the figure, the lower end of the platen holder 10 is bent into a U-shape, into which the end of the platen 9 is inserted and fixed with an adhesive (not shown). By bending the platen holder 10 made of a thin sheet metal into a U-shape in this way, the strength of the platen holder 10 in the y-axis direction is ensured, eliminating the need for the platen base 27, and also in the E direction and the F direction of the Z axis. It satisfies predetermined functions while maintaining elasticity. This further reduces the number of parts, resulting in a simple structure, small size, and light weight.
Moreover, there is no longer a need for strict assembly accuracy.

Next, another embodiment of the platen holder 10 is shown in FIG. As shown in FIG. 3(a), the platen holder 10 has a plurality of holes 29, and as shown in FIG. 3(b), the platen 9 is provided with a protrusion 30, and the tip of the protrusion 30 is The stopper 31 is slightly larger than the hole 29.

Now, FIG. 3(c) shows a sectional view when the platen 9 and platen holder 10 are fixed. As is obvious from the figure, in this embodiment, the adhesive used in fixing the platen and platen holder is also eliminated from the above embodiment, and the platen 9 can be fixed simply by inserting it into the platen holder 10, resulting in an extremely simple structure.

Finally, another embodiment is shown in FIG. In this embodiment, the platen 9 has a slope 32 between the contact surface 24 facing the thermal head printer 8 and the part fixed to the platen holder 10, and the slope 32 on the entrance side with respect to the traveling direction G of the copy paper 3. An eaves 34 of the platen holder 10 is provided to cover the beginning 33. With this, when the copy paper 3 is loaded into the copy machine 1, the starting edge 3A of the copy paper 3 is
This also solves the problem that when passing the copy paper 3 through the transport path 13, the copy paper 3 gets caught in these parts and does not pass through. Further, in the figure, 35 is a fluororesin coating applied to the contact surface 24 of the platen 9, and is provided to improve the sliding between the platen 9 and the copy paper 3. It is covered within the eaves 34.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention provides a new type of platen holder for a flat 7.5'' latin for a line thermal head printer, which has not been available in the past. Smaller and lighter,
It has become possible to improve the ease of assembly and reduce the price, and as an accompanying effect, it has become possible to improve the operability when loading copy paper.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a platen holder according to an embodiment of the present invention, Fig. 2 is a perspective view of an embodiment of the present invention showing a method of fixing the platen, and Fig. 3(a) is an embodiment of the invention and a perspective view of the platen. FIG. 3(b) is a perspective view of a platen holder in an embodiment in which adhesive is not used as a fixing method; FIG. 3(b) is a perspective view of a platen in an embodiment in which adhesive is not used in fixing the platen;
Fig. 3(c) is a cross-sectional view of the structure in the fitted state of an embodiment in which adhesive is not used for fixing the platen, and Fig. 4 is a perspective view of the structure for improving the passage of copy paper. , Fig. 5 is a diagram showing the state of use of the small-sized copying machine, Fig. 6 is a sectional view of the small-sized copying machine, Fig. 7 is a sectional view of the small-sized copying machine with the lower part of the outer shell opened, and Fig. 8 9 is a perspective view showing a conventional platen holder. 1... Copy machine, 3... Copy paper, 9... Platen,
10... Name of Platen Holder's agent: Patent attorney Toshio Nakao. Bebr3, Coach 1'Fuki'slde

Claims (1)

[Claims] 1. A rubber platen that faces a linear thermal head printer and brings thermal paper into close contact with the thermal head printer, and the surface of the platen facing the thermal head printer is a flat surface or has a radius of curvature. A platen holder 2 characterized in that, in a platen having a large curved surface, the platen holder for fixing the platen is made of a thin flat elastic member.The part of the platen holder for fixing the platen is approximately U-shaped. The platen holder 3 according to claim 1, characterized in that the platen holder has a structure in which the platen is attached to a substantially U-shaped portion of the platen holder. The platen according to claim 1, characterized in that the above hole is bored, a projection is provided on the platen, and the projection of the platen fits into the hole of the platen holder to fix the platen. Holder 4 Between the surface of the platen facing the thermal head printer and the part attached to the platen holder, an inclined surface is formed in the direction in which the thermal paper enters with respect to the advancing direction of the thermal paper, and the slope of the platen begins. The platen holder according to claim 2, wherein the portion is covered by the substantially U-shaped end portion of the platen holder.