JPH069959U - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an inexpensive printer that can maintain high-quality print output with little deformation of the platen portion even after long-term use. A print head 1 that is pressed against a platen 3 via a recording paper, a guide rail 2 that forms a moving path of the print head 1, and a retracting unit that moves the print head 1 to the left end of the guide rail 2. The guide rail 2 is twisted at a predetermined angle near its end, and the retracting means retracts the print head 1 to the left end of the guide rail 2 only when the printing process is continuously unnecessary.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printer having a heat-sensitive serial head, and more particularly to a heat-sensitive serial type printer characterized by the shape of a guide rail and capable of preventing unnecessary deformation of the platen portion.

[0002]

[Prior art]

 Various types of printing mechanism have been proposed in the past for thermal serial printers.However, in some types of thermal serial printers, the print head is placed on the recording paper (thermal paper) regardless of whether printing is performed. Was pressed against the printed surface of. In another thermal serial printer, a dedicated motor and a special mechanical component are provided so that the print head is lifted above the printing surface at that position when the printing operation is not performed.

[0003]

[Problems to be solved by the device]

 However, in the above printer of the type where the print head and print surface are always in pressure contact, the print head may stay in the same position for a long time without printing operation.Therefore, in the case of a platen made of a soft material, the specific position is deformed. There was a problem that it did. FIG. 5 illustrates the platen that has been deformed because the print head has been pressed against the same position D for a long time. If the specific portion of the platen is deformed, the head pressure varies depending on the location. For example, when a black solid hard copy is taken, the shade as shown in FIG. 6 is produced. FIG. 6 is a schematic diagram showing the output result of a solid black hard copy, and shows the case where the black portion of the recording paper corresponding to this position is thin due to the deformed portion D in a part of the platen. There is.

In order to solve the problem of platen deformation, a platen made of a hard material can be used. However, in this case, when the print head and the contact surface of the platen are not perfectly parallel to each other, there is a problem that the print head and the recording paper do not contact well. There is no particular problem in this state if the head is about 2 to 3 dots / mm, but it is fatal for a high resolution head such as 6 to 8 dots / mm.

Further, since the problem of platen deformation is that the print head is constantly pressed against the recording paper, the print head can always be lifted from the print surface like the above-mentioned another type of thermal serial printer. It would be good. However, in the case of this type of printer, there is a problem that extra cost is required due to a dedicated motor and the like, which causes an increase in cost.

The present invention has been made in view of this problem, and it is possible to maintain high quality print output with little deformation even when a platen made of a soft member is used for a long period of time. The purpose is to provide an inexpensive printer that can be used.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a printer according to the present invention is provided with a print head that is pressed against a platen portion through a recording paper, a guide rail that forms a moving path of the print head, and an end of the guide rail. A printer having a retracting means for moving the print head to a partial position, wherein the guide rail presses the print head to the platen portion at a position where the print head and the recording paper face each other. However, it has a structure in which the print head is not brought into pressure contact with the platen portion at an end position that does not face the recording paper, and the retracting means determines whether or not the print processing is continuously required, and prints. The print head is moved to the end position of the guide rail only when the operation is continuously unnecessary.

[0008]

[Action]

 The evacuation means determines whether or not the printing process is continuously required. When the printing operation is not continuously required, the evacuation means moves the print head to the end position of the guide rail. When the print head moves to the end position of the guide rail, the print head is not pressed against the platen, so the platen is not pressed unnecessarily and unnecessary deformation of the platen is prevented. it can. It is preferable to use a softer material for the platen in order to press the print head on the recording paper evenly.

[0009]

【Example】

 FIG. 1 is a schematic view of a print head portion of a thermal serial printer which is an embodiment of the present invention. This printer includes a print head 1 that performs a printing operation by making contact with a thermal recording paper (not shown), a guide rail 2 that forms a moving path of the print head 1, and a print head 1 via the recording paper. It is composed of a platen 3 to which is pressed and a control unit (not shown) that moves the print head 1 left and right to perform a printing operation. Here, the control unit is a unit that moves the print head 1 to an arbitrary position on the guide rail 2 or supplies necessary print data to the print head 1, and has a well-known configuration using a microcomputer or the like. Is.

The material of the platen 3 is not particularly limited, but it is preferable to select a relatively soft material, so that the entire heating element of the print head 1 hits the thermal recording paper evenly. Higher quality printing is possible. FIG. 2 shows the shape of the guide rail 2, which is one of the characteristic parts of the present invention, and is formed by twisting a flat plate at the end.

FIGS. 3A and 3B are sectional views showing the positional relationship among the print head 1, the guide rail 2 and the platen 3. Normally, the print head 1 is pressed against the platen 3 via the recording paper (see (a) in FIG. 3), but when the print head 1 reaches the left end of the guide rail 3 (see the broken line in FIG. 1). ), And is in a state of being lifted from the platen 3 (see FIG. 3B). In addition, although the guide rail 2 having a twisted shape is taken as an example here, the guide rail 2 is not limited to this. For example, a guide rail 2 having a shape such that the print head can be gradually lifted from the vicinity where the platen portion is not present. It may be one.

FIG. 4 is a flow chart for explaining the operation contents of the thermal serial printer shown in FIG. Hereinafter, the operation contents of the printer of FIG. 1 will be described with reference to FIG. The control unit determines whether or not a print command has been received, and moves to step ST2 if no print command has been received, or to step ST5 if a print command has been received (step ST1). .

In step ST2, it is determined whether or not the state in which the print command is not received has continued for 5 seconds or more up to the present time, and if it has not continued for 5 seconds or more, the process returns to step ST1 (step ST2 ). On the other hand, when the print command is not received for 5 seconds or more, it is determined whether or not the current print head is in the retreat area (step ST3). Here, the retreat place of the print head is the left end position of the guide rail 3 (see the broken line in FIG. 1), and the position where the print head 1 is not pressed against the platen 3 (see FIG. 3 (b)). ).

If the print head is at the retracted position, nothing is performed and the process returns to step ST1 (step ST3). If the print head is not at the retracted position, the print head 1 is retracted as shown in FIG. The print head 1 is moved to the retracted position at the left end of (step ST4). On the other hand, when it becomes clear that the print command is received by the process of step ST1, the process proceeds to step ST5, and it is determined whether or not the current print head is at the retracted position (step ST5).

When the print head is at the retracted position, the print head is moved to a predetermined print position (step ST6), and when it is not at the retracted position, nothing is done and the process proceeds to step ST7. Then, in step ST7, the print head is operated to form a dot pattern on the thermosensitive recording paper, and thereafter, the process returns to step ST1. In the above description, the print head is retracted when there is no print command for 5 seconds or more, and whether or not the retract processing is performed is managed by time, but the invention is not limited to this. There is no. For example, a “command for retracting the print head” and a “command for returning the position of the print head” may be added so that these two commands are always added at the beginning and end of the print command. That is, the printer always retracts the print head at the end of the process and returns the print head to the print position when starting the process.

[0016]

[Effect of device]

 As described above, the printer according to the present invention is provided with the guide rail having a characteristic shape and the retracting means for retracting the print head as necessary, so that the platen portion can be protected from unnecessary pressure for a long time. I try not to join. Therefore, the platen portion is less likely to be deformed, and high-quality printing can be maintained for a long period of time. Further, in the case of this invention, since no special parts such as a dedicated motor and mechanical parts are required, the above effect can be realized at a low cost.

[Brief description of drawings]

FIG. 1 is a schematic view showing a part of a heat-sensitive serial printer which is an embodiment of the present invention.

FIG. 2 is a schematic view illustrating the appearance of the guide rail shown in FIG.

FIG. 3 is a cross-sectional view illustrating the relationship among a platen, a print head, and a guide rail.

4 is a flow chart for explaining the operation of the apparatus of FIG.

FIG. 5 is a diagram for explaining deformation of a platen in a conventional printer.

FIG. 6 is a diagram for explaining print recording when the platen is deformed.

[Explanation of symbols]

 1 print head 2 guide rail 3 platen ST2-ST4 retracting means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 19/20 L 9212-2C

Claims (1)

[Scope of utility model registration request] 1. A print head that is pressed against a platen portion via a recording paper, a guide rail that forms a moving path of the print head, and a retracting means that moves the print head to an end position of the guide rail. A guide rail presses the print head against the platen portion at a position where the print head and the recording paper face each other, but prints the guide rail at an end position not facing the recording paper. It has a structure in which the head is not brought into pressure contact with the platen portion, and the retreating means determines whether or not the printing process is continuously required, and only when the printing operation is continuously unnecessary, the print head is A printer, wherein the printer is moved to an end position of the guide rail.