JPH0797098A - Printing device - Google Patents

Abstract

PURPOSE:To enable presentable printing always regardless of the size of sheets by grasping the size of a printing sheet, and adjusting a printing start position on the basis of this size. CONSTITUTION:In the inserted state of a sheet 20, a CPU rotates a feed roller 5 in the intake direction by a stepping motor 8. During this intake action, the stepping number of the stepping motor 8 is counted by a counter, and when the rear end of the sheet 20 passes the position of a sensor 3, the driving of the motor 8 is stopped and the count number is confirmed. Hereupon, whether the sheet size is sufficient in relation to the size of a printed image is discriminated. In the case of the sheet 20 being of the printable size, the adjustment quantity is computed so that printing is at the center of the sheet face, for instance, on the sheet 20. The stepping motor 8 is driven by this adjustment quantity, and after the sheet 20 is fed into a printing start position, a printing head 7 is brought into contact with the sheet 20 by a DC motor 9 to start a printing process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing an image or the like.

[0002]

2. Description of the Related Art Normally, in a printing apparatus, a print start position is set regardless of the size of printing paper (especially the size in the paper feeding direction). For example, how many meters from the tip of the paper
The printing start position is set as the position of m, and printing is performed.

[0003]

Such a setting is not a particular problem in a printing apparatus in which the paper size is determined, but it is inconvenient in a printing apparatus in which the user can print using paper of any size to some extent. Occurs.

Consider, for example, a printing apparatus capable of printing an image created by a user on a postcard or the like. For example, it is assumed that the print image size is set to 109 × 76 mm in consideration of 148 × 100 mm, which is the standard size of a postcard. In this case, assuming that a standard size paper (for example, a postcard) is always inserted in the printing apparatus and printed, the length 1
If printing is started at a position of, for example, 20 mm from the front end of the 48 mm paper, the print image (hatched portion PD) is formed at the substantially center of the postcard (paper P) as shown in FIG. It will look good.

However, in addition to standard size postcards, when the user wants to print on postcards of different lengths,
Alternatively, when the user wants to create a card or the like using a paper of any size, there is a problem that the printed image is not printed in a good position.

For example, if the paper P is long, it is shown in FIG.
As shown in FIG. 10B, the print image PD shown as a shaded portion on the sheet P is biased to the front end portion, and when the paper P is short, the print image PD is rearward as shown in FIG. 10C. It is placed in a position that is biased towards the part, and both are unsightly.

Further, printing is performed on a sheet of paper which is pressed between the print head and the platen roller. The major problem here is that the sheet is short and all the sheets are printed during printing. If it is sent before the head, printing may be done on the platen roller. For example, when printing cannot be completed on the short paper P as shown in FIG. 10D, the rest (broken line portion) of the printing is printed on the platen roller, and the platen roller is extremely soiled. Contamination of the platen roller will contaminate the paper inserted thereafter, and will deteriorate the roller function.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and is capable of positionally printing various types of sheets of various sizes and at the same time a platen roller. The purpose is to prevent printing on top.

For this reason, in the printing apparatus capable of performing the printing operation on the inserted printing paper,
By the edge detecting means capable of detecting the edge of the printing paper, the paper feeding means for sucking and discharging the printing paper, and the paper feeding means to the paper edge position of the printing paper detected by the edge detecting means. The print paper size is determined from the feed amount, the print start position on the print paper is calculated based on the print paper size, and the paper feed unit is driven so that printing starts from the print start position. A control means for adjusting the position is provided.

Here, a paper suction / discharge port which is also used as a suction unit and a discharge unit for the printing paper is provided, and the edge detecting means is arranged between the paper suction / discharge port and the paper feeding means for printing. It is configured to detect the presence or absence of paper.

Further, the control means performs control so as not to execute printing when the determined printing paper size is smaller than the paper surface size required for printing.

[0012]

By grasping the size of the printing paper and adjusting the printing start position based on the size, it is possible to always perform good-looking printing regardless of the size of the paper.

Further, since the edge detecting means is arranged between the sheet inlet / outlet port and the sheet feeding means, the size of the sheet inserted by the sheet feeding means depends on the edge detecting means. It is possible to accurately detect with a simple configuration based on the feed amount by the paper feed means until the detection of.

Further, when the discriminating paper size is smaller than the size required as the printing paper, the printing is stopped to prevent the printing on the platen roller.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 schematically shows the structure of the printing apparatus of the embodiment. 1 indicates the entire printing apparatus, 2
Indicates a paper port for inserting paper into the printing apparatus 1 and discharging the paper.

Inside the paper port 2, a sensor 3 for detecting the presence / absence of paper at that position is provided. The sensor 3 is formed of, for example, a light emitting diode 3a and a phototransistor 3b, and the output light from the light emitting diode 3a can be received by the phototransistor 3b. Therefore, when paper is present in the gap between the light emitting diode 3a and the phototransistor 3b,
When the phototransistor 3b does not receive the received light detection output, and when the paper does not exist, the phototransistor 3b provides the received light detection output, whereby the presence or absence of the paper at that position can be detected.

A pinch roller 4 and a feed roller 5 are provided inside the sensor 3 as a paper feeding mechanism. The feed roller 5 is rotated by a stepping motor 8. When the paper is inserted, the paper is pressed against the upper and lower sides by the feed roller 5 and the pinch roller 4, and therefore the feed roller 5 is rotated leftward (counterclockwise) in the figure by the stepping motor 8. And the paper are sent in the suction direction, and the feed roller 5
When is rotated in the right direction (clockwise direction) in the figure by the stepping motor 8, the paper is fed in the discharge direction.

Reference numeral 6 denotes a platen, 7 denotes a print head, and the print head 7 is moved by a DC motor 9 between a position shown by a solid line and a standby position shown by a chain line. When the print head 7 is at the position indicated by the solid line when the paper is on the platen 6, the paper is sandwiched between the platen 6 and the print head 7, and in this state, the print head 7 prints on the paper surface. Is executed.

FIG. 2 shows an internal circuit of the printing apparatus 1, 10 is a control unit (CPU), and 11 is a counter inside the CPU. The CPU 10 can determine the end portion of the sheet to be inserted by taking in the detection output of the sensor 3, that is, the output of the phototransistor 3b. The CPU 10 also controls the driving of the DC motor 9 and the stepping motor 8. When the drive control of the stepping motor 8 is performed, the number of steps is counted by the counter 11.

In this printing apparatus 1, C is used during the printing operation.
PU10 will perform the process of FIG. The printing operation will be described below with reference to FIGS. 3 and 4 to 8. The printing operation is started, for example, by inserting a sheet from the sheet opening 2 and operating a not-shown operation switch by the user to input the operation information to the CPU 10. Alternatively, the user may insert a sheet from the sheet opening 2 and the sensor 3 may detect the presence of the sheet to automatically start the sheet.

For example, when the user inserts a sheet through the sheet opening 2, the leading end of the sheet 20 is pushed into the gap between the feed roller 5 and the pinch roller 4, as shown in FIG. Here, when the user performs a printing operation, the CPU 10 first detects the presence or absence of the paper 20 based on the information from the sensor 3 (F101). If the user performs a printing operation without the paper 20 inserted,
In step F101, it is determined that there is no paper, and the printing operation is not executed. That is, the process proceeds to step F113, and the print stop process and the paper discharge process (drive of the feed roller 5 in the discharge direction) are performed.

In the state shown in FIG. 4 in which the sheet 20 is inserted, the process proceeds to step F102, and the CPU 10 causes the stepping motor 8 to rotate the feed roller 5 in the suction direction as shown by the arrow in the figure. Then, during this suction operation, in the CPU 10, the counter 11 counts the number of steps of the stepping motor 8 (F103).

In the suction of the sheet 20 and the step number counting, the rear end of the sheet 20 passes the position of the sensor 3 as shown in FIG. 5, that is, when the sensor 3 detects that there is no sheet (detection of the rear end of the sheet 20). Time point) (F103, F10
4) At the time of this FIG. 5, the process of the CPU 10 is step F10.
Proceeding to step 5, drive of the stepping motor 8 is stopped.
Then, the count number of the counter 11 at that time is confirmed.

The count number at this time is a numerical value for grasping the size of the inserted paper 20. Paper 2
0 c a length sucked in one step of the stepping motor 8, the count number as X, and the distance from the sensor 3 to the feed roller 5 and b as shown in FIG. 5, the size of the suction direction of the sheet S _P Can be calculated as S _P = (cX + b). Here, it is determined whether the size S _P is sufficient for the size of the print image (F106). If the size of the print image is, for example, 109 mm × 76 mm, and the distance from the feed roller 5 to the contact position (printing position) P _S of the print head 7 is a, the size S _P of the sheet in the suction direction is (1
09 + a) or higher.

Since the maximum suction position of the paper is the position where the rear end of the paper 20 is sandwiched between the feed roller 7 and the pinch roller 4 (if the paper is sucked any further, it cannot be discharged), the portion a cannot be printed. Therefore, (109+
a) If there is no size more than 20
This is because it cannot be printed on top.

If it is determined in step F106 that the inserted paper 20 has an unprintable size (S _P <(109 + a)), the flow advances to step F113 to stop the printing, and the stepping motor The feed roller 5 is rotated to the right in the figure by 8 and the paper 20 is discharged.

By this processing, it is possible to prevent the printing on the platen 6 by executing the printing while the size of the paper 20 is insufficient. It should be noted that when the actual paper size is judged to be sufficient / insufficient, the distance a is a fixed value in the printing apparatus, and the print image size is also fixed at this time, so the paper length is not calculated at this time. In both cases, it suffices to compare only the step number S _P with the predetermined value.

If the paper 20 has a printable size, then a process is carried out so that the print is made on the paper 20 at a good appearance (for example, the center of the paper). That is, the print start position on the paper surface is calculated with respect to the print position P _S to adjust the paper position. For example, the paper 20 of FIG.
In the case of (1), when printing is performed on the shaded portion as the position in the feeding direction, the print image is printed on the approximate center of the paper 20. Therefore, the position of the paper 20 is adjusted as shown in FIG. 6 (in this example, suction is further performed for a predetermined length), and the print start position on the paper surface is adjusted to the print position P _S. .

Assuming that the feed amount of the paper 20 (the number of steps of the stepping motor 8) for this adjusting operation is Y and the length of the printed image (109 mm in the above example) is Z, the feed amount for adjusting. As for Y, Y = (X · c + b−Z) / 2−a) / c can be calculated to calculate the adjustment amount Y for performing printing at the center of the paper.

When the adjustment amount Y is calculated in this way (F107),
Drive the stepping motor 8 for that Y step (F10
8) Put the paper 20 in the position shown in FIG. Note that Y at this time is determined in accordance with the size X of the paper, the distance between a and b in each device, and the length Z of the printed image. It can be in either direction (Y can be a positive or negative value).

When the sheet is fed in the suction or discharge direction by the adjustment step number Y in this way, the DC motor 9 is used to move the sheet as shown in FIG.
As described above, the print head 7 is brought into contact with the paper 20 (F109), and the printing process is started (F110). That is, as shown in FIG. 7, the feed roller 5 is rotated in the direction of the arrow in FIG. When all the print images are printed (F111), the print head 7 is returned to the standby position as shown in FIG. 8, and the paper 20 is ejected as shown in the figure to finish the printing operation.

By the above printing operation, even if the user inserts papers of various different sizes and executes printing, as shown in FIGS. 9A and 9B, for example, the print image (hatched portion) PD is It is located almost at the center of the paper, and it has a good balance and good appearance.

In the above embodiment, the print image size is fixed and the printing is performed substantially in the center of the paper surface. However, for example, the print image size is changed or the paper image is printed by the user's setting operation. It is also possible to intentionally adjust the printing position of the so that it is displaced from the center. When the print image size is changed, the value of Z may be changed in the equation for obtaining Y according to the setting.
Also, even if you intentionally shift the print position,
It suffices to adjust the numerical value according to the amount of deviation. For example, Y =
The value of α may be set as {(X · c + b−Z) / 2−a) + α} / c according to the setting of the deviation amount in the suction or discharge direction.

The structure of the printing apparatus can be modified in various ways other than the embodiment. For example, instead of counting the number of steps of the stepping motor 8, FG, P
A motor having a pulse generator such as G may be provided to perform pulse counting to grasp the paper size.

[0035]

As described above, the printing apparatus of the present invention grasps the size of the printing paper and adjusts the print start position based on the size, so that the printing paper always looks good regardless of the paper size. There is an effect that printing can be performed. Further, since the edge detecting means is arranged between the paper inlet / outlet port and the paper feeding means, the edge detecting means detects the paper edge position for the size of the paper inserted by the paper feeding means. It is possible to accurately detect with a simple configuration based on the feeding amount by the paper feeding means up to. Furthermore, if the determined paper size is less than the required size for printing paper, the printing can be stopped to prevent printing on the platen roller. It is possible to prevent contamination and malfunctions.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a structure of an embodiment of a printing apparatus of the present invention.

FIG. 2 is an explanatory diagram of a circuit block of the printing apparatus according to the embodiment.

FIG. 3 is a flowchart of printing operation control of the printing apparatus according to the embodiment.

FIG. 4 is an explanatory diagram of a printing operation of the printing apparatus according to the embodiment.

FIG. 5 is an explanatory diagram of a printing operation of the printing apparatus according to the embodiment.

FIG. 6 is an explanatory diagram of a printing operation of the printing apparatus according to the embodiment.

FIG. 7 is an explanatory diagram of a printing operation of the printing apparatus according to the embodiment.

FIG. 8 is an explanatory diagram of a printing operation of the printing apparatus according to the embodiment.

FIG. 9 is an explanatory diagram of a print image by the printing apparatus according to the embodiment.

FIG. 10 is an explanatory diagram of a print image by a conventional printing device.

[Explanation of reference numerals] 1 printing device 2 paper port 3 sensor 4 pinch roller 5 feed roller 6 platen 7 print head 8 stepping motor 9 DC motor 10 CPU 11 counter 20 paper

Claims (3)

[Claims] 1. A printing apparatus capable of performing a printing operation with respect to an inserted printing paper, and an end detecting unit capable of detecting an end of the printing paper, and a paper for sucking and discharging the printing paper. The print means determines the print paper size from the feed amount by the feed means and the paper feed means to the paper edge position of the print paper detected by the edge detection means, and the print start position on the print paper based on the print paper size. And a control unit that drives the paper feeding unit to adjust the position of the printing paper so that printing is started from the printing start position. 2. A paper suction / discharge port that also serves as a print paper suction unit and a discharge unit, wherein the edge detection unit is arranged between the paper suction / discharge port and the paper feeding unit, and prints. The printing apparatus according to claim 1, wherein the printing apparatus is configured to detect the presence or absence of paper. 3. The print according to claim 1, wherein the control means performs control so as not to perform printing when the determined printing paper size is less than the paper surface size required for printing. apparatus.