JP3680971B2 - Printing gap control device for printing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a print gap control device that maintains a print gap between a print hammer and a platen of a printing apparatus at an appropriate value.
[0002]
[Prior art]
In a printing apparatus comprising a plurality of printing hammers, for example, a hammer bank having printing hammers arranged at a predetermined pitch along a row direction or a circumferential direction, and a platen that faces the hammer bank and supports a printing medium The printing gap between the printing hammer and the platen is a fixed value using a mechanism in which the printing device user mechanically adjusts the printing gap according to the thickness of the printing medium (for example, paper) before starting printing. Is selected and initialized, or the paper thickness is automatically detected and initialized. Then, the printing apparatus continuously performs printing in the initial setting value state until resetting.
[0003]
[Problems to be solved by the invention]
If printing is continued with the conventional setting method described above, the following problems arise.
[0004]
The printing apparatus receives the print data sent from the host apparatus by the print control circuit, transmits it to the hammer control circuit as the print data corresponding to each print hammer, drives the print hammer, and the matrix type printing apparatus In this case, the hammer bank is shuttled and printing is performed while the print medium is being conveyed. In the printing process, when the printing amount per unit time increases in the printing apparatus, the printing hammer coil generates heat, heat is conducted from the printing hammer, and the entire hammer bank generates heat. As a result, the hammer bank is thermally deformed by the influence of the heat. The thermal deformation amount of the hammer bank differs depending on the material constituting the hammer bank, its structure, and the like, and is unique to the printing apparatus exhibiting the characteristic of being saturated at a certain amount. When printing is continued in the printing apparatus as described above, the printing gap d between the printing hammer and the platen mounted on the hammer bank is generally displaced in a narrowing direction. FIG. 4 is an example showing the relationship between the number of times of printing hammer driving within a predetermined time interval T and the displacement of the printing gap between the printing hammer and the platen. When the printing hammer drive count m = M is reached at a fixed time Ta (= T) immediately after the start of printing, the entire hammer bank is thermally deformed, and the printing gap d between the printing hammer and the platen mounted on the hammer bank is: The initial state value X is displaced by the thermal deformation amount N of the entire hammer bank. That is, the printing gap d between the printing hammer and the platen is (X−N), and is narrowed from the initial state. In the next fixed time Tb (= T), when the printing hammer driving frequency m <M, the saturation state is maintained at the thermal deformation amount N due to the temperature characteristics of the entire hammer bank. That is, the printing gap d between the printing hammer and the platen maintains the state of (X−N). When the printing hammer driving frequency m = 0 at the next fixed time Tc (= T), the thermal deformation is eliminated by the temperature characteristics of the entire hammer bank. That is, the printing gap d between the printing hammer and the platen returns to the initial state value X. FIG. 5 is a side view exaggeratingly showing the displacement state of the print gap between the print hammer and the platen.
[0005]
That is, there is a problem that the print gap between the print hammer and the platen is displaced due to heat generated by the printing operation and cannot be maintained at the value set before the start of printing, and the print quality is deteriorated. An object of the present invention is to solve the above-described problems, and is to minimize a decrease in print quality of a printing apparatus.
[0006]
[Means for Solving the Problems]
The object is to detect a change in the print gap between the print hammer and the platen, and to move the position of at least one of the platen and the hammer bank by the detection output of the print gap change detection means. This is solved by providing position control means for adjusting the print gap. The printing gap fluctuation detecting means activates a timer for a predetermined time in the course of the printing operation of the hammer bank, counts the number of times the printing hammer is driven during the timer operation, and detects that the specified number of driving times M has been reached. This can be realized by a printing hammer driving frequency counting means or a temperature detecting means for detecting heat generation of the printing hammer coil.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an example of the flowchart, and FIG. 3 is a characteristic diagram showing an example of the timing chart.
[0008]
In FIG. 1, 1 is a printing control means, 2 is a hammer control means, and 3 is a hammer. Reference numeral 30 denotes a printing gap fluctuation detecting means. The printing gap fluctuation detecting means 30 includes a printing hammer 3 driving number counting means 4 for counting the number of times the printing hammer 3 is driven, a comparator 5, a timer circuit 6, and a data latch circuit 7. Composed. Reference numeral 40 denotes position control means for moving the platen position and adjusting the print gap between them. The position control means 40 includes the platen position control means 8, the platen position storage circuit 9, the platen drive circuit 10, and a platen (not shown). It consists of a platen drive device that adjusts the position. 11 is a platen.
[0009]
3 will be described with reference to FIGS. 1 and 2 together. In FIG. 3, the operation of the embodiment at a predetermined time T1 (= T) after power-on will be described. After the power is turned on, a timer for a predetermined time T1 (= T) of the timer circuit 6 is started (step S1 in FIG. 2), the counter of the printing hammer drive frequency counting means 4 is reset (step S2), and the platen position storage means 9 Is stored (step S3). Print data is sent from the print control means 1 to the print hammer drive frequency count means 4, and the print hammer drive frequency count means 4 determines the number of times the hammer is driven within a predetermined time T 1 (= T) indicated by the timer circuit 6. Count (step S4). When the comparator 5 detects that the number of driving times counted by the printing hammer driving number counting means 4 has reached a specified value M within a predetermined time T1 (= T) indicated by the timer circuit 6 (step S5, step S5). S6) Immediately after detection, the fact that the number of driving times has reached the specified value M is transmitted from the comparator 5 to the platen position control means 8, and from the platen position control means 8 to the platen position storage circuit 9 along with a position change drive instruction for the platen 11. The reverse amount N is instructed. The platen position storage circuit 9 moves the platen 11 to the platen drive circuit 10 by the retraction amount N according to the instruction from the platen position control means 8 (step S7), and sets the storage information in the platen position storage circuit 9 to be in the reverse state. (Step S8). Although not described in detail in this embodiment, it is also possible to subdivide and set the hammer drive count prescribed value within a predetermined time and to control the platen retraction amount in accordance with each prescribed value. After a predetermined time T1 (= T) instructed by the timer circuit 6 (step S9), the number of hammer driving times counted by the printing hammer driving number counting means 4 is called (step S10). At this time, the number of times the hammer is driven is not 0 (step S11), the timer for the next fixed time T2 (= T) is restarted (step S16), and the counter of the printing hammer drive number counting means 4 is reset ( In step S17, the process proceeds to the next predetermined time T2 (= T) in FIG.
[0010]
Next, the operation at the predetermined time T2 (= T) in FIG. 3 will be described. Print data is sent from the print control means 1 to the print hammer drive frequency count means 4, and the print hammer drive frequency count means 4 determines the number of times the hammer is driven within a predetermined time T 2 (= T) indicated by the timer circuit 6. Count (step S4). Within a predetermined time T2 (= T) instructed by the timer circuit 6, the comparator 5 repeatedly compares and executes whether or not the driving number counted by the printing hammer driving number counting means 4 has reached a specified value M (step S4). , Step S5, Step S6, and Step S9 are repeatedly executed). After a predetermined time T2 (= T) instructed by the timer circuit 6 (step S9), the number of hammer driving times counted by the printing hammer driving number counting means 4 is called (step S10). At this time, the number of times the hammer is driven is not 0 (step S11), the timer for the next fixed time T3 (= T) is restarted (step S16), and the counter of the printing hammer drive number counting means 4 is reset ( In step S17, the process proceeds to the next predetermined time T3 (= T) in FIG. Note that the platen 11 during the predetermined time T2 (= T) at this time is in the position state of the retraction amount N.
[0011]
Next, the operation at the predetermined time T3 (= T) in FIG. 3 will be described. Print data is sent from the print control means 1 to the print hammer drive frequency count means 4, and the print hammer drive frequency count means 4 sets the number of times the hammer is driven within a predetermined time T 3 (= T) indicated by the timer circuit 6. Count (step S4). Within a predetermined time T3 (= T) indicated by the timer circuit 6, the comparator 5 repeatedly compares and executes whether or not the number of driving times counted by the printing hammer driving number counting means 4 has reached a predetermined value M (step S4). , Step S5, Step S6, and Step S9 are repeatedly executed). After a predetermined time T3 (= T) instructed by the timer circuit 6 (step S9), the number of hammer driving times counted by the printing hammer driving number counting means 4 is called (step S10). Since the number of times the hammer is driven at this time is 0 (step S11), the position information of the platen 11 at this time is called from the platen position storage circuit 9 (step S12), and it is determined whether or not the position of the platen 11 is in the retracted state (step S12). Step S13). When the position of the platen 11 is in the retracted state, the platen position control means 8 instructs the platen position storage circuit 9 along with the position change drive instruction for the platen 11 and the advance amount N. That is, an instruction to return the platen 11 to the initial position. The platen position storage circuit 9 moves the platen 11 forward N times to the platen drive circuit 10 in accordance with an instruction from the platen position control means 8 (step S14), and resets the stored information in the platen position storage circuit 9. That is, it is set that the position of the platen 11 is in the initial state (step S15). The timer for the next fixed time T4 (= T) is restarted (step S16), and the counter of the printing hammer drive number counting means 4 is reset (step S17). When the position of the platen 11 is not in the reverse state, that is, in the initial state, the timer for the next fixed time T4 (= T) is restarted (step S16), and the counter of the printing hammer drive frequency counting means 4 is reset. (Step S17).
[0012]
The printing gap fluctuation detecting means is changed to a method corresponding to the number of times of printing hammer driving by the printing hammer driving frequency counting means 4 and timer circuit 6 described above, and an appropriate position of the hammer bank 12 that is thermally linked to the printing hammer coil. It will be easily understood that this can also be realized by using a temperature detection means for directly detecting the heat generated by the printing hammer coil by a temperature detection means such as a thermistor attached to the printer and comparing it with a specified value.
[0013]
【The invention's effect】
As described above in detail, according to the present invention, the print gap between the print hammer and the platen can be maintained at an appropriate value without being affected by heat generated by the printing operation, and high print quality can be maintained. Can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram of an exemplary embodiment of the present invention.
FIG. 2 is an example of the flowchart of FIG.
FIG. 3 is a characteristic diagram illustrating an example of a timing chart in FIG. 1;
FIG. 4 is a characteristic diagram of a conventional example showing the relationship between the number of times of printing hammer driving within a predetermined time interval and the displacement of the printing gap between the printing hammer and the platen.
FIG. 5 is a side view showing a displacement state of a print gap between a print hammer and a platen.
[Explanation of symbols]
1 is a printing control means, 2 is a hammer control means, 3 is a hammer, 4 is a printing hammer driving frequency counting means, 5 is a comparator, 6 is a timer circuit, 7 is a data latch circuit, 8 is a platen position control means, and 9 is A platen position storage circuit, 10 is a platen drive circuit, 11 is a platen, 12 is a hammer bank, 13 is a print medium, 14 is an ink ribbon, 30 is a print gap fluctuation detecting means, and 40 is a position control means.

Claims (2)

A hammerbank having a plurality of print hammer, a platen for supporting the opposite print medium to said hammer bank, a printing gap variation detecting means for detecting the variation of the printing gap between the printing hammer and a platen, indicia-shaped In the printing gap control device of a printing apparatus, characterized in that there is provided a position control means for moving a position of at least one of the platen and the hammer bank and adjusting a printing gap between them by a detection output of the gap fluctuation detection means .
The printing gap fluctuation detecting means activates a timer for a predetermined time in the course of the printing operation of the hammer bank, counts the number of times the printing hammer is driven during the timer operation, and detects that the specified number of driving times M has been reached. A printing gap control device for a printing apparatus, characterized by comprising a printing hammer drive frequency counting means.   A hammer bank having a plurality of printing hammers, a platen that faces the hammer bank and supports a printing medium, a printing gap fluctuation detecting means for detecting fluctuations in a printing gap between the printing hammer and the platen, and the printing In the printing gap control device of a printing apparatus, characterized in that there is provided a position control means for moving the position of at least one of the platen and the hammer bank and adjusting the printing gap between the two according to the detection output of the gap fluctuation detection means.
A printing gap control device for a printing apparatus, wherein the printing gap fluctuation detection means is a temperature detection means for detecting heat generation of a printing hammer coil.

Images