JPS6369678A - Power source protecting apparatus of printer - Google Patents

Abstract

PURPOSE:To hold the printing data in a memory, by stopping the driving of a printing head and that of the motor for moving the printing head when a temp. sensor detects that the temp. of a power source part reaches a tolerant value or more. CONSTITUTION:When a main control part 61 receives the printing command from a higher rank apparatus UCE, said control part 61 imparts an order to a sub-control part 62 and transmits the printing data in a memory 63 and drives a printing head driving motor 27 and a wire dot type printing head 14 through drive circuits 64, 65 to perform printing. When a temp. sensor 49 detects that the temp. of a power source part reaches a tolerant value or more, the main control part 61 issues no printing operation command to the sub-control part 62 and stops only the driving of the motor 27 and that of the printing head, 14. Since the supply of a current to other circuit is continued even when the temp. of the power source part reaches a tolerant value, the printing data in the memory is held and printing operation can be immediately performed by the lowering in the temp. of the power source part and printing operation can be performed at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for protecting a power supply unit in a printer having a print head that consumes relatively large amount of power.

[Conventional technology]

In printers that use a wire-tod type print head, the print head is equipped with a large number of magnets, and printing is performed by excitation of these magnets.The higher the density of characters, symbols, etc. printed, the lower the power consumption required to drive the print head. On the other hand, in order to reduce the cost, a relatively small power supply capacity is used for the power supply section, and this allows the majority of the stain source capacity to be used for driving the print head. In addition to supplying the power source, power is also supplied to each circuit such as a memory that stores print data.

Therefore, if the print head is continuously driven, the temperature of the power supply section will rise and there is a risk that semiconductor elements such as transistors will be destroyed. It is assumed that the main power supply 13 will be restarted as the temperature decreases.

[Problem that the invention seeks to solve]

However, in the past, the main power supply was cut off in response to a rise in the temperature of the power supply section, so the power supply to all circuits was stopped, the power to the memory that stored all print data was also cut off, and the print data was erased. Even if the power supply is restarted, printing cannot be started immediately, and the printing data must be transferred from the host device again. ing.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

That is, in the above-mentioned printer, there is a temperature sensor that detects when the temperature of the power supply unit exceeds a permissible value, and a motor that stops driving the print head and moves the print head according to the detection output of the temperature sensor. A control section for stopping the driving of the motor is provided.

[Effect]

Therefore, if the temperature of the power supply section 5 exceeds the allowable value, the drive for the print head and its movement motor will be stopped, and most of the capacity of the power supply section will be in an unloaded state, causing the temperature of the power supply section to rise further. is blocked, the power supply to the memory is maintained, and the print data in the memory is saved.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 2 is a side view showing the main parts of a horizontal printer;
The paper inserted into the supply port 1 is detected by a paper feed sensor 3 such as a light-emitting diode and a light-receiving transistor provided opposite to each other on guide plates 2m and 2b arranged vertically opposite each other. As the transfer motor 4 rotates according to the detection output, the rollers 3 and 10 rotate in the direction of the arrow via the gears 5 and 6, the pulley T, and the belt 8f.
The sheet of paper is clamped by the holding roller 11i2 that comes into contact with the row 29.degree. 10, and is transported to the right in the figure.

However, between the rows 29 and 10, a platen 13 is provided on the lower side C6, and a wire head printing type print head 14 is provided on the upper side opposite to the platen C6. A paper edge sensor 15 similar to the paper sensor 3 is provided, and when the leading edge of the paper is detected by this,
Based on this position, there is a predetermined transport distance in which the printing start position of the paper coincides directly below the print head 14, so when the paper is transported by this transport distance, the motor 4 stops and enters a printing standby state.

The 0-shaped head 14 is connected to the supply port 1 by a mechanism omitted in the figure.
When viewed from the side, it moves in both left and right directions, and is supported so that it can move forward and backward in a direction perpendicular to the paper surface, and the gap between the paper surface and the tip 14 is automatically determined according to the thickness of the paper.
Printing is performed while moving in the left and right direction in accordance with the start of printing O, motor 4 rotates to perform a line feed when printing for one line is completed, and then printing is performed while moving in the opposite direction, The above O operation is repeated, and as printing progresses, the paper is gradually transferred to the O discharge port i6N on the right side of the figure.

Note that a power supply section 18 is housed in a cylindrical body located approximately halfway between the print head 14 and the discharge port 16, and supplies power to each section.

FIG. 3 is a cutaway perspective view of the main parts showing how the print head 14 is supported. An ink ribbon cartridge 22 is installed between the side plates 21m and 2Ib on both sides of the print head 14, and an ink ribbon cartridge 22 is mounted on the back side of the ink ribbon cartridge 22, which is movable in the vertical direction. A movable guide shaft 23 is provided, and the print head 14 is fixed to a horizontal protrusion 24 of a support base 24 through which the movable guide shaft 23 passes through the lower part and slides into the support base 24C + upper opening 24b. In contrast to the vertical movement,
In the horizontal direction, a sleeve 25 is engaged with the support base 24.
A movable guide shaft 23 of the support base 24 is provided with a fixed guide shaft 26 passing through the fixed guide shaft 26 in a sliding manner.
Rotation about the movable guide shaft 23 is prevented.
If it is raised and lowered by a mechanism using an eccentric cam, which is omitted in the diagram,
The print head 14 freely moves forward and backward relative to the paper surface.

Further, a motor 27 for moving the print head 14 is fixed on the outside of the side plate 211, and as the motor 27 rotates, a part of the synchro belt 30 stretched between the pulleys 2B and 29 is connected to the support stand 24. Since it is locked, the support base 24 moves in the left-right direction, and the print head 14 also moves accordingly.

In addition, as the motor 27 rotates, the pulleys 31 and 32
At the same time, an ink ribbon 34 stretched over the lower surface of the tip of the print head 140 through the cartridge 22 via the belt 33 is also driven, and circulates in response to printing.

Therefore, the print head 14 reciprocates from the left to the right and from the right to the left in response to forward and reverse rotation of the motor 2T, and by driving the print head 141c each time this bidirectional movement is performed, printing from both directions is possible. This is done as each line.

FIG. 4 shows the power supply section 18t, with the bottom being a plan view and FIG. 4B being a side view, in which the main power connector 42 is connected to the circuit board 41.
Transformer 43. Capacitor 44. Connector 4 for power supply
5, etc., and the heat sinks 46 and 47 are installed on the transformer 43.
and 1iii of capacitor 44! Fix it towards JJA,
A transistor 4 for primary side switching is mounted on the heat sink 46.
8 and a temperature sensor 49 are fixed, while a secondary side stabilizing transistor 5Ot- is fixed to the heat sink 4T, and these constitute a switching power supply circuit.

Further, the temperature sensor 49 is led out by a lead wire 51 and connected to a control unit mounted on a separate circuit board via a connector 45. Various necessary electronic components omitted in the diagram are mounted.

FIG. 1 is a block diagram of the circuit configuration for controlling the
Microprocessor? a main control unit (hereinafter referred to as MCT) 61 consisting of a CPU (hereinafter referred to as CPU) and a memory, etc.;
and memory for storing print data, etc. (hereinafter referred to as MM)
83 is provided, and the MCT 61 is provided with the output of the temperature sensor (hereinafter referred to as T8) 49 shown in FIG.
) and all data is exchanged.

In addition, while the 5CT 62 is given commands from the MCT 61, the 5CT 62 receives commands from the MCT 61,
Movement motor using a step motor (hereinafter referred to as SPM)
27, and also drives a print head (hereinafter referred to as PHD) 14 via the DRV 65.

The MCTs 61 and 5CTs 62 are designed such that each CPU executes instructions in a corresponding memory and performs predetermined control operations while accessing necessary data from the memory.

FIG. 5 is a flowchart mainly showing the main part of the control situation by the MCT 61, including the message "Print command received?" from the UCE.
If J101 becomes Y (YES), the "Temperature>Tolerance?"102"J&: of the power supply section 18 is determined based on the output of T849.
If this is N (No), "Execute printing process" 1
11, gives a command to 5CT62 and MM63
The print data in MM63 is transferred, the print data in MM63 is checked, and "Is there any other print data? J" While 112 is Y, steps 102 and subsequent steps are repeated.

Therefore, according to step 111K, the io PHDl 4 and 8PM27 are driven under the control of the 8CT62, and a printing operation is performed.

In response to the above, the temperature of the power supply section 18 rises, and step 10
If 2 is Y, press ``Do not execute printing process'' 121 and press S.
After not giving a printing operation command to C'r62, or giving a printing operation stop command if it is in the printing operation, again judge "Temperature>Tolerance? J122" in the same way as step 102, and this is N. After that, the process moves to step 111.

Therefore, in response to step 121, 5CT62.

Since the PHDf4 and SPM27 are not driven or are stopped, the thick portion of the power supply section 18 is in an unloaded state υ, which prevents further temperature rise and prevents power supply to other circuits. Please continue, MM
If the print data etc. in 63 do not disappear, the temperature of the power supply section 18 decreases as the load is reduced, and step 122 becomes N, the printing operation can be started or restarted immediately.

As the TS49, a thermal guard (manufactured by Tohoku Kinzoku), etc., which has a switching function that closes the circuit when a predetermined temperature is reached, is suitable.

However, it is also possible to use a temperature sensing element such as a thermistor as T849 and compare its detection output with the allowable temperature O data for all MCT61s to determine the temperature rise.
The same effect can be applied not only to the wire tod type but also to other types that require a relatively large current, and the power supply unit 18 may not be a switching power supply circuit but may be a rectification stabilization circuit or the like.

Furthermore, the MCT151 and 8CT62 may be integrated, and in addition to the step motor, various motors can be used as the SPM27 as long as the transfer amount can be predicted, and it is applicable not only to horizontal printers but also to various types of printers. Various modifications are possible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the drive of the print head and its movement motor is stopped in response to a rise in the temperature of the power supply unit, and the drive of the print head and its movement motor is stopped, and the power supply to other circuits is continued. The data is retained and printing can be performed immediately as the temperature of the power supply decreases, but it becomes O.
Overall, the speed of printing processing is realized, and a remarkable effect can be obtained in various printers.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a block diagram of the circuit configuration, Fig. 2 is a side view showing the main parts, Fig. 3 is a cutaway perspective view of the main parts showing how the print head is supported, and Fig. 4 The figure shows the power supply section, 4) is a plan view, (B) is a side view, and FIG. 5 is a flowchart of the control situation. 14 @-@PHD (print head), 1B---Kyoden deep section, 27-@-φSPM (motor), 49・Φ・-T
S (temperature sensor), 61---MCT (main control section)
, 62----5CT (1!It control section), 63-@
--M! (memory), 64, 65” ---DRY
(drive circuit). Patent applicant: Tamura Electric Co., Ltd. Urasakusho Co., Ltd. Agent: NEC Corporation Yamakawa number 4! t (2 others) CE on 1st floor 1'4 27 Figure 4 (A) (B)

Claims (1)

[Claims] In a printer that has a print head that consumes relatively large power and is equipped with a power supply unit that supplies the power required to drive the print head from a large portion of the power supply capacity and also supplies power to the memory, the temperature of the power supply unit is within an allowable range. A temperature sensor that detects when the temperature exceeds a temperature value, and a control unit that stops driving the print head and stops driving a motor that moves the print head according to the detection output of the temperature sensor. Features printer power protection device.