JPH0528650U - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention detects the thickness of the printer paper and automatically controls the mechanism of the printing unit and the paper feeding unit. It is characterized by preventing damage and maintaining printing quality suitable for paper thickness. [Structure] A sheet thickness detecting sensor 2 mounted near a sheet supply port, a storage circuit 11 for holding sheet thickness detection information of the sensor 2, and a drive control of a motor 3 according to a level value stored in the storage circuit 11. Driver circuit 12 for
A carriage 4 and a paper guide 6 whose gap with the platen 5 is adjusted by the motor 3 and a head drive circuit 13 for controlling the pin drive current of the head 7 according to the level value stored in the storage circuit 11 are provided. The gap between the platen 5 and the paper guide 6 is automatically set according to the paper thickness detected by the sensor 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printer having a paper thickness adjusting mechanism.

[0002]

[Prior Art]

 Dot printers are widely used as printing devices for various office automation equipment such as word processors and personal computers.

Conventionally, the adjustment of the paper thickness of a dot printer has been realized by the user's manual operation. Specifically, the user has adjusted the copy control lever 1 shown in FIG. 2 according to the thickness of the paper and as a guide by experience. Here, the conventional model has a copy control lever (see reference numeral 1 in Fig. 2) that allows the paper thickness to be adjusted in 5 steps (from 1st copy to 5th copy), and by adjusting the lever as desired, the machine can be adjusted. The position of the carriage was moved to change the gap between the platen and the head.

Further, conventionally, the state of the copy control lever (see reference numeral 1 in FIG. 2) is checked by firmware, and a mechanism for changing the printing pressure by increasing the head current for three or more copies is provided. There is also an apparatus in which the user operates the copy control lever according to the thickness of the paper to change the printing pressure so as to maintain an appropriate printing density according to the thickness of the paper.

[0005]

[Problems to be solved by the device]

 Conventionally, if the user prints while operating the copy control lever (see reference numeral 1 in FIG. 2) by mistake, the head pin may be broken. For example, if the lever operation is neglected when changing from the third copy paper to the first copy paper, the gap between the platen and the head is too wide, and therefore the printing pressure of the head is strong and the pin breaks.

The present invention has been made in view of the above circumstances, and automatically detects the paper thickness of the printer and automatically controls the mechanism such as the printing unit and the paper feeding unit, so that the head pin breaks due to an operation error of the paper thickness setting. It is an object of the present invention to provide a dot printer equipped with a paper thickness automatic detection mechanism that can always avoid the inconveniences such as the above and can always ensure the print quality suitable for the paper thickness.

[0007]

[Means for Solving the Problems]

 The present invention is a sensor that is installed near the paper supply port and that detects the amount of light transmitted through the paper, a memory circuit that converts the amount of light transmitted by this sensor into a paper thickness detection level, and stores the memory circuit. And a driver circuit for controlling the drive motor for the carriage and the paper guide according to the level value.

Further, according to the present invention, the gap between the platen and the head is automatically set according to the paper thickness detected by the sensor, and the multi-sheet paper is judged by the moving amount of the driving motor to drive the head. The feature is that optimum print quality is obtained by controlling the current value.

[0009]

[Action]

 The present invention detects the thickness of the paper manually inserted or autoloaded in the supply port by the sensor based on the amount of light transmission, converts this to the paper thickness detection level, and stores it in the memory circuit. The carriage of the printing unit and the paper guide drive motor of the paper feeding unit are drive-controlled according to the level value stored in the storage circuit. This control eliminates the need for the user to manually adjust the mechanical thickness of the paper thickness to adjust the feed gap according to the paper thickness.

Further, the sensor also determines the presence / absence of paper at the same time. Further, the gap between the platen and the head is automatically set according to the paper thickness detected by the sensor, and the head current value is changed by judging the multi-part paper by the movement amount of the drive motor.

As a result, operability can be improved and optimum print quality can be obtained without requiring manual adjustment by the user for adjusting the sheet thickness and adjusting lever (copy control lever) for each multi-part sheet. Also, it is possible to prevent breakage of the head pin and secondary damage of the paper jam due to the operation error and setting error of the adjustment lever, and the automatic gap control according to the paper thickness can always maintain the proper print quality.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

In FIGS. 1 to 3, reference numeral 1 is a copy control lever, which has conventionally been used to manually adjust the paper thickness, but in the present invention, it is an auxiliary one. Is provided and is not necessarily required.

Reference numeral 2 is a sensor that detects the thickness of the sheet by the amount of transmitted light. When the sheet is inserted, the sheet thickness is detected by the amount of transmitted light of the sensor 2, converted into a voltage level, and supplied to the driver circuit 12. Reference numeral 3 is a drive motor, which drives the carriage 4 and the paper guide 6 under the drive control of the driver circuit 12. That is, the drive motor 3 is driven by the driver circuit 12 with the amount of movement detected by the sensor 2 according to the voltage level according to the sheet thickness.

Reference numeral 4 denotes a carriage on which a head 7 is mounted, and the drive motor 3 controls the movement of the head 7 together with the head 7 in the direction of the arrow in FIG. 1 to determine the gap between the platen 5 and the head 7. Reference numeral 5 is a platen, and the gap between the platen 5 and the head 7 is determined by the movement of the carriage 4 in the platen direction (arrow direction in FIG. 1). Reference numeral 6 denotes a paper guide, which is moved by the drive motor 3 in the platen direction (arrow direction in FIG. 1).

Reference numeral 7 denotes a print head having a wire dot configuration, which is conveyed in the line (row) direction by the carriage 4. In this embodiment, when the print is not performed, the drive motor 3 drives the platen in the platen direction (see FIG. 1). It moves in the direction of the arrow) and the gap is adjusted with the platen 5. Reference numeral 11 is a memory circuit (L), which holds a voltage level according to the amount of transmitted light of the paper thickness detected by the sensor 2, and is realized by using a register.

Reference numeral 12 is a driver circuit (D-CN), which drives and controls the drive motor 3 according to the detection signal by the sensor 2 stored in the storage circuit 11, and outputs a signal according to the movement amount to the head drive circuit (H-CN). DR) 13.

Reference numeral 13 is a head drive circuit (H-DR) 13 that drives and controls the wire dot pin of the head 7, and controls the printing pressure of the wire dot pin according to a signal received from the driver circuit 12.

The operation of the embodiment of the present invention will be described below. First, when the paper is set, the paper thickness detection sensor 2 at the paper supply port detects the paper thickness from the amount of transmission of the printing paper. The sensor 2 outputs the thickness of the paper as a voltage level value to the storage circuit 11.

As a result, the voltage level according to the amount of transmitted light of the paper thickness detected by the sensor 2 is held in the storage circuit 11. The voltage level signal according to the amount of transmitted light of the paper thickness held by the sensor 2 is output to the driver circuit 12.

The driver circuit 12 drives the motor 3 in accordance with the data content (voltage level according to the amount of transmitted light of the sheet thickness) held in the memory circuit 11, and the gap between the platen 5 and the sheet guide 6 that is appropriate for the sheet thickness is obtained. Make adjustments. At this time, the contents of the storage circuit 11 are also used for determining the presence or absence of paper. Here, for example, when the paper to be printed supplied to the paper supply port has a paper thickness of two or more copies, the carriage 4 and the paper guide 6 are moved in the arrow direction of FIG. To be done. If the paper to be printed supplied to the paper supply port has a thickness of 3 to 5 copies, the head drive circuit 13 increases the current value of the head 7 according to the signal received from the driver circuit 12 and the wire Controls the printing pressure of dot pins to maintain printing quality on multi-part paper. After the printing is completed, when the sensor 2 detects the paper end (no paper), the memory circuit 11 is cleared. As a result, the gap between the platen 5 and the paper guide 6 is automatically adjusted even during continuous operations using one copy paper and multiple copies.

Although the above description has described the automatic control of the mechanism by detecting the paper thickness of the dot printer, the OCR (optical character reading device) or the LBP (line-beam printer) which conveys the paper is used. The mechanical control can be applied in the same configuration as the above embodiment.

[0023]

[Effect of the device]

 As described above, according to the present invention, it is not necessary for the user to adjust the adjustment lever (copy control lever) for each paper thickness and multi-part paper, which can greatly improve the operability, and the operation error and the setting of the adjustment lever. It is possible to prevent breakage of the head pin due to mistakes or the like and secondary damage such as paper jam. In addition, the automatic mechanical gap control based on the paper thickness allows the optimum print quality to be maintained at all times, and eliminates any trouble related to the adjustment lever (copy control lever).

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a mechanical portion of the embodiment shown in FIG.

FIG. 3 is a perspective view showing a configuration of a mechanism section of the embodiment shown in FIG.

[Explanation of symbols]

1 ... Copy control lever, 2 ... Paper thickness detection sensor, 3 ... Drive motor, 4 ... Carriage, 5 ... Platen,
6 ... Paper guide, 7 ... Head, 11 ... Storage circuit (L),
12 ... Driver circuit (D-CN), 13 ... Head drive circuit (H-DR).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G06K 13/063 B 2116-5L

Claims (3)

[Scope of utility model registration request] 1. A printer comprising a paper thickness detection unit mounted near a paper supply port, and a circuit for controlling a specific drive unit of a printing mechanism according to the paper thickness detected by the detection unit. 2. A sensor mounted near a paper supply port for detecting a transmitted light amount by projecting a fixed amount of light onto a printing paper, and a storage means for converting the transmitted light amount of the sensor into a paper thickness detection level and storing the level. And a driver circuit for controlling the carriage and the paper guide driving motor according to the level value stored in the storage means. 3. A gap between the platen and the head is set by moving the head of a driving motor according to the thickness of the paper, and multi-part paper is judged from the amount of movement of the driving motor to change the head current value. The printer according to claim 1, wherein the printer is a printer.