JPH11138924A - Means for detecting size of recording medium and line printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means for detecting the size of a recording medium, e.g. a print sheet, in a line printer surely even when detection of the size of some type of recording medium based on the reflected light is difficult. SOLUTION: Size of a recording medium being set on a printer can be detected surely by measuring the position of a home position detecting plate 56 intercepting a transmission type optical sensor 55 and the position of a recording medium size detecting plate 52 moving in synchronism with a recording medium retainer 51 being set on a recording medium supply means 50 using the transmission type optical sensor 55.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line printer having recording medium supply means capable of detecting the size of a recording medium such as printing (printing) paper.

[0002]

2. Description of the Related Art Printing (printing) by this type of printer
Conventionally, a recording medium size (paper width) such as printing paper is set by a host computer, and print data is transferred to a printer for printing. In this case, it is necessary to set a recording medium in the printer in advance,
When the size of the recording medium set in the printer is different from the size of the recording medium set by the host computer, particularly when the size of the recording medium set in the printer is smaller than the size of the recording medium set by the host computer. In this case, printing is performed outside the recording medium (for example, on a paper feed roller).

For this reason, conventionally, a reflection type optical sensor or the like is provided on a print head to detect the size of the recording medium set in the printer, and detects the reflected light from the recording medium to obtain the recording medium area. Then, the area other than the recording medium is detected, and the size of the recording medium is recognized to prevent printing on the area other than the recording medium.

[0004]

However, there are various types of recording media of this kind, such as plain paper, OHP (overhead projector) sheets, background paper, glossy paper, and the like. Since the type of detection is difficult (for example, an OHP sheet), and the reflected light from the recording medium varies from recording medium to recording medium, the recording medium and a medium other than the recording medium (for example, a paper feed roller) are determined. There is a problem that setting of the threshold value is extremely difficult.

The present invention has been made in view of the above situation, and has as its object to provide a means for reliably detecting the size of a recording medium in which it is difficult to detect reflected light as described above. .

[0006]

Therefore, according to the present invention, there is provided a line printer having a recording medium size detecting means or a size error notifying means according to any one of the following items (1) and (2). This aims to achieve the above object.

(1) In a line printer in which a carriage unit on which a recording medium supply means and a recording head are mounted has a home position detection plate and a transmission optical sensor which is turned on / off by the plate, the recording medium supply While holding a recording medium size detection plate that moves in synchronization with a recording medium press provided on the means, it is set in the printer by measuring the position between the home position detection plate and the recording medium size detection plate. Recording medium size detection means for detecting a recording medium size.

(2) In the line printer described in (1), the size of the recording medium set in the printer is detected by measuring the position between the home position detecting plate and the recording medium size detecting plate. And a means for notifying a recording medium size error when the detected recording medium size is different from the recording medium size sent from the host device.

[0009]

According to the construction of the present invention as described above, a transmission optical sensor for detecting a home position of a carriage provided in advance on a carriage unit, a home position detection plate for shutting off the transmission optical sensor, and a recording medium The transmission type optical sensor measures the position of the recording medium size detection plate that moves in synchronization with the recording medium press provided on the supply means, thereby reliably detecting the recording medium size set in the printer. Can be.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on a plurality of examples with reference to the drawings.

[0011]

FIG. 1 is a block diagram showing a schematic configuration of a control system of an ink jet printer according to a first embodiment.

<Structure> In FIG. 1, a CPU 21 in the form of a microprocessor is
A program and recording command data stored in a program memory 24 in the form of a ROM, a data memory 23 in the form of an EEPROM, and the like, and a command read from the host apparatus 100 into the working memory 25 in the form of a RAM. The recording operation is controlled based on a signal (command) and a recording information signal.

Further, the CPU 21 operates the carriage motor 31 via the output port 26 and the carriage motor control circuit 34 to thereby control the carriage motor 3
1 or by operating the sheet feed motor 32 via the sheet feed motor control circuit 30,
The transport function 33 is operated. Further, the CPU 21 drives the recording head 57A via the head driving circuit 29 based on the recording information stored in the working memory 25 to record a desired image on a recording medium 60 shown in FIG. be able to.

Next, this embodiment will be described in detail with reference to FIGS. FIG. 2 is a side view of the printer, and FIG.
FIG. 2 is a top view of the printer. In both figures, reference numeral 50 denotes a recording medium supply (holding) unit for holding the recording medium 60 in the printer. Reference numeral 51 denotes an arrow A for setting the recording medium 60 in parallel with the recording medium transport direction arrow B
This is a recording medium press for pressing the recording medium 60 by moving in the direction. Reference numeral 52 denotes a recording medium size (paper width) detection plate that moves in synchronization with the recording medium holder 51.

<Control Operation> FIG. 4 is a flowchart showing a control operation sequence according to this embodiment. First, the recording medium size A to be printed is set by the host device 100 of FIG. 1 (step S1), and a print start signal is transferred to the printer (step S2). When the print start signal is transferred, the printer starts detecting the recording medium size B set in the recording medium holding means 50 shown in FIGS. In order to detect the recording medium size B, the printer moves the carriage unit 57 shown in FIGS. 1 to 3 and starts searching for a home position (step S3).

When the carriage unit 57 scans at a speed F, the number of motor steps N
When the moving distance is FNmm, the width of the paper width detection plate is set to FNmm, and the width of the home position detection plate 56 is set to FNmm or more.

When the carriage 57 is scanning at the speed F, the transmission type optical sensor 55
When the sensor 55 is turned off, a signal is transmitted to the CPU 21 via the recording head control circuit 29, and the CPU 21 transmits the signal to the carriage motor control circuit 34 via the output port 26. Start counting.

If the count value of the number of steps is ≤N, it is determined that the plate is the sheet width detection plate 52, and the carriage 57 continues scanning at the speed F. If the count value of the number of steps is> N, it is determined that the plate is the home position detection plate 56 (step S4).

After the home position is determined, the carriage 57
Starts scanning in direction C at speed F (step S
5). When the transmission optical sensor 55 separates from the home position detection plate 56 and the sensor is turned on, the CPU
A step 21 starts counting the number of steps of the CR motor 31. When the sensor is turned off by the sheet width detection plate 52, the CPU 21 ends the counting (step S6). The CPU 21 detects the recording medium size B set in the printer by comparing the counted motor step value with the recording medium size corresponding to each step value stored in the program memory 24 (step S7). .

If the detected recording medium size B is equal to the recording medium size A set by the host 57 (step S8), printing is started (step S9). If A 場合 B, a recording medium error is displayed on the host 57 (step S11). Here, when the recording medium B set in the printer is changed and printing is started, the printer detects the changed recording medium B size, and printing is not started until size A = size B.

(Second Embodiment) In the printer configuration of the first embodiment, the size of the recording medium set in the printer is detected by measuring the distance between the home position detection plate 56 and the recording medium size detection plate 52. A recording medium size error is displayed only when the recording medium size A set by the apparatus and the recording medium size B set in the printer are A> B, and when A ≦ B, printing is started.

[0022]

As described above, according to the present invention,
By using a transmission optical sensor that is provided on the carriage and detects the home position of the carriage in advance, the size of the recording medium set in the printer can be detected without the need to add an electrical component, and the recording medium other than the recording medium can be detected. (For example, a paper feed roller) can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a control system according to an embodiment;

FIG. 2 is a side view of the printer according to the embodiment.

FIG. 3 is a top view of the printer according to the embodiment.

FIG. 4 is a flowchart of a control operation sequence according to the embodiment.

[Explanation of symbols]

 Reference Signs List 21 CPU 22 Interface 23 Data memory 24 Program memory 25 Working memory 26 Output port 27 Input port 28A-D Operation keys 29 Recording head control circuit 30 Sheet feed motor control circuit 31 Carriage motor 32 Sheet feed motor 33 Carriage motor control circuit 40 Power supply Circuit 41 Paper feed roller 50 Recording medium supply (holding) means 51 Recording medium press 52 Recording medium size (paper width) detection plate 53 Printer back chassis 54 Carriage unit shaft 55 Transmission optical sensor 56 Home position detection plate 57 Carriage unit 57A Recording Head 100 Host device

Claims (2)

[Claims] 1. A line printer in which a carriage unit on which a recording medium supply unit and a recording head are mounted has a home position detection plate and a transmission optical sensor which is turned on / off by the plate. While holding the recording medium size detection plate provided in synchronization with the recording medium press provided above, the recording set in the printer by measuring the position between the home position detection plate and the recording medium size detection plate. Recording medium size detection means for detecting a medium size. 2. The line printer according to claim 1, wherein a size of the recording medium set in the printer is detected by measuring a position between the home position detection plate and the recording medium size detection plate. And a means for notifying a recording medium size error when the recording medium size transmitted from the host device is different from the recording medium size.