JPH04217542A - Discriminating apparatus for recording medium of printer - Google Patents

Abstract

PURPOSE:To automatically discriminate numerous kinds of recording media by utilizing not only light transmission characteristics and reflection characteristics of the recording media but also scattering characteristics in a printer. CONSTITUTION:A light emitting body 2 is placed on one side of a passage 8 with a recording medium 7 interposed, while a first light receiving body 5 and a second light receiving body 6 are placed on the other side of the passage 8 with the recording medium 7 interposed. Light emitted from the light emitting body 2 directly transmits through the recording medium 7 or passes through the recording medium 7 after it is reflected and scattered by the recording medium 7 and then is incident to the first light receiving body 5 and the second light receiving body 6. A type of the recording medium 7 is discriminated based on a photoelectric conversion output according to the incident light to the first light receiving body 5 and the second light receiving body 6.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium discriminating device for a printing device, and more particularly to a recording medium discriminating device for a printing device capable of printing on a plurality of types of recording media.

0002

[Prior Art] Some conventional printing equipment can now print on transparent film, translucent film, Yupo paper (white paper with surface treatment), etc. in addition to plain paper. There are some.

[0003] Such conventional printing equipment uses reflective optical sensors and transmissive optical sensors to detect the presence or absence of a recording medium.
Although it detects end marks, it is generally not possible to determine the type of recording medium.

[0004] However, in printing equipment, it is sometimes necessary to clarify the type of recording medium in order to optimize the print quality. It was now possible to set the type of recording medium.

However, if the user sets the recording medium type on the printing device using a dip switch or operation, it is undesirable because it may cause incorrect settings when the number of recording media types increases. In order to be compatible with different media, it is necessary for printing equipment to automatically determine the type of recording medium.

For this reason, conventional printing equipment is equipped with a recording medium discrimination device to distinguish between transparent film and plain paper.
A device that automatically discriminates the type of recording medium has already been proposed (see Japanese Patent Laid-Open No. 193841/1999).

[0007]

[Problems to be Solved by the Invention] However, the above-mentioned conventional recording medium discrimination device for printing equipment utilizes a transmission type optical sensor and a reflective type optical sensor, and uses a combination of the photoelectric conversion outputs of these optical sensors to detect whether a transparent film is detected or not. There are problems in that there are only a few types of recording media that can be discriminated, and it is difficult to distinguish between transparent film and translucent film, and between plain paper and Yupo paper.

[0008] In view of the above-mentioned points, an object of the present invention is to obtain a strong light at a position close to a light source when the material is made of a material that easily transmits light, such as a transparent film, but at a position far from the light source, light is not easily scattered. It also takes advantage of the light scattering properties of the recording medium, such as white paper such as thermal paper, which scatters a lot and averages the light horizontally, making it possible to detect the light even at a position far from the light source. Therefore, it is an object of the present invention to provide a recording medium discrimination device for a printing device that can automatically discriminate between various types of recording media.

[0009]

[Means for Solving the Problems] A recording medium discriminating device for a printing device according to the present invention includes a light emitting body disposed on one side of the recording medium passing path, and a light emitting body disposed on the other side of the recording medium passing path. It is characterized by having a plurality of photoreceptors disposed on the side, and a determining means for determining the type of recording medium based on the photoelectric conversion output from the plurality of photoreceptors.

0010

[Operation] In the recording medium discrimination device for printing equipment of the present invention, a light emitter is arranged on one side across the passage of the recording medium, and a plurality of photoreceptors are arranged on the other side across the passage of the recording medium. The determining means determines the type of recording medium based on the photoelectric conversion outputs from the plurality of photoreceptors.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a sectional view showing the configuration of a sensor section in a recording medium discrimination device for a printing device according to an embodiment of the present invention. This sensor section includes a light source bracket 1 placed on one side of a passage path 8 for the recording medium 7, a light emitting body 2 made of an infrared light emitting diode attached to the light source bracket 1, and a light source provided on the light source bracket 1. a reflector 3,
A light receiving bracket 4 is arranged to face the light source bracket 1 on the other side of the passage path 8 of the recording medium 7, and a phototransistor is attached to the light receiving bracket 4 so as to face the light emitter 2. 1 photoreceptor 5 and a second phototransistor mounted on the light receiving bracket 4 at a position slightly away from the position facing the light emitter 2.
It is configured to include a photoreceptor 6.

The surface of the light source side bracket 1 facing the light receiving bracket 4 has a recess 1a, which forms a light guide path for guiding the scattered light from the light emitter 2 reflected by the recording medium 7. . Further, the reflector 3 is provided integrally or separately in the recess 1a, and makes it possible to diffusely reflect scattered light.

FIG. 2 is a circuit diagram of a circuit section in the recording medium discriminating device for printing equipment according to this embodiment. This circuit section is
A light emitter 2 made of an infrared light emitting diode, a first photoreceptor 5 and a second photoreceptor 6 made of a phototransistor, voltage dividing reference resistors R1, R2 and R3, and a brightness adjustment resistor R4.
, voltage dividing resistors R5, R6, R7, and R8, backflow prevention resistors R9 and R10, pull-up resistors R11 and R12, smoothing capacitors C1 and C2, backflow prevention diodes D1 and D2, and comparator CP1.
and CP2.

A power source (not shown) is connected to one end of the first photoreceptor 5 (collector of the phototransistor) via a voltage dividing reference resistor R1, and the other end of the first photoreceptor 5 (emitter of the phototransistor). is grounded via the smoothing capacitor C1 and the voltage dividing resistor R7, and is also connected to the inverting input terminal of the comparator CP1 via the backflow prevention resistor R9.

Further, the power supply is connected to one end of the second photoreceptor 6 (collector of the phototransistor) via a voltage dividing reference resistor R2.
The other end of the second photoreceptor 6 (emitter of the phototransistor) is connected to a smoothing capacitor C2 and a voltage dividing resistor R.
8 and is grounded via a backflow prevention resistor R.
10 to the inverting input terminal of the comparator CP2.

Furthermore, the power supply is connected to the non-inverting input terminal of the comparator CP1 and the non-inverting input terminal of the comparator CP2 via the voltage dividing reference resistor R3, and the power supply is connected to the non-inverting input terminal of the comparator CP1 and the non-inverting input terminal of the comparator CP2.
The non-inverting input terminal of P2 is connected to the output port A of a general-purpose input/output port (not shown; hereinafter abbreviated as IO port) via a backflow prevention diode D1 and voltage dividing resistor R5, and also It is connected to the output port B of the IO port via a prevention diode D2 and a voltage dividing resistor R6.

The output terminal of the comparator CP1 is connected to the power supply via a pull-up resistor R11, and is also connected to the I
Connected to input port A of O port, comparator CP
The output terminal of No. 2 is connected to the power supply via a pull-up resistor R12, and is also connected to the input port B of the IO port.

Referring to FIG. 3, a microprocessor (
The recording medium determination process performed by the MPU (not shown) includes an initial step S1, a recording medium determination step S2, a measurement end determination step S3, a recording medium determination step S4, and a printing condition setting step. It consists of S5.

FIG. 4 is a table showing the values of output ports A and B used for determining the recording medium 7 in the recording medium determining step S2. In this embodiment, it is assumed that the printing device uses thermal paper as a recording medium in the normal mode.

Next, an explanation will be given of the operation of the recording medium discriminating device for printing equipment of this embodiment configured as described above.

First, the MPU performs initial processing of the printing device, such as feeding the recording medium 7, and inserts the recording medium 7 into the passage path 8 of the sensor section of the recording medium discriminating device (step S1). Then, depending on the type of recording medium 7, the light emitted from the light emitter 2 may directly pass through the recording medium 7, or may directly pass through the recording medium 7.
The light is scattered by the recording medium 7, reflected by the reflector 3, and then passes through the recording medium 7, so that a photoelectric conversion output corresponding to the type of the recording medium 7 is obtained on the first photoreceptor 5 and the second photoreceptor 6. .

(1) When the recording medium 7 is a translucent film, since the recording medium 7 transmits light relatively well and has high scattering properties, the light from the light emitter 2 causes the first photoreceptor 5 to become a translucent film. When the second photoreceptor 6 receives the transmitted light from the recording medium 7, the inverting input terminal of the comparator CP1 becomes a high level voltage, and when the second photoreceptor 6 receives the scattered light from the recording medium 7, the inverting input terminal of the comparator CP2 also becomes a high level voltage. .

(2) When the recording medium 7 is a transparent film, the recording medium 7 transmits light well but has low scattering properties, so the light from the light emitting body 2 causes the first photoreceptor 5 to pass through the recording medium 7.
By receiving the transmitted light from the recording medium 7, the inverting input terminal of the comparator CP1 becomes a high level voltage.
The inverting input terminal of No. 2 becomes a low level voltage.

(3) When there is no recording medium 7, the first photoreceptor 5 receives the transmitted light of the recording medium 7 due to the light from the light emitter 2, while the second photoreceptor 6 does not receive the light. , the inverting input terminal of comparator CP1 becomes a high level voltage, and the voltage of the inverting input terminal of comparator CP2 becomes “0”.
” becomes.

(4) When the recording medium 7 is thermal paper, since the recording medium 7 does not transmit much light, the first photoreceptor 5 receives the little transmitted light of the recording medium 7 due to the light from the light emitter 2. As a result, the inverting input terminal of the comparator CP1 becomes a medium level voltage, and as the second photoreceptor 6 receives a small amount of scattered light from the recording medium 7, the inverting input terminal of the comparator CP2 becomes a medium level voltage.

(5) When the recording medium 7 is Yupo paper, the recording medium 7 hardly transmits light, so the first photoreceptor 5 does not receive much of the light transmitted through the recording medium 7 due to the light from the light emitter 2. As a result, the inverting input terminal of the comparator CP1 becomes a low level voltage, and since the second photoreceptor 6 does not receive much of the scattered light from the recording medium 7, the voltage at the inverting input terminal of the comparator CP2 also becomes a low level voltage.

(6) In the case of a failure or light interruption of the recording medium discrimination device, no photoelectric conversion output can be obtained on the first photoreceptor 5 and the second photoreceptor 6, so the voltage at the inverting input terminals of comparators CP1 and CP2 are respectively “0”.

Next, the MPU sets the values of output ports A and B in the order of input ports A and B from the top side according to the order of entries in the table of FIG.
The recording medium in the entry immediately before the recording medium in which the value of is the first combination of "0" and "0" is determined to be the type of recording medium 7 loaded in the printing device (step S2). If no recording medium is listed in the previous entry, the recording medium in the previous entry is determined to be the type of recording medium 7 loaded in the printing device.

For example, when the recording medium 7 is a translucent film, when measuring the value of the input port B, the output port A
and B are "0" and "1" as in the second transparent film entry in the table of FIG.
V), the inverting input terminal of the comparator CP2 becomes a high level voltage (for example, 3.3 V), and the value of the input port B becomes "1". Therefore, it is determined that the type of recording medium 7 loaded in the printing device is a translucent film, which is the entry immediately before the transparent film. At this time, among the counters (not shown) provided for each type of recording medium, a counter (not shown) corresponding to the translucent film is selected.
(which is cleared to zero in the initial state) is added by 1.

[0030] This determination of the recording medium 7 is repeated a predetermined number of times (for example, 200 times), and when the number of measurements is completed (step S3), a counter provided for each type of recording medium is counted. The value of the counter with the largest value is divided by the number of measurements to determine whether or not the recording medium has been determined to be of the type at a predetermined percentage (for example, 95%) or more (step S4), and if the predetermined percentage is not met. If so, it is assumed that the type of recording medium 7 could not be determined, and control is returned to step S2, and if necessary, the type of recording medium 7 can be determined.
After sending the recording medium 7 for a while, the determination of the recording medium 7 is performed again. If the ratio is equal to or higher than the specified ratio in step S4, it is assumed that the type of recording medium 7 has been determined, and printing conditions are set, such as adjusting the enable time of the thermal recording head to the type of recording medium 7 (step S5). Move to main processing.

By the way, in the above embodiment, the case where the number of photoreceptors is two was explained as an example, but the number of photoreceptors may be three or more.

Furthermore, in the above embodiment, the circuit section was configured as shown in FIG. 2, and the recording medium discrimination process was performed as shown in FIG. It goes without saying that the invention is not limited to this example.

The recording medium discrimination device of the present invention can be applied not only to discrimination of types of recording media such as film and paper, but also to discrimination of types of solutions, glass, etc.

[0034]

Effects of the Invention As explained above, the present invention does not discriminate the type of recording medium based only on the transmitted light or reflected light of the recording medium, but also automatically determines the type of recording medium by taking into account scattered light. This makes it possible to distinguish between many types of recording media, and eliminates the need for manual operations to set the type of recording media on the printing device, saving the user's time and effort. This has the effect of eliminating erroneous settings due to operational errors in the type of recording medium.

Furthermore, since the recording medium discrimination device of the present invention can be easily manufactured using only existing electronic components, it has the advantage that the device is inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a sensor section of a recording medium discrimination device for a printing device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a circuit section of a recording medium discrimination device for a printing device according to the present embodiment.

FIG. 3 is a flowchart showing recording medium discrimination processing in the recording medium discrimination device of the printing device according to the present embodiment.

FIG. 4 is a diagram showing a table used to discriminate recording media in the recording medium discriminating device of the printing device according to the present embodiment.

[Explanation of symbols]

1 Light source bracket 1a Recessed part 2. Luminous body 3 Reflector 4 Light receiving bracket 5 First photoreceptor 6 Second photoreceptor 7 Recording medium 8 Passage route C1, C2 Smoothing capacitor CP1, CP2 Comparator D1, D2 Diode for backflow prevention R1, R2, R3　Divided voltage reference resistance R4 Brightness adjustment resistor R5, R6, R7, R8 voltage dividing resistor R9, R10 Backflow prevention resistance R11, R12 Pull-up resistor

Claims (1)

[Claims] Claim 1: A light emitting body disposed on one side of a recording medium passing path, a plurality of light receiving bodies disposed on the other side of the recording medium passing path, and these plurality of light receiving bodies. 1. A recording medium discriminating device for a printing device, comprising: discriminating means for discriminating the type of recording medium based on a photoelectric conversion output from the recording medium.