JPS61219831A - Apparatus for detecting moving distance - Google Patents

Abstract

PURPOSE:To detect the relative moving distance and direction of a scale and a sensor, by providing two sets of mark groups each having a plurality of marks arranged thereto at predetermined intervals so as to provide phase difference in the arrangement direction of the marks and using the number of pulses and phases obtained from a pair of sensors reading the mark groups. CONSTITUTION:Two sets of mark groups 2a, 2b each having a plurality of marks arranged thereto at predetermined intervals (b) are provided on a scale 1 so as to provide phase difference (c). A knob movable in parallel to the scanning direction of a manuscript is provided in the vicinity of the original platen of a copying machine and a sensor plate 3 is provided to the lower part of said knob. The sensor plate is provided with sensors 4a, 4b having light emitting elements 5a, 5b and light receiving elements 6a, 6b in order to read the mark groups 2a, 2b. Whereupon, when the knob is moved in order to indicate a copy position, the relative moving distance of the sensors and the scale can be detected from the number of pulse signals obtained from the sensors 4a, 4b and the relative moving direction thereof can be detected from the phases of the pulse signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a moving distance detecting device for detecting the moving distance from a reference point in each left and right direction in a copying machine or the like.

[Conventional technology]

For example, when using a copy machine to copy only the necessary parts,
A knob that is movable in parallel to the scanning direction of the original is provided near the document mounting table, and the position to be copied is designated by this knob.

At this time, in order to detect the position of the original with respect to the reference point, connect a wire to the position designation knob, wrap a part of this wire around the rotation shaft of the position low encoder, and then connect the wire to the position designation knob. is moved left and right from the reference point to, for example, the edge of the document, and the distance traveled in the left and right directions from the reference point is converted into the direction and amount of rotation of the shaft, and the distance traveled is detected by identifying this. Detection devices are known.

[Problem that the invention seeks to solve]

However, in the detection device using the above-mentioned rotary encoder etc., wires for converting linear motion into rotational motion,
Since a pulley and the like are required, the detection device becomes large and cannot be installed in, for example, a small copying machine, and the mechanism is complicated and the price becomes high.

[Means and effects for solving the problem] In the present invention, a first mark group in which i number of marks are repeatedly arranged at a predetermined interval in a predetermined direction on a scale;
forming a second mark group in which a plurality of marks are repeatedly arranged in a predetermined direction at predetermined intervals adjacent to the mark group and shifted by a predetermined interval in the arrangement direction, and reading the marks of this scale with a pair of sensors; By detecting the number and phase of pulse signals obtained from each of the pair of sensors, the relative moving distance between the scale and the sensor is detected.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 indicates a scale, and marks 2 are repeatedly arranged in the longitudinal direction of the scale l at intervals of a predetermined width a2 on the upper stage of the scale 1 to form an upper mark group 2a. The upper mark group 2a and the mark 2, which are adjacent to each other and are spaced apart by a distance C, are formed by etching a scale l made of stainless steel, for example, and applying black paint to the etched portion. For example, a and b are 1
@JC is set to 0.5 fin, and the outputs of the pair of sensors described below are shifted by half a phase.

In FIG. 2, numeral 3 indicates a sensor plate for reading the marks 2 on the scale 1, and an upper sensor 4a for reading the upper mark group 2a is provided on the lower surface of the sensor plate 3.
and a lower sensor 4 for reading the lower mark group 2b.
b is attached.

Note that this sensor plate 3 is fixed to the lower part of a knob (not shown) that is movably provided in the vicinity of a document table of a copying machine, for example, in parallel to the scanning direction of the document.

Each sensor 4a, 4b is attached with a light emitting element such as a light emitting diode 5a, 5b and a detection element such as a phototransistor 6a, 6b, and as shown in FIG. is reflected by a portion other than the mark 2, and the phototransistor 6a,
6b, and in the mark 2 part, the light emitting diode 5a,
Light from 5b is absorbed. The sensor plate 3 reads the mark 2 on the scale 1 by being moved in the direction of the arrow.

FIG. 4 shows a circuit diagram of a moving distance detecting device according to the present invention, in which a series circuit of a resistor 8a and a light emitting diode 5a is connected between the power supply terminal 7a and the ground, and a resistor 9a,
A series circuit of variable resistor 10a and phototransistor 6a is connected.

A transistor 1 is connected to the collector of the phototransistor 6a.
1a (7) Heath is connected, transistor 11a
The collector of the transistor Ila is connected to the power supply terminal 7a via the resistor 12a, and the emitter of the transistor Ila is grounded. These light emitting diode 5a, phototransistor 6a,
Upper mark group 2a of scale 1 with transistor lla etc.
An upper stage sensor circuit 13a is configured to read the .

The output of the upper stage sensor circuit 13a, that is, the transistor l
The collector output of la is supplied to positive trigger input terminals IB and 2B of monostable multi-bibreaks (hereinafter referred to as mono-multi) 16a and 16b via two inverters 148.15a connected in series. These pair of monomultis 16a and 16b are constructed from a commercially available integrated circuit for monomultiples, such as 74LS123, and the truth table thereof is as shown in FIG. In the truth table, "H" is high level, 'L' is low level, X"LvH"
or "L", "T" is the rising edge of the input signal, "L" is the falling edge of the input signal, "
"Open" indicates a positive pulse and "U" indicates a negative pulse. For example, when the input CLR is "L", the output Q is "L" and the output port is "L" regardless of the states of input A and input B. H"
become. Also, the input CLR is “H” and the input is “H”.
At the time of “L”, mono multi is triggered when input B rises.

Further, a lower sensor circuit 13b for reading the lower mark group 2b of the scale l is provided, but since it has the same configuration as the upper sensor circuit 13a, a description thereof will be omitted. The output of the lower sensor circuit 13b is supplied to the negative trigger input terminal IA of the monomulti 16a via two inverters 14b and 15b connected in series. Mono multi 16a, 1
6b negative trigger input terminals IA, 2A and clear terminal ICL
Inverters 17a and 18a are connected between R and 2CLR.
, 17b and 18b are connected in series, respectively;
Connection point between inverters 17a and 18a, inverter 17
The connection point between b and 18b is a delay capacitor 1, respectively.
It is grounded via 9a and 19b. Also, inverter 1
The output of 7a is the negative trigger input terminal 2A of mono multi 16b.
supplied to

In addition, the power terminals 20a, 20b and the monomulti 16a, 1
Between the predetermined terminal of 6b, monomulti 16a, 16b
resistor 21a which determines the time constant of.

21b, capacitors 22a, 22b and diode 2
3a and 23b are connected.

Output terminals 24a, 24b are led out from the negative output terminals 10°20 of the monomultis 16a, 16b, and the output terminals 24a
The signal obtained is supplied to the 7-knob input terminal.

Next, the operation will be explained.

Now, when the sensor plate 3 is moved to the right in FIG. 3, the signal S1 supplied to the positive trigger input terminal IB of the monomulti 16a becomes a high level (
The signal S2 becomes low level (hereinafter referred to as "L") at time t4, and the signal S2 supplied to the negative trigger input terminal IA goes high at time t2 as shown in FIG. 6B.
' and becomes "L" at time t5. Also clear terminal I
Since the signal S3 supplied to the CLR is a signal obtained by slightly delaying the signal S2, the signal S3 is delayed at the time t3 as shown in FIG. 6C.
The signal becomes "H" at time t6, and becomes "L" at time t6.

Furthermore, since the signal S5 supplied to the positive trigger input terminal 2B of the monomulti 16b is the same as the signal S1, the signal S5 supplied to the negative trigger input terminal 2A is as shown in FIG.
Since signal 6 is a signal obtained by inverting the phase of signal S2, it becomes as shown in FIG. 6H, and the signal S7 supplied to clear terminal 2CLR becomes a signal obtained by slightly delaying signal S6 as shown in FIG. .

At time t1, as shown in FIGS. 6A and 6B, the signals Sl and S5 supplied to the positive trigger input terminals IB and 2B rise, but at this time, as shown in FIG. Since the clear terminal ICLR is at "L", the monomulti 16a is not triggered, as can be seen from the truth table in FIG.

At this time, as shown in FIG. 6H, the two negative trigger input terminals of the monomulti 16b are at °H'',
b is also not triggered. Therefore, monomulti 16a, 16b
The inverting output terminals 1 and 2Q remain at "H".

Next, at time t2, as shown in FIG. 6H, when the signal S6 supplied to the negative trigger input terminal 2A falls, at this time the positive trigger input terminal 2B is "H" and the clear terminal 2
Since CLR is 'H', the inverting output terminal 20 becomes 'L', and the output terminal 24b receives a signal S as shown in Fig. 6H.
8 is obtained.

Next, at time t3, when the clear terminal 2CLR becomes L''', the monomulti 16b is forcibly reset regardless of its time constant, and the inverted output terminal 2Φ of the mono multi 16b becomes "H" again.

Next, at time t4, as shown in FIG. 6A, the signals Sl, S
5 falls, but this signal 31. S5 is mono multi 1
Since the signal is supplied to the positive trigger input terminals IB and 2B of 6a and 16b, it does not affect the monomulti 16a and 15b.

Next, at time t5, as shown in FIG. 6B, the signal S2 supplied to the negative trigger input terminal LA falls, but at this time, as shown in FIG. 6A, the positive trigger input terminal IB of the monomulti 16a falls. Since it is "L", the monomulti 16B is not triggered.

By repeating the above operations, the sensor plate 3
When moved to the right, the output terminal 24a receives a signal S4 with continuous "H" as shown in Figure 6, and the output terminal 24b receives the end of mark 2 as shown in Figure 6H. A signal S8 which is "L" for a predetermined period is obtained every time. Naoko”
The period during which the signal S8 becomes "L" is determined by the propagation time of the inverters 17a and 18a and the delay time by the delay capacitor 19a.This signal S8 is supplied to the up terminal of the up/down counter 25.
The count value increases. Therefore, if the count value of the up-down counter 25 when the sensor plate 3 is positioned as a reference is set in advance to a predetermined reference value, the count value of the up-down counter 25 can be compared with the reference value, and the sensor plate 3 can be The distance and direction of movement can be detected.

Next, when the sensor plate 3 is moved to the left in Fig. 3,
As shown in FIG. 7A, the signal S1 supplied to the positive trigger input terminal IB of the monomulti 16a becomes 1H'' at time t9, becomes ``L'' at time t12, and the signal S1 is supplied to the negative trigger input terminal IA.
The signal S2 supplied to
It becomes "H" at time tlO, becomes "L" at time tlO, and the signal S3 supplied to the clear terminal ICLR becomes as shown in FIG. 7C.

Further, the signal s5 supplied to the positive trigger input terminal 2B of the monomulti 16b becomes as shown in FIG. 7E, and the signal s6 supplied to the negative trigger input terminal 2A becomes as shown in FIG. The signal s7 supplied to the terminal 2CLR is a signal obtained by slightly delaying the signal S6, as shown in FIG. 7G.

First, at time t7, as shown in FIG. 7F, the signal s6 supplied to the negative trigger input terminal 2A falls.
is not triggered.

Next, at time t9, as shown in FIGS. 7A and 7E, the signals Sl, which are supplied to the positive trigger input terminals IB, 2B,
S5 rises, but at this time, as shown in FIG. 7B, the negative trigger input terminal IA of the monomulti 16a is "H", so the mono multi 16a is not triggered. At this time, as shown in FIG. 7G, the clear terminal 2C of the monomulti 16b
Since LR is L", the mono multi 16b is also not triggered. Therefore, the inverted output terminal 1i of the mono multi 16a, 16b
:S and 2Q remain at 'H'.

Next, when the signal S2 falls at time tlo as shown in FIG. Inverted output terminal I of multi 16a
O becomes "L", and a signal S4 as shown in the seventh diagram is obtained at the output terminal 24a.

Next, when the clear terminal I CLR becomes "L" at time 111, the monomulti 16a is reset, and the monomulti 1
The inverting output terminal lΦ of 6a becomes "H" again.

By repeating the above operations, the sensor plate 3
When moved to the left, a signal S8 with continuous "H" as shown in Figure 6H is obtained at the output terminal 24b, and the end of mark 2 as shown in Figure 6 is obtained at the output terminal 24a. A signal S4 that remains "L" for a predetermined period is obtained every time, and this causes the up/down counter 25 to go down
Su's 7? =r 7' The count value of the count counter 25 decreases. Therefore, by comparing the count value of the up/down counter 25 with a reference value, the moving distance and direction of the sensor plate 3 can be detected.

In the embodiment of the present invention, the sensor plate 3 is moved relative to the scale l, but the relationship may be reversed.

〔Effect of the invention〕

As described above, according to the present invention, a pair of mark groups are formed adjacent to each other on a scale with a predetermined distance deviated from each other, and the marks on the scale are read by a pair of sensors, and the number and phase of the obtained pulse signals are obtained. By detecting this, it is possible to detect the moving distance and direction with a small and lightweight device. Therefore, there is an effect that it can be applied to, for example, a small-sized copying machine.

[Brief explanation of drawings]

Fig. 1 is a plan view of the scale, Fig. 2 is a plan view of the sensor plate, Fig. 3 is a side view of the scale and sensor plate, Fig. 4 is a circuit diagram of the moving distance detection device, and Fig. 5 is a truth table. , FIG. 6, and FIG. 7 are waveform diagrams. l scale 2: Mark 3: Sensor plate 4: Sensor 5: Light emitting diode 6: Phototransistor 7.207 Power supply terminal 8, 9.12.21: Resistor 10: Variable resistor 11: Transistor 13: Sensor circuit 14.15 , 17.18: Inverter 16: Monomulti 19: IL extension capacitor 22: Capacitor 23
Diode 24; Output terminal 25 Near-tube down counter Patent applicant Fuji Xerox Co., Ltd. Agent
Masu Tebori (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] 1. A first mark group in which a plurality of marks are repeatedly arranged at a predetermined interval in a predetermined direction, and a plurality of marks adjacent to the first mark group and shifted by a predetermined interval in the arrangement direction in a predetermined direction. A scale on which a second mark group repeatedly arranged at intervals is formed, a pair of sensors for reading the marks of this scale, and the number and phase of pulse signals obtained from each of the pair of sensors are detected, and the above-mentioned A moving distance detection device comprising a scale and means for detecting a relative moving distance of the sensor.