JPH0444101A - Auto-slice device - Google Patents

Abstract

PURPOSE:To automatically set a proper slice level by defining the amplification factor of an amplifier means and the output voltage of a voltage generating means as the amplification level and the slice level of each signal respectively when the output voltage of the amplifier means exceeds the output voltage of the voltage generating means. CONSTITUTION:The voltage Vh obtained by amplifying the signal output by an amplifier means 11 is inputted to a comparison means 13 together with the output voltage Vs of a voltage generating means 12. The means 13 compares the levels of the Vh and Vs with each other and informs a control means 14 of the result of this comparison. The means 14 sends the control signals to both means 11 and 12 to increase the Vh and to reduce the Vs respectively when the Vh is smaller than the Vs. Then the means 14 discontinues the transmission of the control signals when the Vh exceeds the Vs. At this time point, both the Vh and the Vs are fixed. Therefore the Vs is automatically set at a level slightly lower than the Vh. As a result, a proper slice level is automatically set.

Description

[Detailed Description of the Invention] [Summary] Regarding an auto-slice device that sets the amplification level and slice level of a signal, the purpose of this invention is to automatically set an appropriate slice level, and the present invention provides an amplification means for amplifying the signal; , a voltage generation means for generating a predetermined voltage, a comparison means for comparing the output voltages of the amplification means and the voltage generation means, and an output voltage of the amplification means and the voltage based on the comparison result of the comparison means. control means for changing the output voltage of the generation means, and the amplification factor of the amplification means and the output voltage of the voltage generation means respectively when the output voltage of the amplification means becomes larger than the output voltage of the voltage generation means; The signal is configured to have an amplification level and a slice level.

[Industrial application field]

The present invention relates to an autoslicing device that sets the amplification level and slicing level of a signal.

Optical sensors have conventionally been used in automatic teller machines and facsimile machines to detect the position of bankbooks and documents. An optical sensor consists of a light-emitting element and a light-receiving element arranged opposite each other, and the light emitted from the light-emitting element is detected by the light-receiving element, and the output changes depending on the presence or absence of an object between the light-emitting element and the light-receiving element. It is something to be used. The presence or absence of an object is determined by detecting a preset slice level and the magnitude of the output of the light receiving element.

Therefore, in order to maintain object detection accuracy, it is required to appropriately adjust the output level of the light receiving element and its slice level.

[Conventional technology]

FIGS. 3(a) and 3(b) are diagrams for explaining a method of detecting the presence or absence of an object using an optical sensor, for example,
Used to detect pages and positions of bankbooks and manuscripts.

As shown in FIG. 3(a), the optical sensor consists of an LED III and a phototransistor 112 arranged facing each other, and the light irradiated by the LED III is transmitted to the phototransistor 112.
The light is received by the resistor 122 and converted into a signal voltage Vp by the resistor 122. Then, in the comparator 117, the signal voltage Vp
and the slice voltage Vs generated by the voltage source 123 are compared and detected.

When the original 121 is not inserted between L E Dll and the phototransistor 112, most of the light irradiated by the LEDll enters the phototransistor 112, and the signal voltage Vp takes the maximum value. a)
When the LED III is moved along the direction shown in FIG.
decreases. As shown in FIG. 2(b), conventionally, the slice voltage Vs is adjusted manually by adjusting the voltage source 123.
is set to an appropriate value lower than the maximum value of the signal voltage Vp, and the presence or absence of the document 121 is detected by monitoring the output of the comparison section 117.

[Problem to be solved by the invention]

Generally, in devices such as facsimile machines and automatic teller machines, a large number of optical sensors such as those described above are placed within the same device in order to detect the presence or absence of documents and passbooks at various locations within the device. The relative positional relationship of phototransistors is limited by the shape of the device, etc., and usually differs depending on each optical sensor. However, since the output of the phototransistor is affected by the positional relationship with the LED, the output level of the phototransistor differs for each photosensor. Therefore, it is necessary to adjust the output level and slice level of the phototransistor for each optical sensor. If such adjustment work is performed manually on a device that has a large number of optical sensors, it not only takes time to set up and increases the manufacturing cost of the equipment (also, the accuracy of object detection depends on each individual optical sensor). There was a problem in that variations occurred and the reliability of the operation of the equipment was reduced.

Therefore, an object of the present invention is to automatically set an appropriate slice level.

[Means to solve the problem]

The solution to the above problem is to provide an amplification means for amplifying a signal, a voltage generation means for generating a predetermined voltage, a comparison means for comparing the output voltages of the amplification means and the voltage generation means, and a comparison means for comparing the output voltages of the amplification means and the voltage generation means. The amplification includes a control means for changing the output voltage of the amplification means and the output voltage of the voltage generation means based on a comparison result, and the amplification is performed when the output voltage of the amplification means becomes larger than the output voltage of the voltage generation means. This is achieved by an autoslicing device characterized in that the amplification factor of the means and the output voltage of the voltage generating means are set to the amplification level and slice level of the signal, respectively.

[For production]

FIG. 1 shows a block diagram of the principle of the present invention.
11 is an amplification means, 12 is a voltage generation means, 13 is a comparison means, and 14 is a control means.

As shown in the figure, the voltage vh obtained by amplifying the signal output by the amplifying means 11 and the output voltage V of the voltage generating means 12
s is input to the comparison means 13. The comparison means 13 compares vh and Vs and notifies the control means 14 of the result. In the control means 14, when vh is smaller than Vs, a control signal is sent to the amplification means 11 and the voltage generation means 12 to increase vh and decrease Vs, so that vh becomes Vs.
When the signal becomes larger than that, stop sending the above control signal,
At this point, vh and Vs are fixed. By the above method,
Vs is automatically set to a level slightly lower than vh, and the amplification factor of the amplification means 11 at this time is used as the signal amplification level, and the output voltage of the voltage generation means 12 is used as the slice level. I can do it.

Embodiment C] FIGS. 2(a) and 2(b) are diagrams for explaining the present invention in detail. In this example, the LED l shown in FIG.
This article describes a method for setting an appropriate amplification level and slice level for the output of the phototransistor 112 in advance when using an optical sensor consisting of a phototransistor 112 and a phototransistor 112 for object detection, and describes how to set the amplification level and slice level appropriately for the output of the phototransistor 112. is LEDIII
This is done before inserting an object between the phototransistor 112 and the phototransistor 112.

First, the output of the phototransistor 112 receiving light from the LED III is input to the amplifiers 113a, 113b...1.
After being amplified and converted into a voltage vh by one of the voltage generators 13d, the voltage is input to the comparison unit 117. Amplifiers 113a, 113b
. . 113d are arranged in descending order of amplification factor, and one of them is selected by an MPX (analog multiplexer) 114. In addition, the dividing resistor 115a,
115b...115h is selected by the MPX 116 and input to the comparator 117. Vs is highest when the divided resistor 115a is selected, and becomes smaller as the divided resistors 115b...115h are selected. Comparison unit 117 has, for example, a comparator function, and compares the magnitudes of vh and Vs, and outputs 0 when vh is smaller than Vs, and outputs 1 when it is larger.

On the other hand, the gain adjustment register 118 includes amplifiers 113a and 1
Numerical values 113a and 11 corresponding to 13b...113d
3b ・--113d is set, and 113a → 113 is set at a constant time interval TI according to instructions from the CPU 119.
Transition occurs in the order of b→...→113d. The set value is then sent from the gain adjustment register 118 to the MPX 114, and the MPX 114 selects the amplifier corresponding to this value.

Therefore, a voltage vh that rises in a stepwise manner is applied to the comparator 117 as shown in FIG. 1b). Similarly, the slice adjustment register 120 has a dividing resistor 1.
Numerical values corresponding to 15a, 115b...115h are set, and these numerical values are changed from 115h→...→115b→11 at fixed time intervals T2 according to instructions from the CPU.
Transition occurs in the order of 5a. and slice adjustment register 12
A value within 0 is sent to the MPX 116, and the MPX 116 selects the voltage Vs corresponding to this value. Therefore, the comparator 117 receives the voltage VS that falls stepwise as shown in FIG. 1(b).

While the output of the comparator 117 is O, the CPU 119 controls the gain adjustment register 118 and the slice adjustment register 1.
20, if the numerical transition instruction is continued and the numerical transition instruction is stopped when vh and Vs are reversed and the output of the comparator 117 becomes 1, vh and Vs become as shown in FIG. 2 (c). It is fixed at the value indicated by the dotted line. At this time, the positional relationship of Vs is automatically set to a relatively low level within the range of the increase in Vs ΔVs with respect to vh, and the amplification factor of the amplifier selected in this way is set as a signal. , and Vs can be used as the slice level.

As described above, even if the absolute value of the output of the phototransistor in each optical sensor is different, the slice level can be automatically set according to the output level, and the above ΔVs can be set to a small value in advance. By setting , it is possible to suppress variations in object detection accuracy.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to automatically set the signal amplification level and slice level, so that it is possible to make the object detection characteristics uniform for a large number of optical sensors and shorten the adjustment time. It is valid.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the principle of the present invention, Figure 2 (a)
is a block diagram showing an embodiment of the present invention, FIG. 2(b) is a diagram showing the relationship between input and output voltages in the comparison section, FIG.
Figure (b) is a diagram showing the relationship between signal voltage and slice level. In the figure, 11 is an amplification means, 12 is a voltage generation means, 13 is a comparison means, 14 is a control means, and 111 is an LED. 112 is a phototransistor, 113a, 113b---1136 is an amplifier, 114
．． 116 is MPX (7st:lgua/lz-]-7"
117 is a comparison section, 118 is a gain adjustment register, and 119 is a CPU. 120 is an 8-slice adjustment register, 121 is a document, 122 is a resistor, and 123 is a voltage source. A block diagram showing the problems of the conventional example FIG. 3 (a) A block diagram showing the embodiment of the present invention FIG. 2 (a) A diagram showing the relationship between the signal voltage and the slice level FIG. 3 (b)
) −> Time

Claims (1)

[Claims] An amplification means (11) for amplifying a signal, a voltage generation means (12) for generating a predetermined voltage, and an output voltage of the amplification means (11) and the voltage generation means (12). a comparison means (13) for comparing the magnitude; and a comparison means (13) for comparing the amplification means (13) based on the comparison result of the comparison means (13).
control means (14) for changing the output voltage of the voltage generating means (11) and the output voltage of the voltage generating means (12), the output voltage of the amplifying means (11) is controlled by the voltage generating means (12);
) when the output voltage of the amplifying means (11
1. An auto-slicing device characterized in that the amplification factor of ) and the output voltage of the voltage generating means (12) are set to be an amplification level and a slicing level of the signal, respectively.