CN207472754U - A kind of digital display type whiteness instrument - Google Patents

Abstract

Digital display type whiteness instrument provided by the utility model includes sequentially connected silicon photocell sample circuit, postposition amplifying circuit, double integration circuit, microcontroller and display circuit, the double integration circuit is also associated with reference voltage generating circuit, forward and reverse integrated signal switching switch is provided in double integration circuit, forward and reverse integrated signal switching switch is controlled by microcontroller.The signal that the whiteness instrument receives and processes double integration circuit feedback using microcontroller realizes " zeroing " and " correction " of whiteness instrument, calculates whiteness value with the conversion of logical relation, is inherently eliminated the unstability brought by component self-characteristic.

Description

A kind of digital display type whiteness instrument

Technical field

The utility model is related to whiteness test instrument technical field more particularly to a kind of digital display type whiteness instrument.

Background technology

Whiteness instrument is the whiteness for measuring body surface, need to be to the whiteness of product suitable for textile, printing and dyeing, chemical fibre etc. Test." zeroing " and " correction " function can be all designed with per money whiteness instrument, makes each whiteness instrument in benchmark in same standard white plate To obtain consistent results when testing same sample.

Whiteness instrument is essentially all to design circuit according to function y=kx+b, which is illustrated：

X is exactly the electric signal that silicon photocell receives sample surfaces reflection light and generates, and is variation；

Y is exactly the whiteness value that we want, and is result；

B is constant, and fixed value because silicon photocell has a characteristic in itself, is exactly in no reception light, can also export One small voltage（This is exactly b values）, make whiteness instrument when testing blackboard（During dull thread）Whiteness value is also not zero, this is solid There is characteristic that can not eliminate, then just there is " zeroing " function, purpose seeks to generate a direction as this b value size Opposite voltage-b offsets this voltage, so as to obtain whiteness value y=kx that we want since zero whiteness；

K is proportionality coefficient, directly affects the size of y values." correction " process is exactly to adjust this k value, makes whiteness instrument right In the case of answering standard white plate x values, standard white plate whiteness value y values are obtained.

Precisely with the quality of the two Functional Designs of " zeroing " and " correction ", the height of whiteness instrument accuracy is directly affected It is low.General whiteness instrument is all to realize " zeroing " and " correction " function respectively using knob potentiometer, but with work circuit board Work operation, the Current Voltage of each component can because characteristic electron, Parameters variation and have minor change, cause to show numerical value It changes, so these whiteness instrument are generally first powered before testing, a period of time allows its circuit to enter metastable state and just carries out school Just tested again.Even if being corrected, but for this mechanical adjusting of knob potentiometer, in test, result is also There is variation, this is because the mechanical property of turn knob potentiometer itself can not be eliminated in this circuit design.

Utility model content

The purpose of this utility model is that existing whiteness instrument is solved using test result caused by mechanical adjusting method The problem of accuracy is low provides a kind of digital display type whiteness instrument, and it is anti-that which using microcontroller receives and processes double integration circuit The signal of feedback realizes " zeroing " and " correction " of whiteness instrument, calculates whiteness value with the conversion of logical relation, fundamentally disappears Except the unstability brought by component self-characteristic.

Digital display type whiteness instrument provided by the utility model includes sequentially connected silicon photocell sample circuit, postposition amplification electricity Road, double integration circuit, microcontroller and display circuit, double integration circuit are also associated with reference voltage generating circuit；Double integration circuit Forward and reverse integrated signal switching switch is inside provided with, forward and reverse integrated signal switching switch is controlled by microcontroller.

Preferably, double integration circuit includes add circuit, sampled voltage timing integrating circuit, level pressure reverse integral circuit；

Postposition amplifying circuit, add circuit, sampled voltage timing integrating circuit and microcontroller are sequentially connected, and level pressure is reversely accumulated Parallel circuit connects sampled voltage timing integrating circuit and microcontroller.

Preferably, level pressure reverse integral circuit is with being mounted with power supply and forward and reverse integrated signal switching switch.

Preferably, preamplifier is installed in silicon photocell sample circuit.

Preferably, display circuit is LCD display circuit.

The beneficial effects of the utility model are：

Digital display type whiteness instrument provided by the utility model abandons using turn knob potentiometer as adjustment means, then uses number Word formula scheme, because " zeroing " and " correction " the two adjustment amounts have not needed to circuit carrier to realize adjustment in itself, they are only It is a number, SCM program can be used to handle, because SCM program is a kind of logical relation, without electrical object conduct Carrier naturally not has the influence for electrically changing and bringing, is brought not by component self-characteristic so being inherently eliminated Stability.

Description of the drawings

Fig. 1 is the circuit block diagram of digital display type whiteness instrument provided by the utility model.

Specific embodiment

The utility model is described further below in conjunction with attached drawing, the embodiment being exemplified below only represents a kind of or several Kind preferred forms, should not form the limitation to the utility model.

Embodiment one：

As shown in Figure 1, digital display type whiteness instrument provided by the utility model includes sequentially connected silicon photocell sample circuit （10）, postposition amplifying circuit（20）, double integration circuit（30）, microcontroller（50）And display circuit（60）, double integration circuit（30） It is also associated with reference voltage generating circuit（40）；Double integration circuit（30）Forward and reverse integrated signal switching switch is inside provided with, just Reverse integral signal shift switch is by microcontroller（50）Control.

Wherein, double integration circuit（30）Including add circuit（31）, sampled voltage timing integrating circuit（32）, level pressure it is reversed Integrating circuit（33）, forward and reverse integrated signal switching switch is installed on level pressure reverse integral circuit（33）It is interior, and level pressure is reversely accumulated Parallel circuit（33）With being mounted with power supply.Postposition amplifying circuit（20）, add circuit（31）, sampled voltage timing integrating circuit（32） And microcontroller（50）It is sequentially connected, level pressure reverse integral circuit（33）Connect sampled voltage timing integrating circuit（32）And microcontroller （50）.

Wherein, silicon photocell sample circuit（10）Preamplifier is inside installed.

Display circuit（60）For LCD display circuit.

Its course of work of digital display type whiteness instrument provided by the utility model is as follows：

With the blue light illumination sample surfaces of wavelength 457nm, pass through silicon photocell sample circuit（10）Sample surfaces are reflected Light intensity back is converted into electric signal a, and ultra-weak electronic signal a then is zoomed into electric signal b by preamplifier.

Electric signal b enters postposition amplifying circuit（20）It is further amplified, the electric signal c relatively easily detected, this The voltage of electric signal c is exactly that we want the signal surveyed.As long as the voltage value of this voltage value and standard white plate is compared, It can obtain whiteness value of the sample relative to standard white plate.

Reference voltage generating circuit（40）It generates and to double integration circuit（30）Output reference voltage Ur（1.06V）.Benchmark Voltage is exactly the benchmark zero of this double integration circuit, and Direct/Reverse is as intermediate point.For this double integration circuit（30） For, be forward voltage more than reference voltage 1.06V, be backward voltage less than 1.06V, and power supply be 0 V, less than 1.06V, That is power supply relative datum voltage be -1.06V, so this circuit just using power supply makes as a backward voltage With.

Electric signal c and reference voltage Ur are through add circuit（31）Superposition, obtains positive integrated signal d.

Level pressure reverse integral circuit（33）From power supply receive reverse integral signal e, microcontroller（50）Utilize three poles The forward and reverse integrated signal switching switch of management and control system so that positive integrated signal d and reverse integral signal e alternately enter sampled voltage Timing integrating circuit（32）.The positive integrated signal d of collector connection of triode, emitter connection power supply.When triode is cut When only, signal d is obtained since electric signal c has been superimposed 1.06V, is more than 1.06V certainly, therefore is positive integration input；When three poles When pipe is connected, positive integrated signal d is forced to be pulled down to 0 V of ground, and less than reference voltage 1.06V, that is, -1.06V's is reversed Integrated signal e is inputted.

Forward and reverse integrated signal switching switch first allows positive integrated signal d to enter sampled voltage timing integrating circuit（32）, Entry time is by microcontroller（50）Program setting, the positive time of integration T1 for reaching setting are switched to reverse integral signal e at once Input.

Double integration circuit（30）To microcontroller output voltage signal f.When positive integrated signal d enters sampled voltage timing product Parallel circuit（32）Afterwards, the voltage of output voltage signal f can decline always, after reverse signal e entrance is switched to, output electricity Pressure signal f can reverse the impetus of decline, rise all the way.While switching, microcontroller（50）Start to voltage uphill process timing, When voltage signal f voltages reach the comparison voltage of 3.17V, timing terminates, microcontroller（50）The time that meeting recording voltage rises, That is reverse integral time T2.Here it is a double integrator processes（Forward direction integration and reverse integral）.Then forward and reverse integrated signal Switching switch is switched to positive integrated signal d again, continues next round detection conversion, and cycle is continuous.

In integrating circuit, input voltage and the time of integration are proportional relationships.And in this double integration circuit, just It is equal to reverse integral value to integrated value, then obtains formula：

In above-mentioned formula：Ui is input voltage；Voltage on the basis of Ur；T1 is the positive time of integration；When T2 is reverse integral Between.

Because reference voltage Ur is known 1.06V, known to positive time of integration T1（By program setting）, input voltage Ui （That is the voltage of electric signal c）Only with reverse integral time T2 there are proportionate relationship, so, as long as microcontroller（50）Count out reversed product T2 between timesharing, it is possible to know input voltage Ui.Then by SCM program by input voltage Ui and the electricity of standard white plate Pressure value is compared, it is possible to be obtained whiteness value of the sample relative to standard white plate, and be passed through display circuit（60）Display.

Finally it should be noted that above example is only to illustrate the technical solution of the utility model rather than to this practicality The limitation of novel protected range, although being explained in detail with reference to preferred embodiment to the utility model, the common skill of this field Art personnel should be appreciated that without departing from the concept of the premise utility various modifications and improvements can be made, these are all Belong to the scope of protection of the utility model.Therefore, the protection domain of the utility model patent should be determined by the appended claims.

Claims (5)

1. a kind of digital display type whiteness instrument, it is characterised in that：The digital display type whiteness instrument is sampled including sequentially connected silicon photocell Circuit, postposition amplifying circuit, double integration circuit, microcontroller and display circuit, the double integration circuit are also associated with reference voltage Generation circuit；Forward and reverse integrated signal switching switch, forward and reverse integrated signal switching switch are provided in double integration circuit It is controlled by microcontroller.

2. digital display type whiteness instrument according to claim 1, it is characterised in that：The double integration circuit include add circuit, Sampled voltage timing integrating circuit, level pressure reverse integral circuit；

The postposition amplifying circuit, add circuit, sampled voltage timing integrating circuit and microcontroller are sequentially connected, and the level pressure is anti- Sampled voltage timing integrating circuit and microcontroller are connected to integrating circuit.

3. digital display type whiteness instrument according to claim 2, it is characterised in that：The level pressure reverse integral circuit is mounted with electricity Source and forward and reverse integrated signal switching switch.

4. digital display type whiteness instrument according to claim 1, it is characterised in that：It is equipped in the silicon photocell sample circuit Preamplifier.

5. digital display type whiteness instrument according to claim 1, it is characterised in that：The display circuit is LCD display circuit.