JPH0527565A - Lamp light quantity controller - Google Patents

Abstract

PURPOSE:To always accurately control a lamp by executing control considering a complicated factor by using fuzzy inference even to the secular change of the lamp itself. CONSTITUTION:The lamp light quantity controller having a lamp driving means(lamp regulator) 104 which variably controls the emitted light quantity of the lamp is provided with state quantity detecting means 106, 108, 110, 112 and 114 for detecting the specified quantity of state related to the control of the light quantity of the lamp, a fuzzy rule means 101 for previously regulating the relation between each fuzzy set expressing the quantity of state and each fuzzy set expressing controlled variable supplied to the driving means 104, and an inference means 100 for inferring the controlled variable based on such a degree that the quantity of state belongs to the specified fuzzy set according to the rule outputted from the means 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp light quantity control device suitable for application to an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art Conventionally, as a lamp light amount control device of this type, a control device for a lamp for illuminating a document incorporated in a copying machine has been known. FIG. 7 shows an example of such a lamp light amount control device, which is a DC controller 7 in this figure.
Reference numeral 02 determines the optimum light amount of the document illumination lamp 707 according to the input power supply voltage, the initial photosensitive drum sensitivity shift, the copy density key setting, the document density, and the reduction copy magnification, and this is used as a light amount adjustment signal (LINT). Informed the lamp regulator 704.

[0003]

However, in the above-mentioned conventional example, when the photosensitive drum is deteriorated due to aging, optical system parts such as the platen glass and the reflection mirror are contaminated, or the characteristics of the lamp regulator 704 itself. Change with time, the light quantity of the lamp 707 changes, so the service person of the copying machine must readjust the light quantity every certain period (for VR606 light quantity control in FIG. 7). Volume 703 (a), VR6
01 AE volume 703 (b) or the like is used).

In addition, when the adjustment is performed, it is necessary to actually make a copy and perform fine adjustment while comparing the shades of the copy, which makes it difficult to determine the adjustment amount.

In order to omit this adjustment, it is possible to equip the copying machine with means for directly detecting the light quantity of the lamp and the sensitivity of the photosensitive drum. In that case, the parameters of the conventional light quantity control are used. That is, in addition to the input power supply voltage, the initial photosensitive drum sensitivity shift, the copy density key setting, the document density, and the reduction copy magnification, the light amount of the lamp and the photosensitive drum sensitivity must be newly set.

As described above, there is a drawback that the number of parameters increases and it becomes difficult to formulate the relationship between all the parameters and the control amount to perform the control operation.

That is, in order to perform the optimal light quantity control, it seems that the number of parameters (state quantities) for determining the light quantity control quantity is large, or the relationship between the control quantity and the parameter is ambiguous. In the case where there is such a parameter, it is difficult to formulate the relationship between the parameter and the control amount in the conventional example.

Therefore, in view of the above points, an object of the present invention is to provide a lamp light quantity control device capable of accurately controlling the lamp light quantity by always calculating an optimum control quantity.

[0009]

In order to achieve such an object, the present invention is a lamp light quantity control device provided with a lamp driving means for variably controlling the light emission quantity of a lamp, and a predetermined state quantity related to the lamp light quantity control. And a fuzzy rule means for predefining a relationship between each of the fuzzy sets representing the state quantity and each of the fuzzy sets representing the control quantity supplied to the driving means, and the fuzzy rule. Inference means for inferring the control amount based on the degree to which the state quantity belongs to a predetermined fuzzy set according to the rule output from the means.

Further, in the lamp light quantity control device provided with a lamp driving means for variably controlling the light emission quantity of the lamp, state quantity detecting means for detecting a state quantity relating to at least one of the lamp light quantity control state and the lamp light quantity state. ,
A membership function storing means for storing a membership function in which the state quantity and the control quantity of the lamp driving means are respectively expressed by a fuzzy set, and a rule expressing the relationship between the state quantity and the control quantity in the form of a fuzzy proposition. A fuzzy rule storing means for storing and a matching degree for calculating the degree of conformity of the state quantity detected by the state quantity detecting means to the fuzzy set based on the membership function of the state quantity stored in the membership function storing means. It is also possible to include a degree calculation unit and an inference unit that calculates the control amount according to each rule stored in the fuzzy rule storage unit based on the degree of conformity calculated by the degree of conformity calculation unit. .

Here, the state quantity detecting means is one of the input state voltage, the initial drum sensitivity, the set value of the copy density key, the original density, the reduction magnification of the lamp, the light quantity of the lamp, and the photosensitive drum sensitivity as the state quantity. It is preferable to detect at least one.

Further, the control amount is a light amount adjustment signal input to the lamp regulator, a change rate of the light amount adjustment signal,
It is preferable to use at least one of the correction values of the light amount adjustment signal.

[0013]

According to the present invention, in controlling the light quantity of the lamp,
When the number of parameters (state quantities) is large and it is difficult to formulate the relationship between all the parameters and the controlled variables, or the relationship between the parameters and the controlled variables is ambiguous, such as when adjusting the amount of light with time. , It becomes possible to determine an appropriate control amount by fuzzy reasoning for these ambiguous relations.

[0014]

EXAMPLES Examples of the present invention will be described in detail below.

Embodiment 1 FIGS. 1 to 4 show a first embodiment of the present invention. Figure 1
It is a block diagram which shows the whole structure of a present Example.

In FIG. 1, reference numeral 100 denotes a CPU, which performs fuzzy inference which will be described in detail later. Further, 100 (a) and 100 (b) are a counter and a timer, which are used when the rate of change of the light quantity of the lamp is obtained from the state quantity (for example, the light quantity of the lamp) detected by each sensor or the like.

Reference numeral 101 is a ROM (read only memory)
2 in addition to the fuzzy rules detailed with respect to FIG. 2 and the membership function detailed with respect to FIG.
The control program 100 to be executed by 100 is stored.

Reference numeral 102 denotes a RAM (random access memory), which is used as a work area memory when performing fuzzy inference to be described later.

Reference numeral 103 denotes a D / A converter, which is an actual control amount calculated by fuzzy inference described later (see FIG. 4).
Reference) from the CPU 100, and outputs this as a light amount adjustment signal (LINT).

Reference numeral 104 denotes a lamp regulator, which responds to a light quantity adjustment signal (LINT) to illuminate the original 105.
Control the voltage applied to.

Reference numeral 105 denotes a document illumination lamp which is controlled based on the fuzzy inference, and the lamp regulator 10
The light quantity is controlled by 4.

Reference numeral 106 is a lamp light amount sensor used as one of state quantity detecting means, and 107 is an A / D converter. Information indicating the light amount of the lamp is input to the CPU 100 as one of the parameters for light amount control.

Reference numeral 108 is a photosensitive drum sensitivity detecting means used as one of the state quantity detecting means, 110 is an original density sensor used as one of the state quantity detecting means, and 112 is an input power supply voltage detecting means used as one of the state quantity detecting means. . That is, the photosensitive drum sensitivity, the document density, and the input power supply voltage are input to the CPU 100 via the A / D converters 109, 111, and 113, respectively, as one of the parameters for controlling the light amount.

Reference numeral 114 denotes an operation unit used as one of state quantity detecting means, which includes copy density setting keys 114 (a),
A reduction ratio setting key 114 (b) and an initial drum sensitivity setting key 114 (c) are provided. That is, as one of the parameters for controlling the light amount, the set value of the copy density key, the reduction copy magnification, and the initial drum sensitivity are input to the CPU 100 via the I / O (interface) circuit 115.

In the fuzzy control performed in this embodiment, the input power supply voltage obtained as the state quantity, the initial drum sensitivity,
Of the setting values of the copy density key, document density, reduction copy magnification, lamp light intensity, and photosensitive drum sensitivity, for example,
(A) Input power supply voltage and (b) lamp light intensity are used.

Further, as the control amount in this embodiment,
Of the light amount adjustment signal (LINT) input to the lamp regulator 104, the change rate of the light amount adjustment signal, and the correction value of the light amount adjustment signal, for example, the light amount adjustment signal (LINT) input to the lamp regulator (c) is used.

The fuzzy sets of these state quantities and control quantities are defined by the membership function shown in FIG. Here, FIG. 3A shows the membership function of the input power supply voltage,
FIG. 3B is a membership function of the light quantity of the lamp, and FIG.
(C) shows the membership function of the light amount adjustment signal (LINT) input to the lamp regulator 104.

As can be seen from FIG. 3, the input power supply voltage, the light quantity of the lamp, and the light quantity adjustment signal 104 input to the lamp regulator 104 each have three fuzzy sets.

For example, fuzzy labels "VL", "VM", and "VH" are attached to three fuzzy sets of the input power supply voltage. Here, VL (Voltage Low); a fuzzy set representing "the input power supply voltage is small" VM (Voltage Middle); a fuzzy set representing "the input power supply voltage is medium" VH (Voltage High); "the input power supply voltage is large" Is a fuzzy set.

The degree of belonging to each fuzzy set takes an arbitrary value between "0" and "1". Taking FIG. 3A as an example, when the input power supply voltage is 100 V, the degree of belonging to the fuzzy set with the fuzzy label VM, that is, the fitness is “1.0”, and the degree of belonging to VL. “0.0”, the degree of belonging to VH is “0.
It is 0 ".

To determine the light amount adjustment signal (LINT) input to the lamp regulator 104, for example, the following <rule 5> and <rule 6> fuzzy rules are used.

<Rule 5> IF (V = VM AND R = RM) THEN L = LM <Rule 6> IF (V = VM AND R = RH) THEN L = LL where V = input power supply voltage R = lamp Light amount L = light amount adjustment signal input to the lamp regulator 104.

FIG. 2 shows all fuzzy rules including Rule 5 and Rule 6 above.

Next, the light amount adjustment signal (LINT) input to the lamp regulator 104 is converted into the above-mentioned <Rule 5>,
A method of making a decision based on <Rule 6> and the membership function (see FIG. 3) will be described with reference to FIG.

First, inferring according to <Rule 6> (see the upper part of FIG. 4), the input power supply voltage X belongs to the fuzzy set of the VM with a degree of μX from the membership function of the input power supply voltage. For the light quantity Y of the lamp, it belongs to the fuzzy set of RH by the degree of μY due to the membership function of the light quantity of the lamp.

Then, the minimum value of the obtained μX and μY is determined, and the minimum value is taken as the degree to which the condition part of <Rule 6> is satisfied, and the membership function of the value and the light quantity adjustment signal input to the lamp regulator. (MIN in this case) is calculated. The calculation result is a trapezoid shown by the hatched portion of the set S shown in the upper right of FIG.

Next, when inferring according to <Rule 5> (see the middle part of FIG. 4), the operation result becomes a trapezoid shown by the shaded portion of the set T.

Then, the inference result of each rule thus obtained, that is, the shaded portion of the set S and the shaded portion of the set T are combined. The combined result is the shaded portion of the set U shown in FIG. 4. The center of gravity (point P) of this set is calculated to obtain a representative value, and the light amount adjustment signal (LINT) input to the lamp regulator 104 is determined.

In this embodiment, the fuzzy rule,
ROM 101 for membership functions, control programs, etc.
(See FIG. 1), and using the RAM 102, the CPU 1
Although the calculation is performed with 00, in order to improve the processing speed, the operation amount corresponding to the input of the state amount is calculated in advance, and the ROM that outputs this value is used.
You may perform these fuzzy control.

The state quantity is not limited to the input power supply voltage and the light quantity of the lamp, but is related to the lamp light quantity control such as the initial drum sensitivity, the set value of the copy density key, the document density, the reduction copy magnification, and the photosensitive drum sensitivity. Any state quantity can be used as the state quantity of the present invention.

Moreover, the number of state quantities is not limited to two, and any number can be combined.

Further, the operation amount is not limited to the light amount adjustment signal (LINT) input to the lamp regulator 104, and the change rate of the light amount adjustment signal or the correction value of the light amount adjustment signal may be used.

The fuzzy inference algorithm described above is
This is an example, and the algorithm may be modified.
For example, instead of taking the center of gravity of the area when synthesizing a plurality of rules, the value on the horizontal axis with respect to the maximum value on the vertical axis may be used as the inference result. Also, the number and contents of fuzzy rules can be appropriately modified based on experience.

Embodiment 2 FIG. 5 shows a fuzzy rule in a second embodiment of the present invention.

In FIG. 5, E indicates the sensitivity of the initial drum. EL, EM, and EH are EL; a fuzzy set that represents "the initial drum sensitivity is low"EM; a fuzzy set that represents "medium initial drum sensitivity"EH; a fuzzy that represents "the initial drum sensitivity is high" It is a set.

Since the method for obtaining the optimum light amount adjustment signal to be input to the lamp regulator is the same as the method in the first embodiment, its details are omitted.

Embodiment 3 FIG. 6 shows fuzzy rules in a third embodiment of the present invention.

In FIG. 6, F indicates the set value of the copy density key.

FL, FM and FH are respectively   FL: Fuzzy set representing "the set value of the copy density key is small"   FM: A fuzzy set representing "the set value of the copy density key is medium"   FH: Fuzzy set representing "the set value of the copy density key is large" Is.

Since the method for obtaining the optimum light amount adjustment signal to be input to the lamp regulator is the same as the method in the first embodiment, the details will be omitted.

As described above, according to the respective embodiments of the present invention, the input power supply voltage, the initial drum sensitivity, the set value of the copy density key, the document density, the reduction copy magnification, the light amount of the lamp, the photosensitive drum sensitivity, etc. In the control of the light quantity of the lamp of the copying machine, the performance of which is governed by many vague variable factors (state quantities) that are related to each other. It is possible to calculate the quantity) and automatically control the light quantity adjustment signal input to the lamp regulator.

[0052]

As described above, according to the present invention, the control of the light quantity of the lamp is not fixedly performed even with respect to the change of the lamp itself or the like, but the control considering the complicated factors is performed by using the fuzzy inference. Because of the structure, accurate lamp control is always possible.

Further, at this time, since the control amount is determined based on a plurality of parameters, even if there is an error in a part of the input data, it is possible to prevent a large error in the control amount.

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire embodiment of the present invention.

FIG. 2 is a diagram showing a fuzzy rule in the first embodiment of the present invention.

FIG. 3 is a diagram showing a membership function in the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of fuzzy inference according to the first embodiment of this invention.

FIG. 5 is an explanatory diagram showing fuzzy rules in the second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing fuzzy rules in a third embodiment of the present invention.

FIG. 7 is an explanatory diagram of a conventional example.

[Explanation of symbols]

100 CPU 101 ROM 104 lamp regulator 105 Original illumination lamp 106 Light intensity sensor 108 drum sensitivity detecting means 110 Document density sensor 112 Input power supply voltage detection means 114 Operation part

Claims (6)

[Claims] 1. A lamp light quantity control device comprising a lamp driving means for variably controlling the amount of light emitted from a lamp, a state quantity detecting means for detecting a predetermined state quantity related to the lamp light quantity control, and each of the state quantities representing the state quantity. A fuzzy rule means that predefines a relationship between the fuzzy set and each fuzzy set that represents the control amount supplied to the driving means, and the state quantity is a predetermined fuzzy according to a rule output from the fuzzy rule means. A lamp light quantity control device comprising: an inference unit that infers the control amount based on the degree of belonging to a set. 2. The state quantity detecting means according to claim 1,
A lamp characterized by detecting at least one of an input power supply voltage, an initial drum sensitivity, a set value of a copy density key, a document density, a reduction copy magnification, a lamp light quantity, and a photosensitive drum sensitivity as the state quantity. Light control device. 3. The control amount according to claim 1, wherein the control amount is at least one of a light amount adjustment signal input to a lamp regulator, a change rate of the light amount adjustment signal, and a correction value of the light amount adjustment signal. Lamp light intensity control device. 4. A lamp light quantity control device comprising a lamp driving means for variably controlling a light emission quantity of a lamp, and a state quantity detecting means for detecting a state quantity relating to at least one of a lamp light quantity control state and a lamp light quantity state. A membership function storing means for storing a membership function in which the state quantity and the control quantity of the lamp driving means are expressed by fuzzy sets, and a rule expressing the relationship between the state quantity and the control quantity in the form of a fuzzy proposition. A fuzzy rule storing means for storing the state quantity, and a fitness of the state quantity detected by the state quantity detecting means with respect to the fuzzy set, based on a membership function of the state quantity stored in the membership function storing means. A goodness-of-fit calculation means, based on the goodness-of-fit calculated by the goodness-of-fit calculation means,
A lamp light amount control device comprising: an inference unit that calculates the control amount according to each rule stored in the fuzzy rule storage unit. 5. The state quantity detecting means according to claim 4,
A lamp characterized by detecting at least one of an input power supply voltage, an initial drum sensitivity, a set value of a copy density key, a document density, a reduction copy magnification, a lamp light quantity, and a photosensitive drum sensitivity as the state quantity. Light control device. 6. The control amount according to claim 4, wherein the control amount is at least one of a light amount adjustment signal input to the lamp regulator, a change rate of the light amount adjustment signal, and a correction value of the light amount adjustment signal. Lamp light intensity control device.