JP2000171416A - Medium data detecting apparatus, image forming apparatus, medium data detecting method, image forming method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus utilizing a medium data detecting apparatus for detecting the quality or state of paper by a non-contact technique and capable of avoiding the generation of jamming. SOLUTION: A medium data detecting apparatus is constituted of light source/electromagnetic wave sources 11, 12, 13 for separately irradiating paper 15 with a plurality of lights or electromagnetic waves containing frequency components of 1GHz-10THz, a photodetector unit 16 for electrically detecting transmitted lights or electromagnetic waves from the paper 15 and a CPU unit 18 estimating the quality or kind of the paper 15. On the basis of the state of the paper estimated by the medium data detecting apparatus, the control process of image forming operation to the paper 15 is altered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium information detecting device and a medium information detecting method for detecting the state of a medium such as paper without contact, an image forming apparatus such as a copying machine using the medium information detecting device, and the like. The present invention relates to an image forming method and a storage medium for realizing these methods.

[0002]

2. Description of the Related Art Conventionally, as a technique for identifying a medium such as a copy medium or a print medium by a non-contact method, for example, OH
A device using a transmission type sensor or the like for distinguishing between P paper and paper is known.

However, there is no technique capable of detecting the quality of the paper itself, the back of the paper, and the information in the paper by a non-contact method.

[0004]

As described above, conventionally, since the quality of the paper itself, the back of the paper, and the information in the paper cannot be detected, it is not possible to check the quality of the paper, and the In the forming apparatus, problems such as jams (paper jams) often occur with poor quality paper.
Further, the presence of information by printing on the back side of the paper often deteriorates copy / print quality.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a medium information detecting device and a medium information detecting method capable of detecting paper quality and the state of paper by a non-contact method. It is another object of the present invention to provide an image forming apparatus and an image forming method that can prevent a jam from occurring using the medium information detecting device. Still another object of the present invention is to provide a storage medium for realizing the medium information detecting method and the image forming method.

[0006]

In order to achieve the above object, a medium information detecting device according to the first aspect of the present invention comprises:
Irradiation means for separately irradiating one medium with a plurality of lights or electromagnetic waves including frequency components in the range of GHz to 10 THz, and electrically transmitting light or transmitted electromagnetic waves from the medium which has been irradiated with the light or electromagnetic waves. It is provided with a detecting means for detecting, and an estimating means for estimating a state of the medium based on detection information of the detecting means.

According to a second aspect of the present invention, there is provided the medium information detecting apparatus according to the first aspect, further comprising a humidity measuring device for measuring a humidity of a surrounding environment of the medium, wherein the medium information estimating means. Is characterized in that the medium information is estimated with reference to the measurement information of the humidity meter.

According to a third aspect of the present invention, in the medium information detecting apparatus according to the first or second aspect, the detecting means comprises a bolometer or an antenna array. .

According to a fourth aspect of the present invention, in the medium information detecting apparatus according to any one of the first to third aspects, the irradiating means includes a plurality of points having different frequencies at a plurality of points on the medium. The medium information estimating means compares the detection information of each of the points detected by the detecting means, and estimates the state of the medium according to the comparison result. And

According to a fifth aspect of the present invention, in the medium information detecting device, the medium is paper, and the state of the medium is the quality of the paper and the quality of the paper. It is characterized by including a kind and a kind and state of a predetermined substance attached to the paper.

According to a sixth aspect of the present invention, in the medium information detecting apparatus according to the fifth aspect, the predetermined substance is ink or toner.

According to a seventh aspect of the present invention, there is provided an image forming apparatus having the medium information detecting device according to any one of the first to sixth aspects, wherein the state of the medium estimated by the medium information detecting device is provided. , The control process of the image forming operation for the medium is changed.

According to an eighth aspect of the present invention, there is provided an image forming apparatus having the medium information detecting device according to any one of the first to sixth aspects, wherein the state of the medium estimated by the medium information detecting device is provided. , The image forming operation on the medium is prohibited.

According to a ninth aspect of the present invention, there is provided a medium information detecting method, wherein a plurality of lights or electromagnetic waves including frequency components in a range of 1 GHz to 10 THz are separately irradiated on one medium, and the medium after the irradiation processing is irradiated. A detection process for detecting transmitted light or a transmitted electromagnetic wave from the electronic device by electrical means, and an estimation process for estimating a state of the medium based on detection information of the detection process.

According to a tenth aspect of the present invention, in the medium information detecting method of the ninth aspect,
The estimation process estimates the state of the medium with reference to the humidity of the surrounding environment of the medium.

In the medium information detecting method according to the present invention, in the medium information detecting method according to the ninth or tenth aspect, the electrical means of the detecting process may include:
A bolometer or an antenna array is used.

According to a twelfth aspect of the present invention, in the medium information detecting method according to any one of the ninth to eleventh aspects, the irradiating process includes the step of irradiating the plurality of points having different frequencies to a plurality of points on the medium. And the estimation processing compares the detection information of each point detected in the detection processing, and estimates the state of the medium according to the comparison result.

According to a thirteenth aspect of the present invention, in the medium information detecting method of the ninth to twelfth aspects, the medium is paper, and the state of the medium is the quality and the quality of the paper. It is characterized by including a kind and a kind and state of a predetermined substance attached to the paper.

According to a fourteenth aspect of the present invention, in the medium information detecting method of the thirteenth aspect, the predetermined substance is ink or toner.

According to a fifteenth aspect of the present invention, there is provided an image forming method comprising: estimating a state of a medium with the medium information detecting device according to any one of the first to sixth aspects; and performing an image forming operation on the medium based on the estimation result. The control process is changed.

According to a sixteenth aspect of the present invention, there is provided an image forming method comprising: estimating a state of a medium by the medium information detecting device according to any one of the first to sixth aspects; and forming an image on the medium based on the estimation result. It is characterized by prohibition.

A storage medium according to a seventeenth aspect of the present invention
A storage medium storing a computer-readable program that executes a medium information detection method of detecting a state of a medium in a non-contact manner, wherein the medium information detection method includes:
An irradiation step of separately irradiating one medium with a plurality of lights or electromagnetic waves including frequencies in the range of GHz to 10 THz, and the state of the medium based on electrical detection information of transmitted light or transmitted electromagnetic waves from the medium. And an estimating step of estimating.

In the storage medium according to the present invention, the estimating step estimates the state of the medium with reference to the humidity of the surrounding environment of the medium. And

In a storage medium according to a nineteenth aspect of the present invention, in the storage medium according to the seventeenth or eighteenth aspect, the irradiating step includes the step of irradiating the plurality of light or electromagnetic waves having different frequencies respectively to a plurality of points on the medium. Irradiate,
The estimating step is characterized in that the electrical detection information at each of the points is compared, and the state of the medium is estimated according to the comparison result.

According to a twentieth aspect of the present invention, in the storage medium according to any one of the seventeenth to nineteenth aspects, the medium is paper, and the state of the medium is the quality and type of the paper and the type of the paper. It is characterized by including a kind and a state of a predetermined substance attached to.

According to a twenty-first aspect of the present invention, in the storage medium according to the twentieth aspect, the predetermined substance is ink or toner.

A storage medium according to a twenty-second aspect of the present invention is a storage medium storing a computer-readable program for executing an image forming method for forming an image on a medium, wherein the image forming method is A step of changing a control process of an image forming operation on the medium based on the state of the medium estimated using the medium information detecting device according to any one of claims 1 to 6.

A storage medium according to a twenty-third aspect of the present invention is a storage medium storing a computer-readable program for executing an image forming method for forming an image on a medium, wherein the image forming method is A step of prohibiting an image forming operation on the medium based on the state of the medium estimated using the medium information detecting device according to any one of claims 1 to 6.

[0029]

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

FIG. 1 is a block diagram showing a configuration of a medium information detecting device according to one embodiment of the present invention.

This medium information detecting device is provided with, for example, three light sources or electromagnetic wave sources 11, 12, and 13. The light sources or the electromagnetic wave sources 11 and 12 generate light or electromagnetic waves of frequencies f1 and f2, respectively, and the difference signal of the frequency f3 includes a frequency component of 1 GHz to 10 THz.

Similarly, the light source or the electromagnetic wave source 13 generates light or an electromagnetic wave having a frequency f4,
The signal of frequency f5, which is the difference from the signal of No. 1, and the signal of frequency f6, which is the difference between the signal of frequency f4 and the signal of the frequency f2, are signals containing frequency components of 1 GHz to 10 THz.

In the figure, reference numeral 14 denotes a heterodyne crystal which is a crystal capable of heterodyne modulation, and a light source or electromagnetic wave sources 11, 12, 13
When the light or the electromagnetic wave generated in step (1) is incident, the light or the electromagnetic wave having the frequencies f3, f5, and f6 including the frequency components of 1 GHz to 10 THz is output by heterodyne modulation. Here, the light or the electromagnetic waves having the frequencies f3, f5, and f6 are light or electromagnetic waves having mutually different frequencies.
They are not generated at the same time, but are generated sequentially.

When the light or the electromagnetic wave output from the heterodyne crystal 14 is irradiated on the paper 15, only the light or the electromagnetic wave having the frequency component of 1 GHz to 10 THz passes through the paper 15 and is transmitted to the light receiving element in the light receiving element unit 16. To reach.

The transmitted light or transmitted electromagnetic wave information converted into an electric signal by the light receiving element unit 16 is sent to a CPU unit 18 through a signal line 17, where it is converted into digital information, and is converted into digital information by using an arithmetic process or a map. The state of the paper 15 is determined.

As described above, in the present embodiment, light or an electromagnetic wave is applied to a paper to determine the quality of the paper. This method uses the following principle.

That is, the frequency band around 1 GHz to 10 THz corresponds to the resonance frequency band of molecules of various substances, and is a region where the attenuation rate can be changed depending on the constituent materials of paper. From this, 1T to 10T
In the light or electromagnetic wave range of HZ, the amount of water contained in paper,
The transmittance of light or electromagnetic waves changes depending on the paper material and the printed ink (toner). The present embodiment utilizes this fact.

FIG. 2 shows the attenuation characteristics of electromagnetic waves.
Temperature: 20 ° C, Pressure: 1013mbar, Absolute humidity:
It is a measurement under an environmental condition of 7.5 g / m3. L in the figure
1, L2 and L3 are 0.25 mm / h and 25 m, respectively.
m / h and 150 mm / h in the case of rain.
In the case of 1 g / m3 of fog.

FIG. 3 shows the light receiving element unit 1 shown in FIG.
6 is an actual structure diagram, and FIG. 4 is an equivalent circuit diagram thereof.

The light receiving element unit 16 is composed of a silicon oxide film (SiO 2) on a p-type silicon substrate (p-Si) 31.
2) A long wire antenna part 34 and an electrode part 35 are formed by a vapor deposition method via 32. The anatene length of the long wire antenna section 34 is preferably an integral multiple of the wavelength λ / 2, and the electrode section 35 is connected to the long wire antenna section 34 with the same material (aluminum, tungsten, etc.) as the long wire antenna section 34. ing.

The tip of the long wire antenna 34 is
Through a through hole (contact hole) 36 on the p-Si substrate 31, a point contact Schottky barrier diode 30 is formed at the DO point with the p-Si substrate 31.

An aluminum (Al) electrode 33 is deposited on the back surface of the p-Si substrate 31. That is, through the Al electrode 33, the back side of the p-Si substrate 31 (that is, the anode side of the Schottky barrier diode 30)
Is connected to a ground line to the CPU unit 18 and is also connected to one end of a load circuit 40 in which a resistor 42 and a microcapacitor 43 are connected in parallel.

The other end of the load circuit 40 is connected to the positive input terminal (+) of the operational amplifier 44, and the output terminal of the operational amplifier 44 is feedback-connected to the negative input terminal (-). The operational amplifier 44 is configured to operate as a buffer, and the output terminal of the operational amplifier 44 is connected to the signal line 17. And the signal line 17
The ground line is connected to an A / D conversion input terminal and a ground terminal of the CPU unit 18, respectively.

The positive input terminal (+) of the operational amplifier 44 is connected to the positive side of the bias power supply 41, and the electrode 35 is connected to the negative side of the bias power supply 41.

As the light receiving element unit 16, FIG.
It is also possible to configure an array sensor using the light receiving elements having the structure shown in FIG. 1 as an array, and to detect information from the paper 15 as a medium at high speed. Further, a bolometer can naturally be used as the light receiving element unit 16.

Next, the operation of the light receiving element unit 16 and the CPU unit 18 will be described.

First, when the transmitted light or transmitted electromagnetic wave (in the range of 1 GHz to 10 THz) from the paper 15 reaches the long wire antenna section 34 of the light receiving element unit 16, the transmitted light or transmitted electromagnetic wave causes the long wire antenna section 34 to transmit. A high-frequency voltage of that frequency is induced.

The homodyne detection is performed by the Schottky barrier diode 30 optimally biased by the bias power supply 41, and a DC signal induced by the light or the electromagnetic wave appears between the resistors 42. The signal smoothed by the capacitor 43 is buffered by the operational amplifier 44 and output to the signal line 17.

The CPU unit 18 A / D (analog / digital) converts the voltage of the signal line 17 and reads it into an internal memory. Then, the value is compared with a value obtained by an experiment in advance, and the one showing the closest value is determined as the paper used at that time.

It should be noted that the CPU unit 18
It is also possible to insert an amplifier for amplifying the voltage signal output to the signal line 17 between the A / D converter of FIG.

The CPU unit 18 can also take in the measured values of the environment sensor 19 as shown in FIG. 1 and determine the state of the paper 15 by referring to the values. That is, a humidity / temperature measurement unit is used as the environment sensor 19, and a value including the temperature and humidity information read by the humidity / temperature measurement unit is compared with a map value obtained in advance by experiment to determine the state of the paper 15. You do it. In this case,
Based on the humidity information, the amount of water contained in the paper 15 can be estimated from the experimental map value.

More specifically, as shown in FIG. 5 showing humidity and output voltage characteristics when f = fα, the CPU unit 18
A map of data corresponding to the output voltage characteristics of the light receiving element unit 16 (representing various paper states) and humidity information is created in a memory inside. If f changes, this characteristic naturally changes, so a map of information on the change in f is also required. FIG. 5 shows a map representing the characteristics of paper 1 and paper 2 when f = f3 and f = f5.

As a method for detecting the paper quality, first, a plurality of points on the paper 15 are irradiated with electromagnetic waves having a plurality of wavelengths. The response characteristics are received by the light receiving element unit 16 and the response characteristics due to a plurality of electromagnetic waves are
To record. Then, the difference amount between the response results from the plurality of electromagnetic waves is obtained by calculation, and the result is compared between the values at each point. As a result, it is possible to know the fluctuation of the response characteristic for each location due to the stain on the paper, the paper quality, and the like. That is, it is possible to determine the state of paper quality, the type of toner when printing is performed, and the like, based on the magnitude of the difference between the pieces of difference information.

As described above, in the present embodiment, a plurality of lights or electromagnetic waves containing frequency components in the range of 1 GHz to 10 THZ are separately irradiated on paper, and the transmitted light or transmitted electromagnetic waves are detected by electrical means. Therefore, it is possible to estimate and detect the paper quality or the paper state using the detection information.

Next, an application example of the medium information detecting device of the present invention will be described.

FIG. 6 is a block diagram showing a configuration when the medium information detecting device of the first embodiment is applied to a copying machine.

As shown in the figure, a copying machine 50 is connected to the CPU unit 18 in the medium information detecting device shown in FIG. The copying machine 50 includes a controller 51 for controlling a copying process. Controller 5
1 has a process speed control unit 52 and a power supply control unit 53 configured by software.

The process speed control unit 52
The power supply control unit 53 is a software part for controlling a power supply such as a developing bias. The controller 51 is configured to optimally control the software of the process speed control unit 52 and the power supply control unit 53 by appropriately changing parameters according to the environment.

With the above configuration, when the controller 51 receives the information of the paper 15 detected by the CPU unit 18,
The controller 51 sets the control parameters of the process speed control unit 52 and the power supply control unit 53 so as to be optimal for the paper 15. The control parameters are, for example, parameters such as a developing bias voltage and a process speed.

A plurality of points on the paper 15 are irradiated with a plurality of light or electromagnetic waves having different wavelengths, and the response characteristics are received by the light receiving element unit 16. Is recorded by the CPU unit 18, and a difference amount of a response result by a plurality of light or electromagnetic waves is obtained by calculation, whereby the process control of the copying machine 50 can be performed. For example, in an ordinary paper copying process, when unusable carbon paper is mixed, the difference amount indicates an abnormal value. In such a case, the CPU unit 18 determines to stop the copying process, and instructs the CPU unit 18 to stop the copying process. The command is sent to the copier 50.

Further, when the variation of the difference amount of the response result exceeds a certain value and enters an area where it can be determined that the paper quality is inferior, the copying process is changed (for example, the process speed is reduced) or copying is performed. To ban
CPU unit 18 sends control information to copier 50. Such control can prevent a jam from occurring.

It is also possible to prohibit copying when special paper used for bills or the like is detected.

The control method can be realized by storing and operating a program corresponding to the above-described control method in a storage device or the like in the CPU unit 18.

The present invention is not limited to the apparatus of the above-described embodiment, but may be applied to a system composed of a plurality of devices or an apparatus composed of one device. A storage medium storing program codes of software for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (or CPU unit or MPU) of the system or apparatus reads out the program code stored in the storage medium. It goes without saying that it will be completed by execution.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, and a ROM can be used. Also,
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an OS or the like running on the computer performs part of the actual processing based on the instructions of the program code. Alternatively, it goes without saying that a case is also included in which the functions of the above-described embodiments are implemented by performing the entire process.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the next program code. Needless to say, the extended function may be performed by a CPU or the like provided in an expansion board or an expansion unit to perform a part or all of the actual processing, and the processing may realize the functions of the above-described embodiments. No.

[0067]

As described in detail above, the medium information detecting apparatus according to the first, fourth, fifth and sixth aspects of the present invention, and the ninth, twelfth, thirteenth, and thirteenth aspects of the present invention. A medium information detection method according to the invention of claim 14, and claim 1
According to the storage medium according to the invention described in claim 19, claim 20, and claim 21, for example, from a medium such as paper, the quality and type of paper and the type and It becomes possible to estimate the state and the like.

According to the medium information detecting device according to the second aspect, the medium information detecting method according to the tenth aspect, and the storage medium according to the eighteenth aspect,
Since the condition of paper and other media is estimated by referring to measurement information from a humidity meter that measures the humidity of the surrounding environment of the media, it is possible to more accurately estimate the status of media such as paper. Become.

According to the medium information detecting device according to the third aspect of the present invention and the medium information detecting method according to the eleventh aspect of the present invention, the transmitted light or the transmitted electromagnetic wave from the medium irradiated with the light or the electromagnetic wave is provided. The bolometer or antenna array is used as the detection means for electrically detecting the transmitted light or electromagnetic waves transmitted through the bolometer. In this case, the mounting can be made small and high-quality high-speed detection becomes possible.

According to the image forming apparatus of the present invention, the image forming method of the present invention, and the storage medium of the present invention, Since the control process of the image forming operation on the medium is changed based on the estimated state of the medium, the process speed and the like can be set to optimal conditions according to the type of paper, and the occurrence of jams can be improved. Image formation becomes possible.

According to the image forming apparatus of the present invention, the image forming method of the present invention, and the storage medium of the present invention, Based on the estimated state of the medium, the image forming operation on the medium is prohibited.
An image can be formed without a jam.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a medium information detection device according to an embodiment of the present invention.

FIG. 2 is a graph showing attenuation characteristics of an electromagnetic wave.

FIG. 3 is an actual structural diagram of a light receiving element unit 16 shown in FIG.

FIG. 4 is an equivalent circuit diagram of the light receiving element unit 16 shown in FIG.

FIG. 5 is a diagram showing humidity and output voltage characteristics when f = fα.

FIG. 6 is a block diagram illustrating a configuration when the medium information detection device according to the first embodiment is applied to a copying machine;

[Explanation of symbols]

 11, 12, 13 light source or electromagnetic wave source 14 heterodyne crystal 15 paper 16 light receiving element unit 17 signal line 18 CPU unit 50 copier 51 controller 52 process speed control unit 53 power supply control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2G059 AA01 AA05 BB10 BB15 CC10 CC20 EE01 FF06 GG03 GG06 JJ30 KK01 MM05 MM09 MM10 2H027 DA14 DC02 DE02 DE07 EC06 EC07 EE08 EK03 3F048 AA01 AA02 DCA13 CB01 JJ35 KZ42 LL02

Claims (23)

[Claims] 1. An irradiating means for separately irradiating one medium with a plurality of lights or electromagnetic waves including frequency components in the range of 1 GHz to 10 THz, and transmitted light or transmitted light from said medium which has been irradiated with said light or electromagnetic waves. A medium information detection device comprising: a detection unit that electrically detects an electromagnetic wave; and an estimation unit that estimates a state of the medium based on detection information of the detection unit. 2. The apparatus according to claim 1, further comprising a humidity measuring device for measuring a humidity of a surrounding environment of the medium, wherein the medium information estimating means estimates the medium information by referring to measurement information of the humidity measuring device. The medium information detecting device according to claim 1, wherein 3. The medium information detecting device according to claim 1, wherein said detecting means comprises a bolometer or an antenna array. 4. The irradiating means irradiates a plurality of points of the medium with the plurality of lights or electromagnetic waves having different frequencies, respectively, and the medium information estimating means includes a plurality of the points detected by the detecting means. 4. The medium information detecting device according to claim 1, wherein the detected information is compared, and the state of the medium is estimated according to the comparison result. 5. The medium according to claim 1, wherein the medium is paper, and the state of the medium includes the quality and type of the paper and the type and state of a predetermined substance attached to the paper. Item 5. The medium information detecting device according to Item 4. 6. The medium information detecting device according to claim 5, wherein the predetermined substance is ink or toner. 7. An image forming apparatus having the medium information detecting device according to claim 1, wherein an image forming operation for the medium is performed based on a state of the medium estimated by the medium information detecting device. An image forming apparatus, wherein a control process is changed. 8. An image forming apparatus having the medium information detecting device according to claim 1, wherein an image forming operation for the medium is performed based on a state of the medium estimated by the medium information detecting device. An image forming apparatus characterized by prohibiting. 9. A method of separately irradiating one medium with a plurality of lights or electromagnetic waves including frequency components in the range of 1 GHz to 10 THz, and transmitting transmitted light or transmitted electromagnetic waves from the medium after the irradiation processing by electrical means. A medium information detection method, comprising: performing a detection process for detecting; and an estimation process for estimating a state of the medium based on detection information of the detection process. 10. The medium information detection method according to claim 9, wherein the estimation processing estimates the state of the medium with reference to the humidity of the surrounding environment of the medium. 11. The medium information detection method according to claim 9, wherein a bolometer or an antenna array is used as the electric means for the detection processing. 12. The irradiating process irradiates a plurality of points of the medium with the plurality of lights or electromagnetic waves having different frequencies, and the estimating process includes detecting information of each of the points detected in the detecting process. 12. The medium information detecting method according to claim 9, wherein the medium information is estimated according to a result of the comparison. 13. The medium according to claim 9, wherein the medium is paper, and the state of the medium includes the quality and type of the paper and the type and state of a predetermined substance attached to the paper. Item 13. A medium information detecting method according to Item 12. 14. The medium information detection method according to claim 13, wherein the predetermined substance is ink or toner. 15. A medium information detecting apparatus according to claim 1, wherein a state of the medium is estimated, and a control process of an image forming operation on the medium is changed based on the estimation result. Image forming method. 16. An image forming method, comprising: estimating a state of a medium with the medium information detecting device according to claim 1; and prohibiting image formation on the medium based on the estimation result. 17. A storage medium storing a computer-readable program for executing a medium information detection method for non-contactly detecting a state of a medium, wherein the medium information detection method is in a range of 1 GHz to 10 THz. An irradiation step of separately irradiating a single medium with a plurality of lights or electromagnetic waves including a frequency of, and an estimation step of estimating a state of the medium based on electrical detection information of transmitted light or transmitted electromagnetic waves from the medium. A storage medium comprising: 18. The storage medium according to claim 17, wherein the estimating step estimates the state of the medium with reference to the humidity of the surrounding environment of the medium. 19. The irradiating step includes irradiating a plurality of points of the medium with the plurality of lights or electromagnetic waves having different frequencies, and the estimating step compares electrical detection information of the respective points, and compares the comparison. 18. The medium according to claim 17, wherein a state of the medium is estimated according to a result.
8. The storage medium according to 8. 20. The medium according to claim 17, wherein the medium is paper, and the state of the medium includes the quality and type of the paper and the type and state of a predetermined substance attached to the paper. Item 20. The storage medium according to Item 19. 21. The storage medium according to claim 20, wherein said predetermined substance is ink or toner. 22. A storage medium storing a computer-readable program for executing an image forming method for forming an image on a medium, wherein the image forming method is described in any one of claims 1 to 6. A storage medium characterized by comprising a step of changing a control process of an image forming operation on a medium based on a state of the medium estimated using the medium information detection device. 23. A storage medium storing a computer-readable program for executing an image forming method for forming an image on a medium, wherein the image forming method is described in any one of claims 1 to 6. A storage medium comprising a step of prohibiting an image forming operation on a medium based on a state of the medium estimated using the medium information detection device.