JPH01299472A - Apparatus for generating electric signal corresponding to surface potential distribution - Google Patents

Abstract

PURPOSE:To make it possible to decrease the dispersion in sensitivity of individual detecting element in an apparatus to a large extent, by providing a one-line detecting head, a reference- potential setting member, a one-line memory means, and a subtracting means. CONSTITUTION:A plurality of surface potential detecting elements are aligned in a straight line in a detecting head EDA. A time series signal for one line is outputted from the detecting head EDA and supplied to a movable contact point (c) of a switch SW. In a signal processing circuit SDA, at first the contact point (c) is switched to a fixed contact point (a). A surface potential is generated in a recording medium in correspondence with the black part of the optical image of an object. A reference-potential setting member VP has a region wherein a predetermined constant surface potential Vb which is equal to said surface potential in the medium D is provided. The surface potential for one line in the member VP is detected and stored in a line memory LM1. Then the switch is changed to a contact point (b). The surface potential for every one line in the medium D is detected. Each output signal is supplied to a subtracting circuit SUB. In the circuit SUB, the signal from the memory LM1 is subtracted from said output signal. The difference signal is sent to an output terminal 10. Therefore, the effect of dispersion in the range of white - black is drastically decreased.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to high-resolution charge image information reading devices, other devices, etc.
The present invention relates to a generation device for generating an electrical signal corresponding to a surface potential distribution used for detecting the surface potential distribution.

(Conventional Technique #f) As means for detecting surface potential, various methods have been known that have been adopted in various DC type surface potentiometers, AC type surface potentiometers, etc. The meter measures the surface potential at one location on the surface of the object to be detected, and is used for the purpose of extracting an electrical signal corresponding to a charge image formed one-dimensionally or two-dimensionally on the surface of the object to be detected. By the way, in recent years, as the demand for high-quality and high-resolution reproduced images has increased, new television systems such as so-called HDTV and HDTV have been proposed. As is well known, there are
In order to obtain high-quality and high-resolution playback images, an imaging device that can generate video signals that can reproduce high-quality and high-resolution playback images is required. In an imaging device that uses an image pickup tube as an element, there is a limit to miniaturization of the electron beam diameter in the image pickup tube, so high resolution cannot be expected by miniaturizing the electron beam diameter, and Since the target capacity increases in proportion to the target area, it is impossible to achieve higher resolution by increasing the target area. The frequency band of the video signal is several tens of megabytes
Hz to several hundred MHz or more, which poses a problem in terms of S/N.
Since it was difficult to generate a video signal capable of reproducing high-resolution reproduced images, in order to solve the above problem, the applicant company first developed an imaging system using a light-to-light conversion element. In addition to obtaining high-resolution optical images using the device,
We are proposing an imaging system and a recording system in which the optical image is recorded as a high-resolution charge image on a recording medium having a charge storage layer using a light-charge conversion element.

In addition, as the demand for recording various information signals at high recording densities has increased in recent years, it has become possible to record information signals at high density using recording media made based on various structural and operating principles. It is well known that reproduction has come to be carried out. For example, an information signal is recorded by forming irregularities corresponding to the information signal on the signal surface of a recording medium, and the recorded information signal is optically processed. Recording and reproducing apparatuses that perform playback by means or by detecting changes in capacitance are already in practical use for recording and playing back video and audio signals.
In order to meet the demands for high-density recording and reproduction in various technical fields, by irradiating the recording layer of the recording medium with a recording beam whose intensity is modulated by the information signal, the recording layer of the recording medium can be physically adjusted according to the information signal. Research has also begun on recording media in which information signals are recorded by causing changes or chemical changes, but in recent years it has become easy to obtain semiconductor lasers that operate stably. It is well known that various types of optical discs that use laser light for high-density recording and reproduction have already been put into practical use, or that research and development is currently underway to put them into practical use. For example, recorded optical discs (playback-only optical discs) that have been copied in large numbers from master discs on which information signals are recorded using pits formed as geometrical concave or convex parts are, for example, video discs or compact discs.・In addition to discs that are starting to become popular in ordinary households, optical discs (write-once optical discs) that can be added and recorded only once by the user, and erasable optical discs are becoming popular for office file memories and other uses. A lot of research and development is being carried out to put this into practical use, and so far, even write-once optical discs and erasable optical discs have been developed whose recording layer is heated by the spot of a laser beam.
When classified based on the type of physical change in which information signals are recorded, there are pit-forming types, bubbles or unevenness-forming types, magneto-optical types, and phase-change types (where light transmittance changes due to thermal energy). .

Various formats have been proposed, which can be roughly divided into types such as thermal transformation type (which causes changes in reflectance, absorption rate, etc.), as well as recording,
Many proposals have been made for recording media in which the reproduction operation is performed using energy other than light, and various proposals have also been made for recording and reproduction devices using these recording media. In recording and reproducing devices using various types of recording media, the configuration of the device for performing high-density recording is complicated and large-scale, and erasable recording media have not been used in the past, as mentioned above. Even if it has been proposed, for example, in the case of a magnetic recording medium, erasing is easy, but on the other hand, there is a problem in high-density recording, and in the case of an optical disk, for example, high-density recording is easy, but Since there was a problem that erasing could not be performed by simple means, the applicant company created a recording device that does not have the above problem by first introducing a transparent electrode into which the laser beam is incident and transmitting the laser beam through the transparent electrode. It is provided with an electrode for forming an electric field between the photoconductive layer member into which the laser beam is incident and the above-mentioned transparent electrode, and an electric field generated in response to the electric field between the photoconductive layer member and the above-mentioned electrode. The recording medium has a charge retention layer that retains charges, and the electric field between the photoconductive layer member □ and the electrode is changed in accordance with the information signal to be recorded. A recording device, the schematic configuration of which is shown in FIG. 6, has also been proposed in which information signals to be recorded are recorded in the form of a charge pattern on a charge retention layer member.

In FIG. 6, D is a recording medium, and this recording medium has a laminated structure of an insulator M1 that functions as a charge retention layer and an electrode E, and the above-mentioned insulator M1 is attached on top of the insulator M1. It is made using a material (eg, silicone resin) that has an extremely high insulation resistance value that allows it to retain charge for a long time.

This recording medium tray is rotated at a predetermined number of rotations by, for example, a rotation drive mechanism (not shown). In FIG. 6, WA is a recording system configured to emit from a lens 7 a laser beam whose intensity is modulated by the information signal to be recorded, and the recording system WA in the illustrated example is Laser light source 8, lens 9. Polarizer 3, optical modulator 4, information signal source to be recorded 5. Analyzer 6
, lens 7.

The laser beam emitted from the lens 7 of the recording system WA described above passes through the transparent electrode Etw and is applied to the photoconductor layer PCE. Since a voltage is applied between the transparent electrode Etw and the recording medium from the power source Vw,
As described above, when the laser beam whose intensity is modulated by the information signal from the recording system WA is incident on the photoconductor layer PCE, the electrical resistance value of the portion of the photoconductor layer PCE to which the laser beam is applied decreases. Then, a discharge occurs between the insulating layer IL of the recording medium and the insulating layer IL of the recording medium at that portion, and as a result, charges corresponding to the information signal are attached to the surface of the insulating layer IL of the recording medium.

The charge image corresponding to the above-mentioned information signal cannot be extracted as a time-series electric signal corresponding to the charge image even if a conventional general surface electrometer is used. There is a need for an electrical signal generator that can be easily extracted as an electrical signal, and the applicant company has previously developed an electrical signal generator that corresponds to the surface potential distribution as shown in FIG. 7. That is, a plurality of field effect transistors for voltage detection whose gate electrodes are individually applied with voltages generated by electrostatic induction corresponding to the surface potential of each of the plurality of points on the object to be detected, and the plurality of voltages described above. Analog switching means for individually controlling the opening and closing of the output signals of the detection field effect transistors, and a voltage corresponding to the voltage generated by electrostatic induction corresponding to the surface potential of each of the plurality of locations of the object to be detected. and means for supplying a switching control signal to the analog switching means such that the signals are sent to the common output line through the analog switching means in a predetermined order. The above problems were solved by proposing an electric signal generator.

That is, FIG. 7 is a block diagram showing a schematic configuration of an electric signal generating device corresponding to the previously proposed surface potential distribution, and FIG. FIG. 9 is a diagram showing a configuration example of a structure (detection head) EDA of an electric signal generator corresponding to the previously proposed surface potential distribution, and FIG. 9 is a waveform diagram for explaining the operation.

In the electric signal generator corresponding to the previously proposed surface potential distribution shown in FIG. 7, E DI.

EO2, ED3, . ．． ED2゜ED3
. . . EDn is an individual connection line Q1. Q
2゜Q3...Q, n, voltage detection field effect transistors DPI, DF2. The portions connected to the gate electrodes of DF3-DFn, each consisting of the individual minute voltage detection electrodes mentioned above and the individual voltage detection field effect transistors to which they are connected, are connected to the detection object. An individual surface potential detection element is constituted by including a voltage detection field effect transistor whose gate electrode is applied with a voltage generated by electrostatic induction corresponding to the surface potential of a specific portion.

Then, each of the above-mentioned voltage detection field effect transistors D
Fl, D F2. The drain electrodes of D F3-D Fn are commonly connected to the operating power supply V, and a constant voltage is supplied thereto, and each of the voltage detection field effect transistors DPI, DF2, DF3, . . . D
The source electrodes of Fn are connected to individual switching field effect transistors SFI, SF2゜SF3...SF.
The respective source electrodes of the individual switching field effect transistors SFI, SF2, SF3, . . . SFn are connected in common to the output terminal 1. . RQ in FIG. 7 indicates load resistance.

The individual switching field effect transistor S
Fl, S F2. Each gate electrode in SF3-5Fn receives switching pulses PL, P2 . P3...Pn is supplied.

Switching pulses PL, P2 . As is clear from the waveform diagram illustrated in FIG. 9, P3...Pn are supplied to the clock terminal 2 of the shift register SR ((a) in FIG. 9).
By the clock signal Pc shown in FIG.
As illustrated in b) to (d), Pi-
Shift register S sequentially as +P2→P3→...
Since the output is from R, the individual switching field effects 1 to transistors S Fl, S F2. SF
3-3 One selected one of F n is sequentially turned on on the time axis.

So each individual connection line Q1. Q2. Q
3...An voltage detection field effect transistors DFl, DF2 . DF3... A plurality of voltage detection electrodes EDI, ED2... connected to the gate electrodes of DFn.
ED3...The voltage corresponding to the surface potential of each of the plurality of locations of the object to be detected occurring at EDn is determined by the voltage detection field effect transistors DFl, D described above.
F2. From the source side of D F3 .=D Fn, respective corresponding switching field effect transistors S Fl, S F2 . Since it is supplied to the S F3-3 F n train, the shift register S mentioned above
From R to switching pulse PL, P2. Individual switching field effect transistors S Fl, which are turned on one after another as F3... are sequentially output.
SF2. From the source side of S F3-3 F rl, individual voltage detection electrodes E are connected by electrostatic induction corresponding to the surface potential of each of the multiple locations on the object to be detected.
Di, E D2. A voltage corresponding to the voltage generated at E D3 - E Dn is sent out to the output terminal 1 in series on the time axis.

Therefore, for example, as shown in FIG. 8, a plurality of voltage detection electrodes E Di, E D2. E D3...E I)
The detection head EDA and the object to be detected, which are provided so that n are arranged on one straight line, are connected to the plurality of voltage detection electrodes EDI, ED2 . When ED3-EDn are relatively moved in a direction perpendicular to the direction in which they are aligned, a time-series electric signal corresponding to a two-dimensional charge image formed on the object to be detected is output from output terminal 1. It will be sent to

Note that the detection head EDA illustrated in FIG. 8 includes a plurality of voltage detection electrodes EDI, ED2 . ED3-EDn and connection lines Ql-Qn are connected to base B using well-known thin film technology.
This is a configuration in which P is formed. Detection head ED
The voltage detection electrode provided at A may also be used as the gate electrode of the voltage detection field effect transistor.

(Problems to be Solved by the Invention) The previously proposed electrical signal generation device corresponding to the surface potential distribution has a structure in which the electrodes of the plurality of surface potential detection elements constituting the device are exactly on the same plane. If all field effect transistors for voltage detection are arranged on the top and operate with the same operating characteristics, the surface potential of the object to be detected can be detected accurately.
As a practical problem, in the previously proposed electrical signal generation device that corresponds to the surface potential distribution, the arrangement of the electrodes of each of the plurality of surface potential detection elements used in its configuration is on the same plane. It varies, and
There are also variations in the operating characteristics of the field effect transistors in each of the multiple surface potential detection elements, and therefore the input/output characteristics (expressed as sensitivity in the following description) of each of the multiple surface potential detection elements Even if the surface potential of the object to be detected exhibiting a constant surface potential is detected by the previously proposed electrical signal generation device that corresponds to the surface potential distribution, it will not be obtained as an output. Since the electrical signal fluctuates in magnitude on the time axis according to the variations in sensitivity of the plurality of surface potential detection elements described above, it is difficult to accurately detect the surface potential of the object to be detected. The problem was that I couldn't do it.

In order to solve the above problem, a surface with a surface potential of zero is prepared in advance, and the detection head E when the surface potential of the surface with a surface potential of zero is detected by the detection head EDA.
The output signal from the DA is stored in a storage device, and when the detection head EDA detects the surface potential distribution of the object to be detected, a signal preliminarily stored in the storage device is obtained from the output signal of the detection head EDA. An attempt has been made to remove the influence of fluctuations in magnitude on the time axis that occur in the output signal due to variations in sensitivity of a plurality of surface potential detection elements by subtracting .

FIG. 10 is a block diagram schematically showing an example configuration for realizing the above-mentioned attempt, and in this FIG. 10, D is an object to be detected (recording medium) from which a charge image is detected; Further, the EDA has a detection head having a configuration as shown in FIG. 7 (the detection head ED shown in FIG. 10).
Terminals 1.2 in A correspond to terminals 1, 2 shown in FIG. Note that this point also applies to FIGS. 1 and 4 described later), and the output signal from this detection head EDA is the output signal of a plurality of surface potential detection elements arranged on a - straight line. It is a time-series signal in which the signals are arranged on the time axis, and the detection head EDA described above
The output signal is supplied to the movable contact C of the changeover switch SW in the signal processing circuit SDA.

First, the changeover switch SW is set so that its movable contact C is switched to the fixed contact A side, and the surface potential prepared in advance is set to zero.
The surface potential of one line of that part is detected by the detection head EDA, and the output signal in the form of an analog signal obtained in that state is converted into a digital signal by the analog-to-digital converter ADC and stored in the line memory LM1. let

Next, the movable contact C of the changeover switch SW is switched to the fixed contact side, and the detection head EDA detects the surface potential of the detected object line by line, and the output signal for each line is subtracted. It is supplied as a signal to the subtraction circuit SOB.

This is because the above-mentioned subtraction circuit SUB is supplied with a signal obtained by converting the 1-line digital signal stored in the above-mentioned line memory LMI into an analog signal by the digital-to-analog converter DAC as a subtraction signal. , the output signal from the subtraction circuit SUB is a difference signal obtained by using the output signal detected from the detected object as the subtracted signal and using the signal stored in the storage device as the subtraction signal, and this difference A signal is sent to the output terminal 10 of the signal processing circuit SDA.

The waveform diagrams shown in correspondence with the respective constituent parts of the signal processing circuit SDA shown in the tenth diagram described above are for explaining the operation of the signal processing circuit SDA shown in the tenth diagram described above. The waveform example diagram (A) shown in the figure is one line from the detection head EDA in a portion prepared in advance so that the surface potential is zero (for example, the portion E in FIG. 10). This is an example of an output signal in the form of an analog signal that is output in response to the detection result of the surface potential of the minute (IH), and the waveform example diagram shown in (A') is the same as that shown in (A) above. A part of the signal waveforms shown in the waveform example diagram is enlarged to show output signals from a plurality of surface potential detection elements 1, 2, 3, etc. arranged in a straight line in the detection head EDA. This is a detailed example of a time-series signal in which the signals are arranged on the time axis.

Furthermore, the (opening) waveform example diagram shown in FIG. 10 is, for example, one line ( This is an example of an output signal in the form of an analog signal output corresponding to the detection result of the surface potential of IH),
In addition, in the waveform example diagram shown in (c), the output signal output from the subtracter SUB, that is, the output signal detected from the detected body is used as the subtracted signal and is stored in the storage device. This is an example of a difference signal obtained by subtracting a signal, and according to the signal processing circuit SDA having the configuration shown in FIG. Even if there are variations in sensitivity among the multiple surface potential detection elements in a generator, the charge recorded on the detected body when the surface potential of the part where no charge image is formed is zero. Regarding the statue,
As shown in the waveform example diagram (c) in FIG.

A signal can be obtained in which the influence of fluctuations in magnitude on the time axis that occur in the output signal due to the causes described above is reduced.

However, if the recording of the charge image on the recording medium serving as the object to be detected is performed by a recording device having the configuration described above with reference to FIG. Due to the initial discharge in the recording device, the surface potential of the detected object corresponding to the black part in the optical image of the object to be photographed has a voltage of vb with respect to zero potential as shown in FIG. Therefore, the surface potential generated on the recording medium corresponding to the black, halftone, and white patterns illustrated as the subject pattern in FIG. In the pattern, the voltage corresponding to black is shown as vb, the voltage corresponding to halftone is shown as Vm, and the voltage corresponding to white is shown as Vw.

On the other hand, the sensitivity of each of the plurality of surface potential detection elements used in the configuration of the electric signal generator corresponding to the surface potential distribution is illustrated by, for example, the straight lines α, β, and γ in FIG. As mentioned above, the surface potential generated on the recording medium corresponding to the black part of the object is offset by the voltage vb from the zero potential as described above with reference to FIG. is in a state of
Moreover, if the surface potential generated on the recording medium corresponding to the white of the image is Vw, then in the range from white to black of the image, the surface potential distribution and the corresponding electric signal used in the configuration of the generating device are The detection force of the surface potential detected from each of the plurality of surface potential detection elements in FIG. , β, and γ, which vary widely for the same surface potential on the recording medium, making it difficult to read the charge image on the recording medium in good condition. Because I can't get it out,
Improvement measures were required.

(Means for Solving the Problems) The present invention includes a world effect transistor for voltage detection, in which a voltage generated by electrostatic induction is applied to a gate electrode in correspondence with a surface potential of a specific portion of an object to be detected. A plurality of surface potential detecting elements are arranged in a straight line so that the surface potential of each of the plurality of locations on a straight line of the subject is individually detected by the individual surface potential detecting elements described above. means for converting the output signals of the plurality of surface potential detection elements described above into one line of electrical signals in the form of time-series signals arranged in series on the time axis. a storage device that stores one line of electrical signals based on the surface potential detected for a region having a predetermined constant surface potential approximately equal to the surface potential that should be generated on the detected object in correspondence with the region; Corresponds to a surface potential distribution comprising means for obtaining a difference signal between each line of electrical signals sequentially detected from the object to be detected and the electric signal of the line stored in the storage device. and a voltage detection field effect transistor whose gate electrode is given a voltage generated by electrostatic induction corresponding to the surface potential of a specific part of the object to be detected. means for linearly arranging a plurality of detection elements so that the surface potentials of individual locations on a straight line of the subject are individually detected by the individual surface potential detection elements; means for converting the output signals of the plurality of surface potential detection elements into one line of electric signals in the form of time-series signals arranged in series on the time axis; A storage device that stores one line of electrical signals based on the surface potential detected in a region having a predetermined constant surface potential approximately equal to the surface potential that should be generated on the detected object; means for obtaining a difference signal between each of the detected electric signals for one line and the electric signals for one line stored in the storage device; A detection sensitivity information storage means for storing detection sensitivity information, and detection sensitivity information of each surface potential detection element read from the detection sensitivity information storage means are used to respond to the difference signal described above. The present invention provides an apparatus for generating an electric signal corresponding to a surface potential distribution, which includes means for performing correction.

(Example) Hereinafter, with reference to the accompanying drawings, specific contents of the electric signal generating device corresponding to the surface potential distribution of the present invention will be described in detail.

1 and 4 are block diagrams showing the schematic configuration of an embodiment of an electric signal generating device corresponding to the surface potential distribution of the present invention, respectively, and FIG. 2 is a configuration of a recording medium used to implement the device of the present invention. A plan view showing an example.

3 and 5 are characteristic side views for explaining the operation.

In FIGS. 1 and 4, D is the object to be detected (recording medium) for detecting the charge image, and EDA is the seventh object.
Terminals 1 and 2 in the detection head EDA shown in FIGS. 1 and 4 are the terminals 1 and 2 shown in FIG. 2
It is displayed in correspondence with .

The output signal from the detection head EDA described above is a time-series signal in which output signals from a plurality of surface potential detection elements arranged in a straight line on the detection head EDA are arranged on the time axis. The output signal from the detection head EDA is supplied to the signal processing circuit SDA.

In the embodiment shown in FIG. 4, for the sake of simplification of the drawing,
Although the signal processing circuit SDA is simply shown as a block SDA and its specific configuration is omitted, the signal processing circuit SDA in FIG. 4 also handles the signals described in FIG. 1. A similar configuration to the processing circuit SDA is used.

In FIG. 1, vP has a predetermined constant surface potential vb approximately equal to the surface potential vb generated on the object to be detected (recording medium) D corresponding to the black part in the optical image of the object. Reference potential setting member vP having such a region
, and Vbs is the reference potential setting member vP described above.
This is a power supply for making the surface potential of the object to be a voltage value vb approximately equal to the surface potential vb generated on the object to be detected (recording medium) D corresponding to the black part in the optical image of the object as described above. .

In the embodiment shown in the first figure, a predetermined surface potential vb approximately equal to the surface potential vb generated on the object to be detected (recording medium) D corresponding to the black part in the optical image of the object is used. A reference potential setting member v having a region having
Although P is provided separately from the recording medium, FIG. 2 has the same effect as the area having a constant surface potential vb in the reference potential setting member VP shown in FIG. 1 above. A recording medium is shown in which a region VPa having a charge image is formed on the recording medium itself.

Now, the output signal from the detection head EDA described above is supplied to the movable contact C of the changeover switch SW in the signal processing circuit SDA.The changeover switch SW first switches its movable contact C to the fixed contact a side. It is said that there is
In this state, a predetermined constant surface potential approximately equal to the surface potential vb generated on the detected object (recording medium) D corresponding to the black part in the optical image of the object is set in the reference potential setting member vP described above. Either the detection head EDA detects the area with vb over one line (IH), or the surface potential vb of the area VPa configured on the recording medium in FIG. Detected object (recording medium) D corresponding to the part
The detection head EDA detects the surface potential vb of the area ■Pa, which has a charge image having a predetermined constant surface potential vb approximately equal to the surface potential vb generated in the area.
Detection is performed over a line (IH), and an output signal in the form of an analog signal obtained in that state is converted into a digital signal by an analog-to-digital converter ADC and stored in the line memory LMI.

Next, the movable contact C of the changeover switch SW is switched to the fixed contact side, and the detection head EDA detects the surface potential of the detected object line by line, and the output signal for each line is subtracted. It is supplied as a signal to the subtraction port MSUB.

The above-mentioned subtraction circuit SUB includes the above-mentioned line memory L.
Since the digital signal for one line stored in MI is converted into an analog signal by the digital-to-analog converter DAC and is supplied as the subtraction signal, the output signal from the subtraction circuit SUB is detected. This is the difference signal obtained by using the output signal detected from the body as the signal to be subtracted and the signal stored in the storage device as the subtraction signal, and this difference signal is used for the signal processing in FIGS. It is sent to the output terminal 10 of the circuit SDA.

By the way, the output signal from the signal processing circuit SDA sent to the output terminal 10 of the signal processing circuit SDA shown in FIGS.
The detection head EDA within the surface potential distribution of (recording medium D)
The signal to be subtracted is an output signal in the form of an analog signal, which is output corresponding to the detection result of the surface potential of one line (IH) detected in the subtracted signal.

That is, a plurality of surface potential detection elements each including a voltage detection field effect transistor in which a voltage generated by electrostatic induction corresponding to the surface potential of a specific portion of the object to be detected is applied to a gate electrode. arranged in a straight line,
The surface potentials of individual locations on a straight line of the subject are individually detected by the individual surface potential detection elements described above, and the output signals of the plurality of surface potential detection elements described above are detected on the time axis. An output signal in the form of an analog signal is output in correspondence with the detection result of the surface potential of one line (IH) detected by the detection head EDA, which is configured to be output as a time series signal arranged in series. is the signal to be subtracted, and the signal stored in the storage device (line memory LMI) described above, that is, the surface generated on the detected object (recording medium) D corresponding to the black part in the optical image of the object. A region having a predetermined constant surface potential vb, which is approximately equal to the potential vb, is detected over one line (IH) by the detection head EDA, and an output signal in the form of an analog signal obtained in that state is converted into an analog signal.・Since it is a difference signal obtained by subtracting a signal that has been converted to a digital signal by the digital converter ADC and stored in the line memory LMI and then converted to an analog signal by the digital-to-analog converter DAC, Even if there are variations in sensitivity among the plurality of surface potential detection elements in the electric signal generating device (detection head EDA) that corresponds to the surface potential distribution used to detect the surface charge of the object to be detected, the Figure 1 and 4
Since the signal level of the signal corresponding to the black of the image in the output signal from the signal processing circuit SDA in the figure is the same at the voltage vb shown on the horizontal axis in FIG.
In the range from white to black of the image in the output signal from the signal processing circuit SDA in FIGS. 1 and 4, an electric signal is generated corresponding to the surface potential distribution used for detecting the surface charge of the detected object. The influence of variations in the sensitivity of each of the multiple surface potential detection elements in the device is significantly reduced compared to FIG. 12, which shows the characteristics of the conventional device explained with reference to FIG. 10. I understand that.

The output signal sent from the signal processing circuit SDA to the output terminal 10 in FIGS. 1 and 4 is limited to the range from white to black of the image in the output signal from the signal processing circuit SDA, as described above. Referring to FIG. 10, the influence of variations in the sensitivity of each of the plurality of surface potential detection elements in the electric signal generating device that corresponds to the surface potential distribution used to detect the surface charge of the object to be detected is shown in FIG. Although the characteristics of the conventional device described above are significantly reduced compared to FIG. The signal is a state in which variations in sensitivity of each of the plurality of surface potential detection elements remain as they are.

FIG. 4 shows the variation in signals present in the signals output from the signal processing circuit SDA, that is, the generation of electric signals corresponding to the surface potential distribution used for detecting the surface charge of the object to be detected. This is a block diagram of a device configured to correct variations in sensitivity of each of a plurality of surface potential detection elements in the device. In the embodiment circuit shown in the fourth figure, MUL is a multiplier, and LM2 is a sensitivity correction circuit. a memory for storing coefficients of the multiplier M;
In the UL, by multiplying the output signal from the signal processing circuit SDA by the sensitivity correction coefficient read from the memory LM2, an electric potential corresponding to the surface potential distribution used for detecting the surface charge of the object to be detected is obtained. An output signal with uniform sensitivity of each of the plurality of surface potential detection elements in the signal generation device is sent from the multiplier MUL to the output terminal 11.
It can be supplied to

The sensitivity correction coefficients stored in the memory LM2 described above are used to calculate a plurality of sensitivity correction coefficients when the surface potential of an object to be detected having a known constant surface potential is detected by an electric signal generator corresponding to the surface potential distribution. It can be determined from the output voltage obtained from each of the surface potential detection elements. α in Figure 5.

Kβ, and γ are examples of the aforementioned sensitivity correction coefficients.

(Effects of the Invention) As is clear from the detailed explanation above, the electric signal generation device corresponding to the surface potential distribution of the present invention can generate electrostatic signals corresponding to the surface potential of a specific part of the object to be detected. A plurality of surface potential detection elements each including a field effect transistor for voltage detection, in which a voltage generated by induction is applied to a gate electrode, are arranged in a straight line to detect individual points on a straight line of the subject. Means for individually detecting the surface potential at each location by the individual surface potential detection elements described above, and a time-series signal form in which the output signals of the plurality of surface potential detection elements described above are arranged in series on the time axis. 1
Detection of a region having a predetermined constant surface potential approximately equal to the surface potential that should be generated on the detected object corresponding to a black part in the optical image of the detected object. a storage device that stores one line of electrical signals based on the detected surface potential; one line of electrical signals sequentially detected from the detected object; and one line of electrical signals stored in the storage device. A generator for generating an electric signal corresponding to the surface potential distribution, comprising means for obtaining a difference signal from the electric signal, and a gate for generating a voltage generated by electrostatic induction corresponding to the surface potential of a specific part of the object to be detected. By linearly arranging a plurality of surface potential detection elements including field effect transistors for detecting pressure, which are attached to the electrodes, the surface potential detection elements at individual locations on a straight line of the subject are detected. means for individually detecting potentials by the individual surface potential detection elements described above, and one line in the form of a time-series signal in which the output signals of the plurality of surface potential detection elements described above are arranged in series on the time axis. and a means for converting the area into an electric signal of 1000 nm, and detecting a region having a predetermined constant surface potential approximately equal to the surface potential that should be generated on the detected object corresponding to the black part in the optical image of the object. A storage device that stores one line of electrical signals based on surface potentials detected, one line of electrical signals sequentially detected from the object to be detected, and one line of electrical signals stored in the storage device. means for obtaining a difference signal, a detection sensitivity information storage means for storing detection sensitivity information of each of the plurality of surface potential detection elements, and reading from the detection sensitivity information storage means. and means for correcting the above-mentioned difference signal using information on the detection sensitivity of each surface potential detection element, the present invention In an electric signal generating device that corresponds to the surface potential distribution of , the detection head ED is
An output signal in the form of an analog signal output corresponding to the detection result of the surface potential of one line (IH) detected at A is made to correspond to the subtracted signal, that is, the surface potential of a specific part of the detected object. A plurality of surface potential detection elements each including a field effect transistor for voltage detection, in which a voltage generated by electrostatic induction is applied to the electrode, are arranged in a straight line, and The surface potential of each of the plurality of locations is individually detected by the above-mentioned individual surface potential detection elements, and the output signals of the above-mentioned plurality of surface potential detection 'Mt are serially transmitted on the time axis. An output signal in the form of an analog signal is output in correspondence with the detection result of the surface potential for one line (I-I) detected by the detection head EDA, which is configured to be able to output it in the form of a time-series signal arranged in line. As the signal to be subtracted,
Also, the signal stored in the above-mentioned storage device (line memory LM1) is approximately equal to the surface potential vb generated on the detected object (recording medium) D corresponding to the black part in the optical image of the object. A region having a predetermined constant surface potential vb is detected over one line (IH) by the detection head EDA, and an output signal in the form of an analog signal obtained in that state is detected by an analog-to-digital converter ADC. Convert it to a digital signal and send it to the line.
The output signal is a difference signal obtained by subtracting the signal stored in the memory LMI and converted into an analog signal by the digital-to-analog converter DAC, so the output signal can be used to detect the surface charge of the object to be detected. Even if there are variations in sensitivity among the multiple surface potential detection elements in the electrical signal generation device (detection head EDA) that corresponds to the surface potential distribution used in Since the signal level of the signal is the same at voltage vb, in the range from white to black of the image in the output signal, an electric signal is generated that corresponds to the surface potential distribution used to detect the surface charge of the object to be detected. The influence of variations in the sensitivity of each of the multiple surface potential detection elements in the device is significantly reduced compared to conventional devices, and the surface potential distribution used to detect the surface charge of the object to be detected is A coefficient for correcting the sensitivity of each of the plurality of surface potential detection elements in the electric signal generating device corresponding to the electric signal is stored in a memory, and the above-mentioned output signal is corrected using the coefficient for sensitivity correction. As a result, it is possible to obtain an output signal without variations in sensitivity of each of the plurality of surface potential detection elements in the electric signal generating device that corresponds to the surface potential distribution used for detecting the surface charge of the object to be detected. Therefore, the problems of the conventional devices described above can be satisfactorily solved by the electric signal generating device corresponding to the surface potential distribution of the present invention.

[Brief explanation of the drawing]

1 and 4 are block diagrams showing the schematic configuration of an embodiment of an electric signal generating device corresponding to the surface potential distribution of the present invention, respectively, and FIG. 2 is a configuration of a recording medium used to implement the device of the present invention. A plan view showing an example, FIGS. 3 and 5, and FIG. 12 are characteristic side views for explaining the operation, FIG. 6 is a block diagram of the previously proposed recording device, and FIG. 7 is a surface potential distribution of the previously proposed recording device. A block diagram showing a schematic configuration of a corresponding electric signal generating device, FIG. 8 is a perspective view showing an example of the configuration of the detection head, FIG. 9 is a waveform side view for explaining the operation of the detection head, and FIG. 10 is an already proposed one. FIG. 11 is a block diagram showing a schematic configuration of an embodiment of an electric signal generating device corresponding to the surface potential distribution of FIG. 1, and FIG. 11 is a waveform diagram for explaining problems. 1.2 Terminal in detection head EDA, 3... Polarizer, 4... Optical modulator, 5... Information signal source targeted for recording, 6... Analyzer, 8...・Laser light source,
7.9...Lens, 10...Output terminal of signal processing circuit SDA, IL...Insulating layer functioning as a charge retention layer, E...Electrode, WA...Target for recording A recording system configured so that a laser beam whose intensity is modulated by an information signal can be emitted from a lens 7. Etw...transparent electrode, PCE...photoconductor layer, E
D.I. ED2. ED3 to EDn...Minute voltage detection electrodes arranged in a straight line at even intervals with minute mutual intervals, Q
I, Q 2. Q 3- Q n- connection line, DPI
, DF2°DF3 to DFn...field effect transistors for voltage detection, S Fl, S F2. SF3~SF
N-switching field effect transistor, RQ...
・Load resistance, SR...shift register, EDA・
...Detection head, D...Object to be detected (recording medium) that is the object of charge image detection, SDA...Signal processing circuit, v
P...An area having a predetermined constant surface potential vb approximately equal to the surface potential vb generated on the object to be detected (recording medium) D corresponding to the black part in the optical image of the object. The surface potential of the reference potential setting member VP, V b s . A voltage value v approximately equal to vb
V P a...area configured on the recording medium itself to have a constant surface potential vb, SW...changeover switch, ADC...analog-to-digital converter, DAC... ...Digital-to-analog converter,
LMI...Line memory, LM2...Memory, S
UB...subtraction circuit, MUL...multiplier, patent applicant: Victor Japan Co., Ltd.

Claims (1)

[Claims] 1. A surface potential comprising a voltage detection field effect transistor whose gate electrode is given a voltage generated by electrostatic induction corresponding to the surface potential of a specific portion of the object to be detected. means for linearly arranging a plurality of detection elements so that the surface potentials of individual locations on a straight line of the subject are individually detected by the individual surface potential detection elements; means for converting the output signals of the plurality of surface potential detection elements into one line of electric signals in the form of time-series signals arranged in series on the time axis; 1 based on the surface potential detected in a region having a predetermined constant surface potential approximately equal to the surface potential that should occur on the detection object.
A storage device that stores electrical signals for a line, and a difference signal between each electrical signal for one line sequentially detected from the object to be detected and the electrical signal for one line stored in the storage device. a voltage detection device 2 for generating an electric signal corresponding to a surface potential distribution, comprising means for obtaining a surface potential distribution; By arranging a plurality of surface potential detection elements including field effect transistors in a straight line, the surface potential of each of the plurality of locations on a straight line of the subject is determined by the above-mentioned individual surface potential detection elements. means for converting the output signals of the plurality of surface potential detection elements described above into one line of electric signals in the form of time-series signals arranged in series on the time axis; 1 based on the surface potential detected in a region having a predetermined constant surface potential approximately equal to the surface potential that should be generated on the detected object corresponding to the black part in the optical image of the object.
A storage device that stores electrical signals for a line, and a difference signal between each electrical signal for one line sequentially detected from the object to be detected and the electrical signal for one line stored in the storage device. a detection sensitivity information storage means for storing detection sensitivity information of each of the plurality of surface potential detection elements; and a detection sensitivity information storage means for storing detection sensitivity information of each of the plurality of surface potential detection elements; A device for generating an electric signal corresponding to a surface potential distribution, comprising means for correcting the above-mentioned difference signal using information on the detection sensitivity of the potential detection element.