JPS597109B2 - Kasaneki Kokuuchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overlapping recording device that records a plurality of pieces of information in an overlapping manner on the same recording medium.

Various recording devices are known for recording the output of electronic computers, etc., but since such conventional recording devices only output the data from the computer as is, they do not record other data (for example, framing, etc.). If it is desired to output the data in addition to the other data, it is necessary to apply the other data once to the computer and configure the computer so that the plurality of data are sent out as output from the computer. However, since it is complicated to operate the electronic computer itself every time other data is superimposed, it is preferable that overlapping recording can be performed using a simpler method.

The present invention uses document information obtained by scanning optically formed information on the document, and an electronic computer (not necessarily a computer, but may be a facsimile transmitter, etc.), in short, the recording signal is electrically transmitted. By configuring the structure so that data signals from any source (any signal that is sent out as a binary signal is fine) are recorded in an overlapping manner, the information to be superimposed on the data signal is simply formed optically, and overlapping recording is possible. It is constructed in such a way that it can be done.

Before explaining the present invention in detail, first, a copying apparatus that constitutes the main part thereof will be explained.

In FIG. 1, reference numeral 11 indicates a laser generator which is a light generating means, and a beam 12 from this laser generator 11 is transmitted by an optical modulator 13 according to the voltage applied to the modulator 13. After modulation, this beam 12' is focused by a condenser lens IT and irradiated onto a beam splitter 14 to be separated into two beams 15 and 16.
is irradiated onto the material 18 having the image, which is arranged on the condensing surface of the lens IT. Therefore, from this material 18, it is possible to obtain reflected light 19 corresponding to the image on the material, but this light 19 is converted into an electrical signal by the photoelectric conversion element 20 and then applied to the modulation signal forming circuit 21. do.

This modulation signal forming circuit 21 forms a modulation signal to be applied to the modulator 13, and this modulation signal is such that the signal detected by the photoelectric conversion element 20 is constant with respect to a predetermined reference level. This is a signal that controls the modulator so that the level of . Therefore, if the image on the document is black with little light reflection, a large amount of the beam will reach the modulator 13.
If the image on the material is white with a lot of light reflection, the beam emitted from the modulator 13 is controlled so that a small amount of the beam is emitted from the modulator 13, so that the beam emitted from the modulator 13 has image information. Therefore, the beam 15 split by the beam splitter 15 can be used as it is as a beam for recording information. To further explain the photoelectric conversion element 20 and the modulation signal forming circuit 21 with reference to FIG. The amplified signal is applied to one input terminal 25 of the operational amplifier 24.

Reference numeral 26 indicates a normal voltage regulator which has voltage selection means therein and can derive a desired voltage by switching the means. It is applied to the other input terminal 27 of the operational amplifier 24.

Therefore, when the signal level to the input terminal 25 becomes low, a high level signal is derived from the output terminal 28, and when the signal level to the input terminal 25 becomes high, a low level signal is derived. Therefore, if the modulator 13 is configured so that when the modulation signal level is high, the beam 12 is easily transmitted, and when the modulation signal level is low, it is difficult to transmit, then when there is a lot of reflected light, the beam 12/ can be weakened. When the anti-reflection light is small, the beam 12' is controlled to be weak, and the output signal from the amplifier 23 is controlled to have a constant difference from the output voltage from the constant voltage device.

(However, if there is a lot of reflected light, the level of the output signal of the amplifier 23 will be high, and if there is little reflected light, the level of the output signal of the amplifier 23 will be small.) Therefore, the level of the output signal from the amplifier 23 is always maintained at a constant level, and therefore the beam 12' is intensity-modulated in the modulator 13 in accordance with the image. Figure 3 shows the first,
Fig. 2 shows the signal waveforms at various parts when the beam 12' is deflected to scan over the material shown in Fig. 3a. As shown in the figure, the beam spot 32 is moved in the direction of the arrow p following the dotted line on the material having black parts 30 and 31 on a white background.
When scanning is performed, the modulator is controlled so that the output of the photoelectric conversion element is constant as explained in Figs.
In the portion corresponding to white, a weak beam is derived from the modulator, and in this way, the output of the photoelectric conversion element becomes approximately constant as shown in c.

As described above, since the beam from the modulator contains image information, a copying apparatus can be formed by irradiating the recording medium with the beam 15.

FIG. 4 shows the copying apparatus as described above in more detail. A laser beam emitted from a laser oscillator 34 is guided to an input aperture of a modulator 36 via a reflecting mirror 35. The reflecting mirror 35 is inserted to bend the optical path in order to reduce the space of the apparatus, and can be removed if unnecessary. For the modulator 36, an acousto-optic modulation element using a known acousto-optic effect or an electro-optic element using an electro-optic effect is used.

At the modulator 36, the laser beam is modulated in intensity according to the input signal to the modulator 36.

Furthermore, when the laser oscillator 34 is a semiconductor laser, a gas laser, etc., which is capable of current modulation, or an internal modulation type laser in which a modulation element is incorporated in the oscillation optical path, , the modulator 36 is omitted and the beam is guided directly to the beam expander 37. After the laser beam from the modulator 36 passes through the reflecting mirror 35, the beam diameter is expanded by the beam expander 37 while remaining a parallel beam.

Furthermore, the laser beam whose beam diameter has been expanded is incident on a polyhedral rotating mirror 38 having a plurality of mirror surfaces. The polyhedral rotating mirror 38 is mounted on a shaft supported by a high-precision bearing (for example, an air bearing) and is driven by a motor 39 that rotates at a constant speed (for example, a hysteresis synchronous motor, a DC servo motor), so that the beam expander The emitted beam is swept horizontally, and is further imaged as a spot on the photosensitive drum 41 by an imaging lens (or condensing lens) 40. When collimated light is imaged into a spot by an imaging lens, the minimum diameter of the spot Dmin is, however, f
; focal length λ of the imaging lens; wavelength A of the light used; given by the entrance aperture of the imaging lens; if f and λ are constant, a smaller spot diameter Dnlin can be obtained by increasing A;

The beam expander 37 mentioned above is used to provide this effect. Therefore, if the required Dmin can be obtained by the beam diameter of the laser oscillator, the beam expander 37 is omitted. A beam splitter 42 having a length that covers the entire width of the beam sweep is arranged between the photosensitive drum 41 and the imaging lens 40.

Therefore, a portion 43 of the beam from the rotating polygon mirror 38 is irradiated onto the photosensitive drum 41, and the other portion 44 is irradiated onto a transparent glass 46 for placing a document on a document table 45. Therefore, by rotating the rotating polygon mirror 39, the beam 44
It moves as shown by the application Q on the glass 46. Reference numeral 47 denotes a light receiving element that receives reflected light generated by irradiating the beam 44 onto the original when the original is placed on the glass 46 and converts it into an electrical signal.

Since the document table 45 is moved at a constant speed on the rail 48 in the direction of arrow P by a drive device (not shown), the glass 4
6, and while rotating the rotating polygon mirror 39,
By moving the document table 45 in the direction of arrow P, the entire surface of the document can be scanned.

At this time, it goes without saying that the photosensitive drum 41, which has a photosensitive layer provided on its entire surface, rotates in synchronization with the movement of the document table 45.

Since the light receiving element 46 and the modulator 36 correspond to the photoelectric conversion element 20 and the optical modulator 13 in FIGS. 1 and 2, respectively, the output of the light receiving element 46 causes the By controlling the modulator 36 with a circuit such as
The same information as the material on the document table 45 is recorded on the photosensitive drum 41.

Thereafter, the photosensitive drum 41 is processed by an electrophotographic processing process to visualize the recorded information, and this image is transferred and fixed onto plain paper 47 and output as a hard copy.

Next, the printing section will be explained with reference to FIG. 5 as well.

As an example of the electrophotographic process applied to this embodiment, a photosensitive plate whose basic constituents are a conductive support, a photoconductive layer, and an insulating layer, as described in Japanese Patent Publication No. 42-23910 of the present applicant. The surface of the insulating layer of No. 49 is uniformly charged positively or negatively by a first corona charger, and a charge having a polarity opposite to the charged polarity is created at the interface between the photoconductive layer and the insulating layer or inside the photoconductive layer. is captured, and then the surface of the charged insulating layer is irradiated with the laser beam 43, and at the same time,
An alternating current corona discharge is applied by an alternating current corona discharger 51 to form a pattern on the surface of the insulating layer due to a difference in surface potential that occurs according to the light and dark pattern of the laser beam 43, so that the entire surface of the insulating layer is uniformly covered. After exposing to light and forming a high-contrast electrostatic image on the insulating surface, the electrostatic image is developed and visualized using a developing device 52 using a developer mainly composed of charged colored particles, and then the electrostatic image is visualized on a sheet of paper or the like. Transfer material 53
The visible image is transferred to the image forming apparatus using an internal or external electric field, and then the transferred image is fixed by a fixing means 54 such as an infrared lamp or a hot plate to obtain an electrophotographic print image. After cleaning, the surface of the insulating layer is cleaned by a cleaning device 5.
5 to remove remaining charged particles,
The photosensitive plate 49 is used repeatedly. next,
In the embodiments described so far, the phenomenon that occurs on the photoreceptor when the surface of the insulating layer of the photoreceptor, which has been uniformly charged in advance, is attenuated by alternating current corona discharge to attenuate the charge on the surface of the insulating layer and at the same time is irradiated with laser light. This will be further explained in detail with reference to FIG.

FIG. 6 shows the state of change in surface potential on the surface of the insulating layer of the photoreceptor.

FIG. 6a shows a case where the frequency of the alternating current of the alternating current corona discharge is relatively low.

At this time, the potential of the surface of the insulating layer during AC neutralization can take an intermediate value between the curve shown by the solid line and the curve shown by the dotted line due to the difference in the phase of the AC voltage. However, the laser beam is irradiated for a very short time, for example, 150 nanoseconds in this embodiment, for a specific location on the photoreceptor. Therefore, due to the difference in the potential of the surface of the insulating layer when the laser light is irradiated, the potential of the electrostatic image obtained after the entire surface is exposed may vary, even though the amount of laser light irradiation is constant.
It won't be constant. Therefore, unevenness synchronized with the frequency of the alternating current occurs in the developed image. In the case of application to a copying machine or the like, this phenomenon does not appear because the exposure is performed over the entire AC static elimination area, so the influence of the phase is averaged out. In order to eliminate this phenomenon of unevenness, when the frequency of AC static elimination is increased (Fig. 6b), the amplitude of fluctuations in the surface potential of the insulating layer that are synchronized with the AC frequency remains unchanged while the overall static elimination time remains unchanged. Therefore, the potential difference on the surface of the insulating layer during laser beam irradiation is reduced, and the unevenness of the developed image becomes practically negligible.

This is explained by the equivalent circuit shown in FIG. In Fig. 7, E is the voltage applied to the discharge electrode of the AC corona discharger, Rc is the resistance when the corona current flows between the discharge electrode and the photoreceptor, and Cp is the photoreceptor regarded as a capacitance-only load. It shows the capacitance of the photoreceptor at the time. At this time, the potential on the surface of the insulating layer immediately before entering AC static elimination due to primary charging is o, and the voltage applied to the AC corona discharge electrode is E = EOcOs (
Wt+θ), the potential p on the surface of the insulating layer during AC static elimination is expressed as:

From equation (4), the static elimination time is given by the second term on the right side, and its time constant τ is CpRc.

Further, the amplitude of the fluctuation due to the frequency of AC corona discharge is given by F7; Fconico T-7 from the first term.

Also, from Figure 8, the AC static elimination time tsu is v; drum peripheral speed 1: Given by the width of the static elimination area.

Furthermore, the amount corresponding to Cp in the equivalent circuit of FIG. 7 is proportional to the surface area of the photoreceptor that passes through the static elimination area per unit time.

A: Proportionality constant Here, assuming that static electricity is sufficiently removed under the conditions of CP = CPl, Rc = Rcl, and V = V1, the time constant of static electricity removal in equation (4) is then equal to the AC discharge frequency. The amplitude WO of the fluctuation caused by WO is this amplitude W.

is large enough to cause density unevenness in the developed image. By setting W-W1 (W1>WO), we get
It is assumed that W1 is sufficiently small so as not to cause the density unevenness.

In this way, by changing the frequency of AC corona discharge, the density unevenness can be removed without changing the static elimination time.

Next, assuming that the circumferential speed of the drum is v-αV1-V2, the charge removal time must be τ.Therefore, the charge removal time must be τ2−−.

α Therefore, it can be seen that it is necessary to use a static elimination time constant (alternative) formula in order to sufficiently eliminate static electricity within Td2.

In practice, changing Rc is achieved by changing the distance between the discharge electrode wire and the photoreceptor.

At this time, the amplitude W2 of the fluctuation due to the frequency of the AC corona discharge is as follows, and the condition for W2 so that W2=W1 is determined is W2cp, Rc2=WlcplRel From the formula, it is found that the unevenness of the image does not occur. It is necessary to apply an AC corona frequency greater than a certain value, and that value is proportional to the circumferential speed of the drum.

In this example, the peripheral speed v of the drum is 30 (XIL/
Sec, width of static elimination area 3 degrees x 30? , the capacitance C of the photosensitive plate is 5PF/Cd, the current for AC static elimination is 75μArms,
Voltage, frequency f is 1KHz, Seiden contrast is about 50
It was carried out at 0V. The development was carried out using liquid development and reversal development. From these experiments, the frequency f of AC static elimination is f=2
Under the condition of πω v; Cm/Sec, the unevenness of the image could be removed.

That is, this means that the pitch due to the frequency of AC corona discharge on the photosensitive drum is 0.3 mm. Therefore, the effect of the above formula (self) is achieved under more general conditions. P is the capacitance of the photoreceptor, the width of the static elimination area,
It is a constant determined by the development conditions, etc., and in the above example, it is 0.0.
It was 3.

As still another example, the present applicant's Japanese Patent Publication No. 42-19
An electrophotographic electrostatic image forming process such as that described in Japanese Patent No. 748 is applied.

That is, a photosensitive plate is used whose basic components are a conductive support, a photoconductive layer, and an insulating layer, and the insulating surface is uniformly positively or negatively charged in advance by a first corona discharge, and the photoconductive layer and A charge having a polarity opposite to the charged polarity is captured on the surface of the insulating layer or inside the photoconductive layer, and an alternating current corona discharge is applied to the charged surface to attenuate the charge on the surface of the insulating layer. The process is the same as the first embodiment except for the process of irradiating the laser beam as a signal, forming an electrostatic image on the surface of the insulating layer according to the brightness of the laser beam, and then developing the electrostatic image. . The photoreceptor and laser oscillator used in the first and second embodiments were as follows.

Combination A (a) Laser oscillator He-Ne gas laser wavelength 632.8 mμ (b) Photoreceptor Copper activated cadmium oxide 90t and 10
A photosensitive material obtained by adding vinyl chloride f and mixing with a small amount of thinner is applied to a thickness of about 70 μm on an aluminum foil having a thickness of about 100 μm by a spray method.

Next, a Mylar film having a thickness of about 25 μm was closely laminated on the surface of this photoconductive coating using an adhesive to obtain a photosensitive plate, and the photosensitive member was further wound around a drum made of aluminum. In the case of this photoreceptor, the charge polarity of the first charge is positive. Combination B (a) Laser oscillator: He-Cd laser, wavelength 441.6 mμ (b) A Te layer with a thickness of about 1 μm is vacuum-deposited on the photoreceptor aluminum base, and a layer of Se containing 5% Tel is further deposited with a thickness of about 90 μm. In the case of this photoreceptor, the first charging polarity is negative.

Furthermore, various laser light sources currently announced or to be announced in the future may also be applied to the first and second latent image forming processes.

It is important to devise a combination of photoreceptors whose spectral sensitivity characteristics match the wavelength of each laser. As a laser, Ar gas laser Kr〃 Ar+Kr〃 (Visible) semiconductor laser Dye laser Double wavelength conversion of infrared laser light using a nonlinear crystal (YAG laser, semiconductor laser), etc. can be used.

In the present invention, such a copying apparatus is further provided with a beam detector as shown at 56 in FIG. Become.

The beam detector 56 detects the position of the swept laser beam 43, and uses this detection signal to start the input signal to the modulator 36 for outputting information from a computer or the like onto the photosensitive drum. Decide on timing. As a result, it is possible to greatly reduce the synchronization deviation of horizontal signals due to errors in the division accuracy of each reflective surface of the polyhedral rotating mirror 38 and uneven rotation, and it is possible to obtain a high-quality image. The tolerance range of accuracy required for the drive motor 39 is increased, and the drive motor 39 can be manufactured at a lower cost. In the copying apparatus formed in this manner, the present invention records data signals sent in the form of electrical signals from an electronic computer etc. on one recording medium by superimposing them on information obtained from the material. In order to achieve this object, the present invention changes the driving form of an optical modulator in accordance with a binary signal from an electronic computer.

To explain in more detail with reference to FIG. 9, (however, the parts with the same numbers as those in FIG. 2 are composed of the same members), FIG. 9 has two levels like a binary signal, It also shows a device for recording data signals sent in series in a superimposed manner with information obtained from the material 18.

Reference numeral 60 indicates an application terminal for applying a binary data signal as described above, and the binary data signal applied from this terminal is applied to a switch 61 to control this switch 61.

That is, this switch has a contact piece 62 and contacts 63a and 63b, but when a signal indicating black, for example "1", is applied from the terminal 60, the contact piece 62 and the contact 63b are connected, and the switch outputs white. When a signal indicating, for example, "0" is applied, the contact piece 62 and the contact point 63a are connected. A contact 63a of the switch 61 is connected to the output of the operational amplifier 24, a contact 63b is connected to a constant voltage source 64, and a contact piece 62 is connected to the optical modulator 13.

Therefore, the constant voltage from the constant voltage source 64 is made equal to the voltage derived from the output terminal 28 when the beam 16 is irradiated onto the black area on the material 18 with the contact piece 62 and the contact 63a connected. By placing the contact piece 62 and the contact point 63
By connecting b, the beam 15 can perform the exposure necessary to draw black on a photosensitive drum (not shown). In other words, when a signal corresponding to black arrives from the terminal 60, a constant voltage determined by the constant voltage source 64 is applied to the optical receiver 13 by forcibly connecting the contact piece 62 and the contact point 63b. In other cases, the contact piece 62 and the contact point 63a are connected to perform control as explained in FIG. 2.

Although omitted, in the recording apparatus shown in FIGS. 1, 2, and 9, the beam emitted from the optical modulator 13 is repeatedly deflected in one direction (x direction), and the material is By configuring the beam to move in a direction (Y direction) perpendicular to the deflection of the beam on the material, the entire area on the material is scanned by the beam. As mentioned above, signals from a computer or the like are applied to the terminal 60. Here, the data signal forming device will be briefly explained with reference to FIG. 10.

In FIG. 9, information from an electronic computer applied to a terminal 60 is input in a predetermined format to an interface circuit 66 of the apparatus, either directly or via a storage medium such as a magnetic tape or magnetic dataster. computer jmo
Various instructions from V are sent to the instruction execution circuit 6
7 and is decrypted and executed. Data is stored in data memory 68 in fixed amounts. In the case of character information, the data format is given as a binary code, and in the case of graphic information, it is data in units of pixels that make up the figure, or data of lines that make up the figure (so-called vector data). ). These modes are specified in advance of the data, and the instruction execution circuit 67
The data memory 68 and line data generator 69 are controlled to process data according to the designated mode. A line data generator 69 generates final data for one scan line. In other words, when data is given as a character code, the character generator 7
The character pattern is read from 0 and the character pattern for one line is lined up and buffered, or the character code for one line is buffered and the character pattern is sequentially read from the character generator 70 to modulate the laser beam for one scan line. Create data sequentially.

Even when the data is graphic information, the data is converted into scan line data to create data for sequentially modulating the laser beam for one line scan. Data for one scan line is alternately inputted to line buffers 71 and 72, which are comprised of shift registers or the like, each having a number of bits equal to the number of pixels for one scan line, under the control of a buffer switch control circuit.

Furthermore, line buffer 71 and line buffer 72
The data is sequentially read out bit by bit for one scan line using the beam detection signal from the beam detector 73 as a trigger signal, and is applied to the switch 61 shown in FIG.

While one reflective surface scans the photosensitive drum along a line perpendicular to the rotational direction, data for one scan line stored in the line buffer is applied to the switch 61.

Data signals are read out alternately from line buffers 71 and 72 under the control of a buffer switch control circuit 76. That is, when reading from one line buffer, writing is performed to the other line buffer. With this method, the polyhedral rotating mirror sweeps over the photosensitive drum.
When the spacing from one reflective surface to the next is very short, data can be applied to the modulator without fail. 1
Before scanning a scan line, the photosensitive drum continues to rotate at a constant speed and moves by an appropriate scan line interval.

As described above, according to the present invention, it is possible to perform overlapping recording with an extremely simple configuration, but the present invention is limited to application only to the copying apparatus shown in FIGS. 1 and 2. Rather, it can be applied as is to a copying apparatus as shown in FIG.

That is, as shown in FIG. 11a, the beam transmitted through the material 18 may be detected by the photoelectric conversion element 20, or the condenser lens 17 may be placed between the beam splitter 14 and the material 18. In some cases, it is even possible to omit such a condensing lens altogether.

Furthermore, as shown in FIGS. 11B and 11C, the beam splitter 11 is
The material 18 may be irradiated with the beam that has passed through the photoelectric conversion element 20 as shown in b in this case.
The more reflected light may be detected, or the more transmitted light may be detected.

Also in the embodiments B and c, the condenser lens 17 may be placed between the optical modulator 13 and the beam splitter 14 or between the beam splitter 14 and the material 18, or may be omitted. .

In the embodiments shown in FIGS. 1 and 11A, b, and c, when a laser generator 11 whose generated beam intensity can be controlled by a control signal is used, in other words, a laser generator with a modulation function is used. When a modulator (for example, a current modulated laser) is used, the output of the modulated signal forming circuit 21 can be applied directly to the laser generator, thereby eliminating the optical modulator.

[Brief explanation of the drawing]

FIG. 1 is a program diagram showing an information converting device according to the present invention, FIG. 2 is a program diagram showing the information converting device according to the present invention in more detail, and FIGS. 3A, b, and c show each part of FIG. FIGS. 4 and 5 are explanatory diagrams showing the operation, and FIGS.
Figures A and b are waveform diagrams for explaining AC static elimination, Figures 7 and 8 are equivalent circuits and enlarged explanatory diagrams when performing AC static elimination on a photoreceptor, and Figure 9 is a program diagram showing the present invention. , FIG. 10 is a data signal forming device, and FIGS. 11A, b, and c are block diagrams showing a recording device to which the present invention can be applied.

Claims (1)

[Claims] 1. Modulated light generation means for generating modulated light in response to an applied modulation signal, splitting means for dividing the output light from the modulated light generation means into a plurality of light beams, and one of the divided light beams. Controlling the irradiation means for irradiating onto the material, the detection means for detecting reflected or transmitted light of the luminous flux from the material, and the modulated light generation means so as to keep the detection output of the detection means constant with respect to a certain reference level. control means for controlling the modulated light generating means, when an information signal having binary information to be recorded in superimposition with the material has a signal value of a black information part of the superimposed information, a control means for controlling the modulated light generating means to perform modulation corresponding to the black part of the material; An overlapping recording apparatus comprising: an application means for applying a device input signal; and an irradiation means for irradiating the other divided light flux onto a recording medium.