JPH0248965A - Optical recording head and optical printing device using the same - Google Patents

Abstract

PURPOSE:To print a multi gradation image at high speed without complicating a signal processing system by a method wherein a plurality of electroluminescence elements corresponding to recording parts are selectively actuated to be emitted according to image density information of each recording part. CONSTITUTION:For a head proper 2, a plurality of side emitting electroluminescence elements 4a to 4c composing a recording part K for each pixel are provided, and emission is selectively actuated according to image density by an image control means 5. Intensity of radiation light from a light radiation opening 3 is varied at multi-stages according to the image density, and irradiates a photosensitive material 1 to form a latent image. In that case, fatigue degree of the photosensitive material 1 is detected by a fatigue detection means 6. An emission intensity regulation means 7 gives fatigue degree information to the image control means 5, varies emission intensity from each EL element 4a to 4c, and keeps a latent image electric potential corresponding to each image density information, i.e. development density almost constant. Thus, a multi gradation image can be printed at high speed without complicating a signal processing system.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical recording head using an electroluminescent element as a light emitting source and an optical printer using the same. The present invention relates to an optical recording head and an optical printer using the same.

[Prior Art] Conventionally, this type of optical recording head was disclosed in Japanese Patent Application Laid-open No. 62-106.
There are those described in No. 479 and No. 62-108073.

As shown in FIG. 18, this includes a head main body 101 in which so-called planar light-emitting electroluminescent elements (hereinafter abbreviated as EL elements) 103 are arranged on a glass substrate 102 for each pixel as a recording section. The planar light emitting type EL element 103 includes the glass l (a transparent electrode 104 made of Hiden glass or the like on the root 102, a light emitting! 10
5 and a back electrode 106 made of metal with good reflectance are laminated via an insulator 1107, and an AC control voltage according to image information is applied between the transparent electrode 104 and the back electrode 106. is used. In addition, the sign @10
8 is a moisture-proof protective cover that covers the El element 103.

In this type of optical recording head, when an AC control voltage is applied to both power lines 104 and 106 in the recording section, the light emitting layer 105 emits light and the light is transmitted to the transparent electrode 104.
and is irradiated to the outside through the glass substrate 102. For this reason, the photoreceptor 10 is placed in the light irradiation direction of this type of optical recording head.
9, and the optical image information from the optical recording head is imaged onto the photoreceptor 109 via the convergent light transmission body 110, it becomes possible to construct an optical printer.

[Problems to be Solved by the Invention] Incidentally, in this type of optical recording head, the substantial light emitting area where the picture electrodes 104 and 106 of the light emitting layer 105 of the EL element 103 are superimposed and the recording medium 109 If the above pixel size is set equal, image exposure can be performed on the photoreceptor 109 with one light irradiation of the optical recording head, but the planar emitting type EL element 103 Since the light irradiated from the photoconductor 1 is inevitably diffused,
The intensity of the irradiated light guided to 09(11) is reduced, and the exposure time on the photoreceptor 109 is accordingly increased, resulting in a problem that high-speed printing cannot be met.

As a means to solve such problems, for example, an optical recording head as shown in FIG. 19 has been provided (SID
86 DIGES, pages 210-272).

This is a side-light type ELM element 1 mounted on an insulating substrate 112.
The head body 1 is arranged for each pixel, with 13 as the 8th part.
11, the above-mentioned side-emitting type E L element 11
3, as shown in FIG. 20, a metal base electrode 114 with good reflectance is provided on the insulating substrate 112.
, ZnS:Mn.

ZnS: A light emitting layer 115 such as T b F 3 and a counter electrode 116 made of metal with good reflectance are laminated via an absolutely R layer 117 such as Y2O3, and one end side of the 81-layer body is exposed to the light irradiation port 118. At the same time, a non-conductive glue flap (not shown) is provided on the other end of the laminate, and an AC control voltage is applied between the base electrode 114 and the counter electrode 116 according to the image information. Something like this is used. The common electrode 114 of the EL element 113 in each recording section used in FIG. 19 is configured as a common electrode, and in FIG. Image control switch 120 selectively activates element 113 is an AC power source.

According to this type of optical recording head, as shown in FIG. 21, the refractive index of the light emitting layer 115 is n1=2.4, for example.
, the refractive index of the insulating layer 117 is, for example, about n2=4.3, so of the light emitted at point A in the light emitting layer 115, θ≧
S in-1 (n2/n1) is absolutely 1iff1117
The incident light causes total internal reflection and propagates in the lateral direction as shown by arrow m1, and θ<s i
n-'(n2/n1)t' The light incident on the insulating layer 117 is refracted by the insulating layer 117, then reflected by the base electrode 114 or the counter electrode 116, and then redirected to the insulating layer 1.
The light beam is refracted at 17, propagates toward the side as shown by arrow m2, and side light is emitted from the light irradiation port 118.

In this type of optical recording head, the shape of the light irradiation port 118 in each recording section is flat, so the photoreceptor is not shown.
When writing and exposing one pixel on the top, it is necessary to scan multiple times in the sub-scanning direction or to secure a long scanning time, but since the intensity of the irradiated light in the side direction is originally strong, the 18th
It is more suitable for high-speed printing than the one that accepts drawings.

However, when printing a multi-gradation image with this type of optical recording head, it is necessary to change the intensity of irradiation light for each pixel, and one El element 11 corresponding to each recording section K is used.
It is conceivable to change the control voltage applied to No. 3 in accordance with the image density information, but this would complicate the signal processing system and would be practically impossible.

This invention was made in response to the above problems, and it is possible to print multi-gradation images at high speed using a side-lighting type ELi element without complicating the signal processing system. The present invention provides an optical recording head that enables this, and further provides an optical printer that uses this optical recording head and is capable of constantly realizing good multi-gradation image recording while taking into account 4-degree deterioration due to fatigue of the photoreceptor. This is what we provide.

[Means for solving the problem] That is, the first invention, as shown in FIG. 1(a),
Recording section K in which an EL element is used as a light source for each pixel
It is assumed that the optical recording head is equipped with an optical recording head that irradiates light according to image information from the recording section K toward the photoreceptor 1 side, and one light irradiation port 3 is provided in each recording section, and each recording Multiple side-emitting type ELs with the same light irradiation direction for each section
A head body 2 in which elements 4 (for example, 4a, 4b, 4c) are arranged in series in the light irradiation direction, and a plurality of El elements 4 corresponding to each recording section K are selected according to image density information for each recording section. The image control means 5 is equipped with an image control means 5 that automatically activates the light emission.

Further, second to fourth inventions are optical printers using the optical recording head according to the first invention, and the second invention is an optical printer using the optical recording head according to the first invention, as shown in FIG. An optical printer that forms a latent image at a potential level according to image density information on a photoreceptor 1 using an optical recording head according to the invention, and converts this latent image into a visible image using a developing means. A fatigue detection means 6 detects the degree of fatigue, and the image control means 5 changes the light emission intensity of the plurality of electroluminescent elements 4 for each image density information based on the information from the fatigue detection means 6, The light emitting intensity adjusting means 7 is provided for adjusting the latent image potential level or the current density level corresponding to the image to a substantially constant level.

Furthermore, a third invention forms a latent image at a potential level according to image density information on the photoreceptor 1 with the optical recording head according to the first invention, as shown in FIG. 1(C), This is an optical printer that visualizes this latent image using a developing means, and the latent image potential corresponding to each image density information formed by selective light emission operation of a plurality of electroluminescent probes 4 or these latent images. a monitor means 8 for extracting the image density when the image is developed; and based on the information from the monitor means 8, the light emission intensity of the plurality of electroluminescent probes 4 is changed for each image ail density information in the image control means 5. and a light emission intensity adjusting means 7 for adjusting the latent image potential level or development density level corresponding to each image density information to be substantially constant.
It is equipped with the following.

Furthermore, the fourth invention, as shown in FIG. 1(d),
An optical printer that forms a latent image at a potential level according to image density information on a photoreceptor 1 using an optical recording head according to the first invention, and visualizes this latent image using a developing means, the photosensitive body 1
and the latent image potential corresponding to each image density information formed by the selective light emission operation of the plurality of electroluminescent probes 4, or the developed density when these latent images are developed. The image control means 5 changes the emission intensity of the plurality of electroluminescent elements 4 for each image density information based on the information from the fatigue detection means 6 and the monitor means 8, and It is equipped with a light emission intensity adjusting means 7 that adjusts the latent image potential level or the developed density level corresponding to the information to be substantially constant.

In such technical means, the specific configuration of the side-emitting type EL element 4 constituting each recording section K may be appropriately selected as long as it can propagate light from the light-emitting layer in the side direction. No problem.

In this case, it is necessary to design so that all the light from the side-light type EL elements 4 constituting each recording section K is directed toward the light irradiation port 3. Further, each EL element 4 may be provided individually, but when considering manufacturing workability and wiring workability, it is possible to design so that the constituent members of the EL element 4 are shared to the extent possible. It is.

Further, the image control means 5 includes at least a functional section that determines the fla level of image information and a switching element that selectively drives the EL element 4 according to information from this functional section. If so, you may change the design as appropriate.

Furthermore, the design of the fatigue detection means 6 may be changed as appropriate as long as it can directly or indirectly detect a decrease in photosensitivity due to fatigue caused by long-term use of the photoreceptor 1. In this case, methods for directly detecting the decrease in photosensitivity include detecting changes in the surface potential of the photoreceptor 1 under certain conditions, and methods for indirectly detecting the decrease in photosensitivity. Examples of methods for this include integrating the usage time of the photoreceptor 1 or counting the number of prints to predict the sensitivity deterioration of the photoreceptor 1.

Furthermore, the monitor means 7 may be appropriately selected as long as it can monitor the latent image potential corresponding to each image density information or the developed density that visualizes the latent image at each potential level.

Further, in the second to fourth inventions, the light emission intensity adjusting means 8 is adapted to change the light emission intensity from the EL element 4 corresponding to each image a degree information of the image control means 5 according to each input information. , as long as the reference latent image potential or reference developed density corresponding to each image density information is obtained, the emission intensity may be changed based on a pre-prepared adjustment table, or the monitor output and reference data may be changed. The design may be changed as appropriate, such as configuring a feedback control system based on the difference between the above and the above.Furthermore, the timing of the adjustment operation of the light emission intensity adjustment means 8 can be appropriately selected according to necessity.

[Function] According to the optical recording head according to the first invention, the plurality of side-emitting EL elements 4 (4a to 4C) constituting the recording section K for each pixel of the head main body 2 are connected to the image control means 5. Since the light is selectively emitted depending on the image density, the light irradiation ports 3 in each recording section of the head body 2
The intensity of the irradiated light changes in multiple stages depending on the image density.

Further, in the optical printer according to the second invention, the fatigue detection means 6 detects the degree of fatigue of the photoreceptor 1, and the light emission intensity adjustment means 7 transmits light emission intensity adjustment information based on the fatigue degree to the image control means 5. The image control means 5 changes the light emission intensity from each EL element 4 of the head body 2 based on this light emission intensity adjustment information, and keeps the latent image potential or developed density corresponding to each image density information approximately constant. Keep it.

Furthermore, in the optical printer according to the third invention, the monitor means 8 monitors the i-image potential corresponding to each image density information on the photoreceptor 1 or the developed density based on them, and the light emission intensity adjustment means 7 Light emission intensity adjustment information based on the monitor output is given to the image control means 5, and the image control means 5 changes the light emission intensity from each EL thread 4 of the head main body 2 based on this light emission intensity adjustment information, and displays each image density information. The latent image potential name or development density corresponding to is kept approximately constant.

Furthermore, in the optical printer according to the fourth aspect of the invention, the fatigue detection means 6 detects the degree of fatigue of the photoreceptor 1, while the monitor means 8 detects the latency corresponding to each image density information on the photoreceptor 1. The image potential or the development density based on them is monitored, and the emission intensity adjustment means 7 outputs emission intensity adjustment information based on the degree of fatigue and monitor output to i! ii image 11m to the means 5, and the image control means 5 changes the light emission intensity from each EL element 4 of the head body 2 based on this light emission intensity adjustment information, and adjusts the latent image potential or development corresponding to each image density information. a Keep the concentration approximately constant.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the gW4 drawing.

Embodiment 1 FIG. 2 shows an embodiment of an optical recording head according to the first invention.

In the same figure, the optical recording head H has a head main body 31 on the right, which has a recording section K corresponding to 2048 pixels, and a recording section K divided into groups, for example, every 64 blocks. It is comprised of an image control means 50 that performs control according to data (3-bit data in this embodiment).

In this embodiment, as shown in FIGS. 2 to 4, the recording section includes three side-emitting type EL elements 33 (specifically, 33a, 3
3b, 33C) are arranged in parallel in the depth direction.
: A structure in which a light emitting layer 135 made of TbF3 or the like and a counter electrode 36 made of a metal with good reflectance are laminated with a layer 1137 made of Y2O3 or the like interposed therebetween is used. The base electrode 34 is connected to the front, middle and rear EL cables 33a to 3.
3C, and each base electrode 34a to 34C is common to each recording part K of each block B, and the light emitting layer 3C is formed to have the same width dimension.
5. The counter electrode 36 and the insulating layer 37 are common to the EL elements 33a to 33c in each recording section.

Further, one end surface of each recording section corresponding to one side edge of the insulating substrate 32 is formed as a light irradiation port 38, and the other end surface of this recording section is opened with a non-conductive glue flaper 39. . Note that each recording section is covered with an insulating protective layer 40.

Furthermore, as shown in FIGS. 2 and 4, the image control means 50 is divided into functions for each block B (B1 to B64), and is connected in series to the counter electrode 36 of each recording eIIK, and is An image data presence/absence switch 51 (specifically 51 to 51 ) that opens and closes depending on the presence or absence of image data to be printed is connected in series to the connection portion of the base electrodes 34a to 34c of each recording section, respectively, and is connected in series to the connection portion of the base electrodes 34a to 34c of each recording section, and It is composed of image WI density switches 52 (specifically, 52a to 52C) that open and close according to the density level of data, and an AC power supply 53 interposed between both switches 51 and 52.

Next, the operation of the optical recording head H according to this embodiment will be explained.

Now, focusing on one recording unit K shown in FIG. 4 and looking at the operation process of the recording unit according to multi-tone image data, first, when the multi-tone image data is rooOJ, Since the image data presence/absence switch 51 is off, no AC control voltage is applied to each EL element 33a to 33C in the recording section, and each EL element 33a to 33c does not emit light (see FIG. 5(a)). . Therefore, the intensity of the irradiated light from the light irradiation port 38 becomes O.

Next, when the multi-tone image data is roolJ,
The image data presence/absence switch 51 and the image density switch 52c are turned on, and the other image density switches 52a and 5
2b is maintained in an off operating state. Then, only the EL element 33c in the latter stage of the recording section is controlled by alternating current! 1! A voltage is applied, and only the El element 33C in the latter stage emits light (see FIG. 5(b)), and the intensity of the irradiated light from the light irradiation port 38 increases to 11 as shown at the position in FIG. Become.

Further, when the multi-tone image data is rol 0J, the image data presence/absence switch 51 and the image density switch 52b are turned on, and the other image density switches 52a,
52C is held in the off operating state. Then, the AC control 1ffi pressure is applied only to the middle EL element 33b of the recording section, and this middle EL element 331)
(see FIG. 5(C)), and the intensity of the irradiated light from the light irradiation port 38 becomes L2 as shown at position C in FIG. 6.

Furthermore, when the multi-tone image data is rlooJ,
The image data presence/absence switch 51 and the image density switch 52a are turned on, and the other image density switches 52b and 5 are turned on.
2c is held in the off operating state. Then, the alternating current control voltage is applied only to the EL element 33a at the front stage of the recording section, and only the EL element 33a at the front stage emits light (see FIG. 5(d)), which reduces the irradiation of the light irradiation port 38. The light intensity is 13 as shown at position d in FIG.

In such an operation process, the EL elements 33a to 3
3c, the one placed closer to the light irradiation port 38 causes less loss of light j, so the irradiation light intensity level is L3>
12 > 11 (in this embodiment, [3<11 +12)], in other words, the order of the image Ia degree level is secured.

Furthermore, multi-tone image data is rollJrlolJ
If there is rlloJ MllJF, the image data presence/absence switch 51 is turned on, and the image data switches 51a to 51C are turned on as appropriate, and the corresponding EL is turned on.
The elements 33a to 33c operate to emit light as shown in FIG.
(17>L6>15>14>13).

In this way, in the optical recording head H according to this embodiment, it is possible to variably set the intensity of the irradiation light to each recording section according to the multi-tone image data.

Further, when an optical printer is constructed using the optical recording head H according to this embodiment, as shown in FIG. At the same time, a convergent optical transmission body 20 is disposed between the optical recording head H and the photoreceptor 10, and the optical image information from each recording section K of the optical recording head 1 is convergent optically transmitted. The image may be formed on the photoreceptor 10 through the body 20.

In this case, the optical image information that reaches the photoreceptor 10 is given as an intensity that corresponds to the multi-tone image data.
A recording latent image corresponding to multi-gradation @image data is written on the photoreceptor 10.

In this embodiment, since side-emitting type EL elements 33 are arranged in parallel in each recording section, the light irradiation port 3
The directivity of the irradiated light from 8 is high, as shown in Figure 8.
It is also possible to configure an optical printer without using the convergent light transmission body 20.

Thick MM2 In FIGS. 9 and 10, the basic configuration of the optical recording head H is almost the same as in the first embodiment, but unlike the first embodiment,
Bases tlN located before, middle and after the recording section
&134a, 34b, 34c width dimensions 1a, lb,
lc is set variably, and the substantial light emitting area of each EL element 33a to 33C (base electrode 34a to 3
The respective areas Aa to AC of the light emitting layer 35 in which the EL elements 4C and the counter electrode 36 are superimposed are set variably. In this case, the substantial light emitting areas Aa to AC of each of the EL elements 33a to 33c are as follows: The intensity of the irradiation light irradiated individually from each EL element 33a to 33c is determined by the light irradiation port 38.
It is adjusted so that it remains constant.

Therefore, according to the optical recording head according to this embodiment, in addition to achieving substantially the same functions and effects as those of the first embodiment, each E element 3
Since the irradiation light intensity level at the light irradiation ports 38 of 3a to 33c can be made substantially constant, it is possible to accurately create the irradiation light intensity level according to multi-gradation image data with a certain level difference. Become.

In this embodiment, each El element 33 in the recording section
The substantial light emitting area of each EL element 33a to 33C is variably set so that the intensity of the irradiated light at 38 is constant. The light emitting area may be variably set based on other criteria, such as criteria such as a criteria that more clearly represents the gradation difference in multi-gradation image data.

FIG. 11 shows an embodiment of an optical printer to which the second invention is applied.

In the same figure, reference numeral H denotes an optical recording head having substantially the same configuration as in the first embodiment, consisting of a head main body 31 and an image control means 50, 10 a photoreceptor, 61 a charging corotron for pre-charging the photoreceptor 10, and 62 an optical recording head. A developing device 63 visualizes the latent image written on the photoreceptor 10 by the recording head H; a pre-transfer corotron 63 removes the electric charge of the visualized toner image;
Reference numeral 4 denotes a rolled recording sheet that is continuously supplied from the supply roll 65 to the rotation site, 66 indicates a guide transport roll that guides and transports the rolled recording sheet 64, and 67 moves the toner image on the photoreceptor 10 toward the recording sheet 64 side. 68 is a pre-clean corotron that removes the charge of the residual toner on the photoreceptor 10; 69 is a cleaner that removes the residual toner; and 70 is a fixing device that fixes the toner image on the recording sheet 64.

The optical recording head H in this embodiment is for reproducing 5-gradation image data (including 1 density zero data), and the number of El elements in each recording section is selected to be five, for example. can be changed in 40 steps.

Further, an encoder 7 detects the rotation speed of the photoreceptor 10.
1 is attached, and the output pulses from this encoder 71 are counted by a counter 72. Furthermore,
The count information of the counter 72 is transmitted to the light emission intensity adjusting means 73.
The light emission intensity adjustment means 73 creates light emission intensity adjustment information and outputs it to the image control means 50.

In this embodiment, the light emission intensity adjusting means 73 has an adjustment table as shown in FIG.
The count value of 2 corresponds to the number of prints, and according to the number of prints (in this example, around 1000 sheets), light emission intensity adjustment data a1 corresponding to the change in light emission intensity of each recording section is generated.
~alo is selected. In this case, the contents of the adjustment table are set based on a light attenuation curve determined in advance through experiments or the like for the photoreceptor 10 to be used.

The image control means 50 includes a light emission intensity adjustment means 7.
In response to the emission intensity adjustment data a1 to a10 from 3, image data DT of each density level (specifically, DTO to DT
4), the combination of a plurality of El elements of each recording section is switched and set in order to change the emission intensity of each recording section by the amount of the respective adjustment data.

Next, the operation of the optical printer according to this embodiment will be explained.

Generally, as the number of prints increases, the fatigue of the photoreceptor 10 increases accordingly, and the overall sensitivity of the photoreceptor 10 decreases by the amount of fatigue.

However, in this embodiment, when the number of prints exceeds 1000, for example, the light emission intensity adjustment means 73 selects 82 instead of al as the light emission intensity adjustment data, and sends this to the image control means 50. Therefore, the image control means 5
0 is the image data DT (DTO to D
The combination of EL elements of the recording sections corresponding to T4) is switched, and the light emission intensity from each recording section is changed by 982 adjustment days.

Then, even if the sensitivity of the photoreceptor 10 decreases by the number of prints of 1000 sheets, the decrease in sensitivity will be effectively corrected by the above-mentioned emission intensity adjustment, and the latent image potential corresponding to the image data DT of each density level will be will approximately match the respective reference latent image potentials. Therefore, the developed density when developing the latent image corresponding to the image data DT of each density level also approximately matches the standard B1 density, and the quality of the image transferred to the recording sheet 64 is the same as that of the photoreceptor 10. It is maintained well without being affected by a decrease in sensitivity.

Embodiment 4 FIG. 13 shows an embodiment in which the third invention is applied to an optical printer.

In the figure, the basic configuration of the optical printer is substantially the same as that of the third embodiment, but a different light emission intensity adjustment method for the optical recording head H from that of the third embodiment is adopted. Note that the same constituent elements as in the third embodiment are given the same reference numerals as in the third embodiment, and detailed explanation thereof will be omitted here.

The light emission intensity adjustment method of the optical recording head H used in this embodiment is such that the optical recording head H is applied to the non-image area of the photoreceptor 10 (both ends of the circumferential surface of the photoreceptor 10 outside the image forming area and the ink image area). to form a latent image corresponding to image data DT of each density level (specifically, DTO to DT4'), and convert this latent image potential 2 (specifically, 20-24') into surface potential 1.
At t181, the output from the monitor 82 is input to the monitor 82, and the output from the monitor 82 is input to the light emission intensity adjustment means 83, and the first
As shown in FIG.
The combination of the EL elements of each recording section is switched and set by the image control means 50, and the light emission intensity of each recording section is adjusted.

In this embodiment, as shown in FIG. 14, the specific level of the latent image potential Z corresponding to the image data DT of each density level is the developed density D corresponding to the image data DT of each density level. (Specifically, DO~D4) is set to the level necessary to obtain the values, and its allowable values include the resolution of the emission intensity of the EL strands in each recording section, the optical attenuation curve of the photoreceptor 10 used, and the The developing system is set within a range (for example, ±5%) in which mutual polymerization does not occur.

Therefore, according to the optical printer according to this embodiment, the calibration regarding the light emission intensity adjustment of the optical recording head is performed as follows.
This is carried out according to the flowchart shown in FIG. 15 at predetermined timings (each print cycle, print cycle for a predetermined number of sheets, when the printer is turned on, etc.).

Specifically, when calibration is started, the light emission intensity adjusting means 83 drives the optical recording head H for calibration, and the non-Ii! iif! j4
A latent image corresponding to the image data DT of each density level is formed in the 8Ii area (step 1).

Thereafter, each latent image potential level formed by the above calibration is monitored (step 2), and the light emission intensity adjusting means 83 compares each monitored potential with each reference latent image potential (step 3).

If any one of the monitor potentials does not match the corresponding reference latent image potential, the light emission intensity adjustment means 83 calculates the difference between the mismatch potentials (step 4).
), create emission intensity adjustment data according to this difference,
1ilI Send to image controller control 0. Then, the image control means 50 variably sets the combination of the EL elements of the recording section in order to change the light emission intensity of the corresponding WJ degree relevel image data based on the light emission intensity adjustment data (step 5).

After this, the optical recording head H is again calibrated and driven, and thereafter, the operations of steps 1 to 5 are repeated until all the output potentials match the reference latent image potential.

Then, the actual calibration is completed when all monitor potentials match the reference latent image potential, and thereafter, the image control means 50 sends a print READY signal to the post side and receives image data from the host side. Once obtained, the printing operation is performed (steps 6 to 8).

In this embodiment, the latent image potential is monitored, but the densitometer 84 is
It is also possible to monitor the developed density corresponding to each latent image potential level using the following method.

Embodiment 5 FIG. 16 shows an embodiment in which the fourth invention is applied to an optical printer.

In the figure, the construction of the optical printer is substantially the same as that in the third embodiment, but a light emission intensity adjustment method of the optical recording head H that is different from those in the third and fourth embodiments is adopted. Note that the same constituent elements as in the third embodiment are given the same reference numerals as in the third embodiment, and detailed explanation thereof will be omitted here.

The light emission intensity adjustment method of the optical recording head H used in this embodiment is such that a counter 92 counts the output of an encoder 91 as a means for detecting the rotational speed of the photoreceptor 10, and the optical recording head H is calibrated only once. By driving, the optical recording head H records image data DT of each density level (specifically, DTO to
A latent image corresponding to DT4) is formed, and the latent image potential Z (specifically, ZO to Z4) is monitored by a surface electrometer 93.
4, as well as the counter 92 and monitor 94.
After inputting the output from the light emission intensity adjusting means 95 to the light emission intensity adjustment means 95 and creating light emission intensity adjustment data by the light emission intensity adjustment means 95, this data is sent to the image control means 50, and the image control means 50 controls each recording unit. The combination of ELi elements is switched and set to adjust the light emission intensity of each recording section.

In this embodiment, the light emission intensity adjusting means 95 has an adjustment table as shown in FIG.
The count value of 2 corresponds to the number of prints, and the difference Gp between the monitor output and the reference latent image potential is classified into, for example, the standard, and the number of prints (in this example, in units of 1000 sheets) is calculated.
and the light emission intensity adjustment data a11 corresponding to the light emission intensity change of each recording section of the optical recording head 1] according to the potential difference Gp.
．． a12, . . . are selected for each density level. Note that the contents of the adjustment table are set based on a light attenuation curve determined in advance through experiments or the like for the photoreceptor 10 to be used.

The image control means 50 includes a light emission intensity adjustment means 9
Emission intensity adjustment data a from 5 11. a 12...
..., image data DT(
Specifically, in order to change the emission intensity of each recording section for DTO to DT4 by the amount of the respective adjustment data, the combinations of the plurality of toner elements of each recording section are switched and set.

Next, the operation of the optical printer according to this embodiment will be explained.

Generally, the degree of fatigue of the photoreceptor 10 can be determined depending on the number of prints, but the degree of decrease in sensitivity of the photoreceptor 10 to the light emission intensity based on image data of each density level of the optical recording head H is not consistent. .

However, in this embodiment, the light emission intensity adjusting means 95 has a control function based on the counted value from the counter 92 (corresponding to the number of prints) and the image data of each density level formed by the calibration drive from the monitor 94. Latent image potential information is input.

Then, the emission intensity adjustment means 95 calculates the difference Gp between each monitor 94 potential and the reference latent image potential, and then sets the potential difference Gp to Gl)>50 (V) (first classification).

10<Gp≦50(V) (second classification), Gl)≦10
(V) (third classification), and then access the adjustment table shown in FIG. 17 using the classification of the number of prints and the potential difference Gp as an address signal, and use the image data of each density level as an address signal. The emission intensity adjustment data is individually selected for each time. For example, when the number of prints exceeds 1000, image data DT2, D of a predetermined density level is
Assuming that the potential difference Gp at T3 is in the second and third classifications, the emission intensity adjustment data is a22. a
23 is selected.

The light emission intensity adjustment data selected in this way is sent to the image control means 50, and the image control means 50 switches the combination of EL elements of the recording section corresponding to the image data DT (DTO to DT4) of each density level. The light emission intensity from each recording section is changed by the amount of the respective adjustment data.

Therefore, in this embodiment, when adjusting each emission intensity of the optical recording head H, emission intensity adjustment data is individually selected for each image data of each density level. Since the density correction is performed for each image data of each density level, the light emission intensity of the optical recording head H can be adjusted more precisely accordingly.

In addition, in the fourth embodiment described above, it is necessary to perform calibration driving on the optical recording head H multiple times and process each latent image potential by increasing the potential. , since the number of prints is taken into account as the fatigue information of the photoreceptor 10, it is sufficient to carry out one calibration drive for the optical recording head H, and then process the latent image potential by increasing the potential by two. Compared to 4, the calibration process is am.

[Effects of the Invention] As explained above, according to the optical recording head according to the first invention, the recording section of each pixel is configured by a plurality of side-emitting type E elements, and the El element of each recording section is Since the light emission is activated in an appropriate combination to obtain the irradiation light intensity according to the Ffj image density, multi-gradation images can be printed at high speed without complicating the signal processing system.

Further, according to the optical printer according to the second to fourth aspects of the invention, the light emission intensity corresponding to each image density information of the optical recording head is changed appropriately to correct sensitivity deterioration due to fatigue of the photoreceptor. The latent image potential corresponding to each image density information or the developed density based on this can be kept approximately constant without being affected by sensitivity deterioration due to fatigue of the photoreceptor,
It is possible to maintain good multi-gradation image quality at all times.

In particular, according to the optical printer according to the second aspect, the degree of fatigue of the photoreceptor can be uniquely determined based on the fatigue detection means, and the light emission intensity of the optical recording head can be adjusted, so that the configuration between the bags can be simplified. can be achieved.

On the other hand, according to the optical printer according to claim 3, the latent image potential corresponding to each image density information or the developed density based on this is monitored, and based on this monitor output, the latent image potential corresponding to each image density information of the optical recording head is monitored. Since the light emission intensity is adjusted individually, the light emission intensity of the optical recording head can be adjusted more finely than in the second aspect.

Further, according to the optical printer according to the fourth aspect, each image density information of the optical recording head is determined based on the monitor output of the latent image potential or the developed density corresponding to each image density information while taking into account the degree of fatigue of the photoreceptor. Since the light emitting intensity corresponding to the above is individually adjusted, the light emitting intensity of the optical recording head is adjusted to the same level as that of the third embodiment even if the monitor output processing is simplified compared to the third embodiment. Adjustments can be made with high precision.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic explanatory diagram showing the structure of an optical recording head according to the first invention, and FIG. 1(1) to C) shows the structure of an optical printer according to the second to fourth inventions. FIG. 2 is a perspective view showing Embodiment 1 in which the first invention is applied to an optical recording head, and FIGS. 3 and 4 are shown in FIG.
Line and IV-IV line sectional view, Figure 5 (a) to h)
6 is an explanatory diagram showing a pixel-by-pixel recording pattern of the optical recording head according to Example 1, FIG. 7 and 8 are schematic diagrams showing an example of application of the optical recording head according to the first embodiment to a printer, and FIG. 9 is an explanatory diagram showing a second embodiment in which the first invention is applied to the optical recording head. 10 is a view taken from the X direction in FIG. 9, FIG. 11 is an explanatory diagram showing Embodiment 3 in which the second invention is applied to an optical printer, and FIG. 12 is a light emission intensity adjusting means of Embodiment 3. FIG. 13 is an explanatory diagram showing an example of the adjustment table used in Embodiment 4, FIG. 13 is an explanatory diagram showing Embodiment 4 in which the third invention is applied to an optical printer, and FIG. A graph showing the relationship with the developer density, FIG. 15 is a flowchart showing the operation process of the emission intensity adjusting means used in Example 4, and FIG. 16 shows Example 5 in which the fourth invention is applied to an optical printer. An explanatory diagram, FIG. 17 is an explanatory diagram showing an example of an adjustment table used in the emission intensity adjustment means of Example 5,
FIG. 18 is an explanatory diagram showing a printer using an example of a conventional optical recording head, and FIG. 19 is an oblique view showing another example of the conventional optical recording head. 1 and 20 are perspective views showing rt-s of the side-emitting type EL cord used in FIG. 19,
FIG. 21 is an explanatory diagram showing the operating principle of the side-emitting type EL element according to FIG. 20. [Explanation of symbols] K...Recording section 1...Photoconductor 2...Head body 3...Light irradiation port 4 (4a to 4C)...Side-emitting EL element 5...
・Image control means 6...Fatigue detection means 7...Emission intensity adjustment means 8...Monitoring means

Claims (1)

[Claims] 1) Each pixel is provided with a recording section (K) in which an electroluminescent element is used as a light emitting source;
In the optical recording head that irradiates light according to image information from the photoreceptor (1) toward the photoreceptor (1), one light irradiation port (3) is provided for each recording section (K), and one light irradiation port (3) is provided for each recording section (K). K)
A head main body (2) in which a plurality of side-emitting electroluminescent elements (4: 4a, 4b, 4c) with the same light irradiation direction are provided in series in the light irradiation direction, and an image of each recording section (K). Each recording section (K) according to the density information
A plurality of electroluminescent elements (4:
4a, 4b, 4c) for selectively emitting light. 2) An optical printer in which the optical recording head according to claim 1 forms a latent image on the photoreceptor (1) at a potential level according to image density information, and this latent image is made visible by a developing means. Fatigue detection means (6) for detecting the degree of fatigue of the photoreceptor (1)
Based on the information from the fatigue detection means (6), the image control means (5) selects a plurality of electroluminescent elements (4:4a, 4b, 4b,
4c) An optical printer comprising: a light emission intensity adjusting means (7) for changing the light emission intensity of step 4c) and adjusting the latent image potential level or development density level corresponding to each image density information to be substantially constant. 3) An optical printer that forms a latent image on the photoconductor (1) with the optical recording head according to claim 1 at a potential level corresponding to image density information, and converts this latent image into a visible image using a developing means. , multiple electroluminescent elements (4:4a, 4b
, 4c) for extracting the latent image potential corresponding to each image density information formed by the selective light emission operation or the developed density when these latent images are developed; Based on the information from 8), the image control means (5) changes the luminescence intensity of the plurality of electroluminescent elements (4:4a, 4b, 4c) for each image density information, and adjusts the latency corresponding to each image density information. An optical printer comprising a light emission intensity adjusting means (7) for adjusting an image potential level or a developing density level to a substantially constant level. 4) An optical printer that forms a latent image on the photoconductor (1) with the optical recording head according to claim 1 at a potential level corresponding to image density information, and converts this latent image into a visible image using a developing means. Fatigue detection means (6) for detecting the degree of fatigue of the photoreceptor (1)
and multiple electroluminescent elements (4:4a,
4b, 4c) motor means (8) for extracting the latent image potential corresponding to each image density information formed by the selective light emission operation or the developed density when these latent images are developed;
Based on information from the fatigue detecting means (6) and the monitoring means (8), a plurality of electroluminescent elements (
4: 4a, 4b, 4c)) to adjust the latent image potential level or development density level corresponding to each image density information to a substantially constant level. Features of optical printer.