JPS63218378A - Optical-type recorder - Google Patents

Abstract

PURPOSE:To prolong the effective life of a recording element array, by varying the relative positions of a recording surface and the recording element array in a main scanning direction according to the length of a pseudo-image signal added to the end of an image signal. CONSTITUTION:The length of a pseudo-image signal added to both ends of an image signal is determined by a calculation value (x) preset on a white signal applying counter 8. The calculation value (x) is set arbitrarily and variably, by a white signal application value setting circuit 10. When the length of the pseudo-image signal is variably set, the position of a recording element array 14 in a main scanning direction is varied by a positioning circuit 16 according to the length of the pseudo-image signal, whereby a recording position on a recording surface P is maintained at a constantly fixed position. By this, it is possible to reduce variations in the characteristics of optical recording elements with time, without spoiling positional accuracy in recording, and to prolong the effective life of the recording element array 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an optical recording apparatus that records images on a photosensitive recording surface using a large number of optical recording elements.

2. Description of the Related Art As shown in FIG.
It has a recording element array 4 in which are arranged, a drive circuit 3 that drives each LED with electricity based on an image signal, and a correction circuit 2 that individually corrects variations in the amount of light emitted from each LED,
By individually energizing and driving the LEDs in the recording element array 4 based on the pixel information of the image signal input from the terminal 1, a latent image of a line image is exposed and recorded in the main scanning direction of the photosensitive recording surface P. In this case, the recording operation is performed line by line.The image signal for one line is sent to the correction circuit 2. The correction circuit 2 adds predetermined correction information to the input image signal.The drive circuit 2 selectively energizes only the LED corresponding to the white pixel based on the image signal, and also controls the energization. The time is individually controlled for each LED based on the correction information.Thereby, variations in the amount of light emitted from each LED are corrected, and recording is performed with a constant amount of exposure.

When one line of latent image is exposed and recorded, the recording surface P is moved by one line pitch in the sub-scanning direction, and then
Similarly, the next line of latent images is exposed and recorded. By repeating this operation, latent images of two-dimensional images in the main scanning direction and the sub-scanning direction are exposed and recorded.

Although not shown, the latent image exposed and recorded as described above is formally recorded through processes such as toner development, transfer to recording paper, and thermal fixation.

Problems to be Solved by the Invention However, according to this configuration, the correction circuit 2
Even though the variation in the amount of light emitted by D was once corrected,
There has been a problem in that subsequent use causes large variations over time in the amount of light emitted by the LEDs, which did not exist at the beginning, which ultimately shortens the useful life of the recording element array.

The above problem arises for the following reasons.

That is, the amount of light emitted from the LED decreases depending on the total driving time. It is good if this decline progresses uniformly. However, when an image of a specific pattern, such as a formatted document with vertical ruled lines, is continuously recorded, even within the same recording element array 4, depending on the arrangement position of the LED, some parts are driven to emit light frequently and others are not. However, it comes out. For example, the LED located where the vertical ruled lines of a formatted document are recorded is the same as the LED located elsewhere.
The number of times that the ED and the ED are driven to emit light is significantly higher.

When there is a difference in drive frequency in this way, the amount of light emitted by the LEDs that are driven more frequently decreases depending on the usage time of the recording device, but the amount of light emitted from the LEDs that are driven less frequently decreases depending on the usage time of the recording device. The decline is small compared to the usage time, and this causes variations in the amount of emitted light. This variation increases as the recording apparatus is used, and eventually exceeds the allowable range that can be corrected.

This invention was made in view of the above-mentioned problems, and it is an object of the present invention to extend the effective life of a recording element array by reducing the variation in characteristics that occurs over time in optical recording elements such as LEDs without impairing recording accuracy. The purpose is to provide an optical recording device that can perform

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention adds a pseudo image signal of an arbitrary length representing, for example, a white pixel to the end of the image signal, and also adds the length of the pseudo image signal to the end of the image signal. The recording device is configured to change the relative position of the photosensitive recording surface and the recording element array in the main scanning direction in accordance with the change in the recording element array.

Effect of the Invention With the above-described configuration, the present invention can change the positional relationship between the recorded image based on the actual image signal and the optical recording element, thereby averaging the drive frequency of the optical recording element, and thereby adjusting the optical recording element's performance over time. This makes it possible to reduce the characteristic variations that occur during the printing process, thereby making it possible to extend the useful life of the recording element array.

At this time, the relative position of the photosensitive recording surface and the recording element array in the main scanning direction is changed according to the length of the pseudo image signal, so that the positional relationship between the recorded image based on the actual image signal and the optical recording element changes. However, the recording position on the recording surface is always kept constant. This ensures positional recording accuracy.

Embodiment FIG. 1 shows a schematic configuration of an optical recording apparatus according to an embodiment of the present invention.

In the figure, 6 is a control circuit, 7 is a line counter, 8 is a peak addition counter, 9 is a data counter,
10 is a white addition value setting circuit, 11 is a data buffer consisting of RAM, 12 is a correction circuit, 13 is a drive circuit, LED is a light emitting diode as an optical recording element, and 14 is a large number of L
A recording element array having ED, P is an electrostatic photosensitive recording surface,
15 is a drive power terminal, 16 is a positioning circuit, 17 is a stepping motor, and 18 is a feed screw.

The control circuit 6 monitors the status of each part and controls the operation of each part based on this monitor. This control circuit 6 is composed of a random logic circuit, a microcomputer, or the like.

The line counter 7 is activated by the control signal LENB given from the control circuit 6, and counts the clock X of a predetermined period from zero value. When the count value reaches a predetermined count end value n, a count end signal LCA is sent to the control circuit 6.
Output Y. The counting end value n is set to be slightly larger than the number of pixels included in the image signal for one line in the main scanning direction.The zero day addition counter 8 is activated by the control signal WENB given from the control circuit 6. Then, count the same crosses as above from the closing price. The count value is the predetermined count end value
When the count is reached, a count end signal WCAY is output to the control circuit 6. The counting end value X is arbitrarily and variably set by the white addition value setting circuit 10.

The data counter 9 is activated by the control signal DBNB given from the control circuit 6, and counts the same clock y as described above from zero value. When the count value reaches the count end value m, a count end signal DCAY is output to the control circuit 6. The count end value m is made to match the number of pixels included in the image signal for one line in the main scanning direction. The count value of this data counter 9 is given to the data buffer 11 as an address.

The white additional value setting circuit 10 is configured to be able to variably set an arbitrary value using, for example, a dip switch. The set value is preset in the date adding counter 8 as the counting end value X, and is also given as a set value to the positioning means described later.

Data buffer 1 is an externally input image signal DA.
While TA is temporarily stored, the stored image signal DATA
is sent to the correction circuit 12. Each time the data buffer 11 stores one line worth of image signals in the main scanning direction, it sends a signal DOR to the control circuit 6 indicating that the image signal can be output. The output operation of this data buffer 11 is as follows:
The counting operation of the data counter 9 is instructed by the control signal DENB given from the control circuit 6. When an output operation is instructed, the stored image signal DATA is output for one pixel each time the address given by the count value of the data counter 9 is updated.

The correction circuit 12 generates correction information for individually correcting variations in the amount of light emitted from each LED in the recording element array 14, and outputs this to the drive circuit 13 together with the image signal input from the data buffer 11.

The image signal input operation in the correction circuit 12 is instructed by the control signal LENB given from the control circuit 6, as well as the counting operation of the line counter 7.

The drive circuit 13 selectively conducts energization based on the image signal, and adjusts the energization time to L based on the correction information.
Control each ED individually. As a result, variations in the amount of light emitted from each LED are corrected, and recording is performed with a constant amount of exposure. Note that the power source for selectively driving the LEDs is a dedicated power supply circuit (
(not shown) is supplied separately.

The recording element array 14 includes a large number of LEDs as recording elements.
are arranged in the main scanning direction. In this case, the number of arrays is the same as the counting end value n of the line counter 7. The number of pixels for one line is also slightly larger.
EDs are arranged.

The electrostatic photosensitive recording surface P is formed in the shape of a drum, and is rotated at a speed in a sub-scanning direction perpendicular to the main-scanning direction.

Although not shown, a toner developing section, a transfer section, and the like are arranged at the rotational destination of the recording surface P.

The positioning circuit 16, together with the stepping motor 17 and the feed screw 18, constitutes positioning means for the recording element array 14. This positioning means operates the stepping motor 1 according to the setting value given from the white addition value setting circuit 10, that is, the counting end value X of the day addition counter 8.
By step driving 7, the recording element array 14
The setting position in the main scanning direction is varied by an amount corresponding to the count end value X.

The operation of the optical recording apparatus configured as described above will be explained below.

FIG. 2 shows an example of the operation of the optical recording apparatus described above using a timing chart.

1 and 2, first, data buffer 1
When the image signal DATA for one line is stored in the data buffer 11, the signal DOR is sent from the data buffer 11 to the control circuit 6.

Then, the control circuit 6 issues control signals LENB and WENB. As a result, the line counter 7 and the peak addition counter 8 each start counting clocks. At the same time, the correction circuit 12 starts inputting the image signal. However, at this point, no image signal is output from the data buffer 11.

Therefore, white pixel information represented by no-signal input is input to the correction circuit 12 as a pseudo image signal. This pseudo image signal is inputted one pixel at a time in synchronization with the clock.

When the mountain addition counter 8 counts its counting end value X and issues the counting end signal WCAY, the control circuit 6 cancels the control signal WENB to terminate the operation of the mountain addition counter 8, and also outputs the control signal DENB. It issues a command for the counting operation of the data count 9 and the output operation of the data buffer 11. As a result, the actual image signal DATA is input to the correction circuit 12 instead of the pseudo image signal containing only white pixel information. The input of this image signal DATA is
This process continues until the data counter 9 counts the count end value m and issues the count end signal DCAY. The input is
This is performed for each pixel in synchronization with the clock.

The correction circuit 12 receives an image signal DAT for one line in the main scanning direction.
When A is input and the counting end signal DCAY is issued from the data counter 9, the control circuit 6 outputs the control signal DEN.
Cancel B. As a result, the operation of the data counter 9 is terminated.

Thereafter, a pseudo image signal due to a no-signal input is again input to the correction circuit 12 in synchronization with the clock 2 until the line counter 7 counts the count end value n and issues the count end signal LCAY.

As described above, pseudo image signals of an arbitrary length consisting of an arbitrary number (x, n (x+m)) of white pixel information are added to the front and rear ends of the image signal DATA, respectively, and the correction circuit 13
selectively energizes and drives the LEDs in the recording element array 14 based on the image signal DATA to which the pseudo image signal is added. As a result, a latent image of a line image in which white pixels based on pseudo image signals are arranged at both ends is exposed and recorded on the photosensitive recording surface P.

Here, the number of white pixel information added to the front and rear ends of the image signal, that is, the length of the pseudo image signal x, n (x 10 m)) is determined by the count value X preset in the mountain addition counter 8. It will be done. Furthermore, this count value X is arbitrarily variably set by the white additional value setting circuit 10. Therefore, by operating the white additional value setting circuit 10, it is possible to change the positional relationship between the recorded image based on the actual image signal DATA and the LED. As a result, for example, by changing the LEDs located where vertical ruled lines of a formatted document are recorded, it is possible to correct the fact that the driving frequency of a particular LED is biased toward either a high or a low frequency.

As mentioned above, the optical recording device of the above-mentioned embodiment has the following features:
An arbitrary number (x + n = (x + m)
) is configured to add a pseudo image signal adding means. This pseudo image signal adding means can change the positional relationship between the recorded image based on the actual image signal DATA and the LED, and average the driving frequency of the LED. This makes it possible to reduce variations in characteristics that occur over time in the optical recording elements, thereby extending the useful life of the recording element array 14.

Further, when the length of the pseudo image signal is set variably, the position of the recording element array 14 in the main scanning direction is adjusted according to the length of the pseudo image signal by a positioning means constituted by the positioning circuit 16 or the like. be changed. Accordingly, the recorded image based on the actual image signal and the L
Even if the positional relationship of the EDs changes, the recording position on the recording surface P is always kept constant. This ensures positional recording accuracy.

In the optical recording apparatus of the above-described embodiment, the position of the recording element array 14 is variably set by the positioning means.
It may be configured to variably set the position of. Further, as the optical recording element, for example, an optical recording element such as a liquid crystal shutter or a plasma light emitting element may be used. Furthermore, when a white image is recorded on a black background, a pseudo image signal may be formed using black pixel information.

Effects of the Invention As is clear from the above description, the present invention adds a pseudo image signal of an arbitrary length representing, for example, a white pixel to the end of an image signal, and also adds a pseudo image signal of an arbitrary length to the end of an image signal, and adjusts the exposure according to the length of this pseudo image signal. By changing the relative position of the recording surface and the recording element array in the main scanning direction, the recording position on the recording surface is kept constant while changing the positional relationship between the actual recorded image based on both signals and the optical recording element. It is possible to average the driving frequency of the optical recording element, thereby reducing the variation in characteristics that occurs over time in the optical recording element without impairing the recording accuracy in multiple positions, and thereby reducing the effective lifespan of the recording element array. This has the effect of extending the

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of an optical image recording device according to an embodiment of the present invention, FIG. 2 is a timing chart showing an example of the operation of the main parts, and FIG. 3 is a diagram of a conventional optical image recording device. FIG. 2 is a block diagram showing a schematic configuration. 6... Control circuit, 7... Line counter, 8...
・Counter for adding mountains, 9...Counter for data, 10
... White additional value setting circuit, 11 ... Data buffer consisting of RAM, 12 ... Correction circuit, 13 ... Drive circuit, LED ... Light emitting diode as recording element, 1
4... Recording element array, 15... Drive power supply terminal, P
. . . Electrostatic photosensitive recording surface, 16 . . . Positioning circuit constituting positioning means, 17 . . . Stepper/g motor constituting positioning means, 18 . Name of agent: Patent attorney Toshio Nakao and 1 other person11
Figure 2 Figure 3

Claims (3)

[Claims] (1) A recording element array in which a large number of optical recording elements are arranged in the main scanning direction of a photosensitive recording surface, a drive circuit that individually drives each optical recording element with electricity based on an image signal, and a drive circuit that drives each optical recording element individually based on an image signal; A pseudo image signal adding means for adding a pseudo image signal of an arbitrary length, and a positioning means for variably setting the relative position of the photosensitive recording surface and the recording element array in the main scanning direction according to the length of the pseudo image signal. Optical recording device. (2) The optical recording apparatus according to claim 1, further comprising pseudo image signal adding means for adding a pseudo image signal consisting of an arbitrary number of white pixel information to the end of the image signal. (3) Claim 1 comprising a recording element array in which a large number of light emitting diodes are arranged as an optical recording element.
The optical recording device according to item 1 or 2.