JPH03216356A - Recorder - Google Patents

Abstract

PURPOSE:To obtain a highly qualified image having an excellent contrast constantly by a method wherein an image correction signal related to image recording characteristics of a recorder and an image correction signal related to the use condition of the recorder are outputted to an external device. CONSTITUTION:A recorder B receives image data from an external device A as electric signals and outputs a visible image onto a recording medium. A first signal output means C is provided that outputs an image correction signal related to characteristics intrinsic to the recorder B to the external device. Furthermore, a second signal output means D is provided that outputs an image correction signal related to the use information of the recorder B to the external device A. Therefore, in the external device A, an optimum image correction processing corresponding to the use condition of the recorder can be applied to the aforesaid image data in accordance with the plurality of image correction signals.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a recording device that records image data on a recording medium such as paper, and in particular, the present invention relates to a recording device that records image data on a recording medium such as paper. The present invention relates to a recording device that outputs a high-quality visible image by inputting it in the form of an electrical signal.

[Prior Art] Conventionally, in a recording device (hereinafter referred to as a printer) such as a laser printer that applies electrophotographic technology, when outputting a halftone image, the image signal for recording is first sent to the host of an external device. After performing necessary image processing such as halftone processing and dither processing using a computer, etc., and converting it into a binary image,
A commonly used method is to input information into a printer. In addition, in laser printers and the like, by controlling the laser lighting time (i.e., the image clock in the main scanning direction) on the host computer side and making the laser ON time shorter than the normal 1-dot ON time, halftone images can be printed. It is also done to output.

In this way, it is convenient to perform various types of image processing on the host computer side in terms of data storage capacity, etc. Also, since it is only necessary to handle binary signals in transmission between the host combinator and the printer, data This is very convenient for volume and data transfer.

[Problems to be Solved by the Invention] However, in the conventional printers as described above, when outputting a halftone image, depending on the printer model,
Furthermore, since the gradation characteristics differ depending on the environment in which the printer is placed or the number of prints of the printer (so-called how the printer is used), output images with different densities can be obtained.

For example, even if data for a 4x4 pixel dither pattern as shown in Figure 3 is input from an external device, if it is actually recorded by a conventional device, it will be printed as shown in Figure 4 by a certain printer. In the usage environment, the output density characteristics will be as shown by the solid line curve A in this figure, and if the usage environment and number of prints are different for different printers or even the same printer, the output density characteristics will be as shown by the broken line curve B in this figure. This is the output density characteristic.

As a result, even if the same dither pattern is input to the printer, under certain usage conditions of a certain printer, the low-density parts of the halftone image may be skipped and disappear, or under different usage conditions or with a different printer, the halftone image may disappear. This has caused inconveniences such as dark areas of the image being completely crushed and becoming unrecognizable.

Strictly speaking, not only photographic images, but also character images, especially small character images that are output with thin lines, have a certain printing line width, as the printing line width varies depending on the printer model and its usage conditions. There is an inconvenience that some printers have thicker printers and other printers have thinner printers. Therefore, due to the reasons mentioned above, when multiple printers with different characteristics are used on the same host computer, one Not only when an image processing system is configured, but even when an image processing system is configured using a single printer, depending on the usage conditions of the printer, the overall output image may be blurred, the characters may be thin, or vice versa. This caused some inconveniences, such as the color becoming darker overall and the letters being crushed.

In view of the above-mentioned points, an object of the present invention is to configure an image processing system using, for example, a common external device and multiple types of recording devices with different characteristics. It is an object of the present invention to provide a recording device that can always obtain high-quality output images even under conditions of use.

[Means for Solving the Problems] In order to achieve the above object, the present invention receives image data from an external device as an electrical signal and stores the image data on a recording medium+:TMElm.
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(a) A signal output means for image correction of blood is provided.

In order to achieve the above object, the present invention provides a recording device that receives image data as an electrical signal from an external device and outputs a visible image on a recording medium, and provides an image correction signal related to characteristics unique to the recording device. The apparatus is characterized by comprising a first signal output means for outputting to the external device, and a second signal output means for outputting an image correction signal related to usage information of the recording apparatus to the external device.

Further, one aspect of the present invention is characterized in that the usage information includes environmental information such as temperature and humidity in which the recording device is placed and/or the cumulative number of recorded sheets.

Another aspect of the present invention is that the image correction signal is a signal processed by the external device as a tone correction signal for a halftone image.

[Function] In the present invention, in a recording device that receives image data supplied from an external device as an electrical signal and outputs a visible image, an image correction signal related to the image recording characteristics of the recording device and an image related to the usage conditions of the recording device are used. Since the correction signal and the correction signal are output to the external device, the external device can use the plurality of image correction signals to perform optimal image correction processing on the image data according to the usage conditions of the recording device. As a result, it is possible to always obtain a constant high-quality image with good contrast, regardless of the type of recording device or its usage conditions.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Figure 1 shows the basic configuration of an embodiment of the present invention. In the same figure, C is a recording device B that receives image data as an electrical signal from an external device A and outputs a visible image on a recording medium.
This is a signal output means. D is a second signal output means for outputting an image correction signal regarding usage information of the recording device B to the external device A.

As an example, the usage information includes environmental information such as temperature and humidity where the recording device B is placed and/or the cumulative number of sheets recorded. Further, as an example, the image correction signal is a signal processed by the external device A as a tone correction signal of a halftone image.

;3'' 1 plate holding Figure 2 shows the recording device (1st embodiment) of one embodiment of the present invention.
1 shows a circuit configuration of an image processing system consisting of a printer) and an external device (controller).

In the figure, image data 1 is input from a reader (not shown) or a magnetic disk device (not shown) to a controller, which is an external device, and is stored in a page memory 2. In this embodiment, this image data 1 is 4
This will be explained as bit data.

The image data arranged as a 4-bit multilevel signal in the memory 2 is sequentially read out to the line buffer 3 when printer B starts printing, and is synchronized with the BD signal (not shown), which is the horizontal synchronization signal of printer B. After being taken,
It undergoes digital-to-digital conversion by a RAM (random access memory) 5 which is a look-up table. The lookup table in RAM5 is a ROM (read-on memory) that stores recording device characteristic correction data.
8 and RO where recording device usage condition correction data is stored.
Created by data from M9. ROMg and ROM9
The details will be described later.

Image data 1 input to the controller A is converted in the RAM 5 and then sent to the terminal P of the comparator 7 in synchronization with the reference clock. On the other hand, data of a dither matrix as shown in FIG. 3, for example, is transferred from the dither pattern generation circuit 6 to the terminal Q of the comparator 7 in synchronization with the reference clock. Here, if the data at the terminal P is P and the data Q at the terminal Q, the output data R from the converter 7 is "1" when P≧Q.
Q, it is sent to printer B as "0". In addition, the transmission and reception of signals in each circuit is performed by the CPU of controller A.
(Central processing control unit) 4 and the CPUIO of printer B.

The output signal R of the comparator 7 input to the printer B is
It is input to the laser driver 1l. Laser driver II
drives the laser diode 12 ON/OFF according to the output signal R of "1" or "0".

The laser light emitted from the laser diode 12 is converted into scanning light by the rotating polygon mirror 13, and is scanned by the photoreceptor 1.
8. Scan above. Note that a portion of this scanning light is received by a beam detector (not shown), and a signal used as a BD signal or a synchronization signal for the dither pattern generator 6 is generated from the beam detector.

The photoreceptor 18 is uniformly charged by the charger 15, receives the above-mentioned scanning light, forms a latent image on its surface, and then develops the latent image by the developer 17. The developed pattern on the photoreceptor 18 is transferred onto a transfer material (for example, recording paper) 22 by a transfer charger 19, and fixed onto the transfer device 22 by heat fixing rollers 23 and 24. The developer remaining without being transferred to the surface of the photoreceptor 18 is collected by the cleaner 20. Furthermore, the charge on the photoreceptor 18 is erased by the pre-exposure 21,
The same image forming process described above is repeated again.

FIG. 5A shows the relationship between input image density data and output image density based on the recording device characteristics of the electrophotographic printer as shown in FIG. Due to differences in the characteristics of each device regarding the photoreceptor, developer, charging conditions for forming a latent image, image exposure amount, etc., electrophotographic printers have different characteristics as shown in the characteristic curves a, b, and c in Figure 5 (A). Each device exhibits different output density characteristics. Different nonlinear characteristics caused by these machines or models are linearly corrected by performing nonlinear corrections a', b', and c' in FIG. 5(B).

In this embodiment, the recording device characteristic correction data a', b shown in FIG. 5(B) is stored in advance in the ROM 8 of the controller 8.
', c' are stored, and the device signal generator 25 of printer B outputs to controller B a signal for selecting correction data in the ROMs that is optimal for that device.

In addition, FIG. 6 (A) shows the characteristics of the recording device of the electrophotographic printer as shown in FIG. 2 in the operating environment A (L/L: low temperature, low humidity), B (J/J: normal temperature, normal humidity), (H/
H: high temperature, high temperature). In electrophotographic printers, depending on the environment in which the printer is placed, the charging characteristics and sensitivity characteristics of the photoreceptor and the electrical characteristics of the developer vary, causing changes in density characteristics as shown in FIG. 6(B). A and C in Figure 6 (A) of these characteristic fluctuations depending on the usage environment are obtained by adding the input image density data to the input image density data.
By correcting A' and C' in FIG. 6(B), it is possible to convert the characteristics to the standard recording device characteristics of the device shown in B in FIG. 6(A).

In this embodiment, correction data (recording device usage condition correction data) according to the usage environment shown in FIG. 6(B) is stored in advance in the ROM 9 of the controller 8.
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The temperature and humidity of the usage environment are detected by the environmental sensor 26 (r1: hill, skewer L = pine - h), and the detection output is sent to an A/D (analog/digital) converter 27.
After performing analog-to-digital conversion, the converted data is output to controller B as a signal for selecting correction data in ROMQ that is optimal for the environment.

In this way, the recording device characteristic correction data that has been corrected according to the usage conditions of printer B is input into the RAM 5 of controller A, and a constant high quality can be achieved regardless of the model of printer B or its usage environment. The image can be output from printer B.

The environment sensor 26 is provided in the printer B rather than in the controller A so that the controller A and the printer B can be installed at different locations and can be used in different environments.

The timing for sending the device characteristic signal and usage environment signal to controller A is preferably immediately after controller A and printer B are powered on. It is preferable to use a 4-seater Taste Yami K tile.

Further, the page memory 2 in the controller A in FIG. 2 is not necessarily necessary, and it is of course possible to input image data by sequential processing without using the page memory 2.

FIG. 7 shows the circuit configuration of a second embodiment of the present invention. In this embodiment, the same parts as those in the first embodiment shown in FIG. 2 are given the same reference numerals, and the explanation thereof will be omitted.

The feature of this embodiment is that the ROM 30 for environmental condition correction data is provided in the circuit on the printer B side. Figure 2, 1st
In this embodiment, by providing a ROM 9 on the controller A side that stores a plurality of standardized environmental condition correction data regardless of the printer model, the cost of printer B can be reduced.
can do.

Although the cost of this embodiment is higher than that of the first embodiment, the performance with respect to image quality is superior.

That is, particularly in electrophotographic printers, variations in the image output characteristics of the recording device due to changes in the operating environment vary depending on the model, and some standardized correction data may not be sufficient for correction. In this embodiment, by providing the ROM 30 for environmental condition correction data in the printer B, it is possible to create several types of correction data that are optimal for each printer, so that corrections in response to environmental changes can be performed with high precision. .

Note that the operation in this embodiment is almost the same as that in the first embodiment, so a description thereof will be omitted.

Also, R for storing the device characteristic correction data in FIG.
The OM8 can be installed in the printer B to perform subtle corrections unique to each printing apparatus for each printer. In this case, although the cost is somewhat higher, it is preferable for improving image quality.

FIG. 8 shows a circuit configuration of a third embodiment of the present invention, and the same parts as in FIG. 2 are denoted by the same reference numerals.

Incidentally, among recording apparatuses, particularly in electrophotographic recording apparatuses, image characteristics vary depending on the number of prints used. Figure 9 shows the number of sheets of process cartridge paper used (hereinafter referred to as the number of printed sheets) in a laser printer that uses a so-called process cartridge in which the heart of an electrophotographic recording device, such as the photoreceptor and developing device, are integrated into one unit. It shows the relationship with the density of the halftone image. Figure 10 shows the curves a, b, and c in Figure 9 in the same manner as in Figure 5 (A) or Figure 6 (A) above.
It is a diagram.

In this embodiment, correction data for converting to the standard characteristic curve b in FIG. 10 is stored in advance in the ROM 29 in FIG.
Based on the signal from the process cartridge usage information signal generator 3l in the printer B shown in Fig. 8, the optimum density correction data corresponding to the usage conditions of the process cartridge is stored in the ROM.
Select from 29. The usage information of the process cartridge notch sent from the usage information signal generator 31 includes the cumulative number of prints with that cartridge, as well as the sensor inside the process cartridge. ``But ノ, n 豐波 H 綽星RU 亘1.j-
In this way, in this embodiment, by selecting the optimal device characteristic data for each recording device and adding corrections based on environmental conditions and furthermore, corrections based on the number of prints used, even higher quality can be achieved. images can be obtained.

Note that the following may be considered for the above-mentioned device characteristic signal.

First, when replacing a laser or laser driver in a laser printer, the device characteristic signal is changed to take into account the characteristics of the laser or laser driver. That is, the rise speed of the amount of laser light varies greatly, especially in the case of semiconductor lasers, because the variation in light emission characteristics is large, and the variation in the current rise characteristics of the laser driver is also added to this variation. This is because the change in the rise speed of the amount of laser light has a significant effect on the output image quality of the laser printer.

Second, when replacing a process cartridge, the characteristics of the process cartridge should be taken into consideration.
``To top it all off, it is normal for the photosensitive drums built into process cartridges to vary in charging performance, laser light sensitivity, etc. depending on the manufacturing conditions and from manufacturing set to manufacturing set.

This is because such variations in the photosensitive drum appear as phenomena in which the character line width of the output image becomes thicker or thinner, and the image density becomes thicker or thinner each time the cartridge is replaced.

In addition, as image correction signals, ■ Laser light intensity rise speed correction signal, ■ Process cartridge characteristic correction signal, ■
It goes without saying that two to four signal output means may be provided, such as a correction signal according to the environmental conditions of use, and a correction signal according to the number of prints used.

[Effects of the Invention] As explained above, according to the present invention, a device characteristic signal related to recording characteristic information that differs for each recording device, information related to the environment in which the recording device is used, and the number of sheets used by the recording device The device is configured to output device usage condition signals related to usage conditions such as information on the recording device to an external device such as a host computer or controller, and the external device responds to the recording device and its usage conditions based on the plurality of signals. By applying optimal image processing correction to the image data before sending it to the recording device, the image quality, which varied depending on the recording device and usage conditions, can always be maintained at a constant high quality. Effects can be obtained.

In addition, external devices such as host computers or controllers are originally configured mainly for signal processing, making it easy to perform complex image processing corrections, etc., and have a relatively large storage capacity. It also has the advantage of reducing the cost burden of memory used for correction, and as a result, the entire image processing system, including the recording device and controller, can stably obtain high-quality images at a low cost. can get.

In the above-described embodiments of the present invention, an example of application to a laser beam printer has been described, but the present invention is not limited to this, and can of course be applied to other recording devices such as a thermal transfer printer or an inkjet printer. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing the circuit configuration of an embodiment of the present invention, FIG. 3 is an explanatory diagram showing an example of a dither matrix, and FIG. 4 Figure 5 (A) is a graph showing an example of gradation characteristics when the printer model or usage environment is different.
B) is a graph showing the contents of the lookup table for tone correction regarding the device characteristics in the embodiment of the present invention, and FIGS. 6(A) and (B) are the lookup tables for tone correction related to the usage environment in the embodiment of the present invention. FIG. 8 is a block diagram showing the circuit configuration of still another embodiment of the present invention. FIG. 9 is a graph showing an example of the relationship between the number of prints of the printer and image density. The figure is a graph showing an example of gradation characteristics related to the number of prints output by a printer. 1... Image data, 2... Page memory, 3... Line buffer, 4, 10... CPU, 5... RAM, 6... Dither pattern generation circuit, 7... Comparator , 8, 9, 29. 30...ROM, 25...
Device characteristic signal generator, 26...Environment detection sensor, 27...A/D converter, Drawing sword drawing 4 turtle A1 branch Godoku 5th figure 2, rough faith 11 JjJ talking 1 goichi 6th figure

Claims (1)

[Scope of Claims] 1) A recording device that receives image data as an electrical signal from an external device and outputs a visible image on a recording medium, characterized in that a plurality of image correction signal output means are provided. Recording device. 2) In a recording device that receives image data as an electrical signal from an external device and outputs a visible image on a recording medium, a first controller that outputs an image correction signal related to characteristics unique to the recording device to the external device. A recording apparatus comprising: a signal output means; and a second signal output means for outputting an image correction signal regarding usage information of the recording apparatus to the external device. 3) The recording device according to claim 2, wherein the usage information includes environmental information such as temperature and humidity in which the recording device is placed and/or the cumulative number of sheets recorded. 4) The recording apparatus according to claim 1, wherein the image correction signal is a signal processed by the external device as a tone correction signal of a halftone image.