JPH10315542A - Printing equipment - Google Patents

Abstract

(57) [Summary] (Corrected) [Problem] A printing apparatus that prints on recording paper in accordance with print information output from a higher-level device such as a personal computer, in particular, automatically prints the thickness and size of print characters, etc. Provided is a printing apparatus capable of adjusting density and printing characters and images that are always easy to see. A toner save level analysis / selection unit (31) analyzes commands such as a character type designation command, a character size designation command, and a gradation designation command included in print information, and obtains the result by, for example, analyzing the character type designation command. The character thickness is determined from the character type, for example, “extra fine Mincho”, “fine Mincho Gothic”, etc., and the corresponding density data is selected from the toner save parameter setting value table 32 to select a toner save control unit. Output to 30. When the print engine unit 3 prints the data developed in the image memory unit 29, the toner save control unit 30 performs the printing process of the optimum density on the recording paper according to the above-described density data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing on recording paper in accordance with print information output from a host device such as a personal computer.

[0002]

2. Description of the Related Art As a printing apparatus for printing on recording paper in accordance with print information output from a host device such as a personal computer, there is an electrophotographic printer. In this apparatus, for example, a photosensitive drum, a charger, a print head, a developing device, and a transfer roll are arranged in the vicinity of a peripheral surface thereof, and recording paper is supplied between the photosensitive drum and the transfer roll. While the recording paper is being conveyed between the photoconductor drum and the charging roll, the peripheral surface of the photoconductor drum charged to a predetermined level is exposed from the print head, and the formed electrostatic latent image is transferred to the toner in the developing device. The toner image is transferred (transferred) to a recording paper, and the toner image transferred to the recording paper is thermally fixed by a fixing device after the transfer processing, and is discharged outside the apparatus. You.

In the printing apparatus described above, the adjustment of the print density has conventionally been performed as follows. That is, FIGS. 11A and 11B are schematic diagrams for explaining a conventional print density setting method. FIG. 11A shows the print density level, and “A” to “A” shown in FIG. "C", "a" to "c"
Is density data corresponding to each level. In addition, "A" ~
The density data “C” is data when the resolution is 300 DPI, and the density data “a” to “c” have a resolution of 60
This is data at the time of 0 DPI.

[0004] A user of the printing apparatus operates an operation panel (not shown) or selects a normal level or levels 1 to 3 according to a command from a host device. For example, when the normal level is selected, 100% density printing is performed. Do, level 1
At the time of printing, printing is performed at 75% density, at level 2 printing is performed at 50% density, and at level 3 printing is performed at 25% density.

When any one of levels 1 to 3 is selected, density data corresponding to the selected density level is selected from a table (toner save parameter setting value table), and the above-mentioned "A" to "C" is selected. , "A" to "c". Further, the density data of “A” to “C” and “a” to “c” set in the table are fixed values, and the selection of the density levels 1 to 3 requires the user of the printing apparatus to check the print result. Is selected each time.

[0006]

As described above, the conventional setting of the density level is such that the user selects the print level by looking at the actual print result, and repeats the printing process many times while watching the normal print result. Thus, an image having an optimum print density was obtained. Therefore, in the conventional method of setting the density level, the operation is complicated, the recording paper (paper) is wasted, and the toner is wasted.

Further, depending on the characteristics of the printing apparatus, an image having the expected print density is often not obtained as a print result even when the selected density level is the same. Furthermore, depending on the data to be printed, it may be difficult to see the result as a print result. For example, when the lightest level (level 3) is selected, the line formed by one dot also becomes thin, and some characters cannot be distinguished depending on the form of the characters.

[0008] The object of the present invention is to solve the above-mentioned conventional situation,
Print density is automatically changed according to the thickness and size of print characters, print gradation, etc., and print processing of characters and images that are always easy to see is performed. As a result, printing that eliminates waste of toner and waste of recording paper is achieved. An apparatus is provided.

[0009]

According to a first aspect of the present invention, there is provided an apparatus for analyzing print information input from a higher-level device, comprising: a print unit included in the print information analyzed by the analysis unit; This can be attained by providing a printing apparatus having print density setting means for automatically setting print density according to characteristics, and print processing means for performing print processing in accordance with the print density set by the print density setting means.

The analyzing means analyzes various commands included in the print information. In particular, the analyzing means analyzes a printing characteristic command supplied from a higher-level device such as a personal computer, and analyzes the command by a printing density setting means. The density is set according to the printing characteristics thus set. The print density setting means is, for example, a special print density setting circuit or a CP.
It consists of U and print density setting software, and automatically sets print density according to print characteristics.

Therefore, by printing the density set by the print density setting means on the recording paper by the print processing means, for example, it is possible to obtain an image having a print density corresponding to the print characteristics, and to obtain a print image which is extremely easy to see. Obtainable. In addition, since the level is automatically set, it is not necessary to set the level a plurality of times by manual operation, so that waste of toner and waste of recording paper can be eliminated.

According to a second aspect of the present invention, the printing density setting unit refers to a table prepared in advance according to the printing characteristics. This is the configuration for setting.

That is, in the above table, toner density setting parameters are set in advance, data for realizing an optimum print density according to each print characteristic are set, and density data corresponding to the above print characteristic is read from the table. By performing printing processing of a density according to the printing density on the recording paper, printing at an optimum density can be performed.

With this configuration, it is possible to automatically obtain an extremely easy-to-view printed image, and to reduce waste of toner and recording paper. The description of claim 3 makes the description of claim 1 or 2 more specific, and the printing characteristic is, for example, the thickness of a character.

With this configuration, a character type table obtained by analyzing the character type designation command by the analysis means is selected by referring to, for example, a character type table set according to the difference in character thickness, and automatically. The printing process can be performed at the optimal print density. For example, thick characters can be printed lightly without being too dark, thin characters can be printed darkly without being too light,
In particular, the inconvenience that thin characters become thin and unreadable can be solved.

[0016] The description of claim 4 also makes the description of claim 1 or 2 more specific, and the printing characteristic is:
For example, the size of a character. With such a configuration, for example, by referring to a table set according to the character size (size) and analyzing the character size designation command by the analyzing means, optimal printing is performed from the point data indicating the character size obtained. Concentration can be selected automatically. For example, large size characters are printed too light without being too dark, and small size characters are printed too dark without being too light.

According to a fifth aspect of the present invention, the description of the first or second aspect is made more specific.
For example, there is print gradation. With this configuration, the analysis unit automatically selects the gradation included in the print information by referring to, for example, a table set according to the gradation of the image, and performs print processing with an optimum print density. be able to. For example, an image with a large number of gradations is printed too light without being too dark, and an image with a small number of gradations is printed too dark without being too light. You can print with

The sixth aspect of the present invention makes the first or second aspect of the present invention more specific, and the identification of the printing characteristics utilizes, for example, a compression ratio. That is,
Pattern data with a high compression ratio has a high compression efficiency because the pattern of the original image data is simple, and can be judged to be an image similar to a character image. Conversely, pattern data with a low compression ratio has a complicated original image data. Yes, for example, when there is a high possibility of halftone or image data, and therefore a high compression ratio is obtained, the toner supply amount is reduced, and when the compression ratio is low, the toner supply amount is increased, and printing that is easy to read is performed. It can be configured.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is a diagram showing a system configuration of a printing apparatus according to a first embodiment. As shown in FIG. 1, the printing apparatus 1 includes an interface control unit 2 and a print engine unit 3. The interface control unit 2 includes an MPU (ultra small central processing unit) 4 for controlling the whole, and the MPU 4 includes a system ROM 5 in which a control program is stored,
A system RAM 6 for temporarily storing processing / computation data by U4, a font ROM 7 for storing shape data of characters to be printed out, and an external I / O for connecting to an external host device (upper device) 8 such as a personal computer. / F (interface) control unit 9, a memory / I / O (input / output) control unit 10 for controlling input / output of data and signals to and from a memory and other input / output devices, and counts output signals of predetermined sensors and the like. Counter 11 is connected.

The external I / F controller 9 and the memory I / F
The O control units 10 are connected to each other, and
The O control unit 10 further includes a video I / F control unit 12 for transmitting and receiving print data and control signals to and from the print engine unit 3,
A buzzer control unit 14 for controlling the sound emission / stop of the buzzer 13 and an operation / display control unit 16 for detecting a key input operation of the operation / display unit 15 and driving the display of the liquid crystal display device are connected.

Next, the print engine unit 3 as a print processing unit includes an engine control unit 18 for controlling a printing operation. The engine control unit 18 transmits and receives print data and control signals to and from the interface control unit 2. The video I / F control unit 19, the printer head 17, the toner / drum set 20, the fixing unit 21, the transfer unit 22, and the cassette sheet feeding unit 23 are connected. Further, a drive load 24 such as a drive motor, a transport motor, and a paper guide lever (not shown) are also connected to the engine control unit 18. The detection signals from sensors Sn such as a paper feed sensor and a paper discharge sensor (not shown) Is output to the video I / F control unit 19.

FIG. 2 is a diagram specifically explaining the functional configuration of the interface control unit 2 described above. The reception buffer 26 corresponds to a part of the system RAM 6 in the interface control unit 2 described above, and the command data analysis / execution unit 27 corresponds to the MPU 4. Receive buffer 26
Receives print information supplied from the host device 8 and stores print information for a predetermined page. Then, the reception buffer 26
When a predetermined amount of print information is stored in the command data analyzing / executing unit 27 (MPU 4), the print information is analyzed according to the control of the command data analysis / execution unit 27 (MPU 4). The drawing unit 28 also corresponds to the MPU 4, and when the print information obtained as a result of the above-described analysis processing is a character code, the drawing unit 28 reads the corresponding pattern data from the font ROM 7 and writes it to the image memory unit 29.

Further, the toner save control unit 30 controls image data (pattern data) output from the image memory unit 29.
Is output to the print engine unit 3, the amount of toner used is controlled. There are various methods for controlling the amount of toner used, for example, switching of a developing bias voltage,
There are methods such as adjustment of the exposure amount and control of the amount of charge on the photosensitive drum, which will be described in detail later.

The above-described control of the toner amount by the toner save control unit 30 is analyzed and selected by the toner save level analysis / selection unit 31, and is performed in accordance with the set density data.

Here, the analysis result of the command data analysis / execution unit 27 is output to the toner save level analysis / selection unit 31, and the output of the toner save parameter setting value table 32 is also supplied. Further, the toner save level analysis / selection unit 31 and the toner save parameter set value table 32 have a function as a print density setting unit.

The table shown in FIG. 3 shows a part of the toner save parameter setting value table 32, and shows a specific example of the table in the automatic mode described later. FIG. 4B also shows a part of the toner save parameter setting value table 32, showing a specific example in the level setting mode. Here, the table in FIG. 4B is a table of the print density according to the resolution with respect to the manually set level setting value, and has the same configuration as that of the conventional example. On the other hand, the table in the automatic mode shown in FIG. 3 is a table of the print density according to the character thickness (character type). In this case, the resolution data is also taken into account. The character thickness data is data included in the print information output from the host device 8, and specifically, is a character type designation command included in the print information.

The commands included in the print information include a character size designation command, a line type designation command,
There is a gradient designation command. Next, the processing operation of the first embodiment in the above configuration will be described below.

First, as described above, when a predetermined amount of print information including image data is supplied from the host device 8 to the reception buffer 26, the command data analysis / execution unit 27 performs print information analysis processing, and In the section 29, one page of pattern data is developed. If the character information designation command is included in the print information analyzed by the command data analysis / execution unit 27 during this time, the command data is output to the toner save level analysis / selection unit 31. After that, the MPU 4 continues the printing process according to the flowchart shown in FIG.

That is, it is determined whether or not the mode is the toner save mode (step (hereinafter referred to as S) 1). If the mode is not the toner save mode, normal setting is performed (S2), and the printing process is continued. The determination as to whether the mode is the toner save mode can be made by analyzing a command output from the host device 8. Further, the setting can be made by operating the operation / display unit 15 of the printing apparatus 1.

Here, when it is determined that the toner save mode is set in the above determination (Y in S1), it is determined whether the print density setting processing is automatically performed (or performed manually) (S3). ). This determination can also be made by analyzing a command output from the host device 8, or can be set by operating the operation / display unit 15. Here, for example, when it is determined that the manual setting is performed as in the related art (N in S3), the user of the printing apparatus 1 operates the operation / display unit 15 to select one of the density levels 1 to 4. (S4). FIG. 4A shows the toner consumption for each level 1 to 4 selected at this time. For example, if the normal level is 100% of toner consumption,
The toner consumption is 75% at level 1, 50% at level 2, 35% at level 3, and 25% at level 4.

On the other hand, if it is determined in the above-mentioned determination (S3) that the mode is the automatic mode (Y in S3), a process of analyzing the thickness of the character font is performed (S5). That is, the toner save level analysis / selection unit 3 determines the thickness of the print character.
1 analyzes the character typeface (character type) included in the print information (S5). At this time, if the print information includes the character type designation command as described above, the character type designation command is supplied to the toner save level analysis / selection unit 31, and the toner save level analysis / selection unit 31 analyzes the character type designation command. Then, corresponding density data is selected from the toner save parameter setting value table 32 (table shown in FIG. 3) according to the analysis result (S6).

As described above, the toner save parameter setting value table 32 is shown in FIGS. 3 and 4B, and refers to the table of FIG. 3 in the automatic mode. For example, if it is determined from the analysis result of the character type designation command that the character type is “extra fine Mincho”, the character thickness is determined to be extra fine line characters. Then, referring to the resolution at this time, for example, if the resolution is 300 DPI, "A"
Is output, and if the resolution is 600 DPI, "a" is output as density data (S7). Also, for example, if the character type is found to be in the form of “Thin Mincho Gothic” from the analysis result of the character type designation command, the thickness of the character is determined to be a thin line character. "B" is output as data and the resolution is 600 DPI
If so, "b" is output as the density data (S7).

If the character type obtained from the character type designation command is another format shown in FIG. 3, the data of the thickness of the corresponding character shown in FIG. 3 is output as density data. Therefore, as described above, the toner save level analysis /
The density data analyzed and selected by the selection unit 31 is output to the toner save control unit 30, and the toner save control unit 30 prints the density corresponding to the character used.

For example, when it is determined that the character is in the “fine-thick Mincho” format and that a fine line character is used as the character thickness, “A” or “a” is selected as the density data as described above. Printing is performed in a dark state with a toner consumption of 75%. Therefore, the data expanded in the image memory unit 29 based on the data having the high print density is printed by the print engine unit 3, prints extremely thin characters with a high density, and prints characters that can be clearly read. be able to.

The analysis result of the character type designation command is
When it is determined that the character is of “extreme gothic” format and that a thick character is used as the character thickness, “D” or “d” shown in FIG. Thin printing with an amount of 25% is performed.
Therefore, when thick characters are printed as described above, a low print density is selected, and the pattern data developed in the image memory unit 29 is printed on recording paper.

In this case, since the characters to be printed on the recording paper are in a thick "extreme gothic" format, there is no problem that the characters cannot be read even if a relatively thin printing process is performed. Further, by selecting the print density as described above, it is possible to save toner and to prevent waste of recording paper.

In the above-described processing, if any one of levels 1 to 4 is selected (S3 = N, S4), the selection of density data is shown in FIGS. 4 (a) and 4 (b). Thus, the corresponding density data "A '" to "D'", "a '" to
“D ′” is selected, and the same print processing as in the conventional example is performed.

Here, several methods for controlling the print density performed by the toner save control unit 30 described above are conceivable.
Representative examples are shown below. First, there is a method in which the developing bias voltage is switched to control the amount of toner attached to the photosensitive drum during development.
In this case, a developing bias voltage control signal is output from the engine control unit 18 in the print engine unit 3 to the toner / drum set 20 to control the bias voltage of the developing roll. By this control, the amount of toner (image) adhered based on the electrostatic latent image formed on the photosensitive drum is adjusted,
The print density recorded on the recording paper after the transfer can be adjusted.

As another method, when an electrostatic latent image is formed on a photosensitive drum, the exposure amount is adjusted to control the charge of the formed electrostatic latent image, thereby adjusting the print density. . For example, when the printing apparatus 1 is a laser printer, the light emission output of the laser diode is changed to the toner save control unit 3 described above.
By changing according to the density data set to 0, the print density of the image data can be adjusted.

Further, as another method, the electrostatic latent image is developed by controlling the voltage value of a charger for initially charging the photosensitive drum and changing the voltage value according to, for example, density data set in the toner save control unit 30. It is possible to control the amount of toner adsorbed at the time of printing and to adjust the print density.

There are various other print density adjustment methods, and the present invention is not limited to a specific toner save method. Further, the present invention is not limited to the laser printer, but can be similarly implemented in other printing apparatuses such as an LED printer. <Second Embodiment> Next, a second embodiment of the present invention will be described. Note that, also in this example, the configuration of the printing apparatus 1 is the same as that of FIG. 2 of the above-described embodiment, and the configuration of the interface control unit 2 is basically the same as that of FIG. However, the configuration of the toner save parameter setting value table 32 shown in FIG. 2 is different.

FIG. 6 shows a table configuration in the automatic mode set in the toner save parameter setting value table 32. In this example, the print density is automatically set according to the character size. In the table, the character size point (data), the character size corresponding to the point (data), and the density data “E” corresponding to the resolution are set. "~
“H” and “e” to “h” are registered. For example, when the character size is 1 to 5 points, it is a very small letter, when the character size is 5 to 10 points, it is a small / medium character, when the character size is 10 to 15 points, it is a capital letter, and the character size is 15 or more. Is a very uppercase letter, and density data “E” to “H”,
“E” to “h” are registered.

Next, a printing process in the printing apparatus according to the second embodiment having the above configuration will be described. When a predetermined amount of print information including image data is supplied from the host device 8 to the reception buffer 26, the command data analysis and execution
7, the print information is analyzed by the image memory unit 2.
9, one page of pattern data is developed.

During this time, the process is performed according to the flowchart shown in FIG. 7. First, it is determined whether the mode is the toner save mode (S1). If the mode is not the toner save mode, normal setting is performed (S2), and the printing process is continued. The determination as to whether or not the toner save mode is made is made by analyzing a command output from the host device 8 or by operating the operation / display unit 15 of the printing apparatus, as described above.

Here, if the toner save mode is set in the above determination (Y in S1), it is determined whether the print density setting process is automatically performed (or is performed by manual setting) (S3). Here, for example, when it is determined that the manual setting is performed as in the related art (N in S3), the user of the printing apparatus 1 operates the operation / display unit 15 to select one of the density levels 1 to 4 (S4). ).

On the other hand, in the above determination (S3), when it is determined that the mode is the automatic mode (Y in S3), the character size is analyzed (S5 '). That is, the toner save level analysis / selection unit 3 determines the size of the print character.
Numeral 1 analyzes a character size designation command included in print information. At this time, if the character size designation command included in the print information is 1 to 5 points, it is determined from the table of FIG. 6 that the character size is extremely small, and the corresponding density data is selected from the table (S6). . For example, when it is determined that the analysis result of the character size is 4 points and is a very small letter, "E" is output as the density data when the resolution is 300 DPI, and "e" is output as the density data when the resolution is 600 DPI. Output. For example, when it is determined that the analysis result of the character size is 20 points, “H” is selected as the density data and the resolution is set to 600 points.
For DPI, "h" is selected as the density data.

As described above, when the character size to be printed on the recording paper is small, the print density is increased, and when the character size to be printed is large, the print density is reduced. It is possible to print characters and the like that do not occur.

It should be noted that lowering the print density for large characters does not make it particularly difficult to read. In this respect, it is possible to eliminate waste of toner and eliminate test printing a plurality of times, thereby preventing waste of recording paper.

In the above-described processing, if any one of levels 1 to 4 is selected (S3 is N, S4), the selection of density data is performed in the same manner as in the first embodiment. FIG.
As shown in (a) and (b), corresponding density data “A ′” to “D ′” and “a ′” to “d ′” are selected,
The same print processing as in the conventional example is performed.

As described in the first embodiment, the specific method of changing the print density set as described above includes a method of switching the developing bias voltage, a method of adjusting the exposure amount, and a method of A method of adjusting the initial charging voltage for the drum, or the like can be used. <Third Embodiment> Next, a third embodiment of the present invention will be described. In this embodiment, the configuration of the printing apparatus is the same as that of FIG. 1 of the above-described embodiment, and the configuration of the interface control unit 2 is basically the same as that of FIG. However, the configuration of the toner save parameter setting value table 32 shown in FIG.

FIG. 8 shows a table configuration of the automatic mode set in the toner save parameter setting value table 32 used in this embodiment. In this example, the gradation specifying command included in the print data is analyzed and the print density is automatically set. The table shows the gradation values of the image data and the density data “I” to "L", "i"-"l"
Is registered. For example, when the gradation value is binary, the density data outputs “I” when the resolution is 300 DPI, and outputs “i” when the resolution is 600 DPI.
When the gradation value is 3 to 4, the density data outputs “J” if the resolution is 300 DPI, and the resolution is 600.
If it is a DPI, "j" is output. Hereinafter, the relationship between the gradation value and the density data is as shown in FIG.

Next, the printing operation of the printing apparatus of the third embodiment having the above-described configuration will be described. 2 above
As in the first embodiment, when a predetermined amount of print information including image data is supplied from the host device 8 to the reception buffer 26, the command data analysis / execution unit 27 performs print information analysis processing, and the image memory unit 29 Is developed for one page of pattern data. During this time, the process is performed according to the flowchart shown in FIG. 9, and it is determined whether or not the toner save mode is set (S1). If the toner save mode is not set, the normal setting is performed (S2). In some cases, it is determined whether the print density setting process is automatically performed (S1 is Y, S3). For example, if it is determined that the mode is the automatic mode (S3 is Y), an analysis process of the tone value of the image data is performed (S5). ”).

In this process, the number of gradations of the image data supplied from the host device 8 is determined, and the analysis processing of the gradation designation command included in the print information is performed. At this time, the result of the analysis processing of the gradation designation command indicates that the gradation number is “2”.
If the value is "value", the density data "I" or "i" according to the resolution is selected as the density data (S6). On the other hand, when the analysis result of the gradation designation command is equal to or greater than the number of gradations "7 values", the density data "L" or "1" according to the resolution is selected as the density data (S6).

That is, when the gradation value is binary, the gradation of the image data is poor, and the image is clarified by increasing the toner density, while the gradation value is high such as 7 or more. If it has a value, the clarity of the image is not degraded even if the toner concentration is reduced, and there is almost no effect on the character discrimination. Therefore, as described above, the density data can be varied according to the number of gradations of the image data, and the printing processing with the density most suitable for the number of gradations can be performed.

The specific method of changing the print density set as described above includes a method of switching the developing bias voltage and a method of adjusting the exposure amount as described in the first and second embodiments. For example, a method of adjusting the initial charging voltage to the photosensitive drum can be used.

In the above three examples, the print density is adjusted in accordance with the character thickness, the character size, and the gradation value of the image data. The MPU 4 may recognize the ratio between the amount (character code amount) and the image data amount (bitmap data amount) and switch the print density. Further, the configuration may be such that the print density is switched by recognizing the amount of halftone image data.

Further, even if the table is set in the toner save mode in advance, if there is a large amount of character data, the print density is set to be high so that the characters are clear. For example, if the print density is too high, the image is returned and the image is crushed, making it difficult to see. Therefore, it may be set so that the print density is reduced and printing is performed.

The interface control unit 2
, The generated pattern data is stored in the image memory unit 2
In order to increase the memory capacity when storing the data in the storage unit 9 and to perform high-speed printing processing with a reduced data transfer amount, compression processing is performed and stored in the image memory unit 29, and the compressed data is output to the print engine unit 3 and printed. The engine unit 3 may perform a decompression process and print. In this case, the compression ratio of the image data in the compression processing may be identified, and the print density may be set according to the result. In other words, pattern data having a high compression ratio has a good compression efficiency because the pattern of the original image data is simple, and such a simple pattern has many images similar to a character image,
Therefore, even if printing is performed at a high density, the printing result is easy to see, but on the other hand, pattern data having a low compression ratio is complicated in the original image data, and is likely to be halftone or image data. In this case, printing at a low density is easier to see. FIG. 10 is a diagram showing the above relationship.

Therefore, when the high compression ratio is obtained in the compression stroke for the above-described reason, the toner supply amount is reduced, and when the compression ratio is low, the toner supply amount is increased, and printing is performed in a manner that is easy to see. It can be. The compression ratio can be determined by comparing the data amount of the data of one page before and after the image compression processing, for example.

[0060]

As described above, according to the printing apparatus of the present invention, the print density corresponding to the print characteristics is automatically set and the print processing is performed, so that an image having the print density corresponding to the print characteristics is obtained. This makes it possible to obtain an extremely easy-to-view printed image.

Further, since the print density is automatically set, it is not necessary to set the density level by manual operation, so that waste of toner can be prevented and recording paper can be wasted.

Further, it is possible to perform a printing process with an optimum printing density for printing characteristics such as character thickness, character size, and gradation value.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a system configuration of a printing apparatus according to a first embodiment.

FIG. 2 is a diagram specifically illustrating a functional configuration of an interface control unit.

FIG. 3 is a diagram showing a part of a toner save parameter setting value table and showing a specific example of the table in an automatic mode.

FIG. 4A is a diagram illustrating a density level,
FIG. 6B is a diagram illustrating a part of a toner save parameter setting value table, and a specific example of the table in a manual mode.

FIG. 5 is a flowchart illustrating a printing example in which a print density is changed based on a difference in character thickness.

FIG. 6 is a diagram showing a part of a toner save parameter setting value table and showing a specific example of the table in an automatic mode.

FIG. 7 is a flowchart illustrating a print example in which a print density is changed based on a difference in character size.

FIG. 8 is a diagram showing a part of a toner save parameter setting value table and showing a specific example of the table in an automatic mode.

FIG. 9 is a flowchart illustrating a print example in which a print density is changed based on a difference in the number of gradations of image data.

FIG. 10 is a diagram illustrating a setting relationship of print density depending on a difference in compression ratio.

FIG. 11 is a diagram illustrating a conventional toner save parameter setting value table, illustrating an example of a manual mode.

[Explanation of symbols]

 Reference Signs List 1 printing device 2 interface control unit 3 print engine unit 4 MPU 5 system ROM 6 system RAM 7 font ROM 8 host device 9 external I / F control unit 10 memory / I / O control unit 11 counter 12 video I / O control unit 13 Buzzer 14 Buzzer control unit 15 Operation / display unit 16 Operation / display control unit 17 Printer head 18 Engine control unit 19 Video I / O control unit 20 Toner / drum set 21 Fixing unit 22 Transfer unit 23 Cassette feeding unit 24 Drive load 26 Receive buffer 27 Command data analysis / execution unit 28 Drawing unit 29 Image memory 30 Toner save control unit 31 Toner save level analysis / selection unit 32 Toner save parameter setting value table

Claims (6)

[Claims] An analyzing means for analyzing print information input from a host device; a print density setting means for automatically setting a print density in accordance with a print characteristic included in the print information analyzed by the analyzing means; A printing apparatus, comprising: printing processing means for performing a printing process in accordance with a print density set by a density setting means. 2. The printing apparatus according to claim 1, wherein said print density setting means sets a print density by referring to a table created in advance according to said print characteristics. 3. The printing apparatus according to claim 1, wherein the printing characteristic is character thickness. 4. The printing apparatus according to claim 1, wherein the printing characteristic is a character size. 5. The printing apparatus according to claim 1, wherein the print characteristic is print gradation. 6. The printing apparatus according to claim 1, wherein the identification of the printing characteristics uses a compression ratio.