JP2000311250A - Printing device and method and print control device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw a rectangle gradient fill object via a triangle gradient fill processing circuit. SOLUTION: The positions of two points set on a diagonal line of a rectangle gradient fill object 4001 are designated together with the density of the said positions. The density of two sides opposite to each other are decided by the density of a vertex, and the object 4001 is drawn so as to connect both opposed sides with a slow density gradient. Then, a rectangle is divided by its diagonal line and the density of a side where every vertex is positioned is given as the density of vertex of a triangle, and this triangle is drawn by a triangle gradient fill processing circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus such as a printer which performs rendering for each object, and a printing method.

[0002]

2. Description of the Related Art In recent years, as a data processing system, a host computer and a bidirectional interface (for example, IEEE1284.4, IEEE1394, USB) have been used.
, Etc.) and a printer connected via the printer. In such a system, output information input from the host is analyzed on the printer side, and data suitable for the printer engine is generated and printed. For example, if the engine is a laser beam printer, develop bitmap data as output data, modulate the laser beam based on this data, scan and expose the photosensitive drum to form an image, and print the image on a recording medium. Form.

When a printer has an emulation function, the printer can process a plurality of printer control language systems, and can execute print processing while switching between an emulation mode and a native mode according to an application executed by a user. Such a printer is provided in advance with a switch for switching the control language of the printer and a card slot for issuing a switching instruction.

[0004] In many cases, it is possible to directly connect to an image input device such as a scanner or a digital camera without using a host computer, to obtain image data from the image input device and print the image data.

In addition, various new image processing techniques have been adopted due to the recent improvement in the processing capability of host computers. An image processing technique called a gradient fill, which is used to fill a certain area with a smooth density gradient (shading), is one of them. With reference to FIG. 3, the difference between the conventional method and the filling with the gradation of the area using the gradient fill object will be described. FIG. 3A shows a conventional technique, in which the objects (here, band-shaped objects) filled with different densities are arranged and drawn to express the gradation of the area. In the case of this method, there is a density difference between the objects as shown by the rectangle on the right side of FIG.

FIG. 3B shows a drawing example of a rectangular area by the gradient fill technique. In this example,
The coordinates of the diagonal points of the rectangle and the density at that point (in this example, 0 = black; 255 = white 8-bit gradation expression) are specified, and the density is continuous from one point to the other point. Filling is performed while calculating the density for each pixel in the image area so that the image transitions.

As shown in the right figure of FIG. 3B, a vertex is represented by a set (x, x) of XY coordinates (however, the vertical direction in the figure is the X axis) and its density.
y, c), the coordinates and density of vertex 1 are represented by (x
1, y1, c1), the coordinates and density of vertex 2 are (x2, y
2, c2), if any pixel in the rendering area is (xn, yn, cn), the density cn of each pixel of the rectangular gradient fill object is constant in the horizontal direction (Y-axis direction) : Cn = (c2−c1) / (x2−x1) × xn When the density is constant in the vertical direction (X-axis direction): cn = (c2−c1) / (y2−y1) × yn

FIG. 3C shows a case where a triangle is used as a gradient fill object. By specifying the density of the vertices of the triangle in this way, it is possible to freely determine the direction of the gradation even for the same shape.

The density of any one pixel of the triangular gradient fill object can be obtained by solving the following cubic equation when three vertices are applied to the coordinates in the same manner as the rectangular gradient fill object.

X1 × n + y1 × m + 1 = c1 x2 × n + y2 × m + 1 = c2 x3 × n + y3 × m + 1 = c3 n, m, l are constants in the gradient fill object mainly in the horizontal or vertical direction by the above rectangle. There are a type that draws a simple gradation and a type that draws a constant gradation in a free direction using a triangle. The triangle gradient fill object can draw a constant gradation in the horizontal direction or the vertical direction depending on the position of the vertices and how to give the color.

In order to print an image created by a host computer or the like using a gradient fill with an image quality equivalent to that of the host computer by a printing apparatus, the printing apparatus performs a gradient fill process in the same manner as the host computer. Configuration must be installed. In a printing apparatus, rendering processing (image generation processing) needs to be performed at high speed in order to speed up printing.
In particular, when a banding process of dividing an image into bands and recording the images in parallel with the rendering is performed by an electrophotographic method or the like, the upper limit of the time required for generating (rendering) an image of one band is limited to the recording of one band. Limited by time. The printing device had to perform the rendering processing within the time limit.

[0012]

For this reason, it is necessary for the printing apparatus to be equipped with a circuit for executing the gradient fill processing at high speed by hardware. As described above, the gradient processing includes methods such as the rectangular gradient fill processing and the triangle gradient fill processing. In order to support all the gradient fill drawing methods, circuits corresponding to all of them must be mounted. However, there is a problem that the cost of the product increases. Unless a gradient fill processing circuit is provided to reduce the cost, processing that is not provided cannot be performed, and an object cannot be formed with image quality comparable to that of a host computer.

The present invention has been made in view of the above conventional example, and realizes efficient use of hardware resources in a printing apparatus and load distribution between a host computer and the printing apparatus, thereby reducing the manufacturing cost of the printing apparatus. The purpose is to let them.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and has the following configuration. That is, a rendering means for rendering a triangular object in which the position of the vertex and the density of the vertex are specified so as to connect the specified density with a smooth density gradient, and a rectangle in which the position of the vertex and the density of the vertex are specified Dividing means for dividing the object into triangular objects whose vertex positions and vertex densities are designated.

The dividing means divides a rectangular object in which the position of a vertex on a diagonal line and the density of a side including the vertex are designated by the density of the vertex into two triangular objects each having the diagonal line as one side. Then, as the density of each vertex of each triangle object, the same density as the side of the rectangular object including the vertex is given.

A printing control device connected to a printing device, wherein the printing device draws an object whose vertex position and density of the vertex are specified such that the specified density is connected with a smooth density gradient. Determining means for determining whether the printing apparatus has the rendering means; and rendering the object if the printing apparatus does not have the rendering means, and printing if the printing apparatus has the rendering means. Rendering means for rendering the object by a device.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the configuration of a laser beam printer suitable for applying this embodiment will be described. In addition,
The printer to which the present embodiment is applied is not limited to a laser beam printer, but may be a printer of another printing method such as an ink jet printer.

FIG. 1 is a sectional view showing a configuration of a laser beam printer to which the present invention can be applied, and shows a case of a laser beam printer (LBP), for example.

In FIG. 1, reference numeral 1000 denotes an LBP main body, which inputs and stores print information (character codes, etc.), form information, macro instructions, and the like supplied from an externally connected host computer, and stores these information. , A corresponding character pattern, form pattern or the like is created, and an image is formed on a recording medium such as recording paper. Reference numeral 1012 denotes an operation panel on which switches and LED indicators for operation are arranged, and 1001 denotes an LBP main body 1
This is a printer control unit that controls the entire 000 and analyzes character information and the like supplied from the host computer. A control unit 1001 of the printer mainly converts character information into a video signal of a corresponding character pattern and outputs the video signal to a laser driver 1002. Laser driver 100
2 is a circuit for driving the semiconductor laser 1003,
The laser light 1004 emitted from the semiconductor laser 1003 is turned on / off according to the input video signal. The laser beam 1004 is oscillated in the left-right direction by the rotary polygon mirror 1005 to scan and expose the electrostatic drum 1006. As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 1006. This latent image is developed by a developing unit 1007 disposed around the electrostatic drum 1006, and then transferred to a recording sheet. This recording paper uses a cut sheet, and the cut sheet recording paper is LBP10
The sheet is stored in a sheet cassette 1008 attached to the sheet feeder 00, taken into the apparatus by a sheet feed roller 1011, and supplied to an electrostatic drum 1006. The LBP body 1000 has at least one or more card slots (not shown), and includes an optional font card,
Control cards with different language systems (emulation cards)
It is configured to be able to connect.

FIG. 2 is a block diagram illustrating the configuration of a printer control system according to an embodiment of the present invention. Here, a laser beam printer (FIG. 1) will be described as an example. Note that, if the functions of the present invention are executed, whether the system is a single device or a system including a plurality of devices, L
The present invention can be applied to a system in which processing is performed via a network such as an AN.

In FIG. 1, reference numeral 2000 denotes a host computer which executes a document in which graphics, images, characters, tables (including spreadsheets, etc.) are mixed based on a document processing program or the like stored in a program ROM of a ROM 2004. The CPU 2002 controls each device connected to the system device 2005.

A control program of the CPU 2002 and the like are stored in the ROM 2004 for program of the ROM 2004, and font data and the like used in the above document processing are stored in the font ROM of the ROM 2004.
A data ROM 2004 stores various data used when performing the above-described document processing and the like. 2003 is RAM for C
It functions as a main memory, a work area, and the like of the PU 2002. 2006 is a keyboard controller (KBC)
The key input from the keyboard 2010 or a pointing device (not shown) is controlled. A CRT controller (CRTC) 2007 has a CRT display (CRT) 2
011 is controlled. A memory controller (MC) 2008 controls access to an external memory 2012 such as a hard disk (HD) for storing boot programs, various applications, font data, user files, and editing files, or a floppy disk (FD). Reference numerals 2009 and 2026 denote processing units for controlling I / O between devices. In these units, synchronous communication and asynchronous communication are controlled. This processing unit is, as a specific example, IEEE1
An interface such as 394 can be used, but any type of interface can be used as long as the interface can perform synchronous communication and asynchronous communication. In addition, information on whether synchronous communication is possible or impossible in the present invention is managed in this part. Other processing units can obtain the information by issuing a communication request or the like to this processing unit. Also, control may be performed by a unique data stack (not shown).

In the printer 2020, reference numeral 2022 denotes a printer CPU, which is a program RO in the ROM 2020.
M or a control program stored in the external memory 20
Based on a control program and the like stored in the system bus 31, overall control of accents with various devices connected to the system bus 2025 is performed.
(Printer Engine) 202 connected via the
8 outputs an image signal as output information. The program ROM of the ROM 2024 has a CPU 202 as shown in the flowcharts of FIGS.
2 and the like. The data ROM of the ROM 2024 has an external memory 203 such as a hard disk.
In the case of a printer without 1, information used on the host computer is stored. The CPU 2022 can communicate with the host computer via the input unit 2026, and is configured to notify the host computer 2000 of information in the printer and the like.

Reference numeral 2023 denotes a RAM functioning as a main memory, a work area, and the like of the CPU 2022, which is designed so that the memory capacity can be expanded by an optional RAM connected to an extension port (not shown). The RAM 20
Reference numeral 23 denotes storage of print data transmitted from the stamp host in this embodiment, output information development, an environment data storage area, and N
Used for VRAM and the like. Hard disk (H
D) The access to the external memory 2031 such as an IC card is controlled by a memory controller (MC) 2028. Further, a transmission buffer according to the present invention is also created here. The external memory 2031 is connected as an option, and includes font data, an emulation program,
Stores form data and the like. Reference numeral 2040 denotes the above-described operation panel on which switches for operation, an LED display device, and the like are arranged.

Triangular gradient fill processing circuit 20
Reference numeral 32 denotes a circuit for generating the triangular gradient fill object shown in FIG. 3C, and generates a triangular gradation image using the coordinates and density of three vertices as input parameters.

The above-mentioned external memory is not limited to one. At least one external memory can be connected, and in addition to a built-in font, a plurality of external memories storing an option card and a program for interpreting a printer control language of a different language can be connected. It may be configured as follows. Further, N (not shown)
It may have a VRAM and store printer mode setting information from the operation panel 2040.

<Gradient Fill Processing> An embodiment of processing of a gradient fill object will be described below with reference to FIGS. The printing apparatus according to the present embodiment divides a rectangular gradient fill object into two triangle gradient fill objects, and converts each triangle into a triangle gradient fill processing circuit 203.
Process 2 Here, a rectangle having a constant gradation in the vertical direction is divided. However, a gradation that is constant in the horizontal direction can be similarly processed.

FIG. 4 is a diagram illustrating a process of dividing a rectangular gradient fill object into triangular gradient fill objects according to the present embodiment. Rectangle gradient fill object 4001
Is an object with a constant gradient in the vertical direction. The triangular gradient fill object has its two vertices equal in density,
A constant gradation drawing can be performed in the vertical direction with respect to the side connecting the vertices. That is, two points (x1, y1, c
1), (x2, y2, c2) give a rectangular gradient fill object, which is (x1, y1, c1), (x1, y2, c1),
The vertices are (x2, y1, c2) and (x2, y2, c2), and the vertices (x1, y1, c1) and (x1, y2, c
1), and the density transitions at a constant density gradient such that the isodensity line is parallel to the side connecting vertex (x2, y1, c2) and vertex (x2, y2, c2). Rendered as a rectangular image area. Such rectangular image areas are (x1, y1, c1), (x1, y2, c1),
A triangle gradient fill object defined by (x2, y1, c2) and (x1, y1, c1), (x
2, y1, c2) and (x2, y2, c2) can be obtained by rendering each of the triangle gradient fill objects and combining them.

Therefore, the rectangular gradient fill object 4001 defined by the positions of the end points of the diagonal lines on the coordinate plane and the respective densities has two diagonal lines each having an oblique side and having a density equal to the density of the corresponding side of the rectangle. Right triangle 4002 and triangle 4003
And can be divided into

FIG. 5 is a flowchart showing the entire flow of the division processing and printing of the rectangular gradient fill object in the printer 2020 having the triangular gradient fill object processing circuit 2032.

First, in step S5001, print data is received from the host computer. The processing from steps S5002 to S5004 is performed on the print objects in all the received print data.

In step S5002, it is determined whether the object to be processed is a gradient fill object. If it is not a gradient fill object, do nothing. However, although omitted in the figure, it goes without saying that processing corresponding to the object is performed. If the object is a gradient fill object in step S5002, step S500
In step 3, the gradient fill is divided.
When all the division processes are completed, in step S5005, the triangle region divided by the triangle gradient fill object processing circuit 2032 is rendered, and the obtained image is printed.

FIG. 6 is a flowchart showing details of the gradient fill object dividing process in step S5003 in FIG. First, in step S6001, it is determined whether the object is a rectangular object. If it is a rectangular object, in step S6002, it is divided into two triangular gradient fill objects as shown in FIG. In step S6003, step S6003 is performed for all gradient fill objects.
It is determined that the determinations of 6001 and S6002 are performed.

[Effects of the Invention in the First Embodiment] By converting a rectangular gradient fill object into a triangular gradient fill object and printing it in this way, a printer having only a triangular gradient fill object can be used. Also,
It is possible to process rectangular gradient fill objects. Further, since a processing circuit for a rectangular gradient fill object is not required, an inexpensive printer can be created.

Further, since the rectangle is divided into triangles inside the printer, there is no need for the user to be aware of the difference from other printers on the network, and the compatibility with the user is excellent.

<Second Embodiment> Next, FIGS.
The process of distributing the load between the host computer and the printer will be described with reference to the flowchart of FIG. In the present embodiment, it is assumed that the printer can process the image object.

FIG. 7 shows a flow of acquiring the gradient fill object drawing capability of the printer by the host computer.

In step S7001, a bidirectional communication is used to inquire of the printer whether or not the drawing capability of the gradient fill object exists. In step 7002, a response from the printer is waited. When a response is received from the printer, the information is stored in a nonvolatile storage device on the host computer in step S7003.

FIG. 8 shows a case where a print request is received from the user.
It is a flowchart which shows the processing procedure of making a gradient fill object into an image object by a host computer.

In step S8001, it is determined whether the print object of the print data to be created is a gradient fill object. If the object is not a gradient fill object, in step S8005, the process is performed on the original object. If the object is a gradient fill object, step S8
In 002, it is determined with reference to the capability of the printer acquired in the procedure of FIG. If the image data can be processed by the printer, print data is created in step S8004 without changing the gradient fill object. Therefore, the rendering processing of the gradient fill object as described in the first embodiment and the related art is performed by the printer.

On the other hand, if the processing cannot be performed by the printer, all calculations for each pixel of the gradient fill object are performed in step S8003, and print data is created as an image object. In step S8006, the process proceeds to step S8001 for all print objects included in the print data.
It is determined whether or not the processing in step S8005 has been performed, and the processing ends when all processing is completed.

In this embodiment, when the drawing capability is obtained from the printer in FIG. 7, the determination is made only based on the presence or absence of the drawing capability. However, for example, referring to the capability of the printer processor and the capability of the host computer, etc. A more detailed load distribution may be performed so that the processing can be performed most quickly.

[Effect of the Invention in the Second Embodiment] When the gradient object cannot be processed by the printer, the host computer converts the gradient object into an object that can be processed by the printer and transmits it as print data. As a result, no special circuit is required for the printer, and a beautiful gradation drawing by the gradient fill can be performed, so that an inexpensive printer can be created.

[Brief description of the drawings]

FIG. 1 is a sectional view of a printing apparatus according to a first embodiment.

FIG. 2 is a block diagram of a printing apparatus according to the first embodiment.

FIG. 3 is a diagram illustrating specifications (rectangular and triangular) of gradient fill drawing according to the first embodiment.

FIG. 4 is a diagram illustrating division of a triangular gradient fill object of a rectangular gradient fill object according to the first embodiment.

FIG. 5 is a flowchart illustrating an overall flow of a process of dividing a rectangular gradient fill object into triangular gradient fill objects in the printer according to the first embodiment.

FIG. 6 is a flowchart showing a detailed flow of a process of dividing a rectangular gradient fill object according to the first embodiment.

FIG. 7 is a flowchart illustrating a flow of a process of acquiring a gradient fill drawing ability from a printer of a host computer in the second embodiment.

FIG. 8 is a flowchart illustrating a flow of a print object conversion process on the host computer in load distribution between the host computer and the printer according to the second embodiment.

Claims (7)

[Claims] 1. A rendering means for rendering a triangle object having a specified vertex position and a vertex density so as to connect the specified density with a smooth density gradient, and specifying the vertex position and the vertex density. A dividing unit that divides the rectangular object into triangular objects whose vertex positions and vertex densities are designated. 2. The method according to claim 1, wherein the dividing unit comprises: a rectangular object in which the position of a vertex on a diagonal line and the density of a side including the vertex are designated by the density of the vertex; 2. The printing apparatus according to claim 1, wherein the same density as the sides of the rectangular object including the vertices is given as the density of each vertex of each triangle object. 3. 3. A printing control device connected to a printing device, wherein the printing device connects an object with a designated vertex position and a designated vertex density with a smooth density gradient at the designated density. Determining means for determining whether or not to have a rendering means for rendering, if the printing apparatus does not have the rendering means, renders the object; if the printing apparatus has the rendering means, A printing unit for drawing the object by the printing device. 4. A printing method for printing using a drawing means for drawing a triangular object in which the position of a vertex and the density of the vertex are specified so as to connect the specified density with a smooth density gradient. Dividing a rectangular object having the specified vertex position and vertex density into a triangular object having the specified vertex position and vertex density; and
A drawing step of drawing by the drawing means. 5. The method according to claim 1, wherein the dividing step includes a process of setting two triangular objects each having a diagonal line as one side, the rectangular object having the position of a vertex on a diagonal line and the density of a side including the vertex specified by the density of the vertex. The printing method according to claim 4, wherein the same density as that of the side of the rectangular object including the vertex is given as the density of each vertex of each triangle object. 6. A printing control method for controlling a printing apparatus, the printing apparatus connecting an object having a specified vertex position and a specified vertex density with a specified density having a smooth density gradient. A determining step of determining whether to have a rendering unit for rendering, and rendering the object if the printing device does not have the rendering unit, and rendering the object if the printing device has the rendering unit. A printing step of drawing the object by a printing device. 7. A dividing step of dividing a rectangular object, whose vertex position and vertex density is designated, into a triangular object having a vertex position and vertex density designated by a computer; A rendering step of rendering a triangle object having a vertex density designated such that the designated density is connected by a smooth density gradient, and a rendering step of rendering the triangle object divided by the division step. A computer-readable storage medium storing a computer program.