JP3772952B2 - Display device, control method thereof, and information recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device, a control method thereof, and an information recording medium on which a program for realizing the display is recorded.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a display device that is connected to a host device and displays characters and graphics according to command data transmitted from the host device, for example, a customer display used in a POS (Point Of Sales) terminal has been provided.
[0003]
A customer display used in such a POS terminal or the like is connected to a host device or a printing device (printer). The command data transmitted from the host device is received, and if it is an instruction for the customer display, it is interpreted and displayed. If it is an instruction for a device other than itself, such as a printer, the command data is ignored.
[0004]
By providing such a function, a customer display can be arranged between the host device and the printer using the existing command data communication line between the host device and the printer prepared in the store, Display devices have already been proposed in which a printer can be arranged between the host device and the customer display.
[0005]
In a display device such as a customer display, various display methods such as a light bulb method, an LED method, a liquid crystal method, an electroluminescence method, a plasma display method, a CRT (CathodeRay Tube) method, and the like are used. In order to make the display easier to see, it is necessary to increase the brightness contrast. When an element that emits light is used, power is consumed in the element, and in an element that does not transmit light, power is consumed in a backlight or the like.
[0006]
[Problems to be solved by the invention]
There is a great demand for reducing the power consumption of such display devices. In particular, a display device with low power consumption that stops power supply to the display device is desired during standby, particularly when no useful information is displayed on the display device.
[0007]
The present invention has been made to solve the above problems, and provides a low power consumption display device particularly suitable for a customer display, a control method thereof, and an information recording medium on which a program for realizing these is recorded. For the purpose.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.
[0009]
The display device of the present invention is configured to include a display unit, a storage unit, a reception unit, an interpretation unit, a power supply control unit, and a display control unit.
[0010]
The display unit includes a plurality of non-overlapping areas, and each of the areas can adopt any of a plurality of display states.
[0011]
The storage unit stores a display state to be adopted by each area of the display unit.
[0012]
The receiving unit receives command data including command data that designates a display state to be adopted by each region of the display unit.
[0013]
The interpretation unit interprets the received command data, and causes the storage unit to store the display state to be adopted by each area of the display unit.
[0014]
The power control unit stops power supply to the display unit when each of the display states stored in the storage unit remains in the predetermined display state for a predetermined time, and otherwise supplies power.
[0015]
The display control unit causes the display state to be adopted in the area of the display unit corresponding to each of the display states stored in the storage unit.
[0016]
In addition, each region of the display unit of the display device of the present invention can adopt either a lighting state or a light-off state as a display state, and the predetermined display state is configured to be a light-off state. Can do.
[0017]
Further, in the display device of the present invention, the command data includes command data for designating a transmission destination of the command data, and the interpreter is configured to select a device other than the display device from the command data for designating the display device as the command data transmission destination. The command data received until the command data designated as the command data transmission destination is interpreted, and each of the display states to be adopted can be stored in the storage unit.
[0018]
The display device of the present invention can be configured to further include a transmission unit.
[0019]
The transmission unit transmits the received command data.
[0020]
The control method of the present invention includes a plurality of non-overlapping regions, each of the regions can adopt any of a plurality of display states, a power supply unit that supplies power to the display unit, The display device is controlled to include a reception process, an interpretation process, a power supply control process, and a display control process.
[0021]
In the receiving process, the command data including the command data specifying the display state to be adopted by each area of the display unit is received.
[0022]
The interpretation process, interprets the received command data, causes store display state to be adopted each region of the display unit.
[0023]
In the power control process, if each of the stored display states remains in the predetermined display state for a predetermined time, the power supply unit stops power supply; otherwise, the power supply unit supplies power. Let it be done.
[0024]
In the display control step, the display state is adopted in the display area corresponding to each of the stored display states.
[0025]
Further, in the control method of the present invention, each region of the display unit can adopt either a lighting state or a light-off state as a display state, and the predetermined display state is configured to be a light-off state. be able to.
[0026]
Further, in the control method of the present invention, the command data includes command data for designating a transmission destination of the command data, and in the interpretation step, from the command data for designating the display device as the command data transmission destination, other than the display device. The command data received up to the command data designated as the command data transmission destination is interpreted, and the display state to be adopted by each area of the display unit can be stored.
[0027]
Moreover, the control method of the present invention can be configured to further include a transmission step.
[0028]
In the transmission step, the received command data is transmitted.
[0029]
A program for realizing the display device of the present invention and its control method is recorded on a computer-readable information recording medium such as a compact disk, a flexible disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, and a semiconductor memory. can do.
[0030]
The computer-readable information program recorded on the recording medium of the present invention, CPU included in the display device: by executing the control device such as a (CentralProcessingUnit central processing unit), and the display device, and a control method thereof Can be realized.
[0031]
Independent of these devices, a computer-readable information recording medium in which the program of the present invention is recorded can be distributed and sold, or updated from a host device.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below. In addition, embodiment described below is for description and does not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.
[0033]
(First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a display device of the present invention. Hereinafter, a description will be given with reference to FIG.
[0034]
The display device 101 is controlled by the CPU 102.
[0035]
The display unit 103 is divided into grid-like regions of horizontal w dots and vertical h dots, and each region can be in either a lighted state or an unlit state. For example, values such as w = 256 and h = 64 can be adopted.
[0036]
The power controller 104 supplies power to each element of the display device 101. Further, the power supply to the display unit 103 can be stopped or started by an instruction from the CPU 102. For easy understanding, a power supply line from the power controller 104 to each element of the display device 101 is not shown.
[0037]
The display device 101 receives power from the outside via the power connector 105, and the switch 106 is used to turn on / off the entire display device 101.
[0038]
The host-side interface 107 of the display device 101 receives command data transmitted from the host device. Further, the command data received by the host side interface 107 can be transmitted as it is to another device via the other device side interface 108.
[0039]
The command data received by the host-side interface 107 is interpreted by the CPU 102, and in the VRAM (VideoRAM) area secured in the RAM (Random Access Memory) 109, which of the grid-like areas of the screen is turned on and which is turned off. Or remember.
[0040]
When the command data is a command to display a character, the image definition of the character is read from a ROM (Read Only Memory) 110, and this image definition is expanded in the VRAM area.
[0041]
Based on the image developed by the CPU 102 in the VRAM area, the display unit 103 turns on / off each area. This control is performed by a display controller (not shown) included in the display unit 103. The display controller scans the VRAM area at predetermined time intervals, and determines whether each area is turned on or off based on the value stored therein. Alternatively, an interrupt (such as a vertical synchronization interrupt in a CRT or the like) is generated for the CPU 102 every predetermined time, and during this interrupt processing, the CPU 102 controls and operates the display unit 103 according to the value of the VRAM area. Also good.
[0042]
The counter 111 measures the elapsed time by a real time clock or by counting clock signals supplied to the CPU 102. Further, an embodiment in which an interrupt is generated for the CPU 102 when the counter 111 reaches a predetermined value can be adopted.
[0043]
The identification number of the printing apparatus can be set by the dip switch 112. In this embodiment, the identification number can be selected from 256 types of 0 to 255.
[0044]
In this embodiment, a command system of the following format is adopted as the command data. For example, the following commands are prepared. Note that 0x is a prefix representing a hexadecimal number.
[0045]
・ "0x1b0x3dn" Select the device with identification number n.
・ "0x20 ~ 0x7e" Displays the corresponding ASCII characters.
・ "0x0a" Insert a line feed.
・ "0x0c" Clear the screen.
[0046]
In addition to this, it is possible to prepare a command for displaying a kanji or a graphics image, a command for assigning a window to a part of the screen, and designating drawing for the window.
[0047]
In the above command system, the command data format is the same as that of the printer, so that even if command data for multiple devices are sent to the same communication line using a communication line in a bus connection, this is not possible on the device side. Can be discriminated.
[0048]
Further, in the ROM 110, an IPL (Initial Program Loader) executed by the CPU 102 and a BIOS (Basic Input Output System) program are also recorded. These programs can be updated (version up) from the host device via the host-side interface 107.
[0049]
Here, the display unit 103 functions as a display unit, the RAM 109 functions as a storage unit, the host-side interface 107 functions as a reception unit, the CPU 102 functions as an interpretation unit, and the power supply controller 104 functions as a CPU 102. And the CPU 102 functions as a display control unit. The other device side interface 108 functions as a transmission unit.
[0050]
The ROM 110 and an information recording medium (a flexible disk, a CD-ROM (Compact Disk ROM), a hard disk, etc.) on which a program for upgrading the storage contents of the ROM 110 is recorded are the computer-readable information recording medium of the present invention. Function as.
[0051]
FIG. 2 is a schematic diagram showing a state of a storage area secured in the RAM 109. Hereinafter, a description will be given with reference to FIG.
[0052]
The selection flag area 201 stores a value indicating whether or not the display device 101 is currently selected. For example, 1 is stored if selected, and 0 is stored if not selected. Immediately after the power is turned on, the display device 101 is initialized to a state (0) that is not selected.
[0053]
The cursor position area 202 stores the position of the cursor where the character is to be displayed next. Immediately after the power is turned on, it is initialized to coordinates (0,0).
[0054]
The VRAM area 203 stores information as to whether or not each square area (dot) of the display unit 103 is lit. That is, the VRAM area 203 corresponds to a line buffer in a printer or the like. In the present embodiment, since it is only necessary to store two states of lighting / extinguishing per dot, it is sufficient to prepare a 1-byte area with 8 dots. The VRAM area 203 is expressed as an array.
[0055]
As in the case of the line buffer of the printer, the first (0th) element contains information on the on / off of coordinates (0,0) to (0,7), and the next (first) element contains On / off information of coordinates (0,8) to (0,15) is the nth element, coordinates (n / w, n% w) to (n / w, n% w + 7) If the information is stored like the information on lighting / extinguishing, the affinity when a graphics drawing command is added is improved. Here, “/” is an operator for dividing an integer, and “%” is an operator for obtaining a remainder after division.
[0056]
Therefore, in the present embodiment, h is preferably a multiple of 8. In this case, the number of bytes s necessary for the VRAM area 203 is s = w × h / 8.
[0057]
In the present embodiment, lighting is represented by 1 and extinguishing is represented by 0. When the byte value of a certain element in the VRAM area 203 is 0, all the 8-dot areas corresponding to the element are in the extinguished state.
[0058]
The s byte area of the VRAM area 203 is initialized to 0 immediately after the power is turned on.
[0059]
In addition, a reception buffer area 204 is provided in the RAM 109. Similar to a general printer, the display device 101 of the present invention also buffers command data by a reception interrupt. That is, when the host side interface 107 detects the arrival of the command data, an interrupt is applied to the CPU 102, and the CPU 102 receives the command data through the host side interface 107 during the interrupt process, and this is received as a reception buffer in the RAM 109. The data is sequentially stored in 204, and the interrupt process is terminated.
[0060]
(Control processing)
FIG. 3 is a flowchart showing a flow of control processing for controlling the display device 101. This control process is executed after the display device 101 is initialized.
[0061]
First, the CPU 102 checks whether there is command data received by the host side interface (step S401). If not (Step S401 : No), the process waits (Step S402) and returns to Step S401. It waits for the command data to be stored in the reception buffer 204 by the reception interrupt.
[0062]
If there is command data (step S401 : Yes), it is read (step S403), and it is checked whether it is a device selection command (step S404). If it is a device selection command (step S404 : Yes), the number of the device selected by the command is checked (step S405).
[0063]
When the number of the selected device matches the device number set by the DIP switch or the like of the display device 101 (step S405 : selection), 1 is stored in the selection flag area in the RAM 109 (step S406), and step S401. Return to. On the other hand, if they do not match (step S405 : non-selected), 0 is stored in the selection flag area in the RAM 109 (step S407), and the process returns to step S401.
[0064]
On the other hand, if it is not a selected device command (step S404 : No), the value stored in the selection flag area 201 in the RAM 109 is checked (step S408), and if the value of the selection flag area 201 is 0 (step S408 : 0). Return to step S401. When the value of the selection flag area 201 is 1 (step S408 : 1), the type of the command is examined (step S409).
[0065]
When the command is an ASCII byte value (0x20 to 0x7e) (step S409 : ASCII), the corresponding ASCII character definition is read from the ROM 110 (step S410), and the value of the cursor position area 202 is determined according to the size of the font definition. If necessary, scroll processing is performed (step S412), the image of the font definition is expanded at the cursor position in the VRAM area 203 (step S413), and the value in the cursor position area 202 is set to the next character. Is updated to the position to be displayed (step S414).
[0066]
Further, it is checked whether or not all the values in the VRAM area 203 are 0 (step S415). If all the values are 0 (step S415 : Yes), that is, if any area of the display unit 103 is not lit. Then, the supply of power to the display unit 103 is stopped (step S416). On the other hand, when there is a place other than 0 (step S415 : No), that is, when any of the display units 103 wants to light the area, power is supplied to the display unit 103 (step S417).
[0067]
When the power supply to the display unit 103 is controlled, the process returns to step S401.
[0068]
If the command is a line feed command (step S409 : 0x0a), the value of the cursor position area 202 is advanced by one line, and if necessary, the VRAM area 203 is scrolled (step S421), and the process proceeds to step S415.
[0069]
If the command is a screen erase command (step S409 : 0x0c), all the values in the VRAM area 203 are set to 0 (step S430), and the process proceeds to step S416.
[0070]
For the processing executed in the adjustment of the value of the cursor position area 202 (step S412) and the scroll processing of the VRAM area 203 (step S421), the same technique as the known technique used in the existing window system or character display system is used. Can be used.
[0071]
Hereinafter, the procedure of the cursor position adjustment and the scroll process executed in step S412 will be described with reference to FIG. FIG. 4 is a flowchart showing the procedure executed in step S412.
[0072]
In this embodiment, the width of the screen is w and the height is h. The font used is the same size for all characters, the font width is dw, and the font height is dh. The font height is a multiple of 8. The coordinate value stored in the cursor position area 202 is described as (x, y).
[0073]
First, it is checked whether or not the font can be displayed even if it is displayed (step S501). That is, it is checked whether x + dw <w. If it does not fit (step S501 : No), the value of the cursor position area 202 is updated to (0, y + dh) (step S502). That is, values are substituted such as x ← 0, y ← y + dh. Thereby, a line feed can be realized.
[0074]
Next, it is checked whether or not the cursor position is within the screen (step S503).
That is, it is checked whether y <h.
[0075]
If it does not fit (step S503 : No), the contents stored in the VRAM area 203 are sequentially moved (step S504). Details of the movement are as follows.
[0076]
First, the value of the i + w × dh / 8th element is assigned to the i-th element in order from i = 0 to w × (h-dh) / 8-1.
Next, the value is set to 0 from the w × (h-dh) / 8th element to the w × h / 8-1th element.
[0077]
Further, the value of the cursor position area 202 is updated to (0, w-dh) (step S504). That is, values are substituted such as x ← 0, y ← w-dh. Thereby, scroll-up for one line can be realized.
[0078]
When step S504 ends, this procedure ends. On the other hand, when the font is displayed but fits in that line (step S501 : Yes), or when the cursor position falls within the screen (step S503 : Yes), this procedure is terminated.
[0079]
In this way, after adjusting the cursor position by this procedure, the font definition is expanded in the VRAM area 203 (step S413), and the x coordinate of the cursor position area 202 is updated as x ← x + dw (step S414). ).
[0080]
In the above description, the font size is fixed for ease of understanding, but the same processing can be realized by appropriately changing the size of dw and dh even when using a variable size font. .
[0081]
In step S421, a line feed and scrolling process can be realized by performing the same process as in this procedure.
[0082]
With the above configuration, each time the display image developed in the VRAM area 203 is updated, the CPU 101 checks the value of the VRAM area 203, and if it is not necessary to supply power to the display unit 103, the power controller 104 is controlled, because you stop the power supply to the display unit 103, it is possible to reduce the power consumption of the display device 101, depending on the characteristics of the display unit 103 and power controller 104 performs too frequent on-off On the contrary, there are cases where power consumption increases.
[0083]
Therefore, it is preferable to execute the power supply stop process in steps S415 to S416 in the standby process in step S402. In the standby process, generally, the control of the CPU 102 is transferred to another process for a predetermined time, or the CPU 102 is caused to wait for polling. After that, the process corresponding to the power supply stop process in steps S415 to S416 is executed. In this case, the supply of power to the display unit 103 is stopped when “no area of the display unit 103 is lit and this state continues for a predetermined time”.
[0084]
Further, by using the value of the counter 111, it may be determined whether or not “continue for a predetermined time”.
[0085]
In the present embodiment, even in the display unit 103 and the power supply controller 104 having characteristics as described above, by supplying the power, if necessary, it is possible to achieve power saving.
[0086]
The start and stop of power supply to the display unit 103 according to the present invention is different from the screensaver often used in such computers. In the screen saver, if no operation is performed by the user for a certain period of time, the power supply to the screen is stopped regardless of what is displayed on the screen. For this reason, it may be difficult to determine the operation status of the computer. In the present invention, when something is displayed on the display unit 103, the power supply is not stopped, so that the user can surely understand the display content.
[0087]
(Second Embodiment)
In the above-described embodiment, the display unit 103 can adopt two display states of lighting and extinguishing, but the present invention can be applied to cases where the display unit can perform color display, Even when stage display is possible, it can be applied.
[0088]
Similarly in this case, the display state (color) displayed in each area is stored in the VRAM area. In the present embodiment, when all the values stored in the VRAM area are “color when power is not supplied to the display unit” for a predetermined time , the power supply to the display unit is stopped.
[0089]
In addition, when a liquid crystal display unit is employed, the contrast of light and dark is increased by a backlight or the like, but power supply to the backlight may be controlled by a similar method.
[0090]
( Third embodiment)
In the present embodiment, “power supply control is enabled by the setting of the dip switch 112” is added to the condition for stopping the power supply to the display unit 103 in the above embodiment. Thus, when it is not necessary, the dip switch 112 is set so that the power is always supplied to the display unit 103 when the display device 101 is turned on. it can.
[0091]
(Display device connection)
FIG. 5 is an explanatory diagram showing the connection relationship of command data communication lines between the display device 101 of the present invention, the host device, and the printer for the POS terminal.
[0092]
As shown in FIG. 5A, a communication line can be branched from the host device 601 to the display device 101 and the printer 602 outside these devices.
[0093]
As shown in FIG. 5B, the position of the branch of the communication line can be in the display device 101. In this case, the command data received by the host side interface 107 is output as it is via the other device side interface 108.
[0094]
FIG. 5C shows the communication line branching position in the printer 602.
[0095]
In the mode shown in FIG. 5A and FIG. 5C, the other device side interface 108 can be omitted from the embodiment of the display device 101 described above.
[0096]
【The invention's effect】
As described above, according to the present invention, a low power consumption display device particularly suitable for a customer display, a control method thereof, and a computer-readable information recording medium storing a program for realizing the display device are provided. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a display device of the present invention.
FIG. 2 is a schematic diagram showing a state of a storage area secured in a RAM.
FIG. 3 is a flowchart showing a flow of control processing for controlling the display device.
FIG. 4 is a flowchart showing a procedure of cursor position adjustment and scroll processing.
FIG. 5 is an explanatory diagram showing a connection status of a display device, a host device, and a printer.
[Explanation of symbols]
101 display device 102 CPU
DESCRIPTION OF SYMBOLS 103 Display part 104 Power supply controller 105 Power supply connector 106 Switch 107 Host side interface 108 Other apparatus side interface 109 RAM
110 ROM
111 Counter 112 Dip Switch 201 Selection Flag Area 202 Cursor Position Area 203 VRAM Area 204 Reception Buffer 601 Host Device 602 Printer

Claims (7)

Including a plurality of non-overlapping areas, each of the areas can adopt any of a plurality of display states;
A storage unit for storing a display state to be adopted by each area of the display unit;
A receiving unit that receives command data including command data that is command data and specifies a display state to be adopted by each region of the display unit;
Interpreting the received command data, and storing the display state to be adopted by each region of the display unit in the storage unit,
When each of the display states stored in the storage unit remains in a predetermined display state for a predetermined time, the power supply to the display unit is stopped; otherwise, a power control unit that supplies power ,
A display control unit that causes the display unit to adopt the display state corresponding to each of the display states stored in the storage unit;
With
Each region of the display unit can adopt either a lighting state or a light-off state as a display state, and the predetermined display state is a light-off state ,
The command data includes command data specifying a transmission destination of the command data,
The interpreter interprets command data received between command data designating the display device as a command data transmission destination and command data designating other than the display device as command data transmission destination, Each display state to be adopted is stored in the storage unit. A transmitter for transmitting the received command data;
The display device according to claim 1 , further comprising: Controlling a display device that includes a plurality of non-overlapping regions, each of which includes a display unit that can adopt any of a plurality of display states, and a power supply unit that supplies power to the display unit Control method,
A receiving step for receiving command data including command data for designating a display state to be adopted by each area of the display unit;
Interpreting the received command data and storing a display state to be adopted by each area of the display unit;
When each of the stored display states remains in a predetermined display state for a predetermined time, the power supply unit stops power supply, and otherwise, the power supply unit supplies power. Power control process;
A display control step of adopting the display state in the area of the display unit corresponding to each of the stored display states;
With
Each area of the display unit may employ either the unlit state and the lighting state as the display state, the predetermined display state, with a turned off,
The command data includes command data specifying a transmission destination of the command data,
The interpretation step interprets command data received between command data designating the display device as a command data transmission destination and command data designating a device other than the display device as command data transmission destination, The display state to be adopted by each area of the display unit is stored.
A control method characterized by that . A transmitting step of transmitting the received command data;
The control method according to claim 3 , further comprising: A display device including a plurality of non-overlapping regions, each of the regions can adopt any of a plurality of display states, and a power supply unit that supplies power to the display unit A program to be executed,
Receiving command data including command data for designating a display state to be adopted by each area of the display unit,
Interpreting the received command data, storing the display state to be adopted by each area of the display unit,
If each of the stored display states remains in a predetermined display state for a predetermined time, the power supply unit stops power supply, and if not, the power supply unit supplies power. ,
Adopting the display state in the area of the display unit corresponding to each of the stored display states,
Each area of the display unit can adopt either a lighting state or a light-off state as a display state,
The predetermined display state is a light-off state ,
The command data includes command data specifying a transmission destination of the command data,
The display state to be adopted by each area of the display unit by interpreting the received command data is stored in order to store the display after receiving command data designating the display device as a command data transmission destination. A computer-readable information recording medium having recorded thereon a program for realizing control until command data that designates a device other than the apparatus as a command data transmission destination is received . 6. The computer-readable information recording medium according to claim 5 , wherein a program for further realizing the process of transmitting the received command data is recorded. The computer-readable information recording medium according to claim 5 or 6 , wherein the computer-readable information recording medium is a compact disk, a flexible disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, or a semiconductor memory. Possible information recording medium.

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