Printing device and program

Abstract

To provide a printing device that performs display processing to a display part, which prevents a screen from being disturbed during printing.SOLUTION: A printing device 1 which has a display processing part 184 that makes a display device 3 display a display image and a printing part 16, comprises: a printing processing part 181 that executes printing processing for making the printing part 16 perform printing; an identifying part 182 that identifies whether a state of the printing processing part 181 is a printing state where the printing processing part 181 is executing the printing processing or a stand-by state where the printing processing part 181 is not executing the printing processing; and a display data generating part 183 that generates display data on a color depth determined based on whether the state of the printing processing part 181 identified by the identifying part 182 is the printing state or the stand-by state. The display processing part 184 makes the display part 3 display a display image based on the display data generated by the display data generating part 183.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a printing device and a program. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a printing device that performs display processing on a display unit (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-49696 Summary of the Invention [Problem to be solved by the invention]

[0004] When a processor executes both printing and display processing, it may take a long time to generate display data, and the display processing may not be able to keep up, resulting in a distorted screen displayed on the display unit.

[0005] The present invention has been made in consideration of these points, and has as its object to prevent the screen from becoming distorted during printing in a printing device that performs display processing on a display unit. [Means for solving the problem]

[0006] A printing device according to a first aspect of the present invention is a printing device having a display processing unit that displays a display image on a display unit, and a printing unit, and further comprising: a printing processing unit that executes a printing process that causes the printing unit to print; an identification unit that identifies whether the state of the printing processing unit is a printing state in which the printing processing unit is executing the printing process, or a standby state in which the printing processing unit is not executing the printing process; and a display data generation unit that generates display data of a color depth determined based on whether the state of the printing processing unit identified by the identification unit is the printing state or the standby state, and the display processing unit displays the display image based on the display data generated by the display data generation unit on the display unit.

[0007] The display data generation unit may generate display data of a first color depth when the state of the printing processing unit identified by the identification unit is the standby state, and may generate display data of a second color depth lower than the first color depth when the state identified by the identification unit is the printing state.

[0008] The display data generation unit may identify the number of pixels of the display unit, refer to color depth information stored in a memory unit that associates the number of pixels of the display unit with the color depth in each of the printing state and the standby state, and generate the display data of the color depth associated with the state of the printing processing unit identified by the identification unit and the identified number of pixels of the display unit.

[0009] The display data generation unit may acquire, from the display unit, Extended Display Identification Data (EDID) including information indicating the number of pixels of the display unit, and identify the number of pixels of the display unit based on the acquired EDID. The display data generation unit may set the determined color depth in a display controller that displays the display data on the display unit.

[0010] The display processing unit may add complementary data to the display data generated by the display data generation unit to generate display data of a predetermined bit width, and display the display image based on the generated display data of the predetermined bit width on the display unit.

[0011] The printing device may have the print processing unit, a display data generation unit, and a microcontroller that functions as the display processing unit, and the display data generation unit may identify a first processing amount, which is the processing amount that the microcontroller can allocate to generating display data when the state of the print processing unit identified by the identification unit is the standby state, as well as the number of pixels of the display unit and a refresh rate of the display unit, and determine a color depth to be applied to the display data in the standby state based on the identified first processing amount, the number of pixels, and the refresh rate.

[0012] The printing device may have the print processing unit, a display data generation unit, and a microcontroller that functions as the display processing unit, and the display data generation unit may identify a second processing amount, which is the processing amount that the microcontroller can allocate to generating display data when the state of the print processing unit identified by the identification unit is the printing state, as well as the number of pixels of the display unit and a refresh rate of the display unit, and determine a color depth to be applied to the display data in the printing state based on the identified second processing amount, the number of pixels, and the refresh rate.

[0013] A program according to a second aspect of the present invention causes a printing device having a display processing unit that displays a display image on a display unit and a printing unit to function as a printing processing unit that executes a printing process that causes the printing unit to print, an identification unit that identifies whether the state of the printing processing unit is a printing state in which the printing processing unit is executing the printing process or a standby state in which the printing processing unit is not executing the printing process, a display data generation unit that generates display data of a color depth determined based on whether the state of the printing processing unit is the printing state or the standby state, and the display processing unit that displays a display image based on the display data generated by the display data generation unit on the display unit. [Effects of the Invention]

[0014] According to the present invention, in a printing device that performs display processing on a display unit, it is possible to suppress the screen from becoming distorted during printing. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an overview of a printing device. [Figure 2] FIG. 1 illustrates a configuration of a printing apparatus. [Figure 3] FIG. 2 is a diagram illustrating a configuration of a control unit. [Figure 4] 10A and 10B are diagrams illustrating a method for converting display data in RGB888 format into display data in RGB565 format. [Figure 5] 10A and 10B are diagrams illustrating a method for converting display data in RGB565 format into display data in RGB888 format. [Figure 6] 10 is a flowchart showing a process flow in which the printing device causes the display device to display a display image based on display data. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Outline of Printing Device 1] FIG. 1 is a diagram illustrating an overview of a printing device 1. As shown in FIG. 1, the printing device 1 is, for example, a thermal printer or barcode printer that prints on thermal paper, and is connected to a host PC 2 that controls its own printing and a display device 3 that serves as a display unit. The printing device 1 has a print processing unit that prints product labels, receipts, etc. in accordance with the control of the host PC 2. The printing device 1 also has a data generation unit that generates display data to display a display image on the display device 3 in response to receiving operation input from a user.

[0017] The printing device 1 identifies whether the state of the print processing unit is a printing state in which print processing is being performed, or a standby state in which print processing is not being performed. When the data generation unit generates display data, the printing device 1 generates display data with a color depth determined based on whether the state of the print processing unit is a printing state or a standby state.

[0018] In the past, when a printing device with low processing power simultaneously executed both a printing process and a display data generation process, the display process could not keep up due to the time required to generate the display data, resulting in a distorted screen image displayed on the display device. In response to this, printing device 1 generates display data with a color depth determined based on whether the print processing unit is in a printing state or a standby state, thereby making the color depth of the display data in the printing state lower than the color depth of the display data in the standby state. This allows printing device 1 to quickly generate display data even when the print processing unit is in a printing state, thereby preventing the screen image from becoming distorted during printing.

[0019] [Printing device 1 configuration] Fig. 2 is a schematic diagram of the configuration of the printing device 1. As shown in Fig. 2, the printing device 1 has a bus line 10, a device I / F (interface) 11, a host I / F 12, a display I / F 13, a bridge IC 14, a network I / F 15, a printing unit 16, a storage unit 17, and a control unit 18.

[0020] The device I / F 11, host I / F 12, display I / F 13, network I / F 15, printing unit 16, storage unit 17, and control unit 18 are connected via a bus line 10. The bus line 10 includes a data bus, a control bus, and an address bus.

[0021] The device I / F 11 is, for example, a USB (Universal Serial Bus) device interface, and is an interface for connecting the printer 1 to a host PC 2, which is a device capable of controlling printing by the printer 1.

[0022] The host I / F 12 is, for example, a USB host interface, and is an interface for connecting devices controllable by the printing device 1 to the printing device 1. In this embodiment, the display device 3 is provided with a touch panel that accepts input operations, and the display device 3 is connected to the host I / F 12. In addition to the display device 3, the host I / F 12 is also connected to an input device 4 such as a keyboard, a barcode reader 5, and a storage device 6 such as a USB memory that stores display screen data (e.g., a template) for generating display data, as devices controllable by the printing device 1. Here, the display screen data is assumed to be data corresponding to the first color depth.

[0023] The display I / F 13 is, for example, an interface for displaying display data on the display device 3. A bridge IC 14 is connected to the display I / F 13. The bridge IC 14 functions as a display controller, converts a DSI (Display Serial Interface) signal received from the control unit 18 into a differential serial signal compatible with a digital display standard such as a DisplayPort interface or HDMI (High-Definition Multimedia Interface) (registered trademark), and outputs the signal to the display device 3.

[0024] The network I / F 15 is, for example, a wired LAN interface. The network I / F 15 communicates with an external server 7, for example, to obtain from the server a template, which is data for a display screen to be displayed on the display device 3, and to transfer information required to realize a function related to POS (Point of Sale) on the server 7 side. The information required to realize the POS function is, for example, information required to perform at least one of product information management, sales information management, and inventory information management.

[0025] In another example, the server 7 may be a server that handles logistics management, or a server that receives patient reception at a medical institution and manages electronic medical records of patients.

[0026] The printing unit 16 has, for example, a thermal head that prints on thermal paper, a motor for transporting the thermal paper, a cutter motor that is the power source for a cutter that cuts the thermal paper, a sensor that detects the presence or absence of thermal paper, etc., and prints on the thermal paper under the control of the host PC 2 or the control of the control unit 18.

[0027] The storage unit 17 is a storage medium including a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, etc. The storage unit 17 stores programs executed by the control unit 18. The storage unit 17 is provided with a frame buffer, which is a storage area for temporarily storing display data generated by the control unit 18.

[0028] The control unit 18 is a microcontroller including a processor such as a CPU (Central Processing Unit). Fig. 3 is a diagram illustrating the functions of the control unit 18. By executing a program stored in the storage unit 17, the control unit 18 functions as a print processing unit 181, an identification unit 182, a display data generation unit 183, and a display processing unit 184, as shown in Fig. 3.

[0029] The print processing unit 181 executes print processing to cause the printing unit 16 to print. For example, when the print processing unit 181 receives print data from the host PC 2 via the device I / F 11, it causes the printing unit 16 to print based on the print data.

[0030] The identifying unit 182 identifies whether the state of the print processing unit 181 is a printing state in which the print processing unit 181 is executing a print process, or a standby state in which the print processing unit 181 is not executing a print process. For example, the identifying unit 182 monitors the processing state of the print processing unit 181 to identify whether the state of the print processing unit 181 is a printing state or a standby state.

[0031] In response to receiving an operation from the display device 3 or the input device 4 via the host I / F 12, the display data generation unit 183 generates display data corresponding to the operation. In addition, in response to obtaining information read from a barcode by the barcode reader 5 via the host I / F 12, the display data generation unit 183 generates display data corresponding to the information. For example, the display data generation unit 183 obtains display screen data stored in the storage device 6 via the host I / F 12, and generates display data based on a template or the like as the obtained display screen data.

[0032] The display data generation unit 183 generates display data with a color depth determined based on whether the state of the print processing unit 181 identified by the identification unit 182 is a printing state or a standby state. Specifically, when the state of the print processing unit 181 identified by the identification unit 182 is a standby state, the display data generation unit 183 generates display data with a first color depth based on data for a display screen corresponding to the first color depth stored in the storage device 6. Furthermore, when the state of the print processing unit 181 identified by the identification unit 182 is a printing state, the display data generation unit 183 generates display data with a second color depth lower than the first color depth by reducing the color depth of the data for a display screen corresponding to the first color depth stored in the storage device 6.

[0033] The display data of the first color depth is, for example, RGB888 format display data, i.e., display data with a color depth of 24 bits. The display data of the second color depth is, for example, RGB565 format display data, i.e., display data with a color depth of 16 bits.

[0034] 4 is a diagram illustrating a method for converting display data in RGB888 format into display data in RGB565 format. As shown in FIG. 4, in the display data in RGB888 format, data marked with "R" corresponds to a red component, data marked with "G" corresponds to a green component, and data marked with "B" corresponds to a blue component. As shown in FIG. 4, the display data generation unit 183 converts 24-bit display data in RGB888 format into 16-bit display data in RGB565 format by extracting 5 bits of data (R7 to R3) from the most significant bit (MSB) out of 8-bit data (R0 to R7) corresponding to the red component of the display data in RGB888 format, 6 bits of data (G7 to G2) from the most significant bit out of 8-bit data (G0 to G7) corresponding to the green component, and 5 bits of data (B7 to B3) from the most significant bit out of 8-bit data (B0 to B7) corresponding to the blue component.

[0035] The display data generation unit 183 stores the generated display data in a frame buffer provided in the storage unit 17. Typically, two frame buffers (e.g., frame buffers A and B) are provided. For example, if the refresh rate of the display device 3 is 60 Hz, the display data generation unit 183 generates display data at a cycle of 60 Hz and stores the data alternately in the two frame buffers. According to the present invention, the display data generation unit 183 changes the color depth of the display data stored in the storage unit 17 in accordance with the operating state of the print processing unit 181 as described above, thereby making it possible to adjust the amount of display data.

[0036] The display processing unit 184 causes the display device 3 to display a display image based on the display data generated by the display data generation unit 183. The display processing unit 184 transfers one frame's worth of data stored in the frame buffer to the downstream bridge IC 14. For example, if the refresh rate of the display device 3 is 60 Hz, the display processing unit 184 transfers the display data stored in frame buffer A and frame buffer B to the bridge IC 14 while flipping between frame buffer A and frame buffer B at a cycle of 60 Hz. The display processing unit 184 and the bridge IC 14 are connected via a high-speed serial transfer interface called MIPI (Mobile Industry Processor Interface) DSI.

[0037] As described above, the bridge IC 14 has a bridge function for transferring data transferred via the DSI interface from the display processing unit 184, which is an upstream DSI host, to the display device 3 via the DisplayPort interface or HDMI. The bridge IC 14 can either transfer data in color data format transferred via the DSI interface to the display device 3 in its original format (i.e., transfer data in RGB565 format or RGB888 format to the display device 3 in its original format), or can complement data that has been color-reduced to RGB565 format to 24-bit data in RGB888 format and transfer it to the display device 3.

[0038] FIG. 5 is a diagram illustrating a method for converting display data in RGB565 format into display data in RGB888 format. For example, as shown in FIG. 5, the bridge IC 14 converts display data in RGB565 format into display data in RGB888 format by adding a predetermined number of bits of data at the beginning of each color after the data corresponding to each color element in the RGB565 format display data. For example, the bridge IC 14 adds the first three bits of data (R4 to R2) of the red element as complementary data after the least significant bit (LSB) of the data corresponding to the red element in the RGB565 format display data. The display processing unit 184 also adds the first two bits of data (G5, G4) of the green element as complementary data after the least significant bit of the data corresponding to the green element. The display processing unit 184 also adds the first three bits of data (B4 to B2) of the blue element as complementary data after the least significant bit of the data corresponding to the blue element. Note that the complementary processing in the bridge IC 14 is performed by dedicated hardware, so there are no problems, such as delays in data to be transferred to the display device 3.

[0039] As described above, when display data generation unit 183 generates display data to be stored in the frame buffer, the amount of data for one frame is adjusted by adjusting the color depth of the display data, but this is not limiting. When display data generation unit 183 generates display data, it may store the display data in the frame buffer without changing the color depth, and display processing unit 184 may adjust the amount of data for one frame by adjusting the color depth of the display data stored in the frame buffer.

[0040] Here, if the display device 3 is capable of displaying 24-bit display data in RGB888 format but is not capable of displaying 16-bit display data in RGB565 format, and 16-bit display data in RGB565 format is stored in the frame buffer, a problem occurs in that even if the display processing unit 184 outputs the display data stored in the frame buffer to the bridge IC 14, the display image cannot be displayed on the display device 3.

[0041] In response to this, when the color depth of the display data generated by the display data generation unit 183 is the second color depth, i.e., when the display device 3 does not support displaying 16-bit display data in RGB565 format, the display processing unit 184 may add complementary data to the display data to generate display data of a predetermined bit width corresponding to the first color depth.

[0042] For example, the display processing unit 184 acquires EDID (Extended Display Identification Data) that includes information indicating a color data format supported by the display device 3, and determines whether the display device 3 is capable of displaying display data in RGB565 format based on the information included in the EDID. If the display processing unit 184 determines that the display device 3 is not capable of displaying 16-bit display data in RGB565 format, it converts the 16-bit display data in RGB565 format stored in the frame buffer into 24-bit (predetermined bit width) display data in RGB888 format by a process similar to the process shown in Fig. 5.

[0043] The display processing unit 184 then outputs the generated display data in RGB888 format to the bridge IC 14, thereby causing the display device 3 to display a display image based on the display data of the predetermined bit width. In this way, the printing device 1 can cause the display device 3 to display a display image corresponding to the display data, even if the display device 3 does not support display of 16-bit display data in RGB565 format.

[0044] The display data generation unit 183 may set the determined color depth in the bridge IC 14, which functions as a display controller that displays the display data on the display device 3. This allows the bridge IC 14 to display on the display device 3 a display image based on data in a color format that corresponds to the color depth determined by the display data generation unit 183 and that is transferred from an upstream DSI host via the DSI interface.

[0045] [Operation flow] Next, a description will be given of the flow of processing in which the printing device 1 causes the display device 3 to display a display image based on display data. Fig. 6 is a flowchart showing the flow of processing in which the printing device 1 causes the display device 3 to display a display image based on display data. Note that this flowchart starts when the display data generation unit 183 receives an operation from the display device 3 or the input device 4 via the host I / F 12, or when the barcode reader 5 reads a barcode and the display data generation unit 183 acquires information indicated by the barcode.

[0046] First, the identifying unit 182 identifies whether the state of the print processing unit 181 is a printing state in which the print processing unit 181 is executing a print process, or a standby state in which the print processing unit 181 is not executing a print process (S1).

[0047] Next, the display data generation unit 183 determines whether the state of the print processing unit 181 identified by the identification unit 182 is a standby state (S2). If the display data generation unit 183 determines that the state of the print processing unit 181 is a standby state (YES in S2), the process proceeds to S3. If the display data generation unit 183 determines that the state of the print processing unit 181 is not a standby state but a printing state (NO in S2), the process proceeds to S6.

[0048] In S3, the display data generation unit 183 determines the color depth of the display data to be the first color depth and generates display data at the first color depth. Then, the display data generation unit 183 stores the generated display data in the frame buffer (S4). Next, the display processing unit 184 outputs the display data stored in the frame buffer to the bridge IC 14 using DSI transfer as described above (S5). As a result, the bridge IC 14 displays a display image based on the display data transferred from the DSI host on the display device 3 via the DisplayPort interface or HDMI.

[0049] In S6, the display data generation unit 183 determines the color depth of the display data to be the second color depth and generates display data at the second color depth. Then, the display data generation unit 183 stores the generated display data in the frame buffer (S7). Next, the display processing unit 184 determines, based on the EDID acquired from the display device 3, whether the display device 3 can display a display image based on the display data at the second color depth (S8). If the display processing unit 184 determines that the display device 3 can display a display image based on the display data at the second color depth (YES in S8), the process proceeds to S10. If the display processing unit 184 determines that the display device 3 cannot display a display image based on the display data at the second color depth (NO in S8), the process proceeds to S9, where the display processing unit 184 adds complementary data to the display data at the second color depth stored in the frame buffer to generate display data of a predetermined bit width corresponding to the first color depth.

[0050] In S10, the display processing unit 184 outputs the display data of the second color depth stored in the frame buffer or the display data of the first color depth converted from the display data to the bridge IC 14. As a result, the bridge IC 14 causes the display device 3 to display an image based on the display data.

[0051] [Variation 1] In the above-described embodiment, the display data generation unit 183 generates display data of a first color depth when the print processing unit 181 is in a standby state, and generates display data of a second color depth when the print processing unit 181 is in a printing state, but this is not limited to this.

[0052] For example, the display data generation unit 183 may determine the color depth based on the number of pixels of the display device 3 and the state of the print processing unit 181 identified by the identification unit 182, and generate display data of the determined color depth. In this case, the storage unit 17 stores color depth information that associates the number of pixels of the display device expected to be connected to the printing device 1 with the color depth in each of the printing state and the standby state.

[0053] The display data generation unit 183 identifies the number of pixels of the display device 3. For example, the display data generation unit 183 acquires, from the display device 3, EDID including information indicating the number of pixels of the display device 3, and identifies the number of pixels of the display device 3 based on the information indicating the number of pixels included in the EDID.

[0054] After identifying the number of pixels of the display device 3, the display data generation unit 183 refers to the color depth information stored in the storage unit 17 and determines the color depth associated with the state of the print processing unit 181 identified by the identification unit 182 and the identified number of pixels of the display device 3 as the color depth of the display data to be generated. Then, the display data generation unit 183 generates display data with the determined color depth.

[0055] By doing this, the printing device 1 can generate display data at a color depth that is appropriate for the number of pixels of the display device adopted as the display device 3 and that does not cause delays in generating the display data.

[0056] [Variation 2] Furthermore, when the state of the print processing unit identified by the identification unit 182 is the standby state, the display data generation unit 183 may identify a first processing amount, which is the processing amount that the control unit 18 as a microcontroller can allocate to generating display data, the number of pixels of the display device 3, and the refresh rate of the display device 3. For example, the display data generation unit 183 acquires EDID from the display device 3, and identifies the number of horizontal and vertical pixels and the refresh rate of the display device 3 based on the EDID. Furthermore, the display data generation unit 183 identifies the maximum data processing amount of the control unit 18 as the first processing amount.

[0057] Then, the display data generation unit 183 may determine the color depth to be applied to the display data in the standby state based on the specified first processing amount, the number of pixels of the display device 3, and the refresh rate. For example, when the first processing amount is Q1, the number of pixels in the horizontal direction of the display device 3 is H, the number of pixels in the vertical direction is V, the refresh rate is Rf, the maximum value of the pixel clock frequency is fpmax, and the color depth is Cdp, the following formula (1) must hold. Q1 > fpmax × Cdp > H × V × Rf × Cdp ··· Formula (1)

[0058] Based on the magnitude relationship between Q1 in formula (1) and H × V × Rf × Cdp, the following formula (2) holds. Cdp < Q1 / (H × V × Rf) ··· Formula (2)

[0059] Therefore, the display data generation unit 183 determines the color depth from the color depths that the display device 3 can obtain such that the specified first processing amount, the number of pixels of the display device 3, the refresh rate, and the color depth of the display device 3 satisfy formula (2).

[0060] Further, when the state of the printing processing unit 181 specified by the specifying unit 182 is the printing state, the display data generation unit 183 may specify the second processing amount, which is the processing amount that the control unit 18 as a microcontroller can allocate to the generation of display data, the number of pixels of the display device 3, and the refresh rate of the display device.

[0061] For example, as described above, the display data generation unit 183 specifies the number of pixels in the horizontal and vertical directions and the refresh rate of the display device 3 based on the EDID. Also, the display data generation unit 183 specifies the second processing amount based on the maximum data processing amount of the control unit 18 and the data processing amount used by the control unit 18 when the state of the printing processing unit 181 is the printing state. Here, the display data generation unit 183 may specify the second processing amount based on the occupancy rate of the RAM of the storage unit 17 of the thread corresponding to the printing processing unit 181 when the state of the printing processing unit 181 is the printing state and the maximum data processing amount of the control unit 18.

[0062] Then, the display data generation unit 183 may determine the color depth to be applied to the display data in the printing state based on the specified second processing amount, pixel clock frequency, number of pixels of the display device 3, and refresh rate. For example, when the second processing amount is Q2, the number of pixels in the horizontal direction of the display device 3 is H, the number of pixels in the vertical direction is V, the refresh rate is Rf, the maximum value of the pixel clock frequency is fpmax, and the color depth is Cdp, the following formula (3) must hold. Q2 > fpmax × Cdp > H × V × Rf × Cdp ··· Formula (3)

[0063] Based on the magnitude relationship between Q2 in formula (3) and H × V × Rf × Cdp, the following formula (4) holds. Cdp < Q2 / (H × V × Rf) ··· Formula (4)

[0064] [[ID=ID=14]]Therefore, the display data generation unit 183 determines the color depth from the possible color depths of the display device 3 such that the specified second processing amount, number of pixels of the display device 3, refresh rate, and color depth of the display device 3 satisfy formula (4).

[0065] By doing so, the printing device 1 can generate display data with a color depth suitable for the specifications of the microcontroller it has and the specifications of the display device 3, and without causing a delay in the generation of the display data.

[0066] [Modification Example 3] Also, in the above-described embodiment, it is assumed that the external display device 3 is connected to the printing device 1, but it is not limited to this. The printing device 1 may have a display unit as the display device 3, and the display processing unit 184 may display a display image based on the display data generated by the display data generation unit 183 on the display unit of the printing device 1.

[0067] [Effect of the Printing Device 1] As described above, the printing device 1 according to this embodiment identifies whether the state of the print processing unit is a printing state in which print processing is being performed, or a standby state in which print processing is not being performed, generates display data with a color depth determined based on whether the identified state of the print processing unit is a printing state or a standby state, and displays a display image based on the generated display data on the display device 3. In this way, the printing device 1 can prevent the screen from becoming distorted during printing in a printing device that performs display processing on the display unit.

[0068] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0069] 1 Printing device 2. Host PC 3 Display device 4 Input Devices 5 Barcode reader 6 Storage device 7 Server 10 Bus Lines 11 Device I / F 12 Host I / F 13 Display I / F 14 Bridge IC 15 Network I / F 16 Printing Department 17 Memory section 18 Control Unit 181 Print processing unit 182 Specific section 183 Display data generation unit 184 Display processing section

Claims

1. A printing device having a display processing unit that displays a display image on a display unit and a printing unit, a print processing unit that executes a print process to cause the printing unit to print; a determination unit that determines whether the state of the print processing unit is a printing state in which the print processing unit is executing the print processing or a standby state in which the print processing unit is not executing the print processing; a display data generating unit that generates display data of a color depth determined based on whether the state of the print processing unit identified by the identifying unit is the printing state or the standby state; and the display processing unit causes the display unit to display the display image based on the display data generated by the display data generation unit. Printing device.

2. the display data generation unit generates display data of a first color depth when the state of the print processing unit identified by the identification unit is the standby state, and generates display data of a second color depth lower than the first color depth when the state identified by the identification unit is the printing state. The printing device of claim 1 .

3. the display data generation unit specifies the number of pixels of the display unit, and refers to color depth information stored in a storage unit that associates the number of pixels of the display unit with color depths in the printing state and the standby state, and generates the display data of the color depth associated with the state of the print processing unit specified by the specification unit and the specified number of pixels of the display unit. The printing device of claim 1 .

4. the display data generation unit acquires, from the display unit, Extended Display Identification Data (EDID) including information indicating the number of pixels of the display unit, and identifies the number of pixels of the display unit based on the acquired EDID. The printing device according to claim 3 .

5. the display data generation unit sets the determined color depth in a display controller that displays the display data on the display unit. The printing device of claim 1 .

6. the display processing unit generates display data of a predetermined bit width by adding complementary data to the display data generated by the display data generation unit, and causes a display unit to display the display image based on the generated display data of the predetermined bit width. The printing device of claim 1 .

7. the printing device has a microcontroller that functions as the print processing unit, the display data generating unit, and the display processing unit; the display data generation unit identifies a first processing amount, which is a processing amount that the microcontroller can allocate to generating display data when the state of the print processing unit identified by the identification unit is the standby state, the number of pixels of the display unit, and a refresh rate of the display unit, and determines a color depth to be applied to the display data in the standby state based on the identified first processing amount, the number of pixels, and the refresh rate. The printing device of claim 1 .

8. the printing device has a microcontroller that functions as the print processing unit, the display data generating unit, and the display processing unit; the display data generation unit identifies a second processing amount, which is a processing amount that the microcontroller can allocate to generating display data when the state of the print processing unit identified by the identification unit is the printing state, the number of pixels of the display unit, and a refresh rate of the display unit, and determines a color depth to be applied to the display data in the printing state based on the identified second processing amount, the number of pixels, and the refresh rate. The printing device of claim 1 .

9. a printing device having a display processing unit that displays a display image on a display unit and a printing unit; a print processing unit that executes a print process to cause the printing unit to print; a determination unit that determines whether the state of the print processing unit is a printing state in which the print processing unit is executing the print processing or a standby state in which the print processing unit is not executing the print processing; a display data generating unit that generates display data having a color depth determined based on whether the state of the print processing unit is the printing state or the standby state; and the display processing unit causing the display unit to display a display image based on the display data generated by the display data generation unit; A program that functions as a

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