Bird's-eye view image display device, display device, and work machine

Abstract

The present invention implements a bird's-eye view image display device, a display device, and a work machine with which it is possible to enhance safety around a work machine during input operation using a touch panel. A work machine (1) comprises a bird's-eye view image display device (30) that displays a bird's-eye view image around the work machine. This bird's-eye view image display device comprises: a bird's-eye view image display panel (31) having a touch panel (312); a determination unit (323) for determining whether the work machine is in an operable state; and an input control unit (3222). The input control unit displays an input screen and receives an input when a predetermined touch operation is performed on the touch panel if the work machine is determined to be in an inoperable state, and does not display the input screen and does not receive an input even when a predetermined touch operation is performed if the work machine is determined to be in an operable state.

Description

Overhead image display device, display device, work equipment

[0001] The present invention relates to an overhead image display device, a display device, and a work machine.

[0002] A conventional technique for displaying an overhead image, which is created by stitching together images captured by multiple cameras mounted on a work machine such as a construction machine, on a display unit in a driver's cab is known (see, for example, Patent Document 1). The display device (display unit) in Patent Document 1 has a touch panel on the screen, allowing instructions to be input by touch operation.

[0003] Japanese Patent Application Publication No. 2021-30804

[0004] As in the conventional technology described above, in a configuration in which the display device installed in the driver's cab of a work machine has a touch panel, it is expected that an input screen such as a setting screen will be displayed and various settings will be made using the touch panel.

[0005] However, inside the cab of the work machine, multiple operating parts consisting of levers and buttons, such as levers to operate the work equipment, levers to operate the traveling equipment, and levers to rotate the rotating body, are arranged while ensuring space for the operator.

[0006] Therefore, when performing input operations using a touch panel, there is a risk that a part of the body, such as an elbow or arm, may come into contact with the operating part, causing the work machine to operate unintentionally and threatening safety around the work machine.When performing input operations, the operator's attention is focused on the input screen, so it is thought that touching the operating part with a part of the body is more likely to occur than when the work machine is being operated and work is being performed.

[0007] An aspect of the present disclosure aims to provide an overhead image display device, a display device, and a work machine that can increase safety around the work machine during input operations using a touch panel.

[0008] In order to solve the above problems, an overhead image display device according to one aspect of the present disclosure is an overhead image display device mounted on a work machine, and comprises: a screen unit having a touch panel; an overhead image generation unit that generates an overhead image of the surroundings of the work machine based on images captured by a plurality of cameras mounted on the work machine; a determination unit that determines whether the work machine is in an operable state or an inoperable state; a display control unit that displays the overhead image on the screen unit; and an input control unit that controls input using the touch panel; when the determination unit determines that the work machine is in an inoperable state, the input control unit displays an input screen on the screen unit and accepts input when a predetermined touch operation is performed on the touch panel; and when the determination unit determines that the work machine is in an operable state, the input control unit does not display the input screen on the screen unit and does not accept input even when a predetermined touch operation is performed on the touch panel.

[0009] In order to solve the above problems, a display device according to one embodiment of the present disclosure is a display device mounted on a work machine and having a touch panel on a screen unit, and is equipped with a screen control unit that controls the screen unit, and a judgment unit that judges whether the work machine is in a state where it can operate or not, and when the judgment unit judges that the work machine is in a state where it cannot operate, the screen control unit displays an input screen on the screen unit and accepts input when a predetermined touch operation is performed on the touch panel, and when the judgment unit judges that the work machine is in a state where it can operate, the screen control unit does not display an input screen on the screen unit and does not accept input even when a predetermined touch operation is performed on the touch panel.

[0010] According to one aspect of the present disclosure, it is possible to realize an overhead image display device, a display device, and a work machine that can increase safety around the work machine during input operations using a touch panel.

[0011] Fig. 4 is a schematic perspective view showing the overall configuration of a work machine according to an embodiment of the present invention. Fig. 5 is a perspective view showing a part of the front side of the interior of a cabin in the work machine shown in Fig. 1. Fig. 6 is a control block diagram showing the configuration of the work machine shown in Fig. 1. Fig. 7 is a diagram showing an example of screen transitions when performing setting operations using an overhead image display panel in the work machine shown in Fig. 1. Fig. 8 is a continuation of Fig. 4.

[0012] [First Embodiment] Hereinafter, one embodiment of the present invention will be described in detail.

[0013] 1 is a schematic perspective view showing the overall configuration of a work machine 1 according to this embodiment. In this embodiment, the work machine 1 is exemplified by a backhoe, which is one type of construction machine.

[0014] As shown in Figure 1, the work machine 1 includes a traveling device 2, a revolving body 3, and a working device 4. The revolving body 3 is supported on the frame of the traveling device 2 via a bearing body so as to be able to rotate about a vertical axis (an axis in the up-down direction). The revolving body 3 includes the working device 4, a cabin (operator's compartment) 5, a prime mover 6, a hood 7, a counterweight 8, etc.

[0015] The cabin 5 has a driver's seat inside where an operator (driver) sits. In the following description, the front side of the operator seated in the driver's seat will be referred to as the front, the rear side of the operator as the rear, the left side of the operator as the left side, and the right side of the operator as the right side. The cabin 5 is installed to the left of the rotating body 3.

[0016] The prime mover 6 is located at the rear of the revolving unit 3 and is covered by a hood 7. The counterweight 8 is a weight for balancing the weight with the working device 4, and is located below (below) the hood 7. The prime mover 6 may be an internal combustion engine or an electric motor.

[0017] The work device 4 is a device that operates using hydraulic pressure as a working fluid pressure, and is installed at the front of the work machine 1, specifically at the front of the revolving body 3. The work device 4 performs work such as excavation and ground leveling.

[0018] (Interior of Cabin) Fig. 2 is a perspective view showing a portion of the front side of the interior of the cabin 5. As shown in Fig. 2, inside the cabin 5, a main display panel 21 and an overhead image display panel (screen unit) 31 are installed in front of a driver's seat (not shown). The main display panel 21 displays various information and the like to inform the operator under the control of a work machine control device 20 (described later). The overhead image display panel 31 displays an overhead image of the surroundings of the work machine 1 under the control of an image display calculation device 32 (described later).

[0019] In this embodiment, the main display panel 21 is installed in front of the driver's seat, and the overhead image display panel 31 is installed diagonally below and to the left of the main display panel 21. The overhead image display panel 31 has a larger screen size than the main display panel.

[0020] Additionally, as shown in FIG. 2, inside the cabin 5, a plurality of operation levers 16 for operating the traveling device 2, the revolving body 3, the working device 4, etc. are arranged.

[0021] (Block diagram of work machine) Figure 3 is a control block diagram that shows a schematic configuration of the work machine 1 according to this embodiment. As shown in Figure 3, the work machine 1 includes, in addition to the traveling device 2, the revolving body 3, the work device 4, the main display panel 21, and the overhead image display panel 31, a hydraulic unit 19, a control valve unit 18, an operation unit 15, a work machine control device 20, an overhead image display device 30, and a plurality of cameras 40.

[0022] Although not shown, the hydraulic section 19 includes the prime mover 6, a hydraulic tank, a hydraulic pump, etc., and outputs hydraulic pressure. The control valve section 18 controls the flow of hydraulic pressure output from the hydraulic section 19. In Figure 3, thick lines indicate the flow of hydraulic pressure.

[0023] The hydraulic pressure from the hydraulic unit 19 is sent to the hydraulic motor 12 of the traveling device 2 to operate the traveling device 2, sent to the hydraulic motor 13 of the rotating body 3 to operate the rotating body 3, and sent to the hydraulic cylinder 14 to operate the working device 4.

[0024] The operating unit 15 operates the control valve unit 18. The operating unit 15 includes an unload lever 17 in addition to the operating lever 16 described above that operates the traveling device 2, the revolving body 3, the working device 4, etc.

[0025] The unload lever 17 is an operating lever of a safety device that switches between an operable state and an inoperable state the traveling device 2, the revolving body 3, and the working device 4. By operating the unload lever 17, the hydraulic motor and hydraulic cylinder (hydraulic actuator) of the working machine 1 can be switched between an operable state and an inoperable state.

[0026] When the unload lever 17 is pulled up, the hydraulic path leading to the hydraulic motor and hydraulic cylinder is blocked, and no hydraulic pressure is sent out, so that the traveling unit 2, the revolving unit 3, and the working unit 4 cannot operate, i.e., the working machine 1 cannot operate.

[0027] When the unload lever 17 is pulled down, the hydraulic path leading to the hydraulic motor and the hydraulic cylinder is opened, and hydraulic pressure is sent in response to the operation of the operating lever 16 by the operating unit 15. This enables the traveling device 2, the revolving body 3, and the working device 4 to operate, i.e., the working machine 1 to operate.

[0028] A signal indicating the content of the operation by the operation unit 15 is transmitted to the work machine control device 20, for example, via a port input.

[0029] The work machine control device 20 is made up of an ECU, which is configured by a microcomputer that controls each part of the work machine 1. The above-mentioned main display panel 21 is connected to the work machine control device 20. The main display panel 21 displays various images, characters, etc. based on various information supplied from the work machine control device 20.

[0030] The work machine control device 20 transmits a signal indicating the state of the unload lever 17, among the signals indicating the content of the operation received from the operation unit 15, to the overhead image display device 30. In other words, whether the unload lever 17 is in a pulled-up state or a pulled-down state is transmitted to the overhead image display device 30 via, for example, CAN communication or the like.

[0031] The overhead image display device 30 is a display device that includes the above-mentioned overhead image display panel 31 and an image display calculation device 32, and is connected to a plurality of cameras 40. The plurality of cameras 40 capture images for generating an overhead image of the periphery of the work machine 1, and are arranged, for example, on the left, right, and rear of the revolving unit 3. The plurality of cameras 40 output the captured images to the image display calculation device 32. Note that the captured images from each camera 40 may be displayed individually.

[0032] The overhead image display panel 31 includes a monitor 311 that displays an overhead image on a display screen, and a touch panel 312 that is provided on the display screen of the monitor 311. When the touch panel 312 is touched with a finger or the like, an operation signal generated by the touch panel 312 is supplied to the image display calculation device 32.

[0033] The image display calculation device 32 includes an overhead image generation unit 321 , a screen control unit 322 , and a determination unit 323 .

[0034] The overhead image generating unit 321 uses captured images obtained from the multiple cameras 40 to generate an overhead image of the surroundings of the work machine 1 with the work machine 1 at the center.

[0035] The determination unit 323 determines whether the work machine 1 is in an operable state or an inoperable state. In this embodiment, the determination unit 323 determines whether the work machine 1 is in an operable state or an inoperable state based on a signal indicating the state of the unload lever 17 received via the work machine control device 20.

[0036] The screen control unit 322 controls the overhead image display panel 31, and supplies a video signal to the monitor 311 to display an image on the monitor 311. The screen control unit 322 also receives an operation signal supplied from the touch panel 312.

[0037] The screen control unit 322 includes a display control unit 3221 and an input control unit 3222. The display control unit 3221 displays an overhead image on the overhead image display panel 31. Specifically, the display control unit 3221 supplies the overhead image generated by the overhead image generation unit 321 to the overhead image display panel 31, and causes the monitor 311 to display the overhead image.

[0038] When the determination unit 323 determines that the work machine 1 is in an inoperable state, the input control unit 3222 displays an input screen on the overhead image display panel 31 and accepts input when a predetermined touch operation is performed on the touch panel 312. When the determination unit 323 determines that the work machine 1 is in an operable state, the input control unit 3222 does not display the input screen on the overhead image display panel 31 and does not accept input even when a predetermined touch operation is performed on the touch panel 312.

[0039] In this embodiment, when the determination unit 213 determines that the work machine 1 is in an inoperable state, the input control unit 3222 displays a predetermined icon for displaying an input screen in response to a predetermined touch operation being performed on the touch panel 312. When the displayed icon is touched, the input control unit 3222 displays the input screen and accepts input.

[0040] In addition, in this embodiment, when the input control unit 3222 is in a state where it is accepting input and the state switches to a state where the judgment unit 323 can make a judgment, it ends the display of the input screen and ends the acceptance of input.

[0041] Furthermore, in this embodiment, when the input control unit 3222 finishes accepting input, the display control unit 3221 displays the overhead image on the overhead image display panel 31 .

[0042] In this embodiment, a setting screen for making various settings for displaying an overhead image is displayed as an input screen, and setting operations using the touch panel 312 are accepted.

[0043] (Screen Transition of Overhead Image Display Panel) The procedure for displaying the setting screen on the overhead image display panel 31 will be described below with reference to Figures 4 and 5. Figure 4 is a diagram showing an example of screen transitions when performing setting operations using the overhead image display panel 31 in the work machine 1. Figure 5 is a continuation of Figure 4.

[0044] 4, in the normal mode, an overhead image 50 centered on the work machine 1 is displayed on surface D of the overhead image display panel 31. In the normal mode, the operator performs a predetermined touch operation on screen D on which the overhead image 50 is displayed.

[0045] The predetermined touch operation is, for example, an operation of touching a predetermined area on the screen D a predetermined number of times. Specifically, for example, it is an operation of touching the upper left corner of the screen D a predetermined number of times, i.e., N times. Needless to say, the number of touches and the area to be touched are not limited to the upper left corner of the screen D, but may be another corner of the screen D, or an operation of touching diagonally opposite corners of the screen D in a predetermined order. Note that in this embodiment, the predetermined area to be the target of the predetermined touch operation is displayed in a display mode indistinguishable from other areas, and the predetermined touch operation is performed by a so-called hidden operation.

[0046] The response to a predetermined touch operation differs depending on the state of the unload lever 17. In other words, when the unload lever 17 is raised and the work machine 1 is in an inoperable state, performing a predetermined touch operation causes a predetermined icon 55 for displaying a setting screen to be displayed superimposed on the overhead image 50 on the screen D, as shown by reference numeral 1002 in Fig. 4 .

[0047] On the other hand, when the unload lever 17 is lowered and the work machine 1 is in a state where it can operate, the specified icon 55 does not appear, as shown by reference numeral 1003 in Figure 4, and there is no change in the screen D on which the overhead image 50 is displayed.

[0048] Since the predetermined icon 55 is not displayed, the operator notices that the unload lever 17 is lowered, and the operator pulls up the unload lever 17 and performs the same operation again. As a result, the predetermined icon 55 for displaying the setting screen is displayed on the screen D superimposed on the overhead image 50, as shown by the reference numeral 1002.

[0049] Touching a predetermined icon 55 transitions from normal mode to setting mode. In this embodiment, as shown by reference numeral 1004 in Fig. 5 , a language selection screen (input screen) 51 for selecting a language is first displayed on screen D. When a desired language is touched on the language selection screen 51, a setting screen 52 in the selected language is displayed as shown by reference numeral 1005 in Fig. 5 . Note that the display of the predetermined icon 55 ends if a predetermined time has passed since it was displayed without being touched.

[0050] The setting screen 52 displays a display key K1 for returning from the setting mode to the normal mode, a display key K2 for proceeding to a calibration screen for calibrating the multiple cameras 40, a display key K3 for proceeding to a fine adjustment screen for fine adjustment, etc. By touching the display keys K2, K3, etc., a deeper setting screen is displayed.

[0051] When the unload lever 17 is pulled down while the setting screen 52 or a deeper setting screen corresponding to the display keys K2 and K3 of the setting screen 52 is displayed, the setting mode ends and the normal mode is restored. That is, the display of the setting screen on screen D ends, and as shown by reference numeral 1006 in Fig. 5, an overhead image 50 with the work implement 1 at its center is displayed on screen D. The same applies when the unload lever 17 is pulled down while the language selection screen 51 is displayed, and the normal mode is restored.

[0052] (Description of effects) As described above, in the overhead image display device 30 mounted on the work machine 1, when the work machine 1 is in a state where it cannot operate, by performing a specified touch operation, an input screen is displayed on the overhead image display panel 31, making it possible to input using the touch panel 312, but when the work machine 1 is in a state where it can operate, the input screen is not displayed and input is not possible even if a specified touch operation is performed.

[0053] Therefore, even if a part of the body such as an elbow or arm touches the operation unit 15 while the setting screen 52 is displayed and a setting operation is being performed using the touch panel 312, none of the traveling device 2, the rotating body 3, and the working device 4 will operate, and the working machine 1 will not move at all.

[0054] This prevents the work machine 1 from operating unintentionally during the setting operation, ensuring safety around the work machine 1 during the setting operation.

[0055] It is also possible to configure the system so that the input screen, which is the language selection screen 51 or the setting screen 52, is directly displayed by performing a predetermined touch operation when the work machine 1 is unable to operate, but in this embodiment, a predetermined icon 55 for displaying the input screen is first made to appear when a predetermined touch operation is performed when the work machine 1 is unable to operate.

[0056] Therefore, even if an operator who is unaware that the overhead image display device 30 has an input function via the touch panel 312 accidentally performs a predetermined touch operation, the input screen will not be displayed unless the operator notices the appearance of the icon 55. This makes it possible to provide a configuration suitable for specifications in which only limited personnel, such as service personnel who perform maintenance on the work machine 1, use the input function via the touch panel 312.

[0057] In addition, in this embodiment, when the determination unit 323 determines that the work machine 1 is switched from an inoperable state to an operable state while the bird's-eye view image display device 30 is accepting input using the touch panel 312, the bird's-eye view image display device 30 stops displaying the input screen, such as the setting screen, and stops accepting input. In other words, if the unload lever 17 is pulled down during a setting operation, the setting screen is forcibly cleared and the setting operation becomes impossible.

[0058] As a result, if an attempt is made to operate the work machine 1 during the setting operation, the setting operation will be forcibly prevented from being performed, thereby further ensuring safety around the work machine 1 during the setting operation.

[0059] Furthermore, in this embodiment, when the work machine 1 switches from an inoperable state to an operable state and the display of an input screen such as a setting screen is terminated, an overhead image is displayed in place of the input screen. If the input screen were simply configured to disappear, the operator might mistakenly believe that an error has occurred, but by doing so, the operator can clearly recognize that the state has changed to one in which input using the touch panel 312 is no longer possible.

[0060] In this embodiment, the unload lever 17 is used as an example of the safety device, but a button may be used depending on the model of the work machine. In short, the safety device may be any device that can switch the traveling device 2, the revolving body 3, and the work device 4 between an operable state and an inoperable state.

[0061] Furthermore, the unload lever 17 does not necessarily have to switch all of the traveling device 2, the rotating body 3 and the working device 4 between an operable state and an inoperable state, but may switch only some of the traveling device 2, the rotating body 3 and the working device 4 between an operable state and an inoperable state.

[0062] In addition, instead of the unload lever 17, a locking mechanism (safety device) may be provided that mechanically switches some or all of the traveling device 2, the rotating body 3, and the working device 4 between a locked state (operable state) and an unlocked state (inoperable state).

[0063] Also, for example, the work machine control device 20 may send signal information indicating whether the prime mover 6 of the hydraulic unit 19 is operating to the overhead image display device 30, and the judgment unit 323 may use this information to judge whether the work machine 1 is in a state where it can operate or not.

[0064] [Example of implementation by software] The functions of the overhead image display device 30 (hereinafter referred to as the "device") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device.

[0065] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The functions described in each of the above embodiments are realized by executing the program using the control device and storage device.

[0066] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0067] Furthermore, some or all of the functions of the control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of the control blocks can also be realized by, for example, a quantum computer.

[0068] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0069] (Summary) The overhead image display device in aspect 1 of the present invention is an overhead image display device mounted on a work machine, and comprises a screen unit having a touch panel, an overhead image generation unit that generates an overhead image of the surroundings of the work machine based on images captured by a plurality of cameras mounted on the work machine, a determination unit that determines whether the work machine is in an operable state or an inoperable state, a display control unit that displays the overhead image on the screen unit, and an input control unit that controls input using the touch panel, wherein when the determination unit determines that the work machine is in an inoperable state, the input control unit displays an input screen on the screen unit and accepts input when a predetermined touch operation is performed on the touch panel, and when the determination unit determines that the work machine is in an operable state, the input control unit does not display the input screen on the screen unit and does not accept input even when a predetermined touch operation is performed on the touch panel.

[0070] According to the above configuration, the work machine can be prevented from operating unintentionally during input operations using the touch panel, thereby ensuring safety around the work machine during input operations.

[0071] In the overhead image display device of aspect 2 of the present invention, in aspect 1, the input control unit may display a predetermined icon on the screen unit for displaying the input screen when a predetermined touch operation is performed on the touch panel when the judgment unit has determined that the work machine is in a state where it cannot operate, and when the icon is touched, the input screen is displayed and input is accepted.

[0072] According to the above configuration, even if a specified touch operation is performed by accident, the input screen will not be displayed unless the user notices the appearance of the icon, making the configuration suitable for specifications where only a limited number of people use the touch panel input function.

[0073] In the overhead image display device of aspect 3 of the present invention, in aspect 1 or 2, the input control unit may terminate the display of the input screen and terminate the acceptance of input when, while accepting the input, the judgment by the judgment unit switches from a state in which the work machine cannot operate to a state in which the work machine can operate.

[0074] According to the above configuration, if an attempt is made to operate the work machine during an input operation, the input operation will be forcibly prevented from being performed, thereby further ensuring safety around the work machine during the input operation.

[0075] In the overhead image display device according to Aspect 4 of the present invention, in accordance with Aspect 3, the display control unit may display the overhead image on the screen unit when the input control unit has finished accepting input.

[0076] According to the above configuration, the disappearance of the input screen is not an error, but the operator can clearly recognize that the state has shifted to one in which input using the touch panel is no longer possible.

[0077] In the overhead image display device in aspect 5 of the present invention, in aspects 1, 2, 3 or 4, the specified touch operation is an operation of touching a specified area of ​​the screen unit a specified number of times, and the display control unit may display in the specified area in a manner that makes it impossible to identify that it is the target area of ​​the specified touch operation.

[0078] A working machine in aspect 6 of the present invention is a working machine comprising a traveling device, a rotating body that rotates relative to the traveling device, a working device provided on the rotating body, a driver's cab provided on the rotating body, and a safety device that switches at least one of the traveling device, the rotating body, and the working device between an operable state and an inoperable state, and is equipped with an overhead image display device described in any of aspects 1 to 4, and a plurality of cameras arranged on the rotating body, the screen unit is installed in the driver's cab, and the judgment unit uses information based on a signal output from the safety device to judge whether the working machine is in a state where it can operate or not.

[0079] The display device in aspect 7 of the present invention is a display device mounted on a work machine and having a touch panel on a screen portion, and is equipped with a screen control unit that controls the screen portion, and a judgment unit that judges whether the work machine is in a state where it can operate or not, and when the judgment unit judges that the work machine is in a state where it cannot operate, the screen control unit displays an input screen on the screen portion and accepts input when a predetermined touch operation is performed on the touch panel, and when the judgment unit judges that the work machine is in a state where it can operate, the screen control unit does not display the input screen on the screen portion and does not accept input even when a predetermined touch operation is performed on the touch panel.

[0080] In the display device of aspect 8 of the present invention, in aspect 7, the specified touch operation is an operation of touching a specified area of ​​the screen unit a specified number of times, and the screen control unit may display in the specified area in a manner that makes it impossible to identify that it is the target area of ​​the specified touch operation.

[0081] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0082] REFERENCE SIGNS LIST 1 Work machine 2 Travel device 3 Swing body 4 Work device 15 Operation unit 16 Operation lever 17 Unload lever (safety device) 30 Bird's-eye view image display device 31 Bird's-eye view image display panel (screen unit) 32 Image display calculation unit 40 Multiple cameras 50 Bird's-eye view image 51 Language selection screen (input screen) 52 Setting screen (input screen) 55 Prescribed icon 323 Determination unit 311 Monitor 312 Touch panel 321 Bird's-eye view image generation unit 322 Screen control unit 3221 Display control unit 3222 Input control unit

Claims

1. An overhead image display device mounted on a work machine, comprising: a screen unit having a touch panel; an overhead image generation unit that generates an overhead image of the surroundings of the work machine based on images captured by multiple cameras mounted on the work machine; a determination unit that determines whether the work machine is in an operable state or not; a display control unit that displays the overhead image on the screen unit; and an input control unit that controls input using the touch panel, wherein the input control unit displays an input screen on the screen unit and accepts input when a predetermined touch operation is performed on the touch panel when the determination unit determines that the work machine is in an operable state, and does not display the input screen on the screen unit and does not accept input when a predetermined touch operation is performed on the touch panel when the determination unit determines that the work machine is in an operable state.

2. The overhead image display device of claim 1, wherein the input control unit displays a predetermined icon on the screen unit to display the input screen when a predetermined touch operation is performed on the touch panel when the judgment unit has determined that the work machine is in an inoperable state, and displays the input screen and accepts input when the icon is touched.

3. The overhead image display device of claim 1, wherein the input control unit, when accepting the input, terminates the display of the input screen and terminates the acceptance of the input when the judgment unit determines that the work machine is inoperable to operable.

4. The overhead image display device according to claim 3, wherein the display control unit displays the overhead image on the screen unit when the input control unit finishes accepting input.

5. The overhead image display device according to claim 1, wherein the predetermined touch operation is an operation of touching a predetermined area of ​​the screen a predetermined number of times, and the display control unit displays the predetermined area in a manner that makes it impossible to identify that it is the target area of ​​the predetermined touch operation.

6. A work machine comprising: a traveling device; a rotating body that rotates relative to the traveling device; a working device provided on the rotating body; a driver's cab provided on the rotating body; and a safety device that switches at least one of the traveling device, the rotating body and the working device between an operable state and an inoperable state, the work machine comprising: an overhead image display device described in any one of claims 1 to 5; and a plurality of cameras arranged on the rotating body, the screen unit being installed in the driver's cab, and the judgment unit using information based on a signal output from the safety device to judge whether the work machine is in an operable state or an inoperable state.

7. A display device mounted on a work machine and having a touch panel on a screen section, comprising: a screen control section that controls the screen section; and a judgment section that judges whether the work machine is in an operable state or not, wherein the screen control section displays an input screen on the screen section and accepts input when a predetermined touch operation is performed on the touch panel when the judgment section judges that the work machine is in an operable state, and does not display the input screen on the screen section and does not accept input when a predetermined touch operation is performed on the touch panel when the judgment section judges that the work machine is in an operable state.

8. The display device according to claim 7, wherein the predetermined touch operation is an operation of touching a predetermined area of ​​the screen unit a predetermined number of times, and the screen control unit displays in the predetermined area in a manner that makes it impossible to identify that the area is the target area of ​​the predetermined touch operation.

Images