JP2015129904A - Projector, control method of projector, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector that can easily switch between a state where an image having a drawing written therein (image having drawing data superimposed on input image data) is projected and a state where only an image before writing a drawing therein (image of input image data) is projected.SOLUTION: When a projector 1 receives a display changeover operation in a drawing state (Figure 4(a)) where drawing data D1 is superimposed on image data G1 to be displayed as an image, switches to a non-drawing state (Figure 4(b)) where only an image of the image data is projected, and when the projector 1 receives a drawing operation by an electronic pen 40 in the non-drawing state, switches to the drawing state (Figure 4(a)) where the drawing data D1 is superimposed to be projected as an image.

Description

The present invention relates to a projector that projects an image, a projector control method, and a display device.

When a presentation or school lesson is performed using a projector, there are times when it is desired to write and describe characters and figures in the projected image. In this case, there is a method of inputting characters and figures by operating a pointing device such as a mouse on the screen of a personal computer (personal computer) connected to the projector and inputting image data.

Patent Document 1 discloses an electronic blackboard system that operates an electronic pen (pen-type input device) on an image projected on a screen and writes characters and figures.
In Patent Document 2, there is an optical blackboard in which an image projection unit that projects an image from the back side of a screen is provided with a predetermined image display at an input position by an input of an instruction operation given to the front side of the screen. It is disclosed. Note that Patent Document 2 describes performing drawing control from a pen-type element and erasing the drawing screen.

JP 2011-140154 A JP-A-8-160539

When drawing (drawing data) such as characters and figures with an electronic pen is written on a projected image (image data), there is a case where it is desired to return to the image before writing and check the image. However, in an apparatus such as the electronic blackboard system of Patent Document 1, in order to erase these drawings, the drawing data must be designated one by one or selected and erased. Further, when the drawing data is returned to the original state and drawing is continued after erasure, a complicated operation such as saving and calling the drawing data somewhere is required. Moreover, in the optical blackboard of patent document 2, only a drawing image is erase | eliminated at once by a pen-type element, and after deleting, a drawing image cannot be restored again.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A projector according to this application example stores image data input from an image input terminal and image projection means for projecting projection data on a projection surface by superimposing drawing data from an indicator and the drawing data. Storage means, input operation means for receiving a display switching operation for switching a projection state of the image data, and when the display switching operation is received, the image data,
And control means for switching between a drawing state in which the drawing data stored in the storage means is superimposed and projected, and a non-drawing state in which only the image data is projected without superimposing the drawing data. It is characterized by.

According to this application example, for example, when a display switching operation is performed while drawing (drawing data) such as a character or a figure is written on an image (image data) with an indicator such as an electronic pen, the image data is The drawing state in which drawing data is superimposed and projected as an image is switched to a non-drawing state in which only image data is projected as an image without superimposing drawing data. As a result, it is possible to easily switch and project the image before drawing and the image after drawing without requiring a complicated operation, so that the images can be easily compared with each other. Become.

Application Example 2 In the projector according to the application example described above, the projector includes a plurality of image input terminals, the storage unit stores drawing data corresponding to each of the plurality of image input terminals, and accepts the display switching operation. If it is the drawing state, it is switched to the non-drawing state, and if it is the non-drawing state, it is switched to the next image input terminal, and the drawing state or non-drawing based on the image data and drawing data of the image input terminal. It is preferable to switch to the state.

According to this application example, when drawing data corresponding to each of image data of a plurality of image input terminals is stored and a display switching operation is performed, the display state of each image input terminal is displayed in the order of the drawing state and the non-drawing state. Switch. Thereby, for each image at each image input terminal, it is possible to switch and project the image before drawing the corresponding drawing data and the image after drawing. Therefore, it is possible to easily compare and confirm each other image for each image input terminal. When drawing is not performed, the image input terminal can be switched by a display switching operation.

Application Example 3 A projector control method according to this application example includes: an image projection step of projecting image data input from an image input terminal and drawing data by an indicator on the projection plane; and the drawing data Storing the image data, the input operation step for receiving a display switching operation for switching the projection state of the image data, the image data when the display switching operation is received, and the drawing data stored in the storage step. And a display switching step for switching between a drawing state in which the image data is superimposed and a non-drawing state in which only the image data is projected without superimposing the drawing data.

According to this application example, for example, when a display switching operation is performed while drawing (drawing data) such as a character or a figure is written on an image (image data) with an indicator such as an electronic pen, the image data is The drawing state in which drawing data is superimposed and projected as an image is switched to a non-drawing state in which only image data is projected as an image without superimposing drawing data. As a result, it is possible to easily switch and project the image before drawing and the image after drawing without requiring a complicated operation, so that the images can be easily compared with each other. Become.

Application Example 4 A display device according to this application example is a display device that displays an image on a display surface.
The display device includes: image display means for superimposing image data input from an image input terminal and drawing data by an indicator and displaying the data on the display surface; storage means for storing the drawing data; An input operation means for accepting a display switching operation for switching a display state;
When the display switching operation is accepted, a drawing state in which the image data and the drawing data stored in the storage unit are superimposed and displayed, and only the image data is displayed without superimposing the drawing data. And a control means for switching between drawing states.

According to this application example, for example, when a display switching operation is performed while drawing (drawing data) such as a character or a figure is written on an image (image data) with an indicator such as an electronic pen, the image data is The drawing state in which the drawing data is superimposed and displayed as an image is switched to the non-drawing state in which only the image data is displayed as an image without superimposing the drawing data. As a result, it is possible to easily switch and display the image before drawing and the image after drawing without requiring a complicated operation, and it is possible to easily compare each other's images. Become.

Explanatory drawing which shows the usage form of a projector. The external view of an electronic pen. The block diagram which shows the circuit structure of a projector. The figure which shows the screen transition at the time of the display switching operation of a projector. The flowchart which shows operation | movement of a projector.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The following embodiments do not limit the invention according to the claims,
Not all combinations of features in the embodiments are essential for the solution of the invention.

(Embodiment)
FIG. 1 is an explanatory diagram showing a usage pattern of the projector 1 of the present embodiment.
As shown in FIG. 1, the projector 1 is suspended from the head of the user H, and the user H performs a drawing operation using the electronic pen 40 on the projection surface SC on which the projector 1 projects an image. The projector 1 detects operation information such as a position indicated by the electronic pen 40 by a pen operation detection unit 25 (see FIG. 3) described later. Then, the projector 1 combines the drawing data D1 based on the drawing operation of the electronic pen 40 with the image data G1, and projects it onto the projection screen SC.

FIG. 2 is an external view of the electronic pen 40.
As shown in FIG. 2, the electronic pen 40 has a pen-shaped housing 40 </ b> A having a sharp tip, and the housing 40
The tip of A is provided with a nib switch 40B and a light emitting unit 40C that emits infrared light.
A pen operation detection unit 25 of the projector 1 described later picks up infrared light and detects the operation position of the electronic pen 40.
Note that the electronic pen 40 in the present embodiment corresponds to an indicator.

FIG. 3 is a block diagram illustrating a circuit configuration of the projector 1 according to the present embodiment.
As shown in FIG. 3, the projector 1 includes an image input terminal 6, an image projection unit 10, and an OSD.
The processing means 16, the image signal processing means 17, the image signal input means 18, the control means 20, the storage means 21, the light source control means 22, the input operation means 23, the pen operation detection means 25, the power supply terminal 30, the power supply unit 31, etc. These are housed inside or outside the housing of the projector 1 (not shown).

The image projection means 10 includes a light source 11 and three liquid crystal light valves 12R as light modulators.
12G, 12B, a projection lens 13 as a projection optical system, liquid crystal driving means 14 and the like. The image projection means (image display means) 10 modulates the light emitted from the light source 11 with the liquid crystal light valves 12R, 12G, and 12B, and projects the light from the projection lens 13, thereby projecting the projection surface S.
Display the image on C etc.

The light source 11 includes a discharge-type light source lamp 11a made of an ultra-high pressure mercury lamp, a metal halide lamp, or the like, and a reflector 11b that reflects light emitted from the light source lamp 11a toward the liquid crystal light valves 12R, 12G, and 12B. ing.
Light emitted from the light source 11 is converted into light having a substantially uniform luminance distribution by an integrator optical system (not shown), and red (R), which is the three primary colors of light, by a color separation optical system (not shown).
After being separated into green (G) and blue (B) color light components, the liquid crystal light valve 12R respectively.
, 12G, 12B.

The liquid crystal light valves 12R, 12G, and 12B are configured by a liquid crystal panel in which liquid crystal is sealed between a pair of transparent substrates. In the liquid crystal light valves 12R, 12G, and 12B, a plurality of pixels (not shown) arranged in a matrix are formed, and a driving voltage can be applied to the liquid crystal for each pixel.
When the liquid crystal driving unit 14 applies a driving voltage corresponding to the input image information to each pixel, each pixel is set to a light transmittance corresponding to the image information. Therefore, the light emitted from the light source 11 is modulated by passing through the liquid crystal light valves 12R, 12G, and 12B, and image light corresponding to image information is formed for each color light.
The formed image light of each color is synthesized for each pixel by a color synthesis optical system (not shown) to become color image light, and then enlarged and projected onto the projection surface SC or the like by the projection lens 13.

In the present embodiment, the projector 1 that projects using the light source lamp 11 a as the light source 11.
However, the present invention can also be applied to a projector that uses an LED (Light Emitting Diode) light source or a laser light source as a light source.

In the present embodiment, the image projection unit 10 includes three liquid crystal light valves 12R and 12G.
, 12B is used as an example, but a light modulation device of another display system such as a reflective liquid crystal display system or a micromirror device system (light switch display system) may be employed. .

The image signal input means 18 receives image information from an external image output device such as a video reproduction device or a personal computer through a plurality of image input terminals 6 via a cable or a communication device (not shown). The input image information is output to the image signal processing unit 17 based on an instruction from the control unit 20. Note that the image signal input unit 18 may include a receiving unit for wireless communication, optical communication, or the like, and input an image signal wirelessly from an external device.

The image signal processing unit 17 converts the image information input from the image signal input unit 18 into image information representing the gradation of each pixel of the liquid crystal light valves 12R, 12G, and 12B based on an instruction from the control unit 20. Here, the converted image information is classified into red (R), green (G), and blue (B) color lights, and a plurality of pixels corresponding to all the pixels of the liquid crystal light valves 12R, 12G, and 12B. Consists of values. The pixel value defines the light transmittance of the corresponding pixel, and the intensity (gradation) of light transmitted through each pixel and emitted is defined by this pixel value.

The OSD processing unit 16 performs processing for superimposing and displaying an OSD (on-screen display) image such as a menu image or a message image on the projection image based on an instruction from the control unit 20. The OSD processing means 16 includes an OSD memory (not shown)
OSD image information representing graphics, fonts, and the like for forming a D image is stored.

When the control unit 20 instructs to superimpose the OSD image, the OSD processing unit 16 reads necessary OSD image information from the OSD memory, and outputs an image signal so that the OSD image is superimposed at a predetermined position on the projected image. The OSD image information is synthesized with the image information input from the processing means 17. The image information combined with the OSD image information is output to the liquid crystal driving means 14.
If there is no instruction to superimpose the OSD image from the control means 20, the OSD processing means 16 directly uses the image information input from the image signal processing means 17 as the liquid crystal driving means 14.
Output to.

When the liquid crystal driving unit 14 drives the liquid crystal light valves 12R, 12G, and 12B according to the image information input from the OSD processing unit 16, the liquid crystal light valves 12R, 12G, and 12B form images according to the image information, and this image Is projected from the projection lens 13.

The control means 20 includes a CPU (Central Processing Unit), a RAM (Random Access Memory) used for temporary storage of various data, and the like, and operates according to a control program (not shown) stored in the storage means 21. As a result, the overall operation of the projector 1 is controlled. That is, the control unit 20 functions as a computer together with the storage unit 21. The control unit 20 performs control to switch the projector 1 between a drawing state in which drawing data of the electronic pen 40 is projected onto image data and a non-drawing state in which only image data is projected.

The storage means 21 is composed of a rewritable nonvolatile memory such as a flash memory or FeRAM, a control program for controlling the operation of the projector 1, various setting data for defining the operating conditions of the projector 1, etc. Is remembered. The storage unit 21 stores drawing data (D1, D2, etc. shown in FIG. 4) by the electronic pen 40.

The light source control unit 22 controls the supply and stop of power to the light source 11 based on an instruction from the control unit 20, and switches between turning on and off the light source 11.

Although not shown, the input operation means 23 includes a plurality of operation keys for the user H to give various instructions to the projector 1, and a main body key provided on the outer surface of a housing (not shown) of the projector 1. Consists of.

The operation keys of the input operation means 23 include a power key for alternately switching on / off the power, an input switching key for switching a plurality of image input terminals 6, and a menu for displaying a setting menu in a superimposed manner. There are a direction key (four operation keys corresponding to up / down / left / right) used for selecting an item in a key, a setting menu, etc., a determination key for confirming a selected item, a cancel key for canceling an operation, and the like.
In the present embodiment, the operation of the input switching key corresponds to the display switching operation, and an operation of switching between the drawing state and the non-drawing state is performed for the image input terminal 6 being selected. Specifically, the drawing state of a certain image input terminal 6, the non-drawing state, the drawing state of the next image input terminal, and the non-drawing state are switched in this order. The display during the display switching operation will be described with reference to FIG.

When the user H operates various operation keys of the input operation unit 23, the input operation unit 23 outputs an operation signal corresponding to the operation content of the user H to the control unit 20. Input operation means 2
3 may be configured to include a remote controller (remote controller) signal receiving means (not shown) and a remote controller (not shown) capable of remote operation. In this case, the remote controller emits an operation signal such as an infrared ray corresponding to the operation content of the user H, and the remote control signal receiving means receives it and transmits it to the control means 20 as control information.

The pen operation detection unit 25 is configured by an image sensor or the like (not shown), and the operation position (coordinates) of the electronic pen 40 and the pressing state of the pen tip switch 40B (see FIG. 2) are determined based on an instruction from the control unit 20. The pen operation state is detected, and the detected pen operation information is notified to the control means 20.

Power such as AC 100 V is supplied to the power supply unit 31 from the outside through the power supply terminal 30.
The power supply unit 31 converts, for example, a commercial power supply (AC power supply) into a DC power supply having a predetermined voltage, and supplies the converted power to each unit of the projector 1. In addition, the power supply unit 31 stops supplying power (operating power) necessary for image projection to each unit (power-on state) and operating power supply based on an instruction from the control unit 20. It is possible to switch between a state (standby state) of waiting for an operation for turning on.

Next, FIG. 4 shows an example of the transition of the projected image during the table switching operation of the projector 1 according to this embodiment.
This will be described with reference to the screen transition diagram of FIG.
In FIG. 4, in the projector 1, image data G1 and G2 are input to two image input terminals 6A and 6B (see FIG. 3), respectively. 4A and 4C are diagrams showing examples of display (projection) in the drawing state, and FIGS. 4B and 4D are diagrams showing examples of display in the non-drawing state. In addition, FIG.
FIGS. 4A and 4D show a state in which the image data G1 input to the image input terminal 6A is displayed as an image. FIGS. 4C and 4D show the image data G2 input to the image input terminal 6B. The state displayed as.
In the following description, the expression “data is displayed (projected) as an image on the projection surface” is abbreviated as “data is displayed (projected)”.

As shown in FIG. 4A, the projector 1 is in a drawing state, and drawing data D1 by the electronic pen 40 is superimposed on the image data G1 and projected onto the projection plane SC. In this state, when a display switching operation is performed, the state transitions to the non-drawing state of FIG.

As shown in FIG. 4B, the drawing data D1 is erased from the display in the drawing state of FIG. 4A, and only the image data G1 is projected onto the projection plane SC. This state is a non-drawing state. Although the drawing data D1 is erased from the screen, it is stored in the storage means 21 (see FIG. 3) and is displayed when the drawing state is set again. When the display switching operation is performed in the state of FIG. 4B, the display is switched to the image input terminal 6B. Next, the drawing data D corresponding to the image input terminal 6B
If 2 is stored in the storage unit 21, the state transitions to the drawing state of FIG. 4C, and if the drawing data D2 is not stored, the state transitions to the non-drawing state of FIG. When a drawing operation with the electronic pen 40 is accepted in the non-drawing state of FIG. 4B, the drawing state of FIG.

As shown in FIG. 4C, the projector 1 enters the drawing state, and the drawing data D2 corresponding to the image data G2 is superimposed and projected onto the projection plane SC. If display switching operation is performed in the state of FIG.4 (c), it will change to the non-drawing state of FIG.4 (d).

As shown in FIG. 4D, the drawing data D2 is erased from the display in the drawing state of FIG. 4C, and only the image data G2 is projected on the projection screen SC. Although the drawing data D2 is erased from the screen, it is stored in the storage means 21 (see FIG. 3) and is displayed when the drawing state is set again. When the display switching operation is performed in the state of FIG. 4D, the display is switched to the image input terminal 6A. Next, if the drawing data D1 corresponding to the image input terminal 6A is stored in the storage means 21, the state transitions to the drawing state of FIG. 4A, and if the drawing data D1 is not stored, the drawing data D1 of FIG. Transition to the non-drawing state. In the non-drawing state of FIG.
When a drawing operation with the electronic pen 40 is received, the drawing state of FIG.

In FIG. 4, the image data G <b> 1 and G <b> 2 of the two image input terminals 6 </ b> A and 6 </ b> B has been described, but the transition similarly occurs when there are three or more image input terminals 6.

Next, the operation of the projector 1 of the present embodiment will be described using the flowchart of FIG.
5A and 5B are flowcharts showing the operation of the projector 1. FIG. 5A shows an operation when a display switching operation is accepted, and FIG. 5B shows an operation when a drawing operation by the electronic pen 40 is accepted.

[Operation when display switching operation is accepted]
As shown in FIG. 5A, when a display switching operation by the input operation means 23 is accepted while the projector 1 is operating (step S101), the process proceeds to step S102.
Step S101 corresponds to an input operation step.

In step S102, the control unit 20 checks whether or not the projector 1 is set to the drawing state. In the drawing state (step S102: Y), step S104.
Transition to. On the other hand, when it is not in the drawing state, that is, in the non-drawing state (step S102: N), the process proceeds to step S103.

In step S103, the control unit 20 switches to the next image input terminal 6 by the image signal input unit 18, and causes the image projection unit 10 to project the input image data.
Transition to 105.

In step S104, the control means 20 deletes the drawing data being projected, and step S104
Transition to 107.

In step S105, the control means 20 checks whether drawing data corresponding to the image data of the image input terminal 6 selected in step S103 is stored in the storage means 21. If the corresponding drawing data is stored (step S105: Y), the process proceeds to step S106. On the other hand, if the corresponding drawing data is not stored (step S
105: N), the process proceeds to step S107.

In step S <b> 106, the control unit 20 reads out drawing data corresponding to the image data of the image input terminal 6 from the storage unit 21 and superimposes it. Next, the projector 1 is set to a drawing state, and the process proceeds to step S108.
Note that step S106 corresponds to an image projection step.

In step S107, the control unit 20 switches the projector 1 to the non-drawing state, and transitions to step S108.
Note that steps S101 to S107 correspond to a display switching step.

  In step S108, the operation flow ends, and the process returns to the original process.

[Operation When Projector 1 Accepts Drawing Operation] As shown in FIG.
While the projector 1 is operating, a drawing operation with the electronic pen 40 is accepted (step S20).
1) and the process proceeds to step S202.

In step S202, the control unit 20 checks whether or not the projector 1 is set to the non-drawing state. In the non-drawing state (step S202: Y), step S2
Transition to 03. On the other hand, in the non-drawing state, that is, in the drawing state (step S202: N
) Transitions to step S204.

In step S203, the control means 20 switches the projector 1 to the drawing state,
The process proceeds to step S204.

In step S204, the control unit 20 causes the image projection unit 10 to project the drawing data corresponding to the drawing operation with the electronic pen 40 onto the image data (FIGS. 4A and 4C).
Reference), and the process proceeds to step S205.
Note that step S204 corresponds to an image projection step.

In step S205, the control unit 20 stores the drawing data projected in step S204 in the storage unit 21, and the process proceeds to step S206.
Note that step S205 corresponds to a storage step.

  In step S206, the operation flow is ended, and the process returns to the original process.

According to the embodiment described above, the following effects can be obtained.
According to the projector 1 of the present embodiment, the electronic pen 4 is applied to the projected image (image data).
When the display switching operation is performed while drawing (drawing data) such as characters and figures is written with 0, the drawing state in which the drawing data is superimposed on the image data and projected as an image is displayed without superimposing the drawing data. Switch to a non-rendering state where only image data is projected as an image. As a result, it is possible to easily switch and project the image before drawing and the image after drawing without requiring a complicated operation, so that the images can be easily compared with each other. Become.

Further, when drawing data corresponding to each of the image data of the plurality of image input terminals 6 is stored and a display switching operation is performed, the display state of each image input terminal 6 is switched in the order of the drawing state and the non-drawing state. Thereby, for each image of each image input terminal 6, it is possible to switch and project the image before drawing the corresponding drawing data and the image after drawing.
Therefore, it is possible to easily compare and confirm the images of each image input terminal 6 for each image. When drawing is not performed, the image input terminal 6 can be switched by a display switching operation.

By using the projector 1 of the present embodiment, various presentations, lessons at school, and the like can be efficiently advanced in order to achieve the effects described above.

Moreover, you may change this embodiment as follows.
(Modification 1) In the above embodiment, the image input terminal 6 includes image signal detection means for detecting whether or not an image signal is input, and only the image input terminal 6 to which the image signal (data) is input. You may make it switch.

(Modification 2) In the above embodiment, after performing the display switching operation, it may be displayed for a predetermined time whether it is in the drawing state or the non-drawing state.
(Modification 3) Moreover, although the aspect applied to the projector 1 which projects an image was illustrated in embodiment mentioned above, the technical idea of this invention is not limited to such a projector 1. FIG. For example, by applying to a display device that displays an image on the display surface, when drawing of characters, figures, etc. is written on the displayed image with the electronic pen 40, the image is returned to the image before writing and the image is confirmed. Problems that cannot be solved, and that, after erasing, when drawing data is returned to its original state and drawing is continued, such a problem that complicated operations such as saving and calling the drawing data somewhere are necessary can be solved.
Such a display device is assumed to be a cathode ray tube (CRT), a liquid crystal display, a plasma display, an organic EL display, a head mounted display, or the like.

DESCRIPTION OF SYMBOLS 1 ... Projector, 6, 6A, 6B ... Image input terminal, 10 ... Image projection means, 11 ... Light source, 12R, 12G, 12B ... Liquid crystal light valve, 13 ... Projection lens, 14 ... Liquid crystal drive means, 16 ... OSD processing means , 17 ... Image signal processing means, 18 ... Image signal input means, 20 ...
Control means, 21 ... Storage means, 22 ... Light source control means, 23 ... Input operation means, 25 ... Pen operation detection means, 30 ... Power supply terminal, 31 ... Power supply unit, 40 ... Electronic pen, 40A ... Housing, 40B ... Pen Tip switch, 40C... Light emitting section, G1, G2... Image data, D1, D2.
C: Projection plane.

Claims (4)

A projector that projects an image onto a projection surface,
The projector includes an image projection unit that superimposes image data input from an image input terminal and drawing data by an indicator and projects the image onto the projection surface;
Storage means for storing the drawing data;
Input operation means for receiving a display switching operation for switching the projection state of the image data;
When the display switching operation is accepted, a drawing state in which the image data and the drawing data stored in the storage unit are superimposed and projected, and only the image data is projected without superimposing the drawing data. Control means for switching between drawing states;
A projector, comprising: The projector according to claim 1,
A plurality of the image input terminals;
The storage means stores drawing data corresponding to each of the plurality of image input terminals,
When the display switching operation is received, the drawing state is switched to the non-rendering state, and the non-rendering state is switched to the next image input terminal, and the image data and the rendering data of the image input terminal are used. A projector characterized by switching to a drawing state or a non-drawing state. A method of controlling a projector that projects an image on a projection surface,
An image projection step of projecting the image data input from the image input terminal and the drawing data by the indicator onto the projection surface in a superimposed manner;
A storage step for storing the drawing data;
An input operation step of accepting a display switching operation for switching the projection state of the image data;
When the display switching operation is accepted, a drawing state in which the image data and the drawing data saved in the storing step are superimposed and projected, and only the image data is projected without superimposing the drawing data A display switching step for switching between drawing states;
A projector control method comprising the steps of: A display device for displaying an image on a display surface,
The display device includes image display means for superimposing image data input from an image input terminal and drawing data by an indicator on the display surface;
Storage means for storing the drawing data;
Input operation means for receiving a display switching operation for switching the display state of the image data;
When the display switching operation is accepted, a drawing state in which the image data and the drawing data stored in the storage unit are superimposed and displayed, and only the image data is displayed without superimposing the drawing data. Control means for switching between drawing states;
A display device comprising:

Images