Imaging device, and method for controlling imaging device

Abstract

This imaging device is configured to be able to adjust the position of a lens, and comprises: a holding unit that holds a plurality of control parameters for controlling the lens to a fixed position, the control parameters respectively corresponding to a plurality of imaging distances in the imaging device; a setting unit that accepts designation of any of the plurality of imaging distances; and a control unit that moves the lens to the fixed position using a control parameter corresponding to the imaging distance designated in the setting unit.

Description

IMAGING DEVICE AND METHOD FOR CONTROLLING IMAGING DEVICE

[0001] The present disclosure relates to an imaging device and a control method for the imaging device.

[0002] Conventionally, information processing devices equipped with a photographing device such as a camera have become widespread. Examples of such information processing devices include a reading device such as a barcode reader, which acquires various information by analyzing images captured by the camera. Furthermore, since the distance between the subject and the information processing device varies depending on the situation, the camera lens position and focus position are adjusted according to the distance. For example, Patent Document 1 discloses a configuration in which, when an operating mode for close-up photography is selected in a camera-equipped electronic device, the focus position of the lens is adjusted to the corresponding position.

[0003] Japanese Patent Application Publication No. 2004-309689

[0004] The present disclosure has been devised in view of the above-described conventional circumstances, and aims to improve the convenience for users when taking pictures using an imaging device.

[0005] The present disclosure provides an imaging device configured to adjust the position of a lens, the imaging device having: a storage unit that stores a plurality of control parameters for controlling the lens to a fixed position corresponding to each of a plurality of shooting distances in the imaging device; a setting unit that accepts designation of one of the plurality of shooting distances; and a control unit that moves the lens to the fixed position using the control parameter corresponding to the shooting distance designated by the setting unit.

[0006] The present disclosure also provides a control method for an imaging device configured to adjust the position of a lens, the control method including: a setting step of accepting designation of one of a plurality of shooting distances of the imaging device; and a control step of moving the lens to a fixed position using a control parameter corresponding to the shooting distance designated in the setting step from among a plurality of control parameters for controlling the lens to a fixed position, the control parameters being predefined corresponding to each of a plurality of shooting distances of the imaging device.

[0007] Any combination of the above components and conversion of the expressions of the present disclosure between devices, systems, etc. are also valid aspects of the present disclosure.

[0008] According to the present disclosure, it is possible to improve the convenience for a user when taking a photograph using a photographing device.

[0009] FIG. 1 is a block diagram showing an example of the configuration of an information processing device according to an embodiment of the present invention; FIG. 2 is a schematic diagram showing an example of the configuration of a lens unit according to an embodiment of the present invention; FIG. 3 is a table for explaining settings according to an embodiment of the present invention; FIG. 4 is a schematic diagram showing an example of the configuration of a UI screen according to an embodiment of the present invention;

[0010] (Background to the present disclosure) Conventionally, information processing devices equipped with an imaging device such as a camera have been widely used, and an example thereof is a reading device such as a barcode reader. When using such a reading device, the distance to the reading target may change, so the reading accuracy is improved by adjusting the lens position of the camera and the focus position according to the distance. Known methods for adjusting the focus position include switching using an autofocus (AF) function or fixed parameters as described in Patent Document 1.

[0011] For example, the AF function automatically adjusts the lens position to achieve the appropriate focus without user intervention. Since the focus adjustment is performed by shifting the lens at regular intervals, it can take a long time to complete the focus adjustment if there is a large difference between the lens position at the start of the adjustment and the desired lens position. Furthermore, because individual errors occur in the configuration around the lens, it is difficult to position the lens in the same position when control parameters for lens position are used in common between devices. Therefore, even if the same control parameters are used, the lens position will vary from device to device. For example, Patent Document 1 discloses that the lens focus position is adjusted when a close-up shooting mode is selected, but does not take individual errors into consideration.

[0012] Hereinafter, with appropriate reference to the accompanying drawings, embodiments specifically disclosing an imaging device and a control method for an imaging device according to the present disclosure will be described in detail. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0013] In this embodiment, a reading device such as a code reader for codes including barcodes will be described as an example of an information processing device equipped with a camera as an imaging device. However, the present invention is not limited to this, and the information processing device may also be a mobile terminal such as a smartphone or tablet terminal, a POS terminal, or an imaging device itself such as a digital camera.

[0014] 1 is a block diagram showing an example of the configuration of a reading device 100 according to this embodiment. The reading device 100 includes a control unit 101, a storage unit 102, a camera 103, a display unit 104, an operation unit 105, a communication unit 106, and an external IF 107. The components of the reading device 100 may be configured to be able to communicate with each other via an internal bus (not shown).

[0015] The control unit 101 executes various functions described below by reading and executing various programs and data stored in the storage unit 102. The control unit 101 may be configured using, for example, a Central Processing Unit (hereinafter referred to as CPU), a Micro Processing Unit (hereinafter referred to as MPU), a Digital Signal Processor (hereinafter referred to as DSP), a Graphical Processing Unit (hereinafter referred to as GPU), or a Field Programmable Gate Array (hereinafter referred to as FPGA).

[0016] The storage unit 102 is a storage area for storing and holding various data, and may be composed of, for example, a non-volatile storage area such as a read only memory (hereinafter referred to as ROM), a flash memory, a hard disk drive (hereinafter referred to as HDD), a volatile storage area such as a random access memory (hereinafter referred to as RAM), etc. In this embodiment, the storage unit 102 holds at least a camera control program 110, a lens position setting parameter 111, and a reading program 112.

[0017] The camera control program 110 is a program for controlling the operation of the camera 103. The lens position setting parameters 111 are parameters for controlling the position of the lens in the lens unit 120 provided in the camera 103. The reading program 112 is a program for reading predetermined information from an image captured via the camera 103. In this embodiment, an example is shown in which a barcode is read from an image to obtain information, but the present invention is not limited to this, and for example, a QR code (registered trademark), character recognition, or other reading operations may also be used.

[0018] The camera 103 is an imaging device for capturing images of the surroundings of the reading device 100. The camera 103 includes a lens unit 120, and is configured to be able to switch imaging conditions such as the angle of view and focal length by controlling the lens unit 120. An example of the configuration of the lens unit 120 will be described with reference to FIG. 2.

[0019] The display unit 104 displays various data, processing results, etc. In this embodiment, the display unit 104 may display images captured by the camera 103, information read from the images, etc. The operation unit 105 is composed of, for example, switches and buttons, and is used to accept user operations, etc. The display unit 104 and the operation unit 105 may be integrated into one unit, for example, a touch panel display.

[0020] The communication unit 106 communicates with an external device (not shown) via a wired or wireless network, transmitting and receiving various data and signals. The communication method used by the communication unit 106 is not particularly limited, and may support a plurality of communication methods. For example, a wide area network (hereinafter referred to as WAN), a local area network (hereinafter referred to as LAN), power line communication, short-range wireless communication (e.g., Bluetooth (registered trademark) or Wi-Fi (registered trademark)), etc. may be used. The external IF 107 is an interface with an external device, and transmits and receives various control signals to and from the external device.

[0021] In this embodiment, an example in which the camera 103 is built into the reading device 100 is shown, but an external camera may also be used. Also, although an example in which one camera 103 and one lens unit 120 are provided is shown, multiple cameras or multiple lens units may be provided, each of which may be configured to be controllable.

[0022] (Lens Unit) Fig. 2 shows a cross section of an example configuration of the lens unit 120 according to this embodiment. The lens unit 120 includes a lens 121, a sensor 122, a drive unit 123, a lens holder 124, a cam 125, and a cam groove 126. In the example of Fig. 2, only one lens 121 is shown as the optical system, but the optical system may further include multiple lenses, reflecting mirrors, and the like. The sensor 122 is configured from a light-receiving element such as a Charge Coupled Device (hereinafter, referred to as CCD), and receives and detects light from the outside and outputs the light as a signal.

[0023] The drive unit 123 is configured by an actuator such as a voice coil motor (hereinafter referred to as VCM), and is configured to move the lens holder 124 in a predetermined direction. In the example of Fig. 2, by changing the engagement state between the cam 125 and the cam groove 126, the lens holder 124 can be moved within a predetermined range in the vertical direction of the drawing, i.e., along the shooting direction, as shown in Figs. 2(a) to 2(c). Fig. 2(a) shows an example in which the lens holder 124 is retracted, and Fig. 2(c) shows an example in which the lens holder 124 is in its most protruding state.

[0024] (Lens Position Control) Lens position control will be explained using Figure 3. Lens control will be explained using AF control and control using a fixed value (more specifically, fixed focus). In addition, the characteristics of each lens control are shown as reading speed, compatible reading distance, individual variations in reading distance, and reading range. In addition, three terminals A to C will be used as examples to explain individual errors when using each lens control method.

[0025] First, the AF control method determines the appropriate lens position by gradually shifting the lens position. Therefore, the reading range when the AF function is operating is wide. As a result, the range of possible reading distances is wide, and the effect of variations in reading distances between individual devices is small and stable. However, due to the control method, the speed at which the lens position is determined and reading is completed is slow.

[0026] Next, we will explain control using common fixed values ​​for the control parameters that determine the lens position. In this case, the speed until reading is completed is improved. However, due to individual errors or manufacturing errors of the driving unit 123 such as an actuator, for example, each terminal may be controlled to a different lens position even with the same control parameters. As shown in Figure 3, different lens positions can result in variations in the reading range. As a result, the reading distance becomes unstable and the reading accuracy can also decrease.

[0027] Therefore, in this embodiment, fixed control parameters corresponding to the reading distance are used for each terminal. Fixed control parameters are defined for each reading distance, and the lens position is controlled by switching between them, enabling control that takes into account reading speed and individual errors. In this example, two control parameters, one for a short reading distance and one for a medium reading distance, are defined and stored in advance for each individual terminal. Note that the control parameters are not limited to two levels, short distance and medium distance, and may be defined in advance in more levels, taking into account the usage situation and usage site of the reading device, etc.

[0028] (UI Screen Example) Fig. 4 shows an example of the configuration of a UI screen that allows the user of the reading device 100 to specify a desired reading distance. The UI screen 400 is displayed on the display unit 104 of the reading device 100, and allows the user to select a predefined reading distance. Here, an example of a screen configuration is shown that allows the user to specify a short distance or a medium distance as the reading distance. By selecting entry 401 and pressing the OK button 403, it is possible to control the shooting distance to be a short distance. Similarly, by selecting entry 402 and pressing the OK button 403, it is possible to control the shooting distance to be a medium distance.

[0029] 5 is a flowchart of a control process of the lens unit 120 according to this embodiment. This process flow may be implemented, for example, by the control unit 101 reading out various programs and data stored in the storage unit 102. This process flow may be started, for example, when a user of the reading device 100 starts up the reading device 100 and the camera 103 and instructs the reading program 112 to start a reading operation. It is also assumed that, before this process is executed, lens position setting parameters 111 corresponding to the structure of the camera 103 of the reading device 100 are set and stored in advance.

[0030] In step S501, the control unit 101 starts a reading operation based on a user instruction. At this time, the control unit 101 may set any function as a default focus function, and in this example, the AF function is set.

[0031] In step S502, the control unit 101 determines whether a mode switching instruction has been received from the user. The mode switching instruction may be given, for example, by pressing a switch constituting the operation unit 105. If a mode switching instruction has been received (step S502: YES), the processing of the control unit 101 proceeds to step S503. On the other hand, if a mode switching instruction has not been received (step S502: NO), the processing of the control unit 101 proceeds to step S509.

[0032] In step S503, the control unit 101 displays a UI screen for mode setting on the display unit 104. In this example, the UI screen 400 shown in FIG.

[0033] In step S504, the control unit 101 determines whether or not a designation of the short distance mode has been accepted via the UI screen 400. If a designation of the short distance mode has been accepted (step S504: YES), the processing of the control unit 101 proceeds to step S505. On the other hand, if a designation of the short distance mode has not been accepted, that is, if a designation of the medium distance mode has been accepted (step S504: NO), the processing of the control unit 101 proceeds to step S506.

[0034] In step S505, the control unit 101 reads out the control parameters for the lens position in the close-up mode from the lens position setting parameters 111 stored in the storage unit 102. Then, the process of the control unit 101 proceeds to step S507.

[0035] In step S506, the control unit 101 reads out the lens position control parameters for the medium distance mode from the lens position setting parameters 111 stored in the storage unit 102. The control unit 101 then proceeds to step S507. Note that steps S504 to S506 may be further added depending on the number of modes set in advance. For example, if a long distance mode can be set, the corresponding processing is performed.

[0036] In step S507, the control unit 101 adjusts the lens position of the lens unit 120 based on the read parameters. Then, the process of the control unit 101 proceeds to step S508.

[0037] In step S508, the control unit 101 performs a reading operation based on the lens position adjusted in step S507. For example, the control unit 101 performs image acquisition, image analysis, information extraction, etc. Then, the process of the control unit 101 proceeds to step S510.

[0038] In step S509, the control unit 101 performs a reading operation in the currently set mode. For example, if the AF function is used as the default focus function and this is set, as described above, the lens position is not a fixed control parameter, so the reading operation is performed while adjusting the lens position as appropriate. Then, the processing of the control unit 101 proceeds to step S510.

[0039] In step S510, the control unit 101 determines whether or not to end the reading operation. For example, the control unit 101 may determine that the reading operation is to be ended when an instruction to stop the reading program 112 is received from the user. If the reading operation is to be ended (step S510: YES), this processing flow ends. On the other hand, if the reading operation is not to be ended (step S510: NO), the processing of the control unit 101 returns to step S502 and the processing is repeated.

[0040] As described above, according to this embodiment, an imaging device (e.g., 100) configured to be able to adjust the position of a lens (e.g., 120) includes a holding unit (e.g., 102) that holds a plurality of control parameters (e.g., 111) for controlling the lens to a fixed position corresponding to each of a plurality of shooting distances in the imaging device, a setting unit (e.g., 101, 105, 400) that accepts designation of one of a plurality of shooting distances, and a control unit (e.g., 101, 110) that moves the lens to the fixed position using the control parameter corresponding to the shooting distance designated by the setting unit.

[0041] This makes it possible to improve the convenience for users when taking pictures with the imaging device, and in particular when a reading device or the like is required to perform a reading operation immediately at a predetermined reading distance, it is possible to improve the responsiveness and improve the convenience for users when performing a reading operation.

[0042] Furthermore, the control parameters differ from device to device.

[0043] This makes it possible to define the lens position according to the device, taking into account individual variations in the device, and as a result, it becomes possible to control the reading distance to an appropriate level according to the device.

[0044] Furthermore, at least two of the short distance, the medium distance, and the long distance can be designated as the plurality of photographing distances.

[0045] This makes it possible to switch and use control parameters corresponding to a plurality of stages of shooting distances that are assumed in advance.

[0046] Furthermore, when the setting unit receives an operation from the user, the setting unit causes the display unit to display a screen for receiving designation of one of a plurality of shooting distances.

[0047] This allows the user to switch to a desired shooting distance at a timing desired by the user.

[0048] The photographing device is a reading device (for example, a code reader).

[0049] This makes it possible to improve the convenience of the reading operation by the user in the photographing device provided in the reading device as well.

[0050] Other Embodiments In the above embodiment, an example was shown in which the UI screen was displayed depending on whether a mode switching instruction was received from the user in step S502 of FIG. However, this is not limited to this, and a configuration in which the UI screen is displayed based on other conditions may also be used. For example, when performing a reading operation using a function other than the AF function, it may be determined whether the focus position is aligned with the reading target, and the UI screen may be displayed if it is detected that the focus position is not aligned for a certain period of time.

[0051] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to these examples. It is clear to those skilled in the art that various modifications, alterations, substitutions, additions, deletions, and equivalents may be made within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention.

[0052] Although various embodiments have been described above, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

[0053] This application is based on a Japanese patent application (Patent Application No. 2023-061592) filed on April 5, 2023, the contents of which are incorporated herein by reference.

[0054] The present disclosure is useful as an imaging device and a control method for an imaging device.

[0055] DESCRIPTION OF SYMBOLS 100...Reading device 101...Control unit 102...Storage unit 103...Camera 104...Display unit 105...Operation unit 106...Communication unit 107...External IF 110...Camera control program 111...Lens position setting parameter 112...Reading program 120...Lens unit 121...Lens 122...Sensor 123...Drive unit 124...Lens holding unit 125...Cam 126...Cam groove

Claims

1. A reading device configured to be able to adjust the position of a lens, a holding unit that holds a plurality of control parameters for controlling the lens to a fixed position that differs for each individual reader, the control parameters corresponding to a plurality of reading distances in the reader; a setting unit that accepts designation of one of the plurality of reading distances; a control unit that moves the lens to the fixed position using the control parameter that corresponds to the reading distance specified by the setting unit.

2. (delete)

3. The reading device according to claim 1 , wherein at least two of a short distance, a medium distance, and a long distance can be specified as the plurality of reading distances.

4. The reading device according to claim 1 , wherein the setting unit, upon receiving an operation from a user, causes a display unit to display a screen for receiving designation of one of the plurality of reading distances.

5. (delete)

6. A method for controlling a reading device configured to be able to adjust the position of a lens, comprising: a setting step of accepting a designation of one of a plurality of reading distances of the reading device; a control step of moving the lens to a fixed position by using a control parameter corresponding to the reading distance specified in the setting step from among a plurality of control parameters for controlling the lens to a fixed position that differs for each individual reading device, the control parameters being predefined corresponding to each of a plurality of reading distances in the reading device; A method for controlling a reading device having the above structure.

7. The method for controlling a reading device according to claim 6 , wherein at least two of a short distance, a medium distance, and a long distance can be specified as the plurality of reading distances.

8. The method for controlling a reading device according to claim 6 , wherein the setting step displays a screen for accepting designation of one of the plurality of reading distances when an operation from a user is accepted.