Image writing and capture device

Abstract

Title: Writing and Image Capture Device The invention relates to a writing and image capture device (1), comprising: - a pen body (2) extending along a central axis (20), and having two lateral finger positioning zones (21) located on either side of a median sagittal plane (MSP) of the pen body (2) passing through the central axis (20), the body (2) also having a ventral region (22) intended to be oriented towards a writing surface; - writing means (3) received in the body, and comprising a writing tip (31) emerging from the body (2), the tip (31) being coaxial with the central axis (20); - a camera (4) inserted in a housing (24), and fixedly mounted relative to the tip (31), the camera (4) comprising a front lens (41) located near the lateral finger positioning zones (21) fingers, towards the tip of the point (31). Figure for the abbreviation: Fig. 1

Description

Title of the invention: Image writing and capture device technical field

[0001] The field of the invention is that of the design and manufacture of handwriting writing devices, and of digital image acquisition of this writing.

[0002] The invention relates more particularly to a pen integrating a camera to directly acquire digital images of handwriting made using the pen. State of the art

[0003] In the field of the invention, the document published under number CN218675994U is known.

[0004] This device comprises a pen body receiving writing means with a writing tip such as a lead. The pen body is equipped with an acquisition camera which is positioned at a distance from the end of the lead. The camera is configured to pivot about an axis perpendicular to the axis of the lead, the camera axis intersecting the axis of the lead, so as to optimize the capture angle.

[0005] Such a design of a writing device has the disadvantages of providing images that are not satisfactory for the realization of handwriting recognition by software, in particular due to the obstruction of the camera's optical field by the user's hand, and of not presenting a harmonious integration of this camera.

[0006] The device described in the document published under number CN209869835U is also known.

[0007] This device comprises a pen body containing writing means having a writing tip. The pen body is equipped with a camera located near the tip of the nib. The pen body has recesses on its surface forming finger positioning zones. The camera is configured to acquire images of text and transmit them to a text identification module. The camera is configured to pivot about an axis perpendicular to the axis of the nib and is mounted to pivot relative to the axis of the nib so that it can be retracted inside the pen body and extended to achieve an optimal imaging angle.

[0008] Thanks to its placement near the tip, the camera's optical field is not obstructed by the user's hand when grasping the pen. However, this pen design has the drawback of a deployable camera, hindering its seamless integration and presenting a risk of weakness. structural, both at the level of the hinge allowing the camera's mobility relative to the pen body, and at the level of the camera's connector which must withstand camera deployments and retractions.

[0009] Patent document published under number US11301063B2 is also known. This document discloses a device comprising a pen body receiving writing means having a writing tip of the type employing a ball supplied with ink contained in a tube. The pen body is equipped with several cameras arranged near the ball. The axis of the camera and the axis of the pen body lie in the same plane, and the axis of the camera is inclined with respect to the axis of the pen body. The cameras are oriented away from, and not toward, the tip.

[0010] This device features seamless integration of its cameras, even during use, as the cameras are contained within the pen body. However, this device has the drawback of requiring the implementation of multiple sensors, including at least two cameras.

[0011] Finally, a device is also known that has three outward-facing cameras distributed around the periphery of a lead, behind it. This pen allows for a good grip that does not obstruct the cameras near the lead. The three cameras detect the movement of the lead and are linked to a sensor that detects pressure on the lead. The detection of pressure and movement makes it possible to deduce the content of what is written.

[0012] This design implies having at least two cameras and a pressure sensor for the mine, which presents a drawback in terms of the number of sensors to manage. Technical problem

[0013] The invention aims in particular to overcome these drawbacks of the prior art.

[0014] More specifically, the invention aims to provide a handwriting and image capture device for the writing produced with the device, for the purpose of optical character recognition, which has a shape that most closely resembles that of a classic pen, and does not involve the implementation of multiple capture means.

[0015] The invention also aims to provide such a device which optimizes the acquisition images obtained for their analysis for optical character recognition. Summary of the invention

[0016] These objectives, as well as others that will appear subsequently, are achieved through the invention, which relates to a device for writing and capturing images, comprising: - a pen body extending along a central axis, and having two lateral finger positioning zones located on either side of a median sagittal plane of the pen body passing through the central axis, the body also having a ventral region intended to be oriented towards a writing surface, and a dorsal region opposite to the ventral region with respect to the central axis; - writing means received in the body, and comprising a writing point emerging from the body, the point being coaxial with the central axis; - a camera inserted in a housing provided in the dorsal region of the body, and mounted fixed relative to the tip, the camera comprising a front lens defining an optical axis, the front lens being located near the lateral finger positioning areas, in the direction of the tip; characterized in that the optical axis and the central axis are non-coplanar, and in that the camera presents an optical field in which the tip is located.

[0017] The device according to the invention makes it possible to capture images of the writing produced with the device, for the purpose of optical character recognition. This device has a shape most closely resembling that of a conventional pen, and at a minimum requires only a single acquisition camera.

[0018] Thanks to its design, the images obtained using the device tend to be particularly suitable for analysis by a computer system for processing optical character recognition data.

[0019] The relative positioning of the front lens between the lateral finger positioning zones and the tip prevents a user's grip from interfering with the camera's optical field.

[0020] Furthermore, the positioning of the tip of the pen within the optical field serves as a particularly beneficial reference point for computer analysis of optical recognition. Finally, the relative orientation of the optical axis with respect to the central axis, that is to say, the non-coplanar aspect of the optical axis and the central axis, makes it possible to optimize the camera's optical field capacity to capture sufficient information about what has just been written by a user for computer analysis of optical recognition, despite the different ways in which a pen is held.

[0021] According to a preferred embodiment, the writing means comprise an ink storage reservoir coupled to the writing tip, the reservoir having a flexible tubular shape, and the pen body has a passage for receiving the writing means, the passage having: - a terminal portion opening from which the writing point emerges, the terminal portion extending longitudinally while being centered on the central axis; - at least one off-center portion of the central axis extending in line with the terminal portion, the housing being provided in the body of the pen in a manner opposite to the portion that is offset from the central axis.

[0022] Thanks to the open-ended portion and the tip, which are centered on the central axis, writing with the device is natural for the user. The offset portion(s) of the writing element receiving passage optimize the available volume within the pen body for housing the camera. Tests have demonstrated that the torsion of the flexible tubular ink reservoir, imposed by its insertion into the offset portion(s), does not impede the flow of ink to the tip for writing.

[0023] Preferably, according to an orthogonal projection onto the median sagittal plane, the optical axis is oriented to move away from the central axis towards the tip of the point from the body, in a direction going from the ventral region 22 towards the dorsal region.

[0024] According to a preferred feature, according to an orthogonal projection onto the median sagittal plane, the optical axis forms an angle Al with the central axis, with 0° < Al < 18°, preferably with 6° < Al < 14°, even more preferably with Al = 11°.

[0025] At 0° or above 0° for Al, the characters closest to the tip are partially legible. The characters furthest away are only very partially legible.

[0026] At 6° or above 6° for Al, the characters closest to the tip are partially readable and the characters furthest away are also partially readable.

[0027] At 18° or below 18° for Al, the character closest to the tip is partially visible, the characters near the tip are legible. The characters furthest from the tip are legible.

[0028] At 14° or below 14° for Al, the characters closest to the tip are legible. The characters furthest from the tip are partially legible.

[0029] According to an alternative embodiment, according to an orthogonal projection onto a median transverse plane passing through the central axis and extending orthogonally to the median sagittal plane, the optical axis is oriented to cross and then move away from the central axis towards the tip of the point, from the body.

[0030] This variant is particularly suitable for right-handed people.

[0031] According to another embodiment, according to an orthogonal projection onto a median transverse plane passing through the central axis and extending orthogonally to the median sagittal plane, the optical axis is oriented to intersect and then move away from the central axis towards the tip of the point, from the body, and in a direction from right to left in a top view with the point facing downwards.

[0032] This variant is particularly suitable for left-handed people.

[0033] Advantageously characterized in that, according to an orthogonal projection onto the median transverse plane, the optical axis forms an angle A2 with the central axis, with 0° < A2 < 30°, preferably with 5° < A2 < 25°, preferably A2 = 22°.

[0034] At 0° or above 0° for A2, the character closest to the tip is completely identifiable, the other characters closest to the tip are partially legible and the characters furthest away are very partially legible.

[0035] At 5° or above 5° for A2, the characters closest to the tip are completely identifiable and the characters furthest away are legible or partially legible.

[0036] At 30° or below 30° for A2, some characters far from the tip are partially identifiable, the characters closest to the tip are not readable.

[0037] At 25° or below 25° for A2, the characters closest to the tip are completely identifiable and the characters furthest away are legible or partially legible.

[0038] According to a preferred feature, according to an orthogonal projection onto the median transverse plane, the center of the front lens is offset by a distance of 0.5 mm to 1 mm from the central axis, preferably by 0.8 mm, and in that, according to an orthogonal projection onto the median sagittal plane, the center of the front lens is offset by a distance of 1 mm to 1.75 mm from the central axis, preferably by 1.4 mm

[0039] According to an advantageous design, the pen body has, along the central axis: - a main part substantially cylindrical of revolution, presenting the two lateral finger positioning zones, and extending towards the end of the body from which the tip emerges to a through opening of the housing in which the camera is inserted; - an end part extending from the main part, tapering to the end of the body from which the tip emerges, the end part having a recess around the optical axis.

[0040] This design promotes the freest possible optical field for the camera while allowing good integration of the tip end into this optical field.

[0041] Preferably, according to an orthogonal projection on the central axis, the center of the front lens and the end of the body from which the tip emerges are spaced at a distance of 8 to 24 mm.

[0042] These values ​​allow for the optimization of handwriting capture using the camera, with too small a distance tending to prevent the capture of a large number of characters necessary for optical character recognition, and too great a distance requiring the device to be gripped by the fingers at the lateral positioning areas too far from the tip of the device. Brief description of the drawings

[0043] Other features and advantages of the invention will become more apparent upon reading the following description of various preferred embodiments of the invention, given by way of illustrative and non-limiting examples, and the accompanying drawings, among which: • [Fig.1] [Fig.1] is a schematic representation according to a top front perspective view of a device according to the invention; • [Fig.2] [Fig.2] is a schematic representation from a front view of a pen body of the device according to the invention; • [Fig.3] [Fig.3] is a schematic representation of the pen body according to a side view; • [Fig.4] [Fig.4] is a schematic representation of the pen body such as that positioned on the [Fig.3], with the internal contour lines visible; • [Fig. 5] [Fig. 5] is a schematic view of the pen body from a view of above ; • [Fig. 6] [Fig. 6] is a schematic representation of the pen body such as that positioned on the [Fig.5], with the internal contour lines visible; • [Fig.7] [Fig.7] is a schematic illustration of the device in progress of use; • [Fig.8] [Fig.8] is a schematic representation of positioning relative to the device in relation to a writing support, of a writing produced with the device, and of rating scores associated with relative positionings; • [Fig.9] [Fig.9] is a graph illustrating scores assigned based on of the value of an angle A2; • [Fig. 10] [Fig. 10] is a graph illustrating scores assigned according to the value of an angle Al; • [Fig. 11] [Fig. 11] is a graph illustrating scores assigned according to the value of a distance D3; • [Fig. 12] [Fig. 12] is a table listing images of a text acquired using a camera of the device according to the invention, with specific parameters; • [Fig. 13] [Fig. 13] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 14] [Fig. 14] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 15] [Fig. 15] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 16] [Fig. 16] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 17] [Fig. 17] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 18] [Fig. 18] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 19] [Fig. 19] is a table listing images of a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig.20] [Fig.20] is a table listing images from a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 21] [Fig. 21] is a table listing images from a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters; • [Fig. 22] [Fig. 22] is a table listing images from a text acquired using two types of camera for two embodiments of the device according to the invention, with specific parameters. Detailed description

[0044] With reference to figures 1 and 7, a writing and image capture device 1, according to the invention, is shown.

[0045] This device 1 comprises: - a pen body 2; - writing tools 3; - a camera 4 designed to capture images of writing produced using device 1.

[0046] As will subsequently appear, the camera 4 is inserted into a housing 24 presented by the pen body 2.

[0047] With reference to figures 1 to 6, the pen body 2 has a longitudinal shape.

[0048] According to the present embodiment, this body 2 is an end piece intended to be coupled to a base to form a set of dimensions similar to those of a classic pen.

[0049] According to one conceivable embodiment, the body 2 can extend to have dimensions similar to those of a conventional pen.

[0050] The pen body 2 extends along a central axis 20.

[0051] The writing means 3 are received in body 2.

[0052] These writing means 3 include a writing tip 31 which emerges from the body 2.

[0053] This point 31 can correspond to a mine.

[0054] Alternatively, this tip 31 may include a writing ball.

[0055] The tip 31 can also be formed into a porous material intended to be soaked in ink.

[0056] This tip 31 is coaxial with the central axis 20. Tests have shown that aligning this tip 31 with the central axis 20 improves the user experience.

[0057] As will become apparent later, and according to the present embodiment, the writing means 3 comprise an ink storage reservoir coupled to the writing tip 31. This reservoir is designed to supply the tip 31 with ink.

[0058] According to the present embodiment, the reservoir has a flexible tubular shape.

[0059] The pen body 2 has, along the central axis 20: - a main part 201 substantially cylindrical of revolution, intended to be grasped by a user to write using device 1; - an end part 202 extending from the main part 201 thinning out to one end of the body 2 from which the writing tip 31 emerges.

[0060] The body 2 has two lateral finger positioning areas 21. More specifically, the main part 201 of the pen body 2 has the two lateral finger positioning areas 21.

[0061] These two lateral finger positioning zones 21 are essentially diametrically opposed to each other on the body 2.

[0062] In other words, the two lateral finger positioning zones 21 are located on either side of a median sagittal plane PSM of the pen body 2 passing through the central axis 20.

[0063] As a reminder, a median sagittal plane is a vertical plane that divides a body into two substantially equal lateral parts.

[0064] Each lateral zone 21 is formed by a recess.

[0065] This prompts the user of the device to grasp the body 2 in the correct direction.

[0066] The main part 201 extends longitudinally, along the central axis 20, in direction of the end of the body 2 from which the tip 31 emerges, and up to an opening through the housing 24 into which the camera 4 is inserted.

[0067] The end part 202, for its part, extends from the main part 201, thinning out to the end of the body 2 from which the tip 31 emerges.

[0068] With reference to Figures 1 to 6, the pen body 2 also features: - a ventral region 22; - a dorsal region 23.

[0069] When writing with the device 1, the ventral region 22 is designed to be oriented towards a writing support, such as a sheet of paper.

[0070] The dorsal region is opposite to the ventral region 22 with respect to the central axis 20. When grasping the device 1, the user must naturally position their middle finger, and / or their ring and little finger on the side of the ventral region 22 of the body 2.

[0071] The body 2 has a median transverse plane PTM which passes through the central axis 20, and which extends orthogonally to the median sagittal plane PSM.

[0072] The ventral region 22 and the dorsal region 23 are located on either side of the median transverse plane PTM.

[0073] As mentioned previously, the device 1 includes a camera 4, and this camera 4 is inserted into a housing 24.

[0074] Housing 24 is provided in the dorsal region 23 of body 2.

[0075] The camera 4 is fixed relative to the tip 31, in the housing 24.

[0076] This housing 24 has an open end allowing the camera to capture images in front of the device 1.

[0077] The camera 4 includes a front lens 41 which is the optical element of the camera 4 exposed to the external volume of the device 1.

[0078] Camera 4 also includes a photographic sensor.

[0079] According to the present embodiment, the front lens 41 is directly coupled to the photographic sensor.

[0080] The assembly formed by the front lens 41 and the photographic sensor has an external shape substantially cylindrical of revolution.

[0081] The front lens 41 defines an optical axis 40. This optical axis 40 passes through the optical center of the front lens 41.

[0082] The camera 4 has an optical field. This optical field corresponds to the portion of space located in front of the front lens 41, and which is captured by the photographic sensor.

[0083] With more specific reference to Figures 4 and 6, the camera 4, and in particular its front lens 41 and its image sensor, have a very specific orientation relative to the pen body 2. These orientations are represented by: - an angle A2 formed between an orthogonal projection of the optical axis 40 in the median transverse plane PTM and the central axis 20; - an angle Al formed between an orthogonal projection of the optical axis 40 in the median sagittal plane PMS and the central axis 20; - a distance D3, measured between an orthogonal projection onto the central axis 20 of the center of the front lens 41 and the end of the body 2 from which the tip 31 emerges.

[0084] The camera 4 includes elements complementary to the assembly described above, such as a connector, however these elements do not necessarily assume a fixed position relative to the substantially cylindrical external shape of revolution of the assembly.

[0085] As illustrated in Figures 4 and 6, the front lens 41 is located along the central axis 20 near the lateral finger positioning areas 21, in the direction of the tip of the point 31. The expression "located along" does not imply that the front lens is positioned directly on the central axis 20.

[0086] The housing unit 24 located in the dorsal region 23 has two portions, of which: - a front portion 241 which houses the front lens 41, and thus also the photographic sensor; - a rear portion 242 which accommodates, for example, the additional elements of camera 4.

[0087] The front portion 241 has a substantially cylindrical shape of revolution, adapted to the shape of the assembly formed by the front lens 41 and the photographic sensor.

[0088] The front portion 241 has an axis of revolution which extends coaxially with the optical axis 40 of the front lens 4L

[0089] The rear portion 242 has a modified orientation relative to that of the front portion 241. More specifically, the rear portion 242 forms a bend with the front portion 241. This is possible thanks to the complementary elements of the camera 4 which do not necessarily have to be located in the extension of the assembly described above.

[0090] Camera 4 is in particular of the "endoscopic camera" type.

[0091] An "endoscopic camera" is a miniaturized imaging device designed to capture images in confined spaces. The camera 4 consists of an optical lens, a rectangular image sensor, and a flexible ribbon.

[0092] For example, the "endoscopic camera" type camera 4 has a diameter between 3.5 and 5 mm.

[0093] As can be seen in figures 1 to 4, the end part 202 of the pen body 2 has a recess 203 around the optical axis 40.

[0094] More specifically, the end part 202 comprises a cylindrical front sub-part 2021 of revolution having the opening from which the tip 31 emerges, and a rear sub-part 2022 joining the front sub-part 2021 to the main part 201.

[0095] The rear sub-part 2022 has a truncated conical shape of revolution, tapering from the main part 201 towards the tip 31. This rear sub-part 2022 thus has the recess 203.

[0096] This allows the camera 4 to capture images incorporating the tip 31, as detailed later, without implying the production of a bulk by integrating the camera 4 on the pen body 2.

[0097] In addition to this recess 203, according to the present embodiment, the front sub-part 2021 has a flat 2031 aligned with the recess 203, having the same technical effect as that of the recess 203.

[0098] Preferably, the recesses forming the lateral areas 21 extend further on the ventral region 22 than on the dorsal region 23. This allows the user to optimize their grip on the body 2 to prevent their fingers from coming into the optical field of the camera 4.

[0099] As mentioned previously, and with reference to figures 1, 2, 4, and 6, the writing means 3 are received in the body 2 of the pen.

[0100] For this purpose, the pen body 2 has a passage 25 for receiving the writing means 3.

[0101] This passage 25 presents: - a terminal portion 251 opening from which emerges the writing point 31; - at least one off-center portion 252.

[0102] According to the present embodiment, the passage 25 has two offset portions 252. It is conceivable embodiments in which the passage 25 would have one or more than two offset portions 252.

[0103] The terminal portion 251 extends longitudinally while being centered on the central axis 20. The terminal portion 251 is in particular cylindrical of revolution and its axis of revolution extends coaxially with the central axis 20.

[0104] The two offset portions 252 extend in line with the terminal portion 251. More precisely, a first offset portion 252 extends from of the terminal portion 251, presenting an extension axis intersecting with the axis of revolution of the terminal portion 251. A second offset portion 252 extends from the first offset portion 252, again with an extension axis offset from the axis of revolution of the terminal portion 251.

[0105] The terminal portion 251 is located in the front sub-part 2021 of the end part 202 of the body 2, while the first offset portion 252 is located, at least in part, in the rear sub-part 2022 of the end part 202 of the body 2.

[0106] The ink storage reservoir, which has a flexible tubular shape, is housed in these offset portions 252. Tests have validated that the bends formed by the offsets of these portions do not limit the ink supply to the tip 31.

[0107] In addition, the offset portion 252 is provided in the ventral region 22 of the body 2 of the pen, which makes it possible to provide space in the body 2 to house the camera 4.

[0108] In other words, the housing 24 is provided in the body 2 of the pen in a manner opposite to the offset portion 252 with respect to the central axis 20.

[0109] With reference to [Fig.7], the device 1 described above is shown being held in a user's hand M, and used to write a text T.

[0110] As mentioned previously, the device 1 must be held in a grip which tends to be standardized thanks to the presence of lateral finger positioning zones 21.

[0111] Classically, a pen tends to be held at an angle of less than 90° to the writing surface.

[0112] The device 1 is thus designed so that the ventral region 22 is oriented towards the writing support, while the dorsal region 23 is designed to be oriented in the opposite direction to the writing support relative to the ventral region 22 of the pen body 2.

[0113] In this way, the positioning of the camera 4 in the dorsal region 23 tends to optimize the number of characters of the text T that can be captured by the camera 4.

[0114] In addition to this inclination, different orientations of a pen are possible depending on the habits of the person using it.

[0115] Fig. 8 illustrates three ways of holding the pen body 2 of the device associated with scores, this view corresponding to a top view of a writing support, and orientations of the central axis 20 of the pen body 2 with respect to the written text T.

[0116] It can be observed: - a score i, in which the device is held inwards (with a slight tilt); - a score m, in which the device is held facing the writing surface (with a slight tilt); - a score e, in which the device is held outwards (with a slight tilt).

[0117] In order to optimize the number of characters of the text T which are collected in the images captured by the camera 4, the orientation and positioning of the camera 4, and of its optical axis 40 in relation to the pen body 2 and the tip 31 have been the subject of a plurality of tests.

[0118] First, the optical axis 40 and the central axis 20 are non-coplanar. This tends to optimize the number of characters of the text T that tend to be captured in an image.

[0119] Furthermore, the camera 4 has an optical field in which the tip of the point 31 is located. This data is particularly important since it serves as a reference point to enable subsequent optical recognition of the text in the images captured by the camera 4 by software.

[0120] The presence of the tip of the point 31 is necessary, however it is also sought to minimize it.

[0121] Preferably, the camera 4 is oriented around the central axis of the housing 24 so that the tip 31 is located in a corner of the optical field which is rectangular in shape (rectangular shape defined by the photographic sensor).

[0122] The tip 31 may be located in an area in the right third of the image, and / or the lower third of the image. Preferably, the tip 31 is located in an area in the right quarter of the image, and / or the lower quarter of the image. Even more preferably, the tip 31 is located in an area in the right fifth of the image, and / or the lower fifth of the image.

[0123] The tables in Figures 12 to 22 illustrate the images captured in the three orientations, with, from left to right, the orientations i (held inwards), m (held towards the support - middle), and e (held outwards). Each row of three images corresponds to the images captured either by sensor C1, which is an endoscopic sensor with a resolution of 640 pixels by 480 pixels, or by sensor C2, which is an endoscopic sensor with a resolution of 416 pixels by 416 pixels.

[0124] For each table, at least one of the parameters described below was modified in order to measure its impact on the i / m / e scores, these scores then being reported and translated into the graphs in Figures 9, 10, and 11.

[0125] The calculation of a score is carried out as follows: - The most degraded image between sensor Cl and C2 is systematically chosen for evaluation; - The position of the mine is noted from 0 to 2 points: 2 points if visible and well positioned, 1 point if visible but poorly positioned, 0 points if not visible or very poorly positioned; - The surrounding letters are evaluated individually: 'e' from 0 to 1 point, 's' from 0 to 2 points, and 't' from 0 to 3 points, according to their degree of visibility; - The letter groups 'ce' and 'ci' are valued up to 1 point each, with intermediate scores for partial visibility; - The weighting of the letters increases with their proximity to the mine, reflecting their relative importance in the evaluation.

[0126] By way of example, for the angle Al = 21° illustrated in [Fig. 15], the analysis of the most degraded images from sensor C2 gives the following results: - A score i = 2.5 is obtained, composed of 0 points for the mine not visible, 2 points for the identification of 'this', and 0.5 points for 'e' partially visible; - A score m = 3 is calculated, comprising 0 points for the mine not visible, 2 points for the identification of 'this', and 1 point for 'e' fully visible; - A score e = 1 is awarded, resulting from 0 points for the non-visible mine and 1 point for the unique identification of the character 'e'.

[0127] As an example, for the distance D3 = 8mm illustrated in [Fig.20], the analysis of the most degraded images from sensor C2 gives the following results: - A score i = 6.5 is obtained, composed of 2 points for the mine visible and well positioned, 0 points for 't', 2 points for 's', 1 point for 'e', ​​1 point for 'ci' and 0.5 points for 'ce' partially visible; - A score m = 7 is obtained, composed of 2 points for the mine being visible and well positioned, 2 points for 't' being partially legible, 2 points for 's' and 1 point for 'e' being fully visible; - A score of e = 7.5 is obtained, composed of 2 points for the mine visible and well positioned, 3 points for 't' fully legible, 2 points for 's' and 0.5 points for 'e' partially visible.

[0128] For each table, we find the following parameters: - the angle A2 formed between an orthogonal projection of the optical axis 40 in the median transverse plane PTM and the central axis 20; - the angle Al formed between an orthogonal projection of the optical axis 40 in the median sagittal plane PMS and the central axis 20; - the distance D3, measured between an orthogonal projection onto the central axis 20 of the center of the front lens 41 and the end of the body 2 from which the tip 31 emerges.

[0129] For the table in [Fig. 13], the parameters are as follows: - angle A2 = 22°; - angle Al = 6°; - distance D3 = 20.5 mm.

[0130] In these tests where the influence of the angle Al is studied more particularly, the results are slightly degraded because the tip takes up too much space on the image, which prevents the capture of certain characters.

[0131] For the table in [Fig. 14], the parameters are as follows: - angle A2 = 22°; - angle Al = 13°; - distance D3 = 20.5 mm.

[0132] In these tests where the influence of the angle Al is studied more particularly, the results are slightly degraded because it is difficult to identify the last character of the word written by the user.

[0133] For the table in [Fig. 15], the parameters are as follows: - angle A2 = 22°; - angle Al = 21°; - distance D3 = 20.5 mm.

[0134] In these tests, where the influence of angle Al is studied in particular, the results are degraded because the lens and sensor are no longer sufficiently oriented on the text and the tip, which prevents the capture of a large number of characters. It is also observed that the tip is no longer visible in the image.

[0135] For the table in [Fig. 16], the parameters are as follows: - angle A2 = 22°; - angle Al = 25°; - distance D3 = 20.5 mm.

[0136] In these tests, where the influence of angle Al is studied in particular, the results are very degraded because the lens and camera sensor are no longer oriented towards the text and the tip. Very few characters are visible, the most important characters of the word 'is' are not visible, and the tip is no longer visible.

[0137] For the table in [Fig. 17], the parameters are as follows: - angle A2 = 5°; - angle Al = 11°; - distance D3 = 20.5 mm.

[0138] In these tests, where the influence of angle A2 is studied in particular, the results are satisfactory because the point can be identified in the lower right corner of the image. Furthermore, the three most important characters, as well as other additional characters, can be identified. However, when the device is rotated inwards (i), the point almost overlaps the last character (here, the character 't'), which can prove problematic.

[0139] For the table in [Fig. 18], the parameters are as follows: - angle A2 = -10°; - angle Al = 11°; - distance D3 = 20.5 mm.

[0140] In these tests where the influence of angle A2 is studied more particularly, the results are degraded because the lens and the camera sensor are too eccentric with respect to the text, which prevents the capture of a certain number of characters, particularly when the device is held facing the sheet (m) and towards the outside (e) on the sheet.

[0141] For the table in [Fig. 19], the parameters are as follows: - angle A2 = 22°; - angle Al = 11°; - distance D3 = 27 mm.

[0142] In these tests where the influence of the distance D3 is studied more particularly, the results are degraded because the lens and the camera sensor are too far away from the text, which prevents the capture of a number of characters.

[0143] For the table in [Fig.20], the parameters are as follows: - angle A2 = 22°; - angle Al = 11°; - distance D3 = 8 mm.

[0144] In these tests, where the influence of the distance D3 is studied in particular, the results are degraded because the lens and camera sensor are a little too close to the user's handwriting. The focal length is well maintained and there is no optical blur, but the last character written by the user is difficult or impossible to identify.

[0145] For the table in [Fig.21], the parameters are as follows: - angle A2 = 22°; - angle Al = 11°; - distance D3 = 20.5 mm.

[0146] In these tests, the results are satisfactory because the point can be identified in the lower right corner of the image. Furthermore, the three most important characters can be identified, as well as other additional characters.

[0147] For the table in [Fig.22], the parameters are as follows: - angle A2 = 22°; - angle Al = 11°; - distance D3 = 11.5 mm.

[0148] In these tests, where the influence of the distance D3 is studied in particular, the results are slightly degraded because in almost all cases it is possible to identify the point in the lower right corner of the image as well as the three characters the most important ones. However, in some cases it can be difficult to identify the last letter typed by the user.

[0149] For the table in [Fig. 12], the parameters are as follows: - angle A2 = 35°; - angle Al = 11°; - distance D3 = 11.5 mm.

[0150] In these tests, where the influence of angle A2 is studied more particularly, the results are very degraded because the lens and the camera sensor are too eccentric with respect to the text, which prevents the capture of a large number of characters.

[0151] With reference to the graph in [Fig.9], the impact of the value of angle A2 is studied.

[0152] The design described below relates to embodiments applicable to a writing device 1 intended to be used by a right-handed person, but which can also be used by left-handed people depending on how they hold a pen.

[0153] A possible functional range for A2 is as follows: 0° < A2 < 30°.

[0154] The optimal operating range for this value of angle A2 is from 5 to 25°.

[0155] The closer the angle is to 90°, the more the sensor is offset, capturing an image to the left where the user has not yet written. As a result, the images degrade significantly, and the tip or words become invisible. The closer the angle is to -90°, the more the images degrade significantly, and the tip or characters become invisible because the sensor is too far off-center.

[0156] It follows from the above that, according to an orthogonal projection onto a median transverse plane PTM passing through the central axis 20 and extending orthogonally to the median sagittal plane PSM, the optical axis 40 is oriented to cross and then move away from the central axis 20 towards the tip of the point 31, from the body 2, and in a direction going from left to right according to a top view with the point oriented downwards as illustrated in [Fig.6].

[0157] This left-to-right direction can also be likened to a direction from a right lateral side to a left lateral side of the pen body 2.

[0158] Moreover, within the range 5° < A2 < 25°, the angle A2 = 22° emerges as an optimal value.

[0159] According to an alternative, unrepresented design of the writing device 1 intended for use by a left-handed person, the values ​​of angle A2 are also applicable.

[0160] However, in this situation, the camera 4 has an orientation contrary to that of the device adapted for right-handed people.

[0161] More precisely, in this left-handed variant, according to an orthogonal projection onto a median transverse plane PTM passing through the central axis 20 and extending orthogonally to the median sagittal plane PSM, the optical axis 40 is oriented to cross and then move away from the central axis 20 towards the tip of the point 31, from the body 2, and in a direction going from right to left in a top view with the point oriented downwards.

[0162] This right-to-left direction can also be likened to a direction from a left lateral side to a right lateral side of the pen body 2.

[0163] With reference to the graph in [Fig. 10], the impact of the value of angle Al is studied.

[0164] A possible functional range for Al is: 0° < Al < 18°.

[0165] The optimal operating range for this value is from 6° to 14°.

[0166] The closer one gets to 0°, the more the result degrades because of the tip which is The point of the device is too prominent in the image (taking up too much space) and prevents the camera sensor from correctly capturing certain characters when the device is held facing inwards (i) or outwards (e). The closer the angle is to 25°, the more pronounced the degradation becomes, as the point of the device no longer appears in the image, and only a few characters, or even none at all, are captured compared to the point of the device.

[0167] It follows from the above that, according to an orthogonal projection onto the median sagittal plane PSM, the optical axis 40 is oriented to move away from the central axis 20 in the direction of the tip of the point 31 from the body 2, in a direction going from the ventral region 22 towards the dorsal region 23.

[0168] Moreover, within the range 6° < Al < 14°, the angle Al = 11° emerges as an optimal value.

[0169] With reference to the graph in [Fig. 11], we study the impact of the distance D3.

[0170] The optimal operating range for this distance D3 is from 8 mm to 24 mm.

[0171] As the distance approaches 0 mm, the result degrades rapidly because characters are missing and the tip eventually becomes indistinguishable from the image. Conversely, as the distance approaches 30 mm, experiments with 50 testers revealed that all users placed their fingers in front of the sensor, which degraded the result.

[0172] With reference to [Fig.2], further tests have determined that an offset of the position of the lens relative to the central axis 20, and in a frontal plane orthogonal to the median sagittal plane and the median transverse plane is desirable, in particular to reduce the bulk of the pen body 2 and to provide volume for the ink reserve of the writing means.

[0173] Thus, according to an orthogonal projection onto the median sagittal plane PSM, the center of the front lens 41 is offset by a distance DI of 1 to 1.75 mm from the central axis 20, preferably by 1.4 mm.

[0174] Furthermore, according to an orthogonal projection onto the median transverse plane PTM, the center of the front lens 41 is offset by a distance D2 of 0.5 to 1 mm from the central axis 20, preferably by 0.8 mm.

Claims

Demands

1. A writing and image-capturing device (1) comprising: - a pen body (2) extending along a central axis (20), and having two lateral finger positioning zones (21) located on either side of a median sagittal plane (MSP) of the pen body (2) passing through the central axis (20), the body (2) also having a ventral region (22) intended to be oriented towards a writing surface, and a dorsal region (23) opposite the ventral region (22) with respect to the central axis (20); - writing means (3) received in the body, and comprising a writing tip (31) emerging from the body (2), the tip (31) being coaxial with the central axis (20);- a camera (4) inserted in a housing (24) formed in the dorsal region (23) of the body (2), and fixedly mounted relative to the tip (31), the camera (4) comprising a front lens (41) defining an optical axis (40), the front lens (41) being located near the lateral finger positioning areas (21), in the direction of the tip (31); characterized in that the optical axis (40) and the central axis (20) are non-coplanar, and in that the camera (4) presents an optical field in which the tip (31) is located.

2. Device (1) according to the preceding claim, characterized in that the writing means (3) comprise an ink storage reservoir coupled to the writing tip (31), the reservoir having a flexible tubular shape, and in that the pen body (2) has a passage (25) for receiving the writing means (3), the passage (25) having: - an open terminal portion (251) from which the writing tip (31) emerges, the terminal portion (251) extending longitudinally and being centered on the central axis (20); - at least one offset portion (252) from the central axis (20) extending in line with the terminal portion (251), the housing (24) being provided in the pen body (2) opposite the offset portion (252) with respect to the central axis (20).

3. Device (1) according to any one of the preceding claims, characterized in that, according to an orthogonal projection onto the median sagittal plane (MSP), the optical axis (40) is oriented to move away from the central axis (20) towards the tip of the point (31) from the body (2), in a direction going from the ventral region (22) towards the dorsal region (23).

4. Device (1) according to the preceding claim, characterized in that, according to an orthogonal projection onto the median sagittal plane (MSP), the optical axis (40) forms an angle Al with the central axis (20), with 0° < Al < 18°, preferably with 6° < Al < 14°, even more preferably with Al = 11°.

5. Device (1) according to any one of the preceding claims, characterized in that, according to an orthogonal projection onto a median transverse plane (MTP) passing through the central axis (20) and extending orthogonally to the median sagittal plane (MSP), the optical axis (40) is oriented to cross and then move away from the central axis (20) towards the tip of the point (31), from the body (2), and in a direction from left to right according to a top view with the point oriented downwards.

6. Device (1) according to any one of claims 1 to 4, characterized in that, according to an orthogonal projection onto a median transverse plane (MTP) passing through the central axis (20) and extending orthogonally to the median sagittal plane (MSP), the optical axis (40) is oriented to cross and then move away from the central axis (20) towards the tip of the point (31), from the body (2), and in a right-to-left direction according to a top view with the point oriented downwards.

7. Device (1) according to claim 5 or 6, characterized in that, according to an orthogonal projection onto the median transverse plane (MTP), the optical axis (40) forms an angle A2 with the central axis (20), with 0° < A2 < 30°, preferably with 5° < A2 < 25°, even more preferably A2 = 22°.

8. Device (1) according to any one of claims 5 to 7, characterized in that, according to an orthogonal projection onto the median transverse plane (MTP), the center of the front lens (41) is offset by a distance (D2) of 0.5 to 1 mm from the central axis (20), preferably by 0.8 mm, and in that, according to an orthogonal projection onto the median sagittal plane (MSP), the center of the front lens (41) is offset by a distance (D1) of 1 to 1.75 mm from the central axis (20), preferably by 1.4 mm.

9. Device (1) according to any one of the preceding claims, characterized in that the pen body (2) has, along the central axis (20): - a main part (201) substantially cylindrical in revolution, having the two lateral finger positioning zones (21), and extending towards the end of the body (2) from which the tip (31) emerges to a through opening of the housing (24) into which the camera (4) is inserted; - an end part (202) extending from the main part (201) thinning out to the end of the body (2) from which the tip (31) emerges, the end part (202) having a recess (203) around the optical axis (40).

10. Device (1) according to any one of the preceding claims, characterized in that according to an orthogonal projection onto the central axis (20), the center of the front lens (41) and the end of the body (2) from which the tip (31) emerges are separated by a distance (D3) of 8 to 24 mm.

Images