Image input device

Abstract: An image input device of a portable type, which includes a light source (3) for reading an original docu­ ment, a photo-electric converting element (4) for converting reflected light from the original document into an electri­ cal signal, a memory function section (5) having a solid state memory element (6) for storing output of the photo-­ electric converting element (4), an output port (14) for external connection, and operating keys (12, 13) for operat­ ing the image input device.

Description: BACKGROUND OF THE INVENTION The present invention generally relates to an image input device of a portable type, for reading images (including characters) from an information medium. An image input device having the features of the preamble of independent claim 1 is known from EP-A-0 146 472. This device comprises a semiconductor card as a solid state memory element. SUMMARY OF THE INVENTION It is the object of the present invention to provide an image input device of highly flexible usability. This object is solved by the device having the features of independent claim 1. According to claim 1, the element casing is a lens casing which houses a lens. A set of lenses is provided, which lenses are arranged to provide for different magnifications when projecting the image of the information medium onto the photo-electric converting means. Due to the exchangeable lenses, this device can be flexibly used for enlarging or diminishing images. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which: Fig. 1 is a schematic longitudinal sectional view of an image input device according to one preferred embodiment of the present invention; Fig. 2 is a schematic side sectional view showing, on an enlarged scale, a memory function section employed in the image input device of Fig. 1; Fig. 3 is an electrical block diagram showing general construction of the image input device of Fig. 1; Fig. 4 is a schematic longitudinal sectional view showing one construction of a casing to be employed in the image input device of Fig. 1; Fig. 5 is a view similar to Fig. 1, which particularly shows a second embodiment thereof; Fig. 6 is also a view similar to Fig. 5, which particularly shows a modification thereof; Fig. 7 is a cross section showing part of the arrangement of Fig. 6 on an enlarged scale; Fig. 8 is a view similar to Fig. 1, which particularly shows a third embodiment thereof; and Fig. 9 is a view similar to Fig. 8, which particularly shows a modification thereof. DETAILED DESCRIPTION OF THE INVENTION Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring now to the drawings, there is shown in Fig. 1, an image input device M1 according to one preferred embodiment of the present invention, which generally includes a casing 1 of a cylindrical pen-like shape made, for example, of a synthetic resin and having an opening 2 at its convergent tip, a light source 3 and a photo-electric converting element 4 provided within the casing 1 in positions adjacent to the opening 2, a memory function section 5 provided at the upper portion of the casing 1, an input operating key 12 and an output operating key 13 disposed at an intermediate portion of the casing 1, an output port 14 for connection with external appliances, and a resilient stopper means or clip H connected at its one end to the upper outer surface of the casing 1 for retaining the image input device M1 when it is carried in a pocket of a suit, etc. The photo-electric converting element 4 is composed of a CCD (charge coupled device) having a plurality of independent light receiving regions or photodiode arrays, etc., although not particularly shown. As shown in Fig. 2, the memory function section 5 further includes a solid memory element 6 composed of a RAM (random access memory), a memory refresh circuit 7, a CPU (central processing unit) 8, and a power source 9 which are accommodated in a container 10 having connecting pins 11 extending outwardly therefrom. Fig. 3 shows a block diagram for an electrical circuit construction in the arrangement of Figs. 1 and 2 described above, in which the photo-electric converting element 4, the memory element 6, and the operating keys 12 and 13 are coupled with the CPU 8, which is connected to the output port 14 as shown. Now, in the state where the image input device M1 is placed on the original document or information medium O as shown in Fig. 1, when the device M1 is slid in one direction, with the input operating key 12 depressed, light emitted by the light source 3 through the opening 2 and reflected by the original document O is incident upon the photo-electric converting element 4, which converts the information into an electrical signal to be applied to the CPU 8 through a signal line (not shown). The CPU 8 converts the output signal of the photo-electric converting element 4 into a digital value, and also, causes the converted data to be stored in the solid state memory element 6. Therefore, the inputted image information is memorized and retained. For output of the memorized image information, upon depression of the output operating key 13, with an external appliance (not shown) being connected to the output port 14, the image information successively read out from the solid state memory element 6 is transmitted to the external appliance through the output port 14. As the external appliance, a printer, CRT display, facsimile equipment or the like may be connected to the image input device M1. In the above embodiment, since the memory refresh circuit 7, the CPU 8, the solid state memory element 6 and the power source 9 are integrally formed as the memory function section 5, memory retaining function may be continuously maintained, even when the memory function section 5 is taken out of the image input device M1. Accordingly, by exchanging the memory function section 5 as a cartridge, the device M1 may cope with various applications without being restricted by the memory capacity. For making the memory function section 5 to be exchangeable as described above, it may be, for example, so arranged that the casing 1 is divided into upper and lower portions respectively provided with fitting means 1a and 1b at corresponding edges thereof as shown in Fig. 4 for engagement or disengagement therebetween. It is to be noted here that the above embodiment may, for example, be so modified that, apart from the power source 9 within the memory function section 5, another power source (not shown) is provided also in the casing 1. As is seen from the foregoing description, according to the first embodiment of the present invention, it is very convenient, since the image input is memorized when necessary by carrying about only the image input device, and the memorized information may be outputted as required, while the device can be formed compact in size and light in weight. Furthermore, since the external appliance is not limited to one kind for a specific use, the output of the device may be directed to various applications. Referring also to Fig. 5, there is shown an image input device M2 according to a second embodiment of the present invention. The image input device M2 also includes a casing 21 of a cylindrical shape made, for example, of a synthetic resin and having an opening 22 at the convergent forward end thereof, which is slid over an information medium or original document O during input of an image information, a resilient stopper means or clip H fixed at its one end to the upper outer face of the casing 21, an output port 26 having connecting pins 27 for external connection, and provided in a first recess 28 formed at the upper portion of the casing 21 to receive a connector (not shown) for connection with an external appliance to achieve a stable electrical coupling therewith, and input and output operating keys 29 and 30 provided in a second recess 31 formed on the casing 21 at a position below the first recess 28. Within the casing 21, there are disposed a power source 32, a memory function section 33, a photo-electric converting element 34, a light source 35, a diffraction grating 36 and an image forming lens 37, etc. in that order from the upper portion of said casing 21. The memory function section 33 includes a solid state memory element 39 such as a RAM (random access memory) or the like, and a CPU 38, etc. The photo-electric converting element 34 is composed of a CCD having a plurality of independent light receiving regions or photo-diode arrays as in the first embodiment. The light source 35 may be constructed by a semiconductor laser and the like. Since the electrical circuit construction of the image input device M2 of Fig. 5 is generally the same as in the first embodiment (Fig. 3), detailed description thereof is abbreviated here for brevity. In Fig. 5, zero order light (non-diffracted light) by the diffraction grating 36, in the light emitted from the light source 35, is converged into a predetermined size onto the information medium O through the image forming lens 37 so as to irradiate the reading region on the information medium O. The light reflected therefrom is converged by the image forming lens 37, and thereafter, is diffracted by the diffraction grating 36, thereby to form an image on the photo-electric converting element 34. Now, in the state where the image input device M2 is placed on the information medium O as shown in Fig. 5, when the device M2 is slid in one direction, with the input operating key 29 depressed, the image information in the form of light led to the photo-electric converting element 34 as described above is converted into an electrical signal by the converting element 34 so as to be applied to the CPU 38 through a signal line (not shown). The CPU 38 converts the output signal of the photo-electric converting element 34 into a digital value, and also, causes the converted data to be stored in the solid state memory element 39, and thus, the inputted image information is memorized and retained. For output of the memorized image information, upon depression of the output operating key 30, with an external appliance (not shown) being connected to the output port 26, the image information successively read out from the solid state memory element 39 is transmitted to the external appliance through the output port 26. As the external appliance, a printer, CRT display, facsimile equipment or the like may be connected to the image input device M2 as in the first embodiment described earlier. In the arrangement of Fig. 5, the light source 35 and the point on the information medium O are not in a conjugate relation. On the other hand, owing to the necessity for forming the image information of the information medium O, on the photo-electric converting element 34, it is required that the point on the information medium O and the light receiving surface of the photo-electric converting element 34 should naturally be in the conjugate relation, and the light source 35 and the photo-electric converting element 34 must be disposed in different positions with respect to the direction of optical axis, which arrangement, however, undesirably complicates the construction of the casing 21, thus being disadvantageous to the compact size of the casing 1. Accordingly, in a modified image input device M2B as shown in Fig. 6, by imparting a lens effect (power) to the diffraction grating 36, the light source 35 and the photo-electric converting element 34 are arranged to be disposed at the same position with respect to the direction of optical axis. By such arrangement as described above, not only simplification of the casing structure and compact size of the image input device are achieved, but also, the light source 35 and the photo-electric converting element 34 can be mounted within one housing as shown in Fig. 7. As described earlier, semiconductor devices are normally employed for the light source 35 and the photo-electric converting element 34, and since such semiconductor devices tend to be deteriorated in the characteristics thereof due to influence of the atmosphere such as moisture, oxygen, etc., hermetic sealing is required therefor. However, in the construction in which the light source 35 and the photo-electric converting element 34 are considerably deviated in positions with respect to the direction of optical axis as shown in Fig. 5, the light source 35 and the photo-electric converting element 34 must be sealed separately, but in the arrangement of Fig. 6, since the light source 35 and the photo-electric converting element 34 are located at the same position with respect to the optical axis direction, they may be accommodated in one hermetically sealed housing as shown in Fig. 7. In the arrangement of Fig. 7, the housing includes a stem 40 having terminal pins 41 extending downwardly therefrom, a cap 42 mounted on said stem 40 and having an opening 43 formed at its upper portion, and the diffraction grating 36 is attached to the cap 42 so as to close the opening 43. The light source 35 and the photo-electric converting element 34 are disposed side by side on a flat surface 40a of the stem 40, while an optical detector 44 for monitoring, which outputs a correction signal for making the light amount constant by directly receiving light of the light source 35, is provided on a stepped portion 40b lower in height than the flat surface 40a of the stem 40 by one step. In Fig. 7, although there is shown the example in which the diffraction grating is employed as a window for the hermetic sealing for simplification of the device, this may be replaced by an ordinary glass plate, with the diffraction grating 36 being provided at the inner side or outer side of the sealing. It is to be noted that the arrangement in Fig. 5 may be so modified that the photo-electric converting element 34 is disposed on the optical axis, and the light source 35 is provided outside the optical axis, with respective positions thereof in the direction of optical axis for the image forming lens 37 being maintained. Meanwhile, in the arrangement of Fig. 6, the positions of the light source 35 and the photo-electric element 34 may be exchanged to each other, and by imparting light diffusing effect to the diffraction grating 36, similar effect may be obtained. As is also referred to earlier, by arranging the memory function section 33 replaceable in the form of a cartridge, it is possible to cause the image input device to correspond to various applications without restriction by the memory capacity. For allowing the memory function section to be replaceable as referred to above, the casing 21 may, for example, be divided into upper and lower portions, with fitting means being provided thereon for selective engagement or disengagement therebetween. According to the second embodiment of the present invention as described so far, the image input is conveniently memorized when necessary by carrying about only the image input device, and the memorized information may be outputted as required, while the device can be formed compact in size and light in weight. Moreover, since the external appliance is not limited to one kind for a specific use, the output of the device may be directed to various applications as in the first embodiment. Referring further to Fig. 8, there is shown an image input device M3 according to a third embodiment of the present invention. The image input device M3 similarly includes a casing 51 of a cylindrical shape made, for example, of a synthetic resin and having an opening 52 at the convergent forward end thereof which is slid over an information medium or original document O during input of an image information, with the casing 51 being composed of a main body portion 51a and a forward end portion 51b which is detachably mounted onto the main body portion 51a for exchanging through a fitting construction 54, and with a detachable spare forward end portion 51c for replacement being held on the other end (i.e., the upper end in Fig. 8) of the casing 51, a resilient stopper means or clip H fixed at its one end to the upper outer face of the casing 21, an output port 56 having connecting pins 57 for external connection, and provided in a first recess 58 formed at the upper portion of the casing 51 to receive a connector (not shown) for connection with an external appliance to achieve a stable electric coupling therewith, and input and output operating keys 59 and 60 provided in a second recess 61 formed on the casing 51 at a position below the first recess 58. Within the casing 51, there are disposed a power source 62, a memory function section 63, a photo-electric converting element 64, a light source 65, a diffraction grating 66 and a first condenser lens 67 and a second condenser lens 68, etc., in that order from the upper portion of said casing 51. The memory function section 63 includes a solid state memory element 71 such as a RAM (random access memory) or the like, and a CPU 70, etc. The photo-electric converting element 64 is composed of a CCD having a plurality of independent light receiving regions or photo-diode arrays as in the previous embodiments. The light source 65 may be constructed by a semiconductor laser and the like. The diffraction grating 66, and the first and second condenser lenses 67 and 68 constitute the image forming optical system 69 for converging light emitted from the light source 65 onto the information medium O and also, for leading the reflected light to the photo-electric converting element 64 to form the image, and in the optical system, the second condenser lens 68 is mounted at the forward end portion 51b of the casing 51 as referred to earlier. Accordingly, by replacing this forward end portion 51b with the spare forward end portion 51c, the second condenser lens 68′ may be replaced by another second condenser lens 68 having a different focal length. Since the electric circuit construction of the image input device M3 of Fig. 8 is the same as in the first embodiment (Fig. 3), detailed description thereof is abbreviated here for brevity. In Fig. 8, zero order light (non-diffracted light) by the diffraction grating 66, in the light emitted from the light source 65, is converged into a predetermined size onto the information medium O through the first and second condenser lenses 67 and 68 so as to irradiate the reading region on the information medium O. The light reflected therefrom is converged by the first and second condenser lenses 68 and 67, and thereafter, if diffracted by the diffraction grating 66, thereby to form an image on the photo-electric converting element 64. Now, in the state where the image input device M3 is placed on the information medium O as shown in Fig. 8, when the device M3 is slid in one direction, with the input operating key 59 depressed, the image information in the form of light led to the photo-electric converting element 64 as described above is converted into an electrical signal by the converting element 64 so as to be applied to the CPU 70 through a signal line (not shown). The CPU 70 converts the output signal of the photo-electric converting element 64 into a digital value, and also, causes the converted data to be stored in the solid state memory element 71, and thus, the inputted image information is memorized and retained. For output of the memorized image information, upon depression of the output operating key 60, with an external appliance (not shown) being connected to the output port 56, the image information successively read out from the solid state memory element 71 is transmitted to the external appliance through the output port 56. As the external appliance, a printer, CRT display, facsimile equipment or the like may be connected to the image input device M3 as in the previous embodiments described earlier. Referring also to Fig. 9, in a modification M3B of the image input device M3 for the third embodiment of Fig. 8, the forward end of the main body 51a for the casing 51 is formed into a reduced diameter portion T for constituting a completed casing for the image input device M3B even by the main body 51a alone so as to be used as it is, with the second condenser lens 68 being also provided in the main body 51a for the purpose. However, in order to meet the requirement for variable magnifications, interchangeable or exchangeable first and second units 74 and 75 having condense lenses 72 and 73 respectively are arranged to be detachably mounted onto the reduced diameter portion T in a piled-up state as shown. The condenser lenses 72 and 73 of the first and second units 74 and 75 and the second condenser lens 68 accommodated in the main body 51a respectively have different focal lengths, and various magnifications may be achieved according to combinations thereof. Needless to say, the first and second units 74 and 75 may be used in the state where only either one of them is mounted on the main body 51a. In the third embodiment as shown in Fig. 8, although enlargement or contraction of the input image may be selected according to exchange or combination of the condenser lenses, variation in the brightness according thereto is anticipated. It is to be noted, however, that such variation in the brightness with respect to the input image can be readily corrected in terms of a circuit arrangement, by imparting an automatic gain control function or a function to control slice level during conversion of a analog value of the light amount into a digital value, to a circuit for treating the input signal. As is clear from the foregoing description, in the third embodiment as described so far also, since only the image input device can be carried about for memorizing the image input when necessary, and also for outputting the image information as required, it is extremely convenient to use, while the input device can be made compact in size and light in weight. Moreover, the output of the device can be applied to various applications, since the external appliance is not limited to a specific one.

Claims: An image input device of portable type, comprising: a device casing (51a); a light source (3) housed within said device casing, for emitting light onto an information medium (O); photo-electric converting means (4) housed within said device casing, for developping an image signal representative of an image on said information medium as reflected by said light emitted from said light source; a memory function section (5) having a solid state memory element for storing said image signal from said photo-electric converting means; an output port (14) provided at said device casing, for removably connecting external devices with said memory function section; and at least one operating key (12, 13) provided at said device housing, for operating said image input device; characterized in that a set of lenses (68, 68′; 72, 73), with each having a lens casing (51b, 51c; 74, 75), is provided, said lenses being arranged to provide for different magnifications when projecting the image of said information medium onto said photo-electric converting means; and said device casing (51a) and said lens casings are arranged in a way that each lens casing can be removably fixed to the device casing. A device as claimed in claim 1, wherein said lens casings (74, 75) are arranged in a way that at least two of them can be serially fixed one to the other. A device according to claim 1 or claim 2, wherein said memory means (5) is arranged in a memory casing (10) having connecting pins (11); and said device casing and said memory casing are arranged in a way that the memory casing can be removably fixed to the device casing, whereby the connecting pins contact an output means of said photo-electric converting means. A device as claimed in claim 3, wherein said device casing (51a) is arranged as a pen-like casing, said lens casing (51b) can be fixed to one end of said device casing, and said memory casing (10) can be fixed to the other end of said device casing. A device as claimed in one of the claims 3 or 4, wherein said exchangeable memory means (5) comprises a RAM (9), memory refresh means (7), a CPU (8), and a power source (6). A device as claimed in claim 5, wherein said signal from said photo-electric converting means (4) is converted to a digital signal by said CPU, and said digital signal is stored in said RAM. A device as claimed in one of the preceding claims, which comprises an image forming optical means (36, 37) for converting said light from said light source (35) onto said information medium, and for directing said light reflected from said information medium towards said photo-electric converting means (34). A device as claimed in one of the preceding claims, wherein said light source (3; 35) comprises a semiconductor laser. A device as claimed in one of the preceding claims, wherein said photo-electric converting means (4; 34) comprises a CCD. A device as claimed in claim 7, wherein said image forming optical means comprises diffraction grating means (36) and a lens (37). A device as claimed in claim 10, wherein said light source (35), said photo-electric converting means (34) and said diffraction grating means (36) are hermetically sealed in a unit.

Inventors: ISHIKAWA TOSHIO, KURATA YUKIO, ISHIKAWA, TOSHIO, KURATA, YUKIO
Applicants: SHARP KK, SHARP KABUSHIKI KAISHA
Application year: 1988
Main classification: H04N1
IPC codes: H04N1