# US 2013/0154705 A1 · Electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154705 A1 - Document ID: US20130154705A1 - Status: Published application - Kind: A1 - Application number: 13/711,414 - Filed: 2012-12-11 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: Canon Kabushiki Kaisha - Inventors: Katsuhito Sakurai; Itsutaku Sano - Web page: https://patentgrep.com/patent/US20130154705A1 ## CPC - H03K 3/86: Generating pulses by means of delay lines and not covered by the preceding subgroups - H03K 4/026: {using digital techniques} - H03K 5/2472: {using field effect transistors (H03K5/2436 takes precedence)} - H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H10F 39/199: {Back-illuminated image sensors} - H10F 39/802: {Geometry or disposition of elements in pixels, e.g. address-lines or gate electrodes} - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract An electronic device according to one or more embodiments of the present invention comprises an output line, a current mirror circuit and a comparator. Current signals from a plurality of signal sources are output to the output line. The current mirror circuit is electrically connected to the output line. The comparator is configured to compare a mirrored current signal from the current mirror circuit with a reference current signal. The comparator is configured to output a signal representing a comparison result of amplitudes of the mirrored current signal and the reference current signal. ## Claims ### Claim 1 An electronic device comprising: an output line for current signals from a plurality of signal sources being output to the output line; a current mirror circuit electrically connected to the output line; and a comparator configured to compare a mirrored current signal from the current mirror circuit with a reference current signal, and to output a signal representing a comparison result of amplitudes of the mirrored current signal and the reference current signal. ### Claim 2 (depends on 1) The electronic device according to claim 1, further comprising the plurality of the signal sources, wherein each of the plurality of the signal sources includes a photoelectric conversion unit and an amplification unit configured to output, to the output line, a current signal based on an amount of charges generated by the photoelectric conversion unit. ### Claim 3 (depends on 2) The electronic device according to claim 2, further comprising an analog to digital convertor configured to convert the mirrored current signal into a digital signal, based on a signal representing a comparison result output from the comparator. ### Claim 4 (depends on 3) The electronic device according to claim 3, further comprising a ramp current signal source configured to output a ramp current signal, wherein the ramp current signal is the reference signal to be input to the comparator. ### Claim 5 (depends on 4) The electronic device according to claim 4, wherein at least one transistor included in the amplification unit and elements connected thereto form the same circuitry structure as at least one transistor included in the ramp current signal source and elements connected thereto form. ### Claim 6 (depends on 2) The electronic device according to claim 2, wherein the current mirror circuit includes a gain control unit configured to control an amplification factor of the mirrored current signal to the current signal from the signal source. ### Claim 7 (depends on 6) The electronic device according to claim 6, wherein the current mirror circuit includes a plurality of output-side transistors arranged in parallel on an output side of the current mirror circuit, and wherein the gain control unit is configured to change a number of the output-side transistors being connected, thereby controlling the amplification factor. ### Claim 8 (depends on 7) The electronic device according to claim 7, wherein the gain control unit includes a plurality of gain control switches corresponding to the plurality of the output-side transistors. ### Claim 9 (depends on 6) The electronic device according to claim 6, wherein the gain control unit is configured to control the amplification factor for one of the plurality of the signal sources individually outputting the current signal. ### Claim 10 (depends on 6) The electronic device according to claim 6, wherein the gain control unit is configured to control the amplification factor to be a first value for one of the plurality of the signal sources individually outputting the current signal, and to control the amplification factor to be a second value, smaller than the first value, for two or more of the plurality of the signal sources simultaneously outputting the current signals. ### Claim 11 (depends on 2) The electronic device according to claim 2, wherein the plurality of the signal sources are configured to simultaneously output current signals from two or more of the signal sources to the output line, and wherein the output line is configured such that the current signals simultaneously output to the output line are summed up at the output line. ### Claim 12 (depends on 11) The electronic device according to claim 11, further comprising a bias current source configured to provide each of the plurality of the signal sources with a bias current, wherein the bias current source is configured to provide a first bias current for one of the plurality of the signal sources individually outputting the current signal, and to provide a second bias current, having a larger amplitude than that of the first bias current, for two or more of the plurality of the signal sources simultaneously outputting the current signals. ### Claim 13 (depends on 2) The electronic device according to claim 2, wherein only one or more transistors for outputting the mirrored current signal and one or more transistors for outputting the reference current signal are electrically connected to an output node of the comparator, a signal representing a comparison result being output to the output node. ### Claim 14 (depends on 2) The electronic device according to claim 2, wherein a number of transistors connected to the output line is larger than a number of transistors connected to an output node of the comparator, a signal representing a comparison result being output to the output node. ### Claim 15 (depends on 2) The electronic device according to claim 2, further comprising a first semiconductor substrate, wherein the photoelectric conversion unit is provided in the first semiconductor substrate, wherein the output line is provided on a first surface of the first semiconductor substrate, and wherein the photoelectric conversion unit is configured to convert incident light from a second surface of the first semiconductor substrate, opposite to the first surface, into a charge. ### Claim 16 (depends on 15) The electronic device according to claim 15, further comprising a second semiconductor substrate facing to the first surface of the first semiconductor substrate, wherein the output line is provided between the first and second semiconductor substrates, and wherein either one of or both of the current mirror circuit and the amplification unit is/are provided in the second semiconductor substrate. ### Claim 17 An electronic device comprising: an output line for current signals from a plurality of signal sources being output to the output line; an impedance conversion portion electrically connected to the output line; and a comparator configured to compare a current signal from the impedance conversion portion with a reference current signal, and to output a signal representing a comparison result of amplitudes of the current signal from the impedance conversion portion and the reference current signal. ### Claim 18 (depends on 17) The electronic device comprising according to claim 17, wherein the impedance conversion portion includes a common gate amplifier. ### Claim 19 (depends on 17) The electronic device comprising according to claim 17, wherein the impedance conversion portion includes a current mirror circuit. ### Claim 20 An electronic device comprising: an output line; a plurality of the signal sources, each of the plurality of the signal sources including a photoelectric conversion unit and an amplification unit configured to output, to the output line, a current signal based on an amount of charges generated by the photoelectric conversion unit; a current mirror circuit electrically connected to the output line; a ramp current signal source configured to output a ramp current signal, a comparator configured to compare a mirrored current signal from the current mirror circuit with the ramp current signal, and to output a signal representing a comparison result of amplitudes of the mirrored current signal and the ramp current signal; an analog to digital convertor configured to convert the mirrored current signal into a digital signal, based on a signal representing a comparison result output from the comparator; and a bias current source configured to provide each of the plurality of the signal sources with a bias current, wherein the current mirror circuit includes a gain control unit configured to control an amplification factor of the mirrored current signal to the current signal from the signal source, wherein the gain control unit is configured to control the amplification factor to be a first value for one of the plurality of the signal sources individually outputting the current signal, and to control the amplification factor to be a second value, smaller than the first value, for two or more of the plurality of the signal sources simultaneously outputting the current signals, wherein the bias current source is configured to provide a first bias current for one of the plurality of the signal sources individually outputting the current signal, and to provide a second bias current, having a larger amplitude than that of the first bias current, for two or more of the plurality of the signal sources simultaneously outputting the current signals, and wherein a number of the signal sources electrically connected to the output line is larger than a number of transistors connected to an output node of the comparator, the signal representing the comparison result being output to the output node.